bluuebunny/crossref_metadata_2025 huggingface dataset:
Short-term solar PV forecasting using computer vision: The search for optimal CNN architectures for incorporating sky images and PV generation history
Authors: Venugopal Vignesh , Sun Yuchi , Brandt Adam R.
Published: November 2019

Cloud movement makes short-term forecasting of solar photovoltaic (PV) panel output challenging. A better PV forecast can realize value for both grid operators and commercial or industrial customers with solar assets. In this study, we build convolutional neural network (CNN) based models to forecast power output from PV panels 15 min into the future. Model inputs are the PV power output history and ground-based sky images for the past 15 min. The key challenge is ensuring that due importance is given to each type of input. We systematically explore 28 methods of “fusing” these heterogeneous inputs in our CNN. These methods of fusion (MoF) belong to 4 families. We also systematically explore the many hyperparameters related to model training and tuning. Limited resources preclude an exhaustive search. We apply a three-stage “funnel” approach instead, wherein we narrow our search to the most promising one of these 28 MoF. We find that a two-step autoregression-CNN MoF has the best performance followed closely by a “mix-in” MoF that performs feature expansion and reduction to give appropriate importance to the two types of inputs. The two-step autoregression-CNN model has a forecast skill (FS) of 17.1% relative to smart persistence on the test set comprising 20 complete days (9 sunny, FS = 22%; 11 cloudy, FS = 16.9%). This optimization results in the improvement of FS from 14.1% for a previously published nonoptimized “baseline” model, a CNN wherein the PV history was simply concatenated to the end of the image-sourced vector obtained after convolution, pooling, and flattening operations.
Oscillatory regimes of compressible 2.5D viscous linear magnetic reconnection
Authors: McMahon Liam C.
Published: November 2019

We investigate the dynamics and energetics of magnetic reconnection in a general linear magnetohydrodynamic (MHD) model. Our investigation is threefold: First, we formulate a generalized 2.5D linearized MHD system in the presence of viscous, pressure, collisionless, and axial magnetic effects. Second, we find, in accordance with previous studies, that viscous effects, while reducing the rate of reconnection, boost the rate of total energy release. Moreover, viscous dissipation, as opposed to resistive dissipation, is unlikely to be impeded by pressure forces. Third, we compare two different equilibrium axial magnetic field profiles. One profile emulates a quasiseparatrix layer and the other profile emulates a 3D null point. In 2.5D, these profiles actually correspond to a hyperbolic field threaded by an axial field and a null line, respectively. We show evidence that fast reconnection is only attainable in the presence of a null.
Ultrafast ultrasound imaging in acoustic microbubble trapping
Authors: Peng Hanmin , Qian Xuejun , Mao Linli , Jiang Laiming , Sun Yizhe , Zhou Qifa
Published: November 2019

The lack of actively targeted nanocarriers and a low drug concentration in lesions are two of the main problems in targeted therapy for clinical use. In this paper, an ultrasound-induced trapping and ultrafast imaging system for flowing microbubbles is proposed to increase the effective drug dose and achieve real-time positioning. A finite element method model is established to analyze microbubble tracing in a fluid flow model at 2.5 MHz, which demonstrates how the interaction of acoustic radiation force (ARF) and flowing drag force is able to trap microbubbles and move them to a specific location. This motion can be explicitly imaged and captured by ultrafast plane wave imaging with a 1D array ultrasound probe at 18 MHz. The use of this plane wave and ARF technique can be beneficial for fast localization, monitoring, and manipulation of drug delivery bubbles for targeted release at 10 mm depth in a noninvasive and feasible way. Therefore, this ultrasound technology can be a useful tool to increase the local drug concentration in an accurate location for clinical use.
Hydration dynamics in aqueous Pluronic P123 solution: Concentration and temperature dependence
Authors: Mukherjee Kallol , Barman Anjan , Biswas Ranjit
Published: November 2019

Here, we report the concentration (0 ≤ wt. % ≤ 30) and temperature (293 ≤ T/K ≤ 318) dependent structural and dynamical changes in an aqueous solution of a triblock copolymer (Pluronic P123) using dielectric relaxation spectroscopy (DRS), covering a frequency regime, 0.2 ≤ ν/GHz ≤ 50. Remarkable existence of slow water molecules, ∼2 times slower than bulk type water, along with bulk-like water molecules has been detected in the present DR measurements. Differential scanning calorimetric measurements support this DR observation. The signature of the sol-gel phase transition (∼15.0 wt. %, 293 K) and temperature induced extensive dehydration (>60%) for P123 molecules, which are the other notable findings of the present work. Moreover, the rate of dehydration with temperature has been found to depend on the phase of the medium. However, dehydration follows a nonlinear pattern in both sol and gel phases. A subnanosecond (∼90 ps) component, possibly originating from the hydrogen bond relaxation dynamics of the terminal C–O–H of polymer chains, has also been observed.
Lanczos-based equation-of-motion coupled-cluster singles-and-doubles approach to the total photoionization cross section of valence excited states
Authors: Cabral Tenorio Bruno Nunes , Chaer Nascimento Marco Antonio , Rocha Alexandre Braga , Coriani Sonia
Published: November 2019

Excitation energies and oscillator strengths of the first two electronically excited states of helium, water, sulfur dioxide, molecular nitrogen, and carbon monoxide were obtained from an asymmetric-Lanczos-based formulation of the equation-of-motion coupled cluster singles and doubles approach. The total photoionization cross sections were generated by two different methodologies: an analytic continuation procedure based on the Padé approximants and the Stieltjes imaging technique. The results are compared with theoretical photoionization cross sections from algebraic diagrammatic construction [ADC(2)] and ADC(2)-x calculations [M. Ruberti et al., J. Chem. Phys. 140, 184107 (2014)] and with available experimental data.
Stabilization and tuning of perpendicular magnetic anisotropy in room-temperature ferromagnetic transparent CeO2 films
Authors: Figueiredo-Prestes Nicholas , Oliveira Ronei C. , Tavares Mariana A. B. , Costa Daniel S. , Mazzaro Irineu , Jurca Hugo F. , Zarpellon Juliana , Martins Maximiliano D. , Deranlot Cyrile , George Jean-Marie , Mosca Dante H.
Published: November 2019

The development of multifunctional materials that combine optical transparency to room-temperature magnetism is still a great challenge. Here, we present an investigation on the room-temperature ferromagnetism of ceria (CeO2) nanocrystalline films integrated to cobalt and platinum multilayered films (Co/Pt-ML) with perpendicular magnetic anisotropy (PMA). The magnetic coupling between Co/Pt-ML and CeO2 films spaced by Pt interlayers with different thicknesses (from 3 nm to 20 nm) enable stabilization and tuning of PMA along with the stacking at remanence. CeO2 films on the Co/Pt-ML films exhibit domain structures consisting of nonconnected labyrinthine patterns dominated by protruding fingers similar to that of individual Co/Pt-ML films. Our present results demonstrate that the PMA of Co/Pt-ML films can be used to exploit the room-temperature ferromagnetism of transparent CeO2 films and their multifunctionalities for emerging transparent electronics and spintronics such as high-density magnetic devices.
X-ray intensity, stability, and source size characterizations for the 10 kV/5 mA water cooled upgraded Manson source at the Atomic Energy Commission for Laser MégaJoule Facility
Authors: Hubert S. , Boubault F.
Published: November 2019

Calibration of x-ray cameras integrated within plasma diagnostics for Laser MégaJoule’s experiment is of great interest for interpretations of physical phenomena. At the Atomic Energy and Alternative Energy Commission, an x-ray calibration laboratory has been trying for many years to provide the most relevant calibrations. In the soft x-ray range (<1.5 keV), a model 5 Manson source is used in combination with a concave grating monochromator equipped permanently with an absolute calibrated silicon drift detector. To reduce the calibration time achieved with this experimental setup, the Manson source has been modified to reach an emission current of up to 5 mA (100 µA for a standard source model) while keeping the x-ray monochromatic intensity constant within ∼2% for several operating hours. A water cooling system has been integrated within the anode carousel and an emission current regulation system inside a completely redesigned power supply. In this work, we present characterization of the source size and x-ray intensity as a function of both source voltage and emission current, as well as the stability of this new source. Both arms of the source have been used: one for monitoring the monochromatic spectra and x-ray intensity and the other to measure the source size. An x-ray spot was observed to be evolved from the oval shape toward the annular one as the emission current increases. For fixed emission current, the source size is reduced as the voltage increases. The x-ray intensity has significantly been increased to a maximum factor of ∼20 (depending on the anode) while being constant within around 2% as expected.
Charge generation from as-electrospun polystyrene fiber mat with uncontacted/contacted electrode
Authors: Ishii Yuya , Kurihara Shintaro
Published: November 2019

Micrometer/submicrometer electromechanical polymer fibers are promising components for wearable pressure sensors and energy harvesters because of their high mechanical flexibility, low weight, and excellent breathability. Recently, the excellent electromechanical properties of mats of the as-electrospun micrometer/submicrometer polymer fibers have been reported; however, these devices have a contacting electrode/fiber mat/electrode structure. In this study, the electrical output properties of an as-electrospun polystyrene fiber mat with one electrode not in contact and/or in contact with the fiber mat were theoretically and experimentally investigated. The electric charges were output when the uncontacted electrode approached the fiber mat, and the amount of electric charges increased monotonically during the approach even after the electrode contacted the fiber mat and indented. The amount of electric charges was determined using theoretical functions. At the maximum displacement of the electrode, the average maximum output voltage had an absolute value of 2.28 ± 0.04 V when using the electrode with an area of 5.0 × 10−5 m2, a load of 10.1 MΩ, and a displacement time of approximately 15 ms. These experimental and theoretical findings can pave the way for the development of soft, lightweight, and breathable wearable pressure sensors and energy harvesters from a variety of materials and unique structures.
High-temperature continuous molecular beam source for aggressive elements: An example of zinc
Authors: Dudek J. , Puczka K. , Urbańczyk T. , Koperski J.
Published: November 2019

Expansion of Zn2 or ZnRg (Rg = rare gas atom) in a molecular supersonic beam constitutes a considerable technical challenge due to the high zinc melting point and high zinc reactivity with stainless steel at high temperatures. In order to overcome these difficulties and meet the requirements for spectroscopy of van der Waals molecules containing zinc, a high-temperature source-module of the supersonic molecular beam for aggressive elements was designed. The module was tested in the laser-induced fluorescence excitation spectroscopy experiment using the b30u+43P1←X10g+(41S0) bound ← bound transitions in Zn2. The new source-module can be used for other aggressive elements for which a laser-vaporization technique has been used to date.
Superionic liquids in conducting nanoslits: A variety of phase transitions and ensuing charging behavior
Authors: Dudka Maxym , Kondrat Svyatoslav , Bénichou Olivier , Kornyshev Alexei A. , Oshanin Gleb
Published: November 2019

We develop a theory of charge storage in ultranarrow slitlike pores of nanostructured electrodes. Our analysis is based on the Blume-Capel model in an external field, which we solve analytically on a Bethe lattice. The obtained solutions allow us to explore the complete phase diagram of confined ionic liquids in terms of the key parameters characterizing the system, such as pore ionophilicity, interionic interaction energy, and voltage. The phase diagram includes the lines of first- and second-order, direct and re-entrant phase transitions, which are manifested by singularities in the corresponding capacitance-voltage plots. Testing our predictions experimentally requires monodisperse, conducting ultranarrow slit pores, to permit only one layer of ions, and thick pore walls, to prevent interionic interactions across the pore walls. However, some qualitative features, which distinguish the behavior of ionophilic and ionophobic pores and their underlying physics, may emerge in future experimental studies of more complex electrode structures.
Unidirectional large-amplitude oscillatory shear flow of human blood
Authors: Saengow Chaimongkol , Giacomin Alan Jeffrey , Dimitrov Andrea Stephanie
Published: November 2019

Blood is a non-Newtonian suspension of red and white cells, platelets, fibrinogen, and cholesterols in Newtonian plasma. To assess its non-Newtonian behaviors, this work considers a newly proposed blood test, unidirectional large-amplitude oscillatory shear flow (udLAOS). In the laboratory, we generate this experiment by superposing LAOS onto steady shear flow in such a way that the shear rate never changes sign. It is thus intended to best represent the unidirectional pulsatile flow in veins and arteries. To model human blood, we consider the simplest model that can predict infinite-shear viscosity, the corotational Jeffreys fluid. We arrive at an exact analytical expression for the shear stress response of this model fluid. We discover fractional harmonics comprising the transient part of the shear stress response and both integer and fractional harmonics, the alternant part. By fractional, we mean that these occur at frequencies other than integer multiples of the superposed oscillation frequency. We generalize the corotational Jeffreys fluid to multimode to best represent three blood samples from three healthy but different donors. To further improve our model predictions, we consider the multimode Oldroyd 8-constant framework, which contains the corotational Jeffreys fluid as a special case. In other words, by advancing from the multimode corotational Jeffreys fluid to the multimode Oldroyd 8-constant framework, five more model parameters are added, yielding better predictions. We find that the multimode corotational Jeffreys fluid adequately describes the steady shear viscosity functions measured for three different healthy donors. We further find that adding two more specific nonlinear constants to the multimode corotational Jeffreys fluid also adequately describes the behaviors of these same bloods in udLAOS. This new Oldroyd 5-constant model may find usefulness in monitoring health through udLAOS.
Revisiting the photoabsorption spectrum of NH3 in the 5.4–10.8 eV energy region
Authors: Limão-Vieira P. , Jones N. C. , Hoffmann S. V. , Duflot D. , Mendes M. , Lozano A. I. , Ferreira da Silva F. , García G. , Hoshino M. , Tanaka H.
Published: November 2019

We present a comprehensive revisited experimental high-resolution vacuum ultraviolet (VUV) photoabsorption spectrum of ammonia, NH3, covering for the first time the full 5.4–10.8 eV energy-range, with absolute cross sections determined. The calculations on the vertical excitation energies and oscillator strengths were performed using the equation-of-motion coupled cluster method restricted to single and double excitation levels and used to help reanalyze the observed Rydberg structures in the photoabsorption spectrum. The VUV spectrum reveals several new features that are not previously reported in the literature, with particular reference to the vibrational progressions of the (D̃1E′←X̃1A1′), the (F̃1E′←X̃1A1′), and the (G̃1A2″←X̃1A1′) absorption bands. In addition, new Rydberg members have been identified in nda1′←1a2″D̃′′1A2″←X̃1A1′, where n > 3 has not been reported before as well as in nde″←1a2″F̃1E′←X̃1A1′ and in nsa1′←1a2″G̃1A2″←X̃1A1′. The measured absolute photoabsorption cross sections have been used to calculate the photolysis lifetime of ammonia in the Earth’s atmosphere (0–50 km).
Tunable high-quality Fano resonance in coupled terahertz whispering-gallery-mode resonators
Authors: Yuan Shixing , Chen Liao , Wang Ziwei , Wang Ruolan , Wu Xiaojun , Zhang Xinliang
Published: November 2019

Fano resonance is widely discussed in designing functional terahertz components, such as sensors, filters, modulators, and group delay modules. Usually, a high quality (Q) factor and flexible tunability of Fano resonance are key requirements for these applications. Here, we present tunable terahertz Fano resonance with a Q factor of 2095 at 0.439 THz in coupled terahertz whispering-gallery-mode resonators (WGMRs). Coupling between a relatively low Q (578) quartz ring and a high Q (2095) silicon ring is employed to generate high Q Fano resonance. The resonant frequency of the Fano resonance can be actively manipulated by tuning the resonant frequency of the high Q WGMR, which is achieved through utilizing an electrical thermo-optic tuning method; meanwhile, the resonance intensity of the Fano resonance can be engineered by adjusting the coupling strength between two WGMRs. This coupled-WGMR scheme delivers tunable high Q Fano resonance and may contribute to the design of high-performance configurable terahertz devices.
Improvements in amino acid assembly imaging can help understand life formation
Authors: Bandari Anashe
Published: November 2019

Previous studies of amino acid island formation have been in conditions not viable for biological systems, but a combination of techniques allows for more realistic imaging.
C3 and C4 plant leaf breakdown and assimilation by aquatic macroinvertebrates in streams of the Brazilian Atlantic Forest
Authors: Augusto Fernanda G. , Figueiredo Aline F. , Camargo Plinio B. , Coletta Luciana D. , Mazzi Edmar A. , Martinelli Luiz A.
Published: November 2019

The breakdown of allochthonous plants is of great importance in providing energy and nutrients in streams. In this regard, shredder macroinvertebrates play an important role in decomposing organic matter. Changes in land use strongly influence the type of material entering a stream, which ultimately affects the food chain dependent on this material. This study compared the decay of C3 (Mollinedia schottiana) and C4 (Brachiaria brizantha) plants in the montane Atlantic Forest of Brazil using litterbag experiments in two streams draining watersheds of different land uses. Concomitantly, we investigated the colonisation and assimilation of these plant detritus by aquatic macroinvertebrates. The breakdown of C4 plants in the forest stream was faster than that of C3 plants; however, aquatic macroinvertebrates did not assimilate the C4 carbon. These results support other studies that have shown a greater abundance of shredders in montane tropical streams (lower temperature) than in lowland streams. Moreover, the findings of this study support the view that changes in land use alter the structure of the benthic community, and that these changes can alter the leaf breakdown process.
Otolith microchemistry: a useful tool for investigating stock structure of yellowfin tuna (Thunnus albacares) in the Indian Ocean
Authors: Artetxe-Arrate Iraide , Fraile Igaratza , Crook David A. , Zudaire Iker , Arrizabalaga Haritz , Greig Alan , Murua Hilario
Published: November 2019

A better understanding of the stock structure of yellowfin tuna (Thunnus albacares) in the Indian Ocean is needed to ensure the sustainable management of the fishery. In this study, carbon and oxygen stable isotopes (δ13C and δ18O) and trace elements (138Ba, 55Mn, 25Mg and 88Sr) were measured in otoliths of young-of-the-year (YOY) and age-1 yellowfin tuna collected from the Mozambique Channel and north-west Indian Ocean regions. Elemental profiles showed variation in Ba, Mg and Mn in YOY otolith composition, but only Mn profiles differed between regions. Differences in YOY near-core chemistry were used for natal-origin investigation. Ba, Mg and Mn were sufficiently different to discriminate individuals from the two regions, in contrast with carbon and oxygen stable isotopes. A linear discriminant analysis resulted in 80% correct classification of yellowfin tuna to their natal origin. Classification success increased to 91% using a random forest algorithm. Finally, a unique larval source was detected among age-1 yellowfin tuna. The signal of these fish resembled that of YOY from a north-west Indian Ocean origin, highlighting the importance of local production. The present study supports the use of otolith chemistry as a promising approach to analyse yellowfin stock structure in the Indian Ocean.
Oxidation of methionine residues activates the high-threshold heat-sensitive ion channel TRPV2
Authors: Fricke Tabea C. , Echtermeyer Frank , Zielke Johannes , de la Roche Jeanne , Filipovic Milos R. , Claverol Stéphane , Herzog Christine , Tominaga Makoto , Pumroy Ruth A. , Moiseenkova-Bell Vera Y. , Zygmunt Peter M. , Leffler Andreas , Eberhardt Mirjam J.
Published: November 2019

Significance

Redox sensitivity is a common property of temperature-sensitive transient receptor potential (TRP) ion channels. Here we show that oxidation sensitizes and activates rodent TRPV2 orthologs known to have a high temperature threshold (>50 °C), but also the heat-insensitive human TRPV2. This oxidation-induced channel gating is intact in cell-free membrane patches, cysteine-independent but reduced upon replacement of the methionine residues M528 and M607. Blocking of TRPV2 and the reducing agent DTT reduce phagocytosis in macrophages which also generate heat-induced membrane currents following oxidation. These data reveal a methionine-dependent redox sensitivity of TRPV2 which may resemble a decisive endogenous mechanism enabling channel activation.
Structural studies of the eIF4E–VPg complex reveal a direct competition for capped RNA: Implications for translation
Authors: Coutinho de Oliveira Luciana , Volpon Laurent , Rahardjo Amanda K. , Osborne Michael J. , Culjkovic-Kraljacic Biljana , Trahan Christian , Oeffinger Marlene , Kwok Benjamin H. , Borden Katherine L. B.
Published: November 2019

Viruses have transformed our understanding of mammalian RNA processing, including facilitating the discovery of the methyl-7-guanosine (m
7
G) cap on the 5′ end of RNAs. The m
7
G cap is required for RNAs to bind the eukaryotic translation initiation factor eIF4E and associate with the translation machinery across plant and animal kingdoms. The potyvirus-derived viral genome-linked protein (VPg) is covalently bound to the 5′ end of viral genomic RNA (gRNA) and associates with host eIF4E for successful infection. Divergent models to explain these observations proposed either an unknown mode of eIF4E engagement or a competition of VPg for the m
7
G cap-binding site. To dissect these possibilities, we resolved the structure of VPg, revealing a previously unknown 3-dimensional (3D) fold, and characterized the VPg–eIF4E complex using NMR and biophysical techniques. VPg directly bound the cap-binding site of eIF4E and competed for m
7
G cap analog binding. In human cells, VPg inhibited eIF4E-dependent RNA export, translation, and oncogenic transformation. Moreover, VPg formed trimeric complexes with eIF4E–eIF4G, eIF4E bound VPg–
luciferase
RNA conjugates, and these VPg–RNA conjugates were templates for translation. Informatic analyses revealed structural similarities between VPg and the human kinesin EG5. Consistently, EG5 directly bound eIF4E in a similar manner to VPg, demonstrating that this form of engagement is relevant beyond potyviruses. In all, we revealed an unprecedented modality for control and engagement of eIF4E and show that VPg–RNA conjugates functionally engage eIF4E. As such, potyvirus VPg provides a unique model system to interrogate eIF4E.
RAMP3 determines rapid recycling of atypical chemokine receptor-3 for guided angiogenesis
Authors: Mackie Duncan I. , Nielsen Natalie R. , Harris Matthew , Singh Smriti , Davis Reema B. , Dy Danica , Ladds Graham , Caron Kathleen M.
Published: November 2019

Significance

G-protein–coupled receptors (GPCRs) exist within multi-protein complexes on the surface of cells in order to respond to a wide variety of extracellular stimuli such as neurotransmitters, migratory cues, hormones, light, and odors. In this study, we discover and characterize an expanded repertoire of GPCRs that interact with receptor-activity–modifying proteins (RAMPs)—a class of proteins that can modulate the type and consequences of extracellular signals to GPCRs. Specifically, we find that RAMP interaction with chemokine GPCRs is essential for enabling these receptors to bind and degrade extracellular migratory cues and thereby establish gradients for directed cellular migration. In the absence of these critical proteins, the process of blood vessel sprouting within the postnatal retina is dysfunctional.
Superlattice-induced ferroelectricity in charge-ordered La
1/3
Sr
2/3
FeO
3
Authors: Park Se Young , Rabe Karin M. , Neaton Jeffrey B.
Published: November 2019

Significance

Charge-order–driven ferroelectrics are an emerging class of materials with promise for high-frequency electron-dominated polarization switching, distinct from conventional ferroelectrics. However, only a few systems exhibiting this behavior have been experimentally realized thus far. With continued development of layer-by-layer growth techniques with a high level of composition control, the exploration of charge-ordered ferroelectrics can be extended to artificially structured superlattices. Here, we use density-functional theory to explore an experimentally realized bulk perovskite iron-oxide solid solution with robust charge ordering and find that in superlattices formed by layered cation ordering, bulk charge ordering is maintained and can lead to charge-order–driven ferroelectricity. Our results suggest that other broad classes of mixed valence materials may be promising candidates for discovery of electronic ferroelectrics.
Single-cell transcriptomics reveals expansion of cytotoxic CD4 T cells in supercentenarians
Authors: Hashimoto Kosuke , Kouno Tsukasa , Ikawa Tomokatsu , Hayatsu Norihito , Miyajima Yurina , Yabukami Haruka , Terooatea Tommy , Sasaki Takashi , Suzuki Takahiro , Valentine Matthew , Pascarella Giovanni , Okazaki Yasushi , Suzuki Harukazu , Shin Jay W. , Minoda Aki , Taniuchi Ichiro , Okano Hideyuki , Arai Yasumichi , Hirose Nobuyoshi , Carninci Piero
Published: November 2019

Supercentenarians, people who have reached 110 y of age, are a great model of healthy aging. Their characteristics of delayed onset of age-related diseases and compression of morbidity imply that their immune system remains functional. Here we performed single-cell transcriptome analysis of 61,202 peripheral blood mononuclear cells (PBMCs), derived from 7 supercentenarians and 5 younger controls. We identified a marked increase of cytotoxic CD4 T cells (CD4 cytotoxic T lymphocytes [CTLs]) as a signature of supercentenarians. Furthermore, single-cell T cell receptor sequencing of 2 supercentenarians revealed that CD4 CTLs had accumulated through massive clonal expansion, with the most frequent clonotypes accounting for 15 to 35% of the entire CD4 T cell population. The CD4 CTLs exhibited substantial heterogeneity in their degree of cytotoxicity as well as a nearly identical transcriptome to that of CD8 CTLs. This indicates that CD4 CTLs utilize the transcriptional program of the CD8 lineage while retaining CD4 expression. Indeed, CD4 CTLs extracted from supercentenarians produced IFN-γ and TNF-α upon ex vivo stimulation. Our study reveals that supercentenarians have unique characteristics in their circulating lymphocytes, which may represent an essential adaptation to achieve exceptional longevity by sustaining immune responses to infections and diseases.
Accelerated evolution of oligodendrocytes in the human brain
Authors: Berto Stefano , Mendizabal Isabel , Usui Noriyoshi , Toriumi Kazuya , Chatterjee Paramita , Douglas Connor , Tamminga Carol A. , Preuss Todd M. , Yi Soojin V. , Konopka Genevieve
Published: November 2019

Recent discussions of human brain evolution have largely focused on increased neuron numbers and changes in their connectivity and expression. However, it is increasingly appreciated that oligodendrocytes play important roles in cognitive function and disease. Whether both cell types follow similar or distinctive evolutionary trajectories is not known. We examined the transcriptomes of neurons and oligodendrocytes in the frontal cortex of humans, chimpanzees, and rhesus macaques. We identified human-specific trajectories of gene expression in neurons and oligodendrocytes and show that both cell types exhibit human-specific up-regulation. Moreover, oligodendrocytes have undergone more pronounced accelerated gene expression evolution in the human lineage compared to neurons. We highlighted human-specific coexpression networks with specific functions. Our data suggest that oligodendrocyte human-specific networks are enriched for alternative splicing and transcriptional regulation. Oligodendrocyte networks are also enriched for variants associated with schizophrenia and other neuropsychiatric disorders. Such enrichments were not found in neuronal networks. These results offer a glimpse into the molecular mechanisms of oligodendrocytes during evolution and how such mechanisms are associated with neuropsychiatric disorders.
Roles of singleton tryptophan motifs in COPI coat stability and vesicle tethering
Authors: Travis Sophie M. , Kokona Bashkim , Fairman Robert , Hughson Frederick M.
Published: November 2019

Coat protein I (COPI)-coated vesicles mediate retrograde transport from the Golgi to the endoplasmic reticulum (ER), as well as transport within the Golgi. Major progress has been made in defining the structure of COPI coats, in vitro and in vivo, at resolutions as high as 9 Å. Nevertheless, important questions remain unanswered, including what specific interactions stabilize COPI coats, how COPI vesicles recognize their target membranes, and how coat disassembly is coordinated with vesicle fusion and cargo delivery. Here, we use X-ray crystallography to identify a conserved site on the COPI subunit α-COP that binds to flexible, acidic sequences containing a single tryptophan residue. One such sequence, found within α-COP itself, mediates α-COP homo-oligomerization. Another such sequence is contained within the lasso of the ER-resident Dsl1 complex, where it helps mediate the tethering of Golgi-derived COPI vesicles at the ER membrane. Together, our findings suggest that α-COP homo-oligomerization plays a key role in COPI coat stability, with potential implications for the coordination of vesicle tethering, uncoating, and fusion.
Pubertal stress recalibration reverses the effects of early life stress in postinstitutionalized children
Authors: Gunnar Megan R. , DePasquale Carrie E. , Reid Brie M. , Donzella Bonny , Miller Bradley S.
Published: November 2019

Nonhuman animal models reveal that the hypothalamic–pituitary–adrenocortical (HPA) axis calibrates to the harshness of the environment during a sensitive period in infancy. Humans exposed to depriving institutional care in infancy show reduced HPA axis responsivity, even years after they are placed in supportive, well-resourced families. This study examined whether puberty opens a window of opportunity to recalibrate the HPA axis toward more typical reactivity when children shift from harsh deprived conditions in infancy into supportive conditions in childhood and adolescence. Participants (
n
= 129 postinstitutionalized, 68.2% female;
n
= 170 comparison, 52.4% female) completed 3 annual sessions beginning at ages 7 to 15 (
M
= 11.28, SD = 2.31). Each session assessed pubertal stage via nurse examination and cortisol reactivity to the Trier social stress test for children. The linear mixed-effects model controlling for sex and between-individual differences in pubertal stage showed a significant group by pubertal stage interaction: within-individual increases in pubertal stage were associated with increases in cortisol stress reactivity for postinstitutionalized youth but not nonadopted comparison youth. This study indicates that pubertal development reopens a window of opportunity for the HPA axis to recalibrate based on significant improvements in the supportiveness of the environment relative to that in infancy. The peripubertal period may be an important time in development where the caregiving environment has a substantial impact on the HPA axis and, perhaps, other stress-mediating systems. Future research is needed to examine the mechanisms of recalibration and whether HPA recalibration impacts physical and psychological health.
Veil-of-ignorance reasoning favors the greater good
Authors: Huang Karen , Greene Joshua D. , Bazerman Max
Published: November 2019

The “veil of ignorance” is a moral reasoning device designed to promote impartial decision making by denying decision makers access to potentially biasing information about who will benefit most or least from the available options. Veil-of-ignorance reasoning was originally applied by philosophers and economists to foundational questions concerning the overall organization of society. Here, we apply veil-of-ignorance reasoning in a more focused way to specific moral dilemmas, all of which involve a tension between the greater good and competing moral concerns. Across 7 experiments (
n
= 6,261), 4 preregistered, we find that veil-of-ignorance reasoning favors the greater good. Participants first engaged in veil-of-ignorance reasoning about a specific dilemma, asking themselves what they would want if they did not know who among those affected they would be. Participants then responded to a more conventional version of the same dilemma with a moral judgment, a policy preference, or an economic choice. Participants who first engaged in veil-of-ignorance reasoning subsequently made more utilitarian choices in response to a classic philosophical dilemma, a medical dilemma, a real donation decision between a more vs. less effective charity, and a policy decision concerning the social dilemma of autonomous vehicles. These effects depend on the impartial thinking induced by veil-of-ignorance reasoning and cannot be explained by anchoring, probabilistic reasoning, or generic perspective taking. These studies indicate that veil-of-ignorance reasoning may be a useful tool for decision makers who wish to make more impartial and/or socially beneficial choices.
Metamaterials with engineered failure load and stiffness
Authors: Injeti Sai Sharan , Daraio Chiara , Bhattacharya Kaushik
Published: November 2019

Significance

A structure that fails at large loads is expected to be dense and stiff. This is because in conventional materials failure load depends directly on stiffness and density. This paper shows that the addition of engineered internal stresses in truss-like structures allows decoupling of these properties, increasing the failure load 2-fold while maintaining constant the density and stiffness. A similar approach could also be used to control locations and paths of failure in architected materials.
Colorectal cancer-associated microbiota contributes to oncogenic epigenetic signatures
Authors: Sobhani Iradj , Bergsten Emma , Couffin Séverine , Amiot Aurélien , Nebbad Biba , Barau Caroline , de’Angelis Nicola , Rabot Sylvie , Canoui-Poitrine Florence , Mestivier Denis , Pédron Thierry , Khazaie Khashayarsha , Sansonetti Philippe J.
Published: November 2019

Sporadic colorectal cancer (CRC) is a result of complex interactions between the host and its environment. Environmental stressors act by causing host cell DNA alterations implicated in the onset of cancer. Here we investigate the stressor ability of CRC-associated gut dysbiosis as causal agent of host DNA alterations. The epigenetic nature of these alterations was investigated in humans and in mice. Germ-free mice receiving fecal samples from subjects with normal colonoscopy or from CRC patients were monitored for 7 or 14 wk. Aberrant crypt foci, luminal microbiota, and DNA alterations (colonic exome sequencing and methylation patterns) were monitored following human feces transfer. CRC-associated microbiota induced higher numbers of hypermethylated genes in murine colonic mucosa (vs. healthy controls’ microbiota recipients). Several gene promoters including SFRP1,2,3, PENK, NPY, ALX4, SEPT9, and WIF1 promoters were found hypermethylated in CRC but not in normal tissues or effluents from fecal donors. In a pilot study (
n
= 266), the blood methylation levels of 3 genes (
Wif1
,
PENK
, and
NPY
) were shown closely associated with CRC dysbiosis. In a validation study (
n
= 1,000), the cumulative methylation index (CMI) of these genes was significantly higher in CRCs than in controls. Further, CMI appeared as an independent risk factor for CRC diagnosis as shown by multivariate analysis that included fecal immunochemical blood test. Consequently, fecal bacterial species in individuals with higher CMI in blood were identified by whole metagenomic analysis. Thus, CRC-related dysbiosis induces methylation of host genes, and corresponding CMIs together with associated bacteria are potential biomarkers for CRC.
Structure of the zinc-finger antiviral protein in complex with RNA reveals a mechanism for selective targeting of CG-rich viral sequences
Authors: Meagher Jennifer L. , Takata Matthew , Gonçalves-Carneiro Daniel , Keane Sarah C. , Rebendenne Antoine , Ong Heley , Orr Victoria K. , MacDonald Margaret R. , Stuckey Jeanne A. , Bieniasz Paul D. , Smith Janet L.
Published: November 2019

Infection of animal cells by numerous viruses is detected and countered by a variety of means, including recognition of nonself nucleic acids. The zinc finger antiviral protein (ZAP) depletes cytoplasmic RNA that is recognized as foreign in mammalian cells by virtue of its elevated CG dinucleotide content compared with endogenous mRNAs. Here, we determined a crystal structure of a protein-RNA complex containing the N-terminal, 4-zinc finger human (h) ZAP RNA-binding domain (RBD) and a CG dinucleotide-containing RNA target. The structure reveals in molecular detail how hZAP is able to bind selectively to CG-rich RNA. Specifically, the 4 zinc fingers create a basic patch on the hZAP RBD surface. The highly basic second zinc finger contains a pocket that selectively accommodates CG dinucleotide bases. Structure guided mutagenesis, cross-linking immunoprecipitation sequencing assays, and RNA affinity assays show that the structurally defined CG-binding pocket is not required for RNA binding per se in human cells. However, the pocket is a crucial determinant of high-affinity, specific binding to CG dinucleotide-containing RNA. Moreover, variations in RNA-binding specificity among a panel of CG-binding pocket mutants quantitatively predict their selective antiviral activity against a CG-enriched HIV-1 strain. Overall, the hZAP RBD RNA structure provides an atomic-level explanation for how ZAP selectively targets foreign, CG-rich RNA.
Hidden resources in the
Escherichia coli
genome restore PLP synthesis and robust growth after deletion of the essential gene
pdxB
Authors: Kim Juhan , Flood Jake J. , Kristofich Michael R. , Gidfar Cyrus , Morgenthaler Andrew B. , Fuhrer Tobias , Sauer Uwe , Snyder Daniel , Cooper Vaughn S. , Ebmeier Christopher C. , Old William M. , Copley Shelley D.
Published: November 2019

Significance

The evolution of new metabolic pathways has been a driver of diversification from the last universal common ancestor 3.8 billion y ago to the present. Bioinformatic evidence suggests that many pathways were assembled by recruiting promiscuous enzymes to serve new functions. However, the processes by which new pathways have emerged are lost in time. We have little information about the environmental conditions that fostered emergence of new pathways, the genome context in which new pathways emerged, and the types of mutations that elevated flux through inefficient new pathways. Experimental laboratory evolution has allowed us to evolve a new pathway and identify mechanisms by which mutations increase fitness when an inefficient new pathway becomes important for survival.
Pollination of Cretaceous flowers
Authors: Bao Tong , Wang Bo , Li Jianguo , Dilcher David
Published: November 2019

Insect pollination of flowering plants (angiosperms) is responsible for the majority of the world’s flowering plant diversity and is key to the Cretaceous radiation of angiosperms. Although both insects and angiosperms were common by the mid-Cretaceous, direct fossil evidence of insect pollination is lacking. Direct evidence of Cretaceous insect pollination is associated with insect-gymnosperm pollination. Here, we report a specialized beetle-angiosperm pollination mode from mid-Cretaceous Burmese amber (99 mega-annum [Ma]) in which a tumbling flower beetle (Mordellidae),Angimordella burmitinagen. et sp. nov., has many tricolpate pollen grains attached.A. burmitinaexhibits several specialized body structures for flower-visiting behavior including its body shape and pollen-feeding mouthparts revealed by X-ray microcomputed tomography (micro-CT). The tricolpate pollen in the amber belongs to the eudicots that comprise the majority of extant angiosperm species. These pollen grains exhibit zoophilous pollination attributes including their ornamentation, size, and clumping characteristics. Tricolpate pollen grains attached to the beetle’s hairs are revealed by confocal laser scanning microscopy, which is a powerful tool for investigating pollen in amber. Our findings provide direct evidence of insect pollination of Cretaceous angiosperms, extending the range insect-angiosperm pollination association by at least 50 million years. Our results support the hypothesis that specialized insect pollination modes were present in eudicots 99 million years ago.
Second language pragmatic attrition after studying abroad
Authors: Fukazawa Seiji , Kida Shusaku
Published: November 2019

This research examined the attrition and/or maintenance of second language pragmatic competence among Japanese
learners of English after returning home from studying in the United Kingdom (U.K.). Participants were university students who had
studied abroad (SA) for four months at two U.K. universities and had lived in a homestay environment. A pragmatic appropriateness
judgment task of request-making sentences was administered at the end of the SA and six months after returning home, in which the
accuracy and speed of appropriateness judgment of these request sentences were compared. The results demonstrated a loss of (a)
judgment accuracy for under-polite inappropriate requests, but not for appropriate requests; and (b) automatic processing of
request-making sentences, evaluated using the coefficient of variation, for both under- and over-polite inappropriate requests.
These results suggest that pragmatic attrition does occur after SA but does not occur at the same time for every aspect of
pragmatic competence examined.
Radio-frequency hands-on for nuclear fusion Master’s students
Authors: Hillairet Julien , Achard J , Ragona R
Published: November 2019

High-power continuous-wave radio-frequency (RF) systems in the megawatt range are commonly used in nuclear fusion experiments. Such kinds of RF systems being rather rare, Master’s students do not know how these systems are used in practice – even students engaged in nuclear fusion courses. This is the reason why, as part of the French and European Master’s in fusion physics and technologies, dedicated practical work on topics related to plasma RF heating are proposed to students. Over a few days, these students discover how to perform RF measurements and succeed in characterizing real-scale components used in plasma RF heating experiments. This paper details four hands-on approaches which have been conducted over eight years with several tens of students having no prior knowledge in RF engineering.
Spectral characterization of an industrial EUV light source for nanolithography
Authors: Torretti F , Liu F , Bayraktar M , Scheers J , Bouza Z , Ubachs W , Hoekstra R , Versolato O
Published: November 2019

The emission spectra from an industrial, droplet-based, laser-produced plasma, extreme ultraviolet light source for nanolithography are here presented and analyzed. The dependence of spectral features on the CO2-drive-laser intensity is studied by changing the beam spot size at constant pulse energy and duration. We characterize the spectrum by fitting the results of atomic structure calculations to the short-wavelength region (7–11 nm), where the contributions from various charge states can be resolved, and obtain the relative contributions of charge states Sn9+ –Sn15+ . These relative contributions are compared to charge state populations as calculated with the non-equilibrium plasma kinetics code flychk. The calculations are shown to be in good qualitative agreement with the results, showing that the effective plasma temperature, and with it, the shape of the unresolved, main emission feature at 13.5 nm, is a remarkably weak function of laser intensity under this source normal operating conditions.
Advanced laser-driven ion sources and their applications in materials and nuclear science
Authors: Passoni M , Arioli F M , Cialfi L , Dellasega D , Fedeli L , Formenti A , Giovannelli A C , Maffini A , Mirani F , Pazzaglia A , Tentori A , Vavassori D , Zavelani-Rossi M , Russo V
Published: November 2019

The investigation of superintense laser-driven ion sources and their potential applications offers unique opportunities for multidisciplinary research. Plasma physics can be combined with materials and nuclear science, radiation detection and advanced laser technology, leading to novel research challenges of great fundamental and applicative interest. In this paper we present interesting and comprehensive results on nanostructured low density (near-critical) foam targets for TW and PW-class lasers, obtained in the framework of the European Research Council ENSURE project. Numerical simulations and experimental activities carried out at 100 s TW and PW-class laser facilities have shown that targets consisting of a solid foil coated with a nanostructured low-density (near-critical) foam can lead to an enhancement of the ion acceleration process. This stimulated a thorough numerical investigation of superintense laser-interaction with nanostructured near-critical plasmas. Thanks to a deep understanding of the foam growth process via the pulsed laser deposition technique and to the complementary capabilities of high-power impulse magnetron sputtering, advanced multi-layer targets based on near-critical films with carefully controlled properties (e.g. density gradients over few microns length scales) can now be manufactured, with applications outreaching the field of laser-driven ion acceleration. Additionally, comprehensive numerical and theoretical work has allowed the design of dedicated experiments and a realistic table-top apparatus for laser-driven materials irradiation, ion beam analysis and neutron generation, that exploit a double-layer target to reduce the requirements for the laser system.