bluuebunny/crossref_metadata_2025_split huggingface dataset:
Development of novel projection-type imaging mass spectrometer
Authors: Aoki J. , Toyoda M. 
Published: May 2021

We developed a novel imaging mass spectrometer based on our accumulating technology for projection-type imaging mass spectrometry, the simulation of an accurate ion trajectory, and the theory for ion optics. The newly developed apparatus yields high spatial resolution with a substantially shorter image-acquisition time compared with conventional scanning-type imaging mass spectrometers. In order to maintain a high mass resolution, a multi-turn time-of-flight mass spectrometer is combined with post-extraction differential acceleration methods. Consequently, a mass resolution of m/Δm ∼ 10 000 and a spatial resolution of 1 μm were achieved simultaneously in this study. Application of our newly established apparatus to biological samples accomplished successful imaging mass spectrometry by exhibiting an organ-specific distribution of endogenous ions as well as a localized distribution of exogenously applied ions with an ultra-high spatial resolution image in the size of 18.5 megapixels.
Coupling between slow waves and sharp-wave ripples engages distributed neural activity during sleep in humans
Authors: Skelin Ivan , Zhang Haoxin , Zheng Jie , Ma Shiting , Mander Bryce A. , Kim McManus Olivia , Vadera Sumeet , Knight Robert T. , McNaughton Bruce L. , Lin Jack J. 
Published: May 2021

SignificanceHippocampal sharp wave/ripples (SWRs) are implicated in binding distributed subcortical/cortical neuronal populations during sleep, supporting hippocampal-dependent memory consolidation. We assessed the activation and functional interactions between distributed populations during SWRs using intracranial electrophysiological recordings from human epileptic patients. Consistent phase relation between the hippocampal SWRs and local subcortical/cortical slow-wave activity (SWA) or spindles was a strong predictor of local neuronal activation during SWRs. In addition, individual SWR amplitude and SWA phase difference between the cortical sites during SWRs predicted the functional coupling between the distant cortical populations. Our findings suggest the SWR–SWA coupling as a mechanism for selecting and organizing the distributed populations for participation in global memory consolidation.
Odor-driven face-like categorization in the human infant brain
Authors: Rekow Diane , Baudouin Jean-Yves , Poncet Fanny , Damon Fabrice , Durand Karine , Schaal Benoist , Rossion Bruno , Leleu Arnaud 
Published: May 2021

Significance
The adult human brain is organized in unimodal regions responding selectively to categories of environmental sensory stimuli. Here, we document the origin of category-selective visual brain responses in infancy, demonstrating the key contribution of other senses. Visual categorization is recorded neurally in 4-mo-old infants presented with rapid trains of natural images of nonface objects. A concurrent maternal odor initiates the neural response to periodically presented face-like objects categorized as faces in the specialized right hemisphere. This observation provides invaluable clues to understand how the developing visual system builds upon multisensory experience to start categorizing ambiguous and complex unimodal sensory inputs.
The SHREAD gene therapy platform for paracrine delivery improves tumor localization and intratumoral effects of a clinical antibody
Authors: Smith Sheena N. , Schubert Rajib , Simic Branko , Brücher Dominik , Schmid Markus , Kirk Niels , Freitag Patrick C. , Gradinaru Viviana , Plückthun Andreas 
Published: May 2021

Significance
A challenge in cancer therapy is delivering high, consistent levels of therapeutics to tumors. Protein-based therapeutics (e.g., antibodies) are typically delivered intravenously and require multiple doses to get sufficient levels to traffic into tumors to exert an effect. Yet healthy tissues are also exposed to similar drug levels, which can lead to significant side effects. This study uses sophisticated three-dimensional imaging of transparent tumors to characterize a versatile gene therapy platform using adenovirus that solves this problem by producing drugs directly in the tumor. This approach increases the tumor-to-bloodstream level of a model antibody 1,800-fold in comparison to direct administration. Thus, this system could allow for the local production of highly potent drugs with greatly reduced risk of systemic toxicities.
Coastal eutrophication drives acidification, oxygen loss, and ecosystem change in a major oceanic upwelling system
Authors: Kessouri Faycal , McWilliams James C. , Bianchi Daniele , Sutula Martha , Renault Lionel , Deutsch Curtis , Feely Richard A. , McLaughlin Karen , Ho Minna , Howard Evan M. , Bednaršek Nina , Damien Pierre , Molemaker Jeroen , Weisberg Stephen B. 
Published: May 2021

Significance
We conduct a modeling study of the effects of enhanced coastal nutrient export from human activities on the carbon, nitrogen, and oxygen cycles of the Southern California Bight, in the context of emerging global climate change. The modeling approach used is innovative in the breadth of its scope, and simulations are generally consistent with local measurements. The human effects on the regional ecosystem from coastal nitrogen inputs of 23 million people are substantial, leading to significant increases in the photosynthesis and biomass of phytoplankton and increased oxygen loss and acidification of the water column. These changes are likely to compress habitat for a variety of marine organisms, with cascading ecological effects and implications for marine resources and water-quality management.
An additive algorithm for origami design
Authors: Dudte Levi H. , Choi Gary P. T. , Mahadevan L. 
Published: May 2021

Significance
Origami, the art of paper folding, is an emerging platform for mechanical metamaterials. Prior work on the design of origami-based structures has focused on simple geometric constructions for limited spaces of origami typologies or global constrained optimization problems that are difficult to solve. Here, we reverse the mathematical, computational, and physical paradigm of origami design by proposing a simple local marching approach that leads to a constructive theorem on the geometry of compatible growth directions at the boundary of a given folded seed. We show how this discovery yields a simple algorithm for the additive design of all developable quadrilateral surfaces, enabling the design of novel foldable metastructures from flat sheets at any scale.
On the evolution of chaperones and cochaperones and the expansion of proteomes across the Tree of Life
Authors: Rebeaud Mathieu E. , Mallik Saurav , Goloubinoff Pierre , Tawfik Dan S. 
Published: May 2021

Significance
Across the Tree of Life, life’s phenotypic diversity has been accompanied by a massive expansion of the protein universe. Compared with simple prokaryotes that harbor thousands of proteins, plants and animals harbor hundreds of thousands of proteins that are also longer, multidomain, and comprise a variety of folds and fold combinations, repeated segments, and beta-rich architectures that make them prone to misfolding and aggregation. Surprisingly, the relative representation of core chaperones, those dedicated to maintaining the folding quality of these increasingly complex proteomes, did not change from prokaryotic to mammalian genomes. To reconcile the expanding proteomes, core chaperones have rather increased in cellular abundance and evolved to function cooperatively as a network, combined with their supporting workforce, the cochaperones.
A synthetic C4 shuttle via the β-hydroxyaspartate cycle in C3 plants
Authors: Roell Marc-Sven , Schada von Borzyskowski Lennart , Westhoff Philipp , Plett Anastasija , Paczia Nicole , Claus Peter , Schlueter Urte , Erb Tobias J. , Weber Andreas P.M. 
Published: May 2021

SignificancePhotorespiration is essential for photosynthesis in an oxygen-containing atmosphere. By mass flow, photorespiration is exceeded only by photosynthetic carbon assimilation. Photorespiration, initiated by the oxygenation reaction of Rubisco, is a major constraint on the photosynthetic efficiency of C3 plants and consequently on crop yield. Mitigating the negative effects of photorespiration holds potential for yield increases and contributes to achieving food and energy security for a growing population. This work presents a synthetic bypass to natural photorespiration (i.e., the conversion of photorespiratory glycolate into a C4 compound via a recently discovered microbial glycolate assimilation pathway, the β-hydroxyaspartate cycle [BHAC]). Simultaneous expression of four enzymes of microbial origin in the land plant modelArabidopsis thalianaenables efficient glycolate conversion into BHAC products.
Microchemomechanical devices using DNA hybridization
Authors: Zhu Guolong , Hannel Mark , Sha Ruojie , Zhou Feng , Ben Zion Matan Yah , Zhang Yin , Bishop Kyle , Grier David , Seeman Nadrian , Chaikin Paul 
Published: May 2021

Significance
With simple DNA origami lever arms arranged in hinges and accordion structures, we amplify the nanometer displacements from DNA hairpin zippers to 4-μm motion, easily observable and quantified in real space and real time with conventional optical microscopy. Mechanically pulling a bead tethered on the accordion end, we measure high-energy recovery and retraction speeds up to 50 μm/s. On longer time scales, we have also opened and closed the hinges with light and heat. DNA nanotechnology, and particularly DNA origami, combined with colloids and emulsions can provide powerful architectures. The present study is a step toward activating such colloidal/cellular scale devices using DNA as a power source/fuel. We envision artificial active flagella, cilia, micropumps, and other cellular scale devices.
Background-free dual-mode optical and13C magnetic resonance imaging in diamond particles
Authors: Lv Xudong , Walton Jeffrey H. , Druga Emanuel , Wang Fei , Aguilar Alessandra , McKnelly Tommy , Nazaryan Raffi , Liu Fanglin Linda , Wu Lan , Shenderova Olga , Vigneron Daniel B. , Meriles Carlos A. , Reimer Jeffrey A. , Pines Alexander , Ajoy Ashok 
Published: May 2021

SignificanceWe report on progress toward combining magnetic resonance imaging (MRI) and optical imaging in diamond microparticles. Our approach relies on the nitrogen vacancy (NV) center-driven optical nuclear hyperpolarizability in diamond particles, that renders them “bright” in MRI while simultaneously fluorescing optically. Both imaging modes allow suppression of background signals. We elucidate how such “dual-mode” imaging can perform better than either modes taken separately, leveraging relative strengths of optics and MRI with respect to resolution and imaging in scattering media. Finally, we propose a protocol for accelerated imaging that exploits the Fourier conjugacy in images obtained via optics and MRI. Our work suggests methods to combine optical and RF imaging in classes of deployable nanoparticles.
Critical slowing down suggests that the western Greenland Ice Sheet is close to a tipping point
Authors: Boers Niklas , Rypdal Martin 
Published: May 2021

SignificanceIt has been suggested that, in response to anthropogenic global warming, the Greenland Ice Sheet may reach a tipping point beyond which its current configuration would become unstable. A crucial nonlinear mechanism for the existence of this tipping point is the positive melt-elevation feedback: Melting reduces ice sheet height, exposing the ice sheet surface to warmer temperatures, which further accelerates melting. We reveal early-warning signals for a forthcoming critical transition from ice-core-derived height reconstructions and infer that the western Greenland Ice Sheet has been losing stability in response to rising temperatures. We show that the melt-elevation feedback is likely to be responsible for the observed destabilization. Our results suggest substantially enhanced melting in the near future.
Gut microbiome contributions to altered metabolism in a pig model of undernutrition
Authors: Chang Hao-Wei , McNulty Nathan P. , Hibberd Matthew C. , O’Donnell David , Cheng Jiye , Lombard Vincent , Henrissat Bernard , Ilkayeva Olga , Muehlbauer Michael J. , Newgard Christopher B. , Barratt Michael J. , Lin Xi , Odle Jack , Gordon Jeffrey I. 
Published: May 2021

SignificanceEmploying an intergenerational model of diet restriction (DR) that reduces weight gain, we identify differences in carbohydrate metabolic enzyme gene content of DR versus full-fed (FF) pig gut microbiomes as animals experienced a phased-feeding program administered to farm-raised pigs during their growth cycle. Gnotobiotic mice harboring DR or FF pig microbiomes and fed a corn/soy-dominated pig diet disclosed that the DR microbiome has reduced capacity to produce butyrate, a key diet-derived energy source, and alters hepatic energy metabolism. Combining studies of farm animal microbiome development with functional assays of their microbiomes in gnotobiotic mice should help generate husbandry recommendations for promoting healthy growth of animals during this time of increasing food insecurity and mandates to eliminate subtherapeutic antibiotics for growth-promotion.
Encapsulation of ribozymes inside model protocells leads to faster evolutionary adaptation
Authors: Lai Yei-Chen , Liu Ziwei , Chen Irene A. 
Published: May 2021

SignificanceOrganization into cells is believed to have been crucial for the emergence of life, as the cell membrane would prevent loss of biochemical contents and define an evolutionary entity. RNA is a candidate primordial biomolecule, as it can encode and transmit information and also fold into catalytically active structures. Biomolecules are known to behave differently inside cells compared to bulk solution due to differences in the biophysical environment. However, the consequences of encapsulation on early evolution are unknown. We found that, in a lipid-rich environment, ribozyme encapsulation would promote greater activity and faster adaptation. Better RNA catalysts experience greater gains in a “rich-get-richer” phenomenon. Rather than acting as passive containers, protocells would provide functional and evolutionary benefits to encapsulated contents.
Accidental synthesis of a previously unknown quasicrystal in the first atomic bomb test
Authors: Bindi Luca , Kolb William , Eby G. Nelson , Asimow Paul D. , Wallace Terry C. , Steinhardt Paul J. 
Published: May 2021

Significance
This article reports the discovery of a heretofore unknown icosahedral quasicrystal created by the detonation of the first nuclear device at Alamogordo, NM, on 16 July 1945 (the Trinity test). Like all quasicrystals, the new example violates crystallographic symmetry rules that apply to ordinary (periodic) crystals. It was found in a sample of red trinitite, a combination of glass fused from natural sand and anthropogenic copper from transmission lines used during the test. The new quasicrystal is the oldest extant anthropogenic quasicrystal known, whose place and moment of origin are known from the historic records of the Trinity test. The thermodynamic/shock conditions that formed it are roughly comparable to those that formed natural quasicrystals recently found in meteorites.
HIV envelope tail truncation confers resistance to SERINC5 restriction
Authors: Haider Tafhima , Snetkov Xenia , Jolly Clare 
Published: May 2021

Significance
SERINCs and IFITMs are potent lentiviral restriction factors that inhibit infection by blocking viral entry into cells. Specifically, SERINCs inhibit viral fusion by targeting the envelope glycoprotein (Env) by a mechanism that remains incompletely understood. Here, we report that truncation of the Env cytoplasmic tail (CT) of HIV-1 and HIV-2 confers complete resistance to SERINC and IFITM restriction. Notably, while the EnvCT of HIV-1 is necessary for viral replication in T cells, HIV-2 does not require the EnvCT. Our data suggest a mechanism by which human lentiviruses can evade restriction that is mediated by the EnvCT but reveal key differences in the likely fitness cost imposed by this on pandemic HIV-1 and nonpandemic HIV-2.
The unintended consequences of US immigration enforcement policies
Authors: Ryo Emily 
Published: May 2021

Significance
Every day, thousands of immigrants in the United States are held in immigration detention under conditions that are no different than those facing the criminally incarcerated. Thousands of other immigrants are deported to their countries of origin without the opportunity to be heard before an immigration judge. US policymakers hope that these punitive enforcement policies will deter individuals from attempting to enter the United States without authorization. Yet this study of individuals in El Salvador, Guatemala, Honduras, and Mexico finds no evidence that such policies change their intentions to migrate to the United States. On the other hand, the survey analysis indicates that immigration detention may foster beliefs that the US immigration system lacks procedural and outcome fairness.
Roles of KLF4 and AMPK in the inhibition of glycolysis by pulsatile shear stress in endothelial cells
Authors: Han Yue , He Ming , Marin Traci , Shen Hui , Wang Wei-Ting , Lee Tzong-Yi , Hong Hsiao-Chin , Jiang Zong-Lai , Garland Theodore , Shyy John Y.-J. , Gongol Brendan , Chien Shu 
Published: May 2021

Significance
This work identifies mechanotransduction mechanisms by which blood flow regulates glycolysis in vascular endothelium. We demonstrate that atheroprotective flow pattern decreases glycolysis, an energy-demanding metabolic process, in endothelium in vitro and in vivo. GCKR, an inhibitor of glycolytic flux, is up-regulated by atheroprotective flow, in contrast to the down-regulation of other glycolysis genes. As a pioneer transcription factor induced by atheroprotective flow, KLF4 epigenetically remodels the GCKR promoter and thus transactivates GCKR. At the posttranslational level, atheroprotective flow–activated AMPK phosphorylates GCKR and hence increases GCKR binding to hexokinase, the key enzyme in glycolysis. The translational significance of these findings builds on the identification of these atheroprotective mechanisms in an animal model with a high level of voluntary wheel running.
Hypothenemus hampei (coffee berry borer).
Authors: Baker Peter 
Published: May 2021

Abstract

H. hampei, otherwise known as the coffee berry borer, is the most serious pest of coffee in many of the major coffee-producing countries in the world. The scolytid beetle feeds on the cotyledons and has been known to attack 100% of berries in a heavy infestation. Crop losses can be very severe and coffee quality from damaged berries is poor. H. hampei has been transported around the world as a contaminant of coffee seed and very few coffee-producing countries are free from the borer. Its presence in Hawaii was confirmed in 2010 and Papua New Guinea and Nepal remain free of the pest: in Papua New Guinea an incursion prevention programme was mounted in 2007 (ACIAR, 2013) to reduce chances of invasion from Papua Province (Indonesia). There is no simple and cheap method of control of H. hampei.
Epiphyas postvittana (light brown apple moth).
Authors: Suckling D. 
Published: May 2021

Abstract

E. postvittana is a small, bell-shaped moth, whose caterpillars feed on a very wide range of plants. The eggs, larvae and pupae can be associated with plant material and readily transported. The pest status of this insect in horticultural crops is very significant. It is native to Australia and was distributed to New Zealand, Hawaii, New Caledonia and the UK with apples [Malus domestica] or other plant material in the late 1800s. It has since spread throughout lowland New Zealand, and in recent years has spread through southern parts of the UK, and Ireland. In Hawaii, it appears to be confined to altitudes above 1100 m, and can largely be considered a pest of temperate regions.
Commercial finance for development: a back door for financialisation
Authors: Karwowski Ewa 
Published: May 2021

SUMMARY
The global Covid-19 pandemic has accelerated a trend under way for the last decade: the enlistment of private-sector commercial finance for development. This finance can be brought in through (1) regular cross-border flows, (2) blended finance and (3) impact bonds. This briefing argues that intensified foreign financial inflows are likely to draw African economies further into financialisation, which increases financial instability and can undermine the democratic process, jeopardising just socio-economic development. Specifically, the short-termism of portfolio flows requires costly reserve accumulation, foreign direct investment exposes firms to demands for shareholder value generation, and external debt introduces exchange rate risk for domestic borrowers.
Experimental determination of first Townsend ionization coefficient in mixtures of He and N2
Authors: Talviste Rasmus , Paris Peeter , Raud Jüri , Plank Toomas , Jõgi Indrek 
Published: May 2021

Abstract
First Townsend ionization coefficient α in gas mixture of He with N2 is relevant for modeling of the development and chemical activity of atmospheric pressure plasma jets. This study determined α from measurements of current versus electrode separation in a steady-state non-self-sustaining Townsend discharge set-up. The measurements were carried out in absolute pressure range of 10–800 Torr and reduced electric field E/N range of 20–1000 Td. The effect of the N2 concentration in the gas mixture on the density normalized ionization coefficient α/N depended on the reduced electric field strength E/N. At E/N values below 200 Td, increased N2 content reduced the α/N while at E/N values above 200 Td, increased N2 content increased the plateau value of α/N. Reasonably good coincidence was observed between calculation performed with Bolsig+ and measured α/N. The discrepancy between experimental results and calculations at N2 percentage in the mixture below 5% and E/N values below 200 Td can be attributed to the Penning effect.
Floquet scattering of quadratic band-touching semimetals through a time-periodic potential well
Authors: Bera Sandip , Mandal Ipsita 
Published: May 2021

Abstract
We consider tunneling of quasiparticles through a rectangular quantum well, subject to periodic driving. The quasiparticles are the itinerant charges in two-dimensional and three-dimensional semimetals having a quadratic bandtouching (QBT) point in the Brillouin zone. To analyze the time-periodic Hamiltonian, we assume a non-adiabatic limit where the Floquet theorem is applicable. By deriving the Floquet scattering matrices, we chalk out the transmission and shot noise spectra of the QBT semimetals. The spectra show Fano resonances, which we identify with the (quasi)bound states of the systems.
Modified gravity in the interior of population II stars
Authors: Chowdhury Shaswata , Sarkar Tapobrata 
Published: May 2021

Abstract
We study the effects of a beyond-Horndeski theory of modified gravity
in the interior of a population II star. We consider a simple phenomenological model of a
1.1M
☉ star that has left the main sequence, has a thin Hydrogen burning shell with a partially degenerate
isothermal core, surrounded by a radiative envelope having two regions of distinct opacities.
Using suitable matching conditions at the two internal boundaries, a numerical analysis of the resulting
stellar equations in modified gravity is carried out. While overall, gravity may be weakened, resulting in a decrease of
the luminosity and an increase of the radius of the star, some of these effects are reversed near the core.
It is suggested how the model, within its limitations, can yield a bound on the modified gravity parameter.