bluuebunny/crossref_metadata_2025 huggingface dataset:
High sensitivity analysis of nanogram quantities of glycosaminoglycans using ToF-SIMS
Authors: Hook Andrew L. , Hogwood John , Gray Elaine , Mulloy Barbara , Merry Catherine L. R.
Published: May 2021

Glycosaminoglycans (GAGs) are important biopolymers that differ in the sequence of saccharide units and in post polymerisation alterations at various positions, making these complex molecules challenging to analyse. Here we describe an approach that enables small quantities (<200 ng) of over 400 different GAGs to be analysed within a short time frame (3–4 h). Time of flight secondary ion mass spectrometry (ToF-SIMS) together with multivariate analysis is used to analyse the entire set of GAG samples. Resultant spectra are derived from the whole molecules and do not require pre-digestion. All 6 possible GAG types are successfully discriminated, both alone and in the presence of fibronectin. We also distinguish between pharmaceutical grade heparin, derived from different animal species and from different suppliers, to a sensitivity as low as 0.001 wt%. This approach is likely to be highly beneficial in the quality control of GAGs produced for therapeutic applications and for characterising GAGs within biomaterials or from in vitro cell culture.
Ultrafast excited state dynamics and light-switching of [Ru(phen)2(dppz)]2+ in G-quadruplex DNA
Authors: Yang Chunfan , Zhou Qian , Jiao Zeqing , Zhao Hongmei , Huang Chun-Hua , Zhu Ben-Zhan , Su Hongmei
Published: May 2021

The triplet metal to ligand charge transfer (3MLCT) luminescence of ruthenium (II) polypyridyl complexes offers attractive imaging properties, specifically towards the development of sensitive and structure-specific DNA probes. However, rapidly-deactivating dark state formation may compete with 3MLCT luminescence depending on different DNA structures. In this work, by combining femtosecond and nanosecond pump-probe spectroscopy, the 3MLCT relaxation dynamics of [Ru(phen)2(dppz)]2+ (phen = 1,10-phenanthroline, dppz = dipyridophenazine) in two iconic G-quadruplexes has been scrutinized. The binding modes of stacking of dppz ligand on the terminal G-quartet fully and partially are clearly identified based on the biexponential decay dynamics of the 3MLCT luminescence at 620 nm. Interestingly, the inhibited dark state channel in ds-DNA is open in G-quadruplex, featuring an ultrafast picosecond depopulation process from 3MLCT to a dark state. The dark state formation rates are found to be sensitive to the content of water molecules in local G-quadruplex structures, indicating different patterns of bound water. The unique excited state dynamics of [Ru(phen)2(dppz)]2+ in G-quadruplex is deciphered, providing mechanistic basis for the rational design of photoactive ruthenium metal complexes in biological applications.
The chiral Hall effect in canted ferromagnets and antiferromagnets
Authors: Kipp Jonathan , Samanta Kartik , Lux Fabian R. , Merte Maximilian , Go Dongwook , Hanke Jan-Philipp , Redies Matthias , Freimuth Frank , Blügel Stefan , Ležaić Marjana , Mokrousov Yuriy
Published: May 2021

The anomalous Hall effect has been indispensable in our understanding of numerous magnetic phenomena. This concerns both ferromagnetic materials, as well as diverse classes of antiferromagnets, where in addition to the anomalous and recently discovered crystal Hall effect, the topological Hall effect in noncoplanar antiferromagnets has been a subject of intensive research in the past decades. Here, we uncover a distinct flavor of the Hall effect emerging in generic canted spin systems. We demonstrate that upon canting, the anomalous Hall effect acquires a contribution which is sensitive to the sense of imprinted vector chirality among spins. We explore the origins and basic properties of corresponding chiral Hall effect, and closely tie it to the symmetry properties of the system. Our findings suggest that the chiral Hall effect and corresponding chiral magneto-optical effects emerge as useful tools in characterizing an interplay of structure and chirality in complex magnets, as well as in tracking their chiral dynamics and fluctuations.
Size dependent nature of the magnetic-field driven superconductor-to-insulator quantum-phase transitions
Authors: Zhang Xiaofu , Lita Adriana E. , Liu Huanlong , Verma Varun B. , Zhou Qiang , Nam Sae Woo , Schilling Andreas
Published: May 2021

The nature of the magnetic-field driven superconductor-to-insulator quantum-phase transition in two-dimensional systems at zero temperature has been under debate since the 1980s, and became even more controversial after the observation of a quantum-Griffiths singularity. Whether it is induced by quantum fluctuations of the superconducting phase and the localization of Cooper pairs, or is directly driven by depairing of these pairs, remains an open question. We herein experimentally demonstrate that in weakly-pinning systems and in the limit of infinitely wide films, a sequential superconductor-to-Bose insulator-to-Fermi insulator quantum-phase transition takes place. By limiting their size to smaller than the effective penetration depth, however, the vortex interaction alters, and the superconducting state re-enters the Bose-insulating state. As a consequence, one observes a direct superconductor-to-Fermi insulator in the zero-temperature limit. In narrow films, the associated critical-exponent products diverge along the corresponding phase boundaries with increasing magnetic field, which is a hallmark of the quantum-Griffiths singularity.
Micro-slips in an experimental granular shear band replicate the spatiotemporal characteristics of natural earthquakes
Authors: Houdoux David , Amon Axelle , Marsan David , Weiss Jérôme , Crassous Jérôme
Published: May 2021

Memory effects in seismology—such as the occurrence of aftershock sequences—are implicitly assumed to be governed by the time since the main event. However, experiments are yet to identify if memory effects are structural or time-dependent mechanisms. Here, we use laser interferometry to examine the fluctuations of deformation which naturally emerge along an experimental shear fault within a compressed frictional granular medium. We find that deformation occurs as a succession of localized micro-slips distributed along the fault. The associated distributions of released seismic moments, as well as the memory effects in strain fluctuations and the time correlations between successive events, follow exactly the empirical laws of natural earthquakes. We use a methodology initially developed in seismology to reveal at the laboratory scale the underlying causal structure of this behavior and identify the triggering kernel. We propose that strain, not time, controls the memory effects in our fault analog.
Ensemble forecasting greatly expands the prediction horizon for ocean mesoscale variability
Authors: Thoppil Prasad G. , Frolov Sergey , Rowley Clark D. , Reynolds Carolyn A. , Jacobs Gregg A. , Joseph Metzger E. , Hogan Patrick J. , Barton Neil , Wallcraft Alan J. , Smedstad Ole Martin , Shriver Jay F.
Published: May 2021

Mesoscale eddies dominate energetics of the ocean, modify mass, heat and freshwater transport and primary production in the upper ocean. However, the forecast skill horizon for ocean mesoscales in current operational models is shorter than 10 days: eddy-resolving ocean models, with horizontal resolution finer than 10 km in mid-latitudes, represent mesoscale dynamics, but mesoscale initial conditions are hard to constrain with available observations. Here we analyze a suite of ocean model simulations at high (1/25°) and lower (1/12.5°) resolution and compare with an ensemble of lower-resolution simulations. We show that the ensemble forecast significantly extends the predictability of the ocean mesoscales to between 20 and 40 days. We find that the lack of predictive skill in data assimilative deterministic ocean models is due to high uncertainty in the initial location and forecast of mesoscale features. Ensemble simulations account for this uncertainty and filter-out unconstrained scales. We suggest that advancements in ensemble analysis and forecasting should complement the current focus on high-resolution modeling of the ocean.
Snowfall-albedo feedbacks could have led to deglaciation of snowball Earth starting from mid-latitudes
Authors: de Vrese Philipp , Stacke Tobias , Caves Rugenstein Jeremy , Goodman Jason , Brovkin Victor
Published: May 2021

Simple and complex climate models suggest a hard snowball – a completely ice-covered planet – is one of the steady-states of Earth’s climate. However, a seemingly insurmountable challenge to the hard-snowball hypothesis lies in the difficulty in explaining how the planet could have exited the glaciated state within a realistic range of atmospheric carbon dioxide concentrations. Here, we use simulations with the Earth system model MPI-ESM to demonstrate that terminal deglaciation could have been triggered by high dust deposition fluxes. In these simulations, deglaciation is not initiated in the tropics, where a strong hydrological cycle constantly regenerates fresh snow at the surface, which limits the dust accumulation and snow aging, resulting in a high surface albedo. Instead, comparatively low precipitation rates in the mid-latitudes in combination with high maximum temperatures facilitate lower albedos and snow dynamics that – for extreme dust fluxes – trigger deglaciation even at present-day carbon dioxide levels.
A systematic investigation on the impact of the level of oxidation at sulfur and the configuration of R/S-sulfoxide on the solid structure
Authors: Zhou Yanan , Ma Hongzhi , Yang Zhongxing , Wu Chengjun , Sun Tiemin
Published: May 2021

In this work, the two aspects, different oxidation states of sulfur and diastereomeric sulfoxides, were combined to comprehend the role of crystal packing and different weak intermolecular interactions in the solid state.
Template-free synthesis of hierarchical nanocrystal UiO-66 and its adsorption thermodynamics for n-heptane and methyl cyclohexane
Authors: Liu Zongjian , Sun Zhicong , Zhang Lin , Xu Lifei , Lu Xinyue , Cui Qun , Wang Haiyan
Published: May 2021

NH4OH can induce rapid crystallization of the precursors, whereas acetic acid can effectively stabilize such precursors and control the balance between nucleation and growth of UiO-66.
Interplay of halogen and hydrogen bonding in a series of heteroleptic iron(iii) complexes
Authors: Díaz-Torres Raúl , Echeverría Jorge , Loveday Oliver , Harding Phimphaka , Harding David J.
Published: May 2021

The impact of the halogen substituent on supramolecular preferences that influence packing is explored in a series of heteroleptic iron(iii) complexes.
Effect of the in-plane aspect ratio of a graphene filler on anisotropic heat conduction in paraffin/graphene composites
Authors: Matsubara Hiroki , Ohara Taku
Published: May 2021

The analysis of molecular-scale heat transfer in paraffin/graphene composite based on molecular dynamics simulation suggests an important effect of the in-plane aspect ratio of a graphene filler on the effective thermal conductivity of the composite.
Advances in nanofluidics for water purification and filtration: molecular dynamics (MD) perspective
Authors: Shahbabaei Majid , Kim Daejoong
Published: May 2021

Worldwide industrialization and population growth have caused dramatic environmental pollution that has led to a water crisis.
Influence of simulated food and oral processing on carotenoid and chlorophyll in vitro bioaccessibility among six spinach genotypes
Authors: Hayes Micaela , Corbin Sydney , Nunn Candace , Pottorff Marti , Kay Colin D. , Lila Mary Ann , Iorrizo Massimo , Ferruzzi Mario G.
Published: May 2021

Spinach processing and simulated mastication impact the bioaccessibility of carotenoids and chlorophylls with a spinach matrix.
Casein-fed mice showed faster recovery from DSS-induced colitis than chicken-protein-fed mice
Authors: Yu Lili , Zhao Di , Nian Yingqun , Li Chunbao
Published: May 2021

Gavage of A. muciniphila accelerated the recovery from colitis by regulating the mRNA level of TNF-α and MUC2, and mucus thickness. Several genera may play an important role in recovery from DSS-induced colitis.
Metabolic profiles of Lactobacillus paraplantarum in biofilm and planktonic states and investigation of its intestinal modulation and immunoregulation in dogs
Authors: Liu Lei , Guo Shuyu , Chen Xing , Yang Shuhui , Deng Xi , Tu Mingxia , Tao Yufei , Xiang Wenliang , Rao Yu
Published: May 2021

The biofilm Lactobacillus paraplantarum L-ZS9 shows higher density and stronger resistance than the planktonic state. It regulated the intestinal microbiome and immunity activity of the host through the production of various metabolites.
Label-free inertial-ferrohydrodynamic cell separation with high throughput and resolution
Authors: Liu Yang , Zhao Wujun , Cheng Rui , Puig Alicia , Hodgson Jamie , Egan Mary , Cooper Pope Christen N. , Nikolinakos Petros G. , Mao Leidong
Published: May 2021

Inertial-ferrohydrodynamic cell separation (inertial-FCS) can rapidly sort cells with high throughput and differentiate the cells based on their physical diameter difference with ∼1–2 μm separation resolution.
Metal-ion batteries for electric vehicles: current state of the technology, issues and future perspectives
Authors: Verma Jaya , Kumar Deepak
Published: May 2021

Batteries based on metals-ions have the potential to meet the future needs of electric vehicle applications. This article reviews the key technological developments and scientific challenges of a broad range of Li-ion, Mg-ion and Al-ion batteries for electric vehicles.
High temperature treatment of hemicellulose in pulp-impregnated effluent improves the pre-hydrolysis efficiency
Authors: Jin Meitong , Shi Yunfen , Du Xinhong , Wu Song , Wang Lei , Qiao Nan , Yu Dayu
Published: May 2021

At 121 °C, the heat transfer effect and the movement of H3O+ are improved, thus the pre-hydrolysis is accelerated.
Mechanism and kinetic properties for the complete series reactions of chloro(thio)phenols with O(3P) under high temperature conditions
Authors: Teng Zhuochao , Zhao Xianwei , Wang Hetong , Li Ying , Han Yanan , Sun Yanhui , Xu Fei
Published: May 2021

Under pyrolysis or combustion conditions, chlorophenols (CPs) and chlorothiophenols (CTPs) can readily form chlorophenoxy radicals (CPRs) and chlorotriophenoxy radicals (CTPRs) by abandoning the phenoxyl-H and sulfydryl-H, respectively.
Multiplexed droplet loop-mediated isothermal amplification with scorpion-shaped probes and fluorescence microscopic counting for digital quantification of virus RNAs
Authors: Tan Ya-Ling , Huang A-Qian , Tang Li-Juan , Jiang Jian-Hui
Published: May 2021

The development of multiplexed dLAMP with scorpion-shaped probes and fluorescence microscopic counting affords simultaneous digital quantification of multiple virus RNAs.
A phosphate semiconductor-induced built-in electric field boosts electron enrichment for electrocatalytic hydrogen evolution in alkaline conditions
Authors: Li Zichuang , Pei Yu , Ma Ruguang , Wang Yuandong , Zhu Yufang , Yang Minghui , Wang Jiacheng
Published: May 2021

A built-in electric field, by coupling n-type semiconductors with metallic clusters (Ru/BiPO4), makes electron-deficient BiPO4 favourable for H2O-splitting and optimizes H adsorption on electron-rich Ru clusters, boosting the HER process.
Rapid and efficient removal of Cr(vi) by a core–shell magnetic mesoporous polydopamine nanocomposite: roles of the mesoporous structure and redox-active functional groups
Authors: Yang Qian , Wang Huilin , Li Fangbai , Dang Zhi , Zhang Lijuan
Published: May 2021

Chromium is recognized as one of the most harmful heavy metal pollutants.
Defect engineering for creating and enhancing bulk photovoltaic effect in centrosymmetric materials
Authors: Mai Haoxin , Lu Teng , Sun Qingbo , Langley Julien , Cox Nicholas , Kremer Felipe , Duong The , Catchpole Kylie , Chen Hua , Yi Zhiguo , Frankcombe Terry J. , Liu Yun
Published: May 2021

A defect-engineering strategy is reported to enhance the photovoltaic performance of BiNbO4. Synergetic effects: enhanced light absorption, ferroelectric-like depolarization and interfacial polarization on BiNbO4 homojunction lead to an increase in the photovoltaic effects.
Ultrafast resistive-type γ-Fe2O3–rGO nanohybrid-based humidity sensor – a respiratory monitoring tool
Authors: Kumar Atul , Kumar Anil , Varma G. D.
Published: May 2021

The resistive-type humidity-sensing device fabricated by integrating a thin film of iron oxide–rGO nanohybrids on flexible tempered glass provides an excellent tool for monitoring different activities like breathing, non-contact, humidity and voice sensing.
Tick–human interactions: from allergic klendusity to the α-Gal syndrome
Authors: Cabezas-Cruz Alejandro , Hodžić Adnan , Mateos-Hernández Lourdes , Contreras Marinela , de la Fuente José
Published: May 2021

Ticks and the pathogens they transmit, including bacteria, viruses, protozoa, and helminths, constitute a growing burden for human and animal health worldwide. The ability of some animal species to acquire resistance to blood-feeding by ticks after a single or repeated infestation is known as acquired tick resistance (ATR). This resistance has been associated to tick-specific IgE response, the generation of skin-resident memory CD4+ T cells, basophil recruitment, histamine release, and epidermal hyperplasia. ATR has also been associated with protection to tick-borne tularemia through allergic klendusity, a disease-escaping ability produced by the development of hypersensitivity to an allergen. In addition to pathogen transmission, tick infestation in humans is associated with the α-Gal syndrome (AGS), a type of allergy characterized by an IgE response against the carbohydrate Galα1-3Gal (α-Gal). This glycan is present in tick salivary proteins and on the surface of tick-borne pathogens such as Borrelia burgdorferi and Anaplasma phagocytophilum, the causative agents of Lyme disease and granulocytic anaplasmosis. Most α-Gal-sensitized individuals develop IgE specific against this glycan, but only a small fraction develop the AGS. This review summarizes our current understanding of ATR and its impact on the continuum α-Gal sensitization, allergy, and the AGS. We propose that the α-Gal-specific IgE response in humans is an evolutionary adaptation associated with ATR and allergic klendusity with the trade-off of developing AGS.
Identification and validation of ADME genes as prognosis and therapy markers for hepatocellular carcinoma patients
Authors: Wang Jukun , Han Ke , Zhang Chao , Chen Xin , Li Yu , Zhu Linzhong , Luo Tao
Published: May 2021

Purpose: ADME genes are genes involved in drug absorption, distribution, metabolism, and excretion (ADME). Previous studies report that expression levels of ADME-related genes correlate with prognosis of hepatocellular carcinoma (HCC) patients. However, the role of ADME gene expression on HCC prognosis has not been fully explored. The present study sought to construct a prediction model using ADME-related genes for prognosis of HCC.

Methods: Transcriptome and clinical data were retrieved from The Cancer Genome Atlas (TCGA) and International Cancer Genome Consortium (ICGC), which were used as training and validation cohorts, respectively. A prediction model was constructed using univariate Cox regression and Least Absolute Shrinkage and Selection Operator (LASSO) analysis. Patients were divided into high- and low-risk groups based on the median risk score. The predictive ability of the risk signature was estimated through bioinformatics analyses.

Results: Six ADME-related genes (CYP2C9, ABCB6, ABCC5, ADH4, DHRS13, and SLCO2A1) were used to construct the prediction model with a good predictive ability. Univariate and multivariate Cox regression analyses showed the risk signature was an independent predictor of overall survival (OS). A single-sample gene set enrichment analysis (ssGSEA) strategy showed a significant relationship between risk signature and immune status. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed differentially expressed genes (DEGs) in the high- and low-risk groups were enriched in biological process (BP) associated with metabolic and cell cycle pathways.

Conclusion: A prediction model was constructed using six ADME-related genes for prediction of HCC prognosis. This signature can be used to improve HCC diagnosis, treatment, and prognosis in clinical use.
An unsupervised person re‐identification approach based on cross‐view distribution alignment
Authors: Jia Xibin , Wang Xing , Mi Qing
Published: May 2021

Unsupervised clustering is a kind of popular solution for unsupervised person re‐identification (re‐ID). However, due to the influence of cross‐view differences, the results of clustering labels are not accurate. To solve this problem, an unsupervised re ID method based on cross‐view distributed alignment (CV‐DA) to reduce the influence of unsupervised cross‐view is proposed. Specifically, based on a popular unsupervised clustering method, density clustering DBSCAN is used to obtain pseudo labels. By calculating the similarity scores of images in the target domain and the source domain, the similarity distribution of different camera views is obtained and is aligned with the distribution with the consistency constraint of pseudo labels. The cross‐view distribution alignment constraint is used to guide the clustering process to obtain a more reliable pseudo label. The comprehensive comparative experiments are done in two public datasets, i.e. Market‐1501 and DukeMTMC‐reID. The comparative results show that the proposed method outperforms several state‐of‐the‐art approaches with mAP reaching 52.6% and rank1 71.1%. In order to prove the effectiveness of the proposed CV‐DA, the proposed constraint is added into two advanced re‐ID methods. The experimental results demonstrate that the mAP and rank increase by 0.5–2% after using the cross‐view distribution alignment constraint comparing with that of the associated original methods without using CV‐DA.
Enthesiopathie und Enthesitis
Authors: Kretschmer Peter
Published: May 2021

Enthesitiden sind bei rheumatischen Systemerkrankungen aus der Gruppe der Spondyloarthritiden, besonders bei Morbus Bechterew und Psoriasisarthritis, häufig anzutreffen. Häufigste Lokalisation ist die Ferse. Eine Enthesiopathie, insbesondere an den unteren Extremitäten, kann lange vor anderen Symptomen auftreten und sollte immer an die Möglichkeit einer rheumatischen Ursache denken lassen. Als bildgebende Verfahren sind MRT und Ultraschall (Power-Doppler) sinnvoll. Therapeutisch sind Krankengymnastik, lokale physikalische Maßnahmen und Einlagen bzw. Orthesen hilfreich. Die medikamentös-therapeutischen Möglichkeiten der Enthesitis sind beschränkt auf NSAR und TNF-α-Blocker, wobei jedoch letztere bisher nicht für die alleinig vorliegende Enthesitis zugelassen sind.
Tendinopathien
Authors: Kamp Rainer
Published: May 2021

Der Begriff Tendinopathie beschreibt ein großes Spektrum nicht rupturierter klinischer Zustände an Sehnen, die mit Schmerzen, Schwellungen, Funktionsminderung und anderen Symptomen auftreten können. Diese können als Folge sowohl primärer und akuter als auch chronisch degenerativer pathologischer Gewebsveränderungen auftreten. „Tendinopathie“ ist dabei ein Oberbegriff für pathologische Veränderungen innerhalb der Sehne, die als Fehler bei der Herstellung einer homöostatischen Antwort des Sehnengewebes auf unterschiedliche Reize, Belastungen und Traumata bezeichnet werden können 2. Die Ätiologie von Sehnenschäden ist multifaktoriell.
Sulfur-Based Chiral Iodoarenes: An Underexplored Class of Chiral Hypervalent Iodine Reagents
Authors: Wirth Thomas , Elsherbini Mohamed , Osi Arnaud , Alharbi Haifa , Karam Fatemah
Published: May 2021

Chiral hypervalent iodine reagents are active players in modern stereoselective organic synthesis. Structurally diverse chiral hypervalent iodine reagents have been synthesised and extensively studied, but hypervalent iodine reagents containing chiral sulfur stereogenic centre are scarce and their synthesis is challenging. A small library of iodoarenes containing chiral sulfinamide and chiral sulfoximine moieties has been synthesised using commercially available reagents. The oxidation of the chiral iodoarene precursors to iodine(III) reagents was cumbersome due to facile overoxidation of the sulfoxide moiety and hence loss of chirality under various oxidation conditions. Oxidation of chiral sulfonimidoyl derivatives to the corresponding hypervalent iodine reagents was successful and led to novel sulfur-based chiral iodine(III) reagents.
Use of Vasopressors in Extremely Preterm Infants in First Week of Life
Authors: Zaveri Parul G. , Walker Amanda M. , Upadhyay Kirtikumar , Talati Ajay J.
Published: May 2021

Objective A significant variability exists for diagnosis and treatment of hypotension in extremely preterm infants. Benefits of the use of vasopressors remain unclear. We wanted to identify the risk factors associated with use of vasopressors in the first week of life and their impact on outcomes of extremely preterm infants.

Study Design Retrospective review of all newborns ≤28 weeks of gestational age (GA) admitted in neonatal intensive care unit from October 1, 2012, to October 31, 2015, done. Data regarding antenatal and neonatal characteristics and outcomes were recorded. Study infants were divided into two cohorts and compared based on vasopressor use. Chi-square, t-test, and multiple logistic regression were performed as appropriate and significance set at p <0.05.

Results Of 213 extremely preterm infants, 90 (42.3%) received vasopressors in first week of life. The mean arterial pressure (MAP) at admission in these infants was significantly lower than that of infants who did not require vasopressors (27 ± 8 vs. 30 ± 6 mm Hg, p < 0.05). Vasopressors were initiated within 24 hours in 91% of babies. After controlling for other variables, use of vasopressors was significantly higher in infants with lower birth weight (odds ratio [OR]: 3.2, 95% confidence interval [CI]: 1.6–8.3), 5-minute Apgar's score ≤5 (OR: 1.8, 95% CI: 1.2–3.12), and admission hypothermia (OR: 2.7, 95% CI: 1.3–4.9). The use of vasopressors was significantly associated with severe intraventricular hemorrhage (IVH), even after controlling for other significant variables (OR: 5.9, 95% CI: 1.6–9.3).

Conclusion Lower birth weight, low 5-minute Apgar's score, and admission hypothermia are characteristics associated with early use of vasopressors in extremely preterm infants. Infants treated with vasopressors are at a higher risk of developing severe IVH.

Key Points
Informing action for United Nations SDG target 8.7 and interdependent SDGs: Examining modern slavery from space
Authors: Boyd Doreen S. , Perrat Bertrand , Li Xiaodong , Jackson Bethany , Landman Todd , Ling Feng , Bales Kevin , Choi-Fitzpatrick Austin , Goulding James , Marsh Stuart , Foody Giles M.
Published: May 2021

This article provides an example of the ways in which remote sensing, Earth observation, and machine learning can be deployed to provide the most up to date quantitative portrait of the South Asian ‘Brick Belt’, with a view to understanding the extent of the prevalence of modern slavery and exploitative labour. This analysis represents the first of its kind in estimating the spatiotemporal patterns in the Bull’s Trench Kilns across the Brick Belt, as well as its connections with various UN Sustainable Development Goals (SDGs). With a principal focus on Sustainable Development Goal Target 8.7 regarding the effective measures to end modern slavery by 2030, the article provides additional evidence on the intersections that exist between SDG 8.7 and those relating to urbanisation (SDG 11, 12), environmental degradation and pollution (SDG 3, 14, 15), and climate change (SDG 13). Our findings are then used to make a series of pragmatic suggestions for mitigating the most extreme SDG risks associated with brick production in ways that can improve human lives and human freedom.
Sample test array and recovery (STAR) platform at the National Ignition Facility
Authors: Moore Nathan W. , Bell Kate S. , Hilborn Haley , Woodworth Brandon N. , Mesh Mikhail , Bruss Donald E. , Franke Brian C. , Poole Patrick L. , Hohlfelder Robert J. , Zarick Thomas , Romero Randall , Chantler Gary R. , Esquivel Carlos A. , May Mark J. , Flanagan Timothy M. , Blue Brent E.
Published: May 2021

We have developed the Sample Test Array and Recovery (STAR) platform for the National Ignition Facility (NIF) for studying the thermal and hydrodynamic responses of materials in extreme environments. The STAR platform expands the range of obtainable fluences and quadruples the rate that materials experiments can be conducted at the NIF. Example configurations are demonstrated for fluences spanning 0.56–34 J/cm2 with environmental isolation for post-shot material recovery and inspection and up to 1740 J/cm2 without isolation, with surface heating rates of up to 2 × 1014 K/s. An example experiment involving thermally driven shock and spallation of aluminum alloy 7075 is briefly discussed.
Underwater plasma breakdown characteristics with respect to highly pressurized drilling applications
Authors: Akhter M. , Mallams J. , Tang X. , Staack D.
Published: May 2021

Deep earth drilling is a key technique to extract oil, gas, and geothermal heat from the earth. Many complex energy focusing methods have been explored as an alternative approach to reach these resources but most of them require high energy. However, by utilizing short time span liquid plasma discharges, energy focusing can be achieved within traditional drilling systems. These discharges induce a rapid expansion process and a resulting shockwave. It is believed that this focused energy will lower the required cutting force to progress through the rock. Lowering the required cutting force will allow for lower drill bit wear, quicker rate of penetration, and an overall cost savings of the project. Plasma breakdown characteristics at drilling relevant pressures, ranging from 1 to 350 atm, were studied. A resistance–capacitance circuit with an air gapped spark switch was utilized to generate pulsed plasma between the pressurized electrodes. It was found that the required breakdown voltage increases as the pressure increases. It was also found that a plasma channel formation and an associated breakdown may or may not occur between the electrodes at different pressures due to variation in required breakdown voltages. Breakdown time-lag in the dielectric medium (tap water, 780 μS cm−1) increased as the pressure was increased, which indicated a higher voltage drop at higher pressures (>100 atm). The plasma generated cavitation bubble with an associated shockwave occurred as pressures were increased. However, the bubble radius and the bubble duration decreased as the pressure was increased. The plasma generated shockwave speeds fall within the expected speed of sound in water. Finally, preliminary rock cracking tests were performed on granite at high pressures (340 and 272 atm) and it was found that plasma is able to create cracks in the rock.
A Reynolds shear stress model for constant-pressure boundary layers
Authors: Dey J. , P. Phani Kumar
Published: May 2021

Closure models for the Reynolds shear stress in wall-bounded flows are mostly based on various turbulence quantities like the turbulent kinetic energy (k), its dissipation rate (ϵ), the Reynolds stress (vr2) in the wall-normal direction, the mean flow velocity gradient (S), the normalized strain rate (Sk/ϵ), etc.; vr is the intensity of the fluctuating velocity component in the wall-normal direction (y). Close to the wall, (u′v′¯) is known to vary with y approximately as ∼y3. With an emphasis on this near-wall feature, a closure model is proposed here in terms of k, (vr/ur), and a weighted mean strain rate (Skvr+/ϵ); ur is the intensity of the fluctuating velocity component in the streamwise direction. The choice of ur in the present proposal is in view of the fact that, although the energy associated with ur2 in a simple flow, for example, is distributed to vr2 by fluctuating pressure, it has never been used in past closure models. In terms of the known approximate variations of k,vr,ur, etc., with y in the near-wall region, the present model suggests (u′v′¯)∼y3.25 and so nearly retains its known approximate variation ∼y3 (for small y). It is suggested here that vr+ in the weighted strain rate damps the strain rate (Sk/ϵ) significantly in the near-wall region and plays a similar role in Durbin's model [“Near-wall turbulence closure modeling without damping functions,” Theor. Comput. Fluid Dyn. 3, 1 (1991)]. It is also reported here that vr≈k1/2 and ur≈(ϵ/S)1/2 in the outer region, and these velocity scales are associated with (Sk/ϵ)∼ constant in this region; alternatively, in terms of these velocity scales, the normalized strain rate (Sk/ϵ) is the ratio of the Reynolds stresses (vr2/ur2) in the outer region.
Spin-crossover materials: Getting the most from x-ray crystallography
Authors: Pillet Sébastien
Published: May 2021

The physical phenomenon of spin-crossover in molecular crystals is a multiscale process whose properties rely on the supramolecular organization of the spin-crossover active elements, their interactions within the crystal packing, and their dynamics. The delicate balance between short-range and long-range structural reorganizations upon the spin transition is at the origin of remarkable and fascinating physical phenomena such as thermal, light-induced and pressure-induced hysteresis, multi-step transitions, or multimetastablility. A complete understanding of the various phenomena associated with spin-crossover requires a comprehensive and thorough characterization of the overall structural architecture at all scales, which goes beyond the average static crystal structure. This Tutorial surveys the practical use of x-ray crystallography notably in non-ambient conditions to provide a direct view of the physical processes operating in spin-crossover molecular solids from bulk single crystals to nanocrystalline powder. Advanced x-ray crystallography methods are reviewed and illustrated with a series of model examples.
Planar Hall effect in c-axis textured films of Bi85Sb15 topological insulator
Authors: Budhani Ramesh C. , Higgins Joshua S. , McAlmont Deandre , Paglione Johnpierre
Published: May 2021

Measurements of the planar Hall effect (PHE) and anisotropic magnetoresistance (AMR) in polycrystalline films of topological insulator Bi85Sb15 are reported. The observation of PHE and AMR in these films of carrier density ≈2 × 1019 electrons/cm3 is like the behavior of in-plane field transport in thin films of metallic ferromagnets. However, the amplitudes of PHE (ΔρPHE) and AMR (Δρxx) are at variance. ΔρPHE and Δρxx also undergo a sign reversal near ≈160 K. We compare these results with the reported PHE of topological insulators and Weyl semimetals and discuss possible scenarios for anisotropic backscattering of charge carriers in this non-magnetic alloy.
Impact ionization coefficients and critical electric field in GaN
Authors: Maeda Takuya , Narita Tetsuo , Yamada Shinji , Kachi Tetsu , Kimoto Tsunenobu , Horita Masahiro , Suda Jun
Published: May 2021

Avalanche multiplication characteristics in a reverse-biased homoepitaxial GaN p–n junction diode are experimentally investigated at 223–373 K by novel photomultiplication measurements utilizing above- and below-bandgap illumination. The device has a non-punch-through one-side abrupt p–-n+ junction structure, in which the depletion layer mainly extends to the p-type region. For above-bandgap illumination, the light is absorbed at the surface p+-layer, and the generated electrons diffuse and reach the depletion layer, resulting in an electron-injected photocurrent. On the other hand, for below-bandgap illumination, the light penetrates a GaN layer and is absorbed owing to the Franz–Keldysh effect in the high electric field region (near the p–n junction interface), resulting in a hole-induced photocurrent. The theoretical (non-multiplicated) photocurrents are calculated elaborately, and the electron- and hole-initiated multiplication factors are extracted as ratios of the experimental data to the calculated values. Through the mathematical analyses of the multiplication factors, the temperature dependences of the impact ionization coefficients of electrons and holes in GaN are extracted and formulated by the Okuto–Crowell model. The ideal breakdown voltage and the critical electric field for GaN p–n junctions of varying doping concentration are simulated using the obtained impact ionization coefficients, and their temperature dependence and conduction-type dependence were discussed. The simulated breakdown characteristics show good agreement with data reported previously, suggesting the high accuracy of the impact ionization coefficients obtained in this study.
Sustainability of beef production from brigalow lands after cultivation and mining. 2. Acland Grazing Trial pasture and cattle performance
Authors: Melland Alice R. , Newsome Tom , Paton Colin J. , Clewett Jeffrey F. , Bennett John McL , Eberhard Jochen , Baillie Craig P.
Published: May 2021

Context Agricultural land used for open-cut coal mining in Queensland is required by law to be returned to a safe, stable and self-sustaining state for agriculture. Aims The aim of this research was to identify whether rehabilitated pastures on post-mine soil at a site near Acland could viably support cattle production. Methods Five years of field data from Botanal pasture assessments, pasture quality, cattle liveweights and faecal observations, plus supplementary cattle liver data, were used to compare pasture and cattle performance from mined and unmined previously cultivated brigalow land. Subtropical pasture species were sown in 2007 (Rehab1, 22 ha), 2010 (Rehab 2, 32 ha) and 2012 (Rehab3, 22 ha) in three rehabilitated paddocks and in 2012 in an unmined (Control, 21 ha) paddock. The paddocks were grazed for 117–190 days of each year by Angus cattle. Key results Mean total standing dry matter in grazed pasture over the five trial years was consistently higher in Rehab 2 (5656 kg/ha) than in the other paddocks. Rehab 1 (3965 kg/ha) and Rehab 3 (3609 kg/ha) performed at an intermediate level and the Control paddock produced less pasture (2871 kg/ha). Grass leaf crude protein was higher in Rehab 2 than in the other paddocks and declined significantly (P < 0.001) across all paddocks as pasture aged. Pasture species remained perennial, palatable and productive in all paddocks; however, pasture yield, quality and composition trends over time suggested that pasture rundown occurred across all paddocks. The mean liveweight gain (LWG) per head when grazing the trial paddocks (trial LWG) was higher (P < 0.05) in the Rehab 2 cohort than the other paddock cohorts in Years 3 and 5, and trial LWG in the Control cohort was not significantly (P > 0.05) different from one or more of the rehabilitated paddock cohorts each year. Cattle production per hectare during the trial grazing periods was also consistently highest in Rehab 2 (5-year mean trial LWG 131 kg/ha) compared with the other paddocks (67–80 kg/ha). Conclusion The rehabilitated pastures in use by the mine were considered at least as productive as the surrounding unmined brigalow landscape. Implications The Acland rehabilitation process was considered successful in establishing pastures that were able to viably support cattle production.
Line-transect versus point-transect sampling: the effects of survey area and survey effort on method efficiency for Geoffroy’s spider monkeys
Authors: Hutschenreiter Anja , Ramos-Fernández Gabriel , Aureli Filippo
Published: May 2021

Abstract Context Line-transect sampling is considered to be a more efficient survey method than point-transect sampling to estimate population densities and abundance of many animal species. Aims In the present study, we tested whether this claim holds true when surveying arboreal fast-moving primate species occurring at low densities, and whether the potential difference in efficiency can be explained by the difference in the size of the survey area between the methods. We further examined the impact of survey effort for point-transect sampling. Methods We conducted line- and point-transect sampling for Geoffroy’s spider monkeys (Ateles geoffroyi) in the same locations and compared the numbers of detected individual monkeys and the probability of their occurrence per survey between the two methods. We further compared the data from point-transect sampling gathered within three different waiting periods. Key results We found a higher probability to detect monkeys and a higher number of monkeys during line-transect sampling than during point-transect sampling, but more spider monkeys were detected at point transects when controlling for the size of the survey area. More monkey detections were made during the first 10 min than during the second and third 10-min periods of point-transect surveys. Conclusions We showed that line-transect sampling is more efficient than point-transect sampling when surveying Geoffroy’s spider monkeys in a flat landscape of tropical forest with homogenous visibility. We discuss factors influencing survey results and recommend 20 min as the maximum waiting time at point transects when surveying arboreal mammals. Implications Our study has provided a quantitative approach to compare efficiency across survey methods for fast-moving arboreal animals that occur at low densities, and supports the use of point-transect sampling in sites where line-transect sampling is not feasible, such as in human-modified landscapes.
Knl1 participates in spindle assembly checkpoint signaling in maize
Authors: Su Handong , Liu Yang , Wang Chunhui , Liu Yalin , Feng Chao , Sun Yishuang , Yuan Jing , Birchler James A. , Han Fangpu
Published: May 2021

Significance

The spindle assembly checkpoint (SAC) signaling controls the attachments of kinetochores to spindle microtubules rigorously. However, how SAC proteins connect to the kinetochores is largely unknown in plants. Here, we identified the constitutive component of the central kinetochore protein Knl1 in maize and revealed a conserved function of Knl1 in cell division. A helical conformation with hydrophobic amino acids in the middle of a Knl1 protein was involved in the recruitment of an SAC protein, which is different from the Mps1-mediated phosphorylation of MELT modules that are described in yeast and mammalian cells. This region, detected in maize Knl1, is conserved in monocots but displays high divergence in eudicots, suggesting distinct kinetochore architectures with SAC signaling in plant lineages.
BRET-based effector membrane translocation assay monitors GPCR-promoted and endocytosis-mediated G
q
activation at early endosomes
Authors: Wright Shane C. , Lukasheva Viktoriya , Le Gouill Christian , Kobayashi Hiroyuki , Breton Billy , Mailhot-Larouche Samuel , Blondel-Tepaz Élodie , Antunes Vieira Nichelle , Costa-Neto Claudio , Héroux Madeleine , Lambert Nevin A. , Parreiras-e-Silva Lucas Tabajara , Bouvier Michel
Published: May 2021

Significance

G protein–coupled receptors (GPCRs) have been proposed to signal in multiple compartments within the cell, a phenomenon that could have important implications for our understanding of receptor pharmacology and disease treatment. However, directly measuring G protein activity in subcellular compartments remains a challenge, and the mechanism underlying their translocation and activation remains elusive. Using a biosensor that specifically measures the presence of GTP-loaded G
q/11
at endosomes, our findings reveal the mechanism underlying G
q
trafficking and signaling in the endosome and provide a powerful tool to directly monitor G protein movement and activation in subcellular compartments.
Parkbus – A Combined Sustainable Transportation Solution for Residents and Visitors
Authors: Dodds Rachel , Issaev Boris
Published: May 2021

This case recounts how Parkbus, a social innovation organization founded in 2010 in Ontario, Canada, simultaneously improved access for people with less mobility to experience nature, and reduced carbon emissions and congestion. Through partnerships with key Canadian organizations such as the Toronto Dominion Bank, Mountain Equipment Co-op and Parks Canada, this case highlights a sustainable transportation and tourism innovation, as well as positive externalities and opportunities that can be created by small but well-placed and well-timed initiatives.

Information

© Rachel Dodds 2021
Exploring the Case: Parkbus – A Sustainable Transport Solution for Both Residents and Visitors
Authors: Dodds Rachel , Issaev Boris
Published: May 2021

Introduction

The Parkbus case raises important questions about how tourism can be implemented more sustainably and highlights issues relating to eco-mobility in both access for marginalized groups to the outdoors as well as carbon reduction through transportation. In the exploration of the case, first three key issues are raised about mobility in and around protected areas. Then some avenues are identified for study and some discussion questions are provided for use in seminars and the classroom.

This case is suitable for students from marketing, tourism development, transportation, planning and sustainability related courses.
Bag of visual words based machine learning framework for disbond characterisation in composite sandwich structures using guided waves
Authors: Sikdar Shirsendu , Pal Joy
Published: May 2021

This paper presents a machine learning framework that uses the bag of visual words (BOVW) for structural health monitoring (SHM) of a composite sandwich structure (CSS) using ultrasonic guided wave (GW) signals. Towards this, experimental analysis of GW propagation in CSS has been carried out for the healthy-state and multiple skin-to-core disbond cases. The registered time-domain signals from the assigned piezoelectric transducer networks on the CSS are converted to time-frequency scalograms by performing a continuous wavelet transform. Eventually, a BOVW based machine learning framework is proposed that uses the speeded-up-robust features for the features extraction and support vector machine for classification of CSSs with and without skin-to-core disbond. The proposed machine learning framework shows its SHM potential to characterise the CSS for healthy and disbond conditions (different locations) with high validation and test accuracy for an unseen dataset. A series of parametric studies are also carried out to analyse the influence of different grid sizes and polynomial order for the proposed framework.
Exact solutions in radiation reaction and the radiation-free direction
Authors: Ekman Robin , Heinzl Tom , Ilderton Anton
Published: May 2021

We present new exact solutions of the Landau–Lifshitz (LL) and higher-order LL equations describing particle motion, with radiation reaction, in intense electromagnetic fields. Through these solutions and others we compare the phenomenological predictions of different equations in the context of the conjectured ‘radiation-free direction’ (RFD). We confirm analytically in several cases that particle orbits predicted by the LL equation indeed approach the RFD at extreme intensities, and give time-resolved signals of this behaviour in radiation spectra.