bluuebunny/crossref_metadata_2025 huggingface dataset:
Evidence for Adsorption of Chlorine Species on Iron (III) (Hydr)oxides in the Sheepbed Mudstone, Gale Crater, Mars
Authors: Peretyazhko T. S. , Ralston S. J. , Sutter B. , Ming D. W.
Published: April 2020

Ancient aquatic environments in Yellowknife Bay, Gale crater, Mars, could create favorable conditions for adsorption of chlorine compounds (perchlorate and chloride) on Fe (III) (hydr)oxides present in the Sheepbed mudstone, such as akaganeite and ferrihydrite. In this work, 5.2 mM ClO4− and 1.7 to 12 mM Cl− were adsorbed onto ferrihydrite and 5.2 mM ClO4− was adsorbed onto akaganeite at ultraacidic (pH 2–2.5), acidic (pH 3.8–4.5), and near‐neutral (pH 6.2–7.7) pH. Samples were characterized by evolved gas analysis and compared to the data collected for the Cumberland sample from the Sheepbed mudstone. Evolved gas analysis showed that ferrihydrite with 0.5–1 wt.% ClO4− adsorbed under ultraacidic and acidic conditions had a well‐resolved O2 peak at 306 °C due to the thermal decomposition of adsorbed ClO4−. All akaganeite samples with 0.5 wt.% adsorbed ClO4− had a weak peak at 312 °C tentatively assigned to decomposing perchlorate. Evolved gas analysis demonstrated that 0.5–2 wt.% Cl− adsorbed on ferrihydrite at ultraacidic and acidic pH was the main contributor to HCl evolved at >470 °C. Comparison with martian observations indicated that the temperature of the O2 peak originating from ClO4− adsorbed on ferrihydrite matched well with the thermal evolution of O2 from the Cumberland. Evolved HCl originating from Cl− adsorbed on ferrihydrite was within the temperature range of the high‐temperature HCl release from Cumberland (~770 °C). These observations suggest that ferrihydrite containing adsorbed ClO4− and Cl− could exist in the mudstone. Experimental results are consistent with adsorption at acidic pH < 4 environments through postdepositional water‐rock interactions of ferrihydrite with acid‐sulfate groundwater containing dissolved chloride and perchlorate.
Coral Records at the Northern Edge of the Western Pacific Warm Pool Reveal Multiple Drivers of Sea Surface Temperature, Salinity, and Rainfall Variability Since the End of the Little Ice Age
Authors: Ramos R. D. , Goodkin N. F. , Fan T.‐Y.
Published: April 2020

Reconstructions of key climate parameters prior to anthropogenic influences serve to constrain decadal to multicentury natural climate variability. In the western Pacific region, relatively few reconstructions exist north of the Western Pacific Warm Pool (WPWP), a region critical to global climate. In this study, we collected a coral core from Houbihu, southern Taiwan, and generated a 225‐year reconstruction of annual and wintertime sea surface temperature, dry season sea surface salinity, and wet season rainfall records derived from paired Porites Sr/Ca and δ18O profiles extending back to the end of the Little Ice Age (1850 CE). Multidecadal sea surface temperature trends generally track regional surface temperature reconstructions, indicating the dominant influence of solar and volcanic radiative forcings. Reconstructed dry season sea surface salinity reflects an advection signal linked to the East Asian Winter Monsoon and the Pacific Decadal Oscillation, both influencing variations in the Kuroshio Intrusion across the Luzon Strait. Reconstructed wet season rainfall, on the other hand, reveals influence of the Pacific Decadal Oscillation on the decadal variability of local and regional rainfall patterns. Relative to the late 1900s, our climate reconstructions document cooler and drier (high salinity and low rainfall) conditions during the end of the Little Ice Age, supporting other lines of evidence of a retracted WPWP region during this period. In the late 20th to early 21st century, our climate reconstructions record warming and freshening (low salinity and high rainfall) trends, highlighting the potential impact of anthropogenic forcing in the extension of the WPWP.
Flow Loss in Deltaic Distributaries: Impacts on Channel Hydraulics, Morphology, and Stability
Authors: Esposito C. R. , Georgiou I. Y. , Straub K. M.
Published: April 2020

The most comprehensive data sets documenting hydraulic and sediment transport regimes in the lower reaches of alluvial rivers come from systems that are managed to prevent flow loss from the channel into the overbank environment. Even moderate losses can have significant impacts on in‐channel velocity and sediment transport; therefore, a full understanding of flow loss and its effects is an important prerequisite to insights into channel function and to designing effective management strategies. We use the term flow loss for losses of water that are locally small relative to the main channel discharge. We present a unique data set documenting discharge, channel geometry, and water surface elevation from three distributary channel networks in the Mississippi River Delta where flow loss is widespread. We apply our data to validate a 1‐D hydraulic model, which then drives a previously validated model of sediment transport. Results from the modeling effort demonstrate that velocity and sediment transport trends are substantially modulated by flow loss in the ranges observed in distributary networks. The effect of flow loss on distributary channels established, we then examine how flood control infrastructure may have impacted the morphological evolution of the lowermost reaches of a large alluvial river like the Mississippi. The expected outcome of preventing flow loss is erosion in the channel's lowermost reach, in agreement with observational data. Finally, we develop a theoretical metric for a stable channel, and show that flow loss is a potentially important and understudied contributor to the long‐term behavior of distributary channels.
Getting to the Bottom of Slow-Motion Earthquakes
Authors: Chakravorty Adityarup
Published: April 2020

For close to 20 years, slow-motion earthquakes have been an enigma. Core samples provide new clues to their origins.
Eight Lessons from COVID-19 to Guide Our Climate Response
Authors: Cartier Kimberly
Published: April 2020

The global response to the ongoing pandemic can teach us how we should, and shouldn’t, respond to the climate crisis. And most important, it shows that we can do something.
Surface Conduction Model for Fractal Porous Media
Authors: Wang Hongtao , Revil André
Published: April 2020

The electrical conductivity of natural water‐saturated porous materials has two contributions, one associated with conduction in the pore network and a second one associated with the electrical double layer coating the surface of the mineral grains, and called surface conductivity. We model the effect of material texture on surface conductivity based on fractal theory. We demonstrate that surface conductivity obeys a power‐law dependence (that we called surface Archie's law) on the specific surface area. The power exponent is theoretically related to the porosity exponent entering Archie's law and to the fractal dimension of the pore network. A permeability model is derived by combining the new surface Archie's law and the Kozeny‐Carman model. We show that our model is consistent with both numerical finite element simulations on synthetic porous media and experimental data.
Subseasonal Vacillations in the Winter Stratosphere
Authors: Hardiman S. C. , Scaife A. A. , Dunstone N. J. , Wang L.
Published: April 2020

Simple models of wave‐mean flow interaction in the Northern Hemisphere winter stratosphere suggest the existence of subseasonal vacillations in the strength of the polar vortex. Here, we define a sinusoidal fit to the daily deseasonalized stratospheric wind. A suitable fixed period and amplitude for the sine waves is identified. Their mean value, equivalent to polar vortex strength, and phase, equivalent to the timing of sudden stratospheric warmings during winter, varies from year to year. These vacillations explain much of the subseasonal and interannual variability in the monthly mean vortex strength and, consistent with wave‐mean flow interaction theory, their amplitude correlates positively with the magnitude of winter mean planetary wave driving. Furthermore, they allow skillful prediction of the vortex strength one month ahead. Identifying and understanding this subseasonal variability has potential implications for winter seasonal forecasts, as the December–February mean behavior may miss important subseasonal events.
Author Correction: Complete polarization control in multimode fibers with polarization and mode coupling
Authors: Xiong Wen , Hsu Chia Wei , Bromberg Yaron , Antonio-Lopez Jose Enrique , Correa Rodrigo Amezcua , Cao Hui
Published: April 2020

An amendment to this paper has been published and can be accessed via a link at the top of the paper.
Neurogranin as a cognitive biomarker in cerebrospinal fluid and blood exosomes for Alzheimer’s disease and mild cognitive impairment
Authors: Liu Weilin , Lin Huawei , He Xiaojun , Chen Lewen , Dai Yaling , Jia Weiwei , Xue Xiehua , Tao Jing , Chen Lidian
Published: April 2020

Alzheimer’s disease (AD) is a progressive neurodegenerative disorder with clinical, biological, and pathological features occurring along a continuum from normal to end-stage disease. Currently, the diagnosis of AD depends on clinical assessments and post-mortem neuropathology, which is unbenefited early diagnosis and progressive monitoring. In recent years, clinical studies have reported that the level of cerebrospinal fluid (CSF) and blood neurogranin (Ng) are closely related to the occurrence and subsequent progression of AD. Therefore, the study used meta-analysis to identify the CSF and blood Ng levels for the development of diagnosis biomarker of patients with AD and mild cognitive impairment (MCI). We searched the Pubmed, Embase, Cochrane Library, and Web of Science databases. A total of 24 articles eligible for inclusion and exclusion criteria were assessed, including 4661 individuals, consisting of 1518 AD patients, 1501 MCI patients, and 1642 healthy control subjects. The level of CSF Ng significantly increased in patients with AD and MCI compared with healthy control subjects (SMD: 0.84 [95% CI: 0.70–0.98], P < 0.001; SMD: 0.53 [95% CI: 0.40–0.66], P = 0.008), and higher in AD patients than in MCI patients (SMD: 0.18 [95% CI: 0.07–0.30], P = 0.002), and CSF Ng level of patients with MCI-AD who progressed from MCI to AD was significantly higher than that of patients with stable MCI (sMCI) (SMD: 0.71 [95% CI: 0.25–1.16], P = 0.002). Moreover, the concentration of Ng in blood plasma exosomes of patients with AD and MCI was lower than that of healthy control subjects (SMD: −6.657 [95% CI: −10.558 to −2.755], P = 0.001; and SMD: −3.64 [95% CI: −6.50 to −0.78], P = 0.013), and which in patients with AD and MCI-AD were also lower than those in patients with sMCI (P < 0.001). Furthermore, regression analysis showed a negative relationship between MMSE scores and CSF Ng levels in MCI patients (slope = −0.249 [95% CI: −0.003 to −0.495], P = 0.047). Therefore, the Ng levels increased in CSF, but decreased in blood plasma exosomes of patients with AD and MCI-AD, and highly associated with cognitive declines. These findings provide the clinical evidence that CSF and blood exosomes Ng can be used as a cognitive biomarker for AD and MCI-AD, and further studies are needed to define the specific range of Ng values for diagnosis at the different stages of AD.
Tet2-mediated epigenetic drive for astrocyte differentiation from embryonic neural stem cells
Authors: He Fei , Wu Hao , Zhou Liqiang , Lin Quan , Cheng Yin , Sun Yi E.
Published: April 2020

DNA methylation and demethylation at CpG di-nucleotide sites plays important roles in cell fate specification of neural stem cells (NSCs). We have previously reported that DNA methyltransferases, Dnmt1and Dnmt3a, serve to suppress precocious astrocyte differentiation from NSCs via methylation of astroglial lineage genes. However, whether active DNA demethylase also participates in astrogliogenesis remains undetermined. In this study, we discovered that a Ten-eleven translocation (Tet) protein, Tet2, which was critically involved in active DNA demethylation through oxidation of 5-Methylcytosine (5mC), drove astrocyte differentiation from NSCs by demethylation of astroglial lineage genes including Gfap. Moreover, we found that an NSC-specific bHLH transcription factor Olig2 was an upstream inhibitor for Tet2 expression through direct association with the Tet2 promoter, and indirectly inhibited astrocyte differentiation. Our research not only revealed a brand-new function of Tet2 to promote NSC differentiation into astrocytes, but also a novel mechanism for Olig2 to inhibit astrocyte formation.
Regulation of sister chromatid cohesion by nuclear PD-L1
Authors: Yu Jia , Qin Bo , Moyer Ann M. , Nowsheen Somaira , Tu Xinyi , Dong Haidong , Boughey Judy C. , Goetz Matthew P. , Weinshilboum Richard , Lou Zhenkun , Wang Liewei
Published: April 2020

Programmed death ligand-1 (PD-L1 or B7-H1) is well known for its role in immune checkpoint regulation, but its function inside the tumor cells has rarely been explored. Here we report that nuclear PD-L1 is important for cancer cell sister chromatid cohesion. We found that depletion of PD-L1 suppresses cancer cell proliferation, colony formation in vitro, and tumor growth in vivo in immune-deficient NSG mice independent of its role in immune checkpoint. Specifically, PD-L1 functions as a subunit of the cohesin complex, and its deficiency leads to formation of multinucleated cells and causes a defect in sister chromatid cohesion. Mechanistically, PD-L1 compensates for the loss of Sororin, whose expression is suppressed in cancer cells overexpressing PD-L1. PD-L1 competes with Wing Apart-Like (WAPL) for binding to PDS5B, and secures proper sister chromatid cohesion and segregation. Our findings suggest an important role for nuclear PD-L1 in cancer cells independent of its function in immune checkpoint.
Taking stock of national climate policies to evaluate implementation of the Paris Agreement
Authors: Roelfsema Mark , van Soest Heleen L. , Harmsen Mathijs , van Vuuren Detlef P. , Bertram Christoph , den Elzen Michel , Höhne Niklas , Iacobuta Gabriela , Krey Volker , Kriegler Elmar , Luderer Gunnar , Riahi Keywan , Ueckerdt Falko , Després Jacques , Drouet Laurent , Emmerling Johannes , Frank Stefan , Fricko Oliver , Gidden Matthew , Humpenöder Florian , Huppmann Daniel , Fujimori Shinichiro , Fragkiadakis Kostas , Gi Keii , Keramidas Kimon , Köberle Alexandre C. , Aleluia Reis Lara , Rochedo Pedro , Schaeffer Roberto , Oshiro Ken , Vrontisi Zoi , Chen Wenying , Iyer Gokul C. , Edmonds Jae , Kannavou Maria , Jiang Kejun , Mathur Ritu , Safonov George , Vishwanathan Saritha Sudharmma
Published: April 2020

Many countries have implemented national climate policies to accomplish pledged Nationally Determined Contributions and to contribute to the temperature objectives of the Paris Agreement on climate change. In 2023, the global stocktake will assess the combined effort of countries. Here, based on a public policy database and a multi-model scenario analysis, we show that implementation of current policies leaves a median emission gap of 22.4 to 28.2 GtCO2eq by 2030 with the optimal pathways to implement the well below 2 °C and 1.5 °C Paris goals. If Nationally Determined Contributions would be fully implemented, this gap would be reduced by a third. Interestingly, the countries evaluated were found to not achieve their pledged contributions with implemented policies (implementation gap), or to have an ambition gap with optimal pathways towards well below 2 °C. This shows that all countries would need to accelerate the implementation of policies for renewable technologies, while efficiency improvements are especially important in emerging countries and fossil-fuel-dependent countries.
Task-induced attention load guides and gates unconscious semantic interference
Authors: Hung Shao-Min , Wu Daw-An , Shimojo Shinsuke
Published: April 2020

The tight relationship between attention and conscious perception has been extensively researched in the past decades. However, whether attentional modulation extended to unconscious processes remained largely unknown, particularly when it came to abstract and high-level processing. Here we use a double Stroop paradigm to demonstrate that attention load gates unconscious semantic processing. We find that word and color incongruencies between a subliminal prime and a supraliminal target cause slower responses to non-Stroop target words—but only if the task is to name the target word (low-load task), and not if the task is to name the target’s color (high-load task). The task load hypothesis is confirmed by showing that the word-induced incongruence effect can be detected in the color-naming task, but only in the late, practiced trials. We further replicate this task-induced attentional modulation phenomenon in separate experiments with colorless words (word-only) and words with semantic relationship but no orthographic similarities (semantics-only).
Seismic evidence for subduction-induced mantle flows underneath Middle America
Authors: Zhu Hejun , Stern Robert J. , Yang Jidong
Published: April 2020

Laboratory experiments and geodynamic simulations demonstrate that poloidal- and toroidal-mode mantle flows develop around subduction zones. Here, we use a new 3-D azimuthal anisotropy model constructed by full waveform inversion, to infer deep subduction-induced mantle flows underneath Middle America. At depths shallower than 150 km, poloidal-mode flow is perpendicular to the trajectory of the Middle American Trench. From 300 to 450 km depth, return flows surround the edges of the Rivera and Atlantic slabs, while escape flows are inferred through slab windows beneath Panama and central Mexico. Furthermore, at 700 km depth, the study region is dominated by the Farallon anomaly, with fast axes perpendicular to its strike, suggesting the development of lattice-preferred orientations by substantial stress. These observations provide depth-dependent seismic anisotropy for future mantle flow simulations, and call for further investigations about the deformation mechanisms and elasticity of minerals in the transition zone and uppermost lower mantle.
Single-shot ultrafast imaging attaining 70 trillion frames per second
Authors: Wang Peng , Liang Jinyang , Wang Lihong V.
Published: April 2020

Real-time imaging of countless femtosecond dynamics requires extreme speeds orders of magnitude beyond the limits of electronic sensors. Existing femtosecond imaging modalities either require event repetition or provide single-shot acquisition with no more than 1013 frames per second (fps) and 3 × 102 frames. Here, we report compressed ultrafast spectral photography (CUSP), which attains several new records in single-shot multi-dimensional imaging speeds. In active mode, CUSP achieves both 7 × 1013 fps and 103 frames simultaneously by synergizing spectral encoding, pulse splitting, temporal shearing, and compressed sensing—enabling unprecedented quantitative imaging of rapid nonlinear light-matter interaction. In passive mode, CUSP provides four-dimensional (4D) spectral imaging at 0.5 × 1012 fps, allowing the first single-shot spectrally resolved fluorescence lifetime imaging microscopy (SR-FLIM). As a real-time multi-dimensional imaging technology with the highest speeds and most frames, CUSP is envisioned to play instrumental roles in numerous pivotal scientific studies without the need for event repetition.
Structural basis for DNA damage-induced phosphoregulation of MDM2 RING domain
Authors: Magnussen Helge M. , Ahmed Syed F. , Sibbet Gary. J. , Hristova Ventzislava A. , Nomura Koji , Hock Andreas K. , Archibald Lewis J. , Jamieson Andrew G. , Fushman David , Vousden Karen H. , Weissman Allan M. , Huang Danny T.
Published: April 2020

Phosphorylation of MDM2 by ATM upon DNA damage is an important mechanism for deregulating MDM2, thereby leading to p53 activation. ATM phosphorylates multiple residues near the RING domain of MDM2, but the underlying molecular basis for deregulation remains elusive. Here we show that Ser429 phosphorylation selectively enhances the ubiquitin ligase activity of MDM2 homodimer but not MDM2-MDMX heterodimer. A crystal structure of phospho-Ser429 (pS429)-MDM2 bound to E2–ubiquitin reveals a unique 310-helical feature present in MDM2 homodimer that allows pS429 to stabilize the closed E2–ubiquitin conformation and thereby enhancing ubiquitin transfer. In cells Ser429 phosphorylation increases MDM2 autoubiquitination and degradation upon DNA damage, whereas S429A substitution protects MDM2 from auto-degradation. Our results demonstrate that Ser429 phosphorylation serves as a switch to boost the activity of MDM2 homodimer and promote its self-destruction to enable rapid p53 stabilization and resolve a long-standing controversy surrounding MDM2 auto-degradation in response to DNA damage.
Intron retention is a hallmark and spliceosome represents a therapeutic vulnerability in aggressive prostate cancer
Authors: Zhang Dingxiao , Hu Qiang , Liu Xiaozhuo , Ji Yibing , Chao Hsueh-Ping , Liu Yan , Tracz Amanda , Kirk Jason , Buonamici Silvia , Zhu Ping , Wang Jianmin , Liu Song , Tang Dean G.
Published: April 2020

The role of dysregulation of mRNA alternative splicing (AS) in the development and progression of solid tumors remains to be defined. Here we describe the first comprehensive AS landscape in the spectrum of human prostate cancer (PCa) evolution. We find that the severity of splicing dysregulation correlates with disease progression and establish intron retention as a hallmark of PCa stemness and aggressiveness. Systematic interrogation of 274 splicing-regulatory genes (SRGs) uncovers prevalent genomic copy number variations (CNVs), leading to mis-expression of ~68% of SRGs during PCa development and progression. Consequently, many SRGs are prognostic. Surprisingly, androgen receptor controls a splicing program distinct from its transcriptional regulation. The spliceosome modulator, E7107, reverses cancer aggressiveness and inhibits castration-resistant PCa (CRPC) in xenograft and autochthonous PCa models. Altogether, our studies establish aberrant AS landscape caused by dysregulated SRGs as a hallmark of PCa aggressiveness and the spliceosome as a therapeutic vulnerability for CRPC.
Improved GPCR ligands from nanobody tethering
Authors: Cheloha Ross W. , Fischer Fabian A. , Woodham Andrew W. , Daley Eileen , Suminski Naomi , Gardella Thomas J. , Ploegh Hidde L.
Published: April 2020

Antibodies conjugated to bioactive compounds allow targeted delivery of therapeutics to cell types of choice based on that antibody’s specificity. Here we develop a new type of conjugate that consists of a nanobody and a peptidic ligand for a G protein-coupled receptor (GPCR), fused via their C-termini. We address activation of parathyroid hormone receptor-1 (PTHR1) and improve the signaling activity and specificity of otherwise poorly active N-terminal peptide fragments of PTH by conjugating them to nanobodies (VHHs) that recognize PTHR1. These C-to-C conjugates show biological activity superior to that of the parent fragment peptide in vitro. In an exploratory experiment in mice, a VHH-PTH peptide conjugate showed biological activity, whereas the corresponding free peptide did not. The lead conjugate also possesses selectivity for PTHR1 superior to that of PTH(1-34). This design approach, dubbed “conjugation of ligands and antibodies for membrane proteins” (CLAMP), can yield ligands with high potency and specificity.
Myosin-VIIa is expressed in multiple isoforms and essential for tensioning the hair cell mechanotransduction complex
Authors: Li Sihan , Mecca Andrew , Kim Jeewoo , Caprara Giusy A. , Wagner Elizabeth L. , Du Ting-Ting , Petrov Leonid , Xu Wenhao , Cui Runjia , Rebustini Ivan T. , Kachar Bechara , Peng Anthony W. , Shin Jung-Bum
Published: April 2020

Mutations in myosin-VIIa (MYO7A) cause Usher syndrome type 1, characterized by combined deafness and blindness. MYO7A is proposed to function as a motor that tensions the hair cell mechanotransduction (MET) complex, but conclusive evidence is lacking. Here we report that multiple MYO7A isoforms are expressed in the mouse cochlea. In mice with a specific deletion of the canonical isoform (Myo7a-ΔC mouse), MYO7A is severely diminished in inner hair cells (IHCs), while expression in outer hair cells is affected tonotopically. IHCs of Myo7a-ΔC mice undergo normal development, but exhibit reduced resting open probability and slowed onset of MET currents, consistent with MYO7A’s proposed role in tensioning the tip link. Mature IHCs of Myo7a-ΔC mice degenerate over time, giving rise to progressive hearing loss. Taken together, our study reveals an unexpected isoform diversity of MYO7A expression in the cochlea and highlights MYO7A’s essential role in tensioning the hair cell MET complex.
Super-tough MXene-functionalized graphene sheets
Authors: Zhou Tianzhu , Wu Chao , Wang Yanlei , Tomsia Antoni P. , Li Mingzhu , Saiz Eduardo , Fang Shaoli , Baughman Ray H. , Jiang Lei , Cheng Qunfeng
Published: April 2020

Flexible reduced graphene oxide (rGO) sheets are being considered for applications in portable electrical devices and flexible energy storage systems. However, the poor mechanical properties and electrical conductivities of rGO sheets are limiting factors for the development of such devices. Here we use MXene (M) nanosheets to functionalize graphene oxide platelets through Ti-O-C covalent bonding to obtain MrGO sheets. A MrGO sheet was crosslinked by a conjugated molecule (1-aminopyrene-disuccinimidyl suberate, AD). The incorporation of MXene nanosheets and AD molecules reduces the voids within the graphene sheet and improves the alignment of graphene platelets, resulting in much higher compactness and high toughness. In situ Raman spectroscopy and molecular dynamics simulations reveal the synergistic interfacial interaction mechanisms of Ti-O-C covalent bonding, sliding of MXene nanosheets, and π-π bridging. Furthermore, a supercapacitor based on our super-tough MXene-functionalized graphene sheets provides a combination of energy and power densities that are high for flexible supercapacitors.
Arctic avian predators synchronise their spring migration with the northern progression of snowmelt
Authors: Curk Teja , Pokrovsky Ivan , Lecomte Nicolas , Aarvak Tomas , Brinker David F. , Burnham Kurt , Dietz Andreas , Dixon Andrew , Franke Alastair , Gauthier Gilles , Jacobsen Karl-Otto , Kidd Jeff , Lewis Stephen B. , Øien Ingar J. , Sokolov Aleksandr , Sokolov Vasiliy , Solheim Roar , Weidensaul Scott , Wiebe Karen , Wikelski Martin , Therrien Jean-François , Safi Kamran
Published: April 2020

Migratory species display a range of migration patterns between irruptive (facultative) to regular (obligate), as a response to different predictability of resources. In the Arctic, snow directly influences resource availability. The causes and consequences of different migration patterns of migratory species as a response to the snow conditions remains however unexplored. Birds migrating to the Arctic are expected to follow the spring snowmelt to optimise their arrival time and select for snow-free areas to maximise prey encounter en-route. Based on large-scale movement data, we compared the migration patterns of three top predator species of the tundra in relation to the spatio-temporal dynamics of snow cover. The snowy owl, an irruptive migrant, the rough-legged buzzard, with an intermediary migration pattern, and the peregrine falcon as a regular migrant, all followed, as expected, the spring snowmelt during their migrations. However, the owl stayed ahead, the buzzard stayed on, and the falcon stayed behind the spatio-temporal peak in snowmelt. Although none of the species avoided snow-covered areas, they presumably used snow presence as a cue to time their arrival at their breeding grounds. We show the importance of environmental cues for species with different migration patterns.
Real-time detection and identification of nematode eggs genus and species through optical imaging
Authors: Qazi Farah , Khalid Asma , Poddar Arpita , Tetienne Jean-Philippe , Nadarajah Athavan , Aburto-Medina Arturo , Shahsavari Esmaeil , Shukla Ravi , Prawer Steven , Ball Andrew S. , Tomljenovic-Hanic Snjezana
Published: April 2020

Nematode eggs are pervasive pathogens that infect billions of people and livestock every year. Adult parasitic nematode worms can be distinguished based on their size and morphology. However, their eggs, particularly their species Ascaris lumbricoides and Ascaris suum cannot be identified from each other. Identifying eggs of helminths from wastewater and sludge is important from a public health perspective to minimize the spread of Ascaris infections. Numerous methods exist for nematode identification, from a morphological-based approach to high throughput sequencing technology. However, these techniques are not consistent and often laborious and time-consuming. In this study, we demonstrate that non-invasive real-time identification of eggs is possible based on their intrinsic fluorescence. Using confocal microscopy, we investigate the autofluorescence properties of five species of nematode eggs and observe clear differences between genus and for the first time their species in sludge samples. This non-invasive imaging technique could lead to better understanding of these species and may assist in early control of diseases.
A Self-Assembling Lipidic Peptide and Selective Partial V2 Receptor Agonist Inhibits Urine Production
Authors: Patel Sunish , Volpe Antonella Bavuso , Awwad Sahar , Schätzlein Andreas G. , Haider Shozeb , Liu Boqian , Uchegbu Ijeoma F.
Published: April 2020

Lipidised analgesic peptide prodrugs self-assemble into peptide nanofibers; with the nanofiber morphology protecting the peptide from plasma degradation and improving therapeutic efficacy. Extending this learning, we hypothesised that a self-assembling lipidized peptide arginine vasopressin (AVP) receptor agonist, that had not been designed as a prodrug, could prove pharmacologically active and control urine production. The only approved AVP receptor agonist, desmopressin is indicated for the treatment of central diabetes insipidus (DI), bedwetting, haemophilia A and von Willebrand disease. Desmopressin is well tolerated by most patients, however adverse effects, such as hyponatraemia and water intoxication necessitate a strict fluid intake, thus motivating the search for alternative DI treatments. Selective V2 receptor agonism is required for anti-DI activity and we hypothesised that our new lipidized peptide (METx) would lead to selective AVP receptor agonism. METx was synthesised and characterised and then tested for activity against the V2, V1a and OT uterine receptors and not tested against the V1b receptor as METx was not expected to cross the blood brain barrier. METx was also tested in vivo in a healthy rat model. METx forms nanofibers and is a partial V2 receptor agonist (determined by measuring MDCK cell line cAMP accumulation), producing 57% of AVP’s maximal activity (EC50 = 2.7 nM) and is not a V1a agonist up to a concentration of 1 μM (determined by measuring A7r5 cell line D-myo-inositol-1-phosphate accumulation). METx is a weak OT receptor antagonist, reducing the frequency of OT induced contractions (EC50 = 350 nM) and increasing the OT EC50 from 0.081 nM to 21 nM at a concentration of 600 nM. METx (41 nM) had no effect on spontaneous uterine contractions and METx (100 nM) had no effect on OT induced uterine contractions. Simulated binding studies show that binding avidity to the receptors follows the trend: V2 > OT > V1a. On intravenous injection, a nanoparticle formulation of METx reduced urine production in a healthy rat model in a dose responsive manner, with 40 mg kg−1 METx resulting in no urine production over 4 hours. The lipidized self-assembling peptide – METx - is a selective competitive V2 receptor agonist and an anti-diuretic.
N-glycosylation of α1D-adrenergic receptor N-terminal domain is required for correct trafficking, function, and biogenesis
Authors: Janezic Eric M. , Lauer Sophia My-Linh , Williams Robert George , Chungyoun Michael , Lee Kyung-Soon , Navaluna Edelmar , Lau Ho-Tak , Ong Shao-En , Hague Chris
Published: April 2020

G protein-coupled receptor (GPCR) biogenesis, trafficking, and function are regulated by post-translational modifications, includingN-glycosylation of asparagine residues. α1D-adrenergic receptors (α1D-ARs) – key regulators of central and autonomic nervous system function – contain two putativeN-glycosylation sites within the large N-terminal domain at N65 and N82. However, determining the glycosylation state of this receptor has proven challenging. Towards understanding the role of these putative glycosylation sites, site-directed mutagenesis and lectin affinity purification identified N65 and N82 asbona fideacceptors forN-glycans. Surprisingly, we also report that simultaneously mutating N65 and N82 causes early termination of α1D-AR between transmembrane domain 2 and 3. Label-free dynamic mass redistribution and cell surface trafficking assays revealed that single and double glycosylation deficient mutants display limited function with impaired plasma membrane expression. Confocal microscopy imaging analysis and SNAP-tag sucrose density fractionation assays revealed the dual glycosylation mutant α1D-AR is widely distributed throughout the cytosol and nucleus. Based on these novel findings, we propose α1D-AR transmembrane domain 2 acts as an ER localization signal during active protein biogenesis, and that α1D-AR N-terminal glycosylation is required for complete translation of nascent, functional receptor.
Transcutaneous Electrical Nerve Stimulation Improves Stair Climbing Capacity in People with Knee Osteoarthritis
Authors: Iijima Hirotaka , Eguchi Ryo , Shimoura Kanako , Yamada Keisuke , Aoyama Tomoki , Takahashi Masaki
Published: April 2020

This study aimed to examine the effect of transcutaneous electrical nerve stimulation (TENS) on stair climbing capacity in individuals with pre-radiographic to mild knee osteoarthritis (OA). This is a secondary analysis of data from a single, participant-blinded, randomized controlled trial with a pre-post design. Participants with pre-radiographic to mild knee OA (mean age, 59.1 years; 72.9% women) were randomly assigned into two groups, a TENS (n = 30) and a sham-TENS groups (n = 29). TENS or sham-TENS treatments were applied to all participants by using the prototype TENS device with pre-specified parameters. The primary outcome measures included valid and reliable functional measures for stair climbing (stair-climb test [SCT]), visual analog scale for knee pain during the SCT, and quadriceps muscle strength. TENS improved SCT time by 0.41 s (95% confidence interval [CI]: 0.07, 0.75). The time reduction in the transition phase explains the TENS therapeutic effect. Post-hoc correlation analyses revealed a non-significant but positive relationship between the pain relief effect and improved 11-step SCT time in the TENS group but not in the sham-TENS group. These results indicate that the TENS intervention may be an option for reducing the burden of early-stage knee OA.
Behavioral and neuronal study of inhibition of return in barn owls
Authors: Lev-Ari Tidhar , Zahar Yael , Agarwal Arpit , Gutfreund Yoram
Published: April 2020

Inhibition of return (IOR) is the reduction of detection speed and/or detection accuracy of a target in a recently attended location. This phenomenon, which has been discovered and studied thoroughly in humans, is believed to reflect a brain mechanism for controlling the allocation of spatial attention in a manner that enhances efficient search. Findings showing that IOR is robust, apparent at a very early age and seemingly dependent on midbrain activity suggest that IOR is a universal attentional mechanism in vertebrates. However, studies in non-mammalian species are scarce. To explore this hypothesis comparatively, we tested for IOR in barn owls (Tyto alba) using the classical Posner cueing paradigm. Two barn owls were trained to initiate a trial by fixating on the center of a computer screen and then turning their gaze to the location of a target. A short, non-informative cue appeared before the target, either at a location predicting the target (valid) or a location not predicting the target (invalid). In one barn owl, the response times (RT) to the valid targets compared to the invalid targets shifted from facilitation (lower RTs) to inhibition (higher RTs) when increasing the time lag between the cue and the target. The second owl mostly failed to maintain fixation and responded to the cue before the target onset. However, when including in the analysis only the trials in which the owl maintained fixation, an inhibition in the valid trials could be detected. To search for the neural correlates of IOR, we recorded multiunit responses in the optic tectum (OT) of four head-fixed owls passively viewing a cueing paradigm as in the behavioral experiments. At short cue to target lags (<100 ms), neural responses to the target in the receptive field (RF) were usually enhanced if the cue appeared earlier inside the RF (valid) and were suppressed if the cue appeared earlier outside the RF (invalid). This was reversed at longer lags: neural responses were suppressed in the valid conditions and were unaffected in the invalid conditions. The findings support the notion that IOR is a basic mechanism in the evolution of vertebrate behavior and suggest that the effect appears as a result of the interaction between lateral and forward inhibition in the tectal circuitry.
Psychometric assessment and validation of the dysphagia severity rating scale in stroke patients
Authors: Everton Lisa F. , Benfield Jacqueline K. , Hedstrom Amanda , Wilkinson Gwenllian , Michou Emilia , England Timothy J. , Dziewas Rainer , Bath Philip M. , Hamdy Shaheen
Published: April 2020

Post stroke dysphagia (PSD) is common and associated with poor outcome. The Dysphagia Severity Rating Scale (DSRS), which grades how severe dysphagia is based on fluid and diet modification and supervision requirements for feeding, is used for clinical research but has limited published validation information. Multiple approaches were taken to validate the DSRS, including concurrent- and predictive criterion validity, internal consistency, inter- and intra-rater reliability and sensitivity to change. This was done using data from four studies involving pharyngeal electrical stimulation in acute stroke patients with dysphagia, an individual patient data meta-analysis and unpublished studies (NCT03499574, NCT03700853). In addition, consensual- and content validity and the Minimal Clinically Important Difference (MCID) were assessed using anonymous surveys sent to UK-based Speech and Language Therapists (SLTs). Scores for consensual validity were mostly moderate (62.5–78%) to high or excellent (89–100%) for most scenarios. All but two assessments of content validity were excellent. In concurrent criterion validity assessments, DSRS was most closely associated with measures of radiological aspiration (penetration aspiration scale, Spearman rank rs = 0.49, p < 0.001) and swallowing (functional oral intake scale, FOIS, rs = −0.96, p < 0.001); weaker but statistically significant associations were seen with impairment, disability and dependency. A similar pattern of relationships was seen for predictive criterion validity. Internal consistency (Cronbach’s alpha) was either “good” or “excellent”. Intra and inter-rater reliability were largely “excellent” (intraclass correlation >0.90). DSRS was sensitive to positive change during recovery (medians: 7, 4 and 1 at baseline and 2 and 13 weeks respectively) and in response to an intervention, pharyngeal electrical stimulation, in a published meta-analysis. The MCID was 1.0 and DSRS and FOIS scores may be estimated from each other. The DSRS appears to be a valid tool for grading the severity of swallowing impairment in patients with post stroke dysphagia and is appropriate for use in clinical research and clinical service delivery.
How climate change and wildlife management affect population structure in wild boars
Authors: Vetter Sebastian G. , Puskas Zsófia , Bieber Claudia , Ruf Thomas
Published: April 2020

Global climate change affects many species and contributes to the exceptional population growth of wild boar populations and thus to increasing human-wildlife conflicts. To investigate the impact of climate change on wild boar populations we extended existing models on population dynamics. We included for the first time different juvenile conditions to account for long-lasting effects of juvenile body mass on adult body mass and reproductive success. Our analysis shows that incorporating phenotypes, like body mass differences within age classes, has strong effects on projected population growth rates, population structures and the relative importance of certain vital rates. Our models indicated that an increase in winter temperatures and food availability will cause a decrease in mean body mass and litter size within Central European wild boar populations. We further analysed different hunting regimes to identify their effects on the population structure as well as their efficiency in limiting population growth. While targeting juveniles had the lowest effect on population structure, such strategies are, however, rather ineffective. In contrast, culling predominantly yearlings seems very effective. Despite being equally effective, only focusing on adults will not result in a reduction of population size due to their low proportion within populations.
A quantitative method to assess muscle edema using short TI inversion recovery MRI
Authors: Dahlqvist Julia R. , Salim Ruth , Thomsen Carsten , Vissing John
Published: April 2020

Muscle inflammation is an important component of disease pathophysiology in several muscular dystrophies. Hyperintensities on MRI sequences with short TI inversion recovery (STIR) reflect edema, or inflammation (STIR+). Conventionally, STIR evaluation has been done by visual inspection. In this study, we developed a quantitative STIR method, and tested its ability to identify STIR+ lesions in healthy controls and patients with Facioscapulohumeral muscular dystrophy and compared the results with visual STIR evaluation and quantitative T2 relaxation time mapping. The method was based on pixel-by-pixel histograms of the distribution of signal intensities from muscles. Signal intensities from healthy control muscles were averaged and used to define an upper reference limit. Muscles with >2.5% pixels above the limit were defined as being STIR+. The new method showed agreement with T2 relaxation time mapping in 95% of muscles. The visual STIR method only showed agreement with the quantitative STIR method and T2 relaxation time mapping in 88 and 84%, respectively. STIR sequences are available on most MR scanners and the post-processing used in the new quantitative method can be performed using free software. We therefore believe that the new method can play an important role in identifying STIR+ lesions in patients with neuromuscular diseases.
Structural and physicochemical changes in almond milk during in vitro gastric digestion: impact on the delivery of protein and lipids
Authors: Wang Xin , Ye Aiqian , Singh Harjinder
Published: April 2020

The gastric digestion of almond milk in a human gastric simulator resulted in major structural and physicochemical changes. The changes had significant impact on the rate of delivery of protein and lipids to the small intestine.
DNA damage is inversely associated to blood levels of DHA and EPA fatty acids in Brazilian children and adolescents
Authors: de Barros Tamiris Trevisan , Venâncio Vinicius de Paula , Hernandes Lívia Cristina , Greggi Antunes Lusânia Maria , Hillesheim Elaine , Salomão Roberta Garcia , Mathias Mariana Giaretta , Coelho-Landell Carolina Almeida , Toffano Roseli Borges Donegá , Almada Maria Olimpia Ribeiro do Vale , Camelo- José Simon , Moco Sofia , Ued Fábio da Veiga , Kaput Jim , Monteiro Jacqueline Pontes
Published: April 2020

This study aimed to investigate the association between DNA damage and blood levels of docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), retinol, beta-carotene and riboflavin in Brazilian children and adolescents.
Role of acid mixtures etching on the surface chemistry and sodium ion storage in Ti3C2Tx MXene
Authors: Anayee Mark , Kurra Narendra , Alhabeb Mohamed , Seredych Mykola , Hedhili Mohamed Nejib , Emwas Abdul-Hamid , Alshareef Husam N. , Anasori Babak , Gogotsi Yury
Published: April 2020

Optimizing the etchants for MXene synthesis to remove etching byproducts, obtain pristine surface chemistry, and improve energy storage performance.
Regulation of the rutile/anatase TiO2 heterophase interface by Ni12P5 to improve photocatalytic hydrogen evolution
Authors: Qiu Chengwei , Lin Jinjin , Shen Jinni , Liu Dan , Zhang Zizhong , Lin Huaxiang , Wang Xuxu
Published: April 2020

Loading Ni12P5 on an anatase/rutile surface reduces its photocatalytic activity, while embedding Ni12P5 within its junction interface enhances its photocatalytic activity.
Tandem post-synthetic modification of a zeolitic imidazolate framework for CXCR4-overexpressed esophageal squamous cell cancer imaging and therapy
Authors: Cao Yi , Jiang Zhenqi , Li Yanying , Wang Yinjie , Yang Yong , Akakuru Ozioma Udochukwu , Li Juan , Wu Aiguo
Published: April 2020

Tandem post-synthetic modification of zeolitic imidazolate framework-7 with CXCR-4 inhibitors and Mn ions for esophageal squamous cell cancer imaging and therapy.
AgFeS2 nanoparticles as a novel photothermal platform for effective artery stenosis therapy
Authors: Peng Xuan , Liu Junchao , Ming Chen , Li Bo , Zhao Zhen , Ye Kaichuang , Zeng Min , Zou Rujia , Lu Xinwu , Hu Junqing
Published: April 2020

Based on DFT calculations, a novel photo-response hyperthermia platform of AgFeS2 nanoparticles modified with mPEG-DSPE was developed for atherostenosis therapy.
Conductive-bridging random-access memories for emerging neuromorphic computing
Authors: Cha Jun-Hwe , Yang Sang Yoon , Oh Jungyeop , Choi Shinhyun , Park Sangsu , Jang Byung Chul , Ahn Wonbae , Choi Sung-Yool
Published: April 2020

This review covers CBRAM-based artificial synapses and neurons towards emerging computing applications from the operation principles of CBRAMs to state-of-the-art experimental demonstrations.
High polarization, endurance and retention in sub-5 nm Hf0.5Zr0.5O2 films
Authors: Lyu Jike , Song Tingfeng , Fina Ignasi , Sánchez Florencio
Published: April 2020

High polarization, endurance and retention are reached in epitaxial Hf0.5Zr0.5O2 films as thin as sub-5 nm.
Sonochemical synthesis of polyoxometalate-stabilized gold nanoparticles for point-of-care determination of acetaminophen levels: preclinical study in an animal model
Authors: Bastami Tahereh Rohani , Ghaedi Abolphazl , Mitchell Scott G. , Javadian-Saraf Aida , Karimi Mohammad
Published: April 2020

The aim of this study is the accurate detection of acetaminophen (AP) for point-of-care (POC) clinical diagnosis. The concentration of acetaminophen was measured in over-the-counter pharmaceutical tablets and in serum samples taken from mice.
Nanostructured manganese oxides electrode with ultra-long lifetime for electrochemical capacitors
Authors: Gaire Madhu , Liang Kun , Luo Sijun , Subedi Binod , Adireddy Shiva , Schroder Kurt , Farnsworth Stan , Chrisey Douglas B.
Published: April 2020

We describe the instantaneous fabrication of a highly porous three-dimensional (3D) nanostructured manganese oxides-reduced graphitic oxide (MnOx-rGO) electrode by using a pulse-photonic processing technique.
Hypercrosslinked phenothiazine-based polymers as high redox potential organic cathode materials for lithium-ion batteries
Authors: Zhang Ying , Gao Panpan , Guo Xinya , Chen Han , Zhang Ruiqiang , Du Ya , Wang Baofeng , Yang Haishen
Published: April 2020

Hypercrosslinked conductive polymers with phenothiazine motifs were achieved and studied as organic cathode materials, exhibiting excellent electrochemical performance.
Properties of amorphous iron phosphate in pseudocapacitive sodium ion removal for water desalination
Authors: Bentalib Abdulaziz , Pan Yanbo , Yao Libo , Peng Zhenmeng
Published: April 2020

Amorphous iron phosphate (FePO4) exhibits excellent capacity, reversibility and stability in pseudocapacitive sodium ion removal for water desalination.