bluuebunny/crossref_metadata_2025_split huggingface dataset:
Heading direction with respect to a reference point modulates place-cell activity
Authors: Jercog P. E. , Ahmadian Y. , Woodruff C. , Deb-Sen R. , Abbott L. F. , Kandel E. R. 
Published: May 2019

AbstractThe tuning of neurons in area CA1 of the hippocampus emerges through a combination of non-spatial input from different sensory modalities and spatial information about the animal’s position and heading direction relative to the spatial enclosure being navigated. The positional modulation of CA1 neuronal responses has been widely studied (e.g. place tuning), but less is known about the modulation of these neurons by heading direction. Here, utilizing electrophysiological recordings from CA1 pyramidal cells in freely moving mice, we report that a majority of neural responses are modulated by the heading-direction of the animal relative to a point within or outside their enclosure that we call a reference point. The finding of heading-direction modulation relative to reference points identifies a novel representation encoded in the neuronal responses of the dorsal hippocampus.
The viral protein corona directs viral pathogenesis and amyloid aggregation
Authors: Ezzat Kariem , Pernemalm Maria , Pålsson Sandra , Roberts Thomas C. , Järver Peter , Dondalska Aleksandra , Bestas Burcu , Sobkowiak Michal J. , Levänen Bettina , Sköld Magnus , Thompson Elizabeth A. , Saher Osama , Kari Otto K. , Lajunen Tatu , Sverremark Ekström Eva , Nilsson Caroline , Ishchenko Yevheniia , Malm Tarja , Wood Matthew J. A. , Power Ultan F. , Masich Sergej , Lindén Anders , Sandberg Johan K. , Lehtiö Janne , Spetz Anna-Lena , EL Andaloussi Samir 
Published: May 2019

AbstractArtificial nanoparticles accumulate a protein corona layer in biological fluids, which significantly influences their bioactivity. As nanosized obligate intracellular parasites, viruses share many biophysical properties with artificial nanoparticles in extracellular environments and here we show that respiratory syncytial virus (RSV) and herpes simplex virus type 1 (HSV-1) accumulate a rich and distinctive protein corona in different biological fluids. Moreover, we show that corona pre-coating differentially affects viral infectivity and immune cell activation. In addition, we demonstrate that viruses bind amyloidogenic peptides in their corona and catalyze amyloid formation via surface-assisted heterogeneous nucleation. Importantly, we show that HSV-1 catalyzes the aggregation of the amyloid β-peptide (Aβ42), a major constituent of amyloid plaques in Alzheimer’s disease, in vitro and in animal models. Our results highlight the viral protein corona as an acquired structural layer that is critical for viral–host interactions and illustrate a mechanistic convergence between viral and amyloid pathologies.
The valley Zeeman effect in inter- and intra-valley trions in monolayer WSe2
Authors: Lyons T. P. , Dufferwiel S. , Brooks M. , Withers F. , Taniguchi T. , Watanabe K. , Novoselov K. S. , Burkard G. , Tartakovskii A. I. 
Published: May 2019

AbstractMonolayer transition metal dichalcogenides (TMDs) hold great promise for future information processing applications utilizing a combination of electron spin and valley pseudospin. This unique spin system has led to observation of the valley Zeeman effect in neutral and charged excitonic resonances under applied magnetic fields. However, reported values of the trion valley Zeeman splitting remain highly inconsistent across studies. Here, we utilize high quality hBN encapsulated monolayer WSe2 to enable simultaneous measurement of both intervalley and intravalley trion photoluminescence. We find the valley Zeeman splitting of each trion state to be describable only by a combination of three distinct g-factors, one arising from the exciton-like valley Zeeman effect, the other two, trion specific, g-factors associated with recoil of the excess electron. This complex picture goes significantly beyond the valley Zeeman effect reported for neutral excitons, and eliminates the ambiguity surrounding the magneto-optical response of trions in tungsten based TMD monolayers.
Human mobility patterns and malaria importation on Bioko Island
Authors: Guerra Carlos A. , Kang Su Yun , Citron Daniel T. , Hergott Dianna E. B. , Perry Megan , Smith Jordan , Phiri Wonder P. , Osá Nfumu José O. , Mba Eyono Jeremías N. , Battle Katherine E. , Gibson Harry S. , García Guillermo A. , Smith David L. 
Published: May 2019

AbstractMalaria burden on Bioko Island has decreased significantly over the past 15 years. The impact of interventions on malaria prevalence, however, has recently stalled. Here, we use data from island-wide, annual malaria indicator surveys to investigate human movement patterns and their relationship to Plasmodium falciparum prevalence. Using geostatistical and mathematical modelling, we find that off-island travel is more prevalent in and around the capital, Malabo. The odds of malaria infection among off-island travelers are significantly higher than the rest of the population. We estimate that malaria importation rates are high enough to explain malaria prevalence in much of Malabo and its surroundings, and that local transmission is highest along the West Coast of the island. Despite uncertainty, these estimates of residual transmission and importation serve as a basis for evaluating progress towards elimination and for efficiently allocating resources as Bioko makes the transition from control to elimination.
Ocean predation and mortality of adult Atlantic salmon
Authors: Strøm John Fredrik , Rikardsen Audun Håvard , Campana Steven E. , Righton David , Carr Jonathan , Aarestrup Kim , Stokesbury Michael J. W. , Gargan Patrick , Javierre Pablo Caballero , Thorstad Eva Bonsak 
Published: May 2019

AbstractPredation and mortality are often difficult to estimate in the ocean, which hampers the management and conservation of marine fishes. We used data from pop-up satellite archival tags to investigate the ocean predation and mortality of adult Atlantic salmon (Salmo salar) released from 12 rivers flowing into the North Atlantic Ocean. Data from 156 tagged fish revealed 22 definite predation events (14%) and 38 undetermined mortalities (24%). Endothermic fish were the most common predators (n = 13), with most of these predation events occurring in the Gulf of St. Lawrence and from the Bay of Biscay to the Irish Shelf. Predation by marine mammals, most likely large deep-diving toothed whales (n = 5), and large ectothermic fish (n = 4) were less frequent. Both the estimated predation rates (ZP) and total mortality rates (ZM) where higher for Atlantic salmon from Canada, Ireland, and Spain (ZP = 0.60–1.32 y−1, ZM = 1.73–3.08 y−1) than from Denmark and Norway (ZP = 0–0.13 y−1, ZM = 0.19–1.03 y−1). This geographical variation in ocean mortality correlates with ongoing population declines, which are more profound for southern populations, indicating that low ocean survival of adults may act as an additional stressor to already vulnerable populations.
CHA2DS2-VASc score and left atrial volume dilatation synergistically predict incident atrial fibrillation in hypertension: an observational study from the Campania Salute Network registry
Authors: Rapacciuolo Antonio , Mancusi Costantino , Canciello Grazia , Izzo Raffaele , Strisciuglio Teresa , de Luca Nicola , Ammirati Giuseppe , de Simone Giovanni , Trimarco Bruno , Losi Maria-Angela 
Published: May 2019

AbstractArterial hypertension is a leading risk factor for developing atrial fibrillation. CHA2DS2-VASc score can help to decide if patients with atrial fibrillation need anticoagulation. Whether CHA2DS2-VASc may predicts incident atrial fibrillation and how it interacts with left atrial dilatation is unknown. We tested this hypothesis in a large registry of treated hypertensive patients. From 12154 hypertensive patients we excluded those with prevalent atrial fibrillation (n 51), without follow-up (n 3496), or carotid ultrasound (n 1891), and low ejection fraction (i.e. <50%, n 119). A CHA2DS2-VASc score ≥3 was compared with CHA2DS2-VASc score ≤2. Incident symptomatic or occasionally detected atrial fibrillation was the end-point of the present analysis. At baseline, 956 (15%) patients exhibited high CHA2DS2-VASc; they were older, most likely to be women, obese and diabetic, with lower glomerular filtration rate, and higher prevalence of left ventricular hypertrophy, left-atrial dilatation and carotid plaque (all p < 0.005). Prevalent Stroke/TIA was found only in the subgroup with high CHA2DS2-VASc. During follow-up (median = 54 months) atrial fibrillation was identified in 121 patients, 2.57-fold more often in patients with high CHA2DS2-VASc (95% Cl 1.71–4.86 p < 0.0001). In multivariable Cox analysis, CHA2DS2-VASc increased incidence of atrial fibrillation by 3-fold, independently of significant effect of left-atrial dilatation (both p < 0.0001) and other markers of organ damage. Incident AF is more than doubled in hypertensive patients with CHA2DS2-VASc ≥3. Coexisting CHA2DS2-VASc score >3 and LA dilatation identify high risk subjects potentially needing more aggressive management to prevent AF and associated cerebrovascular ischemic events.
Viscoelastic and shear-thinning effects of aqueous exopolymer solution on disk and sphere settling
Authors: Mrokowska Magdalena M. , Krztoń-Maziopa Anna 
Published: May 2019

AbstractIn this study, xanthan gum is used as a model exopolymer to demonstrate potential effects of non-Newtonian properties of natural aquatic systems on settling dynamics of particles. Rheological measurements combined with settling experiments using visualization methods revealed that instantaneous velocity fluctuations and a flow pattern formed around a particle are the effects of solution viscoelasticity and shear-thinning properties and that the average settling velocity depends on the exopolymer concentration and particle size. Our study showed that in the considered conditions a disk-shaped particle settles preferably in vertical position with a negative wake behind. The understanding of these processes is essential in technology and engineering and is necessary to improve prediction accuracy of large-scale sedimentation processes and biogeochemical cycles in the ocean involving settling of minerals, marine snow, microplastics, and locomotion of microorganisms.
The origin of rare alkali metals in geothermal fluids of southern Tibet, China: A silicon isotope perspective
Authors: Wang Wei , Wei Hai-Zhen , Jiang Shao-Yong , Tan Hong-Bing , Eastoe Christopher J. , Williams-Jones Anthony E. , Hohl Simon V. , Wu He-Pin 
Published: May 2019

AbstractGeothermal waters from the Semi, Dagejia and Kawu hot springs in the Shiquanhe-Yarlung Zangbo geothermal field of southern Tibet (China) are highly enriched in rare alkali metals (RAM). However, the enrichment mechanism is still hotly debated. Here, we report the first silicon isotope data of these geothermal waters to unravel the origin of the extreme RAM enrichments. Sinter precipitation in the spring vents and water-rock interaction in the deep reservoir controlled both the silicon budget and silicon isotope fractionation. The rates of water-rock interaction and sinter precipitation in three spring sites decrease in the sequences Semi > Kawu > Dagejia, and Dagejia > Kawu > Semi respectively. Silicon isotope fractionation during sinter precipitation (i.e. Δ30Siprecipitate-solution < −0.1‰) is less than that due to water-rock interaction (i.e. Δ30Sisolution-rocks at least as high as −0.47‰), which makes it possible to use the δ30Si signatures of springs to evaluate the intensity of water-rock interaction. Based on the available evidence, a conceptual model of RAM enrichment is proposed: (i) persistent magmatic activity in southern Tibet provided the initial enrichment of the RAM in host rocks and a heat sources for the deep reservoirs of geothermal systems; (ii) the high Cl− content and long residence time (thousands of years) promote the leaching of RAM from the silicate host rocks.
Target identification, screening and in vivo evaluation of pyrrolone-fused benzosuberene compounds against human epilepsy using Zebrafish model of pentylenetetrazol-induced seizures
Authors: Tanwar Garima , Mazumder Arindam Ghosh , Bhardwaj Vijay , Kumari Savita , Bharti Richa , Yamini  , Singh Damanpreet , Das Pralay , Purohit Rituraj 
Published: May 2019

AbstractPyrrolone-fused benzosuberene (PBS) compounds were semi-synthesized from α,β,γ-Himachalenes extracted from the essential oil of Cedrus deodara following amino-vinyl-bromide substituted benzosuberenes as intermediates. These PBSs compounds classified as an attractive source of therapeutics. The α-isoform of PI3K which is a pivotal modulator of PI3K/AKT/mTOR signaling pathway, responsible for neurological disorders like epilepsy, found as a potential target molecule against these 17 semi-synthesized PBS compounds using in silico ligand-based pharmacophore mapping and target screening. The compounds screened using binding affinities, ADMET properties, and toxicity that were accessed by in silico docking simulations and pharmacokinetics profiling. Ultimately two compounds viz., PBS-8 and PBS-9 were selected for further in vivo evaluation using a zebrafish (Danio rerio) model of pentylenetetrazol (PTZ)-induced clonic convulsions. Additionally, gene expression studies performed for the genes of the PI3K/AKT/mTOR pathway which further validated our results. In conclusion, these findings suggested that PBS-8 is a promising candidate that could bedeveloped as a potential antiepileptic.
Quantification of very low-abundant proteins in bacteria using the HaloTag and epi-fluorescence microscopy
Authors: Lepore Alessia , Taylor Hannah , Landgraf Dirk , Okumus Burak , Jaramillo-Riveri Sebastián , McLaren Lorna , Bakshi Somenath , Paulsson Johan , Karoui M. El 
Published: May 2019

AbstractCell biology is increasingly dependent on quantitative methods resulting in the need for microscopic labelling technologies that are highly sensitive and specific. Whilst the use of fluorescent proteins has led to major advances, they also suffer from their relatively low brightness and photo-stability, making the detection of very low abundance proteins using fluorescent protein-based methods challenging. Here, we characterize the use of the self-labelling protein tag called HaloTag, in conjunction with an organic fluorescent dye, to label and accurately count endogenous proteins present in very low numbers (<7) in individual Escherichia coli cells. This procedure can be used to detect single molecules in fixed cells with conventional epifluorescence illumination and a standard microscope. We show that the detection efficiency of proteins labelled with the HaloTag is ≥80%, which is on par or better than previous techniques. Therefore, this method offers a simple and attractive alternative to current procedures to detect low abundance molecules.
Effects of 1,8-cineole on neuropathic pain mediated by P2X2 receptor in the spinal cord dorsal horn
Authors: Zheng Xiao-bo , Zhang Ya-ling , Li Qing , Liu Yi-guo , Wang Xiang-dong , Yang Bao-lin , Zhu Gao-chun , Zhou Cong-fa , Gao Yun , Liu Zeng-xu 
Published: May 2019

AbstractAs an intractable health threat, neuropathic pain is now a key problem in clinical therapy, which can be caused by lesions affecting the peripheral nervous systems. 1,8-cineole is a natural monoterpene cyclic ether present in eucalyptus and has been reported to exhibit anti-inflammatory and antioxidant effects. Research has shown that 1,8-cineole inhibits P2X3 receptor-mediated neuropathic pains in dorsal root ganglion. The P2X2 and P2X3 receptors participate in the transmission of algesia and nociception information by primary sensory neurons. In the present study, We thus investigated in the spinal cord dorsal horn whether 1,8-cineole inhibits the expression of P2X2 receptor-mediated neuropathic pain. This study used rats in five random groups: group of chronic constriction injury(CCI) with dimethysulfoxide control (CCI + DMSO); group of CCI; sham group(Sham); group of CCI treated with a low dose 1,8-cineole (CCI + 50 mg/kg); group of CCI with a high dose (CCI + 100 mg/kg). We observed the effects of 1,8-cineole on thermal withdrawal latency (TWL) and mechanical withdrawal threshold (MWT). We examined P2X2 receptors mRNA change in rat spinal cord dorsal horn by In situ nucleic acid hybridization(ISH) and Quantitative realtime polymerase chain reaction (qRT-PCR) methods. Western Blotting and Immunohistochemical staining methods were used to observe P2X2 receptor protein expressions in the rat spinal cord dorsal horn. It demonstrated that oral administration of 1,8-cineole inhibits over-expression of P2X2 receptor protein and mRNA in the spinal cord and dorsal horn in the CCI rats. And the study explored new methods for the prevention and treatment of neuropathic pain.
Cognitive and Microbiome Impacts of Experimental Ancylostoma ceylanicum Hookworm Infections in Hamsters
Authors: Pan Samuel C. , Ward Doyle V. , Yin Yunqiang , Hu Yan , Elfawal Mostafa A. , Clark Robert E. , Aroian Raffi V. 
Published: May 2019

AbstractHookworms are one of the most prevalent and important parasites, infecting ~500 million people worldwide. Hookworm disease is among the leading causes of iron-deficiency anemia in the developing world and is associated with significant growth stunting and malnutrition. In humans, hookworms appear to impair memory and other forms of cognition, although definitive data are hard to come by. Here we study the impact of a human hookworm parasite, Ancylostoma ceylanicum, on cognition in hamsters in a controlled laboratory setting. We developed tests that measure long-term memory in hamsters. We find that hookworm-infected hamsters were fully capable of detecting a novel object. However, hookworm-infected hamsters were impaired in detecting a displaced object. Defects could be discerned at even at low levels of infection, whereas at higher levels of infection, hamsters were statistically unable to distinguish between displaced and non-displaced objects. These spatial memory deficiencies could not be attributed to defects in infected hamster mobility or to lack of interest. We also found that hookworm infection resulted in reproducible reductions in diversity and changes in specific taxanomic groups in the hamster gut microbiome. These data demonstrate that human hookworm infection in a laboratory mammal results in a specific, rapid, acute, and measurable deficit in spatial memory, and we speculate that gut alterations could play some role in these cognitive deficits. Our findings highlight the importance of hookworm elimination and suggest that finer tuned spatial memory studies be carried out in humans.
Water-content related alterations in macro and micro scale tendon biomechanics
Authors: Lozano Pamela F. , Scholze Mario , Babian Carsten , Scheidt Holger , Vielmuth Franziska , Waschke Jens , Ondruschka Benjamin , Hammer Niels 
Published: May 2019

AbstractThough it is known that the water content of biological soft tissues alters mechanical properties, little attempt has been made to adjust the tissue water content prior to biomechanical testing as part of standardization procedures. The objective of this study was to examine the effects of altered water content on the macro and micro scale mechanical tissues properties. Human iliotibial band samples were obtained during autopsies to osmotically adapt their water content. Macro mechanical tensile testing of the samples was conducted with digital image correlation, and micro mechanical tests using atomic force microscopy. Analyses were conducted for elastic moduli, tensile strength, and strain at maximum force, and correlations for water content, anthropometric data, and post-mortem interval. Different mechanical properties exist at different water concentrations. Correlations to anthropometric data are more likely to be found at water concentrations close to the native state. These data underline the need for adapting the water content of soft tissues for macro and micro biomechanical experiments to optimize their validity. The osmotic stress protocol provides a feasible and reliable standardization approach to adjust for water content-related differences induced by age at death, post-mortem interval and tissue processing time with known impact on the stress-strain properties.
Diagenetic and shear-induced transitions of frictional strength of carbon-bearing faults and their implications for earthquake rupture dynamics in subduction zones
Authors: Kaneki Shunya , Hirono Tetsuro 
Published: May 2019

AbstractSubduction-related diagenetic reactions affect fault strength and are thus important for understanding earthquake rupture dynamics in subduction zones. Carbonaceous material (CM) is found worldwide in active plate-boundary and intracontinental faults, yet the effect of its transformation on frictional strength and rupture dynamics remains unknown. We conducted high-velocity friction experiments together with organochemical analyses on CM in the form of lignite, bituminous coal, anthracite and graphite. Results clearly show that an increase in CM maturity and crystallinity leads to a decrease in the peak friction coefficient (from 0.5 to 0.2). We also infer that friction applied to low-grade CM increases its maturity, but friction applied to high-grade CM reduces its maturity. These findings suggest that both diagenetic and shear-induced transformations of CM strongly affect the frictional strength of CM-bearing faults, potentially affecting the depth-dependences of frictional strength and rupture dynamics on plate-subduction faults.
Nanoscale reorganization of sarcoplasmic reticulum in pressure-overload cardiac hypertrophy visualized by dSTORM
Authors: Hadipour-Lakmehsari Sina , Driouchi Amine , Lee Shin-Haw , Kuzmanov Uros , Callaghan Neal I. , Heximer Scott P. , Simmons Craig A. , Yip Christopher M. , Gramolini Anthony O. 
Published: May 2019

AbstractPathological cardiac hypertrophy is a debilitating condition characterized by deleterious thickening of the myocardium, dysregulated Ca2+ signaling within cardiomyocytes, and contractile dysfunction. Importantly, the nanoscale organization, localization, and patterns of expression of critical Ca2+ handling regulators including dihydropyridine receptor (DHPR), ryanodine receptor 2 (RyR2), phospholamban (PLN), and sarco/endoplasmic reticulum Ca2+-ATPase 2A (SERCA2A) remain poorly understood, especially during pathological hypertrophy disease progression. In the current study, we induced cardiac pathological hypertrophy via transverse aortic constriction (TAC) on 8-week-old CD1 mice, followed by isolation of cardiac ventricular myocytes. dSTORM super-resolution imaging was then used to visualize proteins at nanoscale resolution at two time points and we quantified changes in protein cluster properties using Voronoi tessellation and 2D Fast Fourier Transform analyses. We showed a decrease in the density of DHPR and RyR2 clusters with pressure-overload cardiac hypertrophy and an increase in the density of SERCA2A protein clusters. PLN protein clusters decreased in density in 2-week TAC but returned to sham levels by 4-week TAC. Furthermore, 2D-FFT analysis revealed changes in molecular organization during pathological hypertrophy, with DHPR and RyR2 becoming dispersed while both SERCA2A and PLN sequestered into dense clusters. Our work reveals molecular adaptations that occur in critical SR proteins at a single molecule during pressure overload-induced cardiomyopathy. Nanoscale alterations in protein localization and patterns of expression of crucial SR proteins within the cardiomyocyte provided insights into the pathogenesis of cardiac hypertrophy, and specific evidence that cardiomyocytes undergo significant structural remodeling during the progression of pathological hypertrophy.