bluuebunny/crossref_metadata_2025_split huggingface dataset:
The contribution of fire to the late Miocene spread of grasslands in eastern Eurasia (Black Sea region)
Authors: Feurdean Angelica , Vasiliev Iuliana 
Published: May 2019

AbstractGrasslands are globally extensive, but the processes governing their ecology and evolution remain unclear. The role of fire for the expansion of ancestral C3grasslands is particularly poorly understood. Here we present the first biomass combustion record based on late Miocene to Pleistocene (~10–1.9 Ma) charcoal morphologies (grass, herbs, wood) from the Black Sea, and test the extent of fire events and their role in the rise of open grassy habitats in eastern Eurasia. We show that a mixed regime of surface and crown fires under progressively colder and, at times, drier climates from the late Miocene to Pliocene (8.5–4.6 Ma) accelerated the forest to open woodland transition and sustained a more flammable ecosystem. A tipping point in the fire regime occurred at 4.3 Ma (mid-Pliocene), when increasingly cold and dry conditions led to the dominance of grasslands, and surface, litter fires of low intensity. We provide alternative mechanisms of C3plant evolution by highlighting that fire has been a significant ecological agent for Eurasian grasslands. This study opens a new direction of research into grassland evolutionary histories that can be tested with fossil records of fire alongside climate and vegetation as well as with dynamic vegetation modells.
Epirubicin-loaded marine carrageenan oligosaccharide capped gold nanoparticle system for pH-triggered anticancer drug release
Authors: Chen Xiangyan , Han Wenwei , Zhao Xia , Tang Wei , Wang Fahe 
Published: May 2019

AbstractGold nanoparticles (AuNPs) and the pH stimuli-responsive drug delivery system have been extensively applied in cancer treatment. Carrageenan derived from marine red algae shows a promising application prospect for drug delivery as a nanomaterial for its biodegradability, abundance, and non-toxicity. Carrageenan oligosaccharide (CAO) was used as a biocompatible reductant for green synthesis of CAO-AuNPs, and the obtained CAO-AuNPs were further used as a delivery system for pH-triggered delivery of epirubicin (EPI). The EPI-CAO-AuNPs were demonstrated to be spherical and homogeneous with mean diameter of 141 ± 6 nm by means of electron microscopy and Malvern particle size analyzer. Results showed that the release of EPI from EPI-CAO-AuNPs was significant under acidic condition that simulated cancer environment, while it was negligible under physiological pH in vitro. Confocal laser scanning microscope and flow cytometry analysis showed that EPI-CAO-AuNPs were localized in cellular nucleus and induced more apoptosis of HCT-116 and HepG2 cells than free EPI. A new pH-triggered anticancer drug release was achieved by EPI-CAO-AuNPs system for the first time. The developed EPI-CAO-AuNPs nanosystem shows a promising prospect for pH-triggered delivery of antitumor drugs, and our work provides a new idea for targeted drug delivery by using biocompatible marine carbohydrates as nanomaterial.
Hybridization speeds adaptive evolution in an eight-year field experiment
Authors: Mitchell Nora , Owens Gregory L. , Hovick Stephen M. , Rieseberg Loren H. , Whitney Kenneth D. 
Published: May 2019

AbstractHybridization is a common phenomenon, yet its evolutionary outcomes remain debated. Here, we ask whether hybridization can speed adaptive evolution using resynthesized hybrids between two species of Texas sunflowers (Helianthus annuusandH. debilis) that form a natural hybrid in the wild (H. annuusssp.texanus). We established separate control and hybrid populations and allowed them to evolve naturally in a field evolutionary experiment. In a final common-garden, we measured fitness and a suite of key traits for these lineages. We show that hybrid fitness evolved in just seven generations, with fitness of the hybrid lines exceeding that of the controls by 14% and 51% by the end of the experiment, though only the latter represents a significant increase. More traits evolved significantly in hybrids relative to controls, and hybrid evolution was faster for most traits. Some traits in both hybrid and control lineages evolved in an adaptive manner consistent with the direction of phenotypic selection. These findings show a causal pathway from hybridization to rapid adaptation and suggest an explanation for the frequently noted association between hybridization and adaptive radiation, range expansion, and invasion.
A spatial stream-network approach assists in managing the remnant genetic diversity of riparian forests
Authors: Rodríguez-González Patricia María , García Cristina , Albuquerque António , Monteiro-Henriques Tiago , Faria Carla , Guimarães Joana B. , Mendonça Diogo , Simões Fernanda , Ferreira Maria Teresa , Mendes Ana , Matos José , Almeida Maria Helena 
Published: May 2019

AbstractQuantifying the genetic diversity of riparian trees is essential to understand their chances to survive hydroclimatic alterations and to maintain their role as foundation species modulating fluvial ecosystem processes. However, the application of suitable models that account for the specific dendritic structure of hydrographic networks is still incipient in the literature. We investigate the roles of ecological and spatial factors in driving the genetic diversity ofSalix salviifolia, an Iberian endemic riparian tree, across the species latitudinal range. We applied spatial stream-network models that aptly integrate dendritic features (topology, directionality) to quantify the impacts of multiple scale factors in determining genetic diversity. Based on thedrift hypothesis, we expect that genetic diversity accumulates downstream in riparian ecosystems, but life history traits (e.g. dispersal patterns) and abiotic or anthropogenic factors (e.g. drought events or hydrological alteration) might alter expected patterns. Hydrological factors explained the downstream accumulation of genetic diversity at the intermediate scale that was likely mediated by hydrochory. The models also suggested upstream gene flow within basins that likely occurred through anemophilous and entomophilous pollen and seed dispersal. Higher thermicity and summer drought were related to higher population inbreeding and individual homozygosity, respectively, suggesting that increased aridity might disrupt the connectivity and mating patterns among and within riparian populations.
Impact of surface-area-to-volume ratio, internal viscosity and membrane viscoelasticity on red blood cell deformability measured in isotonic condition
Authors: Renoux Céline , Faivre Magalie , Bessaa Amel , Da Costa Lydie , Joly Philippe , Gauthier Alexandra , Connes Philippe 
Published: May 2019

AbstractOsmotic gradient ektacytometry is the gold standard to assess red blood cell (RBC) deformability. It has been proposed that, when measured in isotonic condition, RBC deformability at low shear stress would depend on membrane elasticity while it would be influenced by internal viscosity when measured at high shear stress, but this hypothesis needs to be further addressed. Healthy RBCs were rigidified by treatment with lysolecithine (LPC), diamide or nystatine associated with hyperosmolar solutions (OSMO), which reduces membrane surface area, decreases membrane elasticity or promotes cell dehydration, respectively. Diamide treatment resulted in a decrease in isotonic RBC deformability at all shear stresses tested (i.e. from 0.3 to 30 Pa). LPC and OSMO treatments caused a decrease in isotonic RBC deformability above 3 Pa only. Isotonic RBC deformability from patients with hereditary spherocytosis or sickle cell disease was mainly decreased above 1.69 Pa. Our findings indicate that decreased isotonic RBC deformability at shear stresses above 3 Pa would be related to a reduction in the surface-area-to-volume ratio and/or to a loss of membrane elasticity and/or to an increase in internal viscosity while a decrease of RBC deformability below 3 Pa would reflect a loss of membrane elasticity.
Origin of gall-inducing from leaf-mining in Caloptilia micromoths (Lepidoptera, Gracillariidae)
Authors: Guiguet Antoine , Ohshima Issei , Takeda Seiji , Laurans Françoise , Lopez-Vaamonde Carlos , Giron David 
Published: May 2019

AbstractIn insects, the gall-inducing life-style has evolved independently many times. Several evolutionary pathways leading to this lifestyle have been proposed. While there is compelling evidence supporting surface-feeders and stem-borers as ancestral states of insect gall-inducers, an evolutionary pathway from leaf-miners remains hypothetical. Here we explored this question by comparing the developmental processes of two micromoths, a gall-inducer Caloptilia cecidophora (Lep., Gracillariidae), and its non-gall-inducing relative C. ryukyuensis. Like other Caloptilia, the first and second instars of C. cecidophora are leaf-miners and the gall is initiated inside the leaf mine by the third instar, thus suggesting leaf-mining as an ancestral, plesiomorphic state in this case. This is the first example of an insect species switching from leaf-mining to gall-inducing during larval development. The first two leaf-mining instars of C. cecidophora exhibit an absence of growth and a reduced time duration compared to C. ryukyuensis. The shortening of the duration of leaf-mining stages is apparently compensated in C. cecidophora by a larger egg size than C. ryukyuensis, and an additional larval instar during the gall phase.
Molecular and environmental analysis of Campania (Italy) sweet cherry (Prunus avium L.) cultivars for biocultural refugia identification and conservation
Authors: Muccillo Livio , Colantuoni Vittorio , Sciarrillo Rosaria , Baiamonte Giuseppe , Salerno Giovanni , Marziano Mario , Sabatino Lina , Guarino Carmine 
Published: May 2019

AbstractConservation of agrobiodiversity is a major concern worldwide. Several strategies have been designed and programmed to reduce biodiversity erosion due to anthropic and non-anthropic causes. To this end, we set up a multidisciplinary approach based on the genetic analysis of selected cultivars and recognition of the environmental parameters. We genotyped the sweet cherry cultivars of Campania region in southern Italy by using simple sequence repeats and further investigated them by cluster analysis, disclosing a homogeneous genetic constitution, different from that of commercial accessions. By structure analysis we identified three distinct genetic clusters, each characterized by common and distinct alleles. Survey of the cultivars’ geographical distribution by quartic kernel function identified four preferred districts further characterized for soil origin, pedologic, agronomic features and urbanization impact. We correlated these environmental parameters, typical of the identified areas, with the three genetic pools and found a statistically significant association for each cluster. When we overlaid the cultivation traditions and cultural heritage, we found they have a dominant role; on these premises, we generated new territorial maps. In conclusion, we propose a novel methodological approach based on molecular, geo-pedological and cultural parameters with the aim to recognize biocultural refugia and preserve endangered or valuable cultivars.
miR-150-5p represses TP53 tumor suppressor gene to promote proliferation of colon adenocarcinoma
Authors: Liu Fang , Di Wang Xiao 
Published: May 2019

AbstractMicroRNAs (miRNAs) play a critical role in regulation of numerous biological processes and pathogenesis of a variety of diseases. In addition, miRNAs contribute to carcinogenesis by acting as oncogenic or tumor suppressive. Circulating miRNAs including miR-150-5p are associated with colorectal cancer progression, and the putative targets of miR-150-5p include tumor suppressor gene, TP53. Here we sought to investigate the role of miR-150-5p-TP53 signaling pathway in proliferation of colon cancer and to determine expression levels of miR-miR-150-5p and TP53 in colon adenocarcinoma and adjacent non-cancerous tissue samples, or in human colon adenocarcinoma cell lines. MTT assay was used to determine proliferation and apoptosis in cell lines. Furthermore, we used Western blot to determine levels of cell cycle regulators with anti-miR-150-5p or apoptosis with overexpression of TP53. Our results show that expression levels of miR-150-5p were significantly elevated in clinical specimens from cancer patients. We further showed that inhibition of miR-150-5p increased TP53, and in turn, suppression of proliferation of colon adenocarcinoma. Moreover, inhibition of miR-150-5p or overexpression of TP53 caused cell arrest or apoptosis in colon adenocarcinoma. Our results support that miR-150-5p-TP53 pathway plays an important role in regulation of proliferation, cell arrest, and apoptosis in colon cancer, and could be an attractive target for therapy.
G protein-coupled estrogen receptor mediates anti-inflammatory action in Crohn’s disease
Authors: Jacenik Damian , Zielińska Marta , Mokrowiecka Anna , Michlewska Sylwia , Małecka-Panas Ewa , Kordek Radzisław , Fichna Jakub , Krajewska Wanda M. 
Published: May 2019

AbstractEstrogens exert immunomodulatory action in many autoimmune diseases. Accumulating evidence highlights the meaningful impact of estrogen receptors in physiology and pathophysiology of the colon. However, the significance of G protein-coupled estrogen receptor (GPER) on Crohn’s disease (CD), one of the inflammatory bowel disease (IBD) types, is still elusive. Our study revealed GPER overexpression at the mRNA and protein levels in patients with CD. To evaluate the effects of GPER activation/inhibition on colitis development, a murine 2, 4, 6-trinitrobenzene sulfonic acid (TNBS)-induced model of CD was used. We showed that activation of GPER reduces mortality, improves macroscopic and microscopic scores and lowers C-reactive protein (CRP) level. The impact of estrogen signaling on the suppression of the intestinal inflammation was proved by immunohistochemistry. It was demonstrated that GPER activation is accompanied by modulation of extracellular-signal regulated kinase (ERK) signaling pathway and expression level of genes involved in signal transmission and immune response as well as the expression of some microRNAs (miR-145, miR-148-5p and miR-592). Our study revealed that the membrane-bound estrogen receptor GPER mediates anti-inflammatory action and seems to be a potent therapeutic target in maintaining remission in CD.
Improvement of cognitive control and stabilization of affect by prefrontal transcranial direct current stimulation (tDCS)
Authors: Wiegand Ariane , Sommer Anja , Nieratschker Vanessa , Plewnia Christian 
Published: May 2019

AbstractCognitive control of information processing is an essential prerequisite of human behavior. Particularly, focusing attention in the face of failure poses a common challenge. Previous work has demonstrated that transcranial direct current stimulation (tDCS) of the dorsolateral prefrontal cortex (dlPFC) can improve cognitive control in a challenging and repeatedly frustrating task. In a randomized, sham-controlled, crossover design 22 healthy, male participants performed an adaptive 2-back version of the Paced Auditory Serial Addition Task (PASAT), parallel to anodal or sham tDCS over the left dlPFC and the return electrode on the right upper arm. Before and after the 2-back PASAT, the affective state was assessed by means of the Positive and Negative Affective Schedule (PANAS). We observed an interaction between stimulation condition and task performance driven by an increase in performance with anodal tDCS and no improvement with sham stimulation. In addition, after the 2-back PASAT we found a higher positive and a trend towards lower negative affect with anodal as compared to sham tDCS. Our data support and extend previous results showing improved processing speed under anodal stimulation associated with a reduced task-induced negative affect indicating an improvement of cognitive control. Further studies will investigate long-term effects and clinical applicability.
Characterization of XPR1/SLC53A1 variants located outside of the SPX domain in patients with primary familial brain calcification
Authors: López-Sánchez Uriel , Nicolas Gaël , Richard Anne-Claire , Maltête David , Charif Mahmoud , Ayrignac Xavier , Goizet Cyril , Touhami Jawida , Labesse Gilles , Battini Jean-Luc , Sitbon Marc 
Published: May 2019

AbstractPrimary familial brain calcification (PFBC) is a rare neurological disease characterized by deposits of calcium phosphate in the basal ganglia and other regions of the brain. Pathogenic variants in the XPR1/SLC53A1 gene, which encodes the only known inorganic phosphate exporter, cause an autosomal dominant form of PFBC. These variants are typically located in the SPX N-terminal domain of the protein. Here, we characterize three XPR1 variants outside of SPX in three PFBC patients with an apparently sporadic presentation: c.1375C > T p.(R459C), c.1855A > G p.(N619D) and c.1886T > G p.(I629S), with the latter identified as the first XPR1/SLC53A1 de novo mutation to occur in a PFBC proband. When tested in an in vitro physiological complementation assay, the three XPR1 variants were impaired in phosphate export function, although they were normally expressed at the cell surface and could serve as functional receptors for retrovirus entry. Moreover, peripheral blood cells from the p.N619D patient could be assayed ex vivo and displayed significantly impaired phosphate export. Our results establish for the first time the clinical and molecular characteristics of XPR1 variants located outside the SPX domain and assert a direct link between these variants, deficient phosphate export, and PFBC. Moreover, we unveiled new structural features in XPR1 C-terminal domain that play a role in phosphate export and disease.
Computer-generated holograms for complex surface reliefs on azopolymer films
Authors: Oscurato Stefano Luigi , Salvatore Marcella , Borbone Fabio , Maddalena Pasqualino , Ambrosio Antonio 
Published: May 2019

AbstractThe light-driven superficial structuration observed on the surface of films of azobenzene-containing polymers follows the optical field distribution of the illuminating light pattern, i.e. the light polarization state and the intensity distribution. The ability to precisely manipulate the illuminating intensity pattern can hence provide a new level in the range of complex light-induced superficial textures accessible onto azopolymer film surfaces. In this respect, digital holography, based on the principles of the Computer-Generated Holograms (CGHs), and actually implemented by means of a versatile liquid crystal spatial light modulator, can represent a unique experimental tool in the field of the light-induced mass migration in azo-materials. In the present work, we demonstrate the possibility to precisely control the features and the quality of complex light patterns generated through CGHs in order to induce arbitrarily complex surface reliefs onto the surface of an azopolymer. The results shown here can potentially broaden the range of possible applications of photo-responsive azopolymer films in the fields of surface engineering, biology and photonics.
Electrical transportation mechanisms of molybdenum disulfide flakes-graphene quantum dots heterostructure embedded in polyvinylidene fluoride polymer
Authors: Ooi Poh Choon , Mohammad Haniff Muhammad Aniq Shazni , Mohd Razip Wee M. F. , Goh Boon Tong , Dee Chang Fu , Mohamed Mohd Ambri , Majlis Burhanuddin Yeop 
Published: May 2019

AbstractIn the interest of the trend towards miniaturization of electronic gadgets, this study demonstrates a high-density data storage device with a very simple three-stacking layer consisting of only one charge trapping layer. A simple solution-processed technique has been used to fabricate the tristable non-volatile memory. The three-stacking layer was constructed in between two metals to form a two-terminal metal-insulator-metal structure. The fabricated device showed a large multilevel memory hysteresis window with a measured ON/OFF current ratio of 107 that might be attributed to the high charge trapped in molybdenum disulphide (MoS2) flakes-graphene quantum dots (GQDs) heterostructure. Transmission electron microscopy was performed to examine the orientation of MoS2-GQD and mixture dispersion preparation method. The obtained electrical data was used further to speculate the possible transport mechanisms through the fabricated device by a curve fitting technique. Also, endurance cycle and retention tests were performed at room temperature to investigate the stability of the device.
Inverse cascade of the vortical structures near the contact line of evaporating sessile droplets
Authors: Ghasemi Abbas , Ahmet Tuna Burak , Li Xianguo 
Published: May 2019

AbstractMicroscopic imaging as well as the particle image velocimetry (PIV) are carried out to evaluate the concentration, velocity and vorticity fields near the contact line of the nano-particles-laden evaporating sessile droplets. After the onset of the linear thermocapillary instabilities due to the Marangoni perturbations, the non-linear state sets in and the micro-scale jet-like vortex structures are ejected from the contact line towards the center of the droplet. Afterwards, the jet-like vortical structures expand in the spanwise directions and start to interact with the neighbouring structures. Two types of the inverse cascade mechanisms are found to occur. In the first kind, the vortices of the similar length scale merge and continuously produce larger vortices and corresponding wavelength growth. The second inverse cascade mechanism takes place due to the entrainment of the smaller vortices into the larger structures. Both inverse cascade processes are identified as the continuous feeding of the kinetic energy from the smaller scales to the larger scales. For individual micro-jets the velocity field characterizes the jet-like vortex structures ejected from the contact line towards the droplet center opposing the bulk flow from the center towards the contact line. In addition, the vorticity field overlaid by the velocity streamlines identify the sense of rotation of the low pressure zones on either side of the micro-jet as well as the high pressure stagnation point at the tip.
Prognostic role of ARID1A negative expression in gastric cancer
Authors: Ashizawa Mai , Saito Motonobu , Min Aung Kyi Thar , Ujiie Daisuke , Saito Katsuharu , Sato Takahiro , Kikuchi Tomohiro , Okayama Hirokazu , Fujita Shotaro , Endo Hisahito , Sakamoto Wataru , Momma Tomoyuki , Ohki Shinji , Goto Akiteru , Kono Koji 
Published: May 2019

AbstractAT-rich interactive domain 1A (ARID1A) functions as a tumor suppressor and several therapeutic targets in ARID1A-mutated cancers are under development. Here, we investigated the prognostic value of ARID1A for gastric cancer and its association with expression of PD-L1 and p53. ARID1A expression was examined by immunohistochemistry and negative expression of ARID1A was detected in 39 (19.5%) of 200 cases in a test cohort and in 40 (18.2%) of 220 cases in a validation cohort. Negative expression of ARID1A was associated with worse overall survival in undifferentiated cases, particularly early-stage cases. Negative expression of ARID1A was detected in 11 (50%) of 22 PD-L1-positive cases and in 68 (17.1%) of 398 PD-L1-negative cases in a combined cohort. Negative expression of ARID1A was detected in 45 (22%) of 205 p53-positive cases and in 34 (15.8%) of 215 p53-negative cases in a combined cohort. In addition, expression of EZH2, a potential synthetic lethal target in ARID1A-mutated tumors, was detected in 79 ARID1A-negative cases. An ARID1A-knockdown gastric cancer cell line was subjected to microarray analysis, but no actionable targets or pathways were identified. The present results indicate that ARID1A may serve as an early-stage prognostic biomarker for undifferentiated gastric cancer.