bluuebunny/crossref_metadata_2025_split huggingface dataset:
Live and inanimate predator-associated cues suppress the population of sap-feeding prey and induce polyphenism
Authors: Khudr Mouhammad Shadi , Dobberke Tabea , Buzhdygan Oksana Y. , Wurst Susanne 
Published: December 2019

AbstractNon-consumptive effect of predation is a well-researched subject of which certain non-consumptive and predator-mimetic facets are yet to be investigated in plant-parasite systemsOne clone of the green peach aphidMyzus persicae(Sulzer), raised on a model cropBrassica oleracea(L.), was exposed to different regimes of risks associated with ladybirdCoccinella septempunctata(L.). This encompassed consumption, consumption alternated by non-consumptive effects, isolated predators, dead predator, predator dummy, as well as dummy, plants or soil cued with predator-borne suspension, and predator removal (exposure to plants previously visited and marked by a predator).Over time, the respective risk regimes variably negatively impacted the prey population; the corpses, cued plants and dummies had considerable persistent negative effects on aphid reproductive success, contrary to the observation under predator removal. By the end of the experiment, polyphenism (winged morph production) also differed and was animated under the presence of a starved isolated predator; but faded when a predator corpse was present; and vanished under the dummy. Our findings, in this model aphid-crop system, contribute to the rapidly developing area of the ecology of fear, as we provide insights and novel means for aphid management that merit further examination across different eco-agricultural contexts.
UPϕ phages, a new group of filamentous phages found in several members ofEnterobacteriales
Authors: Shapiro Jason W. , Putonti Catherine 
Published: December 2019

AbstractFilamentous phages establish chronic infections in their bacterial hosts, and new phages are secreted by infected bacteria for multiple generations, typically without causing host death. Often, these viruses integrate in their host’s genome by co-opting the host’s XerCD recombinase system. In several cases, these viruses also encode genes that increase bacterial virulence in plants and animals. Here, we describe a new filamentous phage, UPϕ901, which we originally found integrated in a clinical isolate of uropathogenicEscherichia coli. UPϕ901 and closely related phages can be found in published genomes of over 200 other bacteria, including strains ofCitrobacter koseri,Salmonella enterica,Yersinia enterocolitica, andKlebsiella pneumoniae. Its closest relatives are consistently found in urine or in the blood and feces of patients with urinary tract infections. More distant relatives can be found in isolates from other environments, including sewage, water, soil, and contaminated food. Each of these phages, which we collectively call “UPϕ viruses,” also harbors two novel genes of unknown function.
Serotonergic Axons as Fractional Brownian Motion Paths: Insights into the Self-organization of Regional Densities
Authors: Janušonis Skirmantas , Detering Nils , Metzler Ralf , Vojta Thomas 
Published: December 2019

ABSTRACTAll vertebrate brains contain a dense matrix of thin fibers that release serotonin (5-hydroxytryptamine), a neurotransmitter that modulates a wide range of neural, glial, and vascular processes. Perturbations in the density of this matrix have been associated with a number of mental disorders, including autism and depression, but its self-organization and plasticity remain poorly understood. We introduce a model based on reflected Fractional Brownian Motion (FBM), a rigorously defined stochastic process, and show that it recapitulates some key features of regional serotonergic fiber densities. Specifically, we use supercomputing simulations to model fibers as FBM-paths in two-dimensional brain-like domains and demonstrate that the resultant steady state distributions approximate the fiber distributions in physical brain sections immunostained for the serotonin transporter (a marker for serotonergic axons in the adult brain). We suggest that this framework can support predictive descriptions and manipulations of the serotonergic matrix and that it can be further extended to incorporate the detailed physical properties of the fibers and their environment.
Touch-induced Mechanical Strain in Somatosensory Neurons is Independent of Extracellular Matrix Mutations inC. elegans
Authors: Nekimken Adam L. , Pruitt Beth L. , Goodman Miriam B. 
Published: December 2019

AbstractCutaneous mechanosensory neurons are activated by mechanical loads applied to the skin, and these stimuli are proposed to generate mechanical strain within sensory neurons. Using a microfluidic device to deliver controlled stimuli to intact animals and large, immobile, and fluorescent protein-tagged mitochondria as fiducial markers in the touch receptor neurons (TRNs), we visualized and measured touch-induced mechanical strain inC. elegansworms. At steady-state, touch stimuli sufficient to activate TRNs induce an average strain of 3.1% at the center of the actuator and this strain decays to near zero at the edges of the actuator. We also measured strain in animals carrying mutations affecting links between the extracellular matrix (ECM) and the TRNs but could not detect any differences in touch-induced mechanical strain between wild-type and mutant animals. Collectively, these results demonstrate that touching the skin induces local mechanical strain in intact animals and suggest that a fully intact ECM is not essential for transmitting mechanical strain from the skin to cutaneous mechanosensory neurons.
Evolution of olfactory receptors tuned to mustard oils in herbivorous Drosophilidae
Authors: Matsunaga Teruyuki , Reisenman Carolina E. , Goldman-Huertas Benjamin , Brand Philipp , Miao Kevin , Suzuki Hiromu C. , Verster Kirsten I. , Ramírez Santiago R. , Whiteman Noah K. 
Published: December 2019

ABSTRACTThe diversity of herbivorous insects is attributed to their propensity to specialize on toxic plants. In an evolutionary twist, toxins betray the identity of their bearers when herbivores co-opt them as cues for host-plant finding, but the mechanisms underlying this process are poorly understood. We focused onScaptomyza flava, an herbivorous drosophilid specialized on isothiocyanate (ITC)-producing (Brassicaceae) plants, and identifiedOr67bparalogs that were triplicated as mustard-specific herbivory evolved. Using heterologous systems for the expression of olfactory receptors, we found thatS. flavaOr67bs, but not homologs from microbe-feeding relatives, responded selectively to ITCs, each paralog detecting different ITC subsets. Consistent with this,S. flavawas attracted to ITCs, as wasDrosophila melanogasterexpressingS. flavaOr67b3 in the homologousOr67bolfactory circuit. Thus, our results show that plant toxins were likely co-opted as olfactory attractants through gene duplication and functional specialization (neofunctionalization and subfunctionalization) in drosophilid flies.
Activity and cytosolic Na+regulates synaptic vesicle endocytosis
Authors: Zhu Yun , Li Dainan , Huang Hai 
Published: December 2019

ABSTRACTRetrieval of synaptic vesicles via endocytosis is essential for maintaining sustained synaptic transmission, especially for neurons that fire action potentials at high frequencies. However, how activity regulates synaptic vesicles recycling is largely unknown. Here we report that Na+substantially accumulated in the mouse calyx of Held terminals during repetitive high-frequency spiking. Elevated presynaptic Na+accelerated both slow and rapid forms of endocytosis and facilitated endocytosis overshoot but did not affect the readily releasable pool size, Ca2+influx, or exocytosis. To examine whether this facilitation of endocytosis is related to the Na+-dependent vesicular content change, we dialyzed increasing concentrations of glutamate into the presynaptic cytosol or blocked the vesicular glutamate uptake with bafilomycin and found the rate of endocytosis was not affected by regulating the glutamate content in the presynaptic terminal. Endocytosis is critically dependent on intracellular Ca2+, and the activity of Na+/Ca2+exchanger (NCX) may be altered when the Na+gradient is changed. However, neither NCX blocker nor change of extracellular Na+concentration affected the endocytosis rate. Moreover, two-photon Ca2+imaging showed that presynaptic Na+did not affect the action potential-evoked intracellular Ca2+transient and decay. Therefore, we revealed a novel mechanism of cytosolic Na+in accelerating vesicle endocytosis. During high-frequency synaptic transmission, when large amounts of synaptic vesicles are fused, Na+accumulated in terminals, facilitated vesicle recycling and sustained reliable synaptic transmission.
Geometry-based navigation in the dark: Layout symmetry facilitates spatial learning in the house cricket,Acheta domesticus, in the absence of visual cues
Authors: Baran Bartosz , Krzyżowski Michał , Rádai Zoltán , Francikowski Jacek , Hohol Mateusz 
Published: December 2019

AbstractThe capacity to navigate by layout geometry has been widely recognized as a robust navigational strategy. It was reported in various species, albeit most studies were performed with vision-based paradigms. In the presented study, we aimed to investigate layout symmetry-based navigation in the house cricket,Acheta domesticus, in the absence of visual cues. For this purpose, we used a non-visual paradigm modeled on the Tennessee Williams setup. We also verified the inaccessibility of visual cues for tested insects using antennal positioning reflex towards looming stimulus and by testing the performance of blinded crickets. In the main experiment, we tested the crickets’ capacity to learn to find a cool spot positioned centrally in heated arenas of different shapes (i.e., circular, square, triangular, and asymmetric quadrilateral). We found that the symmetry of the arena significantly facilitates crickets’ learning to find the cool spot, indicated by the increase of time spent on the cool spot and decrease of the latency of locating it in subsequent trials. To investigate possible mechanisms utilized by crickets during the experiment, we analyzed insects’ approach paths to the spot. The trajectories were grouped in four distinct clusters corresponding to both heuristic and directed strategies of approaching the target, with the dominance of a semi-directed strategy (thigmotactic phase preceding direct navigation to the target). Against these results, we discuss the possibility of insects’ navigation by using a non-visual space representation and possible limitations of navigation capacities in such conditions in relation to multimodally-guided navigation.
Deep, soft, and dark sounds induce autonomous sensory meridian response
Authors: Koumura Takuya , Nakatani Masashi , Liao Hsin-I , Kondo Hirohito M. 
Published: December 2019

AbstractThere has been a growing interest in the autonomous sensory meridian response (ASMR). The ASMR is characterized by a tingling sensation around the scalp and neck and often induces a feeling of relaxation and a reduction of a negative mood. However, it is still unknown what factors affect the ASMR. The present study focused on stimulus characteristics and individuals’ mood states and personality traits. Participants filled out self-reported questionnaires (the Profile of Mood States, Beck Depression Inventory, and Big Five Inventory) and reported ASMR estimates throughout a 17-min experiment while listening to binaural tapping and brushing sounds. Cross-correlation results showed that the ASMR estimates were strongly associated with the acoustic features of auditory stimuli, such as their amplitude, spectral centroid, and spectral bandwidth. This indicates that low-pitched sounds with dark timbre trigger the ASMR. The maximum ASMR was observed around 2 s after the acoustic features changed, suggesting that the sluggishness of multisensory integration may lead to the ASMR experience. In addition, individual differences in the ASMR experience were closely linked to participants’ mood states, such as anxiety, but not to their personality traits. Our results provide important clues to understand the mechanisms of auditory-somatosensory interactions.Significant StatementsThe autonomous sensory meridian response (ASMR) is characterized by a tingling, electrostatic-like sensation across the scalp and back of the neck. This phenomenon can be triggered by a variety of audiovisual stimuli, and many people seek out the ASMR via the internet to receive a feeling of relaxation and reduce a negative mood. We show that the ASMR is induced about 2 s after acoustic features, such as the amplitude, spectral centroid, and spectral bandwidth are changed. This suggests that low-pitched sounds with dark timbre lead to the ASMR experience. The stimulus-driven ASMR effect is found regardless of the personality traits or mood states of participants. Our findings provide a critical clue to understand the mechanisms of auditory–somatosensory interactions.
z-STED imaging and spectroscopy to investigate nanoscale membrane structure and dynamics
Authors: Barbotin Aurélien , Urbančič Iztok , Galiani Silvia , Eggeling Christian , Booth Martin , Sezgin Erdinc 
Published: December 2019

AbstractSuper-resolution STED microcopy provides optical resolution beyond the diffraction limit. The resolution can be increased laterally (xy/2D) or axially (z/3D). 2D STED has been extensively used to elucidate the nanoscale membrane structure and dynamics, via imaging or combined with spectroscopy techniques such as fluorescence correlation spectroscopy (FCS) and spectral imaging. On the contrary, z-STED has not been used in this context. Here, we show that a combination of z-STED with FCS or spectral imaging enables us to see previously unobservable aspects of cellular membranes. We show that thanks to an axial resolution of approximately 100 nm, z-STED can be used to distinguish axially close-by membranes, early endocytic vesicles or tubular membrane structures. Combination of z-STED with FCS and spectral imaging showed diffusion dynamics and lipid organization in these structures, respectively.
Bayesian inference of the gene expression states of single cells from scRNA-seq data
Authors: Breda Jérémie , Zavolan Mihaela , van Nimwegen Erik 
Published: December 2019

AbstractIn spite of a large investment in the development of methodologies for analysis of single-cell RNA-seq data, there is still little agreement on how to best normalize such data, i.e. how to quantify gene expression states of single cells from such data. Starting from a few basic requirements such as that inferred expression states should correct for both intrinsic biological fluctuations and measurement noise, and that changes in expression state should be measured in terms of fold-changes rather than changes in absolute levels, we here derive a unique Bayesian procedure for normalizing single-cell RNA-seq data from first principles. Our implementation of this normalization procedure, called Sanity (SAmpling Noise corrected Inference of Transcription activitY), estimates log expression values and associated errors bars directly from raw UMI counts without any tunable parameters.Comparison of Sanity with other recent normalization methods on a selection of scRNA-seq datasets shows that Sanity outperforms other methods on basic downstream processing tasks such as clustering cells into subtypes and identification of differentially expressed genes. More importantly, we show that all other normalization methods present severely distorted pictures of the data. By failing to account for biological and technical Poisson noise, many methods systematically predict the lowest expressed genes to be most variable in expression, whereas in reality these genes provide least evidence of true biological variability. In addition, by confounding noise removal with lower-dimensional representation of the data, many methods introduce strong spurious correlations of expression levels with the total UMI count of each cell as well as spurious co-expression of genes.
Characterization of human iPSC-derived astrocytes with potential for disease modeling and drug discovery
Authors: Soubannier Vincent , Maussion Gilles , Chaineau Mathilde , Sigutova Veronika , Rouleau Guy , Durcan Thomas , Stifani Stefano 
Published: December 2019

ABSTRACTAstrocytes play a number of key functions in health and disease. Reactivation of astrocytes occurs in most, if not all, neurological diseases. Most current information on the mechanisms underlying astrogliosis derives from studies using rodent experimental systems, mainly because the ability to study human astrocytes under healthy and pathological conditions has been hampered by the difficulty in obtaining primary human astrocytes. Here we describe robust and reliable derivation of astrocytes from human induced pluripotent stem cells (iPSCs). Phenotypically characterized human iPSC-derived astrocytes exhibit typical traits of physiological astrocytes, including spontaneous and induced calcium transients. Moreover, human iPSC-derived astrocytes respond to stimulation with a pro-inflammatory combination of tumor necrosis factor alpha, interleukin 1-alpha, and complement component C1q by undergoing changes in gene expression patterns suggesting acquisition of a reactive astrocyte phenotype. Together, these findings provide evidence suggesting that human iPSC-derived astrocytes are a suitable experimental model system to study astrocyte function and reactivation in healthy and pathological conditions of the human nervous system.
Membrane insertion of chromogranin B for granule maturation in regulated secretion
Authors: Yadav Gaya P. , Wang Haiyuan , Ouwendijk Joke , Annamalai Mani , Cross Stephen , Wang Qiaochu , Hagan D. Walker , Mathews Clayton , Phelps Edward A. , Verkade Paul , Zhu Michael X. , Jiang Qiu-Xing 
Published: December 2019

ABSTRACTRegulated secretion serves responses to specific stimuli in eukaryotes. An anion conductance was found essential for maturation and acidification of secretory granules four decades ago, but its genetic identity was unknown. We now demonstrate that chromogranin B (CHGB), an obligate granule protein, constitutes the long-sought anion channel. High-pressure freezing immuno-electron microscopy and biochemical assays showed native CHGB in close proximity to secretory granule membranes, and its membrane-bound and soluble forms both reconstituted Cl-channels. Release of secretory granules delivered CHGB clusters to plasma membranes, which dominate whole-cell anion conductance. Intragranular pH measurements and cargo maturation assays found that CHGB channels supported proinsulin - insulin conversion and dopamine-loading in neuroendocrine cells. β-cells fromChgb-/-mice exhibited significant granule deacidification, accounting for hyperproinsulinemia, altered glucose-tolerance response and lower dopamine concentration in chromaffin granules in these animals. Membrane insertion of well-conserved CHGB is thus indispensable for granule maturation in exocrine, endocrine and neuronal cells.HighlightsNative CHGB is amphipathic and distributes in the lumen and membranes of secretory granules with contrastingly different destinies and functions.Native CHGB, once delivered to cell surface via granule exocytosis, dominates anion conductance in plasma membranes.CHGB channels facilitate granule acidification and cargo maturation in cultured and primary neuroendocrine cells.CHGB channels from bovine, rat and mouse cells all serve the long-missing, intra-organellar anion shunt pathway in the secretory granules for regulated secretion.
Lithium attenuates d‐amphetamine‐induced hyperlocomotor activity in mice via inhibition of interaction between cyclooxygenase‐2 and indoleamine‐2,3‐dioxygenase
Authors: Phan Dieu‐Hien , Shin Eun‐Joo , Jeong Ji Hoon , Tran Hai‐Quyen , Sharma Naveen , Nguyen Bao Trong , Jung Tae Woo , Nah Seung‐Yeol , Saito Kuniaki , Nabeshima Toshitaka , Kim Hyoung‐Chun 
Published: December 2019

AbstractIn the present study, we investigated whether mood stabilizer lithium (Li) protects against d‐amphetamine (AMP)‐induced mania‐like behaviours via modulating the novel proinflammatory potential. Repeated treatment with AMP resulted in significant increases in proinflammatory cyclooxygenase‐2 (COX‐2) and indolemaine‐2,3‐dioxygenase‐1 (IDO)‐1 expression in the prefrontal cortex (PFC) of mice. However, AMP treatment did not significantly change IDO‐2 and 5‐lipoxygenase (5‐LOX) expression, suggesting that proinflammatory parameters such as COX‐2 and IDO‐1 are specific for AMP‐induced behaviours. AMP‐induced initial expression of COX‐2 (15 minutes post‐AMP) was earlier than that of IDO‐1 (1 hour post‐AMP). Mood stabilizer Li and COX‐2 inhibitor meloxicam significantly attenuated COX‐2 expression 15 minutes post‐AMP, whereas IDO‐1 inhibitor 1‐methyl‐DL‐tryptophan (1‐MT) did not affect COX‐2 expression. However, AMP‐induced IDO‐1 expression was significantly attenuated by Li, meloxicam or 1‐MT, suggesting that COX‐2 is an upstream molecule for the induction of IDO‐1 caused by AMP. Consistently, co‐immunoprecipitation between COX‐2 and IDO‐1 was observed at 30 minutes, 1, 3, and 6 hours after the final AMP treatment. This interaction was also significantly inhibited by Li, meloxicam or 1‐MT. Furthermore, AMP‐induced hyperlocomotion was significantly attenuated by Li, meloxicam or 1‐MT. We report, for the first time, that mood stabilizer Li attenuates AMP‐induced mania‐like behaviour via attenuation of interaction between COX‐2 and IDO‐1, and that the interaction of COX‐2 and IDO‐1 may be critical for the therapeutic intervention mediated by mood stabilizer.
Risk of preterm birth after prior term cesarean
Authors: Visser L , Slaager C , Kazemier BM , Rietveld AL , Oudijk MA , de Groot CJM , Mol BW , de Boer MA 
Published: December 2019

ObjectiveTo determine the risk of overall preterm birth (PTB) and spontaneous PTB in a pregnancy after a caesarean section (CS) at term.DesignLongitudinal linked national cohort study.SettingThe Dutch Perinatal Registry (1999–2009).Population268 495 women with two subsequent singleton pregnancies were identified.MethodsA cohort study based on linked registered data from two subsequent pregnancies in the Netherlands.Main outcome measuresThe incidence of overall PTB and spontaneous PTB with subgroup analysis on gestational age at first delivery and type of CS (planned or unplanned).ResultsOf 268 495 women with a singleton first pregnancy who delivered at term, 15.76% (n = 42 328) had a CS. The incidence of PTB in the second pregnancy was 2.79% (n = 1182) in women with a previous CS versus 2.46% (n = 5570) in women with a previous vaginal delivery (adjusted odds ratio [aOR] 1.14, 95% confidence interval [CI] 1.07–1.21). This increased risk is mainly driven by an increased risk of spontaneous PTB after previous CS at term (aOR 1.50, 95% CI 1.38–1.70). Analysis for type of CS compared with vaginal delivery showed an aOR on spontaneous PTB of 1.86 (95% CI 1.58–2.18) for planned CS and an aOR of 1.40 (95% CI 1.24–1.58) for unplanned CS.ConclusionsCS at term is associated with a marginally increased risk of spontaneous PTB in a subsequent pregnancy.Tweetable abstractCaesarean section at term is associated with a marginally increased risk of spontaneous PTB in a subsequent pregnancy.
Insider Trading, Informativeness, and Price Efficiency Around the World
Authors: Kim Donghyun , Ng Lilian , Wang Qinghai , Wang Xiaoqiong 
Published: December 2019

AbstractThis paper provides the first direct evidence of the impact of enforcing insider regulations on the informativeness of insider trades and stock price efficiency across 44 countries with varying levels of insider trading regulations. Results suggest that insider purchases earn abnormal profits, especially in countries with active enforcement of insider trading regulations. We further show that while insiders trade less before earnings announcements in countries with active enforcement, their stock prices react more to earnings news than those in countries without active enforcement. Overall, our results support the view that effective insider trading regulation promotes price efficiency.