bluuebunny/crossref_metadata_2025_split huggingface dataset:
Octopaminergic neurons have multiple targets inDrosophilalarval mushroom body calyx and regulate behavioral odor discrimination
Authors: Hilary Wong J Y , Wan Bo Angela , Bland Tom , Montagnese Marcella , McLachlan Alex , O’Kane Cahir J , Zhang Shuo Wei , Masuda-Nakagawa Liria M 
Published: April 2018

AbstractDiscrimination of sensory signals is essential for an organism to form and retrieve memories of relevance in a given behavioural context. Sensory representations are modified dynamically by changes in behavioral state, facilitating context-dependent selection of behavior, through signals carried by noradrenergic input in mammals, or octopamine (OA) in insects. To understand the circuit mechanisms of this signaling, we characterized the function of two OA neurons, sVUM1 neurons, that originate in the subesophageal zone (SEZ) and target the input region of the memory center, the mushroom body (MB) calyx, in larvalDrosophila. We find that sVUM1 neurons target multiple neurons, including olfactory projection neurons (PNs), the inhibitory neuron APL, and a pair of extrinsic output neurons, but relatively few mushroom body intrinsic neurons, Kenyon cells. PN terminals carried the OA receptor Oamb, aDrosophilaα1-adrenergic receptor ortholog. Using an odor discrimination learning paradigm, we showed that optogenetic activation of OA neurons compromised discrimination of similar odors but not learning ability. Our results suggest that sVUM1 neurons modify odor representations via multiple extrinsic inputs at the sensory input area to the MB olfactory learning circuit.
Unique mapping of structural and functional connectivity on cognition
Authors: Zimmermann J. , Griffiths J.G. , McIntosh A.R. 
Published: April 2018

AbstractThe unique mapping of structural and functional brain connectivity (SC, FC) on cognition is currently not well understood. It is not clear whether cognition is mapped via a global connectome pattern or instead is underpinned by several sets of distributed connectivity patterns. Moreover, we also do not know whether the pattern of SC and of FC that underlie cognition are overlapping or distinct. Here, we study the relationship between SC and FC and an array of psychological tasks in 609 subjects from the Human Connectome Project (HCP). We identified several sets of connections that each uniquely map onto different aspects of cognitive function. We found a small number of distributed SC and a larger set of cortico-cortical and cortico-subcortical FC that express this association. Importantly, SC and FC each show unique and distinct patterns of variance across subjects and differential relationships to cognition. The results suggest that a complete understanding of connectome underpinnings of cognition calls for a combination of the two modalities.Significance StatementStructural connectivity (SC), the physical white-matter inter-regional pathways in the brain, and functional connectivity (FC), the temporal co-activations between activity of brain regions, have each been studied extensively. Little is known, however, about the distribution of variance in connections as they relate to cognition. Here, in a large sample of subjects (N = 609), we showed that two sets of brain-behavioural patterns capture the correlations between SC, and FC with a wide range of cognitive tasks, respectively. These brain-behavioural patterns reveal distinct sets of connections within the SC and the FC network and provide new evidence that SC and FC each provide unique information for cognition.
Chromosomally Encoded mcr-5 in Colistin Non-susceptible Pseudomonas aeruginosa
Authors: Snesrud Erik , Maybank Rosslyn , Kwak Yoon I. , Jones Anthony R. , Hinkle Mary K. , Gann Patrick Mc 
Published: April 2018

AbstractWhole genome sequencing (WGS) of historical Pseudomonas aeruginosa clinical isolates identified a chromosomal copy of mcr-5 within a Tn3-like transposon in P. aeruginosa MRSN 12280. The isolate was non-susceptible to colistin by broth microdilution and genome analysis revealed no mutations known to confer colistin resistance. To the best of our knowledge this is the first report of mcr in colistin non-susceptible P. aeruginosa.
Congenital glaucoma with anterior segment dysgenesis in individuals with biallelicCPAMD8variants
Authors: Siggs Owen M , Souzeau Emmanuelle , Taranath Deepa A , Zhou Tiger , Dubowsky Andrew , Javadiyan Shari , Chappell Angela , Narita Andrew , Elder James E , Pater John , Ruddle Jonathan B , Smith James EH , Kearns Lisa S , Staffieri Sandra E , Hewitt Alex W , Mackey David A , Burdon Kathryn P , Craig Jamie E 
Published: April 2018

AbstractPurposeCongenital glaucoma is a significant cause of irreversible blindness. In some instances glaucoma is associated with developmental abnormalities of the ocular anterior segment, which can impair drainage of aqueous humor, leading to an increase in intraocular pressure.MethodsGenome sequencing was performed on a parent-proband congenital glaucoma trio, with exome sequencing of 79 additional individuals with suspected primary congenital glaucoma.ResultsWe describe a unique ocular anterior segment dysgenesis associated with congenital glaucoma in four individuals from three unrelated families. In each case, disease was associated with compound heterozygous variants inCPAMD8, a gene of unknown function recently associated with ocular anterior segment dysgenesis, myopia, and ectopia lentis.CPAMD8expression was highest in neural crest-derived tissues of the adult anterior segment, suggesting thatCPAMD8variation may cause malformation of key drainage structures and the development of high intraocular pressure and glaucoma.ConclusionsThis study reveals a unique genetic cause of childhood glaucoma, and expands the phenotypic spectrum ofCPAMD8-associated ocular disease.
Cancer modeling by Transgene Electroporation in Adult Zebrafish (TEAZ)
Authors: Callahan Scott J. , Tepan Stephanie , Zhang Yan M , Lindsay Helen , Burger Alexa , Campbell Nathaniel R. , Kim Isabella S. , Hollmann Travis J. , Studer Lorenz , Mosimann Christian , White Richard M. 
Published: April 2018

AbstractTransgenic animals are invaluable for modeling cancer genomics, but often require complex crosses of multiple germline alleles to obtain the desired combinations. Zebrafish models have advantages in that transgenes can be rapidly tested by mosaic expression, but these typically lack spatial and temporal control of tumor onset, which limits their utility for the study of tumor progression and metastasis. To overcome these limitations, we have developed a method called Transgene Electroporation in Adult Zebrafish (TEAZ). TEAZ can deliver DNA constructs with promoter elements of interest to drive fluorophores, oncogenes, or CRISPR-Cas9-based mutagenic cassettes in specific cell types. Using TEAZ, we created a highly aggressive melanoma model by expression of BRAFV600Ein spatially constrained melanocytes in the context of p53 deficiency and Cas9-mediated inactivation of Rb1. Unlike prior models that take ~4 months to develop, we found that TEAZ leads to tumor onset in ~7 weeks and these develop in fully immunocompetent animals. As the resulting tumors initiated at highly defined locations, we could track their progression via fluorescence and documented deep invasion into tissues and metastatic deposits. TEAZ can be deployed to other tissues and cell types such as the heart with the use of suitable transgenic promoters. The versatility of TEAZ makes it widely accessible for rapid modeling of somatic gene alterations and cancer progression at a scale not achievable in other in vivo systems.
sFlt-1 commutes unfolded protein response into endoplasmic reticulum stress in trophoblast cells in preeclamptic pregnancies
Authors: Mochan Sankat , Dhingra Manoj Kumar , Gupta Sunil Kumar , saxena Shobhit , Arora Pallavi , Rani Neerja , Sharma Arundhati , Luthra Kalpana , Dwivedi Sadanand , Bhatla Neerja , Kumar Rani , Dhingra Renu 
Published: April 2018

AbstractPreeclampsia (PE) and its subtypes (early and late onset) are serious concerns all across the globe affecting about 8% of total pregnancies and accounts for approximately 60,000 deaths annually with a predominance in developing under-developed and countries. The two-stage model in the progression of this disease, deficient spiral artery remodelling and an imbalance between angiogenic (VEGF) and anti-antigenic factor(s) (sFlt-1) are well established facts pertaining to this disease. The presence of increased sFlt-1, high oxidative stress and Endoplasmic reticulum stress (ER stress) have been proposed in preeclamptic pregnancies. Recently, the role of endoplasmic reticulum stress in the onset of the variant forms of PE highlighted a new window to explore further. In our previous studies, we demonstrated that sFlt-1 can induce apoptosis and oxidative stress in trophoblast cells. However the role of sFlt-1, in inducing ER stress is not known so far. In the present study, we for the first time demonstrated significant ER stress in the placental cells (BeWo Cells) (in vitro) when exposed to sera from preeclamptic pregnancies having increased concentration of sFlt-1. The expression of ER stress markers (GRP78, eIF2α, XBP1, ATF6 and CHOP) at both transcript and protein levels were compared (between preeclamptic and normotensive non-proteinuric women) at three different time points (8h, 14h and 24hrs), analyzed and found to be significant (p<0.05).ConclusionOur results suggested that sFlt-1, released from placental cells in preeclampsia may be one of the various factors having potential to induce endoplasmic reticulum stress in BeWo cells.
Learning recurrent dynamics in spiking networks
Authors: Kim Christopher M. , Chow Carson C. 
Published: April 2018

AbstractSpiking activity of neurons engaged in learning and performing a task show complex spatiotemporal dynamics. While the output of recurrent network models can learn to perform various tasks, the possible range of recurrent dynamics that emerge after learning remains unknown. Here we show that modifying the recurrent connectivity with a recursive least squares algorithm provides sufficient flexibility for synaptic and spiking rate dynamics of spiking networks to produce a wide range of spatiotemporal activity. We apply the training method to learn arbitrary firing patterns, stabilize irregular spiking activity of a balanced network, and reproduce the heterogeneous spiking rate patterns of cortical neurons engaged in motor planning and movement. We identify sufficient conditions for successful learning, characterize two types of learning errors, and assess the network capacity. Our findings show that synaptically-coupled recurrent spiking networks possess a vast computational capability that can support the diverse activity patterns in the brain.
Ecological assessment of the River Nile around Gizert El-Warrak by Phytoplankton and macroinvertebrates assemblages
Authors: Mahmoud Kadria M.A. , Sayed Sara S.M. , Habib Mohamed R. 
Published: April 2018

AbstractBiological assessment is considered a useful tool for assessing the ecological status of the aquatic ecosystems. Therefore, the goal of the present study was to use phytoplankton and macroinvertebrates as biological tools for ecological assessment of the River Nile around Gizert El-Warrak. A total of 33 phytoplankton species identified in the studied stations; these include 16 species of Chlorophyta, 5 species of Cyanophyta and 12 species of Bacillariophyta. All investigated stations characterized by high organic pollution according to Palmer′s index. Trophic state index showed a hyper-eutrophic status in stations S1, S2, S4, S6 and S8 and an eutrophic status in stations S3, S5 and S7.Gastropoda and Oligochaeta were the most dominant of macroinvertebrates taxa recorded 50.8 and 24.6%, respectively. Diversity Index (H′) ranged (1.14 – 2) which indicated that the structure of macroinvertebrates habitat was poor. Also, Evenness Index (J) ranged (0.016 – 0.043) which indicated that individuals were not distributed equally. The values of biotic index depending on macroinvertebrates categories showed that the River Nile’s water quality is fairly poor with significant organic pollution.Summary statementBioassessment based on non-taxonomic measurements of algae and biotic indices of macroinvertebrates may be considered as vital methods that reflect disturbances in aquatic systems for both short-term and long-term.
Typical visual-field locations facilitate access to awareness for everyday objects
Authors: Kaiser Daniel , Cichy Radoslaw M. 
Published: April 2018

AbstractIn real-world vision, humans are constantly confronted with complex environments that contain a multitude of objects. These environments are spatially structured, so that objects have different likelihoods of appearing in specific parts of the visual space. Our massive experience with such positional regularities prompts the hypothesis that the processing of individual objects varies in efficiency across the visual field: when objects are encountered in their typical locations (e.g., we are used to seeing lamps in the upper visual field and carpets in the lower visual field), they should be more efficiently perceived than when they are encountered in atypical locations (e.g., a lamp in the lower visual field and a carpet in the upper visual field). Here, we provide evidence for this hypothesis by showing that typical positioning facilitates an object’s access to awareness. In two continuous flash suppression experiments, objects more efficiently overcame inter-ocular suppression when they were presented in visual-field locations that matched their typical locations in the environment, as compared to non-typical locations. This finding suggests that through extensive experience the visual system has adapted to the statistics of the environment. This adaptation may be particularly useful for rapid object individuation in natural scenes.
Recombination rate variation shapes barriers to introgression across butterfly genomes
Authors: Martin Simon H. , Davey John W. , Salazar Camilo , Jiggins Chris D. 
Published: April 2018

ABSTRACTHybridisation and introgression can dramatically alter the relationships among groups of species, leading to phylogenetic discordance across the genome and between populations. Introgression can also erode species differences over time, but selection against introgression at certain loci acts to maintain post-mating species barriers. Theory predicts that species barriers made up of many loci throughout the genome should lead to a broad correlation between introgression and recombination rate, which determines the extent to which selection on deleterious foreign alleles will affect neutral alleles at physically linked loci. Here we describe the variation in genealogical relationships across the genome among three species ofHeliconiusbutterflies:H. melpomene,H. cydnoandH. timareta, using whole genomes of 92 individuals, and ask whether this variation can be explained by heterogeneous barriers to introgression. We find that species relationships vary predictably at the chromosomal scale. By quantifying recombination rate and admixture proportions, we then show that rates of introgression are predicted by variation in recombination rate. This implies that species barriers are highly polygenic, with selection acting against introgressed alleles across most of the genome. In addition, long chromosomes, which have lower recombination rates, produce stronger barriers on average than short chromosomes. Finally, we find a consistent difference between two species pairs on either side of the Andes, which suggests differences in the architecture of the species barriers. Our findings illustrate how the combined effects of hybridisation, recombination and natural selection, acting at multitudes of loci over long periods, can dramatically sculpt the phylogenetic relationships among species.
Travelling waves in somitogenesis: collective cellular properties emerge from time-delayed juxtacrine oscillation coupling
Authors: Tomka Tomas , Iber Dagmar , Boareto Marcelo 
Published: April 2018

AbstractThe sculpturing of the vertebrate body plan into segments begins with the sequential formation of somites in the presomitic mesoderm (PSM). The rhythmicity of this process is controlled by travelling waves of gene expression. These kinetic waves emerge from coupled cellular oscillators and sweep across the PSM. In zebrafish, the oscillations are driven by autorepression ofhergenes and are synchronized via Notch signalling. Mathematical modelling has played an important role in explaining how collective properties emerge from the molecular interactions. Increasingly more quantitative experimental data permits the validation of those mathematical models, yet leads to increasingly more complex model formulations that hamper an intuitive understanding of the underlying mechanisms. Here, we review previous efforts, and design a mechanistic model of theher1oscillator, which represents the experimentally viableher7;hes6double mutant. This genetically simplified system is ideally suited to conceptually recapitulate oscillatory entrainment and travelling wave formation, and to highlight open questions. It shows that three key parameters, the autorepression delay, the juxtacrine coupling delay, and the coupling strength, are sufficient to understand the emergence of the collective period, the collective amplitude, and the synchronization of neighbouring Her1 oscillators. Moreover, two spatiotemporal time delay gradients, in the autorepression and in the juxtacrine signalling, are required to explain the collective oscillatory dynamics and synchrony of PSM cells. The highlighted developmental principles likely apply more generally to other developmental processes, including neurogenesis and angiogenesis.
TheDrosophilamitochondrial citrate carrier regulates L-2-hydroxyglutarate accumulation by coupling the tricarboxylic acid cycle with glycolysis
Authors: Li Hongde , Hurlburt Alexander J. , Tennessen Jason M. 
Published: April 2018

AbstractThe oncometabolites D- and L-2-hydroxyglutarate (2HG) broadly interfere with cellular metabolism, physiology, and gene expression. A key regulator of 2HG metabolism is the mitochondrial citrate carrier (CIC), which, when mutated, promotes excess D-/L-2HG accumulation. The mechanism by which CIC influences 2HG levels, however, remains unknown. Here we studied theDrosophilagenescheggia(sea), which encodes the fly CIC homolog, to explore the mechanisms linking mitochondrial citrate efflux to L-2HG metabolism. Our findings demonstrate that decreasedDrosophilaCIC activity results in elevated glucose catabolism and increased lactate production, thereby creating a metabolic environment that inhibits L-2HG degradation.
Whole-brain white matter organization, intelligence, and educational attainment
Authors: Bathelt J. , Scerif G. , Nobre K. , Astle D.E. 
Published: April 2018

AbstractGeneral cognitive ability, sometimes referred to as intelligence, is associated with educational attainment throughout childhood. Most studies that have explored the neural correlates of intelligence in childhood focus on individual brain regions. This analytical approach is designed to identify restricted sets of voxels that overlap across participants. By contrast, we explored the relationship between white matter connectome organization, intelligence, and education. In both a sample of typically-developing children (N=63) and a sample of struggling learners (N=139), the white matter connectome efficiency was strongly associated with intelligence and educational attainment. Further, intelligence mediated the relationship between connectome efficiency and educational attainment. In contrast, a canonical voxel-wise analysis failed to identify any significant relationships. The results emphasize the importance of distributed brain network properties for cognitive or educational ability in childhood. Our findings are interpreted in the context of a developmental theory, which emphasizes the interaction between different subsystems over developmental time.
A novel emotional and cognitive approach to welfare phenotyping in rainbow trout exposed to poor water quality
Authors: Colson V , Mure A , Valotaire C , Calvez JM Le , Goardon L , Labbé L , Leguen I , Prunet P 
Published: April 2018

AbstractRecent scientific evidence for fish sentience has stressed the need for novel sentience-based detection tools of fish welfare impairment in commercial farms. In order to mimic a well-characterised stress situation, rainbow trout (Oncorhynchus mykiss) were exposed to poor water quality (hypoxia combined with high ammonia level) for three weeks (stressed group, S) and compared to a non-stressed control group (NS). After a return to water quality standard, emotional responses were assessed in fish subjected to two potentially threatening situations: (i) social isolation in a novel environment and (ii) human presence. In addition, we used an appetitive-conditioning paradigm to determine whether previous chronic deterioration of water quality disturbs cognitive abilities in fish. Spontaneous behaviour in the tanks was also recorded during the environmental challenge as a reference for fish activity. We observed that in S fish, plasma cortisol levels were increased before and after social isolation in a novel environment compared to the plasma cortisol levels in the NS group, despite the absence of a behavioural difference between the two groups. Under deteriorated water quality, fish locomotor activity was globally reduced and this reduction was correlated to increased shoaling behaviour. Farmers can use these first behavioural modifications as a sentinel detector for fish welfare impairment. More importantly, we demonstrated that reactivity to a human presence in a home-environment and food-anticipatory behaviour were both inhibited in the S group. We consider that these two sentience-based tests are highly relevant for fish welfare assessment at the group level and are easy to use in the aquaculture industry.
Dynamic Extreme Aneuploidy (DEA) in the vegetable pathogen Phytophthora capsici sheds light on instant evolution and intractability
Authors: Hu Jian , Shrestha Sandesh , Zhou Yuxin , Liu Xili , Lamour Kurt 
Published: April 2018

summaryOomycete plant pathogens are notoriously difficult to control, and individual isolates are highly unstable; making routine research challenging. Sequencing reveals extreme aneuploidy for single-spore progeny of the vegetable pathogen Phytophthora capsici; a phenomenon dubbed Dynamic Extreme Aneuploidy (DEA). Although extreme, the aneuploidy appears to be moderately stable. A single sporulating plant lesion may produce an armada of genetically unique individuals and helps explain the rapid increase of advantageous alleles (e.g. drug resistance), mating type switches to allow sex and the widely observed phenomenon, loss of heterozygosity (LOH). Investigation of other oomycetes indicate this phenomenon is not unique to P. capsici.