bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabarcoding analysis on European coastal samples reveals new molecular metazoan diversity
Authors: López-Escardó David , Paps Jordi , de Vargas Colomban , Massana Ramon , Ruiz-Trillo Iñaki , del Campo Javier
Published: June 2018

Although animals are among the best studied organisms, we still lack a full description of their diversity, especially for microscopic taxa. This is partly due to the time-consuming and costly nature of surveying animal diversity through morphological and molecular studies of individual taxa. A powerful alternative is the use of high-throughput environmental sequencing, providing molecular data from all organisms sampled. We here address the unknown diversity of animal phyla in marine environments using an extensive dataset designed to assess eukaryotic ribosomal diversity among European coastal locations. A multi-phylum assessment of marine animal diversity that includes water column and sediments, oxic and anoxic environments, and both DNA and RNA templates, revealed a high percentage of novel 18S rRNA sequences in most phyla, suggesting that marine environments have not yet been fully sampled at a molecular level. This novelty is especially high among Platyhelminthes, Acoelomorpha, and Nematoda, which are well studied from a morphological perspective and abundant in benthic environments. We also identified, based on molecular data, a potentially novel group of widespread tunicates. Moreover, we recovered a high number of reads for Ctenophora and Cnidaria in the smaller fractions suggesting their gametes might play a greater ecological role than previously suspected.
Cooperation on dynamic networks within an uncertain reputation environment
Authors: Lozano Pablo , Antonioni Alberto , Tomassini Marco , Sánchez Angel
Published: June 2018

Reputation plays a key role among the mechanisms supporting cooperation in our society. This is a well-known observation and, in fact, several studies have shown that reputation may substantially increase cooperation among subjects playing Prisoner’s Dilemma games in the laboratory. Unfortunately, recent experiments indicate that when reputation can be faked cooperation can still be maintained at the expense of honest subjects who are deceived by the dishonest ones. As experimental work is limited due to financial and other reasons, we present here an agent-based simulation model inspired by, and calibrated against, the results obtained in the experiment. We thus simulate much larger population sizes over longer times, and test other model parameters to see whether the observed behavior generalizes in those yet untried conditions. The results show that the collective behavior is qualitatively similar in larger systems and stable over longer times horizons. We conclude that the findings of the experimental work are meaningful, taking into account that the model is strictly tailored to our particular experimental setting and therefore it is a possible explanation of our observations whose applicability to other contexts requires further research. We argue that simulations like the ones presented here may also be useful to cheaply and quickly suggest settings and options to enhance and facilitate further experiments, which, in turn, may provide new tests of the models themselves.
C–H bond sulfonylation of anilines with the insertion of sulfur dioxide under metal-free conditions
Authors: Zhou Kaida , Zhang Jun , Lai Lifang , Cheng Jiang , Sun Jiangtao , Wu Jie
Published: June 2018

2-Sulfonylanilines are generated in moderate to good yields through a three-component reaction of anilines, DABCO·(SO2)2, and aryldiazonium tetrafluoroborates under mild conditions. No metal catalysts or additives are needed for this transformation.
Nonstoichiometric oxides as a continuous homologous series: linear free-energy relationship in oxygen exchange
Authors: Chizhik Stanislav A. , Nemudry Alexander P.
Published: June 2018

A novel methodology based on the continuous homologous series is suggested for the analysis of oxygen exchange in practically important non-stoichiometric oxides. Linear free-energy relationship is established analogous to Brønsted equation or Taffel plot.
In situ surface engineering of ultrafine Ni2P nanoparticles on cadmium sulfide for robust hydrogen evolution
Authors: Wang Junfang , Wang Peifang , Hou Jun , Qian Jin , Wang Chao , Ao Yanhui
Published: June 2018

Here we report the in situ growth of well-dispersed ultrafine Ni2P nanoparticles on CdS nanorods by a simple solvothermal method and a further surface phosphatization treatment for the first time.
Elucidating metal hydride reactivity using late transition metal boryl and borane hydrides: 2c–2e terminal hydride, 3c–2e bridging hydride, and 3c–4e bridging hydride
Authors: Li Yinwu , Liu Jiahao , Hou Cheng , Shao Youxiang , Qu Ling-Bo , Zhao Cunyuan , Ke Zhuofeng
Published: June 2018

A general trend for the hydrogenation reactivity of metal hydride(s): 3c–4e bridging hydride > 2c–2e terminal hydride > 3c–2e bridging hydride.
Visible light-driven methanol dehydrogenation and conversion into 1,1-dimethoxymethane over a non-noble metal photocatalyst under acidic conditions
Authors: Chao Yuguang , Lai Jianping , Yang Yong , Zhou Peng , Zhang Yelong , Mu Zijie , Li Shiying , Zheng Jianfeng , Zhu Zhenping , Tan Yisheng
Published: June 2018

The dehydrogenation and conversion of methanol into 1,1-dimethoxymethane (DMM) was achieved over noble metal free photocatalyst CdS/Ni2P under visible light.
Hybrid dimers based on metal-substituted Keggin polyoxometalates (metal = Ti, Ln) for cyanosilylation catalysis
Authors: An Haiyan , Zhang Yumeng , Hou Yujiao , Hu Tao , Yang Wei , Chang Shenzhen , Zhang Jianjun
Published: June 2018

Six hybrid dimers 1–6 constructed from [PW10Ti2O40]7−/[PW11LnO39]4− and lanthanide–organic units are reported, which as heterogeneous catalysts show high activity for cyanosilylation under solvent-free conditions.
Cd2NF, an analogue of CdO
Authors: Manjunath Krishnappa , Prasad Suchitra , Waghmare Umesh V. , Rao C. N. R.
Published: June 2018

Cd2NF, isoelectronic with CdO, exhibits a quasimetallic nature and is a good photocatalyst for hydrogen evolution.
The dual-luminescence mechanism of the ESIPT chemosensor tetrasubstituted imidazole core compound: a TDDFT study
Authors: Qiao Na , Wei Ning-Ning , Zhang Jianing , Hao Ce
Published: June 2018

The dual-luminescence mechanism of the tetrasubstituted imidazole core (TIC) compound was theoretically explored by considering the excited-state intramolecular proton transfer (ESIPT) process in the present study.
Ultrathin nanosheet-assembled [Ni3(OH)2(PTA)2(H2O)4]·2H2O hierarchical flowers for high-performance electrocatalysis of glucose oxidation reactions
Authors: Zheng Shasha , Li Bing , Tang Yijian , Li Qing , Xue Huaiguo , Pang Huan
Published: June 2018

Ultrathin nanosheet-assembled metal–organic framework hierarchical flowers have been regarded as very promising electrocatalysts for glucose oxidation reactions.
Semiconducting edges and flake-shape evolution of monolayer GaSe: role of edge reconstructions
Authors: Wang Ning , Cao Dan , Wang Jun , Liang Pei , Chen Xiaoshuang , Shu Haibo
Published: June 2018

Edge reconstructions lead to the enhanced stability and semiconducting properties in finite-sized 2D group-III metal monochalcogenides, such as GaSe and InSe.
Staudinger/aza-Wittig reaction to accessNβ-protected amino alkyl isothiocyanates
Authors: Santhosh L. , Durgamma S. , Shekharappa Shekharappa , Sureshbabu Vommina V.
Published: June 2018

General strategy of the Staudinger/aza-Wittig reaction has been effectively employed as anad hocapproach for accessingNβ-protected alkyl isothiocyanates fromNβ-protected alkyl azides.
Novel dual-site fluorescent probe for monitoring cysteine and sulfite in living cells
Authors: Guo Xin , Xia Lili , Huang Jinxin , Wang Yiming , Gu Yueqing , Wang Peng
Published: June 2018

A dual-site fluorescence probe LC-1 was developed for the detection of Cys and SO32−.
Fluorescent supramolecular hydrogels self-assembled from tetraphenylethene (TPE)/single amino acid conjugates
Authors: Chu Nien-Tzu , Chakravarthy Rajan Deepan , Shih Nai-Chia , Lin Yen-Hsu , Liu Yen-Chu , Lin Jhong-Hua , Lin Hsin-Chieh
Published: June 2018

TPE-Ser molecules exhibit non-covalent interactions necessary for hydrogelation under physiological pH conditions.
Synthesis of heterometallic metal–organic frameworks and their performance as electrocatalyst for CO2 reduction
Authors: Perfecto-Irigaray Maite , Albo Jonathan , Beobide Garikoitz , Castillo Oscar , Irabien Angel , Pérez-Yáñez Sonia
Published: June 2018

The solventless synthesis of heterometallic metal–organic frameworks and their proficient behavior as electrocatalysts in the CO2 reduction to alcohols is presented.
Detection of Helicobacter pylori in dental plaque using a DNA biosensor for noninvasive diagnosis
Authors: Chen Li-Li , Cui Hui-Fang , Fan Shuang-Fei , Li Zong-Yi , Han Shuang-Yin , Ma Xin , Luo Shu-Wen , Song Xiaojie , Lv Qi-Yan
Published: June 2018

H. pylori in dental plaque was detected with a DNA biosensor with results correlating well with the 13C urea breath test.
Mesoporous magnetic silica particles modified with stimuli-responsive P(NIPAM–DMA) valve for controlled loading and release of biologically active molecules
Authors: Tanjim Mustahida , Rahman Mohammad A. , Rahman Mohammad M. , Minami Hideto , Hoque Sheikh M. , Sharafat Mostafa K. , Gafur Muhammad A. , Ahmad Hasan
Published: June 2018

Mesoporous submicron-sized Fe3O4 particles modified with mesoporous SiO2 layer were functionalized with a stimuli-responsive polymer valve for use as microcapsules.
Flexible and highly sensitive artificial electronic skin based on graphene/polyamide interlocking fabric
Authors: Yin Fuxing , Yang Jinzheng , Peng Huifen , Yuan Wenjing
Published: June 2018

Skin-like pressure sensors based on graphene/polyamide interlocking fabric exhibit high sensing performance and various sensing functions.
Carboxylic ester-terminated fulleropyrrolidine as an efficient electron transport material for inverted perovskite solar cells
Authors: Chang Junwei , Wang Ying-Chiao , Song Changjian , Zhu Liping , Guo Qiang , Fang Junfeng
Published: June 2018

Fulleropyrrolidine (CPTA-E) is used as an electron transport layer for high-efficiency inverted perovskite solar cells.
Highly sensitive detection of polarized light using a new group IV–V 2D orthorhombic SiP
Authors: Li Chunlong , Wang Shanpeng , Li Chenning , Yu Tongtong , Jia Ning , Qiao Jie , Zhu Min , Liu Duo , Tao Xutang
Published: June 2018

Seeded flux growth of bulk o-SiP single crystals with layered structure and in-plane anisotropic photoresponse.
Evolution of structure and ferroelectricity in Aurivillius Bi4Bin−3Fen−3Ti3O3n+3 thin films
Authors: Song Dongpo , Yang Jie , Yang Bingbing , Chen Liangyu , Wang Fang , Zhu Xuebin
Published: June 2018

The optimized ferroelectric properties in Aurivillius films with higher n are well suited to ferroelectric-based data storage and for further exploration of single-phase multiferroics.
Applying the fractional derivative Zener model to fitting the time‐dependent material viscoelasticity tested by nanoindentation
Authors: Wei Long Fei , Li Wei , Feng Zhi Qiang , Liu Jian Tao
Published: June 2018

Material viscoelasticity is of particular importance for polymers, biotissues and many others, due to the significant influence not only on the elastic response of structures, but also on their failure mechanism in actual applications. In this study, the experimental tests by nanoindentations are categorized according to the objective parameter combined with the indenter shape into four distinct cases, and the Fractional Derivative Zener model (FDZM) is employed to characterize this time‐dependent property. The explicit data‐fitting formulas are derived to determine the relaxation modulus and creep compliance tested with the conical and spherical indenters. Besides, a fitting scheme is provided to facilitate the identification of these viscoelastic parameters. In comparison with the general methods adopting the Prony series or empirical models, two silent merits present: (1) fewer model coefficients necessitate being determined based on the experimental data; (2) the relaxation modulus G(t) and the creep compliance J(t) can be obtained through one indentation test, and their exact interconversion is guaranteed as well. Several sets of experimental data are applied to examine the validity of the developed approach, and three more examples are adopted to demonstrate the exact interconversion between G(t) and J(t). A few concluding remarks are drawn eventually.
Optimum design of the stator parameters for noise and vibration reduction in BLDC motor
Authors: Jafarboland Mehrdad , Farahabadi Hossein Bagherian
Published: June 2018

A new optimum structural design is presented here in order to shift the natural frequencies of the stator structure in brushless DC motor to the highest values at different mode shapes and increase the stator stiffness. Shifting the stator natural frequencies to higher values reduces or eliminates the severe effects of the structural resonances as the coincidence of the natural frequencies and the components of the motor electromagnetic excitation forces occur at higher frequencies at which the forces have lower amplitudes. In the proposed structural design, some parameters relating to stator slot are optimised to shift the stator's natural frequencies to the highest values without changing the slot areas and the stator outer diameter as the problem constraints. The optimisation is done by the response surface methodology combined with the modal analysis by the finite element method (FEM). The validity of the optimisation method is confirmed by FEM simulations and experimental tests at different speed regions. Moreover, the performances of the prototype and optimum motors are analysed by FEM and experimental tests to show that the stator parameters optimisation process does not cause any negative influences on the quality of the motor performance.
The black hole retention fraction in star clusters
Authors: Pavlík Václav , Jeřábková Tereza , Kroupa Pavel , Baumgardt Holger
Published: June 2018

Context. Recent research has been constraining the retention fraction of black holes (BHs) in globular clusters by comparing the degree of mass segregation with N-body simulations. They are consistent with an upper limit of the retention fraction being 50% or less.

Aims. In this work, we focus on direct simulations of the dynamics of BHs in star clusters. We aim to constrain the effective distribution of natal kicks that BHs receive during supernova (SN) explosions and to estimate the BH retention fraction.

Methods. We used the collisional N-body code nbody6 to measure the retention fraction of BHs for a given set of parameters, which are: the initial mass of a star cluster, the initial half-mass radius, and σBH, which sets the effective Maxwellian BH velocity kick distribution. We compare these direct N-body models with our analytic estimates and newest observational constraints.

Results. The numerical simulations show that for the one-dimensional velocity kick dispersion σBH < 50 km s−1, clusters with radii of 2 pc and that are initially more massive than 5 × 103 M⊙ retain more than 20% of BHs within their half-mass radii. Our simple analytic model yields a number of retained BHs that is in good agreement with the N-body models. Furthermore, the analytic estimates show that ultra-compact dwarf galaxies should have retained more than 80% of their BHs for σBH ≤ 190 km s−1. Although our models do not contain primordial binaries, in the most compact clusters with 103 stars, we have found evidence of delayed SN explosions producing a surplus of BHs compared to the IMF due to dynamically formed binary stars. These cases do not occur in the more populous or expanded clusters.
Static and dynamic modeling of organic thin film transistors: effect of channel length on the Mayer–Neldel rule energy and quasistatic capacitances
Authors: Arfaoui Nawel , Boukhili Walid , Mahdouani Mounira , Puigdollers Joaquim , Bourguiga Ramzi
Published: June 2018

In this work, pentacene based thin film transistors (TFTs) with different channel lengths (L = 2.5, 5, 10 and 20 μm) have been fabricated and characterized electrically. Exploiting the electrical characteristics, we have analyzed the channel length effect on the key parameters of fabricated TFTs. We found that the performance of pentacene-TFTs was enormously enhanced by the reduction of channel length .We have also examined the influence of contact and channel resistances (RCandRch) on the electrical proprieties of fabricated TFTs, using the transmission line method (TLM). Then, we have modeled the dependence of the total resistanceRTon the gate voltageVGusing the grain boundary trapping Meyer–Neldel rule (GBT-MNR) model and we have successfully reproduced, the output characteristic of pentacene TFTs using the overall resistance extracted from the GBT-MNR model. Finally, in order to investigate the channel length effect on the dynamic behavior of fabricated devices, we have reported a dynamic model based on the quasistatic assumptions which were used for metal-oxide-semiconductor field-effect transistor (MOSFET). Accordingly, we have presented a simple small-signal equivalent circuit to calculate theoretically the capacitances of pentacene-TFTs for different channel lengths.
An Overview of FGF19 and FGF21: The Therapeutic Role in the Treatment of the Metabolic Disorders and Obesity
Authors: Babaknejad Nasim , Nayeri Hashem , Hemmati Roohullah , Bahrami Somaye , Esmaillzadeh Ahmad
Published: June 2018

Fibroblast growth factors (FGFs) are responsible for the regulation of a wide range of biological functions, among which cellular proliferation, survival, migration, and differentiation could be pointed out. FGF19 controls the enterohepatic bile acid/cholesterol system, and FGF21 modulates fatty acid/glucose metabolism. Obesity, type 2 diabetes, coronary artery disease, and cancer, all can alter FGF21 circulating concentrations. In contrast to FGF21, metabolic diseases exhibit reduced serum FGF19 levels. Accordingly, FGF19 and FGF21 play important roles in regulating glucose and lipid metabolism. Hence, we present here a timely review on the relationship between FGF19/21 and metabolic diseases, especially obesity, and their probable role in development and treatment of obesity seems necessary.
An Efficient Method for the Preparation of N-Formamides using Propylphosphonic Anhydride (T3P®)
Authors: Kandula Venu , Gudipati Ramakrishna , Chatterjee Anindita , Yennam Satyanarayana , Behera Manoranjan
Published: June 2018

The synthesis of N-formamides from aromatic amines and formic acid using propylphosphonic anhydride (T3P®) as a green coupling reagent is described. By using this method, aryl, heteroaryl and fluorinated aryl-containing formamides were synthesized in high yield and purity. The significant features of this method include easy work up, high purity and reduced toxicity of the reaction.
Prothrombin Time and Hemorrhagic Death in Dicumarolized Rats Receiving Pituitary and Adrenal Hormones
Authors: van Cauwenberge H , Jaques L. B
Published: June 2018

1. Rats receiving dicumarol were given injections of desoxycorticosterone, cortisone, hydrocortisone, ACTH, somatotropin, sodium salicylate, adrenaline, reserpine, histamine, 10% sodium chloride intraperitoneally. A high incidence of hemorrhagic death was observed with desoxycorticosterone, ACTH, STH, sodium salicylate, 10% sodium chloride, histamine, adrenaline, reserpine. Little hemorrhage was observed with cortisone and hydrocortisone.

2. The mortality resulting from 10% sodium chloride stress in dicumarolized rats was not depressed by dial, or phenergan, or pretreatment with cortisone. The mortality was prevented by treatment with vitamin Ki before giving the stress agent.

3. The mean prothrombin time with dicumarol in rats appeared to be increased by the administration of ACTH, sodium salicylate, 10% sodium chloride, desoxycorticosterone, adrenaline and histamine. No modification was observed by cortisone, dial, reserpine. With hydrocortisone — there was an increase the day after giving the steroid, but the prothrombin time was nearly normal 2 days later.

4. Steroids were tested for their ability to protect adrenalectomized rats from hemorrhage with dicumarol. Desoxycorticosterone had no action in this regard. Cortisone and hydrocortisone were effective with cortisone being more active.
Congenital Hypoproconvertinemia A Report on 12 Cases with Total Deficiency and 19 Cases with Partial Deficiency
Authors: Voss Dieter , Waaler Bjarne A
Published: June 2018

Investigations on 12 patients with a total and 19 patients with a partial deficiency of proconvertin (factor VII) are reported. All patients proved to have the same deficiency and it was distinguishable from Stuart-Prower factor deficiency. The differentiation between proconvertin deficiency and Stuart-Prower factor deficiency is discussed.
Final report, on-going key comparison BIPM.QM-K1, ozone at ambient level, comparison with NPLI, February 2018
Authors: Viallon le , Idrees Faraz , Moussay Philippe , Wielgosz Robert , Sharma Chhemendra , Radha Radhakrishnan Soman , Shukla Devesh Kumar
Published: June 2018

As part of the ongoing key comparison BIPM.QM-K1, a comparison has been performed between the ozone national standard of India maintained by the CSIR-National Physical Laboratory, India (NPLI) and the common reference standard of the key comparison, maintained by the Bureau International des Poids et Mesures (BIPM). The instruments have been compared over a nominal ozone amount-of-substance fraction range from 0 nmol/mol to 500 nmol/mol.

KEY WORDS FOR SEARCH

Ozone, Standard Reference Photometer

Main text

To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/.

The final report has been peer-reviewed and approved for publication by the CCQM, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).
Improved de novo genome assembly and analysis of the Chinese cucurbit Siraitia grosvenorii, also known as monk fruit or luo-han-guo
Authors: Xia Mian , Han Xue , He Hang , Yu Renbo , Zhen Gang , Jia Xiping , Cheng Beijiu , Deng Xing Wang
Published: June 2018

Background

Luo-han-guo (Siraitia grosvenorii), also called monk fruit, is a member of the Cucurbitaceae family. Monk fruit has become an important area for research because of the pharmacological and economic potential of its noncaloric, extremely sweet components (mogrosides). It is also commonly used in traditional Chinese medicine for the treatment of lung congestion, sore throat, and constipation. Recently, a single reference genome became available for monk fruit, assembled from 36.9x genome coverage reads via Illumina sequencing platforms. This genome assembly has a relatively short (34.2 kb) contig N50 length and lacks integrated annotations. These drawbacks make it difficult to use as a reference in assembling transcriptomes and discovering novel functional genes.

Findings

Here, we offer a new high-quality draft of the S. grosvenorii genome assembled using 31 Gb (~73.8x) long single molecule real time sequencing reads and polished with ~50 Gb Illumina paired-end reads. The final genome assembly is approximately 469.5 Mb, with a contig N50 length of 432,384 bp, representing a 12.6-fold improvement. We further annotated 237.3 Mb of repetitive sequence and 30,565 consensus protein coding genes with combined evidence. Phylogenetic analysis showed that S. grosvenorii diverged from members of the Cucurbitaceae family approximately 40.9 million years ago. With comprehensive transcriptomic analysis and differential expression testing, we identified 4,606 up-regulated genes in the early fruit compared to the leaf, a number of which were linked to metabolic pathways regulating fruit development and ripening.

Conclusions

The availability of this new monk fruit genome assembly, as well as the annotations, will facilitate the discovery of new functional genes and the genetic improvement of monk fruit.
On the use of Gaia magnitudes and new tables of bolometric corrections
Authors: Casagrande L , VandenBerg Don A
Published: June 2018

The availability of reliable bolometric corrections and reddening estimates, rather than the quality of parallaxes, will be one of the main limiting factors in determining the luminosities of a large fraction of Gaia stars. With this goal in mind, we provide GaiaGBP, G, and GRP synthetic photometry for the entire MARCS grid and test the performance of our synthetic colours and bolometric corrections against space-borne absolute spectrophotometry. We find indication of a magnitude-dependent offset in Gaia DR2 G magnitudes, which must be taken into account in high-accuracy investigations. Our interpolation routines are easily used to derive bolometric corrections at desired stellar parameters and to explore the dependence of Gaia photometry on Teff, $\log \,g$, $\rm {[Fe/H]}$, $[\alpha /\rm {Fe}]$, and E(B − V). Gaia colours for the Sun and Vega, and Teff-dependent extinction coefficients are also provided.
Maternal Hepatitis B Infection and Pregnancy Outcomes in the United States: A Population-Based Cohort Study
Authors: Bajema Kristina L , Stankiewicz Karita Helen C , Tenforde Mark W , Hawes Stephen E , Heffron Renee
Published: June 2018

Background

Hepatitis B virus (HBV) infection in pregnancy has been associated with risk of adverse maternal and infant outcomes in highly endemic settings, but this association is not well characterized in the United States.

Methods

We conducted a retrospective population-based cohort study in Washington State using linked birth certificate and hospital discharge records from 1992–2014. Among pregnant women with hepatitis B (n = 4391) and a hepatitis B–negative group (n = 22 410), we compared the risk of gestational diabetes, pre-eclampsia, eclampsia, placenta previa, preterm delivery, low birthweight, small for gestational age, and large for gestational age using multivariate logistic regression.

Results

Hepatitis B–infected pregnant women were more likely to be Asian (61% vs 8%, P < .001), foreign-born (76% vs 23%, P < .001), and older in age (77% vs 64% ≥26 years, P < .001). They were less commonly overweight or obese (33% vs 50%, P < .001). There was a lower risk of small for gestational age infants among HBV-infected women (adjusted RR [aRR], 0.79; 95% confidence interval [CI], 0.67–0.93). The risk of other adverse outcomes was not significantly different between hepatitis B–infected and –negative women (gestational diabetes: aRR, 1.11; 95% CI, 0.92–1.34; pre-eclampsia: aRR, 1.06; 95% CI, 0.82–1.35; eclampsia: aRR, 2.31; 95% CI, 0.90–5.91; placenta previa: aRR, 1.16; 95% CI, 0.35–3.84; preterm delivery: aRR, 1.15; 95% CI, 0.98–1.34; low birth weight: aRR, 1.08; 95% CI, 0.90–1.29; large for gestational age: aRR, 1.01; 95% CI, 0.82–1.24).

Conclusions

In a low-burden setting in the United States, hepatitis B infection was not associated with adverse pregnancy outcomes.
The dynamic neural code of the retina for natural scenes
Authors: Maheswaranathan Niru , McIntosh Lane T. , Tanaka Hidenori , Grant Satchel , Kastner David B. , Melander Josh B. , Nayebi Aran , Brezovec Luke , Wang Julia , Ganguli Surya , Baccus Stephen A.
Published: June 2018

Understanding how the visual system encodes natural scenes is a fundamental goal of sensory neuroscience. We show here that a three-layer network model predicts the retinal response to natural scenes with an accuracy nearing the fundamental limits of predictability. The model’s internal structure is interpretable, in that model units are highly correlated with interneurons recorded separately and not used to fit the model. We further show the ethological relevance to natural visual processing of a diverse set of phenomena of complex motion encoding, adaptation and predictive coding. Our analysis uncovers a fast timescale of visual processing that is inaccessible directly from experimental data, showing unexpectedly that ganglion cells signal in distinct modes by rapidly (< 0.1 s) switching their selectivity for direction of motion, orientation, location and the sign of intensity. A new approach that decomposes ganglion cell responses into the contribution of interneurons reveals how the latent effects of parallel retinal circuits generate the response to any possible stimulus. These results reveal extremely flexible and rapid dynamics of the retinal code for natural visual stimuli, explaining the need for a large set of interneuron pathways to generate the dynamic neural code for natural scenes.
Pinned, locked, pushed, and pulled traveling waves in structured environments
Authors: Wang Ching-Hao , Matin Sakib , George Ashish B. , Korolev Kirill S.
Published: June 2018

Traveling fronts describe the transition between two alternative states in a great number of physical and biological systems. Examples include the spread of beneficial mutations, chemical reactions, and the invasions by foreign species. In homogeneous environments, the alternative states are separated by a smooth front moving at a constant velocity. This simple picture can break down in structured environments such as tissues, patchy landscapes, and microfluidic devices. Habitat fragmentation can pin the front at a particular location or lock invasion velocities into specific values. Locked velocities are not sensitive to moderate changes in dispersal or growth and are determined by the spatial and temporal periodicity of the environment. The synchronization with the environment results in discontinuous fronts that propagate as periodic pulses. We characterize the transition from continuous to locked invasions and show that it is controlled by positive density-dependence in dispersal or growth. We also demonstrate that velocity locking is robust to demographic and environmental fluctuations and examine stochastic dynamics and evolution in locked invasions.
Transcranial direct current stimulation (tDCS) over the left prefrontal cortex does not affect time-trial self-paced cycling performance: Evidence from oscillatory brain activity and power output
Authors: Holgado Darías , Zandonai Thomas , Ciria Luis F. , Zabala Mikel , Hopker James , Sanabria Daniel
Published: June 2018

Objectives

To test the hypothesis that transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) influences performance in a 20-min time-trial self-paced exercise and electroencephalographic (EEG) oscillatory brain activity in a group of trained male cyclists.

Design

The study consisted of a pre-registered (https://osf.io/rf95j/), randomised, sham-controlled, single-blind, within-subject design experiment.

Methods

36 trained male cyclists, age 27 (6.8) years, weight 70.1 (9.5) Kg; VO2max: 54 (6.13) ml.min−1.kg−1, Maximal Power output: 4.77 (0.6) W/kg completed a 20-min time-trial self-paced exercise in three separate sessions, corresponding to three stimulation conditions: anodal, cathodal and sham. tDCS was administered before each test during 20-min at a current intensity of 2.0 mA. The anode electrode was placed over the DLPFC and the cathode in the contralateral shoulder. In each session, power output, heart rate, sRPE and EEG (at baseline and during exercise) was measured.

Results

There were no differences (F = 0.31, p > 0.05) in power output between the stimulation conditions: anodal (235 W [95%CI 222 - 249 W]; cathodal (235 W [95%CI 222 - 248 W] and sham (234 W [95%CI 220 - 248 W]. Neither heart rate, sRPE nor EEG activity were affected by tDCS (all Ps > 0.05).

Conclusion

tDCS over the left DLFC did not affect self-paced exercise performance in trained cyclists. Moreover, tDCS did not elicit any change on oscillatory brain activity either at baseline or during exercise. Our data suggest that the effects of tDCS on endurance performance should be taken with caution.
A simple and flexible computational framework for inferring sources of heterogeneity from single-cell dynamics
Authors: Dharmarajan Lekshmi , Kaltenbach Hans-Michael , Rudolf Fabian , Stelling Joerg
Published: June 2018

The availability of high-resolution single-cell data makes data analysis and interpretation an important open problem, for example, to disentangle sources of cell-to-cell and intra-cellular variability. Nonlinear mixed effects models (NLMEs), well established in pharmacometrics, account for such multiple sources of variations, but their estimation is often difficult. Single-cell analysis is an even more challenging application with larger data sets and models that are more complicated. Here, we show how to leverage the quality of time-lapse microscopy data with a simple two-stage method to estimate realistic dynamic NLMEs accurately. We demonstrate accuracy by benchmarking with a published model and dataset, and scalability with a new mechanistic model and corresponding dataset for amino acid transporter endocytosis in budding yeast. We also propose variation-based sensitivity analysis to identify time-dependent causes of cell-to-cell variability, highlighting important sub-processes in endocytosis. Generality and simplicity of the approach will facilitate customized extensions for analyzing single-cell dynamics.
Facilitation of hERG channels by blockers: a mechanism predicted to reduce lethal cardiac arrhythmias
Authors: Furutani Kazuharu , Tsumoto Kunichika , Chen I-Shan , Handa Kenichiro , Yamakawa Yuko , Sack Jon T. , Kurachi Yoshihisa
Published: June 2018

Fatal cardiac arrhythmias are caused by some, but not all, drugs that inhibit the cardiac rapid delayed-rectifier current (IKr) by blocking hERG channels. Here, we propose a novel mechanism that could make certain hERG blockers less proarrhythmic. Several drugs that block hERG channels, yet have favorable cardiac safety profiles, also evoke another effect; they increase the current amplitude upon low-voltage depolarization (facilitation). Voltage-clamp recordings of hERG block and facilitation by nifekalant, a Class III antiarrhythmic agent, constrained a model of human cardiac IKr. In human ventricular action potential simulations, nifekalant showed its therapeutic ability to suppress ectopic excitations, with or without facilitation. Without facilitation, excessive IKr block evoked early afterdepolarizations, which cause lethal arrhythmias. Facilitation prevented early afterdepolarizations at the same degree of block by increasing IKr during repolarization phase of action potentials. Thus, facilitation is proposed to reduce the arrhythmogenic risk of hERG blockers.

Abbreviations

AP: action potential; APD: action potential duration; APD90: action potential duration measured at 90% repolarization; EAD: early afterdepolarization; hERG: human ether-ago-go-related gene; ICaL: L-type Ca2+ channel current; Inet: net ionic current; IK1: inward-rectifier potassium current; IKr: rapid component of the delayed-rectifier potassium current; INa: sodium current; ORd: O’Hara-Rudy dynamic
Not-so-working memory: Drift in fMRI pattern representations during maintenance predicts errors in a visual working memory task
Authors: Lim Phui Cheng , Ward Emily J. , Vickery Timothy J. , Johnson Matthew R.
Published: June 2018

Working memory (WM) is critical to many aspects of cognition, but it frequently fails. Much WM research has focused on capacity limits, but even for single, simple features, the fidelity of individual representations is limited. Why is this? We used fMRI and a pattern-based index of “representational drift” to investigate how ongoing changes in brain activity patterns throughout the WM maintenance period predicted performance, using a delayed-match-to-sample task for a single item with a single critical feature: orientation. In trials where the target and probe stimuli matched, participants incorrectly reported more non-matches when their activity patterns drifted away from the target. In trials where the target and probe did not match, participants incorrectly reported more matches when their activity patterns drifted towards the probe. Our results suggest that WM errors are not simply due to unstructured noise, but also drift within representation space that can be indexed by neuroimaging.
Deep sequencing of circulating exosomal microRNA allows non-invasive glioblastoma diagnosis
Authors: Ebrahimkhani Saeideh , Vafaee Fatemeh , Hallal Susannah , Wei Heng , Lee Maggie Yuk T. , Young Paul E. , Satgunaseelan Laveniya , Shivalingam Brindha , Suter Catherine M. , Buckland Michael E. , Kaufman Kimberley L.
Published: June 2018

Exosomes are nano-sized extracellular vesicles released by many cells that contain molecules characteristic of their cell-of-origin, including microRNA. Exosomes released by glioblastoma cross the blood-brain-barrier into the peripheral circulation, and carry molecular cargo distinct to that of ‘free-circulating’ miRNA. In this pilot study, serum exosomal-microRNAs were isolated from glioblastoma (n=12) patients and analyzed using unbiased deep sequencing. Results were compared to sera from age- and gender-matched healthy controls, and to grades II-III (n=10) glioma patients. Significant differentially expressed microRNAs were identified, and the predictive power of individual and subsets of microRNAs were tested using univariate and multivariate analyses. Additional sera from glioblastoma patients (n=4) and independent sets of healthy (n=9) and non-glioma (n=10) controls were used to further test the specificity and predictive power of this unique exosomal-microRNA signature. Twenty-six microRNAs were differentially expressed in serum exosomes from glioblastoma patients’ relative to healthy controls. Random forest modeling and data partitioning selected seven miRNAs (miR-182-5p, miR-328-3p, miR-339-5p, miR-340-5p, miR-485-3p, miR-486-5p and miR-543) as the most stable for classifying glioblastoma. Strikingly, within this model, six iterations of these miRNA classifiers could distinguish glioblastoma patients from controls with perfect accuracy. The seven-miRNA panel was able to correctly classify all specimens in validation cohorts (n=23). Also identified were 23 dysregulated miRNAs in IDHMUTgliomas, a partially overlapping yet distinct signature of lower grade glioma. Serum exosomal-miRNA signatures can accurately diagnose glioblastoma preoperatively. miRNA signatures identified are distinct from previously reported ‘free-circulating’ miRNA studies in GBM patients, and appear to be superior.
The swimming plus-maze test: a novel high-throughput model for assessment of anxiety-related behaviour in larval zebrafish. (Danio rerio)
Authors: Varga Zoltán K , Zsigmond Áron , Pejtsik Diána , Varga Máté , Demeter Kornél , Mikics Éva , Haller József , Aliczki Manó
Published: June 2018

Larval zebrafish (Danio rerio) has the potential to supplement rodent models due to the availability of resource efficient methods implying high-throughput screening and high-resolution imaging techniques. Although behavioural models are available in larvae, only a few, insensitive approaches can be employed to assess anxiety. Here we present the swimming plus-maze (SPM) test paradigm to assess anxiety-related states in young zebrafish. The “+” shaped apparatus consists of arms of different depth representing differentially aversive context. The paradigm was validated i.) in larval and juvenile zebrafish, ii.) after administration of compounds affecting human anxiety and iii.) in differentially aversive experimental conditions. Furthermore, we compared the SPM with conventional “anxiety tests” of larvae such as the open tank and light/dark tank tests to identify their shared characteristics. We clarified that the preference towards deeper water is conserved trough the ontogenesis and can be abolished by anxiolytic or enhanced by anxiogenic agents, respectively. The behavioural read-out is insensitive to the aversiveness of the platform and unrelated to behaviours assessed by conventional tests utilizing larval fish. Taken together, we developed a sensitive high-throughput test measuring anxiety-related responses of larval zebrafish, which likely reflect bottom-dwelling behaviour of adults, potentially supporting larva-based integrative approaches.
The complete mitochondrial genome of Melon thrips, Thrips palmi (Thripinae) and comparative analysis: A vector for Tospoviruses
Authors: Chakraborty Rajasree , Tyagi Kaomud , Kundu Shantanu , Rahaman Iftikar , Singha Devkant , Chandra Kailash , Patnaik Srinivas , Kumar Vikas
Published: June 2018

The melon thrips, Thrips palmi is a serious pest and vector for plant viruses on a wide range of economically important crops. DNA barcoding evidenced the presence of cryptic diversity in T. palmi and that warrants exhaustive molecular data. Our present study is on decoding the first complete mitochondrial genome of T. palmi (15,333 bp) through NGS technology. The mitogenome contains 37 genes, including 13 PCGs, two rRNAs, 22 tRNAs, and two control regions. The comparative analyses were conducted for gene arrangements, nucleotide composition, codon usage and phylogenetic relationship with other thrips mitogenomes. The nucleotide composition was 78.29% AT, and 21.72% GC with positive AT skewness (0.09) and negative GC skewness (−0.06). The ATN initiation codons were observed in 12 PCGs except cox1 with unique start codon (TTG). The RSCU analysis revealed Phe, Leu, Ile, Tyr, Asn, Lys and Met were the most frequently used amino acids in all PCGs. The codon CGG (Arg) was absent in T. palmi as compared to other thrips mitogenomes. The Ka/Ks ratio ranges from 0.078 in cox1 to 0.913 in atp8. We observed the typical cloverleaf secondary structure in most of the tRNA genes with a few exceptions; absence of DHU stem and loop in trnV and trnS, absence of DHU loop in trnE, lack of T-arm and loop in trnN. The position of trnS1 (between cox3 and CR2) is unique in T. palmi among all the studied thrips mitogenomes. The mitogenome contained 24 intergenic spacer regions and 12 overlapping regions. The CR2 is 63.77% similar to CR1, indicating a possible duplication and translocation in control region. Both the ML and BI phylogenetic trees revealed the close relationships of Thrips with Scirtothrips as compared to Frankliniella. Thus, more mitogenomes on the diverse thrips species is required to understand the in-depth phylogenetic and evolutionary relationships.
Group Size as a Trade Off Between Fertility and Predation Risk: Implications for Social Evolution
Authors: Dunbar R.I.M. , Carron Padraig Mac
Published: June 2018

Cluster analysis reveals a fractal pattern in the sizes of baboon groups, with peaks at ∼20, ∼40, ∼80 and ∼160. Although all baboon species individually exhibit this pattern, the two largest are mainly characteristic of the hamadryas and gelada. We suggest that these constitute three pairs of linear oscillators (20/40, 40/80 and 80/160), where in each case the higher value is set by limits on female fertility and the lower by predation risk. The lower pair of oscillators form an ESS in woodland baboons, with choice of oscillator being determined by local predation risk. Female fertility rates would naturally prevent baboons from achieving the highest oscillator with any regularity; nonetheless, hamadryas and gelada have been able to break through this fertility ‘glass ceiling’ and we suggest that they have been able to do so by using substructuring (based partly on using males as ‘hired guns’). This seems to have allowed them to increase group size significantly so as to occupy higher predation risk habitats (thereby creating the upper oscillator).
The meiotic recombination landscape ofDrosophila virilisis robust to mitotic damage during hybrid dysgenesis
Authors: Hemmer Lucas W. , Dias Guilherme , Smith Brittny , Vaerenberghe Kelley Van , Howard Ashley , Bergman Casey M. , Blumenstiel Justin P.
Published: June 2018

Germline DNA damage is a double-edged sword. Programmed double-strand breaks establish the foundation for meiotic recombination and chromosome segregation. However, double-strand breaks also pose a significant challenge for genome stability. Because of this, meiotic double-strand break formation is tightly regulated. However, natural selection can favor selfish behavior in the germline and transposable elements can cause double-strand breaks independent of the carefully regulated meiotic process. To understand how the regulatory mechanisms of meiotic recombination accommodate unregulated transposition, we have characterized the female recombination landscape in a syndrome of hybrid dysgenesis inDrosophila virilis. In this system, a cross between two strains ofD. viriliswith divergent transposable element and piRNA profiles results in germline transposition of diverse transposable elements, reduced fertility, and male recombination. We sought to determine how increased transposition during hybrid dysgenesis might perturb the meiotic recombination landscape. Our results show that the overall frequency and distribution of meiotic recombination is extremely robust to germline transposable element activation. However, we also find that hybrid dysgenesis can result in mitotic recombination within the female germline. Overall, these results show that landscape of meiotic recombination may be insensitive to the DNA damage caused by transposition during early development.
Scarless gene tagging of transcriptionally silent genes in hiPSCs to visualize cardiomyocyte sarcomeres in live cells
Authors: Roberts Brock , Arakaki Joy , Gerbin Kaytlyn A. , Malik Haseeb , Nelson Angelique , Hendershott Melissa C. , Hookway Caroline , Ludmann Susan A. , Mueller Irina A. , Yang Ruian , Rafelski Susanne M. , Gunawardane Ruwanthi N.
Published: June 2018

We describe a multi-step CRISPR/Cas9 gene editing method to create endogenously tagged GFP-fusions of transcriptionally silent genes in human induced pluripotent stem cells (hiPSCs), allowing visualization of proteins that are only expressed upon differentiation. To do this, we designed a donor template containing the monomeric EGFP (mEGFP) fusion tag and an mCherry selection cassette delivered in tandem to a target locus via homology directed repair (HDR). mCherry expression was driven by a constitutive promoter and served as a drug-free, excisable selection marker. Following selection, the mCherry cassette was excised with Cas9, creating an mEGFP-fusion with the target gene. We achieved scarless excision by using repetitive sequences to guide microhomology-mediated end joining (MMEJ) and introduce linker sequences between the mEGFP tag and the target gene. Using this strategy, we successfully tagged genes encoding the cardiomyocyte sarcomeric proteins troponin I (TNNI1), alpha-actinin (ACTN2), titin (TTN), myosin light chain 2a (MYL7), and myosin light chain 2v (MYL2) with mEGFP in undifferentiated hiPSCs. This methodology provides a general strategy for scarlessly introducing tags to transcriptionally silent loci in hiPSCs.