bluuebunny/crossref_metadata_2025 huggingface dataset:
MicroRNA Expression Profiling in the Prefrontal Cortex: Putative Mechanisms for the Cognitive Effects of Adolescent High Fat Feeding
Authors: Labouesse Marie A. , Polesel Marcello , Clementi Elena , Müller Flavia , Markkanen Enni , Mouttet Forouhar , Cattaneo Annamaria , Richetto Juliet
Published: May 2018

The medial prefrontal cortex (mPFC), master regulator of higher-order cognitive functions, is the only brain region that matures until late adolescence. During this period, the mPFC is sensitive to stressful events or suboptimal nutrition. For instance, high-fat diet (HFD) feeding during adolescence markedly impairs prefrontal-dependent cognition. It also provokes multiple changes at the cellular and synaptic scales within the mPFC, suggesting that major transcriptional events are elicited by HFD during this maturational period. The nature of this transcriptional reprogramming remains unknown, but may include epigenetic processes, in particular microRNAs, known to directly regulate synaptic functions. We used high–throughput screening in the adolescent mouse mPFC and identified 38 microRNAs differentially regulated by HFD, in particular mir-30e-5p. We used a luciferase assay to confirm the functional effect of mir-30e-5p on a chosen target: Ephrin-A3. Using global pathway analyses of predicted microRNA targets, we identified biological pathways putatively affected by HFD. Axon guidance was the top-1 pathway, validated by identifying gene expression changes of axon guidance molecules following HFD. Our findings delineate major microRNA transcriptional reprogramming within the mPFC induced by adolescent HFD. These results will help understanding the contribution of microRNAs in the emergence of cognitive deficits following early-life environmental events.
A non-invasive approach to estimate the energetic requirements of an increasing seabird population in a perturbed marine ecosystem
Authors: Gaglio Davide , Sherley Richard B. , Ryan Peter G. , Cook Timothée R.
Published: May 2018

There is a growing desire to integrate the food requirements of predators living in marine ecosystems impacted by humans into sustainable fisheries management. We used non-invasive video-recording, photography and focal observations to build time-energy budget models and to directly estimate the fish mass delivered to chicks by adult greater crested ternsThalasseus bergiibreeding in the Benguela ecosystem. Mean modelled adult daily food intake increased from 140.9 g·d−1of anchovyEngraulis capensisduring incubation to 171.7 g·d−1and 189.2 g·d−1when provisioning small and large chicks, respectively. Modelled prey intake expected to be returned to chicks was 58.3 g·d−1(95% credible intervals: 44.9–75.8 g·d−1) over the entire growth period. Based on our observations, chicks were fed 19.9 g·d−1(17.2–23.0 g·d−1) to 45.1 g·d−1(34.6–58.7 g·d−1) of anchovy during early and late provisioning, respectively. Greater crested terns have lower energetic requirements at the individual (range: 15–34%) and population level (range: 1–7%) than the other Benguela endemic seabirds that feed on forage fish. These modest requirements – based on a small body size and low flight costs – coupled with foraging plasticity have allowed greater crested terns to cope with changing prey availability, unlike the other seabirds species using the same exploited prey base.
Cancer Characteristic Gene Selection via Sample Learning Based on Deep Sparse Filtering
Authors: Liu Jian , Cheng Yuhu , Wang Xuesong , Zhang Lin , Wang Z. Jane
Published: May 2018

Identification of characteristic genes associated with specific biological processes of different cancers could provide insights into the underlying cancer genetics and cancer prognostic assessment. It is of critical importance to select such characteristic genes effectively. In this paper, a novel unsupervised characteristic gene selection method based on sample learning and sparse filtering, Sample Learning based on Deep Sparse Filtering (SLDSF), is proposed. With sample learning, the proposed SLDSF can better represent the gene expression level by the transformed sample space. Most unsupervised characteristic gene selection methods did not consider deep structures, while a multilayer structure may learn more meaningful representations than a single layer, therefore deep sparse filtering is investigated here to implement sample learning in the proposed SLDSF. Experimental studies on several microarray and RNA-Seq datasets demonstrate that the proposed SLDSF is more effective than several representative characteristic gene selection methods (e.g., RGNMF, GNMF, RPCA and PMD) for selecting cancer characteristic genes.
Cell behavior of the highly sticky bacterium Acinetobacter sp. Tol 5 during adhesion in laminar flows
Authors: Furuichi Yoshihide , Iwasaki Keita , Hori Katsutoshi
Published: May 2018

It is important to characterize how medically, industrially, or environmentally important bacteria adhere to surfaces in liquid flows in order to control their cell adhesion and subsequent biofilm formation. Acinetobacter sp. Tol 5 is a remarkably sticky bacterium that autoagglutinates through the adhesive nanofiber protein AtaA, which is applicable to cell immobilization in bioprocesses. In this study, the adhesion and behavior of Tol 5 cells in laminar flows were investigated using flow cell systems. Tol 5 cells autoagglutinated through AtaA and formed cell clumps during flowing. The cell clumps rather than single cells went downward due to gravity and adhered to the bottom surface. Under appropriate shear stress, a twin vortex was caused by a separated flow generated at the rear of the pre-immobilized cell clumps and carried the small cell clumps to this location, resulting in their stacking there. The rearward immobilized cell clumps developed into a large, stable aggregate with a streamlined shape, independent of cell growth. Cell clumps hardly ever developed under weak shear stress that could not generate a twin vortex and were broken up under excessively strong shear stress. These cell behaviors including the importance of clumping are interesting features in the bacterial adhesion processes.
Synthetic Lethality-based Identification of Targets for Anticancer Drugs in the Human Signaling Network
Authors: Liu Lei , Chen Xiujie , Hu Chunyu , Zhang Denan , Shao Zhuo , Jin Qing , Yang Jingbo , Xie Hongbo , Liu Bo , Hu Ming , Ke Kehui
Published: May 2018

Chemotherapy agents can cause serious adverse effects by attacking both cancer tissues and normal tissues. Therefore, we proposed a synthetic lethality (SL) concept-based computational method to identify specific anticancer drug targets. First, a 3-step screening strategy (network-based, frequency-based and function-based screening) was proposed to identify the SL gene pairs by mining 697 cancer genes and the human signaling network, which had 6306 proteins and 62937 protein-protein interactions. The network-based screening was composed of a stability score constructed using a network information centrality measure (the average shortest path length) and the distance-based screening between the cancer gene and the non-cancer gene. Then, the non-cancer genes were extracted and annotated using drug-target interaction and drug description information to obtain potential anticancer drug targets. Finally, the human SL data in SynLethDB, the existing drug sensitivity data and text-mining were utilized for target validation. We successfully identified 2555 SL gene pairs and 57 potential anticancer drug targets. Among them, CDK1, CDK2, PLK1 and WEE1 were verified by all three aspects and could be preferentially used in specific targeted therapy in the future.
Basal interferon signaling and therapeutic use of interferons in controlling rotavirus infection in human intestinal cells and organoids
Authors: Hakim Mohamad S. , Chen Sunrui , Ding Shihao , Yin Yuebang , Ikram Aqsa , Ma Xiao-xia , Wang Wenshi , Peppelenbosch Maikel P. , Pan Qiuwei
Published: May 2018

Rotavirus (RV) primarily infects enterocytes and results in severe diarrhea, particularly in children. It is known that the host immune responses determine the outcome of viral infections. Following infections, interferons (IFNs) are produced as the first and the main anti-viral cytokines to combat the virus. Here we showed that RV predominantly induced type III IFNs (IFN-λ1), and to a less extent, type I IFNs (IFN-α and IFN-β) in human intestinal cells. However, it did not produce detectable IFN proteins and thus, was not sufficient to inhibit RV replication. In contrast, we revealed the essential roles of the basal IFN signaling in limiting RV replication by silencing STAT1, STAT2 and IRF9 genes. In addition, exogenous IFN treatment demonstrated that RV replication was able to be inhibited by all types of IFNs, both in human intestinal Caco2 cell line and in primary intestinal organoids. In these models, IFNs significantly upregulated a panel of well-known anti-viral IFN-stimulated genes (ISGs). Importantly, inhibition of the JAK-STAT cascade abrogated ISG induction and the anti-RV effects of IFNs. Thus, our study shall contribute to better understanding of the complex RV-host interactions and provide rationale for therapeutic development of IFN-based treatment against RV infection.
Development of in vitro and in vivo neutralization assays based on the pseudotyped H7N9 virus
Authors: Tian Yabin , Zhao Hui , Liu Qiang , Zhang Chuntao , Nie Jianhui , Huang Weijing , Li Changgui , Li Xuguang , Wang Youchun
Published: May 2018

H7N9 viral infections pose a great threat to both animal and human health. This avian virus cannot be handled in level 2 biocontainment laboratories, substantially hindering evaluation of prophylactic vaccines and therapeutic agents. Here, we report a high-titer pseudoviral system with a bioluminescent reporter gene, enabling us to visually and quantitatively conduct analyses of virus replications in both tissue cultures and animals. For evaluation of immunogenicity of H7N9 vaccines, we developed an in vitro assay for neutralizing antibody measurement based on the pseudoviral system; results generated by the in vitro assay were found to be strongly correlated with those by either hemagglutination inhibition (HI) or micro-neutralization (MN) assay. Furthermore, we injected the viruses into Balb/c mice and observed dynamic distributions of the viruses in the animals, which provides an ideal imaging model for quantitative analyses of prophylactic and therapeutic monoclonal antibodies. Taken together, the pseudoviral systems reported here could be of great value for both in vitro and in vivo evaluations of vaccines and antiviral agents without the need of wild type H7N9 virus.
In-vivo activation of vomeronasal neurons shows adaptive responses to pheromonal stimuli
Authors: Silvotti Lucia , Cavaliere Rosa Maria , Belletti Silvana , Tirindelli Roberto
Published: May 2018

In most mammals, the vomeronasal system has a pivotal role in mediating socio-sexual behaviours. The vomeronasal organ senses pheromones through the activation of specific receptors. Pheromone binding to cognate receptors activates Ca-influx via the gating of a cation channel that generates membrane depolarisation. The ex-vivo activation of vomeronasal neurons (VSNs) by pheromonal stimuli has been largely investigated by electrophysiological and imaging techniques; however, few studies have been carried out to determine the physiological responses of VSNs, in-vivo. By tracking the phosphorylation of S6 ribosomal protein as a marker of neuronal activity, we show that S6 becomes phosphorylated (pS6) in mouse VSNs stimulated by intraspecific and heterospecific pheromonal cues. We observed that female scent induces pS6 immunoreactivity in the apical VSNs of male vomeronasal epithelium, whereas male cues stimulate S6 phosphorylation in both the basal and apical VSNs of females. We also show that this dimorphic pattern of pS6 immunoreactivity is reproduced when heterospecific stimuli are used. Moreover, we found that a consistent proportion of VSNs is activated by both heterospecific and intraspecific pheromones. Additionally, we have evidence of adaptive responses to S6 phosphorylation when stimulation with cues of the same and opposite sex and of different species is sustained.
The effect of duplex Surface mechanical attrition and nitriding treatment on corrosion resistance of stainless steel 316L
Authors: Li Nana , Wang Ning
Published: May 2018

Surface mechanical attrition treatment (SMAT) fabricates a nanostructured layer on the surface of 316L that possesses excellent mechanical properties. In this paper a duplex process combining SMAT with nitriding was performed, then the microstructure, hardness and corrosion properties of the treated materials were investigated by using X-ray diffraction (XRD), transmission electron microscopy (TEM), hardness tests, potentiodynamic polarization measurements, X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The results showed that this duplex surface treatment can effectively increase the hardness and corrosion resistance of the treated surface both at room temperature and in the simulated steam generator (SG) condition at high temperature and high pressure.
Transcriptome analysis in Hevea brasiliensis latex revealed changes in hormone signalling pathways during ethephon stimulation and consequent Tapping Panel Dryness
Authors: Montoro Pascal , Wu Shuangyang , Favreau Bénédicte , Herlinawati Eva , Labrune Cécile , Martin-Magniette Marie-Laure , Pointet Stéphanie , Rio Maryannick , Leclercq Julie , Ismawanto Sigit , Kuswanhadi
Published: May 2018

Tapping Panel Dryness (TPD) affects latex production in Hevea brasiliensis. This physiological syndrome involves the agglutination of rubber particles, which leads to partial or complete cessation of latex flow. Latex harvesting consists in tapping soft bark. Ethephon can be applied to stimulate latex flow and its regeneration in laticifers. Several studies have reported transcriptome changes in bark tissues. This study is the first report on deep RNA sequencing of latex to compare the effect of ethephon stimulation and TPD severity. Trees were carefully selected for paired-end sequencing using an Illumina HiSeq 2000. In all, 43 to 60 million reads were sequenced for each treatment in three biological replicates (slight TPD trees without ethephon stimulation, and slight and severe TPD trees with ethephon treatment). Differentially expressed genes were identified and annotated, giving 8,111 and 728 in response to ethephon in slight TPD trees and in ethephon-induced severe TPD trees, respectively. A biological network of responses to ethephon and TPD highlighted the major influence of metabolic processes and the response to stimulus, especially wounding and jasmonate depression in TPD-affected trees induced by ethephon stimulation.
Organocatalytic synthesis of densely functionalized oxa-bridged 2,6-epoxybenzo[b][1,5]oxazocine heterocycles
Authors: Gurubrahamam Ramani , Nagaraju Koppanathi , Chen Kwunmin
Published: May 2018

An interesting organocascade reaction was developed to provide privileged epoxy-bridged azaheterocyclic skeletons.
Populating surface-trapped electrons towards SERS enhancement of W18O49 nanowires
Authors: Gu Ling-Jun , Ma Chun-Lan , Zhang Xiao-Hua , Zhang Wei , Cong Shan , Zhao Zhi-Gang
Published: May 2018

The population of surface-trapped electrons determines the SERS performance of a W18O49 substrate, as proved by construction of metal–semiconductor or organic–semiconductor interfaces.
How to treat C–F stretching vibrations? A vibrational CD study on chiral fluorinated molecules
Authors: Kreienborg Nora M. , Merten Christian
Published: May 2018

Due to the poor prediction of harmonic frequencies, vibrational modes containing C–F stretching motions are often strongly misplaced by common hybrid functionals. Herein we show that M06-2X functional performs exceptionally good in these cases.
Two-dimensional nitrides as highly efficient potential candidates for CO2 capture and activation
Authors: Morales-Salvador Raul , Morales-García Ángel , Viñes Francesc , Illas Francesc
Published: May 2018

The performance of novel two-dimensional nitrides in carbon capture and storage (CCS) is analyzed for a broad range of pressures and temperatures.
Solar light harvesting with multinary metal chalcogenide nanocrystals
Authors: Stroyuk Oleksandr , Raevskaya Alexandra , Gaponik Nikolai
Published: May 2018

The paper reviews the current state in synthesis, photovoltaic, photocatalytic and photoelectrochemical applications of multinary metal chalcogenide nanocrystals and nanostructures.
Tuning nanosheet Fe2O3 photoanodes with C3N4 and p-type CoOx decoration for efficient and stable water splitting
Authors: Mei Zongwei , Li Yehuan , Yang Xiaoyang , Ren Wenju , Tong Shengfu , Zhang Ning , Zhao Wenguang , Lin Yuan , Pan Feng
Published: May 2018

Fe2O3 photoanodes are ideal candidates for photoelectrochemical (PEC) water splitting.
Varied spin crossover behaviour in a family of dinuclear Fe(ii) triple helicate complexes
Authors: Archer Rosanna J. , Scott Hayley S. , Polson Matthew I. J. , Williamson Bryce E. , Mathonière Corine , Rouzières Mathieu , Clérac Rodolphe , Kruger Paul E.
Published: May 2018

A family of dinuclear Fe(ii) triple helicate complexes has been structurally characterised and their spin crossover behaviour studied using a variety of variable temperature physical techniques.
Chiroptical and magnetic properties of star-shaped FeIII4 complexes from chiral Schiff bases. Structural and magnetic correlations based on continuous shape measures
Authors: Mayans Julia , Font-Bardia Mercè , Escuer Albert
Published: May 2018

An enantiomeric FeIII4 pair of clusters have been synthesized employing enantiomerically pure Schiff bases and magnetically characterized. The star shaped FeIII4 system has been reviewed in light of Continuous Shape Measures (CShM) to analyze structural and/or magnetic correlations.
The effect of an electron-withdrawing group in the imidazolium cation: the case of nitro-functionalized imidazolium salts as acidic catalysts for the acetylation of glycerol
Authors: Morais Eduardo M. , Grillo Igor B. , Stassen Hubert K. , Seferin Marcus , Scholten Jackson D.
Published: May 2018

A simple and inexpensive nitration of the imidazolium cation can considerably increase its acidic activity in the acetylation of glycerol.
Formal [4 + 2] cycloaddition of imines with alkoxyisocoumarins
Authors: Jarvis Claire L. , Jemal Neyra M. , Knapp Spencer , Seidel Daniel
Published: May 2018

A new preparation of δ-lactams is reported.
Hydrogen storage in Mg2Ni(Fe)H4 nano particles synthesized from coarse-grained Mg and nano sized Ni(Fe) precursor
Authors: Chen Xi , Zou Jianxin , Huang Shuqing , He Guangli , Zhao Ning , Zeng Xiaoqin , Ding Wenjiang
Published: May 2018

Mg2Ni(Fe)H4 was synthesized from precursors of coarse grained Mg powder and Ni(Fe) nano particles with improved hydrogen sorption kinetics and thermodynamics as compared to Mg2Ni(Fe)H4.
Polyimide film with low thermal expansion and high transparency by self-enhancement of polyimide/SiC nanofibers net
Authors: Liu Feiyan , Liu Zhihong , Gao Shuyu , You Qingliang , Zou Liyong , Chen Jia , Liu Jiyan , Liu Xueqing
Published: May 2018

Polyimide films with low thermal expansion and high transparency were fabricated by homogeneity enhancement of nanofibers net. The nanofibers net that composed of polyimide and SiC nanoparticles is obtained by electrospinning technic.
Highly sensitive sensing of hydroquinone and catechol based on β-cyclodextrin-modified carbon dots
Authors: Lin Zhong-Yi , Kuo Yuan-Chieh , Chang Chih-Jui , Lin Yu-Syuan , Chiu Tai-Chia , Hu Cho-Chun
Published: May 2018

In the proposed study, an efficient method for a carbon dot@β-cyclodextrin (C-dot@β-CD)-based fluorescent probe was developed for the analyses of catechol (CC) and hydroquinone (HQ) at trace levels in water samples.
Ultraflexible, stretchable and fast-switching electrochromic devices with enhanced cycling stability
Authors: Liu Qian , Xu Zijie , Qiu Wu , Hou Chen , Wang Yanan , Yao Peijian , Yu Rui , Guo Wenxi , Liu Xiang Yang
Published: May 2018

We present a flexible sandwiched tungsten trioxide/silver nanotrough network/poly(3,4-ethylenedioxythiophene)–poly(styrene sulfonate) multi-layer transparent conducting electrode with prominent conductivity and transparency.
Diffusion doping route to plasmonic Si/SiOxnanoparticles
Authors: Bubenov Sergei S. , Dorofeev Sergey G. , Eliseev Andrei A. , Kononov Nikolay N. , Garshev Alexey V. , Mordvinova Natalia E. , Lebedev Oleg I.
Published: May 2018

An electrically active impurity was introduced into Si/SiOxnanoparticles with high temperature annealing in phosphorus vapor.
The physicochemical properties of a room-temperature liquidus binary ionic liquid mixture of [HNMP][CH3SO3]/[Bmim]Cl and its application for fructose conversion to 5-hydroxymethylfurfural
Authors: Xiao Yuyan , Huang Xirong
Published: May 2018

A liquidus mixture of [HNMP][CH3SO3]/[Bmim]Cl has been characterized and tried as medium for room-temperature conversion of fructose into HMF.
Recent progress on graphene-based substrates for surface-enhanced Raman scattering applications
Authors: Lai Huasheng , Xu Fugang , Zhang Yue , Wang Li
Published: May 2018

Graphene-based SERS substrates are classified and introduced, and their applications in biosensing-related fields are reviewed.
A low temperature and air-sinterable copper–diamine complex-based metal organic decomposition ink for printed electronics
Authors: Dong Yue , Lin Zhijie , Li Xiaodong , Zhu Qi , Li Ji-Guang , Sun Xudong
Published: May 2018

A Cu–diamine formulated ink for obtaining flexible conductive Cu films in an air atmosphere at temperatures as low as 130 °C.
Curcumin improves age-related and surgically induced osteoarthritis by promoting autophagy in mice
Authors: Zhang Guowang , Cao Jiaqing , Yang Erzhu , Liang Bo , Ding Jianing , Liang Jiaming , Xu Jianguang
Published: May 2018

Reduced autophagy has been implied in chondrocyte death and osteoarthritis. Curcumin (Cur) owns therapeutic effect against osteoarthritis (OA) and enhances autophagy in various tumor cells. Whether the cartilage protection of curcumin is associated with autophagy promotion and the potential signaling pathway involved remains unclear. The present study aimed to investigate the role of autophagy in the anti-OA activity of curcumin using spontaneous and surgically induced OA mice model. Spontaneous and surgically induced OA mice model was established and treated with Cur. Articular cartilage destruction and proteoglycan loss were scored through Safranin O/Fast green staining. Apoptotic cell death was detected with TUNEL (terminal deoxynucleotidyl transferase-mediated dTUP-biotin nick end labeling assay) staining and Western blot for caspase-3, Bcl-2 associated X protein (Bax), and Bcl-2 (B-cell lymphoma-2). Light chain 3 (LC3) immunohistochemistry was used to evaluate autophagy. In vitro, primary chondrocytes were treated with interleukin 1 beta (IL-1β) and Cur. Autophagy was inhibited using 3-methyladenine. Apoptosis and autophagy were detected using flow cytometry and Western blotting assay. Curcumin treatment enhanced autophagy, reduced apoptosis, and cartilage loss in both OA models. In vitro, curcumin treatment improved IL-1β induced autophagy inhibition, cell viability decrease, and apoptosis. Mechanistically, in vivo studies suggested curcumin promoted autophagy through regulating Akt/mTOR pathway. In conclusion, our results demonstrate that curcumin-induced autophagy via Akt/mTOR signaling pathway contributes to the anti-OA effect of curcumin.
Comparison of the oxidative reactivity of recombinant fetal and adult human hemoglobin: implications for the design of hemoglobin-based oxygen carriers
Authors: Simons Michelle , Gretton Svetlana , Silkstone Gary G.A. , Rajagopal Badri S. , Allen-Baume Victoria , Syrett Natalie , Shaik Thoufieq , Leiva-Eriksson Nelida , Ronda Luca , Mozzarelli Andrea , Strader Michael B. , Alayash Abdu I. , Reeder Brandon J. , Cooper Chris E.
Published: May 2018

Hemoglobin (Hb)-based oxygen carriers (HBOCs) have been engineered to replace or augment the oxygen carrying capacity of erythrocytes. However, clinical results have generally been disappointing, in part due to the intrinsic oxidative toxicity of Hb. The most common HBOC starting material is adult human or bovine Hb. However, it has been suggested that fetal Hb may offer advantages due to decreased oxidative reactivity. Large-scale manufacturing of HBOC will likely and ultimately require recombinant sources of human proteins. We, therefore, directly compared the functional properties and oxidative reactivity of recombinant fetal (rHbF) and recombinant adult (rHbA) Hb. rHbA and rHbF produced similar yields of purified functional protein. No differences were seen in the two proteins in: autoxidation rate; the rate of hydrogen peroxide reaction; NO scavenging dioxygenase activity; and the NO producing nitrite reductase activity. The rHbF protein was: less damaged by low levels of hydrogen peroxide; less damaging when added to human umbilical vein endothelial cells (HUVEC) in the ferric form; and had a slower rate of intrinsic heme loss. The rHbA protein was: more readily reducible by plasma antioxidants such as ascorbate in both the reactive ferryl and ferric states; less readily damaged by lipid peroxides; and less damaging to phosphatidylcholine liposomes. In conclusion in terms of oxidative reactivity, there are advantages and disadvantages to the use of rHbA or rHbF as the basis for an effective HBOC.
The Development of Bilingual Narrative Retelling Among Spanish–English Dual Language Learners Over Two Years
Authors: Lucero Audrey
Published: May 2018

Purpose

This exploratory study investigates the development of oral narrative retell proficiency among Spanish–English emergent bilingual children longitudinally from kindergarten to second grade in Spanish and English as they learned literacy in the 2 languages concurrently.

Method

Oral narrative retell assessments were conducted with children who spoke Spanish at home and were enrolled in a dual language immersion program (
N
= 12) in the spring of kindergarten and second grade. Retells were transcribed and coded for vocabulary and grammar at the microlevel (Miller, Andriacchi, & Nockerts, 2015, 2016) and story structure at the macrolevel (Heilmann, Miller, Nockerts, & Dunaway, 2010).

Results

In microstructure paired-sample
t
tests, children showed significant improvements in vocabulary in both languages (Spanish total number of words η
2
= .43, Spanish number of different words η
2
= .44, English total number of words η
2
= .61, English number of different words η
2
= .62) but not grammar by second grade. At the macrostructure level, children showed significantly higher performance in English only (English narrative scoring scheme η
2
= .47).

Conclusions

The finding that children significantly improved in vocabulary in both languages but in overall story structure only in English suggests that discourse skills were being facilitated in English whereas Spanish discourse development may have stagnated even within a dual language immersion program. Results contribute to what is currently known about bilingual oral narrative development among young Spanish speakers enrolled in such programs and can inform assessment and instructional decisions.
Catching a star before explosion: the luminous blue variable progenitor of SN 2015bh
Authors: Boian I. , Groh J. H.
Published: May 2018

In this paper we analyse the pre-explosion spectrum of SN2015bh by performing radiative transfer simulations using the CMFGEN code. This object has attracted significant attention due to its remarkable similarity to SN2009ip in both its pre- and post-explosion behaviour. They seem to belong to a class of events for which the fate as a genuine core-collapse supernova or a non-terminal explosion is still under debate. Our CMFGEN models suggest that the progenitor of SN2015bh had an effective temperature between 8700 and 10 000 K, had a luminosity in the range ≃1.8−4.74 × 106 L⊙, contained at least 25% H in mass at the surface, and had half-solar Fe abundances. The results also show that the progenitor of SN2015bh generated an extended wind with a mass-loss rate of ≃6 × 10−4 to 1.5 × 10−3 M⊙ yr−1 and a velocity of 1000km s−1. We determined that the wind extended to at least 2.57 × 1014 cm and lasted for at least 30 days prior to the observations, releasing 5 × 10−5 M⊙ into the circumstellar medium. In analogy to 2009ip, we propose that this is the material that the explosive ejecta could interact at late epochs, perhaps producing observable signatures that can be probed with future observations. We conclude that the progenitor of SN2015bh was most likely a warm luminous blue variable of at least 35 M⊙ before the explosion. Considering the high wind velocity, we cannot exclude the possibility that the progenitor was a Wolf–Rayet (WR) star that inflated just before the 2013 eruption, similar to HD5980 during its 1994 episode. If the star survived, late-time spectroscopy may reveal either a similar luminous blue variable (LBV) or a WR star, depending on the mass of the H envelope before the explosion. If the star exploded as a genuine supernova (SN), 2015bh would be a remarkable case of a successful explosion after black hole formation in a star with a possible minimum mass 35 M⊙ at the pre-SN stage.
The interaction of multiple stellar winds in stellar clusters: potential flow
Authors: Scherer K. , Noack A. , Kleimann J. , Fichtner H. , Weis K.
Published: May 2018

Context. While several studies have investigated large-scale cluster winds resulting from an intra-cluster interaction of multiple stellar winds, as yet they have not provided details of the bordering flows inside a given cluster.

Aims. The present work explores the principal structure of the combined flow resulting from the interaction of multiple stellar winds inside stellar clusters.

Methods. The theory of complex potentials is applied to analytically investigate stagnation points, boundaries between individual outflows, and the hydrodynamic structure of the asymptotic large-scale cluster wind. In a second part, these planar considerations are extended to fully three-dimensional, asymmetric configurations of wind-driving stars.

Results. We find (i) that one can distinguish regions in the large-scale cluster wind that are determined by the individual stellar winds, (ii) that there are comparatively narrow outflow channels, and (iii) that the large-scale cluster wind asymptotically approaches spherical symmetry at large distances.

Conclusions. The combined flow inside a stellar cluster resulting from the interaction of multiple stellar winds is highly structured.
Detecting the Yarkovsky effect among near-Earth asteroids from astrometric data
Authors: Del Vigna A. , Faggioli L. , Milani A. , Spoto F. , Farnocchia D. , Carry B.
Published: May 2018

We present an updated set of near-Earth asteroids with a Yarkovsky-related semimajor axis drift detected from the orbital fit to the astrometry. We find 87 reliable detections after filtering for the signal-to-noise ratio of the Yarkovsky drift estimate and making sure the estimate is compatible with the physical properties of the analysed object. Furthermore, we find a list of 24 marginally significant detections for which future astrometry could result in a Yarkovsky detection. A further outcome of the filtering procedure is a list of detections that we consider spurious because they are either unrealistic or not explicable by the Yarkovsky effect. Among the smallest asteroids of our sample, we determined four detections of solar radiation pressure in addition to the Yarkovsky effect. As the data volume increases in the near future, our goal is to develop methods to generate very long lists of asteroids that have a Yarkovsky effect that is reliably detected and have limited amounts of case by case specific adjustments. Furthermore, we discuss the improvements this work could bring to impact monitoring. In particular, we exhibit two asteroids for which the adoption of a non-gravitational model is needed to make reliable impact predictions.
Effect of rotational excitation of H2 on isotopic exchange reaction with OD− at low temperatures
Authors: Roučka Š. , Rednyk S. , Kovalenko A. , Tran T. D. , Plašil R. , Kálosi Á. , Dohnal P. , Gerlich D. , Glosík J.
Published: May 2018

Aims. This paper presents experimentally obtained rate coefficients for the weakly endothermic reaction OD− + H2 → OH− + HD with ortho- and para-hydrogen at astrophysically relevant temperatures between 10 and 300 K.

Methods. The reaction was studied with normal and para-enriched (99.5% para-H2) hydrogen in a 22-pole ion trap. The measured temperature dependencies of reaction rate coefficients are analyzed using a model which assumes that the rotational energies of the two reactants are equivalent to the translational energy in driving the reaction.

Results. At room temperature, the rate coefficients of reactions with both nuclear spin variants reach 7 × 10−11 cm3 s−1, which is in good agreement with the previous results from ion trap and swarm experiments with normal hydrogen. Cooling down the trap slows down the reaction and leads, at a nominal trap temperature of 11 K, to a rate coefficient below 10−14 cm3 s−1 for para-enriched hydrogen. The fitted reaction endothermicity of 25.3 ± 2.2 meV agrees well with the literature value calculated in the Born-Oppenheimer approximation, ΔH0 = 24.0 meV. A simpler evaluation procedure, fitting the data with Arrhenius functions, results in pk = 16.8 × 10−11 exp(−234 K/T) cm3 s−1 for pure para-hydrogen and ok = 9.4 × 10−11 exp(−101 K/T) cm3 s−1 for pure orthohydrogen.
Study of the technical performance of localized irrigation and its environmental and agroeconomic impact in the first areas of collective reconversion at the irrigated perimeter of the Tadla - Beni Moussa perimeter of the west – Morocco
Authors: Mouradi Abdellah , Ait Yacine Zehor , El Harti Abderrazak
Published: May 2018

The evaluation of the performance of the localized irrigation system involved a selected sample of farmers to reflect the diversity of the study area. The hydraulic diagnosis revealed the absence of apparent malfunctioning anomalies of the installations studied (Coefficient of Distribution Uniformity ≥ 90% with average application efficiencies and overall of 90.54 and 86.83% respectively). In terms of the combined use of surface and underground irrigation water this new technique has saved about 30% compared to conventional irrigation. The agro-economic evaluation revealed that the crops practiced have high value-added and optimize the value of irrigation water. The environmental impact has resulted in an average drawdown of the static level of groundwater of 2.59 m due mainly to the new irrigation method introduced, which limited the percolation of water to the aquifer. The drip-to-drip transition resulted in an increase in salinity relative compared to the reference situation (+ 0.59 %, or 0.01 mS / cm) but to different degrees depending on the prospecting soil horizon. The practice of fertilization remains the major and probable cause of soil salinization of aquifers. The effect of soluble salts on the soil was investigated through the risks associated with sodium, which showed that the soil permeability problem does not arise at this time (SAR ≤ 15). The residual sodium carbonate remains less than 1.25 meq / l thus not causing soil dispersion.
Physicochemical and bacteriological characterization of raw sewage from the Meknes region Morocco
Authors: Hassan Ouallal , Hamzaoui Najia El , Mohammed Sbiti , Mohammed Machkor , Lahcen Messaoudi , Mohamed Azrour
Published: May 2018

The region of Meknes suffers from a significant delay in the water sector, including sewage treatment. The Urban waste water in the region originates from various activities; households, industry, agriculture and hospital. These waters are released in to nature without any treatment, which constitutes a serious risk for the environment. The objective of this research is to characterize the physicochemical and bacteriological pollution of the three sewage collectors of the Meknes region (Aïn Choubbik, Oued Ouislane and Aïn Taoujdate). Indeed, the pollution parameters; biological and chemical oxygen demand are abnormally high, which indicates clearly that waste waters is rich of reducing or oxidizing organic materials. Ammonium, nitrogen, phosphorus and heavy metals concentrations exceed the limit values. So these waters are classified as bad or very bad quality. On the one hand, the presence of a large bacterial load indicates fecal contamination. The total coliform, fecal coliform and fecal streptococci levels are high exceeding exceed the values specified the WHO guidelines and the Moroccan standards. This situation is likely to cause serious and irreparable damage to the environment groundwater. To counter this, make the necessary investment in sewage treatment and other remedial measures is key to preventing pollution and its spread.
Integrating the environment in local strategic planning : Guidelines (Case of Morocco)
Authors: Benbrahim Hafsa
Published: May 2018

Since 2010, an advanced regionalization project has been initiated by Morocco, which plans to consolidate the processes of decentralization and deconcentration by extending the powers of the regions and other local authorities. This project, institutionalized in the 2011 Constitution, defines the territorial organization of the Kingdom and reinforces decentralization according to a model of advanced regionalization. Through advanced regionalization, Morocco aims at integrated and sustainable development in economic, social, cultural and environmental terms, through the development of the potential and resources of each region. However, in order to honor this commitment of advanced regionalization, local authorities must be assisted in adopting a local strategic planning approach, allowing them to develop territorial plans for sustainable development in accordance with the national legal framework, specifically the Framework law 99-12, and international commitments in terms of environmental protection. This research deals with the issue of environmental governance in relation to the role and duties of local authorities. Thus, the main goal of our study is to present the guidelines to be followed by the local authorities to improve the quality of the environment integration process in the local strategic planning with the aim of putting it in a perspective of sustainable development.
Modelling soil salinity in Oued El Abid watershed, Morocco
Authors: Mouatassime Sabri El , Boukdir Ahmed , Karaoui Ismail , Arioua Abdelkrim , Messlouhi Rachid , El Amrani Idrissi Abdelkhalek
Published: May 2018

Soil salinisation is a phenomenon considered to be a real threat to natural resources in semi-arid climates. The phenomenon is controlled by soil (texture, depth, slope etc.), anthropogenic factors (drainage system, irrigation, crops types, etc.), and climate factors. This study was conducted in the watershed of Oued El Abid in the region of Beni Mellal-Khenifra, aimed at localising saline soil using remote sensing and a regression model. The spectral indices were extracted from Landsat imagery (30 m resolution). A linear correlation of electrical conductivity, which was calculated based on soil samples (ECs), and the values extracted based on spectral bands showed a high accuracy with an R2 (Root square) of 0.80. This study proposes a new spectral salinity index using Landsat bands B1 and B4. This hydro-chemical and statistical study, based on a yearlong survey, showed a moderate amount of salinity, which threatens dam water quality. The results present an improved ability to use remote sensing and regression model integration to detect soil salinity with high accuracy and low cost, and permit intervention at an early stage of salinisation.
Quantification of soil loss in various lithological areas of the western Middle Atlas Central: application to the Ras-Elma, Tamelalet and Sebab watershed (Tigrigra watershed, Morocco)
Authors: Achiban Hassan , Taous Ali , El-Khantoury Ismail , El Mderssa Mohamed , Amechrouq Ali
Published: May 2018

The present study proposes to evaluate the extent of erosion according to the lithology in three sub-watersheds (Ras Elma, Sebab and Tamelalet) belonging to the Tigrigra basin and evolving in humid climatic context. The methodology adopts the revised universal soil loss equation (RUSLE). The results obtained make it possible to establish erosion class maps via GIS. A clear spatial difference in soil loss is observed, between the three sub-basins and in proportion to the lithology: on average 42.15 t/ha/year on Paleozoic schistose soils, against 17.06 t/ha/year on carbonate substrates Mesozoic and 8.46 t/ha/year on quaternary basalts. Correlations between soil loss and RUSLE factors are established. Soil infiltration regimes on different substrates are studied.
Estimation of Particle Material And Dissolved Flows During Floods In The Inaouene Watershed. (Northeast Of Morocco)
Authors: Sibari Hayat , Haida Souad , Foutlane Mohamed
Published: May 2018

This work aims to estimate the contributions of the Inaouene River during the floods. It is in this context that the dissolved and particulate matter flows were measured during the flood periods followed by the 1996/97 study year at the two hydrological stations Bab Marzouka (upstream) and El Kouchat (downstream). The specific flows of dissolved materials calculated upstream and downstream of the Inaouene watershed correspond respectively to 257 t/ km2/year and 117 t/ km2/year. Chlorides represent 30% and 41% respectively of the total dissolved transport upstream and downstream. The potential mechanical degradation affecting the Inaouene watershed can deliver a solid load estimated at 6.106 t/year corresponding to a specific flow of 2142 t/km2/year.
Frequency-domain analysis method for analyzing and improving the steady-state characteristics of microcantilever in tapping-mode atomic force microscopy
Authors: Gu Xiaohui , Sun Lining , Ru Changhai
Published: May 2018

In tapping-mode AFM, the steady-state characteristics of microcantilever are extremely important to determine the AFM performance. Due to the external excitation signal and the tip-sample interactions, the solving process of microcantilever motion equation will become very complicated with the traditional time-domain analysis method. In this paper, we propose the novel frequency-domain analysis method to analyze and improve the steady-state characteristics of microcantilever. Compared with the previous methods, this new method has three prominent advantages. Firstly, the analytical expressions of amplitude and phase of cantilever system can be derived conveniently. Secondly, the stability of the cantilever system can be accurately determined and the stability margin can be obtained quantitatively in terms of the phase margin and the magnitude margin. Thirdly, on this basis, external control mechanism can be devised quickly and easily to guarantee the high stability of the cantilever system. With this novel method, we derive the frequency response curves and discuss the great influence of the intrinsic parameters on the system stability, which provides theoretical guidance for selecting samples to achieve better AFM images in the experiments. Moreover, we introduce a new external series correction method to significantly increase the stability margin. The results indicate that the cantilever system is no longer easily disturbed by external interference signals.
Influence of as-built surface and heat treatment on the fatigue resistance of Additively Layer Manufacturing (ALM) AlSi10Mg alloy.
Authors: Domfang Ngnekou Julius Noel , Nicolai Julien , Nadot Yves , Henaff Gilbert , Ridosz Lionel
Published: May 2018

This work concerns the fatigue resistance of a AlSi10Mg material produced by additive manufacturing, and more precisely the competition between as built manufacturing surface and as-machined surface on the fatigue resistance. Samples were built by a powder-bed process with an EOS-M280 machine using standard in two configurations (0° and 90°) in order to evaluate the impact of building direction on fatigue life. The impact of as-built surface on fatigue behavior is quantified for each specimen configuration. A T6 heat treatment is performed on samples in order to evaluate the impact of microstructure on fatigue behavior. For each configurations, the S-N curves is determined in as-built and T6 materials with a load ratio R= -1. The fracture surfaces are carefully analyzed in order to determine the critical defect size for each sample. A Kitagawa type diagram representing the fatigue limit as a function of the defect size is derived from these measurements. All the results were compared to those obtained in asmachined samples.
Hydrogen-assisted fatigue crack propagation in a pure BCC iron. Part II: Accelerated regime manifested by quasi-cleavage fracture at relatively high stress intensity range values
Authors: Birenis Domas , Ogawa Yuhei , Matsunaga Hisao , Takakuwa Osamu , Yamabe Junichiro , Prytz Øystein , Thøgersen Annett
Published: May 2018

Hydrogen effect on fatigue performance at relatively high values of stress intensity factor range, ΔK, of pure BCC iron has been studied with a combination of various electron microscopy techniques. Hydrogen-assisted fatigue crack growth rate is manifested by a change of fracture features at the fracture surface from ductile transgranular in air to quasi-cleavage in hydrogen gas. Grain reference orientation deviation (GROD) analysis has shown a dramatic suppression of plastic deformation around the crack wake in samples fatigued in hydrogen. These results were verified by preparing site-specific specimens from different fracture features by using Focused Ion Beam (FIB) technique and observing them with Transmission Electron Microscope (TEM). The FIB lamella taken from the sample fatigued in air was decorated with dislocation cell structure indicating high amount of plasticity, while the lamella taken from the quasi-cleavage surface of the sample fatigued in hydrogen revealed a distribution of dislocation tangles which corresponds to smaller plastic strain amplitude involved at the point of fracture. These results show that a combination of critical hydrogen concentration and critical stress during fatigue crack growth at high ΔK values triggers cleavage-like fracture due to reduction of cohesive force between matrix atoms.
Evolution Study of the Surface States of Low Carbon Microalloyed Steel before and after Corrosion in NaCl Solution
Authors: Benkafada Faouzia , Kerdoud Djahida , Bouchoucha Ali
Published: May 2018

Surface topography is of paramount interest in science, technology, and industry. In this work investigation of the evolution of the surface with multiparameter characterization was carried out using optical profiler. Surface profile is measured two-dimensionally applying Gaussian filter of cutoff 0.8 mm. Ra, Rq, Rsk, Rku, Rp, Rvand Rzvalues according to the standard ISO 4287 were measured. Following ISO 25178, 3D roughness parameters: Sa, Sq, Ssk, Sku, Spand Svvalues were reported. The appearance of the texture of our microalloyed steel has been indicated by evaluating the texture aspect Str. Analysis of Abott-Firestone curves and related parameters Smrand Sdcwas presented. Some significant characterization parameters such as surface hardness, weight loss and corrosion rate were analysed and compared.