bluuebunny/crossref_metadata_2025 huggingface dataset:
Non-toxic engineered carbon nanodiamond concentrations induce oxidative/nitrosative stress, imbalance of energy metabolism, and mitochondrial dysfunction in microglial and alveolar basal epithelial cells
Authors: Fresta Claudia G. , Chakraborty Aishik , Wijesinghe Manjula B. , Amorini Angela M. , Lazzarino Giacomo , Lazzarino Giuseppe , Tavazzi Barbara , Lunte Susan M. , Caraci Filippo , Dhar Prajnaparamita , Caruso Giuseppe
Published: February 2018

Engineered nanoparticles are finding a wide spectrum of biomedical applications, including drug delivery and capacity to trigger cytotoxic phenomena, potentially useful against tumor cells. The full understanding of their biosafety and interactions with cell processes is mandatory. Using microglial (BV-2) and alveolar basal epithelial (A549) cells, in this study we determined the effects of engineered carbon nanodiamonds (ECNs) on cell viability, nitric oxide (NO) and reactive oxygen species (ROS) production, as well as on energy metabolism. Particularly, we initially measured decrease in cell viability as a function of increasing ECNs doses, finding similar cytotoxic ECN effects in the two cell lines. Subsequently, using apparently non-cytotoxic ECN concentrations (2 µg/mL causing decrease in cell number < 5%) we determined NO and ROS production, and measured the concentrations of compounds related to energy metabolism, mitochondrial functions, oxido-reductive reactions, and antioxidant defences. We found that in both cell lines non-cytotoxic ECN concentrations increased NO and ROS production with sustained oxidative/nitrosative stress, and caused energy metabolism imbalance (decrease in high energy phosphates and nicotinic coenzymes) and mitochondrial malfunctioning (decrease in ATP/ADP ratio).

These results underline the importance to deeply investigate the molecular and biochemical changes occurring upon the interaction of ECNs (and nanoparticles in general) with living cells, even at apparently non-toxic concentration. Since the use of ECNs in biomedical field is attracting increasing attention the complete evaluation of their biosafety, toxicity and/or possible side effects both in vitro and in vivo is mandatory before these highly promising tools might find the correct application.
Dural effects of oxidative stress on cardiomyogenesis via Gata4 transcription and protein ubiquitination
Authors: Li Tao , Zhang Xia , Jiang Kesheng , Liu Jing , Liu Zhiqiang
Published: February 2018

Abstract

Oxidative stress generates reactive oxygen species (ROS) that can promote or inhibit cardiac differentiation of stem cells dependent on the intensity of stimuli as well as cellular context in redox and differentiation status. In the current study, we confirmed that suitable intensity of hydrogen peroxide at the formation stage of embryoid bodies (EBs) effectively favored the formation of spontaneously beating cardiomyocytes from P19 embryonal carcinoma cells. Mechanistic studies implicated that extrinsic ROS enhanced the Caspase-mediated degradation of Oct4 and Nanog, two factors that governing pluripotent property. Further experiments suggested that a cohort of Nanog together with histone deacetylase 4 (Hdac4) played a critical role in establishing and maintaining the silent transcriptional status of Gata4 and Nkx2.5 in undifferentiated cells. Thus, an impulse of hydrogen peroxide depleted Nanog and Hdac4 via a caspase-dependent manner to ameliorate the repression on Gata4 and Nkx2.5 promoters, thereby generating a persistent activation on cardiac differentiation program. Meanwhile, we found that excessive ROS-activated JNK cascade to facilitate the ubiquitination and subsequent degradation of Gata4 protein. Overall, our results indicate that suitable ROS promotes the activation of Gata4 in transcription, while excessive ROS targets Gata4 protein for proteasome-dependent degradation. Gata4 is an important modulator balancing the promoting and inhibitory effects of oxidative stress on differentiation program of cardiomyogenesis.
Temporal requirements for ISL1 in sympathetic neuron proliferation, differentiation, and diversification
Authors: Zhang Qingquan , Huang Ru , Ye Youqiong , Guo Xiaoxia , Lu Jun , Zhu Fugui , Gong Xiaohui , Zhang Qitong , Yan Jie , Luo Lina , Zhuang Shaowei , Chen Yihan , Zhao Xiaodong , Evans Sylvia M. , Jiang Cizhong , Liang Xingqun , Sun Yunfu
Published: February 2018

Malformations of the sympathetic nervous system have been associated with cardiovascular instability, gastrointestinal dysfunction, and neuroblastoma. A better understanding of the factors regulating sympathetic nervous system development is critical to the development of potential therapies. Here, we have uncovered a temporal requirement for the LIM homeodomain transcription factor ISL1 during sympathetic nervous system development by the analysis of two mutant mouse lines: an Isl1 hypomorphic line and mice with Isl1 ablated in neural crest lineages. During early development, ISL1 is required for sympathetic neuronal fate determination, differentiation, and repression of glial differentiation, although it is dispensable for initial noradrenergic differentiation. ISL1 also plays an essential role in sympathetic neuron proliferation by controlling cell cycle gene expression. During later development, ISL1 is required for axon growth and sympathetic neuron diversification by maintaining noradrenergic differentiation, but repressing cholinergic differentiation. RNA-seq analyses of sympathetic ganglia from Isl1 mutant and control embryos, together with ISL1 ChIP-seq analysis on sympathetic ganglia, demonstrated that ISL1 regulates directly or indirectly several distinct signaling pathways that orchestrate sympathetic neurogenesis. A number of genes implicated in neuroblastoma pathogenesis are direct downstream targets of ISL1. Our study revealed a temporal requirement for ISL1 in multiple aspects of sympathetic neuron development, and suggested Isl1 as a candidate gene for neuroblastoma.
Loss of NDRG2 in liver microenvironment inhibits cancer liver metastasis by regulating tumor associate macrophages polarization
Authors: Li Mengyang , Lai Xiaofeng , Zhao Ying , Zhang Yuan , Li Minghui , Li Danxiu , Kong Jing , Zhang Yong , Jing Pengyu , Li Huichen , Qin Hongyan , Shen Liangliang , Yao Libo , Li Jipeng , Dou Kefeng , Zhang Jian
Published: February 2018

The liver is the predominant metastatic site for several types of malignancies. Tumor-associated macrophages (TAMs) in the liver play crucial roles in the metastasis process. Shifting tumor-promoting M2-like TAMs toward the M1-like phenotype, which exerts tumor suppressor functions via phagocytosis and the secretion of inhibitory factors, may be a potential therapeutic strategy for liver cancer metastasis treatment.

We first cloned NDRG2 (N-myc downstream-regulated gene 2) and verified its tumor suppressor role in multiple solid tumors, including colorectal cancer and hepatocellular carcinoma. However, its role in the tumor-associated liver microenvironment, especially in TAMs, has not been illustrated. By establishing a liver cancer metastasis model in wild-type (WT) and Ndrg2 knockout (Ndrg2−/−) mice, we found that the loss of the tumor suppressor Ndrg2 in liver microenvironment significantly suppressed the growth of liver colonies. In addition, this process was accompanied by a higher proportion of M1-like TAM infiltration in Ndrg2−/− mice. Interestingly, bone marrow (BM) transplantation revealed that BM-derived macrophages (BMDMs) rather than liver resident Kupffer cells were responsible for the inhibitory effect. We further demonstrated that loss of Ndrg2 influenced TAM polarization via the NF-κB pathway. Inhibition of IκBα phosphorylation in cancer cell-conditioned medium-stimulated BMDMs decreased M1 marker expression in Ndrg2−/− macrophages. Finally, in vitro, invasion, migration, and proliferation assays confirmed that NF-κB participated in the tumor suppressor function of Ndrg2−/− macrophages. Collectively, our findings highlight the role of NDRG2 in the regulation of TAM polarization and its function in promoting cancer liver metastasis.
Impaired autophagic flux is associated with the severity of trauma and the role of A2AR in brain cells after traumatic brain injury
Authors: Zeng Xu-Jia , Li Ping , Ning Ya-Lei , Zhao Yan , Peng Yan , Yang Nan , Zhao Zi-Ai , Chen Jiang-Fan , Zhou Yuan-Guo
Published: February 2018

Recent studies have shown that after traumatic brain injury (TBI), the number of autophagosomes is markedly increased in brain cells surrounding the wound; however, whether autophagy is enhanced or suppressed by TBI remains controversial. In our study, we used a controlled cortical impact system to establish models of mild, moderate and severe TBI. In the mild TBI model, the levels of autophagy-related protein 6 (Beclin1) and autophagy-related protein 12 (ATG12)-autophagy-related protein 5 (ATG5) conjugates were increased, indicating the enhanced initiation of autophagy. Furthermore, the level of the autophagic substrate sequestosome 1 (SQSTM1) was decreased in the ipsilateral cortex. This result, together with the results observed in tandem mRFP-GFP-LC3 adeno-associated virus (AAV)-infected mice, indicates that autophagosome clearance was also increased after mild TBI. Conversely, following moderate and severe TBI, there was no change in the initiation of autophagy, and autophagosome accumulation was observed. Next, we used chloroquine (CQ) to artificially impair autophagic flux in the injured cortex of the mild TBI model and found that the severity of trauma was obviously exacerbated. In addition, autophagic flux and trauma severity were significantly improved in adenosine A2A receptor (A2AR) knockout (KO) mice subjected to moderate TBI. Thus, A2AR may be involved in regulating the impairment of autophagic flux in response to brain injury. Our findings suggest that whether autophagy is increased after TBI is associated with whether autophagic flux is impaired, and the impairment of autophagic flux exacerbates the severity of trauma. Furthermore, A2AR may be a target for alleviating the impairment in autophagic flux after TBI.
Flubendazole inhibits glioma proliferation by G2/M cell cycle arrest and pro-apoptosis
Authors: Zhou Xumin , Liu Jumei , Zhang Jinming , Wei Yong , Li Hua
Published: February 2018

Flubendazole, FDA-approved anthelmintic, has been widely used in treating testinal parasites. In the recent years, Flubendazole has been reported to exert anticancer activities. On the other hand, little was known about the effects of Flubendazole on gliomas. Here we demonstrated a novel effect of flubendazole on glioma cells. We found that Flubendazole inhibited cell proliferation and promoted cell apoptosis of glioma cell lines in vitro, and suppressed tumor growth in xenograft models by intraperitoneal injection. However, Flubendazole might have no influence on cell migration. Mechanism study reaveled that Flubendazole caused cell cycle arrest in G2/M phase, which partly account for the suppressed proliferation. Consistently, Flubendazole induced P53 expression and reduced Cyclin B1 and p-cdc2 expression in glioma cells. In addition, Flubendazole promoted cell apoptosis by regulating the classical apoptosis protein BCL-2 expression. These observations suggest that Flubendazole exerts anti-proliferation and pro-apoptosis effects in Glioma through affecting the cell cycle and intrinsic apoptotic signaling, and indicate a novel utilization of Flubendazole in the treatment of Glioma.
Prostaglandin D2 amplifies lupus disease through basophil accumulation in lymphoid organs
Authors: Pellefigues Christophe , Dema Barbara , Lamri Yasmine , Saidoune Fanny , Chavarot Nathalie , Lohéac Charlotte , Pacreau Emeline , Dussiot Michael , Bidault Caroline , Marquet Florian , Jablonski Mathieu , Chemouny Jonathan M. , Jouan Fanny , Dossier Antoine , Chauveheid Marie-Paule , Gobert Delphine , Papo Thomas , Karasuyama Hajime , Sacré Karim , Daugas Eric , Charles Nicolas
Published: February 2018

In systemic lupus erythematosus (SLE), autoantibody production can lead to kidney damage and failure, known as lupus nephritis. Basophils amplify the synthesis of autoantibodies by accumulating in secondary lymphoid organs. Here, we show a role for prostaglandin D2(PGD2) in the pathophysiology of SLE. Patients with SLE have increased expression of PGD2receptors (PTGDR) on blood basophils and increased concentration of PGD2metabolites in plasma. Through an autocrine mechanism dependent on both PTGDRs, PGD2induces the externalization of CXCR4 on basophils, both in humans and mice, driving accumulation in secondary lymphoid organs. Although PGD2can accelerate basophil-dependent disease, antagonizing PTGDRs in mice reduces lupus-like disease in spontaneous and induced mouse models. Our study identifies the PGD2/PTGDR axis as a ready-to-use therapeutic modality in SLE.
Extraction condition optimization and effects of drying methods on physicochemical properties and antioxidant activities of polysaccharides from Astragalus cicer L.
Authors: Shang Hongmei , Wang Menghan , Li Ran , Duan Mengying , Wu Hongxin , Zhou Haizhu
Published: February 2018

Response surface methodology (RSM) including three variables was performed to optimize the extraction parameters of Astragalus cicer L. polysaccharides (ACPs). The influence of different drying techniques on the physicochemical properties and antioxidant abilities of ACPs were evaluated. The ACPs were dried with hot air (HD), vacuum (VD) and freeze drying (FD) methods. The optimal conditions for ACPs extraction were as follows: water to raw material ratio of 25 mL/g, extraction time of 61 min and temperature of 75 °C. Under these parameters, an ACPs yield of 10.97% was obtained. HPLC analysis showed that the monosaccharide compositions of the three ACPs dried with HD, VD or FD techniques were identical. The three ACPs exhibited antioxidant abilities in a concentration-dependent manner. ACPs dried with the FD method (FD-ACPs) had the best antioxidant activities, which might be related to their smaller molecular weight and higher uronic acid content. At the determined concentration of 1 mg/mL, the ferric reducing power, and DPPH and ABTS free radical scavenging capacities of FD-ACPs were 0.762, 75.30% and 99.21%, respectively. Therefore, FD was a good choice for the drying of Astragalus cicer L. polysaccharides.
Shikonin exerts antitumor activity in Burkitt’s lymphoma by inhibiting C-MYC and PI3K/AKT/mTOR pathway and acts synergistically with doxorubicin
Authors: Ni Fan , Huang Xianbo , Chen Zhenzhen , Qian Wenbin , Tong Xiangmin
Published: February 2018

Burkitt’s lymphoma (BL) is a highly aggressive malignancy molecularly characterized by deregulation of the C-MYC proto-oncogene. Recently, it has been confirmed that phosphatidylinositol-3-kinase (PI3K) pathway activation is a crucial element in the malignant transformation of the B cells in BL. Despite the better outcome of adults with BL treated with high-intensity chemotherapy regimens, the overall survival rate for patients older than 60 years remains dismal. Shikonin, a natural naphthoquinone derived from Chinese herbal medicine plant, has the potential to induce cell death in a series of human cancer. In the present study, we investigated the effect and molecular mechanisms of Shikonin in treatment with BL. Shikonin suppressed cellular proliferation and induced caspase-dependent apoptosis in BL cells. Inhibition of C-MYC and suppression of PI3K/AKT/mTOR pathway played critical roles in SHK-induced apoptosis in BL both in vitro and in vivo. Besides, Shikonin potentiated doxorubicin-induced growth inhibition and apoptosis in vitro. Furthermore, the growth of a subcutaneous xenograft tumor model of BL was significantly inhibited by shikonin. Importantly, we did not find the effect of shikonin on liver function in mice. In summary, these data suggest that shikonin may be an encouraging chemotherapeutic agent in the clinical treatment of BL.
Photonic Generation of Triangular-shaped Waveform Based on External Modulation
Authors: Yuan Jin , Ning Tigang , Li Jing , Pei Li , Zheng Jingjing , Li Yueqin
Published: February 2018

We present a novel approach for triangular-shaped waveform generation by applying optical single sideband (OSSB) modulation and optical carrier suppression (OCS) modulation to an input signal. Firstly, an OSSB modulated signal consists of an optical carrier and +1st-order sideband, is initially generated with a dual-drive Mach-Zehnder modulator (DD-MZM1) driven by a quadruple frequency RF signal. By tuning the amplitude of the RF signal and the bias of the DD-MZM1, the power ratio between the carrier and the +1st-order sideband is controlled as 19 dB. These two components are then transmitted to a DD-MZM2 which is driven by a fundamental frequency. After OCS modulation, four sidebands are existed in optical spectra of the modulated signal. By utilizing a fiber Bragg grating (FBG) to remove the undesired sideband, an output signal that features a triangular-shaped waveform is finally achieved.
fNIRS Optodes’ Location Decider (fOLD): a toolbox for probe arrangement guided by brain regions-of-interest
Authors: Zimeo Morais Guilherme Augusto , Balardin Joana Bisol , Sato João Ricardo
Published: February 2018

The employment of functional near-infrared spectroscopy (fNIRS) as a method of brain imaging has increased over the last few years due to its portability, low-cost and robustness to subject movement. Experiments with fNIRS are designed in the face of a limited number of sources and detectors (optodes) to be positioned on selected portion(s) of the scalp. The optodes locations represent an expectation of assessing cortical regions relevant to the experiment’s hypothesis. However, this translation process remains a challenge for fNIRS experimental design. In the present study, we propose an approach that automatically decides the location of fNIRS optodes from a set of predefined positions with the aim of maximizing the anatomical specificity to brain regions-of-interest. The implemented method is based on photon transport simulations on two head atlases. The results are compiled into the publicly available “fNIRS Optodes’ Location Decider” (fOLD). This toolbox is a first-order approach to bring the achieved advancements of parcellation methods and meta-analyses from functional magnetic resonance imaging to more precisely guide the selection of optode positions for fNIRS experiments.
Probing semiconductivity in crystals of stable semiquinone radicals: organic salts of 5,6-dichloro-2,3-dicyanosemiquinone (DDQ) radical anions
Authors: Molčanov Krešimir , Stalke Dietmar , Šantić Ana , Demeshko Serhiy , Stilinović Vladimir , Mou Zhongyu , Kertesz Miklos , Kojić-Prodić Biserka
Published: February 2018

The structural parameters and semiconductivity of crystals with stacked 5,6-dichloro-2,3-dicyanosemiquinone (DDQ) radicals were studied for a series of nine salts of DDQ with substituted N-ethyl- and N-methylpyridinium cations.
Metamagnetism stabilized giant magnetoelectric coupling in ferroelectric xBaTiO3–(1 − x)BiCoO3 solid solution
Authors: Patra Lokanath , Pan Zhao , Chen Jun , Azuma Masaki , Ravindran P.
Published: February 2018

xBaTiO3–(1 − x)BiCoO3 shows metamagnetism induced giant magnetoelectric for x < 0.45 and magnetic to nonmagnetic transition for higher x values.
Thermal properties of lauric acid filled in carbon nanotubes as shape-stabilized phase change materials
Authors: Feng Yanhui , Wei Runzhi , Huang Zhi , Zhang Xinxin , Wang Ge
Published: February 2018

A relationship between the melting temperature shift and the structural properties of lauric acid confined in carbon nanotubes based on the Gibbs–Thomson equation.
Approaches to target tractability assessment – a practical perspective
Authors: Brown Kristin K. , Hann Michael M. , Lakdawala Ami S. , Santos Rita , Thomas Pamela J. , Todd Kieran
Published: February 2018

The assessment of the suitability of novel targets to intervention by different modalities, e.g. small molecules or antibodies, is increasingly seen as important in helping to select the most progressable targets at the outset of a drug discovery project.
Synthesis of graphene quantum dot/metal–organic framework nanocomposites as yellow phosphors for white light-emitting diodes
Authors: Pan Dengyu , Wang Lijun , Li Zhen , Geng Bijiang , Zhang Chen , Zhan Jing , Yin Luqiao , Wang Liang
Published: February 2018

Graphene quantum dots (GQDs) and a metal–organic framework were assembled to form a nanocomposite for solving the GQDs’ fluorescence quenching problem in WLEDs.
Zero- and two-dimensional hybrid carbon phosphors for high colorimetric purity white light-emission
Authors: Ding Yamei , Chang Qing , Xiu Fei , Chen Yingying , Liu Zhengdong , Ban Chaoyi , Cheng Shuai , Liu Juqing , Huang Wei
Published: February 2018

Zero- and two-dimensional hybrid carbon phosphors have been preparedviaa facile single-step hydrothermal method to realize high colorimetric purity white light-emission.
Investigation of excited state, reductive quenching, and intramolecular electron transfer of Ru(ii)–Re(i) supramolecular photocatalysts for CO2reduction using time-resolved IR measurements
Authors: Koike Kazuhide , Grills David C. , Tamaki Yusuke , Fujita Etsuko , Okubo Kei , Yamazaki Yasuomi , Saigo Masaki , Mukuta Tatsuhiko , Onda Ken , Ishitani Osamu
Published: February 2018

Time-resolved IR spectra indicated fast electron transfer from the reduced photosensitizer to the catalyst.
Carbene insertion into N–H bonds with size-selectivity induced by a microporous ruthenium–porphyrin metal–organic framework
Authors: Chen Lianfen , Cui Hao , Wang Yanhu , Liang Xiang , Zhang Li , Su Cheng-Yong
Published: February 2018

A stable and porous porphyrinic metal–organic framework Ru-PMOF-1(Hf) has been prepared and used for N–H insertion reactions with high efficiency and selectivity.
A self-powered porous ZnS/PVDF-HFP mechanoluminescent composite film that converts human movement into eye-readable light
Authors: Li Haitao , Zhang Yihe , Dai Han , Tong Wangshu , Zhou Yan , Zhao Junfeng , An Qi
Published: February 2018

A facile self-powered electroluminescent material effectively converts mechanical vibration into light visible to the naked eye.
Direct catalytic enantioselective amination of ketones for the formation of tri- and tetrasubstituted stereocenters
Authors: Trost B. M. , Tracy J. S. , Saget T.
Published: February 2018

A Zn–ProPhenol catalyzed direct amination of α-branched and unbranched ketones produces α-amino carbonyl and β-amino alcohol products.
Thioredoxin regulates G6PDH activity by changing redox states of OpcA in the nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120
Authors: Mihara Shoko , Wakao Hitomi , Yoshida Keisuke , Higo Akiyoshi , Sugiura Kazunori , Tsuchiya Akihiro , Nomata Jiro , Wakabayashi Ken-ichi , Hisabori Toru
Published: February 2018

Glucose 6-phosphate dehydrogenase (G6PDH) catalyzes the first reaction in the oxidative pentose phosphate pathway. In green plant chloroplasts, G6PDH is a unique redox-regulated enzyme, since it is inactivated under the reducing conditions. This regulation is accomplished using a redox-active cysteine pair, which is conserved in plant G6PDH. The inactivation of this enzyme under conditions of light must be beneficial to prevent release of CO2 from the photosynthetic carbon fixation cycle. In the filamentous, heterocyst-forming, nitrogen-fixing cyanobacterium Anabaena sp. PCC 7120 (Anabaena 7120), G6PDH plays a pivotal role in providing reducing power for nitrogenase, and its activity is also reported to be suppressed by reduction, though Anabaena G6PDH does not conserve the critical cysteines for regulation. Based on the thorough analyses of the redox regulation mechanisms of G6PDH from Anabaena 7120 and its activator protein OpcA, we found that m-type thioredoxin regulates G6PDH activity by changing the redox states of OpcA. Mass spectrometric analysis and mutagenesis studies indicate that Cys393 and Cys399 of OpcA are responsible for the redox regulation property of this protein. Moreover, in vivo analyses of the redox states of OpcA showed that more than half of the OpcA is present as an oxidized form, even under conditions of light, when cells are cultured under the nitrogen-fixing conditions. This redox regulation of OpcA might be necessary to provide reducing power for nitrogenase by G6PDH in heterocysts even during the day.
Implementation Research: Embracing Practitioners' Views
Authors: Feuerstein Julie L. , Olswang Lesley B. , Greenslade Kathryn J. , Dowden Patricia , Pinder Gay Lloyd , Madden Jodi
Published: February 2018

Purpose

This research explores practitioners' perspectives during the implementation of triadic gaze intervention (TGI), an evidence-based protocol for assessing and planning treatment targeting gaze as an early signal of intentional communication for young children with physical disabilities.

Method

Using qualitative methods, 7 practitioners from 1 early intervention center reported their perceptions about (a) early intervention for young children with physical disabilities, (b) acceptability and feasibility in the use of the TGI protocol in routine practice, and (c) feasibility of the TGI training. Qualitative data were gathered from 2 semistructured group interviews, once before and once after TGI training and implementation.

Results

Qualitative results documented the practitioners' reflections on recent changes to early intervention service delivery, the impact of such change on TGI adoption, and an overall strong enthusiasm for the TGI protocol, despite some need for adaptation.

Conclusion

These results are discussed relative to adapting the TGI protocol and training, when considering how to best bring about change in practice. More broadly, results highlighted the critical role of researcher–practitioner collaboration in implementation research and the value of qualitative data for gaining a richer understanding of practitioners' perspectives about the implementation process.
Tutorial and Guidelines on Measurement of Sound Pressure Level in Voice and Speech
Authors: Švec Jan G. , Granqvist Svante
Published: February 2018

Purpose

Sound pressure level (SPL) measurement of voice and speech is often considered a trivial matter, but the measured levels are often reported incorrectly or incompletely, making them difficult to compare among various studies. This article aims at explaining the fundamental principles behind these measurements and providing guidelines to improve their accuracy and reproducibility.

Method

Basic information is put together from standards, technical, voice and speech literature, and practical experience of the authors and is explained for nontechnical readers.

Results

Variation of SPL with distance, sound level meters and their accuracy, frequency and time weightings, and background noise topics are reviewed. Several calibration procedures for SPL measurements are described for stand-mounted and head-mounted microphones.

Conclusions

SPL of voice and speech should be reported together with the mouth-to-microphone distance so that the levels can be related to vocal power. Sound level measurement settings (i.e., frequency weighting and time weighting/averaging) should always be specified. Classified sound level meters should be used to assure measurement accuracy. Head-mounted microphones placed at the proximity of the mouth improve signal-to-noise ratio and can be taken advantage of for voice SPL measurements when calibrated. Background noise levels should be reported besides the sound levels of voice and speech.
The MUCHFUSS photometric campaign
Authors: Schaffenroth V. , Geier S. , Heber U. , Gerber R. , Schneider D. , Ziegerer E. , Cordes O.
Published: February 2018

Hot subdwarfs (sdO/Bs) are the helium-burning cores of red giants, which have lost almost all of their hydrogen envelope. This mass loss is often triggered by common envelope interactions with close stellar or even substellar companions. Cool companions like late-type stars or brown dwarfs are detectable via characteristic light-curve variations like reflection effects and often also eclipses. To search for such objects, we obtained multi-band light curves of 26 close sdO/B binary candidates from the MUCHFUSS project with the BUSCA instrument. We discovered a new eclipsing reflection effect system (P= 0.168938 d) with a low-mass M dwarf companion (0.116M⊙). Three more reflection effect binaries found in the course of the campaign have already been published; two of them are eclipsing systems, and in one system only showing the reflection effect but no eclipses, the sdB primary is found to be pulsating. Amongst the targets without reflection effect a new long-period sdB pulsator was discovered and irregular light variations were found in two sdO stars. The found light variations allowed us to constrain the fraction of reflection effect binaries and the substellar companion fraction around sdB stars. The minimum fraction of reflection effect systems amongst the close sdB binaries might be greater than 15% and the fraction of close substellar companions in sdB binaries may be as high as 8.0%. This would result in a close substellar companion fraction to sdB stars of about 3%. This fraction is much higher than the fraction of brown dwarfs around possible progenitor systems, which are solar-type stars with substellar companions around 1 AU, as well as close binary white dwarfs with brown dwarf companions. This might suggest that common envelope interactions with substellar objects are preferentially followed by a hot subdwarf phase.
Disentangling Complexity in Bayesian Automatic Adaptive Quadrature
Authors: Adam Gheorghe , Adam Sanda
Published: February 2018

The paper describes a Bayesian automatic adaptive quadrature (BAAQ) solution for numerical integration which is simultaneously robust, reliable, and efficient. Detailed discussion is provided of three main factors which contribute to the enhancement of these features: (1) refinement of them-panel automatic adaptive scheme through the use of integration-domain-length-scale-adapted quadrature sums; (2) fast early problem complexity assessment – enables the non-transitive choice among three execution paths: (i) immediate termination (exceptional cases); (ii) pessimistic – involves time and resource consuming Bayesian inference resulting in radical reformulation of the problem to be solved; (iii) optimistic – asks exclusively for subrange subdivision by bisection; (3) use of the weaker accuracy target from the two possible ones (the input accuracy specifications and the intrinsic integrand properties respectively) – results in maximum possible solution accuracy under minimum possible computing time.
Fractional Stochastic Field Theory
Authors: Honkonen Juha
Published: February 2018

Models describing evolution of physical, chemical, biological, social and financial processes are often formulated as differential equations with the understanding that they are large-scale equations for averages of quantities describing intrinsically random processes. Explicit account of randomness may lead to significant changes in the asymptotic behaviour (anomalous scaling) in such models especially in low spatial dimensions, which in many cases may be captured with the use of the renormalization group. Anomalous scaling and memory effects may also be introduced with the use of fractional derivatives and fractional noise. Construction of renormalized stochastic field theory with fractional derivatives and fractional noise in the underlying stochastic differential equations and master equations and the interplay between fluctuation-induced and built-in anomalous scaling behaviour is reviewed and discussed.
New Possibilities and Applications of the Least Squares Collocation Method
Authors: Shapeev Vasiliy , Belyaev Vasiliy , Golushko Sergey , Idimeshev Semyon
Published: February 2018

Least squares collocation method (LSC) is a versatile numerical method for solving boundary value problems for PDE. The present article demonstrates the abilities of LSC to solve various problems – in particular, calculations of bending of isotropic irregular shaped plates and multi-layered anisotropic plates. In order to achieve higher accuracy, new versions of the method utilize high-degree polynomial spaces. The numerical experiments demonstrate high accuracy of the solutions.
Directed Percolation: Calculation of Feynman Diagrams in the Three-Loop Approximation
Authors: Adzhemyan Loran Ts. , Hnatič Michal , Kompaniets Mikhail V. , Lučivjanský Tomáš , Mižišin Lukáš
Published: February 2018

The directed bond percolation process is an important model in statistical physics. By now its universal properties are known only up to the second-order of the perturbation theory. Here, our aim is to put forward a numerical technique with anomalous dimensions of directed percolation to higher orders of perturbation theory and is focused on the most complicated Feynman diagrams with problems in calculation. The anomalous dimensions are computed up to three-loop order in ε = 4 − d.
Diffusion Processes in the A-Model of Vector Admixture: Turbulent Prandtl Number
Authors: Jurčišinová Eva , Jurčišin Marián , Remecky Richard
Published: February 2018

Using analytical approach of the field theoretic renormalization-group technique in two-loop approximation we model a fully developed turbulent system with vector characteristics driven by stochastic Navier-Stokes equation. The behaviour of the turbulent Prandtl number PrA,tis investigated as a function of parameterAand spatial dimensiond> 2 for three cases, namely, kinematic MHD turbulence (A= 1), the admixture of a vector impurity by the Navier-Stokes turbulent flow (A= 0) and the model of linearized Navier-Stokes equation (A= −1). It is shown that forA= −1 the turbulent Prandtl number is given already in the one-loop approximation and does not depend ondwhile turbulent Prandt numbers in first two cases show very similar behaviour as functions of dimensiondin the two-loop approximation.
Quark-Parton Model and Relativistic Quantum Mechanics
Authors: Kostenko Boris
Published: February 2018

An attempt to treat the asymptotic freedom and the quark confinement as a self-consistent problem in the framework of relativistic quantum mechanics is realized. It is shown that the confinement of quarks induces a change of their helicities together with a simultaneous alteration of orbital momenta, so that the total angular momentum of each quark is conserved. This observation may cast light on the so-called proton spin puzzle after some additional numerical estimations.
Near-Perfect Matchings on Cylinders Cm × Pn of Odd Order
Authors: Perepechko Sergey N.
Published: February 2018

A close relationship was established between the number of perfect and nearperfect matchings on cylinders Cm×Pn. Generating functions are obtained for the number of near-perfect matchings in these graphs for fixed odd m ≤ 13. A conjecture is put forth on the properties of the denominators of generating functions for arbitrary odd m.
Extrapolation of Functions of Many Variables by Means of Metric Analysis
Authors: Kryanev Alexandr , Ivanov Victor , Romanova Anastasiya , Sevastianov Leonid , Udumyan David
Published: February 2018

The paper considers a problem of extrapolating functions of several variables. It is assumed that the values of the function of m variables at a finite number of points in some domain D of the m-dimensional space are given. It is required to restore the value of the function at points outside the domain D. The paper proposes a fundamentally new method for functions of several variables extrapolation. In the presented paper, the method of extrapolating a function of many variables developed by us uses the interpolation scheme of metric analysis. To solve the extrapolation problem, a scheme based on metric analysis methods is proposed. This scheme consists of two stages. In the first stage, using the metric analysis, the function is interpolated to the points of the domain D belonging to the segment of the straight line connecting the center of the domain D with the point M, in which it is necessary to restore the value of the function. In the second stage, based on the auto regression model and metric analysis, the function values are predicted along the above straight-line segment beyond the domain D up to the point M. The presented numerical example demonstrates the efficiency of the method under consideration.
The Influence of the Relaxation Time on the Dynamic Hysteresis in Perovskite Solar Cells
Authors: Palici Alexandra , Nemnes George Alexandru , Besleaga Cristina , Pintilie Lucian , Anghel Dragos-Victor , Pintilie Ioana , Manolescu Andrei
Published: February 2018

We investigate the dynamic behavior of perovskite solar cells by focusing on the relaxation time τ, which corresponds to the slow de-polarization process from an initial bias pre-poled state. The dynamic electrical model (DEM) is employed for simulating the J-V characteristics for different bias scan rates and pre-poling conditions. Depending on the sign of the initial polarization normal or inverted hysteresis may be induced. For fixed pre-poling conditions, the relaxation time, in relation to the bias scan rate, governs the magnitude of the dynamic hysteresis. In the limit of large τ the hysteretic effects are vanishing for the typical range of bias scan rates considered, while for very small τ the hysteresis is significant only when it is comparable with the measurement time interval.
Time Based Global Track Reconstruction in CBM
Authors: Ablyazimov Timur , Friese Volker , Ivanov Victor
Published: February 2018

The paper describes the approaches, implemented by the authors, for the track reconstruction in data, subdivided to time slices, in the CBM experiment.
Nuclotron Beam Momentum Estimation Using Multiwire Proportional Chambers and Drift Chambers in the BM@N Experiment
Authors: Kapishin Mikhail , Lenivenko Vasilisa , Palichik Vladimir , Voytishin Nikolay
Published: February 2018

The BM@N experiment is considered as the first phase of NICA Mega science project. The energy of the beam will vary from 1 to 6 GeV/u. The beams delivered by Nuclotron will be of different types from protons to Au. The ability to reconstruct the beam momentum with high precision is one way for showing that the tracking detectors are tuned in the right way and the reconstruction procedure performs well.

A quick overview of the experimental setup is given in the work along with the description of some of the main tracking detectors. The beam momentum reconstruction procedure is described and results are presented for different values of the beam energy.
Light Ion Beams for Energy Production in ADS
Authors: Paraipan Mihaela , Baldin Anton A. , Baldina Elina G. , Tyutyunikov Serguey I.
Published: February 2018

A comparative study of the energy efficiency of proton beams with an energy from 0.5 GeV to 4 GeV and light ion beams (7Li, 9Be, 11B, and 12C) with energies from 0.25 AGeV to 1 AGeV in natural and enriched quasi-infinite U target is presented. The numerical results on the particle transport and interaction are obtained using the code Geant4. The following target optimization issues are addressed: the beam window dimensions, and the possibility to use a core from low Z materials. The best solution for ADS from the point of view of the energy gain and miniaturization is obtained for 7Li or 9Be beam with an energy of 0.3–0.4 AGeV and a target with Be core.
Radioactivity Registered With a Small Number of Events
Authors: Zlokazov Victor , Utyonkov Vladimir
Published: February 2018

The synthesis of superheavy elements asks for the analysis of low statistics experimental data presumably obeying an unknown exponential distribution and to take the decision whether they originate from one source or have admixtures. Here we analyze predictions following from non-parametrical methods, employing only such fundamental sample properties as the sample mean, the median and the mode.
Symbolic and Numerical Modeling of Nonlinear Dynamics of Particles in Accelerators
Authors: Andrianov Sergey , Sboeva Ekaterina
Published: February 2018

This paper is devoted to one of the methods of symbolic computation, which based on perturbation theory and constructed in the framework of matrix formalism. This method can be used for solving optimization problems and preliminary modeling in accelerator physics. There are presented the main theoretical positions and demonstration the result of this method on example of one of classical problems.
Web Platform for Sharing Modeling Software in the Field of Nonlinear Optics
Authors: Dubenskaya Julia , Kryukov Alexander , Demichev Andrey
Published: February 2018

We describe the prototype of a Web platform intended for sharing software programs for computer modeling in the rapidly developing field of the nonlinear optics phenomena. The suggested platform is built on the top of the HUBZero open-source middleware. In addition to the basic HUBZero installation we added to our platform the capability to run Docker containers via an external application server and to send calculation programs to those containers for execution. The presented web platform provides a wide range of features and might be of benefit to nonlinear optics researchers.
Application of Artificial Neural Networks and Singular-Spectral Analysis in Forecasting the Daily Traffic in the Moscow Metro
Authors: Ivanov Victor , Osetrov Evgenii
Published: February 2018

In this paper, we investigate the possibility of applying various approaches to solving the problem of medium-term forecasting of daily passenger traffic volumes in the Moscow metro (MM): 1) on the basis of artificial neural networks (ANN); 2) using the singular-spectral analysis implemented in the package “Caterpillar”-SSA; 3) sharing the ANN and the “Caterpillar”-SSA approach. We demonstrate that the developed methods and algorithms allow us to conduct medium-term forecasting of passenger traffic in the MM with reasonable accuracy.
SaaS Platform for Time Series Data Handling
Authors: Oplachko Ekaterina , Rykunov Stanislav , Ustinin Mikhail
Published: February 2018

The paper is devoted to the description of MathBrain, a cloud-based resource, which works as a “Software as a Service” model. It is designed to maximize the efficiency of the current technology and to provide a tool for time series data handling. The resource provides access to the following analysis methods: direct and inverse Fourier transforms, Principal component analysis and Independent component analysis decompositions, quantitative analysis, magnetoencephalography inverse problem solution in a single dipole model based on multichannel spectral data.
Concept of a Cloud Service for Data Preparation and Computational Control on Custom HPC Systems in Application to Molecular Dynamics
Authors: Puzyrkov Dmitry , Polyakov Sergey , Podryga Viktoriia , Markizov Sergey
Published: February 2018

At the present stage of computer technology development it is possible to study the properties and processes in complex systems at molecular and even atomic levels, for example, by means of molecular dynamics methods. The most interesting are problems related with the study of complex processes under real physical conditions. Solving such problems requires the use of high performance computing systems of various types, for example, GRID systems and HPC clusters. Considering the time consuming computational tasks, the need arises of software for automatic and unified monitoring of such computations. A complex computational task can be performed over different HPC systems. It requires output data synchronization between the storage chosen by a scientist and the HPC system used for computations. The design of the computational domain is also quite a problem. It requires complex software tools and algorithms for proper atomistic data generation on HPC systems. The paper describes the prototype of a cloud service, intended for design of atomistic systems of large volume for further detailed molecular dynamic calculations and computational management for this calculations, and presents the part of its concept aimed at initial data generation on the HPC systems.
Modeling Thermal Effects in Metals Irradiated by Copper Nanoclusters
Authors: Batgerel Balt , Dimova Stefka , Kupenova Temenujka , Puzynin Igor , Puzynina Taisia , Hristov Ivan , Hristova Radoslava , Tukhliev Zafar , Sharipov Zarif
Published: February 2018

One of the promising areas in condensed matter physics is the study of the interaction of nanoclusters with various metallic targets. In this paper we investigate the thermal processes in metals irradiated with nanoclusters by the molecular dynamics method. In the framework of this method wave effects of the heat transfer are obtained, a feature which is absent in the thermal spike model. We repost results of computer simulation of the structural changes in irradiated copper targets of different sizes depending on the energy (in the range of 10–50 eV/atom) of copper nanoclusters.
Numerical Investigation of the Time Discretization Impact on the Accuracy of a Point Target Localization by UWB Radar
Authors: Buša Ján , Kocur Dušan , Švecová Mária
Published: February 2018

UWB radar technologies enable localization of moving persons (targets) situated behind nonmetallic obstacles. Under exact knowledge of the propagation times, from the transmitting to the receiving antennas, of the radar emitted electromagnetic wave (time of arrival, TOA), a highly accurate target localization can be achieved. Since TOA estimates only are available, their use for target localization may result in a sizeable target localization error. In this paper we study the influence of TOA quantization on the point target localization accuracy using numerical simulation methods.
On the Thermodynamic Equilibrium Distribution of a Charge in a Homogeneous Chain with a Defect
Authors: Fialko Nadezhda , Pyatkov Maxim , Lakhno Victor
Published: February 2018

Based on the semi-classical Holstein Hamiltonian we consider charge transfer along a DNA chain of sites at different thermostat temperatures. Recently, using the computer simulation, it has been shown that the charge distribution in homogeneous chains in thermodynamic equilibrium depends not only on the temperature, but also on the length of the chain. We have studied numerically the case of polyadenine fragments with a defect site in the middle of the chain. The results demonstrate qualitatively similar behavior of thermodynamic equilibrium quantities in the case of the homogeneous chain and of the chain with a defect. Insertion of a trap-site enhances the stability of polaron states.
Simulation of AntiMatter–Matter Interactions in Geant4
Authors: Galoyan Aida , Uzhinsky Vladimir , Ribon Alberto
Published: February 2018

Cross sections of antiproton and antinucleus interactions with nuclei are calculated using stochastic averaging method. A new implementation of the Quark-Gluon-String Model (QGSM) is proposed for simulation of multi-particle production in antinucleus-nucleus collisions. A combination of the cross sections and the new implementation of QGSM allows experimental data on antiproton and antinucleus interactions with nuclei to be described. The combination is included in the well-known Geant4 simulation toolkit.
Hidden Attractors in a Model of a Bubble Contrast Agent Oscillating Near an Elastic Wall
Authors: Garashchuk Ivan , Sinelshchikov Dmitry , Kudryashov Nikolay
Published: February 2018

A model describing the dynamics of a spherical gas bubble in a compressible viscous liquid is studied. The bubble is oscillating close to an elastic wall of finite thickness under the influence of an external pressure field which simulates a contrast agent oscillating close to a blood vessel wall. Here we investigate numerically the coexistence of chaotic and periodic attractors in this model. One of the tools applied for seeking coexisting attractors is the perpetual points method. This method can be helpful for localizing coexisting attractors, occurring in various physically realistic ranges of variation of the control parameters. We provide some examples of coexisting attractors to demonstrate the importance of the multistability problem for the applications.