bluuebunny/crossref_metadata_2025 huggingface dataset:
A docitive Q‐learning approach towards joint resource allocation and power control in self‐organised femtocell networks
Authors: Shahid Adnan , Aslam Saleem , Kim Hyung Seok , Lee Kyung‐Geun
Published: February 2014

Femtocell is a technology that contributes towards the escalation of coverage as well as throughput. By virtue of uncertain deployment of femtocells, self‐organisation is a viable solution for resource allocation. In this study, we are projecting a docitive Q‐learning (DQL) paradigm for joint resource allocation and power control (JRAPC). Moreover, the proposed learning paradigm is compared with independent Q‐learning for the same JRAPC problem. In the proposed DQL paradigm, femto base stations, which are agents, learn the strategies by exploiting Q‐learning and share their learned strategies with their neighbours. Concerning the shared channel environment, the problem function is formulated as the maximisation of femtocell capacity while maintaining the quality of service requirement of the macrousers. The impact of the proposed DQL paradigm is investigated on system capacity and femtocell capacity. Furthermore, comparison is carried out with the considered independent learning paradigm in terms of convergence, min‐max capacity and the effect of femtocell density. Also, the fairness index is computed to have further insight. The results illustrate that DQL‐based JRAPC outperforms its counterpart. Copyright © 2014 John Wiley & Sons, Ltd.
Metastatic signature in lung cancer is associated with sensitivity to anti‐integrin αV monoclonal antibody intetumumab
Authors: Liu Huiqing , Park Jaehong , Manning Carol , Goehlmann Hinrich W.H. , Marshall Deborah J.
Published: February 2014

Intetumumab is a fully human monoclonal antibody that inhibits αv integrins. It has been shown in in vitro assays to effectively inhibit cell viability, metastasis, and adhesion of human cancer cells and endothelial cells. However, the response to Intetumumab varies in different tumor cell lines. To understand the growth inhibition mechanism of Intetumumab and to identify a molecular signature that can predict sensitivity, we focused on lung cancer cell lines and performed a series of proliferation assays. We then assessed the global gene expression profiles, DNA copy number variations, and microRNA profiles from a total of 23 lung cancer lines. The results revealed that lung cancer sensitivity to Intetumumab is associated with several chromosomal alterations, particularly genetic loss at chromosome arm 19p, which resulted in gene expression changes. We identified a genetic signature that can be used to predict Intetumumab sensitivity for lung cancer cell lines. Independently, microRNA analysis revealed a panel of signature microRNAs that includes several markers of epithelial to mesenchymal transition and tumor metastasis such as miR‐200 family and miR‐205. Both the genetic and microRNA signatures provide insights into the potential mechanism of Intetumumab activity and serve as the first step to develop a patient stratification strategy for Intetumumab therapy in lung cancer. © 2014 Wiley Periodicals, Inc.
Label‐fusion‐segmentation and deformation‐based shape analysis of deep gray matter in multiple sclerosis: The impact of thalamic subnuclei on disability
Authors: Magon Stefano , Chakravarty M. Mallar , Amann Michael , Weier Katrin , Naegelin Yvonne , Andelova Michaela , Radue Ernst‐Wilhelm , Stippich Christoph , Lerch Jason P. , Kappos Ludwig , Sprenger Till
Published: February 2014

Deep gray matter (DGM) atrophy has been reported in patients with multiple sclerosis (MS) already at early stages of the disease and progresses throughout the disease course. We studied DGM volume and shape and their relation to disability in a large cohort of clinically well‐described MS patients using new subcortical segmentation methods and shape analysis. Structural 3D magnetic resonance images were acquired at 1.5 T in 118 patients with relapsing remitting MS. Subcortical structures were segmented using a multiatlas technique that relies on the generation of an automatically generated template library. To localize focal morphological changes, shape analysis was performed by estimating the vertex‐wise displacements each subject must undergo to deform to a template. Multiple linear regression analysis showed that the volume of specific thalamic nuclei (the ventral nuclear complex) together with normalized gray matter volume explains a relatively large proportion of expanded disability status scale (EDSS) variability. The deformation‐based displacement analysis confirmed the relation between thalamic shape and EDSS scores. Furthermore, white matter lesion volume was found to relate to the shape of all subcortical structures. This novel method for the analysis of subcortical volume and shape allows depicting specific contributions of DGM abnormalities to neurological deficits in MS patients. The results stress the importance of ventral thalamic nuclei in this respect. Hum Brain Mapp 35:4193–4203, 2014. © 2014 Wiley Periodicals, Inc.
Extracting and summarizing white matter hyperintensities using supervised segmentation methods in Alzheimer's disease risk and aging studies
Authors: Ithapu Vamsi , Singh Vikas , Lindner Christopher , Austin Benjamin P. , Hinrichs Chris , Carlsson Cynthia M. , Bendlin Barbara B. , Johnson Sterling C.
Published: February 2014

Precise detection and quantification of white matter hyperintensities (WMH) observed in T2‐weighted Fluid Attenuated Inversion Recovery (FLAIR) Magnetic Resonance Images (MRI) is of substantial interest in aging, and age‐related neurological disorders such as Alzheimer's disease (AD). This is mainly because WMH may reflect co‐morbid neural injury or cerebral vascular disease burden. WMH in the older population may be small, diffuse, and irregular in shape, and sufficiently heterogeneous within and across subjects. Here, we pose hyperintensity detection as a supervised inference problem and adapt two learning models, specifically, Support Vector Machines and Random Forests, for this task. Using texture features engineered by texton filter banks, we provide a suite of effective segmentation methods for this problem. Through extensive evaluations on healthy middle‐aged and older adults who vary in AD risk, we show that our methods are reliable and robust in segmenting hyperintense regions. A measure of hyperintensity accumulation, referred to as normalized effective WMH volume, is shown to be associated with dementia in older adults and parental family history in cognitively normal subjects. We provide an open source library for hyperintensity detection and accumulation (interfaced with existing neuroimaging tools), that can be adapted for segmentation problems in other neuroimaging studies. Hum Brain Mapp 35:4219–4235, 2014. © 2014 Wiley Periodicals, Inc.
High‐grade cervical abnormalities and cervical cancer in women following a negative Pap smear with and without an endocervical component: A cohort study with 10 years of follow‐up
Authors: Sultana Farhana , English Dallas R. , Simpson Julie A. , Canfell Karen , Gertig Dorota M. , Saville Marion
Published: February 2014

The proportion of Pap smears containing an endocervical component (ECC) has been declining in Australia. Given that ECC negative (ECC−) smears may be associated with reduced sensitivity, we undertook a retrospective cohort study to estimate rates of histologically confirmed high‐grade cervical abnormality (HGA) and cancer in women with negative Pap smears with and without an ECC. Women 18‐69 years with at least two Pap smears between 1 January 2001 and 31 December 2010 with the first smear in that period (index smear) showing no abnormality were eligible. Follow‐up ended at date of the first abnormal smear, date of histological diagnosis, date of hysterectomy, date of death, or 31 December 2010, whichever came first. ECC status was treated as a time varying exposure. Follow‐up was split at each smear after the index smear. Poisson regression was used to estimate adjusted incidence rates and incidence rate ratios (IRR) by ECC status. The incidence rate of histologically confirmed HGA was significantly lower following ECC− smears than after ECC+ smears (adjusted IRR: 0.69, 95%Confidence Interval (CI) 0.62‐0.77), particularly at older ages (interaction between ECC status and age, p = 0.001). In contrast, the overall rate of invasive cancer was not significantly different after ECC− than after ECC+ smears (IRR: 1.27, 95%CI 0.90‐1.77). In conclusion, women had a lower rate of confirmed HGA and no significant increase in the rate of invasive cervical cancer following ECC− smears. This study does not support differential (accelerated) follow‐up in women with a negative smear without an endocervical component.
Physicochemical and adsorption properties of hypercross‐linked polystyrene with ultimate cross‐linking density
Authors: Tsyurupa Maria P. , Blinnikova Zinaida K. , Borisov Yuri A. , Ilyin Mikhail M. , Klimova Tamara P. , Mitsen Kiril V. , Davankov Vadim A.
Published: February 2014

The paper describes unexpected properties of hypercross‐linked polystyrenes with ultimate cross‐linking degrees of 300, 400, and 500%, where three, four, or five methylene links, respectively, could bind each polystyrene phenyl ring to its spacious neighbors. The polymers exhibit a strong electron spin resonance signal, unusual spectra in IR, UV, and visible ranges, and they are not typical dielectrics. The nonfunctionalized hypercross‐linked polymers absorb significant amounts of inorganic acids, salts, and bases due to interactions of protons or other cations with electron‐donating fragments of the aromatic network with the high extent of mutual connectivity and also due to dispersion interactions of anions with the polymer matrix.
Convexity characteristic of Calderón–Lozanovskiĭ sequence spaces
Authors: Yan Yaqiang , Hou Zhentao
Published: February 2014

Hudzik, Kamińska and Mastyło obtained some geometric properties of Calderón–Lozanovskiĭ function spaces which are defined on a nonatomic σ‐measure space in Houston. J. Math. 22 (1996), but left the case of atomic measure unsolved. We studied the relevant problems for the sequence spaces and obtained the following main results:

For the Calderón–Lozanovskiĭ sequence spaces , is order continuous if and only if and e is order continuous.

Let Φ be strictly convex on , then the convex characteristic whenever e is not order continuous or ; if e is uniformly monotone and , then .

For the Orlicz‐Lorentz sequence space , if or , or ω is not regular; if Φ is strictly convex on , and ω is regular.
Mutation spectrum and genotype‐phenotype correlations in a large French cohort of MYH9‐Related Disorders
Authors: Saposnik Béatrice , Binard Sylvie , Fenneteau Odile , Nurden Alan , Nurden Paquita , Hurtaud‐Roux Marie‐Françoise , Schlegel Nicole ,   the French MYH9 network
Published: February 2014

MYH9‐Related Disorders are a group of rare autosomal dominant platelet disorders presenting as nonsyndromic forms characterized by macrothrombocytopenia with giant platelets and leukocyte inclusion bodies or as syndromic forms combining these hematological features with deafness and/or nephropathy and/or cataracts. They are caused by mutations in the MYH9 gene encoding the nonmuscle myosin heavy chain II‐A (NMMHC‐IIA). Until now, at least 49 MYH9 mutations have been reported in isolated cases or small series but only rarely in large series. We report the results of an 8‐year study of a large cohort of 109 patients from 37 sporadic cases and 39 unrelated families. We have identified 43 genetic variants, 21 of which are novel to our patients. A majority, 33 (76.7%), were missense mutations and six exons were preferentially targeted, as previously published. The other alterations were three deletions of one nucleotide, one larger deletion of 21 nucleotides, and one duplication. For the first time, a substitution T>A was found in the donor splice site of intron 40 (c.5765+2T>A). Seven patients, four from the same family, had two genetic variants. The analysis of the genotype‐phenotype relationships enabled us to improve the knowledge of this heterogeneous but important rare disease.
Enhanced water and cryoprotectant permeability of porcine oocytes after artificial expression of human and zebrafish aquaporin‐3 channels
Authors: Morató Roser , Chauvigné François , Novo Sergi , Bonet Sergi , Cerdà Joan
Published: February 2014

One of the major obstacles for the vitrification of mature porcine oocytes with ethylene glycol is their low permeability to this cryoprotectant, which results in osmotic stress‐induced cell damage and low survival. Pig blastocysts, on the other hand, show enhanced water and cryoprotectant permeability, which has been related to the transcriptional activation of aquaporin‐3 (AQP3) channels at this stage of development. In this study, we asked if expression of cRNAs encoding two aquaglyceroporins, human AQP3 (hAQP3) or the zebrafish Aqp3b‐T85A mutant, in porcine oocytes can increase their permeability. Microinjection of germinal‐vesicle‐stage oocytes with enhanced green fluorescent protein (EGFP) or AQP3 cRNAs resulted in the expression of the corresponding proteins in ∼26% of the metaphase‐II stage oocytes at 40–44 hr of in vitro culture; co‐injection of EGFP cRNA appeared to be a suitable marker for oocyte selection since all EGFP‐positive oocytes also expressed the corresponding aquaporin. Using this method, we found that mature oocytes co‐expressing EGFP and hAQP3 or EGFP and Aqp3b‐T85A showed approximately a twofold increase of the hydraulic conductivity (Lp) with respect non‐injected or EGFP alone‐injected oocytes in a 0.43 M sucrose or 1.3 M ethylene glycol solution, whereas the ethylene glycol permeability (PEG) of EGFP + hAQP3 and EGFP + Aqp3b‐T85A oocytes was 6.7‐ and 12‐fold higher, respectively, than control oocytes. These data demonstrate that the artificial expression of aquaglyceroporins in porcine metaphase‐II oocytes improves their permeability, and that the zebrafish Aqp3b‐T85A mutant is more efficient than the human channel at increasing the oocyte permeability to ethylene glycol. Mol. Reprod. Dev. 81: ???–???, 2014. © 2014 Wiley Periodicals, Inc.
Self‐healing polymeric materials towards non‐structural recovery of functional properties
Authors: Zhu Min , Rong Min Zhi , Zhang Ming Qiu
Published: February 2014

Self‐healing of polymers and polymer composites initially represented a process capable of autonomic restoration of mechanical strength upon cracking of the materials, but it is moving into the area of restoration of functionality. This mini‐review is focused on recent efforts to develop functional polymers with built‐in stimuli‐responsive ability to heal for recovery of their specific physical or chemical properties. Molecular design and synthesis, compounding and assembly of organic and inorganic species, inherent reversibility, etc., are summarized. It is hoped that much more interest will be aroused in this emerging and promising frontier topic. © 2014 Society of Chemical Industry
Lighting the way or stealing the shine? An examination of the duality in star scientists' effects on firm innovative performance
Authors: Kehoe Rebecca R. , Tzabbar Daniel
Published: February 2014

Do star employees enhance or constrain the innovative performance of an organization? Using data from 456 biotechnology firms between 1973 and 2003, we highlight the duality of the effects that stars have on firm performance. We show that while stars positively affect firms' productivity, their presence constrains the emergence of other innovative leaders in an organization. We find that firm productivity and innovative leadership among non‐stars in a firm are greatest when a star has broad expertise and collaborates frequently. We offer cross‐disciplinary insights into the role of human capital as a source of competitive advantage, suggesting that the value of human capital in a firm is contingent on the mutual dependence inherent in high‐status employees' relationships with other individuals in a firm. Copyright © 2014 John Wiley & Sons, Ltd.
Nrf2 Regulates Neurogenesis and Protects Neural Progenitor Cells Against Aβ Toxicity
Authors: Kärkkäinen Virve , Pomeshchik Yuriy , Savchenko Ekaterina , Dhungana Hiramani , Kurronen Antti , Lehtonen Sarka , Naumenko Nikolay , Tavi Pasi , Levonen Anna-Liisa , Yamamoto Masayuki , Malm Tarja , Magga Johanna , Kanninen Katja M. , Koistinaho Jari
Published: February 2014

Neural stem/progenitor cells (NPCs) proliferate and produce new neurons in neurogenic areas throughout the lifetime. While these cells represent potential therapeutic treatment of neurodegenerative diseases, regulation of neurogenesis is not completely understood. We show that deficiency of nuclear factor erythroid 2-related factor (Nrf2), a transcription factor induced in response to oxidative stress, prevents the ischemia-induced increase in newborn neurons in the subgranular zone of the dentate gyrus. Consistent with this finding, the growth of NPC neurospheres was increased by lentivirus-mediated overexpression of Nrf2 gene or by treatment with pyrrolidine dithiocarbamate (PDTC), an Nrf2 activating compound. Also, neuronal differentiation of NPCs was increased by Nrf2 overexpression or PDTC treatment but reduced by Nrf2 deficiency. To investigate the impact of Nrf2 on NPCs in Alzheimer’s disease (AD), we treated NPCs with amyloid beta (Aβ), a toxic peptide associated with neurodegeneration and cognitive abnormalities in AD. We found that Aβ1–42-induced toxicity and reduction in neurosphere proliferation were prevented by Nrf2 overexpression, while Nrf2 deficiency enhanced the Aβ1–42-induced reduction of neuronal differentiation. On the other hand, Aβ1–40 had no effect on neurosphere proliferation in wt NPCs but increased the proliferation of Nrf2 overexpressing neurospheres and reduced it in Nrf2-deficient neurospheres. These results suggest that Nrf2 is essential for neuronal differentiation of NPCs, regulates injury-induced neurogenesis and provides protection against Aβ-induced NPC toxicity. Stem Cells  2014;32:1904–1916
PRL2/PTP4A2 Phosphatase Is Important for Hematopoietic Stem Cell Self-Renewal
Authors: Kobayashi Michihiro , Bai Yunpeng , Dong Yuanshu , Yu Hao , Chen Sisi , Gao Rui , Zhang Lujuan , Yoder Mervin C. , Kapur Reuben , Zhang Zhong-Yin , Liu Yan
Published: February 2014

Hematopoietic stem cell (HSC) self-renewal is tightly controlled by cytokines and other signals in the microenvironment. While stem cell factor (SCF) is an early acting cytokine that activates the receptor tyrosine kinase KIT and promotes HSC maintenance, how SCF/KIT signaling is regulated in HSCs is poorly understood. The protein tyrosine phosphatase 4A (PTP4A) family (aka PRL [phosphatase of regenerating liver] phosphatases), consisting of PTP4A1/PRL1, PTP4A2/PRL2, and PTP4A3/PRL3, represents an intriguing group of phosphatases implicated in cell proliferation and tumorigenesis. However, the role of PTP4A in hematopoiesis remains elusive. To define the role of PTP4A in hematopoiesis, we analyzed HSC behavior in Ptp4a2 (Prl2) deficient mice. We found that Ptp4a2 deficiency impairs HSC self-renewal as revealed by serial bone marrow transplantation assays. Moreover, we observed that Ptp4a2 null hematopoietic stem and progenitor cells (HSPCs) are more quiescent and show reduced activation of the AKT and ERK signaling. Importantly, we discovered that the ability of PTP4A2 to enhance HSPC proliferation and activation of AKT and ERK signaling depends on its phosphatase activity. Furthermore, we found that PTP4A2 is important for SCF-mediated HSPC proliferation and loss of Ptp4a2 decreased the ability of oncogenic KIT/D814V mutant in promoting hematopoietic progenitor cell proliferation. Thus, PTP4A2 plays critical roles in regulating HSC self-renewal and mediating SCF/KIT signaling. Stem Cells  2014;32:1956–1967
Barx2 and Pax7 Have Antagonistic Functions in Regulation of Wnt Signaling and Satellite Cell Differentiation
Authors: Zhuang Lizhe , Hulin Julie-Ann , Gromova Anastasia , Tran Nguyen Thi Diem , Yu Ruth T. , Liddle Christopher , Downes Michael , Evans Ronald M. , Makarenkova Helen P. , Meech Robyn
Published: February 2014

The canonical Wnt signaling pathway is critical for myogenesis and can induce muscle progenitors to switch from proliferation to differentiation; how Wnt signals integrate with muscle-specific regulatory factors in this process is poorly understood. We previously demonstrated that the Barx2 homeobox protein promotes differentiation in cooperation with the muscle regulatory factor (MRF) MyoD. Pax7, another important muscle homeobox factor, represses differentiation. We now identify Barx2, MyoD, and Pax7 as novel components of the Wnt effector complex, providing a new molecular pathway for regulation of muscle progenitor differentiation. Canonical Wnt signaling induces Barx2 expression in muscle progenitors and perturbation of Barx2 leads to misregulation of Wnt target genes. Barx2 activates two endogenous Wnt target promoters as well as the Wnt reporter gene TOPflash, the latter synergistically with MyoD. Moreover, Barx2 interacts with the core Wnt effectors β-catenin and T cell-factor 4 (TCF4), is recruited to TCF/lymphoid enhancer factor sites, and promotes recruitment of β-catenin. In contrast, Pax7 represses the Wnt reporter gene and antagonizes the activating effect of Barx2. Pax7 also binds β-catenin suggesting that Barx2 and Pax7 may compete for interaction with the core Wnt effector complex. Overall, the data show for the first time that Barx2, Pax7, and MRFs can act as direct transcriptional effectors of Wnt signals in myoblasts and that Barx2 and Wnt signaling participate in a regulatory loop. We propose that antagonism between Barx2 and Pax7 in regulation of Wnt signaling may help mediate the switch from myoblast proliferation to differentiation. Stem Cells  2014;32:1661–1673
Game playing
Authors: Rosin Christopher D.
Published: February 2014

Game playing has been a core domain of artificial intelligence research since the beginnings of the field. Game playing provides clearly defined arenas within which computational approaches can be readily compared to human expertise through head‐to‐head competition and other benchmarks. Game playing research has identified several simple core algorithms that provide successful foundations, with development focused on the challenges of defeating human experts in specific games. Key developments include minimax search in chess, machine learning from self‐play in backgammon, and Monte Carlo tree search in Go. These approaches have generalized successfully to additional games. While computers have surpassed human expertise in a wide variety of games, open challenges remain and research focuses on identifying and developing new successful algorithmic foundations. WIREs Cogn Sci 2014, 5:193–205. doi: 10.1002/wcs.1278

This article is categorized under:

Computer Science > Artificial Intelligence
THz and mid-IR spectroscopy of interstellar ice analogs: methyl and carboxylic acid groups
Authors: Ioppolo S. , McGuire B. A. , Allodi M. A. , Blake G. A.
Published: February 2014

A fundamental problem in astrochemistry concerns the synthesis and survival of complex organic molecules (COMs) throughout the process of star and planet formation. While it is generally accepted that most complex molecules and prebiotic species form in the solid phase on icy grain particles, a complete understanding of the formation pathways is still largely lacking. To take full advantage of the enormous number of available THz observations (e.g.,Herschel Space Observatory, SOFIA, and ALMA), laboratory analogs must be studied systematically. Here, we present the THz (0.3–7.5 THz; 10–250 cm−1) and mid–IR (400–4000 cm−1) spectra of astrophysically-relevant species that share the same functional groups, including formic acid (HCOOH) and acetic acid (CH3COOH), and acetaldehyde (CH3CHO) and acetone ((CH3)2CO), compared to more abundant interstellar molecules such as water (H2O), methanol (CH3OH), and carbon monoxide (CO). A suite of pure and mixed binary ices are discussed. The effects on the spectra due to the composition and the structure of the ice at different temperatures are shown. Our results demonstrate that THz spectra are sensitive to reversible and irreversible transformations within the ice caused by thermal processing, suggesting that THz spectra can be used to study the composition, structure, and thermal history of interstellar ices. Moreover, the THz spectrum of an individual species depends on the functional group(s) within that molecule. Thus, future THz studies of different functional groups will help in characterizing the chemistry and physics of the interstellar medium (ISM).
Low toxicity functionalised imidazolium salts for task specific ionic liquid electrolytes in dye-sensitised solar cells: a step towards less hazardous energy production
Authors: Ghavre Mukund , Byrne Owen , Altes Lena , Surolia Praveen K. , Spulak Marcel , Quilty Brid , Thampi K. Ravindranathan , Gathergood Nicholas
Published: February 2014

Tandem evaluation of ionic liquids and imidazolium salts toxicity and performance in dye sensitised solar cells is presented.
Smart tailoring of the surface chemistry in GPTMS hybrid organic–inorganic films
Authors: Carboni Davide , Pinna Alessandra , Malfatti Luca , Innocenzi Plinio
Published: February 2014

The tuning of epoxide opening in GPTMS films allows for smart tailoring of the surface chemistry.
Photovoltaic performance of novel push–pull–push thienyl–Bodipy dyes in solution-processed BHJ-solar cells
Authors: Sutter Alexandra , Retailleau Pascal , Huang Wei-Ching , Lin Hao-Wu , Ziessel Raymond
Published: February 2014

Original flat push–pull–push dyes have been engineered from thienyl–Bodipy–triphenylamine frameworks for solar cell application.
Facile synthesis of ultrathin worm-like Au nanowires for highly active SERS substrates
Authors: Wang Ai-Jun , Lv Jing-Jing , Zhou Dan-Ling , Weng Xuexiang , Qin Su-Fang , Feng Jiu-Ju
Published: February 2014

Ultrathin worm-like Au nanowires were facilely synthesized and used for the fabrication of porous Au films as highly active SERS substrates.
Taurospongins B and C, new acetylenic fatty acid derivatives possessing a taurine amide residue from a marine sponge of the family Spongiidae
Authors: Kubota Takaaki , Suzuki Haruna , Takahashi-Nakaguchi Azusa , Fromont Jane , Gonoi Tohru , Kobayashi Jun'ichi
Published: February 2014

Two new acetylenic fatty acid derivatives possessing a taurine amide residue, taurospongins B (1) and C (2), have been isolated from an Okinawan marine sponge of the family Spongiidae.
Biscarbazolylmethane-based cyanine: a two-photon excited fluorescent probe for DNA and selective cell imaging
Authors: Zheng Yong-Chao , Zheng Mei-Ling , Chen Shu , Zhao Zhen-Sheng , Duan Xuan-Ming
Published: February 2014

We report a novel biscarbazole-based cyanine with a large Stokes shift and TPA cross-section as a light-up probe for DNA and selective TPEF cell imaging.
Correlation between preparation conditions and the photoluminescence properties of Sn2+ centers in ZnO–P2O5 glasses
Authors: Masai Hirokazu , Tanimoto Toshiro , Okumura Shun , Teramura Kentaro , Matsumoto Syuji , Yanagida Takayuki , Tokuda Yomei , Yoko Toshinobu
Published: February 2014

Sn2+ centers exhibiting high quantum efficiency were observed in zinc phosphate glasses prepared under inert conditions.
Uranium perturbs signaling and iron uptake response in Arabidopsis thaliana roots
Authors: Doustaly Fany , Combes Florence , Fiévet Julie B. , Berthet Serge , Hugouvieux Véronique , Bastien Olivier , Aranjuelo Iker , Leonhardt Nathalie , Rivasseau Corinne , Carrière Marie , Vavasseur Alain , Renou Jean-Pierre , Vandenbrouck Yves , Bourguignon Jacques
Published: February 2014

The early plant root response to uranyl was characterized using complete Arabidopsis transcriptome microarrays.
Bax channel triplet: co-operativity and voltage gating
Authors: Lin Shang H. , Cherian Nuval , Wu Benjamin , Phee Hyo , Cho Christy , Colombini Marco
Published: February 2014

Bax, despite being a cytosolic protein, has the distinct ability to form channels in the mitochondrial outer membrane, which are capable of releasing proteins that initiate the execution phase of apoptosis. When studied in a planar phospholipid membrane system, full-length activated Bax can form conducting entities consistent with linearly organized three-channel units displaying steep voltage-gating (n=14) that rivals that of channels in excitable membranes. In addition, the channels display strong positive co-operativity possibly arising from the charge distribution of the voltage sensors. On the basis of functional behaviour, one of the channels in this functional triplet is oriented in the opposite direction to the others often resulting in conflicts between the effects of the electric field and the positive co-operativity of adjacent channels. The closure of the first channel occurs at positive potentials and this permits the second to close, but at negative potentials. The closure of the second channel in turn permits closure of the third, but at positive potentials. Positive co-operativity manifests itself in a number of ways including the second and the third channels opening virtually simultaneously. This extraordinary behaviour must have important, although as yet undefined, physiological roles.
Putative quantum criticality in the (Cr90Ir10)100−yVy alloy system
Authors: Fernando P. R. , Prinsloo A. R. E. , Sheppard C. J. , Lodya L.
Published: February 2014

Quantum criticality (QC) in spin-density-wave antiferromagnetic Cr and Cr alloy systems is a topic of current interest. In the present study, V was used as a tuning parameter to drive the Néel transition temperature (TN) of the (Cr90Ir10)100−yVy alloy series with 0 ≤ y ≤ 14.3 to zero and search for effects of QC in the process. The magnetic properties and possible QC behaviour (QCB) in this alloy system were investigated through electrical resistivity (ρ), specific heat (Cp), and susceptibility (χ) measurements as a function of temperature (T), indicating that TN is suppressed to zero at a critical concentration yc ≈ 9. The Sommerfeld coefficient (γ) is considered a key indicator of QCB and a peak is observed in γ(y) at yc on decreasing y through this concentration, followed by a sharp decreasing trend. This behaviour is reminiscent of that observed for γ of the prototypical Cr100−xVx QC system and allows for the classification of yc in the (Cr90Ir10)100−yVy alloy system as a possible QC point.
Formation and evolution of ripples on ion-irradiated semiconductor surfaces
Authors: Kang M. , Wu J. H. , Ye W. , Jiang Y. , Robb E. A. , Chen C. , Goldman R. S.
Published: February 2014

We have examined the formation and evolution of ripples on focused-ion-beam (FIB) irradiated compound semiconductor surfaces. Using initially normal-incidence Ga+ FIB irradiation of InSb, we tuned the local beam incidence angle (θeff) by varying the pitch and/or dwell time. For single-pass FIB irradiation, increasing θeff induces morphological evolution from pits and islands to ripples to featureless surfaces. Multiple-pass FIB irradiation of the rippled surfaces at a fixed θeff leads to island formation on the ripple crests, followed by nanorod (NR) growth. This ripple-NR transition provides an alternative approach for achieving dense arrays of NRs.
Modeling ion sensing in molecular electronics
Authors: Chen Caroline J. , Smeu Manuel , Ratner Mark A.
Published: February 2014

We examine the ability of molecules to sense ions by measuring the change in molecular conductance in the presence of such charged species. The detection of protons (H+), alkali metal cations (M+), calcium ions (Ca2+), and hydronium ions (H3O+) is considered. Density functional theory (DFT) is used within the Keldysh non-equilibrium Green's function framework (NEGF) to model electron transport properties of quinolinedithiol (QDT, C9H7NS2), bridging Al electrodes. The geometry of the transport region is relaxed with DFT. The transport properties of the device are modeled with NEGF-DFT to determine if this device can distinguish among the M+ + QDT species containing monovalent cations, where M+ = H+, Li+, Na+, or K+. Because of the asymmetry of QDT in between the two electrodes, both positive and negative biases are considered. The electron transmission function and conductance properties are simulated for electrode biases in the range from −0.5 V to 0.5 V at increments of 0.1 V. Scattering state analysis is used to determine the molecular orbitals that are the main contributors to the peaks in the transmission function near the Fermi level of the electrodes, and current-voltage relationships are obtained. The results show that QDT can be used as a proton detector by measuring transport through it and can conceivably act as a pH sensor in solutions. In addition, QDT may be able to distinguish among different monovalent species. This work suggests an approach to design modern molecular electronic conductance sensors with high sensitivity and specificity using well-established quantum chemistry.
Development of a thermal and electrical energy management in residential building micro-grid
Authors: Esmaeili S. , Vahidi B. , Parvizimosaed M. , Brahman F.
Published: February 2014

Global warming and pressing concern about CO2 emission along with increasing fuel and oil cost have brought about great challenges for energy companies and homeowners. In this regard, a potential candidate solution is widely used for Distributed Energy Resources, which are capable of providing high quality, low-cost heat and power to off-grid or remote facilities. To appropriately manage thermal and electrical energy, a Smart Energy Management System (SEMS) with hierarchical control scheme has been presented. The developed SEMS model results in mixed integer non-linear programming optimization problem with the objective function of minimizing the operation cost as well as considering emissions. Moreover, the optimization problem has been solved for deterministic and stochastic scheduling algorithms. The novelty of this work is basically reliant on using data mining approach to reduce forecasting error. Several case studies have been carried out to evaluate the performance of proposed data mining method on both energy cost and expected cost.
Rota-Baxter operators on $\mathrm{sl(2,\mathbb {C})}$ sl (2,C) and solutions of the classical Yang-Baxter equation
Authors: Pei Jun , Bai Chengming , Guo Li
Published: February 2014

We explicitly determine all Rota-Baxter operators (of weight zero) on $\mathrm{sl(2,\mathbb {C})}$ sl (2,C) under the Cartan-Weyl basis. For the skew-symmetric operators, we give the corresponding skew-symmetric solutions of the classical Yang-Baxter equation in $\mathrm{sl(2,\mathbb {C})}$ sl (2,C), confirming the related study by Semenov-Tian-Shansky. In general, these Rota-Baxter operators give a family of solutions of the classical Yang-Baxter equation in the six-dimensional Lie algebra $\mathrm{sl(2,\mathbb {C})}\ltimes _{{\rm ad}^{\ast }} \mathrm{sl(2,\mathbb {C})}^{\ast }$ sl (2,C)⋉ ad * sl (2,C)*. They also give rise to three-dimensional pre-Lie algebras which in turn yield solutions of the classical Yang-Baxter equation in other six-dimensional Lie algebras.
Hydrogen peroxide detection with quartz-enhanced photoacoustic spectroscopy using a distributed-feedback quantum cascade laser
Authors: Ren Wei , Jiang Wenzhe , Sanchez Nancy P. , Patimisco Pietro , Spagnolo Vincenzo , Zah Chung-en , Xie Feng , Hughes Lawrence C. , Griffin Robert J. , Tittel Frank K.
Published: February 2014

A quartz-enhanced photoacoustic spectroscopy sensor system was developed for the sensitive detection of hydrogen peroxide (H2O2) using its absorption transitions in the v6 fundamental band at ∼7.73 μm. The recent availability of distributed-feedback quantum cascade lasers provides convenient access to a strong H2O2 absorption line located at 1295.55 cm−1. Sensor calibration was performed by means of a water bubbler that generated titrated average H2O2 vapor concentrations. A minimum detection limit of 12 parts per billion (ppb) corresponding to a normalized noise equivalent absorption coefficient of 4.6 × 10−9 cm−1W/Hz1/2 was achieved with an averaging time of 100 s.
Role of dislocation scattering on electron mobility in coalescent epitaxial lateral overgrowth layers of InP
Authors: Oyama Yutaka
Published: February 2014

In order to clarify the effects of dislocation scattering on electron transport properties, temperature dependent (15-300 K) Hall-effect measurements were applied to the dislocated coalescent and dislocation-free non-coalescent ELO layers of InP prepared by the liquid phase epitaxy. The coalescent ELO layers contain a large number of dislocations, and the non-coalescent ELO layers are dislocation-free. Taking into account, the various electron scattering mechanisms in compound semiconductors, the temperature dependences of electron mobility were analyzed. It is shown that the dislocation scattering based on the charged dislocation line model is dominant transport mechanism in the dislocated coalescent ELO layers at low temperature.
An amorphous alloy core medium frequency magnetic-link for medium voltage photovoltaic inverters
Authors: Rabiul Islam Md. , Guo Youguang , Wei Lin Zhi , Zhu Jianguo
Published: February 2014

The advanced magnetic materials with high saturation flux density and low specific core loss have led to the development of an efficient, compact, and lightweight multiple-input multiple-output medium frequency magnetic-link. It offers a new route to eliminate some critical limitations of recently proposed medium voltage photovoltaic inverters. In this paper, a medium frequency magnetic-link is developed with Metglas amorphous alloy 2605S3A. The common magnetic-link generates isolated and balanced multiple DC supplies for all of the H-bridge inverter cells of the medium voltage inverter. The design and implementation of the prototype, test platform, and the experimental test results are analyzed and discussed. The medium frequency non-sinusoidal excitation electromagnetic characteristics of alloy 2605S3A are also compared with that of alloy 2605SA1. It is expected that the proposed new technology will have great potential for future renewable power generation systems and smart grid applications.
Meta-atom cluster acoustic metamaterial with broadband negative effective mass density
Authors: Chen Huaijun , Zhai Shilong , Ding Changlin , Liu Song , Luo Chunrong , Zhao Xiaopeng
Published: February 2014

We design a resonant meta-atom cluster, via which a two-dimensional (2D) acoustic metamaterial (AM) with broadband negative effective mass density from 1560 Hz to 5580 Hz is fabricated. Experimental results confirm that there is only weak interaction among the meta-atoms in the cluster. And then the meta-atoms in the cluster independently resonate, resulting in the cluster becoming equivalent to a broadband resonance unit. Extracted effective refractive indices from reflection and transmission measurements of the 2D AM appear to be negative from 1500 Hz to 5480 Hz. The broadband negative refraction has also been demonstrated by our further experiments. We expect that this meta-atom cluster AM will significantly contribute to the design of broadband negative effective mass density AM.
Unexpected magnetic anisotropy induced by oxygen vacancy in anatase TiO2: A first-principles study
Authors: Shao Bin , He Ying-fang , Feng Min , Lu Yuan , Zuo Xu
Published: February 2014

Based on first-principles calculation, the magnetic anisotropy of anatase TiO2 with oxygen vacancy (VO) has been investigated. It has been predicted that VO induces a remarkably large magnetic anisotropy energy (MAE) and orbital moment in TiO2. By calculating the band structures near the Fermi energy, the origin of the unexpected MAE is attributed to the perturbation between the occupied dxz and the empty dyz orbitals, whose degeneracy in the pristine TiO2 is lifted by the lower C2v symmetry induced by the VO. The orbital contribution to the anisotropic saturation magnetization has been emphasized and correlated to the experiments.
The dipolar interaction in CoFeB/MgO/CoFeB perpendicular magnetic tunnel junction
Authors: Tsai C. C. , Cheng Chih-Wei , Weng Yi-Chien , Chern G.
Published: February 2014

Ultrathin CoFeB/MgO/CoFeB system with perpendicular magnetic anisotropy is a promising candidate for the high density magnetic random access memory. However, a dipolar interaction between the CoFeB layers may introduce a minor loop shift (Hs) and causes uncertainty during the operation. In this report, we systematically studied the dipolar effect in these structures and found that the coupling may be either ferromagnetic or antiferromagnetic (15 Oe > Hs > −15 Oe) depending upon the CoFeB thickness (0.9–1.4 nm). A modified Fabry-Perot model, which accounts the Bloch wave interference, may explain the present observations of the dipolar effect in the perpendicular junctions of CoFeB/MgO/CoFeB.
Compact modelling of ferroelectric tunnel memristor and its use for neuromorphic simulation
Authors: Wang Zhaohao , Zhao Weisheng , Kang Wang , Zhang Yue , Klein Jacques-Olivier , Ravelosona Dafiné , Chappert Claude
Published: February 2014

Ferroelectric tunnel memristor (FTM) was recently discovered. Its resistance can be continuously tuned by controlling the growth of domain in ferroelectric tunnel barrier. Experiments show its large OFF/ON resistance ratio (>102) and high operation speed (∼10 ns), providing great potential to build up multi-level storage and neuromorphic circuits. However, the corresponding electrical model for circuit simulation is still lacking. In this Letter, we developed a compact model for a voltage-controlled ferroelectric tunnel memristor based on experimental results and ferroelectric switching dynamics. The memristive behavior of this model was demonstrated by resistance measurements as a function of the amplitude and duration of programming voltage pulses, and the accuracy was validated by the relative good agreement between simulation results and experimental measurement. Our model was used to simulate a FTM-based spike-timing dependent plasticity circuit to show its use in neuromorphic circuits.
The early stage of formation of self-organized nanocolumns in thin films: Monte Carlo simulations versus atomic-scale observations in Ge-Mn
Authors: Mouton I. , Talbot E. , Pareige C. , Lardé R. , Blavette D.
Published: February 2014

Formation kinetics of self-organized nanocolumns during epitaxial growth of a thin film composed of immiscible elements (A,B) has been investigated using Kinetic Monte Carlo simulations. Simulated nanostructures show a good agreement with those observed in Ge-Mn using Atom Probe Tomography and Transmission Electron Microscopy. Self organisation is observed although the rigid lattice simulations used do not account for misfit elastic strain. Simulations reveal that the final nanostructure, in term of number density and diameter of nanocolumns, is controlled by the early stages of growth of the film. The influence of both growth temperature and solute concentration on the nanostructure features is discussed in details.
Native defects affecting the Li atom distribution tune the optical emission of ZnO:Li epitaxial thin film
Authors: Sahu R. , Dileep K. , Loukya B. , Datta R.
Published: February 2014

It is found that the oxygen vacancy (VO) defect concentration affecting the separation between individual species in LiZn-Lii complex influences the optical emission property of Li0.06Zn0.94O epitaxial thin film grown by pulsed laser deposition. The film grown under low oxygen partial pressure (n-type conductivity)/higher partial pressure (resistive-type) has broad emission at ∼2.99 eV/∼2.1 eV and a narrower emission at 3.63 eV/3.56 eV, respectively. First principle based mBJLDA electronic structure calculation suggests that the emission at 2.99 eV is due to the LiZn-Lii pair complex and the emission at 2.1 eV is when the component species are away from each other.
Siting ‘Scientific Spaces' in the US: The Push and Pull of Regional Development Strategies and National Innovation Policies
Authors: Clark Jennifer J
Published: February 2014

The term ‘science park’ evokes a “you know it when you see it” consensus among policy experts. Although the function of science parks is broadly understood as collaborative applied research between universities, industry, and governments, the physical and institutional form of these ‘cooperative research centers' shows significant variation. In this paper I present a typology of such centers in the current US context and discuss how they are changing. Using evidence from one high-tech industry, I underscore the agglomerated nature of basic and applied science—a key argument in the rethinking of decisions around public investments in scientific spaces. Finally, I conclude that US innovation policy is shifting to a more explicitly metropolitan orientation, recognizing the importance of proximity and agglomeration. Implicit in this shift is a reevaluation of the geography of public investment in technology infrastructure as it pertains to cities and regions.
The classical elements in written Chinese
Authors: Zhang Zheng-sheng
Published: February 2014

There has been a common belief that the presence of classical Chinese elements may be an important characteristic of the written style in modern Chinese. An empirical study employing the multi-feature, multi-dimensional framework for studying register variation (Biber 1988) and the statistical method of correspondence analysis confirms that there is indeed a classical dimension in modern written Chinese; but it is only one of two dimensions. The quantitative results further show that the classical dimension is not the primary dimension. The more important dimension is that of ‘literate vs. non-literate’, which has not received as much attention. The separation of the classical from the literate dimension makes it possible to account for the fact that registers having more classical Chinese elements are not necessarily more literate and vice versa. Another intriguing finding from the study is that classical Chinese elements are not monolithic; there seem to be four different types, which are distributed differently along the literate as well as the classical dimension. The difference in word length and integrability is hypothesized to account for the different types.
Restrictiveness, exclusivity, adversativity, and mirativity
Authors: Wang Yu-Fang , Tsai Mei-Chi , Schams Wayne , Yang Chi-Ming
Published: February 2014

Mandarin Chinese zhishi (similar to English ‘only’), comprised of the adverb zhi and the copula shi, can act as an adverb (ADV) or a discourse marker (DM). This study analyzes the role of zhishi in spoken discourse, based on the methodological and theoretical principles of interactional linguistics and conversation analysis. The corpus used in this study consists of three sets of data: 1) naturally-occurring daily conversations; 2) radio/TV interviews; and 3) TV panel discussions on current political affairs. As a whole, this study reveals that the notions of restrictiveness, exclusivity, and adversativity are closely associated with ADV zhishi and DM zhishi. In addition, the present data show that since zhishi is often used to express a ‘less than expected’ feeling, it can be used to indicate mirativity (i.e. language indicating that an utterance conveys the speaker’s surprise). The data also show that the distribution of zhishi as an adverb or discourse marker depends on turn taking systems and speech situations in spoken discourse. Specifically, the ADV zhishi tends to occur in radio/TV interviews and TV panel news discussions, while the DM zhishi occurs more often in casual conversations.