bluuebunny/crossref_metadata_2025 huggingface dataset:
A novel summation impedance protection adaptive to high‐resistance earth fault detection
Authors: Tong Ning , He Shan , Lin Xiangning , Zhang Rui , Yang Dexian
Published: May 2015

While the high‐resistance earth fault frequently occurs on extra high voltage (EHV) transmission lines, existing protection schemes show great limitation for coping with this kind of fault scenario when the fault resistance is very high. In this paper, a novel protection methodology combining the measured impedance of the two ends is introduced, and a so‐called summation impedance protection, making use of this critical information, is thus put forward and assessed. Emphasis is placed on the principle of the summation impedance protection and its adaptive thresholds. A simulation model based on EMTDC/PSCAD, by which the performance of the summation impedance protection is evaluated, is then established. As confirmed by quantitative theoretical and experimental studies, the results indicate that the proposed protection scheme works well even when the fault resistance is extremely high under the internal fault condition, and it keeps itself from maloperation as an effect of its adaptive thresholds wherever an external fault occurs. These results highlight the necessity to work in conjunction with the existing main protections of transmission lines, by which means an enhanced ability to cope with the high‐resistance single‐phase earth fault can be achieved. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Conjugated Linoleic Acid Supplementation has no Impact on Aerobic Capacity of Healthy Young Men
Authors: Tajmanesh Milad , Aryaeian Naheed , Hosseini Mostafa , Mazaheri Reza , Kordi Ramin
Published: May 2015

This study investigated the effect of conjugated linoleic acid (CLA) on the aerobic capacity and anthropometric measurements of humans. Although this effect has been shown in animal studies, human studies have reported controversial results. In this double‐blind, placebo‐controlled, randomized clinical trial, 80 non‐trained healthy young men received a 50:50 mixture of cis‐9,trans‐11 and trans‐10 cis‐12 CLA (CLA 4 × 0.8 g day−1) ora placebo (PLA; soybean oil) in an 8‐week intervention. Maximal oxygen consumption (VO2 max), time to exhaustion, weight, body mass index (BMI) and waist circumference (WC) were measured. CLA had no effect on VO2 max (p = 0.5) also no change was seen in time to exhaustion (p = 0.51), weight (p = 0.7), BMI (p = 0.7) and WC (p = 0.8) vs PLA. Our results suggest that CLA has no significant effect on VO2 max, time to exhaustion and anthropometric measurements in untrained healthy young male students.
Frontline employees’ collaboration in industrial service innovation: routes of co-creation’s effects on new service performance
Authors: Santos-Vijande María Leticia , López-Sánchez José Ángel , Rudd John
Published: May 2015

From a Service-Dominant Logic (S-DL) perspective, employees constitute operant resources that firms can draw to enhance the outcomes of innovation efforts. While research acknowledges that frontline employees (FLEs) constitute, through service encounters, a key interface for the transfer of valuable external knowledge into the firm, the range of potential benefits derived from FLE-driven innovation deserves more investigation. Using a sample of knowledge intensive business services firms (KIBS), this study examines how the collaboration with FLEs along the new service development (NSD) process, namely FLE co-creation, impacts on service innovation performance following two routes of different effects. Partial least squares structural equation modeling (PLS-SEM) results indicate that FLE co-creation benefits the NS success among FLEs and firm’s customers, the constituents of the resources route. FLE co-creation also has a positive effect on the NSD speed, which in turn enhances the NS quality. NSD speed and NS quality integrate the operational route, which proves to be the most effective path to impact the NS market performance. Accordingly, KIBS managers must value their FLEs as essential partners to achieve successful innovation from an internal and external perspective, and develop the appropriate mechanisms to guarantee their effective involvement along the NSD process.
How Relationship Conditions Affect Suppliers’ Resource Inputs
Authors: Baxter Roger , Kleinaltenkamp Michael
Published: May 2015

For partners in buyer-seller relationships to work effectively in transmitting and integrating resources as well as for value creation, each partner needs to invest in the relationship and needs to make it easy for the other partner to access their resources. However, every investment is risky and it is not certain whether investment objectives will be achieved. Thus, this paper addresses the question of which factors drive intention to invest in a customer relationship from a supplier's perspective. We propose and test three factors as positive investment drivers: the relationship quality; the suppliers’ expectation of future access to their customers’ important and intangible resources; and the relationship value perceived by the supplier. By analyzing interview and survey data from managers, the study finds support for the propositions. Relationship value and expectation of future access to the customers’ resources have direct effects on suppliers’ intentions to invest. Relationship quality also has a strong effect, mediated by the other two drivers.
Architectural proteins, transcription, and the three‐dimensional organization of the genome
Authors: Cubeñas-Potts Caelin , Corces Victor G.
Published: May 2015

Architectural proteins mediate interactions between distant sequences in the genome. Two well‐characterized functions of architectural protein interactions include the tethering of enhancers to promoters and bringing together Polycomb‐containing sites to facilitate silencing. The nature of which sequences interact genome‐wide appears to be determined by the orientation of the architectural protein binding sites as well as the number and identity of architectural proteins present. Ultimately, long range chromatin interactions result in the formation of loops within the chromatin fiber. In this review, we discuss data suggesting that architectural proteins mediate long range chromatin interactions that both facilitate and hinder neighboring interactions, compartmentalizing the genome into regions of highly interacting chromatin domains.
Factors affecting the uptake of cervical cancer screening among nurses in Singapore
Authors: Tay Kaijun , Tay Sun K. , Tesalona Katherine C. , Rashid Nadia M.R. , Tai Esther Y.S. , Najib Sitti J.M.
Published: May 2015

Objective

To identify factors other than socioeconomic status that influence participation in cervical cancer screening.

Methods

A prospective, questionnaire‐based, cross‐sectional study was conducted among all female nurses working at Singapore General Hospital, Singapore, between November 1 and December 15, 2013. Characteristics assessed included age, knowledge score (0–10, on the basis of 10 true‐or‐false statements), perceived risk of cervical cancer, and health facility use.

Results

Among 2000 nurses, 1622 (81.1%) responded. The mean knowledge score was 4.70 ± 1.76. Among 1593 nurses who reported on self‐perception of risk, 97 (6.1%) reported high risk, 675 (42.4%) reported low risk, and 821 (51.5%) reported uncertainty. Of the 815 nurses reporting on their history of screening, 344 (42.2%) were screened regularly, 103 (12.6%) underwent opportunistic screening, and 368 (45.2%) had never undergone screening. The likelihood of screening was increased among women aged 35–49 years, those who had recent experience of medical screening, those who had recently had a specialist consultation, or those who had recently had a consultation with a gynecologist (P < 0.001 for all). Nurses undergoing regular screening reported positive effects of a doctor's recommendation, husband's encouragement, people talking about screening, and people close to the respondent undergoing screening.

Conclusion

Advocacy and herd signaling positively influenced the cervical cancer screening rate.
Factors associated with contraceptive ideation among urban men in Nigeria
Authors: Babalola Stella , Kusemiju Bola , Calhoun Lisa , Corroon Meghan , Ajao Bolanle
Published: May 2015

Objective

To determine factors influencing the readiness of urban Nigerian men to adopt contraceptive methods.

Methods

The data were derived from a cross‐sectional household survey conducted in Ibadan and Kaduna between September and November 2012. The sample included 2358 men from both cities. An ideation framework was constructed and a multilevel analysis performed to identify factors associated with positive thinking about contraception.

Results

Correlates of ideation operated at the individual, household, and community levels. There is considerable cluster‐level variability in ideation score. The key correlates included exposure to family planning promotion campaigns, education, age, religion, marital status, and community norms. Compared with no education, high education is associated with an approximately 6.7‐point increase in ideation score (P < 0.001). Men with a high level of NURHI program exposure had an average ideation score that was about 3.4 points higher than for their peers with no exposure (P < 0.001). The ideation score for Muslims was lower by approximately 1.7 points, on average, than for Christians (P < 0.001).

Conclusion

A comprehensive strategy of communication and behavior change activities surrounding contraceptive use should be tailored to meet the needs of specific groups of men. Community‐level interventions designed to mobilize community members and change social norms that hinder the spread of ideational characteristics that favor contraceptive use should be part of this comprehensive strategy.
A Comparison of Biceps Labrum Complex Findings in Patients with and without Superior Migration of the Humeral Head in Large or Massive Rotator Cuff Tears
Authors: Mura Nariyuki , Harada Mikio , Tsuruta Daisaku , Ogino Toshihiko , Takagi Michiaki
Published: May 2015

Background

The purpose of this study was to clarify the relationship between superior migration of the humeral head and findings of biceps labrum complex (BLC) in large or massive rotator cuff tears.

Methods

Forty-nine shoulders that underwent surgery for torn supraspinatus and infraspinatus tendons were included. Patients were divided into two groups according to the acromio—humeral interval (AHI). Arthroscopic findings of BLC were classified into five types; Type 0; normal shape, Type 1: fraying; Type 2: detachment; Type 3: attrition of BLC and superior glenoid; and Type 4: defect.

Results

The group without migration (AHI ≥ 7 mm) consisted of 21 shoulders and that with migration (AHI < 7 mm) was 28 shoulders. There were significantly more patients with Types 2, 3, and 4 in the group with migration than without migration.

Conclusion

This study indicates a potential relationship between BLC injury and superior humeral head migration accompanied by a rotator cuff tear.
Age and sedimentary record of inland eolian sediments in Lithuania, NE European Sand Belt
Authors: Kalińska-Nartiša Edyta , Thiel Christine , Nartišs Māris , Buylaert Jan-Pieter , Murray Andrew S.
Published: May 2015

We present a study based on four inland eolian locations in Eastern, Central and Southeastern Lithuania belonging to the northeastern part of the ‘European Sand Belt’ (ESB). Although there have been several previous studies of the ESB, this north-eastern extension has not been investigated before in any detail. The sedimentary structural–textural features are investigated and a chronology was derived using optically stimulated luminescence on both quartz and feldspar. The sedimentary structures and the rounding and surface characteristics of the quartz grains argue for a predominance of eolian transport. Additionally, some structural alternations and a significant contribution of non-eolian grains are interpreted as inherited local glacial/glaciofluvial-bearing lithologies.

Three main (glaciolacustrine–) eolian phases are distinguished based on the position in the landscape and the luminescence ages: (1) Anolder eolian seriesaround 15 to 16 ka, possibly correlated with the cold GS-2a event according to the GRIP stratigraphy, and (2) ayounger eolian seriesaround 14.0 ka, possibly representing the GI-1d and 1c events. Theolder eolian seriesis underlain by (3) aglaciolacustrine–eolian seriesfor which the period of deposition remains uncertain due to the significant discrepancy between the ages based on quartz and feldspar.
New chronology for the southern Kalahari Group sediments with implications for sediment-cycle dynamics and early hominin occupation
Authors: Matmon Ari , Hidy Alan J. , Vainer Shlomy , Crouvi Onn , Fink David , Erel Yigal , Team ASTER , Arnold M. , Aumaître G. , Bourlès D. , Keddadouche K. , Horwitz Liora K. , Chazan Michael
Published: May 2015

Kalahari Group sediments accumulated in the Kalahari basin, which started forming during the breakup of Gondwana in the early Cretaceous. These sediments cover an extensive part of southern Africa and form a low-relief landscape. Current models assume that the Kalahari Group accumulated throughout the entire Cenozoic. However, chronology has been restricted to early–middle Cenozoic biostratigraphic correlations and to OSL dating of only the past ~ 300 ka. We present a new chronological framework that reveals a dynamic nature of sedimentation in the southern Kalahari. Cosmogenic burial ages obtained from a 55 m section of Kalahari Group sediments from the Mamatwan Mine, southern Kalahari, indicate that the majority of deposition at this location occurred rapidly at 1–1.2 Ma. This Pleistocene sequence overlies the Archaean basement, forming a significant hiatus that permits the possibility of many Phanerozoic cycles of deposition and erosion no longer preserved in the sedimentary record. Our data also establish the existence of a shallow early–middle Pleistocene water body that persisted for > 450 ka prior to this rapid period of deposition. Evidence from neighboring archeological excavations in southern Africa suggests an association of high-density hominin occupation with this water body.
Perceptions relating to body size, weight loss and weight-loss interventions in black South African women: a qualitative study
Authors: Draper Catherine E , Davidowitz Kesiah J , Goedecke Julia H
Published: May 2015

Objective

A higher tolerance for a larger body size has been associated with obesity in black South African (SA) women. The aim of the present study was to explore perceptions regarding body size and weight loss in a sample of black women from a low-income community in Cape Town, SA.

Design

Qualitative pilot study including five focus groups. Data were analysed using thematic analysis.

Setting

Khayelitsha, Cape Town, SA.

Subjects

Twenty-one black SA women.

Results

The majority of participants had positive perceptions of overweight/obesity, which were influenced by community and cultural perceptions, but some inconsistencies were observed as overweight/obesity was also associated with ill health. Participants identified many benefits to weight loss, but due to the association with sickness, they were concerned about being stigmatised in their community. Although participants had knowledge about healthy eating, the main barrier to eating healthily included the perceived higher cost of healthier food and food insecurity. All participants saw exercise as a strategy to lose weight and improve health, and were interested in participating in a community-based exercise intervention, but negative community perceptions and conflicting views regarding who should lead the intervention were identified as barriers.

Conclusions

These findings highlight the complexities surrounding participants’ perceptions regarding body size, weight loss and weight-loss interventions, and emphasise low socio-economic status as a barrier to change. The study also highlights the strong influence of cultural ideals and community perceptions on personal perceptions. These findings underscore the necessity for culturally appropriate weight-loss interventions in low-income, transitioning communities.
Dynamics of the Earth's Surface in the Eastern Tibetan Plateau
Authors: Wheeling Kate
Published: May 2015

River erosion increased rapidly following rock uplift events in the plateau approximately 11 million years ago.
Bill that Limits Earth Science Funding Wins OK in House
Authors: Showstack Randy
Published: May 2015

The controversial America COMPETES legislation would restrict Earth science funding at several U.S. federal agencies, including the National Science Foundation.
Geoscience Community Reacts to Vote on America COMPETES Bill
Authors: Showstack Randy
Published: May 2015

Legislation that would restrict funding for geoscience at federal agencies raises concerns about the research program budgets.
High-performance green flexible electronics based on biodegradable cellulose nanofibril paper
Authors: Jung Yei Hwan , Chang Tzu-Hsuan , Zhang Huilong , Yao Chunhua , Zheng Qifeng , Yang Vina W. , Mi Hongyi , Kim Munho , Cho Sang June , Park Dong-Wook , Jiang Hao , Lee Juhwan , Qiu Yijie , Zhou Weidong , Cai Zhiyong , Gong Shaoqin , Ma Zhenqiang
Published: May 2015

Today’s consumer electronics, such as cell phones, tablets and other portable electronic devices, are typically made of non-renewable, non-biodegradable, and sometimes potentially toxic (for example, gallium arsenide) materials. These consumer electronics are frequently upgraded or discarded, leading to serious environmental contamination. Thus, electronic systems consisting of renewable and biodegradable materials and minimal amount of potentially toxic materials are desirable. Here we report high-performance flexible microwave and digital electronics that consume the smallest amount of potentially toxic materials on biobased, biodegradable and flexible cellulose nanofibril papers. Furthermore, we demonstrate gallium arsenide microwave devices, the consumer wireless workhorse, in a transferrable thin-film form. Successful fabrication of key electrical components on the flexible cellulose nanofibril paper with comparable performance to their rigid counterparts and clear demonstration of fungal biodegradation of the cellulose-nanofibril-based electronics suggest that it is feasible to fabricate high-performance flexible electronics using ecofriendly materials.
Influence of external magnetic field and magnetic-site dilution on the magnetic dynamics of a one-dimensional Tb(iii)–radical complex
Authors: Li Leilei , Liu Shuang , Li Han , Shi Wei , Cheng Peng
Published: May 2015

A new Tb(iii)–NITR complex was obtained, which showed a 1D zig-zag chain structure and field-induced dual relaxation processes.
Chemoenzymatic one-pot synthesis in an aqueous medium: combination of metal-catalysed allylic alcohol isomerisation–asymmetric bioamination
Authors: Ríos-Lombardía Nicolás , Vidal Cristian , Cocina María , Morís Francisco , García-Álvarez Joaquín , González-Sabín Javier
Published: May 2015

The ruthenium-catalysed isomerisation of allylic alcohols was coupled, for the first time, with asymmetric bioamination in a one-pot process in an aqueous medium.
Highly active, chemo- and enantioselective Pt-SPO catalytic systems for the synthesis of aromatic carboxamides
Authors: Gulyás Henrik , Rivilla Ivan , Curreli Simona , Freixa Zoraida , van Leeuwen Piet W. N. M.
Published: May 2015

Platinum complexes of the chiral non-racemizing SPO ligand1have been discovered to be the first artificial transition metal complexes providing kinetic resolution in the hydration of a racemic chiral nitrile.
Synthesis of N, F and S co-doped graphene quantum dots
Authors: Kundu Sumana , Yadav Ram Manohar , Narayanan T. N. , Shelke Manjusha V. , Vajtai Robert , Ajayan P. M. , Pillai Vijayamohanan K.
Published: May 2015

A schematic representation of the ultrafast synthetic method for preparing highly luminescent N, F and S co-doped graphene quantum dots from MWCNTs.
Photochemical degradation of the UV filter octyl methoxycinnamate in solution and in aggregates
Authors: Hanson Kerry M. , Narayanan Swathi , Nichols Valerie M. , Bardeen Christopher J.
Published: May 2015

The photodegradation of the ultraviolet (UV) filter octyl methoxycinnamate (OMC) is investigated in both dilute solution and in aggregated form. In dilute solution, the ratio of trans and cis isomers achieved at the photostationary state is solvent-dependent because of variations in the isomerization quantum yield. The two isomeric forms at the photostationary state are highly resistant to further photodegradation and no other UVA-absorbing species are formed. Aggregation of OMC, either in a neat film or in aqueous colloidal suspensions, leads to irreversible photodegradation of the molecule and the formation of multiple photoproducts. In addition to previously identified photoproducts like the UVB-absorbing cis and trans isomers and photodimers, we find photoproduct species whose absorption extends into the UVA. Characterization of the photophysical properties of these species indicates that they have long-lived excited-states (τ
f > 1 ns, 400 nm), unlike the isomeric forms of OMC (τ
f < 30 ps, 266 nm), and that excitation at 405 nm can sensitize the formation of singlet oxygen. These results show that the environment of OMC affects the photochemistry of the molecule and that the environmental conditions must be taken into account when considering the molecule’s stability. In particular, aggregation of OMC molecules results in complex photochemistry that can produce species whose absorption extends into UVA and are capable of generating reactive oxygen species.
Enhanced visible-active photochromism of a polyoxometalates/TiO2composite film by combining Bi2O3nanoparticles
Authors: Wang Xiansheng , Sun Yan , Liu Changcheng , Feng Wei , Zou Donglei
Published: May 2015

Photochromic hybrid film sensitive to visible light was fabricated by introducing Bi2O3into PMoA/TiO2composite as a visible light sensitizer.
Hyperbranched fluorene-alt-carbazole copolymers with spiro[3.3]heptane-2,6-dispirofluorene as the core and their application in white polymer light-emitting devices
Authors: Wu Yuling , Li Jie , Liang Wenqing , Yang Junli , Sun Jing , Wang Hua , Liu Xuguang , Xu Bingshe , Huang Wei
Published: May 2015

A potential hyperbranched structure with 2,7-fluorene-alt-3,6-carbazole and 4,7-dithienyl-2,1,3-benzothiadiazole branches, and a three-dimensional-structured spiro[3.3]heptane-2,6-dispirofluorene core is synthesized for efficient and stable WPLEDs.
Discovery of NAD(P)H:quinone oxidoreductase 1 (NQO1) inhibitors with novel chemical scaffolds by shape-based virtual screening combined with cascade docking
Authors: Bian Jinlei , Qian Xue , Deng Bang , Xu Xiaoli , Guo Xiaoke , Wang Yalou , Li Xiang , Sun Haopeng , You Qidong , Zhang Xiaojin
Published: May 2015

A number of novel NAD(P)H:quinone oxidoreductase 1 (NQO1) inhibitors were discovered from the ChemDiv database via a simple protocol.
Ultraviolet photoelectrical properties of a n-ZnO nanorods/p-diamond heterojunction
Authors: Sang Dandan , Li Hongdong , Cheng Shaoheng , Wang Qiliang , Liu Junsong , Wang Qinglin , Wang Shuang , Han Chong , Chen Kai , Pan Yuewu
Published: May 2015

The n-ZnO nanorods/p-diamond heterojunction was fabricated and it shows high performance ultraviolet photoresponse properties.
Photodeposition synthesis of a ZnO nanoporous layer
Authors: Guan Jia-Jian , Wang Hao-Qi , Liang Hong , Cheng Nan-Pu , Lin Hua , Li Qing , Li Yuan , Qin Li-Zhao
Published: May 2015

A photodeposition methodology is investigated to synthesize novel ZnO nanoporous layer with high yield and uniformity on TiO2 nanotubes.
Synthesis of B-doped hollow carbon spheres as efficient non-metal catalyst for oxygen reduction reaction
Authors: Lu Hui-Jia , Li Ying , Zhang Lin-Qun , Li He-Nan , Zhou Zhi-Xin , Liu An-Ran , Zhang Yuan-Jian , Liu Song-Qin
Published: May 2015

Synthesis scheme and morphology of B-doped hollow carbon spheres applied as an efficient non-metal catalyst for oxygen reduction reaction.
Cofactor composition and function of a H2-sensing regulatory hydrogenase as revealed by Mössbauer and EPR spectroscopy
Authors: Roncaroli Federico , Bill Eckhard , Friedrich Bärbel , Lenz Oliver , Lubitz Wolfgang , Pandelia Maria-Eirini
Published: May 2015

A regulatory hydrogenase is characterised by Mössbauer, EPR and FTIR yielding insight into structure and function of this dihydrogen sensor.
NiCo2O4@NiO hybrid arrays with improved electrochemical performance for pseudocapacitors
Authors: Liu Xijun , Liu Junfeng , Sun Xiaoming
Published: May 2015

A novel hierarchical NiCo2O4@NiO array is developed for electrochemical capacitors. Such a 3D hybrid electrode exhibits high capacity and excellent cycling stability. The enhanced performance could be attributed to the synergetic contribution of the composite and unique hierarchical architecture.
Selective chemical modification of soy protein for a tough and applicable plant protein-based material
Authors: Ma Li , Yang Yuhong , Yao Jinrong , Shao Zhengzhong , Huang Yufang , Chen Xin
Published: May 2015

A tough, stable, and antimicrobial soy protein film is obtained from the slight chemical modification on the polypeptide chain, which broadens the application area of such a cheap, abundant and sustainable natural material.
Single molecule magnets grafted on gold: magnetic properties from ab initio molecular dynamics
Authors: Lunghi Alessandro , Iannuzzi Marcella , Sessoli Roberta , Totti Federico
Published: May 2015

The adsorption process on gold and its consequences on the magnetic behavior of an {Fe4} SMM have been highlighted through AIMD.
The influence of surface topography on the field emission of nanostructured copper oxide thin films grown by oblique incidence deposition
Authors: Chatterjee S. , Kumar M. , Pal A. , Thakur I. , Som T.
Published: May 2015

The surface morphology dependent field electron emission characteristic of copper oxide thin films shows superior field emission of obliquely sputter deposited thin film (turn-on field ∼1.3 V μm−1) compared to normally deposited film.
Simple two‐adders CIC compensator
Authors: Romero D. E. T. , Salgado G. M. , Dolecek G. J.
Published: May 2015

The design of the simplest compensation filters available for cascaded integrator‐comb (CIC) decimators to date is introducted. These filters require only two additions and can be straightforwardly realised in terms of the integer d as a design parameter, which depends on K, the number of cascaded CIC filters. The proposed compensators have the minimum phase property, useful for low‐delay applications.
Robust medical image watermarking technique for accurate detection of tampers inside region of interest and recovering original region of interest
Authors: Eswaraiah Rayachoti , Sreenivasa Reddy Edara
Published: May 2015

Transmission of medical images among remote places is a general practice in telemedicine. Medical images may be modified intentionally or accidentally as the transmission of these may take place through unsecure networks such as internet. Before making any diagnostic decisions, the medical practitioner has to verify the integrity of region of interest (ROI) in the received medical image in order to avoid wrong diagnosis. Watermarking can be used for checking the integrity of medical images. In this study, the authors propose a novel medical image watermarking method based on integer wavelet transform (IWT). This proposal verifies the integrity of ROI, precisely identifies tampered blocks inside ROI, provides robustness to the data embedded inside region of non‐interest (RONI) and recovers original ROI. In the proposed method, the medical image is segmented into ROI and RONI regions. Hash value of ROI, recovery data of ROI and data of patient are embedded into RONI using IWT. Experimental results show that the proposed method provides robustness to the watermark data embedded inside RONI and accurately detects and localises tampered areas inside ROI and recovers the original ROI.
Electric characteristics analysis on power drive system based on negative input‐resistance compensator
Authors: Wang Na , Zhou Yuanjun , Sun Jing , Bai Long
Published: May 2015

A power drive system is a typical load for the 270 V DC power distribution systems of more electric aircraft. It may cause instability of power grid, including voltage transients and current transients. A negative input‐resistance compensator with current limitation is proposed to solve the stability problem as well as to decrease both voltage transients and current transients. The main emphasis is placed on the transient characteristics research of power drive system with the proposed compensator. A dc network admittance model is established to select proper parameters for the compensator. Simulation and experiments show that the designed compensator increases system stability while satisfying the transient requirements of the power distribution system.
Voltage balancing technique in a space vector modulated 5‐level multiple‐pole multilevel diode clamped inverter
Authors: Raj Pinkymol Harikrishna , Maswood Ali I. , Ooi Gabriel H.P. , Lim Ziyou
Published: May 2015

Unbalanced voltage across the dc‐link capacitors of classical diode clamped multilevel inverters (DCMI) generates lower order harmonics in the output voltage and increases the voltage stress on the switching devices which may result in permanent damage to the switching devices. This study proposes a space vector modulation (SVM) based voltage balancing strategy for a new 5‐level multiple‐pole multilevel diode‐clamped inverter (M2DCI) topology to eliminate the voltage drift phenomena. The 5‐level M2DCI topology which is derived from 3‐level DCMI topology uses lesser number of clamping diodes compared with the conventional 5‐level DCMI topology. An effective switching function model of a new multilevel inverter is derived and is used for dc‐link capacitor voltage control. The method utilises the redundant vector property to balance the dc‐link capacitor voltages without using any auxiliary hardware. The dependence of the capacitor voltage variation on the load power factor and modulation index has been extensively studied for 5‐level M2DCI. The range of operation for the new topology with the proposed control strategy is also presented based on the simulation studies in the Matlab/Simulink® and PSIM environment and verified using experimental results.
Does Government‐sponsored Advertising Increase Social Welfare? A Theoretical and Empirical Investigation
Authors: Carpio Carlos E. , Isengildina‐Massa Olga
Published: May 2015

The main objective of this study was to analyze the effect of advertising on social welfare in a perfectly competitive market where the level of advertising is chosen by a social planner. The theoretical model revealed that social planner‐sponsored advertising that increases the equilibrium price of the advertised good can increase society's welfare if the effect of advertising in consumers' utility is higher than the consumer welfare‐reducing price effect. The empirical illustration focuses on the U.S. state of South Carolina's “buy local” food products campaign. The findings suggest that this government‐sponsored advertising campaign increases total welfare.
Reverse engineering of logic-based differential equation models using a mixed-integer dynamic optimization approach
Authors: Henriques David , Rocha Miguel , Saez-Rodriguez Julio , Banga Julio R.
Published: May 2015

Motivation: Systems biology models can be used to test new hypotheses formulated on the basis of previous knowledge or new experimental data, contradictory with a previously existing model. New hypotheses often come in the shape of a set of possible regulatory mechanisms. This search is usually not limited to finding a single regulation link, but rather a combination of links subject to great uncertainty or no information about the kinetic parameters.

Results: In this work, we combine a logic-based formalism, to describe all the possible regulatory structures for a given dynamic model of a pathway, with mixed-integer dynamic optimization (MIDO). This framework aims to simultaneously identify the regulatory structure (represented by binary parameters) and the real-valued parameters that are consistent with the available experimental data, resulting in a logic-based differential equation model. The alternative to this would be to perform real-valued parameter estimation for each possible model structure, which is not tractable for models of the size presented in this work. The performance of the method presented here is illustrated with several case studies: a synthetic pathway problem of signaling regulation, a two-component signal transduction pathway in bacterial homeostasis, and a signaling network in liver cancer cells.

Supplementary information:  Supplementary data are available at Bioinformatics online.

Contact:  julio@iim.csic.es or saezrodriguez@ebi.ac.uk
Bayesian mixture analysis for metagenomic community profiling
Authors: Morfopoulou Sofia , Plagnol Vincent
Published: May 2015

Motivation: Deep sequencing of clinical samples is now an established tool for the detection of infectious pathogens, with direct medical applications. The large amount of data generated produces an opportunity to detect species even at very low levels, provided that computational tools can effectively profile the relevant metagenomic communities. Data interpretation is complicated by the fact that short sequencing reads can match multiple organisms and by the lack of completeness of existing databases, in particular for viral pathogens. Here we present metaMix, a Bayesian mixture model framework for resolving complex metagenomic mixtures. We show that the use of parallel Monte Carlo Markov chains for the exploration of the species space enables the identification of the set of species most likely to contribute to the mixture.

Results: We demonstrate the greater accuracy of metaMix compared with relevant methods, particularly for profiling complex communities consisting of several related species. We designed metaMix specifically for the analysis of deep transcriptome sequencing datasets, with a focus on viral pathogen detection; however, the principles are generally applicable to all types of metagenomic mixtures.

Availability and implementation: metaMix is implemented as a user friendly R package, freely available on CRAN: http://cran.r-project.org/web/packages/metaMix

Contact:  sofia.morfopoulou.10@ucl.ac.uk

Supplementary information:  Supplementary data are available at Bionformatics online.
tmle.npvi: targeted, integrative search of associations between DNA copy number and gene expression, accounting for DNA methylation
Authors: Chambaz Antoine , Neuvial Pierre
Published: May 2015

Summary: We describe the implementation of the method introduced by Chambaz et al. in 2012. We also demonstrate its genome-wide application to the integrative search of new regions with strong association between DNA copy number and gene expression accounting for DNA methylation in breast cancers.

Availability and implementation: An open-source R package tmle.npvi is available from CRAN (http://cran.r-project.org/).

Contact:  pierre.neuvial@genopole.cnrs.fr
pwOmics: an R package for pathway-based integration of time-series omics data using public database knowledge
Authors: Wachter Astrid , Beißbarth Tim
Published: May 2015

Summary: Characterization of biological processes is progressively enabled with the increased generation of omics data on different signaling levels. Here we present a straightforward approach for the integrative analysis of data from different high-throughput technologies based on pathway and interaction models from public databases. pwOmics performs pathway-based level-specific data comparison of coupled human proteomic and genomic/transcriptomic datasets based on their log fold changes. Separate downstream and upstream analyses results on the functional levels of pathways, transcription factors and genes/transcripts are performed in the cross-platform consensus analysis. These provide a basis for the combined interpretation of regulatory effects over time. Via network reconstruction and inference methods (Steiner tree, dynamic Bayesian network inference) consensus graphical networks can be generated for further analyses and visualization.

Availability and implementation: The R package pwOmics is freely available on Bioconductor (http://www.bioconductor.org/).

Contact:  astrid.wachter@med.uni-goettingen.de
PopGeV: a web-based large-scale population genome browser
Authors: Shi Xinyi , Peng Jing , Yu Xiaohan , Zhang Xiaohong , Li Dongye , Liu Baohui , Kong Fanjiang , Yuan Xiaohui
Published: May 2015

Motivation: The development of high-throughput sequencing technology has made it possible for more and more researchers to use population sequencing data to mine genes associated with specific traits. However, the massive amounts of sequencing data have also brought new challenges to the researchers. The question of how to browse population genomic data in an easy and intuitive manner must be addressed. Web-based genome browsers allow user to conveniently view the results of genomic analyses, but heavy usage can reduce the response speed of the webpage, which limits its usefulness in the display of large-scale genome data. IndexedDB technology is a good solution to this problem; it supports web browsers and so creates local databases. In this way, data can be read from the local storage, achieving a smooth display of population genomic data.

Results: PopGeV has the following characteristics. First, it uses a new encoding method for compression of population SNP and INDEL data. IndexedDB technology is used to download the results to local storage so that users can browse the results smoothly even when the network traffic is heavy. Second, PopGeV identify similar genomic regions between two individuals based on SNP data. Population diversity indexes are calculated when comparing two populations. Third, user defined annotation information can be integrated for user-friendly mining of gene functions. Simulation shows that PopGeV can smoothly display analysis results of population genome containing over 500 individuals with 2 millions SNP data.

Availability and implementation: PopGeV is available at www.soyomics.com/popgev/

Contact:  yuanxh@iga.ac.cn
Diffusion maps for high-dimensional single-cell analysis of differentiation data
Authors: Haghverdi Laleh , Buettner Florian , Theis Fabian J.
Published: May 2015

Motivation: Single-cell technologies have recently gained popularity in cellular differentiation studies regarding their ability to resolve potential heterogeneities in cell populations. Analyzing such high-dimensional single-cell data has its own statistical and computational challenges. Popular multivariate approaches are based on data normalization, followed by dimension reduction and clustering to identify subgroups. However, in the case of cellular differentiation, we would not expect clear clusters to be present but instead expect the cells to follow continuous branching lineages.

Results: Here, we propose the use of diffusion maps to deal with the problem of defining differentiation trajectories. We adapt this method to single-cell data by adequate choice of kernel width and inclusion of uncertainties or missing measurement values, which enables the establishment of a pseudotemporal ordering of single cells in a high-dimensional gene expression space. We expect this output to reflect cell differentiation trajectories, where the data originates from intrinsic diffusion-like dynamics. Starting from a pluripotent stage, cells move smoothly within the transcriptional landscape towards more differentiated states with some stochasticity along their path. We demonstrate the robustness of our method with respect to extrinsic noise (e.g. measurement noise) and sampling density heterogeneities on simulated toy data as well as two single-cell quantitative polymerase chain reaction datasets (i.e. mouse haematopoietic stem cells and mouse embryonic stem cells) and an RNA-Seq data of human pre-implantation embryos. We show that diffusion maps perform considerably better than Principal Component Analysis and are advantageous over other techniques for non-linear dimension reduction such as t-distributed Stochastic Neighbour Embedding for preserving the global structures and pseudotemporal ordering of cells.

Availability and implementation: The Matlab implementation of diffusion maps for single-cell data is available at https://www.helmholtz-muenchen.de/icb/single-cell-diffusion-map.

Contact:  fbuettner.phys@gmail.com, fabian.theis@helmholtz-muenchen.de

Supplementary information:  Supplementary data are available at Bioinformatics online.
Prenatal Transmission of Syphilis and Human Immunodeficiency Virus in Brazil: Achieving Regional Targets for Elimination
Authors: Cerda Rodrigo , Perez Freddy , Domingues Rosa Maria S.M. , Luz Paula M. , Grinsztejn Beatriz , Veloso Valdilea G. , Caffe Sonja , Francke Jordan A. , Freedberg Kenneth A. , Ciaranello Andrea L.
Published: May 2015

Background.  The Pan-American Health Organization has called for reducing (1) human immunodeficiency virus (HIV) mother-to-child transmission (MTCT) to ≤0.30 infections/1000 live births (LB), (2) HIV MTCT risk to ≤2.0%, and (3) congenital syphilis (CS) incidence to ≤0.50/1000 LB in the Americas by 2015.

Methods.  Using published Brazilian data in a mathematical model, we simulated a cohort of pregnant women from antenatal care (ANC) through birth. We investigated 2 scenarios: “current access” (89.1% receive one ANC syphilis test and 41.1% receive 2; 81.7% receive one ANC HIV test and 18.9% receive birth testing; if diagnosed, 81.0% are treated for syphilis and 87.5% are treated for HIV) and “ideal access” (95% of women undergo 2 HIV and syphilis screenings; 95% receive appropriate treatment). We conducted univariate and multivariate sensitivity analyses on key inputs.

Results.  With current access, we projected 2.95 CS cases/1000 LB, 0.29 HIV infections/1000 LB, 7.1% HIV MTCT risk, and 11.11 intrauterine fetal demises (IUFD)/1000 pregnancies, with significant regional variation. With ideal access, we projected improved outcomes: 1.00 CS cases/1000 LB, 0.10 HIV infections/1000 LB, HIV MTCT risk of 2.4%, and 10.65 IUFD/1000 pregnancies. Increased testing drove the greatest improvements. Even with ideal access, only HIV infections/1000 LB met elimination goals. Achieving all targets required testing and treatment >95% and reductions in prevalence and incidence of HIV and syphilis.

Conclusions.  Increasing access to care and HIV and syphilis antenatal testing will substantially reduce HIV and syphilis MTCT in Brazil. In addition, regionally tailored interventions reducing syphilis incidence and prevalence and supporting HIV treatment adherence are necessary to completely meet elimination goals.
Balancing Enthusiasm for Innovative Technologies with Optimizing Value: An Approach to Adopt New Laboratory Tests for Infectious Diseases Using Bloodstream Infections as Exemplar
Authors: Culbreath Karissa , Petti Cathy A.
Published: May 2015

A number of exciting new technologies have emerged to detect infectious diseases with greater accuracy and provide faster times to result in hopes of improving the provision of care and patient outcomes. However, the challenge in evaluating new methods lies not in the technical performance of tests but in (1) defining the specific advantages of new methods over the present gold standards in a practicable way and (2) understanding how advanced technologies will prompt changes in medical and public health decisions. With rising costs to deliver care, enthusiasm for innovative technologies should be balanced with a comprehensive understanding of clinical and laboratory ecosystems and how such factors influence the success or failure of test implementation. Selecting bloodstream infections as an exemplar, we provide a 6-step model for test adoption that will help clinicians and laboratorians better define the value of a new technology specific to their clinical practices.
A Coalescent Model of a Sweep from a Uniquely Derived Standing Variant
Authors: Berg Jeremy J. , Coop Graham
Published: May 2015

The use of genetic polymorphism data to understand the dynamics of adaptation and identify the loci that are involved has become a major pursuit of modern evolutionary genetics. In addition to the classical “hard sweep” hitchhiking model, recent research has drawn attention to the fact that the dynamics of adaptation can play out in a variety of different ways, and that the specific signatures left behind in population genetic data may depend somewhat strongly on these dynamics. One particular model for which a large number of empirical examples are already known is that in which a single derived mutation arises and drifts to some low frequency before an environmental change causes the allele to become beneficial and sweeps to fixation. Here, we pursue an analytical investigation of this model, bolstered and extended via simulation study. We use coalescent theory to develop an analytical approximation for the effect of a sweep from standing variation on the genealogy at the locus of the selected allele and sites tightly linked to it. We show that the distribution of haplotypes that the selected allele is present on at the time of the environmental change can be approximated by considering recombinant haplotypes as alleles in the infinite alleles model. We show that this approximation can be leveraged to make accurate predictions regarding patterns of genetic polymorphism following such a sweep. We then use simulations to highlight which sources of haplotypic information are likely to be most useful in distinguishing this model from neutrality, as well as from other sweep models, such as the classic hard sweep, and multiple mutation soft sweeps. We find that in general, adaptation from a uniquely derived standing variant will be difficult to detect on the basis of genetic polymorphism data alone, and when it can be detected, it will be difficult to distinguish from other varieties of selective sweeps.
Dynamic effects of extrinsic noise in a simple oscillatory gene network with delayed negative-feedback regulation: an electronic modeling approach
Authors: Santillán Moisés
Published: May 2015

Gene expression is intrinsically stochastic due to the small number of molecules involved in some of the underlying biochemical reactions. The resulting molecule-count random fluctuations are known as biochemical noise. The dynamic effects of intrinsic noise (that originated within the system) have been widely studied. However, the effects of the noise coming from other sources the system is in contact with, or extrinsic noise, is not so well understood. In this work we introduce an electronic model for a simple gene oscillatory network, with delayed negative-feedback regulation. Notably, this model accounts for the intrinsic biochemical noise due to the slow promoter switching between the active and inactive states; but dismisses biochemical noise due to mRNA and protein production and degradation. We characterize the oscillatory behavior of this gene network by varying all the relevant parameter values within biologically meaningful ranges. Finally, we investigate how different sources of extrinsic noise affect the system dynamic behavior. To simulate extrinsic noise we consider stochastic time series coming from another circuit simulating a gene network. Our results indicate that, depending on the parameter affected by extrinsic noise and the power spectra of the stochastic time series, the system quasi-periodic behavior is affected in different ways.