bluuebunny/crossref_metadata_2025 huggingface dataset:
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Authors: Londhe Vedang A. , Tomi Tomoko , Nguyen Tam T. , Lopez Benjamin , Smith Jeffrey B.
Published: June 2015

Background: Lung maturation can be disrupted through pro‐inflammatory processes including intra‐uterine amniotic infection, mechanical ventilation, or oxidative stress. Lincr, originally identified as a gene induced in the lung by lipopolysaccharide (LPS), is also expressed in the developing lung. The Lung‐inducible Neuralized‐related C3HC4 RING domain (LINCR) protein is structurally related to Drosophila Neuralized, a regulator of the developmentally important Notch signaling pathway. LINCR is expressed in alveolar epithelial type II cells in the mature lung, and its expression is markedly increased by LPS and inflammatory cytokines. To test the hypothesis that targeted overexpression of LINCR in lung epithelium would interfere with normal lung development, we generated double transgenic mice that conditionally overexpress LINCR in lung epithelium under the control of doxycycline.

Results: Single transgenic controls and double transgenic mice not treated with doxycycline were unaffected, but double transgenic mice exposed to doxycycline starting at embryonic day 6 developed markedly hypoplastic lungs with decreased numbers of alveoli and large cysts lined with a proximalized and poorly differentiated epithelium expressing Hairy/Enhancer of Split 1, an effector of Notch signaling. The phenotype was similar to that caused by overexpression of activated Notch1 in lung epithelium.

Conclusions: LINCR may exert its effects on distal lung development in this model through activation of the Notch signaling pathway. Developmental Dynamics 244:827–838, 2015. © 2015 Wiley Periodicals, Inc.
Endogenous prostaglandin E2 potentiates anti‐inflammatory phenotype of macrophage through the CREB‐C/EBP‐β cascade
Authors: Na Yi Rang , Jung Daun , Yoon Bo Ruem , Lee Won Woo , Seok Seung Hyeok
Published: June 2015

Macrophages have important functions in tissue homeostasis, but the exact mechanisms regarding wide spectrum of macrophage phenotype remain unresolved. In this study, we report that mouse bone marrow derived naïve macrophages produce prostaglandin E2 (PGE2) endogenously, resulting in anti‐inflammatory gene expression upon differentiation induced by macrophage colony stimulating factor (M‐CSF). Cyclooxygenase (COX) inhibition by indomethacin reduced endogenous PGE2 production of macrophages and subsequently reduced arg1, IL10 and Mrc1, YmI and FizzI gene expressions. Of note, PGE2 phosphorylates CREB via EP2 and EP4 receptor ligation, thereby transcriptionally increasing C/EBP‐β expression in BALB/c bone marrow derived macrophages. Activated CREB directly binds to the CREB‐responsive element of the C/EBP‐β promoter, such that PGE2 ultimately reinforces arg1, IL10 and Mrc1 gene expression. Cyclic AMP activator forskolin also phosphorylated CREB and induced the C/EBP‐β cascade, but this was completely blocked by the PKA inhibitor, H89. Consequently, M‐CSF grown macrophages inhibited T‐cell proliferation but the inhibition ability was reduced when the COX is inhibited by indomethacin or macrophage C/EBP‐β expression was decreased by siRNA transduction. Our results collectively describe the molecular basis for homeostatic macrophage differentiation by endogenous PGE2.
Miniaturized Enzymatic Biosensor via Biofunctionalization of the Insulator of Nanoelectrode Ensembles
Authors: Habtamu Henok B. , Ugo Paolo
Published: June 2015

An innovative second generation enzymatic microbiosensor was developed exploiting the properties of nanoelectrode ensembles (NEEs) prepared by electroless gold deposition in track‐etched polycarbonate (PC) membranes. As a case study, a miniaturized glucose biosensor was developed and characterized. The micro‐NEE glucose biosensor was obtained by immobilizing glucose oxidase (GOx) on the nonconductive PC component of the NEE, while the Au nanoelectrodes were used exclusively as transducers. (Ferrocenylmethyl)trimethylammonium cation (FA+) was used as the redox mediator. The immobilization of GOx on the PC did not affect the electrochemical performances of the NEE nor the catalytic activity of the enzyme. The proposed biosensor showed outstanding analytical performances with a detection limit of 36 µM. The nanostructured biosensor was miniaturized down to a micro‐NEE with overall radius of 400 µm, without any degradation of the analytical performances.
Enhanced Electrochemiluminescence of Luminol on Indium Tin Oxide Modified with Dendrimer‐Encapsulated Au Nanoparticles
Authors: Lee Soon Bo , Kwon Jihye , Kim Joohoon
Published: June 2015

Enhanced electrochemiluminescence (ECL) of luminol was reported with the use of dendrimer‐encapsulated Au nanoparticle (Au DEN)‐modified ITOs in the presence of hydrogen peroxide, which was applied for sensitive ECL‐based electroanalysis of hydrogen peroxide. The enhanced ECL of luminol in the presence of hydrogen peroxide was attributed to facile electrochemical oxidation of luminol/hydrogen peroxide on the Au DEN‐modified ITOs at potentials as low as ∼0.4 V (vs. Ag/AgCl). Spooling ECL spectroscopy measurements indicated that the enhanced ECL emission of luminol/hydrogen peroxide system on the Au DEN‐modified ITOs originated from excited 3‐aminophthalate as same as that obtained on bare ITOs. Stability of Au DENs on ITO surfaces was also addressed and found to be closely related with the presence of chloride ions in electrolyte solutions.
Over 2 Years of Outdoor Operational and Storage Stability of ITO‐Free, Fully Roll‐to‐Roll Fabricated Polymer Solar Cell Modules
Authors: Angmo Dechan , Krebs Frederik C.
Published: June 2015

We report on the stability of large‐area (100 cm2), low‐cost, indium‐tin‐oxide (ITO)‐free modules over two years (>17 500 h) under outdoor operational conditions in Denmark and under indoor storage condition by following ISOS‐O‐3 and ISOS‐D‐2 protocols. Irrespective of the testing regimes (storage and outdoor), all modules maintain the maximum power point (MPP) above T80 (the duration over which a solar cell retains above 80 % of its initial MPP) over two years using a simple low‐cost packaging barrier with a water vapor transmission rate (WVTR) of 0.04 g m−2 day−1, an oxygen transmission rate (OTR) of 0.01 cm3 m−2 bar−1 day−1, and a UV cut‐off at 390 nm. Unlike previous studies, localized degradation through edges and contact points in the modules are not overwhelming even after more than two years; therefore, the differences in degradation under long‐term outdoor and storage conditions could be probed. The results suggest that oxygen permeation may be mainly responsible for degradation under outdoor conditions, whereas WVTR has a larger bearing under storage conditions.
Tenax extraction as a simple approach to improve environmental risk assessments
Authors: Harwood Amanda D. , Nutile Samuel A. , Landrum Peter F. , Lydy Michael J.
Published: June 2015

It is well documented that using exhaustive chemical extractions is not an effective means of assessing exposure of hydrophobic organic compounds in sediments and that bioavailability-based techniques are an improvement over traditional methods. One technique that has shown special promise as a method for assessing the bioavailability of hydrophobic organic compounds in sediment is the use of Tenax-extractable concentrations. A 6-h or 24-h single-point Tenax-extractable concentration correlates to both bioaccumulation and toxicity. This method has demonstrated effectiveness for several hydrophobic organic compounds in various organisms under both field and laboratory conditions. In addition, a Tenax bioaccumulation model was developed for multiple compounds relating 24-h Tenax-extractable concentrations to oligochaete tissue concentrations exposed in both the laboratory and field. This model has demonstrated predictive capacity for additional compounds and species. Use of Tenax-extractable concentrations to estimate exposure is rapid, simple, straightforward, and relatively inexpensive, as well as accurate. Therefore, this method would be an invaluable tool if implemented in risk assessments. Environ Toxicol Chem 2015;34:1445–1453. © 2015 SETAC
Examining the Internal Structure of the Test of English‐for‐Teaching (TEFT™)
Authors: Gu Lin , Turkan Sultan , Garcia Gomez Pablo
Published: June 2015

ELTeach is an online professional development program developed by Educational Testing Service (ETS) in collaboration with National Geographic Learning. The ELTeach program consists of two courses: English‐for‐Teaching and Professional Knowledge for English Language Teaching (ELT). Each course includes a coordinated assessment leading to a score report and certificate for teachers of English as a foreign language (EFL). The Test of English‐for‐Teaching (TEFT™), the assessment component of the English‐for‐Teaching course, measures EFL teachers' command of English for teaching English in classroom settings, as presented in the course. In this study, we examined the internal structure of the TEFT assessment. Results of the analyses demonstrated the role of both skill and content in representing the test's internal structure. The final parcel model had a higher‐order general factor and four first‐order factors corresponding to reading, writing, listening, and speaking. The findings support the current score reporting practice, that is, to report a total scaled score along with score information on language skills and on language use in specific content areas.
Climate change and eastern Africa: a review of impact on major crops
Authors: Adhikari Umesh , Nejadhashemi A. Pouyan , Woznicki Sean A.
Published: June 2015

Global warming has become one of the major challenges in maintaining global food security. This paper reviews the impacts of climate change on fourteen strategic crops for eight sub‐Saharan Africa countries. Climate change is projected to increase median temperature by 1.4–5.5°C and median precipitation by −2% to 20% by the end of the 21st century. However, large levels of uncertainty exist with temporal and spatial variability of rainfall events. The impact of climate change on crop yields in the region is largely negative. Among the grain crops, wheat is reported as the most vulnerable crop, for which up to 72% of the current yield is projected to decline. For other grain crops, such as maize, rice and soybean, up to 45% yield reductions are expected by the end of this century. Two grain crops, millet and sorghum, are more resilient to climate change for which projected impacts on crop yields are <20%. Root crops, such as sweet potato, potato and cassava are projected to be less affected than the grain crops with changes to crop yields ranging from about −15% to 10%. For the two major export crops, tea and coffee, up to 40% yield loss is expected due to the reduction in suitable areas caused by temperature increase. Similar loss of suitable areas is also expected for banana and sugarcane production, however, this reduction is due to rainfall variability in lowland areas. Other crops such as cotton and sugarcane are projected to be more susceptible to precipitation variation that will vary significantly in the region. In order to mitigate the long‐term impacts of climate change on agricultural sectors, the development of small‐scale irrigation systems and water harvesting structures seems promising, however, affordability of such measures remains a key issue.
Development of Selective Electroless‐Deposited Electrode in Heterojunction with Intrinsic Thin‐Layer Solar Cell
Authors: Kim Areum , Park Hyunjin , Choi Eunmi , Cui Yinhua , Lee Seon Jea , Pyo Sung Gyu
Published: June 2015

In this paper, we describe selective deposition of a major electrode and a protection electrode in a heterojunction with intrinsic thin‐layer (HIT) type solar cell. Sn and Ni were used for the protection electrode to prevent the oxidation of Cu, which was used for the main electrode. SEM and TEM were used to analyze the microstructural evolution and changes in the interface as a result of each electroless deposition. Finally, the performance of our solar cell created via electroless deposition was evaluated. We determined the photovoltaic conversion efficiency (PCE) to be 16.4 %, the fill factor (FF) to be 72.2 %, the open circuit voltage (Voc) to be 681 mV, and the short circuit current (Jsc) to be 33.0 mA/cm2. These output values match the performance of an Ag screen‐printed solar cell and demonstrate the possibility of commercializing an inexpensive HIT solar cell with high efficiency.
Classifying CT/MR findings in patients with suspicion of hepatocellular carcinoma: Comparison of liver imaging reporting and data system and criteria‐free Likert scale reporting models
Authors: Zhang Yu‐Dong , Zhu Fei‐Peng , Xu Xun , Wang Qing , Wu Chen‐Jiang , Liu Xi‐Sheng , Shi Hai‐Bin
Published: June 2015

Purpose

To compare the Liver Imaging Reporting and Data System (LI‐RADS) and a criteria‐free Likert scale (LS) reporting models for classifying computed tomography/magnetic resonance imaging (CT/MR) findings of suspicious hepatocellular carcinoma (HCC).

Materials and Methods

Imaging data of 281 hepatic nodules in 203 patients were retrospectively included. Imaging characteristics including diameter, arterial hyperenhancement, washout, and capsule were reviewed independently by two groups of readers using LI‐RADS and LS (range, score 1–5). LS is primarily based on the overall impression of image findings without using fixed criteria. Interreader agreement (IRA), intraclass agreement (ICA), and diagnostic performance were determined by Fleiss, Cohen's kappa (κ), and logistic regression, respectively.

Results

There were 167 contrast‐enhanced CT (CECT) versus 114 MR data. Overall, IRA was moderate (κ = 0.47, 0.52); IRA was moderate‐to‐good for arterial hyperenhancement, washout, and capsule (κ = 0.56‐0.69); excellent for diameter and tumor embolus (κ = 0.99). Overall, ICA between LI‐RADS and LS was moderate (κ = 0.44‐0.50); ICA was good for scores 1–2 (κ = 0.71–0.90), moderate for scores 3 and 5 (κ = 0.41–0.52), but very poor for score 4 (κ = 0.11–0.19). LI‐RADS produced significantly lower accuracy (78.6% vs. 87.2%) and sensitivity (72.1% vs. 92.8%), higher specificity (97.3% vs. 71.2%) and positive likelihood ratio (+LR: 26.32 vs. 3.23) in diagnosis of HCC. CECT produced relatively low IRA, ICA, and diagnostic ability against MR.

Conclusion

There were substantial variations in liver observations between LI‐RADS and LS. Further study is needed to investigate ICA between CECT and MR.J. Magn. Reson. Imaging 2016;43:373–383.
Conceptualisation of the characteristics of advanced practitioners in the medical radiation professions
Authors: Smith Tony , Harris Jillian , Woznitza Nick , Maresse Sharon , Sale Charlotte
Published: June 2015

Professions grapple with defining advanced practice and the characteristics of advanced practitioners. In nursing and allied health, advanced practice has been defined as ‘a state of professional maturity in which the individual demonstrates a level of integrated knowledge, skill and competence that challenges the accepted boundaries of practice and pioneers new developments in health care’. Evolution of advanced practice in Australia has been slower than in the United Kingdom, mainly due to differences in demography, the health system and industrial relations. This article describes a conceptual model of advanced practitioner characteristics in the medical radiation professions, taking into account experiences in other countries and professions. Using the CanMEDS framework, the model includes foundation characteristics of communication, collaboration and professionalism, which are fundamental to advanced clinical practice. Gateway characteristics are: clinical expertise, with high level competency in a particular area of clinical practice; scholarship and teaching, including a masters qualification and knowledge dissemination through educating others; and evidence‐based practice, with judgements made on the basis of research findings, including research by the advanced practitioner. The pinnacle of advanced practice is clinical leadership, where the practitioner has a central role in the health care team, with the capacity to influence decision making and advocate for others, including patients. The proposed conceptual model is robust yet adaptable in defining generic characteristics of advanced practitioners, no matter their clinical specialty. The advanced practice roles that evolve to meet future health service demand must focus on the needs of patients, local populations and communities.
The Impact Of Gelatin Weight Ratio On Hydroxyapatite‐gelatin Composites And Their SBF Behaviour
Authors: Özsağıroğlu Tuğba Başargan , Nasün‐Saygılı Gülhayat
Published: June 2015

Hydroxyapatite is a bioceramic owing biocompatibility, bioactivity, osteoconductivity, nontoxicity and noninflammatory. With its unique properties, it is found applications in repairing of bone and as coatings for metallic prostheses. Bone consists of hydroxyapatite crystals as the major component of the mineral phase and collagen as the major component of the organic phase. By the inspiration of bone structure, hydroxyapatite‐polymer composites have been drawing attention for years. In this work, hydroxyapatite was participated with gelatin which is similar to collagen. Spray dryer is used as drying medium to investigate the effect of different weight gelatin ratios on powder. Moreover, in‐vitro studies were conducted to investigate their bioactivity on a selected sample. The results showed that these materials may be suitable for bio‐applications.
Preparation and Characterization of P3H:PCBM Blend Nanoparticles and Their Plasmonic Modification
Authors: Ghazy Omayma
Published: June 2015

In this work blends of poly(3‐hexylthiophene (P3HT) and [6,6]‐phenyl C61 butyric acid methyl ester (PCBM) in nanoparticles were prepared using the miniemulsion method. The two materials were blended in two different methods. The first is latex blending by mixing two dispersions of the two materials. The second is by incorporating both the two materials in each particle of the dispersion (blend nanoparticles). The TEM results showed the spherical morphology of the particles. Their absorption spectrum confirmed that the optical properties of the P3HT and PCBM did not alter by the blending in nanoparticles. The particles were then decorated with silver nanoparticles. The TEM results confirmed the adhesion of the silver nanoparticles to the surface of the blend nanoparticles. In addition the absorption spectrum of the blend nanoparticles was modified by the plasmonic absorption. The approach is useful for the fabrication and optimization of the hetero junction layer (HJL) of organic solar cells.
Polymerization Kinetic Analysis of some Glycerol and Glucose Based Polymers
Authors: Rusu Gerlinde , Nitu Sabina , Rusnac Lucian , Bandur Geza
Published: June 2015

The present study is focused on the synthesis of polymers starting from renewable resources. The two monomers were prepared by reaction of the corresponding derivative of glycerol (2,2‐dimethyl‐1,3‐dioxolane‐4‐yl‐methyl acrylate) and glucose (3‐O‐acryloyl‐1,25,6‐di‐O‐isopropylidene‐α‐glucofuranose) with acryloyl chloride, M1 and M2. Different molar ratio were used for the copolymers synthesis (M1:M2=3:1 and 5:1). The homo and co‐polymerization processes were investigated by Differential Scanning Calorimetry (DSC). Based on DSC data the activation energies were estimated by the following methods described by: Kissinger, Flynn–Wall–Ozawa (FWO) and Kissinger–Akahira–Sunose (KAS) The thermal stabilities of the resulting polymers were evaluated from the thermo gravimetrical (TG) analysis.
Enzymatic Modification of Different Lignins Through Oxidative Coupling with Hydrophilic Compounds
Authors: Fiţigău Ionita Firuta , Boeriu Carmen Gabriela , Peter Francisc
Published: June 2015

The enzymatic oxidative coupling of five technical lignins from different sources and with different molecular properties, with glucosamine and the tripeptide glycil‐tyrosyl‐glycine was studied in acetone/water mixture, using laccase as catalyst. The modified lignin was isolated and the product was characterized by means of size exclusion chromatography, FT‐IR and 31P‐NMR, in order to evidence the main lignin modifications after laccase coupling reactions. An important increase of the molecular weight and significant structural modifications were observed for the product obtained after the coupling reactions of Organosolv Hardwood Lignin and Alkali pretreated Wheat straw Lignin with glucosamine and glycil‐tyrosyl‐glycine, demonstrating the achievement of the modification reactions.
Transparent electromagnetic absorber for stable angle of incidence
Authors: Hong Ic‐Pyo
Published: June 2015

In this letter, a transparent electromagnetic absorber that provides stability for an angle of incidence and wide absorption bandwidth is presented using resistive frequency selective surface as circuit analogue structure at X‐band. The transparency of proposed structure is implemented using a transparent resistive film made of an indium‐tin‐oxide (ITO) and soda‐lime glass as dielectric spacer. Reflection loss characteristics for different angles of both TE and TM polarizations are presented through simulations. We then fabricated the proposed structure to verify the simulation results. The comparisons between the simulation and measured results show good agreements. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2023–2025, 2015
Gain enhancement of a wide‐slot antenna using dual‐layer, bandstop frequency selective surface as a substrate
Authors: Chatterjee Ayan , Parui Susanta Kumar
Published: June 2015

A technique for enhancing the gain of a conventional wide‐slot antenna over the wide frequency band using a dual‐layer, low‐profile, bandstop frequency selective surface (FSS) is presented in this article. The dual‐layer FSS exhibits transmission below −10 dB and a linear phase variation with frequency in the range of 4–7 GHz. Unit cell dimension on the order of 0.2λ is used for the FSS layers with respect to the center frequency of operation. The FSS is used as a substrate below the antenna that allows in‐phase reflection of radiated waves leading to enhancement in its gain in the broadside direction over entire operating band. An improvement of upto 3‐dBi gain is achieved over 4–6.5 GHz frequency band with a peak gain of 8.4 dBi. Spacing between the antenna and FSS layers is much less than the conventional quarter wavelength value. Simulation and measurement results are presented in each case. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2016–2020, 2015
Wideband high‐gain low‐profile dual‐polarized stacked patch antenna array with parasitic elements
Authors: Yang Tian Yang , Hong Wei , Zhang Yan
Published: June 2015

To realize wideband high‐gain dual‐polarized radiation, the proposed antenna array consists of two microstrip feeding networks and two groups, altogether 13 metal radiation patches. One group, namely four of the patches, are two‐layer stacked octagonal patches excited by feeding networks directly, and the other group of nine patches, are parasitic rectangular patches for improving both impedance bandwidth and gain level. The height of the antenna array is 7 mm (∼0.083λ0@3.55 GHz). The measured impedance bandwidths for VSWR < 1.5 at both ports are 12.6% (3.35–3.8 GHz). The isolation between the two ports is greater than 20 dB over the whole operating band. The measured gain is 16.2 dBi and the cross‐polarization level is less than −15 dB. The proposed structure possesses the features of low cost, low profile, high gain, wide band, and so forth. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2012–2016, 2015
Design of triband bandpass filter using novel hexa‐mode stub‐loaded ring resonator
Authors: Lin Lei , Wu Bian , Su Tao , Liang Chang‐hong
Published: June 2015

A novel hexa‐mode stub‐loaded ring resonator is proposed. Due to its symmetry, even‐odd‐mode method is applied to analyze the resonance characteristics. All the six modes equivalent circuits are quarter‐wavelength uniform impedance resonators (UIRs). Stub–stub coupling is introduced to split two identical modes and produce two transmission zeros (TZs). Then a triband bandpass filter operating at 1.5, 2.4, and 3.5 GHz is designed using the proposed resonator. The center frequency and bandwidth of each passband can be independently controlled. Two extra TZs were generated by the hook‐shape feedlines and a relatively wide stopband was achieved. Finally, the designed filter was fabricated and measured, and the measured results have good agreement with the simulated ones. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2005–2008, 2015
An averaged estimation of field strength into an enclosed large cavity with PCB board
Authors: Jeong In Hwan , Lee Jae W. , Cho Choon S. , Lee Young S. , Kwon Jong‐Hwa
Published: June 2015

In this article, two analysis methods, which are called as one is the combination of coplanar strip line analysis and Baum–Liu–Tesche (BLT) equation and the other combination of PoWer Balance (PWB) method and BLT equation, are used to predict the field strength level from the plane wave outside into an large enclosure with aperture and PCB boards inside. In realistic situations, an electrically large enclosure with an aperture has a drawback in calculating the field distribution inside the cavity precisely because of multiple reflections and resonance phenomena. Commercially available software based on the previously well‐established algorithms such as finite difference time domain (FDTD), finite element method (FEM), method of moment (MOM), and so on require much time consumption to carry out the field analysis within a limitation of accuracy, especially in the regime of high frequency. However, to overcome these resource and time‐consumption problem, PWB method based on statistical theory and BLT equation applying topological method are introduced and combined to give a reasonably good field estimation result. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2029–2031, 2015
An on‐wafer embedded passive device using chip‐in‐substrate packaging technology
Authors: Liang Junge G. , Kim Eun Seong , Wang Cong , Youn Je‐Hyun , Park Min Chul , Kim Nam Young
Published: June 2015

In this article, a new packaging technology called chip‐in‐substrate packaging (CiSP) technology, which embeds passive components such as inductors and capacitors on silicon substrates, is arranged for a three‐dimensional structure. As the parasitic capacitance of the inductors and capacitors are increased by CiSP, a lower self‐resonance frequency compared with bare chips can be avoided using a printed circuit board with low thickness and low permittivity. To verify CiSP on the circuit level, a diplexer circuit is simulated from measured components and is composed of two series LC resonators to apply a GSM band (880–960 MHz) and a DCS band (1.71–1.88 GHz). An insertion loss of 0.76 dB at 0.96 GHz for GSM and 0.772 dB at 1.71 GHz for DCS are realized by CiSP technology. Moreover, the minimum rejections of 19.1 dB at 1.71 GHz for GSM and 20.8 dB at 0.96 GHz for DCS are realized with the maximum rejections for the DCS and GSM bands of 37.6 and 33.7 dB, respectively. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2060–2067, 2015
The characteristics of a wideband ESPAR antenna using Koch fractal shaped elements
Authors: Kim Kyu‐Bo , Lee Seung‐Hwan , Choi Hak‐Keun
Published: June 2015

This article suggests a new 5‐element electrically steerable passive array radiators (ESPAR) antenna using a Koch fractal structure for the purpose of adding wideband characteristics to the conventional ESPAR antenna, and its characteristics were confirmed through design and fabrication. The Koch fractal ESPAR antenna with a monopole structure where two crossed boards stand vertically on a circular ground has four parasitic elements arranged around a single active element with a fixed radius and reactance is loaded on each parasitic element. It satisfied the return loss less than −15 dB from 1.7 to 2.4 GHz on the 700 MHz band and showed directivity and gain that have similar radiation patterns according to frequency. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2108–2112, 2015
Microwave backscattering of a spherical conductor coated by lossless metamaterials with an intervening air gap
Authors: Jamil Adnan G. , Rao Tenneti C. K.
Published: June 2015

A theoretical study of the electromagnetic backscattering from a lossless metamaterial (MTM) coated conducting sphere with an intervening air gap is presented in this article. The boundary‐value technique is used to obtain the normalized backscattering cross section. A comparison of backscattering characteristics is provided using different kinds of MTMs for the coating. The MTM coating combined with the added feature of an air gap (practically realized by replacing air with styrofoam) indicate that it is possible to achieve low EM backscattering over a broad range of frequencies for certain cases. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2099–2104, 2015
A bidirectional WDM‐PON‐ROF communication network architecture based on optical sextuple frequency
Authors: Li Guang , Zhang Xiao Min , Chen Yin , Huang Xu Guang
Published: June 2015

A unusual bidirectional low cost WDM‐PON‐ROF communication network architecture using optical sextuple frequency which is based on photoelectron coherent modulation through a Double‐Arm‐Mach‐Zehnder‐Modulator with a number of different wavelength characteristics is provided and analyzed theoretically. After transmitting more than 25 km in a standard single mode fiber, the clear eye‐diagram and good bit error rate are obtained for wireless signal, wired signal and upstream signal communication. In this communication network architecture, because of no laser source, the base‐station (BS) is not complicated, and because of the optical sextuple frequency signal, the ultra high frequency of the local oscillator is greatly reduced. Compared with recent schemes, the outlays of switching center and BS are greatly decreased. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2079–2083, 2015
Hybrid liquid crystal–photonic crystal fiber tunable interferometer
Authors: Poudereux David , Quintana Xabier , Corredera Pedro , Geday Morten A. , Otón José M.
Published: June 2015

Two tunable interferometers based on photonic crystal fibers (PCF) and liquid crystals (LC) were designed and fabricated. In the first interferometer, the LC peripherally surrounds the PCF, while in the second, much more sensitive to external fields, the LC partially fills the fiber cladding holes. The devices may be applied to optical communications and sensing. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2075–2079, 2015
Comprehensive study of ultra broadband GCPW‐MS transition on thin films
Authors: El‐Gibari Mohammed , Averty Dominique , Halbwax Mathieu , Vilcot Jean‐Pierre , Li Hongwu
Published: June 2015

Back‐to‐back GCPW‐MS‐GCPW (Grounded Coplanar Waveguide‐Microstrip lines) transitions realized on benzocyclobutene polymer thin films (20 μm) and using copper metallization are presented in this article. The achieved experimental bandwidth is 82 GHz with a remarkably lower cutoff frequency of only 1.5 GHz and insertion loss of 0.5 dB. This performance is obtained without neither making via holes in the substrate nor patterning the bottom ground plane. These transitions make easier and faster manufacturing and characterization, by means of coplanar probes, of microwave devices realized from materials in thin film and whose driving electrode is a MS line. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2041–2045, 2015
Compact MIMO antenna for LTE 2500 and UWB applications
Authors: Wu Yanjie , Long Yunliang
Published: June 2015

This letter presents a compact multiple‐input multiple‐output (MIMO) ultrawideband (UWB) antenna, and this MIMO antenna consists of two coplanar waveguide ‐fed monopole antenna elements and an improved ground‐plane. These two antenna elements are symmetrically arranged on a FR4 substrate with dimensions 33.8 × 29 × 0.8 mm3. The improved ground‐plane has several ground stubs and windows, and they are applied as decoupling structure to improve the isolation as well as impedance matching. Simulation and measurement are used to study the antenna performance, results show that the antenna has a wide impedance bandwidth of 2.2–10.6 GHz with |S11| ≤ −9 dB, low mutual coupling of less than −12 dB and −17 dB over the range of 2.5–4.2 GHz and 5.6–10 GHz, respectively, and LTE 2500 and UWB operation bands can be covered successfully. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2046–2049, 2015
A compact spiral‐coupled directional coupler for a mobile RFID reader via integrated passive technology
Authors: Wang Cong , Jeon Hamhee , Kim Nam‐Young
Published: June 2015

This article presents the design and implementation of a high‐performance, compact spiral‐coupled directional coupler using an advanced integrated passive device (IPD) fabrication process on a GaAs substrate for use in mobile radio frequency identification (RFID) reader applications. The IPD fabrication step is introduced specifically to enable the directional coupler, which is constructed by the transformation of the intertwined mutual inductors and air‐bridges, to have a compact size and high Q‐factor. The fabricated coupler achieves only 0.43 dB of insertion loss S21 and it exhibits the coupling S31 of 15.7 dB and the isolation S41 of 27.2 dB. This presented coupler has an extra small size of only 0.72 × 0.82 mm2 and an operational frequency of 910 MHz, which is appropriate for use in an RFID reader system. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2142–2146, 2015
Effects of Bragg reflector annealing on performance factors of FBAR‐based ultramass‐sensitive sensors
Authors: Yim Munhyuk , Lee Eunju , Kim Yeongseon , Yoon Giwan
Published: June 2015

We present the film bulk acoustic wave resonator‐based ultramass‐sensitive (FBAR‐UMS) sensors in which their resonance characteristic improvements, mainly due to Bragg reflector (BR) annealing, favorably influence their performance factors. We fabricated two kinds of FBAR‐UMS sensors, respectively, with nonannealed and annealed BRs (namely, nonannealed and annealed sensors) and investigated the effects of BR annealing on their performance factors by comparing their resonance frequency shift (−Δfr), measured before and after each mass loading (Δm). As a result, the annealed sensors showed much larger mass‐loading effect and detectable mass range than the nonannealed ones. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2134–2137, 2015
Simple dual band‐notched UWB antenna loaded with single U‐shaped resonator
Authors: Li Hui , Kang Le , Mi Da‐Wei , Yin Ying‐Zeng
Published: June 2015

A simple dual band‐notched antenna is proposed for ultra‐wideband (UWB) applications. The basic UWB antenna, which consists of a half ring‐shaped patch and a trapezoidal ground, occupies a compact area of 25 × 25 mm2. By introducing a single U‐shaped resonator on the patch, dual band‐notched function is realized without increasing the antenna size. An additional resonance near 3 GHz can be excited by the U‐shaped resonator combined with the half ring‐shaped radiator. And the antenna impedance at 3.5 GHz is also affected which leads to a notched band. Besides, reverse currents can be produced along the resonator to produce the other notched band at 5.5 GHz. Experimental results show that the designed antenna has a wide impedance bandwidth (return loss ≤10 dB) ranging from 2.97 to 12 GHz with two rejection bands operating at 3.5 and 5.5 GHz. Meanwhile, the antenna also exhibits moderate gains and omnidirectional radiation patterns over the operating bands except at the undesired frequencies, which make it a suitable candidate for UWB applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2129–2134, 2015
A wideband horizontally polarized omnidirectional antenna for LTE indoor base stations
Authors: Zhu Quanjiang , Yang Shiwen , Chen Zong
Published: June 2015

A wideband horizontally polarized omnidirectional antenna is proposed for 4G LET indoor base stations. Within the band from 1.71 GHz to 2.69 GHz, the antenna achieves a return loss of greater than 14 dB. The antenna consists of four arc printed dipoles which are arranged on a circumference and fed in phase. By attaching a pair of parasitic elements around each dipole, the bandwidth of the antenna is improved significantly. Moreover, by introducing four pairs of directors, the antenna gain variation in the azimuth plane is reduced to 1 dB in the operating band, and omnidirectional radiation patterns are achieved. The measured results are in good agreement with the simulated results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2112–2116, 2015
Wideband, hybrid rectangular water antenna for DVB‐H applications
Authors: Xing Lei , Huang Yi , Xu Qian , AlJa'afreh Saqer
Published: June 2015

In this article, a wideband, hybrid rectangular water antenna is proposed to cover the digital video broadcasting‐handheld (DVB‐H) band. The hybrid structure combines a dielectric resonator antenna (DRA) and a monopole antenna to effectively double the available bandwidth without compromising other characteristics. With a proper design, the resonance of the DRA and the resonance from the feeding probe are combined to produce a wideband response. The proposed antenna has an extremely wide bandwidth from 464 to 1017 MHz (for S11 < −6 dB), or a fractional bandwidth of 74.6%. Both the computer simulations and measurements are conducted to validate the antenna performance. It is demonstrated that this new antenna is an promising candidate for DVB‐H applications. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2160–2164, 2015
A broadband 180° hybrid ring coupler using a microstrip‐to‐slotline inverter
Authors: Riaan Ferreira , Johan Joubert
Published: June 2015

A broadband 180° 3‐dB hybrid coupler with over 118% bandwidth. Excellent agreement between simulated and experimental results was achieved. The coupler requires simple manufacturing techniques and a single layer substrate. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2164–2168, 2015
Wideband vertical microstrip‐to‐microstrip transition with three‐pole filtering response
Authors: Yang Li , Zhu Lei , Choi Wai‐Wa , Tam Kam‐Weng
Published: June 2015

A wideband vertical microstrip‐to‐micrstrip transition is presented by utilizing the composite microstrip/slotline resonators. With the coupling between two 50‐Ω microstrip lines on top and bottom layers, respectively, and a uniform slotline resonator on the common ground plane, a proposed three‐pole wideband filtering performance for the signal transmission through different layers can be achieved. To verify the expected results, a vertical transition prototype is simulated, fabricated and measured. Good agreement between the simulation and measurement results is gained. An operating band from 3.51 to 8.25 GHz with maximum insertion loss of 1.5 dB and group delay < 0.4 ns is achieved in measurement. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2213–2216, 2015
High‐selectivity triband bandpass filter based on dual‐plane microstrip/slotline structure
Authors: Shi Li‐Yun , Wang Ning , Wu Lin‐Sheng
Published: June 2015

A compact and high‐selectivity triband bandpass filter (BPF) is proposed. The filter has a dual‐plane structure, consisting of a pair of dual‐mode open‐loop microstrip resonators and a dual‐mode slotline resonator. Using this structure, three passbands as well as five transmission zeros near the passband edges can be generated simultaneously. The triband BPF operating at 1.2 GHz (GPS application), 1.8 GHz (DCS application), and 2.4 GHz (WLAN application) is designed and fabricated. Measurement results agree well with the simulated results. © 2015 Wiley Periodicals, Inc. Microwave Opt Technol Lett 57:2225–2228, 2015
Limitations of suction‐controlled triaxial tests in the characterization of unsaturated soils
Authors: Zhang X.
Published: June 2015

Behavior of unsaturated soils is influenced by many factors, and the influences of these factors are usually coupled together. Suction‐controlled triaxial (SCTX) tests are considered to allow researchers to investigate influences of individual variables on unsaturated soils under specified stress path with controls of stresses, pore water, and air pressures. In the past 50 years, SCTX testing method has been established as a standard approach to characterize constitutive behavior of unsaturated soils. Most important concepts for modern unsaturated soil mechanics were developed upon results from the SCTX tests. Among these, one of the most important contributions in the constitutive modeling of elasto‐plastic behavior for unsaturated soils is the Barcelona basic model (BBM) proposed by Alonso et al. in 1990. The BBM successfully explained many features of unsaturated soils and received extensive acceptance.

However, the SCTX tests are designed based upon the divide‐and‐conquer approach in which an implicit assumption is used: soil behavior is stress‐path independent. However, it is well‐established that unsaturated soil behavior is elasto‐plastic and stress‐path dependent. It is found that the SCTX tests in fact cannot control the stress path of an unsaturated soil during loading. This incapability, in combination with complicated loading/collapse behavior of unsaturated soils, makes the SCTX tests for characterizing unsaturated soil questionable. This paper discusses the limitations of the SCTX tests in the characterization of unsaturated soils. A possible solution to the problem was proposed based on a newly developed modified state surface approach. The discussions are limited for isotropic conditions. Copyright © 2015 John Wiley & Sons, Ltd.
Rethinking Decentralization: Assessing Challenges to a Popular Public Sector Reform
Authors: Smoke Paul
Published: June 2015

Decentralization is among the most globally ubiquitous public sector reforms. In the past few decades, many countries have taken formal steps to empower local governments, typically with a mix of stated developmental and governance goals. Although decentralization receives much attention, our systematic practical knowledge about it remains limited, and it is fair to say that it often does not meet expectations. Even supporters have begun to express frustration, and references to stalled decentralization or even recentralization have emerged in both policy debates and in practice. This paper briefly recaps what decentralization was expected to achieve, broadly summarizes what we know about performance, and highlights factors that support and impede reform. It also discusses weaknesses and challenges in how decentralization has been conceived, analyzed, designed, and implemented. The core argument is that this type of reform is more diverse and complex than has conventionally been acknowledged and that more careful analysis and strategic action tailored to a specific country are needed to help to realize more effective and sustainable decentralization. The paper closes with thoughts about future directions for how we conceptualize and pragmatically approach this diverse and consequential reform. Copyright © 2015 John Wiley & Sons, Ltd.
Performance Measurement and Management in the Public Sector: Some Lessons from Research Evidence
Authors: Gao Jie
Published: June 2015

During the past decade, there has been an explosion in the literature on performance‐oriented reforms around the globe. What are the major topics discussed in this literature? What can scholars and practitioners learn from it? This study provides an overview of the major themes, strategies, challenges, and outcomes of performance measurement and management reforms by reviewing the literature produced during this period. It shows that useful strategies and tools have been developed for public sector organizational performance improvement. Apart from continuing efforts to examine the role of measurement per se, there has been a shift in focus from performance measurement to performance management in this literature. Nevertheless, research evidence from both developed and developing countries shows that most reforms achieve only mixed results, with both costs and gains and with daunting challenges, such as gaming, remaining. The paper concludes by discussing issues that deserve attention from future research. Copyright © 2015 John Wiley & Sons, Ltd.
The Risks of Chinese Subnational Debt for Public Financial Management
Authors: Guess George M. , Ma Jun
Published: June 2015

This paper examines the important challenge to effective public financial management (PFM) of fiscal risk. In the case of China, a middle‐income country with space to borrow, a major source of risk to the central government is exposure from subnational government debts. In order to control this exposure and manage it properly, it is important that the level of debt be included in consolidated balance sheets and that liabilities be recognized. This is important not only for narrow maintenance of financial position (or PFM discipline) purposes but also to increase national welfare. Managing fiscal risks from this broader perspective suggests that governments may want to absorb particular risks for purposes such as: unemployment, old age, and poverty spending. Governments often need to cost‐effectively bear some of these risks in order lower social costs and maximize national well‐being. But to do this properly, the government must know first the stock and flow of its total debt. To date, subnational debts in China have not been properly quantified, and available donor tools such as the Public Expenditure and Financial Accountability (PEFA) framework are weak. Copyright © 2015 John Wiley & Sons, Ltd.
BULLYING PREVENTION: A CALL FOR COLLABORATIVE EFFORTS BETWEEN SCHOOL NURSES AND SCHOOL PSYCHOLOGISTS
Authors: Kub Joan , Feldman Marissa A.
Published: June 2015

Bullying among children and adolescents is recognized as a significant global public health problem, as it has serious health consequences. Schools are important sites in which to address violence prevention, specifically bullying prevention, and to promote positive youth development. The Ottawa Charter for Health Promotion outlines five action points (building healthy public policy, creating supportive environments, strengthening community actions, developing personal skills, and reorienting health services) that should be considered when creating a positive school climate focused on health promotion. Using the position statements of school nurses and school psychologists, we outline their complementary roles in bullying prevention and intervention. In addition, because the global and national school health models call for building partnerships and enhancing communication among professionals within the schools and with the community to achieve health goals, we discuss how these two professional groups can work collaboratively to address bullying as a school health issue.