bluuebunny/crossref_metadata_2025 huggingface dataset:
An Experimental Evaluation of using Waste Cooking Oil Biodiesel in a Diesel Engine
Authors: El‐Adawy M. , Ibrahim Amr , El‐Kassaby M. M.
Published: November 2013

Waste‐cooking‐oil biodiesel has a great potential to be widely used as an alternative, renewable fuel for diesel engines in the near future. The aim of this investigation was to experimentally study the effect of using different blends of waste‐cooking‐oil biodiesel and diesel fuel on the diesel‐engine performance, combustion characteristics, and emissions. It was found that increasing the percentage of biodiesel in the fuel blend from 0 to 50 % decreased engine torque and thermal efficiency by 9 and 11 %, respectively, for an engine speed of 1500 rpm. On the other hand, the engine fuel consumption increased by 17 %. In addition, the CO and HC emissions decreased by 31 and 40 %, respectively, whereas CO2 and NOx emissions increased by 17 and 40 %, respectively. It was also found that the ignition delay period decreased and the total combustion duration increased with increasing percentage of biodiesel in the fuel blend.
The Architecture of Diagnostic Research: From Bench to Bedside—Research Guidelines Using Liver Stiffness as an Example
Authors: Colli Agostino , Fraquelli Mirella , Casazza Giovanni , Conte Dario , Nikolova Dimitrinka , Duca Piergiorgio , Thorlund Kristian , Gluud Christian
Published: November 2013

The diagnostic research process can be divided into five phases, designed to establish the clinical utility of a new diagnostic test—the index test. The aim of the present review is to illustrate the study designs that are appropriate for each diagnostic phase, using clinical examples regarding liver fibrosis diagnosed with transient elastography, when possible. Phase 0 is the preclinical pilot phase during which the validity, reliability, and reproducibility of the index test are assessed in healthy and diseased people. Phase I is designed to describe the distribution of the index test results in healthy people and its normal values. Phase IIA comprises studies designed to estimate the accuracy (sensitivity and specificity) of the index test in discriminating between diseased and nondiseased people in a clinically relevant population. Phase IIB studies allow the comparison of the accuracy of different index tests; Phase IIC studies aim to evaluate the possible harms of incorporating the index test in a diagnostic-therapeutic strategy. In phase III, diagnostic test-therapeutic randomized clinical trials aim to assess the benefits and harms of the new diagnostic-therapeutic strategy versus the present strategy. Phase IV comprises large surveillance cohort studies that aim to assess the effectiveness of the new diagnostic-therapeutic strategy in clinical practice.

Conclusion :

As common in clinical research, giving excessive weight to the results of single studies and trials is likely to divert from the totality of evidence obtained through the systematic reviews of these studies, conducted with rigorous methodology and statistical methods. (Hepatology 2014;60:408-418)
ASSESSING THE PERFORMANCE OF SMALLHOLDER IRRIGATION AND DERIVING BEST MANAGEMENT PRACTICES IN SOUTH AFRICA
Authors: Gomo T. , Senzanje A. , Mudhara M. , Dhavu K.
Published: November 2013

The performance of smallholder irrigation schemes is multidimensional and can be looked at from different perspectives. This study assessed the technical performance of the Mooi River irrigation scheme (MRIS) to derive a comprehensive set of best management practices (BMPs). This was done acknowledging that the farmer is now the water manager, in line with participatory irrigation management (PIM) and irrigation management transfer (IMT) concepts. Five performance indicators related to water supply and delivery and agricultural performance were assessed through the field measurement method during spring and summer of the 2010/2011 season. Farmers were interviewed through a questionnaire to gather suggestions on ways to improve the performance of their scheme. Their responses helped in the selection of the BMPs for the scheme which were then ranked using the analytic hierarchy process (AHP). The results show a scheme average conveyance efficiency of 86.4%, maximum dependability of irrigation interval between water applications of 2.57 in spring and the scheme relative irrigation supply of 1.48. Agricultural performance indicators—output per unit irrigation supply and water productivity (ET)—were found to be 0.64 and 5.37 kg m‐3, respectively. Irrigation scheduling was the most preferred BMP by the farmers, while volumetric measurement of irrigation water used by each block was the least preferred. This study concludes that water management in smallholder schemes is poor, thus affecting performance of these schemes, and that farmers are aware of the problems and possible solutions to perennial problems hindering performance in smallholder schemes. The study recommends deepening farmers' participation in policy formulation and derivation of BMPs. Copyright © 2013 John Wiley & Sons, Ltd.
Patient‐centered blood management
Authors: Hohmuth Benjamin , Ozawa Sherri , Ashton Maria , Melseth Richard L.
Published: November 2013

BACKGROUND

Transfusions are common in hospitalized patients but carry significant risk, with associated morbidity and mortality that increases with each unit of blood received. Clinical trials consistently support a conservative over a liberal approach to transfusion. Yet there remains wide variation in practice, and more than half of red cell transfusions may be inappropriate. Adopting a more comprehensive approach to the bleeding, coagulopathic, or anemic patient has the potential to improve patient care.

METHODS

We present a patient‐centered blood management (PBM) paradigm. The 4 guiding principles of effective PBM that we present include anemia management, coagulation optimization, blood conservation, and patient‐centered decision making.

RESULTS

PBM has the potential to decrease transfusion rates, decrease practice variation, and improve patient outcomes.

CONCLUSION

PBM's value proposition is highly aligned with that of hospital medicine. Hospitalists' dual role as front‐line care providers and quality improvement leaders make them the ideal candidates to develop, implement, and practice PBM. Journal of Hospital Medicine 2014;9:60–65. © 2013 Society of Hospital Medicine
Syntheses of [3H2]T0901317 and a labeled structural isomer, and characterization of the dispersed labeled compounds via 19F NMR
Authors: Fauber Benjamin P. , Johnson Adam R. , Bowerman Stephen , Burton Brenda , Colebrook Adam , Flynn Annerley , Harrold Gareth , Huhn Steve , Jones Gary , Lockey Peter , Norman Maxine , René Olivier , Wong Harvey
Published: November 2013

The synthesis and characterization of [3H2]T0901317 and a structural isomer are described. The structural assignments of the closely related labeled compounds were primarily accomplished via 19F NMR analyses of the corresponding ethanolic compound dispersions.
Synthesis of Amphiphilic Polymers Based on Fatty Acids and Glycerol‐Derived Monomers – A Study of Their Self‐Assembly in Water
Authors: Rotta Jefferson , Pham Phuoc Dien , Lapinte Vincent , Borsali Rédouane , Minatti Edson , Robin Jean‐Jacques
Published: November 2013

Amphiphilic polymers are synthesized from various biobased compounds involving telomerization of glycerin‐derived acrylate monomers with mercaptan‐modified fatty acids. The effects of the chemical structure of the saturated or unsaturated hydrophobic block are investigated. Dynamic and static light scattering measurements, transmission electronic microscopy, and atomic force microscopy observations show that these copolymers are capable of self‐assembling into nanosized spherical particles in aqueous solution, made from compound micelles. The critical micellar concentration of these polymers is in the range of 10–60 mg L−1 determined by fluorescence. These biobased polymers could have applications in various industrial fields, such as cosmetics and agrochemicals.

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Multiplexed and data‐independent tandem mass spectrometry for global proteome profiling
Authors: Chapman John D. , Goodlett David R. , Masselon Christophe D.
Published: November 2013

One of the most important early developments in the field of proteomics was the advent of automated data acquisition routines that allowed high‐throughput unattended data acquisition during HPLC introduction of peptide mixtures to a tandem mass spectrometer. Prior to this, data acquisition was orders of magnitude less efficient being based entirely on lists of predetermined ions generated in a prior HPLC‐MS experiment. This process, known generically as data‐dependent analysis, empowered the development of shotgun proteomics where hundreds to thousands of peptide sequences are matched per experiment. In their most popular implementation, the most abundant ionized species from every precursor ion scan at each moment in chromatographic time are successively selected for isolation, activation and tandem mass analysis. While extremely powerful, this strategy has one primary limitation in that detectable dynamic range is restricted (in a top‐down manner) to the peptides that ionize the best. To circumvent the serial nature of the data‐dependent process and increase detectable dynamic range, the concepts of multiplexed and data‐independent acquisition (DIA) have emerged. Multiplexed‐data acquisition is based on more efficient co‐selection and co‐dissociation of multiple precursor ions in parallel, the data from which is subsequently de‐convoluted to provide polypeptide sequences for each individual precursor ion. DIA has similar goals, but there is no real‐time ion selection based on prior precursor ion scans. Instead, predefined m/z ranges are interrogated either by fragmenting all ions entering the mass spectrometer at every single point in chromatographic time; or by dividing the m/z range into smaller m/z ranges for isolation and fragmentation. These approaches aim to fully utilize the capabilities of mass spectrometers to maximize tandem MS acquisition time and to address the need to expand the detectable dynamic range, lower the limit of detection, and improve the overall confidence of peptide identifications and relative protein quantification measurements. This review covers all aspects of multiplexed‐ and data‐independent tandem mass spectrometry in proteomics, from experimental implementations to advances in software for data interpretation. © 2013 Wiley Periodicals, Inc. Mass Spec Rev 33: 452–470, 2014.
Routing optimization for underwater optical networks in swarm configuration
Authors: Tabacchiera Marco , Persia Samuela , Cidronelli Paolo , Betti Silvello
Published: November 2013

Underwater wireless networks have been deeply studied in the last few years. Particular attention has been recently devoted to swarm networks, which can operate and take decision in collaborative manner. In swarm networks, the limited distance between nodes can be exploited by implementing optical links when the characteristics of the communication channel make it possible. With respect to acoustic communications, that solution can lead to an increase in data rate, to the absence of signal latency and to significant energy saving. A performance analysis is presented for an underwater swarm network in case of optical link among mobile nodes, considering LED optical transmitter and typical parameters for the communication channel. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:34–38, 2014
X‐band voltage‐controlled oscillator with built‐in envelope detection
Authors: Chen Cheng‐Yu , Li Hsiao‐Yun , Fu Jia‐Shiang
Published: November 2013

A wide‐tuning‐range X‐band voltage‐control oscillator (VCO) with built‐in envelope detectors is designed and measured. The VCO is implemented using a 0.18‐μm CMOS technology. The VCO core is composed of a cross‐coupled pair and a parallel‐LC resonator. The variable capacitance is implemented using MOS varactors. Large varactor capacitance and small transistor size are used to reduce the tuning‐range degradation due to the parasitic capacitance of the cross‐coupled pair and buffer amplifier. Each single‐ended output of the differential buffer amplifier is connected to a Greinacher voltage doubler, which serves as an envelope detector that senses the output power of the VCO and translates it into a dc voltage. The chip area of the VCO is 1.25 × 0.6 mm2. The measured frequency tuning range and FoMT (at 1‐MHz offset) are 31.7% and −192.5 dBc/Hz, respectively. The relation between the VCO output power and detector output voltage is characterized. Using the relation, the envelope detectors can be used for real‐time monitoring of the power level at any location in a chip, providing built‐in self‐test capability. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:11–14, 2014
Broadband and miniaturization of tilted beam antenna using CSRR splits and flower‐spiral structure
Authors: Li Si‐jia , Cao Xiang‐yu , Gao Jun , Zheng Qiu‐rong , Yang Huan‐huan
Published: November 2013

A miniaturized broadband circularly polarized antenna with tilted beam is designed and fabricated using the complementary split ring resonator (CSRR) splits and flower‐spiral (FS) structure. This antenna is composed of a FS structure, helix feed line, and ground plane loaded five CSRR splits. The voltage standing wave ratio is improved through the FS structure based on the Archimedean spiral arm. And the axial ratio is improved due to the five CSRR splits and FS structure. Simulated and measured results both confirm that the ground plane is reduced about 75.2% and the bandwidth significantly broadened from about 10.5% to about 27.6%. Experimental data show a reasonably good agreement between the simulation and measured results. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:27–31, 2014
High reference impedance reflectometer for nonresonant matching of near‐field microwave microscope tip probe
Authors: Glay David , Fellahi Abdelhatif El , Lasri Tuami
Published: November 2013

In this letter, we present a nonresonant high impedance reflectometer integrating a tip probe dedicated to near‐field microwave microscopy. A 1‐kohms reflectometer is fabricated by using lumped elements to validate the approach proposed to solve the problem of impedance mismatch between the probe and the measurement system. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:64–69, 2014
A compact wideband planar microstrip‐fed quasi‐yagi antenna with a C‐shape reflector
Authors: Wang Hao , Li Ping , Wu Ting , Wei Shi Xiao
Published: November 2013

A compact wideband planar microstrip‐fed quasi‐Yagi antenna is presented. Through optimizing the structure of the C‐shape reflector, a broadband impedance bandwidth of 75.3% (1.83 ∼ 4.04 GHz) for return loss less than −10 dB and a gain of 3.83 ∼ 8.48 dBi are obtained. Simulation based on HFSS and measurement results are provided and discussed. The agreements between the simulation and measurement results indicate that the antenna is suitable for wireless communication applications and phased arrays. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:241–244, 2014
High‐performance wide stop band low‐pass filter using a vertically coupled DGS‐DMS‐resonators and interdigital capacitor
Authors: Boutejdar Ahmed , Omar Abbas , Burte Edmund
Published: November 2013

Using the simple multilayer technique and defected ground structure‐defected microstrip structure (DGS‐DMS) methods, a novel wide stop band low‐pass filter is proposed and implemented using coupled DMS and DGS resonators. The filter consists of two cascaded λ/2‐DMS‐resonators, which are etched on a 50 Ω microstrip feed line and vertically coupled with two cascaded DGS resonators. They are etched, opposed to the DMS‐Elements, on the ground plane. The proposed miniaturized low‐pass filters using DMS and DGS have been simulated and fabricated on a substrate with dimensions of 3.3 cm × 1.5 cm. The substrate has a relative dielectric constant of 3.38 and a thickness of 0.813 mm. The interdigital‐DGS‐DMS LPF achieved insertion loss less than 0.5 dB and a wide rejection in the stop band with overall 20 dB attenuation up to 8 GHz. The simulated and measured results show good agreement and validate the proposed approach. Such filter structures are expected to be applied widely for microwave integrated circuit and in modern communication systems. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:87–91, 2014
Broadband radar absorbing material based on orthogonal arrangement of CSRR etched artificial magnetic conductor
Authors: Zhao Yi , Cao Xiang‐yu , Gao Jun , Li Wen‐qiang
Published: November 2013

In this article, a novel design method of broadband radar absorbing material is proposed. This method is based on orthogonal arrangement of complementary split‐ring resonator etched artificial magnetic conductors, which exhibit polarization‐dependent features. Owing to phase cancellation, scattering energy along the boresight is reduced over a wide frequency range. Measured results demonstrate that the frequency range of −10 dB RCS reduction spans from 7.38 to 10.47 GHz with the bandwidth up to 34.6%, validating the effectiveness of the method. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:158–161, 2014
Single‐, dual‐, and triple‐band metamaterial‐inspired electrically small planar magnetic dipole antennas
Authors: Turkmen Oznur , Turhan‐Sayan Gonul , Ziolkowski Richard W.
Published: November 2013

The design and performance characteristics of metamaterial‐inspired electrically small, single, dual and triple band antennas at the GSM (1.93–1.99 GHz), ISM (2.43–2.4835 GHz), and WiMAX (3.3–3.6 GHz) frequencies are reported. These antennas are based on a coaxially fed printed dipole integrated in a planar configuration with capacitively loaded loops (CLLs) as its near‐field resonant parasitic radiators. In the proposed topology, the number of operating frequencies is determined by the number of CLLs. These antennas are geometrically simple, operate as magnetic dipoles (directivities ∼1.6−2.0 dB), and have high (≥80%) radiation efficiencies at all of their operating frequencies. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:83–87, 2014
Investigation of the power transistor size related to the efficiency of switching‐mode RF CMOS power amplifier
Authors: Hwang Hoyong , Seo Donghwan , Park Jonghoon , Park Changkun
Published: November 2013

In this work, we analyzed the efficiency of a switching‐mode RF CMOS power amplifier with the following design parameters: the on resistance and the parasitic capacitance of the power transistor. The power amplifier is composed of a class‐D type driver stage and a class‐E type power stage. The power consumption of the driver stage, the load impedance of the power stage, and the loss of the output matching networks are considered for a numerical analysis. We investigated the normalized drain efficiency according to the variable supply voltage of the power stage for polar transmitter applications. From the simulated results of the power amplifier, we successfully proved the feasibility of using the numerical analysis. The designed power amplifier is implemented using 0.13 μm RF CMOS process to verify the numerical results by means of an experiment. A distributed active transformer is used for an output matching network. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:110–117, 2014
Pattern and frequency reconfigurable monopole disc antenna using PIN diodes and MEMS switches
Authors: Abou Al‐alaa Mohammed , Elsadek H. A. , Abdallah E. A. , Hashish E. A.
Published: November 2013

Dual reconfigurable microstrip disc antenna is investigated in this article starting from conventional disc. Modifications are added to produce three reconfigurable shapes. First is pattern reconfigurability by rotating the radiation pattern 60°. Second is frequency reconfigurability. Third shape is dual reconfigurability that merges between frequency and radiation pattern changes. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:187–195, 2014
Frequency‐reconfigurable monopole antenna with wide tuning range for cognitive radio
Authors: Cao Yunfei , Cheung S. W. , Sun X. L. , Yuk T. I.
Published: November 2013

The design of a frequency‐reconfigurable planar monopole antenna with a wide tuning range for cognitive radio is presented. The radiator of the antenna consists of two sections, Section I and Section II, which are connected together using a PIN‐diode. Section I is meandering and responsible for generating a high‐frequency band at about 2.69 GHz. Section II has a U‐shape and, together with Section I, generates a low‐frequency band at about 2.39 GHz. The PIN‐diode is used to select whether only Section I or both Sections I and II together to work as the radiator for the antenna. The radiator has a very compact size of only 11.5 × 8.4 mm2. Continuous tuning for the low‐ and high‐frequency bands is accomplished by placing a varactor on Section I of the radiator. The varactor and the PIN diode are biased using very simple DC circuits. The frequency‐reconfigurable antenna is studied, designed, and optimized using computer simulation. Measurement is used for verification of the simulation results. Results show that the antenna can be tuned from 2.69 to 3.0 GHz using Section I and from 2.39 to 2.62 GHz using both Sections I and II together. Using the PIN‐diode, the antenna can achieve a wide tuning range of 2.39 to 3.0 GHz. The antenna performance in terms of tuning range, radiation pattern, realized peak gain, and efficiency is presented. The feeding cable used in measurement causes substantial discrepancies between the simulated and measured results. A simulation cable model is used to verify such cable effects. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:145–152, 2014
1–6 GHz ultrawideband 4 W single‐ended GaN power amplifier
Authors: Giofre Rocco , Colantonio Paolo , Giannini Franco
Published: November 2013

In this contribution, the design approach and the experimental results of an ultrawideband power amplifier in GaN technology is presented. The amplifier is designed in a single‐ended configuration by using a 0.5 μm GaN HEMT with 1 mm gate periphery. The realized amplifier shows an efficiency higher than 40% with an output power greater than 36 dBm and an associated gain around 10 dB from 1 to 6 GHz. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:215–217, 2014
Prototype phantoms for characterization of ultralow field magnetic resonance imaging
Authors: Boss Michael A. , Mates John A. B. , Busch Sarah E. , SanGiorgio Paul , Russek Stephen E. , Buckenmaier Kai , Irwin Kent D. , Cho Hsiao‐Mei , Hilton Gene C. , Clarke John
Published: November 2013

Purpose

Prototype phantoms were designed, constructed, and characterized for the purpose of calibrating ultralow field magnetic resonance imaging (ULF MRI) systems. The phantoms were designed to measure spatial resolution and to quantify sensitivity to systematic variation of proton density and relaxation time, T1.

Methods

The phantoms were characterized first with conventional magnetic resonance scanners at 1.5 and 3 T, and subsequently with a prototype ULF MRI scanner between 107 and 128
.

Results

The ULF system demonstrated a 2‐mm spatial resolution and, using T1 measurements, distinguished aqueous solutions of MnCl2 differing by 20
[Mn2+].

Conclusion

The prototype phantoms proved well‐matched to ULF MRI applications, and allowed direct comparison of the performance of ULF and clinical systems. Magn Reson Med 72:1793–1800, 2014. © 2013 Wiley Periodicals, Inc.
Difluoro‐ and Trifluoromethylation of Electron‐Deficient Alkenes in an Electrochemical Microreactor
Authors: Arai Kenta , Watts Kevin , Wirth Thomas
Published: November 2013

Electrochemical microreactors, which have electrodes integrated into the flow path, can afford rapid and efficient electrochemical reactions without redox reagents due to the intrinsic properties of short diffusion distances. Taking advantage of electrochemical microreactors, Kolbe electrolysis of di‐ and trifluoroacetic acid in the presence of various electron‐deficient alkenes was performed under constant current at continuous flow at room temperature. As a result, di‐ and trifluoromethylated compounds were effectively produced in either equal or higher yields than identical reactions under batch conditions previously reported by Uneyamas group. The strategy of using electrochemical microreactor technology is useful for an effective fluoromethylation of alkenes based on Kolbe electrolysis in significantly shortened reaction times.
CLL/SLL diagnosed in an adolescent
Authors: Luskin Marlise , Wertheim Gerald , Morrissette Jennifer , Daber Robert , Biegel Jaclyn , Wilmoth Donna , Kersun Leslie , King Rebecca , Paessler Michele , Simon Cara , Aplenc Richard , Loren Alison
Published: November 2013

Chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL) is a disease of older adults. Pediatric CLL/SLL is vanishingly rare in the literature. We present a case of CLL/SLL diagnosed in a 17‐year‐old male. The pathologic findings of this case were those of classic CLL/SLL with an ATM deletion, a characteristic genetic abnormality in CLL/SLL. Management guidelines for CLL/SLL are tailored to older adults making determination of the optimal therapy for this patient a unique challenge. Pediatr Blood Cancer 2014;61:1107–1110. © 2013 Wiley Periodicals, Inc.
Characterisation of the Metabolism of Pogostone In Vitro and In Vivo Using Liquid Chromatography with Mass Spectrometry
Authors: Li Yucui , Su Ziren , Lin Shuhai , Li Chuwen , Zhao Ya , Gao Xiang , Lai Yongquan , Wu Xiaoli , Wu Hanzhi , Cai Zongwei , Lai Xiaoping
Published: November 2013

Introduction

Pogostone possesses potent anti‐bacterial and anti‐fungal activities and has been used for the quality control of essential oil of Pogostemon cablin. Pogostone is easily absorbed after oral administration but its metabolism in mammals remains elusive.

Objective

To investigate the metabolic profile of pogostone in vitro and in vivo.

Methods

High‐performance liquid chromatography coupled with mass spectrometry (LC–MS) techniques were employed. Orbitrap MS and ion trap tandem mass spectrometry (MS/MS) were utilised to analyse the metabolism of pogostone by virtue of the high sensitivity and high selectivity in the measurement. In vitro experiment was carried out using rat liver microsomes while the in vivo study was conducted on rats, which were orally administered with pogostone (80 mg/kg).

Results

In total, three mono‐hydroxylated, one di‐hydroxylated, one mono‐oxygenated, one di‐oxygenated metabolite, one hydrolysis and one hydroxy conjugated metabolites were found. In addition hydroxylation was demonstrated to be a major metabolic pathway of pogostone.

Conclusion

LC–MS was demonstrated to be a powerful tool for the metabolite identification of pogostone. The tentative identification of metabolites provides an insight for the metabolic clues of pogostone. Copyright © 2013 John Wiley & Sons, Ltd.
Enhancement of redox stability and electrochromic performance of aromatic polyamides by incorporation of (3,6‐dimethoxycarbazol‐9‐yl)‐triphenylamine units
Authors: Wang Hui‐Min , Hsiao Sheng‐Huei
Published: November 2013

New series aromatic polyamides with (carbazol‐9‐yl)triphenylamine units were synthesized from a newly synthesized diamine monomer, 4,4′‐diamino‐4″‐(3,6‐dimethoxycarbazol‐9‐yl) triphenylamine, and aromatic dicarboxylic acids via the phosphorylation polyamidation technique. These polyamides exhibit good solubility in many organic solvents and can be solution‐cast into flexible and strong films with high thermal stability. They show well‐defined and reversible redox couples during oxidative scanning, with a strong color change from colorless neutral form to yellowish green and blue oxidized forms at applied potentials scanning from 0.0 to 1.3 V. They show enhanced redox‐stability and electrochromic performance as compared to the corresponding analogs without methoxy substituents on the active sites of the carbazole unit. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2014, 52, 272–286
Architecture and function of metallopeptidase catalytic domains
Authors: Cerdà‐Costa Núria , Xavier Gomis‐Rüth Francesc
Published: November 2013

The cleavage of peptide bonds by metallopeptidases (MPs) is essential for life. These ubiquitous enzymes participate in all major physiological processes, and so their deregulation leads to diseases ranging from cancer and metastasis, inflammation, and microbial infection to neurological insults and cardiovascular disorders. MPs cleave their substrates without a covalent intermediate in a single‐step reaction involving a solvent molecule, a general base/acid, and a mono‐ or dinuclear catalytic metal site. Most monometallic MPs comprise a short metal‐binding motif (HEXXH), which includes two metal‐binding histidines and a general base/acid glutamate, and they are grouped into the zincin tribe of MPs. The latter divides mainly into the gluzincin and metzincin clans. Metzincins consist of globular ∼130–270‐residue catalytic domains, which are usually preceded by N‐terminal pro‐segments, typically required for folding and latency maintenance. The catalytic domains are often followed by C‐terminal domains for substrate recognition and other protein–protein interactions, anchoring to membranes, oligomerization, and compartmentalization. Metzincin catalytic domains consist of a structurally conserved N‐terminal subdomain spanning a five‐stranded β‐sheet, a backing helix, and an active‐site helix. The latter contains most of the metal‐binding motif, which is here characteristically extended to HEXXHXXGXX(H,D). Downstream C‐terminal subdomains are generally shorter, differ more among metzincins, and mainly share a conserved loop—the Met‐turn—and a C‐terminal helix. The accumulated structural data from more than 300 deposited structures of the 12 currently characterized metzincin families reviewed here provide detailed knowledge of the molecular features of their catalytic domains, help in our understanding of their working mechanisms, and form the basis for the design of novel drugs.
Plant resistance to aphid feeding: behavioral, physiological, genetic and molecular cues regulate aphid host selection and feeding
Authors: Smith C Michael , Chuang Wen‐Po
Published: November 2013

Aphids damage major world food and fiber crops through direct feeding and transmission of plant viruses. Fortunately, the development of many aphid‐resistant crop plants has provided both ecological and economic benefits to food production. Plant characters governing aphid host selection often dictate eventual plant resistance or susceptibility to aphid herbivory, and these phenotypic characters have been successfully used to map aphid resistance genes. Aphid resistance is often inherited as a dominant trait, but is also polygenic and inherited as recessive or incompletely dominant traits. Most aphid‐resistant cultivars exhibit constitutively expressed defenses, but some cultivars exhibit dramatic aphid‐induced responses, resulting in the overexpression of large ensembles of putative aphid resistance genes. Two aphid resistance genes have been cloned. Mi‐1.2, an NBS‐LRR gene from wild tomato, confers resistance to potato aphid and three Meloidogyne root‐knot nematode species, and Vat, an NBS‐LRR gene from melon, controls resistance to the cotton/melon aphid and to some viruses. Virulence to aphid resistance genes of plants occurs in 17 aphid species – more than half of all arthropod biotypes demonstrating virulence. The continual appearance of aphid virulence underscores the need to identify new sources of resistance of diverse sequence and function in order to delay or prevent biotype development. © 2013 Society of Chemical Industry
Impact of GPS radio occultation measurements in the ECMWF system using adjoint‐based diagnostics
Authors: Cardinali Carla , Healy Sean
Published: November 2013

In this article, a comprehensive assessment of the impact of radio occultation (RO) observations in the operational ECMWF assimilation and forecast system is presented using different diagnostic tools. In particular, the observations' influence in the assimilation process and the related contribution to the short‐range forecast error of radio occultation observations is evaluated with recently developed diagnostic tools based on the adjoint version of the assimilation and forecast model. The sensitivity with respect to observation error variances is also evaluated for the assimilated observations. GPS‐RO is found to have the largest mean influence among satellite observations in the analysis. It is the fourth best satellite system for analysis information content and the second largest satellite contributor together with IASI and AIRS to decreasing the 24 h forecast error. For the whole observing system, with the exception of radiosondes and polar atmospheric motion vectors, the forecast error sensitivity to the observation error variance indicates that a deflation of the assumed observation errors would improve the forecast skill. For RO observations at all vertical levels, but predominantly between 10 and 20 km, a deflation of the observation error variance is suggested. Interestingly, the sensitivity computation recommends reducing the assumed errors mostly in layers where the weight given to GPS‐RO data is quite large.
Challenging Beliefs, Practices, and Content: How Museum Educators Change
Authors: ALLEN LAUREN B. , CROWLEY KEVIN J.
Published: November 2013

Educators in informal settings can be a key part of the learning experience, yet they are often poorly supported as professionals. This study followed the professional development of museum educators who participated in iterative implementation of a new school trip program focused on climate change. The learner‐centered pedagogy, inquiry format, and controversial content of this program all presented challenges to the educators’ existing models of learning and teaching in the museum. We offer four case studies that explore how part‐time museum docents engaged in reflective practice through iterative implementation and how their approaches to learning and teaching in the museum changed, or failed to change. Findings have implications for addressing the challenge of effective professional development for informal educators, particularly in content areas that may be scientifically challenging or socially controversial.
Background Stress Inventory: Developing a Measure of Understudied Stress
Authors: Terrill Alexandra L. , Gjerde Jill M. , Garofalo John P.
Published: November 2013

Background stress is an understudied source of stress that involves both ambient stress and daily hassles upon which new stressors are superimposed. To date, an accurate measure of the background stress construct has not been available. We developed the Background Stress Inventory, a 25‐item self‐report measure that asks respondents to indicate how distressed they have felt over the past month and the majority of the past year across five domains: financial, occupation, environment, health and social. Seven hundred seventy‐two participants completed the paper‐and‐pencil measure; the sample was randomly split into two separate subsamples for analyses. Exploratory factor analysis suggested five factors corresponding to these domains, and confirmatory factor analysis showed acceptable global fit (X2(255) = 456.47, comparative fit index = 0.94, root mean square error of approximation = 0.045). Cronbach's alpha (0.89) indicated good internal reliability. Construct validity analyses showed significant positive relationships with measures of perceived stressfulness (r = 0.62) and daily hassles (0.41),p's < 0.01. Depressive symptoms (0.62) and basal blood pressure (0.21) were both significantly associated with background stress,p's < 0.01. The importance of the proposed measure is reflected in the limited research base on the impact of background stress. Systematic investigation of this measure will provide insight into this understudied form of chronic stress and its potential influence on both psychological and physical endpoints. Copyright © 2013 John Wiley & Sons, Ltd.
Stat–The First Year
Authors: Fisher Nicholas I
Published: November 2013

Stat, a new statistical journal designed for rapid communication of interesting and novel research, was launched in August 2012. During its first year of operation, 21 articles were published on a wide variety of topics and with theory inspired by a diverse range of applications. Additionally, an associated blog, StatBlog, was established with its own panel of Associate Editors to enable rapid and timely discussion of published articles.

This report and an associated post on StatBlog reflect briefly on the establishment of the journal, and on current and emerging issues relating to publication of statistical research. Copyright © 2013 John Wiley & Sons, Ltd.
Information, knowledge and wisdom
Authors: Nisselle Paul
Published: November 2013

Paul Nisselle explains the importance of ensuring that information provided to a patient has been received and understood, and that whatever decisions the patient makes are properly informed. Copyright © 2013 John Wiley & Sons
Medico‐legal claims: current challenges
Authors: Badenoch David
Published: November 2013

David Badenoch argues that there needs to be a better balance between providing proper compensation for the patient who has been negligently damaged and the rapidly increasing number and value of medical claims. Copyright © 2013 John Wiley & Sons
Urban rivers: novel ecosystems, new challenges
Authors: Francis Robert A.
Published: November 2013

Urban rivers can be considered novel or hybrid ecosystems, and as such have experienced substantial biotic and abiotic changes that render them problematic to return to historic system states. Many urban river interventions have limited ecological benefits because such novelty is not considered, and fundamental changes in state are extremely difficult, if not impossible, to reverse while maintaining the societal functions of the system. Consequently, interventions have tended to focus on societal benefits rather than ecological improvements. But perhaps a more appropriate response is to embrace the ecological novelty inherent to urban rivers rather than trying to reverse or remove it, and find ways to enhance ecological function alongside novel conditions and species assemblages. Ecological engineering techniques have only been applied in a limited way to heavily urbanized rivers, but may represent the best options available within these highly compromised systems. The development of such techniques presents several challenges, including understanding and accepting biotic and abiotic novelty, increasing ecological functioning and resilience rather than restoring extirpated species, and rigorously testing interventions to determine efficacy. In part this will require a cultural shift in perception of urban rivers, particularly among managers, engineers and conservationists, to allow novel habitat creation and the establishment of atypical biotic assemblages. Such change sits within a wider ecological agenda to incorporate a greater range of species alongside humans in the urban environment, and improve urban ecosystem services. Urban rivers also present notable scientific opportunities, including more radical experimentation, system cocreation, and comparisons across global urban regions. WIREs Water 2014, 1:19–29. doi: 10.1002/wat2.1007

This article is categorized under:

Water and Life > Conservation, Management, and Awareness

Water and Life > Nature of Freshwater Ecosystems
Vertebrate female germline—the acquisition of femaleness
Authors: Tanaka Minoru
Published: November 2013

The cellular and molecular characteristics of female germ cells have primarily been studied in the mammalian ovary. In most female mammals, all primordial germ cells (PGCs) develop into oocytes early during ovary formation, and germline stem cells are few in number or absent in postnatal ovaries (Lei L, Spradling AC. Female mice lack adult germ‐line stem cells but sustain oogenesis using stable primordial follicles. Proc Natl Acad Sci USA 2013, 110:8585–8590). Research efforts in the field have largely focused on meiosis and follicular development, but a fundamental question regarding establishment of femaleness, which is very important to understand the ‘female’ germline, has not been discussed sufficiently. Recent work has revealed the presence of germline stem cells in the vertebrate ovary, using the teleost fish, medaka (Oryzias latipes) (Nakamura S, Kobayashi K, Nishimura T, Higashijima S, Tanaka, M. Identification of germline stem cells in the ovary of teleost medaka. Science 2010, 328:1561–1563). This discovery allows direct comparison between female and male germline stem cells and raises an interesting and heretofore unaddressed issue regarding femaleness of germline stem cells. In this article, the germ cell behavior in the ovaries of different species is reviewed and compared, the molecular mechanisms underlying the generation of female germ cells are discussed, and the relationship between female germ cells and the surrounding somatic cells is examined.

This article is categorized under:

Early Embryonic Development > Gametogenesis

Adult Stem Cells, Tissue Renewal, and Regeneration > Tissue Stem Cells and Niches

Comparative Development and Evolution > Organ System Comparisons Between Species
Is the Gene-Environment Interaction Paradigm Relevant to Genome-Wide Studies? The Case of Education and Body Mass Index
Authors: Boardman Jason D. , Domingue Benjamin W. , Blalock Casey L. , Haberstick Brett C. , Harris Kathleen Mullan , McQueen Matthew B.
Published: November 2013

This study uses data from the Framingham Heart Study to examine the relevance of the gene-environment interaction paradigm for genome-wide association studies (GWAS). We use completed college education as our environmental measure and estimate the interactive effect of genotype and education on body mass index (BMI) using 260,402 single-nucleotide polymorphisms (SNPs). Our results highlight the sensitivity of parameter estimates obtained from GWAS models and the difficulty of framing genome-wide results using the existing gene-environment interaction typology. We argue that SNP-environment interactions across the human genome are not likely to provide consistent evidence regarding genetic influences on health that differ by environment. Nevertheless, genome-wide data contain rich information about individual respondents, and we demonstrate the utility of this type of data. We highlight the fact that GWAS is just one use of genome-wide data, and we encourage demographers to develop methods that incorporate this vast amount of information from respondents into their analyses.
Cumulative Childhood Adversity, Educational Attainment, and Active Life Expectancy Among U.S. Adults
Authors: Montez Jennifer Karas , Hayward Mark D.
Published: November 2013

Studies of the early-life origins of adult physical functioning and mortality have found that childhood health and socioeconomic context are important predictors, often irrespective of adult experiences. However, these studies have generally assessed functioning and mortality as distinct processes and used cross-sectional prevalence estimates that neglect the interplay of disability incidence, recovery, and mortality. Here, we examine whether early-life disadvantages both shorten lives and increase the number and fraction of years lived with functional impairment. We also examine the degree to which educational attainment mediates and moderates the health consequences of early-life disadvantages. Using the 1998–2008 Health and Retirement Study, we examine these questions for non-Hispanic whites and blacks aged 50–100 years using multistate life tables. Within levels of educational attainment, adults from disadvantaged childhoods lived fewer total and active years, and spent a greater portion of life impaired compared with adults from advantaged childhoods. Higher levels of education did not ameliorate the health consequences of disadvantaged childhoods. However, because education had a larger impact on health than did childhood socioeconomic context, adults from disadvantaged childhoods who achieved high education levels often had total and active life expectancies that were similar to or better than those of adults from advantaged childhoods who achieved low education levels.
Protein disulfide engineering
Authors: Dombkowski Alan A. , Sultana Kazi Zakia , Craig Douglas B.
Published: November 2013

Improving the stability of proteins is an important goal in many biomedical and industrial applications. A logical approach is to emulate stabilizing molecular interactions found in nature. Disulfide bonds are covalent interactions that provide substantial stability to many proteins and conform to well‐defined geometric conformations, thus making them appealing candidates in protein engineering efforts. Disulfide engineering is the directed design of novel disulfide bonds into target proteins. This important biotechnological tool has achieved considerable success in a wide range of applications, yet the rules that govern the stabilizing effects of disulfide bonds are not fully characterized. Contrary to expectations, many designed disulfide bonds have resulted in decreased stability of the modified protein. We review progress in disulfide engineering, with an emphasis on the issue of stability and computational methods that facilitate engineering efforts.
Precession-driven flows in non-axisymmetric ellipsoids
Authors: Noir J. , Cébron D.
Published: November 2013

We study the flow forced by precession in rigid non-axisymmetric ellipsoidal containers. To do so, we revisit the inviscid and viscous analytical models that have been previously developed for the spheroidal geometry by, respectively, Poincaré (Bull. Astronomique, vol. XXVIII, 1910, pp. 1–36) and Busse (J. Fluid Mech., vol. 33, 1968, pp. 739–751), and we report the first numerical simulations of flows in such a geometry. In strong contrast with axisymmetric spheroids, where the forced flow is systematically stationary in the precessing frame, we show that the forced flow is unsteady and periodic. Comparisons of the numerical simulations with the proposed theoretical model show excellent agreement for both axisymmetric and non-axisymmetric containers. Finally, since the studied configuration corresponds to a tidally locked celestial body such as the Earth’s Moon, we use our model to investigate the challenging but planetary-relevant limit of very small Ekman numbers and the particular case of our Moon.
Role of subtotal tonsillectomy (‘tonsillotomy’) in children with sleep disordered breathing
Authors: Wood J M , Cho M , Carney A S
Published: November 2013

Introduction:

Sleep disordered breathing in children causes disturbance in behaviour and also in cardiorespiratory and neurocognitive function. Subtotal tonsillectomy (‘tonsillotomy’) has been performed to treat sleep disordered breathing, with outcomes comparable to established therapies such as total tonsillectomy or adenoidectomy. This review critically assesses the role of subtotal tonsillectomy in a paediatric setting.

Method:

The Medline database (1966 to October 2012) was electronically searched using key terms including subtotal or intracapsular tonsillectomy, tonsillotomy, tonsillectomy, paediatrics, and sleep disordered breathing.

Results:

Eighteen papers were identified and reviewed. Subtotal tonsillectomy would appear to have an efficacy equal to that of total tonsillectomy for the treatment of sleep disordered breathing, and has significant benefits in reducing post-operative pain and analgesia use. Subtotal tonsillectomy patients appear to have less frequent post-operative haemorrhage compared with total tonsillectomy patients.

Conclusion:

In children, subtotal tonsillectomy is associated with fewer post-operative complications whilst having a comparable effect in improving sleep disordered breathing, compared with total tonsillectomy.