bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel balanced BPF design using half‐mode substrate integrated waveguide with common‐mode suppression
Authors: Ho Min‐Hua , Li Cheng‐Siou
Published: March 2013

The contribution of this letter is to propose a novel balanced bandpass filter (BPF) design of the half‐mode substrate integrated waveguide (HMSIW) using open‐stubs for the common‐mode (CM) suppression. The HMSIW is a half‐mode waveguide alike structure, which is composed of a substrate sided with a thru‐via array emulating the shorted side‐wall of the half‐mode waveguide. As compared with some other planar structures, such as microstrip line, coplanar waveguide, and slotline, the HMSIW possesses a relatively high quality factor and is immune of the waveguide's notorious bulkiness and high fabrication cost. The insertion losses of the proposed balanced BPF are extremely low in differential mode (DM) and the CM rejection levels are over 30 dB in the DM's passband. The thru‐via array that existed in the HMSIW is eliminated in this balanced BPF design, greatly decreasing the fabrication complexity. Prototype of the proposed balanced BPF is fabricated and measured. Agreements between measured and simulated data are observed, validating the circuit performance. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1112–1115, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27510
Direct synthesis procedure for sub‐harmonic stub band‐pass and band‐stop filters
Authors: Stander T. , Sinha S.
Published: March 2013

A non‐iterative synthesis procedure for sub‐harmonic stub (SHS) band‐pass and band‐stop filters is presented. The method ensures better agreement between the synthesized filter response and the original prototype function than was possible previously without iterative techniques. The procedure is illustrated for two L‐band microstrip filters, with good agreement between modeled and measured responses. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:995–998, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27513
A compact CPW‐FED UWB antenna with independent dual band‐notched characteristics
Authors: Liu Xianglong , Yin Yingzeng , Liu Pingan
Published: March 2013

In this article, a new design of a coplanar waveguide fed (CPW‐fed) ultra‐wideband (UWB) antenna with dual band‐notched characteristics is presented. To achieve ultra‐wideband impedance matching, the tapered geometry is adopted. The two meandered split resonant slots that are etched on this antenna are to reduce the possible interferences with the band of 3.2–3.8 GHz and 5.1–5.8 GHz, which cover both WLAN and WiMAX. The upper slot (shorter in length) controls the higher band, while the lower one (longer in length) controls the lower band. Antennas with and without slots are analyzed and compared, which indicates the ability of two incorporated slots to tune the notch‐band independently. A prototype is fabricated and measured, and the good agreement between simulated and measured results manifests the effectiveness of this design. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1126–1130, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27519
A high‐performance CMOS power amplifier for 60 GHz short‐range communication systems
Authors: Chang Jing‐Ning , Lin Yo‐Sheng
Published: March 2013

A 60 GHz power amplifier for direct‐conversion transceiver using standard 90 nm CMOS technology is reported.The power amplifier comprises three cascaded common‐source stages with inductive load and inter‐stage matching. To increase the saturated output power (Psat) and power‐added efficiency (PAE), the output stage adopts a two‐way power dividing and combining architecture. Instead of the area‐consumed Wilkinson power divider and combiner, miniature low‐loss LC power divider and combiner are used. This in turn results in further Psat and PAE enhancement. Over the 57 ∼ 64 GHz frequency band of interest, the power amplifier consumes 44.4 mW and achieves power gain (S21) of 12.04 ± 1 dB, input‐port input return loss (S11) of −6 to −9.4 dB, output‐port input return loss (S22) of −10.4 to −26.4 dB, and reverse isolation (S12) of −29.2 to −30.6 dB. At 60 GHz, the power amplifier achieves Psat of 11.4 mW and maximum PAE of 15.8%. To the authors' knowledge, this is the best PAE ever reported for a 60 GHz CMOS power amplifier. In addition, the measured output 1‐dB compression point (OP1 dB) is 6 dBm at 60 GHz. These results demonstrate that the proposed power amplifier architecture is very promising for 60‐GHz short‐range communication systems. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1155–1160, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27522
A new siw resonator excitation method and its equivalent circuit
Authors: Ladani Faezeh Tork , Jam Shahrokh , Safian Reza
Published: March 2013

This article presents a new method for excitation of substrate integrated waveguide (SIW) cavity resonators which is suitable for multilayer structures and provides a method for exciting SIW cavities.The structure is analyzed and its equivalent circuit is presented to give a better insight of the structure's response through circuit theory. The analytical discussion is validated by simulations using Ansoft HFSS and ADS softwares. A three‐pole narrowband SIW filter has been designed by this method of cavity coupling as one of possible applications of the presented structure. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1133–1138, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27527
Simple notches design for ultra‐wideband monopole antennas with coplanar‐waveguide‐coupled‐fed
Authors: Zhang J. , Cheung S. W. , Liu L. , Yuk T. I.
Published: March 2013

In this article, the design of a ultra‐wideband (UWB) monopole antenna with coplanar‐waveguide (CPW)‐coupled‐fed is presented. The antenna is composed of a trapezium patch with a CPW‐fed printed on one side of the substrate and an elliptical radiator on the other side. By simply cutting slits on the radiation patch, a single, dual, and triple band notched characteristics can be achieved. Parametric studies on the antenna and slits are carried out by computer simulation. Results show that the notch frequencies can be set by using dimensions of the slits. The antennas are designed and optimized using computer simulation. For verification, the antennas with single and dual band‐notched characteristics are fabricated and measured. The simulated and measured results on the return loss, radiation pattern, peak gain, and efficiency of the antenna are presented. Due to the small ground‐plane size of the antenna, the feeding cable used in the measurement equipment significantly affects the measured results and leads to large discrepancies between the simulated and measured results at low frequencies. To study this, the simulation model of the feeding cable is also used in simulation and results show that the discrepancies are substantially reduced. © 2013 Wiley Periodicals, Inc. Microwave Opt Technol Lett 55:1017–1027, 2013; View this article online at wileyonlinelibrary.com. DOI 10.1002/mop.27530
In vivo maps of extracellular pH in murine melanoma by CEST–MRI
Authors: Delli Castelli D , Ferrauto Giuseppe , Cutrin Juan Carlos , Terreno Enzo , Aime Silvio
Published: March 2013

Purpose

A novel method based on the use of Yb‐HPDO3A as MRI Para‐CEST agent for in vivo pH mapping of the tumor region in a melanoma murine model is reported. This method does not require the knowledge of the concentration of the imaging agent.

Methods

C57BL/6‐mice were inoculated with B16‐F10 cells. CEST–MR images of tumor and bladder were acquired upon the i.v. administration of Yb‐HPDO3A (1.2 mmol/Kg). pH was assessed by the use of a ratiometric method.

Results

Yb‐HPDO3A distributes well in the extracellular space of the tumor allowing the detection of good levels of saturation transfer (ST). It is excreted throughout kidneys and accumulated in the bladder thus yielding a strong CEST signal from urine. By comparing the ST% obtained upon selective irradiation of the two OH resonances belonging to the two isomeric forms of Yb‐HPDO3A, it has been possible to measure the extracellular pH for each voxel (0.22 mm3). The obtained pH‐maps of tumors show a great heterogeneity. Marked differences are associated to tumor staging.

Conclusion

The application of Yb‐HPDO3A to measure extracellular tumor pH provides a good spatio‐temporal resolution and it does not require the prior knowledge of the contrast agent concentration. The herein reported data support the potential clinical translation of Yb‐HPDO3A. Magn Reson Med 71:326–332, 2014. © 2013 Wiley Periodicals, Inc.
Manganese‐enhanced MRI of rat brain based on slow cerebral delivery of manganese(II) with silica‐encapsulated MnxFe1–xO nanoparticles
Authors: Chen Wei , Lu Fang , Chen Chiao‐Chi V. , Mo Kuan‐Chi , Hung Yann , Guo Zhi‐Xuan , Lin Chia‐Hui , Lin Ming‐Huang , Lin Yu‐Hsuan , Chang Chen , Mou Chung‐Yuan
Published: March 2013

In this work, we report a monodisperse bifunctional nanoparticle system, MIO@SiO2‐RITC, as an MRI contrast agent [core, manganese iron oxide (MIO); shell, amorphous silica conjugated with rhodamine B isothiocyanate (RITC)]. It was prepared by thermal decomposition and modified microemulsion methods. The nanoparticles with varying iron to manganese ratios displayed different saturated magnetizations and relaxivities. In vivo MRI of rats injected intravenously with MIO@SiO2‐RITC nanoparticles exhibited enhancement of the T1 contrast in brain tissue, in particular a time‐delayed enhancement in the hippocampus, pituitary gland, striatum and cerebellum. This is attributable to the gradual degradation of MIO@SiO2‐RITC nanoparticles in the liver, resulting in the slow release of manganese(II) [Mn(II)] into the blood pool and, subsequently, accumulation in the brain tissue. Thus, T1‐weighted contrast enhancement was clearly detected in the anatomic structure of the brain as time progressed. In addition, T2*‐weighted images of the liver showed a gradual darkening effect. Here, we demonstrate the concept of the slow release of Mn(II) for neuroimaging. This new nanoparticle‐based manganese contrast agent allows one simple intravenous injection (rather than multiple infusions) of Mn(II) precursor, and results in delineation of the detailed anatomic neuroarchitecture in MRI; hence, this provides the advantage of the long‐term study of neural function. Copyright © 2013 John Wiley & Sons, Ltd.
A low‐cost, mechanically simple apparatus for measuring eddy current‐induced magnetic fields in MRI
Authors: Gilbert Kyle M. , Martyn Klassen L. , Menon Ravi S.
Published: March 2013

The fidelity of gradient waveforms in MRI pulse sequences is essential to the acquisition of images and spectra with minimal distortion artefacts. Gradient waveforms can become nonideal when eddy currents are created in nearby conducting structures; however, the resultant magnetic fields can be characterised and compensated for by measuring the spatial and temporal field response following a gradient impulse. This can be accomplished using a grid of radiofrequency (RF) coils. The RF coils must adhere to strict performance requirements: they must achieve a high sensitivity and signal‐to‐noise ratio (SNR), have minimal susceptibility field gradients between the sample and surrounding material interfaces and be highly decoupled from each other. In this study, an apparatus is presented that accomplishes these tasks with a low‐cost, mechanically simple solution. The coil system consists of six transmit/receive RF coils immersed in a high‐molarity saline solution. The sensitivity and SNR following an excitation pulse are sufficiently high to allow accurate phase measurements during free‐induction decays; the intrinsic susceptibility matching of the materials, because of the unique design of the coil system, results in sufficiently narrow spectral line widths (mean of 19 Hz), and adjacent RF coils are highly decoupled (mean S12 of −47 dB). The temporal and spatial distributions of eddy currents following a gradient pulse are measured to validate the efficacy of the design, and the resultant amplitudes and time constants required for zeroth‐ and first‐order compensation are provided. Copyright © 2013 John Wiley & Sons, Ltd.
A conservative compact difference scheme for the coupled Klein–Gordon–Schrödinger equation
Authors: Sun Qihang , Zhang Luming , Wang Shanshan , Hu Xiuling
Published: March 2013

In this article, a conservative compact difference scheme is presented for the periodic initial‐value problem of Klein–Gordon–Schrödinger equation. On the basis of some inequalities about norms and the priori estimates, convergence of the difference solution is proved with order O(h4 +τ 2) in maximum norm. Numerical experiments demonstrate the accuracy and efficiency of the compact scheme. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2013
Simple numerical method to study traveling‐wave solutions of a diffusive problem with nonlinear advection and reaction
Authors: Macias‐Diaz Jorge , Villa J.
Published: March 2013

In this manuscript, we propose a simple, two‐step, finite‐difference scheme to approximate the solutions of an advective Fisher's equation. The method proposed is nonlinear, explicit and, in the linear regime, it approximates the solutions of the equation of interest with a consistency of first order in time and second order in space. We prove that the technique is capable of preserving the positive, the bounded, and the temporally and spatially monotone characters of initial approximations; moreover, we establish that the method is conditionally stable under suitable constraints on the model and numerical parameters. Some simulations are provided to evince the validity of our analytical results. © 2013 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq 2013
Fluoroalkyl end‐capped oligomers possessing nonflammable characteristic in calcium carbonate nanocomposites
Authors: Saito Tomoya , Kakehi Hiroshi , Kato Yoshihiro , Miura Masashi , Isu Norifumi , Sawada Hideo
Published: March 2013

Calcium chloride reacted with sodium carbonate in the presence of a variety of fluoroalkyl end‐capped oligomers such as fluoroalkyl end‐capped acrylic acid oligomer (RF‐[ACA]n‐RF), 2‐methacryloyloxyethanesulfonic acid oligomer (RF‐[MES]n‐RF), N,N‐dimethylacrylamide oligomer (RF‐[DMAA]n‐RF) and acryloylmorpholine oligomer (RF‐[ACMO]n‐RF) to afford the corresponding fluorinated oligomers/calcium carbonate composites. Each fluorinated oligomer/calcium carbonate composite thus obtained is nanometer size‐controlled very fine particles (25–114 nm) possessing a good dispersibility and stability in a variety of solvents including water. Thermal stability of these fluorinated calcium carbonate nanocomposites was studied by thermogravimetic analyses measurements. Fluorinated oligomes, in which the theoretical oligomer content in the composites is 19%, were able to give no weight loss corresponding to the content of oligomer in each case even after calcination at 800 °C. On the other hand, a slight weight loss corresponding to the contents of oligomers in the composites after calcination at 800 °C was observed in RF‐(MES)n‐RF/, RF‐(DMAA)n‐RF/ and RF‐(ACMO)n‐RF/calcium carbonate nanocomposites, in which the theoretical contents of the oligomers were 36–53%, although RF‐(ACA)n‐RF/calcium carbonate nanocomposites gave a clear weight loss corresponding to the contents of oligomer under similar conditions. Fluorinated oligomers/calcium carbonate nanocomposites possessing no weight loss at 800 °C were applied to the surface modification of poly(methyl methacrylate) (PMMA) to exhibit a good oleophobicity imparted by fluorines on the surfaces. Interestingly, these fluorinated calcium carbonate nanocomposites after calcination at 800 °C were found to exhibit the similar oleophobic characteristic on the modified PMMA surfaces as well as that of the nanocomposites before calcination. Copyright © 2013 John Wiley & Sons, Ltd.
Non‐invasive prenatal testing with cell‐free DNA: US physician attitudes toward implementation in clinical practice
Authors: Musci Thomas J. , Fairbrother Genevieve , Batey Annette , Bruursema Jennifer , Struble Craig , Song Ken
Published: March 2013

Objective

The aim of this study was to assess awareness, potential adoption, and current utilization of non‐invasive prenatal testing (NIPT) analysis for common fetal aneuploidies among obstetricians.

Methods

A 36‐item web‐based survey was designed to assess the current practice of fetal aneuploidy screening and knowledge and utilization of NIPT for fetal trisomy. Practicing obstetricians in the United States were invited via email to participate in the survey.

Results

Of the 101 obstetricians that completed the survey (27% academic‐based, 73% private practice), 97% offer screening to high‐risk patients and 91% offer screening to average‐risk patients. With regard to current screening tests, the top three advantages were as follows: recommendation by professional societies, no risk to the pregnancy, and long history/experience with the test, whereas the top three limitations were as follows: patient anxiety, risks of follow‐up invasive testing, and high false positives. NIPT had been used by 32% of respondents and 22% were familiar with NIPT and the associated clinical data. The majority of physicians predicted that they would offer NIPT to high‐risk women (86.1%) and average‐risk women (76.2%) within 12 months.

Conclusion

Obstetricians plan to increase their utilization of NIPT and expect that the majority of both high‐risk and average‐risk patients will be offered NIPT as an option. © 2013 John Wiley & Sons, Ltd.
Preparation, characterization, and properties of polyacrylonitrile–silica gel anion exchange composite fibers
Authors: Khan Asif Ali , Baig Umair
Published: March 2013

This article reports the preparation of new anion exchange composite fibers (AECFs). These AECFs were prepared by simple stirring of polyacrylonitrile (PAN) and silica gel in different stoichiometric ratios. The physicochemical characterization of the prepared AECFs was characterized by Fourier transform infrared spectroscopy, scanning electron microscopy, X‐ray diffraction analysis, thermogravimetric analysis (TGA, differential thermal analysis, and differential thermal gravimetry), and elemental analysis (CHNS/O). Ion‐exchange behavior was also observed. The results indicate that addition of silica gel affects the structure and properties of the composite fibers. The addition of silica gel also changes the thermal stability of PAN–silica gel AECFs. The ion‐exchange capacity of the resulting AECFs was found to be 1.98 mequiv/g. POLYM. ENG. SCI., 2013. © 2013 Society of Plastics Engineers
Discharge Counseling for Patients with Heart Failure or Myocardial Infarction: A Best Practices Model Developed by Members of the American College of Clinical Pharmacy's Cardiology Practice and Research Network Based on the Hospital to Home (H2H) Initiative
Authors: Wiggins Barbara S. , Rodgers Jo E. , DiDomenico Robert J. , Cook Abigail M. , Page Robert L.
Published: March 2013

Hospital to Home is a quality‐based initiative led by the American College of Cardiology and the Institute for Healthcare Improvement, aimed at reducing 30‐day hospital readmission rates for patients with heart failure or myocardial infarction. Several factors have been shown to attribute to early readmission for these conditions including comorbidities, environmental factors, insufficient discharge planning, lack of health literacy, and nonadherence to drug therapy. Pharmacists play a significant role in reducing readmissions by ensuring that appropriate evidence‐based pharmacotherapy regimens have been prescribed during hospitalization; monitoring for drug duplications, medication errors, and adverse reactions; and performing medication reconciliation. Studies have demonstrated the role of pharmacists in reducing medication‐related visits to the emergency department as well as hospital readmissions, solely by preventing adverse drug events. Although all of these factors impact early readmissions, providing quality counseling to the patient as well as the patients' caregiver(s) at discharge is critical in order to optimize adherence as well as outcomes. In order to accomplish the goal of reducing readmissions, health care providers must partner together across the continuum of care and include pharmacists as pivotal members of the health care team. In this best practice statement, we summarize key components of discharge counseling for patients with heart failure or myocardial infarction including medication use, medication dose and frequency, drug interactions, medications to avoid, common adverse effects, role of the medication in the disease state, signs and symptoms of the disease, diet, the patient's role in self‐care (lifestyle modifications), and when patients should seek medical advice.
Proteolytic factors in exosomes
Authors: Shimoda Masayuki , Khokha Rama
Published: March 2013

Exosomes are small microvesicles secreted from the late endosomal compartment of cells. Although an increasing body of evidence indicates that they play a pivotal role in cell‐to‐cell communication, the biological functions of exosomes are far from fully understood. Recent work has revealed detailed proteomic profiles of exosomes from cell lines and body fluids, which may provide clues to understanding their biological significance and general importance in human diseases. Metalloproteinases include the cell surface‐anchored sheddases a disintegrin and metalloproteinases, as well as cell surface‐bound and soluble matrix metalloproteinases and these extracellular proteases have been detected in exosomes by proteomic analyses. Exosomes play a key role in the transfer of proteins to other cells and metalloproteinases may provide a novel platform where ectodomain shedding by these membrane proteases alters the makeup of the recipient cell's surface. This review aims to address some of the facets of exosome biology with particular emphasis on the proteolytic factors and we discuss their potential involvement in human diseases, especially tumor biology.
Electronic effect of ionic‐pair substituents
Authors: Chen Hang , Jia Lu , Xu Xuan , Mao Jianyong , Wang Yong , Wang Congmin , Li Haoran
Published: March 2013

For conventional organic substituents, an almost linear relationship can be established between the para Hammett constants in aqueous solutions and chemical shifts or natural population analysis charges (NPA charges). Based on these correlations, the Hammett constants of six synthesized ionic‐pair substituents were estimated via the chemical shifts, which were well in agreement with the results calculated by NPA charges. The para Hammett constants of 89 different ionic‐pair substituents (77 anion‐cationic and 12 cation‐anionic) were therefore calculated in the gas phase based on the density functional theory method. The results show that both the anion‐cationic and cation‐anionic substituents are electron‐withdrawing groups and the different cation–anion combinations could tune the Hammett constants of the ionic‐pair substituents in a range from 0.03 to 0.77. Copyright © 2013 John Wiley & Sons, Ltd.
Ensemble‐based characterization of unbound and bound states on protein energy landscape
Authors: Ruvinsky Anatoly M. , Kirys Tatsiana , Tuzikov Alexander V. , Vakser Ilya A.
Published: March 2013

Physicochemical description of numerous cell processes is fundamentally based on the energy landscapes of protein molecules involved. Although the whole energy landscape is difficult to reconstruct, increased attention to particular targets has provided enough structures for mapping functionally important subspaces associated with the unbound and bound protein structures. The subspace mapping produces a discrete representation of the landscape, further called energy spectrum. We compiled and characterized ensembles of bound and unbound conformations of six small proteins and explored their spectra in implicit solvent. First, the analysis of the unbound‐to‐bound changes points to conformational selection as the binding mechanism for four proteins. Second, results show that bound and unbound spectra often significantly overlap. Moreover, the larger the overlap the smaller the root mean square deviation (RMSD) between the bound and unbound conformational ensembles. Third, the center of the unbound spectrum has a higher energy than the center of the corresponding bound spectrum of the dimeric and multimeric states for most of the proteins. This suggests that the unbound states often have larger entropy than the bound states. Fourth, the exhaustively long minimization, making small intrarotamer adjustments (all‐atom RMSD ≤ 0.7 Å), dramatically reduces the distance between the centers of the bound and unbound spectra as well as the spectra extent. It condenses unbound and bound energy levels into a thin layer at the bottom of the energy landscape with the energy spacing that varies between 0.8–4.6 and 3.5–10.5 kcal/mol for the unbound and bound states correspondingly. Finally, the analysis of protein energy fluctuations showed that protein vibrations itself can excite the interstate transitions, including the unbound‐to‐bound ones.
Towards a Global Agenda on Migration and Development? Evidence from Senegal
Authors: Kabbanji Lama
Published: March 2013

The migration‐development nexus has been of increasing importance in international relations between African and European countries since 2000. Linking migration to development has spurred political interest in the development potential of migrants as a substitute for official development assistance. This paper analyses the convergence in discourse and practices on migration and development in the context of migration policies formulated to manage migration between Africa and Europe. The discourse on migration and development is mobilised by different actors to justify their actions; it stems from different migration management concepts and frameworks advocated by the European Union, particularly in its Global Approach to Migration. The migration and development discourse is sustained by increased funding from the European Union and some member states to instil a particular view of the nexus between migration and development. The case of Senegal in this paper illustrates the application of the dominant discourse. The first section provides an analysis of the discourse mobilised by different actors at the European and African levels to justify the promotion of the migration‐development nexus. The second section scrutinises the practices and roles of the actors involved in the design and implementation of recent programmes in Senegal. Copyright © 2013 John Wiley & Sons, Ltd.
Integrating Remediation and Reuse to Achieve Whole‐System Sustainability Benefits
Authors: Holland Karin , Karnis Stella , Kasner Dennis A. , Butler Paul Brandt , Hadley Paul W. , Nathanail Paul , Ryan John , Smith L. Maile , Wice Rick
Published: March 2013

This perspective article was prepared by members of the Sustainable Remediation Forum (SURF), a professional nonprofit organization seeking to advance the state of sustainable remediation within the broader context of sustainable site reuse. SURF recognizes that remediation and site reuse, including redevelopment activities, are intrinsically linked—even when remediation is subordinate to or sometimes a precursor of reuse. Although the end of the remediation life cycle has traditionally served as the beginning of the site's next life cycle, a disconnect between these two processes remains. SURF recommends a holistic approach that brings together remediation and reuse on a collaborative parallel path and seeks to achieve whole‐system sustainability benefits. This article explores the value of integrating remediation into the reuse process to fully exploit synergies and minimize the costs and environmental impacts associated with bringing land back into beneficial use. © 2013 Wiley Periodicals, Inc.
Creosote DNAPL Recovery‐Well Design for Mass Removal
Authors: Coll Frederic R. , Paschl Kurt P.
Published: March 2013

Sites with dense nonaqueous‐phase liquid (DNAPL) contamination present significant remediation challenges in terms of technical practicability and cost. Remedial approaches to DNAPL sites often follow a management approach rather than removal or eradication approaches, particularly due to the uncertainties associated with the benefits of partial source mass removal, as complete source removal is unlikely. Mass‐removal technologies should be evaluated for all DNAPL sites, although implementation of recovery technologies will be limited to a few sites based upon site‐specific factors. Sitewide remedial strategies that employ source reduction, where applicable, and incorporate associated risk‐reduction technologies, including monitored natural attenuation, are advised. Creosote DNAPL sites are particularly challenging, as they are predominantly composed of low‐solubility polycyclic aromatic hydrocarbons that form long‐term continuing sources. Additionally, the physical properties of creosote DNAPL, including high viscosity and relatively low density, result in significant migration potential and considerable dissolved‐phase groundwater impacts. An innovative creosote DNAPL source recovery well design was developed to achieve separate‐phase removal of pooled creosote DNAPL. The design presented herein employs modified circulation‐well technology to mobilize DNAPL to the engineered recovery well, where it is gravity‐settled into a sump to permit separate‐phase mass removal of the emplaced DNAPL source without groundwater production or treatment. A discharge mass flux protocol was developed to verify dissolved‐phase plume stability and the benefit of the source mass removal. © 2013 Wiley Periodicals, Inc.
Integrating Natural Resource Damage Assessment and Environmental Cleanup Activities at CERCLA and RCRA Sites
Authors: Duchesne Matthew S.
Published: March 2013

Although the release or threatened release of hazardous substances into the environment often creates liability for both cleanup costs and natural resource damages liability, the process of planning and conducting cleanup and the process of assessing natural resource damages are most often conducted separately. However, the substantial similarities between the two processes often present opportunities to integrate significant steps in each. Such integration has the potential to reduce both the cost of measuring and, often, resolving the full range of environmental claims at a given cleanup site and the time it takes to do so. It can also lead to faster restoration of injured natural resources and the services they provide to the public and the environment. One key reason for the lack of integration is the fact that cleanup managers generally know little if anything about the natural resource damage assessment process, while the public officials authorized to assess damages to natural resources know little about the cleanup process. This article identifies the similarities between the cleanup and natural resource damage assessment processes and provides guidance on when and how to integrate the two. © 2013 Wiley Periodicals, Inc.
Matrix Diffusion Modeling Applied to Long‐Term Pump‐and‐Treat Data: 1. Method Development
Authors: McDade James M. , Kulkarni Poonam R. , Seyedabbasi M. Ahmad , Newell Charles J. , Gandhi Deepa , Gallinatti John D. , Cocianni Virgilio , Ferguson Du'Bois J.
Published: March 2013

Despite the installation in the 1980s and 1990s of hydraulic containment systems around known source zones (four slurry walls and ten pump‐and‐treat systems), trichloroethene (TCE) plumes persist in the three uppermost groundwater‐bearing units at the Middlefield‐Ellis‐Whisman (MEW) Superfund Study Area in Mountain View, California. In analyzing TCE data from 15 recovery wells, the observed TCE mass discharge decreased less than an order of magnitude over a 10‐year period despite the removal of an average of 11 pore volumes of affected groundwater. Two groundwater models were applied to long‐term groundwater pump‐and‐treat data from 15 recovery wells to determine if matrix diffusion could explain the long‐term persistence of a TCE plume. The first model assumed that TCE concentrations in the plume are controlled only by advection, dispersion, and retardation (ADR model). The second model used a one‐dimensional diffusion equation in contact with two low‐permeability zones (i.e., upper and lower aquitard) to estimate the potential effects of matrix diffusion of TCE into and out of low‐permeability media in the plume. In all 15 wells, the matrix diffusion model fit the data much better than the ADR model (normalized root mean square error of 0.17 vs. 0.29; r2 of 0.99 vs. 0.19), indicating that matrix diffusion is a likely contributing factor to the persistence of the TCE plume in the non‐source‐capture zones of the MEW Study Area's groundwater‐extraction wells. © 2013 Wiley Periodicals, Inc.
Anti‐Government Is Not the Solution to the Problem—Anti‐Government Is the Problem: The Role of Ideology in Presidential Response to Natural Disasters From San Francisco to Katrina
Authors: Skidmore Max J.
Published: March 2013

This article examines the varied national responses to selected disasters. Rather than attempting to provide a rating of presidents or to duplicate previous studies, it identifies political ideology as an element in response effectiveness. Presidents who perform more effectively tend to be those who are inclined toward activism, who accept an active role for government, who understand the implications of a given situation, and who learn from the experiences of their predecessors.
An effect of measurement conditions on the depth resolution for low‐energy dual‐beam depth profiling using TOF‐SIMS
Authors: Murase Atsushi , Mitsuoka Takuya , Tomita Mitsuhiro , Takenaka Hisataka , Morita Hiromi
Published: March 2013

An effect of measurement conditions on the depth resolution was investigated for dual‐beam time of flight‐secondary ion mass spectrometry depth profiling of delta‐doped‐boron multi‐layers in silicon with a low‐energy sputter ion (200 eV – 2 keV O2+) and with a high‐energy primary ion (30 keV Bi+). The depth resolution was evaluated by the intensity ratio of the first peak and the subsequent valley in B+ depth profile for each measurement condition. In the case of sputtering with the low energy of 250 eV, the depth resolution was found to be affected by the damage with the high‐energy primary ion (Bi+) and was found to be correlated to the ratio of current density of sputter ion to primary ion. From the depth profiles of implanted Bi+ primary ion remaining at the analysis area, it was proposed that the influence of high‐energy primary ion to the depth resolution can be explained with a damage accumulation model. Copyright © 2013 John Wiley & Sons, Ltd.
Variable selection for multiply‐imputed data with application to dioxin exposure study
Authors: Chen Qixuan , Wang Sijian
Published: March 2013

Multiple imputation (MI) is a commonly used technique for handling missing data in large‐scale medical and public health studies. However, variable selection on multiply‐imputed data remains an important and longstanding statistical problem. If a variable selection method is applied to each imputed dataset separately, it may select different variables for different imputed datasets, which makes it difficult to interpret the final model or draw scientific conclusions. In this paper, we propose a novel multiple imputation‐least absolute shrinkage and selection operator (MI‐LASSO) variable selection method as an extension of the least absolute shrinkage and selection operator (LASSO) method to multiply‐imputed data. The MI‐LASSO method treats the estimated regression coefficients of the same variable across all imputed datasets as a group and applies the group LASSO penalty to yield a consistent variable selection across multiple‐imputed datasets. We use a simulation study to demonstrate the advantage of the MI‐LASSO method compared with the alternatives. We also apply the MI‐LASSO method to the University of Michigan Dioxin Exposure Study to identify important circumstances and exposure factors that are associated with human serum dioxin concentration in Midland, Michigan. Copyright © 2013 John Wiley & Sons, Ltd.
Nitrative Stress Causes Nitration, Oxidation, and Subunit Cross Linking in Human Hemoglobin
Authors: Barbieri Marica , Roncone Raffaella , Gabbini Roberta , Nicolis Stefania , Monzani Enrico , Galliano Monica , Casella Luigi
Published: March 2013

Hemoglobin (Hb) is the most abundant protein in human blood and we showed that under oxidative/nitrative stress conditions it is susceptible to cysteine oxidation, tyrosine nitration, and formation of a dimer of Hb subunits through tyrosine linkage. In the presence of hydrogen peroxide, Hb and its subunits efficiently convert nitrite into reactive nitrogen species, through reactions that are typical of peroxidases. If an exogenous phenolic substrate is present, Hb promotes its nitration with a fivefold higher efficiency with respect to the peroxidase‐like phenol coupling reaction. In the absence of an exogenous substrate, the protein itself undergoes covalent modification. Trypsin treatment of Hb modified under conditions mimicking pathophysiological conditions, followed byHPLC‐ESI‐MS/MS analysis, allowed detection of nitration of Yα24, Yα42, Yβ130 and Yβ145, and conversion of Cα104, Cβ93 and Cβ112 into cysteine sulfinic acids. As additional biomarkers of nitrative stress, we found a covalent dimer of Hb αβ subunits and covalently linked heme‐peptide. The dimer is selectively nitrated at Yα42. In a preliminary analysis of samples of human blood we found that low amounts of the dimer of subunits are always present. Therefore, if a correlation between the extent of Hb subunits coupling and pathological states could be established, this dimer could become an easily detectable biomarker of pathological conditions.
Freudenthal Gauge Theory
Authors: Marrani Alessio , Qiu Cong-Xin , Shih Sheng-Yu Darren , Tagliaferro Anthony , Zumino Bruno
Published: March 2013

Abstract

We present a novel gauge field theory, based on theFreudenthal Triple System(FTS), a ternary algebra with mixed symmetry (not completely symmetric) structure constants. The theory, namedFreudenthal Gauge Theory(FGT), is invariant under two (off-shell) symmetries: the gauge Lie algebra constructed from theFTStriple product and a novelglobalnon-polynomial symmetry, the so-calledFreudenthal duality.

Interestingly, a broad class ofFGTgauge algebras is provided by the Lie algebras “of type$ {{\mathfrak{e}}_7} $” which occur as conformal symmetries of Euclidean Jordan algebras of rank 3, and asU-duality algebras of the corresponding (super)gravity theories inD= 4.

We prove aNo-Go Theorem, stating the incompatibility of the invariance underFreudenthal dualityand the coupling to space-time vectorand/orspinor fields, thus forbidding non-trivial supersymmetric extensions ofFGT.

We also briefly discuss the relation betweenFTSand the triple systems occurring in BLG-type theories, in particular focusing on superconformal Chern-Simons-matter gauge theories inD= 3.
Selection‐delayed population dynamics in baleen whales and beyond
Authors: Witting Lars
Published: March 2013

While it is known that population cycles are driven by delayed density‐dependent feedbacks, the search for a common feedback mechanism in natural populations with cyclic dynamics has remained unresolved for almost a century. To identify the existence and cause of delayed feedbacks I apply six age‐ and sex‐structured population dynamics models to seven species of baleen whales (suborderMysticeti) that were heavily depleted by past commercial whaling. The six models include a predator–prey model with killer whale (Orcinus orca) as the predator, and five singe‐species models based on (1) exponential growth, (2) density‐regulated growth, (3) density‐regulated growth with depensation, (4) delayed density‐regulated growth and (5) selection‐delayed dynamics. The latter model has a density‐regulated growth rate that is accelerated and decelerated by the intra‐specific natural selection that arises from the density‐dependent competitive interactions between the individuals in the population. Essential parameters are estimated by a Bayesian statistical framework, and it is shown that baleen whales have a delayed recovery relative to density‐regulated growth. The time‐lag is not explained by depensation, or by interactions with prey or predators. It is instead resolved by a selection‐delayed acceleration of the intrinsic growth rate. The results are discussed in relation to the literature on cyclic dynamics, and it is noted (1) that selection‐delayed dynamics is both theoretically and empirically sufficient for cyclic population dynamics, (2) that it is widespread in natural populations owing to the widespread occurrence of otherwise unexplained phenotypic cycles in populations with cyclic dynamics, and (3) that there is a lack of empirical evidence showing that predator–prey interactions is a sufficient cause for the cyclic dynamics of natural populations. The conclusion stresses the importance of intra‐specific delays in cyclic dynamics, and suggests that it is the acceleration of the growth rate, and not the growth rate itself, that is determined by the density‐dependent environment.
Review of the NURE Assessment of the U.S. Gulf Coast Uranium Province
Authors: Hall Susan M.
Published: March 2013

Historic exploration and development were used to evaluate the reliability of domestic uranium reserves and potential resources estimated by the U.S. Department of Energy national uranium resource evaluation (NURE) program in the U.S. Gulf Coast Uranium Province. NURE estimated 87 million pounds of reserves in the $30/lb U3O8 cost category in the Coast Plain uranium resource region, most in the Gulf Coast Uranium Province. Since NURE, 40 million pounds of reserves have been mined, and 38 million pounds are estimated to remain in place as of 2012, accounting for all but 9 million pounds of U3O8 in the reserve or production categories in the NURE estimate. Considering the complexities and uncertainties of the analysis, this study indicates that the NURE reserve estimates for the province were accurate. An unconditional potential resource of 1.4 billion pounds of U3O8, 600 million pounds of U3O8 in the forward cost category of $30/lb U3O8 (1980 prices), was estimated in 106 favorable areas by the NURE program in the province. Removing potential resources from the non-productive Houston embayment, and those reserves estimated below historic and current mining depths reduces the unconditional potential resource 33% to about 930 million pounds of U3O8, and that in the $30/lb cost category 34% to 399 million pounds of U3O8. Based on production records and reserve estimates tabulated for the region, most of the production since 1980 is likely from the reserves identified by NURE. The potential resource predicted by NURE has not been developed, likely due to a variety of factors related to the low uranium prices that have prevailed since 1980.
Consumption of Dietary n‐3 Fatty Acids Decreases Fat Deposition and Adipocyte Size, but Increases Oxidative Susceptibility in Broiler Chickens
Authors: González‐Ortiz Gemma , Sala Roser , Cánovas Elisa , Abed Nourhène , Barroeta Ana C.
Published: March 2013

The aim of this study was to determine the effects of an omega‐3 (n‐3) polyunsaturated fatty acid (PUFA)‐enriched diet on animal fat depots and lipid oxidation in the blood and meat of broiler chickens. Abdominal fat pad (AFP), sartorius muscle and liver histology were used to assess the effect of the dietary fat on animal lipid depots. A total of 60 female broilers (14 days old) was randomly divided into two groups which received a diet containing 10 % of tallow (S diet), rich in saturated fatty acids or 10 % of a blend of fish oil and linseed oil (N3 diet), rich in n‐3 PUFA from 14 to 50 days of life. Both absolute and relative weights of AFP in N3 animals were lower than in the S group (P < 0.05). These results paralleled with a lower adipocyte mean area (P < 0.001) obtained in N3‐fed animals, leading to a higher number of fat cells per unit of surface measured (383.4 adipocytes/mm2 vs. 273.7 adipocytes/mm2). Similarly, fat content and the intramuscular fat‐occupied area of muscle were lower in N3 (P < 0.0001) than in the S‐fed birds. Neither macroscopic nor microscopic differences were observed in the liver. The inclusion of dietary n‐3 PUFA increased meat and erythrocyte oxidation susceptibility; however, the erythrocytes from the S group were less resistant to osmotic changes. Results indicate that feeding an n‐3 PUFA diet influences fat distribution and the oxidative status of broiler chickens.
Running-in process of Si-SiO
x
/SiO2 pair at nanoscale—Sharp drops in friction and wear rate during initial cycles
Authors: Chen Lei , Kim Seong H. , Wang Xiaodong , Qian Linmao
Published: March 2013

Using an atomic force microscope, the running-in process of a single crystalline silicon wafer coated with native oxide layer (Si-SiO
x
) against a SiO2 microsphere was investigated under various normal loads and displacement amplitudes in ambient air. As the number of sliding cycles increased, both the friction force F
t of the Si-SiO
x
/SiO2 pair and the wear rate of the silicon surface showed sharp drops during the initial 50 cycles and then leveled off in the remaining cycles. The sharp drop in F
t appeared to be induced mainly by the reduction of adhesion-related interfacial force between the Si-SiO
x
/SiO2 pair. During the running-in process, the contact area of the Si-SiO
x
/SiO2 pair might become hydrophobic due to removal of the hydrophilic oxide layer on the silicon surface and the surface change of the SiO2 tip, which caused the reduction of friction force and the wear rate of the Si-SiO
x
/SiO2 pair. A phenomenological model is proposed to explain the running-in process of the Si-SiO
x
/SiO2 pair in ambient air. The results may help us understand the mechanism of the running-in process of the Si-SiO
x
/SiO2 pair at nanoscale and reduce wear failure in dynamic microelectromechanical systems (MEMS).
Milestones in the quest for best management of patients with HELLP syndrome (microangiopathic hemolytic anemia, hepatic dysfunction, thrombocytopenia)
Authors: Martin James Nello
Published: March 2013

In the 3 decades since the original description and naming of the dangerous pregnancy complication called HELLP syndrome, many milestones have been passed in pursuit of a better understanding of the disorder and its best management. It is worthwhile to review the milestones through which we have passed internationally in obstetrics as the peril that this disorder poses to pregnancy has been exposed. Factors of importance for emphasis will be definitions, reasons why the triple classification system impacts practice, the important role glucocorticoids have in reversing the pathogenesis of the disorder if used early, the excellent results reported for mothers when all components of the Mississippi Protocol are utilized for patient care, and the place of plasma exchange in special situations. Our challenge for the future is to delay or prevent HELLP's development prior to potential viability so that stillbirths and very preterm losses can be reduced or eliminated.