bluuebunny/crossref_metadata_2025 huggingface dataset:
Innovation at Work: Save Chlorine, Save Money
Authors: Caughell Marq
Published: June 2018

This article discusses an innovative chlorine management system at the William E. Dunn Water Reclamation Facility in Pinellas County, Florida. Laying the chlorine tanks horizontally on an off‐centered fulcrum resulted in a more efficient chlorine management system.
Minimize MicrofiItration Membrane Maintenance
Authors: Feldman Eileen McCarthy , Crossley Ian A. , Ruge Richard
Published: June 2018

This article discusses a system design to minimize microfiltration membrane maintenance at the Westchester Joint Water Works in Mamaroneck, New York. Several cleaning steps were used to remove contaminants from membrane fibers and keep them free of fouling. Frequent air agitation, backpulsing, and deconcentration were used to remove solids from the fibers. More aggressive cleaning programs‐‐ maintenance and recovery cleaning‐‐ were used with chemicals to remove fouling. The wastes produced from each of these steps must be handled carefully and within the constraints of local utilities, available property, and capital/operational costs.
What's the Best Way to Tap a Water Main?
Authors: Kline Pat
Published: June 2018

This month's question asks about the best way to tap a water main. The answer begins by discussing dry taps and wet, or hot, taps and goes on to discuss valve terminology, the art of tapping, tapping machines, operational considerations, terminology specific to threads and ductile iron main connecting to a copper service line, and computing the correct number of hand turns necessary for engagement.
Phosphate Residuals … Checking for True Blue Samples
Authors: Spon Robert
Published: June 2018

This article discusses measuring orthophosphate (OP) and polyphosphate (PP) chemical residuals in water systems. Water sampling steps are provided for determining the quantity of OP, PP, or a combination of the chemicals in a water system, along with other considerations that can create inconsistent OP residuals and misleading results. A table is included in the article of phosphate dosage and residual OP comparison.
Align Technology With Business and Operational Requirements
Authors: Serjeantson Bill , Gaberdiel Phil , McKinney Scott
Published: June 2018

This article stresses the importance of a clearly defined strategy and guidance plan to ensure the continued optimized performance of a supervisory control and data acquisition (SCADA) system. The article lists various aspects of a utility's performance that are negatively affected by a SCADA system that is at or near the end of its expected service life. The article also lists the benefits of adhering to a SCADA master plan for establishing system reliability to meet business needs and attain strategic visions. Also, essential outcomes that must be addressed by a SCADA system master plan are provided.
A Winning Combination: High‐Tech Metering Advances Deliver Widespread Benefits
Authors: Johnson Rodney , Ishac Saad , Field Darrel
Published: June 2018

This article discusses an effort by the Detroit Water and Sewerage Department (DWSD) to implement an advanced metering infrastructure, meter data management, and a workforce management (WFM) system to deal with significant infrastructure challenges, increasing regulatory requirements, competitive pressures, and demanding customers. The article provides a brief overview of the DWSD, along with both drive‐by and fixed‐base automatic meter reading (AMR) systems. Various measures are discussed that DWSD used to ease the transition with its customers including a community relations program, and the following technical aspects: meter interface units (MIUs) and cell collection units (CCUs); fixed network application server (FNAS); customer billing and management system (CBMS); and, workforce management (WFM) system. Business process enhancements gained by the installation of the AMI/MDM and WFM systems are listed, along with security and leak detection measures, and consumption patterns.
How Can I Better Prepare for the Water Treatment Plant Operator's Exam?
Authors: Kline Pat
Published: June 2018

This month's question asks about studying for the water treatment plant operator exam. The answer discusses educational theory, and lists psychologist Howard Gardner's eight categories of intelligence. The article emphasizes determining your own learning style, and finding educational material that corresponds to your style and the need‐to‐know information for the exam. Forming study groups, discussing study topics with co‐workers, and watching training videos are all suggested for helping with preparation for the exam. The article also provides a list of study resources.
Leadership: Nurture Future Leaders Today
Authors: Gerstberger Richard L.
Published: June 2018

This article presents the reorganization of the Aurora (Colorado) Water Department as an example of developing a strategic plan that focuses on organizational assessment, leadership competency and development, and succession planning. Employees throughout the organization understood the changes that were made, and cooperation between sections was at an all‐time high. For the first time, people examined how their decisions affected others outside of their sections. Employees related to business initiatives and future goals in daily decisions.
Retention: Recognize, Reward, and Retain Operators
Authors: Berahzer Stacey Isaac
Published: June 2018

This article discusses a survey done by the University of North Carolina Environmental Finance Center to ask more than 300 water operators at small systems in North Carolina about current job satisfaction. The project was part of a program to address operator turnover at small water systems, and clarify the relationship between governing boards and operators. The article discusses topics that include: aging workforce; voluntary turnover; job satisfaction; organizational incentives; recognition; water operators as professionals; award programs; and, merit pay incentives. The article includes an inset, “Apprenticeship Program Enhances Training, Reduces Turnover”, that presents the Operator Apprenticeship Program at the Fayetteville (North Carolina) Public Works Commission.
A Water Treatment Plant Tour and the Magic Kingdom: What Do They Have in Common?
Authors: Rowland Kerry
Published: June 2018

This article presents the four service quality standards called “keys to the kingdom” by Disney's Magic Kingdom as an excellent guide for operator's who give water treatment plant tours to the public. The keys include safety, courtesy, show, and efficiency.
Recycled Water Consider a Drought‐Proof Water Supply
Authors: Chalmers R. Bruce , Patel Mehul , Cutler Donald
Published: June 2018

This article discusses treating previously wasted sewer water at three advanced recycled water treatment facilities (AWTFs) that include: Groundwater Replenishment (GWR) System, Orange County (California) Water District (OCWD); Water Replenishment District (WRD), Southern California's Leo J. Vander Lans Water Treatment Plant; and, South District Water Reclamation Plant (SDWRP), Miami‐Dade Water and Sewer Department (MDWASD). AWTF benefits and challenges are discussed, along with critical agency management support, the importance of preliminary design in setting parameters for an entire project, lessons learned from testing and initial operation, and start‐up concerns.
Improve Accuracy With Proper Water Meter Installation
Authors: Burke Lonnie , Hannah Craig
Published: June 2018

This article discusses the importance of proper water meter installation, focusing on the following types of meters: positive‐displacement and volumetric meters; inferential or velocity‐type meters; Woltmann or turbine‐type meters; and, compound meters.
USEPA Approves On‐line Monitoring of Chlorine Residuals
Authors: McTigue Nancy E.
Published: June 2018

This article discusses U.S. Environmental Protection Agency's Method 334.0, Determination of Residual Chlorine in Drinking Water Using an On‐line Chlorine Analyzer. Now utilities have an approved method specifically for on‐line chlorine residual monitoring. Online instruments operated according to the method will produce analytical results comparable to other approved methods and are suitable for compliance reporting under federal regulations. The method incorporates several quality assurance measures that utilities must incorporate in their standard operating procedures. This development is particularly important for utilities using on‐line amperometric chlorine analyzers, which have historically been used for process control. The article discusses key quality assurance and control procedures that include the following: the on‐line instrument is calibrated using aqueous standards or the results from paired grab samples collected at the same point and time; the grab samples are analyzed for chlorine using a method approved for drinking water compliance monitoring; the on‐line analyzer's accuracy is periodically verified and adjusted based on grab sample analysis results; and, the analyst demonstrates competency in using the method.
Spatial Trends Shed Light on Arsenic Concentrations
Authors: Bradshaw Jonathan L. , Gurian Patrick L. , Kumar Arun , Breen David E.
Published: June 2018

To better understand geographic trends in arsenic occurrence, researchers recently used an interactive visualization technique to link geospatially referenced arsenic concentration information from a water quality database with data contained in digital terrain elevation data (DTED) files. DTED files allow users to develop 3‐D plots of arsenic concentration and topography. The study used the U.S. Geological Survey arsenic point database, which contains water quality data for the United States and its territories. Researchers used technical computing software that allows users to specify subset columns within a graphical user interface.
Plant Performance Picture Emerges With Instrumentation
Authors: Schreppel Connie
Published: June 2018

This article discusses recent advances in water treatment plant instrumentation and laboratory equipment that allow Mohawk Valley Water Authority (MVWA) operators to use their ingenuity to optimize water treatment. To better understand and improve the treatment process, operators have incorporated streaming current monitors (SCMs), coagulant charge analyzers (CCAs), particle counters, UV254 analyzers, and on‐line chlorine analyzers into their routine. Supervisory control and data acquisition (SCADA) system monitoring screens display data as water travels through the process train and into the distribution system.
Bulk‐Water System Enhances Security, Minimizes Disruption
Authors: Hughes David M. , Ericsson Dave
Published: June 2018

This article describes a new bulk‐water fill station that was moved to a more convenient location on the grounds of the Ridley Creek Water Treatment Plant in Media, Pennsylvania. This new fill station can be accessed from outside the plant fence line and operated automatically around the clock without disrupting personnel. The article describes how it is constructed and operated, and reports on the costs incurred by the project.
Battling Nitrification With Blacklights
Authors: White Brian , Adams Martin
Published: June 2018

This article discusses a full‐scale tank retrofit by the Los Angeles Department of Water and Power (LADWP) that included suspending a bank of fluorescent blacklights in the headspace of Mount Washington Tank 2 to prevent nitrification from occurring in the covered storage facility. The article explains the process by which nitrification was occurring after LADWP changed from chlorine to chloramines as its secondary disinfectant, and discusses the full‐scale pilot project along with near‐ultraviolet (UVA) radiation lighting design and validation.
Internal Joint Restraint Rescues Port of Tampa
Authors: Thames Roy
Published: June 2018

This article discusses a project by the Port of Tampa, Florida, to replace a ductile‐iron pipeline that had been eaten through by corrosive, aggressive soil over a period of 35 years. The Tampa Water Department decided on replacing the pipeline with PVC pipe that included an internal joint restraint that eliminated the need for external fixtures. The article discusses installation of the pipe, and explains the internal joint restraint process, which along with the lightweight PVC pipe allowed for quicker installation. The article also discusses PVC product suitability for resisting corrosive soil and holding up to pressure from traffic on an overhead intersection.
Safeguard Water Quality With Chemical‐Feed Maintenance
Authors: Hardy David K.
Published: June 2018

This article discusses guidelines for optimizing chemical quality and application for chemical‐feed equipment, including: chemical storage facilities; chemical feeders; mixers and diffusers; piping; and, ejectors. The article provides a basic maintenance checklist for regular maintenance of chemical‐feed equipment.
Filter Rerating Increases Production
Authors: Lew Julia , Pickle Todd , Johnson David , Wert Eric
Published: June 2018

This article discusses a filter rerating study conducted by the Southern Nevada Water Authority (SNWA), which demonstrated that increased filter loads didn't affect public health, and provided additional capacity without the high cost of construction. The article discusses SNWA's testing protocol, filter loading rate, filter effluent turbidity, filter average run time, and evaluates filter production. The study demonstrated that SNWA's filters could be operated safely at increased loading rates of up to 7.5 gpm/ft2 while maintaining filter effluent water quality, thus saving the utility more than $10 million in construction costs alone.
Fire and Ice: Tame Temperature Extremes in Water Tanks
Authors: Kearney Frank S. , Stevens Bruce P. , Fiske Peter
Published: June 2018

This article discusses challenges caused by large variations in average temperatures in Old Town, Maine. Thermal stratification issues in water tanks during both summer and winter were addressed by installing submersible mixers. Uniform water temperatures, chlorine odors, decreases in overall disinfectant residual demand, and operational costs were all improved after installing submersible mixers.
Mapping Ground Water Rule Requirements: Source Water Compliance and Assessment Monitoring
Authors: McMahan Erin K. , Lopez‐Carbo Maria
Published: June 2018

This is the third of five columns developed by the U.S. Environmental Protection Agency (USEPA), summarizing key components of the Ground Water Rule (GWR). This column discusses the components of compliance monitoring and assessment source water monitoring. Compliance monitoring is required for groundwater systems (GWSs) that have notified the state that they reliably provide 4‐log treatment of viruses, and as a form of corrective action or in lieu of triggered source water monitoring. Assessment source water monitoring is a tool available to a state that suspects a system's groundwater source might be vulnerable to fecal contamination.
Large‐Diameter Mains: Estimate and Extend Service LIFE
Authors: Higgins Michael S.
Published: June 2018

Implemented on about 500 miles of pipe, the asset management approach described in this article represents state‐of‐the‐art large‐diameter prestressed concrete cylinder pipe (PCCP) management. This approach can safely extend the life of PCCP water mains by relying on pipe sections in good condition or with moderate damage and managing risk through isolated repairs and long‐term structural monitoring. The risk associated with each pipe section is updated as structural monitoring results are acquired.
Mapping Ground Water Rule Requirements: Consumer Confidence Report, Public Notification, and Special Notice
Authors: McMahan Erin K. , Lopez‐Carbo Maria
Published: June 2018

This is the fifth and final column in a series developed by the U.S. Environmental Protection Agency (USEPA), Office of Ground Water and Drinking Water, summarizing key components of the Ground Water Rule (GWR). The previous four columns in the series focused on source water monitoring, compliance monitoring, sanitary surveys, and corrective action. This final column discusses GWR requirements regarding the Public Notification (PN) Rule, Consumer Confidence Report (CCR) Rule, and Special Notice.
A Small Utility Can Reap Big Benefits With a GIS
Authors: Mumaw Stephanie
Published: June 2018

This article discusses how the goals for implementing a GIS in a small to medium‐sized community should be approached from a different perspective. The article discusses a few key steps to follow when planning a GIS that works within budget, provides the same functionality as one designed for a big‐city department at a fraction of the cost, is housed on‐site, and is operated by city staff. Customizing the system, fine tuning data accumulation, performing in‐house maintenance, and educating stakeholders are key components to a successful system.
Optimize Sustainable, Reliable Water Supplies
Authors: Rehring John , Borchert Claudia
Published: June 2018

The municipal water utility in Santa Fe, New Mexico, had to enforce substantial mandatory restrictions in 2002 to meet peak day water demands. The city developed a long‐range plan to provide a reliable, sustainable water supply for current and future customers. At a time when many other Southwest communities face increasing water needs, Santa Fe's long‐range planning method can serve as an integrated, community‐based planning model. Santa Fe's process sought to take advantage of both surface water supplies and groundwater sources and optimize resources, conservation programs, and infrastructure.
Small City Tackles Radium in Well Water
Authors: Qureshi Naeem , Volkart Greg
Published: June 2018

This article discusses a pilot study by the city of Goodview, Minnesota, for the removal of radium with hydrous manganese oxide (HMO) and coprecipitation with iron from its well water. Dual media, sand, and manganese greensand media were tested in the pilot plant, and results showed that the manganese greensand media had the lowest filter headloss buildup and would produce the longest filter runs. The media also produced the best quality water with the highest removal rate of radium and iron.
Passive Mixing Systems Improve Storage Tank Water Quality
Authors: Duer Michael
Published: June 2018

Modeling and field monitoring are helping utilities understand the complexities of water storage tank mixing and how to identify and correct mixing problems. This article discusses optimizing turnover and achieving complete mixing with passive mixing systems in order to eliminate mixing problems and improve water quality.
How Do I Know if My Distribution System Management Efforts Are Effective?
Authors: Lauer William C.
Published: June 2018

This article discusses resources for basic information on distribution system operation, along with the Partnership for Safe Water's new Distribution System Optimization Program. System operators can use this program to determine the optimization status of their systems, identify areas for improvement, and measure the effect of changes made. The Partnership for Safe Water is a voluntary self‐directed performance improvement program supported by six of the largest national drinking water organizations. The program's goal is to help utilities provide a new level of safety by conducting comprehensive self‐assessments and implementing indicated performance‐improvement measures.
How Often Should Residential Water Meters Be Replaced?
Authors: Mercer Ken
Published: June 2018

This month's question asks how to determine when to replace residential water meters. The optimum service life of a meter depends on prevailing water rates, rate of meter wear (and loss of accurate registration), repair and maintenance costs, and inflation and discount rates. Ultimately, there's no standard time period for meter replacement that can be broadly applied to all utilities. The article recommends a cumulative flow‐based meter replacement program, if specific water‐use data can be obtained. The article lists other information that is needed to optimize such a meter replacement program.
How Do We Deal With Invasive Mussels?
Authors: Mercer Ken
Published: June 2018

This month's question asks about the current methods of dealing with invasive mussels. The article states that control strategies should address the degree of permissible infestation, water quality, existing facility systems, economics, permit requirements, and environmental regulations. The article individually discusses some of the more commonly used control strategies and treatment options, and also mentions other less common treatment options.
Preventing the Perfect Storm: Public Health Relies on Risk Management
Authors: Burlingame Gary A. , Rayburn Chris , Blaha Frank J.
Published: June 2018

This article discusses the simultaneous occurrence of certain events that can cause a major disaster in a utility's distribution system. Specifically, the article discusses the top four concerns for distribution systems, as indicated by actual records of contamination and waterborne disease outbreaks, including: cross‐connections and backflow of contaminated water; contamination resulting from storage facility design, operation, or maintenance; contamination caused by main installation, repair, or rehabilitation practices; and, contaminant intrusion caused by pressure conditions and physical gaps in distribution system infrastructure.
Smart Grids: Smart Meters Are Getting Smarter
Authors: Quraishi Arif A. , Siegert Dennis
Published: June 2018

This article discusses the smart grid concept as more than smart‐metering technology; a smart grid is the communication network on which automated (AMR)/advanced metering infrastructure (AMI) operates, turning smart metering into a smart grid that can provide other capabilities. The article discusses a financing tool called “performance contracting” that makes it possible to overcome the daunting investment required up front. The city of Cuyahoga Falls, Ohio, is presented as an example of the immediate benefits of initiating a smart grid concept and its potential.
Nitrosamines: Economics of the Unknown
Authors: Rosenfeldt Erik , Bishop Mark , Stanford Ben
Published: June 2018

This article discusses the effectiveness of using chloramination to comply with the Stage 2 Disinfectants and Disinfection Byproducts Rule (Stage 2 DBPR), if potential nitrosamine formation during and after chloramination might be the result.
Tank‐Mounted AMR Saves Rural Community Time, Money
Authors: Klein David , Davis Josh
Published: June 2018

When the Monroe County Water District (MCWD) in Paris, Missouri, decided to convert from radio frequency (RF) to automatic meter reading (AMR), the utility wanted to install antenna systems on eight key water towers. During this process, however, U.S. Environmental Protection Agency (USEPA) personnel expressed concern about potential risk of damage to the tanks' protective surfaces, limited handrail mounting options, and the range that would be required to link the service area for automatic water, gas, and electric billing.
Volunteering Pays Nothing but Dividends
Authors: Owen Christine
Published: June 2018

This article discusses the priceless value of volunteerism, a kind of enlightened self‐interest ‐ a way to serve a common cause that also serves your own interest. Local AWWA sections have plenty of volunteer opportunities, and the article mentions some of the benefits that come from Young Professionals (YPs) volunteer opportunities, such as enhancing a resume with volunteer activities that demonstrate your commitment and interest in the industry, not to mention the value received from industry networking.
Hydrofracking: Is it Worth the Risk?
Authors: Easley Paul R.
Published: June 2018

This article discusses the increase of hydrofracking in the last few years as a way to extract gas from sizable but hard‐to‐reach deposits. The hydrofracking process technology is discussed, along with environmental and human health concerns associated with hydraulic fracturing that include the contamination of groundwater, risks to air quality, the migration of gases and hydraulic fracturing chemicals to the surface, and potential mishandling of waste. The potential costs associated with possible environmental cleanup processes, loss of land value, and human and animal health concerns are undetermined. The process introduces hundreds of tons of fracturing chemicals into a watershed over a period of several decades and could be accompanied by gradual dispersion of low levels of toxic chemicals into the environment and water supplies through multiple pathways.
Representative Sampling
Authors: Geddes Linda
Published: June 2018

Intake offers Opflow readers guidelines and best practices collected from AWWA Manuals of Water Supply Practices.
Surface Water Treatment Rule Requirements
Authors: Stark Blake
Published: June 2018

Intake offers Opflow readers guidelines and best practices collected from AWWA Manuals of Water Supply Practices.
Pipeline Renewal Benefits
Authors: Ambler Edward “Alan”
Published: June 2018

Intake offers Opflow readers guidelines and best practices collected from AWWA Manuals of Water Supply Practices.
Locating Lead Service Lines
Authors: Olson Paul J.
Published: June 2018

Intake offers Opflow readers guidelines and best practices collected from AWWA Manuals of Water Supply Practices.
Modified Backwash Techniques
Authors: Emerson Brock
Published: June 2018

Intake offers Opflow readers guidelines and best practices collected from AWWA Manuals of Water Supply Practices.
Retracted: Silencing ARHGAP9 correlates with the risk of breast cancer and inhibits the proliferation, migration, and invasion of breast cancer
Authors: Wang Tianyi , Ha Minwen
Published: June 2018

Breast cancer (BC) is one of the most common malignant tumors in women, and screening relevant genes and markers that are involved in BC tumor genesis and progression is of great value. We previously found that messenger RNA expression of ARHGAP9 was high in BC tissue, but it is unclear whether ARHGAP9 participates in the progression of human BC. In this study, we found that ARHGAP9 expression was correlated with poor patient survival, American Joint Committee on Cancer clinical staging, tumor size, and tumor differentiation. MCF‐7 and MDA‐MB‐231 cells exhibited higher expression of ARHGAP9 than other human BC cell lines (HCC1937, MDA‐MB‐453, ZR‐75‐1, and Hs 578T). Knockdown of ARHGAP9 in human BC cells markedly reduced the cell proliferation, migration, and invasive ability of MCF‐7 and MDA‐MB‐231 cells. Furthermore, small interfering RNA (siRNA) of ARHGAP9 also induced G0‐G1 cell cycle arrest and apoptosis in MCF‐7 and MDA‐MB‐231 cells. Expressions of cell cycle markers (CDK2 and CCNB1) and invasion‐related protein (RhoC and MTA1) were downregulated in siRNA‐ARHGAP9‐transfected cells. siRNA of ARHGAP9 also inhibited the phosphorylation of mitogen‐activated protein kinases in BC cells. In conclusion, the abnormal expression of ARHGAP9 may correlate with the genesis, development, and diagnosis of BC.
MiR‐128‐1‐5p regulates tight junction induced by selenium deficiency via targeting cell adhesion molecule 1 in broilers vein endothelial cells
Authors: Pan Tingru , Hu Xueyuan , Liu Tianqi , Xu Zhe , Wan Na , Zhang Yiming , Li Shu
Published: June 2018

Vein endothelial cells (VECs) constitute an important barrier for macromolecules and circulating cells from the blood to the tissues, stabilizing the colloid osmotic pressure of the blood, regulating the vascular tone, and rapidly changing the intercellular connection, and maintaining normal physiological function. Tight junction has been discovered as an important structural basis of intercellular connection and may play a key role in intercellular connection injuries or vascular diseases and selenium (Se) deficiency symptoms. Hence, we replicated the Se‐deficient broilers model and detected the specific microRNA in response to Se‐deficient vein by using quantitative real time‐PCR (qRT‐PCR) analysis. Also, we selected miR‐128‐1‐5p based on differential expression in vein tissue and confirmed its target gene cell adhesion molecule 1 (CADM1) by the dual luciferase reporter assay and qRT‐PCR in VECs. We made the ectopic miR‐128‐1‐5p expression for the purpose of validating its function on tight junction. The result showed that miR‐128‐1‐5p and CADM1 were involved in the ZO‐1‐mediated tight junction, increased paracellular permeability, and arrested cell cycle. We presumed that miR‐128‐1‐5p and Se deficiency might trigger tight junction. Interestingly, miR‐128‐1‐5p inhibitor and fasudil in part hinder the destruction of the intercellular structure caused by Se deficiency. The miR‐128‐1‐5p/CADM1/tight junction axis provides a new avenue toward understanding the mechanism of Se deficiency, revealing a novel regulation model of tight junction injury in vascular diseases.
Mesenchymal stromal cells from amniotic fluid are less prone to senescence compared to those obtained from bone marrow: An in vitro study
Authors: Alessio Nicola , Pipino Caterina , Mandatori Domitilla , Di Tomo Pamela , Ferone Angela , Marchiso Marco , Melone Mariarosa A.B. , Peluso Gianfranco , Pandolfi Assunta , Galderisi Umberto
Published: June 2018

Mesenchymal stromal cells (MSCs) are considered to be an excellent source in regenerative medicine. They contain several cell subtypes, including multipotent stem cells. MSCs are of particular interest as they are currently being tested using cell and gene therapies for a number of human diseases. They represent a rare population in tissues; for this reason, they require, before being transplanted, an in vitro amplification. This process may induce replicative senescence, thus affecting differentiation and proliferative capacities. Increasing evidence suggests that MSCs from fetal tissues are significantly more plastic and grow faster than MSCs from bone marrow. Here, we compare amniotic fluid mesenchymal stromal cells (AF‐MSCs) and bone marrow mesenchymal stromal cells (BM‐MSCs) in terms of cell proliferation, surface markers, multidifferentiation potential, senescence, and DNA repair capacity. Our study shows that AF‐MSCs are less prone to senescence with respect to BM‐MSCs. Moreover, both cell models activate the same repair system after DNA damage, but AF‐MSCs are able to return to the basal condition more efficiently with respect to BM‐MSCs. Indeed, AF‐MSCs are better able to cope with genotoxic stress that may occur either during in vitro cultivation or following transplantation in patients. Our findings suggest that AF‐MSCs may represent a valid alternative to BM‐MSCs in regenerative medicine, and, of great relevance, the investigation of the mechanisms involved in DNA repair capacity of both AF‐MSCs and BM‐MSCs may pave the way to their rational use in the medical field.
Population Pharmacokinetic/Pharmacodynamic Analyses of Avatrombopag in Patients With Chronic Liver Disease and Optimal Dose Adjustment Guide With Concomitantly Administered CYP3A and CYP2C9 Inhibitors
Authors: Nomoto Maiko , Ferry Jim , Hussein Ziad
Published: June 2018

Avatrombopag, a c‐Mpl agonist, has been developed to provide an alternative therapy to standard platelet transfusion care for the treatment of thrombocytopenia. The main objectives of this article were to describe the pharmacokinetics (PK) of avatrombopag, to characterize the pharmacokinetic/pharmacodynamic (PK/PD) relationship between plasma avatrombopag concentrations and platelet count, and to identify potential intrinsic and extrinsic factors affecting PK or PK/PD in patients with chronic liver disease (CLD). Platelet count following avatrombopag administration with and without concomitant medication was further simulated using the final population PK/PD model to explore potential dose adjustments. Avatrombopag PK was described by a 1‐compartment model with combined first‐ and zero‐order absorption and linear elimination. The relationship between the plasma avatrombopag concentrations and platelet count was well described by a 6‐compartment life‐span model with a linear drug effect. The final PK and PK/PD models included statistically significant but not clinically relevant effects of body weight and CLD on apparent volume distribution and East Asian ethnicity, albumin, and thrombopoietin level on the slope parameter in the PK/PD relationship. PK/PD simulations showed comparable elevation in platelet count with and without concomitant cytochrome P450 (CYP) 3A and CYP2C9 inhibitors for the dosing regimens of 40 and 60 mg for 5 days, with predictions of <10% of CLD patients exceeding platelet count >200 × 109/L. Dose adjustment is therefore not necessary with concomitant use of CYP3A and CYP2C9 interacting drugs considering the limited treatment duration (ie, 5 days) and lack of significant safety concerns in CLD patients.
Pairs and triples of forbidden subgraphs and the existence of a 2‐factor
Authors: Aldred R. E. L. , Fujisawa Jun , Saito Akira
Published: June 2018

Let be a set of connected graphs, each of which has order at least three, and suppose that there exist infinitely many connected ‐free graphs of minimum degree at least  two and all except for finitely many of them have a 2‐factor. In [J. Graph Theory, 64
(2010), 250–266], we proved that if , then one of the members in is a star. In this article, we determine the remaining members of and hence give a complete characterization of the pairs and triples of forbidden subgraphs.
Iron deposition quantification: Applications in the brain and liver
Authors: Yan Fuhua , He Naying , Lin Huimin , Li Ruokun
Published: June 2018

Iron has long been implicated in many neurological and other organ diseases. It is known that over and above the normal increases in iron with age, in certain diseases there is an excessive iron accumulation in the brain and liver. MRI is a noninvasive means by which to image the various structures in the brain in three dimensions and quantify iron over the volume of the object of interest. The quantification of iron can provide information about the severity of iron‐related diseases as well as quantify changes in iron for patient follow‐up and treatment monitoring. This article provides an overview of current MRI‐based methods for iron quantification, specifically for the brain and liver, including: signal intensity ratio, R2,
,
, phase, susceptibility weighted imaging and quantitative susceptibility mapping (QSM). Although there are numerous approaches to measuring iron, R2 and
are currently preferred methods in imaging the liver and QSM has become the preferred approach for imaging iron in the brain.

Level of Evidence: 5

Technical Efficacy: Stage 5

J. Magn. Reson. Imaging 2018. J. MAGN. RESON. IMAGING 2018;48:301–317.
Chromosomally integrated human herpesvirus 6 in the Japanese population
Authors: Miura Hiroki , Kawamura Yoshiki , Hattori Fumihiko , Kozawa Kei , Ihira Masaru , Ohye Tamae , Kurahashi Hiroki , Yoshikawa Tetsushi
Published: June 2018

The objectives of the work are to elucidate the incidence and virological findings of chromosomally integrated human herpesvirus 6 (ciHHV‐6) in Japanese population and to analyze an association between ciHHV‐6 and the clinical manifestation of exanthema subitum (ES). Real‐time polymerase chain reaction was performed to determine HHV‐6 DNA loads in 2347 cord blood samples from healthy neonates (cohort A), febrile children less than 5 years old (cohort B), and hematopoietic cell transplant recipients (cohort C). CiHHV‐6 was confirmed by detection of high copy numbers of viral DNA in somatic cells. The integration site was determined by fluorescent in situ hybridization analysis. In the ciHHV‐6 subjects of cohorts A and B, HHV‐6 antibody titers were measured, the history of ES was obtained, and the incidence of ES was compared with non–ciHHV‐6 children without primary HHV‐6B infection in the cohort B. CiHHV‐6 was detected in 14 (0.60%) of the 2347 samples: A (6/1006, 0.60%), B (6/790, 0.76%), and C (2/551, 0.36%). The integration sites were on chromosome 22q in seven cases, Yp in two cases, and 17q and Xp in one case. No past history of ES was observed in 11 of the 12 subjects. Nine children with ciHHV‐6 underwent serological analysis and were found to be positive for HHV‐6 IgG antibodies. Incidence of ES was statistically higher in the control subjects than the ciHHV‐6 subjects (P = 0.0039). In Japan, the frequency of ciHHV‐6 was 0.60%. A high incidence of ciHHV‐6A, specifically in chromosome 22, is a characteristic finding among the Japanese. CiHHV‐6 may interfere with the clinical symptoms of primary HHV‐6B infection.
Prevalence of hepatitis B virus, hepatitis C virus, and human immunodeficiency virus among blood donors of Mekelle blood bank, Northern Ethiopia: A three‐year retrospective study
Authors: Degefa Berhanu , Gebreeyesus Teklehaymanot , Gebremedhin Zufan , Melkamu Getachew , Gebrekidan Atsebaha , Hailekiros Haftamu , Tsegay Ephrem , Niguse Selam , Abdulkader Mahmud
Published: June 2018

Blood transfusion services are a vital and integral part of modern healthcare services. However, the risk of transfusion transmittable infections (TTI) has been a major handicap. Therefore, this study was aimed at determining the prevalence of hepatitis B virus (HBV), hepatitis C virus (HCV), and human immunodeficiency virus (HIV) among blood donors. A retrospective study was conducted to collect data about the blood donors who consecutively donated blood from October 2011 to 2014. A three‐year retrospective study was conducted in Mekelle Blood Bank. A data abstraction format was used to collect the sociodemographic and clinical data, and the prevalence of HBV, HCV, and HIV was determined. Data were analyzed using STATA version 10 analytical software. P value less than 0.05 was considered significant in all the analyses. A total of 10 728 blood donors, median (interquartile range) of age 30 (23‐45) years and 3750 (34.9%) males were enrolled in this study. Of the participants 407(3.79%), 143(1.33%), and 111(1.03%) blood donors were positive for HBV, HCV, and HIV, respectively. HBV‐HIV coinfections were found 10 (1.93%) blood donors, followed by HBV‐HCV and HIV‐HCV. A significant association between sex and marital status with HBV and HIV infection was found. However, significant association of HCV was observed among sex (
X
2 = 33.18,
P < 0.001) and occupational (
X
2 = 84.33,
P < 0.001). A significant percentage of HBV, HCV, and HIV among blood donors was observed. To select a donor and collect safe blood risk factors exposing blood donor should be studied, and community‐based prevalence studies on TTI are also required.
Improving portfolio diversification: Identifying the right baskets for putting your eggs
Authors: Sharma Prateek , Vipul
Published: June 2018

We measure the economic value of diversification for international multiasset investment strategies. This study implements five existing diversification measures and proposes a novel measure of diversification, the unsystematic risk ratio (URR). Only the URR and the effective number of bets measures predict the future risk‐adjusted performance. These relations are robust to the choice of investment horizon and degree of relative risk aversion. The diversification benefits are larger for the frontier and emerging markets than for the developed markets, for multiasset strategies than for single asset class strategies, and for the pre‐crisis and post‐crisis periods than for the financial crisis period.
A filtering impedance transformer with high transforming ratio
Authors: Chen Shiyong , Li Meng , Yu Yantao , Tang Mingchun
Published: June 2018

A filtering impedance transformer with high transforming ratio and good suppression out of band is presented in this article. Design parameters of the proposed configuration are analyzed. For verification, a 50 to 500 Ω transformer operating at 3 GHz has been designed, fabricated, and measured. The measured maximum insertion is about 0.87 dB and the measured return loss is better than 18 dB from 2.71 to 3.29 GHz, which are in good agreements with the simulated ones.
Two‐terminal InGaAs microwave amplifier
Authors: Wang Hanbin , Zhang Yifei , Shi Yanpeng , Ling Haotian , Wang Qingpu , Liu Fengqi , Yang Fuhua , Xu Kunyuan , Xin Qian , Song Aimin
Published: June 2018

The feasibility of using a 2‐terminal InGaAs planar Gunn structure as a microwave amplifier is proposed and verified. By achieving a pronounced negative differential resistance with a peak‐to‐valley current ratio of 1.20, our devices are able to amplify microwaves at a high gain of 17 dB. When compared with commonly used 3‐terminal transistor‐based microwave amplifiers, the proposed devices not only have a simple structure but also are capable of achieving high operating frequencies even with relatively large feature sizes. The device with a channel length of 4 μm has a positive gain up to about 77 GHz, and the 2‐μm device is able to amplify microwaves well beyond 110 GHz. Furthermore, the planar Gunn amplifier shows a good linearity over a wide input power range from −45 to about 0 dBm. A good operation stability has also been demonstrated despite having no substrate thinning and heat sink.
Annular CPW‐FED directivity‐variable array antenna loaded with Schottky diodes
Authors: Yang Dae‐Geun , Kim Kyung‐Soo , Kim Dong‐Ju , Jang Eun‐Seok , Kim Che‐Young
Published: June 2018

A novel high‐speed directivity‐variable array antenna is designed, fabricated and characterized. The passive LC elements and varactor/PIN diodes used in conventional antennas are replaced with an annular coplanar waveguide (CPW) and Schottky diodes, in order to overcome the problem of out‐of‐band radiation. The proposed antenna consists of 3 dipole antennas on the upper side of the substrate, and a CPW with 4 Schottky diodes on the bottom side of the substrate. The antenna was designed and characterized at 2.45 GHz. Measurement results demonstrate that the proposed antenna exhibits beam steering and mirror‐image pattern pairs capability.
Controllable and wide spurious suppression power divider with a bandpass‐filtering and high isolation
Authors: Kim Phirun , Chaudhary Girdhari , Jeong Yongchae
Published: June 2018

This article presents a bandpass‐filtering power divider with a controllable and wide spurious frequency. The proposed structure consists of four stepped‐impedance resonators (SIR) that are directly coupled to the output ports of the power divider with an electrical length of θ. The spurious frequency can be controlled by changing the ratio of the SIR. Moreover, the isolation resistor provides an effective isolation between the output ports and an effective output return loss over wide stopbands. For the experiment validation, the power dividers with the stepped‐impedance ratios of 0.83 and 1.43 were designed, fabricated, and measured at the center frequency of 2.6 GHz. The measured results are in good agreement with the simulated results.
A simpler reference antenna gain measurement method
Authors: Selvan Krishnasamy T. , Sharma Satish K. , Mishra Ghanshyam , George Roshin Rose
Published: June 2018

A simpler reference antenna gain measurement method, involving only 2 antennas—the test antenna and a reference antenna—is considered in this communication. It is shown that using this method, which can facilitate quick measurements, the gain of the test antenna can be measured nearly as accurately as through conventional measurement methods, including the 2‐antenna method. Careful gain measurements are done to this end by performing the Vector Network Analyzer's full 2 port calibration between the antenna under test and transmit end cables. The measured gain values using the proposed method are compared with the established gain measurement methods to prove the methodology. Though this possibility appears to be known to some antenna engineers, a demonstration has not yet been reported to the best of the authors’ knowledge. This communication presents such a demonstration.
Miniaturized impedance inverter 2.4 GHz filter with optimal transmission zeroes
Authors: Soleiman Meiguni Javad , Mazdarani Alireza
Published: June 2018

A compact bandpass microstrip filter with high selectivity capability is fully investigated in this article. The basic characteristics, circuit models, and design formulas are explained completely. This technique provides more freedoms for putting the transmission zeroes with negative coupling structures in appropriate frequencies and leads to highly selective, low profile and compact filters. To validate the procedure, 3 design examples based on impedance inverter (K), admittance inverter (J) and λ/4 resonators are presented. All of the filters operate at 2.4 GHz with the fractional bandwidth more than 10% but different values in source–resonator–load couplings. The latter is obtained by tilting the middle J‐inverter toward the main line. For tilt‐angle equal to 90°, more than 50 dB null‐depth has been achieved in filters stop‐band near 8% of passband edges showing the appropriate figure of merit for this symmetrical filter. Simulated results performed by CST Microwave Studio and measured results are in good agreement with the theoretical peers.
A compact UWB‐BPF based on microstrip‐to‐CPW transition with multiple transmission zeros
Authors: Ghazali Abu Nasar , Sazid Mohd , Virdee Bal
Published: June 2018

A hybrid microstrip‐to‐coplanar waveguide (CPW) based broadside coupled ultra‐wideband (UWB) bandpass filter (BPF) of compact nature with multiple transmission zeros (TZ) is proposed. The CPW in ground consists of a short circuited multiple mode resonator (MMR), which is in conjugation with two microstrip lines on the top, arranged in back‐to‐back manner. Initially, the impedance ratio of the MMR is adjusted to place its resonant modes quasi‐equally within the UWB passband and later the dimensions of microstrip lines are optimized to enhance the broadside coupling. The setup generates a passband with reduced insertion loss, small group delay and multiple TZ. The presence of TZs provide sharp roll‐offs at either passband edges and a wide stopband. The experimental BPF is fabricated and its measured data validated against simulation results. The proposed structure measures 14.6 × 9.6 mm2.
Analytical expression for calculating large‐signal gain of RF power amplifiers
Authors: Guezzen Fethi , Tamoum Mohammed , Allam Rachid
Published: June 2018

This article provides simplified analytical expressions and methodology for predicting the power gain and output power of RF LDMOSFET power amplifier. This method avoids the use of the complex nonlinear device models and Harmonic Balance circuits simulators. For validation of our method, a 2.5 GHz‐10 W RF power amplifier is implemented. The measured, simulated and calculated results match very well.
Improved profile reconstruction via virtual transformation
Authors: Ahmad Falih
Published: June 2018

A technique based on a virtual transformation is developed to improve the accuracy of electromagnetic inversion based on the Riccati equation. Examples are given in which the technique is applied. Excellent agreement between exact profile values and those produced by the technique is demonstrated.
High‐gain and wideband aperture coupled feed patch antenna using four split ring resonators
Authors: Yoon Na Nae , Ha‐Van Nam , Seo Chulhun
Published: June 2018

In this article, a high‐gain and wideband antenna that is adapted arrays of four split ring resonators (4SRRs) in S‐band was proposed. An aperture‐coupled patch array antenna was designed with wideband characteristics and arrayed in the 4 × 1 with high‐gain characteristics. To increase the gain more, arrays of 4SRRs based on metamaterial were used. The proposed metamaterial unit cell consists of four split ring resonators and an embedded capacitor to control the frequency characteristics easily. The proposed metamaterial's permeability was found to be near to zero. The proposed 4SRRs was arrayed and applied to the aperture‐coupled patch array antenna. The proposed arrays 4SRRs resonators improve the antenna gain by 2 dB, between 3 and 3.4 GHz.