bluuebunny/crossref_metadata_2025 huggingface dataset:
A sequential scaled pairwise selection approach to edge detection in nonparanormal graphical models
Authors: Jiang Yiwei , Chen Zehua
Published: February 2016

We deal with the problem of edge detection in high‐dimensional nonparanormal graphical models. A nonparanormal graphical model is first transformed into a Gaussian graphical model. Then a sequential scaled pairwise selection (SSPS) method which we propose is applied to the transformed model. The SSPS method is a neighbourhood detection approach which makes use of conditional regression models. First the response vector in each individual conditional regression model is scaled, then the response vectors are pooled together to form a single model. The features in this single model are selected pairwise by a sequential procedure, which reflects the intrinsic symmetry of the edges. At each step of the procedure, the current residual vector is projected into the space spanned by each pair of columns of the design matrix which correspond to the symmetric edges, and the selected set of edges is then augmented by the pair with the largest projection norm. The extended BIC (EBIC) is used as the stopping rule for the sequential procedure. The selection consistency of the SSPS method is established. Simulation studies and the analysis of a real data set are carried out to compare the SSPS method with other existing methods. The simulation studies demonstrate that the SSPS method outperforms the other methods. In addition, the SSPS method is computationally more appealing. The Canadian Journal of Statistics 44: 25–43; 2016 © 2016 Statistical Society of Canada
Understanding the Development of Environmental Resistance Among Microbes: A Review
Authors: Srivastava Jatin , Chandra Harish , Singh Nandita , Kalra Swinder J. S.
Published: February 2016

Indiscriminate industrial development and increased human population have altered the environmental conditions all over the world, creating challenges for various life forms on earth. Environmental pollutants such as toxic metals and hazardous organic compounds are fatal for life and the most concerned global issue of the debates. Microbes are integrated part of all ecosystems and without the microbial activity, sustainability of ecosystems is impossible. Environmental pollutants exert huge selection pressure on environmental microbial community and eventually cause the evolution of genetically stable determinants. Scientific contributions in the last two decades has strengthened our knowledge of extensively drug resistant variants of microbes, intrinsic and acquired resistance among microbes, and the exchange of the genetic information between them. Understanding of environmental resistance among microbes, scientific researches directly link two different field viz., medical and environmental microbiology. Bacterial species such as Acinetobacter baumannii, Bacillus cereus, and Escherichia coli are reported to have resistance against both, the toxic metals and antibiotics. This paper reviews the development of environmental resistance among microbes having resistance to antibiotics along with the gist of associated environmental risk.
Double Linear Gradient Biointerfaces for Determining Two‐Parameter Dependent Stem Cell Behavior
Authors: Kühn Philipp T. , Zhou Qihui , van der Boon Torben A. B. , Schaap‐Oziemlak Aneta M. , van Kooten Theo G. , van Rijn Patrick
Published: February 2016

Two‐parameter contributions of stiffness and wettability display altered behavior of hBM‐MSCs as compared to solely investigating the wettability of the biointerface with a homogenous stiffness. The importance of double parameter influence is identified by using newly developed double linear wettability–stiffness gradients. The interfaces show that substrate stiffness can influence cell adhesion and spreading both positively and negatively in combination with wettability. This effect is validated by decoupling the stiffness gradient using a wettability gradient composed of a monolayer on glass ensuring a homogenous stiffness.
The Self‐Assembly of Helical Peptide Building Blocks
Authors: Mondal Sudipta , Gazit Ehud
Published: February 2016

The self‐assembly of peptide building blocks represents a central direction in bionanotechnology. A β‐sheet secondary structure serves as the basis of numerous peptide‐based bionanomaterials owing to their association with several neurodegenerative diseases. Although the α‐helix embodies the most common secondary structure motif in proteins, the utilization of this module as a building block for supramolecular aggregation is much less explored. In this Focus Review, we will discuss the advancement made so far to induce higher level organization in helical peptide building blocks. The primary design strategies involving coiled coil proteins mimetic approaches, incorporation of noncoded and synthetic amino acids and conjugation of peptides to aliphatic alkyl tails will be dealt with in detail. In parallel, we will also outline the self‐assembled materials developed in these progressions. Finally, possible future prospects of such assembly modules will be briefed.
Femtosecond Stimulated Raman Spectroscopy
Authors: Dietze Daniel R. , Mathies Richard A.
Published: February 2016

Femtosecond stimulated Raman spectroscopy (FSRS) is an ultrafast nonlinear optical technique that provides vibrational structural information with high temporal (sub‐50 fs) precision and high spectral (10 cm−1) resolution. Since the first full demonstration of its capabilities ≈15 years ago, FSRS has evolved into a mature technique, giving deep insights into chemical and biochemical reaction dynamics that would be inaccessible with any other technique. It is now being routinely applied to virtually all possible photochemical reactions and systems spanning from single molecules in solution to thin films, bulk crystals and macromolecular proteins. This review starts with an historic overview and discusses the theoretical and experimental concepts behind this technology. Emphasis is put on the current state‐of‐the‐art experimental realization and several variations of FSRS that have been developed. The unique capabilities of FSRS are illustrated through a comprehensive presentation of experiments to date followed by prospects.
Do seasonal patterns of rat snake (Pantherophis obsoletus) and black racer (Coluber constrictor) activity predict avian nest predation?
Authors: DeGregorio Brett A. , Weatherhead Patrick J. , Ward Michael P. , Sperry Jinelle H.
Published: February 2016

Avian nest success often varies seasonally and because predation is the primary cause of nest failure, seasonal variation in predator activity has been hypothesized to explain seasonal variation in nest success. Despite the fact that nest predator communities are often diverse, recent evidence from studies of snakes that are nest predators has lent some support to the link between snake activity and nest predation. However, the strength of the relationship has varied among studies. Explaining this variation is difficult, because none of these studies directly identified nest predators, the link between predator activity and nest survival was inferred. To address this knowledge gap, we examined seasonal variation in daily survival rates of 463 bird nests (of 17 bird species) and used cameras to document predator identity at 137 nests. We simultaneously quantified seasonal activity patterns of two local snake species (N = 30 individuals) using manual (2136 snake locations) and automated (89,165 movements detected) radiotelemetry. Rat snakes (Pantherophis obsoletus), the dominant snake predator at the site (~28% of observed nest predations), were most active in late May and early June, a pattern reported elsewhere for this species. When analyzing all monitored nests, we found no link between nest predation and seasonal activity of rat snakes. When analyzing only nests with known predator identities (filmed nests), however, we found that rat snakes were more likely to prey on nests during periods when they were moving the greatest distances. Similarly, analyses of all monitored nests indicated that nest survival was not linked to racer activity patterns, but racer‐specific predation (N = 17 nests) of filmed nests was higher when racers were moving the greatest distances. Our results suggest that the activity of predators may be associated with higher predation rates by those predators, but that those effects can be difficult to detect when nest predator communities are diverse and predator identities are not known. Additionally, our results suggest that hand‐tracking of snakes provides a reliable indicator of predator activity that may be more indicative of foraging behavior than movement frequency provided by automated telemetry systems.
Differential responses of cryptic bat species to the urban landscape
Authors: Lintott Paul R. , Barlow Kate , Bunnefeld Nils , Briggs Philip , Gajas Roig Clara , Park Kirsty J.
Published: February 2016

Urbanization is a key global driver in the modification of land use and has been linked to population declines even in widespread and relatively common species. Cities comprise a complex assortment of habitat types yet we know relatively little about the effects of their composition and spatial configuration on species distribution. Although many bat species exploit human resources, the majority of species are negatively impacted by urbanization. Here, we use data from the National Bat Monitoring Programme, a long‐running citizen science scheme, to assess how two cryptic European bat species respond to the urban landscape. A total of 124 × 1 km2 sites throughout Britain were surveyed. The landscape surrounding each site was mapped and classified into discrete biotope types (e.g., woodland). Generalized linear models were used to assess differences in the response to the urban environment between the two species, and which landscape factors were associated with the distributions of P. pipistrellus and P. pygmaeus. The relative prevalence of P. pygmaeus compared to P. pipistrellus was greater in urban landscapes with a higher density of rivers and lakes, whereas P. pipistrellus was frequently detected in landscapes comprising a high proportion of green space (e.g., parklands). Although P. pipistrellus is thought to be well adapted to the urban landscape, we found a strong negative response to urbanization at a relatively local scale (1 km), whilst P. pygmaeus was detected more regularly in wooded urban landscapes containing freshwater. These results show differential habitat use at a landscape scale of two morphologically similar species, indicating that cryptic species may respond differently to anthropogenic disturbance. Even species considered relatively common and well adapted to the urban landscape may respond negatively to the built environment highlighting the future challenges involved in maintaining biodiversity within an increasingly urbanized world.
Tolerance to multiple climate stressors: a case study of Douglas‐fir drought and cold hardiness
Authors: Bansal Sheel , Harrington Constance A. , St. Clair John Bradley
Published: February 2016

Drought and freeze events are two of the most common forms of climate extremes which result in tree damage or death, and the frequency and intensity of both stressors may increase with climate change. Few studies have examined natural covariation in stress tolerance traits to cope with multiple stressors among wild plant populations.

We assessed the capacity of coastal Douglas‐fir (Pseudotsuga menziesii var. menziesii), an ecologically and economically important species in the northwestern USA, to tolerate both drought and cold stress on 35 populations grown in common gardens. We used principal components analysis to combine drought and cold hardiness trait data into generalized stress hardiness traits to model geographic variation in hardiness as a function of climate across the Douglas‐fir range.

Drought and cold hardiness converged among populations along winter temperature gradients and diverged along summer precipitation gradients. Populations originating in regions with cold winters had relatively high tolerance to both drought and cold stress, which is likely due to overlapping adaptations for coping with winter desiccation. Populations from regions with dry summers had increased drought hardiness but reduced cold hardiness, suggesting a trade‐off in tolerance mechanisms.

Our findings highlight the necessity to look beyond bivariate trait–climate relationships and instead consider multiple traits and climate variables to effectively model and manage for the impacts of climate change on widespread species.
Tackling intraspecific genetic structure in distribution models better reflects species geographical range
Authors: Marcer Arnald , Méndez‐Vigo Belén , Alonso‐Blanco Carlos , Picó F. Xavier
Published: February 2016

Genetic diversity provides insight into heterogeneous demographic and adaptive history across organisms’ distribution ranges. For this reason, decomposing single species into genetic units may represent a powerful tool to better understand biogeographical patterns as well as improve predictions of the effects of GCC (global climate change) on biodiversity loss. Using 279 georeferenced Iberian accessions, we used classes of three intraspecific genetic units of the annual plant Arabidopsis thaliana obtained from the genetic analyses of nuclear SNPs (single nucleotide polymorphisms), chloroplast SNPs, and the vernalization requirement for flowering. We used SDM (species distribution models), including climate, vegetation, and soil data, at the whole‐species and genetic‐unit levels. We compared model outputs for present environmental conditions and with a particularly severe GCC scenario. SDM accuracy was high for genetic units with smaller distribution ranges. Kernel density plots identified the environmental variables underpinning potential distribution ranges of genetic units. Combinations of environmental variables accounted for potential distribution ranges of genetic units, which shrank dramatically with GCC at almost all levels. Only two genetic clusters increased their potential distribution ranges with GCC. The application of SDM to intraspecific genetic units provides a detailed picture on the biogeographical patterns of distinct genetic groups based on different genetic criteria. Our approach also allowed us to pinpoint the genetic changes, in terms of genetic background and physiological requirements for flowering, that Iberian A. thaliana may experience with a GCC scenario applying SDM to intraspecific genetic units.
Resource quality affects weapon and testis size and the ability of these traits to respond to selection in the leaf‐footed cactus bug,Narnia femorata
Authors: Sasson Daniel A. , Munoz Patricio R. , Gezan Salvador A. , Miller Christine W.
Published: February 2016

The size of weapons and testes can be central to male reproductive success. Yet, the expression of these traits is often extremely variable. Studies are needed that take a more complete organism perspective, investigating the sources of variation in both traits simultaneously and using developmental conditions that mimic those in nature. In this study, we investigated the components of variation in weapon and testis sizes using the leaf‐footed cactus bug,Narnia femorata(Hemiptera: Coreidae) on three natural developmental diets. We show that the developmental diet has profound effects on both weapon and testis expression and scaling. Intriguingly, males in the medium‐quality diet express large weapons but have relatively tiny testes, suggesting complex allocation decisions. We also find that heritability, evolvability, and additive genetic variation are highest in the high‐quality diet for testis and body mass. This result suggests that these traits may have an enhanced ability to respond to selection during a small window of time each year when this diet is available. Taken together, these results illustrate that normal, seasonal fluctuations in the nutritional environment may play a large role in the expression of sexually selected traits and the ability of these traits to respond to selection.
Population‐level responses of life history traits to flow regime in three common stream fish species
Authors: Bennett Micah G. , Whiles Matt R. , Whitledge Gregory W.
Published: February 2016

Trait‐based approaches may improve understanding in ecology by linking environmental variation to fitness‐related characteristics of species. Most trait–environment studies focus on assemblage‐level relationships; yet intraspecific trait variation is important for community, ecosystem, and evolutionary processes, and has substantial implications for these approaches. Assessing population‐level trait–environment relationships could test the generality of trait models whilst assessing intraspecific variation. We evaluated the generality of the trilateral life history model (TLHM opportunistic, periodic, and equilibrium endpoints) for fishes – a well‐studied trait–environment model at the assemblage level – to populations of three stream fishes in the Midwestern United States in relation to flow regime. The TLHM adequately described major trade‐offs in traits amongst populations in all species. Some TLHM flow‐based predictions were confirmed, with periodic traits (high fecundity) favoured at sites with greater flow seasonality and lower flow variability in two species, and equilibrium traits (large eggs) in more stable flow conditions in two species. Size at maturity was also inversely related to variability in one species. However, relationships contradicting the TLHM were also found. Coupled with the explanatory power of the TLHM for populations, supporting relationships suggest that synthesizing habitat template models with demographic life history theory could be valuable. Trait–environment models that are well‐supported at multiple levels of biological organization could improve understanding of the impacts of environmental change on populations and communities and the valuable ecosystem services that they support. Copyright © 2016 John Wiley & Sons, Ltd.
On‐chip generation of monodisperse giant unilamellar lipid vesicles containing quantum dots
Authors: Park Youn‐Hee , Lee Do‐Hyun , Um Eujin , Park Je‐Kyun
Published: February 2016

Monodispersed lipid vesicles have been used as a drug delivery vehicle and a biochemical reactor. To generate monodispersed lipid vesicles in the nano‐ to micrometer size range, an extrusion step should be included in conventional hand‐shaking method of lipid vesicle synthesis. In addition, lipid vesicles as a drug carrier still need to be improved to effectively encapsulate concentrated biomolecules such as cells, proteins, and target drugs. To overcome these limitations, this paper reports a new microfluidic platform for continuous synthesis of small‐sized (∼10 μm) giant unilamellar vesicles (GUVs) containing quantum dots (QDs) as a nanosized model drug. To generate GUVs, we introduced an additional cross‐flow to break vesicles into small size. 1,2 ‐ dimyristoyl‐sn‐glycero ‐ 3 ‐ phosphocholine (DMPC) in an octanol–chloroform mixture was used in the construction of self‐assembled membrane. Consequently, we have successfully demonstrated the fabrication of monodispersed GUVs with 7−12 μm diameter containing QDs. The proposed synthesis method of cell‐sized GUVs would be highly desirable for applications such as multipurpose drug encapsulation and delivery.
Rainfall‐triggered shallow landslides: infiltration dynamics in a physical hillslope model
Authors: Lora M. , Camporese M. , Troch P. A. , Salandin P.
Published: February 2016

In this study, we investigate the triggering of shallow landslides through the analysis of physical experiments performed in an artificial hillslope. The physical model consists of a reinforced concrete box containing a soil prism with maximum height of 3.5 m, length of 6 m, and width of 2 m. In order to analyse and examine the factors leading to the failure and the triggering modes, the hillslope is equipped with sensors to monitor the pore water pressure and moisture content response to rainfall in a 60 cm thick sand layer overlying a sandy clay soil. Two experiments were performed with different degrees of the sand initial compaction, to investigate the role of porosity on the hydrologic response and the subsequent failure. The experimental results showed that, with initially loose sand, the failure occurred suddenly, without premonitory signs, the soil behaving like a viscous fluid. The collected data showed a rapid increase of the water pressure contextual to the failure of the sand layer. In the second experiment, with initially dense sand, three levels of instability were observed: (i) abundant runoff with limited erosion of the ground surface; (ii) local slip detachments involving a soil thickness of few centimetres; and (iii) a slow advancement of the entire sand layer volume. The hydrologic dynamics observed in the landslide experiments were simulated with numerical solutions of the Richards equation. The results of the simulations agree well with the experiments for the loose sand, while for the dense sand the comparison between experimental and numerical results shows some limitations related to the assumptions of single phase and rigid soil matrix implicit in the Richards equation. Copyright © 2016 John Wiley & Sons, Ltd.
Modelling water, nutrients, and organic carbon in forested catchments: a HYPE application
Authors: Pers Charlotta , Temnerud Johan , Lindström Göran
Published: February 2016

Both monitoring and model simulation are useful for understanding and detecting changes in the environment. To understand and simulate leaching in small forested catchments, it is important to have knowledge of soil processes. Here, we describe recent development of the Hydrological Predictions for the Environment (HYPE) model for forested catchments. HYPE includes an organic carbon (OC) variable in addition to previously published nitrogen (N), phosphorus (P), and water flow models. The aspects addressed in the current study included P concentrations under low‐flow conditions and high concentrations of inorganic N. HYPE was further developed based on nine small forested catchments (0.5–200 ha) in Sweden, which were calibrated separately using local data. The model (excluding the OC variable) was tested on a larger set of forest catchments from the operational HYPE model of Sweden (S‐HYPE). We observed the following: (1) dissolved organic P could make a significant contribution to the total P concentration in a stream during low‐flow periods, (2) the inorganic N concentration simulated in a stream improved when part of the atmospheric N was retained in the soil, (3) the soil flow path formulation was critical for simulating concentration dynamics, and (4) evaluating an additional variable (OC) further elucidated the soil runoff processes in the model. Copyright © 2016 Swedish Meteorological and Hydrological Institute. Hydrological Processes published by John Wiley & Sons, Ltd.
MRI and histopathologic study of a novel cholesterol‐fed rabbit model of xanthogranuloma
Authors: Chen Yuanxin , Hamilton Amanda M. , Parkins Katie M. , Wang Jian‐Xiong , Rogers Kem A. , Zeineh Michael M. , Rutt Brian K. , Ronald John A.
Published: February 2016

Purpose

To develop a rabbit model of xanthogranuloma based on supplementation of dietary cholesterol. The aim of this study was to analyze the xanthogranulomatous lesions using magnetic resonance imaging (MRI) and histological examination.

Materials and Methods

Rabbits were fed a low‐level cholesterol (CH) diet (n = 10) or normal chow (n = 5) for 24 months. In vivo brain imaging was performed on a 3T MR system using fast imaging employing steady state acquisition, susceptibility‐weighted imaging, spoiled gradient recalled, T1‐weighted inversion recovery imaging and T1 relaxometry, PD‐weighted and T2‐weighted spin‐echo imaging and T2 relaxometry, iterative decomposition of water and fat with echo asymmetry and least‐squares estimation, ultrashort TE MRI (UTE‐MRI), and
relaxometry. MR images were evaluated using a Likert scale for lesion presence and quantitative analysis of lesion size, ventricular volume, and T1, T2, and
values of lesions was performed. After imaging, brain specimens were examined using histological methods.

Results

In vivo MRI revealed that 6 of 10 CH‐fed rabbits developed lesions in the choroid plexus. Region‐of‐interest analysis showed that for CH‐fed rabbits the mean lesion volume was 8.5 ± 2.6 mm3 and the volume of the lateral ventricle was significantly increased compared to controls (P < 0.01). The lesions showed significantly shorter mean T2 values (35 ± 12 msec, P < 0.001), longer mean T1 values (1581 ± 146 msec, P < 0.05), and shorter
values (22 ± 13 msec, P < 0.001) compared to adjacent brain structures. The ultrashort
components were visible using UTE‐MRI. Histopathologic evaluation of lesions demonstrated features of human xanthogranuloma.

Conclusion

Rabbits fed a low‐level CH diet develop sizable intraventricular masses that have similar histopathological features as human xanthogranuloma. Multiparametric MRI techniques were able to provide information about the complex composition of these lesions. J. Magn. Reson. Imaging 2016;44:673–682.
Encapsulation of (−)‐epigallocatechin gallate into liposomes and into alginate or chitosan microparticles reinforced with liposomes
Authors: Istenič Katja , Cerc Korošec Romana , Poklar Ulrih Nataša
Published: February 2016

BACKGROUND

(−)‐Epigallocatechin gallate (EGCG) was encapsulated into liposomes that were further incorporated into alginate and chitosan microparticles. The stability of free and encapsulatedEGCGin all three systems was evaluated at differentpHvalues and in fruit nectar. Furthermore, the interactions betweenEGCGand the compounds of the microparticles were studied using Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC).

RESULTS

All three encapsulation systems showed high encapsulation efficiency (>97%) and sustained release; in 14 days, no more than 15% ofEGCGwas released. The encapsulation systems successfully protectedEGCGagainst degradation at alkalinepH. For non‐encapsulatedEGCG, >70% was degraded after 14 days, while there was no significant degradation of encapsulatedEGCGin these three systems. In fruit nectar, >30% of non‐encapsulatedEGCGwas degraded in 14 days, while only 6% ofEGCGencapsulated into liposomes or chitosan microparticles reinforced with liposomes was degraded at that time. TheDSCandFTIRanalyses showed that the main interactions occurred between the liposomes and theEGCG.

CONCLUSION

This study demonstrates that liposomes as well as alginate and chitosan microparticles reinforced with liposomes have the potential to enhanceEGCGstability in food products during storage. © 2016 Society of Chemical Industry
Advances in genomics for the improvement of quality in coffee
Authors: Tran Hue TM , Lee L Slade , Furtado Agnelo , Smyth Heather , Henry Robert J
Published: February 2016

Coffee is an important crop that provides a livelihood to millions of people living in developing countries. Production of genotypes with improved coffee quality attributes is a primary target of coffee genetic improvement programmes. Advances in genomics are providing new tools for analysis of coffee quality at the molecular level. The recent report of a genomic sequence for robusta coffee, Coffea canephora, is a major development. However, a reference genome sequence for the genetically more complex arabica coffee (C. arabica) will also be required to fully define the molecular determinants controlling quality in coffee produced from this high quality coffee species. Genes responsible for control of the levels of the major biochemical components in the coffee bean that are known to be important in determining coffee quality can now be identified by association analysis. However, the narrow genetic base of arabica coffee suggests that genomics analysis of the wild relatives of coffee (Coffea spp.) may be required to find the phenotypic diversity required for effective association genetic analysis. The genomic resources available for the study of coffee quality are described and the potential for the application of next generation sequencing and association genetic analysis to advance coffee quality research are explored. © 2016 Society of Chemical Industry
Power pole density informs spatial prioritization for mitigating avian electrocution
Authors: Dwyer James F. , Harness Rick E. , Gerber Brian D. , Landon Melissa A. , Petersen Paul , Austin Daryl D. , Woodbridge Brian , Williams Gary E. , Eccleston Duncan
Published: February 2016

Raptor and corvid electrocutions cause continental conservation concerns for breeding, migrating, and wintering birds. Although concerns are widespread, mitigation is implemented primarily at local scales of individual electric utilities. By not considering landscape‐scale patterns, conservation strategies may fail to focus mitigation where efforts are needed most. To enable resource managers to consider electrocution risk at larger scales, we developed a regional model of distribution power pole (pole) density in a grid of 1‐km2cells throughout Colorado and Wyoming. To do so, we obtained data on pole locations from a sample of electric utilities covering 31% of Colorado and Wyoming, and developed a predictive model of poles throughout the remainder of the 2 states. Pole density was influenced by road lengths, number of oil and gas wells, slope, development, and land cover. Poles were densest in areas with high road lengths, high numbers of wells, and relatively flat terrain, and in areas developed for agriculture or human residences. When model predictions are viewed together with species‐specific habitat maps, locations where high pole densities overlap habitat suggest areas where mitigating electrocution risk could be prioritized. Communication between resource managers and local utilities could then clarify the poles that caused the highest risk to raptors from electrocution. Thus, the model provides a framework for systematic spatial prioritization in support of regional conservation planning to minimize electrocution of raptors and corvids. © 2016 The Wildlife Society.
d‐Allulose supplementation normalized the body weight and fat‐pad mass in diet‐induced obese mice via the regulation of lipid metabolism under isocaloric fed condition
Authors: Han Youngji , Han Hye Jin , Kim Ae‐Hyang , Choi Ji‐Young , Cho Su‐Jung , Park Yong Bok , Jung Un Ju , Choi Myung‐Sook
Published: February 2016

Scope

A number of findings suggest that zero‐calorie d‐allulose, also known as d‐psicose, has beneficial effects on obesity‐related metabolic disturbances. However, it is unclear whether d‐allulose can normalize the metabolic status of diet‐induced obesity without having an impact on the energy density. We investigated whether 5% d‐allulose supplementation in a high fat diet(HFD) could normalize body fat in a diet‐induced obesity animal model under isocaloric pair‐fed conditions.

Methods and results

Mice were fed an HFD with or without various sugar substitutes (d‐glucose, d‐fructose, erytritol, or d‐allulose, n = 10 per group) for 16 wk. Body weight and fat‐pad mass in the d‐allulose group were dramatically lowered to that of the normal group with a simultaneous decrease in plasma leptin and resistin concentrations. d‐allulose lowered plasma and hepatic lipids while elevating fecal lipids with a decrease in mRNA expression of CD36, ApoB48, FATP4, in the small intestine in mice. In the liver, activities of both fatty acid synthase and β‐oxidation were downregulated by d‐allulose to that of the normal group; however, in WAT, fatty acid synthase was decreased while β‐oxidation activity was enhanced.

Conclusion

Taken together, our findings suggest that 5% dietary d‐allulose led to the normalization of the metabolic status of diet‐induced obesity by altering lipid‐regulating enzyme activities and their gene‐expression level along with fecal lipids.
Accelerating method of moments based package‐board 3D parasitic extraction using FPGA
Authors: Devi Anant , Gandhi Maulik , Varghese Kuruvilla , Gope Dipanjan
Published: February 2016

In this article, a Field Programmable Gate Array (FPGA)‐based hardware accelerator for 3D electromagnetic extraction, using Method of Moments (MoM) is presented. As the number of nets or ports in a system increases, leading to a corresponding increase in the number of right‐hand‐side (RHS) vectors, the computational cost for multiple matrix‐vector products presents a time bottleneck in a linear‐complexity fast solver framework. In this work, an FPGA‐based hardware implementation is proposed toward a two‐level parallelization scheme: (i) matrix level parallelization for single RHS and (ii) pipelining for multiple‐RHS. The method is applied to accelerate electrostatic parasitic capacitance extraction of multiple nets in a Ball Grid Array (BGA) package. The acceleration is shown to be linearly scalable with FPGA resources and speed‐ups over 10× against equivalent software implementation on a 2.4 GHz Intel Core i5 processor is achieved using a Virtex‐6 XC6VLX240T FPGA on Xilinx's ML605 board with the implemented design operating at 200 MHz clock frequency. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:776–783, 2016
K band class‐C MESFET based frequency quadrupler with highly selective SIW bandpass filter for inter satellite communication
Authors: Patel Romil , Patel Amit
Published: February 2016

This article presents the single stage active frequency quadrupler design for generating a tone in the K band (23.5 GHz) frequency range using GaAs MESFET device. Harmonics current generation characteristics of GaAs MESFET (NE900000) is modeled and analyzed in reference with gate voltage. Based on this, its optimum operating class‐C is decided for its application as a frequency quadrupler. Using this model and introducing resonator (Idler) based harmonic rejection techniques, a narrowband −0.310 dBm output power ×4 frequency multiplier from C‐band to K‐band implemented using 0.5 μm GaAs MESFET. As the device operated in class‐C operating condition, it produces harmonics content due to clipping of output signal. At the output of the proposed multiplier design, a highly selective surface integrated waveguide (SIW) based bandpass filter (with Q is better than 120) is attached, which provides excellent rejection of fundamental component (>90 dBc) and other harmonics assuring minimum rejection of 30 dBc. The proposed design consumes 60 mW power and provides ∼−7 dB conversion gain with input power having 7 dBm. Feasibility and layout geometry of the proposed design has been evaluated and simulated on the substrate RT‐Duroid5880 using Agilent ADS software. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:767–776, 2016
Wavelength‐resolved measurement of gain recovery in an erbium‐doped fiber amplifier
Authors: Kuroda Keiji , Yoshikuni Yuzo
Published: February 2016

We report on wavelength‐resolved measurements of gain recovery in an erbium‐doped fiber amplifier using a wavelength‐selectable distributed feedback (DFB) laser as a light source. Recovery profiles of the gain are obtained for a wavelength range from 1528 to 1559 nm by applying a single‐wavelength pump‐probe method. Although the recovery time slightly decreases as the wavelength increases, it is nearly constant over the measured wavelength range. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:751–754, 2016
Antenna with three dimensional 3D printed substrates
Authors: Patel S. S. , Garcia Zuazola I. J. , Whittow W. G.
Published: February 2016

In this letter, 3D printing technology is used to modify the substrate shape with the aim of modifying the antenna's performance. The antenna substrate is made using a 3D printer and commercially available materials. A ridge near the center of the patch has been used to downshift the resonant frequency of the antenna. The effect of the ridge shape has been investigated via simulations and measurements. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:741–744, 2016
Antennas on paper using ink‐jet printing of nano‐silver particles for wireless sensor networks in train environment
Authors: Dancila Dragos , Moossavi Reza , Siden Johan , Zhang Zhibin , Rydberg Anders
Published: February 2016

This article presents the design, manufacturing, and measurements of antennas on paper, realized using ink‐jet printing of conductive inks based on nano‐silver particles (nSPs). The extraction of the substrate characteristics such as the dielectric constant and dielectric loss is performed using a printed ring resonator technique. The characterization of the nSPs conductive inks assesses different parameters as sintering time and temperature. Two antennas are realized corresponding to the most common needs for wireless sensor networks in Trains Environment. The first one is a patch antenna characterized by a broadside radiation pattern and suited for operation on metallic structures. The second one is a quasi‐yagi antenna, with an end fire radiation pattern and higher directivity, without requiring a metallic ground plane. Both antennas present a good matching (S11 < −20 dB and S11 < −30 dB, respectively) and acceptable efficiency (55% and 45%, respectively) for the paper substrate used at the center frequency of 2.4 GHz, corresponding to the first channel of the IEEE 802.15.4 band. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:754–759, 2016
Compact MIMO antenna for Bluetooth, WiMAX, WLAN, and UWB applications
Authors: Huang Hui‐Fen , Xiao Shu‐Guang
Published: February 2016

This paper presents a compact multiple‐input‐multiple‐output (MIMO) antenna for wireless portable device applications. It entirely covers the Bluetooth (2.4–2.484 GHz), Worldwide Interoperability for Microwave Access (WiMAX) (3.4–3.69 GHz), Wireless Local Area Network (WLAN) (5.15–5.825 GHz), and ultra‐wideband (UWB) (3.1–10.6 GHz) operating bands. This antenna consists of two planar polygon printed monopole(PM) antennas, a rectangular slot and a triangular trim on the antenna element to lower down the low‐cutoff frequency for improving the impedance matching, and a stepped ground stub to improve the isolation. Two rounded corners are simultaneously used on the ground for the impedance matching at medium‐high frequency. The results of simulation and measurement prove that the −10 dB bandwidth of this antenna is from 2.4 to 11 GHz, and the isolation is less than −15 dB in the entire band, which can satisfy the actual requirements according to most literatures. The envelope correlation coefficient is less than 0.02. The size of this antenna array is 40 × 36 mm2. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:783–787, 2016
A MEMS microwave phase detector with broadband performance operable at X‐band
Authors: Han Juzheng , Liao Xiaoping
Published: February 2016

This letter presents the design, fabrication, and measurement of a broadband MEMS microwave phase detector for X‐band, 8–12 GHz. In order to realize the broadband performance, a two‐section power combiner is designed and utilized for the configuration of the phase detector. Stable sensitivities of phase detection are revealed by measurements within the bandwidth 8–12 GHz. The sensitivities are all better than 7.1, 22.1, 33.4, 42.0, and 51.2 mV/mW at 10, 50, 100, 150, and 200 mW input power, respectively. Moreover, the discrepancies are less than 1.8, 5.1, 7.3, 9.3, and 10.9 mV/mW at the above powers for different frequencies. The measured output voltage versus the phase difference at 200 mW, 10 GHz is normalized and compared to the theoretical value. The relative error is less than 8.5%. The response times of this presented phase detector are also obtained by measurement. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:806–809, 2016
Compact varactor‐tuned dual‐mode filter with center frequency and bandwidth control
Authors: Zhao Xiao‐Min , Wu Qiu‐Yi , Liu Xiang‐Jun , Shi Xiao‐Wei
Published: February 2016

This article presents a novel compact tunable bandpass filter (BPF) with center frequency and bandwidth control based on open‐circuited stub‐loaded half‐wavelength resonator (SLR). Analyses of frequency and bandwidth tunable of the proposed resonators and external quality factor implemented by tunable J inverter to gain a stable filtering performance are discussed. Both theory and experiment are provided to validate the proposed filter. From the experimental results, it is found that the proposed filter can keep a constant bandwidth over the frequency tuning range with an insertion loss of less than 0.9 dB and increase the 1‐dB bandwidth from 120 MHz to 430 MHz when center frequency locates at 1.3 GHz with an insertion loss of 0.5–1.7 dB. Simulation and measurements are in excellent agreement. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:803–806, 2016
Effects of taper parameters on free spectral range of non‐adiabatic tapered optical fibers for sensing applications
Authors: Musa B. , Mustapha Kamil Y. , Abu Bakar M. H. , Noor A. S. M. , Ismail A. , Mahdi M. A.
Published: February 2016

We investigated the effects of taper parameters on the free spectral range of transmission spectrum of non‐adiabatic tapers. From experimental results, the optimum profile for the tapered fiber in terms of taper angle, waist diameter, and length are 11.500 mrad, 10 μm, and 20 mm, respectively. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:798–803, 2016
Reconfigurable active integrated antenna with log‐periodic matching network structures and reduced PIN diodes for WLAN/WiMAX applications
Authors: Mazloum Jalil
Published: February 2016

A novel reconfigurable active integrated antenna for WiMAX/WLAN applications is presented. By using a radiating patch with a pair of folded microstrip arms in the active feedback antenna two new resonances can be achieved. Also a novel reconfigurable low noise amplifier (RLNA) with log‐Periodic matching network structures and reduced PIN diode for WiMAX/WLAN applications is presented. By using new design of dual output matching network and reduced pin diode, a novel design of the RLNA is performed. In ordinary way to switch between two frequencies, we need two pin diodes in input matching networks, and two pin diodes in output matching network. But for the first time, in this article by using dual‐band matching network and log‐periodic relationship between matching networks lengths, we reduced number of pin diodes from four to one. By using the [S] parameters of the active element, a novel design of the microwave oscillator is performed. Simulated and experimental results obtained for this antenna show that the proposed Active Integrated Antenna (AIA) has a good return loss and radiation behavior within the WiMAX/WLAN frequency range. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:787–791, 2016
Miniaturized planar ultra‐wideband slot antenna with an interference suppressing capability
Authors: Masoumi Masoume , Amiri Zhaleh , Ghaedi Farshad , Sahraban Amene , Hayati Soghra , shokry Majed , Virdee Bal.S
Published: February 2016

A microstrip‐fed ultra‐wideband printed monopole antenna is presented in this article. The advantages of this miniaturized antenna are capability to eliminate the interference from wireless local area network (WLAN) frequency band and wide impedance bandwidth (IBW). To provide an ultra‐wideband of 124.55% (3.05–13.12GHz) simply the aperture of ground plane is adjusted. Furthermore by embedding a pair of T‐shaped stubs (PTSS) in the slot a band notched from 4.98 GHz to 5.96 GHz is realized. These functionalities are obtained while the total dimension of the antenna was 20 × 18 × 1.6 mm3. In this article analysis of antenna parameters like radiation characteristics, survey of surface currents and antenna gain will be presented. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:813–817, 2016
Analysis of a microstrip antenna with variation on substrate PBG hexagonal
Authors: Guimarães Ádller de O. , da Silva José P. , Pereira Jonathan P. P.
Published: February 2016

In this article, we analyzed the influence of a photonic band gap (PBG) substrate on the radiation properties of microstrip antenna with a rectangular patch. Antenna parameters as the return loss (S11), bandwidth, gain and electric field density were analyzed. The proposed PBG structure presents three different settings, with variation in the diameter of the air holes printed on dielectric substrate. The obtained results showed a better performance in the parameters of the PBG antenna when compared with the reference antenna and have been validated experimentally by measuring the return loss in function of the operating frequency, obtained from the construction of prototypes. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:826–831, 2016
Dual‐band differential filter with complete band independence
Authors: Corona‐Chavez Alonso , Kataria Tejinder Kaur , Olvera‐Cervantes Jose Luis
Published: February 2016

In this article a novel dual band filter was presented for differential mode operation. In this design, there is complete design independence between both bands. It will be shown that the filters can be designed independently and then merged together to form the final structure. A dual band filter is presented with experimental and simulated results showing good agreement. This circuit was suitable for two‐dimensional fabrication without crossovers. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:864–868, 2016
A new model of metasurface used for linear‐to‐circular polarization conversion in antenna array
Authors: Montalvão Emanuele S. R. , Montalvão Augusto C. P. S. , Campos Antonio L. P. S. , Gomes Neto Alfredo
Published: February 2016

In this article, the authors propose a new model of metasurface able to convert linearly polarized signals in circularly polarized signals for a planar antenna array designed to operate at the ISM frequency band (2.45 GHz). All simulated results were obtained using the Ansoft HFSS™ software. The prototypes were produced and their transmission characteristics were measured. A good agreement between simulated and measured results was obtained. The proposed structure presents a linear‐to‐circular polarization conversion feature, with good bandwidth and axial ratio. Besides, the structure is simple and maintains the advantages of low profile and low cost. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:861–864, 2016
A skewed omega for LHM characteristics
Authors: Panda Asit K. , Mishra Rabindra K. , Sahu Sudhakar
Published: February 2016

This letter reports numerical and experimental study on a concentric‐edge‐coupled low‐loss MTM structure composed of concentric skewed omega inclusion and capacitive strip wire unit cells for DNG behavior via transmission and reflection characteristics. Modified NRW method provides effective medium parameters, refractive index, and the dispersion characteristic from simulated S‐parameters. It is shown that this MTM exhibits DNG behavior over 3.65–4.53 GHz band. It also investigates the effect of geometrical parameters, like strip width, slit gap, length and width of each side, and arc length on magnetic resonant frequency. Incidence of perpendicularly polarized electromagnetic wave on a host medium embedding metallic skewed omega inclusions interact shows negative material parameters for the composite media in the frequency band of interest. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:847–850, 2016