bluuebunny/crossref_metadata_2025 huggingface dataset:
Particle capture efficiency of different-aged needles of Norway spruce under moderate and severe drought
Authors: Räsänen Janne V. , Holopainen Toini , Joutsensaari Jorma , Pasanen Pertti , Kivimäenpää Minna
Published: May 2014

Trees can remove particulate matter from the atmosphere, improving air quality and providing ecosystem services. Particle removal capacity is known to differ between tree species, but the influence of environmental factors on the removal capacity is still unclear. In this study, we measured particle capture efficiency (Cp) of Norway spruce (Picea abies (L.) Karst.) in wind tunnel experiments under three watering treatments (well watered, moderate drought, and severe drought) and determined needle characteristics (stomatal conductance and density, wax condition, and needle area) that affect particle uptake. Trees were exposed in the wind tunnel to 0.7 μm (geometric mean diameter) NaCl particles with a mass concentration of 1 mg·m−3, and the Cp of the tree was determined for the current-year (C) and previous-year (C+1) needles. Overall, the Cp was significantly higher for C+1 needles than for C needles for all watering treatments. There was also a trend for higher Cp of C+1 needles of less watered trees, but this was not observed for C needles. We suggest that greater erosion of the wax layer of C+1 needles compared with C needles increases hydrophilicity of the C+1 needle surface and this, in interaction with low stomatal conductance, led to the higher Cp.
Laboratory gas injection tests of compacted bentonite buffer material for TRU waste disposal
Authors: Namiki Kazuto , Asano Hidekazu , Takahashi Shinichi , Shimura Tomoyuki , Hirota Ken
Published: May 2014

The Radioactive Waste Management Funding and Research Center (RWMC) is leading a research programme to evaluate the gas transport mechanisms through a TRU (TRans-Uranium) waste disposal facility in Japan and acquire information on gas migration properties. In this paper we describe a series of laboratory gas injection tests using the bentonite adopted for use in Japanese TRU disposal, as well as an attempted visualization of the gas migration path inside the bentonite used as a buffer. By building a conceptual model from the results of these tests, the characteristics of gas migration through to breakthrough for bentonite can now be better understood in the context of Japanese TRU disposal. Thanks to the outcome of this research project, advanced knowledge may be applied to the conceptualization of TRU waste disposal.
Useful functions
Authors: Laubsch Joachim
Published: May 2014

It frequently happens that a LISP programmer wants a function to produce a data-structure or function containing constant and variable substructures. The usual solution is to program a form containing a lot of data-structure composing functions (like LIST, CONS and APPEND). The resulting expression is hard to decipher for humans unless more mnemonic constructor-functions are defined. A simple way out is to write the resulting structure with its variable substructures especially marked.
A system to understand incorrect programs
Authors: Wertz Harald
Published: May 2014

This paper presents a systems (PHENARETE) which understands and improves incompletely defined LISP programs, such as those written by students beginning to program in LISP. This system takes, as input, the program without any additional information. In order to understand the program, the system meta-evaluates it, using a library of "pragmatic rules", describing the construction and correction of general program constructs, and a set of "specialists", describing the syntax and semantics of the standard LISP functions. The system can use its understanding of the program to detect errors in it, to debug them and, eventually, to justify its proposed modification. This paper gives a brief survey of the working of the system, emphasizing on some commented examples.
Mechanical construction of a new efficient FLATTEN
Authors: Kodratoff Yves , Jouannaud Jean-Pierre
Published: May 2014

An efficient function FLATTEN is "well-known" and due to Mc CARTHY[5]. We give below a version of it, using the predicates NULL and ATOM.
Leveraging Human Mobility for Communication in Body Area Networks
Authors: Hauer Jan-Hinrich
Published: May 2014

When a person is walking the RF signal strength of an on-body communication link may exhibit significant fluctuation with peak-to-peak amplitudes beyond 20 dB. Instantaneous signal strength may be noisy, but the smoothed signal typically exhibits a period that matches the person's stride period. We present an opportunistic packet scheduler that extracts a set of Received Signal Strength Indicator (RSSI) samples from application traffic and utilizes an accelerometer to monitor the person's gait cycle. Packets are scheduled based on previous RSSI peaks and the current offset within the gait cycle. We formulate the task of finding a nonoverlapping packet schedule among the different body area network (BAN) devices as a linear programming problem and present an efficient way of solving it with the simplex method. Our experimental evaluation shows that outdoors BAN links with PRR (ratio of correctly received to transmitted packets) values between 50% and 90% can typically be turned into reliable links with PRR values well above 90%. Indoors the improvements are smaller, but still significant at low transmission power. The main price is an increase in packet delivery latency. The energy consumed by the devices is marginal, but the coordinator spends more energy due to signal processing.
Temporal Adaptive Link Quality Prediction with Online Learning
Authors: Liu Tao , Cerpa Alberto E.
Published: May 2014

Link quality estimation is a fundamental component of the low-power wireless network protocols and is essential for routing protocols in Wireless Sensor Networks (WSNs). However, accurate link quality estimation remains a challenging task due to the notoriously dynamic and unpredictable wireless environment. In this article we argue that, in addition to the estimation of current link quality, prediction of the future link quality is more important for the routing protocol to establish low-cost delivery paths. We propose to apply machine learning methods to predict the link quality in the near future to facilitate the utilization of intermediate links with frequent quality changes. Moreover, we show that, by using online learning methods, our adaptive link estimator (TALENT) adapts to network dynamics better than statically trained models without the need of a priori data collection for training the model before deployment. We implemented TALENT in TinyOS with Low-Power Listening (LPL) and conducted extensive experiments in three testbeds. Our experimental results show that the addition of TALENT increases the delivery efficiency 1.95 times on average compared with a 4B, state-of-the-art link quality estimator, as well as improves the end-to-end delivery rate when tested on three different wireless testbeds.
Combinatorial Filters
Authors: Tovar Benjamin , Cohen Fred , Bobadilla Leonardo , Czarnowski Justin , Lavalle Steven M.
Published: May 2014

A problem is introduced in which a moving body (robot, human, animal, vehicle, and so on) travels among obstacles and binary detection beams that connect between obstacles or barriers. Each beam can be viewed as a virtual sensor that may have many possible alternative implementations. The task is to determine the possible body paths based only on sensor observations that each simply report that a beam crossing occurred. This is a basic filtering problem encountered in many settings, under a variety of sensing modalities. Filtering methods are presented that reconstruct the set of possible paths at three levels of resolution: (1) the possible sequences of regions (bounded by beams and obstacles) visited, (2) equivalence classes of homo-topic paths, and (3) the possible numbers of times the path winds around obstacles. In the simplest case, all beams are disjoint, distinguishable, and directed. More complex cases are then considered, allowing for any amount of beams overlapping, indistinguishability, and lack of directional information. The method was implemented in simulation. An inexpensive, low-energy, easily deployable architecture was also created which implements the beam model and validates the methods of the article with experiments.
Connected Coverage in Wireless Networks with Directional Antennas
Authors: Yu Zuoming , Teng Jin , Bai Xiaole , Xuan Dong , Jia Weijia
Published: May 2014

In this article, we address a new unexplored problem: what are the optimal patterns to achieve connected coverage in wireless networks with directional antennas. As their name implies, directional antennas can focus their transmission energy in a certain direction. This feature leads to lower cross-interference and larger communication distance. It has been shown that, with proper scheduling mechanisms, directional antennas may substantially improve networking performance in wireless networks. In this article, we propose a set of deployment patterns to achieve full coverage and up to 2-connectivity under two different antenna models, namely the sector model and the knob model. These patterns are optimal under most combinations of communication and sensing ranges. We also introduce with detailed analysis several fundamental theorems and conjectures. Finally, we examine a more realistic physical model, where there might be strong interference and both the sensing range and the communication range might be irregular. The results show that our designed patterns work well even in unstable and fickle physical environments.
Occupancy Modeling and Prediction for Building Energy Management
Authors: Erickson Varick L. , Carreira-Perpiñán Miguel Á. , Cerpa Alberto E.
Published: May 2014

Heating, cooling and ventilation accounts for 35% energy usage in the United States. Currently, most modern buildings still condition rooms assuming maximum occupancy rather than actual usage. As a result, rooms are often over-conditioned needlessly. Thus, in order to achieve efficient conditioning, we require knowledge of occupancy. This article shows how real time occupancy data from a wireless sensor network can be used to create occupancy models, which in turn can be integrated into building conditioning system for usage-based demand control conditioning strategies. Using strategies based on sensor network occupancy model predictions, we show that it is possible to achieve 42% annual energy savings while still maintaining American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE) comfort standards.
Defending against Frequency-Based Attacks on Distributed Data Storage in Wireless Networks
Authors: Liu Hongbo , Wang Hui , Chen Yingying , Jia Dayong
Published: May 2014

As wireless networks become more pervasive, the amount of the wireless data is rapidly increasing. One of the biggest challenges of wide adoption of distributed data storage is how to store these data securely. In this work, we study the frequency-based attack, a type of attack that is different from previously well-studied ones, that exploits additional adversary knowledge of domain values and/or their exact/approximate frequencies to crack the encrypted data. To cope with frequency-based attacks, the straightforward 1-to-1 substitution encryption functions are not sufficient. We propose a data encryption strategy based on 1-to-
n
substitution via dividing and emulating techniques to defend against the frequency-based attack, while enabling efficient query evaluation over encrypted data. We further develop two frameworks, incremental collection and clustered collection, which are used to defend against the global frequency-based attack when the knowledge of the global frequency in the network is not available. Built upon our basic encryption schemes, we derive two mechanisms, direct emulating and dual encryption, to handle updates on the data storage for energy-constrained sensor nodes and wireless devices. Our preliminary experiments with sensor nodes and extensive simulation results show that our data encryption strategy can achieve high security guarantee with low overhead.
Essential Knowledge Aggregation, Delivery, and Assessment
Authors: Schagaev Igor , Kirk Brian , Bacon Liz
Published: May 2014

It is clear that the use of ICT for education has not yet achieved its potential. In this paper we present our vision on the further development and widening of learning through the enhanced use of ICT. In this context, learning is considered as having a framework with several essential and connected processes. Web semantic methods now enable the monitoring of knowledge and curriculum updates. Substantial research is required, as well as an understanding of how the human brain manages various channels of information delivery. We consider knowledge delivery in combination with textual, visual, and audio information. Its efficiency can be improved when we discover and apply methods used for successful performances and plays. A paradigm shift from in-class assessment toward self-assessment assisted by individually tailored ICT increases the efficiency of learning. As a first step, an individual assessment tool (app) for iOS is briefly described.
Electroanalysis at the Nanoscale
Authors: Dawson Karen , O'Riordan Alan
Published: May 2014

This article reviews the state of the art of silicon chip–based nanoelectrochemical devices for sensing applications. We first describe analyte mass transport to nanoscale electrodes and emphasize understanding the importance of mass transport for the design of nanoelectrode arrays. We then describe bottom-up and top-down approaches to nanoelectrode fabrication and integration at silicon substrates. Finally, we explore recent examples of on-chip nanoelectrodes employed as sensors and diagnostics, finishing with a brief look at future applications.
Teacher Effects and Teacher-Related Policies
Authors: Jackson C. Kirabo , Rockoff Jonah E. , Staiger Douglas O.
Published: May 2014

The emergence of large longitudinal data sets linking students to teachers has led to rapid growth in the study of teacher effects on student outcomes by economists over the past decade. One large literature has documented wide variation in teacher effectiveness that is not well explained by observable student or teacher characteristics. A second literature has investigated how educational outcomes might be improved by leveraging teacher effectiveness through processes of recruitment, assignment, compensation, evaluation, promotion, and retention. These two lines of inquiry are closely tied; the first tells us about the importance of individual teachers, and the second tells us how this information can be used in policy and practice. We review the most recent findings in economics on the importance of teachers and on teacher-related policies aimed at improving educational production.
Nanoscale Phenomena in Oxide Heterostructures
Authors: Sulpizio Joseph A. , Ilani Shahal , Irvin Patrick , Levy Jeremy
Published: May 2014

Recent advances in creating complex oxide heterostructures, interfaces formed between two different transition-metal oxides, have heralded a new era of materials and physics research, enabling a uniquely diverse set of coexisting physical properties to be combined with an ever-increasing degree of experimental control. These systems have exhibited varied phenomena such as superconductivity, magnetism, and ferroelasticity, all of which are gate tunable, demonstrating their promise for fundamental discovery and technological innovation. To fully exploit this richness, it is necessary to understand and control the physics on the smallest scales, making the use of nanoscale probes essential. Using the prototypical LaAlO3/SrTiO3 interface as a guide, we explore the exciting developments in the physics of oxide-based heterostructures, with a focus on nanostructures and the nanoscale probes employed to unravel their complex behavior.
Stochastic Virtual Tests for High-Temperature Ceramic Matrix Composites
Authors: Cox Brian N. , Bale Hrishikesh A. , Begley Matthew , Blacklock Matthew , Do Bao-Chan , Fast Tony , Naderi Mehdi , Novak Mark , Rajan Varun P. , Rinaldi Renaud G. , Ritchie Robert O. , Rossol Michael N. , Shaw John H. , Sudre Olivier , Yang Qingda , Zok Frank W. , Marshall David B.
Published: May 2014

We review the development of virtual tests for high-temperature ceramic matrix composites with textile reinforcement. Success hinges on understanding the relationship between the microstructure of continuous-fiber composites, including its stochastic variability, and the evolution of damage events leading to failure. The virtual tests combine advanced experiments and theories to address physical, mathematical, and engineering aspects of material definition and failure prediction. Key new experiments include surface image correlation methods and synchrotron-based, micrometer-resolution 3D imaging, both executed at temperatures exceeding 1,500°C. Computational methods include new probabilistic algorithms for generating stochastic virtual specimens, as well as a new augmented finite element method that deals efficiently with arbitrary systems of crack initiation, bifurcation, and coalescence in heterogeneous materials. Conceptual advances include the use of topology to characterize stochastic microstructures. We discuss the challenge of predicting the probability of an extreme failure event in a computationally tractable manner while retaining the necessary physical detail.
Lipoteichoic Acid Synthesis and Function in Gram-Positive Bacteria
Authors: Percy Matthew G. , Gründling Angelika
Published: May 2014

Lipoteichoic acid (LTA) is an important cell wall polymer found in gram-positive bacteria. Although the exact role of LTA is unknown, mutants display significant growth and physiological defects. Additionally, modification of the LTA backbone structure can provide protection against cationic antimicrobial peptides. This review provides an overview of the different LTA types and their chemical structures and synthesis pathways. The occurrence and mechanisms of LTA modifications with d-alanyl, glycosyl, and phosphocholine residues will be discussed along with their functions. Similarities between the production of type I LTA and osmoregulated periplasmic glucans in gram-negative bacteria are highlighted, indicating that LTA should perhaps be compared to these polymers rather than lipopolysaccharide, as is presently the case. Lastly, current efforts to use LTAs as vaccine candidates, synthesis proteins as novel antimicrobial targets, and LTA mutant strains as improved probiotics are highlighted.
Cortical Control of Whisker Movement
Authors: Petersen Carl C.H.
Published: May 2014

Facial muscles drive whisker movements, which are important for active tactile sensory perception in mice and rats. These whisker muscles are innervated by cholinergic motor neurons located in the lateral facial nucleus. The whisker motor neurons receive synaptic inputs from premotor neurons, which are located within the brain stem, the midbrain, and the neocortex. Complex, distributed neural circuits therefore regulate whisker movement during behavior. This review focuses specifically on cortical whisker motor control. The whisker primary motor cortex (M1) strongly innervates brain stem reticular nuclei containing whisker premotor neurons, which might form a central pattern generator for rhythmic whisker protraction. In a parallel analogous pathway, the whisker primary somatosensory cortex (S1) strongly projects to the brain stem spinal trigeminal interpolaris nucleus, which contains whisker premotor neurons innervating muscles for whisker retraction. These anatomical pathways may play important functional roles, since stimulation of M1 drives exploratory rhythmic whisking, whereas stimulation of S1 drives whisker retraction.
The Role of Trees in Agroecology and Sustainable Agriculture in the Tropics
Authors: Leakey Roger R.B.
Published: May 2014

Shifting agriculture in the tropics has been replaced by sedentary smallholder farming on a few hectares of degraded land. To address low yields and low income both, the soil fertility, the agroecosystem functions, and the source of income can be restored by diversification with nitrogen-fixing trees and the cultivation of indigenous tree species that produce nutritious and marketable products. Biodiversity conservation studies indicate that mature cash crop systems, such as cacao and coffee with shade trees, provide wildlife habitat that supports natural predators, which, in turn, reduce the numbers of herbivores and pathogens. This review offers suggestions on how to examine these agroecological processes in more detail for the most effective rehabilitation of degraded land. Evidence from agroforestry indicates that in this way, productive and environmentally friendly farming systems that provide food and nutritional security, as well as poverty alleviation, can be achieved in harmony with wildlife.
Somebody's Children or Nobody's Children? How the Sociological Perspective Could Enliven Research on Foster Care
Authors: Wildeman Christopher , Waldfogel Jane
Published: May 2014

Social scientists have long been concerned about how the fortunes of parents affect their children, with acute interest in the most marginalized children. Yet little sociological research considers children in foster care. In this review, we take a three-pronged approach to show why this inattention is problematic. First, we provide overviews of the history of the foster care system and how children end up in foster care, as well as an estimate of how many children ever enter foster care. Second, we review research on the factors that shape the risk of foster care placement and foster care caseloads and how foster care affects children. We close by discussing how a sociological perspective and methodological orientation—ranging from ethnographic observation to longitudinal mixed methods research, demographic methods, and experimental studies—can foster new knowledge around the foster care system and the families it affects.
Trends in the Rates of Pediatric Pyeloplasty for Ureteropelvic Junction Obstruction over 19 Years: A PHIS Database Study
Authors: Akhavan Ardavan , Merguerian Paul A. , Larison Cindy , Goldin Adam B. , Shnorhavorian Margarett
Published: May 2014

Background. Over the past 20 years, the management of ureteropelvic junction obstruction (UPJ) has shifted. While many urologists note a decrease in the number of pyeloplasties performed over time, the nature of the change in practice has yet to be defined. In the current study, we utilize a national, multi-institutional database of children’s hospitals to evaluate trends in patients undergoing pyeloplasty as well as the rate of surgical reconstruction over the past 20 years.Material/Methods. We queried the Pediatric Health Information System (PHIS) database for all children undergoing primary pyeloplasty between 1992 and 2011. Clinical variables, including age at time of surgery, gender, length of stay (LOS), and geographic region, were determined. Age-adjusted rate of repair was also calculated per 100,000 PHIS inpatients.Results. 6,013 patients were included in the study, of which 71.6% were male and 64.2% were under the age of 24 months at time of surgery. Over the study period, the median age at time of surgery increased from 2–4 months to 12–14 months (P<0.01). LOS decreased from a median of 5 days to 2 days (P<0.001). The rate of surgery increased by 10.6 pyeloplasties per 100,000 PHIS inpatients from 1992 to 2011 (P<0.01). The highest rate of pyeloplasty was in the northeast. The increase in pyeloplasties performed from 1992 to 1999 was specific to children aged greater than 24 months, while rates stayed the same in infants younger than 2 years during the same time period. In contrast, from 1999 to 2011, the rate of pyeloplasty decreased in patients less than 2 years of age, while the rate remained constant in patients over age 2.Conclusion. The rate of pyeloplasty increased in PHIS hospitals from 1992 to 2011. Trends are due to an increase in surgery in infants younger than 2 years from 1992 to 1999, followed by a progressive surgical rate decline, characterized by a shift towards patients older than 2 years of age.
An Integrated Contraflow Strategy for Multimodal Evacuation
Authors: Hua Jingyi , Ren Gang , Cheng Yang , Ran Bin
Published: May 2014

To improve the efficiency of multimodal evacuation, a network aggregation method and an integrated contraflow strategy are proposed in this paper. The network aggregation method indicates the uncertain evacuation demand on the arterial subnetwork and balances accuracy and efficiency by refining the local road subnetworks. The integrated contraflow strategy contains three arterial configurations: noncontraflow to shorten the strategy setup time, full‐lane contraflow to maximize the evacuation network capacity, and bus contraflow to realize the transit cycle operation. The application of this strategy takes two steps to provide transit priority during evacuation: solve the transit‐based evacuation problem with a minimum‐cost flow model, firstly, and then address the auto‐based evacuation problem with a bilevel network flow model. The numerical results from optimizing an evacuation network for a super typhoon justify the validness and usefulness of the network aggregation method and the integrated contraflow strategy.
The Combination Forecasting of Electricity Price Based on Price Spikes Processing: A Case Study in South Australia
Authors: Wang Jianzhou , Xiao Ling , Shi Jun
Published: May 2014

Electricity price forecasting holds very important position in the electricity market. Inaccurate price forecasting may cause energy waste and management chaos in the electricity market. However, electricity price forecasting has always been regarded as one of the largest challenges in the electricity market because it shows high volatility, which makes electricity price forecasting difficult. This paper proposes the use of artificial intelligence optimization combination forecasting models based on preprocessing data, called “chaos particles optimization (CPSO) weight-determined combination models.” These models allow for the weight of the combined model to take values of[-1,1]. In the proposed models, the density-based spatial clustering of applications with noise (DBSCAN) algorithm is used to identify outliers, and the outliers are replaced by a new data-produced linear interpolation function. The proposed CPSO weight-determined combination models are then used to forecast the projected future electricity price. In this case study, the electricity price data of South Australia are simulated. The results indicate that, while the weight of the combined model takes values of[-1,1], the proposed combination model can always provide adaptive, reliable, and comparatively accurate forecast results in comparison to traditional combination models.
Mathematical Modelling of Radiative Hydromagnetic Thermosolutal Nanofluid Convection Slip Flow in Saturated Porous Media
Authors: Uddin Mohammed Jashim , Bég Osman Anwar , Ismail Ahmad Izani Md.
Published: May 2014

High temperature thermal processing of nanomaterials is an active area of research. Many
techniques are being investigated to manipulate properties of nanomaterials for medical implementation. In this paper, we investigate thermal radiation processing of a nanomaterial fluid sheet extruded in porous media. A mathematical model is developed using a Darcy drag force model. Instead of using linear radiative heat flux, the nonlinear radiative heat flux in the Rosseland approximation is taken into account which makes the present study more meaningful and practically useful. Velocity slip and thermal and mass convective boundary conditions are incorporated in the model. The Buongiornio nanofluid model is adopted wherein Brownian motion and thermophoresis effects are present. The boundary layer conservation equations are transformed using appropriate similarity variables and the resulting nonlinear boundary value problem is solved using Maple 14 which uses the Runge‐Kutta‐Fehlberg fourth fifth order numerical method. Solutions are validated with previous nonmagnetic and nonradiative computations from the literature, demonstrating excellent agreement. The influence of Darcy number, magnetic field parameter, hydrodynamic slip parameter, convection‐conduction parameter, convection‐diffusion parameter, and conduction‐radiation parameter on the dimensionless velocity, temperature, and nanoparticle concentration fields is examined in detail. Interesting patterns of relevance are observed to improve manufacturing
of nanofluids.
Safety Characterization and Antimicrobial Properties of Kefir-IsolatedLactobacillus kefiri
Authors: Carasi Paula , Díaz Mariángeles , Racedo Silvia M. , De Antoni Graciela , Urdaci María C. , Serradell María de los Angeles
Published: May 2014

Lactobacilli are generally regarded as safe; however, certain strains have been associated with cases of infection. Our workgroup has already assessed many functional properties ofLactobacillus kefiri, but parameters regarding safety must be studied before calling them probiotics. In this work, safety aspects and antimicrobial activity ofL. kefiristrains were studied. None of theL. kefiristrains tested causedα- orβ-hemolysis. All the strains were susceptible to tetracycline, clindamycin, streptomycin, ampicillin, erythromycin, kanamycin, and gentamicin; meanwhile, two strains were resistant to chloramphenicol. On the other hand, allL. kefiristrains were able to inhibit both Gram(+) and Gram(−) pathogens. Regarding thein vitroresults,L. kefiriCIDCA 8348 was selected to performin vivostudies. Mice treated daily with an oral dose of 108CFU during 21 days showed no signs of pain, lethargy, dehydration, or diarrhea, and the histological studies were consistent with those findings. Moreover, no differences in proinflammatory cytokines secretion were observed between treated and control mice. No translocation of microorganisms to blood, spleen, or liver was observed. Regarding these findings,L. kefiriCIDCA 8348 is a microorganism isolated from a dairy product with a great potential as probiotic for human or animal use.
Microbiological Quality of Fresh Produce from Open Air Markets and Supermarkets in the Philippines
Authors: Vital Pierangeli G. , Dimasuay Kris Genelyn B. , Widmer Kenneth W. , Rivera Windell L.
Published: May 2014

This study is the first in the Philippines to conduct a comprehensive assessment of the prevalence of bacterial pathogens and somatic phages in retailed fresh produce used in salad preparation, namely, bell pepper, cabbage, carrot, lettuce, and tomato, using culture and molecular methods. Out of 300 samples from open air and supermarkets, 16.7% tested positive for thermotolerantEscherichia coli, 24.7% forSalmonellaspp., and 47% for somatic phages. Results show that counts range from 0.30 to 4.03 log10 CFU/g forE. coli, 0.66 to ≥2.34 log10 MPN/g forSalmonellaspp., and 1.30 to ≥3.00 log10PFU/g for somatic phages. Statistical analyses show that there was no significant difference in the microbial counts between open air and supermarkets (α=0.05). TaqMan and AccuPower Plus DualStar real-time polymerase chain reaction (RT-PCR) was used to confirm the presence of these organisms. The relatively high prevalence of microorganisms observed in produce surveyed signifies reduction in shelf-life and a potential hazard to food safety. This information may benefit farmers, consumers, merchants, and policy makers for foodborne disease detection and prevention.
Simplified Stability Criteria for Delayed Neutral Systems
Authors: Zhang Xinghua , Gao Xiangyu , Su Min
Published: May 2014

For a class of linear time‐invariant neutral systems with neutral and discrete constant delays, several existing asymptotic stability criteria in the form of linear matrix inequalities (LMIs) are simplified by using matrix analysis techniques. Compared with the original stability criteria, the simplified ones include fewer LMI variables, which can obviously reduce computational complexity. Simultaneously, it is theoretically shown that the simplified stability criteria and original ones are equivalent; that is, they have the same conservativeness. Finally, a numerical example is employed to verify the theoretic results investigated in this paper.
Failure Mode Analysis and Performance Optimization of the Hierarchical Corrugated Truss Structure
Authors: Li Gang , Fang Yaochu
Published: May 2014

The theories of elastic plates and Kirchhoff's sandwich plates are used to analyze the failure modes of the second order hierarchical corrugated truss structure, and a plate model is presented. Besides the six competing failure modes obtained in the literature using the elementary elastic beam theory, another five competing failure modes have been identified herein, including the plate buckling, infinitely wide plate buckling, sandwich plate buckling, infinitely wide sandwich plate buckling, and surface wrinkling. Expressions for the compressive collapse strengths of these modes are derived and used to construct collapse mechanism maps for second order trusses, which is effective for selecting the geometries of second order trusses. By comparing with the result of the finite element method (FEM) it is shown that the plate model has higher accuracy than the beam model, and the infinite wide plate model has the highest accuracy when the length-width ratio of the large struts is greater than 1.0. Finally, three optimization models are proposed. The performance of a second order hierarchical corrugated truss structure has been optimized, and the geometric parameters under the optimal performance can be obtained, which can provide a more convenient way to achieve a desired scheme for designers.
Existence of Nontrivial Solutions for Perturbed Elliptic System inℝN
Authors: Jiang Juan
Published: May 2014

We consider the perturbed nonlinear elliptic system-ε2Δu+V(x)u=K(x)|u|2*-2u+Hu(u,v),  x∈ℝN,-ε2Δv+V(x)v=K(x)|v|2*-2v+Hv(u,v),  x∈ℝN, whereN≥3,2*=2N/(N-2)is the Sobolev critical exponent. Under proper conditions onV,H, andK, the existence result and multiplicity of the system are obtained by using variational method providedεis small enough.
Pneumomediastinum Associated with Pneumopericardium and Epidural Pneumatosis
Authors: Bilir Ozlem , Yavasi Ozcan , Ersunan Gokhan , Kayayurt Kamil , Giakoup Baris
Published: May 2014

Spontaneous pneumomediastinum is a relatively rare benign condition. It may rarely be associated with one or combination of pneumothorax, epidural pneumatosis, pneumopericardium, or subcutaneous emphysema. We present a unique case with four of the radiological findings in a 9-year-old male child who presented to our emergency department with his parents with complaints of unproductive cough, dyspnea, and swelling on chest wall. Bilateral subcutaneous emphysema was palpated on anterior chest wall from sternum to midaxillary regions. His anteroposterior and lateral chest radiogram revealed subcutaneous emphysema and pneumomediastinum. His thorax computed tomography to rule out life-threatening conditions revealed bilateral subcutaneous, mediastinal, pericardial, and epidural emphysema without pneumothorax. He was transferred to pediatric intensive care unit for close monitorization and conservative treatment. He was followed-up by chest radiographs. He was relieved from symptoms and signs around the fifth day and he was discharged at the seventh day. Diagnosis of pneumomediastinum is often made based on physical findings and plain radiographs. It may not be as catastrophic as it is seen. Close cardiopulmonary monitorization is mandatory for complications and accompanying conditions. Most patients with uncomplicated spontaneous pneumomediastinum respond well to oxygen and conservative management without any specific treatment.
Chaotic Extension Neural Network‐Based Fault Diagnosis Method for Solar Photovoltaic Systems
Authors: Yu Kuo-Nan , Yau Her-Terng , Li Jian-Yu
Published: May 2014

At present, the solar photovoltaic system is extensively used. However, once a fault occurs, it is inspected manually, which is not economical. In order to remedy the defect of unavailable fault diagnosis at any irradiance and temperature in the literature with chaos synchronization based intelligent fault diagnosis for photovoltaic systems proposed by Hsieh et al., this study proposed a chaotic extension fault diagnosis method combined with error back propagation neural network to overcome this problem. It used the nn toolbox of matlab 2010 for simulation and comparison, measured current irradiance and temperature, and used the maximum power point tracking (MPPT) for chaotic extraction of eigenvalue. The range of extension field was determined by neural network. Finally, the voltage eigenvalue obtained from current temperature and irradiance was used for the fault diagnosis. Comparing the diagnostic rates with the results by Hsieh et al., this scheme can obtain better diagnostic rates when the irradiances or the temperatures are changed.
Clinical Genetics of Alzheimer’s Disease
Authors: Zou Zhangyu , Liu Changyun , Che Chunhui , Huang Huapin
Published: May 2014

Alzheimer’s disease (AD) is the most common progressive neurodegenerative disease and the most common form of dementia in the elderly. It is a complex disorder with environmental and genetic components. There are two major types of AD, early onset and the more common late onset. The genetics of early-onset AD are largely understood with mutations in three different genes leading to the disease. In contrast, while susceptibility loci and alleles associated with late-onset AD have been identified using genetic association studies, the genetics of late-onset Alzheimer’s disease are not fully understood. Here we review the known genetics of early- and late-onset AD, the clinical features of EOAD according to genotypes, and the clinical implications of the genetics of AD.
Epidemiology of Carbapenemase-Producing Enterobacteriaceae andAcinetobacter baumanniiin Mediterranean Countries
Authors: Djahmi Nassima , Dunyach-Remy Catherine , Pantel Alix , Dekhil Mazouz , Sotto Albert , Lavigne Jean-Philippe
Published: May 2014

The emergence and global spread of carbapenemase-producing Enterobacteriaceae andAcinetobacter baumanniiare of great concern to health services worldwide. Theseβ-lactamases hydrolyse almost allβ-lactams, are plasmid-encoded, and are easily transferable among bacterial species. They are mostly of the KPC, VIM, IMP, NDM, and OXA-48 types. Their current extensive spread worldwide in Enterobacteriaceae is an important source of concern. Infections caused by these bacteria have limited treatment options and have been associated with high mortality rates. Carbapenemase producers are mainly identified amongKlebsiella pneumoniae,Escherichia coli, andA. baumanniiand still mostly in hospital settings and rarely in the community. The Mediterranean region is of interest due to a great diversity and population mixing. The prevalence of carbapenemases is particularly high, with this area constituting one of the most important reservoirs. The types of carbapenemase vary among countries, partially depending on the population exchange relationship between the regions and the possible reservoirs of each carbapenemase. This review described the epidemiology of carbapenemases produced by enterobacteria andA. baumanniiin this part of the world highlighting the worrisome situation and the need to screen and detect these enzymes to prevent and control their dissemination.
An Improved Antiwindup Design Using an Anticipatory Loop and an Immediate Loop
Authors: Wang Qing , Ran Maopeng , Dong Chaoyang , Ni Maolin
Published: May 2014

We present an improved antiwindup design for linear invariant continuous‐time systems with actuator saturation nonlinearities. In the improved approach, two antiwindup compensators are simultaneously designed: one activated immediately at the occurrence of actuator saturation and the other activated in anticipatory of actuator saturation. Both the static and dynamic antiwindup compensators are considered. Sufficient conditions for global stability and minimizing the induced L2 gain are established, in terms of linear matrix inequalities (LMIs). We also show that the feasibility of the improved antiwindup is similar to the traditional antiwindup. Benefits of the proposed approach over the traditional antiwindup and a recent innovative antiwindup are illustrated with well‐known examples.
Rough Atanassov’s Intuitionistic Fuzzy Sets Model over Two Universes and Its Applications
Authors: Luo Shuqun , Xu Weihua
Published: May 2014

Recently, much attention has been given to the rough set models based on two universes. And many rough set models based on two universes have been developed from different points of view. In this paper, a novel model, that is, rough Atanassov’s intuitionistic fuzzy sets model over two different universes, is firstly proposed from Atanassov’s intuitionistic point of view. We study some important properties of approximation operators and investigate the rough degree in the novel model. Furthermore, an illustrated example is employed to demonstrate the conceptual arguments of the model. Finally, rough Atanassov’s intuitionistic fuzzy sets approach to decision is presented in the generalized approximation space over two universes by considering the problem about how to arrange patients to see the doctor reasonably, from which it can be found that the method is valuable and useful in real life.
Computation of Stability Delay Margin of Time‐Delayed Generator Excitation Control System with a Stabilizing Transformer
Authors: Ayasun Saffet , Eminoğlu Ulaş , Sönmez Şahin
Published: May 2014

This paper investigates the effect of time delays on the stability of a generator excitation control system compensated with a stabilizing transformer known as rate feedback stabilizer to damp out oscillations. The time delays are due to the use of measurement devices and communication links for data transfer. An analytical method is presented to compute the delay margin for stability. The delay margin is the maximum amount of time delay that the system can tolerate before it becomes unstable. First, without using any approximation, the transcendental characteristic equation is converted into a polynomial without the transcendentality such that its real roots coincide with the imaginary roots of the characteristic equation exactly. The resulting polynomial also enables us to easily determine the delay dependency of the system stability and the sensitivities of crossing roots with respect to the time delay. Then, an expression in terms of system parameters and imaginary root of the characteristic equation is derived for computing the delay margin. Theoretical delay margins are computed for a wide range of controller gains and their accuracy is verified by performing simulation studies. Results indicate that the addition of a stabilizing transformer to the excitation system increases the delay margin and improves the system damping significantly.
On Generalized Difference Hahn Sequence Spaces
Authors: Raj Kuldip , Kiliçman Adem
Published: May 2014

We construct some generalized difference Hahn sequence spaces by mean of sequence of modulus functions. The topological properties and some inclusion relations of spaceshpℱ,u,Δrare investigated. Also we compute the dual of these spaces, and some matrix transformations are characterized.
The Reactants’ Phase State: A Nonnegligible Factor in Tetralin Hydrogenation Catalysts Evaluation
Authors: Luo Mingjian , Wang Qingfa , Zhang Xiangwen , Hu Bing
Published: May 2014

The effects of reactants’ phase states (gas-liquid and single gas phase) on tetralin hydrogenation were investigated in the fixed bed. The kinetics of tetralin hydrogenation under different phase states was analyzed. Results showed that, without phase transition, the tetralin conversion increased with the rise of temperature. However, it decreased dramatically around the dew point of the feed at which the reactants’ phase state transferred from gas-liquid phase into gas phase. It was also observed that the gas-liquid phase state was favorable to reduce the deactivation of catalyst in the tetralin hydrogenation.
The Inhibitory Effect of Resveratrol on Elastin Amyloidogenesis
Authors: Pepe Antonietta , Delaunay Florian , Bracalello Angelo , Bochicchio Brigida
Published: May 2014

The role of polyphenols in the prevention of degenerative diseases is emerging in the last years. In this report, we will investigate in vitro the inhibitory effect of resveratrol on elastin amyloidogenesis. The effect of resveratrol on molecular structure was investigated by circular dichroism spectroscopy, while the inhibitory effect on self-assembly was evaluated by turbidimetry as a function of temperature and by atomic force microscopy.
Electrical Discharge Machining of Al (6351)-5% SiC-10% B4C Hybrid Composite: A Grey Relational Approach
Authors: Suresh Kumar S. , Uthayakumar M. , Thirumalai Kumaran S. , Parameswaran P. , Mohandas E.
Published: May 2014

The goal of the present experimental work is to optimize the electrical discharge machining (EDM) parameters of aluminum alloy (Al 6351) matrix reinforced with 5 wt.% silicon carbide (SiC) and 10 wt.% boron carbide (B4C) particles fabricated through the stir casting route. Multiresponse optimization was carried out through grey relational analysis (GRA) with an objective to minimize the machining characteristics, namely electrode wear ratio (EWR), surface roughness (SR) and power consumption (PC). The optimal combination of input parameters is identified, which shows the significant enhancement in process characteristics. Contributions of each machining parameter to the responses are calculated using analysis of variance (ANOVA). The result shows that the pulse current contributes more (83.94%) to affecting the combined output responses.
Nanosheet‐Assembled ZnO Microflower Photocatalysts
Authors: Zhang Siwen , Yin Bosi , Jiao Yang , Liu Yang , Qu Fengyu , Wu Xiang
Published: May 2014

Large scale ZnO microflowers assembled by numerous nanosheets are synthesized through a facile and effective hydrothermal route. The structure and morphology of the resultant products are characterized by X‐ray diffraction (XRD) and scanning electron microscope (SEM). Photocatalytic properties of the as‐synthesized products are also investigated. The results demonstrate that eosin red aqueous solution can be degraded over 97% after 110 min under UV light irradiation. In addition, methyl orange (MO) and Congo red (CR) aqueous solution degradation experiments also are conducted in the same condition, respectively. It showed that nanosheet‐assembled ZnO microflowers represent high photocatalytic activities with a degradation efficiency of 91% for CR with 90 min of irradiation and 90% for MO with 60 min of irradiation. The reported ZnO products may be promising candidates as the photocatalysts in waste water treatment.