bluuebunny/crossref_metadata_2025 huggingface dataset:
Cloud Detection for High-Resolution Satellite Imagery Using Machine Learning and Multi-Feature Fusion
Authors: Bai Ting , Li Deren , Sun Kaimin , Chen Yepei , Li Wenzhuo
Published: August 2016

The accurate location of clouds in images is prerequisite for many high-resolution satellite imagery applications such as atmospheric correction, land cover classifications, and target recognition. Thus, we propose a novel approach for cloud detection using machine learning and multi-feature fusion based on a comparative analysis of typical spectral, textural, and other feature differences between clouds and backgrounds. To validate this method, we tested it on 102 Gao Fen-1(GF-1) and Gao Fen-2(GF-2) satellite images. The overall accuracy of our multi-feature fusion method for cloud detection was more than 91.45%, and the Kappa coefficient for all the tested images was greater than 80%. The producer and user accuracy were also higher at 93.67% and 95.67%, respectively; both of these values were higher than the values for the other tested feature fusion methods. Our results show that this novel multi-feature approach yields better accuracy than other feature fusion methods. In post-processing, we applied an object-oriented method to remove the influence of highly reflective ground objects and further improved the accuracy. Compared to traditional methods, our new method for cloud detection is accurate, exhibits good scalability, and produces consistent results when mapping clouds of different types and sizes over various land surfaces that contain natural vegetation, agriculture land, built-up areas, and water bodies.
Submerged and Emergent Land Cover and Bathymetric Mapping of Estuarine Habitats Using WorldView-2 and LiDAR Imagery
Authors: Halls Joanne , Costin Kaitlyn
Published: August 2016

Tidal creeks are small estuarine watersheds characterized by low freshwater input, marine to brackish salinity, and subtidal, intertidal, and supratidal habitats. Most people are familiar with large rivers and estuaries, but the smaller tidal watersheds comprise a greater percentage of the coastline. As the population along coasts rises there is growing concern about water quality and increased sedimentation rates. Therefore, these smaller tidal creek watersheds are at risk to pollution, decreased environmental health, and deterioration of protective salt marshes. The purpose of this study was to test methods for high spatial resolution mapping of benthic (submerged) and emergent habitats as well as the derivation of bathymetry using DigitalGlobe’s WorldView-2 imagery. An intensive field effort was conducted to test and assess several image processing techniques. Results concluded that: (1) supervised habitat classification produced the highest map accuracy (95%); (2) sand, water, scrub/shrub, and docks/rubble were mapped the most accurately at greater than 95%; (3) saltmarsh habitats (high and low density cordgrass, Spartina alterniflora, and black needlerush, Juncus roemerianus), mud, and oyster beds were between 80 and 85% accurate; (4) pan-sharpening and atmospheric correction did not improve map accuracy; (5) LiDAR (light detection and ranging) data increased habitat map accuracy; and (6) WorldView-2 imagery was capable of deriving water depth and these data increased the map accuracy of benthic habitats. The project produced habitat maps for benthic and emergent species at high spatial resolution (4 m2) which will be useful for studying the dynamic processes in this tidal environment. The data and methods developed here could be used by state and local government planning agencies to assess potential long-term changes and develop appropriate management strategies.
An Effective Cuckoo Search Algorithm for Node Localization in Wireless Sensor Network
Authors: Cheng Jing , Xia Linyuan
Published: August 2016

Localization is an essential requirement in the increasing prevalence of wireless sensor network (WSN) applications. Reducing the computational complexity, communication overhead in WSN localization is of paramount importance in order to prolong the lifetime of the energy-limited sensor nodes and improve localization performance. This paper proposes an effective Cuckoo Search (CS) algorithm for node localization. Based on the modification of step size, this approach enables the population to approach global optimal solution rapidly, and the fitness of each solution is employed to build mutation probability for avoiding local convergence. Further, the approach restricts the population in the certain range so that it can prevent the energy consumption caused by insignificant search. Extensive experiments were conducted to study the effects of parameters like anchor density, node density and communication range on the proposed algorithm with respect to average localization error and localization success ratio. In addition, a comparative study was conducted to realize the same localization task using the same network deployment. Experimental results prove that the proposed CS algorithm can not only increase convergence rate but also reduce average localization error compared with standard CS algorithm and Particle Swarm Optimization (PSO) algorithm.
Empirical Study on Designing of Gaze Tracking Camera Based on the Information of User’s Head Movement
Authors: Pan Weiyuan , Jung Dongwook , Yoon Hyo , Lee Dong , Naqvi Rizwan , Lee Kwan , Park Kang
Published: August 2016

Gaze tracking is the technology that identifies a region in space that a user is looking at. Most previous non-wearable gaze tracking systems use a near-infrared (NIR) light camera with an NIR illuminator. Based on the kind of camera lens used, the viewing angle and depth-of-field (DOF) of a gaze tracking camera can be different, which affects the performance of the gaze tracking system. Nevertheless, to our best knowledge, most previous researches implemented gaze tracking cameras without ground truth information for determining the optimal viewing angle and DOF of the camera lens. Eye-tracker manufacturers might also use ground truth information, but they do not provide this in public. Therefore, researchers and developers of gaze tracking systems cannot refer to such information for implementing gaze tracking system. We address this problem providing an empirical study in which we design an optimal gaze tracking camera based on experimental measurements of the amount and velocity of user’s head movements. Based on our results and analyses, researchers and developers might be able to more easily implement an optimal gaze tracking system. Experimental results show that our gaze tracking system shows high performance in terms of accuracy, user convenience and interest.
A Sensor Fusion Method Based on an Integrated Neural Network and Kalman Filter for Vehicle Roll Angle Estimation
Authors: Vargas-Meléndez Leandro , Boada Beatriz , Boada María , Gauchía Antonio , Díaz Vicente
Published: August 2016

This article presents a novel estimator based on sensor fusion, which combines the Neural Network (NN) with a Kalman filter in order to estimate the vehicle roll angle. The NN estimates a “pseudo-roll angle” through variables that are easily measured from Inertial Measurement Unit (IMU) sensors. An IMU is a device that is commonly used for vehicle motion detection, and its cost has decreased during recent years. The pseudo-roll angle is introduced in the Kalman filter in order to filter noise and minimize the variance of the norm and maximum errors’ estimation. The NN has been trained for J-turn maneuvers, double lane change maneuvers and lane change maneuvers at different speeds and road friction coefficients. The proposed method takes into account the vehicle non-linearities, thus yielding good roll angle estimation. Finally, the proposed estimator has been compared with one that uses the suspension deflections to obtain the pseudo-roll angle. Experimental results show the effectiveness of the proposed NN and Kalman filter-based estimator.
Through Wall Radar Classification of Human Micro-Doppler Using Singular Value Decomposition Analysis
Authors: Ritchie Matthew , Ash Matthew , Chen Qingchao , Chetty Kevin
Published: August 2016

The ability to detect the presence as well as classify the activities of individuals behind visually obscuring structures is of significant benefit to police, security and emergency services in many situations. This paper presents the analysis from a series of experimental results generated using a through-the-wall (TTW) Frequency Modulated Continuous Wave (FMCW) C-Band radar system named Soprano. The objective of this analysis was to classify whether an individual was carrying an item in both hands or not using micro-Doppler information from a FMCW sensor. The radar was deployed at a standoff distance, of approximately 0.5 m, outside a residential building and used to detect multiple people walking within a room. Through the application of digital filtering, it was shown that significant suppression of the primary wall reflection is possible, significantly enhancing the target signal to clutter ratio. Singular Value Decomposition (SVD) signal processing techniques were then applied to the micro-Doppler signatures from different individuals. Features from the SVD information have been used to classify whether the person was carrying an item or walking free handed. Excellent performance of the classifier was achieved in this challenging scenario with accuracies up to 94%, suggesting that future through wall radar sensors may have the ability to reliably recognize many different types of activities in TTW scenarios using these techniques.
Discovery of Novel Bacterial Cell-Penetrating Phylloseptins in Defensive Skin Secretions of the South American Hylid Frogs, Phyllomedusa duellmani and Phyllomedusa coelestis
Authors: Yang Nan , Li Lei , Wu Di , Gao Yitian , Xi Xinping , Zhou Mei , Wang Lei , Chen Tianbao , Shaw Chris
Published: August 2016

Phylloseptin (PS) peptides, derived from South American hylid frogs (subfamily Phyllomedusinae), have been found to have broad-spectrum antimicrobial activities and relatively low haemolytic activities. Although PS peptides have been identified from several well-known and widely-distributed species of the Phyllomedusinae, there remains merit in their study in additional, more obscure and specialised members of this taxon. Here, we report the discovery of two novel PS peptides, named PS-Du and PS-Co, which were respectively identified for the first time and isolated from the skin secretions of Phyllomedusa duellmani and Phyllomedusa coelestis. Their encoding cDNAs were cloned, from which it was possible to deduce the entire primary structures of their biosynthetic precursors. Reversed-phase high-performance liquid chromatography (RP-HPLC) and tandem mass spectrometry (MS/MS) analyses were employed to isolate and structurally-characterise respective encoded PS peptides from skin secretions. The peptides had molecular masses of 2049.7 Da (PS-Du) and 1972.8 Da (PS-Co). They shared typical N-terminal sequences and C-terminal amidation with other known phylloseptins. The two peptides exhibited growth inhibitory activity against E. coli (NCTC 10418), as a standard Gram-negative bacterium, S. aureus (NCTC 10788), as a standard Gram-positive bacterium and C. albicans (NCPF 1467), as a standard pathogenic yeast, all as planktonic cultures. Moreover, both peptides demonstrated the capability of eliminating S. aureus biofilm.
Presence of the Cyanotoxin Microcystin in Arctic Lakes of Southwestern Greenland
Authors: Trout-Haney Jessica , Wood Zachary , Cottingham Kathryn
Published: August 2016

Cyanobacteria and their toxins have received significant attention in eutrophic temperate and tropical systems where conspicuous blooms of certain planktonic taxa release toxins into fresh water, threatening its potability and safe use for recreation. Although toxigenic cyanobacteria are not confined to high nutrient environments, bloom-forming species, or planktonic taxa, these other situations are studied les often studied. For example, toxin production in picoplankton and benthic cyanobacteria—the predominant photoautotrophs found in polar lakes—is poorly understood. We quantified the occurrence of microcystin (MC, a hepatotoxic cyanotoxin) across 18 Arctic lakes in southwestern Greenland. All of the focal lakes contained detectable levels of MC, with concentrations ranging from 5 ng·L−1 to >400 ng·L−1 during summer, 2013–2015. These concentrations are orders of magnitude lower than many eutrophic systems, yet the median lake MC concentration in Greenland (57 ng·L−1) was still 6.5 times higher than the median summer MC toxicity observed across 50 New Hampshire lakes between 1998 and 2008 (8.7 ng·L−1). The presence of cyanotoxins in these Greenlandic lakes demonstrates that high latitude lakes can support toxigenic cyanobacteria, and suggests that we may be underestimating the potential for these systems to develop high levels of cyanotoxins in the future.
SPI Based Meteorological Drought Assessment over a Humid Basin: Effects of Processing Schemes
Authors: Zhou Han , Liu Yuanbo
Published: August 2016

Meteorological drought monitoring is important for drought early warning and disaster prevention. Regional meteorological drought can be evaluated and analyzed with standardized precipitation index (SPI). Two main processing schemes are frequently adopted: (1) mean of all SPI calculated from precipitation at individual stations (SPI-mean); and (2) SPI calculated from all-station averaged precipitation (precipitation-mean). It yet remains unclear if two processing schemes could make difference in drought assessment, which is of significance to reliable drought monitoring. Taking the Poyang Lake Basin with monthly precipitation recorded by 13 national stations for 1957–2014, this study examined two processing schemes. The precipitation mean and SPI mean were respectively calculated with the Thiessen Polygon weighting approach. Our results showed that the two SPI series individually constructed from two schemes had similar features and monitoring trends of regional meteorological droughts. Both SPI series had a significantly positive correlation (p < 0.005) with the number of precipitation stations. The precipitation-mean scheme reduced the extent of precipitation extremes and made the precipitation data more clustered in some certain, it made less precipitation deviate from the precipitation-mean series farther when less precipitation occurred universally, which would probably change the drought levels. Alternatively, the SPI-mean scheme accurately highlighted the extremes especially for those with wide spatial distribution over the region. Therefore, for regional meteorological drought monitoring, the SPI-mean scheme is recommended for its more suitable assessment of historical droughts.
Understanding Farmers’ Decision-Making in Agricultural Water Fee Payment in China: The Role of Mental Accounting
Authors: Zhang Weikang , Fu Xinhong , Lu Jing , Zhang Lin , Michael Kwamega , Liu Guoqiang , Yang Fan , Liu Yuying
Published: August 2016

To better understand farmers’ refusal to pay agricultural water fees under the current policy in rural China and their corresponding negative emotions, this paper applies mental accounting, a behavioral economics framework, to explore how the governmental policies of reform of rural taxes and fees, direct agricultural subsidy programs, and agricultural water fees individually influence farmers’ decisions in paying the agricultural water fees. Using fieldwork data from 577 farmers and 20 water managers in Sichuan, we explore farmers’ information processing regarding paying agricultural water fees via three sequential mental accounting processes, with the associated underlying principles and measures behind each process. We find that the information processing in three mental accounting scenarios related to the agricultural water fee elucidates farmers’ observed behaviors in rural China. Generally, in the three mental accounting scenarios, two conditional intuitive expectations and nine conditional intuitive preferences are formed; however, the conditions of those expectations or preferences cannot be matched with the facts due to the reform of rural taxes and fees, the direct agricultural subsidy programs, and the internal attributes of agricultural water fee, which interpret those negative behaviors in rural China. Additionally, this paper offers a view into how previous policies create negative psychological externalities (such as farmers’ psychological dependence on the government) through mental accounting to negatively influence agents’ subsequent decision-making; it highlights the significance of underlying mental factors and information processing of negative behaviors in policymaking for managing or conserving common pool resources.
New insights on the origin of the woody flora of the Chihuahuan Desert: The case of Lindleya
Authors: Marilyn Vásquez‐Cruz , Victoria Sosa
Published: August 2016

PREMISE OF THE STUDY:

We reconstructed aspects of the evolutionary history of Lindleya, a shrubby element in the rose family, as a model for identifying the ancestral area of the biota of the Chihuahuan Desert and for understanding the effect that pre‐Pleistocene or Pleistocene climate fluctuations had on the evolution of the plants of this desert.

METHODS:

We conducted phylogenetic, biogeographic, and phylogeographic analyses based on one nuclear DNA and two plastid markers sequenced for 20 populations comprising 153 accessions and representing the species’ entire distribution range. We carried out ecological niche modeling to forecast Lindleya's potential distribution under Current, Last Interglacial, and Last Glacial Maximum conditions.

KEY RESULTS:

The ancestral area of Lindleya populations was probably in the central and southern parts of the Chihuahuan Desert. Levels of genetic and haplotype variation were the highest in the northernmost and southernmost areas and low levels of genetic variation in the central part. Extended Bayesian skyline plots including all populations identified a slight demographic expansion ∼1 Ma. The predicted potential distribution during the Last Glacial Maximum was very restricted.

CONCLUSIONS:

We suggest that pre‐Pleistocene changes had an influence on the divergence of Lindleya populations. We also suggest that the ancestral area for Lindleya was the Chihuahuan Desert and that the uplift of the Trans‐Mexican Volcanic Belt isolated the Tehuacán Valley populations. Genetic and demographic analyses as well as and ecological niche modeling indicate that populations of Lindleya experienced genetic bottlenecks and that they have expanded since the Last Glacial Maximum.
NEAR-INFRARED CIRCULAR AND LINEAR POLARIMETRY OF MONOCEROS R2
Authors: Kwon Jungmi , Tamura Motohide , Hough James H. , Nagata Tetsuya , Kusakabe Nobuhiko
Published: August 2016

We have conducted simultaneous JHK

s
-band imaging circular and linear polarimetry of the Monoceros R2 (Mon R2) cluster. We present results from deep and wide near-infrared linear polarimetry of the Mon R2 region. Prominent and extended polarized nebulosities over the Mon R2 field are revisited, and an infrared reflection nebula associated with the Mon R2 cluster and two local reflection nebulae, vdB 67 and vdB 69, is detected. We also present results from deep imaging circular polarimetry in the same region. For the first time, the observations show relatively high degrees of circular polarization (CP) in Mon R2, with as much as approximately 10% in the K

s
band. The maximum CP extent of a ring-like nebula around the Mon R2 cluster is approximately 0.60 pc, while that of a western nebula, around vdB 67, is approximately 0.24 pc. The extended size of the CP is larger than those seen in the Orion region around IRc2, while the maximum degree of CP of ∼10% is smaller than those of ∼17% seen in the Orion region. Nonetheless, both the CP size and degree of this region are among the largest in our infrared CP survey of star-forming regions. We have also investigated the time variability of the degree of the polarization of several infrared sources and found possible variations in three sources.
II ZWICKY 23 AND FAMILY: A GROUP IN INTERACTION
Authors: Wehner Elizabeth M. H. , Gallagher III John S. , Cigan Phillip J. , Rudie Gwen C.
Published: August 2016

II Zw 23 (UGC 3179) is a luminous (M

B
 ∼ −21) nearby compact narrow emission line starburst galaxy with blue optical colors and strong emission lines. We present a photometric and morphological study of II Zw 23 and its interacting companion, KPG103a, using data obtained with the WIYN 3.5 m telescope in combination with a WFPC2 image from the Hubble Space Telescope archives. II Zw 23 has a highly disturbed outer structure with long trails of debris that may be contributing material toward the production of tidal dwarfs. Its central regions appear disky, a structure that is consistent with the overall rotation pattern observed in the Hα velocity field measured from Densepak observations obtained with WIYN. We find additional evidence for interaction in this system, including the discovery of a new tidal loop extending from an associated dwarf galaxy, which appears to be in the process of disrupting along its orbit. We also present Hα equivalent widths and discuss the relative star formation rates across this interacting system.
DICKE’S SUPERRADIANCE IN ASTROPHYSICS. II. THE OH 1612 MHz LINE
Authors: Rajabi Fereshteh , Houde Martin
Published: August 2016

We apply the concept of superradiance that was introduced by Dicke in 1954 to the OH molecule 1612 MHz spectral line, which is often used for the detection of masers in the circumstellar envelopes of evolved stars. Because the detection of 1612 MHz OH masers in the outer shells of envelopes of these stars implies the existence of a population inversion and a high level of velocity coherence, and that these are two necessary requirements for superradiance, we investigate whether superradiance can also happen in these regions. Superradiance is characterized by high-intensity, spatially compact, burst-like features taking place over timescales on the order of seconds to years, depending on the size and physical conditions present in the regions harboring such sources of radiation. Our analysis suggests that superradiance provides a valid explanation for previous observations of intensity flares detected in that spectral line for the U Orionis Mira star and the IRAS 18276-1431 preplanetary nebula.
A HOT BIG BANG THEORY: MAGNETIC FIELDS AND THE EARLY EVOLUTION OF THE PROTOLUNAR DISK
Authors: Gammie C. F. , Liao Wei-Ting , Ricker P. M.
Published: August 2016

The leading theory for the formation of Earth’s Moon invokes a collision between a Mars-sized body and the proto-Earth to produce a disk of orbiting material that later condenses to form the Moon. We show that the disk opacity is large, and cooling is therefore inefficient (

). In this regime, angular momentum transport in the disk leads to steady heating unless

. Following earlier work by Charnoz and Michaut, and Carballido et al., we show that once the disk is completely vaporized it is well coupled to the magnetic field. We consider a scenario in which turbulence driven by magnetic fields leads to a brief, hot phase where the disk is geometrically thick, with strong turbulent mixing. The disk cools by spreading until it decouples from the field. We point out that approximately half the accretion energy is dissipated in the boundary layer where the disk meets the Earth’s surface. This creates high entropy material close to the Earth, driving convection and mixing. Finally, a hot magnetized disk could drive bipolar outflows that remove mass and angular momentum from the Earth–Moon system.
CRITICAL DIFFERENCES OF ASYMMETRIC MAGNETIC RECONNECTION FROM STANDARD MODELS
Authors: Nitta S. 新田伸也 , Wada T. 和田智秀 , Fuchida T. 淵田泰介 , Kondoh K. 近藤光志
Published: August 2016

We have clarified the structure of asymmetric magnetic reconnection in detail as the result of the spontaneous evolutionary process. The asymmetry is imposed as ratio k of the magnetic field strength in both sides of the initial current sheet (CS) in the isothermal equilibrium. The MHD simulation is carried out by the HLLD code for the long-term temporal evolution with very high spatial resolution. The resultant structure is drastically different from the symmetric case (e.g., the Petschek model) even for slight asymmetry k = 2. (1) The velocity distribution in the reconnection jet clearly shows a two-layered structure, i.e., the high-speed sub-layer in which the flow is almost field aligned and the acceleration sub-layer. (2) Higher beta side (HBS) plasma is caught in a lower beta side plasmoid. This suggests a new plasma mixing process in the reconnection events. (3) A new large strong fast shock in front of the plasmoid forms in the HBS. This can be a new particle acceleration site in the reconnection system. These critical properties that have not been reported in previous works suggest that we contribute to a better and more detailed knowledge of the reconnection of the standard model for the symmetric magnetic reconnection system.
CARBON STARS FROM LAMOST DR2 DATA
Authors: Ji Wei , Cui Wenyuan , Liu Chao , Luo Ali , Zhao Gang , Zhang Bo
Published: August 2016

In this work, we present the new catalog of carbon stars from the LAMOST DR2 catalog. In total, 894 carbon stars are identified from multiple line indices measured from the stellar spectra. We are able to identify the carbon stars by combining the CN bands in the red end with C2 and other lines. Moreover, we also classify the carbon stars into spectral sub-types of C–H, C–R, and C–N. These sub-types show distinct features in the multi-dimensional line indices, implying that in the future they can be used to identify carbon stars from larger spectroscopic data sets. While the C–N stars are clearly separated from the others in the line index space, we find no clear separation between the C–R and C–H sub-types. The C–R and C–H stars seem to smoothly transition from one to another. This may hint that the C–R and C–H stars may not be different in their origins, instead their spectra look different because of different metallicities. Due to the relatively low spectral resolution and lower signal-to-noise ratio, the ratio of 12C/13C is not measured and thus the C–J stars are not identified.
DISCO: A 3D MOVING-MESH MAGNETOHYDRODYNAMICS CODE DESIGNED FOR THE STUDY OF ASTROPHYSICAL DISKS
Authors: Duffell Paul C.
Published: August 2016

This work presents the publicly available moving-mesh magnetohydrodynamics (MHD) code DISCO. DISCO is efficient and accurate at evolving orbital fluid motion in two and three dimensions, especially at high Mach numbers. DISCO employs a moving-mesh approach utilizing a dynamic cylindrical mesh that can shear azimuthally to follow the orbital motion of the gas. The moving mesh removes diffusive advection errors and allows for longer time-steps than a static grid. MHD is implemented in DISCO using an HLLD Riemann solver and a novel constrained transport (CT) scheme that is compatible with the mesh motion. DISCO is tested against a wide variety of problems, which are designed to test its stability, accuracy, and scalability. In addition, several MHD tests are performed which demonstrate the accuracy and stability of the new CT approach, including two tests of the magneto-rotational instability, one testing the linear growth rate and the other following the instability into the fully turbulent regime.
A SOLAR-PUMPED FLUORESCENCE MODEL FOR LINE-BY-LINE EMISSION INTENSITIES IN THE B–X, A–X, AND X–X BAND SYSTEMS OF 12C14N
Authors: Paganini L. , Mumma M. J.
Published: August 2016

We present a new quantitative model for detailed solar-pumped fluorescent emission of the main isotopologue of CN. The derived fluorescence efficiencies permit estimation and interpretation of ro-vibrational infrared line intensities of CN in exospheres exposed to solar (or stellar) radiation. Our g-factors are applicable to astronomical observations of CN extending from infrared to optical wavelengths, and we compare them with previous calculations in the literature. The new model enables extraction of rotational temperature, column abundance, and production rate from astronomical observations of CN in the inner coma of comets. Our model accounts for excitation and de-excitation of rotational levels in the ground vibrational state by collisions, solar excitation to the

and

electronically excited states followed by cascade to ro-vibrational levels of

, and direct solar infrared pumping of ro-vibrational levels in the

state. The model uses advanced solar spectra acquired at high spectral resolution at the relevant infrared and optical wavelengths and considers the heliocentric radial velocity of the comet (the Swings effect) when assessing the exciting solar flux for a given transition. We present model predictions for the variation of fluorescence rates with rotational temperature and heliocentric radial velocity. Furthermore, we test our fluorescence model by comparing predicted and measured line-by-line intensities for

(1–0) in comet C/2014 Q2 (Lovejoy), thereby identifying multiple emission lines observed at IR wavelengths.
A COMPARISON OF STELLAR ELEMENTAL ABUNDANCE TECHNIQUES AND MEASUREMENTS
Authors: Hinkel Natalie R. , Young Patrick A. , Pagano Michael D. , Desch Steven J. , Anbar Ariel D. , Adibekyan Vardan , Blanco-Cuaresma Sergi , Carlberg Joleen K. , Mena Elisa Delgado , Liu Fan , Nordlander Thomas , Sousa Sergio G. , Korn Andreas , Gruyters Pieter , Heiter Ulrike , Jofré Paula , Santos Nuno C. , Soubiran Caroline
Published: August 2016

Stellar elemental abundances are important for understanding the fundamental properties of a star or stellar group, such as age and evolutionary history, as well as the composition of an orbiting planet. However, as abundance measurement techniques have progressed, there has been little standardization between individual methods and their comparisons. As a result, different stellar abundance procedures determine measurements that vary beyond the quoted error for the same elements within the same stars. The purpose of this paper is to better understand the systematic variations between methods and offer recommendations for producing more accurate results in the future. We invited a number of participants from around the world (Australia, Portugal, Sweden, Switzerland, and the United States) to calculate 10 element abundances (C, O, Na, Mg, Al, Si, Fe, Ni, Ba, and Eu) using the same stellar spectra for four stars (HD 361, HD 10700, HD 121504, and HD 202206). Each group produced measurements for each star using (1) their own autonomous techniques, (2) standardized stellar parameters, (3) a standardized line list, and (4) both standardized parameters and a line list. We present the resulting stellar parameters, absolute abundances, and a metric of data similarity that quantifies the homogeneity of the data. We conclude that standardization of some kind, particularly stellar parameters, improves the consistency between methods. However, because results did not converge as more free parameters were standardized, it is clear there are inherent issues within the techniques that need to be reconciled. Therefore, we encourage more conversation and transparency within the community such that stellar abundance determinations can be reproducible as well as accurate and precise.
Middle East respiratory syndrome coronavirus (MERS-CoV) outbreak perceptions of risk and stress evaluation in nurses
Authors: Bukhari Elham Essa , Temsah Mohamad Hani , Aleyadhy Ayman A , Alrabiaa Abdulkareem A , Alhboob Ali An , Jamal Amr A , Binsaeed Abdulaziz A
Published: August 2016

Introduction: Saudi Arabia was affected by an outbreak of Middle East respiratory syndrome coronavirus (MERS-CoV). We aimed to determine the perception of risk and level of stress among nurses. Methodology: A questionnaire survey was administered to determine the perceptions of risk of MERS-CoV infection. Results: The majority of the participants were females (332; 86.0%), and there were 54 (14.0%) males. Of the 386 respondents, nurses constituted the majority of the respondents (293; 75.9%), and there were 34 doctors (8.8%). The percentage of exposure was found to be greater in those who were working in the intensive care unit (ICU) (89; 23%). There was a significant difference in the worry and fear scale of contracting the MERS-CoV infection between participants who worked in isolation areas, ICUs, and emergency rooms (mean: 3.01 ± 1.1) compared to participants who worked in areas that are less likely to admit and have MERS-CoV suspected or positive cases (mean: 2.77 ± 1.1; p = 0.031. Females were significantly more worried and fearful of contracting the virus compared to males (mean: 2.92 ± 1.1 versus 2.61 ± 1.0, respectively; p = 0.045). Conclusions: MERS-CoV caused a relatively significant level of distress among nurses. There was a difference in the worry and fear scale of contracting the MERS-CoV infection between participants who worked in areas likely to admit and have MERS-CoV suspected or positive cases. After the campaign, the level of confidence got higher and the participants were more adherent to the infection control precautions.
Ebola outbreak preparedness and preventive measures among healthcare providers in Saudi Arabia
Authors: Almutairi Khalid M. , Alodhayani Abdulaziz Alhomaidi , Moussa Mahaman , Aboshaiqah Ahmad E. , Tumala Regie B. , Vinluan Jason M.
Published: August 2016

Introduction: As medical professionals on the front lines in the outbreaks of infectious disease like Ebola Virus Disease (EVD), healthcare providers must have sufficient knowledge, skills, and best practices to protect themselves and the public from the disease. The purpose of this study is to identify the level of awareness, attitudes and practices among healthcare workers in relation to precautionary measures to EVD. Methodology: A total of 177 physicians and 545 nurses participated in a descriptive cross-sectional study from a tertiary government hospital in Saudi Arabia. All subjects answered a self-administered questionnaire focusing on their level of awareness, concerns, and clinical practice related to EVD. Results: Majority of the participants were knowledgeable about the etiology, mode of transmission, signs and symptoms, and treatment of EVD. All of the participants had high levels of concern about EVD (p=0.001) and about the implementation of strict standard infection control precautionary measures. The study found that greater infection control measures were taken by the participants including frequent hand washing, use of personal protective equipment, and avoiding normal activities such as going to work, school, travel, etc. if fever symptoms appear. Conclusion: A combination of evidence based knowledge about EVD and high levels of concern of healthcare providers in relation to precautionary measures to EVD are the main factors leading to strict compliance with the infection control measures recommended in this study. Additionally, healthcare providers must be trained in infection control and adhere to the universal infection control standard guidelines to facilitate prevention and precaution.
Detection of Mycobacterium avium subsp. paratuberculosis in Iranian patients with type 1 diabetes mellitus by PCR and ELISA
Authors: Hesam Shariati Sonia , Alaei Anoosha , Keshavarz Rouhollah , Mosavari Nader , Rabbani Ali , Niegowska Magdalena , Sechi Leonardo A , Feizabadi Mohammad Mehdi
Published: August 2016

Introduction: Mycobacterium avium subsp. paratuberculosis (MAP) is the causative agent of paratuberculosis or Johne’s disease in ruminants. Its role in triggering autoimmunity, including type 1 diabetes mellitus (T1DM), has been reported in recent years. Due to the high contamination rate of MAP in Iran’s livestock and the increasing outbreak of T1DM, we investigated this association in a small group of patients with T1DM in Iran. Methodology: Blood samples of 29 T1DM patients and 29 healthy control subjects were tested through enzyme-linked immunosorbent assay (ELISA) to detect antibodies against MAP3865c and ZnT8 homologous epitopes and the presence of MAP DNA. Blood samples were also cultured in mycobacterial growth indicator tubes and Herrold's egg yolk medium containing mycobactin J. Results: The results of ELISA showed a significant difference between T1DM patients and healthy group. IS900 was also detected in 51.72% of T1DM patients but in none of the control group. None of the samples grew in culture media. Conclusions: Due to the presence of MAP DNA and antibodies against MAP peptides in a significant number of T1DM patients compared with healthy control subjects, we may consider MAP as a possible trigger of T1DM in Iran. This indicates that exposure to MAP occurred in the positive subjects. Identifying the sources of contamination and routes of MAP transmission to humans seems necessary to prevent and reduce the burden of MAP infection in Iran.
Detection and identification of coxsackievirus B3 from sera of an Indonesian patient with undifferentiated febrile illness
Authors: Wiyatno Ageng , Antonjaya Ungke , Ma'roef Chairin Nisa , Riswari Silvita Fitri , Djauhari Hofiya , Artika I Made , Monagin Corina , Schneider Bradley S. , Myint Khin Saw , Alisjahbana Bachti , Safari Dodi , Kosasih Herman
Published: August 2016

Introduction: Coxsackievirus B3 (CVB3) virus has been implicated as the causative agent of various outbreaks of clinical disease, including hand, foot, and mouth diseases, aseptic meningitis, acute myocarditis, and inflammatory cardiomyopathy. Methodology: Two hundred and nine undiagnosed cryopreserved specimens obtained from factory workers in Bandung, Indonesia, who displayed symptoms of acute febrile illness were gathered. Total RNA was isolated from serum and tested by conventional polymerase chain reaction (PCR) using Enterovirus genus-level primers and confirmed by sequencing. Concurrently, the virus was isolated in LLC-MK2 cells. Results: CVB3 virus was identified in an archived specimen from a patient who presented with symptoms of fever, headache, myalgia, and nausea. Sequencing results of the VP1 region from both the clinical sample and tissue culture supernatant showed 97% homology to a CVB3 virus isolate from Taiwan. Virus propagation in LLC-MK2 cell culture exhibited severe cytopathic effects two days post-inoculation. Conclusions: We report the first case of CVB3 from an undifferentiated febrile illness specimen from Indonesia.
Serological and molecular analysis on the relationships between type 2 diabetes mellitus and hepatitis B virus infection
Authors: Zhu Huijuan , Wang Yiying , Yu Lugang , Xu Yunfang , Zhou Hui , Ding Yi , Wang Aili , Liu Xingxiang , Dong Chen
Published: August 2016

Introduction: This study aimed to further analyze the associations between type 2 diabetes mellitus (T2DM) and hepatitis B virus (HBV) infection, and to investigate the relationships between T2DM and the mutations within the HBV major hydrophilic region (MHR). Methodology: In this cross-sectional study, 3,377 persons (338 T2DM patients and 3,039 non-diabetics) were randomly selected. HBsAg detection was performed by enzyme-linked immunosorbent assay. The HBV MHR was amplified, sequenced, and analyzed by nested PCR. Results: The seroprevalence of HBsAg was 21.30% in T2DM patients (72/338), which was significantly higher than in non-diabetics (15.53%). Compared to persons without T2DM, the proportion of T2DM patients positive for HBsAg was significantly elevated in males, people > 55 years (p = 0.039), and people with a body mass index (BMI) ≥ 24 kg/m2. Totally, 112 genotype B and 111 genotype C HBV sequences were isolated. No significant difference in HBV genotype distribution was observed between T2DM patients and non-diabetics. Compared to genotype C HBV-infected cases in non-diabetics, the amino acid substitution rates in the MHR were significantly higher in T2DM patients (p = 0.003). Moreover, seven HBV strains with stop codon mutations within the HBV S gene were identified: three from T2DM patients (5.45%) and four from non-diabetics (2.38%). Conclusions: In China, T2DM is significantly associated with chronic HBV infections and genotype C HBV MHR mutations. Being males, > 55 years of age, and ≥ 24 kg/m2 of BMI are the risk factors of HBV infection in T2DM patients.
Mutations of domain V in 23S ribosomal RNA of macrolide-resistant Mycoplasma gallisepticum isolates in Egypt
Authors: Ammar Ahmed M , Abd El-Aziz Norhan K , Gharib Ahlam A , Ahmed Hanaa K , Lameay Amira E
Published: August 2016

Introduction: Avian mycoplasmas impose a significant economic burden to the poultry industry. In recent years, macrolide-resistant Mycoplasma gallisepticum have occasionally been encountered in Egypt. Methodology: This study was designed to document the involvement of macrolide-resistant M. gallisepticum in respiratory organs of chickens suffering respiratory problems. Concurrently, an exhaustive molecular characterization of the intrinsic resistance of recovered isolates to macrolides was done. Results: Of 120 chickens showing respiratory problems, 14 (11.67%) M. gallisepticum were isolated and genetically identified; 8 of them were recovered from air sacs, 4 from lungs, and 2 from tracheas. Broth microdilution of all M. gallisepticum isolates showed various degrees of minimum inhibitory concentrations (MICs) against macrolides: erythromycin (0.25–32 µg/mL), tylosin (0.0625–4 µg/mL), and tiamulin (0.031–2 µg/mL). Nucleotide sequencing of domain V (peptidyl transferase region) of the 23S rRNA gene of macrolide-resistant M. gallisepticum isolates revealed transition mutations at positions 2068 and 2069 (corresponding to 2058 and 2059 in Escherichia coli numbering) in an isolate and at position 2067 (corresponding to 2057 in E. coli numbering) in three isolates as hot spots for macrolide resistance. Surprisingly, a transversion mutation at position 2621 (corresponding to 2611 in E. coli numbering) was reported in one of the recovered isolates as a first report. Conclusion: Generation of new mutations is evidence for persistence of M. gallisepticum despite macrolide treatment. Periodic surveys to monitor for the possible appearance of resistant strains are recommended.
Diarrhea-associated pneumococcal meningitis with complicating hydrocephalus in a child in a resource-limited setting
Authors: Shahrin Lubaba , Chisti Mohammod Jobayer , Huq Sayeeda , Islam Md Munirul , Sarker Shafiqul Alam , Begum Mahmuda , Saha Shukla , Ahmed Tahmeed
Published: August 2016

Introduction: Streptococcus pneumonia is the most common and intimidating cause of childhood meningitis. Its delayed diagnosis may be associated with hyponatremia and hypernatremia with fatal outcome. Case presentation: A previously healthy nine-month-old Bangladeshi female infant was diagnosed with diarrhea, pneumonia, and convulsion due to hypernatremia. Pneumonia was confirmed by respiratory distress and radiological findings. Routine cerebrospinal fluid study detected pneumococcal meningitis. Ampicillin, gentamicin, and dexamethasone were promptly started. On day three of hospitalization, convulsion re-appeared with worsening of consciousness level. Antibiotics were switched to ceftriaxone and vancomycin, although ultrasonography of the brain revealed no abnormality. Contrast-enhanced computed tomography scan of the head was performed and revealed dilated ventricles with diffused enhancement of meninges and basal cisterns, demonstrating meningitis with ventriculomegaly. Ceftriaxone was replaced by meropenem to control fever. Magnetic resonance imaging (MRI) of the brain confirmed the progression of hydrocephalus. An emergency ventriculo-peritoneal (VP) shunt operation was performed with continuation of antibiotics for 21 days. After three months, follow-up MRI showed reduction of ventricular size with functioning VP shunt in situ with no neurological deficits. Conclusions: Childhood pneumococcal meningitis may be associated with diarrhea, pneumonia, and other related complication. Appropriate antibiotic therapy alone may not be sufficient to avert complications. Communicating hydrocephalus is potentially an ominous ramification of meningitis even when the ultrasonography result is normal. Rapid diagnosis is imperative to attain good outcome. Evidence advocates further research into the risk factors of meningitis in diarrheal children that may help in early diagnosis and management to reduce meningitis-related fatal outcome.
Multidrug-resistant enterococci in the hospital environment: detection of novel vancomycin-resistant E. faecium clone ST910
Authors: Dziri Raoudha , Lozano Carmen , Ben Said Leila , Bellaaj Ridha , Boudabous Abdellatif , Ben Slama Karim , Torres Carmen , Klibi Naouel
Published: August 2016

Introduction: The role of the hospital environment as a reservoir of resistant bacteria in Tunisia has been poorly investigated; however, it could be responsible for the transmission of multidrug-resistant bacteria. The objective was to study the prevalence of Enterococcus in the environment of a Tunisian hospital and the antibiotic resistance phenotype/genotype in recovered isolates, with special reference to vancomycin resistance. Methodology: A total of 300 samples were taken (March–June, 2013) and inoculated in Slanetz-Bartley agar plates supplemented or not supplemented with 8 µg/mL of vancomycin. Antibiotic resistance genes were tested by polymerase chain reaction (PCR). The clonal relatedness of the vanA isolates was assessed using pulsed-field gel electrophoresis (PFGE) and multilocus sequence testing (MLST). Results: Enterococci were recovered in 33.3% of tested samples inoculated in SB medium. E faecium was the most prevalent species, followed by E. faecalis and E. casseliflavus. Antimicrobial resistance genes detected were as follows (number of isolates): erm(B) (71), tet(M) (18), aph(3’)-IIIa (27), ant(6)-Ia (15), cat(A) (4), and van(C2) (6). Vancomycin-resistant-enterococci (VRE) were recovered from 14 samples (4.7%), when tested in SB-VAN. The 14 VRE (one per positive sample) were identified as E. faecium and contained the van(A),erm(B), tet(M), ant(6)-Ia, and aph(3’)-IIIa genes. Thirteen of the VRE strains were ascribed by PFGE and MLST to a novel clone (new ST910), and only one VRE strain was typed as ST80 included in CC17. Conclusions: The emergence and spread of new clones of VRE, especially in the hospital environment in this country, could become particularly problematic.
Public Health Emergency Operations Center - A critical component of mass gatherings management infrastructure
Authors: Elachola Habidah , Al-Tawfiq Jaffar A , Turkestani Abdulhafiz , Memish Ziad A
Published: August 2016

Mass gatherings (MG) are characterized by the influx of large numbers of people with the need to have infrastructural changes to support these gatherings. Thus, Public Health Emergency Operations Center (PHEOC) is critical management infrastructure for both the delivery of public health functions and for mounting adequate response during emergencies. The recognition of the importance of PHEOC at the leadership and political level is foundational for the success of any public health intervention during MG. The ability of the PHEOC to effectively function depends on appropriate design and infrastructure, staffing and command structure, and plans and procedures developed prior to the event. Multi-ministerial or jurisdictional coordination will be required and PHEOC should be positioned with such authorities. This paper outlines the essential concepts, elements, design, and operational aspects of PHEOC during MG.