bluuebunny/crossref_metadata_2025 huggingface dataset:
Olfaction-based Detection Distance: A Quantitative Analysis of How Far Away Dogs Recognize Tortoise Odor and Follow It to Source
Authors: Cablk Mary E. , Sagebiel John C. , Heaton Jill S. , Valentin Cindee
Published: December 2008

The use of detector dogs has been demonstrated to be effective and safe for finding Mojave desert tortoises and provides certain advantages over humans in field surveys. Unlike humans who rely on visual cues for target identification, dogs use primarily olfactory cues and can therefore locate targets that are not visually obvious. One of the key benefits of surveying with dogs is their efficiency at covering ground and their ability to detect targets from long distances. Dogs may investigate potential targets using visual cues but confirm the presence of a target based on scent. Everything that emits odor does so via vapor-phase molecules and the components comprising a particular scent are carried primarily though bulk movement of the atmosphere. It is the ability to search for target odor and then go to its source that makes dogs ideal for rapid target recognition in the field setting. Using tortoises as targets, we quantified distances that dogs detected tortoise scent, followed it to source, and correctly identified tortoises as targets. Detection distance data were collected during experimental trials with advanced global positioning system (GPS) technology and then analyzed using geographic information system (GIS) modeling techniques. Detection distances ranged from 0.5 m to 62.8 m for tortoises on the surface. We did not observe bias with tortoise size, age class, sex or the degree to which tortoises were handled prior to being found by the dogs. The methodology we developed to quantify olfaction-based detection distance using dogs can be applied to other targets that dogs are trained to find.
Error and Performance Analysis of MEMS-based Inertial Sensors with a Low-cost GPS Receiver
Authors: Park Minha , Gao Yang
Published: December 2008

Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS), have been widely utilized and their applications are becoming popular, not only in military or commercial applications, but also for everyday life. Although GPS measurements are the essential information for currently developed land vehicle navigation systems (LVNS), GPS signals are often unavailable or unreliable due to signal blockages under certain environments such as urban canyons. This situation must be compensated in order to provide continuous navigation solutions. To overcome the problems of unavailability and unreliability using GPS and to be cost and size effective as well, Micro Electro Mechanical Systems (MEMS) based inertial sensor technology has been pushing for the development of low-cost integrated navigation systems for land vehicle navigation and guidance applications. This paper will analyze the characterization of MEMS based inertial sensors and the performance of an integrated system prototype of MEMS based inertial sensors, a low-cost GPS receiver and a digital compass. The influence of the stochastic variation of sensors will be assessed and modeled by two different methods, namely Gauss-Markov (GM) and AutoRegressive (AR) models, with GPS signal blockage of different lengths. Numerical results from kinematic testing have been used to assess the performance of different modeling schemes.
An Electrochemical Detection of Metallothioneins at the Zeptomole Level in Nanolitre Volumes
Authors: Adam Vojtech , Baloun Jiri , Fabrik Ivo , Trnkova Libuse , Kizek Rene
Published: December 2008

An Electrochemical Detection of Metallothioneins at the Zeptomole Level in Nanolitre VolumesWe report on improvement of the adsorptive transfer stripping technique (AdTS) coupled with the differential pulse voltammetry Brdicka reaction to determine a thiol-protein. The current technique has been unable to generate reproducible results when analyzing very low sample volumes (nanolitres). This obstacle can be overcome technically by modifying the current transfer technique including cooling step of the adsorbed analyte. We tested the technique on determination of a promising tumour disease marker protein called metallothionein (MT). The detection limit (3 S/N) of MT was evaluated as 500 zeptomoles per 500 nL (1 pM) and the quantification limit (10 S/N) as 1,500 zeptomoles per 500 nL (3 pM). Further, the improved AdTS technique was utilized to analyze blood serum samples from patients with breast cancer. Based on the results obtained it can be concluded that the improved technique can be used to detect a thiolprotein in very low sample volumes and can also prevent interferences during the washing and transferring step.
Developments in the Field of Conducting and Non-conducting Polymer Based Potentiometric Membrane Sensors for Ions Over the Past Decade
Authors: Faridbod Farnoush , Norouzi Parviz , Dinarvand Rassoul , Ganjali Mohammad Reza
Published: December 2008

Many research studies have been conducted on the use of conjugated polymers in the construction of chemical sensors including potentiometric, conductometric and amperometric sensors or biosensors over the last decade. The induction of conductivity on conjugated polymers by treating them with suitable oxidizing agents won Heeger, MacDiarmid and Shirakawa the 2000 Nobel Prize in Chemistry. Common conjugated polymers are poly(acetylene)s, poly(pyrrole)s, poly(thiophene)s, poly(terthiophene)s, poly(aniline)s, poly(fluorine)s, poly(3-alkylthiophene)s, polytetrathiafulvalenes, polynapthalenes, poly(p-phenylene sulfide), poly(p-phenylenevinylene)s, poly(3,4-ethylenedioxythiophene), polyparaphenylene, polyazulene, polyparaphenylene sulfide, polycarbazole and polydiaminonaphthalene. More than 60 sensors for inorganic cations and anions with different characteristics based on conducting polymers have been reported. There have also been reports on the application of non-conducting polymers (nCPs), i.e. PVC, in the construction of potentiometric membrane sensors for determination of more than 60 inorganic cations and anions. However, the leakage of ionophores from the membranes based on these polymers leads to relatively lower life times. In this article, we try to give an overview of Solid-Contact ISE (SCISE), Single-Piece ISE (SPISE), Conducting Polymer (CP)-Based, and also non-conducting polymer PVC-based ISEs for various ions which their difference is in the way of the polymer used with selective membrane. In SCISEs and SPISEs, the plasticized PVC containing the ionophore and ionic additives govern the selectivity behavior of the electrode and the conducting polymer is responsible of ion-to-electron transducer. However, in CPISEs, the conducting polymer layer is doped with a suitable ionophore which enhances the ion selectivity of the CP while its redox response has to be suppressed.
Absorbance Based Light Emitting Diode Optical Sensors and Sensing Devices
Authors: O’Toole Martina , Diamond Dermot
Published: December 2008

The ever increasing demand for in situ monitoring of health, environment and security has created a need for reliable, miniaturised sensing devices. To achieve this, appropriate analytical devices are required that possess operating characteristics of reliability, low power consumption, low cost, autonomous operation capability and compatibility with wireless communications systems. The use of light emitting diodes (LEDs) as light sources is one strategy, which has been successfully applied in chemical sensing. This paper summarises the development and advancement of LED based chemical sensors and sensing devices in terms of their configuration and application, with the focus on transmittance and reflectance absorptiometric measurements.
Inter-Comparison of ASTER and MODIS Surface Reflectance and Vegetation Index Products for Synergistic Applications to Natural Resource Monitoring
Authors: Miura Tomoaki , Yoshioka Hiroki , Fujiwara Kayo , Yamamoto Hirokazu
Published: December 2008

Synergistic applications of multi-resolution satellite data have been of a great interest among user communities for the development of an improved and more effective operational monitoring system of natural resources, including vegetation and soil. In this study, we conducted an inter-comparison of two remote sensing products, namely, visible/near-infrared surface reflectances and spectral vegetation indices (VIs), from the high resolution Advanced Thermal Emission and Reflection Radiometer (ASTER) (15 m) and lower resolution Moderate Resolution Imaging Spectroradiometer (MODIS) (250 m – 500 m) sensors onboard the Terra platform. Our analysis was aimed at understanding the degree of radiometric compatibility between the two sensors’ products due to sensor spectral bandpasses and product generation algorithms. Multiple pairs of ASTER and MODIS standard surface reflectance products were obtained at randomly-selected, globally-distributed locations, from which two types of VIs were computed: the normalized difference vegetation index and the enhanced vegetation indices with and without a blue band. Our results showed that these surface reflectance products and the derived VIs compared well between the two sensors at a global scale, but subject to systematic differences, of which magnitudes varied among scene pairs. An independent assessment of the accuracy of ASTER and MODIS standard products, in which “in-house” surface reflectances were obtained using in situ Aeronet atmospheric data for comparison, suggested that the performance of the ASTER atmospheric correction algorithm may be variable, reducing overall quality of its standard reflectance product. Atmospheric aerosols, which were not corrected for in the ASTER algorithm, were found not to impact the quality of the derived reflectances. Further investigation is needed to identify the sources of inconsistent atmospheric correction results associated with the ASTER algorithm, including additional quality assessments of the ASTER and MODIS products with other atmospheric radiative transfer codes.
Improving Empirical Mode Decomposition Using Support Vector Machines for Multifocus Image Fusion
Authors: Chen Shaohui , Su Hongbo , Zhang Renhua , Tian Jing , Yang Lihu
Published: December 2008

Empirical mode decomposition (EMD) is good at analyzing nonstationary and nonlinear signals while support vector machines (SVMs) are widely used for classification. In this paper, a combination of EMD and SVM is proposed as an improved method for fusing multifocus images. Experimental results show that the proposed method is superior to the fusion methods based on à-trous wavelet transform (AWT) and EMD in terms of quantitative analyses by Root Mean Squared Error (RMSE) and Mutual Information (MI).
Estimation of Stand Type Parameters and Land Cover Using Landsat-7 ETM Image: A Case Study from Turkey
Authors: Günlü Alkan , Sivrikaya Fatih , Baskent Emin Zeki , Keles Sedat , Çakir Günay , Kadiogullari Ali İhsan
Published: December 2008

Remote sensing has been considered a low-cost, large-area coverage forest information resource ideally suited to broad-scale forest inventory objectives. The objective of this study is to determine stand type parameters such as crown closure, development stage and stand types, and land cover obtained from Landsat 7 ETM image and forest cover type map (stand type map). The research also focuses on classifying and mapping the stand parameters with the spatial analysis functions of GIS. In the study, stand parameters determined by forest cover type map and remote sensing methods were compared and contrasted to evaluate the potential use of the remote sensing methods. The result showed that development stage were estimated with Landsat 7 ETM image using supervised classification with a 0.89 kappa statistic value and 92% overall accuracy assessments. Among the features, development stages were the most successfully classified stand parameters in classification process. According to the spatial accuracy assessment results, development stages also had the highest accuracy of 72.2%. As can be seen in the results, spatial accuracy is lower than classification accuracy. Stand type had the lowest accuracy of 32.8. In conclusion, it could be stated that development stages, crown closure and land cover could be determined at an acceptable level using Landsat 7 ETM image. However, Landsat 7 ETM image do not provide means to map and monitor minor vegetation communities and stand types at stand level due to low spatial resolution. High resolution satellite images could be used either alone or with field survey data.
Classifying Oriental Beech (Fagus orientalis Lipsky.) Forest Sites Using Direct, Indirect and Remote Sensing Methods: A Case Study from Turkey
Authors: Günlü Alkan , Baskent Emin Zeki , Kadiogullari Ali İhsan , Ercanli İlker
Published: December 2008

Determining the productivity of forest sites through various classification techniques is important for making appropriate forest management decisions. Forest sites were classified using direct and indirect (site index) and remote sensing (Landsat 7 ETM and Quickbird satellite image) methods. In the direct method, forest site classifications were assigned according to edafic (soil properties), climate (precipitation and temperature) and topographic (altitude, slope, aspect and landform) factors. Five different forest site classes (dry, moderate fresh, fresh, moist and highly moist) were determined. In the indirect method, the guiding curve was used to generate anamorphic site index (SI) equations resulting in three classes; good (SI=I-II), medium (SI=III) and poor (SI=IV-V). Forest sites were also determined with a remote sensing method (RSM) using supervised classification of Landsat 7 ETM and Quickbird satellite images with a 0.67 kappa statistic value and 73.3% accuracy assessments; 0.88 kappa statistic value and 90.7% accuracy assessments, respectively. Forest sites polygon themes obtained from the three methods were overlaid and areas in the same classes were computed with Geographic Information Systems (GIS). The results indicated that direct and SI methods were consistent as a 3% dry site (19.0 ha) was exactly determined by both the direct and SI methods as a site class IV. Comparison of SI and RMS methods indicated a small difference as the area was highly homogeneous and unmanaged. While 15.4 ha area (open and degraded areas) was not determined by SI but RSM. A 19.0 ha (100%) poor site was determined by the SI method, 14.9 ha (78%) poor site was in Landsat 7 ETM satellite image and 17.4 ha (92%) poor site in Quickbird satellite image. The relationship between direct and SI methods were statistically analyzed using chi-square test. The test indicated a statistically significant relationships between forest sites determined by direct method and Quicbird satellite image (χ2 = 36.794; df = 16; p = 0.002), but no significant relationships with Landsat 7 ETM satellite image (χ2 = 22.291; df = 16; p = 0.134). Moderate association was found between SI method and direct method (χ2 = 16.724; df = 8; p = 0.033).
Analyzing the Variation of Building Density Using High Spatial Resolution Satellite Images: the Example of Shanghai City
Authors: Pan Xian-Zhang , Zhao Qi-Guo , Chen Jie , Liang Yin , Sun Bo
Published: December 2008

Building density is an important issue in urban planning and land management. In the article, building coverage ratio (BCR) and floor area ratio (FAR) values extracted from high resolution satellite images were used to indicate buildings’ stretching on the surface and growth along the third dimension within areas of interest in Shanghai City, P.R. China. The results show that the variation of FAR is higher than that of BCR in the inner circle, and that the newer commercial centers have higher FAR and lower BCR values, while the traditional commercial areas have higher FAR and BCR ratios. By comparing different residential areas, it was found that the historical “Shikumen” areas and the old residential areas built before 1980s have higher BCR and lower FAR, while the new residential areas have higher FAR and lower BCR, except for the villa areas. These results suggest that both older building areas and villa areas use land resources in an inefficient way, and therefore better planning and management of urban land are needed for those fast economic growing regions.
Energy-efficient Organization of Wireless Sensor Networks with Adaptive Forecasting
Authors: Wang Xue , Wang Sheng , Ma Jun-Jie , Bi Dao-Wei
Published: December 2008

Due to the wide potential applications of wireless sensor networks, this topic has attracted great attention. The strict energy constraints of sensor nodes result in great challenges for energy efficiency. This paper proposes an energy-efficient organization method. The organization of wireless sensor networks is formulated for target tracking. Target localization is achieved by collaborative sensing with multi-sensor fusion. The historical localization results are utilized for adaptive target trajectory forecasting. Combining autoregressive moving average (ARMA) model and radial basis function networks (RBFNs), robust target position forecasting is performed. Moreover, an energyefficient organization method is presented to enhance the energy efficiency of wireless sensor networks. The sensor nodes implement sensing tasks are awakened in a distributed manner. When the sensor nodes transfer their observations to achieve data fusion, the routing scheme is obtained by ant colony optimization. Thus, both the operation and communication energy consumption can be minimized. Experimental results verify that the combination of ARMA model and RBFN can estimate the target position efficiently and energy saving is achieved by the proposed organization method in wireless sensor networks.
Temporal Variability Corrections for Advanced Microwave Scanning Radiometer E (AMSR-E) Surface Soil Moisture: Case Study in Little River Region, Georgia, U.S.
Authors: Choi Minha , Jacobs Jennifer M.
Published: December 2008

Statistical correction methods, the Cumulative Distribution Function (CDF) matching technique and Regional Statistics Method (RSM) are applied to adjust the limited temporal variability of Advanced Microwave Scanning Radiometer E (AMSR-E) data using the Common Land Model (CLM). The temporal variability adjustment between CLM and AMSR-E data was conducted for annual and seasonal periods for 2003 in the Little River region, GA. The results showed that the statistical correction techniques improved AMSR-E’s limited temporal variability as compared to ground-based measurements. The regression slope and intercept improved from 0.210 and 0.112 up to 0.971 and -0.005 for the non-growing season. The R2 values also modestly improved. The Moderate Resolution Imaging Spectroradiometer (MODIS) Leaf Area Index (LAI) products were able to identify periods having an attenuated microwave brightness signal that are not likely to benefit from these statistical correction techniques.
Working Principle Simulations of a Dynamic ResonantWall Shear Stress Sensor Concept
Authors: Zhang Xu , Naughton Jonathan W. , Lindberg William R.
Published: December 2008

This paper discusses a novel dynamic resonant wall shear stress sensor concept based on an oscillating sensor operating near resonance. The interaction between the oscillating sensor surface and the fluid above it is modelled using the unsteady laminar boundary layer equations. The numerical experiment shows that the effect of the oscillating shear stress is well correlated by the Hummer number, the ratio of the steady shear force caused by the outside flow to the oscillating viscous force created by the sensor motion. The oscillating shear stress predicted by the fluid model is used in a mechanical model of the sensor to predict the sensor’s dynamic motion. Static calibration curves for amplitude and frequency influences are predicted. These results agree with experimental results on some extent, and shows some expectation for further development of the dynamic resonant sensor concept.
Deployment of a Prototype Plant GFP Imager at the Arthur Clarke Mars Greenhouse of the Haughton Mars Project
Authors: Paul Anna-Lisa , Bamsey Matthew , Berinstain Alain , Braham Stephen , Neron Philip , Murdoch Trevor , Graham Thomas , Ferl Robert J.
Published: December 2008

The use of engineered plants as biosensors has made elegant strides in the past decades, providing keen insights into the health of plants in general and particularly in the nature and cellular location of stress responses. However, most of the analytical procedures involve laboratory examination of the biosensor plants. With the advent of the green fluorescence protein (GFP) as a biosensor molecule, it became at least theoretically possible for analyses of gene expression to occur telemetrically, with the gene expression information of the plant delivered to the investigator over large distances simply as properly processed fluorescence images. Spaceflight and other extraterrestrial environments provide unique challenges to plant life, challenges that often require changes at the gene expression level to accommodate adaptation and survival. Having previously deployed transgenic plant biosensors to evaluate responses to orbital spaceflight, we wished to develop the plants and especially the imaging devices required to conduct such experiments robotically, without operator intervention, within extraterrestrial environments. This requires the development of an autonomous and remotely operated plant GFP imaging system and concomitant development of the communications infrastructure to manage dataflow from the imaging device. Here we report the results of deploying a prototype GFP imaging system within the Arthur Clarke Mars Greenhouse (ACMG) an autonomously operated greenhouse located within the Haughton Mars Project in the Canadian High Arctic. Results both demonstrate the applicability of the fundamental GFP biosensor technology and highlight the difficulties in collecting and managing telemetric data from challenging deployment environments.
Relocating Sensor Nodes to Maximize Cumulative Connected Coverage in Wireless Sensor Networks
Authors: Coskun Vedat
Published: December 2008

In order to extend the availability of the wireless sensor network and to extract maximum possible information from the surveillance area, proper usage of the power capacity of the sensor nodes is important. Our work describes a dynamic relocation algorithm called MaxNetLife, which is mainly based on utilizing the remaining power of individual sensor nodes as well as properly relocating sensor nodes so that all sensor nodes can transmit the data they sense to the sink. Hence, the algorithm maximizes total collected information from the surveillance area before the possible death of the sensor network by increasing cumulative connected coverage parameter of the network. A deterministic approach is used to deploy sensor nodes into the sensor field where Hexagonal Grid positioning is used to address and locate each sensor node. Sensor nodes those are not planned to be actively used in the close future in a specific cell are preemptively relocated to the cells those will be in need of additional sensor nodes to improve cumulative connected coverage of the network. MaxNetLife algorithm also includes the details of the relocation activities, which include preemptive migration of the redundant nodes to the cells before any coverage hole occurs because of death of a sensor node. Relocation Model, Data Aggregation Model, and Energy model of the algorithm are studied in detail. MaxNetLife algorithm is proved to be effective, scalable, and applicable through simulations.
Assessment of Organophosphate and Carbamate Pesticide Residues in Cigarette Tobacco with a Novel Cell Biosensor
Authors: Mavrikou Sophie , Flampouri Kelly , Moschopoulou Georgia , Mangana Olga , Michaelides Alexandros , Kintzios Spiridon
Published: December 2008

The conventional analysis of pesticide residues in analytical commodities, such as tobacco and tobacco products is a labor intensive procedure, since it is necessary to cover a wide range of different chemicals, using a single procedure. Standard analysis methods include extensive sample pretreatment (with solvent extraction and partitioning phases) and determination by GC and HPLC to achieve the necessary selectivity and sensitivity for the different classes of compounds under detection. As a consequence, current methods of analysis provide a limited sample capacity. In the present study, we report on the development of a novel cell biosensor for detecting organophosphate and carbamate pesticide residues in tobacco. The sensor is based on neuroblastoma N2a cells and the measurement of changes of the cell membrane potential, according to the working principle of the Bioelectric Recognition Assay (BERA). The presence of pesticide residues is detected by the degree of inhibition of acetylcholine esterase (AChE). The sensor instantly responded to both the organophoshate pesticide chlorpyriphos and the carbamate carbaryl in a concentration-dependent pattern, being able to detect one part per billion (1 ppb). Additionally, tobacco leaf samples (in blended dry form) were analyzed with both the novel biosensor and conventional methods, according to a double-blind protocol. Pesticide residues in tobacco samples caused a considerable cell membrane hyperpolarization to neuroblastoma cells immobilized in the sensor, as indicated by the increase of the negative sensor potential, which was clearly distinguishable from the sensor’s response against pesticide-free control samples. The observed response was quite reproducible, with an average variation of +5,6%. Fluorescence microscopy observations showed that treatment of the cells with either chlorpyrifos or carbaryl was associated with increased [Ca2+]cyt . The novel biosensor offers fresh perspectives for ultra-rapid, sensitive and low-cost monitoring of pesticide residues in tobacco as well as other food and agricultural commodities.
Alpine Grassland Phenology as Seen in AVHRR, VEGETATION, and MODIS NDVI Time Series - a Comparison with In Situ Measurements
Authors: Fontana Fabio , Rixen Christian , Jonas Tobias , Aberegg Gabriel , Wunderle Stefan
Published: December 2008

This study evaluates the ability to track grassland growth phenology in the Swiss Alps with NOAA-16 Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) time series. Three growth parameters from 15 alpine and subalpine grassland sites were investigated between 2001 and 2005: Melt-Out (MO), Start Of Growth (SOG), and End Of Growth (EOG).We tried to estimate these phenological dates from yearly NDVI time series by identifying dates, where certain fractions (thresholds) of the maximum annual NDVI amplitude were crossed for the first time. For this purpose, the NDVI time series were smoothed using two commonly used approaches (Fourier adjustment or alternatively Savitzky-Golay filtering). Moreover, AVHRR NDVI time series were compared against data from the newer generation sensors SPOT VEGETATION and TERRA MODIS. All remote sensing NDVI time series were highly correlated with single point ground measurements and therefore accurately represented growth dynamics of alpine grassland. The newer generation sensors VGT and MODIS performed better than AVHRR, however, differences were minor. Thresholds for the determination of MO, SOG, and EOG were similar across sensors and smoothing methods, which demonstrated the robustness of the results. For our purpose, the Fourier adjustment algorithm created better NDVI time series than the Savitzky-Golay filter, since latter appeared to be more sensitive to noisy NDVI time series. Findings show that the application of various thresholds to NDVI time series allows the observation of the temporal progression of vegetation growth at the selected sites with high consistency. Hence, we believe that our study helps to better understand largescale vegetation growth dynamics above the tree line in the European Alps.
Molecularly Imprinted Polymers: Thermodynamic and Kinetic Considerations on the Specific Sorption and Molecular Recognition
Authors: Li Songjun , Huang Xing , Zheng Mingxia , Li Wuke , Tong Kejun
Published: December 2008

This article presents a work aiming at thermodynamically and kinetically interpreting the specific sorption and recognition by a molecularly imprinted polymer. Using Boc-L-Phe-OH as a template, the imprinted material was prepared. The result indicates that the prepared polymer can well discriminate the imprint species from its analogue (Boc-D-Phe-OH), so as to adsorb more for the former but less for the latter. Kinetic analysis indicates that this specific sorption, in nature, can be a result of a preferential promotion. The imprint within the polymer causes a larger adsorption rate for the template than for the analogue. Thermodynamic study also implies that the molecular induction from the specific imprint to the template is larger than to the analogue, which thus makes the polymer capable of preferentially alluring the template to bind.
Feature Extraction and Spatial Interpolation for Improved Wireless Location Sensing
Authors: Lee Hyung Keun , Shim Ju-Young , Kim Hee-Sung , Li Binghao , Rizos Chris
Published: December 2008

This paper proposes a new methodology to improve location-sensing accuracy in wireless network environments eliminating the effects of non-line-of-sight errors. After collecting bulks of anonymous location measurements from a wireless network, the preparation stage of the proposed methodology begins. Investigating the collected location measurements in terms of signal features and geometric features, feature locations are identified. After the identification of feature locations, the non-line-of-sight error correction maps are generated. During the real-time location sensing stage, each user can request localization with a set of location measurements. With respected to the reported measurements, the pre-computed correction maps are applied. As a result, localization accuracy improves by eliminating the non-line-of-sight errors. A simulation result, assuming a typical dense urban environment, demonstrates the benefits of the proposed location sensing methodology.
Hemispheric Lateralization of Event-Related Brain Potentials in Different Processing Phases during Unimanual Finger Movements
Authors: Meng Ling-Fu , Lu Chiu-Ping , Li Yi-Wen
Published: December 2008

Previous functional MRI and brain electrophysiology studies have studied the left-right differences during the tapping tasks and found that the activation of left hemisphere was more significant than that of right hemisphere. In this study, we wanted to delineate this lateralization phenomenon not only in the execution phase but also in other processing phases, such as early visual, pre-executive and post-executive phases. We have designed a finger-tapping task to delineate the left-right differences of event related potentials (ERPs) to right finger movement in sixteen right handed college students. The mean amplitudes of ERPs were analyzed to examine the left-right dominance of cortical activity in the phase of early visual process (75-120ms), pre-execution (175-260ms), execution (310-420ms) and post-execution (420-620ms). In the execution phase, ERPs at the left electrodes were significantly more pronounced than those at the right electrodes (F3 > F4, C3 > C4, P3 > P4, O1 > O2) under the situation without comparing the central electrodes (Fz, Cz, Pz, and Oz). No difference was found between left and right electrodes in other three phases except the C3 electrode still showed more dominant than C4 in the pre- and post-execution phase. In conclusion, the phenomenon of brain lateralization occur major in the execution phase. The central area also showed the lateralization in the pre- and post-execution to demonstrate its unique lateralized contributions to unilateral simple finger movements.
Importance of plant traits and herbivory for invasiveness of Phragmites australis (Poaceae)
Authors: Park Mia G. , Blossey Bernd
Published: December 2008

Biological invasions change native plant communities, but theory predicting whether introductions create naturalized or invasive species is lacking. Focusing on either plant traits or interactions of introduced plants with native biota creates unreliable results, and improvements may require integration of trait‐ and interaction‐based approaches. To assess the importance of plant traits and herbivory on invasiveness, we incorporated herbivore effects in comparisons of growth and phenology of invasive Phragmites australis and its native congener P. australis subsp. americanus. Our results were influenced by venue (field or common garden), with extended life span and optimized leaf‐age structure of introduced P. australis indicating greater potential for resource capture. Attack by introduced gallflies affected expression of plant traits, but we found no consistent effect of aphid attack. Origin did not affect leaf emergence or stem height, but preferential gallfly attack stunted native P. australis and delayed senescence. Greater resource capture and lower attack by nonnative herbivores could give introduced P. australis an advantage over the native subspecies. Our results demonstrating the importance of plant traits as well as their modification by interactions with natural enemies questions whether the outcome of plant introductions can be predicted.
Genetic diversity and geographical structure of the pitcher plant Nepenthes vieillardii in New Caledonia: A chloroplast DNA haplotype analysis
Authors: Kurata Kaoruko , Jaffré Tanguy , Setoguchi Hiroaki
Published: December 2008

Among the many species that grow in New Caledonia, the pitcher plant Nepenthes vieillardii (Nepenthaceae) has a high degree of morphological variation. In this study, we present the patterns of genetic differentiation of pitcher plant populations based on chloroplast DNA haplotype analysis using the sequences of five spacers. We analyzed 294 samples from 16 populations covering the entire range of the species, using 4660 bp of sequence. Our analysis identified 17 haplotypes, including one that is widely distributed across the islands, as well as regional and private haplotypes. The greatest haplotype diversity was detected on the eastern coast of the largest island and included several private haplotypes, while haplotype diversity was low in the southern plains region. The parsimony network analysis of the 17 haplotypes suggested that the genetic divergence is the result of long‐term isolation of individual populations. Results from a spatial analysis of molecular variance and a cluster analysis suggest that the plants once covered the entire serpentine area of New Caledonia and that subsequent regional fragmentation resulted in the isolation of each population and significantly restricted seed flow. This isolation may have been an important factor in the development of the morphological and genetic variation among pitcher plants in New Caledonia.
Cytotype variation and allopolyploidy in North American species of the Sphagnum subsecundum complex (Sphagnaceae)
Authors: Ricca Mariana , Beecher Francis W. , Boles Sandra B. , Temsch Eva , Greilhuber Johann , Karlin Eric F. , Shaw A. Jonathan
Published: December 2008

Allopolyploid speciation is likely the predominant mode of sympatric speciation in plants. The Sphagnum subsecundum complex includes six species in North America. Three have haploid gametophytes, and three are thought to have diploid gametophytes. Microsatellite analyses indicated that some plants of S. inundatum and S. lescurii are heterozygous at most loci, but others have only one allele at each locus. Flow cytometry and Feulgen staining showed that heterozygous plants have twice the genome size as plants with one allele per locus; thus, microsatellite patterns can be used to survey the distribution and abundance of haploid and diploid gametophytes. Microsatellite analyses also revealed that S. carolinianum is consistently diploid, but S. lescurii and S. inundatum include both haploid and diploid populations. The frequency of diploid plants in S. lescurii increases with latitude. In an analysis of one population of S. lescurii, both cytotypes co‐occurred but were genetically differentiated with no evidence of interbreeding. The degree of genetic differentiation showed that the diploids were not derived from simple genome duplication of the local haploids. Heterozygosity appears to be fixed or nearly so in diploids, strongly suggesting that although morphologically indistinguishable from the haploids, they are derived by allopolyploidy.
Use of Pharmacogenetics, Enzymatic Phenotyping, and Metabolite Monitoring to Guide Treatment with Azathioprine in Patients with Systemic Lupus Erythematosus
Authors: ASKANASE ANCA D. , WALLACE DANIEL J. , WEISMAN MICHAEL H. , TSENG CHUNG-E , BERNSTEIN LANA , BELMONT H. MICHAEL , SEIDMAN ERNEST , ISHIMORI MARIKO , IZMIRLY PETER M. , BUYON JILL P.
Published: December 2008

Objective.

Individualized therapy based on genetic background and monitoring of metabolites can optimize drug safety and efficacy. Such an approach is available for azathioprine (AZA), the thiopurine antimetabolite. AZA exerts therapeutic effects when metabolized to the active thiopurine nucleotide, 6-thioguanine (6-TGN). In inflammatory bowel disease (IBD), 6-TGN levels in the target range of 235–400 pmol/8 ×108 red blood cells (RBC) are associated with a high likelihood of response. Our objective was to evaluate whether drug escalation based on metabolite levels improves efficacy and maintains safety in patients with systemic lupus erythematosus (SLE).

Methods.

We conducted a 6-month open-label dose-escalation clinical study of patients with active SLE treated with azathioprine dosed by body weight and metabolite levels. The primary endpoint was ≥50% improvement in any one parameter of disease activity, or 50% decrease in glucocorticoid dose.

Results.

Of 50 patients enrolled in the study, 21 achieved clinical responses, 13 of whom had 6-TGN < 235 pmol/8 ×108 RBC. Ten patients had no clinical response at 6 months, yet achieved either therapeutic IBD 6-TGN levels (> 235, n = 4) or received maximum AZA dose ≥3.5 mg/kg (n = 6). In 19 patients the drug was discontinued prematurely due to side effects or SLE activity. For those patients in whom either liver function test or white blood cell count abnormalities were encountered, metabolites guided attribution to drug or disease activity.

Conclusion.

Clinical responses in SLE can occur at levels of 6-TGN lower than the target range established for IBD. During followup, measurements of AZA metabolites may provide a rational approach to safety.
Shifting Our Thinking About Uncommon Disease Trials: The Case of Methotrexate in Scleroderma
Authors: JOHNSON SINDHU R. , FELDMAN BRIAN M. , POPE JANET E. , TOMLINSON GEORGE A.
Published: December 2008

Objective.

Randomized trials for uncommon diseases suffer from methodological challenges: difficulty in recruiting sufficient numbers of patients and low power to detect important treatment effects. Using traditional (frequentist) analysis, p values > 0.05 mean investigators are unable to reject the null hypothesis (of no treatment effect). The medical community often labels trials with p values > 0.05 as “negative.” Our study demonstrates how Bayesian analysis conveys more relevant information to clinicians — using the example of methotrexate (MTX) in systemic sclerosis (SSc).

Methods.

Data from 71 patients with diffuse SSc (n = 35 MTX, n = 36 placebo) in the trial were reanalyzed using Bayesian models. We examined 3 primary outcomes: modified Rodnan skin score (MRSS), University of California Los Angeles (UCLA) skin score, and physician global assessment of overall disease activity. Using noninformative prior probability distributions, the probability of beneficial treatment effects for each outcome and the probability of simultaneous benefit in outcomes were computed.

Results.

The probability that treatment with MTX results in better mean outcomes than placebo was 94% for MRSS, 96% for UCLA skin score, and 88% for physician global assessment. There was 96% probability that at least 2 of 3 primary outcomes were better on treatment.

Conclusion.

Bayesian analysis of uncommon disease trials allows for more flexible and clinically relevant interpretations of the data. From the trial data, clinicians can infer that MTX has a high probability of beneficial effects on skin score and global assessment.
Passion for guns and beliefs in a dangerous world: An examination of defensive gun ownership
Authors: Bélanger Jocelyn J. , Leander N. Pontus , Agostini Maximilian , Kreienkamp Jannis , Stroebe Wolfgang
Published: April 2024

This research examines the notion of defensive gun ownership using the Dualistic Model of Passion. We hypothesized that an obsessive (vs. harmonious) passion for guns would be associated with a belief in a dangerous world (BDW). We expected this relationship to intensify in threatening contexts, leading to a more expansive view on defensive gun ownership. We tested this hypothesis across three threat contexts: a gun‐control message (Study 1, N = 342), a live shooting simulation (Study 2, N = 398), and the aftermath of the Christchurch mass shootings (Study 3, N = 314). In the experimental Study 1, exposure to a gun‐control message increased the intention to purchase guns among those with an obsessive passion (OP) for guns. Study 2 revealed that BDW mediated the relationship between OP and assertive modes of protection, the desire to purchase high‐stopping‐power guns, and anti‐Black racial bias in a shooting task. Study 3 showed that knowledge of the Christchurch attack intensified the link between OP and BDW, leading to increased support for gun access, a willingness to act as a citizen‐protector, and prejudice against Muslims. Comprehending these dynamics can assist policymakers in crafting messaging campaigns for firearm regulation and public safety measures that are more effective.
Diagnostic Accuracy of Raman Spectroscopy Integrated With Polarized Light Microscopy for Calcium Pyrophosphate–Associated Arthritis
Authors: Niessink Tom , Janssen Matthijs , Giesen Tanja , Efdé Monique N. , Comarniceanu Antoaneta C. , Otto Cees , Jansen Tim L.
Published: April 2024

Objective

We studied the performance of integrated Raman polarized light microscopy (iRPolM) for the identification of calcium pyrophosphate (CPP)–associated arthritis (CPPD).

Methods

This is a diagnostic accuracy study including 400 consecutive synovial fluid samples from a single hospital in the Netherlands. Accuracy measures were calculated against polarized light microscopy (PLM) and the 2023 American College of Rheumatology (ACR)/EULAR criteria set for CPPD.

Results

The interrater reliability between iRPolM and the 2023 ACR/EULAR criteria set for CPPD was strong (κ = 0.88). The diagnostic performance of iRPolM compared to the 2023 ACR/EULAR criteria set was sensitivity 86.0% (95% confidence interval [CI] 73.3–94.2), specificity 99.1% (95% CI 97.5–99.8), positive likelihood ratio 100.33 (95% CI 32.3–311.3), negative likelihood ratio 0.14 (95% CI 0.07–0.28), positive predictive value 93.5% (95% CI 82.2–97.8), negative predictive value 98.0% (95% CI 82.2–97.8), and accuracy 97.5% (95% CI 95.5–98.8). We allowed rheumatologists to rate the certainty of their microscopic identification of CPP and found a large correspondence between iRPolM and a certain identification (κ = 0.87), whereas only 10% of the uncertain CPP identifications could be confirmed with iRPolM. We identified several novel particle types in synovial fluid analysis, including calcium carbonate crystals, deposited carotenoids, microplastics, and three types of Maltese cross birefringent objects.

Conclusion

iRPolM can easily identify CPP crystals with a strong diagnostic performance. PLM alone is not specific enough to reliably resolve complicated cases, and the implementation of Raman spectroscopy in rheumatology practice can be of benefit to patients with suspected CPPD.
Large‐Scale Flexible Fabric Biosensor for Long‐Term Monitoring of Sweat Lactate
Authors: Chen Yangyang , Hu Xiaokang , Liang Qimin , Wang Xin , Zhang Huanlei , Jia Kangkang , Li Yuan , Zhang Anning , Chen Peining , Lin Meng , Qiu Longbin , Peng Huisheng , He Sisi
Published: April 2024

Integrating sweat biosensors into daily wear has the potential to effectively monitor personal lactate levels, offering the advantages of convenience, precision, and multi‐point detection. However, existing wearable fabric sweat biosensors have limitations in terms of long‐term repeatable detection and washability due to the difficulty of building a stable layer of recognition materials on the highly curved fiber surface. Here, a long‐term repeatable and washable electrochemical fabric biosensor is reported based on a fiber electrode with multi‐scaled aligned channels for efficient and reliable lactate detection. Through the functionalization of a molecularly imprinted polymer with redox‐sensitive nano reporters, the fabric biosensor exhibits impressive in situ long‐term repeatable detection for more than 400 times, washability, and stability under deformations. The multi‐scaled channels contribute to a desired electric field distribution and thus a reliable interface between the polymer and the fiber. Employing industrial sewing technology, a 20 m (L)  ×  0.5 m (W) sensing fabric is further produced. Ultimately, combined with a wireless communication element, the fabric biosensing system can immediately track lactate levels.
Light‐Driven Multi‐Core/Shell Microdroplets as a Targeted Drug Delivery System
Authors: Yuan Shun , Yao Benjun , Yang Guowei , Lei Hongxiang
Published: April 2024

Targeted drug delivery system (DDS) holds exciting prospects in biomedical clinical research and drug development. However, it faces a significant challenge in achieving stable and safe targeted transportation without drug leakage while obtaining precise and controllable drug dosing with a high drug utilization rate and low side effects. Herein, an optical tweezers‐based light‐driven technique is proposed to transport and construct multi‐core/shell microdroplets enveloping drug carriers and target cells as a novel, safe, and efficient targeted DDS. Drug‐loaded microdroplets with core/shell structures are first fabricated by a new and simple injection extrusion method and then it is transported to a target cell by a dynamic optical trap with a low optical power, which ensures no drug leakage, exogenous materials, and biothermal damage are introduced during the drug delivery process. Next, precise drug dosing is realized by pushing the target cell into the drug‐loaded microdroplet under the actions of optical forces, which constructs a multi‐core/shell microdroplet structure with a pure drug environment to improve the drug action efficiency. Moreover, quantitative drug dosing with a high drug utilization rate can also achieved by controlling the sizes/number of drug droplets inside the microdroplets. This light‐driven DDS is of great interest to frontier medical research and disease treatment fields.