An authoritative global database for active submarine hydrothermal vent fields

NASA Astrophysics Data System (ADS)

Beaulieu, Stace E.; Baker, Edward T.; German, Christopher R.; Maffei, Andrew

2013-11-01

The InterRidge Vents Database is available online as the authoritative reference for locations of active submarine hydrothermal vent fields. Here we describe the revision of the database to an open source content management system and conduct a meta-analysis of the global distribution of known active vent fields. The number of known active vent fields has almost doubled in the past decade (521 as of year 2009), with about half visually confirmed and others inferred active from physical and chemical clues. Although previously known mainly from mid-ocean ridges (MORs), active vent fields at MORs now comprise only half of the total known, with about a quarter each now known at volcanic arcs and back-arc spreading centers. Discoveries in arc and back-arc settings resulted in an increase in known vent fields within exclusive economic zones, consequently reducing the proportion known in high seas to one third. The increase in known vent fields reflects a number of factors, including increased national and commercial interests in seafloor hydrothermal deposits as mineral resources. The purpose of the database now extends beyond academic research and education and into marine policy and management, with at least 18% of known vent fields in areas granted or pending applications for mineral prospecting and 8% in marine protected areas.

Influence of Activity Monitor Location and Bout Duration on Free-Living Physical Activity

ERIC Educational Resources Information Center

Heil, Daniel P.; Bennett, Gary G.; Bond, Kathleen S.; Webster, Michael D.; Wolin, Kathleen Y.

2009-01-01

The purpose of this study was to evaluate the influence of the location (ankle, hip, wrist) where an activity monitor (AM) is worn and of the minimum bout duration (BD) on physical activity (PA) variables during free-living monitoring. Study 1 participants wore AMs at three locations for 1 day while wearing the Intelligent Device for Energy…

The magnetic field of gastrointestinal smooth muscle activity

NASA Astrophysics Data System (ADS)

Bradshaw, Alan; Ladipo, Jk; Richards, William; Wikswo, John

1997-11-01

The gastrointestinal (GI) tract controls the absorption and transport of ingested materials. Its function is determined largely by the electrical activity of the smooth muscle that lines the GI tract. GI electrical activity consists of an omnipresent slowly oscillating wave known as the basic electrical rhythm (BER) that modulates a higher-frequency spiking activity associated with muscle contraction. The BER has been shown to be a reliable indicator of intestinal viability, and thus, recording of smooth muscle activity may have clinical value. The BER is difficult to measure with cutaneous electrodes because layers of low-conductivity fat between the GI tract and the abdominal surface attenuate the potential. On the other hand, the magnetic field associated with GI electrical activity is mostly unaffected by intervening fat layers. We recorded the magnetic fields from GI activity in 12 volunteers using a multichannel Superconducting QUantum Interference Device (SQUID) magnetometer. Characteristics typical of gastric and intestinal BER were apparent in the data. Channels near the epigastrium recorded gastric BER, and channels in intestinal areas recorded small bowel BER. These results suggest that a single multichannel SQUID magnetometer is able to measure gastrointestinal electrical activity from multiple locations around the abdomen simultaneously.

Active experiments in the ionosphere and geomagnetic field variations

NASA Astrophysics Data System (ADS)

Sivokon, V. P.; Cherneva, N. V.; Khomutov, S. Y.; Serovetnikov, A. S.

2014-11-01

Variations of ionospheric-magnetospheric relation energy, as one of the possible outer climatology factors, may be traced on the basis of analysis of natural geophysical phenomena such as ionosphere artificial radio radiation and magnetic storms. Experiments on active impact on the ionosphere have been carried out for quite a long time in Russia as well. The most modern heating stand is located in Alaska; it has been used within the HAARP Program. The possibility of this stand to affect geophysical fields, in particular, the geomagnetic field is of interest.

Locating the feminist scholar: relational empowerment and social activism.

PubMed

VanderPlaat, M

1999-11-01

Over the past decade, the rhetoric of "empowerment" has permeated the health promotion, education, and social welfare literature. Many scholars and professionals, particularly those active in the field of social intervention and community development, have found themselves struggling for location in the emancipatory process. This struggle often is characterized by a profound self-consciousness of privilege and the fear of being perceived as imposing and manipulative. This article explores the tensions inherent in the role of the scholar/activist using illustrations from the author's experience as principal investigator of the Atlantic Regional Evaluation of the Community Action Program for Children. In so doing, it discusses the importance of a relational approach to empowerment, one characterized by mutuality. A commitment to mutuality is seen as a key factor in enhancing the emancipatory capacities of empowerment-based research projects.

Magnetic field feature extraction and selection for indoor location estimation.

PubMed

Galván-Tejada, Carlos E; García-Vázquez, Juan Pablo; Brena, Ramon F

2014-06-20

User indoor positioning has been under constant improvement especially with the availability of new sensors integrated into the modern mobile devices, which allows us to exploit not only infrastructures made for everyday use, such as WiFi, but also natural infrastructure, as is the case of natural magnetic field. In this paper we present an extension and improvement of our current indoor localization model based on the feature extraction of 46 magnetic field signal features. The extension adds a feature selection phase to our methodology, which is performed through Genetic Algorithm (GA) with the aim of optimizing the fitness of our current model. In addition, we present an evaluation of the final model in two different scenarios: home and office building. The results indicate that performing a feature selection process allows us to reduce the number of signal features of the model from 46 to 5 regardless the scenario and room location distribution. Further, we verified that reducing the number of features increases the probability of our estimator correctly detecting the user's location (sensitivity) and its capacity to detect false positives (specificity) in both scenarios.

The research of PSD location method in micro laser welding fields

NASA Astrophysics Data System (ADS)

Zhang, Qiue; Zhang, Rong; Dong, Hua

2010-11-01

In the field of micro laser welding, besides the special requirement in the parameter of lasers, the locating in welding points accurately is very important. The article adopt position sensitive detector (PSD) as hard core, combine optic system, electric circuits and PC and software processing, confirm the location of welding points. The signal detection circuits adopt the special integrate circuit H-2476 to process weak signal. It is an integrated circuit for high-speed, high-sensitivity optical range finding, which has stronger noiseproof feature, combine digital filter arithmetic, carry out repair the any non-ideal factors, increasing the measure precision. The amplifier adopt programmable amplifier LTC6915. The system adapt two dimension stepping motor drive the workbench, computer and corresponding software processing, make sure the location of spot weld. According to different workpieces to design the clamps. The system on-line detect PSD 's output signal in the moving processing. At the workbench moves in the X direction, the filaments offset is detected dynamic. Analyze the X axes moving sampling signal direction could be estimate the Y axes moving direction, and regulate the Y axes moving values. The workbench driver adopt A3979, it is a stepping motor driver with insert transducer and operate easily. It adapts the requirement of location in micro laser welding fields, real-time control to adjust by computer. It can be content up 20 μm's laser micro welding requirement on the whole. Using laser powder cladding technology achieve inter-penetration welding of high quality and reliability.

Muscle Activation During Peripheral Nerve Field Stimulation Occurs Due to Recruitment of Efferent Nerve Fibers, Not Direct Muscle Activation.

PubMed

Frahm, Ken Steffen; Hennings, Kristian; Vera-Portocarrero, Louis; Wacnik, Paul W; Mørch, Carsten Dahl

2016-08-01

Peripheral nerve field stimulation (PNFS) is a potential treatment for chronic low-back pain. Pain relief using PNFS is dependent on activation of non-nociceptive Aβ-fibers. However, PNFS may also activate muscles, causing twitches and discomfort. In this study, we developed a mathematical model, to investigate the activation of sensory and motor nerves, as well as direct muscle fiber activation. The extracellular field was estimated using a finite element model based on the geometry of CT scanned lumbar vertebrae. The electrode was modeled as being implanted to a depth of 10-15 mm. Three implant directions were modeled; horizontally, vertically, and diagonally. Both single electrode and "between-lead" stimulation between contralateral electrodes were modeled. The extracellular field was combined with models of sensory Aβ-nerves, motor neurons and muscle fibers to estimate their activation thresholds. The model showed that sensory Aβ fibers could be activated with thresholds down to 0.563 V, and the lowest threshold for motor nerve activation was 7.19 V using between-lead stimulation with the cathode located closest to the nerves. All thresholds for direct muscle activation were above 500 V. The results suggest that direct muscle activation does not occur during PNFS, and concomitant motor and sensory nerve fiber activation are only likely to occur when using between-lead configuration. Thus, it may be relevant to investigate the location of the innervation zone of the low-back muscles prior to electrode implantation to avoid muscle activation. © 2016 International Neuromodulation Society.

Agreement between selectors at seven Eastern U.S. locations in the second field generation

USDA-ARS?s Scientific Manuscript database

Clone x location interactions are known to be large for many traits in potatoes. Early generation selection in northern breeding programs may eliminate clones that perform better in other locations. The purpose of this study was to examine the agreement between selectors in the second field genera...

Brady's Geothermal Field - March 2016 Vibroseis SEG-Y Files and UTM Locations

DOE Data Explorer

Kurt Feigl

2016-03-31

PoroTomo March 2016 (Task 6.4) Updated vibroseis source locations with UTM locations. Supersedes gdr.openei.org/submissions/824. Updated vibroseis source location data for Stages 1-4, PoroTomo March 2016. This revision includes source point locations in UTM format (meters) for all four Stages of active source acquisition. Vibroseis sweep data were collected on a Signature Recorder unit (mfr Seismic Source) mounted in the vibroseis cab during the March 2016 PoroTomo active seismic survey Stages 1 to 4. Each sweep generated a GPS timed SEG-Y file with 4 input channels and a 20 second record length. Ch1 = pilot sweep, Ch2 = accelerometer output from the vibe's mass, Ch3 = accel output from the baseplase, and Ch4 = weighted sum of the accelerometer outputs. SEG-Y files are available via the links below.

Lightning Prediction using Electric Field Measurements Associated with Convective Events at a Tropical Location

NASA Astrophysics Data System (ADS)

Jana, S.; Chakraborty, R.; Maitra, A.

2017-12-01

Nowcasting of lightning activities during intense convective events using a single electric field monitor (EFM) has been carried out at a tropical location, Kolkata (22.65oN, 88.45oE). Before and at the onset of heavy lightning, certain changes of electric field (EF) can be related to high liquid water content (LWC) and low cloud base height (CBH). The present study discusses the utility of EF observation to show a few aspects of convective events. Large convective cloud showed by high LWC and low CBH can be detected from EF variation which could be a precursor of upcoming convective events. Suitable values of EF gradient can be used as an indicator of impending lightning events. An EF variation of 0.195 kV/m/min can predict lightning within 17.5 km radius with a probability of detection (POD) of 91% and false alarm rate (FAR) of 8% with a lead time of 45 min. The total number of predicted lightning strikes is nearly 9 times less than that measured by the lightning detector. This prediction technique can, therefore, give an estimate of cloud to ground (CG) and intra cloud (IC) lighting occurrences within the surrounding area. This prediction technique involving POD, FAR and lead time information shows a better prediction capability compared to the techniques reported earlier. Thus an EFM can be effectively used for prediction of lightning events at a tropical location.

Effects of location and timing of co-activated neurons in the auditory midbrain on cortical activity: implications for a new central auditory prosthesis

NASA Astrophysics Data System (ADS)

Straka, Małgorzata M.; McMahon, Melissa; Markovitz, Craig D.; Lim, Hubert H.

2014-08-01

Objective. An increasing number of deaf individuals are being implanted with central auditory prostheses, but their performance has generally been poorer than for cochlear implant users. The goal of this study is to investigate stimulation strategies for improving hearing performance with a new auditory midbrain implant (AMI). Previous studies have shown that repeated electrical stimulation of a single site in each isofrequency lamina of the central nucleus of the inferior colliculus (ICC) causes strong suppressive effects in elicited responses within the primary auditory cortex (A1). Here we investigate if improved cortical activity can be achieved by co-activating neurons with different timing and locations across an ICC lamina and if this cortical activity varies across A1. Approach. We electrically stimulated two sites at different locations across an isofrequency ICC lamina using varying delays in ketamine-anesthetized guinea pigs. We recorded and analyzed spike activity and local field potentials across different layers and locations of A1. Results. Co-activating two sites within an isofrequency lamina with short inter-pulse intervals (<5 ms) could elicit cortical activity that is enhanced beyond a linear summation of activity elicited by the individual sites. A significantly greater extent of normalized cortical activity was observed for stimulation of the rostral-lateral region of an ICC lamina compared to the caudal-medial region. We did not identify any location trends across A1, but the most cortical enhancement was observed in supragranular layers, suggesting further integration of the stimuli through the cortical layers. Significance. The topographic organization identified by this study provides further evidence for the presence of functional zones across an ICC lamina with locations consistent with those identified by previous studies. Clinically, these results suggest that co-activating different neural populations in the rostral-lateral ICC rather

Expression of endogenous proteins in maize hybrids in a multi-location field trial in India.

PubMed

Gutha, Linga R; Purushottam, Divakar; Veeramachaneni, Aruna; Tigulla, Sarita; Kodappully, Vikas; Enjala, Chandana; Rajput, Hitendrasinh; Anderson, Jennifer; Hong, Bonnie; Schmidt, Jean; Bagga, Shveta

2018-05-17

Genetically modified (GM) crops undergo large scale multi-location field trials to characterize agronomics, composition, and the concentration of newly expressed protein(s) [herein referred to as transgenic protein(s)]. The concentration of transgenic proteins in different plant tissues and across the developmental stages of the plant is considered in the safety assessment of GM crops. Reference or housekeeping proteins are expected to maintain a relatively stable expression pattern in healthy plants given their role in cellular functions. Understanding the effects of genotype, growth stage and location on the concentration of endogenous housekeeping proteins may provide insight into the contribution these factors could have on transgenic protein concentrations in GM crops. The concentrations of three endogenous proteins (actin, elongation factor 1-alpha, and glyceraldehyde 3-phosphate dehydrogenase) were measured in several different maize hybrids grown across multiple field locations over 2 years. Leaf samples were collected from healthy plants at three developmental stages across the growing seasons, and protein concentrations were quantified by indirect enzyme-linked immunosorbent assay (ELISA) for each protein. In general, the concentrations of these three endogenous proteins were relatively consistent across hybrid backgrounds, when compared within one growth stage and location (2-26%CV), whereas the concentrations of proteins in the same hybrid and growth stage across different locations were more variable (12-64%CV). In general, the protein concentrations in 2013 and 2014 show similar trends in variability. Some degree of variability in protein concentrations should be expected for both transgenic and endogenous plant-expressed proteins. In the case of GM crops, the potential variation in protein concentrations due to location effects is captured in the current model of multi-location field testing.

Design and Test of an Event Detector and Locator for the ReflectoActive Seals System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stinson, Brad J

2006-06-01

The purpose of this work was to research, design, develop and test a novel instrument for detecting fiber optic loop continuity and spatially locating fiber optic breaches. The work is for an active seal system called ReflectoActive{trademark} Seals whose purpose is to provide real time container tamper indication. A Field Programmable Gate Array was used to implement a loop continuity detector and a spatial breach locator based on a high acquisition speed single photon counting optical time domain reflectometer. Communication and other control features were added in order to create a usable instrument that met defined requirements. A host graphicalmore » user interface was developed to illustrate system use and performance. The resulting device meets performance specifications by exhibiting a dynamic range of 27dB and a spatial resolution of 1.5 ft. The communication scheme used expands installation options and allows the device to communicate to a central host via existing Local Area Networks and/or the Internet.« less

Field operating experience in locating and re-recovering landslide-damaged oil wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, R.J.

1974-01-01

Landslides have damaged 65 oil wells on Getty Oil Co.'s leases in the Ventura Avenue field. During a landslide, some wells may remain connected to the surface while other wells may be buried. Well damage ranges from slight bending to complete severing of all casing strings, and depth of damage varies from 15 to 120 ft. Two major problems have been encountered when repair work is planned for a landslide damaged well. The first problem is to locate the undamaged well casing below the landslide. The second problem is to recover the well and replace the damaged casing. Some methodsmore » used by Getty Oil Co. to locate the undamaged portion of a well are conventional surveys, dipneedle surveys, magnetometer surveys, kink-meter surveys, and test holes. Three methods have been used to recover landslide damaged wells in the Ventura Avenue field. The simplest method is an open excavation made with standard earthmoving equipment. This method is limited to shallow depths and locations where the landslide would not be reactivated. To reach greater depths, special methods such as hand-dug or machine-dug shafts must be used. All 3 methods have been used successfully by Getty Oil Co.« less

Influence of active site location on catalytic activity in de novo-designed zinc metalloenzymes.

PubMed

Zastrow, Melissa L; Pecoraro, Vincent L

2013-04-17

While metalloprotein design has now yielded a number of successful metal-bound and even catalytically active constructs, the question of where to put a metal site along a linear, repetitive sequence has not been thoroughly addressed. Often several possibilities in a given sequence may exist that would appear equivalent but may in fact differ for metal affinity, substrate access, or protein dynamics. We present a systematic variation of active site location for a hydrolytically active ZnHis3O site contained within a de novo-designed three-stranded coiled coil. We find that the maximal rate, substrate access, and metal-binding affinity are dependent on the selected position, while catalytic efficiency for p-nitrophenyl acetate hydrolysis can be retained regardless of the location of the active site. This achievement demonstrates how efficient, tailor-made enzymes which control rate, pKa, substrate and solvent access (and selectivity), and metal-binding affinity may be realized. These findings may be applied to the more advanced de novo design of constructs containing secondary interactions, such as hydrogen-bonding channels. We are now confident that changes to location for accommodating such channels can be achieved without location-dependent loss of catalytic efficiency. These findings bring us closer to our ultimate goal of incorporating the secondary interactions we believe will be necessary in order to improve both active site properties and the catalytic efficiency to be competitive with the native enzyme, carbonic anhydrase.

Addressing location uncertainties in GPS-based activity monitoring: A methodological framework

PubMed Central

Wan, Neng; Lin, Ge; Wilson, Gaines J.

2016-01-01

Location uncertainty has been a major barrier in information mining from location data. Although the development of electronic and telecommunication equipment has led to an increased amount and refined resolution of data about individuals’ spatio-temporal trajectories, the potential of such data, especially in the context of environmental health studies, has not been fully realized due to the lack of methodology that addresses location uncertainties. This article describes a methodological framework for deriving information about people’s continuous activities from individual-collected Global Positioning System (GPS) data, which is vital for a variety of environmental health studies. This framework is composed of two major methods that address critical issues at different stages of GPS data processing: (1) a fuzzy classification method for distinguishing activity patterns; and (2) a scale-adaptive method for refining activity locations and outdoor/indoor environments. Evaluation of this framework based on smartphone-collected GPS data indicates that it is robust to location errors and is able to generate useful information about individuals’ life trajectories. PMID:28943777

12 CFR 7.5008 - Location of a national bank conducting electronic activities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 12 Banks and Banking 1 2011-01-01 2011-01-01 false Location of a national bank conducting electronic activities. 7.5008 Section 7.5008 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY BANK ACTIVITIES AND OPERATIONS Electronic Activities § 7.5008 Location of a national bank...

12 CFR 7.5008 - Location of a national bank conducting electronic activities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 12 Banks and Banking 1 2010-01-01 2010-01-01 false Location of a national bank conducting electronic activities. 7.5008 Section 7.5008 Banks and Banking COMPTROLLER OF THE CURRENCY, DEPARTMENT OF THE TREASURY BANK ACTIVITIES AND OPERATIONS Electronic Activities § 7.5008 Location of a national bank...

Decoding illusory self-location from activity in the human hippocampus.

PubMed

Guterstam, Arvid; Björnsdotter, Malin; Bergouignan, Loretxu; Gentile, Giovanni; Li, Tie-Qiang; Ehrsson, H Henrik

2015-01-01

Decades of research have demonstrated a role for the hippocampus in spatial navigation and episodic and spatial memory. However, empirical evidence linking hippocampal activity to the perceptual experience of being physically located at a particular place in the environment is lacking. In this study, we used a multisensory out-of-body illusion to perceptually 'teleport' six healthy participants between two different locations in the scanner room during high-resolution functional magnetic resonance imaging (fMRI). The participants were fitted with MRI-compatible head-mounted displays that changed their first-person visual perspective to that of a pair of cameras placed in one of two corners of the scanner room. To elicit the illusion of being physically located in this position, we delivered synchronous visuo-tactile stimulation in the form of an object moving toward the cameras coupled with touches applied to the participant's chest. Asynchronous visuo-tactile stimulation did not induce the illusion and served as a control condition. We found that illusory self-location could be successfully decoded from patterns of activity in the hippocampus in all of the participants in the synchronous (P < 0.05) but not in the asynchronous condition (P > 0.05). At the group-level, the decoding accuracy was significantly higher in the synchronous than in the asynchronous condition (P = 0.012). These findings associate hippocampal activity with the perceived location of the bodily self in space, which suggests that the human hippocampus is involved not only in spatial navigation and memory but also in the construction of our sense of bodily self-location.

Decoding illusory self-location from activity in the human hippocampus

PubMed Central

Guterstam, Arvid; Björnsdotter, Malin; Bergouignan, Loretxu; Gentile, Giovanni; Li, Tie-Qiang; Ehrsson, H. Henrik

2015-01-01

Decades of research have demonstrated a role for the hippocampus in spatial navigation and episodic and spatial memory. However, empirical evidence linking hippocampal activity to the perceptual experience of being physically located at a particular place in the environment is lacking. In this study, we used a multisensory out-of-body illusion to perceptually ‘teleport’ six healthy participants between two different locations in the scanner room during high-resolution functional magnetic resonance imaging (fMRI). The participants were fitted with MRI-compatible head-mounted displays that changed their first-person visual perspective to that of a pair of cameras placed in one of two corners of the scanner room. To elicit the illusion of being physically located in this position, we delivered synchronous visuo-tactile stimulation in the form of an object moving toward the cameras coupled with touches applied to the participant’s chest. Asynchronous visuo-tactile stimulation did not induce the illusion and served as a control condition. We found that illusory self-location could be successfully decoded from patterns of activity in the hippocampus in all of the participants in the synchronous (P < 0.05) but not in the asynchronous condition (P > 0.05). At the group-level, the decoding accuracy was significantly higher in the synchronous than in the asynchronous condition (P = 0.012). These findings associate hippocampal activity with the perceived location of the bodily self in space, which suggests that the human hippocampus is involved not only in spatial navigation and memory but also in the construction of our sense of bodily self-location. PMID:26236222

Cortical connective field estimates from resting state fMRI activity.

PubMed

Gravel, Nicolás; Harvey, Ben; Nordhjem, Barbara; Haak, Koen V; Dumoulin, Serge O; Renken, Remco; Curčić-Blake, Branislava; Cornelissen, Frans W

2014-01-01

One way to study connectivity in visual cortical areas is by examining spontaneous neural activity. In the absence of visual input, such activity remains shaped by the underlying neural architecture and, presumably, may still reflect visuotopic organization. Here, we applied population connective field (CF) modeling to estimate the spatial profile of functional connectivity in the early visual cortex during resting state functional magnetic resonance imaging (RS-fMRI). This model-based analysis estimates the spatial integration between blood-oxygen level dependent (BOLD) signals in distinct cortical visual field maps using fMRI. Just as population receptive field (pRF) mapping predicts the collective neural activity in a voxel as a function of response selectivity to stimulus position in visual space, CF modeling predicts the activity of voxels in one visual area as a function of the aggregate activity in voxels in another visual area. In combination with pRF mapping, CF locations on the cortical surface can be interpreted in visual space, thus enabling reconstruction of visuotopic maps from resting state data. We demonstrate that V1 ➤ V2 and V1 ➤ V3 CF maps estimated from resting state fMRI data show visuotopic organization. Therefore, we conclude that-despite some variability in CF estimates between RS scans-neural properties such as CF maps and CF size can be derived from resting state data.

Active Electro-Location of Objects in the Underwater Environment Based on the Mixed Polarization Multiple Signal Classification Algorithm

PubMed Central

Guo, Lili; Qi, Junwei; Xue, Wei

2018-01-01

This article proposes a novel active localization method based on the mixed polarization multiple signal classification (MP-MUSIC) algorithm for positioning a metal target or an insulator target in the underwater environment by using a uniform circular antenna (UCA). The boundary element method (BEM) is introduced to analyze the boundary of the target by use of a matrix equation. In this method, an electric dipole source as a part of the locating system is set perpendicularly to the plane of the UCA. As a result, the UCA can only receive the induction field of the target. The potential of each electrode of the UCA is used as spatial-temporal localization data, and it does not need to obtain the field component in each direction compared with the conventional fields-based localization method, which can be easily implemented in practical engineering applications. A simulation model and a physical experiment are constructed. The simulation and the experiment results provide accurate positioning performance, with the help of verifying the effectiveness of the proposed localization method in underwater target locating. PMID:29439495

Physical activity locations in Georgia: frequency of use by socio-demographic group

Treesearch

Lincoln R. Larson; Jason W. Whiting; Gary T. Green; J. M. Bowker

2014-01-01

Active outdoor recreation helps to mitigate health consequences associated with sedentary behavior. Enhanced understanding of socio-demographic differences in physical activity (PA) location preferences could therefore contribute to health promotion.This study examined frequency o fuse fo rvarious PA locations in Georgia,a state with historically high levels of...

A preliminary census of engineering activities located in Sicily (Southern Italy) which may "potentially" induce seismicity

NASA Astrophysics Data System (ADS)

Aloisi, Marco; Briffa, Emanuela; Cannata, Andrea; Cannavò, Flavio; Gambino, Salvatore; Maiolino, Vincenza; Maugeri, Roberto; Palano, Mimmo; Privitera, Eugenio; Scaltrito, Antonio; Spampinato, Salvatore; Ursino, Andrea; Velardita, Rosanna

2015-04-01

The seismic events caused by human engineering activities are commonly termed as "triggered" and "induced". This class of earthquakes, though characterized by low-to-moderate magnitude, have significant social and economical implications since they occur close to the engineering activity responsible for triggering/inducing them and can be felt by the inhabitants living nearby, and may even produce damage. One of the first well-documented examples of induced seismicity was observed in 1932 in Algeria, when a shallow magnitude 3.0 earthquake occurred close to the Oued Fodda Dam. By the continuous global improvement of seismic monitoring networks, numerous other examples of human-induced earthquakes have been identified. Induced earthquakes occur at shallow depths and are related to a number of human activities, such as fluid injection under high pressure (e.g. waste-water disposal in deep wells, hydrofracturing activities in enhanced geothermal systems and oil recovery, shale-gas fracking, natural and CO2 gas storage), hydrocarbon exploitation, groundwater extraction, deep underground mining, large water impoundments and underground nuclear tests. In Italy, induced/triggered seismicity is suspected to have contributed to the disaster of the Vajont dam in 1963. Despite this suspected case and the presence in the Italian territory of a large amount of engineering activities "capable" of inducing seismicity, no extensive researches on this topic have been conducted to date. Hence, in order to improve knowledge and correctly assess the potential hazard at a specific location in the future, here we started a preliminary study on the entire range of engineering activities currently located in Sicily (Southern Italy) which may "potentially" induce seismicity. To this end, we performed: • a preliminary census of all engineering activities located in the study area by collecting all the useful information coming from available on-line catalogues; • a detailed compilation

Location of an intermediate hub for port activities

NASA Astrophysics Data System (ADS)

Burciu, Ş.; Ştefănică, C.; Roşca, E.; Dragu, V.; Ruscă, F.

2015-11-01

An intermediate hub might increase the accessibility level of ports but also hinterland and so it can be considered more than a facility with a transhipment role. These hubs might lead to the development of other transport services and enhance their role in gathering and covering economic centres within hinterlands and also getting the part of logistic facility for the ports, with effects on port utilization and its connectivity to global economy. A new location for a hub terminal leads to reduced transport distances within hinterland, with decreased transport costs and external effects, so with gains in people's life quality. Because the production and distribution systems are relatively fixed on short and medium term and the location decisions are strategic and on long term, the logistic chains activities location models have to consider the uncertainties regarding the possible future situations. In most models, production costs are considered equal, the location problem reducing itself to a problem that aims to minimize the total transport costs, meaning the transport problem. The main objective of the paper is to locate a hub terminal that links the producers of cereals that are going to be exported by naval transportation with the Romanian fluvial-maritime ports (Galaţi, Brăila). GIS environment can be used to integrate and analyse a great amount of data and has the ability of using functions as location - allocation models necessary both to private and public sector, being able to determine the optimal location for services like factories, warehouses, logistic platforms and other public services.

Strings on a Violin: Location Dependence of Frequency Tuning in Active Dendrites.

PubMed

Das, Anindita; Rathour, Rahul K; Narayanan, Rishikesh

2017-01-01

Strings on a violin are tuned to generate distinct sound frequencies in a manner that is firmly dependent on finger location along the fingerboard. Sound frequencies emerging from different violins could be very different based on their architecture, the nature of strings and their tuning. Analogously, active neuronal dendrites, dendrites endowed with active channel conductances, are tuned to distinct input frequencies in a manner that is dependent on the dendritic location of the synaptic inputs. Further, disparate channel expression profiles and differences in morphological characteristics could result in dendrites on different neurons of the same subtype tuned to distinct frequency ranges. Alternately, similar location-dependence along dendritic structures could be achieved through disparate combinations of channel profiles and morphological characteristics, leading to degeneracy in active dendritic spectral tuning. Akin to strings on a violin being tuned to different frequencies than those on a viola or a cello, different neuronal subtypes exhibit distinct channel profiles and disparate morphological characteristics endowing each neuronal subtype with unique location-dependent frequency selectivity. Finally, similar to the tunability of musical instruments to elicit distinct location-dependent sounds, neuronal frequency selectivity and its location-dependence are tunable through activity-dependent plasticity of ion channels and morphology. In this morceau, we explore the origins of neuronal frequency selectivity, and survey the literature on the mechanisms behind the emergence of location-dependence in distinct forms of frequency tuning. As a coda to this composition, we present some future directions for this exciting convergence of biophysical mechanisms that endow a neuron with frequency multiplexing capabilities.

Disrupting frontal eye-field activity impairs memory recall.

PubMed

Wantz, Andrea L; Martarelli, Corinna S; Cazzoli, Dario; Kalla, Roger; Müri, René; Mast, Fred W

2016-04-13

A large body of research demonstrated that participants preferably look back to the encoding location when retrieving visual information from memory. However, the role of this 'looking back to nothing' is still debated. The goal of the present study was to extend this line of research by examining whether an important area in the cortical representation of the oculomotor system, the frontal eye field (FEF), is involved in memory retrieval. To interfere with the activity of the FEF, we used inhibitory continuous theta burst stimulation (cTBS). Before stimulation was applied, participants encoded a complex scene and performed a short-term (immediately after encoding) or long-term (after 24 h) recall task, just after cTBS over the right FEF or sham stimulation. cTBS did not affect overall performance, but stimulation and statement type (object vs. location) interacted. cTBS over the right FEF tended to impair object recall sensitivity, whereas there was no effect on location recall sensitivity. These findings suggest that the FEF is involved in retrieving object information from scene memory, supporting the hypothesis that the oculomotor system contributes to memory recall.

Saccades to a remembered location elicit spatially-specific activation in human retinotopic visual cortex

PubMed Central

Geng, Joy J.; Ruff, Christian C.; Driver, Jon

2008-01-01

The possible impact upon human visual cortex from saccades to remembered target locations was investigated using fMRI. A specific location in the upper-right or upper-left visual quadrant served as the saccadic target. After a delay of 2400 msecs, an auditory signal indicated whether to execute a saccade to that location (go trial) or to cancel the saccade and remain centrally fixated (no-go). Group fMRI analysis revealed activation specific to the remembered target location for executed saccades, in contralateral lingual gyrus. No-go trials produced similar, albeit significantly reduced effects. Individual retinotopic mapping confirmed that on go trials, quadrant-specific activations arose in those parts of ventral V1, V2, and V3 that coded the target location for the saccade, whereas on no-go trials only the corresponding parts of V2 and V3 were significantly activated. These results indicate that a spatial-motor saccadic task (i.e. making an eye-movement to a remembered location) is sufficient to activate retinotopic visual cortex spatially corresponding to the target location, and that this activation is also present (though reduced) when no saccade is executed. We discuss the implications of finding that saccades to remembered locations can affect early visual cortex, not just those structures conventionally associated with eye-movements, in relation to recent ideas about attention, spatial working memory, and the notion that recently activated representations can be ‘refreshed’ when needed. PMID:18510442

Distinct regions of the hippocampus are associated with memory for different spatial locations.

PubMed

Jeye, Brittany M; MacEvoy, Sean P; Karanian, Jessica M; Slotnick, Scott D

2018-05-15

In the present functional magnetic resonance imaging (fMRI) study, we aimed to evaluate whether distinct regions of the hippocampus were associated with spatial memory for items presented in different locations of the visual field. In Experiment 1, during the study phase, participants viewed abstract shapes in the left or right visual field while maintaining central fixation. At test, old shapes were presented at fixation and participants classified each shape as previously in the "left" or "right" visual field followed by an "unsure"-"sure"-"very sure" confidence rating. Accurate spatial memory for shapes in the left visual field was isolated by contrasting accurate versus inaccurate spatial location responses. This contrast produced one hippocampal activation in which the interaction between item type and accuracy was significant. The analogous contrast for right visual field shapes did not produce activity in the hippocampus; however, the contrast of high confidence versus low confidence right-hits produced one hippocampal activation in which the interaction between item type and confidence was significant. In Experiment 2, the same paradigm was used but shapes were presented in each quadrant of the visual field during the study phase. Accurate memory for shapes in each quadrant, exclusively masked by accurate memory for shapes in the other quadrants, produced a distinct activation in the hippocampus. A multi-voxel pattern analysis (MVPA) of hippocampal activity revealed a significant correlation between behavioral spatial location accuracy and hippocampal MVPA accuracy across participants. The findings of both experiments indicate that distinct hippocampal regions are associated with memory for different visual field locations. Copyright © 2018 Elsevier B.V. All rights reserved.

Enzyme/non-enzyme discrimination and prediction of enzyme active site location using charge-based methods.

PubMed

Bate, Paul; Warwicker, Jim

2004-07-02

Calculations of charge interactions complement analysis of a characterised active site, rationalising pH-dependence of activity and transition state stabilisation. Prediction of active site location through large DeltapK(a)s or electrostatic strain is relevant for structural genomics. We report a study of ionisable groups in a set of 20 enzymes, finding that false positives obscure predictive potential. In a larger set of 156 enzymes, peaks in solvent-space electrostatic properties are calculated. Both electric field and potential match well to active site location. The best correlation is found with electrostatic potential calculated from uniform charge density over enzyme volume, rather than from assignment of a standard atom-specific charge set. Studying a shell around each molecule, for 77% of enzymes the potential peak is within that 5% of the shell closest to the active site centre, and 86% within 10%. Active site identification by largest cleft, also with projection onto a shell, gives 58% of enzymes for which the centre of the largest cleft lies within 5% of the active site, and 70% within 10%. Dielectric boundary conditions emphasise clefts in the uniform charge density method, which is suited to recognition of binding pockets embedded within larger clefts. The variation of peak potential with distance from active site, and comparison between enzyme and non-enzyme sets, gives an optimal threshold distinguishing enzyme from non-enzyme. We find that 87% of the enzyme set exceeds the threshold as compared to 29% of the non-enzyme set. Enzyme/non-enzyme homologues, "structural genomics" annotated proteins and catalytic/non-catalytic RNAs are studied in this context.

Active sensing of target location encoded by cortical microstimulation.

PubMed

Venkatraman, Subramaniam; Carmena, Jose M

2011-06-01

Cortical microstimulation has been proposed as a method to deliver sensory percepts to circumvent damaged sensory receptors or pathways. However, much of perception involves the active movement of sensory organs and the integration of information across sensory and motor modalities. The efficacy of cortical microstimulation in such an active sensing paradigm has not been demonstrated. We report a novel behavioral paradigm which delivers microstimulation in real-time based on a rat's movements and show that rats can perform sensorimotor integration with electrically delivered stimuli. Using a real-time whisker tracking system, we delivered microstimulation in barrel cortex of actively whisking rats when their whisker crossed a particular spatial location which defined the target. Rats learned to integrate microstimulation cues with their knowledge of whisker position to infer target location along the rostro-caudal axis in less than 200 ms. In a separate experiment, we found that rats trained to respond to cortical microstimulation responded similarly to whisker deflections while ignoring auditory distracters, suggesting that barrel cortex stimulation may be perceptually similar to somatosensory stimuli. This ability to deliver sensory percepts using cortical microstimulation in an active sensing system might have significant implications for the development of sensorimotor neuroprostheses.

Technologies That Assess the Location of Physical Activity and Sedentary Behavior: A Systematic Review.

PubMed

Loveday, Adam; Sherar, Lauren B; Sanders, James P; Sanderson, Paul W; Esliger, Dale W

2015-08-05

The location in which physical activity and sedentary behavior are performed can provide valuable behavioral information, both in isolation and synergistically with other areas of physical activity and sedentary behavior research. Global positioning systems (GPS) have been used in physical activity research to identify outdoor location; however, while GPS can receive signals in certain indoor environments, it is not able to provide room- or subroom-level location. On average, adults spend a high proportion of their time indoors. A measure of indoor location would, therefore, provide valuable behavioral information. This systematic review sought to identify and critique technology which has been or could be used to assess the location of physical activity and sedentary behavior. To identify published research papers, four electronic databases were searched using key terms built around behavior, technology, and location. To be eligible for inclusion, papers were required to be published in English and describe a wearable or portable technology or device capable of measuring location. Searches were performed up to February 4, 2015. This was supplemented by backward and forward reference searching. In an attempt to include novel devices which may not yet have made their way into the published research, searches were also performed using three Internet search engines. Specialized software was used to download search results and thus mitigate the potential pitfalls of changing search algorithms. A total of 188 research papers met the inclusion criteria. Global positioning systems were the most widely used location technology in the published research, followed by wearable cameras, and radio-frequency identification. Internet search engines identified 81 global positioning systems, 35 real-time locating systems, and 21 wearable cameras. Real-time locating systems determine the indoor location of a wearable tag via the known location of reference nodes. Although the type

Technologies That Assess the Location of Physical Activity and Sedentary Behavior: A Systematic Review

PubMed Central

Sherar, Lauren B; Sanders, James P; Sanderson, Paul W; Esliger, Dale W

2015-01-01

Background The location in which physical activity and sedentary behavior are performed can provide valuable behavioral information, both in isolation and synergistically with other areas of physical activity and sedentary behavior research. Global positioning systems (GPS) have been used in physical activity research to identify outdoor location; however, while GPS can receive signals in certain indoor environments, it is not able to provide room- or subroom-level location. On average, adults spend a high proportion of their time indoors. A measure of indoor location would, therefore, provide valuable behavioral information. Objective This systematic review sought to identify and critique technology which has been or could be used to assess the location of physical activity and sedentary behavior. Methods To identify published research papers, four electronic databases were searched using key terms built around behavior, technology, and location. To be eligible for inclusion, papers were required to be published in English and describe a wearable or portable technology or device capable of measuring location. Searches were performed up to February 4, 2015. This was supplemented by backward and forward reference searching. In an attempt to include novel devices which may not yet have made their way into the published research, searches were also performed using three Internet search engines. Specialized software was used to download search results and thus mitigate the potential pitfalls of changing search algorithms. Results A total of 188 research papers met the inclusion criteria. Global positioning systems were the most widely used location technology in the published research, followed by wearable cameras, and radio-frequency identification. Internet search engines identified 81 global positioning systems, 35 real-time locating systems, and 21 wearable cameras. Real-time locating systems determine the indoor location of a wearable tag via the known location of

Locations of termination shock and heliopause based on Voyager plasma and magnetic field data

NASA Technical Reports Server (NTRS)

Whang, Y. C.; Burlaga, L. F.; Ness, N. F.

1995-01-01

The locations of the termination shock and the heliopause are studied taking into account the effects of pickup protons. The study uses available plasma and magnetic field data from Voyagers over a 14-year period (1978-1991) and Voyager observation of the 1992-93 radio emission event. Outside 30 AU, pickup protons have a significant influence on dynamical structures of the outer heliosphere. The solar wind is treated as a mixture of electrons, solar wind protons, and interstellar pickup protons. If the magnitude of the interstellar magnetic field B(sub int) is given, one can quantitatively study the motion and location of the termination shock. The location is anti-correlated with the sun spot number and the shock has an average speed of approx. 24 km/s. Because B(sub int) is poorly known, additional information is needed in studying the termination shock. Cummings, et al. have used observations of anomalous cosmic rays to estimate the location of the shock. The observations of the 1991 GMIR and GMIR shock and the 1992-93 radio emission event provide another handle for the study of the termination shock and the heliopause. After its penetration through the termination shock, the GMIR shock continued to propagate in the subsonic region of the solar wind and eventually interacted with the heliopause. This interaction produces a transmitted shock propagating outward in the interstellar medium and a reflected shock propagating inward toward the sun in the subsonic solar wind. The plasma frequencies behind the reflected and the transmitted shock can be, respectively, responsible for the 2- and 3-kHz radio emissions. Taking into account the effects of pickup protons we found that the average locations of the termination shock and the heliopause in 1991-92 are at approximately 66 AU and 150 AU, respectively.

Is Field of Study or Location Associated with College Students' Snacking Patterns?

PubMed Central

McArthur, Laura H.; Holbert, Donald; Forsythe, William

2012-01-01

Objective. To compare on- and off-campus snacking patterns among college students pursuing degrees in health-related fields (HRFs) and nonhealth-related fields (NHRFs). Materials and Methods. Snack frequency questionnaire, scales measuring barriers, self-efficacy, and stage of change for healthy snacking, and a snack knowledge test (SKT). Participants. 513 students, 46% HRFs, and 54% NHRFs. The students' mean ± SD BMI was 24.1 ± 4.3 kg/m2 (range 14.6 to 43.8), and 32.2% were overweight/obese. Results. Softdrinks (on-campus), lowfat milk (off-campus), and sports drinks were popular among HRFs and NHRFs. Cost and availability were barriers to healthy snacking, students felt least confident to choose healthy snacks when emotionally upset, and 75% (65%) of HRFs (NHRFs) self-classified in the action stage of change for healthy snacking. The HRFs scored higher on the SKT. Conclusions. Neither location nor field of study strongly influenced snacking patterns, which featured few high-fiber foods. PMID:22288006

A field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.

1994-01-01

The US Bureau of Mines, The University of Arizona, Sandia National Laboratories, and Zonge Engineering and Research Organization, Inc., conducted cooperative field tests of six electromagnetic (EM) geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 m below the surface. The testsite was the University's San Xavier experimental mine near Tucson, AZ. Geophysical surveys using surface and surface-borehole, time-domain electromagnetic (TEM) induction; surface controlled-source audiofrequency magnetotellurics (CSAMT); surface-borehole, frequency-domain electromagnetic (FEM) induction; crosshole FEM; and surface magnetic field ellipticity were conducted beforemore » and during brine injection. The surface TEM data showed a broad decrease in resistivity. CSAMT measurements with the conventional orientation did not detect the brine, but measurements with another orientation indicated some decrease in resistivity. The surface-borehole and crosshole methods located a known fracture and other fracture zones inferred from borehole induction logs. Surface magnetic field ellipticity data showed a broad decrease in resistivity at depth following brine injection.« less

24 CFR 570.309 - Restriction on location of activities.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Restriction on location of activities. 570.309 Section 570.309 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF...

24 CFR 570.301 - Activity locations and float-funding.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 3 2011-04-01 2010-04-01 true Activity locations and float-funding. 570.301 Section 570.301 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF...

24 CFR 570.309 - Restriction on location of activities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Restriction on location of activities. 570.309 Section 570.309 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF...

24 CFR 570.301 - Activity locations and float-funding.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 3 2010-04-01 2010-04-01 false Activity locations and float-funding. 570.301 Section 570.301 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) OFFICE OF ASSISTANT SECRETARY FOR COMMUNITY PLANNING AND DEVELOPMENT, DEPARTMENT OF...

Open magnetic fields in active regions

NASA Technical Reports Server (NTRS)

Svestka, Z.; Solodyna, C. V.; Howard, R.; Levine, R. H.

1977-01-01

Soft X-ray images and magnetograms of several active regions and coronal holes are examined which support the interpretation that some of the dark X-ray gaps seen between interconnecting loops and inner cores of active regions are foot points of open field lines inside the active regions. Characteristics of the investigated dark gaps are summarized. All the active regions with dark X-ray gaps at the proper place and with the correct polarity predicted by global potential extrapolation of photospheric magnetic fields are shown to be old active regions, indicating that field opening is accomplished only in a late phase of active-region development. It is noted that some of the observed dark gaps probably have nothing in common with open fields, but are either due to the decreased temperature in low-lying portions of interconnecting loops or are the roots of higher and less dense or cooler loops.

A far-field-viewing sensor for making analytical measurements in remote locations.

PubMed

Michael, K L; Taylor, L C; Walt, D R

1999-07-15

We demonstrate a far-field-viewing GRINscope sensor for making analytical measurements in remote locations. The GRINscope was fabricated by permanently affixing a micro-Gradient index (GRIN) lens on the distal face of a 350-micron-diameter optical imaging fiber. The GRINscope can obtain both chemical and visual information. In one application, a thin, pH-sensitive polymer layer was immobilized on the distal end of the GRINscope. The ability of the GRINscope to visually image its far-field surroundings and concurrently detect pH changes in a flowing stream was demonstrated. In a different application, the GRINscope was used to image pH- and O2-sensitive particles on a remote substrate and simultaneously measure their fluorescence intensity in response to pH or pO2 changes.

Estimating E-Race European Corn Borer (Lepidoptera: Crambidae) Adult Activity in Snap Bean Fields Based on Corn Planting Intensity and Their Activity in Corn in New York Agroecosystems.

PubMed

Schmidt-Jeffris, Rebecca A; Huseth, Anders S; Nault, Brian A

2016-07-24

European corn borer, Ostrinia nubilalis (Hübner), is a major pest of processing snap bean because larvae are contaminants in pods. The incidence of O. nubilalis-contaminated beans has become uncommon in New York, possibly because widespread adoption of Bt field corn has suppressed populations. Snap bean fields located where Bt corn has been intensively grown in space and time may be at lower risk for O. nubilalis than fields located where Bt corn is not common. To manage O. nubilalis infestation risk, growers determine insecticide application frequency in snap bean based on pheromone-trapping information in nearby sweet corn fields; adult activity is presumed equivalent in both crops. Our goal was to determine if corn planting intensity and adult activity in sweet corn could be used to estimate O. nubilalis populations in snap bean in New York in 2014-2015. Numbers of O nubilalis adults captured in pheromone-baited traps located in snap bean fields where corn was and was not intensively grown were similar, suggesting that O. nubilalis does not respond to local levels of Bt corn in the landscape. Numbers of Ostrinia nubilalis captured in pheromone-baited traps placed by snap bean fields and proximal sweet corn fields were not related, indicating that snap bean growers should no longer make control decisions based on adult activity in sweet corn. Our results also suggest that the risk of O. nubilalis infestations in snap bean is low (∼80% of the traps caught zero moths) and insecticide applications targeting this pest should be reduced or eliminated. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Teaching Business Shops and Stores' Locations through Field Studies

ERIC Educational Resources Information Center

Yang, Daihu; Wang, Ziying; Wu, Xianliang; Fu, Wenru

2014-01-01

Location, where geographic elements interwork spatially and dynamically, has been one of the enduring themes in geographic studies. There are a number of location theories to explain why things are located where they are. Alfred Weber's location theory stresses that the least cost of delivering products is a key factor in location selection, and…

A comparison of coronal X-ray structures of active regions with magnetic fields computed from photospheric observations

NASA Technical Reports Server (NTRS)

Poletto, G.; Vaiana, G. S.; Zombeck, M. V.; Krieger, A. S.; Timothy, A. F.

1975-01-01

The appearances of several X-ray active regions observed on March 7, 1970 and June 15, 1973 are compared with the corresponding coronal magnetic-field topology. Coronal fields have been computed from measurements of the longitudinal component of the underlying magnetic fields, based on the current-free hypothesis. An overall correspondence between X-ray structures and calculated field lines is established, and the magnetic counterparts of different X-ray features are also examined. A correspondence between enhanced X-ray emission and the location of compact closed field lines is suggested. Representative magnetic-field values calculated under the assumption of current-free fields are given for heights up to 200 sec.

Holocene Relative Sea-Level Changes from Near-, Intermediate-, and Far-Field Locations

NASA Astrophysics Data System (ADS)

Walker, J. S.; Khan, N.; Shaw, T.; Ashe, E.; Vacchi, M.; Peltier, W. R.; Kopp, R. E.; Horton, B.

2015-12-01

Holocene relative sea-level (RSL) records exhibit spatial and temporal variability that arises mainly from the interaction of eustatic (land ice volume and thermal expansion) and isostatic (glacio- and hydro-) factors. We fit RSL histories from near-, intermediate-, and far-field locations with noisy-input Gaussian process models to assess rates of RSL change from selected study areas. Records from near-field regions (e.g., Antarctica, Greenland, Canada, Sweden, and Scotland) reveal a complex pattern of RSL fall from a maximum marine limit due to the net effect of eustatic sea-level rise and glacial-isostatic uplift with rates of RSL fall as great as -69 ± 9 m/ka. Intermediate-field regions (e.g., mid-Atlantic and Pacific coasts of the United States, Netherlands, Southern France, St. Croix) display variable rates of RSL rise from the cumulative effect of isostatic and eustatic factors. Fast rates of RSL rise (up to 10 ± 1 m/ka) are found in the early Holocene in regions near the center of forebulge collapse. Far-field RSL records exhibit a mid-Holocene highstand, the timing (between 8 and 4 ka) and magnitude (between <1 and 6 m) of which varies across South America, Africa, Asia and Australia regions.

A photometric study of Be stars located in the seismology fields of COROT

NASA Astrophysics Data System (ADS)

Gutiérrez-Soto, J.; Fabregat, J.; Suso, J.; Lanzara, M.; Garrido, R.; Hubert, A.-M.; Floquet, M.

2007-12-01

Context: In preparation for the COROT mission, an exhaustive photometric study of Be stars located in the seismology fields of the mission has been performed. The very precise and long-time-spanned photometric observations gathered by the COROT satellite will give important clues on the origin of the Be phenomenon. Aims: The aim of this work is to find short-period variable Be stars located in the seismology fields of COROT, and to study and characterise their pulsational properties. Methods: Light curves obtained at the Observatorio de Sierra Nevada, together with data from Hipparcos and ASAS-3 for a total of 84 Be stars, were analysed in order to search for short-term variations. We applied standard Fourier techniques and non-linear least-square fitting to the time series. Results: We found 7 multiperiodic, 21 mono-periodic and 26 non-variable Be stars. Short-term variability was detected in 74% of early-type Be stars and in 31% of mid- to late-type Be stars. We show that non-radial pulsations are more frequent among Be stars than in slow-rotating B stars of the same spectral range. Appendix A is only available in electronic form at http://www.aanda.org

Statistical analysis of the location of the Martian magnetic pileup boundary and bow shock and the influence of crustal magnetic fields

NASA Astrophysics Data System (ADS)

Edberg, N. J. T.; Lester, M.; Cowley, S. W. H.; Eriksson, A. I.

2008-08-01

We use the data set from the magnetometer and electron reflectometer instruments on board the Mars Global Surveyor spacecraft to show that the crustal magnetic fields of Mars affect the location of the magnetic pileup boundary (MPB) and bow shock (BS) globally. We search for crossings of the MPB and BS in the data that were observed over the first 16 months of the mission. To identify the influence of the crustal magnetic fields, all crossings are extrapolated to the terminator plane in order to remove the solar zenith angle (SZA) dependence, and to make it possible to compare crossings independently of location. The MPB crossings that were observed over regions on Mars, which contain strong crustal magnetic fields, are on average located further out than crossings observed over regions with weak crustal fields. This is shown in three separate longitude intervals. We also find that the dayside BS crossings observed over the southern hemisphere of Mars are on average located further out than the BS crossings observed over the northern hemisphere, possibly because of the influence of the crustal fields. We also study the magnetic field strength and its variation at the inside of the MPB and their dependence on the SZA and altitude. We find that the magnitude of the magnetic field in the MPB is closely linked to the altitude of the MPB, with the magnitude increasing as the MPB is observed closer to the planet.

Activity spaces of men who have sex with men: An initial exploration of geographic variation in locations of routine, potential sexual risk, and prevention behaviors.

PubMed

Vaughan, Adam S; Kramer, Michael R; Cooper, Hannah L F; Rosenberg, Eli S; Sullivan, Patrick S

2017-02-01

Theory and research on HIV and among men who have sex with men (MSM) have long suggested the importance of non-residential locations in defining structural exposures. Despite this, most studies within these fields define place as a residential context, neglecting the potential influence of non-residential locations on HIV-related outcomes. The concept of activity spaces, defined as a set of locations to which an individual is routinely exposed, represents one theoretical basis for addressing this potential imbalance. Using a one-time online survey to collect demographic, behavioral, and spatial data from MSM, this paper describes activity spaces and examines correlates of this spatial variation. We used latent class analysis to identify categories of activity spaces using spatial data on home, routine, potential sexual risk, and HIV prevention locations. We then assessed individual and area-level covariates for their associations with these categories. Classes were distinguished by the degree of spatial variation in routine and prevention behaviors (which were the same within each class) and in sexual risk behaviors (i.e., sex locations and locations of meeting sex partners). Partner type (e.g. casual or main) represented a key correlate of the activity space. In this early examination of activity spaces in an online sample of MSM, patterns of spatial behavior represent further evidence of significant spatial variation in locations of routine, potential HIV sexual risk, and HIV prevention behaviors among MSM. Although prevention behaviors tend to have similar geographic variation as routine behaviors, locations where men engage in potentially high-risk behaviors may be more spatially focused for some MSM than for others. Copyright © 2016 Elsevier Ltd. All rights reserved.

Facebook, Twitter Activities Sites, Location and Students' Interest in Learning

ERIC Educational Resources Information Center

Igbo, J. N.; Ezenwaji, Ifeyinwa; Ajuziogu, Christiana U.

2018-01-01

This study was carried out to ascertain the influence of social networking sites activities (twitter and Facebook) on secondary school students' interest in learning It also considered the impact of these social networking sites activities on location of the students. Two research questions and two null hypotheses guided the study. Mean and…

Utilizing Urban Environments for Effective Field Experiences

NASA Astrophysics Data System (ADS)

MacAvoy, S. E.; Knee, K.

2014-12-01

Research surveys suggest that students are demanding more applied field experiences from their undergraduate environmental science programs. For geoscience educators at liberal arts colleges without field camps, university vehicles, or even geology departments, getting students into the field is especially rewarding - and especially challenging. Here, we present strategies that we have used in courses ranging from introductory environmental science for non-majors, to upper level environmental methods and geology classes. Urban locations provide an opportunity for a different type of local "field-work" than would otherwise be available. In the upper-level undergraduate Environmental Methods class, we relied on a National Park area located a 10-minute walk from campus for most field exercises. Activities included soil analysis, measuring stream flow and water quality parameters, dendrochronology, and aquatic microbe metabolism. In the non-majors class, we make use of our urban location to contrast water quality in parks and highly channelized urban streams. Here we share detailed lesson plans and budgets for field activities that can be completed during a class period of 2.5 hours with a $75 course fee, show how these activities help students gain quantitative competency, and provide student feedback about the classes and activities.

24 CFR 4100.3 - Field activities.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 24 Housing and Urban Development 5 2010-04-01 2010-04-01 false Field activities. 4100.3 Section 4100.3 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) NEIGHBORHOOD REINVESTMENT CORPORATION ORGANIZATION AND CHANNELING OF FUNCTIONS § 4100.3 Field activities. The...

24 CFR 4100.3 - Field activities.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 24 Housing and Urban Development 5 2011-04-01 2011-04-01 false Field activities. 4100.3 Section 4100.3 Housing and Urban Development Regulations Relating to Housing and Urban Development (Continued) NEIGHBORHOOD REINVESTMENT CORPORATION ORGANIZATION AND CHANNELING OF FUNCTIONS § 4100.3 Field activities. The...

Improved Location of Microseismic Events in Borehole Monitoring by Inclusion of Particle Motion Analysis: a Case Study at a CBM Field in Indonesia

NASA Astrophysics Data System (ADS)

Verdhora Ry, Rexha; Septyana, T.; Widiyantoro, S.; Nugraha, A. D.; Ardjuna, A.

2017-04-01

Microseismic monitoring and constraining its hypocenters in and around hydrocarbon reservoirs provides insight into induced deformation related to hydraulic fracturing. In this study, we used data from a single vertical array of sensors in a borehole, providing measures of arrival times and polarizations. Microseismic events are located using 1-D velocity models and arrival times of P- and S-waves. However, in the case of all the sensors being deployed in a near-vertical borehole, there is a high ambiguity in the source location. Herein, we applied a procedure using azimuth of P-wave particle motion to constrain and improve the source location. We used a dataset acquired during 1-day of fracture stimulation at a CBM field in Indonesia. We applied five steps of location procedure to investigate microseismic events induced by these hydraulic fracturing activities. First, arrival times for 1584 candidate events were manually picked. Then we refined the arrival times using energy ratio method to obtain high consistency picking. Using these arrival times, we estimated back-azimuth using P-wave polarization analysis. We also added the combination of polarities analysis to remove 180° ambiguity. In the end, we determined hypocenter locations using grid-search method that guided in the back-azimuth trace area to minimize the misfit function of arrival times. We have successfully removed the ambiguity and produced a good solution for hypocenter locations as indicated statistically by small RMS. Most of the events clusters highlight coherent structures around the treatment well site and revealed faults. The same procedure can be applied to various other cases such as microseismic monitoring in the field of geothermal and shale gas/oil exploration, also CCS (Carbon Capture and Storage) development.

Field Demonstration of Electro-Scan Defect Location Technology for Condition Assessment of Wastewater Collection Systems - Paper

EPA Science Inventory

A USEPA-sponsored field demonstration program was conducted to gather technically reliable cost and performance information on the electro-scan (FELL -41) pipeline condition assessment technology. Electro-scan technology can be used to estimate the magnitude and location of pote...

Evaluation of document location during computer use in terms of neck muscle activity and neck movement.

PubMed

Goostrey, Sonya; Treleaven, Julia; Johnston, Venerina

2014-05-01

This study evaluated the impact on neck movement and muscle activity of placing documents in three commonly used locations: in-line, flat desktop left of the keyboard and laterally placed level with the computer screen. Neck excursion during three standard head movements between the computer monitor and each document location and neck extensor and upper trapezius muscle activity during a 5 min typing task for each of the document locations was measured in 20 healthy participants. Results indicated that muscle activity and neck flexion were least when documents were placed laterally suggesting it may be the optimal location. The desktop option produced both the greatest neck movement and muscle activity in all muscle groups. The in-line document location required significantly more neck flexion but less lateral flexion and rotation than the laterally placed document. Evaluation of other holders is needed to guide decision making for this commonly used office equipment. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

FIELD DEMONSTRATION OF INNOVATIVE LEAK DETECTION/LOCATION TECHNOLOGIES COUPLED WITH WALL-THICKNESS SCREENING FOR WATER MAINS

EPA Science Inventory

The U.S. Environmental Protection Agency sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,500-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through Septembe...

Large Solar Flares and Sheared Magnetic Field Configuration

NASA Technical Reports Server (NTRS)

Choudhary, Debi Prasad

2001-01-01

This Comment gives additional information about the nature of flaring locations on the Sun described in the article "Sun unleashes Halloween storm", by R. E. Lopez, et al. What causes the large explosions from solar active regions that unleash huge magnetic storms and adverse space weather? It is now beyond doubt that the magnetic field in solar active regions harbors free energy that is released during these events. Direct measurements of the longitudinal and transverse components of active region magnetic fields with the vector magnetograph at NASA Marshall Space Flight Center (MSFC), taken on a regular basis for the last 30 years, have found key signatures of the locations of powerful flares. A vector magnetograph detects and measures the magnetic shear, which is the deviation of the observed transverse magnetic field direction from the potential field. The sheared locations possess abundant free magnetic energy for solar flares. In addition to active region NOAA 10486, the one that produced the largest flares last October, the NASA/MSFC vector magnetograph has observed several other such complex super active regions, including NOAA 6555 and 6659.

Evaluating the effect of human activity patterns on air pollution exposure using an integrated field-based and agent-based modelling framework

NASA Astrophysics Data System (ADS)

Schmitz, Oliver; Beelen, Rob M. J.; de Bakker, Merijn P.; Karssenberg, Derek

2015-04-01

Constructing spatio-temporal numerical models to support risk assessment, such as assessing the exposure of humans to air pollution, often requires the integration of field-based and agent-based modelling approaches. Continuous environmental variables such as air pollution are best represented using the field-based approach which considers phenomena as continuous fields having attribute values at all locations. When calculating human exposure to such pollutants it is, however, preferable to consider the population as a set of individuals each with a particular activity pattern. This would allow to account for the spatio-temporal variation in a pollutant along the space-time paths travelled by individuals, determined, for example, by home and work locations, road network, and travel times. Modelling this activity pattern requires an agent-based or individual based modelling approach. In general, field- and agent-based models are constructed with the help of separate software tools, while both approaches should play together in an interacting way and preferably should be combined into one modelling framework, which would allow for efficient and effective implementation of models by domain specialists. To overcome this lack in integrated modelling frameworks, we aim at the development of concepts and software for an integrated field-based and agent-based modelling framework. Concepts merging field- and agent-based modelling were implemented by extending PCRaster (http://www.pcraster.eu), a field-based modelling library implemented in C++, with components for 1) representation of discrete, mobile, agents, 2) spatial networks and algorithms by integrating the NetworkX library (http://networkx.github.io), allowing therefore to calculate e.g. shortest routes or total transport costs between locations, and 3) functions for field-network interactions, allowing to assign field-based attribute values to networks (i.e. as edge weights), such as aggregated or averaged

3D magneto-convective heat transfer in CNT-nanofluid filled cavity under partially active magnetic field

NASA Astrophysics Data System (ADS)

Al-Rashed, Abdullah A. A. A.; Kolsi, Lioua; Oztop, Hakan F.; Aydi, Abdelkarim; Malekshah, Emad Hasani; Abu-Hamdeh, Nidal; Borjini, Mohamed Naceur

2018-05-01

A computational study has been performed to investigate the effects of partially active magnetic field on natural convection heat transfer in CNT-nanofluid filled and three-dimensional differentially heated closed space. Two cases are considered to see this effect as magnetic field is applied to upper half (Case I) and lower half (Case II) while remaining walls are insulated. The finite volume method is used to solve governing equations and results are obtained for different governing parameters as Hartmann number (0 ≤ Ha ≤ 100), nanoparticle volume fraction (0 ≤ φ ≤ 0.05) and height of the active zone (0 ≤ LB ≤ 1). It is found that location of magnetic field plays an important role even at the same Hartmann number. Thus, it can be a good parameter to control heat and fluid flow inside the closed space.

Direct-location versus verbal report methods for measuring auditory distance perception in the far field.

PubMed

Etchemendy, Pablo E; Spiousas, Ignacio; Calcagno, Esteban R; Abregú, Ezequiel; Eguia, Manuel C; Vergara, Ramiro O

2018-06-01

In this study we evaluated whether a method of direct location is an appropriate response method for measuring auditory distance perception of far-field sound sources. We designed an experimental set-up that allows participants to indicate the distance at which they perceive the sound source by moving a visual marker. We termed this method Cross-Modal Direct Location (CMDL) since the response procedure involves the visual modality while the stimulus is presented through the auditory modality. Three experiments were conducted with sound sources located from 1 to 6 m. The first one compared the perceived distances obtained using either the CMDL device or verbal report (VR), which is the response method more frequently used for reporting auditory distance in the far field, and found differences on response compression and bias. In Experiment 2, participants reported visual distance estimates to the visual marker that were found highly accurate. Then, we asked the same group of participants to report VR estimates of auditory distance and found that the spatial visual information, obtained from the previous task, did not influence their reports. Finally, Experiment 3 compared the same responses that Experiment 1 but interleaving the methods, showing a weak, but complex, mutual influence. However, the estimates obtained with each method remained statistically different. Our results show that the auditory distance psychophysical functions obtained with the CMDL method are less susceptible to previously reported underestimation for distances over 2 m.

One-inch field of view imaging probe for breast cancer sentinel node location

NASA Astrophysics Data System (ADS)

D'Errico, Giovanni; Scafé, Raffaele; Soluri, Alessandro; Schiaratura, Alfiero; Maria Mangano, Anna; David, Vincenzo; Scopinaro, Francesco

2003-01-01

The already reported 1-in. 2 field of view mini gamma camera known since 1998 with the name of Imaging Probe (IP), has been used for sentinel node localization by a medical equipe that, though trained by the group of nuclear physicians of the University "La Sapienza" who first conceived and used this detector, has used IP in its own Hospital to: (1) gain experience for future use during operations—a cooperative work on IP radio guided orthopaedic operations has already started working, and (2) to start with IP multicenter trials. In six patients with breast cancer, who underwent lymphoscintigraphy for sentinel node biopsy, sentinel node was checked and located with IP and non-imaging Neoprobe 2000 CdTe (Zn) probe, independent of location by means of large field of view Anger camera. Operators who used Neoprobe and IP were blinded to each other and not aware of the results of Anger camera imaging. Anger camera, as well as IP and neoprobe detected 7 nodes in 6 pts. Detection time was 2', 06″ SD 26″ with IP and 2', 18″ SD 47″ with neoprobe 2000. The most difficult to find node required 2 min and 56 s—inside sd—for IP detection and 3 min and 45 s with neoprobe. Subjective impression of being sure of having detected sentinel node was: absolutely sure on 7/7 nodes with IP and on 5/7 nodes with neoprobe.

Suspicious activity recognition in infrared imagery using Hidden Conditional Random Fields for outdoor perimeter surveillance

NASA Astrophysics Data System (ADS)

Rogotis, Savvas; Ioannidis, Dimosthenis; Tzovaras, Dimitrios; Likothanassis, Spiros

2015-04-01

The aim of this work is to present a novel approach for automatic recognition of suspicious activities in outdoor perimeter surveillance systems based on infrared video processing. Through the combination of size, speed and appearance based features, like the Center-Symmetric Local Binary Patterns, short-term actions are identified and serve as input, along with user location, for modeling target activities using the theory of Hidden Conditional Random Fields. HCRFs are used to directly link a set of observations to the most appropriate activity label and as such to discriminate high risk activities (e.g. trespassing) from zero risk activities (e.g loitering outside the perimeter). Experimental results demonstrate the effectiveness of our approach in identifying suspicious activities for video surveillance systems.

Locations of Joint Physical Activity in Parent-Child Pairs Based on Accelerometer and GPS Monitoring

PubMed Central

Dunton, Genevieve Fridlund; Liao, Yue; Almanza, Estela; Jerrett, Micheal; Spruijt-Metz, Donna; Pentz, Mary Ann

2012-01-01

Background Parental factors may play an important role in influencing children’s physical activity levels. Purpose This cross-sectional study sought to describe the locations of joint physical activity among parents and children. Methods Parent-child pairs (N = 291) wore an Actigraph GT2M accelerometer and GlobalSat BT-335 Global Positioning Systems (GPS) device over the same 7-day period. Children were ages 8–14 years. Joint behavior was defined by a linear separation distance of less than 50m between parent and child. Land use classifications were assigned to GPS data points. Results Joint physical activity was spread across residential locations (35%), and commercial venues (24%), and open spaces/parks (20%). Obese children and parents performed less joint physical activity in open spaces/parks than under/normal weight children and parents (p’s < .01). Conclusions Understanding where joint parent-child physical activity naturally occurs may inform location-based interventions to promote these behaviors. PMID:23011914

Effect of Agave tequilana age, cultivation field location and yeast strain on tequila fermentation process.

PubMed

Pinal, L; Cornejo, E; Arellano, M; Herrera, E; Nuñez, L; Arrizon, J; Gschaedler, A

2009-05-01

The effect of yeast strain, the agave age and the cultivation field location of agave were evaluated using kinetic parameters and volatile compound production in the tequila fermentation process. Fermentations were carried out with Agave juice obtained from two cultivation fields (CF1 and CF2), as well as two ages (4 and 8 years) and two Saccharomyces cerevisiae yeast strains (GU3 and AR5) isolated from tequila fermentation must. Sugar consumption and ethanol production varied as a function of cultivation field and agave age. The production of ethyl acetate, 1-propanol, isobutanol and amyl alcohols were influenced in varying degrees by yeast strain, agave age and cultivation field. Methanol production was only affected by the agave age and 2-phenylethanol was influenced only by yeast strain. This work showed that the use of younger Agave tequilana for tequila fermentation resulted in differences in sugar consumption, ethanol and volatile compounds production at the end of fermentation, which could affect the sensory quality of the final product.

Optical Sensor/Actuator Locations for Active Structural Acoustic Control

NASA Technical Reports Server (NTRS)

Padula, Sharon L.; Palumbo, Daniel L.; Kincaid, Rex K.

1998-01-01

Researchers at NASA Langley Research Center have extensive experience using active structural acoustic control (ASAC) for aircraft interior noise reduction. One aspect of ASAC involves the selection of optimum locations for microphone sensors and force actuators. This paper explains the importance of sensor/actuator selection, reviews optimization techniques, and summarizes experimental and numerical results. Three combinatorial optimization problems are described. Two involve the determination of the number and position of piezoelectric actuators, and the other involves the determination of the number and location of the sensors. For each case, a solution method is suggested, and typical results are examined. The first case, a simplified problem with simulated data, is used to illustrate the method. The second and third cases are more representative of the potential of the method and use measured data. The three case studies and laboratory test results establish the usefulness of the numerical methods.

IMPRESS: medical location-aware decision making during emergencies

NASA Astrophysics Data System (ADS)

Gkotsis, I.; Eftychidis, G.; Leventakis, G.; Mountzouris, M.; Diagourtas, D.; Kostaridis, A.; Hedel, R.; Olunczek, A.; Hahmann, S.

2017-09-01

Emergency situations and mass casualties involve several agencies and public authorities, which need to gather data from the incident scene and exchange geo-referenced information to provide fast and accurate first aid to the people in need. Tracking patients on their way to the hospitals can prove critical in taking lifesaving decisions. Increased and continuous flow of information combined by vital signs and geographic location of emergency victims can greatly reduce the response time of the medical emergency chain and improve the efficiency of disaster medicine activity. Recent advances in mobile positioning systems and telecommunications are providing the technology needed for the development of location-aware medical applications. IMPRESS is an advanced ICT platform based on adequate technologies for developing location-aware medical response during emergencies. The system incorporates mobile and fixed components that collect field data from diverse sources, support medical location and situation-based services and share information on the patient's transport from the field to the hospitals. In IMPRESS platform tracking of victims, ambulances and emergency services vehicles is integrated with medical, traffic and crisis management information into a common operational picture. The Incident Management component of the system manages operational resources together with patient tracking data that contain vital sign values and patient's status evolution. Thus, it can prioritize emergency transport decisions, based on medical and location-aware information. The solution combines positioning and information gathered and owned by various public services involved in MCIs or large-scale disasters. IMPRESS solution, were validated in field and table top exercises in cooperation with emergency services and hospitals.

Syringe filtration methods for examining dissolved and colloidal trace element distributions in remote field locations

NASA Technical Reports Server (NTRS)

Shiller, Alan M.

2003-01-01

It is well-established that sampling and sample processing can easily introduce contamination into dissolved trace element samples if precautions are not taken. However, work in remote locations sometimes precludes bringing bulky clean lab equipment into the field and likewise may make timely transport of samples to the lab for processing impossible. Straightforward syringe filtration methods are described here for collecting small quantities (15 mL) of 0.45- and 0.02-microm filtered river water in an uncontaminated manner. These filtration methods take advantage of recent advances in analytical capabilities that require only small amounts of waterfor analysis of a suite of dissolved trace elements. Filter clogging and solute rejection artifacts appear to be minimal, although some adsorption of metals and organics does affect the first approximately 10 mL of water passing through the filters. Overall the methods are clean, easy to use, and provide reproducible representations of the dissolved and colloidal fractions of trace elements in river waters. Furthermore, sample processing materials can be prepared well in advance in a clean lab and transported cleanly and compactly to the field. Application of these methods is illustrated with data from remote locations in the Rocky Mountains and along the Yukon River. Evidence from field flow fractionation suggests that the 0.02-microm filters may provide a practical cutoff to distinguish metals associated with small inorganic and organic complexes from those associated with silicate and oxide colloids.

77 FR 33479 - Information Collection Activities: Oil-Spill Response Requirements for Facilities Located Seaward...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-06

...-0010; OMB Control Number 1014-0007] Information Collection Activities: Oil-Spill Response Requirements... regulations under Part 254, ``Oil-Spill Response Requirements for Facilities Located Seaward of the Coast Line... 254, Oil-Spill Response Requirements for Facilities Located Seaward of the Coast Line. OMB Control...

Positioning actuators in efficient locations for rendering the desired sound field using inverse approach

NASA Astrophysics Data System (ADS)

Cho, Wan-Ho; Ih, Jeong-Guon; Toi, Takeshi

2015-12-01

For rendering a desired characteristics of a sound field, a proper conditioning of acoustic actuators in an array are required, but the source condition depends strongly on its position. Actuators located at inefficient positions for control would consume the input power too much or become too much sensitive to disturbing noise. These actuators can be considered redundant, which should be sorted out as far as such elimination does not damage the whole control performance significantly. It is known that the inverse approach based on the acoustical holography concept, employing the transfer matrix between sources and field points as core element, is useful for rendering the desired sound field. By investigating the information indwelling in the transfer matrix between actuators and field points, the linear independency of an actuator from the others in the array can be evaluated. To this end, the square of the right singular vector, which means the radiation contribution from the source, can be used as an indicator. Inefficient position for fulfilling the desired sound field can be determined as one having smallest indicator value among all possible actuator positions. The elimination process continues one by one, or group by group, until the remaining number of actuators meets the preset number. Control examples of exterior and interior spaces are taken for the validation. The results reveal that the present method for choosing least dependent actuators, for a given number of actuators and field condition, is quite effective in realizing the desired sound field with a noisy input condition, and in minimizing the required input power.

Field Demonstration of Innovative Leak Detection/Location in Conjunction with Pipe Wall Thickness Testing for Water Mains

EPA Science Inventory

The U.S. Environmental Protection Agency (EPA) sponsored a large-scale field demonstration of innovative leak detection/location and condition assessment technologies on a 76-year old, 2,000-ft long, cement-lined, 24-in. cast iron water main in Louisville, KY from July through Se...

The Throw-and-Catch Model of Human Gait: Evidence from Coupling of Pre-Step Postural Activity and Step Location

PubMed Central

Bancroft, Matthew J.; Day, Brian L.

2016-01-01

Postural activity normally precedes the lift of a foot from the ground when taking a step, but its function is unclear. The throw-and-catch hypothesis of human gait proposes that the pre-step activity is organized to generate momentum for the body to fall ballistically along a specific trajectory during the step. The trajectory is appropriate for the stepping foot to land at its intended location while at the same time being optimally placed to catch the body and regain balance. The hypothesis therefore predicts a strong coupling between the pre-step activity and step location. Here we examine this coupling when stepping to visually-presented targets at different locations. Ten healthy, young subjects were instructed to step as accurately as possible onto targets placed in five locations that required either different step directions or different step lengths. In 75% of trials, the target location remained constant throughout the step. In the remaining 25% of trials, the intended step location was changed by making the target jump to a new location 96 ms ± 43 ms after initiation of the pre-step activity, long before foot lift. As predicted by the throw-and-catch hypothesis, when the target location remained constant, the pre-step activity led to body momentum at foot lift that was coupled to the intended step location. When the target location jumped, the pre-step activity was adjusted (median latency 223 ms) and prolonged (on average by 69 ms), which altered the body’s momentum at foot lift according to where the target had moved. We conclude that whenever possible the coupling between the pre-step activity and the step location is maintained. This provides further support for the throw-and-catch hypothesis of human gait. PMID:28066208

The Throw-and-Catch Model of Human Gait: Evidence from Coupling of Pre-Step Postural Activity and Step Location.

PubMed

Bancroft, Matthew J; Day, Brian L

2016-01-01

Postural activity normally precedes the lift of a foot from the ground when taking a step, but its function is unclear. The throw-and-catch hypothesis of human gait proposes that the pre-step activity is organized to generate momentum for the body to fall ballistically along a specific trajectory during the step. The trajectory is appropriate for the stepping foot to land at its intended location while at the same time being optimally placed to catch the body and regain balance. The hypothesis therefore predicts a strong coupling between the pre-step activity and step location. Here we examine this coupling when stepping to visually-presented targets at different locations. Ten healthy, young subjects were instructed to step as accurately as possible onto targets placed in five locations that required either different step directions or different step lengths. In 75% of trials, the target location remained constant throughout the step. In the remaining 25% of trials, the intended step location was changed by making the target jump to a new location 96 ms ± 43 ms after initiation of the pre-step activity, long before foot lift. As predicted by the throw-and-catch hypothesis, when the target location remained constant, the pre-step activity led to body momentum at foot lift that was coupled to the intended step location. When the target location jumped, the pre-step activity was adjusted (median latency 223 ms) and prolonged (on average by 69 ms), which altered the body's momentum at foot lift according to where the target had moved. We conclude that whenever possible the coupling between the pre-step activity and the step location is maintained. This provides further support for the throw-and-catch hypothesis of human gait.

Equatorial measurement of SAID electric fields and relation with the plasmapause location

NASA Astrophysics Data System (ADS)

Nishimura, Y.; Wygant, J.; Ono, T.; Iizima, M.; Kumamoto, A.; Brautigam, D.; Rich, F.

2007-12-01

In order to investigate the equatorial source of subauroral ion drifts (SAID) and its association with the plasmapause position, multi-spacecraft measurements of SAID are presented using the CRRES, Akebono, and DMSP. Direct measurement of the convection electric field and plasmapause density close to the equator is measured by the electric field instrument onboard the CRRES satellite, and the plasmasheet electrons and low energy part of the ring current ions are measured by the low energy plasma instrument. The CRRES satellite is on the dusk inner magnetosphere, and the DMSP-F8 and Akebono satellites are approximately on the same field line. Associated with a substorm onset at 16:40 UT on February 20, 1991, the DMSP-F8 satellite at 19 MLT measures SAID with a maximum westward velocity of 1,500 m/s. The CRRES satellite is on outbound in the inner magnetosphere at ~21 MLT and ~5 RE at the onset of the substorm. It measures increase of DC electric field with 0.4 mV/m in the plasmasphere just after the substorm onset. Thirty minutes later, injection of ring current ions are observed in the plasmasphere with Bz decrease. After the crossing of the plasmapause, the electric field increases to 0.8 mV/m. At the same time, the spacecraft enters the plasmasheet, and the DC electric field disappears. The same time sequence is also identified in other SAID events detected on the dusk inner magnetosphere. The above CRRES measurement indicates that DC electric field is intensified in a narrow region between the ring current and electron plasmasheet after the onset of the substorm. Although the E*B drift points sunward in this region, this region with enhanced electric field is filled with plasmaspheric plasma without abrupt density change. The position where the convection electric field is equal to the corotation electric field locates inside the plasmapause. The plasmapause coincides with inner edge of the plasmasheet. This association suggests that the plasmaspheric plasma is

Where Are Adults Active? An Examination of Physical Activity Locations Using GPS in Five US Cities.

PubMed

Holliday, Katelyn M; Howard, Annie Green; Emch, Michael; Rodríguez, Daniel A; Rosamond, Wayne D; Evenson, Kelly R

2017-08-01

Increasing physical activity (PA) at the population level requires appropriately targeting intervention development. Identifying the locations in which participants with various sociodemographic, body weight, and geographic characteristics tend to engage in varying intensities of PA as well as locations these populations underutilize for PA may facilitate this process. A visual location-coding protocol was developed and implemented in Google Fusion Tables and Maps using data from participants (N = 223, age 18-85) in five states. Participants concurrently wore ActiGraph GT1M accelerometers and Qstarz BT-Q1000X GPS units for 3 weeks to identify locations of moderate-to-vigorous (MVPA) or vigorous (VPA) bouts. Cochran-Mantel-Haenzel general association tests examined usage differences by participant characteristics (sex, age, race/ethnicity, education, body mass index (BMI), and recruitment city). Homes and roads encompassed >40% of bout-based PA minutes regardless of PA intensity. Fitness facilities and schools were important for VPA (19 and 12% of bout minutes). Parks were used for 13% of MVPA bout minutes but only 4% of VPA bout minutes. Hispanics, those without a college degree, and overweight/obese participants frequently completed MVPA bouts at home. Older adults often used roads for MVPA bouts. Hispanics, those with ≤high school education, and healthy/overweight participants frequently had MVPA bouts in parks. Applying a new location-coding protocol in a diverse population showed that adult PA locations varied by PA intensity, sociodemographic characteristics, BMI, and geographic location. Although homes, roads, and parks remain important locations for demographically targeted PA interventions, observed usage patterns by participant characteristics may facilitate development of more appropriately targeted interventions.

Negotiating on location, timing, duration, and participant in agent-mediated joint activity-travel scheduling

NASA Astrophysics Data System (ADS)

Ma, Huiye; Ronald, Nicole; Arentze, Theo A.; Timmermans, Harry J. P.

2013-10-01

Agent-based simulation has become an important modeling approach in activity-travel analysis. Social activities account for a large amount of travel and have an important effect on activity-travel scheduling. Participants in joint activities usually have various options regarding location, participants, and timing and take different approaches to make their decisions. In this context, joint activity participation requires negotiation among agents involved, so that conflicts among the agents can be addressed. Existing mechanisms do not fully provide a solution when utility functions of agents are nonlinear and non-monotonic. Considering activity-travel scheduling in time and space as an application, we propose a novel negotiation approach, which takes into account these properties, such as continuous and discrete issues, and nonlinear and non-monotonic utility functions, by defining a concession strategy and a search mechanism. The results of experiments show that agents having these properties can negotiate efficiently. Furthermore, the negotiation procedure affects individuals’ choices of location, timing, duration, and participants.

An active role for magnetic fields in solar flares

NASA Technical Reports Server (NTRS)

Rust, D. M.

1976-01-01

Observations of photospheric magnetic fields are reviewed to determine whether changes in such fields can be related to flare activity, assuming that magnetic fields play an active role in providing flare energy. An intimate relation between emerging fields and bright flare knots is noted, and it is shown that the activation and eruption of an H-alpha filament is indicative of a major disruption of a magnetic field just prior to a flare. Observations of twisting motions in a filament just before a flare are discussed, erupting untwisting filaments are taken as unambiguous evidence for restructuring of the magnetic fields associated with flares, and it is argued that magnetic-field changes in the midst of most flares are obvious. It is concluded that successive brightenings in a family of loops may be evidence for the spread of a magnetic-field reconnection point from one field concentration to another and that flares may well take place in regions of field-line reconnection. This latter conclusion is illustrated using an empirical flare model that involves field-line reconnection, filament activation, and emerging magnetic flux.

Annual and semiannual variations of the geomagnetic field at equatorial locations

USGS Publications Warehouse

Campbell, W.H.

1981-01-01

For a year of quiet solar-activity level, geomagnetic records from American hemisphere observatories located between about 0?? and 30?? north geomagnetic latitude were used to compare the annual and semiannual variations of the geomagnetic field associated with three separate contributions: (a) the quiet-day midnight level, MDT; (b) the solar-quiet daily variation, Sq; (c) the quiet-time lunar semidiurnal tidal variation, L(12). Four Fourier spectral constituents (24, 12, 8, 6 h periods) of Sq were individually treated. All three orthogonal elements (H, D and Z) were included in the study. The MDT changes show a dominant semiannual variation having a range of about 7 gammas in H and a dominant annual variation in Z having a range of over 8 gammas. These changes seem to be a seasonal response to the nightside distortions by magnetospheric currents. There is a slow decrease in MDT amplitudes with increasing latitude. The Sq changes follow the patterns expected from an equatorial ionospheric dynamo electrojet current system. The dominant seasonal variations occur in H having a range of over 21 gammas for the 24 h period and over 12 gammas for the 12 h period spectral components. The higher-order components are relatively smaller in size. The Sq(H) amplitudes decrease rapidly with increasing latitude. Magnetospheric contributions to the equatorial Sq must be less than a few per cent of the observed magnitude. The L(12) variation shows the ionospheric electrojet features by the dominance of H and the rapid decrease in amplitude with latitude away from the equator. However, the seasonal variation range of over 7 gammas has a maximum in early February and minimum in late June that is not presently explainable by the known ionospheric conductivity and tidal behavior. ?? 1981.

Numerical modelling of GPR electromagnetic fields for locating burial sites

NASA Astrophysics Data System (ADS)

Carcione, José M.; Karczewski, Jerzy; Mazurkiewicz, Ewelina; Tadeusiewicz, Ryszard; Tomecka-Suchoń, Sylwia

2017-11-01

Ground-penetrating radar (GPR) is commonly used for locating burial sites. In this article, we acquired radargrams at a site where a domestic pig cadaver was buried. The measurements were conducted with the ProEx System GPR manufactured by the Swedish company Mala Geoscience with an antenna of 500MHz. The event corresponding to the pig can be clearly seen in the measurements. In order to improve the interpretation, the electromagnetic field is compared to numerical simulations computed with the pseudo-spectral Fourier method. A geological model has been defined on the basis of assumed electromagnetic properties (permittivity, conductivity and magnetic permeability). The results, when compared with the GPR measurements, show a dissimilar amplitude behaviour, with a stronger reflection event from the bottom of the pit. We have therefore performed another simulation by decreasing the electrical conductivity of the body very close to that of air. The comparison improved, showing more reflections, which could be an indication that the body contains air or has been degraded to a certain extent that the electrical resistivity has greatly increased.

Magnetic surveys for locating abandoned wells

USGS Publications Warehouse

,

1995-01-01

Abandoned and unrecorded wells may act as conduits for the contamination of groundwater supplies by oil field brines and other pollutants. The casings of abandoned wells eventually develop leaks, which, if not properly plugged, can allow pollutants to reach freshwater aquifers that supply drinking water. Sources of pollutants include brine ponds, landfill sites, agricultural activities, industrial activities, illegal disposal sites, or accidental spills. The problem is particularly acute in regions where there are old petroleum fields or where water wells have been extensively used for agricultural irrigation. Even urban areas can contain wells that were abandoned and concealed during development. Carefully designed ground magnetic or aeromagnetic surveys can be used to locate abandoned wells by mapping the magnetic disturbances or "anomalies" produced by their steel well casings. The U.S. Geological Survey (USGS) can, at the request of other Federal, State, or local agencies, conduct, process, and interpret such surveys, or it can aid in the design and monitoring of contracts for such surveys.

Object locating system

DOEpatents

Novak, James L.; Petterson, Ben

1998-06-09

A sensing system locates an object by sensing the object's effect on electric fields. The object's effect on the mutual capacitance of electrode pairs varies according to the distance between the object and the electrodes. A single electrode pair can sense the distance from the object to the electrodes. Multiple electrode pairs can more precisely locate the object in one or more dimensions.

Wireless Damage Location Sensing System

NASA Technical Reports Server (NTRS)

Woodard, Stanley E. (Inventor); Taylor, Bryant Douglas (Inventor)

2012-01-01

A wireless damage location sensing system uses a geometric-patterned wireless sensor that resonates in the presence of a time-varying magnetic field to generate a harmonic response that will experience a change when the sensor experiences a change in its geometric pattern. The sensing system also includes a magnetic field response recorder for wirelessly transmitting the time-varying magnetic field and for wirelessly detecting the harmonic response. The sensing system compares the actual harmonic response to a plurality of predetermined harmonic responses. Each predetermined harmonic response is associated with a severing of the sensor at a corresponding known location thereof so that a match between the actual harmonic response and one of the predetermined harmonic responses defines the known location of the severing that is associated therewith.

Coronal holes, large-scale magnetic field, and activity complexes in solar cycle 23

NASA Astrophysics Data System (ADS)

Tavastsherna, K. S.; Polyakow, E. V.

2014-12-01

A correlation among coronal holes (CH), a large-scale magnetic field (LMF), and activity complexes (AC) is studied in this work for 1997-2007 with the use of a coronal hole series obtained from observations at the Kitt Peak Observatory in the HeI 10830 Å line in 1975-2003 and SOHO/EIT-195 Å in 1996-2012 (Tlatov et al., 2014), synoptic Hα charts from Kislovodsk Mountain Astonomical Station, and the catalog of AC cores (Yazev, 2012). From the imposition of CH boundaries on Hα charts, which characterize the positions of neutral lines of the radial components of a large-scale solar magnetic field, it turns out that 70% of CH are located in unipolar regions of their sign during the above period, 10% are in the region of an opposite sign, and 20% are mainly very large CH, which are often crossed by the neutral lines of several unipolar regions. Data on mutual arrangement of CH and AC cores were obtained. It was shown that only some activity comples cores have genetic relationships with CH.

Static and wind tunnel near-field/far-field jet noise measurements from model scale single-flow baseline and suppressor nozzles. Volume 1: Noise source locations and extrapolation of static free-field jet noise data

NASA Technical Reports Server (NTRS)

Jaeck, C. L.

1976-01-01

A test was conducted in the Boeing Large Anechoic Chamber to determine static jet noise source locations of six baseline and suppressor nozzle models, and establish a technique for extrapolating near field data into the far field. The test covered nozzle pressure ratios from 1.44 to 2.25 and jet velocities from 412 to 594 m/s at a total temperature of 844 K.

Applying geographic profiling used in the field of criminology for predicting the nest locations of bumble bees.

PubMed

Suzuki-Ohno, Yukari; Inoue, Maki N; Ohno, Kazunori

2010-07-21

We tested whether geographic profiling (GP) can predict multiple nest locations of bumble bees. GP was originally developed in the field of criminology for predicting the area where an offender most likely resides on the basis of the actual crime sites and the predefined probability of crime interaction. The predefined probability of crime interaction in the GP model depends on the distance of a site from an offender's residence. We applied GP for predicting nest locations, assuming that foraging and nest sites were the crime sites and the offenders' residences, respectively. We identified the foraging and nest sites of the invasive species Bombus terrestris in 2004, 2005, and 2006. We fitted GP model coefficients to the field data of the foraging and nest sites, and used GP with the fitting coefficients. GP succeeded in predicting about 10-30% of actual nests. Sensitivity analysis showed that the predictability of the GP model mainly depended on the coefficient value of buffer zone, the distance at the mode of the foraging probability. GP will be able to predict the nest locations of bumble bees in other area by using the fitting coefficient values measured in this study. It will be possible to further improve the predictability of the GP model by considering food site preference and nest density. (c) 2010 Elsevier Ltd. All rights reserved.

Lightning Activity Analyses with Respect to the SPCZ Location and to Surface Air Humidity Around Tahiti

NASA Astrophysics Data System (ADS)

Ortega, P.; Guignes, T.

2006-12-01

The South Pacific Convergence Zone (SPCZ) is located from the West Pacific warm pool and trends Southeast towards French Polynesia. The Island Climate Update monthly publishes the mean location deduced from the outgoing long-wave radiation anomalies or higher rainfall. On the other hand, the Wide World Lightning Location Network monthly provides data from which the lightning activity distribution in the 0°-30° South latitude and 150°-240° West longitude area can be drawn. Scanning this rectangle from West to East the location of the maximum lightning activity can be located versus the longitude. Fitting the location of these maximum with a polynomial function leads to a curve comparable with the monthly mean position of the SPCZ, showing that this band of cloudiness is the main source of lightning in this whole area. Besides, relations between surface atmospheric parameters, the number of thunder days and the number of flashes recorded around Tahiti have been analyzed using, the absolute humidity and the lightning activity recorded during the last nine years with the help of CIGRE Lightning Flash Counters. Since it is known that the cloud base is closely related to the boundary layer relative humidity, the aim of the analysis was to sort out a correlation between this parameter and the lightning activity. No correlation has been clearly put in evidence with the number of thunder days but the monthly mean values of the amount of flashes recorded exhibit similar oscillation with air humidity over a 9 year long period including the several phases of the ENSO.

Incidence and Location of Pain in Young, Active Patients Following Hip Arthroplasty.

PubMed

Nam, Denis; Nunley, Ryan M; Sauber, Timothy J; Johnson, Staci R; Brooks, Peter J; Barrack, Robert L

2015-11-01

Persistent pain following hip arthroplasty remains a concern, especially in young, active patients. Four hundred twenty patients less than 60 years of age with a pre-symptomatic UCLA score ≥ 6 (196 total hip arthroplasty [THA]; 224 surface replacement arthroplasty [SRA]) completed a pain-drawing questionnaire investigating the location, severity, and frequency of pain around the hip. At a mean of 2.9 years of follow-up, 40% reported pain in at least one location around the hip. There was no difference in the incidence of groin pain between SRA and THA patients (32% vs. 29%, P=0.6), but THA patients had a greater incidence of anterior (25% vs. 8%, P<0.001) and lateral (20% vs. 10%, P=0.01) thigh pain. A high percentage of young, active patients experience persistent pain following hip arthroplasty. Copyright © 2015 Elsevier Inc. All rights reserved.

40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

Code of Federal Regulations, 2013 CFR

2013-07-01

... management activities under a RAP at a location removed from the area where the remediation wastes originated... management activities under a RAP at a location removed from the area where the remediation wastes originated? (a) You may request a RAP for remediation waste management activities at a location removed from the...

40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

Code of Federal Regulations, 2012 CFR

2012-07-01

... management activities under a RAP at a location removed from the area where the remediation wastes originated... management activities under a RAP at a location removed from the area where the remediation wastes originated? (a) You may request a RAP for remediation waste management activities at a location removed from the...

Object locating system

DOEpatents

Novak, J.L.; Petterson, B.

1998-06-09

A sensing system locates an object by sensing the object`s effect on electric fields. The object`s effect on the mutual capacitance of electrode pairs varies according to the distance between the object and the electrodes. A single electrode pair can sense the distance from the object to the electrodes. Multiple electrode pairs can more precisely locate the object in one or more dimensions. 12 figs.

Shock Location Dominated Transonic Flight Loads on the Active Aeroelastic Wing

NASA Technical Reports Server (NTRS)

Lokos, William A.; Lizotte, Andrew; Lindsley, Ned J.; Stauf, Rick

2005-01-01

During several Active Aeroelastic Wing research flights, the shadow of the over-wing shock could be observed because of natural lighting conditions. As the plane accelerated, the shock location moved aft, and as the shadow passed the aileron and trailing-edge flap hinge lines, their associated hinge moments were substantially affected. The observation of the dominant effect of shock location on aft control surface hinge moments led to this investigation. This report investigates the effect of over-wing shock location on wing loads through flight-measured data and analytical predictions. Wing-root and wing-fold bending moment and torque and leading- and trailing-edge hinge moments have been measured in flight using calibrated strain gages. These same loads have been predicted using a computational fluid dynamics code called the Euler Navier-Stokes Three Dimensional Aeroelastic Code. The computational fluid dynamics study was based on the elastically deformed shape estimated by a twist model, which in turn was derived from in-flight-measured wing deflections provided by a flight deflection measurement system. During level transonic flight, the shock location dominated the wing trailing-edge control surface hinge moments. The computational fluid dynamics analysis based on the shape provided by the flight deflection measurement system produced very similar results and substantially correlated with the measured loads data.

Active Region Photospheric Magnetic Properties Derived from Line-of-Sight and Radial Fields

NASA Astrophysics Data System (ADS)

Guerra, J. A.; Park, S.-H.; Gallagher, P. T.; Kontogiannis, I.; Georgoulis, M. K.; Bloomfield, D. S.

2018-01-01

The effect of using two representations of the normal-to-surface magnetic field to calculate photospheric measures that are related to the active region (AR) potential for flaring is presented. Several AR properties were computed using line-of-sight (B_{los}) and spherical-radial (Br) magnetograms from the Space-weather HMI Active Region Patch (SHARP) products of the Solar Dynamics Observatory, characterizing the presence and features of magnetic polarity inversion lines, fractality, and magnetic connectivity of the AR photospheric field. The data analyzed correspond to {≈ }4{,}000 AR observations, achieved by randomly selecting 25% of days between September 2012 and May 2016 for analysis at 6-hr cadence. Results from this statistical study include: i) the Br component results in a slight upwards shift of property values in a manner consistent with a field-strength underestimation by the B_{los} component; ii) using the Br component results in significantly lower inter-property correlation in one-third of the cases, implying more independent information as regards the state of the AR photospheric magnetic field; iii) flaring rates for each property vary between the field components in a manner consistent with the differences in property-value ranges resulting from the components; iv) flaring rates generally increase for higher values of properties, except the Fourier spectral power index that has flare rates peaking around a value of 5/3. These findings indicate that there may be advantages in using Br rather than B_{los} in calculating flare-related AR magnetic properties, especially for regions located far from central meridian.

How to inhibit a distractor location? Statistical learning versus active, top-down suppression.

PubMed

Wang, Benchi; Theeuwes, Jan

2018-05-01

Recently, Wang and Theeuwes (Journal of Experimental Psychology: Human Perception and Performance, 44(1), 13-17, 2018a) demonstrated the role of lingering selection biases in an additional singleton search task in which the distractor singleton appeared much more often in one location than in all other locations. For this location, there was less capture and selection efficiency was reduced. It was argued that statistical learning induces plasticity within the spatial priority map such that particular locations that are high likely to contain a distractor are suppressed relative to all other locations. The current study replicated these findings regarding statistical learning (Experiment 1) and investigated whether similar effects can be obtained by cueing the distractor location in a top-down way on a trial-by-trial basis. The results show that top-down cueing of the distractor location with long (1,500 ms; Experiment 2) and short stimulus-onset symmetries (SOAs) (600 ms; Experiment 3) does not result in suppression: The amount of capture nor the efficiency of selection was affected by the cue. If anything, we found an attentional benefit (instead of the suppression) for the short SOA. We argue that through statistical learning, weights within the attentional priority map are changed such that one location containing a salient distractor is suppressed relative to all other locations. Our cueing experiments show that this effect cannot be accomplished by active, top-down suppression. Consequences for recent theories of distractor suppression are discussed.

Decoding Visual Location From Neural Patterns in the Auditory Cortex of the Congenitally Deaf

PubMed Central

Almeida, Jorge; He, Dongjun; Chen, Quanjing; Mahon, Bradford Z.; Zhang, Fan; Gonçalves, Óscar F.; Fang, Fang; Bi, Yanchao

2016-01-01

Sensory cortices of individuals who are congenitally deprived of a sense can exhibit considerable plasticity and be recruited to process information from the senses that remain intact. Here, we explored whether the auditory cortex of congenitally deaf individuals represents visual field location of a stimulus—a dimension that is represented in early visual areas. We used functional MRI to measure neural activity in auditory and visual cortices of congenitally deaf and hearing humans while they observed stimuli typically used for mapping visual field preferences in visual cortex. We found that the location of a visual stimulus can be successfully decoded from the patterns of neural activity in auditory cortex of congenitally deaf but not hearing individuals. This is particularly true for locations within the horizontal plane and within peripheral vision. These data show that the representations stored within neuroplastically changed auditory cortex can align with dimensions that are typically represented in visual cortex. PMID:26423461

Four Years of Venus Express Magnetic Field Observations: Variable Bow Shock Location and Other Features

NASA Astrophysics Data System (ADS)

Zhang, Tielong; Baumjohann, Wolfgang; Russell, C. T.

Since the Venus Express insertion into a highly elliptical polar orbit with a period of 24 h around the planet Venus, the magnetometer has operated continuously for about 4 years and obtained a wealth of data in the solar minimum at rather low altitude, which was not reached by earlier missions. In this paper, we review the magnetic field observations by Venus Express emphasizing on the variable bow shock location and other space environment features such as the magnetic barrier and the magnetotail.

Perception and Processing of Faces in the Human Brain Is Tuned to Typical Feature Locations

PubMed Central

Schwarzkopf, D. Samuel; Alvarez, Ivan; Lawson, Rebecca P.; Henriksson, Linda; Kriegeskorte, Nikolaus; Rees, Geraint

2016-01-01

Faces are salient social stimuli whose features attract a stereotypical pattern of fixations. The implications of this gaze behavior for perception and brain activity are largely unknown. Here, we characterize and quantify a retinotopic bias implied by typical gaze behavior toward faces, which leads to eyes and mouth appearing most often in the upper and lower visual field, respectively. We found that the adult human visual system is tuned to these contingencies. In two recognition experiments, recognition performance for isolated face parts was better when they were presented at typical, rather than reversed, visual field locations. The recognition cost of reversed locations was equal to ∼60% of that for whole face inversion in the same sample. Similarly, an fMRI experiment showed that patterns of activity evoked by eye and mouth stimuli in the right inferior occipital gyrus could be separated with significantly higher accuracy when these features were presented at typical, rather than reversed, visual field locations. Our findings demonstrate that human face perception is determined not only by the local position of features within a face context, but by whether features appear at the typical retinotopic location given normal gaze behavior. Such location sensitivity may reflect fine-tuning of category-specific visual processing to retinal input statistics. Our findings further suggest that retinotopic heterogeneity might play a role for face inversion effects and for the understanding of conditions affecting gaze behavior toward faces, such as autism spectrum disorders and congenital prosopagnosia. SIGNIFICANCE STATEMENT Faces attract our attention and trigger stereotypical patterns of visual fixations, concentrating on inner features, like eyes and mouth. Here we show that the visual system represents face features better when they are shown at retinal positions where they typically fall during natural vision. When facial features were shown at typical (rather

Examining the spatial congruence between data obtained with a novel activity location questionnaire, continuous GPS tracking, and prompted recall surveys

PubMed Central

2013-01-01

Background Place and health researchers are increasingly interested in integrating individuals’ mobility and the experience they have with multiple settings in their studies. In practice, however, few tools exist which allow for rapid and accurate gathering of detailed information on the geographic location of places where people regularly undertake activities. We describe the development and validation of a new activity location questionnaire which can be useful in accounting for multiple environmental influences in large population health investigations. Methods To develop the questionnaire, we relied on a literature review of similar data collection tools and on results of a pilot study wherein we explored content validity, test-retest reliability, and face validity. To estimate convergent validity, we used data from a study of users of a public bicycle share program conducted in Montreal, Canada in 2011. We examined the spatial congruence between questionnaire data and data from three other sources: 1) one-week GPS tracks; 2) activity locations extracted from the GPS tracks; and 3) a prompted recall survey of locations visited during the day. Proximity and convex hull measures were used to compare questionnaire-derived data and GPS and prompted recall survey data. Results In the sample, 75% of questionnaire-reported activity locations were located within 400 meters of an activity location recorded on the GPS track or through the prompted recall survey. Results from convex hull analyses suggested questionnaire activity locations were more concentrated in space than GPS or prompted-recall locations. Conclusions The new questionnaire has high convergent validity and can be used to accurately collect data on regular activity spaces in terms of locations regularly visited. The methods, measures, and findings presented provide new material to further study mobility in place and health research. PMID:24025119

The association between the parental perception of the physical neighborhood environment and children's location-specific physical activity.

PubMed

D'Haese, Sara; Van Dyck, Delfien; De Bourdeaudhuij, Ilse; Deforche, Benedicte; Cardon, Greet

2015-06-19

The relationship between children's physical neighborhood environment and their physical activity, has been largely investigated. However in recent reviews, only a few significant and consistent direct associations between children's physical neighborhood environment and their physical activity were found. This is possibly due to the fact that the location where children's physical activity took place, is insufficiently specified. Therefore, this study aimed to investigate the association between parental perceived neighborhood characteristics and children's physical activity in clearly defined environments. Children (9-12 years; n = 606) wore an Actigraph accelerometer for 7 days. Parents completed the parental version of the Neighborhood Environmental Walkability Scale questionnaire and reported on children's physical activity in specific locations: physical activity in nearby streets and on sidewalks, physical activity in public recreation spaces and physical activity in the garden. Multilevel logistic regression analyses were conducted in MLwiN 2.30. Children were more likely to be active in nearby streets and on sidewalks, if their parents perceived lower street connectivity (OR = 0.479; 95% CI = 0.33 and 0.70), higher land use mix accessibility (OR = 1.704; 95% CI = 1.25 and 2.33) and more crime safety (OR = 1.879; 95% CI = 1.29 and 2.74). Children whose parents perceived higher presence of recreation facilities (OR = 1.618; CI = 1.23; 2.12) were more likely to be active in public recreation spaces. No environmental neighborhood variables were related to physical activity in the garden and overall moderate- to vigorous-intensity physical activity. The parental perceived physical neighborhood environment relates differently to physical activity in different locations. In order to develop effective interventions, it seems promising to further investigate the association between location-specific physical activity and specific

33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

Code of Federal Regulations, 2012 CFR

2012-07-01

... 33 Navigation and Navigable Waters 3 2012-07-01 2012-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.845 Wisconsin...

33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

Code of Federal Regulations, 2011 CFR

2011-07-01

... 33 Navigation and Navigable Waters 3 2011-07-01 2011-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.845 Wisconsin...

33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 33 Navigation and Navigable Waters 3 2010-07-01 2010-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.845 Wisconsin...

33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

Code of Federal Regulations, 2014 CFR

2014-07-01

... 33 Navigation and Navigable Waters 3 2014-07-01 2014-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.845 Wisconsin...

33 CFR 334.845 - Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore...

Code of Federal Regulations, 2013 CFR

2013-07-01

... 33 Navigation and Navigable Waters 3 2013-07-01 2013-07-01 false Wisconsin Air National Guard, Volk Field military exercise area located in Lake Michigan offshore from Manitowoc and Sheboygan..., DEPARTMENT OF THE ARMY, DEPARTMENT OF DEFENSE DANGER ZONE AND RESTRICTED AREA REGULATIONS § 334.845 Wisconsin...

Spatiotemporal distribution of location and object effects in the electromyographic activity of upper extremity muscles during reach-to-grasp

PubMed Central

Rouse, Adam G.

2016-01-01

In reaching to grasp an object, proximal muscles that act on the shoulder and elbow classically have been viewed as transporting the hand to the intended location, while distal muscles that act on the fingers simultaneously shape the hand to grasp the object. Prior studies of electromyographic (EMG) activity in upper extremity muscles therefore have focused, by and large, either on proximal muscle activity during reaching to different locations or on distal muscle activity as the subject grasps various objects. Here, we examined the EMG activity of muscles from the shoulder to the hand, as monkeys reached and grasped in a task that dissociated location and object. We quantified the extent to which variation in the EMG activity of each muscle depended on location, on object, and on their interaction—all as a function of time. Although EMG variation depended on both location and object beginning early in the movement, an early phase of substantial location effects in muscles from proximal to distal was followed by a later phase in which object effects predominated throughout the extremity. Interaction effects remained relatively small. Our findings indicate that neural control of reach-to-grasp may occur largely in two sequential phases: the first, serving to project the entire upper extremity toward the intended location, and the second, acting predominantly to shape the entire extremity for grasping the object. PMID:27009156

Separating twin images and locating the center of a microparticle in dense suspensions using correlations among reconstructed fields of two parallel holograms.

PubMed

Ling, Hangjian; Katz, Joseph

2014-09-20

This paper deals with two issues affecting the application of digital holographic microscopy (DHM) for measuring the spatial distribution of particles in a dense suspension, namely discriminating between real and virtual images and accurate detection of the particle center. Previous methods to separate real and virtual fields have involved applications of multiple phase-shifted holograms, combining reconstructed fields of multiple axially displaced holograms, and analysis of intensity distributions of weakly scattering objects. Here, we introduce a simple approach based on simultaneously recording two in-line holograms, whose planes are separated by a short distance from each other. This distance is chosen to be longer than the elongated trace of the particle. During reconstruction, the real images overlap, whereas the virtual images are displaced by twice the distance between hologram planes. Data analysis is based on correlating the spatial intensity distributions of the two reconstructed fields to measure displacement between traces. This method has been implemented for both synthetic particles and a dense suspension of 2 μm particles. The correlation analysis readily discriminates between real and virtual images of a sample containing more than 1300 particles. Consequently, we can now implement DHM for three-dimensional tracking of particles when the hologram plane is located inside the sample volume. Spatial correlations within the same reconstructed field are also used to improve the detection of the axial location of the particle center, extending previously introduced procedures to suspensions of microscopic particles. For each cross section within a particle trace, we sum the correlations among intensity distributions in all planes located symmetrically on both sides of the section. This cumulative correlation has a sharp peak at the particle center. Using both synthetic and recorded particle fields, we show that the uncertainty in localizing the axial

Phencyclidine Discoordinates Hippocampal Network Activity But Not Place Fields

PubMed Central

Kao, Hsin-Yi; Kenney, Jana; Kelemen, Eduard

2017-01-01

We used the psychotomimetic phencyclidine (PCP) to investigate the relationships among cognitive behavior, coordinated neural network function, and information processing within the hippocampus place cell system. We report in rats that PCP (5 mg/kg, i.p.) impairs a well learned, hippocampus-dependent place avoidance behavior in rats that requires cognitive control even when PCP is injected directly into dorsal hippocampus. PCP increases 60–100 Hz medium-freguency gamma oscillations in hippocampus CA1 and these increases correlate with the cognitive impairment caused by systemic PCP administration. PCP discoordinates theta-modulated medium-frequency and slow gamma oscillations in CA1 LFPs such that medium-frequency gamma oscillations become more theta-organized than slow gamma oscillations. CA1 place cell firing fields are preserved under PCP, but the drug discoordinates the subsecond temporal organization of discharge among place cells. This discoordination causes place cell ensemble representations of a familiar space to cease resembling pre-PCP representations despite preserved place fields. These findings point to the cognitive impairments caused by PCP arising from neural discoordination. PCP disrupts the timing of discharge with respect to the subsecond timescales of theta and gamma oscillations in the LFP. Because these oscillations arise from local inhibitory synaptic activity, these findings point to excitation–inhibition discoordination as the root of PCP-induced cognitive impairment. SIGNIFICANCE STATEMENT Hippocampal neural discharge is temporally coordinated on timescales of theta and gamma oscillations in the LFP and the discharge of a subset of pyramidal neurons called “place cells” is spatially organized such that discharge is restricted to locations called a cell's “place field.” Because this temporal coordination and spatial discharge organization is thought to represent spatial knowledge, we used the psychotomimetic phencyclidine (PCP

Location, Timing, and Social Structure Patterns Related to Physical Activity Participation in Weight Loss Programs

ERIC Educational Resources Information Center

Gay, Jennifer L.; Trevarthen, Grace

2013-01-01

Less than half of the adults in the United States meet national guidelines for physical activity. Physical activity programs can induce short-term improvements in physical activity. To develop effective interventions, researchers and practitioners should consider the timing, location, and social structure patterns of participants. Using a pretest,…

Location-Enhanced Activity Recognition in Indoor Environments Using Off the Shelf Smart Watch Technology and BLE Beacons.

PubMed

Filippoupolitis, Avgoustinos; Oliff, William; Takand, Babak; Loukas, George

2017-05-27

Activity recognition in indoor spaces benefits context awareness and improves the efficiency of applications related to personalised health monitoring, building energy management, security and safety. The majority of activity recognition frameworks, however, employ a network of specialised building sensors or a network of body-worn sensors. As this approach suffers with respect to practicality, we propose the use of commercial off-the-shelf devices. In this work, we design and evaluate an activity recognition system composed of a smart watch, which is enhanced with location information coming from Bluetooth Low Energy (BLE) beacons. We evaluate the performance of this approach for a variety of activities performed in an indoor laboratory environment, using four supervised machine learning algorithms. Our experimental results indicate that our location-enhanced activity recognition system is able to reach a classification accuracy ranging from 92% to 100%, while without location information classification accuracy it can drop to as low as 50% in some cases, depending on the window size chosen for data segmentation.

Functional MRI Representational Similarity Analysis Reveals a Dissociation between Discriminative and Relative Location Information in the Human Visual System.

PubMed

Roth, Zvi N

2016-01-01

Neural responses in visual cortex are governed by a topographic mapping from retinal locations to cortical responses. Moreover, at the voxel population level early visual cortex (EVC) activity enables accurate decoding of stimuli locations. However, in many cases information enabling one to discriminate between locations (i.e., discriminative information) may be less relevant than information regarding the relative location of two objects (i.e., relative information). For example, when planning to grab a cup, determining whether the cup is located at the same retinal location as the hand is hardly relevant, whereas the location of the cup relative to the hand is crucial for performing the action. We have previously used multivariate pattern analysis techniques to measure discriminative location information, and found the highest levels in EVC, in line with other studies. Here we show, using representational similarity analysis, that availability of discriminative information in fMRI activation patterns does not entail availability of relative information. Specifically, we find that relative location information can be reliably extracted from activity patterns in posterior intraparietal sulcus (pIPS), but not from EVC, where we find the spatial representation to be warped. We further show that this variability in relative information levels between regions can be explained by a computational model based on an array of receptive fields. Moreover, when the model's receptive fields are extended to include inhibitory surround regions, the model can account for the spatial warping in EVC. These results demonstrate how size and shape properties of receptive fields in human visual cortex contribute to the transformation of discriminative spatial representations into relative spatial representations along the visual stream.

Functional MRI Representational Similarity Analysis Reveals a Dissociation between Discriminative and Relative Location Information in the Human Visual System

PubMed Central

Roth, Zvi N.

2016-01-01

Neural responses in visual cortex are governed by a topographic mapping from retinal locations to cortical responses. Moreover, at the voxel population level early visual cortex (EVC) activity enables accurate decoding of stimuli locations. However, in many cases information enabling one to discriminate between locations (i.e., discriminative information) may be less relevant than information regarding the relative location of two objects (i.e., relative information). For example, when planning to grab a cup, determining whether the cup is located at the same retinal location as the hand is hardly relevant, whereas the location of the cup relative to the hand is crucial for performing the action. We have previously used multivariate pattern analysis techniques to measure discriminative location information, and found the highest levels in EVC, in line with other studies. Here we show, using representational similarity analysis, that availability of discriminative information in fMRI activation patterns does not entail availability of relative information. Specifically, we find that relative location information can be reliably extracted from activity patterns in posterior intraparietal sulcus (pIPS), but not from EVC, where we find the spatial representation to be warped. We further show that this variability in relative information levels between regions can be explained by a computational model based on an array of receptive fields. Moreover, when the model's receptive fields are extended to include inhibitory surround regions, the model can account for the spatial warping in EVC. These results demonstrate how size and shape properties of receptive fields in human visual cortex contribute to the transformation of discriminative spatial representations into relative spatial representations along the visual stream. PMID:27242455

Location and deprivation are important influencers of physical activity in primary care populations.

PubMed

Barrett, E M; Hussey, J; Darker, C D

2016-07-01

To investigate the physical activity of adults attending primary care services in the Republic of Ireland and to determine whether the location (urban/rural) and deprivation of the primary care centre influenced physical activity. Cross sectional study. Stratified random sampling based on urban/rural location and deprivation was used to identify three primary care centres from a list of established primary care teams in the Leinster region. The International Physical Activity Questionnaire (IPAQ) was used to collate data on physical activity category (low/moderate/high), total weekly activity (MET-minutes/week) and weekly walking (MET-minutes/week) of participants. Data from 885 participants with a median age of 39 years (IQR 31-53) were analysed. There were significant differences in physical activity between the primary care areas (P < 0.001). Rural mixed deprivation participants were the least active with almost 60% of this group (59.4%, n = 177) classified as inactive (535 median MET-minutes/week, IQR 132-1197). Urban deprived participants were the most active (low active 37.6%, n = 111, 975 median MET-minutes/week, IQR 445-1933). Upon adjustment for multiple factors, rural participants (OR = 2.81, 95% CI 1.97-4.01), urban non-deprived participants (OR = 1.61, 95% CI 1.08-2.39), females (OR = 1.66, 95% CI 1.23-2.23) and older adults (OR = 1.01, 95% CI 1.00-1.02) were more likely to be categorised as low active. Overall 47.2% (n = 418) of all participants were classified within the low physical activity category. Significant disparities exist in the physical activity levels of primary care populations. This has important implications for the funding and planning of physical activity interventions. Copyright © 2016 The Royal Society for Public Health. Published by Elsevier Ltd. All rights reserved.

Microseismic source locations with deconvolution migration

NASA Astrophysics Data System (ADS)

Wu, Shaojiang; Wang, Yibo; Zheng, Yikang; Chang, Xu

2018-03-01

Identifying and locating microseismic events are critical problems in hydraulic fracturing monitoring for unconventional resources exploration. In contrast to active seismic data, microseismic data are usually recorded with unknown source excitation time and source location. In this study, we introduce deconvolution migration by combining deconvolution interferometry with interferometric cross-correlation migration (CCM). This method avoids the need for the source excitation time and enhances both the spatial resolution and robustness by eliminating the square term of the source wavelets from CCM. The proposed algorithm is divided into the following three steps: (1) generate the virtual gathers by deconvolving the master trace with all other traces in the microseismic gather to remove the unknown excitation time; (2) migrate the virtual gather to obtain a single image of the source location and (3) stack all of these images together to get the final estimation image of the source location. We test the proposed method on complex synthetic and field data set from the surface hydraulic fracturing monitoring, and compare the results with those obtained by interferometric CCM. The results demonstrate that the proposed method can obtain a 50 per cent higher spatial resolution image of the source location, and more robust estimation with smaller errors of the localization especially in the presence of velocity model errors. This method is also beneficial for source mechanism inversion and global seismology applications.

Assessing and enhancing the utility of low-cost activity and location sensors for exposure studies.

PubMed

Asimina, Stamatelopoulou; Chapizanis, D; Karakitsios, S; Kontoroupis, P; Asimakopoulos, D N; Maggos, T; Sarigiannis, D

2018-02-20

Nowadays, the advancement of mobile technology in conjunction with the introduction of the concept of exposome has provided new dynamics to the exposure studies. Since the addressing of health outcomes related to environmental stressors is crucial, the improvement of exposure assessment methodology is of paramount importance. Towards this aim, a pilot study was carried out in the two major cities of Greece (Athens, Thessaloniki), investigating the applicability of commercially available fitness monitors and the Moves App for tracking people's location and activities, as well as for predicting the type of the encountered location, using advanced modeling techniques. Within the frame of the study, 21 individuals were using the Fitbit Flex activity tracker, a temperature logger, and the application Moves App on their smartphones. For the validation of the above equipment, participants were also carrying an Actigraph (activity sensor) and a GPS device. The data collected from Fitbit Flex, the temperature logger, and the GPS (speed) were used as input parameters in an Artificial Neural Network (ANN) model for predicting the type of location. Analysis of the data showed that the Moves App tends to underestimate the daily steps counts in comparison with Fitbit Flex and Actigraph, respectively, while Moves App predicted the movement trajectory of an individual with reasonable accuracy, compared to a dedicated GPS. Finally, the encountered location was successfully predicted by the ANN in most of the cases.

Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array

PubMed Central

Sarwar, Mirza Saquib; Dobashi, Yuta; Preston, Claire; Wyss, Justin K. M.; Mirabbasi, Shahriar; Madden, John David Wyndham

2017-01-01

The development of bendable, stretchable, and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables, and flexible handheld devices. Although transparent tactile sensors based on metal mesh, carbon nanotubes, and silver nanowires demonstrate operation in bent configurations, we present a technology that extends the operation modes to the sensing of finger proximity including light touch during active bending and even stretching. This is accomplished using stretchable and ionically conductive hydrogel electrodes, which project electric field above the sensor to couple with and sense a finger. The polyacrylamide electrodes are embedded in silicone. These two widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with a 5-mm pitch. The approach of a finger hovering a few centimeters above the array is readily detectable. Light touch produces a localized decrease in capacitance of 15%. The movement of a finger can be followed across the array, and the location of multiple fingers can be detected. Touch is detectable during bending and stretch, an important feature of any wearable device. The capacitive sensor design can be made more or less sensitive to bending by shifting it relative to the neutral axis. Ultimately, the approach is adaptable to the detection of proximity, touch, pressure, and even the conformation of the sensor surface. PMID:28345045

Bend, stretch, and touch: Locating a finger on an actively deformed transparent sensor array.

PubMed

Sarwar, Mirza Saquib; Dobashi, Yuta; Preston, Claire; Wyss, Justin K M; Mirabbasi, Shahriar; Madden, John David Wyndham

2017-03-01

The development of bendable, stretchable, and transparent touch sensors is an emerging technological goal in a variety of fields, including electronic skin, wearables, and flexible handheld devices. Although transparent tactile sensors based on metal mesh, carbon nanotubes, and silver nanowires demonstrate operation in bent configurations, we present a technology that extends the operation modes to the sensing of finger proximity including light touch during active bending and even stretching. This is accomplished using stretchable and ionically conductive hydrogel electrodes, which project electric field above the sensor to couple with and sense a finger. The polyacrylamide electrodes are embedded in silicone. These two widely available, low-cost, transparent materials are combined in a three-step manufacturing technique that is amenable to large-area fabrication. The approach is demonstrated using a proof-of-concept 4 × 4 cross-grid sensor array with a 5-mm pitch. The approach of a finger hovering a few centimeters above the array is readily detectable. Light touch produces a localized decrease in capacitance of 15%. The movement of a finger can be followed across the array, and the location of multiple fingers can be detected. Touch is detectable during bending and stretch, an important feature of any wearable device. The capacitive sensor design can be made more or less sensitive to bending by shifting it relative to the neutral axis. Ultimately, the approach is adaptable to the detection of proximity, touch, pressure, and even the conformation of the sensor surface.

The Location of Peak Upper Trapezius Muscle Activity During Submaximal Contractions is not Associated With the Location of Myofascial Trigger Points: New Insights Revealed by High-density Surface EMG.

PubMed

Barbero, Marco; Falla, Deborah; Mafodda, Luca; Cescon, Corrado; Gatti, Roberto

2016-12-01

To apply topographical mapping of the electromyography (EMG) amplitude recorded from the upper trapezius muscle to evaluate the distribution of activity and the location of peak activity during a shoulder elevation task in participants with and without myofascial pain and myofascial trigger points (MTrP) and compare this location with the site of the MTrP. Thirteen participants with myofascial pain and MTrP in the upper trapezius muscle and 12 asymptomatic individuals participated. High-density surface EMG was recorded from the upper trapezius muscle using a matrix of 64 surface electrodes aligned with an anatomic landmark system (ALS). Each participant performed a shoulder elevation task consisting of a series of 30 s ramped contractions to 15% or 60% of their maximal voluntary contraction (MVC) force. Topographical maps of the EMG average rectified value were computed and the peak EMG amplitude during the ramped contractions was identified and its location determined with respect to the ALS. The location of the MTrP was also determined relative to the ALS and Spearman correlation coefficients were used to examine the relationship between MTrP and peak EMG amplitude location. The location of the peak EMG amplitude was significantly (P<0.05) different between groups (participants with pain/MTrP: -0.32±1.2 cm at 15% MVC and -0.35±0.9 cm at 60% MVC relative to the ALS; asymptomatic participants: 1.0±1.3 cm at 15% MVC and 1.3±1.1 cm relative to the ALS). However, no correlation was observed between the position of the MTrP and peak EMG amplitude during the ramped contractions at either force level (15%: rs=0.039, P=0.9; 60%: rs=-0.087, P=0.778). People with myofascial pain and MTrP displayed a caudal shift of the distribution of upper trapezius muscle activity compared with asymptomatic individuals during a submaximal shoulder elevation task. For the first time, we show that the location of peak muscle activity is not associated with the location of the MTrP.

Effect of heavy metals on soil enzyme activity at different field conditions in Middle Spis mining area (Slovakia).

PubMed

Angelovičová, Lenka; Lodenius, Martin; Tulisalo, Esa; Fazekašová, Danica

2014-12-01

Heavy metals concentrations were measured in the former mining area located in Hornad river valley (Slovakia). Soil samples were taken in 2012 from 20 sites at two field types (grasslands, heaps of waste material) and two different areas. Total content of heavy metals (Cu, Pb, Zn, Hg), urease (URE), acid phosphatase (ACP), alkaline phosphatase (ALP), soil reaction (pH) were changing depending on the field/area type. The tailing pond and processing plants have been found as the biggest sources of pollution. URE, ACP and ALP activities significantly decreased while the heavy metal contents increased. Significant differences were found among area types in the heavy metal contents and activity of URE. No statistical differences in the content of heavy metals but significant statistical differences for soil pH were found for field types (grassland and heaps). Significant negative correlation was found for URE-Pb, URE-Zn and also between soil reaction and ACP and ALP.

Microalloying of transition metal silicides by mechanical activation and field-activated reaction

DOEpatents

Munir, Zuhair A [Davis, CA; Woolman, Joseph N [Davis, CA; Petrovic, John J [Los Alamos, NM

2003-09-02

Alloys of transition metal suicides that contain one or more alloying elements are fabricated by a two-stage process involving mechanical activation as the first stage and densification and field-activated reaction as the second stage. Mechanical activation, preferably performed by high-energy planetary milling, results in the incorporation of atoms of the alloying element(s) into the crystal lattice of the transition metal, while the densification and field-activated reaction, preferably performed by spark plasma sintering, result in the formation of the alloyed transition metal silicide. Among the many advantages of the process are its ability to accommodate materials that are incompatible in other alloying methods.

AC field exposure study: human exposure to 60-Hz electric fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

Silva, J.M.

1985-04-01

The objective of this study was to develop a method of estimating human exposure to the 60 Hz electric fields created by transmission lines. The Activity Systems Model simulates human activities in a variety of situations where exposure to electric fields is possible. The model combines maps of electric fields, activity maps, and experimentally determined activity factors to provide histograms of time spent in electric fields of various strengths in the course of agricultural, recreational, and domestic activities. For corroboration, the study team measured actual human exposure at locations across the United States near transmission lines ranging in voltage frommore » 115 to 1200 kV. The data were collected with a specially designed vest that measures exposure. These data demonstrate the accuracy of the exposure model presented in this report and revealed that most exposure time is spent in fields of magnitudes similar to many household situations. The report provides annual exposure estimates for human activities near transmission lines and in the home and compares them with exposure data from typical laboratory animal experiments. For one exposure index, the cumulative product of time and electric field, exposure during some of the laboratory animal experiments is two to four orders of magnitude greater than cumulative exposure for a human during one year of outdoor work on a farm crossed by a transmission line.« less

Comparison of imaging modalities and source-localization algorithms in locating the induced activity during deep brain stimulation of the STN.

PubMed

Mideksa, K G; Singh, A; Hoogenboom, N; Hellriegel, H; Krause, H; Schnitzler, A; Deuschl, G; Raethjen, J; Schmidt, G; Muthuraman, M

2016-08-01

One of the most commonly used therapy to treat patients with Parkinson's disease (PD) is deep brain stimulation (DBS) of the subthalamic nucleus (STN). Identifying the most optimal target area for the placement of the DBS electrodes have become one of the intensive research area. In this study, the first aim is to investigate the capabilities of different source-analysis techniques in detecting deep sources located at the sub-cortical level and validating it using the a-priori information about the location of the source, that is, the STN. Secondly, we aim at an investigation of whether EEG or MEG is best suited in mapping the DBS-induced brain activity. To do this, simultaneous EEG and MEG measurement were used to record the DBS-induced electromagnetic potentials and fields. The boundary-element method (BEM) have been used to solve the forward problem. The position of the DBS electrodes was then estimated using the dipole (moving, rotating, and fixed MUSIC), and current-density-reconstruction (CDR) (minimum-norm and sLORETA) approaches. The source-localization results from the dipole approaches demonstrated that the fixed MUSIC algorithm best localizes deep focal sources, whereas the moving dipole detects not only the region of interest but also neighboring regions that are affected by stimulating the STN. The results from the CDR approaches validated the capability of sLORETA in detecting the STN compared to minimum-norm. Moreover, the source-localization results using the EEG modality outperformed that of the MEG by locating the DBS-induced activity in the STN.

Location-Enhanced Activity Recognition in Indoor Environments Using Off the Shelf Smart Watch Technology and BLE Beacons

PubMed Central

Filippoupolitis, Avgoustinos; Oliff, William; Takand, Babak; Loukas, George

2017-01-01

Activity recognition in indoor spaces benefits context awareness and improves the efficiency of applications related to personalised health monitoring, building energy management, security and safety. The majority of activity recognition frameworks, however, employ a network of specialised building sensors or a network of body-worn sensors. As this approach suffers with respect to practicality, we propose the use of commercial off-the-shelf devices. In this work, we design and evaluate an activity recognition system composed of a smart watch, which is enhanced with location information coming from Bluetooth Low Energy (BLE) beacons. We evaluate the performance of this approach for a variety of activities performed in an indoor laboratory environment, using four supervised machine learning algorithms. Our experimental results indicate that our location-enhanced activity recognition system is able to reach a classification accuracy ranging from 92% to 100%, while without location information classification accuracy it can drop to as low as 50% in some cases, depending on the window size chosen for data segmentation. PMID:28555022

Activated by Combined Magnrtic Field Gravitropic Reaction Reply on Nanodose of Biologicaly Active Compounds

NASA Astrophysics Data System (ADS)

Sheykina, Nadezhda; Bogatina, Nina

The new science direction nanotechnologies initiated a big jump in the pharmacology and medicine. This leads to the big development of homeopathy. The most interest appeared while investigating of the reaction of biological object on the nano dose of iologically substances. The changing of concentration (in nmol/l) of biologically active material is also possible during weak energy action. For instance, weak combined magnetic field may change a little the concentration of ions that are oriented parallel to the external magnetic field and, by the analogy with said above, lead to the similar effects. Simple estimations give the value for the threshold to the magnetic field by two orders smaller than the geomagnetic field. By this investigation we wanted to understand whether the analogy in the action of nano dose of biologically active substances and weak combined magnetic field presents and whether the action of one of these factors may be replaced by other one. The effect of one of biologically active substances NPA (Naphtyl-Phtalame Acid) solution with the concentration 0.01 mol/l on the gravitropic reaction of cress roots was investigated. It was shown that its effect was the inhibition of cress roots gravitropic reaction. The same inhibition was achieved by the combined magnetic field action on the cress roots, germinated in water. The alternative component of the combined magnetic field coincided formally with the cyclotron frequency of NPA ions. So the analogy in the action of nano dose of biologically active substances and weak combined magnetic field was shown. The combined magnetic field using allows to decrease sufficiently the dose of biologically active substances. This fact can be of great importance in pharmacy and medicine.

Improved integrated sniper location system

NASA Astrophysics Data System (ADS)

Figler, Burton D.; Spera, Timothy J.

1999-01-01

In July of 1995, Lockheed Martin IR Imaging Systems, of Lexington, Massachusetts began the development of an integrated sniper location system for the Defense Advanced Research Projects Agency and for the Department of the Navy's Naval Command Control & Ocean Surveillance Center, RDTE Division in San Diego, California. The I-SLS integrates acoustic and uncooled infrared sensing technologies to provide an affordable and highly effective sniper detection and location capability. This system, its performance and results from field tests at Camp Pendleton, California, in October 1996 were described in a paper presented at the November 1996 SPIE Photonics East Symposium1 on Enabling Technologies for Law Enforcement and Security. The I-SLS combines an acoustic warning system with an uncooled infrared warning system. The acoustic warning system has been developed by SenTech, Inc., of Lexington, Massachusetts. This acoustic warning system provides sniper detection and coarse location information based upon the muzzle blast of the sniper's weapon and/or upon the shock wave produced by the sniper's bullet, if the bullet is supersonic. The uncooled infrared warning system provides sniper detection and fine location information based upon the weapon's muzzle flash. In addition, the uncooled infrared warning system can provide thermal imagery that can be used to accurately locate and identify the sniper. Combining these two technologies improves detection probability, reduces false alarm rate and increases utility. In the two years since the last report of the integrated sniper location system, improvements have been made and a second field demonstration was planned. In this paper, we describe the integrated sniper location system modifications in preparation for the new field demonstration. In addition, fundamental improvements in the uncooled infrared sensor technology continue to be made. These improvements include higher sensitivity (lower minimum resolvable temperature

Combining global positioning system and accelerometer data to determine the locations of physical activity in children.

PubMed

Oreskovic, Nicolas M; Blossom, Jeff; Field, Alison E; Chiang, Sylvia R; Winickoff, Jonathan P; Kleinman, Ronald E

2012-05-01

National trends indicate that children and adolescents are not achieving sufficient levels of physical activity. Combining global positioning system (GPS) technology with accelerometers has the potential to provide an objective determination in locations where youth engage in physical activity. The aim of this study was to identify the optimal methods for collecting combined accelerometer and GPS data in youth, to best locate where children spend time and are physically active. A convenience sample of 24 mid-school children in Massachusetts was included. Accelerometers and GPS units were used to quantify and locate childhood physical activity over 5 weekdays and 2 weekend days. Accelerometer and GPS data were joined by time and mapped with a geographical information system (GIS) using ArcGIS software. Data were collected in winter, spring, summer in 2009-2010, collecting a total of 26,406 matched datapoints overall. Matched data yield was low (19.1% total), regardless of season (winter, 12.8%; spring, 30.1%; summer, 14.3%). Teacher-provided, pre-charged equipment yielded the most matched (30.1%; range: 10.1-52.3%) and greatest average days (6.1 days) of data. Across all seasons, children spent most of their time at home. Outdoor use patterns appeared to vary by season, with street use increasing in spring, and park and playground use increasing in summer. Children spent equal amounts of physical activity time at home and walking in the streets. Overall, the various methods for combining GPS and accelerometer data provided similarly low amounts of combined data. No combined GPS and accelerometer data collection method proved superior in every data return category, but use of GIS to map joined accelerometer and GPS data can demarcate childhood physical activity locations.

The role of enzyme activities in soil ecosystem services: Location, origin and connection to the phytobiome

USDA-ARS?s Scientific Manuscript database

Soil enzymes are important components of soil quality and its health because of their involvement in ecosystem services related to biogeochemical cycling, global C and organic matter dynamics, and soil detoxification. This talk will provide an overview of the field of soil enzymology, the location a...

Monitoring Location-Specific Physical Activity via Integration of Accelerometry and Geotechnology Within Patients With or At Risk of Diabetic Foot Ulcers: A Technological Report.

PubMed

Crews, Ryan T; Yalla, Sai V; Dhatt, Navdeep; Burdi, Drew; Hwang, Sungsoon

2017-09-01

Physical activity variability is a risk factor for diabetic foot ulcers (DFU). Geographic context may influence variability. This study developed initial methods for monitoring location-specific physical activity in this population. Secondarily, preliminary comparisons in location-specific physical activity were made between patients at risk versus patients with active DFU. Five at-risk and 5 actively ulcerated patients were monitored continuously for 72 hours with physical activity and GPS monitors. A custom algorithm time synchronized the 2 devices' data. On average for all 10 subjects, 1.5 ± 2.1% of activity lacked a corresponding GPS location. 80 ± 11% of self-reported activity events per subject had a GPS identified location. The GPS identified locations were in agreement with the self-reported locations 98 ± 6% of the time. DFU participants' weight-bearing activity was 188% higher at home than away from home. At-risk participants showed similar weight-bearing activity at home as active DFU participants, however, at-risk participants had 132% more weight-bearing activity away-from-home. Objectively monitoring location-specific physical activity proved feasible. Future studies using such methodology may enhance understanding of pathomechanics and treatment of DFU.

Verification of the use of completion-location analysis for initial assessment of reservoir heterogeneity

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDowell, R.R.; Avary, K.L.; Hohn, M.E.

1996-12-31

In 1991, a technique (completion-location analysis) was developed for a U.S. DOE-funded study to give a preliminary assessment of field-scale reservoir heterogeneity in two West Virginia oil fields (Granny Creek and Rock Creek). The study`s conclusions regarding heterogeneity agreed with initial predictions. However, as these fields were investigated specifically because they were thought to be heterogeneous, this test of the analysis was biased. In 1995, as part of a proposal to study siliciclastic strandplain reservoirs, the Jacksonburg- Stringtown field in West Virginia, was selected because it met the depositional criterion and was still being actively produced. Completion-location analysis was undertakenmore » on 214 producing oil wells from the field. Analysis indicated that drilling in the fields is clustered into eight time periods (1890-1903, 1904-1911, 1912-1916, 1917-1934, 1935-1953, 1954-1975, 1975-1985, and 1986-1995). Mapping of the locations of wells for each time period indicated that from 1890-1903 approximately 50% of the current geographic extent of the field was defined. Drilling in the periods 1935-1953, 1954-1975, 1975-1985, and 1985-1995 added significantly to the extent of the field - these episodes, especially 1986-1995, represent the discovery of new production. On this basis, a preliminary prediction was made that Jacksonburg-Stringtown field should exhibit a relatively high degree of reservoir heterogeneity. Subsequent discussions with the producer revealed that the reservoir varies considerably in pay thickness and quality across the field, has localized areas with high water injection rates and early water breakthrough, and has areas of anomalously high production. This suggests significant reservoir heterogeneity and appears to verify the utility of completion-location analysis.« less

Verification of the use of completion-location analysis for initial assessment of reservoir heterogeneity

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDowell, R.R.; Avary, K.L.; Hohn, M.E.

1996-01-01

In 1991, a technique (completion-location analysis) was developed for a U.S. DOE-funded study to give a preliminary assessment of field-scale reservoir heterogeneity in two West Virginia oil fields (Granny Creek and Rock Creek). The study's conclusions regarding heterogeneity agreed with initial predictions. However, as these fields were investigated specifically because they were thought to be heterogeneous, this test of the analysis was biased. In 1995, as part of a proposal to study siliciclastic strandplain reservoirs, the Jacksonburg- Stringtown field in West Virginia, was selected because it met the depositional criterion and was still being actively produced. Completion-location analysis was undertakenmore » on 214 producing oil wells from the field. Analysis indicated that drilling in the fields is clustered into eight time periods (1890-1903, 1904-1911, 1912-1916, 1917-1934, 1935-1953, 1954-1975, 1975-1985, and 1986-1995). Mapping of the locations of wells for each time period indicated that from 1890-1903 approximately 50% of the current geographic extent of the field was defined. Drilling in the periods 1935-1953, 1954-1975, 1975-1985, and 1985-1995 added significantly to the extent of the field - these episodes, especially 1986-1995, represent the discovery of new production. On this basis, a preliminary prediction was made that Jacksonburg-Stringtown field should exhibit a relatively high degree of reservoir heterogeneity. Subsequent discussions with the producer revealed that the reservoir varies considerably in pay thickness and quality across the field, has localized areas with high water injection rates and early water breakthrough, and has areas of anomalously high production. This suggests significant reservoir heterogeneity and appears to verify the utility of completion-location analysis.« less

Non-motor outcomes of subthalamic stimulation in Parkinson's disease depend on location of active contacts.

PubMed

Dafsari, Haidar Salimi; Petry-Schmelzer, Jan Niklas; Ray-Chaudhuri, K; Ashkan, Keyoumars; Weis, Luca; Dembek, Till A; Samuel, Michael; Rizos, Alexandra; Silverdale, Monty; Barbe, Michael T; Fink, Gereon R; Evans, Julian; Martinez-Martin, Pablo; Antonini, Angelo; Visser-Vandewalle, Veerle; Timmermann, Lars

2018-03-16

Subthalamic nucleus (STN) deep brain stimulation (DBS) improves quality of life (QoL), motor, and non-motor symptoms (NMS) in Parkinson's disease (PD). Few studies have investigated the influence of the location of neurostimulation on NMS. To investigate the impact of active contact location on NMS in STN-DBS in PD. In this prospective, open-label, multicenter study including 50 PD patients undergoing bilateral STN-DBS, we collected NMSScale (NMSS), NMSQuestionnaire (NMSQ), Hospital Anxiety and Depression Scale (anxiety/depression, HADS-A/-D), PDQuestionnaire-8 (PDQ-8), Scales for Outcomes in PD-motor examination, motor complications, activities of daily living (ADL), and levodopa equivalent daily dose (LEDD) preoperatively and at 6 months follow-up. Changes were analyzed with Wilcoxon signed-rank/t-test and Bonferroni-correction for multiple comparisons. Although the STN was targeted visually, we employed an atlas-based approach to explore the relationship between active contact locations and DBS outcomes. Based on fused MRI/CT-images, we identified Cartesian coordinates of active contacts with patient-specific Mai-atlas standardization. We computed linear mixed-effects models with x-/y-/z-coordinates as independent, hemispheres as within-subject, and test change scores as dependent variables. NMSS, NMSQ, PDQ-8, motor examination, complications, and LEDD significantly improved at follow-up. Linear mixed-effect models showed that NMS and QoL improvement significantly depended on more medial (HADS-D, NMSS), anterior (HADS-D, NMSQ, PDQ-8), and ventral (HADS-A/-D, NMSS, PDQ-8) neurostimulation. ADL improved more in posterior, LEDD in lateral neurostimulation locations. No relationship was observed for motor examination and complications scores. Our study provides evidence that more anterior, medial, and ventral STN-DBS is significantly related to more beneficial non-motor outcomes. Copyright © 2018. Published by Elsevier Inc.

Pulmonary artery location during microgravity activity: Potential impact for chest-mounted Doppler during space travel

NASA Technical Reports Server (NTRS)

Hadley, A. T., III; Conkin, J.; Waligora, J. M.; Horrigan, D. J., Jr.

1984-01-01

Doppler, or ultrasonic, monitoring for pain manifestations of decompression sickness (the bends) is accomplished by placing a sensor on the chest over the pulmonary artery and listening for bubbles. Difficulties have arisen because the technician notes that the pulmonary artery seems to move with subject movement in a one-g field and because the sensor output is influenced by only slight degrees of sensor movement. This study used two subjects and mapped the position of the pulmonary artery in one-g, microgravity, and two-g environments using ultrasound. The results showed that the pulmonary artery is fixed in location in microgravity and not affected by subject position change. The optimal position corresponded to where the Doppler signal is best heard with the subject in a supine position in a one-g environment. The impact of this result is that a proposed multiple sensor array on the chest proposed for microgravity use may not be necessary to monitor an astronaut during extravehicular activities. Instead, a single sensor of approximately 1 inch diameter and mounted in the position described above may suffice.

Locating single-point sources from arrival times containing large picking errors (LPEs): the virtual field optimization method (VFOM)

NASA Astrophysics Data System (ADS)

Li, Xi-Bing; Wang, Ze-Wei; Dong, Long-Jun

2016-01-01

Microseismic monitoring systems using local location techniques tend to be timely, automatic and stable. One basic requirement of these systems is the automatic picking of arrival times. However, arrival times generated by automated techniques always contain large picking errors (LPEs), which may make the location solution unreliable and cause the integrated system to be unstable. To overcome the LPE issue, we propose the virtual field optimization method (VFOM) for locating single-point sources. In contrast to existing approaches, the VFOM optimizes a continuous and virtually established objective function to search the space for the common intersection of the hyperboloids, which is determined by sensor pairs other than the least residual between the model-calculated and measured arrivals. The results of numerical examples and in-site blasts show that the VFOM can obtain more precise and stable solutions than traditional methods when the input data contain LPEs. Furthermore, we discuss the impact of LPEs on objective functions to determine the LPE-tolerant mechanism, velocity sensitivity and stopping criteria of the VFOM. The proposed method is also capable of locating acoustic sources using passive techniques such as passive sonar detection and acoustic emission.

Review of magnetic field monitoring near active faults and volcanic calderas in California: 1974-1995

USGS Publications Warehouse

Mueller, R.J.; Johnston, M.J.S.

1998-01-01

Differential magnetic fields have been monitored along the San Andreas fault and the Long Valley caldera since 1974. At each monitoring location, proton precession magnetometers sample total magnetic field intensity at a resolution of 0.1 nT or 0.25 nT. Every 10 min, data samples are transmitted via satellite telemetry to Menlo Park, CA for processing and analysis. The number of active magnetometer sites has varied during the past 21 years from 6 to 25, with 12 sites currently operational. We use this network to identify magnetic field changes generated by earthquake and volcanic processes. During the two decades of monitoring, five moderate earthquakes (M5.9 to M7.3) have occurred within 20 km of magnetometer sites located along the San Andreas fault and only one preseismic signal of 1.5 nT has been observed. During moderate earthquakes, coseismic magnetic signals, with amplitudes from 0.7 nT to 1.3 nT, have been identified for 3 of the 5 events. These observations are generally consistent with those calculated from simple seismomagnetic models of these earthquakes and near-fault coseismic magnetic field disturbances rarely exceed one nanotesla. These data are consistent with the concept of low shear stress and relatively uniform displacement of the San Andreas fault system as expected due to high pore fluid pressure on the fault. A systematic decrease of 0.8-1 nT/year in magnetic field has occurred in the Long Valley caldera since 1989. These magnetic field data are similar in form to observed geodetically measured displacements from inflation of the resurgent dome. A simple volcanomagnetic model involving pressure increase of 50 MPa/a at a depth of 7 km under the resurgent dome can replicate these magnetic field observations. This model is derived from the intrusion model that best fits the surface deformation data. ?? 1998 Elsevier Science B.V.

Sensors Locate Radio Interference

NASA Technical Reports Server (NTRS)

2009-01-01

After receiving a NASA Small Business Innovation Research (SBIR) contract from Kennedy Space Center, Soneticom Inc., based in West Melbourne, Florida, created algorithms for time difference of arrival and radio interferometry, which it used in its Lynx Location System (LLS) to locate electromagnetic interference that can disrupt radio communications. Soneticom is collaborating with the Federal Aviation Administration (FAA) to install and test the LLS at its field test center in New Jersey in preparation for deploying the LLS at commercial airports. The software collects data from each sensor in order to compute the location of the interfering emitter.

How Was the Activity? A Visualization Support for a Case of Location-Based Learning Design

ERIC Educational Resources Information Center

Melero, Javier; Hernández-Leo, Davinia; Sun, Jing; Santos, Patricia; Blat, Josep

2015-01-01

Over the last few years, the use of mobile technologies has brought the formulation of location-based learning approaches shaping new or enhanced educational activities. Involving teachers in the design of these activities is important because the designs need to be aligned with the requirements of the specific educational settings. Yet analysing…

Mean-field theory of active electrolytes: Dynamic adsorption and overscreening

NASA Astrophysics Data System (ADS)

Frydel, Derek; Podgornik, Rudolf

2018-05-01

We investigate active electrolytes within the mean-field level of description. The focus is on how the double-layer structure of passive, thermalized charges is affected by active dynamics of constituting ions. One feature of active dynamics is that particles adhere to hard surfaces, regardless of chemical properties of a surface and specifically in complete absence of any chemisorption or physisorption. To carry out the mean-field analysis of the system that is out of equilibrium, we develop the "mean-field simulation" technique, where the simulated system consists of charged parallel sheets moving on a line and obeying active dynamics, with the interaction strength rescaled by the number of sheets. The mean-field limit becomes exact in the limit of an infinite number of movable sheets.

Trash track--active location sensing for evaluating e-waste transportation.

PubMed

Offenhuber, Dietmar; Wolf, Malima I; Ratti, Carlo

2013-02-01

Waste and recycling systems are complex and far-reaching, but its mechanisms are poorly understood by the public, in some cases government organizations and even the waste management sector itself. The lack of empirical data makes it challenging to assess the environmental impact of trash collection, removal and disposal. This is especially the case for the global movement of electronic wastes. Senseable City Lab's Trash Track project tackles this scarcity of data by following the trajectories of individual objects. The project presents a methodology involving active location sensors that were placed on end-of-life products donated by volunteers in the Seattle, Washington area. These tags sent location messages chronicling their journey, some over the course of a month or more. In this paper, the authors focus on the analysis of traces acquired from 146 items of electronic waste, estimating evaluating the environmental impact, including the travel distances and end-of-life treatments for the products. Combining this information with impact evaluation from the US Environmental Protection Agency's Waste Reduction Model (WARM) allows for the creation of environmental impact profiles for individual pieces of trash.

Evaluation of mitochondrial activity by two-photon absorption with near-field multioptical fiber probes

NASA Astrophysics Data System (ADS)

Kanazashi, Yasuaki; Takara, Naoshi; Iwami, Kentaro; Ohta, Yoshihiro; Umeda, Norihiro

2018-04-01

pH measurements enable the direct monitoring and evaluation of mitochondrial activity. We constructed a scanning near-field optical microscopy system with multioptical fiber probes using the two-photon absorption of a pH-sensitive fluorescent dye, SNARF-4F, to measure the activity difference of mitochondrial aggregates. pH can be monitored through the fluorescence intensity ratio (FIR) of SNARF-4F. We derived a calibration curve of the FIR as a function of pH. The FIR dynamic responses were measured by adding hydrochloric acid to the buffer solution. Using the developed system, we simultaneously measured the pH changes at two different locations in the SNARF-4F solution. Mitochondrial samples were prepared using optical tweezers to control the number and position of mitochondria. Mitochondrial pH changes (ΔpH) between 0.05 and 0.57 were observed after adding a nutritional supplement (malate and glutamate). In addition, in the comparative experiment on the activities of two mitochondrial populations, the obtained result suggested that the activity differs depending on the difference in the number of mitochondria.

Neural control of visual search by frontal eye field: effects of unexpected target displacement on visual selection and saccade preparation.

PubMed

Murthy, Aditya; Ray, Supriya; Shorter, Stephanie M; Schall, Jeffrey D; Thompson, Kirk G

2009-05-01

The dynamics of visual selection and saccade preparation by the frontal eye field was investigated in macaque monkeys performing a search-step task combining the classic double-step saccade task with visual search. Reward was earned for producing a saccade to a color singleton. On random trials the target and one distractor swapped locations before the saccade and monkeys were rewarded for shifting gaze to the new singleton location. A race model accounts for the probabilities and latencies of saccades to the initial and final singleton locations and provides a measure of the duration of a covert compensation process-target-step reaction time. When the target stepped out of a movement field, noncompensated saccades to the original location were produced when movement-related activity grew rapidly to a threshold. Compensated saccades to the final location were produced when the growth of the original movement-related activity was interrupted within target-step reaction time and was replaced by activation of other neurons producing the compensated saccade. When the target stepped into a receptive field, visual neurons selected the new target location regardless of the monkeys' response. When the target stepped out of a receptive field most visual neurons maintained the representation of the original target location, but a minority of visual neurons showed reduced activity. Chronometric analyses of the neural responses to the target step revealed that the modulation of visually responsive neurons and movement-related neurons occurred early enough to shift attention and saccade preparation from the old to the new target location. These findings indicate that visual activity in the frontal eye field signals the location of targets for orienting, whereas movement-related activity instantiates saccade preparation.

The 2013 February 17 Sunquake in the Context of the Active Region's Magnetic Field Configuration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Green, L. M.; Valori, G.; Zuccarello, F. P.

Sunquakes are created by the hydrodynamic response of the lower atmosphere to a sudden deposition of energy and momentum. In this study, we investigate a sunquake that occurred in NOAA active region 11675 on 2013 February 17. Observations of the corona, chromosphere, and photosphere are brought together for the first time with a nonlinear force-free model of the active region’s magnetic field in order to probe the magnetic environment in which the sunquake was initiated. We find that the sunquake was associated with the destabilization of a flux rope and an associated M-class GOES flare. Active region 11675 was inmore » its emergence phase at the time of the sunquake and photospheric motions caused by the emergence heavily modified the flux rope and its associated quasi-separatrix layers, eventually triggering the flux rope’s instability. The flux rope was surrounded by an extended envelope of field lines rooted in a small area at the approximate position of the sunquake. We argue that the configuration of the envelope, by interacting with the expanding flux rope, created a “magnetic lens” that may have focussed energy on one particular location of the photosphere, creating the necessary conditions for the initiation of the sunquake.« less

Locations of Halide Ions in Tetragonal Lysozyme Crystals

NASA Technical Reports Server (NTRS)

Lim, Kap; Adimurthy, Ganapathi; Nadarajah, Arunan; Forsythe, Elizabeth L.; Pusey, Marc L.

1998-01-01

surrounding the protein was accurately determined. This was achieved by solving the linearized version of the Poisson-Boltzmann equation for the protein in solution. The solution was computed employing the commercial code Delphi which uses a finite difference technique. This has recently become available as a module in the general protein visualization code Insight II. Partial charges were assigned to the polar groups of lysozyme for the calculations done here. The calculations showed the complexity of the electrostatic field surrounding the protein. Although most of the region near the protein surface had a positive field strength, the active site cleft was negatively charged and this was projected a considerable distance. This might explain the occurrence of "head-to-side" interactions in the formation of lysozyme aggregates in solution. Pockets of high positive field strength were also found in the vicinity of the anion locations obtained from the crystallographic part of this study, confirming the validity of these calculations. This study clearly shows not only the importance of determining the counterion locations in protein crystals and the electrostatic fields surrounding the protein, but also the advantage of performing them together.

Field test of electromagnetic geophysical techniques for locating simulated in situ mining leach solution. Report of investigations/1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tweeton, D.R.; Hanson, J.C.; Friedel, M.J.

1994-01-01

The U.S. Bureau of Mines, the University of Arizona, Sandia National Laboratory, and Zonge Engineering and Research, Inc., conducted cooperative field tests of six electromagnetic geophysical methods to compare their effectiveness in locating a brine solution simulating in situ leach solution or a high-conductivity plume of contamination. The brine was approximately 160 meters below the surface. The test site was the University's San Xavier experimental mine near Tucson, Arizona. Geophysical surveys using surface and surface-borehole time-domain electromagnetics (TEM), surface controlled source audio-frequency magnetotellurics (CSAMT), surface-borehole frequency-domain electromagnetics (FEM), crosshole FEM and surface magnetic field ellipticity were conducted before and duringmore » brine injection.« less

Statistical patterns in the location of natural lightning

NASA Astrophysics Data System (ADS)

Zoghzoghy, F. G.; Cohen, M. B.; Said, R. K.; Inan, U. S.

2013-01-01

Lightning discharges are nature's way of neutralizing the electrical buildup in thunderclouds. Thus, if an individual discharge destroys a substantial fraction of the cloud charge, the probability of a subsequent flash is reduced until the cloud charge separation rebuilds. The temporal pattern of lightning activity in a localized region may thus inherently be a proxy measure of the corresponding timescales for charge separation and electric field buildup processes. We present a statistical technique to bring out this effect (as well as the subsequent recovery) using lightning geo-location data, in this case with data from the National Lightning Detection Network (NLDN) and from the GLD360 Network. We use this statistical method to show that a lightning flash can remove an appreciable fraction of the built up charge, affecting the neighboring lightning activity for tens of seconds within a ˜ 10 km radius. We find that our results correlate with timescales of electric field buildup in storms and suggest that the proposed statistical tool could be used to study the electrification of storms on a global scale. We find that this flash suppression effect is a strong function of flash type, flash polarity, cloud-to-ground flash multiplicity, the geographic location of lightning, and is proportional to NLDN model-derived peak stroke current. We characterize the spatial and temporal extent of the suppression effect as a function of these parameters and discuss various applications of our findings.

Field Evaluations of Tracking/Locating Technologies for Prevention of Missing Incidents.

PubMed

Bulat, Tatjana; Kerrigan, Michael V; Rowe, Meredeth; Kearns, William; Craighead, Jeffrey D; Ramaiah, Padmaja

2016-09-01

Persons with dementia are at risk of a missing incident, which is defined as an instance in which a demented person's whereabouts are unknown to the caregiver and the individual is not in an expected location. Since it is critical to determine the missing person's location as quickly as possible, we evaluated whether commercially available tracking technologies can assist in a rapid recovery. This study examined 7 commercially available tracking devices: 3 radio frequency (RF) based and 4 global positioning system (GPS) based, employing realistic tracking scenarios. Outcome measures were time to discovery and degree of deviation from a straight intercept course. Across all scenarios tested, GPS devices were found to be approximately twice as efficient as the RF devices in locating a "missing person." While the RF devices showed reasonable performance at close proximity, the GPS devices were found to be more appropriate overall for tracking/locating missing persons over unknown and larger distances. © The Author(s) 2016.

System and Method of Locating Lightning Strikes

NASA Technical Reports Server (NTRS)

Medelius, Pedro J. (Inventor); Starr, Stanley O. (Inventor)

2002-01-01

A system and method of determining locations of lightning strikes has been described. The system includes multiple receivers located around an area of interest, such as a space center or airport. Each receiver monitors both sound and electric fields. The detection of an electric field pulse and a sound wave are used to calculate an area around each receiver in which the lighting is detected. A processor is coupled to the receivers to accurately determine the location of the lighting strike. The processor can manipulate the receiver data to compensate for environmental variables such as wind, temperature, and humidity. Further, each receiver processor can discriminate between distant and local lightning strikes.

Shuttle near-field environmental impacts - Conclusions and observations for launching at other locations

NASA Technical Reports Server (NTRS)

Koller, A. M., Jr.; Knott, W. M.

1985-01-01

Near field and far field environmental monitoring activities extending from the first launch of the Space Shuttle at the Kennedy Space Center have provided a database from which conclusions can now be drawn for short term, acute effects of launch and, to a lesser degree, long term cumulative effects on the natural environment. Data for the first 15 launches of the Space Shuttle from Kennedy Space Center Pad 39A are analyzed for statistical significance and reduced to graphical presentations of individual and collective disposition isopleths, summarization of observed environmental impacts (e.g., vegetation damage, fish kills), and supporting data from specialized experiments and laboratory analyses. Conclusions are drawn with regard to the near field environment at Pad A, the effects on the lagoonal complex, and the relationships of these data and conclusions to upcoming operations at Complex 39 Pad B where the environment is significantly different. The paper concludes with a subjective evaluation of the likely impacts at Vandenberg Space Launch Complex 6 for the first Shuttle launch next year.

Field Trial of Distributed Acoustic Sensing in an Active Room-and-Pillar Mine

NASA Astrophysics Data System (ADS)

Wang, H. F.; Zeng, X.; Lord, N. E.; Fratta, D.; Coleman, T.; Maclaughlin, M.

2017-12-01

A Distributed Acoustic Sensing (DAS) field trial was conducted in July 2017 on the floor of the first level of the Lafarge-Conco limestone mine in N. Aurora Illinois. The room-and-pillar mine occupies a wedge-shaped footprint that is approximately 1500 m long by 500 m wide at the midpoint. The mine consists of four levels down to a depth of about 80 m. Pillars are approximately 20-meters on a side and in height. DAS cable was deployed in a shallow groove cut with a pavement saw. The groove was approximately 300-meters long and in the overall shape of an irregular rectangle as it followed a pathway around three pillars in each direction. The groove was 1.25-cm wide and between 2.5 and 7.5-cm deep. Three strands of fiber-optic cable were placed in the groove, positioned one above the other and separated by different materials. The bottom cable was covered with cement to a depth of 1.25-cm and allowed to dry for several days. The middle strand was covered with fines and the top strand was without cover. The DAS array consisted of the three co-located strands connected in series. It recorded signals from daily mine blasts on the afternoons of July 27 and 28. The blast locations were along the mine perimeter at a distance of about 1 km from the array. In addition to the distant blast source, a series of near-array tests were made with a weight-drop source located at surveyed points along the cable and within the array. Average mine-scale velocities were obtained from travel times from blast locations to different DAS channels. Local seismic velocities were obtained from first arrivals of the weight-drop source and from moveout of traces with time. The DAS response and travel times were noted as a function of cable direction. The field test showed that DAS can be used to monitor ground motion within an active mine. The research project is funded by a contract to Montana Tech from the National Institute for Occupational Safety and Health, Office of Mine Safety and Health

Urban Field Experiences for Undergraduate Liberal Arts Students: Using Compromised Environments as Living Laboratories

NASA Astrophysics Data System (ADS)

MacAvoy, S. E.; Knee, K.

2015-12-01

While urban environments may lack the beauty of relatively pristine field sites, they can be used to deliver an effective demonstration of actual environmental damage. Students demanding applied field experiences from their undergraduate environmental science programs can be well served in urban settings. Here, we present strategies for integrating degraded urban systems into the undergraduate field experience. Urban locations provide an opportunity for a different type of local "field-work" than would otherwise be available. In the upper-level undergraduate Environmental Methods class, we relied on a National Park area located a 10-minute walk from campus for most field exercises. Activities included soil analysis, measuring stream flow and water quality parameters, dendrochronology, and aquatic microbe metabolism. In the non-majors class, we make use of our urban location to contrast water quality in parks and highly channelized urban streams. Students spend labs immersed in streams and wetlands heavily impacted by the urban runoff their city generates. Here we share lesson plans and budgets for field activities that can be completed during a class period of 2.5 hours with a $75 course fee, show how these activities help students gain quantitative competency.

Continued development of mature field: west Cameron Block 45 field, Gulf of Mexico

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brand, S.R.; Fox, J.F.

Initial acreage acquisition and exploration of the West Cameron Block 45 field, located offshore Louisiana, were based on reconnaissance gravity surveys that revealed an anomalous high across the area. Several phases of development drilling activity have been conducted in the field since its discovery in March 1949. Nearly four decades after initial exploration began, an integrated field study incorporating all available geological, geophysical, petrophysical, and engineering data was undertaken to evaluate the remaining potential of the field. As a result of this study, a detailed structural and stratigraphic framework was developed, the controls on reservoir production performance were established, andmore » additional drillable prospects were delineated.« less

Effects of growing location on the production of main active components and antioxidant activity of Dasiphora fruticosa (L.) Rydb. by chemometric methods.

PubMed

Liu, Wei; Wang, Dongmei; Hou, Xiaogai; Yang, Yueqin; Xue, Xian; Jia, Qishi; Zhang, Lixia; Zhao, Wei; Yin, Dongxue

2018-05-17

Traditional Chinese medicine (TCM) plays a very important role in the health system of China. The content and activity of active component are main indexes that evaluate the quality of TCM, however they may vary with environmental factors in their growing locations. In this study, effects of environmental factors on the contents of active components and antioxidant activity of Dasiphora fruticosa from the five main production areas of China were investigated. The contents of tannin, total flavonoid and rutin were determined and varied within the range of 7.65-10.69%, 2.30-5.39% and 0.18-0.81%, respectively. Antioxidant activity was determined by DPPH assay, with the DPPH IC 50 values ranged from 8.791 to 32.534μg mL -1 . In order to further explore the cause of these significant geographical variations, the chemometric methods including correlation analysis, principal component analysis, gray correlation analysis, and path analysis were conducted. The results showed environmental factors had significant effect on the active component contents and antioxidant activity. Rapidly available phosphorus (RAP) and rapidly available nitrogen (RAN) were common dominant factors, and a significant positive correlation was observed between RAP and active components and antioxidant activity (P<0.05). Contributed by their high active components and strong antioxidant activity, Bange in Tibet and Geermu in Qinghai Province was selected as a favorable growing location, respectively. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Brain activation and deactivation during location and color working memory tasks in 11-13-year-old children.

PubMed

Vuontela, Virve; Steenari, Maija-Riikka; Aronen, Eeva T; Korvenoja, Antti; Aronen, Hannu J; Carlson, Synnöve

2009-02-01

Using functional magnetic resonance imaging (fMRI) and n-back tasks we investigated whether, in 11-13-year-old children, spatial (location) and nonspatial (color) information is differentially processed during visual attention (0-back) and working memory (WM) (2-back) tasks and whether such cognitive task performance, compared to a resting state, results in regional deactivation. The location 0-back task, compared to the color 0-back task, activated segregated areas in the frontal, parietal and occipital cortices whereas no differentially activated voxels were obtained when location and color 2-back tasks were directly contrasted. Several midline cortical areas were less active during 0- and 2-back task performance than resting state. The task-induced deactivation increased with task difficulty as demonstrated by larger deactivation during 2-back than 0-back tasks. The results suggest that, in 11-13-year-old children, the visual attentional network is differently recruited by spatial and nonspatial information processing, but the functional organization of cortical activation in WM in this age group is not based on the type of information processed. Furthermore, 11-13-year-old children exhibited a similar pattern of cortical deactivation that has been reported in adults during cognitive task performance compared to a resting state.

Gender and Age Differences in Levels, Types and Locations of Physical Activity among Older Adults Living in Car-Dependent Neighborhoods.

PubMed

Li, W; Procter-Gray, E; Churchill, L; Crouter, S E; Kane, K; Tian, J; Franklin, P D; Ockene, J K; Gurwitz, J

2017-01-01

A thorough understanding of gender differences in physical activity is critical to effective promotion of active living in older adults. To examine gender and age differences in levels, types and locations of physical activity. Cross-sectional observation. Car-dependent urban and rural neighborhoods in Worcester County, Massachusetts, USA. 111 men and 103 women aged 65 years and older. From 2012 to 2014, participants were queried on type, frequency and location of physical activity. Participants wore an accelerometer for 7 consecutive days. Compared to women, men had a higher mean daily step count (mean (SD) 4385 (2122) men vs. 3671(1723) women, p=0.008). Men reported higher frequencies of any physical activity and moderate-to-vigorous physical activity, and a lower frequency of physical activity inside the home. Mean daily step counts and frequency of physical activity outside the home decreased progressively with age for both men and women. Women had a sharper decline in frequencies of self-reported physical activity. Men had a significant decrease in utilitarian walking, which women did not (p=0.07). Among participants who reported participation in any physical activity (n=190), more women indicated exercising indoors more often (59% vs. 44%, p=0.04). The three most commonly cited locations for physical activity away from home for both genders were streets or sidewalks, shopping malls, and membership-only facilities (e.g., YMCA or YWCA). The most common types of physical activity, performed at least once in a typical month, with over 40% of both genders reporting, included light housework, brisk walking, leisurely walking, and stretching. Levels, types and location preferences of physical activity differed substantially by gender. Levels of physical activity decreased progressively with age, with greater decline among women. Consideration of these gender differences is necessary to improve the effectiveness of active living promotion programs among older adults.

ACTIVE REGION FILAMENTS MIGHT HARBOR WEAK MAGNETIC FIELDS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Díaz Baso, C. J.; Martínez González, M. J.; Asensio Ramos, A., E-mail: cdiazbas@iac.es

Recent spectropolarimetric observations of active region filaments have revealed polarization profiles with signatures typical of the strong field Zeeman regime. The conspicuous absence in those observations of scattering polarization and Hanle effect signatures was then pointed out by some authors. This was interpreted as either a signature of mixed “turbulent” field components or as a result of optical thickness. In this article, we present a natural scenario to explain these Zeeman-only spectropolarimetric observations of active region (AR) filaments. We propose a two-component model, one on top of the other. Both components have horizontal fields, with the azimuth difference between themmore » being close to 90°. The component that lies lower in the atmosphere is permeated by a strong field of the order of 600 G, while the upper component has much weaker fields, of the order of 10 G. The ensuing scattering polarization signatures of the individual components have opposite signs, so its combination along the line of sight reduces—and even can cancel out—the Hanle signatures, giving rise to an apparent Zeeman-only profile. This model is also applicable to other chromospheric structures seen in absorption above ARs.« less

The effect of cultivar, sowing date and transplant location in field on bolting of Welsh onion (Allium fistulosum L.)

PubMed Central

2013-01-01

Background Bolting reduces the quality and commercial yield of Welsh onion (Allium fistulosum L.) in production. However, seed production is directly dependent on flower induction and bolting. The Welsh onion belongs to the green plant vernalisation type, specific seedling characteristics and sufficient accumulated time at low temperature are indispensible for the completion of its vernalisation process. Only if these conditions for vernalisation are fulfilled, the plants will bolt in the following year. The present investigation evaluated the effects of cultivar, sowing date and transplant location in field on the bolting of Welsh onion at the Horticultural Farm of the College of Horticulture, Northwest A&F University, Yangling, Shannxi Province, China in two succeeding production years: 2010–2011 and 2011–2012. A strip split plot layout within a randomised complete block design with three replications was used. Results The results revealed that all three factors (cultivar, sowing date and transplant location) and their interaction had significant effects on the initiation and final rate of bolting observed by 30 April. The earliest bolting date (14 February, 2011 and 15 February, 2012) and the highest bolting rate (100% in 2011 and 62% in 2012) occurred when the JinGuan cultivar was sown on 20 August and transplanted in a plastic tunnel, whereas the latest date and lowest rate (no bolting observed until 30 April) of bolting occurred when the XiaHei cultivar was sown on 29 September and transplanted in an open field. Conclusions These results suggest that we can control bolting in Welsh onion production by choosing an appropriate cultivar, sowing date and transplant location. Choosing a late bolting cultivar, such as cultivar XiaHei, sowing around October, and transplanting in the open field can significantly delay bolting, while a sowing date in late August should be selected for seed production, and the seedlings should be transplanted in a plastic tunnel to

The effect of cultivar, sowing date and transplant location in field on bolting of Welsh onion (Allium fistulosum L.).

PubMed

Dong, Yinxin; Cheng, Zhihui; Meng, Huanwen; Liu, Hanqiang; Wu, Cuinan; Khan, Abdul Rehman

2013-10-07

Bolting reduces the quality and commercial yield of Welsh onion (Allium fistulosum L.) in production. However, seed production is directly dependent on flower induction and bolting. The Welsh onion belongs to the green plant vernalisation type, specific seedling characteristics and sufficient accumulated time at low temperature are indispensible for the completion of its vernalisation process. Only if these conditions for vernalisation are fulfilled, the plants will bolt in the following year. The present investigation evaluated the effects of cultivar, sowing date and transplant location in field on the bolting of Welsh onion at the Horticultural Farm of the College of Horticulture, Northwest A&F University, Yangling, Shannxi Province, China in two succeeding production years: 2010-2011 and 2011-2012. A strip split plot layout within a randomised complete block design with three replications was used. The results revealed that all three factors (cultivar, sowing date and transplant location) and their interaction had significant effects on the initiation and final rate of bolting observed by 30 April. The earliest bolting date (14 February, 2011 and 15 February, 2012) and the highest bolting rate (100% in 2011 and 62% in 2012) occurred when the JinGuan cultivar was sown on 20 August and transplanted in a plastic tunnel, whereas the latest date and lowest rate (no bolting observed until 30 April) of bolting occurred when the XiaHei cultivar was sown on 29 September and transplanted in an open field. These results suggest that we can control bolting in Welsh onion production by choosing an appropriate cultivar, sowing date and transplant location. Choosing a late bolting cultivar, such as cultivar XiaHei, sowing around October, and transplanting in the open field can significantly delay bolting, while a sowing date in late August should be selected for seed production, and the seedlings should be transplanted in a plastic tunnel to accelerate development of the

Segmentation of lung fields using Chan-Vese active contour model in chest radiographs

NASA Astrophysics Data System (ADS)

Sohn, Kiwon

2011-03-01

A CAD tool for chest radiographs consists of several procedures and the very first step is segmentation of lung fields. We develop a novel methodology for segmentation of lung fields in chest radiographs that can satisfy the following two requirements. First, we aim to develop a segmentation method that does not need a training stage with manual estimation of anatomical features in a large training dataset of images. Secondly, for the ease of implementation, it is desirable to apply a well established model that is widely used for various image-partitioning practices. The Chan-Vese active contour model, which is based on Mumford-Shah functional in the level set framework, is applied for segmentation of lung fields. With the use of this model, segmentation of lung fields can be carried out without detailed prior knowledge on the radiographic anatomy of the chest, yet in some chest radiographs, the trachea regions are unfavorably segmented out in addition to the lung field contours. To eliminate artifacts from the trachea, we locate the upper end of the trachea, find a vertical center line of the trachea and delineate it, and then brighten the trachea region to make it less distinctive. The segmentation process is finalized by subsequent morphological operations. We randomly select 30 images from the Japanese Society of Radiological Technology image database to test the proposed methodology and the results are shown. We hope our segmentation technique can help to promote of CAD tools, especially for emerging chest radiographic imaging techniques such as dual energy radiography and chest tomosynthesis.

Deficiencies of active electronic radiation protection dosimeters in pulsed fields.

PubMed

Ankerhold, U; Hupe, O; Ambrosi, P

2009-07-01

Nowadays nearly all radiation fields used for X-ray diagnostics are pulsed. These fields are characterised by a high dose rate during the pulse and a short pulse duration in the range of a few milliseconds. The use of active electronic dosimeters has increased in the past few years, but these types of dosimeters might possibly not measure reliably in pulsed radiation fields. Not only personal dosimeters but also area dosimeters that are used mainly for dose rate measurements are concerned. These cannot be substituted by using passive dosimeter types. The characteristics of active electronic dosimeters determined in a continuous radiation field cannot be transferred to those in pulsed fields. Some provisional measurements with typical electronic dosimeters in pulsed radiation fields are presented to reveal this basic problem.

Differences in soil biological activity by terrain types at the sub-field scale in central Iowa US

DOE PAGES

Kaleita, Amy L.; Schott, Linda R.; Hargreaves, Sarah K.; ...

2017-07-07

Soil microbial communities are structured by biogeochemical processes that occur at many different spatial scales, which makes soil sampling difficult. Because soil microbial communities are important in nutrient cycling and soil fertility, it is important to understand how microbial communities function within the heterogeneous soil landscape. In this study, a self-organizing map was used to determine whether landscape data can be used to characterize the distribution of microbial biomass and activity in order to provide an improved understanding of soil microbial community function. Points within a row crop field in south-central Iowa were clustered via a self-organizing map using sixmore » landscape properties into three separate landscape clusters. Twelve sampling locations per cluster were chosen for a total of 36 locations. After the soil samples were collected, the samples were then analysed for various metabolic indicators, such as nitrogen and carbon mineralization, extractable organic carbon, microbial biomass, etc. It was found that sampling locations located in the potholes and toe slope positions had significantly greater microbial biomass nitrogen and carbon, total carbon, total nitrogen and extractable organic carbon than the other two landscape position clusters, while locations located on the upslope did not differ significantly from the other landscape clusters. However, factors such as nitrate, ammonia, and nitrogen and carbon mineralization did not differ significantly across the landscape. Altogether, this research demonstrates the effectiveness of a terrain-based clustering method for guiding soil sampling of microbial communities.« less

Differences in soil biological activity by terrain types at the sub-field scale in central Iowa US

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kaleita, Amy L.; Schott, Linda R.; Hargreaves, Sarah K.

Soil microbial communities are structured by biogeochemical processes that occur at many different spatial scales, which makes soil sampling difficult. Because soil microbial communities are important in nutrient cycling and soil fertility, it is important to understand how microbial communities function within the heterogeneous soil landscape. In this study, a self-organizing map was used to determine whether landscape data can be used to characterize the distribution of microbial biomass and activity in order to provide an improved understanding of soil microbial community function. Points within a row crop field in south-central Iowa were clustered via a self-organizing map using sixmore » landscape properties into three separate landscape clusters. Twelve sampling locations per cluster were chosen for a total of 36 locations. After the soil samples were collected, the samples were then analysed for various metabolic indicators, such as nitrogen and carbon mineralization, extractable organic carbon, microbial biomass, etc. It was found that sampling locations located in the potholes and toe slope positions had significantly greater microbial biomass nitrogen and carbon, total carbon, total nitrogen and extractable organic carbon than the other two landscape position clusters, while locations located on the upslope did not differ significantly from the other landscape clusters. However, factors such as nitrate, ammonia, and nitrogen and carbon mineralization did not differ significantly across the landscape. Altogether, this research demonstrates the effectiveness of a terrain-based clustering method for guiding soil sampling of microbial communities.« less

Sports Facilities, Shopping Centers or Homes: What Locations are Important for Adults' Physical Activity? A Cross-Sectional Study.

PubMed

Jansen, Marijke; Ettema, Dick; Pierik, Frank; Dijst, Martin

2016-03-04

Physical activity (PA) is influenced by the built environment. However, little is known about the types of built environment where adults spend their time, and at what levels of PA they engage in those environments. Understanding the effect of the built environment on PA requires insight into PA behavior at different types of locations (e.g., home, work, shopping centers, and sports facilities). Therefore, this study describes where adults aged 45-65 years were active with moderate-to-vigorous intensity (MVPA), and examines associations of socio-demographic factors and neighborhood with MVPA at these locations. Participants' (N = 308) PA was measured for seven days using accelerometers and GPS-devices. Adults spent most minutes of MVPA at home and work. Highest MVPA-ratios of total time spent at a location were achieved in sports facilities and during transport. Neighborhood characteristics and socio-demographic factors such as work status, health status and household structure, had significant effects on MVPA at various locations and on total MVPA. Understanding PA behavior at various locations may provide insights that allow professionals in different domains (e.g., health, landscaping, urban planning) to develop strategies to stimulate PA.

Sports Facilities, Shopping Centers or Homes: What Locations are Important for Adults’ Physical Activity? A Cross-Sectional Study

PubMed Central

Jansen, Marijke; Ettema, Dick; Pierik, Frank; Dijst, Martin

2016-01-01

Physical activity (PA) is influenced by the built environment. However, little is known about the types of built environment where adults spend their time, and at what levels of PA they engage in those environments. Understanding the effect of the built environment on PA requires insight into PA behavior at different types of locations (e.g., home, work, shopping centers, and sports facilities). Therefore, this study describes where adults aged 45–65 years were active with moderate-to-vigorous intensity (MVPA), and examines associations of socio-demographic factors and neighborhood with MVPA at these locations. Participants’ (N = 308) PA was measured for seven days using accelerometers and GPS-devices. Adults spent most minutes of MVPA at home and work. Highest MVPA-ratios of total time spent at a location were achieved in sports facilities and during transport. Neighborhood characteristics and socio-demographic factors such as work status, health status and household structure, had significant effects on MVPA at various locations and on total MVPA. Understanding PA behavior at various locations may provide insights that allow professionals in different domains (e.g., health, landscaping, urban planning) to develop strategies to stimulate PA. PMID:26959041

USGS field activity 08FSH01 on the west Florida shelf, Gulf of Mexico, in August 2008

USGS Publications Warehouse

Robbins, Lisa L.; Knorr, Paul O.; Liu, Xuewu; Byrne, Robert H.; Raabe, Ellen A.

2009-01-01

From August 11 to 15, 2008, a cruise led by the U.S. Geological Survey (USGS) collected air and sea surface partial pressure of carbon dioxide (pCO2), pH, dissolved inorganic carbon (DIC), and total alkalinity (TA) data on the west Florida shelf. Approximately 1,600 data points were collected underway over a 650-kilometer (km) trackline using the Multiparameter Inorganic Carbon Analyzer (MICA). The collection of data extended from Crystal River southward to Marco Island, Florida (~400 km), and westward up to 160 km off the Florida coast. Discrete water samples from approximately 40 locations were also taken at specific localities to corroborate underway data measurements. The USGS St. Petersburg Coastal and Marine Science Center (SPCMSC) assigns a unique identifier to each cruise or field activity. For example, 08FSH01 tells us the data were collected in 2008 for the Response of Florida Shelf (FSH) Ecosystems to Climate Change project, and the data were collected during the first field activity for that study in that calendar year.

Location of Instability During a Bench Press Alters Movement Patterns and Electromyographical Activity.

PubMed

Nairn, Brian C; Sutherland, Chad A; Drake, Janessa D M

2015-11-01

Instability training devices with the bench press exercise are becoming increasingly popular. Typically, the instability device is placed at the trunk/upper body (e.g., lying on a Swiss ball); however, a recent product called the Attitube has been developed, which places the location of instability at the hands by users lifting a water-filled tube. Therefore, the purpose of this study was to analyze the effects of different instability devices (location of instability) on kinematic and electromyographical patterns during the bench press exercise. Ten healthy males were recruited and performed 1 set of 3 repetitions for 3 different bench press conditions: Olympic bar on a stable bench (BENCH), Olympic bar on a stability ball (BALL), and Attitube on a stable bench (TUBE). The eccentric and concentric phases were analyzed in 10% intervals while electromyography was recorded from 24 electrode sites, and motion capture was used to track elbow flexion angle and 3-dimensional movement trajectories and vertical velocity of the Bar/Attitube. The prime movers tended to show a reduction in muscle activity during the TUBE trials; however, pectoralis major initially showed increased activation during the eccentric phase of the TUBE condition. The trunk muscle activations were greatest during the TUBE and smallest during the BAR. In addition, the TUBE showed decreased range of elbow flexion and increased medial-lateral movement of the Attitube itself. The results further support the notion that instability devices may be more beneficial for trunk muscles rather than prime movers.

Association among US locations for orchardgrass production

USDA-ARS?s Scientific Manuscript database

Thirteen orchardgrass (Dacylis glomerata L.) cultivars were evaluated over four years at five U.S. field locations in Kentucky, Pennsylvania, Utah, Virginia, and Wisconsin. The objective was to determine the relationship among the five locations for orchardgrass agronomic performance. Cultivar by en...

Electric field measurement of two commercial active/sham coils for transcranial magnetic stimulation.

PubMed

Smith, James Evan; Peterchev, Angel V

2018-06-22

Sham TMS coils isolate the ancillary effects of their active counterparts, but typically induce low-strength electric fields (E-fields) in the brain, which could be biologically active. We measured the E-fields induced by two pairs of commonly-used commercial active/sham coils. Approach: E-field distributions of the active and sham configurations of the Magstim 70 mm AFC and MagVenture Cool-B65 A/P coils were measured over a 7-cm-radius, hemispherical grid approximating the cortical surface. Peak E-field strength was recorded over a range of pulse amplitudes. Main results: The Magstim and MagVenture shams induce peak E-fields corresponding to 25.3% and 7.72% of their respective active values. The MagVenture sham has an E-field distribution shaped like its active counterpart. The Magstim sham induces nearly zero E-field under the coil's center, and its peak E-field forms a diffuse oval 3-7 cm from the center. Electrical scalp stimulation paired with the MagVenture sham is estimated to increase the sham E-field in the brain up to 10%. Significance: Different commercial shams induce different E-field strengths and distributions in the brain, which should be considered in interpreting outcomes of sham stimulation. © 2018 IOP Publishing Ltd.

Activity classification based on inertial and barometric pressure sensors at different anatomical locations.

PubMed

Moncada-Torres, A; Leuenberger, K; Gonzenbach, R; Luft, A; Gassert, R

2014-07-01

Miniature, wearable sensor modules are a promising technology to monitor activities of daily living (ADL) over extended periods of time. To assure both user compliance and meaningful results, the selection and placement site of sensors requires careful consideration. We investigated these aspects for the classification of 16 ADL in 6 healthy subjects under laboratory conditions using ReSense, our custom-made inertial measurement unit enhanced with a barometric pressure sensor used to capture activity-related altitude changes. Subjects wore a module on each wrist and ankle, and one on the trunk. Activities comprised whole body movements as well as gross and dextrous upper-limb activities. Wrist-module data outperformed the other locations for the three activity groups. Specifically, overall classification accuracy rates of almost 93% and more than 95% were achieved for the repeated holdout and user-specific validation methods, respectively, for all 16 activities. Including the altitude profile resulted in a considerable improvement of up to 20% in the classification accuracy for stair ascent and descent. The gyroscopes provided no useful information for activity classification under this scheme. The proposed sensor setting could allow for robust long-term activity monitoring with high compliance in different patient populations.

Nonpotential features observed in the magnetic field of an active region

NASA Technical Reports Server (NTRS)

Gary, G. A.; Moore, R. L.; Hagyard, M. J.; Haisch, Bernhard M.

1987-01-01

A unique coordinated data set consisting of vector magnetograms, H-alpha photographs, and high-resolution ultraviolet images of a solar active region is used, together with mathematical models, to calculate potential and force-free magnetic field lines and to examine the nonpotential nature of the active region structure. It is found that the overall bipolar magnetic field of the active region had a net twist corresponding to net current of order 3 x 10 to the 12th A and average density of order 4 x 10 to the -4th A/sq m flowing antiparallel to the field. There were three regions of enhanced nonpotentiality in the interior of the active region; in one the field had a marked nonpotential twist or shear with height above the photosphere. The measured total nonpotential magnetic energy stored in the entire active region was of order 10 to the 32nd ergs, about 3 sigma above the noise level.

LSA field test

NASA Technical Reports Server (NTRS)

Jaffe, P.

1979-01-01

Degradation tests indicate that electrical degradation is not a slow monotonically increasing phenomenon as originally thought but occurs abruptly as the result of some traumatic event. This finding has led to a change in the test philosophy. A discussion of this change is presented along with a summary of degradation and failure data from all the sites and results from a variety of special tests. New instrumentation for in-field measurements are described. Field testing activity was expanded by the addition of twelve remote sites located as far away as Alaska and the Canal Zone. Descriptions of the new sites are included.

Geologic evolution of the Lost City Hydrothermal Field

NASA Astrophysics Data System (ADS)

Denny, Alden R.; Kelley, Deborah S.; Früh-Green, Gretchen L.

2016-02-01

The Lost City Hydrothermal Field (LCHF) is a novel serpentinite-hosted vent field located on the Atlantis Massif southern wall. Results of 2 m resolution bathymetry, side scan, and video and still imagery, integrated with direct submersible observations provide the first high-resolution geologic map of the LCHF. These data form the foundation for an evolutionary model for the vent system over the past >120,000 years. The field is located on a down-dropped bench 70 m below the summit of the massif. The bench is capped by breccia and pelagic carbonate deposits underlain by variably deformed and altered serpentinite and gabbroic rocks. Hydrothermal activity is focused at the 60 m tall, 100 m across, massive carbonate edifice "Poseidon," which is venting 91°C fluid. Hydrothermal activity declines south and west of the Poseidon complex and dies off completely at distances greater than 200 m. East of Poseidon, the most recent stage of hydrothermal flow is characterized by egress of diffuse fluids from narrow fissures within a low-angle, anastomosing mylonite zone. South of the area of current hydrothermal activity, there is evidence of two discrete previously unrecognized relict fields. Active venting sites defined by carbonate-filled fissures that cut the carbonate cap rock at the summit of the massif mark the present-day northernmost extent of venting. These spatial relationships reflect multiple stages of field development, the northward migration of venting over time, and the likely development of a nascent field at the massif summit.

Soil Water Measurement Using Actively Heated Fiber Optics at Field Scale.

PubMed

Vidana Gamage, Duminda N; Biswas, Asim; Strachan, Ian B; Adamchuk, Viacheslav I

2018-04-06

Several studies have demonstrated the potential of actively heated fiber optics (AHFO) to measure soil water content (SWC) at high spatial and temporal resolutions. This study tested the feasibility of the AHFO technique to measure soil water in the surface soil of a crop grown field over a growing season using an in-situ calibration approach. Heat pulses of five minutes duration were applied at a rate of 7.28 W m -1 along eighteen fiber optic cable transects installed at three depths (0.05, 0.10 and 0.20 m) at six-hour intervals. Cumulative temperature increase (T cum ) during heat pulses was calculated at locations along the cable. While predicting commercial sensor measurements, the AHFO showed root mean square errors (RMSE) of 2.8, 3.7 and 3.7% for 0.05, 0.10 and 0.20 m depths, respectively. Further, the coefficients of determination (R²) for depth specific relationships were 0.87 (0.05 m depth), 0.46 (0.10 m depth), 0.86 (0.20 m depth) and 0.66 (all depths combined). This study showed a great potential of the AHFO technique to measure soil water at high spatial resolutions (<1 m) and to monitor soil water dynamics of surface soil in a crop grown field over a cropping season with a reasonable compromise between accuracy and practicality.

LOCATING AREAS OF CONCERN

EPA Science Inventory

A simple method to locate changes in vegetation cover, which can be used to identify areas under stress. The method only requires inexpensive NDVI data. The use of remotely sensed data is far more cost-effective than field studies and can be performed more quickly. Local knowledg...

RF power absorption by plasma of low pressure low power inductive discharge located in the external magnetic field

NASA Astrophysics Data System (ADS)

Kralkina, E. A.; Rukhadze, A. A.; Nekliudova, P. A.; Pavlov, V. B.; Petrov, A. K.; Vavilin, K. V.

2018-03-01

Present paper is aimed to reveal experimentally and theoretically the influence of magnetic field strength, antenna shape, pressure, operating frequency and geometrical size of plasma sources on the ability of plasma to absorb the RF power characterized by the equivalent plasma resistance for the case of low pressure RF inductive discharge located in the external magnetic field. The distinguishing feature of the present paper is the consideration of the antennas that generate not only current but charge on the external surface of plasma sources. It is shown that in the limited plasma source two linked waves can be excited. In case of antennas generating only azimuthal current the waves can be attributed as helicon and TG waves. In the case of an antenna with the longitudinal current there is a surface charge on the side surface of the plasma source, which gives rise to a significant increase of the longitudinal and radial components of the RF electric field as compared with the case of the azimuthal antenna current.

Dynamics of Deformable Active Particles under External Flow Field

NASA Astrophysics Data System (ADS)

Tarama, Mitsusuke

2017-10-01

In most practical situations, active particles are affected by their environment, for example, by a chemical concentration gradient, light intensity, gravity, or confinement. In particular, the effect of an external flow field is important for particles swimming in a solvent fluid. For deformable active particles such as self-propelled liquid droplets and active vesicles, as well as microorganisms such as euglenas and neutrophils, a general description has been developed by focusing on shape deformation. In this review, we present our recent studies concerning the dynamics of a single active deformable particle under an external flow field. First, a set of model equations of active deformable particles including the effect of a general external flow is introduced. Then, the dynamics under two specific flow profiles is discussed: a linear shear flow, as the simplest example, and a swirl flow. In the latter case, the scattering dynamics of the active deformable particles by the swirl flow is also considered.

Electric field mill network products to improve detection of the lightning hazard

NASA Technical Reports Server (NTRS)

Maier, Launa M.

1987-01-01

An electric field mill network has been used at Kennedy Space Center for over 10 years as part of the thunderstorm detection system. Several algorithms are currently available to improve the informational output of the electric field mill data. The charge distributions of roughly 50 percent of all lightning can be modeled as if they reduced the charged cloud by a point charge or a point dipole. Using these models, the spatial differences in the lightning induced electric field changes, and a least squares algorithm to obtain an optimum solution, the three-dimensional locations of the lightning charge centers can be located. During the lifetime of a thunderstorm, dynamically induced charging, modeled as a current source, can be located spatially with measurements of Maxwell current density. The electric field mills can be used to calculate the Maxwell current density at times when it is equal to the displacement current density. These improvements will produce more accurate assessments of the potential electrical activity, identify active cells, and forecast thunderstorm termination.

Effects of spatial frequency and location of fearful faces on human amygdala activity.

PubMed

Morawetz, Carmen; Baudewig, Juergen; Treue, Stefan; Dechent, Peter

2011-01-31

Facial emotion perception plays a fundamental role in interpersonal social interactions. Images of faces contain visual information at various spatial frequencies. The amygdala has previously been reported to be preferentially responsive to low-spatial frequency (LSF) rather than to high-spatial frequency (HSF) filtered images of faces presented at the center of the visual field. Furthermore, it has been proposed that the amygdala might be especially sensitive to affective stimuli in the periphery. In the present study we investigated the impact of spatial frequency and stimulus eccentricity on face processing in the human amygdala and fusiform gyrus using functional magnetic resonance imaging (fMRI). The spatial frequencies of pictures of fearful faces were filtered to produce images that retained only LSF or HSF information. Facial images were presented either in the left or right visual field at two different eccentricities. In contrast to previous findings, we found that the amygdala responds to LSF and HSF stimuli in a similar manner regardless of the location of the affective stimuli in the visual field. Furthermore, the fusiform gyrus did not show differential responses to spatial frequency filtered images of faces. Our findings argue against the view that LSF information plays a crucial role in the processing of facial expressions in the amygdala and of a higher sensitivity to affective stimuli in the periphery. Copyright © 2010 Elsevier B.V. All rights reserved.

Uncertainty in georeferencing current and historic plant locations

USGS Publications Warehouse

McEachern, K.; Niessen, K.

2009-01-01

With shrinking habitats, weed invasions, and climate change, repeated surveys are becoming increasingly important for rare plant conservation and ecological restoration. We often need to relocate historical sites or provide locations for newly restored sites. Georeferencing is the technique of giving geographic coordinates to the location of a site. Georeferencing has been done historically using verbal descriptions or field maps that accompany voucher collections. New digital technology gives us more exact techniques for mapping and storing location information. Error still exists, however, and even georeferenced locations can be uncertain, especially if error information is not included with the observation. We review the concept of uncertainty in georeferencing and compare several institutional database systems for cataloging error and uncertainty with georeferenced locations. These concepts are widely discussed among geographers, but ecologists and restorationists need to become more aware of issues related to uncertainty to improve our use of spatial information in field studies. ?? 2009 by the Board of Regents of the University of Wisconsin System.

Optimal Facility-Location

PubMed Central

Goldman, A. J.

2006-01-01

Dr. Christoph Witzgall, the honoree of this Symposium, can count among his many contributions to applied mathematics and mathematical operations research a body of widely-recognized work on the optimal location of facilities. The present paper offers to non-specialists a sketch of that field and its evolution, with emphasis on areas most closely related to Witzgall’s research at NBS/NIST. PMID:27274920

Hysteretic dynamics of active particles in a periodic orienting field

PubMed Central

Romensky, Maksym; Scholz, Dimitri; Lobaskin, Vladimir

2015-01-01

Active motion of living organisms and artificial self-propelling particles has been an area of intense research at the interface of biology, chemistry and physics. Significant progress in understanding these phenomena has been related to the observation that dynamic self-organization in active systems has much in common with ordering in equilibrium condensed matter such as spontaneous magnetization in ferromagnets. The velocities of active particles may behave similar to magnetic dipoles and develop global alignment, although interactions between the individuals might be completely different. In this work, we show that the dynamics of active particles in external fields can also be described in a way that resembles equilibrium condensed matter. It follows simple general laws, which are independent of the microscopic details of the system. The dynamics is revealed through hysteresis of the mean velocity of active particles subjected to a periodic orienting field. The hysteresis is measured in computer simulations and experiments on unicellular organisms. We find that the ability of the particles to follow the field scales with the ratio of the field variation period to the particles' orientational relaxation time, which, in turn, is related to the particle self-propulsion power and the energy dissipation rate. The collective behaviour of the particles due to aligning interactions manifests itself at low frequencies via increased persistence of the swarm motion when compared with motion of an individual. By contrast, at high field frequencies, the active group fails to develop the alignment and tends to behave like a set of independent individuals even in the presence of interactions. We also report on asymptotic laws for the hysteretic dynamics of active particles, which resemble those in magnetic systems. The generality of the assumptions in the underlying model suggests that the observed laws might apply to a variety of dynamic phenomena from the motion of

The 'Arm Force Field' method to predict manual arm strength based on only hand location and force direction.

PubMed

La Delfa, Nicholas J; Potvin, Jim R

2017-03-01

This paper describes the development of a novel method (termed the 'Arm Force Field' or 'AFF') to predict manual arm strength (MAS) for a wide range of body orientations, hand locations and any force direction. This method used an artificial neural network (ANN) to predict the effects of hand location and force direction on MAS, and included a method to estimate the contribution of the arm's weight to the predicted strength. The AFF method predicted the MAS values very well (r 2  = 0.97, RMSD = 5.2 N, n = 456) and maintained good generalizability with external test data (r 2  = 0.842, RMSD = 13.1 N, n = 80). The AFF can be readily integrated within any DHM ergonomics software, and appears to be a more robust, reliable and valid method of estimating the strength capabilities of the arm, when compared to current approaches. Copyright © 2016 Elsevier Ltd. All rights reserved.

Electric current locator

DOEpatents

King, Paul E [Corvallis, OR; Woodside, Charles Rigel [Corvallis, OR

2012-02-07

The disclosure herein provides an apparatus for location of a quantity of current vectors in an electrical device, where the current vector has a known direction and a known relative magnitude to an input current supplied to the electrical device. Mathematical constants used in Biot-Savart superposition equations are determined for the electrical device, the orientation of the apparatus, and relative magnitude of the current vector and the input current, and the apparatus utilizes magnetic field sensors oriented to a sensing plane to provide current vector location based on the solution of the Biot-Savart superposition equations. Description of required orientations between the apparatus and the electrical device are disclosed and various methods of determining the mathematical constants are presented.

Differentiation between Vergence and Saccadic Functional Activity within the Human Frontal Eye Fields and Midbrain Revealed through fMRI

PubMed Central

Alkan, Yelda; Biswal, Bharat B.; Alvarez, Tara L.

2011-01-01

Purpose Eye movement research has traditionally studied solely saccade and/or vergence eye movements by isolating these systems within a laboratory setting. While the neural correlates of saccadic eye movements are established, few studies have quantified the functional activity of vergence eye movements using fMRI. This study mapped the neural substrates of vergence eye movements and compared them to saccades to elucidate the spatial commonality and differentiation between these systems. Methodology The stimulus was presented in a block design where the ‘off’ stimulus was a sustained fixation and the ‘on’ stimulus was random vergence or saccadic eye movements. Data were collected with a 3T scanner. A general linear model (GLM) was used in conjunction with cluster size to determine significantly active regions. A paired t-test of the GLM beta weight coefficients was computed between the saccade and vergence functional activities to test the hypothesis that vergence and saccadic stimulation would have spatial differentiation in addition to shared neural substrates. Results Segregated functional activation was observed within the frontal eye fields where a portion of the functional activity from the vergence task was located anterior to the saccadic functional activity (z>2.3; p<0.03). An area within the midbrain was significantly correlated with the experimental design for the vergence but not the saccade data set. Similar functional activation was observed within the following regions of interest: the supplementary eye field, dorsolateral prefrontal cortex, ventral lateral prefrontal cortex, lateral intraparietal area, cuneus, precuneus, anterior and posterior cingulates, and cerebellar vermis. The functional activity from these regions was not different between the vergence and saccade data sets assessed by analyzing the beta weights of the paired t-test (p>0.2). Conclusion Functional MRI can elucidate the differences between the vergence and saccade

Magnetic Field-Induced T Cell Receptor Clustering by Nanoparticles Enhances T Cell Activation and Stimulates Antitumor Activity

PubMed Central

2015-01-01

Iron–dextran nanoparticles functionalized with T cell activating proteins have been used to study T cell receptor (TCR) signaling. However, nanoparticle triggering of membrane receptors is poorly understood and may be sensitive to physiologically regulated changes in TCR clustering that occur after T cell activation. Nano-aAPC bound 2-fold more TCR on activated T cells, which have clustered TCR, than on naive T cells, resulting in a lower threshold for activation. To enhance T cell activation, a magnetic field was used to drive aggregation of paramagnetic nano-aAPC, resulting in a doubling of TCR cluster size and increased T cell expansion in vitro and after adoptive transfer in vivo. T cells activated by nano-aAPC in a magnetic field inhibited growth of B16 melanoma, showing that this novel approach, using magnetic field-enhanced nano-aAPC stimulation, can generate large numbers of activated antigen-specific T cells and has clinically relevant applications for adoptive immunotherapy. PMID:24564881

Chapter A9. Safety in Field Activities

USGS Publications Warehouse

Lane, Susan L.; Ray, Ronald G.

1998-01-01

The National Field Manual for the Collection of Water-Quality Data (National Field Manual) describes protocols (requirements and recommendations) and provides guidelines for U.S. Geological Survey (USGS) personnel who collect data used to assess the quality of the Nation's surface-water and ground-water resources. This chapter of the manual addresses topics related to personal safety to be used in the collection of water-quality data, including: policies and general regulations on field safety; transportation of people and equipment; implementation of surface-water and ground-water activities; procedures for handling chemicals; and information on potentially hazardous environmental conditions, animals, and plants. Each chapter of the National Field Manual is published separately and revised periodically. Newly published and revised chapters will be announced on the USGS Home Page on the World Wide Web under 'New Publications of the U.S. Geological Survey.' The URL for this page is http://pubs.usgs.gov/publications/ index.html.

Usefulness of C-Reactive Protein as a Disease Activity Marker in Crohn’s Disease according to the Location of Disease

PubMed Central

Yang, Dong-Hoon; Yang, Suk-Kyun; Park, Sang Hyoung; Lee, Ho-Su; Boo, Sun-Jin; Park, Jae-Ho; Na, Soo Young; Jung, Kee Wook; Kim, Kyung-Jo; Ye, Byong Duk; Byeon, Jeong-Sik; Myung, Seung-Jae; Kim, Jin-Ho

2015-01-01

Background/Aims C-reactive protein (CRP) is a serologic activity marker in Crohn’s disease (CD), but it may be less useful in evaluating CD activity in ileal CD patients. We aimed to investigate the usefulness of CRP as a disease activity marker in CD according to disease location. Methods Korean CD patients in a single hospital were evaluated. Factors associated with elevated CRP concentration at the time of diagnosis of CD and the association between the physician’s prediction regarding upcoming surgery and the sites of the lesions directly related to surgery were analyzed. Results Of 435 CD patients, 25.7%, 6.9%, and 67.4% had ileal, colonic, and ileocolonic CD, respectively. Multivariate analysis revealed that an elevated erythrocyte sedimentation rate, reduced serum albumin, CD activity index (CDAI) >220, and ileocolonic/colonic location were associated with an elevated CRP level and that the CRP level was significantly correlated with the CDAI in all CD patients (γ=0.466, p<0.01). However, the correlation coefficient was dependent on the location, with values of 0.395, 0.456, and 0.527 in patients with an ileal, ileocolonic, and colonic disease location, respectively. Surgery for ileal lesions was less predictable than surgery for ileocolonic or colonic lesions during follow-up. Conclusions CRP is less useful as a disease activity marker in patients with ileal CD than those with ileocolonic or colonic CD. PMID:25170056

Theoretical Calculation of the Uv-Vis Spectral Band Locations of Pahs with Unknown Syntheses Procedures and Prospective Carcinogenic Activity

NASA Astrophysics Data System (ADS)

Ona-Ruales, Jorge Oswaldo; Ruiz-Morales, Yosadara

2017-06-01

Annellation Theory and ZINDO/S semiempirical calculations have been used for the calculation of the locations of maximum absorbance (LMA) of the Ultraviolet-Visible (UV-Vis) of 31 C_{34}H_{16} PAHs (molecular mass 424 Da) with unknown protocols of synthesis. The presence of benzo[a]pyrene bay-like regions and dibenzo[a,l]pyrene fjord-like regions in several of the structures that could be linked to an enhancement of the biological behavior and carcinogenic activity stresses the importance of C_{34}H_{16} PAHs in fields like molecular biology and cancer research. In addition, the occurrence of large PAHs in oil asphaltenes exemplifies the importance of these calculations for the characterization of complex systems. The C_{34}H_{16} PAH group is the largest molecular mass group of organic compounds analyzed so far following the Annellation Theory and ZINDO/S methodology. Future analysis using the same approach will provide evidence regarding the LMA of other high molecular mass PAHs.

Single or Multiple? Looking at Location in Movement Notation

ERIC Educational Resources Information Center

Munjee, Tara

2015-01-01

Contemporary discourse embraces notions of human movement in space as occurring in both set, singular locations and also through many locations and ever-changing fields. Mobile conceptions of location and spatiality particularly relate to patterns of everyday contemporary life and are embraced in some artistic and performance practices. Graphic…

Noise Source Location and Flow Field Measurements on Supersonic Jets and Implications Regarding Broadband Shock Noise

NASA Technical Reports Server (NTRS)

Podboy, Gary G.; Wernet, Mark P.; Clem, Michelle M.; Fagan, Amy F.

2017-01-01

An experiment was conducted in an effort to obtain data that would provide a better understanding of the origins of broadband shock noise (BBSN). Phased array noise source location and two types of flow field data (background oriented schlieren and particle image velocimetry) were acquired on unheated, single-stream jets. Results are presented for one subsonic and four supersonic operating conditions. These data show that BBSN is created primarily in the downstream portion of the shock train with peak BBSN production occurring near where the average size of the turbulent structures is equal to the shockcell spacing. These data tend to validate theories that BBSN is created by turbulent structures that are as large or larger than the shock spacing.

FIELD-DRIVEN APPROACHES TO SUBSURFACE CONTAMINANT TRANSPORT MODELING.

EPA Science Inventory

Observations from field sites provide a means for prioritizing research activities. In the case of petroleum releases, observations may include spiking of concentration distributions that may be related to water table fluctuation, co-location of contaminant plumes with geochemi...

Dependence of the location of the Martian magnetic lobes on the interplanetary magnetic field direction

NASA Astrophysics Data System (ADS)

Romanelli, Norberto; Mazelle, Christian; Bertucci, Cesar; Gomez, Daniel

2016-04-01

The magnetic field topology surrounding the Martian atmosphere is mainly the result of gradients in the velocity of the solar wind (SW). Such variations in the SW velocity are in turn the result of a massloading process and forces associated with electric currents flowing around the ionosphere of Mars [Nagy et al 2004, Mazelle et al 2004, Brain et al 2015]. In particular, in the regions where the collisionless regime holds, the interplanetary magnetic field (IMF) frozen into the SW piles up in front of the stagnation region of the flow. At the same time, the magnetic field lines are stretched in the direction of the unperturbed SW as this stream moves away from Mars, giving rise to a magnetotail [Alfvén, 1957]. As a result and in contrast with an obstacle with and intrinsic global magnetic field, the structure and organization of the magnetic field around Mars depends on the direction of the IMF and its variabilities [Yeroshenko et al., 1990; Crider et al., 2004; Bertucci et al., 2003; Romanelli et al 2015]. In this study we use magnetometer data from the Mars Global Surveyor (MGS) spacecraft during portions of the premapping orbits of the mission to study the variability of the Martian-induced magnetotail as a function of the orientation of the IMF. The time spent by MGS in the magnetotail lobes during periods with positive solar wind flow-aligned IMF component B∥IMF suggests that their location as well as the position of the central polarity reversal layer (PRL) are displaced in the direction antiparallel to the IMF cross-flow component B⊥IMF . Analogously, in the cases where B∥IMF is negative, the lobes are displaced in the direction of B⊥IMF. We find this behavior to be compatible with a previously published B⊥IMF analytical model of the IMF draping, where for the first time, the displacement of a complementary reversal layer (denoted as IPRL for inverse polarity reversal layer) is deduced from first principles [Romanelli et al 2014]. We also

Hance_WFSR flasher locations

EPA Pesticide Factsheets

This entry contains two files. The first file, Hance_WFSR Flasher locations.xlxs, contains information describing the location of installed landmark 'flashers' consisting of 2 square aluminum metal tags. Each tag was inscribed with a number to aid field personnel in the identification of landmark location within the West Fork Smith River watershed in southern coastal Oregon. These landmarks were used to calculate stream distances between points in the watershed, including distances between tagging locations and detection events for tagged fish. A second file, named Hance_fish_detection_data1.xlxs contains information on the detection of tagged fish within the West Fork Smith River stream network. The file includes both the location where the fish were tagged and where they were subsequently detected. Together with the information in the WFSR flasher location dataset, these data allow estimation of the minimum distances and directions moved by juvenile coho salmon during the fall transition period.A map locator is provided in Figure 1 in the accompanying manuscript: Dalton J. Hance, Lisa M. Ganio, Kelly M. Burnett & Joseph L. Ebersole (2016) Basin-Scale Variation in the Spatial Pattern of Fall Movement of Juvenile Coho Salmon in the West Fork Smith River, Oregon, Transactions of the American Fisheries Society, 145:5, 1018-1034, DOI: 10.1080/00028487.2016.1194892This dataset is associated with the following publication:Hance, D.J., L.M. Ganio, K.M. Burnett, an

Location-based prospective memory.

PubMed

O'Rear, Andrea E; Radvansky, Gabriel A

2018-02-01

This study explores location-based prospective memory. People often have to remember to do things when in a particular location, such as buying tissues the next time they are in the supermarket. For event cognition theory, location is important for structuring events. However, because event cognition has not been used to examine prospective memory, the question remains of how multiple events will influence prospective memory performance. In our experiments, people delivered messages from store to store in a virtual shopping mall as an ongoing task. The prospective tasks were to do certain activities in certain stores. For Experiment 1, each trial involved one prospective memory task to be done in a single location at one of three delays. The virtual environment and location cues were effective for prospective memory, and performance was unaffected by delay. For Experiment 2, each trial involved two prospective memory tasks, given in either one or two instruction locations, and to be done in either one or two store locations. There was improved performance when people received instructions from two locations and did both tasks in one location relative to other combinations. This demonstrates that location-based event structure influences how well people perform on prospective memory tasks.

Stimulus-response incompatibility activates cortex proximate to three eye fields

NASA Technical Reports Server (NTRS)

Merriam, E. P.; Colby, C. L.; Thulborn, K. R.; Luna, B.; Olson, C. R.; Sweeney, J. A.

2001-01-01

We used functional magnetic resonance imaging (fMRI) to investigate cortical activation during the performance of three oculomotor tasks that impose increasing levels of cognitive demand. (1) In a visually guided saccade (VGS) task, subjects made saccades to flashed targets. (2) In a compatible task, subjects made leftward and rightward saccades in response to foveal presentation of the uppercase words "LEFT" or "RIGHT." (3) In a mixed task, subjects made rightward saccades in response to the lowercase word "left" and leftward saccades in response to the lowercase word "right" on incompatible trials (60%). The remaining 40% of trials required compatible responses to uppercase words. The VGS and compatible tasks, when compared to fixation, activated the three cortical eye fields: the supplementary eye field (SEF), the frontal eye field (FEF), and the parietal eye field (PEF). The mixed task, when compared to the compatible task, activated three additional cortical regions proximate to the three eye fields: (1) rostral to the SEF in medial frontal cortex; (2) rostral to the FEF in dorsolateral prefrontal cortex (DLPFC); (3) rostral and lateral to the PEF in posterior parietal cortex. These areas may contribute to the suppression of prepotent responses and in holding novel visuomotor associations in working memory. Copyright 2001 Academic Press.

Holocene eolian activity in the Minot dune field, North Dakota

USGS Publications Warehouse

Muhs, D.R.; Stafford, Thomas W.; Been, J.; Mahan, S.A.; Burdett, J.; Skipp, G.; Rowland, Z.M.

1997-01-01

Stabilized eolian sand is common over much of the Great Plains region of the United States and Canada, including a subhumid area of ??? 1500 km2 near Minot, North Dakota. Eolian landforms consist of sand sheets and northwest-trending parabolic dunes. Dunes and sand sheets in the Minot field are presently stabilized by a cover of prairie grasses or oak woodland. Stratigraphic studies and accelerator mass spectrometry radiocarbon dating of paleosols indicate at least two periods of eolian sand movement in the late Holocene. Pedologic data suggest that all of the dune field has experienced late Holocene dune activity, though not all parts of the dune field may have been active simultaneously. Similar immobile element (Ti, Zr, La, Ce) concentrations support the interpretation that eolian sands are derived from local glaciofluvial and glaciolacustrine sediments. However, glaciolacustrine and glaciofluvial source sediments have high Ca concentrations from carbonate minerals, whereas dune sands are depleted in Ca. Because noneolian-derived soils in the area are calcareous, these data indicate that the Minot dune field may have had extended periods of activity in the Holocene, such that eolian abrasion removed soft carbonate minerals. The southwest-facing parts of some presently stabilized dunes were active during the 1930s drought, but were revegetated during the wetter years of the 1940s. These observations indicate that severe droughts accompanied by high temperatures are the most likely cause of Holocene eolian activity.

Distinct and overlapping fMRI activation networks for processing of novel identities and locations of objects.

PubMed

Pihlajamäki, Maija; Tanila, Heikki; Könönen, Mervi; Hänninen, Tuomo; Aronen, Hannu J; Soininen, Hilkka

2005-10-01

The ventral visual stream processes information about the identity of objects ('what'), whereas the dorsal stream processes the spatial locations of objects ('where'). There is a corresponding, although disputed, distinction for the ventrolateral and dorsolateral prefrontal areas. Furthermore, there seems to be a distinction between the anterior and posterior medial temporal lobe (MTL) structures in the processing of novel items and new spatial arrangements, respectively. Functional differentiation of the intermediary mid-line cortical and temporal neocortical structures that communicate with the occipitotemporal, occipitoparietal, prefrontal, and MTL structures, however, is unclear. Therefore, in the present functional magnetic resonance imaging (fMRI) study, we examined whether the distinction among the MTL structures extends to these closely connected cortical areas. The most striking difference in the fMRI responses during visual presentation of changes in either items or their locations was the bilateral activation of the temporal lobe and ventrolateral prefrontal cortical areas for novel object identification in contrast to wide parietal and dorsolateral prefrontal activation for the novel locations of objects. An anterior-posterior distinction of fMRI responses similar to the MTL was observed in the cingulate/retrosplenial, and superior and middle temporal cortices. In addition to the distinct areas of activation, certain frontal, parietal, and temporo-occipital areas responded to both object and spatial novelty, suggesting a common attentional network for both types of changes in the visual environment. These findings offer new insights to the functional roles and intrinsic specialization of the cingulate/retrosplenial, and lateral temporal cortical areas in visuospatial cognition.

Polarization: A Key Difference between Man-made and Natural Electromagnetic Fields, in regard to Biological Activity.

PubMed

Panagopoulos, Dimitris J; Johansson, Olle; Carlo, George L

2015-10-12

In the present study we analyze the role of polarization in the biological activity of Electromagnetic Fields (EMFs)/Electromagnetic Radiation (EMR). All types of man-made EMFs/EMR - in contrast to natural EMFs/EMR - are polarized. Polarized EMFs/EMR can have increased biological activity, due to: 1) Ability to produce constructive interference effects and amplify their intensities at many locations. 2) Ability to force all charged/polar molecules and especially free ions within and around all living cells to oscillate on parallel planes and in phase with the applied polarized field. Such ionic forced-oscillations exert additive electrostatic forces on the sensors of cell membrane electro-sensitive ion channels, resulting in their irregular gating and consequent disruption of the cell's electrochemical balance. These features render man-made EMFs/EMR more bioactive than natural non-ionizing EMFs/EMR. This explains the increasing number of biological effects discovered during the past few decades to be induced by man-made EMFs, in contrast to natural EMFs in the terrestrial environment which have always been present throughout evolution, although human exposure to the latter ones is normally of significantly higher intensities/energy and longer durations. Thus, polarization seems to be a trigger that significantly increases the probability for the initiation of biological/health effects.

Polarization: A Key Difference between Man-made and Natural Electromagnetic Fields, in regard to Biological Activity

PubMed Central

Panagopoulos, Dimitris J.; Johansson, Olle; Carlo, George L.

2015-01-01

In the present study we analyze the role of polarization in the biological activity of Electromagnetic Fields (EMFs)/Electromagnetic Radiation (EMR). All types of man-made EMFs/EMR - in contrast to natural EMFs/EMR - are polarized. Polarized EMFs/EMR can have increased biological activity, due to: 1) Ability to produce constructive interference effects and amplify their intensities at many locations. 2) Ability to force all charged/polar molecules and especially free ions within and around all living cells to oscillate on parallel planes and in phase with the applied polarized field. Such ionic forced-oscillations exert additive electrostatic forces on the sensors of cell membrane electro-sensitive ion channels, resulting in their irregular gating and consequent disruption of the cell’s electrochemical balance. These features render man-made EMFs/EMR more bioactive than natural non-ionizing EMFs/EMR. This explains the increasing number of biological effects discovered during the past few decades to be induced by man-made EMFs, in contrast to natural EMFs in the terrestrial environment which have always been present throughout evolution, although human exposure to the latter ones is normally of significantly higher intensities/energy and longer durations. Thus, polarization seems to be a trigger that significantly increases the probability for the initiation of biological/health effects. PMID:26456585

Polarization: A Key Difference between Man-made and Natural Electromagnetic Fields, in regard to Biological Activity

NASA Astrophysics Data System (ADS)

Panagopoulos, Dimitris J.; Johansson, Olle; Carlo, George L.

2015-10-01

In the present study we analyze the role of polarization in the biological activity of Electromagnetic Fields (EMFs)/Electromagnetic Radiation (EMR). All types of man-made EMFs/EMR - in contrast to natural EMFs/EMR - are polarized. Polarized EMFs/EMR can have increased biological activity, due to: 1) Ability to produce constructive interference effects and amplify their intensities at many locations. 2) Ability to force all charged/polar molecules and especially free ions within and around all living cells to oscillate on parallel planes and in phase with the applied polarized field. Such ionic forced-oscillations exert additive electrostatic forces on the sensors of cell membrane electro-sensitive ion channels, resulting in their irregular gating and consequent disruption of the cell’s electrochemical balance. These features render man-made EMFs/EMR more bioactive than natural non-ionizing EMFs/EMR. This explains the increasing number of biological effects discovered during the past few decades to be induced by man-made EMFs, in contrast to natural EMFs in the terrestrial environment which have always been present throughout evolution, although human exposure to the latter ones is normally of significantly higher intensities/energy and longer durations. Thus, polarization seems to be a trigger that significantly increases the probability for the initiation of biological/health effects.

The Mars Crustal Magnetic Field Control of Plasma Boundary Locations and Atmospheric Loss: MHD Prediction and Comparison with MAVEN

NASA Technical Reports Server (NTRS)

Fang, Xiaohua; Ma, Yingjuan; Masunaga, Kei; Dong, Chuanfei; Brain, David; Halekas, Jasper; Lillis, Robert; Jakosky, Bruce M.; Connerney, Jack; Grebowsky, Joseph;

How Much Energy Can Be Stored in Solar Active Region Magnetic Fields?

NASA Astrophysics Data System (ADS)

Linker, J.; Downs, C.; Torok, T.; Titov, V. S.; Lionello, R.; Mikic, Z.; Riley, P.

2015-12-01

Major solar eruptions such as X-class flares and very fast coronal mass ejections usually originate in active regions on the Sun. The energy that powers these events is believed to be stored as free magnetic energy (energy above the potential field state) prior to eruption. While coronal magnetic fields are not in general force-free, active regions have very strong magnetic fields and at low coronal heights the plasma beta is therefore very small, making the field (in equilibrium) essentially force-free. The Aly-Sturrock theorem shows that the energy of a fully force-free field cannot exceed the energy of the so-called open field. If the theorem holds, this places an upper limit on the amount of free energy that can be stored: the maximum free energy (MFE) is the difference between the open field energy and the potential field energy of the active region. In thermodynamic MHD simulations of a major eruption (the July 14, 2000 'Bastille' day event) and a modest event (February 13, 2009, we have found that the MFE indeed bounds the energy stored prior to eruption. We compute the MFE for major eruptive events in cycles 23 and 24 to investigate the maximum amount of energy that can be stored in solar active regions.Research supported by AFOSR, NASA, and NSF.

The role of experience in location estimation: Target distributions shift location memory biases.

PubMed

Lipinski, John; Simmering, Vanessa R; Johnson, Jeffrey S; Spencer, John P

2010-04-01

Research based on the Category Adjustment model concluded that the spatial distribution of target locations does not influence location estimation responses [Huttenlocher, J., Hedges, L., Corrigan, B., & Crawford, L. E. (2004). Spatial categories and the estimation of location. Cognition, 93, 75-97]. This conflicts with earlier results showing that location estimation is biased relative to the spatial distribution of targets [Spencer, J. P., & Hund, A. M. (2002). Prototypes and particulars: Geometric and experience-dependent spatial categories. Journal of Experimental Psychology: General, 131, 16-37]. Here, we resolve this controversy by using a task based on Huttenlocher et al. (Experiment 4) with minor modifications to enhance our ability to detect experience-dependent effects. Results after the first block of trials replicate the pattern reported in Huttenlocher et al. After additional experience, however, participants showed biases that significantly shifted according to the target distributions. These results are consistent with the Dynamic Field Theory, an alternative theory of spatial cognition that integrates long-term memory traces across trials relative to the perceived structure of the task space. Copyright 2009 Elsevier B.V. All rights reserved.

Active stabilization of error field penetration via control field and bifurcation of its stable frequency range

NASA Astrophysics Data System (ADS)

Inoue, S.; Shiraishi, J.; Takechi, M.; Matsunaga, G.; Isayama, A.; Hayashi, N.; Ide, S.

2017-11-01

An active stabilization effect of a rotating control field against an error field penetration is numerically studied. We have developed a resistive magnetohydrodynamic code ‘AEOLUS-IT’, which can simulate plasma responses to rotating/static external magnetic field. Adopting non-uniform flux coordinates system, the AEOLUS-IT simulation can employ high magnetic Reynolds number condition relevant to present tokamaks. By AEOLUS-IT, we successfully clarified the stabilization mechanism of the control field against the error field penetration. Physical processes of a plasma rotation drive via the control field are demonstrated by the nonlinear simulation, which reveals that the rotation amplitude at a resonant surface is not a monotonic function of the control field frequency, but has an extremum. Consequently, two ‘bifurcated’ frequency ranges of the control field are found for the stabilization of the error field penetration.

UV and visible light photocatalytic activity of Au/TiO2 nanoforests with Anatase/Rutile phase junctions and controlled Au locations.

PubMed

Yu, Yang; Wen, Wei; Qian, Xin-Yue; Liu, Jia-Bin; Wu, Jin-Ming

2017-01-24

To magnify anatase/rutile phase junction effects through appropriate Au decorations, a facile solution-based approach was developed to synthesize Au/TiO 2 nanoforests with controlled Au locations. The nanoforests cons®isted of anatase nanowires surrounded by radially grown rutile branches, on which Au nanoparticles were deposited with preferred locations controlled by simply altering the order of the fabrication step. The Au-decoration increased the photocatalytic activity under the illumination of either UV or visible light, because of the beneficial effects of either electron trapping or localized surface plasmon resonance (LSPR). Gold nanoparticles located preferably at the interface of anatase/rutile led to a further enhanced photocatalytic activity. The appropriate distributions of Au nanoparticles magnify the beneficial effects arising from the anatase/rutile phase junctions when illuminated by UV light. Under the visible light illumination, the LSPR effect followed by the consecutive electron transfer explains the enhanced photocatalysis. This study provides a facile route to control locations of gold nanoparticles in one-dimensional nanostructured arrays of multiple-phases semiconductors for achieving a further increased photocatalytic activity.

Determining the sensitivity of the amplitude source location (ASL) method through active seismic sources: An example from Te Maari Volcano, New Zealand

NASA Astrophysics Data System (ADS)

Walsh, Braden; Jolly, Arthur; Procter, Jonathan

2017-04-01

Using active seismic sources on Tongariro Volcano, New Zealand, the amplitude source location (ASL) method is calibrated and optimized through a series of sensitivity tests. By applying a geologic medium velocity of 1500 m/s and an attenuation value of Q=60 for surface waves along with amplification factors computed from regional earthquakes, the ASL produced location discrepancies larger than 1.0 km horizontally and up to 0.5 km in depth. Through the use of sensitivity tests on input parameters, we show that velocity and attenuation models have moderate to strong influences on the location results, but can be easily constrained. Changes in locations are accommodated through either lateral or depth movements. Station corrections (amplification factors) and station geometry strongly affect the ASL locations laterally, horizontally and in depth. Calibrating the amplification factors through the exploitation of the active seismic source events reduced location errors for the sources by up to 50%.

Sport Fields as Potential Catalysts for Physical Activity in the Neighbourhood

PubMed Central

Cutumisu, Nicoleta; Spence, John C.

2012-01-01

Physical activity is associated with access to recreational facilities such as sports fields. Because it is not clear whether objectively- or subjectively-assessed access to facilities exerts a stronger influence on physical activity, we investigated the association between the objective and perceived accessibility of sport fields and the levels of self-reported physical activity among adults in Edmonton, Canada. A sample of 2879 respondents was surveyed regarding their socio-demographics, health status, self-efficacy, levels of physical activity, as well as their perceptions of built environment in relation to physical activity. Neighbourhood-level data were obtained for each respondent based on their residence. Accessibility to facilities was assessed using the enhanced Two-Step Floating Catchment Area method. Geographic Information Systems were employed. A logistic regression was performed to predict physical activity using individual- and neighbourhood-level variables. Women, older individuals, and individuals with higher educational attainment were less likely to be physically active. Also, individuals with higher self-efficacy and higher objectively-assessed access to facilities were more likely to be physically active. Interventions that integrate provision of relevant programs for various population groups and of improved recreational facilities may contribute to sport fields becoming catalysts for physical activity by generating movement both on the site and in the neighbourhood. PMID:22470293

The Field: The Proper Location for Methods Courses.

ERIC Educational Resources Information Center

Cardarelli, Aldo F.

1981-01-01

The position taken here is that extensive field work with children which is built around a particular set of competencies which the university student is responsible to demonstrate will accomplish far more than the campus-centered, inferentially-based lecture approach. Such a program operating at an urban university is outlined. (Author/SJL)

Predictability of dune activity in real dune fields under unidirectional wind regimes

NASA Astrophysics Data System (ADS)

Barchyn, Thomas E.; Hugenholtz, Chris H.

2015-02-01

We present an analysis of 10 dune fields to test a model-derived hypothesis of dune field activity. The hypothesis suggests that a quantifiable threshold exists for stabilization in unidirectional wind regimes: active dunes have slipface deposition rates that exceed the vegetation deposition tolerance, and stabilizing dunes have the opposite. We quantified aeolian sand flux, slipface geometry, and vegetation deposition tolerance to directly test the hypothesis at four dune fields (Bigstick, White Sands Stable, White Sands Active, and Cape Cod). We indirectly tested the hypothesis at six additional dune fields with limited vegetation data (Hanford, Año Nuevo, Skagen Odde, Salton Sea, Oceano Stable, and Oceano Active, "inverse calculation sites"). We used digital topographic data and estimates of aeolian sand flux to approximate the slipface deposition rates prior to stabilization. Results revealed a distinct, quantifiable, and consistent pattern despite diverse environmental conditions: the modal peak of prestabilization slipface deposition rates was 80% of the vegetation deposition tolerance at stabilized or stabilizing dune fields. Results from inverse calculation sites indicate deposition rates at stabilized sites were near a hypothesized maximum vegetation deposition tolerance (1 m a-1), and active sites had slipface deposition rates much higher. Overall, these results confirm the hypothesis and provide evidence of a globally applicable, simple, and previously unidentified predictor for the dynamics of vegetation cover in dune fields under unidirectional wind regimes.

Persistent spatial information in the frontal eye field during object-based short-term memory.

PubMed

Clark, Kelsey L; Noudoost, Behrad; Moore, Tirin

2012-08-08

Spatial attention is known to gate entry into visual short-term memory, and some evidence suggests that spatial signals may also play a role in binding features or protecting object representations during memory maintenance. To examine the persistence of spatial signals during object short-term memory, the activity of neurons in the frontal eye field (FEF) of macaque monkeys was recorded during an object-based delayed match-to-sample task. In this task, monkeys were trained to remember an object image over a brief delay, regardless of the locations of the sample or target presentation. FEF neurons exhibited visual, delay, and target period activity, including selectivity for sample location and target location. Delay period activity represented the sample location throughout the delay, despite the irrelevance of spatial information for successful task completion. Furthermore, neurons continued to encode sample position in a variant of the task in which the matching stimulus never appeared in their response field, confirming that FEF maintains sample location independent of subsequent behavioral relevance. FEF neurons also exhibited target-position-dependent anticipatory activity immediately before target onset, suggesting that monkeys predicted target position within blocks. These results show that FEF neurons maintain spatial information during short-term memory, even when that information is irrelevant for task performance.

Dynamics of a magnetic active Brownian particle under a uniform magnetic field.

PubMed

Vidal-Urquiza, Glenn C; Córdova-Figueroa, Ubaldo M

2017-11-01

The dynamics of a magnetic active Brownian particle undergoing three-dimensional Brownian motion, both translation and rotation, under the influence of a uniform magnetic field is investigated. The particle self-propels at a constant speed along its magnetic dipole moment, which reorients due to the interplay between Brownian and magnetic torques, quantified by the Langevin parameter α. In this work, the time-dependent active diffusivity and the crossover time (τ^{cross})-from ballistic to diffusive regimes-are calculated through the time-dependent correlation function of the fluctuations of the propulsion direction. The results reveal that, for any value of α, the particle undergoes a directional (or ballistic) propulsive motion at very short times (t≪τ^{cross}). In this regime, the correlation function decreases linearly with time, and the active diffusivity increases with it. It the opposite time limit (t≫τ^{cross}), the particle moves in a purely diffusive regime with a correlation function that decays asymptotically to zero and an active diffusivity that reaches a constant value equal to the long-time active diffusivity of the particle. As expected in the absence of a magnetic field (α=0), the crossover time is equal to the characteristic time scale for rotational diffusion, τ_{rot}. In the presence of a magnetic field (α>0), the correlation function, the active diffusivity, and the crossover time decrease with increasing α. The magnetic field regulates the regimes of propulsion of the particle. Here, the field reduces the period of time at which the active particle undergoes a directional motion. Consequently, the active particle rapidly reaches a diffusive regime at τ^{cross}≪τ_{rot}. In the limit of weak fields (α≪1), the crossover time decreases quadratically with α, while in the limit of strong fields (α≫1) it decays asymptotically as α^{-1}. The results are in excellent agreement with those obtained by Brownian dynamics

Dynamics of a magnetic active Brownian particle under a uniform magnetic field

NASA Astrophysics Data System (ADS)

Vidal-Urquiza, Glenn C.; Córdova-Figueroa, Ubaldo M.

2017-11-01

The dynamics of a magnetic active Brownian particle undergoing three-dimensional Brownian motion, both translation and rotation, under the influence of a uniform magnetic field is investigated. The particle self-propels at a constant speed along its magnetic dipole moment, which reorients due to the interplay between Brownian and magnetic torques, quantified by the Langevin parameter α . In this work, the time-dependent active diffusivity and the crossover time (τcross)—from ballistic to diffusive regimes—are calculated through the time-dependent correlation function of the fluctuations of the propulsion direction. The results reveal that, for any value of α , the particle undergoes a directional (or ballistic) propulsive motion at very short times (t ≪τcross ). In this regime, the correlation function decreases linearly with time, and the active diffusivity increases with it. It the opposite time limit (t ≫τcross ), the particle moves in a purely diffusive regime with a correlation function that decays asymptotically to zero and an active diffusivity that reaches a constant value equal to the long-time active diffusivity of the particle. As expected in the absence of a magnetic field (α =0 ), the crossover time is equal to the characteristic time scale for rotational diffusion, τrot. In the presence of a magnetic field (α >0 ), the correlation function, the active diffusivity, and the crossover time decrease with increasing α . The magnetic field regulates the regimes of propulsion of the particle. Here, the field reduces the period of time at which the active particle undergoes a directional motion. Consequently, the active particle rapidly reaches a diffusive regime at τcross≪τrot . In the limit of weak fields (α ≪1 ), the crossover time decreases quadratically with α , while in the limit of strong fields (α ≫1 ) it decays asymptotically as α-1. The results are in excellent agreement with those obtained by Brownian dynamics

MiDAS: the field guide to the microbes of activated sludge.

PubMed

McIlroy, Simon Jon; Saunders, Aaron Marc; Albertsen, Mads; Nierychlo, Marta; McIlroy, Bianca; Hansen, Aviaja Anna; Karst, Søren Michael; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

2015-01-01

The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxonomy is a manual curation of the SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale 16 S rRNA gene amplicon sequencing of full-scale activated sludge communities. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to the available information about their morphology, diversity, physiology and distribution. The use of a common taxonomy across the field will provide a solid foundation for the study of microbial ecology of the activated sludge process and related treatment processes. The online MiDAS field guide is a collaborative workspace intended to facilitate a better understanding of the ecology of activated sludge and related treatment processes--knowledge that will be an invaluable resource for the optimal design and operation of these systems. © The Author(s) 2015. Published by Oxford University Press.

MiDAS: the field guide to the microbes of activated sludge

PubMed Central

McIlroy, Simon Jon; Saunders, Aaron Marc; Albertsen, Mads; Nierychlo, Marta; McIlroy, Bianca; Hansen, Aviaja Anna; Karst, Søren Michael; Nielsen, Jeppe Lund; Nielsen, Per Halkjær

2015-01-01

The Microbial Database for Activated Sludge (MiDAS) field guide is a freely available online resource linking the identity of abundant and process critical microorganisms in activated sludge wastewater treatment systems to available data related to their functional importance. Phenotypic properties of some of these genera are described, but most are known only from sequence data. The MiDAS taxonomy is a manual curation of the SILVA taxonomy that proposes a name for all genus-level taxa observed to be abundant by large-scale 16 S rRNA gene amplicon sequencing of full-scale activated sludge communities. The taxonomy can be used to classify unknown sequences, and the online MiDAS field guide links the identity to the available information about their morphology, diversity, physiology and distribution. The use of a common taxonomy across the field will provide a solid foundation for the study of microbial ecology of the activated sludge process and related treatment processes. The online MiDAS field guide is a collaborative workspace intended to facilitate a better understanding of the ecology of activated sludge and related treatment processes—knowledge that will be an invaluable resource for the optimal design and operation of these systems. Database URL: http://www.midasfieldguide.org PMID:26120139

40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

Code of Federal Regulations, 2011 CFR

2011-07-01

... assumed to be in compliance with this requirement. (e) These alternative locations are remediation waste... 40 Protection of Environment 27 2011-07-01 2011-07-01 false May I perform remediation waste management activities under a RAP at a location removed from the area where the remediation wastes originated...

40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

Code of Federal Regulations, 2014 CFR

2014-07-01

... assumed to be in compliance with this requirement. (e) These alternative locations are remediation waste... 40 Protection of Environment 27 2014-07-01 2014-07-01 false May I perform remediation waste management activities under a RAP at a location removed from the area where the remediation wastes originated...

A Guided Inquiry Activity for Teaching Ligand Field Theory

ERIC Educational Resources Information Center

Johnson, Brian J.; Graham, Kate J.

2015-01-01

This paper will describe a guided inquiry activity for teaching ligand field theory. Previous research suggests the guided inquiry approach is highly effective for student learning. This activity familiarizes students with the key concepts of molecular orbital theory applied to coordination complexes. Students will learn to identify factors that…

Profiling of phenolic compounds and their antioxidant and anticancer activities in pandan (Pandanus amaryllifolius Roxb.) extracts from different locations of Malaysia

PubMed Central

2013-01-01

Background Phytochemicals and antioxidants from plant sources are of increasing interest to consumers because of their roles in the maintenance of human health. Most of the secondary metabolites of herbs are used in a number of pharmaceutical products. Methods Secondary metabolites composition and content of five flavonoids and three phenolic acids were evaluated and determined in Pandanus amaryllifolius extracts from three different locations of Malaysia by RP-HPLC; Total phenolic and total flavonoid content were determined using Folin-Ciocalteau and aluminum chloride colorimetric assay; The antioxidant activity of the extracts was determined by the ferric reducing antioxidant potential (FRAP) assay and 1,1-diphenyl-2-picrylhydrazyl (DPPH) assays. MTT (3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) Assay was employed to screen anticancer activity of extracts against MCF-7 cancer cell line. Results Highest value of total flavonoids (TF) and total phenolics (TP) was observed in pandan extract from Bachok locattion (1.87 mg/g DW and 6.72 mg/g DW) followed by Klang (1.32 mg/g DW; 5.07 mg/g DW) and Pontian (1.12 mg/g DW; 4.88 mg/g DW). Rutin just detected from Bachok location with value of 0.082 mg/g DW. High content of epicatechin (0.035 mg/g DW) and naringin (0.325 mg/g DW) were observed from Bachok location while, highest content of catechin (0.613 mg/g DW) and kaempferol (0.278 mg/g DW) was observed in pandan extract from Klang location. The extract of pandan from Bachok exhibited highest value of gallic acid (0.423 mg/g DW) and cinnamic acid (0.084 mg/g DW). Ferrulic acid just detected from pandan extract of Bachok location with concentration of 0.281mg/g DW. Between studied locations Bachok exhibited highest value of DPPH (64.27%) and FRAP (517.2 μm of Fe (II)/g) activity followed by Klang (52.16%; 448.6 μm of Fe (II)/g) and Pontian (50.10%; 314.8 μm of Fe (II)/g). The preliminary screening showed pandan extracts from 3 locations possessed

Detecting Human Activity Using Acoustic, Seismic, Accelerometer, Video, and E-field Sensors

DTIC Science & Technology

2011-09-01

Detecting Human Activity using Acoustic, Seismic, Accelerometer, Video, and E-field Sensors by Sarah H. Walker and Geoffrey H. Goldman...Adelphi, MD 20783-1197 ARL-TR-5729 September 2011 Detecting Human Activity using Acoustic, Seismic, Accelerometer, Video, and E-field Sensors...DD-MM-YYYY) September 2011 2. REPORT TYPE 3. DATES COVERED (From - To) 4. TITLE AND SUBTITLE Detecting Human Activity using Acoustic

AFRICOM: Does Location Matter?

DTIC Science & Technology

2009-03-01

Locating AFRICOM in Africa would be the first such posting of a unified combatant command ( UCC ) overseas during peacetime, where the nation is not...actively (i.e., kinetically) fighting or defending U.S. interests in its intended Area of Responsibility (AOR). Only two UCCs have resided on foreign soil...governments, the location or relocation of previous UCCs met with similar support and criticisms.18 More importantly, while logic of the preference

Damage Detection/Locating System Providing Thermal Protection

NASA Technical Reports Server (NTRS)

Woodard, Stanley E. (Inventor); Jones, Thomas W. (Inventor); Taylor, Bryant D. (Inventor); Qamar, A. Shams (Inventor)

2010-01-01

A damage locating system also provides thermal protection. An array of sensors substantially tiles an area of interest. Each sensor is a reflective-surface conductor having operatively coupled inductance and capacitance. A magnetic field response recorder is provided to interrogate each sensor before and after a damage condition. Changes in response are indicative of damage and a corresponding location thereof.

Magnetic field configuration associated with solar gamma ray flares in June, 1991

NASA Technical Reports Server (NTRS)

Hagyard, M. J.; West, E. A.; Smith, J. E.; Trussart, F.-M.; Kenney, E. G.

1992-01-01

The vector magnetic field configuration of the solar active region AR 6659 that produced very high levels of flare activity in Jun. 1991 is described. The morphology and evolution of the photospheric fields are described for the period 7-10 Jun., and the flares taking place around these dates and their locations relative to the photospheric fields are indicated. By comparing the observed vector field with the potential field calculated from the observed line-of-sight flux, we identify the nonpotential characteristics of the fields along the magnetic neutral lines where the flares were observed. These results are compared with those from the earlier study of gamma-ray flares.

Cortical Activation Patterns during Long-Term Memory Retrieval of Visually or Haptically Encoded Objects and Locations

ERIC Educational Resources Information Center

Stock, Oliver; Roder, Brigitte; Burke, Michael; Bien, Siegfried; Rosler, Frank

2009-01-01

The present study used functional magnetic resonance imaging to delineate cortical networks that are activated when objects or spatial locations encoded either visually (visual encoding group, n = 10) or haptically (haptic encoding group, n = 10) had to be retrieved from long-term memory. Participants learned associations between auditorily…

A Theory and Experiments for Detecting Shock Locations

NASA Technical Reports Server (NTRS)

Hariharan, S. I.; Johnson, D. K.; Adamovsky, G.

1994-01-01

In this paper we present a simplified one-dimensional theory for predicting locations of normal shocks in a converging diverging nozzle. The theory assumes that the flow is quasi one-dimensional and the flow is accelerated in the throat area. Optical aspects of the model consider propagation of electromagnetic fields transverse to the shock front. The theory consists of an inverse problem in which from the measured intensity it reconstructs an index of refraction profile for the shock. From this profile and the Dale-Gladstone relation, the density in the flow field is determined, thus determining the shock location. Experiments show agreement with the theory. In particular the location is determined within 10 percent of accuracy. Both the theoretical as well as the experimental results are presented to validate the procedures in this work.

Albertian errors in head-mounted displays: I. Choice of eye-point location for a near- or far-field task visualization.

PubMed

Rolland, Jannick; Ha, Yonggang; Fidopiastis, Cali

2004-06-01

A theoretical investigation of rendered depth and angular errors, or Albertian errors, linked to natural eye movements in binocular head-mounted displays (HMDs) is presented for three possible eye-point locations: the center of the entrance pupil, the nodal point, and the center of rotation of the eye. A numerical quantification was conducted for both the pupil and the center of rotation of the eye under the assumption that the user will operate solely in either the near field under an associated instrumentation setting or the far field under a different setting. Under these conditions, the eyes are taken to gaze in the plane of the stereoscopic images. Across conditions, results show that the center of the entrance pupil minimizes rendered angular errors, while the center of rotation minimizes rendered position errors. Significantly, this investigation quantifies that under proper setting of the HMD and correct choice of the eye points, rendered depth and angular errors can be brought to be either negligible or within specification of even the most stringent applications in performance of tasks in either the near field or the far field.

The Strongest Magnetic Field in Sunspots

NASA Astrophysics Data System (ADS)

Okamoto, J.; Sakurai, T.

2017-12-01

Sunspots are concentrations of magnetic fields on the solar surface. Generally, the strongest magnetic field in each sunspot is located in the dark umbra in most cases. A typical field strength in sunspots is around 3,000 G. On the other hand, some exceptions also have been found in complex sunspots with bright regions such as light bridges that separate opposite polarity umbrae, for instance with a strength of 4,300 G. However, the formation mechanism of such strong fields outside umbrae is still puzzling. Here we report an extremely strong magnetic field in a sunspot, which was located in a bright region sandwiched by two opposite-polarity umbrae. The strength is 6,250 G, which is the largest ever observed since the discovery of magnetic field on the Sun in 1908 by Hale. We obtained 31 scanned maps of the active region observed by Hinode/SOT/SP with a cadence of 3 hours over 5 days (February 1-6, 2014). Considering the spatial and temporal evolution of the vector magnetic field and the Doppler velocity in the bright region, we suggested that this strong field region was generated as a result of compression of one umbra pushed by the outward flow from the other umbra (Evershed flow), like the subduction of the Earth's crust in plate tectonics.

40 CFR 270.230 - May I perform remediation waste management activities under a RAP at a location removed from the...

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 26 2010-07-01 2010-07-01 false May I perform remediation waste management activities under a RAP at a location removed from the area where the remediation wastes originated... Plans (RAPs) Obtaining A Rap for An Off-Site Location § 270.230 May I perform remediation waste...

Automatic vehicle location system

NASA Technical Reports Server (NTRS)

Hansen, G. R., Jr. (Inventor)

1973-01-01

An automatic vehicle detection system is disclosed, in which each vehicle whose location is to be detected carries active means which interact with passive elements at each location to be identified. The passive elements comprise a plurality of passive loops arranged in a sequence along the travel direction. Each of the loops is tuned to a chosen frequency so that the sequence of the frequencies defines the location code. As the vehicle traverses the sequence of the loops as it passes over each loop, signals only at the frequency of the loop being passed over are coupled from a vehicle transmitter to a vehicle receiver. The frequencies of the received signals in the receiver produce outputs which together represent a code of the traversed location. The code location is defined by a painted pattern which reflects light to a vehicle carried detector whose output is used to derive the code defined by the pattern.

Can Neural Activity Propagate by Endogenous Electrical Field?

PubMed Central

Qiu, Chen; Shivacharan, Rajat S.; Zhang, Mingming

2015-01-01

It is widely accepted that synaptic transmissions and gap junctions are the major governing mechanisms for signal traveling in the neural system. Yet, a group of neural waves, either physiological or pathological, share the same speed of ∼0.1 m/s without synaptic transmission or gap junctions, and this speed is not consistent with axonal conduction or ionic diffusion. The only explanation left is an electrical field effect. We tested the hypothesis that endogenous electric fields are sufficient to explain the propagation with in silico and in vitro experiments. Simulation results show that field effects alone can indeed mediate propagation across layers of neurons with speeds of 0.12 ± 0.09 m/s with pathological kinetics, and 0.11 ± 0.03 m/s with physiologic kinetics, both generating weak field amplitudes of ∼2–6 mV/mm. Further, the model predicted that propagation speed values are inversely proportional to the cell-to-cell distances, but do not significantly change with extracellular resistivity, membrane capacitance, or membrane resistance. In vitro recordings in mice hippocampi produced similar speeds (0.10 ± 0.03 m/s) and field amplitudes (2.5–5 mV/mm), and by applying a blocking field, the propagation speed was greatly reduced. Finally, osmolarity experiments confirmed the model's prediction that cell-to-cell distance inversely affects propagation speed. Together, these results show that despite their weak amplitude, electric fields can be solely responsible for spike propagation at ∼0.1 m/s. This phenomenon could be important to explain the slow propagation of epileptic activity and other normal propagations at similar speeds. SIGNIFICANCE STATEMENT Neural activity (waves or spikes) can propagate using well documented mechanisms such as synaptic transmission, gap junctions, or diffusion. However, the purpose of this paper is to provide an explanation for experimental data showing that neural signals can propagate by means other than synaptic

Tocopherol activity correlates with its location in a membrane: A new perspective on the anti-oxidant Vitamin E

NASA Astrophysics Data System (ADS)

Marquardt, Drew; Williams, Justin; Kucerka, Norbert; Atkinson, Jeffrey; Katsaras, John; Wassall, Stephen; Harroun, Thad

2013-03-01

There are no proven health benefits to supplementing with Vitamin E, so why do we require it for healthy living? The whole notion that vitamin E is an in-vivo antioxidant is now being seriously questioned. Using neutron diffraction and supporting techniques, we have correlated vitamin E's location in model membranes with its antioxidant activity. experiments were conducted using phosphatidylcholine (PC) bilayers whose fatty acid chains varied in their degree of unsaturation. We observe vitamin E up-right in all lipids examined, with its overall height in the bilayer lipid dependant. Interestingly we observe vitamin E's hydroxyl in the headgroup region of the bilayer for both the fully saturated and poly unsaturated lipids. Vitamin E was most effective at intercepting water borne oxidants than radical initiated within the bilayer core. However for lipids where vitamin E resides slightly lower (glycerol backbone) we observe comparable antioxidant activity against both water borne and hydrocarbon borne oxidants. Thus showing lipid species can modulate the location of vitamin E's activity.

Electric Field Activated Shape Memory Polymer Composite

NASA Technical Reports Server (NTRS)

Kang, Jin Ho (Inventor); Turner, Travis L. (Inventor); Siochi, Emilie J. (Inventor); Penner, Ronald K. (Inventor)

2017-01-01

Provided is an electrically activated shape memory polymer composite capable of thermal shape reformation using electric power to heat the composite through its matrix glass transition temperature. The composite includes an adaptable polymer matrix component using a diglycidyl ether resin, at least one substantially well-dispersed conductive or magnetic nano-filler component, and at least one elastic, laminated layer. Also provided are methods of preparing the composite and methods of activating the composite. A shape reformation of the composite is triggered by applying an electric field at DC and/or at a frequency above about 1.mu.Hz for a sufficient time.

The Electric Field of a Weakly Electric Fish

NASA Astrophysics Data System (ADS)

Rasnow, Brian K.

Freshwater fish of the genus Apteronotus (family Gymnotidae) generate a weak, high frequency electric field (<100 mV/cm, 0.5-10 kHz) which permeates their local environment. These nocturnal fish are acutely sensitive to perturbations in their electric field caused by other electric fish, and nearby objects whose impedance is different from the surrounding water. This thesis presents high temporal and spatial resolution maps of the electric potential and field on and near Apteronotus. The fish's electric field is a complicated and highly stable function of space and time. Its characteristics, such as spectral composition, timing, and rate of attenuation, are examined in terms of physical constraints, and their possible functional roles in electroreception. Temporal jitter of the periodic field is less than 1 musec. However, electrocyte activity is not globally synchronous along the fish's electric organ. The propagation of electrocyte activation down the fish's body produces a rotation of the electric field vector in the caudal part of the fish. This may assist the fish in identifying nonsymmetrical objects, and could also confuse electrosensory predators that try to locate Apteronotus by following its fieldlines. The propagation also results in a complex spatiotemporal pattern of the EOD potential near the fish. Visualizing the potential on the same and different fish over timescales of several months suggests that it is stable and could serve as a unique signature for individual fish. Measurements of the electric field were used to calculate the effects of simple objects on the fish's electric field. The shape of the perturbation or "electric image" on the fish's skin is relatively independent of a simple object's size, conductivity, and rostrocaudal location, and therefore could unambiguously determine object distance. The range of electrolocation may depend on both the size of objects and their rostrocaudal location. Only objects with very large dielectric

Wave field synthesis, adaptive wave field synthesis and ambisonics using decentralized transformed control: Potential applications to sound field reproduction and active noise control

NASA Astrophysics Data System (ADS)

Gauthier, Philippe-Aubert; Berry, Alain; Woszczyk, Wieslaw

2005-09-01

Sound field reproduction finds applications in listening to prerecorded music or in synthesizing virtual acoustics. The objective is to recreate a sound field in a listening environment. Wave field synthesis (WFS) is a known open-loop technology which assumes that the reproduction environment is anechoic. Classical WFS, therefore, does not perform well in a real reproduction space such as room. Previous work has suggested that it is physically possible to reproduce a progressive wave field in-room situation using active control approaches. In this paper, a formulation of adaptive wave field synthesis (AWFS) introduces practical possibilities for an adaptive sound field reproduction combining WFS and active control (with WFS departure penalization) with a limited number of error sensors. AWFS includes WFS and closed-loop ``Ambisonics'' as limiting cases. This leads to the modification of the multichannel filtered-reference least-mean-square (FXLMS) and the filtered-error LMS (FELMS) adaptive algorithms for AWFS. Decentralization of AWFS for sound field reproduction is introduced on the basis of sources' and sensors' radiation modes. Such decoupling may lead to decentralized control of source strength distributions and may reduce computational burden of the FXLMS and the FELMS algorithms used for AWFS. [Work funded by NSERC, NATEQ, Université de Sherbrooke and VRQ.] Ultrasound/Bioresponse to

Local vs. volume conductance activity of field potentials in the human subthalamic nucleus

PubMed Central

Marmor, Odeya; Valsky, Dan; Joshua, Mati; Bick, Atira S; Arkadir, David; Tamir, Idit; Bergman, Hagai; Israel, Zvi

2017-01-01

Subthalamic nucleus field potentials have attracted growing research and clinical interest over the last few decades. However, it is unclear whether subthalamic field potentials represent locally generated neuronal subthreshold activity or volume conductance of the organized neuronal activity generated in the cortex. This study aimed at understanding of the physiological origin of subthalamic field potentials and determining the most accurate method for recording them. We compared different methods of recordings in the human subthalamic nucleus: spikes (300–9,000 Hz) and field potentials (3–100 Hz) recorded by monopolar micro- and macroelectrodes, as well as by differential-bipolar macroelectrodes. The recordings were done outside and inside the subthalamic nucleus during electrophysiological navigation for deep brain stimulation procedures (150 electrode trajectories) in 41 Parkinson’s disease patients. We modeled the signal and estimated the contribution of nearby/independent vs. remote/common activity in each recording configuration and area. Monopolar micro- and macroelectrode recordings detect field potentials that are considerably affected by common (probably cortical) activity. However, bipolar macroelectrode recordings inside the subthalamic nucleus can detect locally generated potentials. These results are confirmed by high correspondence between the model predictions and actual correlation of neuronal activity recorded by electrode pairs. Differential bipolar macroelectrode subthalamic field potentials can overcome volume conductance effects and reflect locally generated neuronal activity. Bipolar macroelectrode local field potential recordings might be used as a biological marker of normal and pathological brain functions for future electrophysiological studies and navigation systems as well as for closed-loop deep brain stimulation paradigms. NEW & NOTEWORTHY Our results integrate a new method for human subthalamic recordings with a development of

Short-Term Memory Maintenance of Object Locations during Active Navigation: Which Working Memory Subsystem Is Essential?

PubMed Central

Baumann, Oliver; Skilleter, Ashley J.; Mattingley, Jason B.

2011-01-01

The goal of the present study was to examine the extent to which working memory supports the maintenance of object locations during active spatial navigation. Participants were required to navigate a virtual environment and to encode the location of a target object. In the subsequent maintenance period they performed one of three secondary tasks that were designed to selectively load visual, verbal or spatial working memory subsystems. Thereafter participants re-entered the environment and navigated back to the remembered location of the target. We found that while navigation performance in participants with high navigational ability was impaired only by the spatial secondary task, navigation performance in participants with poor navigational ability was impaired equally by spatial and verbal secondary tasks. The visual secondary task had no effect on navigation performance. Our results extend current knowledge by showing that the differential engagement of working memory subsystems is determined by navigational ability. PMID:21629686

Locating dayside magnetopause reconnection with exhaust ion distributions

NASA Astrophysics Data System (ADS)

Broll, J. M.; Fuselier, S. A.; Trattner, K. J.

2017-05-01

Magnetic reconnection at Earth's dayside magnetopause is essential to magnetospheric dynamics. Determining where reconnection takes place is important to understanding the processes involved, and many questions about reconnection location remain unanswered. We present a method for locating the magnetic reconnection X line at Earth's dayside magnetopause under southward interplanetary magnetic field conditions using only ion velocity distribution measurements. Particle-in-cell simulations based on Cluster magnetopause crossings produce ion velocity distributions that we propagate through a model magnetosphere, allowing us to calculate the field-aligned distance between an exhaust observation and its associated reconnection line. We demonstrate this procedure for two events and compare our results with those of the Maximum Magnetic Shear Model; we find good agreement with its results and show that when our method is applicable, it produces more precise locations than the Maximum Shear Model.

A standing location detector enabling people with developmental disabilities to control environmental stimulation through simple physical activities with Nintendo Wii Balance Boards.

PubMed

Shih, Ching-Hsiang

2011-01-01

This study evaluated whether two people with developmental disabilities would be able to actively perform simple physical activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards with a newly developed standing location detection program (SLDP, i.e., a new software program turning a Nintendo Wii Balance Board into a standing location detector). This study was carried out using to an ABAB design. The data showed that both participants significantly increased their simple physical activity (target response) to activate the control system to produce environmental stimulation during the B (intervention) phases. The practical and developmental implications of the findings are discussed. Copyright © 2010 Elsevier Ltd. All rights reserved.

Temporal Variations of Magnetic Field Associated with Seismic Activity at Cerro Machin Volcano, Colombia

NASA Astrophysics Data System (ADS)

Londono, J. M.; Serna, J. P.; Guzman, J.

2011-12-01

A study of magnetic variations was carried out at Cerro Machin Volcano, Colombia for the period 2009 -2010, with two permanent magnetometers located at South and North of the central dome, separated about 2.5 km each other. After corrections, we found that there is no clear correlation between volcanic seismicity and temporal changes of magnetic field for each magnetometer station, if they are analyzed individually. On the contrary, when we calculated the residual Magnetic field (RMF), for each magnetometer, and then we made the subtraction between them, and plot it vs time, we found a clear correlation of changes in local magnetic field with the occurrence of volcanic seismicity (ML >1.6). We found a change in the RMF between 1584 nT and 1608 nT, each time that a volcano-tectonic earthquake occurred. The máximum lapse time between the previous change in RMF and the further occurrence of the earthquake is 24 days, with an average of 11 days. This pattern occurred more than 9 times during the studied period. Based on the results, we believed that the simple methodology proposed here, is a good tool for monitoring changes in seismicity associated with activity at Cerro Machín volcano. We suggest that the temporal changes of RMF at Cerro Machín Volcano, are associated with piezo-magnetic effects, due to changes in strain-stress inside the volcano, produced by the interaction between local faulting and magma movement.

Manipulation of Pre-Target Activity on the Right Frontal Eye Field Enhances Conscious Visual Perception in Humans

PubMed Central

Chanes, Lorena; Chica, Ana B.; Quentin, Romain; Valero-Cabré, Antoni

2012-01-01

The right Frontal Eye Field (FEF) is a region of the human brain, which has been consistently involved in visuo-spatial attention and access to consciousness. Nonetheless, the extent of this cortical site’s ability to influence specific aspects of visual performance remains debated. We hereby manipulated pre-target activity on the right FEF and explored its influence on the detection and categorization of low-contrast near-threshold visual stimuli. Our data show that pre-target frontal neurostimulation has the potential when used alone to induce enhancements of conscious visual detection. More interestingly, when FEF stimulation was combined with visuo-spatial cues, improvements remained present only for trials in which the cue correctly predicted the location of the subsequent target. Our data provide evidence for the causal role of the right FEF pre-target activity in the modulation of human conscious vision and reveal the dependence of such neurostimulatory effects on the state of activity set up by cue validity in the dorsal attentional orienting network. PMID:22615759

Locatable-body temperature monitoring based on semi-active UHF RFID tags.

PubMed

Liu, Guangwei; Mao, Luhong; Chen, Liying; Xie, Sheng

2014-03-26

This paper presents the use of radio-frequency identification (RFID) technology for the real-time remote monitoring of body temperature, while an associated program can determine the location of the body carrying the respective sensor. The RFID chip's internal integrated temperature sensor is used for both the human-body temperature detection and as a measurement device, while using radio-frequency communication to broadcast the temperature information. The adopted RFID location technology makes use of reference tags together with a nearest neighbor localization algorithm and a multiple-antenna time-division multiplexing location system. A graphical user interface (GUI) was developed for collecting temperature and location data for the data fusion by using RFID protocols. With a puppy as test object, temperature detection and localization experiments were carried out. The measured results show that the applied method, when using a mercury thermometer for comparison in terms of measuring the temperature of the dog, has a good consistency, with an average temperature error of 0.283 °C. When using the associated program over the area of 12.25 m2, the average location error is of 0.461 m, which verifies the feasibility of the sensor-carrier location by using the proposed program.

Locatable-Body Temperature Monitoring Based on Semi-Active UHF RFID Tags

PubMed Central

Liu, Guangwei; Mao, Luhong; Chen, Liying; Xie, Sheng

2014-01-01

This paper presents the use of radio-frequency identification (RFID) technology for the real-time remote monitoring of body temperature, while an associated program can determine the location of the body carrying the respective sensor. The RFID chip's internal integrated temperature sensor is used for both the human-body temperature detection and as a measurement device, while using radio-frequency communication to broadcast the temperature information. The adopted RFID location technology makes use of reference tags together with a nearest neighbor localization algorithm and a multiple-antenna time-division multiplexing location system. A graphical user interface (GUI) was developed for collecting temperature and location data for the data fusion by using RFID protocols. With a puppy as test object, temperature detection and localization experiments were carried out. The measured results show that the applied method, when using a mercury thermometer for comparison in terms of measuring the temperature of the dog, has a good consistency, with an average temperature error of 0.283 °C. When using the associated program over the area of 12.25 m2, the average location error is of 0.461 m, which verifies the feasibility of the sensor-carrier location by using the proposed program. PMID:24675759

Analysis of the variation of atmospheric electric field during solar events

NASA Astrophysics Data System (ADS)

Tacza, J.; Raulin, J. P.

2016-12-01

We present the capability of a new network of electric field mill sensors to monitor the atmospheric electric field at various locations in South America. The first task is to obtain a diurnal curve of atmospheric electric field variations under fair weather conditions, which we will consider as a reference curve. To accomplish this, we made daily, monthly, seasonal and annual averages. For all sensor location, the results show significant similarities with the Carnegie curve. The Carnegie curve is the characteristic curve in universal time of atmospheric electric field in fair weather and one thinks it is related to the currents flowing in the global atmospheric electric circuit. Ultimately, we pretend to study departures of the daily observations from the standard curve. This difference can be caused by solar, geophysical and atmospheric phenomena such as the solar activity cycle, solar flares and energetic charged particles, galactic cosmic rays, seismic activity and/or specific meteorological events. As an illustration we investigate solar effects on the atmospheric electric field observed at CASLEO (Lat. 31.798°S, Long. 69.295°W, Altitude: 2552 masl) by the method of superposed epoch analysis, between January 2010 and December 2015.

The need for harmonization of methods for finding locations and magnitudes of air pollution sources using observations of concentrations and wind fields

NASA Astrophysics Data System (ADS)

Hanna, Steven R.; Young, George S.

2017-01-01

What do the terms "top-down", "inverse", "backwards", "adjoint", "sensor data fusion", "receptor", "source term estimation (STE)", to name several appearing in the current literature, have in common? These varied terms are used by different disciplines to describe the same general methodology - the use of observations of air pollutant concentrations and knowledge of wind fields to identify air pollutant source locations and/or magnitudes. Academic journals are publishing increasing numbers of papers on this topic. Examples of scenarios related to this growing interest, ordered from small scale to large scale, are: use of real-time samplers to quickly estimate the location of a toxic gas release by a terrorist at a large public gathering (e.g., Haupt et al., 2009);

Characterization of Peripheral Activity States and Cortical Local Field Potentials of Mice in an Elevated Plus Maze Test.

PubMed

Okonogi, Toya; Nakayama, Ryota; Sasaki, Takuya; Ikegaya, Yuji

2018-01-01

Elevated plus maze (EPM) tests have been used to assess animal anxiety levels. Little information is known regarding how physiological activity patterns of the brain-body system are altered during EPM tests. Herein, we monitored cortical local field potentials (LFPs), electrocardiograms (ECGs), electromyograms (EMGs), and respiratory signals in individual mice that were repeatedly exposed to EPM tests. On average, mouse heart rates were higher in open arms. In closed arms, the mice occasionally showed decreased heart and respiratory rates lasting for several seconds or minutes, characterized as low-peripheral activity states of peripheral signals. The low-activity states were observed only when the animals were in closed arms, and the frequencies of the states increased as the testing days proceeded. During the low-activity states, the delta and theta powers of cortical LFPs were significantly increased and decreased, respectively. These results demonstrate that cortical oscillations crucially depend on whether an animal exhibits low-activity states in peripheral organs rather than the EPM arm in which the animal is located. These results suggest that combining behavioral tests with physiological makers enables a more accurate evaluation of rodent mental states.

Are associations between the perceived home and neighbourhood environment and children's physical activity and sedentary behaviour moderated by urban/rural location?

PubMed

Salmon, Jo; Veitch, Jenny; Abbott, Gavin; ChinAPaw, Mai; Brug, Johannes J; teVelde, Saskia J; Cleland, Verity; Hume, Clare; Crawford, David; Ball, Kylie

2013-11-01

Associations between parental perceived home and neighbourhood environments and children's physical activity (PA), and sedentary time (ST) and screen time and moderating effects according to urban/rural location were examined. Data were collected (2007-2008) from a cohort of women (aged 18-45 years) and their children (5-12 years) participating in the Resilience for Eating and Activity Despite Inequality (READI) study. A total of 613 children (47% boys; mean age 9.4±2.2 years) and their mothers were included in the study. Urban children had higher screen time than rural children. Mothers in rural areas reported greater access to physical activity equipment in the home, higher levels of descriptive norms for physical activity, greater knowledge of the neighbourhood, a stronger social network, and higher personal safety than urban mothers. There were five significant interactions between the home and neighbourhood environment and PA/ST according to urban/rural location. Among urban children, the importance of doing PA together as a family was positively associated with ST. Interventions targeting PA and ST may need to target different factors according to urban/rural location. © 2013 Elsevier Ltd. All rights reserved.

Evidence for possible relation between local irregularities in the horizondal deformation field and microseismic activity of the Mygdonian basin(Northern Greece)

NASA Astrophysics Data System (ADS)

Contadakis, M. E.; Leventakis, G.-A. N.

1992-12-01

Geodetic methods have been proved very useful tools for the detection and monitoring of the earth crustal deformation. Using the repeated measurements in the decade 1979-1990 of the 16-point trigonometric network, located in the seismic active area of the lake Volvi in Northern Greece, a continuous strain field was determined for the area and for each epoch of the corresponding surveys. The dominant characteristic of the deformation field of the area relates, in a way, to the system of the surface faults, which appeared after the string earthquake of June 21, 1978. In addition, there is local as well as time variation of the strain field which is well correlated with the microseismic activity of the area. That is, although there is a general tendency of a N-S horizontal extension in accordance with the direction of the stress field of the area, regions of contraction appear in places where microseismic activity has taken place before the epochs of the respective survey. A few shocks in these region, for which reliable fault plane solutions could be defined by Scordilis on 1985,show focal mechanisms conformable to the geodetic results. Seismicity and fault plane solutions, based on a micro-earthquake study of the region during March and April of 1984 by Hatzfeld et al. with the help of a temporary network of 29 portable stations shows a rather complex pattern. The proposed model for the formation and the evolution of a complex graben system conform qualitatively to the geodetic results

47 CFR 73.685 - Transmitter location and antenna system.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 47 Telecommunication 4 2013-10-01 2013-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB above...

47 CFR 73.685 - Transmitter location and antenna system.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 47 Telecommunication 4 2011-10-01 2011-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB above...

47 CFR 73.685 - Transmitter location and antenna system.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 47 Telecommunication 4 2014-10-01 2014-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB above...

47 CFR 73.685 - Transmitter location and antenna system.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 47 Telecommunication 4 2012-10-01 2012-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB above...

47 CFR 73.685 - Transmitter location and antenna system.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 47 Telecommunication 4 2010-10-01 2010-10-01 false Transmitter location and antenna system. 73.685... RADIO BROADCAST SERVICES Television Broadcast Stations § 73.685 Transmitter location and antenna system... and antenna height above average terrain employed, the following minimum field strength in dB above...

Computational and experimental analysis of TMS-induced electric field vectors critical to neuronal activation

NASA Astrophysics Data System (ADS)

Krieg, Todd D.; Salinas, Felipe S.; Narayana, Shalini; Fox, Peter T.; Mogul, David J.

2015-08-01

Objective. Transcranial magnetic stimulation (TMS) represents a powerful technique to noninvasively modulate cortical neurophysiology in the brain. However, the relationship between the magnetic fields created by TMS coils and neuronal activation in the cortex is still not well-understood, making predictable cortical activation by TMS difficult to achieve. Our goal in this study was to investigate the relationship between induced electric fields and cortical activation measured by blood flow response. Particularly, we sought to discover the E-field characteristics that lead to cortical activation. Approach. Subject-specific finite element models (FEMs) of the head and brain were constructed for each of six subjects using magnetic resonance image scans. Positron emission tomography (PET) measured each subject’s cortical response to image-guided robotically-positioned TMS to the primary motor cortex. FEM models that employed the given coil position, orientation, and stimulus intensity in experimental applications of TMS were used to calculate the electric field (E-field) vectors within a region of interest for each subject. TMS-induced E-fields were analyzed to better understand what vector components led to regional cerebral blood flow (CBF) responses recorded by PET. Main results. This study found that decomposing the E-field into orthogonal vector components based on the cortical surface geometry (and hence, cortical neuron directions) led to significant differences between the regions of cortex that were active and nonactive. Specifically, active regions had significantly higher E-field components in the normal inward direction (i.e., parallel to pyramidal neurons in the dendrite-to-axon orientation) and in the tangential direction (i.e., parallel to interneurons) at high gradient. In contrast, nonactive regions had higher E-field vectors in the outward normal direction suggesting inhibitory responses. Significance. These results provide critical new

Active tectonics of the northern Mojave Desert: The 2017 Desert Symposium field trip road log

USGS Publications Warehouse

Miller, David; Reynolds, R.E.; Phelps, Geoffrey; Honke, Jeff; Cyr, Andrew J.; Buesch, David C.; Schmidt, Kevin M.; Losson, G.

2017-01-01

The 2017 Desert Symposium field trip will highlight recent work by the U.S. Geological Survey geologists and geophysicists, who have been mapping young sediment and geomorphology associated with active tectonic features in the least well-known part of the eastern California Shear Zone (ECSZ). This area, stretching from Barstow eastward in a giant arc to end near the Granite Mountains on the south and the Avawatz Mountains on the north (Fig. 1-1), encompasses the two major structural components of the ECSZ—east-striking sinistral faults and northwest-striking dextral faults—as well as reverseoblique and normal-oblique faults that are associated with topographic highs and sags, respectively. In addition, folds and stepovers (both restraining stepovers that form pop-up structures and releasing stepovers that create narrow basins) have been identified. The ECSZ is a segment in the ‘soft’ distributed deformation of the North American plate east of the San Andreas fault (Fig. 1-1), where it takes up approximately 20-25% of plate motion in a broad zone of right-lateral shear (Sauber et al., 1994) The ECSZ (sensu strictu) begins in the Joshua Tree area and passes north through the Mojave Desert, past the Owens Valley-to-Death Valley swath and northward, where it is termed the Walker Lane. It has been defined as the locus of active faulting (Dokka and Travis, 1990), but when the full history from about 10 Ma forward is considered, it lies in a broader zone of right shear that passes westward in the Mojave Desert to the San Andreas fault (Mojave strike-slip province of Miller and Yount, 2002) and passes eastward to the Nevada state line or beyond (Miller, this volume).We will visit several accessible highlights for newly studied faults, signs of young deformation, and packages of syntectonic sediments. These pieces of a complex active tectonic puzzle have yielded some answers to longstanding questions such as: How is fault slip transfer in this area accommodated

Method using a density field for locating related items for data mining

DOEpatents

Wylie, Brian N.

2002-01-01

A method for locating related items in a geometric space transforms relationships among items to geometric locations. The method locates items in the geometric space so that the distance between items corresponds to the degree of relatedness. The method facilitates communication of the structure of the relationships among the items. The method makes use of numeric values as a measure of similarity between each pairing of items. The items are given initial coordinates in the space. An energy is then determined for each item from the item's distance and similarity to other items, and from the density of items assigned coordinates near the item. The distance and similarity component can act to draw items with high similarities close together, while the density component can act to force all items apart. If a terminal condition is not yet reached, then new coordinates can be determined for one or more items, and the energy determination repeated. The iteration can terminate, for example, when the total energy reaches a threshold, when each item's energy is below a threshold, after a certain amount of time or iterations.

Geologic setting of the Snake Pit hydrothermal site: An active vent field on the Mid-Atlantic Ridge

NASA Astrophysics Data System (ADS)

Karson, Jeffrey A.; Brown, Jennifer R.

1988-03-01

The Snake Pit Hydrothermal Site lies on the axis of the Mid-Atlantic Ridge at 23°22' N latitude, about 30 km south of the Kane Transform Intersection. Active ‘black smoker’ vents and a surrounding field of hydrothermal sediment occur at the crest of a laterally extensive neovolcanic ridge. It is one of the first active hydrothermal vent fields to be found on a slow-spreading ridge axis and despite significant differences in its geologic setting from those of the East Pacific Rise, has many similarities to its fast-spreading counterparts. Although preliminary reports have documented many interesting aspects of these vents and their surroundings, new data collected from the manned submersible ALVIN and the deep-towed ANGUS camera system define the regional tectonic setting as well as the local geologic environment of this fascinating area. The Snake Pit vents are located on a local peak of a volcanic constructional ridge at a depth of 3450 m, 700 800 m deeper than vents known from the East Pacific Rise, Galapagos, or Juan de Fuca spreading centers. The vent field is at least 600 m long and up to 200 m wide and is covered by a thick blanket of greenish to yellow-orange hydrothermal sediment. Both active and extinct vents are perched along the crests of steep-sided sulfide mounds that reach heights of over 40 m. High-temperature (350° C) fluids are vented from black smoker chimneys and low-temperature (226° C) fluids seep from sulphide domes and subordinate anhydrite constructions. Water temperatures, flow rates, fluid chemistries, and mineralization are strikingly similar to vents of faster spreading ridge crests; however, a somewhat distinct fauna inhabit the area.

Modelling soil properties in a crop field located in Croatia

NASA Astrophysics Data System (ADS)

Bogunovic, Igor; Pereira, Paulo; Millan, Mesic; Percin, Aleksandra; Zgorelec, Zeljka

2016-04-01

Development of tillage activities had negative effects on soil quality as destruction of soil horizons, compacting and aggregates destruction, increasing soil erosion and loss of organic matter. For a better management in order to mitigate the effects of intensive soil management in land degradation it is fundamental to map the spatial distribution of soil properties (Brevik et al., 2016). The understanding the distribution of the variables in space is very important for a sustainable management, in order to identify areas that need a potential intervention and decrease the economic losses (Galiati et al., 2016). The objective of this work is study the spatial distribution of some topsoil properties as clay, fine silt, coarse silt, fine sand, coarse sand, penetration resistance, moisture and organic matter in a crop field located in Croatia. A grid with 275x25 (625 m2) was designed and a total of 48 samples were collected. Previous to data modelling, data normality was checked using the Shapiro wilk-test. As in previous cases (Pereira et al., 2015), data did not followed the normal distribution, even after a logarithmic (Log), square-root, and box cox transformation. Thus, for modeling proposes, we used the log transformed data, since was the closest to the normality. In order to identify groups among the variables we applied a principal component analysis (PCA), based on the correlation matrix. On average clay content was 15.47% (±3.23), fine silt 24.24% (±4.08), coarse silt 35.34% (±3.12), fine sand 20.93% (±4.68), coarse sand 4.02% (±1.69), penetration resistance 0.66 MPa (±0.28), organic matter 1.51% (±0.25) and soil moisture 32.04% (±3.27). The results showed that the PCA identified three factors explained at least one of the variables. The first factor had high positive loadings in soil clay, fine silt and organic matter and a high negative loading in fine sand. The second factor had high positive loadings in coarse sand and moisture and a high

Helicopter magnetic survey conducted to locate wells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Veloski, G.A.; Hammack, R.W.; Stamp, V.

2008-07-01

A helicopter magnetic survey was conducted in August 2007 over 15.6 sq mi at the Naval Petroleum Reserve No. 3’s (NPR-3) Teapot Dome Field near Casper, Wyoming. The survey’s purpose was to accurately locate wells drilled there during more than 90 years of continuous oilfield operation. The survey was conducted at low altitude and with closely spaced flight lines to improve the detection of wells with weak magnetic response and to increase the resolution of closely spaced wells. The survey was in preparation for a planned CO2 flood for EOR, which requires a complete well inventory with accurate locations formore » all existing wells. The magnetic survey was intended to locate wells missing from the well database and to provide accurate locations for all wells. The ability of the helicopter magnetic survey to accurately locate wells was accomplished by comparing airborne well picks with well locations from an intense ground search of a small test area.« less

Correlation between dielectric property by dielectrophoretic levitation and growth activity of cells exposed to electric field.

PubMed

Hakoda, Masaru; Hirota, Yusuke

2013-09-01

The purpose of this study is to develop a system analyzing cell activity by the dielectrophoresis method. Our previous studies revealed a correlation between the growth activity and dielectric property (Re[K(ω)]) of mouse hybridoma 3-2H3 cells using dielectrophoretic levitation. Furthermore, it was clarified that the differentiation activity of many stem cells could be evaluated by the Re[K(ω)] without differentiation induction. In this paper, 3-2H3 cells exposed to an alternating current (AC) electric field or a direct current (DC) electric field were cultivated, and the influence of damage by the electric field on the growth activity of the cells was examined. To evaluate the activity of the cells by measuring the Re[K(ω)], the correlation between the growth activity and the Re[K(ω)] of the cells exposed to the electric field was examined. The relations between the cell viability, growth activity, and Re[K(ω)] in the cells exposed to the AC electric field were obtained. The growth activity of the cells exposed to the AC electric field could be evaluated by the Re[K(ω)]. Furthermore, it was found that the adverse effects of the electric field on the cell viability and the growth activity were smaller in the AC electric field than the DC electric field.

Mechanoreceptor afferent activity compared with receptor field dimensions and pressure changes in feline urinary bladder.

PubMed

Downie, J W; Armour, J A

1992-11-01

The relationship between vesical mechanoreceptor field dimensions and afferent nerve activity recorded in pelvic plexus nerve filaments was examined in chloralose-anesthetized cats. Orthogonal receptor field dimensions were monitored with piezoelectric ultrasonic crystals. Reflexly generated bladder contractile activity made measurements difficult, therefore data were collected from cats subjected to actual sacral rhizotomy. Afferent activity was episodic and was initiated at different pressure and receptor field dimension thresholds. Maximum afferent activity did not correlate with maximum volume or pressure. Furthermore, activity was not linearly related to intravesical pressure, receptor field dimensions, or calculated wall tension. Pressure-length hysteresis of the receptor fields occurred. The responses of identified afferent units and their associated receptor field dimensions to brief contractions elicited by the ganglion stimulant 1,1-dimethyl-4-phenylpiperazinium iodide (2.5-20 micrograms i.a.), studied under constant volume or constant pressure conditions, are compatible with bladder mechanoreceptors behaving as tension receptors. Because activity generated by bladder mechanoreceptors did not correlate in a simple fashion with intravesical pressure or receptor field dimensions, it is concluded that such receptors are influenced by the viscoelastic properties of the bladder wall. Furthermore, as a result of the heterogeneity of the bladder wall, receptor field tension appears to offer a more precise relationship with the activity of bladder wall mechanoreceptors than does intravesical pressure.

Behavioral and locomotor measurements using an open field activity monitoring system for skeletal muscle diseases.

PubMed

Tatem, Kathleen S; Quinn, James L; Phadke, Aditi; Yu, Qing; Gordish-Dressman, Heather; Nagaraju, Kanneboyina

2014-09-29

The open field activity monitoring system comprehensively assesses locomotor and behavioral activity levels of mice. It is a useful tool for assessing locomotive impairment in animal models of neuromuscular disease and efficacy of therapeutic drugs that may improve locomotion and/or muscle function. The open field activity measurement provides a different measure than muscle strength, which is commonly assessed by grip strength measurements. It can also show how drugs may affect other body systems as well when used with additional outcome measures. In addition, measures such as total distance traveled mirror the 6 min walk test, a clinical trial outcome measure. However, open field activity monitoring is also associated with significant challenges: Open field activity measurements vary according to animal strain, age, sex, and circadian rhythm. In addition, room temperature, humidity, lighting, noise, and even odor can affect assessment outcomes. Overall, this manuscript provides a well-tested and standardized open field activity SOP for preclinical trials in animal models of neuromuscular diseases. We provide a discussion of important considerations, typical results, data analysis, and detail the strengths and weaknesses of open field testing. In addition, we provide recommendations for optimal study design when using open field activity in a preclinical trial.

Informing geobiology through GIS site suitability analysis: locating springs in mantle units of ophiolites

NASA Astrophysics Data System (ADS)

Bowman, A.; Cardace, D.; August, P.

2012-12-01

Springs sourced in the mantle units of ophiolites serve as windows to the deep biosphere, and thus hold promise in elucidating survival strategies of extremophiles, and may also inform discourse on the origin of life on Earth. Understanding how organisms can survive in extreme environments provides clues to how microbial life responds to gradients in pH, temperature, and oxidation-reduction potential. Spring locations associated with serpentinites have traditionally been located using a variety of field techniques. The aqueous alteration of ultramafic rocks to serpentinites is accompanied by the production of very unusual formation fluids, accessed by drilling into subsurface flow regimes or by sampling at related surface springs. The chemical properties of these springs are unique to water associated with actively serpentinizing rocks; they reflect a reducing subsurface environment reacting at low temperatures producing high pH, Ca-rich formation fluids with high dissolved hydrogen and methane. This study applies GIS site suitability analysis to locate high pH springs upwelling from Coast Range Ophiolite serpentinites in Northern California. We used available geospatial data (e.g., geologic maps, topography, fault locations, known spring locations, etc.) and ArcGIS software to predict new spring localities. Important variables in the suitability model were: (a) bedrock geology (i.e., unit boundaries and contacts for peridotite, serpentinite, possibly pyroxenite, or chromite), (b) fault locations, (c) regional data for groundwater characteristics such as pH, Ca2+, and Mg2+, and (d) slope-aspect ratio. The GIS model derived from these geological and environmental data sets predicts the latitude/longitude points for novel and known high pH springs sourced in serpentinite outcrops in California. Field work confirms the success of the model, and map output can be merged with published environmental microbiology data (e.g., occurrence of hydrogen-oxidizers) to showcase

Two substorm studies of relations between westward electric fields in the outer plasmasphere, auroral activity, and geomagnetic perturbations

NASA Technical Reports Server (NTRS)

Carpenter, D. L.; Akasofu, S.

1972-01-01

Temporal variations of the westward component of the magnetospheric convection electric field in the outer plasmasphere were compared to auroral activity near L = 7, and to variations in the geomagnetic field at middle and high latitudes. The substorms occurred on July 29, 1965 near 0530 UT and on August 20, 1965 near 0730 UT. The results on westward electric field E(w) were obtained by the whistler method using data from Eights, Antarctica (L is approximately 4). All sky camera records were obtained from Byrd, Antarctica, (L is approximately 7), located within about 1 hour of Eights in magnetic local time. It was found that E(w) within the outer plasmasphere increased rapidly to substorm levels about the time of auroral expansion at nearby longitudes. This behavior is shown to differ from results on E(w) from balloons, which show E(w) reaching enhanced levels prior to the expansion. A close temporal relation was found between the rapid, substorm associated increases in E(w) and a well known type of nightside geomagnetic perturbation. Particularly well defined was the correlation of E(w) rise and a large deviation of the D component at middle latitudes.

Remote enzyme activation using gold coated magnetite as antennae for radio frequency fields

NASA Astrophysics Data System (ADS)

Collins, Christian B.; Ackerson, Christopher J.

2018-02-01

The emerging field of remote enzyme activation, or the ability to remotely turn thermophilic increase enzyme activity, could be a valuable tool for understanding cellular processes. Through exploitation of the temperature dependence of enzymatic processes and high thermal stability of thermophilic enzymes these experiments utilize nanoparticles as `antennae' that convert radiofrequency (RF) radiation into local heat, increasing activity of the enzymes without increasing the temperature of the surrounding bulk solution. To investigate this possible tool, thermolysin, a metalloprotease was covalently conjugated to 4nm gold coated magnetite particles via peptide bond formation with the protecting ligand shell. RF stimulated protease activity at 17.76 MHz in a solenoid shaped antenna, utilizing both electric and magnetic field interactions was investigated. On average 40 percent higher protease activity was observed in the radio frequency fields then when bulk heating the sample to the same temperature. This is attributed to electrophoretic motion of the nanoparticle enzyme conjugates and local regions of heat generated by the relaxation of the magnetite cores with the oscillating field. Radio frequency local heating of nanoparticles conjugated to enzymes as demonstrated could be useful in the activation of specific enzymes in complex cellular environments.

Interpreting Reservoir Microseismicity Detected During CO2 Injection at the Aneth Oil Field

NASA Astrophysics Data System (ADS)

Rutledge, J. T.

2009-12-01

Microseismic monitoring is expected to be a useful tool in CO2 sequestration projects for mapping pressure fronts and detecting fault activation and potential leakage paths. Downhole microseismic monitoring and several other techniques are being tested for their efficacy in tracking movement and containment of CO2 injected at the Aneth oil field located in San Juan County, Utah. The Southwest Regional Partnership on CO2 Sequestration is conducting the monitoring activities in collaboration with Resolute Natural Resources Company, under the support of the U.S. Department of Energy’s National Energy Technology Laboratory. The CO2 injection at Aneth is associated with a field-wide enhanced oil recovery operation following decades of pressure maintenance and oil recovery by water-flood injection. A 60-level geophone string was cemented into a monitoring well equipped with both 3-component and vertical component geophones spanning from 800 to 1700 m depth. The top of the oil reservoir in the study area is at approximately 1730 m depth. Over the first year of monitoring, approximately 3800 microearthquakes have been detected within about 3 km of the geophone string. The Aneth reservoir events are relatively large with magnitudes ranging from approximately -1 to 1. For comparison, reservoir seismicity induced during hydraulic fracturing treatments typically result in events with magnitudes <-1, unless pre-existing faults are pressurized by the treatments. The Aneth events delineate two NW-SE oriented fracture zones located on opposite flanks of the reservoir. Injection activity is fairly uniform over the entire field area, and the microseismicity does not correlate either temporally or spatially with any anomalous changes in injection or production activities near the source locations. Because the activity is fairly isolated and relatively energetic, I speculate that the seismicity may be due to critically stressed structures driven by longer-term production- and

Auditory-visual integration modulates location-specific repetition suppression of auditory responses.

PubMed

Shrem, Talia; Murray, Micah M; Deouell, Leon Y

2017-11-01

Space is a dimension shared by different modalities, but at what stage spatial encoding is affected by multisensory processes is unclear. Early studies observed attenuation of N1/P2 auditory evoked responses following repetition of sounds from the same location. Here, we asked whether this effect is modulated by audiovisual interactions. In two experiments, using a repetition-suppression paradigm, we presented pairs of tones in free field, where the test stimulus was a tone presented at a fixed lateral location. Experiment 1 established a neural index of auditory spatial sensitivity, by comparing the degree of attenuation of the response to test stimuli when they were preceded by an adapter sound at the same location versus 30° or 60° away. We found that the degree of attenuation at the P2 latency was inversely related to the spatial distance between the test stimulus and the adapter stimulus. In Experiment 2, the adapter stimulus was a tone presented from the same location or a more medial location than the test stimulus. The adapter stimulus was accompanied by a simultaneous flash displayed orthogonally from one of the two locations. Sound-flash incongruence reduced accuracy in a same-different location discrimination task (i.e., the ventriloquism effect) and reduced the location-specific repetition-suppression at the P2 latency. Importantly, this multisensory effect included topographic modulations, indicative of changes in the relative contribution of underlying sources across conditions. Our findings suggest that the auditory response at the P2 latency is affected by spatially selective brain activity, which is affected crossmodally by visual information. © 2017 Society for Psychophysiological Research.

Selective attention to sound location or pitch studied with fMRI.

PubMed

Degerman, Alexander; Rinne, Teemu; Salmi, Juha; Salonen, Oili; Alho, Kimmo

2006-03-10

We used 3-T functional magnetic resonance imaging to compare the brain mechanisms underlying selective attention to sound location and pitch. In different tasks, the subjects (N = 10) attended to a designated sound location or pitch or to pictures presented on the screen. In the Attend Location conditions, the sound location varied randomly (left or right), while the pitch was kept constant (high or low). In the Attend Pitch conditions, sounds of randomly varying pitch (high or low) were presented at a constant location (left or right). Both attention to location and attention to pitch produced enhanced activity (in comparison with activation caused by the same sounds when attention was focused on the pictures) in widespread areas of the superior temporal cortex. Attention to either sound feature also activated prefrontal and inferior parietal cortical regions. These activations were stronger during attention to location than during attention to pitch. Attention to location but not to pitch produced a significant increase of activation in the premotor/supplementary motor cortices of both hemispheres and in the right prefrontal cortex, while no area showed activity specifically related to attention to pitch. The present results suggest some differences in the attentional selection of sounds on the basis of their location and pitch consistent with the suggested auditory "what" and "where" processing streams.

Systems analysis of the installation, mounting, and activation of emergency locator transmitters in general aviation aircraft

NASA Technical Reports Server (NTRS)

Hall, D. S.

1980-01-01

A development program was developed to design and improve the Emergency Locator Transmitter (ELT) transmitter and to improve the installation in the aircraft and its activation subsystem. There were 1135 general aviation fixed wing aircraft accident files reviewed. A detailed description of the damage to the aircraft was produced. The search aspects of these accidents were studied. As much information as possible about the ELT units in these cases was collected. The data should assist in establishing installation and mounting criteria, better design standards for activation subsystems, and requirements for the new ELT system design in the area of crashworthiness.

Coso MT Site Locations

DOE Data Explorer

Doug Blankenship

2011-05-04

This data includes the locations of the MT data collected in and around the Coso Geothermal field that covered the West Flank area. These are the data that the 3D MT models were created from that were discussed in Phase 1 of the West Flank FORGE project. The projected coordinate system is NAD 1927 State Plane California IV FIPS 0404 and the Projection is Lambert Conformal Conic. Units are in feet.

Bilateral frontal activation associated with cutaneous stimulation of elixir field: an FMRI study.

PubMed

Chan, Agnes S; Cheung, Mei-Chun; Chan, Yu Leung; Yeung, David K W; Lam, Wan

2006-01-01

Elixir Field, or Dan Tian, is the area where energy is stored and nourished in the body according to traditional Chinese medicine (TCM). Although Dan Tian stimulation is a major concept in Qigong healing and has been practiced for thousands of years, and while there are some recent empirical evidence of its effect, its neurophysiological basis remains unknown. We used functional magnetic resonance imaging (fMRI) to study brain activations associated with external stimulation of the lower Elixir Field in ten normal subjects, and compared the results with the stimulation of their right hands. While right-hand stimulation resulted in left postcentral gyrus activation, stimulation of the lower Elixir Field resulted in bilateral activations including the medial and superior frontal gyrus, middle and superior temporal gyrus, thalamus, insula, and cingulate gyrus. These findings suggest that stimulation of the Elixir Field is not only associated with activation of the sensory motor cortex but also with cortical regions that mediate planning, attention, and memory.

Control of boundary layer transition location and plate vibration in the presence of an external acoustic field

NASA Technical Reports Server (NTRS)

Maestrello, L.; Grosveld, F. W.

1991-01-01

The experiment is aimed at controlling the boundary layer transition location and the plate vibration when excited by a flow and an upstream sound source. Sound has been found to affect the flow at the leading edge and the response of a flexible plate in a boundary layer. Because the sound induces early transition, the panel vibration is acoustically coupled to the turbulent boundary layer by the upstream radiation. Localized surface heating at the leading edge delays the transition location downstream of the flexible plate. The response of the plate excited by a turbulent boundary layer (without sound) shows that the plate is forced to vibrate at different frequencies and with different amplitudes as the flow velocity changes indicating that the plate is driven by the convective waves of the boundary layer. The acoustic disturbances induced by the upstream sound dominate the response of the plate when the boundary layer is either turbulent or laminar. Active vibration control was used to reduce the sound induced displacement amplitude of the plate.

Neurons with object-centered spatial selectivity in macaque SEF: do they represent locations or rules?

PubMed

Tremblay, Léon; Gettner, Sonya N; Olson, Carl R

2002-01-01

In macaque monkeys performing a task that requires eye movements to the leftmost or rightmost of two dots in a horizontal array, some neurons in the supplementary eye field (SEF) fire differentially according to which side of the array is the target regardless of the array's location on the screen. We refer to these neurons as exhibiting selectivity for object-centered location. This form of selectivity might arise from involvement of the neurons in either of two processes: representing the locations of targets or representing the rules by which targets are selected. To distinguish between these possibilities, we monitored neuronal activity in the SEF of two monkeys performing a task that required the selection of targets by either an object-centered spatial rule or a color rule. On each trial, a sample array consisting of two side-by-side dots appeared; then a cue flashed on one dot; then the display vanished and a delay ensued. Next a target array consisting of two side-by-side dots appeared at an unpredictable location and another delay ensued; finally the monkey had to make an eye movement to one of the target dots. On some trials, the monkey had to select the dot on the same side as the cue (right or left). On other trials, he had to select the target of the same color as the cue (red or green). Neuronal activity robustly encoded the object-centered locations first of the cue and then of the target regardless of the whether the monkey was following a rule based on object-centered location or color. Neuronal activity was at most weakly affected by the type of rule the monkey was following (object-centered-location or color) or by the color of the cue and target (red or green). On trials involving a color rule, neuronal activity was moderately enhanced when the cue and target appeared on opposite sides of their respective arrays. We conclude that the general function of SEF neurons selective for object-centered location is to represent where the cue and target

Integration of Active and Passive Safety Technologies--A Method to Study and Estimate Field Capability.

PubMed

Hu, Jingwen; Flannagan, Carol A; Bao, Shan; McCoy, Robert W; Siasoco, Kevin M; Barbat, Saeed

2015-11-01

The objective of this study is to develop a method that uses a combination of field data analysis, naturalistic driving data analysis, and computational simulations to explore the potential injury reduction capabilities of integrating passive and active safety systems in frontal impact conditions. For the purposes of this study, the active safety system is actually a driver assist (DA) feature that has the potential to reduce delta-V prior to a crash, in frontal or other crash scenarios. A field data analysis was first conducted to estimate the delta-V distribution change based on an assumption of 20% crash avoidance resulting from a pre-crash braking DA feature. Analysis of changes in driver head location during 470 hard braking events in a naturalistic driving study found that drivers' head positions were mostly in the center position before the braking onset, while the percentage of time drivers leaning forward or backward increased significantly after the braking onset. Parametric studies with a total of 4800 MADYMO simulations showed that both delta-V and occupant pre-crash posture had pronounced effects on occupant injury risks and on the optimal restraint designs. By combining the results for the delta-V and head position distribution changes, a weighted average of injury risk reduction of 17% and 48% was predicted by the 50th percentile Anthropomorphic Test Device (ATD) model and human body model, respectively, with the assumption that the restraint system can adapt to the specific delta-V and pre-crash posture. This study demonstrated the potential for further reducing occupant injury risk in frontal crashes by the integration of a passive safety system with a DA feature. Future analyses considering more vehicle models, various crash conditions, and variations of occupant characteristics, such as age, gender, weight, and height, are necessary to further investigate the potential capability of integrating passive and DA or active safety systems.

Long term consistency and location specificity of equine gluteus medius muscle activity during locomotion on the treadmill.

PubMed

Zsoldos, Rebeka R; Voegele, Anna; Krueger, Bjoern; Schroeder, Ulrike; Weber, Andreas; Licka, Theresia F

2018-04-06

The equine m. gluteus medius (GM) is the largest muscle of the horse, its main movement function is the extension of the hip joint. The objective of the present study was to measure equine GM activity in three adjacent locations on GM during walk and trot on a treadmill, in order to document potential differences. Fourteen Haflinger mares were measured using surface electromyography and kinematic markers to identify the motion cycles on three occasions over 16 weeks. The electrodes were placed on left and right gluteus medius muscle over the middle of its widest part and 5 cm lateral and medial of it. For data processing, electrical activity was normalised to its maximum value and timing was normalised to the motion cycle. A Gaussian distribution approach was used to determine up to 10 modes of focussed activity, and results were analysed separately for stance and swing phase of the ipsilateral hindlimb. Fair reliability was found for mean mode values (Cronbach's alpha = 0.66) and good reliability was found for mean mode locations (Cronbach's alpha = 0.71) over the three data collection days. The magnitude of muscle activity identified as mean mode value was much larger at trot than at walk, and mean mode value was significantly different between stance phases of walk and trot for all electrode positions (p < 0.01). The pattern of muscle activity identified as mean mode location was significantly different for walk and trot at all electrode positions, both during stance and swing phases (p < 0.001). This indicates the different timing pattern between the gaits. Results of the three electrode positions on the same muscle during each gait were not significantly different when comparing the same measurement. The middle of the equine GM does not show any indication of functional differentiation during walk and trot on a treadmill; this might be due to lack of segmentation as such, or due to lack of need for segmented use for these very basic main

Mapping the evolution of scientific fields.

PubMed

Herrera, Mark; Roberts, David C; Gulbahce, Natali

2010-05-04

Despite the apparent cross-disciplinary interactions among scientific fields, a formal description of their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society Physics and Astronomy Classification Scheme (PACS) numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using a community finding algorithm, and describe the time evolution of these fields over the course of 1985-2006. The communities we identify map to known scientific fields, and their age depends on their size and activity. We expect our approach to quantifying the evolution of ideas to be relevant for making predictions about the future of science and thus help to guide its development.

Two-year survey comparing earthquake activity and injection-well locations in the Barnett Shale, Texas

PubMed Central

Frohlich, Cliff

2012-01-01

Between November 2009 and September 2011, temporary seismographs deployed under the EarthScope USArray program were situated on a 70-km grid covering the Barnett Shale in Texas, recording data that allowed sensing and locating regional earthquakes with magnitudes 1.5 and larger. I analyzed these data and located 67 earthquakes, more than eight times as many as reported by the National Earthquake Information Center. All 24 of the most reliably located epicenters occurred in eight groups within 3.2 km of one or more injection wells. These included wells near Dallas–Fort Worth and Cleburne, Texas, where earthquakes near injection wells were reported by the media in 2008 and 2009, as well as wells in six other locations, including several where no earthquakes have been reported previously. This suggests injection-triggered earthquakes are more common than is generally recognized. All the wells nearest to the earthquake groups reported maximum monthly injection rates exceeding 150,000 barrels of water per month (24,000 m3/mo) since October 2006. However, while 9 of 27 such wells in Johnson County were near earthquakes, elsewhere no earthquakes occurred near wells with similar injection rates. A plausible hypothesis to explain these observations is that injection only triggers earthquakes if injected fluids reach and relieve friction on a suitably oriented, nearby fault that is experiencing regional tectonic stress. Testing this hypothesis would require identifying geographic regions where there is interpreted subsurface structure information available to determine whether there are faults near seismically active and seismically quiescent injection wells. PMID:22869701

Lay health advisor activity levels: definitions from the field.

PubMed

Altpeter, M; Earp, J A; Bishop, C; Eng, E

1999-08-01

One type of lay health advisor model assumes that an effective mechanism for reaching the underserved is through informal advice-givers called natural helpers. Despite the growing use of this approach, few programs have defined what an active lay health advisor does within the natural helping process. To explore perceptions and definitions of lay health advisors' activity, we conducted semistructured, in-person interviews with four field staff who coordinate the advisors' activities in a breast cancer screening program. These staff viewed lay health advisor activity as fluctuating over the course of a year, occurring along a continuum of participation (inactive, moderately active, active, and superactive), and reflecting varying degrees of proactivity and participation in multiple activities. These results suggest an empirical process for refining the definition of an active lay health advisor, improving advisors' productivity in achieving outreach objectives, and managing and monitoring their ongoing activities.

Locating scatterers while drilling using seismic noise due to tunnel boring machine

NASA Astrophysics Data System (ADS)

Harmankaya, U.; Kaslilar, A.; Wapenaar, K.; Draganov, D.

2018-05-01

Unexpected geological structures can cause safety and economic risks during underground excavation. Therefore, predicting possible geological threats while drilling a tunnel is important for operational safety and for preventing expensive standstills. Subsurface information for tunneling is provided by exploratory wells and by surface geological and geophysical investigations, which are limited by location and resolution, respectively. For detailed information about the structures ahead of the tunnel face, geophysical methods are applied during the tunnel-drilling activity. We present a method inspired by seismic interferometry and ambient-noise correlation that can be used for detecting scatterers, such as boulders and cavities, ahead of a tunnel while drilling. A similar method has been proposed for active-source seismic data and validated using laboratory and field data. Here, we propose to utilize the seismic noise generated by a Tunnel Boring Machine (TBM), and recorded at the surface. We explain our method at the hand of data from finite-difference modelling of noise-source wave propagation in a medium where scatterers are present. Using the modelled noise records, we apply cross-correlation to obtain correlation gathers. After isolating the scattered arrivals in these gathers, we cross-correlate again and invert for the correlated traveltime to locate scatterers. We show the potential of the method for locating the scatterers while drilling using noise records due to TBM.

Magnetic Data Interpretation for the Source-Edge Locations in Parts of the Tectonically Active Transition Zone of the Narmada-Son Lineament in Central India

NASA Astrophysics Data System (ADS)

Ghosh, G. K.

2016-02-01

The study has been carried out in the transition zone of the Narmada-Son lineament (NSL) which is seismically active with various geological complexities, upwarp movement of the mantle material into the crust through fault, fractures lamination and upwelling. NSL is one of the most prominent lineaments in central India after the Himalaya in the Indian geology. The area of investigation extends from longitude 80.25°E to 81.50°E and latitude 23.50°N to 24.37°N in the central part of the Indian continent. Different types of subsurface geological formations viz. alluvial, Gondwana, Deccan traps, Vindhyan, Mahakoshal, Granite and Gneisses groups exist in this area with varying geological ages. In this study area tectonic movement and crustal variation have been taken place during the past time and which might be reason for the variation of magnetic field. Magnetic anomaly suggests that the area has been highly disturbed which causes the Narmada-Son lineament trending in the ENE-WSW direction. Magnetic anomaly variation has been taken place due to the lithological variations subject to the changes in the geological contacts like thrusts and faults in this area. Shallow and deeper sources have been distinguished using frequency domain analysis by applying different filters. To enhance the magnetic data, various types of derivatives to identify the source-edge locations of the causative source bodies. The present study carried out the interpretation using total horizontal derivative, tilt angle derivative, horizontal tilt angle derivative and Cos (θ) derivative map to get source-edge locations. The results derived from various derivatives of magnetic data have been compared with the basement depth solutions calculated from 3D Euler deconvolution. It is suggested that total horizontal derivative, tilt angle derivative and Cos (θ) derivative are the most useful tools for identifying the multiple source edge locations of the causative bodies in this tectonically active

Formulations of the endophytic bacterium Bacillus subtilis Tu-100 suppress Sclerotinia sclerotiorum on oilseed rape and improve plant vigor in field trials conducted at separate locations

USDA-ARS?s Scientific Manuscript database

Sclerotinia sclerotiorum causes serious yield losses in crops in The People’s Republic of China. Two formulations of oilseed rape seed containing the endophytic bacterium Bacillus subtilis Tu-100 were evaluated for suppression of this pathogen in field trials conducted at two independent locations....

The vector structure of active magnetic fields

NASA Technical Reports Server (NTRS)

Parker, E. N.

1985-01-01

Observations are needed to show the form of the strains introduced into the fields above the surface of the Sun. The longitudinal component alone does not provide the basic information, so that it has been necessary in the past to use the filamentary structure observed in H sub alpha to supplement the longitudinal information. Vector measurements provide the additional essential information to determine the strains, with the filamentary structure available as a check for consistency. It is to be expected, then, that vector measurements will permit a direct mapping of the strains imposed on the magnetic fields of active regions. It will be interesting to study the relation of those strains to the emergence of magnetic flux, flares, eruptive prominences, etc. In particular we may hope to study the relaxation of the strains via the dynamical nonequilibrium.

Magnetic Field Configuration of Active Region NOAA 6555 at the Time of a Long Duration Flare on 23 March 1991: An Exception to Standard Flare Reconnection Model

NASA Technical Reports Server (NTRS)

Choudhary, Debi Prasad; Gary, Allen G.

1998-01-01

The high-resolution H(sub alpha) images observed during the decay phase of a long duration flare on 23 March 1991 are used to study the three-dimensional magnetic field configuration of the active region NOAA 6555. Whereas, all the large flares in NOAA 6555 occurred at the location of high magnetic shear and flux emergence, this long duration flare was observed in the region of low magnetic shear at the photosphere. The H(sub alpha) loop activity started soon after the maximum phase of the flare. There were few long loop at the initial phase of the activity. Some of these were sheared in the chromosphere at an angle of about 45 deg with the east-west axis. Gradually, increasing number of shorter loops, oriented along the east-west axis, started appearing. The chromospheric Dopplergrams show blue-shifts at the end points of the loops. By using different magnetic field models, we have extrapolated the photospheric magnetograms to the chromospheric heights. The magnetic field lines computed by using the potential field model correspond to most of the observed H(sub alpha) loops. The height of the H(sub alpha) loops were derived by comparing them with the computed field lines. From the temporal evolution of the H(sub alpha) loop activity, we derive the negative rate of appearance of H(sub alpha) features as a function of height. It is found that the field lines oriented along one of the neutral lines was sheared and low lying. The higher field lines were mostly potential. The paper also outlines a possible scenario for describing the post-flare stage of the observed long duration flare.

Field Assessment of Gopher Tortoise Habitat at Camp Shelby, MS. Phase II: Overstory and Combined Assessments

DTIC Science & Technology

2010-10-17

conditions between active, recently active and randomly selected non-burrow locations at this site. Field surveys were completed in three study areas ...at the installation. On average, burrow sites had a much higher overall occurrence of longleaf pine and significantly lower total basal area as...East Area burrow and non-burrow locations, Camp Shelby, MS 2007 .................. 10 2 Mean basal area per acre for pine and hardwood on T-44, Mars

Location, Location, Location: Where Do Location-Based Services Fit into Your Institution's Social Media Mix?

ERIC Educational Resources Information Center

Nekritz, Tim

2011-01-01

Foursquare is a location-based social networking service that allows users to share their location with friends. Some college administrators have been thinking about whether and how to take the leap into location-based services, which are also known as geosocial networking services. These platforms, which often incorporate gaming elements like…

Heat Retreat Locations in Cities - The Survey-Based Location Analysis of Heat Relief

NASA Astrophysics Data System (ADS)

Neht, Alice; Maximini, Claudia; Prenger-Berninghoff, Kathrin

2017-12-01

The adaptation of cities to climate change effects is one of the major strategies in urban planning to encounter the challenges of climate change (IPCC 2014). One of the fields of climate change adaption is dealing with heat events that occur more frequently and with greater intensity. Cities in particular are vulnerable to these events due to high population and infrastructure density. Proceeding urbanization calls for the existence of sufficient heat retreat locations (HRL) to enable relief for the population from heat in summer. This is why an extensive analysis of HRL is needed. This paper aims at the development of a survey-based location analysis of heat relief by identifying user groups, locations and characteristics of HRL based on a home survey that was conducted in three German cities. Key results of the study show that the majority of the participants of the survey are users of existing HRL, are affected by heat, and perceive heat as a burden in summer. Moreover, HRL that are located in close proximity are preferred by most users while their effect depends on the regional context that has to be considered in the analysis. Hence, this research presents an approach to heat relief that underlines the importance of HRL in cities by referring to selected examples of HRL types in densely populated areas of cities. HRL should especially be established and secured in densely built-up areas of cities. According to results of the survey, most HRL are located in public spaces, and the overall accessibility of HRL turned out to be an issue.

Scattering by multiple cylinders located on both sides of an interface

NASA Astrophysics Data System (ADS)

Lee, Siu-Chun

2018-07-01

The solution for scattering by multiple parallel infinite cylinders located in adjacent half spaces with dissimilar refractive index is presented in this paper. The incident radiation is an arbitrarily polarized plane wave propagating in the upper half space in the plane perpendicular to the axis of the cylinders. The formulation of the electromagnetic field vectors utilized Hertz potentials that are expressed in terms of an expansion of cylindrical wave functions. It accounts for the near-field multiple scattering, Fresnel effect at the interface, and interaction between cylinders in both half spaces. Analytical formulas are derived for the electromagnetic field and Poynting vector in the far-field. The present solution provides the theoretical framework for deducing the solutions for scattering by cylinders located on either side of an interface irradiated by a propagating or an evanescent incident wave. Deduction of these solutions from the present formulation is demonstrated. Numerical results are presented to illustrate the frustration of total internal reflection and scattering of light beyond the critical angle by nanocylinders located in either or both half spaces.

Emerald Field, Natrona County, Wyoming

DOE Office of Scientific and Technical Information (OSTI.GOV)

Swirczynski, R.P.

1978-01-01

The Emerald Field is located on the W.-central Casper Arch in Sect. Nos. 7, 8, 9, and 18, T37N, R84W, Natrona County, Wyo. The Notches Field located in Sect. Nos. 3 and 10, T37N, R85W is 5 miles west of the Emerald Field. Both the Emerald and Notches Field produce oil from structural traps in the Tensleep formation (Pennsylvanian).

Multiwavelength observations of magnetic fields and related activity on XI Bootis A

NASA Technical Reports Server (NTRS)

Saar, Steven H.; Huovelin, J.; Linsky, Jeffrey L.; Giampapa, Mark S.; Jordan, Carole

1988-01-01

Preliminary results of coordinated observations of magnetic fields and related activity on the active dwarf, Xi Boo A, are presented. Combining the magnetic fluxes with the linear polarization data, a simple map of the stellar active regions is constructed.

Response of Cultured Neuronal Network Activity After High-Intensity Power Frequency Magnetic Field Exposure

PubMed Central

Saito, Atsushi; Takahashi, Masayuki; Makino, Kei; Suzuki, Yukihisa; Jimbo, Yasuhiko; Nakasono, Satoshi

2018-01-01

High-intensity and low frequency (1–100 kHz) time-varying electromagnetic fields stimulate the human body through excitation of the nervous system. In power frequency range (50/60 Hz), a frequency-dependent threshold of the external electric field-induced neuronal modulation in cultured neuronal networks was used as one of the biological indicator in international guidelines; however, the threshold of the magnetic field-induced neuronal modulation has not been elucidated. In this study, we exposed rat brain-derived neuronal networks to a high-intensity power frequency magnetic field (hPF-MF), and evaluated the modulation of synchronized bursting activity using a multi-electrode array (MEA)-based extracellular recording technique. As a result of short-term hPF-MF exposure (50–400 mT root-mean-square (rms), 50 Hz, sinusoidal wave, 6 s), the synchronized bursting activity was increased in the 400 mT-exposed group. On the other hand, no change was observed in the 50–200 mT-exposed groups. In order to clarify the mechanisms of the 400 mT hPF-MF exposure-induced neuronal response, we evaluated it after blocking inhibitory synapses using bicuculline methiodide (BMI); subsequently, increase in bursting activity was observed with BMI application, and the response of 400 mT hPF-MF exposure disappeared. Therefore, it was suggested that the response of hPF-MF exposure was involved in the inhibitory input. Next, we screened the inhibitory pacemaker-like neuronal activity which showed autonomous 4–10 Hz firing with CNQX and D-AP5 application, and it was confirmed that the activity was reduced after 400 mT hPF-MF exposure. Comparison of these experimental results with estimated values of the induced electric field (E-field) in the culture medium revealed that the change in synchronized bursting activity occurred over 0.3 V/m, which was equivalent to the findings of a previous study that used the external electric fields. In addition, the results suggested that the

The effect of food location, heat load, and intrusive medical procedures on brushing activity in dairy cows.

PubMed

Mandel, R; Whay, H R; Nicol, C J; Klement, E

2013-10-01

Animals allocate time and effort to a range of core (e.g., sleeping, feeding, drinking) and "luxury" (e.g., playing, exploring) activities. A luxury activity is characterized by low resilience and, as such, will be reduced when time or energy resources are limited, including under conditions of stress or discomfort. One seemingly luxurious activity available to cows on an increasing number of dairy farms is rubbing against an automated brush. The current study examined the effect of distance from food, heat load, and an intrusive medical procedure (i.e., artificial insemination and transrectal pregnancy examination) on the resilience of brush usage. The probability of using the brush decreased significantly when food was located distantly from the brush (mean=0.53) compared with days when food was located closer to the brush (mean=0.81). Brush usage also decreased at high temperature and humidity levels, with an average decrease of 0.062 brushing events for an increase of 1 temperature-humidity index unit (95% confidence interval=-0.93-0.030). In addition, a significant reduction of approximately 50% in brushing activity was observed on days of artificial insemination compared with the preceding 3d and the following 3d. These findings show that brush usage is a low resilience activity that reduces under a range of conditions. It may thus have the potential to be used as an indicator of a range of health and welfare problems in cows. Further research should be conducted to assess the sensitivity and specificity of this suggested tool and its possible contribution to the early detection of morbidity. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Measuring the volume of brain tumour and determining its location in T2-weighted MRI images using hidden Markov random field: expectation maximization algorithm

NASA Astrophysics Data System (ADS)

Mat Jafri, Mohd. Zubir; Abdulbaqi, Hayder Saad; Mutter, Kussay N.; Mustapha, Iskandar Shahrim; Omar, Ahmad Fairuz

2017-06-01

A brain tumour is an abnormal growth of tissue in the brain. Most tumour volume measurement processes are carried out manually by the radiographer and radiologist without relying on any auto program. This manual method is a timeconsuming task and may give inaccurate results. Treatment, diagnosis, signs and symptoms of the brain tumours mainly depend on the tumour volume and its location. In this paper, an approach is proposed to improve volume measurement of brain tumors as well as using a new method to determine the brain tumour location. The current study presents a hybrid method that includes two methods. One method is hidden Markov random field - expectation maximization (HMRFEM), which employs a positive initial classification of the image. The other method employs the threshold, which enables the final segmentation. In this method, the tumour volume is calculated using voxel dimension measurements. The brain tumour location was determined accurately in T2- weighted MRI image using a new algorithm. According to the results, this process was proven to be more useful compared to the manual method. Thus, it provides the possibility of calculating the volume and determining location of a brain tumour.

Higher Education as a Field of Study: Some Future Prospects. ASHE 1986 Annual Meeting Paper.

ERIC Educational Resources Information Center

Cooper, Jack H.

Problems and perspectives about the college professoriate are discussed. Attention is directed to: organization and location of graduate programs; enrollment declines and fluctuation; scholarly activities of professors; consulting and field work; and teaching. One of the recent developments of higher education as a field of study has been that…

Mapping the Evolution of Scientific Fields

PubMed Central

Herrera, Mark; Roberts, David C.; Gulbahce, Natali

2010-01-01

Despite the apparent cross-disciplinary interactions among scientific fields, a formal description of their evolution is lacking. Here we describe a novel approach to study the dynamics and evolution of scientific fields using a network-based analysis. We build an idea network consisting of American Physical Society Physics and Astronomy Classification Scheme (PACS) numbers as nodes representing scientific concepts. Two PACS numbers are linked if there exist publications that reference them simultaneously. We locate scientific fields using a community finding algorithm, and describe the time evolution of these fields over the course of 1985–2006. The communities we identify map to known scientific fields, and their age depends on their size and activity. We expect our approach to quantifying the evolution of ideas to be relevant for making predictions about the future of science and thus help to guide its development. PMID:20463949

A wireless object location detector enabling people with developmental disabilities to control environmental stimulation through simple occupational activities with Nintendo Wii Balance Boards.

PubMed

Shih, Ching-Hsiang; Chang, Man-Ling

2012-01-01

The latest researches have adopted software technology, turning the Nintendo Wii Balance Board into a high performance standing location detector with a newly developed standing location detection program (SLDP). This study extended SLDP functionality to assess whether two people with developmental disabilities would be able to actively perform simple occupational activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards and SLDP software. An ABAB design was adopted in this study to perform the tests. The test results showed that, during the intervention phases, both participants significantly increased their target response (i.e. simple occupational activity) to activate the control system to produce environmental stimulation. The practical and developmental implications of the findings are discussed. Copyright © 2012 Elsevier Ltd. All rights reserved.

ALTERATIONS IN CALCIUM ION ACTIVITY BY ELF AND RF ELECTROMAGNETIC FIELDS

EPA Science Inventory

Alterations in calcium ion activity by ELF and RF electromagnetic fields

Introduction

Calcium ions play many important roles in biological systems. For example, calcium ion activity can be used as an indicator of second-messenger signal-transduction processe...

Microseismic response characteristics modeling and locating of underground water supply pipe leak

NASA Astrophysics Data System (ADS)

Wang, J.; Liu, J.

2015-12-01

In traditional methods of pipeline leak location, geophones must be located on the pipe wall. If the exact location of the pipeline is unknown, the leaks cannot be identified accurately. To solve this problem, taking into account the characteristics of the pipeline leak, we propose a continuous random seismic source model and construct geological models to investigate the proposed method for locating underground pipeline leaks. Based on two dimensional (2D) viscoacoustic equations and the staggered grid finite-difference (FD) algorithm, the microseismic wave field generated by a leaking pipe is modeled. Cross-correlation analysis and the simulated annealing (SA) algorithm were utilized to obtain the time difference and the leak location. We also analyze and discuss the effect of the number of recorded traces, the survey layout, and the offset and interval of the traces on the accuracy of the estimated location. The preliminary results of the simulation and data field experiment indicate that (1) a continuous random source can realistically represent the leak microseismic wave field in a simulation using 2D visco-acoustic equations and a staggered grid FD algorithm. (2) The cross-correlation method is effective for calculating the time difference of the direct wave relative to the reference trace. However, outside the refraction blind zone, the accuracy of the time difference is reduced by the effects of the refracted wave. (3) The acquisition method of time difference based on the microseismic theory and SA algorithm has a great potential for locating leaks from underground pipelines from an array located on the ground surface. Keywords: Viscoacoustic finite-difference simulation; continuous random source; simulated annealing algorithm; pipeline leak location

Lava Field, Syria

NASA Image and Video Library

2015-05-27

In southern Syria, the Azraq-Wadi as Sirhan Depression is the site of young volcanic activity, producing an extensive basaltic volcanic field. The north-northwest to south-southeast structural and fault control of the crust is evident in the straight alignment of numerous chains of cinder cones. At the top of the image, the northeast trending streaks are windblown sand deposits. The image was acquired May 20, 2009, covers an area of 46.5 x 67 km, and is located at 33.3 degrees north, 37.1 degrees east. http://photojournal.jpl.nasa.gov/catalog/PIA19479

Oblique map of the northern Sierra Nevada, California, showing location of gold-bearing areas

USGS Publications Warehouse

Alpha, T.R.; Dodge, F.C.W.; Bliss, J.D.

1987-01-01

Locations of lode gold prospects and mines shown on the map were obtained from the U.S. Geological Survey's Mineral Resource Data System (MRDS), a computerized mineral-resource information file, and plotted in their respective locations (D.F. Huber, written commun., 1986). Some locations from two northern counties, missing from the MRDS retrival, were added. The twenty lode mines believed to be the most productive are cited in table 1. A total of nearly 4,000 sites, including both prospects and mines, were initially plotted, but about a third of those were obscured by topography on the oblique map. Locations of Tertiary river channels and gold-dredging fields were taken from published general references modified by examining specific sources and by cursory field examination. Seven of the major dredge fields are identified in table 2.

Geodesic active fields--a geometric framework for image registration.

PubMed

Zosso, Dominique; Bresson, Xavier; Thiran, Jean-Philippe

2011-05-01

In this paper we present a novel geometric framework called geodesic active fields for general image registration. In image registration, one looks for the underlying deformation field that best maps one image onto another. This is a classic ill-posed inverse problem, which is usually solved by adding a regularization term. Here, we propose a multiplicative coupling between the registration term and the regularization term, which turns out to be equivalent to embed the deformation field in a weighted minimal surface problem. Then, the deformation field is driven by a minimization flow toward a harmonic map corresponding to the solution of the registration problem. This proposed approach for registration shares close similarities with the well-known geodesic active contours model in image segmentation, where the segmentation term (the edge detector function) is coupled with the regularization term (the length functional) via multiplication as well. As a matter of fact, our proposed geometric model is actually the exact mathematical generalization to vector fields of the weighted length problem for curves and surfaces introduced by Caselles-Kimmel-Sapiro. The energy of the deformation field is measured with the Polyakov energy weighted by a suitable image distance, borrowed from standard registration models. We investigate three different weighting functions, the squared error and the approximated absolute error for monomodal images, and the local joint entropy for multimodal images. As compared to specialized state-of-the-art methods tailored for specific applications, our geometric framework involves important contributions. Firstly, our general formulation for registration works on any parametrizable, smooth and differentiable surface, including nonflat and multiscale images. In the latter case, multiscale images are registered at all scales simultaneously, and the relations between space and scale are intrinsically being accounted for. Second, this method is, to

Location, Location, Location!

ERIC Educational Resources Information Center

Ramsdell, Kristin

2004-01-01

Of prime importance in real estate, location is also a key element in the appeal of romances. Popular geographic settings and historical periods sell, unpopular ones do not--not always with a logical explanation, as the author discovered when she conducted a survey on this topic last year. (Why, for example, are the French Revolution and the…

Active subspace uncertainty quantification for a polydomain ferroelectric phase-field model

NASA Astrophysics Data System (ADS)

Leon, Lider S.; Smith, Ralph C.; Miles, Paul; Oates, William S.

2018-03-01

Quantum-informed ferroelectric phase field models capable of predicting material behavior, are necessary for facilitating the development and production of many adaptive structures and intelligent systems. Uncertainty is present in these models, given the quantum scale at which calculations take place. A necessary analysis is to determine how the uncertainty in the response can be attributed to the uncertainty in the model inputs or parameters. A second analysis is to identify active subspaces within the original parameter space, which quantify directions in which the model response varies most dominantly, thus reducing sampling effort and computational cost. In this investigation, we identify an active subspace for a poly-domain ferroelectric phase-field model. Using the active variables as our independent variables, we then construct a surrogate model and perform Bayesian inference. Once we quantify the uncertainties in the active variables, we obtain uncertainties for the original parameters via an inverse mapping. The analysis provides insight into how active subspace methodologies can be used to reduce computational power needed to perform Bayesian inference on model parameters informed by experimental or simulated data.

A Wireless Object Location Detector Enabling People with Developmental Disabilities to Control Environmental Stimulation through Simple Occupational Activities with Nintendo Wii Balance Boards

ERIC Educational Resources Information Center

Shih, Ching-Hsiang; Chang, Man-Ling

2012-01-01

The latest researches have adopted software technology, turning the Nintendo Wii Balance Board into a high performance standing location detector with a newly developed standing location detection program (SLDP). This study extended SLDP functionality to assess whether two people with developmental disabilities would be able to actively perform…

Processing of pitch and location in human auditory cortex during visual and auditory tasks.

PubMed

Häkkinen, Suvi; Ovaska, Noora; Rinne, Teemu

2015-01-01

The relationship between stimulus-dependent and task-dependent activations in human auditory cortex (AC) during pitch and location processing is not well understood. In the present functional magnetic resonance imaging study, we investigated the processing of task-irrelevant and task-relevant pitch and location during discrimination, n-back, and visual tasks. We tested three hypotheses: (1) According to prevailing auditory models, stimulus-dependent processing of pitch and location should be associated with enhanced activations in distinct areas of the anterior and posterior superior temporal gyrus (STG), respectively. (2) Based on our previous studies, task-dependent activation patterns during discrimination and n-back tasks should be similar when these tasks are performed on sounds varying in pitch or location. (3) Previous studies in humans and animals suggest that pitch and location tasks should enhance activations especially in those areas that also show activation enhancements associated with stimulus-dependent pitch and location processing, respectively. Consistent with our hypotheses, we found stimulus-dependent sensitivity to pitch and location in anterolateral STG and anterior planum temporale (PT), respectively, in line with the view that these features are processed in separate parallel pathways. Further, task-dependent activations during discrimination and n-back tasks were associated with enhanced activations in anterior/posterior STG and posterior STG/inferior parietal lobule (IPL) irrespective of stimulus features. However, direct comparisons between pitch and location tasks performed on identical sounds revealed no significant activation differences. These results suggest that activations during pitch and location tasks are not strongly affected by enhanced stimulus-dependent activations to pitch or location. We also found that activations in PT were strongly modulated by task requirements and that areas in the inferior parietal lobule (IPL) showed

Processing of pitch and location in human auditory cortex during visual and auditory tasks

PubMed Central

Häkkinen, Suvi; Ovaska, Noora; Rinne, Teemu

2015-01-01

The relationship between stimulus-dependent and task-dependent activations in human auditory cortex (AC) during pitch and location processing is not well understood. In the present functional magnetic resonance imaging study, we investigated the processing of task-irrelevant and task-relevant pitch and location during discrimination, n-back, and visual tasks. We tested three hypotheses: (1) According to prevailing auditory models, stimulus-dependent processing of pitch and location should be associated with enhanced activations in distinct areas of the anterior and posterior superior temporal gyrus (STG), respectively. (2) Based on our previous studies, task-dependent activation patterns during discrimination and n-back tasks should be similar when these tasks are performed on sounds varying in pitch or location. (3) Previous studies in humans and animals suggest that pitch and location tasks should enhance activations especially in those areas that also show activation enhancements associated with stimulus-dependent pitch and location processing, respectively. Consistent with our hypotheses, we found stimulus-dependent sensitivity to pitch and location in anterolateral STG and anterior planum temporale (PT), respectively, in line with the view that these features are processed in separate parallel pathways. Further, task-dependent activations during discrimination and n-back tasks were associated with enhanced activations in anterior/posterior STG and posterior STG/inferior parietal lobule (IPL) irrespective of stimulus features. However, direct comparisons between pitch and location tasks performed on identical sounds revealed no significant activation differences. These results suggest that activations during pitch and location tasks are not strongly affected by enhanced stimulus-dependent activations to pitch or location. We also found that activations in PT were strongly modulated by task requirements and that areas in the inferior parietal lobule (IPL) showed

The Evaluation of Bioelectrical Activity of Pelvic Floor Muscles Depending on Probe Location: A Pilot Study

PubMed Central

Słupska, Lucyna

2013-01-01

Objectives. The main objective was to determine how the depth of probe placement affects functional and resting bioelectrical activity of the PFM and whether the recorded signal might be dependent on the direction in which the probe is rotated. Participants. The study comprised of healthy, nulliparous women between the ages of 21 and 25. Outcome Measures. Bioelectric activity of the PFM was recorded from four locations of the vagina by surface EMG and vaginal probe. Results. There were no statistically significant differences between the results during functional sEMG activity. During resting sEMG activity, the highest bioelectrical activity of the PFM was observed in the L1 and the lowest in the L4 and a statistically significant difference between the highest and the lowest results of resting sEMG activity was observed (P = 0.0043). Conclusion. Different electrodes placement during functional contraction of PFM does not affect the obtained results in sEMG evaluation. In order to diagnose the highest resting activity of PFM the recording plates should be placed toward the anterior vaginal wall and distally from the introitus. However, all of the PFM have similar bioelectrical activity and it seems that these muscles could be treated as a single muscle. PMID:24392449

Geochemical and geophysical monitoring activities in Campo de Calatrava Volcanic Field (Spain)

NASA Astrophysics Data System (ADS)

Luengo-Oroz, Natividad; Villasante-Marcos, Víctor; López-Díaz, Rubén; Calvo, Marta; Albert, Helena; Domínguez Cerdeña, Itahiza

2017-04-01

The Campo de Calatrava Volcanic Field (CCVF) or Spanish Central Volcanic Zone is located in central continental Spain (Ciudad Real province) and covers about 5000 km2. It includes around 240 eruptive centers, mainly monogenetic basaltic cones but also explosive maar structures. According to K-Ar geochronology, its main activity phase occurred during Pliocene and Pleistocene epochs (between 5 and 1.7 Ma) and involved alkaline to ultraalkaline magmas, although an older ultrapotassic phase is dated around 8.7-6.4 Ma. However, some recent works have proposed Holocene ages for some of the volcanic products, opening the possibility of considering the CCVF "active" according to international standards. Responding to this situation, the Instituto Geográfico Nacional (IGN) has initiated geochemical and geophysical monitoring activities in the CCVF. Here, we describe these ongoing efforts and we report results about groundwater geochemistry at several natural highly-gaseous springs in the area (hervideros), as well as soil temperature, CO2 diffuse flux from the soil and electrical self-potential data mapped on a small degassing structure called La Sima. In order to analyze microseismicity or any seismic anomaly in the CCVF, a seismic station has also been installed close to this degassing structure. Physicochemical parameters (temperature, pH, Eh and electric conductivity) were measured in situ in four springs and samples were taken in order to analyze major ions and trace elements. Total composition of dissolved gases and helium isotopic ratios were also determined. To complete soil temperature, self-potential and gas prospections performed in La Sima, soil gases were sampled at the bottom of the structure at a depth of 20 cm. Analysis of the total gas composition found 957400 ppm of CO2. Low values of O2 and N2 were also detected (5600 and 24800 ppm respectively).

Field Immune Assessment during Simulated Planetary Exploration in the Canadian Arctic

NASA Technical Reports Server (NTRS)

Crucian, Brian; Lee, Pascal; Stowe, Raymond; Jones, Jeff; Effenhauser, Rainer; Widen, Raymond; Sams, Clarence

2006-01-01

Dysregulation of the immune system has been shown to occur during space flight, although the detailed nature of the phenomenon and the clinical risks for exploration class missions has yet to be established. In addition, the growing clinical significance of immune system evaluation combined with epidemic infectious disease rates in third world countries provides a strong rationale for the development of field-compatible clinical immunology techniques and equipment. In July 2002 NASA performed a comprehensive field immunology assessment on crewmembers participating in the Haughton-Mars Project (HMP) on Devon Island in the high Canadian Arctic. The purpose of the study was to evaluate mission-associated effects on the human immune system, as well as to evaluate techniques developed for processing immune samples in remote field locations. Ten HMP-2002 participants volunteered for the study. A field protocol was developed at NASA-JSC for performing sample collection, blood staining/processing for immunophenotype analysis, wholeblood mitogenic culture for functional assessments and cell-sample preservation on-location at Devon Island. Specific assays included peripheral leukocyte distribution; constitutively activated T cells, intracellular cytokine profiles and plasma EBV viral antibody levels. Study timepoints were L-30, midmission and R+60. The protocol developed for immune sample processing in remote field locations functioned properly. Samples were processed in the field location, and stabilized for subsequent analysis at the Johnson Space Center in Houston. The data indicated that some phenotype, immune function and stress hormone changes occurred in the HMP field participants that were largely distinct from pre-mission baseline and post-mission recovery data. These immune changes appear similar to those observed in Astronauts following spaceflight. The sample processing protocol developed for this study may have applications for immune assessment during

Ectomycorrhizal Fungal Communities and Enzymatic Activities Vary across an Ecotone between a Forest and Field.

PubMed

Rúa, Megan A; Moore, Becky; Hergott, Nicole; Van, Lily; Jackson, Colin R; Hoeksema, Jason D

2015-08-28

Extracellular enzymes degrade macromolecules into soluble substrates and are important for nutrient cycling in soils, where microorganisms, such as ectomycorrhizal (ECM) fungi, produce these enzymes to obtain nutrients. Ecotones between forests and fields represent intriguing arenas for examining the effect of the environment on ECM community structure and enzyme activity because tree maturity, ECM composition, and environmental variables may all be changing simultaneously. We studied the composition and enzymatic activity of ECM associated with loblolly pine (Pinus taeda) across an ecotone between a forest where P. taeda is established and an old field where P. taeda saplings had been growing for <5 years. ECM community and environmental characteristics influenced enzyme activity in the field, indicating that controls on enzyme activity may be intricately linked to the ECM community, but this was not true in the forest. Members of the Russulaceae were associated with increased phenol oxidase activity and decreased peroxidase activity in the field. Members of the Atheliaceae were particularly susceptible to changes in their abiotic environment, but this did not mediate differences in enzyme activity. These results emphasize the complex nature of factors that dictate the distribution of ECM and activity of their enzymes across a habitat boundary.

Electric field encephalography for brain activity monitoring.

PubMed

Versek, Craig William; Frasca, Tyler; Zhou, Jianlin; Chowdhury, Kaushik; Sridhar, Srinivas

2018-05-11

likely sensitive to inter-subject variations and choice of scalp locations, so require further investigation. Significance - Enhancement of ssVEP SNR using EFEG has the potential to improve visually based BCIs and diagnostic paradigms. The time domain analysis of tVEPF signals shows robust features in the electric field components that might have clinical relevance beyond classical VEP approaches. . © 2018 IOP Publishing Ltd.

Local versus regional active stress field in 5900m San Gregorio Magno 1 well (southern Apennines, Italy).

NASA Astrophysics Data System (ADS)

Pierdominici, S.; Montone, P.; Mariucci, M. T.

2009-04-01

The aim of this work is to characterize the local stress field in a peculiar sector of the southern Apennines by analyzing borehole breakouts, fractures and logging data along the San Gregorio Magno 1 deep well, and to compare the achieved stress field with the regional one. The study area is characterized by diffuse low-Magnitude seismicity, although in historical times it has been repeatedly struck by moderate to large earthquakes. We have analyzed in detail the 5900m San Gregorio Magno 1 well drilled in 1996-97 by ENI S.p.A. and located very close (1.3 km away) to the Irpinia Fault. This fault was responsible of the strongest earthquake happened in this area, the 23rd November 1980 M6.9 earthquake that produced the first unequivocal historical surface faulting ever documented in Italy. The mainshock enucleated on a fault 38 km-long with a strike of 308° and 60-70° northeast-dipping, consistent with a NE-SW T-axis and a normal faulting tectonic regime. Borehole breakouts, active faults and focal mechanism solutions have allowed to define the present-day stress along and around the San Gregorio Magno 1 well and other analysis (logging data) to discriminate the presence of fracture zones and/or faults at depth. We have considered data from 1200m to the bottom of San Gregorio Magno 1 well. Our analysis of stress-induced wellbore breakouts shows an inhomogeneous direction of minimum horizontal stress (N359+-31°) orientation along the well. This direction is moderately consistent with the Shmin-trend determined from breakouts in other wells in this region and also with the regional active stress field inferred from active faults and earthquake focal plane solutions (N44 Shmin oriented). For this reason we have computed for each breakout zone the difference between the local trend and the regional one; comparing these breakout rotations with the spikes or changing trend of logs we have identified possible fractures or faults at different depths. We have correlated

Transfer of location-specific control to untrained locations.

PubMed

Weidler, Blaire J; Bugg, Julie M

2016-11-01

Recent research highlights a seemingly flexible and automatic form of cognitive control that is triggered by potent contextual cues, as exemplified by the location-specific proportion congruence effect--reduced compatibility effects in locations associated with a high as compared to low likelihood of conflict. We investigated just how flexible location-specific control is by examining whether novel locations effectively cue control for congruency-unbiased stimuli. In two experiments, biased (mostly compatible or mostly incompatible) training stimuli appeared in distinct locations. During a final block, unbiased (50% compatible) stimuli appeared in novel untrained locations spatially linked to biased locations. The flanker compatibly effect was reduced for unbiased stimuli in novel locations linked to a mostly incompatible compared to a mostly compatible location, indicating transfer. Transfer was observed when stimuli appeared along a linear function (Experiment 1) or in rings of a bullseye (Experiment 2). The novel transfer effects imply that location-specific control is more flexible than previously reported and further counter the complex stimulus-response learning account of location-specific proportion congruence effects. We propose that the representation and retrieval of control settings in untrained locations may depend on environmental support and the presentation of stimuli in novel locations that fall within the same categories of space as trained locations.

New strategies to strengthen the soil science knowledge of student during field activities

NASA Astrophysics Data System (ADS)

Benito, Marta; Hontoria, Chiquinquirá; Masaguer, Alberto; Diéguez, Carmen; Almorox, Javier; Pérez, Juana; Santano, Jesús; Mariscal, Ignacio; Gutiérrez, Jesús; Moliner, Ana

2013-04-01

Soil Science can be considered a discipline that serves as a fundamental base for other disciplines such as ecology, agronomy, plant production, etc. In order to demonstrate the relevance and connection to real world it is important to develop field and practical activities. Field activities help student to comprehend soil as part of the landscape and the natural ecosystems. These activities also help them to realize the importance of historical soil use on the quality of todaýs soil and landscapes. It is well known that fieldwork practices are essential to strengthen the soil science knowledge of students and their learning process. These fieldwork practices involve doing a physical activity rather than passively attending lectures or watching demonstrations. The simple visual and tactile observations in the field could be used to predict soil behavior and these direct observations are best made in the field. Students who learned in the field using an active work are more motivated, have more positive attitudes, and place more value in their work than those that learn passively. Therefore, when scheduling the coursework an important time is assigned to field work, which sometimes is not sufficiently profited from the standpoint of student learning taking into consideration the economic effort involved. We are aware that part of the students are simple spectators in the field so we encourage their participation by making them responsible for obtaining part of the information about the place and the types of soils that will be visited. On the other hand, we will invite the students to do some game based exercises, which are fun and force them to work in groups and to pay attention to explanations. Our objective is to present the information in a more attractive way, making the learning of soil profile description and easier task. The exercises that we propose are both field and problem-based learning to make sure that the knowledge is more memorable (non

Phonological Processing in Human Auditory Cortical Fields

PubMed Central

Woods, David L.; Herron, Timothy J.; Cate, Anthony D.; Kang, Xiaojian; Yund, E. W.

2011-01-01

We used population-based cortical-surface analysis of functional magnetic imaging data to characterize the processing of consonant–vowel–consonant syllables (CVCs) and spectrally matched amplitude-modulated noise bursts (AMNBs) in human auditory cortex as subjects attended to auditory or visual stimuli in an intermodal selective attention paradigm. Average auditory cortical field (ACF) locations were defined using tonotopic mapping in a previous study. Activations in auditory cortex were defined by two stimulus-preference gradients: (1) Medial belt ACFs preferred AMNBs and lateral belt and parabelt fields preferred CVCs. This preference extended into core ACFs with medial regions of primary auditory cortex (A1) and the rostral field preferring AMNBs and lateral regions preferring CVCs. (2) Anterior ACFs showed smaller activations but more clearly defined stimulus preferences than did posterior ACFs. Stimulus preference gradients were unaffected by auditory attention suggesting that ACF preferences reflect the automatic processing of different spectrotemporal sound features. PMID:21541252

Earth's Magnetic Field Measurements for the LCLS Undulators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hacker, Kirsten

2010-12-13

Measurements of the earth's magnetic field at several locations at SLAC were conducted to determine the possible field error contribution from tuning the undulators in a location with a different magnetic field than that which will be found in the undulator hall. An average difference of 0.08 {+-} 0.04 Gauss has been measured between the downward earth's field components in the test facility and SLAC tunnel locations.

Supporting Mobile Collaborative Activities through Scaffolded Flexible Grouping

ERIC Educational Resources Information Center

Boticki, Ivica; Looi, Chee-Kit; Wong, Lung-Hsiang

2011-01-01

Within the field of Mobile Computer-Supported Collaborative Learning (mCSCL), we are interested in exploring the space of collaborative activities that enable students to practice communication, negotiation and decision-making skills. Collaboration is via learning activities that circumvent the constraints of fixed seating or locations of…

Effects of reconstructed magnetic field from sparse noisy boundary measurements on localization of active neural source.

PubMed

Shen, Hui-min; Lee, Kok-Meng; Hu, Liang; Foong, Shaohui; Fu, Xin

2016-01-01

Localization of active neural source (ANS) from measurements on head surface is vital in magnetoencephalography. As neuron-generated magnetic fields are extremely weak, significant uncertainties caused by stochastic measurement interference complicate its localization. This paper presents a novel computational method based on reconstructed magnetic field from sparse noisy measurements for enhanced ANS localization by suppressing effects of unrelated noise. In this approach, the magnetic flux density (MFD) in the nearby current-free space outside the head is reconstructed from measurements through formulating the infinite series solution of the Laplace's equation, where boundary condition (BC) integrals over the entire measurements provide "smooth" reconstructed MFD with the decrease in unrelated noise. Using a gradient-based method, reconstructed MFDs with good fidelity are selected for enhanced ANS localization. The reconstruction model, spatial interpolation of BC, parametric equivalent current dipole-based inverse estimation algorithm using reconstruction, and gradient-based selection are detailed and validated. The influences of various source depths and measurement signal-to-noise ratio levels on the estimated ANS location are analyzed numerically and compared with a traditional method (where measurements are directly used), and it was demonstrated that gradient-selected high-fidelity reconstructed data can effectively improve the accuracy of ANS localization.

Antarctic Meteorite Location and Mapping Project (AMLAMP): Antarctic meteorite location map series explanatory text and user's guide to AMLAMP data

NASA Technical Reports Server (NTRS)

Schutt, J.; Fessler, B.; Cassidy, W. A.

1993-01-01

This technical report is an update to LPI Technical Report 89-02, which contained data and information that was current to May 1987. Since that time approximately 4000 new meteorites have been collected, mapped, and characterized, mainly from the numerous ice fields in the Allan Hills-David Glacier region, from the Pecora Escarpment and Moulton Escarpment in the Thiel Mountains-Patuxent region, the Wisconsin Range region, and from the Beardmore region. Meteorite location maps for ice fields from these regions have been produced and are available. This report includes explanatory texts for the maps of new areas and provides information on updates of maps of the areas covered in LPI Technical Report 89-02. Sketch maps and description of locales that have been searched and have yielded single or few meteorites are also included. The meteorite listings for all the ice fields have been updated to include any classification changes and new meteorites recovered from ice fields in the Allan Hills-David Glacier region since 1987. The text has been reorganized and minor errors in the original report have been corrected. Computing capabilities have improved immensely since the early days of this project. Current software and hardware allow easy access to data over computer networks. With various commercial software packages, the data can be used many different ways, including database creation, statistics, and mapping. The databases, explanatory texts, and the plotter files used to produce the meteorite location maps are available through a computer network. Information on how to access AMLAMP data, its formats, and ways it can be used are given in the User's Guide to AMLAMP Data section. Meteorite location maps and thematic maps may be ordered from the Lunar and Planetary Institute. Ordering information is given in Appendix A.

Identification of cardiac rhythm features by mathematical analysis of vector fields.

PubMed

Fitzgerald, Tamara N; Brooks, Dana H; Triedman, John K

2005-01-01

Automated techniques for locating cardiac arrhythmia features are limited, and cardiologists generally rely on isochronal maps to infer patterns in the cardiac activation sequence during an ablation procedure. Velocity vector mapping has been proposed as an alternative method to study cardiac activation in both clinical and research environments. In addition to the visual cues that vector maps can provide, vector fields can be analyzed using mathematical operators such as the divergence and curl. In the current study, conduction features were extracted from velocity vector fields computed from cardiac mapping data. The divergence was used to locate ectopic foci and wavefront collisions, and the curl to identify central obstacles in reentrant circuits. Both operators were applied to simulated rhythms created from a two-dimensional cellular automaton model, to measured data from an in situ experimental canine model, and to complex three-dimensional human cardiac mapping data sets. Analysis of simulated vector fields indicated that the divergence is useful in identifying ectopic foci, with a relatively small number of vectors and with errors of up to 30 degrees in the angle measurements. The curl was useful for identifying central obstacles in reentrant circuits, and the number of velocity vectors needed increased as the rhythm became more complex. The divergence was able to accurately identify canine in situ pacing sites, areas of breakthrough activation, and wavefront collisions. In data from human arrhythmias, the divergence reliably estimated origins of electrical activity and wavefront collisions, but the curl was less reliable at locating central obstacles in reentrant circuits, possibly due to the retrospective nature of data collection. The results indicate that the curl and divergence operators applied to velocity vector maps have the potential to add valuable information in cardiac mapping and can be used to supplement human pattern recognition.

Bucking coil implementation on PMT for active canceling of magnetic field

NASA Astrophysics Data System (ADS)

Gogami, T.; Asaturyan, A.; Bono, J.; Baturin, P.; Chen, C.; Chiba, A.; Chiga, N.; Fujii, Y.; Hashimoto, O.; Kawama, D.; Maruta, T.; Maxwell, V.; Mkrtchyan, A.; Nagao, S.; Nakamura, S. N.; Reinhold, J.; Shichijo, A.; Tang, L.; Taniya, N.; Wood, S. A.; Ye, Z.

2013-11-01

Aerogel and water Čherenkov detectors were employed to tag kaons for a Λ hypernuclear spectroscopic experiment which used the (e,e‧K+) reaction in experimental Hall C at Jefferson Lab (JLab E05-115). Fringe fields from the kaon spectrometer magnet yielded ~5 gauss at the photomultiplier tubes for these detectors. These fields, which could not be easily passively shielded, would result in a lowered kaon detection efficiency if not mitigated. A bucking coil was placed on each photomultiplier tube to actively cancel this magnetic field, thus recovering kaon detection efficiency.

Visual field asymmetries in visual evoked responses

PubMed Central

Hagler, Donald J.

2014-01-01

Behavioral responses to visual stimuli exhibit visual field asymmetries, but cortical folding and the close proximity of visual cortical areas make electrophysiological comparisons between different stimulus locations problematic. Retinotopy-constrained source estimation (RCSE) uses distributed dipole models simultaneously constrained by multiple stimulus locations to provide separation between individual visual areas that is not possible with conventional source estimation methods. Magnetoencephalography and RCSE were used to estimate time courses of activity in V1, V2, V3, and V3A. Responses to left and right hemifield stimuli were not significantly different. Peak latencies for peripheral stimuli were significantly shorter than those for perifoveal stimuli in V1, V2, and V3A, likely related to the greater proportion of magnocellular input to V1 in the periphery. Consistent with previous results, sensor magnitudes for lower field stimuli were about twice as large as for upper field, which is only partially explained by the proximity to sensors for lower field cortical sources in V1, V2, and V3. V3A exhibited both latency and amplitude differences for upper and lower field responses. There were no differences for V3, consistent with previous suggestions that dorsal and ventral V3 are two halves of a single visual area, rather than distinct areas V3 and VP. PMID:25527151

Relationship between location and activity in injurious falls: an exploratory study

PubMed Central

2010-01-01

Background Knowledge about the circumstances under which injurious falls occur could provide healthcare workers with better tools to prevent falls and fall-related injuries. Therefore, we assessed whether older persons who sustain an injurious fall can be classified into specific fall types, based on a combination of fall location and activity up to the moment of the fall. In addition, we assessed whether specific injurious fall types are related to causes of the fall, consequences of the fall, socio-demographic characteristics, and health-related characteristics. Methods An exploratory, cross-sectional study design was used to identify injurious fall types. The study population comprised 333 community-dwelling Dutch elderly people aged 65 years or over who attended an accident and emergency department after a fall. All participants received a self-administered questionnaire after being discharged home. The questionnaire comprised items concerning circumstances of the injurious fall, causes of the fall, consequences of the fall, socio-demographic characteristics and health-related characteristics. Injurious fall types were distinguished by analyzing data by means of HOMALS (homogeneity analysis by means of alternating least squares). Results We identified 4 injurious fall types: 1) Indoor falls related to lavatory visits (hall and bathroom); 2) Indoor falls during other activities of daily living; 3) Outdoor falls near the home during instrumental activities of daily living; 4) Outdoor falls away from home, occurring during walking, cycling, and shopping for groceries. These injurious fall types were significantly related to age, cause of the fall, activity avoidance and daily functioning. Conclusion The face validity of the injurious fall typology is obvious. However, we found no relationship between the injurious fall types and severity of the consequences of the fall. Nevertheless, there appears to be a difference between the prevalence of fractures and the

Hydrogen Field Test Standard: Laboratory and Field Performance

PubMed Central

Pope, Jodie G.; Wright, John D.

2015-01-01

The National Institute of Standards and Technology (NIST) developed a prototype field test standard (FTS) that incorporates three test methods that could be used by state weights and measures inspectors to periodically verify the accuracy of retail hydrogen dispensers, much as gasoline dispensers are tested today. The three field test methods are: 1) gravimetric, 2) Pressure, Volume, Temperature (PVT), and 3) master meter. The FTS was tested in NIST's Transient Flow Facility with helium gas and in the field at a hydrogen dispenser location. All three methods agree within 0.57 % and 1.53 % for all test drafts of helium gas in the laboratory setting and of hydrogen gas in the field, respectively. The time required to perform six test drafts is similar for all three methods, ranging from 6 h for the gravimetric and master meter methods to 8 h for the PVT method. The laboratory tests show that 1) it is critical to wait for thermal equilibrium to achieve density measurements in the FTS that meet the desired uncertainty requirements for the PVT and master meter methods; in general, we found a wait time of 20 minutes introduces errors < 0.1 % and < 0.04 % in the PVT and master meter methods, respectively and 2) buoyancy corrections are important for the lowest uncertainty gravimetric measurements. The field tests show that sensor drift can become a largest component of uncertainty that is not present in the laboratory setting. The scale was calibrated after it was set up at the field location. Checks of the calibration throughout testing showed drift of 0.031 %. Calibration of the master meter and the pressure sensors prior to travel to the field location and upon return showed significant drifts in their calibrations; 0.14 % and up to 1.7 %, respectively. This highlights the need for better sensor selection and/or more robust sensor testing prior to putting into field service. All three test methods are capable of being successfully performed in the field and give

Magnetic fields over active tectonic zones in ocean

USGS Publications Warehouse

Kopytenko, Yu. A.; Serebrianaya, P.M.; Nikitina, L.V.; Green, A.W.

2002-01-01

The aim of our work is to estimate the electromagnetic effects that can be detected in the submarine zones with hydrothermal activity. It is known that meso-scale flows appear in the regions over underwater volcanoes or hot rocks. Their origin is connected with heat flux and hot jets released from underwater volcanoes or faults in a sea bottom. Values of mean velocities and turbulent velocities in plumes were estimated. Quasiconstant magnetic fields induced by a hot jet and a vortex over a plume top are about 1-40 nT. Variable magnetic fields are about 0.1-1 nT. These magnetic disturbances in the sea medium create an additional natural electromagnetic background that must be considered when making detailed magnetic surveys. ?? 2002 Elsevier Science Ltd. All rights reserved.

Increasing Spontaneous Retinal Activity before Eye Opening Accelerates the Development of Geniculate Receptive Fields

PubMed Central

Davis, Zachary W.; Chapman, Barbara

2015-01-01

Visually evoked activity is necessary for the normal development of the visual system. However, little is known about the capacity for patterned spontaneous activity to drive the maturation of receptive fields before visual experience. Retinal waves provide instructive retinotopic information for the anatomical organization of the visual thalamus. To determine whether retinal waves also drive the maturation of functional responses, we increased the frequency of retinal waves pharmacologically in the ferret (Mustela putorius furo) during a period of retinogeniculate development before eye opening. The development of geniculate receptive fields after receiving these increased neural activities was measured using single-unit electrophysiology. We found that increased retinal waves accelerate the developmental reduction of geniculate receptive field sizes. This reduction is due to a decrease in receptive field center size rather than an increase in inhibitory surround strength. This work reveals an instructive role for patterned spontaneous activity in guiding the functional development of neural circuits. SIGNIFICANCE STATEMENT Patterned spontaneous neural activity that occurs during development is known to be necessary for the proper formation of neural circuits. However, it is unknown whether the spontaneous activity alone is sufficient to drive the maturation of the functional properties of neurons. Our work demonstrates for the first time an acceleration in the maturation of neural function as a consequence of driving patterned spontaneous activity during development. This work has implications for our understanding of how neural circuits can be modified actively to improve function prematurely or to recover from injury with guided interventions of patterned neural activity. PMID:26511250

A Dynamic Model of Mercury's Magnetospheric Magnetic Field

PubMed Central

Johnson, Catherine L.; Philpott, Lydia; Tsyganenko, Nikolai A.; Anderson, Brian J.

2017-01-01

Abstract Mercury's solar wind and interplanetary magnetic field environment is highly dynamic, and variations in these external conditions directly control the current systems and magnetic fields inside the planetary magnetosphere. We update our previous static model of Mercury's magnetic field by incorporating variations in the magnetospheric current systems, parameterized as functions of Mercury's heliocentric distance and magnetic activity. The new, dynamic model reproduces the location of the magnetopause current system as a function of systematic pressure variations encountered during Mercury's eccentric orbit, as well as the increase in the cross‐tail current intensity with increasing magnetic activity. Despite the enhancements in the external field parameterization, the residuals between the observed and modeled magnetic field inside the magnetosphere indicate that the dynamic model achieves only a modest overall improvement over the previous static model. The spatial distribution of the residuals in the magnetic field components shows substantial improvement of the model accuracy near the dayside magnetopause. Elsewhere, the large‐scale distribution of the residuals is similar to those of the static model. This result implies either that magnetic activity varies much faster than can be determined from the spacecraft's passage through the magnetosphere or that the residual fields are due to additional external current systems not represented in the model or both. Birkeland currents flowing along magnetic field lines between the magnetosphere and planetary high‐latitude regions have been identified as one such contribution. PMID:29263560

Magnetic field changes activate the trigeminal brainstem complex in a migratory bird

PubMed Central

Heyers, Dominik; Zapka, Manuela; Hoffmeister, Mara; Wild, John Martin; Mouritsen, Henrik

2010-01-01

The upper beak of birds, which contains putative magnetosensory ferro-magnetic structures, is innervated by the ophthalmic branch of the trigeminal nerve (V1). However, because of the absence of replicable neurobiological evidence, a general acceptance of the involvement of the trigeminal nerve in magnetoreception is lacking in birds. Using an antibody to ZENK protein to indicate neuronal activation, we here document reliable magnetic activation of neurons in and near the principal (PrV) and spinal tract (SpV) nuclei of the trigeminal brainstem complex, which represent the two brain regions known to receive primary input from the trigeminal nerve. Significantly more neurons were activated in PrV and in medial SpV when European robins (Erithacus rubecula) experienced a magnetic field changing every 30 seconds for a period of 3 h (CMF) than when robins experienced a compensated, zero magnetic field condition (ZMF). No such differences in numbers of activated neurons were found in comparison structures. Under CMF conditions, sectioning of V1 significantly reduced the number of activated neurons in and near PrV and medial SpV, but not in lateral SpV or in the optic tectum. Tract tracing of V1 showed spatial proximity and regional overlap of V1 nerve endings and ZENK-positive (activated) neurons in SpV, and partly in PrV, under CMF conditions. Together, these results suggest that magnetic field changes activate neurons in and near the trigeminal brainstem complex and that V1 is necessary for this activation. We therefore suggest that V1 transmits magnetic information to the brain in this migratory passerine bird. PMID:20439705

Photon small-field measurements with a CMOS active pixel sensor.

PubMed

Spang, F Jiménez; Rosenberg, I; Hedin, E; Royle, G

2015-06-07

In this work the dosimetric performance of CMOS active pixel sensors for the measurement of small photon beams is presented. The detector used consisted of an array of 520  × 520 pixels on a 25 µm pitch. Dosimetric parameters measured with this sensor were compared with data collected with an ionization chamber, a film detector and GEANT4 Monte Carlo simulations. The sensor performance for beam profiles measurements was evaluated for field sizes of 0.5  × 0.5 cm(2). The high spatial resolution achieved with this sensor allowed the accurate measurement of profiles, beam penumbrae and field size under lateral electronic disequilibrium. Field size and penumbrae agreed within 5.4% and 2.2% respectively with film measurements. Agreements with ionization chambers better than 1.0% were obtained when measuring tissue-phantom ratios. Output factor measurements were in good agreement with ionization chamber and Monte Carlo simulation. The data obtained from this imaging sensor can be easily analyzed to extract dosimetric information. The results presented in this work are promising for the development and implementation of CMOS active pixel sensors for dosimetry applications.

Ectomycorrhizal Fungal Communities and Enzymatic Activities Vary across an Ecotone between a Forest and Field

PubMed Central

Rúa, Megan A.; Moore, Becky; Hergott, Nicole; Van, Lily; Jackson, Colin R.; Hoeksema, Jason D.

2015-01-01

Extracellular enzymes degrade macromolecules into soluble substrates and are important for nutrient cycling in soils, where microorganisms, such as ectomycorrhizal (ECM) fungi, produce these enzymes to obtain nutrients. Ecotones between forests and fields represent intriguing arenas for examining the effect of the environment on ECM community structure and enzyme activity because tree maturity, ECM composition, and environmental variables may all be changing simultaneously. We studied the composition and enzymatic activity of ECM associated with loblolly pine (Pinus taeda) across an ecotone between a forest where P. taeda is established and an old field where P. taeda saplings had been growing for <5 years. ECM community and environmental characteristics influenced enzyme activity in the field, indicating that controls on enzyme activity may be intricately linked to the ECM community, but this was not true in the forest. Members of the Russulaceae were associated with increased phenol oxidase activity and decreased peroxidase activity in the field. Members of the Atheliaceae were particularly susceptible to changes in their abiotic environment, but this did not mediate differences in enzyme activity. These results emphasize the complex nature of factors that dictate the distribution of ECM and activity of their enzymes across a habitat boundary. PMID:29376908

Shaping reverberating sound fields with an actively tunable metasurface.

PubMed

Ma, Guancong; Fan, Xiying; Sheng, Ping; Fink, Mathias

2018-06-26

A reverberating environment is a common complex medium for airborne sound, with familiar examples such as music halls and lecture theaters. The complexity of reverberating sound fields has hindered their meaningful control. Here, by combining acoustic metasurface and adaptive wavefield shaping, we demonstrate the versatile control of reverberating sound fields in a room. This is achieved through the design and the realization of a binary phase-modulating spatial sound modulator that is based on an actively reconfigurable acoustic metasurface. We demonstrate useful functionalities including the creation of quiet zones and hotspots in a typical reverberating environment. Copyright © 2018 the Author(s). Published by PNAS.

Neural field model of memory-guided search.

PubMed

Kilpatrick, Zachary P; Poll, Daniel B

2017-12-01

Many organisms can remember locations they have previously visited during a search. Visual search experiments have shown exploration is guided away from these locations, reducing redundancies in the search path before finding a hidden target. We develop and analyze a two-layer neural field model that encodes positional information during a search task. A position-encoding layer sustains a bump attractor corresponding to the searching agent's current location, and search is modeled by velocity input that propagates the bump. A memory layer sustains persistent activity bounded by a wave front, whose edges expand in response to excitatory input from the position layer. Search can then be biased in response to remembered locations, influencing velocity inputs to the position layer. Asymptotic techniques are used to reduce the dynamics of our model to a low-dimensional system of equations that track the bump position and front boundary. Performance is compared for different target-finding tasks.

Neural field model of memory-guided search

NASA Astrophysics Data System (ADS)

Kilpatrick, Zachary P.; Poll, Daniel B.

2017-12-01

Many organisms can remember locations they have previously visited during a search. Visual search experiments have shown exploration is guided away from these locations, reducing redundancies in the search path before finding a hidden target. We develop and analyze a two-layer neural field model that encodes positional information during a search task. A position-encoding layer sustains a bump attractor corresponding to the searching agent's current location, and search is modeled by velocity input that propagates the bump. A memory layer sustains persistent activity bounded by a wave front, whose edges expand in response to excitatory input from the position layer. Search can then be biased in response to remembered locations, influencing velocity inputs to the position layer. Asymptotic techniques are used to reduce the dynamics of our model to a low-dimensional system of equations that track the bump position and front boundary. Performance is compared for different target-finding tasks.

Magnetic vector field tag and seal

DOEpatents

Johnston, Roger G.; Garcia, Anthony R.

2004-08-31

One or more magnets are placed in a container (preferably on objects inside the container) and the magnetic field strength and vector direction are measured with a magnetometer from at least one location near the container to provide the container with a magnetic vector field tag and seal. The location(s) of the magnetometer relative to the container are also noted. If the position of any magnet inside the container changes, then the measured vector fields at the these locations also change, indicating that the tag has been removed, the seal has broken, and therefore that the container and objects inside may have been tampered with. A hollow wheel with magnets inside may also provide a similar magnetic vector field tag and seal. As the wheel turns, the magnets tumble randomly inside, removing the tag and breaking the seal.

Active control of near-field radiative heat transfer between graphene-covered metamaterials

NASA Astrophysics Data System (ADS)

Zhao, Qimei; Zhou, Ting; Wang, Tongbiao; Liu, Wenxing; Liu, Jiangtao; Yu, Tianbao; Liao, Qinghua; Liu, Nianhua

2017-04-01

In this study, the near-field radiative heat transfer between graphene-covered metamaterials is investigated. The electric surface plasmons (SPs) supported by metamaterials can be coupled with the SPs supported by graphene. The near-field heat transfer between the graphene-covered metamaterials is significantly larger than that between metamaterials because of the strong coupling in our studied frequency range. The relationship between heat flux and chemical potential is studied for different vacuum gaps. Given that the chemical potential of graphene can be tuned by the external electric field, heat transfer can be actively controlled by modulating the chemical potential. The heat flux for certain vacuum gaps can reach a maximum value when the chemical potential is at a particular value. The results of this study are beneficial for actively controlling energy transfer.

Four barriers to the global understanding of biodiversity conservation: wealth, language, geographical location and security.

PubMed

Amano, Tatsuya; Sutherland, William J

2013-04-07

Global biodiversity conservation is seriously challenged by gaps and heterogeneity in the geographical coverage of existing information. Nevertheless, the key barriers to the collection and compilation of biodiversity information at a global scale have yet to be identified. We show that wealth, language, geographical location and security each play an important role in explaining spatial variations in data availability in four different types of biodiversity databases. The number of records per square kilometre is high in countries with high per capita gross domestic product (GDP), high proportion of English speakers and high security levels, and those located close to the country hosting the database; but these are not necessarily countries with high biodiversity. These factors are considered to affect data availability by impeding either the activities of scientific research or active international communications. Our results demonstrate that efforts to solve environmental problems at a global scale will gain significantly by focusing scientific education, communication, research and collaboration in low-GDP countries with fewer English speakers and located far from Western countries that host the global databases; countries that have experienced conflict may also benefit. Findings of this study may be broadly applicable to other fields that require the compilation of scientific knowledge at a global level.

Open field locomotor activity and anxiety-related behaviors in mucopolysaccharidosis type IIIA mice.

PubMed

Lau, Adeline A; Crawley, Allison C; Hopwood, John J; Hemsley, Kim M

2008-08-05

Mucopolysaccharidosis (MPS) IIIA, or Sanfilippo syndrome, is a lysosomal storage disorder characterized by severe and progressive neuropathology. Following an asymptomatic period, patients may present with sleep disturbances, cognitive decline, aggressive tendencies and hyperactivity. A naturally-occurring mouse model of MPS IIIA also exhibits many of these behavioral features and has been recently back-crossed onto a C57BL/6 genetic background. To more thoroughly characterize the behavioral phenotype of congenic MPS IIIA mice, we assessed exploratory activity and unconditioned anxiety-related behavior in the elevated plus maze (EPM) and open field locomotor activity. Although MPS IIIA male mice were less active in the EPM at 18 and 20 weeks of age, they were more likely to explore the open arms than their normal counter-parts suggesting reduced anxiety. Repeated EPM testing reduced exploration of the open arms in MPS IIIA mice. In the open field test, significant reductions in activity were evident in naïve-tested male MPS IIIA mice from 10 weeks of age. Female normal and MPS IIIA mice displayed similar exploratory activity in the open field test. These differences in anxiety and locomotor activity will allow us to evaluate the efficacy of therapeutic regimes for MPS IIIA as a forerunner to developing safe and effective therapies for Sanfilippo patients.

Hydraulic jet pumping in a remote location

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tjondrodiputro, B.; Gaul, R.B.; Gower, G.H.

1986-12-01

Hydraulic jet pumping equipment was installed in six Sembakung field (N.E. Kalimantan) wells by Atlantic Richfield Indonesia Inc., for Pertamina during 1983, and this article presents the experience acquired in the process of installing and operating this type of artificial-lift equipment in a remote location. Characteristics of the wells and equipment are reviewed, and possible future installations in similar circumstances are discussed. Sembakung oil field, discovered in late 1975, contained 17 wells after complete development. By 1983, some were flowing weakly and several zones were dead, indicating the need for some form of artificial lift. The choice of artificial liftmore » methods was limited by the lack of gas-lift gas, absence of a field-wide power distribution system, unavailability of a rod pumping well servicing unit, and lack of roads in the marshy environment. Thus, hydraulic (free-type) jet pumping was selected as the optimum technique. Jet pumps were installed in six of 17 wells in the field at the end of 1983. Downhole equipment was installed using a heli-rig, and all surface equipment was delivered to location using helicopters. Since startup, some operating problems occurred, but they have all been resolved. Well pumping rates range from 340 to 650 bpd gross, with 0 to 50% BSandW. The jet-pumped wells produced satisfactorily through July 1984, at which time operations were turned over to Pertamina Unit IV at the conclusion of the contractual term.« less

Architecture for multi-technology real-time location systems.

PubMed

Rodas, Javier; Barral, Valentín; Escudero, Carlos J

2013-02-07

The rising popularity of location-based services has prompted considerable research in the field of indoor location systems. Since there is no single technology to support these systems, it is necessary to consider the fusion of the information coming from heterogeneous sensors. This paper presents a software architecture designed for a hybrid location system where we can merge information from multiple sensor technologies. The architecture was designed to be used by different kinds of actors independently and with mutual transparency: hardware administrators, algorithm developers and user applications. The paper presents the architecture design, work-flow, case study examples and some results to show how different technologies can be exploited to obtain a good estimation of a target position.

Acute fasting inhibits central caspase-1 activity reducing anxiety-like behavior and increasing novel object and object location recognition.

PubMed

Towers, Albert E; Oelschlager, Maci L; Patel, Jay; Gainey, Stephen J; McCusker, Robert H; Freund, Gregory G

2017-06-01

Inflammation within the central nervous system (CNS) is frequently comorbid with anxiety. Importantly, the pro-inflammatory cytokine most commonly associated with anxiety is IL-1β. The bioavailability and activity of IL-1β are regulated by caspase-1-dependent proteolysis vis-a-vis the inflammasome. Thus, interventions regulating the activation or activity of caspase-1 should reduce anxiety especially in states that foster IL-1β maturation. Male C57BL/6j, C57BL/6j mice treated with the capase-1 inhibitor biotin-YVAD-cmk, caspase-1 knockout (KO) mice and IL-1R1 KO mice were fasted for 24h or allowed ad libitum access to food. Immediately after fasting, caspase-1 activity was measured in brain region homogenates while activated caspase-1 was localized in the brain by immunohistochemistry. Mouse anxiety-like behavior and cognition were tested using the elevated zero maze and novel object/object location tasks, respectively. A 24h fast in mice reduced the activity of caspase-1 in whole brain and in the prefrontal cortex, amygdala, hippocampus, and hypothalamus by 35%, 25%, 40%, 40%, and 40% respectively. A 24h fast also reduced anxiety-like behavior by 40% and increased novel object and object location recognition by 21% and 31%, respectively. IL-1β protein, however, was not reduced in the brain by fasting. ICV administration of YVAD decreased caspase-1 activity in the prefrontal cortex and amygdala by 55%, respectively leading to a 64% reduction in anxiety like behavior. Importantly, when caspase-1 KO or IL1-R1 KO mice are fasted, no fasting-dependent reduction in anxiety-like behavior was observed. Results indicate that fasting decrease anxiety-like behavior and improves memory by a mechanism tied to reducing caspase-1 activity throughout the brain. Copyright © 2017 Elsevier Inc. All rights reserved.

Acute fasting inhibits central caspase-1 activity reducing anxiety-like behavior and increasing novel object and object location recognition

PubMed Central

Towers, Albert E; Oelschlager, Maci L.; Patel, Jay; Gainey, Stephen J.; McCusker, Robert; Freund, Gregory G.

2017-01-01

Background Inflammation within the central nervous system (CNS) is frequently comorbid with anxiety. Importantly, the pro-inflammatory cytokine most commonly associated with anxiety is IL-1β. The bioavailability and activity of IL-1β is regulated by caspase-1-dependent proteolysis vis-a-vis the inflammasome. Thus, interventions regulating the activation or activity of caspase-1 should reduce anxiety especially in states that foster IL-1β maturation. Methods Male C57BL/6j, C57BL/6j mice treated with the capase-1 inhibitor biotin-YVAD-cmk, caspase-1 knockout (KO) mice and IL-1R1 KO mice were fasted for 24 hours or allowed ad libitum access to food. Immediately after fasting, caspase-1 activity was measured in brain region homogenates while activated caspase-1 was localized in the brain by immunohistochemistry. Mouse anxiety-like behavior and cognition were tested using the elevated zero maze and novel object/object location tasks, respectively. Results A 24 h fast in mice reduced the activity of caspase-1 in whole brain and in the prefrontal cortex, amygdala, hippocampus, and hypothalamus by 35%, 25%, 40%, 40%, and 40% respectively. A 24 h fast also reduced anxiety-like behavior by 40% and increased novel object and object location recognition by 21% and 31%, respectively. IL-1β protein, however, was not reduced in the brain by fasting. ICV administration of YVAD decreased caspase-1 activity in the prefrontal cortex and amygdala by 55%, respectively leading to a 64% reduction in anxiety like behavior. Importantly, when caspase-1 KO or IL1-R1 KO mice are fasted, no fasting-dependent reduction in anxiety-like behavior was observed. Conclusions Results indicate that fasting decrease anxiety-like behavior and improves memory by a mechanism tied to reducing caspase-1 activity throughout the brain. PMID:28521881

Locating active-site hydrogen atoms in d-xylose isomerase: Time-of-flight neutron diffraction

PubMed Central

Katz, Amy K.; Li, Xinmin; Carrell, H. L.; Hanson, B. Leif; Langan, Paul; Coates, Leighton; Schoenborn, Benno P.; Glusker, Jenny P.; Bunick, Gerard J.

2006-01-01

Time-of-flight neutron diffraction has been used to locate hydrogen atoms that define the ionization states of amino acids in crystals of d-xylose isomerase. This enzyme, from Streptomyces rubiginosus, is one of the largest enzymes studied to date at high resolution (1.8 Å) by this method. We have determined the position and orientation of a metal ion-bound water molecule that is located in the active site of the enzyme; this water has been thought to be involved in the isomerization step in which d-xylose is converted to d-xylulose or d-glucose to d-fructose. It is shown to be water (rather than a hydroxyl group) under the conditions of measurement (pH 8.0). Our analyses also reveal that one lysine probably has an −NH2-terminal group (rather than NH3+). The ionization state of each histidine residue also was determined. High-resolution x-ray studies (at 0.94 Å) indicate disorder in some side chains when a truncated substrate is bound and suggest how some side chains might move during catalysis. This combination of time-of-flight neutron diffraction and x-ray diffraction can contribute greatly to the elucidation of enzyme mechanisms. PMID:16707576

Propulsion of Active Colloids by Self-Induced Field Gradients.

PubMed

Boymelgreen, Alicia; Yossifon, Gilad; Miloh, Touvia

2016-09-20

Previously, metallodielectric Janus particles have been shown to travel with their dielectric hemisphere forward under low frequency applied electric fields as a result of asymmetric induced-charge electroosmotic flow. Here, it is demonstrated that at high frequencies, well beyond the charge relaxation time of the electric double layer induced around the particle, rather than the velocity decaying to zero, the Janus particles reverse direction, traveling with their metallic hemisphere forward. It is proposed that such motion is the result of a surface force, arising from localized nonuniform electric field gradients, induced by the dual symmetry-breaking of an asymmetric particle adjacent to a wall, which act on the induced dipole of the particle to drive net motion even in a uniform AC field. Although the field is external, since the driving gradient is induced on the particle level, it may be considered an active colloid. We have thus termed this propulsion mechanism "self-dielectrophoresis", to distinguish from traditional dielectrophoresis where the driving nonuniform field is externally fixed and the particle direction is restricted. It is demonstrated theoretically and experimentally that the critical frequency at which the particle reverses direction can be characterized by a nondimensional parameter which is a function of electrolyte concentration and particle size.

Survival and Competitiveness of Bradyrhizobium japonicum Strains 20 Years after Introduction into Field Locations in Poland

PubMed Central

Narożna, Dorota; Pudełko, Krzysztof; Króliczak, Joanna; Golińska, Barbara; Sugawara, Masayuki; Mądrzak, Cezary J.

2015-01-01

It was previously demonstrated that there are no indigenous strains of Bradyrhizobium japonicum forming nitrogen-fixing root nodule symbioses with soybean plants in arable field soils in Poland. However, bacteria currently classified within this species are present (together with Bradyrhizobium canariense) as indigenous populations of strains specific for nodulation of legumes in the Genisteae tribe. These rhizobia, infecting legumes such as lupins, are well established in Polish soils. The studies described here were based on soybean nodulation field experiments, established at the Poznań University of Life Sciences Experiment Station in Gorzyń, Poland, and initiated in the spring of 1994. Long-term research was then conducted in order to study the relation between B. japonicum USDA 110 and USDA 123, introduced together into the same location, where no soybean rhizobia were earlier detected, and nodulation and competitive success were followed over time. Here we report the extra-long-term saprophytic survival of B. japonicum strains nodulating soybeans that were introduced as inoculants 20 years earlier and where soybeans were not grown for the next 17 years. The strains remained viable and symbiotically competent, and molecular and immunochemical methods showed that the strains were undistinguishable from the original inoculum strains USDA 110 and USDA 123. We also show that the strains had balanced numbers and their mobility in soil was low. To our knowledge, this is the first report showing the extra-long-term persistence of soybean-nodulating strains introduced into Polish soils and the first analyzing the long-term competitive relations of USDA 110 and USDA 123 after the two strains, neither of which was native, were introduced into the environment almost 2 decades ago. PMID:26048934

Capturing Location-Privacy Preferences: Quantifying Accuracy and User-Burden Tradeoffs

DTIC Science & Technology

2010-03-01

research groups have developed location - based services , including PARC’s Active Badges [24], Active- Campus [2], MyCampus [17], Intel’s PlaceLab [11], and...groups. In Conference on Human Factors in Computing Systems (CHI), 2008. [2] L. Barkhuus and A. Dey. Location - based services for mobile telephony: A... location - based services . In OnTheMove Conferences (OTM), 2009. [6] K. Connelly, A. Khalil, and Y. Liu. Do I do what I say?: Observed versus stated privacy

A Standing Location Detector Enabling People with Developmental Disabilities to Control Environmental Stimulation through Simple Physical Activities with Nintendo Wii Balance Boards

ERIC Educational Resources Information Center

Shih, Ching-Hsiang

2011-01-01

This study evaluated whether two people with developmental disabilities would be able to actively perform simple physical activities by controlling their favorite environmental stimulation using Nintendo Wii Balance Boards with a newly developed standing location detection program (SLDP, i.e., a new software program turning a Nintendo Wii Balance…

An Object Location Detector Enabling People with Developmental Disabilities to Control Environmental Stimulation through Simple Occupational Activities with Battery-Free Wireless Mice

ERIC Educational Resources Information Center

Shih, Ching-Hsiang

2011-01-01

This study assessed whether two persons with developmental disabilities would be able to actively perform simple occupational activities by controlling their favorite environmental stimulation using battery-free wireless mice with a newly developed object location detection program (OLDP, i.e., a new software program turning a battery-free…

Miller Creek Demonstration Forest ecology activities - a teachers supplement to the field guide

Treesearch

Bill Schustrom; Reed Kuennen; Raymond C. Shearer

1998-01-01

Miller Creek, on the Flathead National Forest in northwestern Montana, is a demonstration forest, showing up to 30 years of forest change. This teachers supplement to the educational field guide (Miller Creek Demonstration Forest - a forest born of fire: a field guide; Gen. Tech. Rep. RMRS-GTR-7, 1998) outlines eight field and classroom activities that teach students a...

Green house emissions, inventories and evaluation of marine environment visa vis offshore oil field development activities Bombay high (west coast) upstream petroleum sector, India

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, J.S.; Ahmed, S.; Negi, C.V.S.

1996-12-31

Wide use of petroleum products contributes significant amount of emission to the global environment and hence maintaining emission inventories are of great importance while assessing the global green house emissions. The present paper describes a brief account of green house emission and inventories for CO{sub 2}, CO, NO{sub x}, HC particulate and SO{sub 2} emissions generated due to upstream petroleum sector activities viz. discharges of gaseous emission, combustion of Natural Gas anti HSD from production and drilling facilities of Bombay offshore area located in Exclusive Economic Zone (EEZ) west coast of India. Besides, authors have also given an account onmore » west coast marine base line status including impact of oil field activities on marine ecosystem.« less

Improving Discoverability of Geophysical Data using Location Based Services

NASA Astrophysics Data System (ADS)

Morrison, D.; Barnes, R. J.; Potter, M.; Nylund, S. R.; Patrone, D.; Weiss, M.; Talaat, E. R.; Sarris, T. E.; Smith, D.

2014-12-01

The great promise of Virtual Observatories is the ability to perform complex search operations across the metadata of a large variety of different data sets. This allows the researcher to isolate and select the relevant measurements for their topic of study. The Virtual ITM Observatory (VITMO) has many diverse geophysical datasets that cover a large temporal and spatial range that present a unique search problem. VITMO provides many methods by which the user can search for and select data of interest including restricting selections based on geophysical conditions (solar wind speed, Kp, etc) as well as finding those datasets that overlap in time. One of the key challenges in improving discoverability is the ability to identify portions of datasets that overlap in time and in location. The difficulty is that location data is not contained in the metadata for datasets produced by satellites and would be extremely large in volume if it were available, making searching for overlapping data very time consuming. To solve this problem we have developed a series of light-weight web services that can provide a new data search capability for VITMO and others. The services consist of a database of spacecraft ephemerides and instrument fields of view; an overlap calculator to find times when the fields of view of different instruments intersect; and a magnetic field line tracing service that maps in situ and ground based measurements to the equatorial plane in magnetic coordinates for a number of field models and geophysical conditions. These services run in real-time when the user queries for data. They will allow the non-specialist user to select data that they were previously unable to locate, opening up analysis opportunities beyond the instrument teams and specialists, making it easier for future students who come into the field.

SU-E-T-381: Evaluation of Calculated Dose Accuracy for Organs-At-Risk Located at Out-Of-Field in a Commercial Treatment Planning System for High Energy Photon Beams Produced From TrueBeam Accelerators

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, L; Ding, G

Purpose: Dose calculation accuracy for the out-of-field dose is important for predicting the dose to the organs-at-risk when they are located outside primary beams. The investigations on evaluating the calculation accuracy of treatment planning systems (TPS) on out-of-field dose in existing publications have focused on low energy (6MV) photon. This study evaluates out-of-field dose calculation accuracy of AAA algorithm for 15MV high energy photon beams. Methods: We used the EGSnrc Monte Carlo (MC) codes to evaluate the AAA algorithm in Varian Eclipse TPS (v.11). The incident beams start with validated Varian phase-space sources for a TrueBeam linac equipped with Millenniummore » 120 MLC. Dose comparisons between using AAA and MC for CT based realistic patient treatment plans using VMAT techniques for prostate and lung were performed and uncertainties of organ dose predicted by AAA at out-of-field location were evaluated. Results: The results show that AAA calculations under-estimate doses at the dose level of 1% (or less) of prescribed dose for CT based patient treatment plans using VMAT techniques. In regions where dose is only 1% of prescribed dose, although AAA under-estimates the out-of-field dose by 30% relative to the local dose, it is only about 0.3% of prescribed dose. For example, the uncertainties of calculated organ dose to liver or kidney that is located out-of-field is <0.3% of prescribed dose. Conclusion: For 15MV high energy photon beams, very good agreements (<1%) in calculating dose distributions were obtained between AAA and MC. The uncertainty of out-of-field dose calculations predicted by the AAA algorithm for realistic patient VMAT plans is <0.3% of prescribed dose in regions where the dose relative to the prescribed dose is <1%, although the uncertainties can be much larger relative to local doses. For organs-at-risk located at out-of-field, the error of dose predicted by Eclipse using AAA is negligible. This work was conducted in part using

Activation of the TRPV1 Thermoreceptor Induced by Modulated or Unmodulated 1800 MHz Radiofrequency Field Exposure.

PubMed

Ruigrok, Hermanus J; Arnaud-Cormos, Delia; Hurtier, Annabelle; Poque, Emmanuelle; de Gannes, Florence Poulletier; Ruffié, Gilles; Bonnaudin, Fabrice; Lagroye, Isabelle; Sojic, Neso; Arbault, Stéphane; Lévêque, Philippe; Veyret, Bernard; Percherancier, Yann

2018-01-01

The existence of effects of radiofrequency field exposure at environmental levels on living tissues and organisms remains controversial, in particular regarding potential "nonthermal" effects produced in the absence of temperature elevation. Therefore, we investigated whether TRPV1, one of the most studied thermosensitive channels, can be activated by the heat produced by radiofrequency fields and by some specific nonthermal interaction with the fields. We have recently shown that TRPV1 activation can be assessed in real-time on live cells using the bioluminescence resonance energy transfer technique. Taking advantage of this innovative assay, we monitored TRPV1 thermal and chemical modes of activation under radiofrequency exposure at 1800 MHz using different signals (CW, GSM, UMTS, LTE, Wi-Fi and WiMAX) at specific absorption rates between 8 and 32 W/kg. We showed that, as expected, TRPV1 channels were activated by the heat produced by radiofrequency field exposure of transiently-transfected HEK293T cells, but found no evidence of TRPV1 activation in the absence of temperature elevation under radiofrequency field exposure. There was no evidence either that, at fixed temperature, radiofrequency exposure altered the maximal efficacy of the agonist Capsaicin to activate TRPV1.

Large-Scale Brain Networks Supporting Divided Attention across Spatial Locations and Sensory Modalities

PubMed Central

Santangelo, Valerio

2018-01-01

Higher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010) to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets. This design allowed comparing a condition in which participants monitored one stimulus/modality (either visual or auditory) in two spatial locations vs. a condition in which participants monitored two stimuli/modalities (both visual and auditory) in one spatial location. The analysis of the independent components (ICs) revealed that dividing attentional resources across two spatial locations necessitated a brain network involving the left ventro- and dorso-lateral prefrontal cortex plus the posterior parietal cortex, including the intraparietal sulcus (IPS) and the angular gyrus, bilaterally. The analysis of Granger causality highlighted that the activity of lateral prefrontal regions were predictive of the activity of all of the posteriors parietal nodes. By contrast, dividing attention across two sensory modalities necessitated a brain network including nodes belonging to the dorsal frontoparietal network, i.e., the bilateral frontal eye-fields (FEF) and IPS, plus nodes belonging to the salience network, i.e., the anterior cingulated cortex and the left and right anterior insular cortex (aIC). The analysis of Granger causality highlights a tight interdependence between the dorsal frontoparietal and salience nodes in trials requiring divided attention between different sensory modalities. The current findings therefore highlighted a dissociation among brain networks

Large-Scale Brain Networks Supporting Divided Attention across Spatial Locations and Sensory Modalities.

PubMed

Santangelo, Valerio

2018-01-01

Higher-order cognitive processes were shown to rely on the interplay between large-scale neural networks. However, brain networks involved with the capability to split attentional resource over multiple spatial locations and multiple stimuli or sensory modalities have been largely unexplored to date. Here I re-analyzed data from Santangelo et al. (2010) to explore the causal interactions between large-scale brain networks during divided attention. During fMRI scanning, participants monitored streams of visual and/or auditory stimuli in one or two spatial locations for detection of occasional targets. This design allowed comparing a condition in which participants monitored one stimulus/modality (either visual or auditory) in two spatial locations vs. a condition in which participants monitored two stimuli/modalities (both visual and auditory) in one spatial location. The analysis of the independent components (ICs) revealed that dividing attentional resources across two spatial locations necessitated a brain network involving the left ventro- and dorso-lateral prefrontal cortex plus the posterior parietal cortex, including the intraparietal sulcus (IPS) and the angular gyrus, bilaterally. The analysis of Granger causality highlighted that the activity of lateral prefrontal regions were predictive of the activity of all of the posteriors parietal nodes. By contrast, dividing attention across two sensory modalities necessitated a brain network including nodes belonging to the dorsal frontoparietal network, i.e., the bilateral frontal eye-fields (FEF) and IPS, plus nodes belonging to the salience network, i.e., the anterior cingulated cortex and the left and right anterior insular cortex (aIC). The analysis of Granger causality highlights a tight interdependence between the dorsal frontoparietal and salience nodes in trials requiring divided attention between different sensory modalities. The current findings therefore highlighted a dissociation among brain networks

Discovering new events beyond the catalogue—application of empirical matched field processing to Salton Sea geothermal field seismicity

DOE PAGES

Wang, Jingbo; Templeton, Dennise C.; Harris, David B.

2015-07-30

Using empirical matched field processing (MFP), we compare 4 yr of continuous seismic data to a set of 195 master templates from within an active geothermal field and identify over 140 per cent more events than were identified using traditional detection and location techniques alone. In managed underground reservoirs, a substantial fraction of seismic events can be excluded from the official catalogue due to an inability to clearly identify seismic-phase onsets. Empirical MFP can improve the effectiveness of current seismic detection and location methodologies by using conventionally located events with higher signal-to-noise ratios as master events to define wavefield templatesmore » that could then be used to map normally discarded indistinct seismicity. Since MFP does not require picking, it can be carried out automatically and rapidly once suitable templates are defined. In this application, we extend MFP by constructing local-distance empirical master templates using Southern California Earthquake Data Center archived waveform data of events originating within the Salton Sea Geothermal Field. We compare the empirical templates to continuous seismic data collected between 1 January 2008 and 31 December 2011. The empirical MFP method successfully identifies 6249 additional events, while the original catalogue reported 4352 events. The majority of these new events are lower-magnitude events with magnitudes between M0.2–M0.8. Here, the increased spatial-temporal resolution of the microseismicity map within the geothermal field illustrates how empirical MFP, when combined with conventional methods, can significantly improve seismic network detection capabilities, which can aid in long-term sustainability and monitoring of managed underground reservoirs.« less

Location, Location, Location: Does Place Provide the Opportunity for Differentiation for Universities?

ERIC Educational Resources Information Center

Winter, Emma; Thompson-Whiteside, Helen

2017-01-01

The fiercely competitive HE market has led HEIs to invest significant resources in building a distinct identity. An HEI's location forms an inherent part of its identity and the uniqueness of location offers an opportunity to differentiate. However there has been limited examination of how location is used by HEIs and little consideration of how…

Location of Buried Mineshafts and Adits Using Reconnaissance Geophysical Methods

NASA Astrophysics Data System (ADS)

Culshaw, Martin; Donnelly, Laurance; McCann, David

Britain has a long history of mining activity, which stretches back some 3000 years to the excavation of flint in East Anglia. The legacy of this long period of activity is the presence of many buried mineshafts and adits, whose location is often unknown precisely and in many cases not even recorded in historical mining records. As has been shown by Donnelly et al (2003) the discovery of a mineshaft in an area of housing development can have a profound effect on property values in its vicinity. Hence, urgent action must be taken to establish at the site investigation stage of a development to determine whether any mineshafts are present at the site so that remedial action can be taken before construction commences. A study of historical information and the drilling may well enable the developer to locate any suspected mineshafts and adits on his site. However, the use of geophysical reconnaissance methods across the whole site may well provide sufficient information to simplify the drilling programme and reduce its cost to a minimum. In this paper a number of rapid reconnaissance geophysical methods are described and evaluated in terms of their success in the location of buried mineshafts and adits. It has shown that a combination of ground conductivity and magnetic surveys provides a most effective approach on open sites in greenfield and brownfield areas. Ground penetrating radar and micro-gravity surveys have proved to be a valuable approach in urban areas where the use of many geophysical methods is prevented by the presence of various types of cultural noise. On a regional scale the infrared thermography method is being increasingly used but care must be taken to overcome certain environmental difficulties. The practical use of all these geophysical methods in the field is illustrated by a number of appropriate case histories.

AC Electric Field Activated Shape Memory Polymer Composite

NASA Technical Reports Server (NTRS)

Kang, Jin Ho; Siochi, Emilie J.; Penner, Ronald K.; Turner, Travis L.

2011-01-01

Shape memory materials have drawn interest for applications like intelligent medical devices, deployable space structures and morphing structures. Compared to other shape memory materials like shape memory alloys (SMAs) or shape memory ceramics (SMCs), shape memory polymers (SMPs) have high elastic deformation that is amenable to tailored of mechanical properties, have lower density, and are easily processed. However, SMPs have low recovery stress and long response times. A new shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive fillers to enhance its thermo-mechanical characteristics. A new composition of shape memory thermosetting polymer nanocomposite (LaRC-SMPC) was synthesized with conductive functionalized graphene sheets (FGS) to enhance its thermo-mechanical characteristics. The elastic modulus of LaRC-SMPC is approximately 2.7 GPa at room temperature and 4.3 MPa above its glass transition temperature. Conductive FGSs-doped LaRC-SMPC exhibited higher conductivity compared to pristine LaRC SMP. Applying an electric field at between 0.1 Hz and 1 kHz induced faster heating to activate the LaRC-SMPC s shape memory effect relative to applying DC electric field or AC electric field at frequencies exceeding1 kHz.

Masseter Muscle Activity in Track and Field Athletes: A Pilot Study

PubMed Central

Nukaga, Hideyuki; Takeda, Tomotaka; Nakajima, Kazunori; Narimatsu, Keishiro; Ozawa, Takamitsu; Ishigami, Keiichi; Funato, Kazuo

2016-01-01

Teeth clenching has been shown to improve remote muscle activity (by augmentation of the Hoffmann reflex), and joint fixation (by decreased reciprocal inhibition) in the entire body. Clenching could help maintain balance, improve systemic function, and enhance safety. Teeth clenching from a sports dentistry viewpoint was thought to be important and challenging. Therefore, it is quite important to investigate mastication muscles’ activity and function during sports events for clarifying a physiological role of the mastication muscle itself and involvement of mastication muscle function in whole body movement. Running is a basic motion of a lot of sports; however, a mastication muscles activity during this motion was not clarified. Throwing and jumping operation were in a same situation. The purpose of this study was to investigate the presence or absence of masseter muscle activity during track and field events. In total, 28 track and field athletes took part in the study. The Multichannel Telemetry system was used to monitor muscle activity, and the electromyograms obtained were synchronized with digital video imaging. The masseter muscle activity threshold was set 15% of maximum voluntary clenching. As results, with few exceptions, masseter muscle activity were observed during all analyzed phases of the 5 activities, and that phases in which most participants showed masseter muscle activity were characterized by initial acceleration, such as in the short sprint, from the commencement of throwing to release in both the javelin throw and shot put, and at the take-off and landing phases in both jumps. PMID:27708727

Case Studies on Location: Taking to the Field in Economics

ERIC Educational Resources Information Center

Smith, Mark Griffin

2007-01-01

The author describes how to conceptualize and organize a successful, multi-day field trip organized around a case study problem. By doing so, the instructor exposes students to diverse perspectives and leads them through the process of policy analysis from collecting and organizing information to identifying the relevant economic concepts and…

Desert Research and Technology Studies (RATS) 2007 Field Campaign Objectives and Results

NASA Technical Reports Server (NTRS)

Kosmo, Joseph; Romig, Barbara

2008-01-01

Desert "RATS" (Research and Technology Studies) is a combined, multi-discipline group of inter-NASA center scientists and engineers, net-working and collaborating with representatives of industry and academia, for the purpose of conducting planetary surface exploration-focused remote field exercises. These integrated testing exercises conducted under representative analog Lunar and Mars surface terrain conditions, provide NASA the capability to validate experimental prototype hardware and software systems as well as to evaluate and develop mission operational techniques in order to identify and establish technical requirements and identify potential technology "gaps" applicable for future planetary human exploration. The 2007 D-RATS field campaign test activities were initiated based on the major themes and objectives of a notional 5-year plan developed for conducting relative analog test activities in support of the engineering evaluation and assessment of various system architectural requirements, conceptual prototype support equipment and selected technologies necessary for the establishment of a lunar outpost. Specifically, the major objectives included measuring task efficiency during robot, human, and human-robot interactive tasks associated with lunar outpost site surveying and reconnaissance activities and deployment of a representative solar panel power and distribution system. In addition, technology demonstrations were conducted with a new Lithium-ion battery and autonomous software to coordinate multiple robot activities. Secondary objectives were evaluating airlock concept mockups and prototype removable space suit over-garment elements for dust mitigation, and upgrades to the prototype extravehicular activities (EVA) communication and information system. Dry run test activities, prior to testing at a designated remote field site location, were initially conducted at the Johnson Space Center (JSC) Remote Field Demonstration Test Site. This is a multi

Noninvasive valve monitor using alternating electromagnetic field

DOEpatents

Eissenberg, David M.; Haynes, Howard D.; Casada, Donald A.

1993-01-01

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

Noninvasive valve monitor using alternating electromagnetic field

DOEpatents

Eissenberg, D.M.; Haynes, H.D.; Casada, D.A.

1993-03-16

One or more electrical coils are carefully located on the outside of a valve body. An alternating current passing through the coil(s) results in an alternating electromagnetic field being transmitted into the valve body and valve internals. The electromagnetic field varies in intensity and polarity in the valve. As the position of a valve internal part is changed, the electromagnetic field throughout the valve body and its internals is altered. A passive receiver coil carefully located on the outside of the valve body detects the intensity of the electromagnetic field at that location as an induced electrical voltage in the coil. With the change in position of the valve internal part, there is a corresponding change in the induced voltage as a result of the alteration in the alternating electromagnetic field at that location. Changes in the voltage provide an indication of the position and motion of valve internals.

78 FR 37760 - Electrical Equipment in Hazardous Locations

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-24

... floating facilities engaged in OCS activities, however, equipment could be installed in hazardous locations... composition and the extent of equipment replacement. The myriad types of MODUs and facilities operating on the.... USCG-2012-0850] RIN 1625-AC00 Electrical Equipment in Hazardous Locations AGENCY: Coast Guard, DHS...

Active noise control: a review of the field.

PubMed

Gordon, R T; Vining, W D

1992-11-01

Active noise control (ANC) is the application of the principle of the superposition of waves to noise attenuation problems. Much progress has been made toward applying ANC to narrow-band, low-frequency noise in confined spaces. During this same period, the application of ANC to broad-band noise or noise in three-dimensional spaces has seen little progress because of the recent quantification of serious physical limitations, most importantly, noncausality, stability, spatial mismatch, and the infinite gain controller requirement. ANC employs superposition to induce destructive interference to affect the attenuation of noise. ANC was believed to utilize the mechanism of phase cancellation to achieve the desired attenuation. However, current literature points to other mechanisms that may be operating in ANC. Categories of ANC are one-dimensional field and duct noise, enclosed spaces and interior noise, noise in three-dimensional spaces, and personal hearing protection. Development of active noise control stems from potential advantages in cost, size, and effectiveness. There are two approaches to ANC. In the first, the original sound is processed and injected back into the sound field in antiphase. The second approach is to synthesize a cancelling waveform. ANC of turbulent flow in pipes and ducts is the largest area in the field. Much work into the actual mechanism involved and the causal versus noncausal aspects of system controllers has been done. Fan and propeller noise can be divided into two categories: noise generated directly as the blade passing tones and noise generated as a result of blade tip turbulence inducing vibration in structures. Three-dimensional spaces present a noise environment where physical limitations are magnified and the infinite gain controller requirement is confronted. Personal hearing protection has been shown to be best suited to the control of periodic, low-frequency noise.

Field Demonstration of Active Desiccant-Based Outdoor Air Preconditioning Systems, Final Report: Phase 3

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fischer, J.

2001-07-09

This report summarizes an investigation of the performance of two active desiccant cooling systems that were installed as pilot systems in two locations--a college dormitory and a research laboratory--during the fall of 1999. The laboratory system was assembled in the field from commercially available Trane air-handling modules combined with a standard total energy recovery module and a customized active desiccant wheel, both produced by SEMCO. The dormitory system was a factory-built, integrated system produced by SEMCO that included both active desiccant and sensible-only recovery wheels, a direct-fired gas regeneration section, and a pre-piped Trane heat pump condensing section. Both systemsmore » were equipped with direct digital control systems, complete with full instrumentation and remote monitoring capabilities. This report includes detailed descriptions of these two systems, installation details, samples of actual performance, and estimations of the energy savings realized. These pilot sites represent a continuation of previous active desiccant product development research (Fischer, Hallstrom, and Sand 2000; Fischer 2000). Both systems performed as anticipated, were reliable, and required minimal maintenance. The dehumidification/total-energy-recovery hybrid approach was particularly effective in all respects. System performance showed remarkable improvement in latent load handling capability and operating efficiency compared with the original conventional cooling system and with the conventional system that remained in another, identical wing of the facility. The dehumidification capacity of the pilot systems was very high, the cost of operation was very low, and the system was cost-effective, offering a simple payback for these retrofit installations of approximately 5 to 6 years. Most important, the dormitory system resolved numerous indoor air quality problems in the dormitory by providing effective humidity control and increased, continuous

Comparative study of microelectrode recording-based STN location and MRI-based STN location in low to ultra-high field (7.0 T) T2-weighted MRI images

NASA Astrophysics Data System (ADS)

Verhagen, Rens; Schuurman, P. Richard; van den Munckhof, Pepijn; Fiorella Contarino, M.; de Bie, Rob M. A.; Bour, Lo J.

2016-12-01

Objective. The correspondence between the anatomical STN and the STN observed in T2-weighted MRI images used for deep brain stimulation (DBS) targeting remains unclear. Using a new method, we compared the STN borders seen on MRI images with those estimated by intraoperative microelectrode recordings (MER). Approach. We developed a method to automatically generate a detailed estimation of STN shape and the location of its borders, based on multiple-channel MER measurements. In 33 STNs of 19 Parkinson patients, we quantitatively compared the dorsal and lateral borders of this MER-based STN model with the STN borders visualized by 1.5 T (n = 14), 3.0 T (n = 10) and 7.0 T (n = 9) T2-weighted MRI. Main results. The dorsal border was identified more dorsally on coronal T2 MRI than by the MER-based STN model, with a significant difference in the 3.0 T (range 0.97-1.19 mm) and 7.0 T (range 1.23-1.25 mm) groups. The lateral border was significantly more medial on 1.5 T (mean: 1.97 mm) and 3.0 T (mean: 2.49 mm) MRI than in the MER-based STN; a difference that was not found in the 7.0 T group. Significance. The STN extends further in the dorsal direction on coronal T2 MRI images than is measured by MER. Increasing MRI field strength to 3.0 T or 7.0 T yields similar discrepancies between MER and MRI at the dorsal STN border. In contrast, increasing MRI field strength to 7.0 T may be useful for identification of the lateral STN border and thereby improve DBS targeting.

Decoding intravesical pressure from local field potentials in rat lumbosacral spinal cord

NASA Astrophysics Data System (ADS)

Im, Changkyun; Park, Hae Yong; Koh, Chin Su; Ryu, Sang Baek; Seo, In Seok; Kim, Yong Jung; Kim, Kyung Hwan; Shin, Hyung-Cheul

2016-10-01

Chronic monitoring of intravesical pressure is required to detect the onset of intravesical hypertension and the progression of a more severe condition. Recent reports demonstrate the bladder state can be monitored from the spiking activity of the dorsal root ganglia or lumbosacral spinal cord. However, one of the most serious challenges for these methods is the difficulty of sustained spike signal acquisition due to the high-electrode-location-sensitivity of spikes or neuro-degeneration. Alternatively, it has been demonstrated that local field potential recordings are less affected by encapsulation reactions or electrode location changes. Here, we hypothesized that local field potential (LFP) from the lumbosacral dorsal horn may provide information concerning the intravesical pressure. LFP and spike activities were simultaneously recorded from the lumbosacral spinal cord of anesthetized rats during bladder filling. The results show that the LFP activities carry significant information about intravesical pressure along with spiking activities. Importantly, the intravesical pressure is decoded from the power in high-frequency bands (83.9-256 Hz) with a substantial performance similar to that of the spike train decoding. These findings demonstrate that high-frequency LFP activity can be an alternative intravesical pressure monitoring signal, which could lead to a proper closed loop system for urinary control.

Identification of active sources inside cavities using the equivalent source method-based free-field recovery technique

NASA Astrophysics Data System (ADS)

Bi, Chuan-Xing; Hu, Ding-Yu; Zhang, Yong-Bin; Jing, Wen-Qian

2015-06-01

In previous studies, an equivalent source method (ESM)-based technique for recovering the free sound field in a noisy environment has been successfully applied to exterior problems. In order to evaluate its performance when applied to a more general noisy environment, that technique is used to identify active sources inside cavities where the sound field is composed of the field radiated by active sources and that reflected by walls. A patch approach with two semi-closed surfaces covering the target active sources is presented to perform the measurements, and the field that would be radiated by these target active sources into free space is extracted from the mixed field by using the proposed technique, which will be further used as the input of nearfield acoustic holography for source identification. Simulation and experimental results validate the effectiveness of the proposed technique for source identification in cavities, and show the feasibility of performing the measurements with a double layer planar array.

Using a simple apparatus to measure direct and diffuse photosynthetically active radiation at remote locations.

PubMed

Cruse, Michael J; Kucharik, Christopher J; Norman, John M

2015-01-01

Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

Using a Simple Apparatus to Measure Direct and Diffuse Photosynthetically Active Radiation at Remote Locations

PubMed Central

Cruse, Michael J.; Kucharik, Christopher J.; Norman, John M.

2015-01-01

Plant canopy interception of photosynthetically active radiation (PAR) drives carbon dioxide (CO2), water and energy cycling in the soil-plant-atmosphere system. Quantifying intercepted PAR requires accurate measurements of total incident PAR above canopies and direct beam and diffuse PAR components. While some regional data sets include these data, e.g. from Atmospheric Radiation Measurement (ARM) Program sites, they are not often applicable to local research sites because of the variable nature (spatial and temporal) of environmental variables that influence incoming PAR. Currently available instrumentation that measures diffuse and direct beam radiation separately can be cost prohibitive and require frequent adjustments. Alternatively, generalized empirical relationships that relate atmospheric variables and radiation components can be used but require assumptions that increase the potential for error. Our goal here was to construct and test a cheaper, highly portable instrument alternative that could be used at remote field sites to measure total, diffuse and direct beam PAR for extended time periods without supervision. The apparatus tested here uses a fabricated, solar powered rotating shadowband and other commercially available parts to collect continuous hourly PAR data. Measurements of total incident PAR had nearly a one-to-one relationship with total incident radiation measurements taken at the same research site by an unobstructed point quantum sensor. Additionally, measurements of diffuse PAR compared favorably with modeled estimates from previously published data, but displayed significant differences that were attributed to the important influence of rapidly changing local environmental conditions. The cost of the system is about 50% less than comparable commercially available systems that require periodic, but not continual adjustments. Overall, the data produced using this apparatus indicates that this instrumentation has the potential to support

Vibration reduction in helicopter rotors using an actively controlled partial span trailing edge flap located on the blade

NASA Technical Reports Server (NTRS)

Millott, T. A.; Friedmann, P. P.

1994-01-01

This report describes an analytical study of vibration reduction in a four-bladed helicopter rotor using an actively controlled, partial span, trailing edge flap located on the blade. The vibration reduction produced by the actively controlled flap (ACF) is compared with that obtained using individual blade control (IBC), in which the entire blade is oscillated in pitch. For both cases a deterministic feedback controller is implemented to reduce the 4/rev hub loads. For all cases considered, the ACF produced vibration reduction comparable with that obtained using IBC, but consumed only 10-30% of the power required to implement IBC. A careful parametric study is conducted to determine the influence of blade torsional stiffness, spanwise location of the control flap, and hinge moment correction on the vibration reduction characteristics of the ACF. The results clearly demonstrate the feasibility of this new approach to vibration reduction. It should be emphasized than the ACF, used together with a conventional swashplate, is completely decoupled from the primary flight control system and thus it has no influence on the airworthiness of the helicopter. This attribute is potentially a significant advantage when compared to IBC.

Architecture for Multi-Technology Real-Time Location Systems

PubMed Central

Rodas, Javier; Barral, Valentín; Escudero, Carlos J.

2013-01-01

The rising popularity of location-based services has prompted considerable research in the field of indoor location systems. Since there is no single technology to support these systems, it is necessary to consider the fusion of the information coming from heterogeneous sensors. This paper presents a software architecture designed for a hybrid location system where we can merge information from multiple sensor technologies. The architecture was designed to be used by different kinds of actors independently and with mutual transparency: hardware administrators, algorithm developers and user applications. The paper presents the architecture design, work-flow, case study examples and some results to show how different technologies can be exploited to obtain a good estimation of a target position. PMID:23435050

Removal of phenol by activated alumina bed in pulsed high-voltage electric field.

PubMed

Zhu, Li-nan; Ma, Jun; Yang, Shi-dong

2007-01-01

A new process for removing the pollutants in aqueous solution-activated alumina bed in pulsed high-voltage electric field was investigated for the removal of phenol under different conditions. The experimental results indicated the increase in removal rate with increasing applied voltage, increasing pH value of the solution, aeration, and adding Fe2+. The removal rate of phenol could reach 72.1% when air aeration flow rate was 1200 ml/min, and 88.2% when 0.05 mmol/L Fe2+ was added into the solution under the conditions of applied voltage 25 kV, initial phenol concentration of 5 mg/L, and initial pH value 5.5. The addition of sodium carbonate reduced the phenol removal rate. In the pulsed high-voltage electric field, local discharge occurred at the surface of activated alumina, which promoted phenol degradation in the thin water film. At the same time, the space-time distribution of gas-liquid phases was more uniform and the contact areas of the activated species generated from the discharge and the pollutant molecules were much wider due to the effect of the activated alumina bed. The synthetical effects of the pulsed high-voltage electric field and the activated alumina particles accelerated phenol degradation.

Seismic Activity at tres Virgenes Volcanic and Geothermal Field

NASA Astrophysics Data System (ADS)

Antayhua, Y. T.; Lermo, J.; Quintanar, L.; Campos-Enriquez, J. O.

2013-05-01

The volcanic and geothermal field Tres Virgenes is in the NE portion of Baja California Sur State, Mexico, between -112°20'and -112°40' longitudes, and 27°25' to 27°36' latitudes. Since 2003 Power Federal Commission and the Engineering Institute of the National Autonomous University of Mexico (UNAM) initiated a seismic monitoring program. The seismograph network installed inside and around the geothermal field consisted, at the beginning, of Kinemetrics K2 accelerometers; since 2009 the network is composed by Guralp CMG-6TD broadband seismometers. The seismic data used in this study covered the period from September 2003 - November 2011. We relocated 118 earthquakes with epicenter in the zone of study recorded in most of the seismic stations. The events analysed have shallow depths (≤10 km), coda Magnitude Mc≤2.4, with epicentral and hypocentral location errors <2 km. These events concentrated mainly below Tres Virgenes volcanoes, and the geothermal explotation zone where there is a system NW-SE, N-S and W-E of extensional faults. Also we obtained focal mechanisms for 38 events using the Focmec, Hash, and FPFIT methods. The results show normal mechanisms which correlate with La Virgen, El Azufre, El Cimarron and Bonfil fault systems, whereas inverse and strike-slip solutions correlate with Las Viboras fault. Additionally, the Qc value was obtained for 118 events. This value was calculated using the Single Back Scattering model, taking the coda-waves train with window lengths of 5 sec. Seismograms were filtered at 4 frequency bands centered at 2, 4, 8 and 16 Hz respectively. The estimates of Qc vary from 62 at 2 Hz, up to 220 at 16 Hz. The frequency-Qc relationship obtained is Qc=40±2f(0.62±0.02), representing the average attenuation characteristics of seismic waves at Tres Virgenes volcanic and geothermal field. This value correlated with those observed at other geothermal and volcanic fields.

Electrophysiological recordings in humans reveal reduced location-specific attentional-shift activity prior to recentering saccades

PubMed Central

Boehler, C. Nicolas; Zhang, Helen H.; Schoenfeld, Mircea A.; Woldorff, Marty G.

2012-01-01

Being able to effectively explore the visual world is of fundamental importance, and it has been suggested that the straight-ahead gaze position within the egocentric reference frame (“primary position”) might play a special role in this context. In the present study we employed human electroencephalography (EEG) to examine neural activity related to the spatial guidance of saccadic eye movements. Moreover, we sought to investigate whether such activity would be modulated by the spatial relation of saccade direction to the primary gaze position (recentering saccades). Participants executed endogenously cued saccades between five equidistant locations along the horizontal meridian. This design allowed for the comparison of isoamplitude saccades from the same starting position that were oriented either toward the primary position (centripetal) or further away from it (centrifugal). By back-averaging time-locked to the saccade onset on each trial, we identified a parietally distributed, negative-polarity EEG deflection contralateral to the direction of the upcoming saccade. Importantly, this contralateral presaccadic negativity, which appeared to reflect the location-specific attentional guidance of the eye movement, was attenuated for recentering saccades relative to isoamplitude centrifugal saccades. This differential electrophysiological signature was paralleled by faster saccadic reaction times and was substantially more apparent when time-locking the data to the onset of the saccade rather than to the onset of the cue, suggesting a tight temporal association with saccade initiation. The diminished level of this presaccadic component for recentering saccades may reflect the preferential coding of the straight-ahead gaze position, in which both the eye-centered and head-centered reference frames are perfectly aligned and from which the visual world can be effectively explored. PMID:22157127

Flowing Active Liquids in a Pipe: Hysteretic Response of Polar Flocks to External Fields

NASA Astrophysics Data System (ADS)

Morin, Alexandre; Bartolo, Denis

2018-04-01

We investigate the response of colloidal flocks to external fields. We first show that individual colloidal rollers align with external flows, as would a classical spin with magnetic fields. Assembling polar active liquids from colloidal rollers, we experimentally demonstrate their hysteretic response: Confined colloidal flocks can proceed against external flows. We theoretically explain this collective robustness, using an active hydrodynamic description, and show how orientational elasticity and confinement protect the direction of collective motion. Finally, we exploit the intrinsic bistability of confined active flows to devise self-sustained microfluidic oscillators.

Stress concentrations at structural discontinuities in active fault zones in the western United States: Implications for permeability and fluid flow in geothermal fields

USGS Publications Warehouse

Siler, Drew; Hinz, Nicholas H.; Faulds, James E.

2018-01-01

Slip can induce concentration of stresses at discontinuities along fault systems. These structural discontinuities, i.e., fault terminations, fault step-overs, intersections, bends, and other fault interaction areas, are known to host fluid flow in ore deposition systems, oil and gas reservoirs, and geothermal systems. We modeled stress transfer associated with slip on faults with Holocene-to-historic slip histories at the Salt Wells and Bradys geothermal systems in western Nevada, United States. Results show discrete locations of stress perturbation within discontinuities along these fault systems. Well field data, surface geothermal manifestations, and subsurface temperature data, each a proxy for modern fluid circulation in the fields, indicate that geothermal fluid flow is focused in these same areas where stresses are most highly perturbed. These results suggest that submeter- to meter-scale slip on these fault systems generates stress perturbations that are sufficiently large to promote slip on an array of secondary structures spanning the footprint of the modern geothermal activity. Slip on these secondary faults and fractures generates permeability through kinematic deformation and allows for transmission of fluids. Still, mineralization is expected to seal permeability along faults and fractures over time scales that are generally shorter than either earthquake recurrence intervals or the estimated life span of geothermal fields. This suggests that though stress perturbations resulting from fault slip are broadly important for defining the location and spatial extent of enhanced permeability at structural discontinuities, continual generation and maintenance of flow conduits throughout these areas are probably dependent on the deformation mechanism(s) affecting individual structures.

The Impact of Expressiveness on the Effectiveness of Privacy Mechanisms for Location Sharing

DTIC Science & Technology

2008-12-01

of the ex- pected billions of dollars in marketing revenue from location - based services [13]. Despite the number of location-sharing applications that...privacy concerns [2, 25]. Many research groups have have developed location - based services : PARC’s Active Badges [37], ActiveCampus [3], MyCampus [29...location within social groups. In CHI ’08, pages 497–506, April 2008. [3] L. Barkhuus and A. Dey. Location - based services for mobile telephony: a study

A unified dynamic neural field model of goal directed eye movements

NASA Astrophysics Data System (ADS)

Quinton, J. C.; Goffart, L.

2018-01-01

Primates heavily rely on their visual system, which exploits signals of graded precision based on the eccentricity of the target in the visual field. The interactions with the environment involve actively selecting and focusing on visual targets or regions of interest, instead of contemplating an omnidirectional visual flow. Eye-movements specifically allow foveating targets and track their motion. Once a target is brought within the central visual field, eye-movements are usually classified into catch-up saccades (jumping from one orientation or fixation to another) and smooth pursuit (continuously tracking a target with low velocity). Building on existing dynamic neural field equations, we introduce a novel model that incorporates internal projections to better estimate the current target location (associated to a peak of activity). Such estimate is then used to trigger an eye movement, leading to qualitatively different behaviours depending on the dynamics of the whole oculomotor system: (1) fixational eye-movements due to small variations in the weights of projections when the target is stationary, (2) interceptive and catch-up saccades when peaks build and relax on the neural field, (3) smooth pursuit when the peak stabilises near the centre of the field, the system reaching a fixed point attractor. Learning is nevertheless required for tracking a rapidly moving target, and the proposed model thus replicates recent results in the monkey, in which repeated exercise permits the maintenance of the target within in the central visual field at its current (here-and-now) location, despite the delays involved in transmitting retinal signals to the oculomotor neurons.

Survival and Competitiveness of Bradyrhizobium japonicum Strains 20 Years after Introduction into Field Locations in Poland.

PubMed

Narożna, Dorota; Pudełko, Krzysztof; Króliczak, Joanna; Golińska, Barbara; Sugawara, Masayuki; Mądrzak, Cezary J; Sadowsky, Michael J

2015-08-15

It was previously demonstrated that there are no indigenous strains of Bradyrhizobium japonicum forming nitrogen-fixing root nodule symbioses with soybean plants in arable field soils in Poland. However, bacteria currently classified within this species are present (together with Bradyrhizobium canariense) as indigenous populations of strains specific for nodulation of legumes in the Genisteae tribe. These rhizobia, infecting legumes such as lupins, are well established in Polish soils. The studies described here were based on soybean nodulation field experiments, established at the Poznań University of Life Sciences Experiment Station in Gorzyń, Poland, and initiated in the spring of 1994. Long-term research was then conducted in order to study the relation between B. japonicum USDA 110 and USDA 123, introduced together into the same location, where no soybean rhizobia were earlier detected, and nodulation and competitive success were followed over time. Here we report the extra-long-term saprophytic survival of B. japonicum strains nodulating soybeans that were introduced as inoculants 20 years earlier and where soybeans were not grown for the next 17 years. The strains remained viable and symbiotically competent, and molecular and immunochemical methods showed that the strains were undistinguishable from the original inoculum strains USDA 110 and USDA 123. We also show that the strains had balanced numbers and their mobility in soil was low. To our knowledge, this is the first report showing the extra-long-term persistence of soybean-nodulating strains introduced into Polish soils and the first analyzing the long-term competitive relations of USDA 110 and USDA 123 after the two strains, neither of which was native, were introduced into the environment almost 2 decades ago. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Modeling place field activity with hierarchical slow feature analysis

PubMed Central

Schönfeld, Fabian; Wiskott, Laurenz

2015-01-01

What are the computational laws of hippocampal activity? In this paper we argue for the slowness principle as a fundamental processing paradigm behind hippocampal place cell firing. We present six different studies from the experimental literature, performed with real-life rats, that we replicated in computer simulations. Each of the chosen studies allows rodents to develop stable place fields and then examines a distinct property of the established spatial encoding: adaptation to cue relocation and removal; directional dependent firing in the linear track and open field; and morphing and scaling the environment itself. Simulations are based on a hierarchical Slow Feature Analysis (SFA) network topped by a principal component analysis (ICA) output layer. The slowness principle is shown to account for the main findings of the presented experimental studies. The SFA network generates its responses using raw visual input only, which adds to its biological plausibility but requires experiments performed in light conditions. Future iterations of the model will thus have to incorporate additional information, such as path integration and grid cell activity, in order to be able to also replicate studies that take place during darkness. PMID:26052279

Field characterization plan for the 216-U-8 vitrified clay pipeline

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rowley, C.A.

1994-01-21

The 216-U-8 Crib was constructed in 1952 and received waste from 1952 to 1960 as described in Appendix A. This description of work details the field activities associated with the characterization of the vitrified clay pipe (VCP) delivery line to the 216-U-8 Crib and subsurface soil sampling along the pipe route in the 200 West Area of Hanford U Plant. It will serves as a field guide for those performing the work. Soil sampling locations will be determined by a combination of radiological surface surveys and internal camera surveys of the VCP line. Depending on the condition of the pipelinemore » and field conditions, the objectives are as follows: examine the internal condition of the VCP with a survey camera to the extent allowed by field conditions; determine precise location and depth of the VCP; document VCP integrity; document gamma radiation profile through the VCP; and correlate any relationships between surface contamination zones at grade above the VCP to identify breaches in the pipe integrity.« less

Electric field measurements from Halley, Antarctica

NASA Astrophysics Data System (ADS)

Nicoll, Keri; Harrison, R. Giles

2016-04-01

Antarctica is a unique location for the study of atmospheric electricity. Not only is it one of the most pollutant free places on Earth, but its proximity to the south magnetic pole means that it is an ideal location to study the effects of solar variability on the atmospheric electric field. This is due to the reduced shielding effect of the geomagnetic field at the poles which leads to a greater flux of incoming Galactic Cosmic Rays (GCRs) as well as an increased probability of energetic particle precipitation from SEPs and relativistic electrons. To investigate such effects, two electric field mills of different design were installed at the British Antarctic Survey Halley base in February 2015 (75. 58 degrees south, 26.66 degrees west). Halley is situated on the Brunt Ice Shelf in the south east of the Weddell Sea and has snow cover all year round. Preliminary analysis has focused on selection of fair weather criteria using wind speed and visibility measurements which are vital to assess the effects of falling snow, blowing snow and freezing fog on the electric field measurements. When the effects of such adverse weather conditions are removed clear evidence of the characteristic Carnegie Curve diurnal cycle exists in the Halley electric field measurements (with a mean value of 50V/m and showing a 40% peak to peak variation in comparison to the 34% variation in the Carnegie data). Since the Carnegie Curve represents the variation in thunderstorm activity across the Earth, its presence in the Halley data confirms the presence of the global atmospheric electric circuit signal at Halley. The work presented here will discuss the details of the Halley electric field dataset, including the variability in the fair weather measurements, with a particular focus on magnetic field fluctuations.

Active subthreshold dendritic conductances shape the local field potential

PubMed Central

Ness, Torbjørn V.; Remme, Michiel W. H.

2016-01-01

Key points The local field potential (LFP), the low‐frequency part of extracellular potentials recorded in neural tissue, is often used for probing neural circuit activity. Interpreting the LFP signal is difficult, however.While the cortical LFP is thought mainly to reflect synaptic inputs onto pyramidal neurons, little is known about the role of the various subthreshold active conductances in shaping the LFP.By means of biophysical modelling we obtain a comprehensive qualitative understanding of how the LFP generated by a single pyramidal neuron depends on the type and spatial distribution of active subthreshold currents.For pyramidal neurons, the h‐type channels probably play a key role and can cause a distinct resonance in the LFP power spectrum.Our results show that the LFP signal can give information about the active properties of neurons and imply that preferred frequencies in the LFP can result from those cellular properties instead of, for example, network dynamics. Abstract The main contribution to the local field potential (LFP) is thought to stem from synaptic input to neurons and the ensuing subthreshold dendritic processing. The role of active dendritic conductances in shaping the LFP has received little attention, even though such ion channels are known to affect the subthreshold neuron dynamics. Here we used a modelling approach to investigate the effects of subthreshold dendritic conductances on the LFP. Using a biophysically detailed, experimentally constrained model of a cortical pyramidal neuron, we identified conditions under which subthreshold active conductances are a major factor in shaping the LFP. We found that, in particular, the hyperpolarization‐activated inward current, I h, can have a sizable effect and cause a resonance in the LFP power spectral density. To get a general, qualitative understanding of how any subthreshold active dendritic conductance and its cellular distribution can affect the LFP, we next performed a systematic