Imaging thunder

NASA Astrophysics Data System (ADS)

Johnson, J. B.; Arechiga, R. O.; Thomas, R. J.; Edens, H. E.; Anderson, J.; Johnson, R. L.

2011-12-01

We use a network of broadband microphones, including a 4-element array, to locate the sources of thunder occurring during an electrical storm in central New Mexico on July 24th, 2009. Combined slowness search and distance ranging are used to identify thunder regions in three dimensions (out to 12 km) and for two overlapping frequency bands (1-10 and 4-40 Hz). Distinct thunder pulses are locatable and used to predict time-of-arrival to neighboring stations and to identify correlated phases across the network. Spatial correlation is also found between the thunder source regions and regions of VHF radiation as located by the New Mexico Lightning Mapping Array (LMA). Some of the misfit between the LMA and thunder locations is attributable to differences in excitation mechanisms of the respective radiation, which is related to current impulses in lightning channels (for thunder) and incremental ionization of the atmosphere (for VHF emissions).

Imaging thunder

NASA Astrophysics Data System (ADS)

Johnson, J. B.; Arechiga, R. O.; Thomas, R. J.; Edens, H. E.; Anderson, J.; Johnson, R.

2011-10-01

We use a network of broadband microphones, including a 4-element array, to locate the sources of thunder occurring during an electrical storm in central New Mexico on July 24th, 2009. Combined slowness search and distance ranging are used to identify thunder regions in three dimensions (out to 12 km) and for two overlapping frequency bands (1-10 and 4-40 Hz). Distinct thunder pulses are locatable and used to predict time-of-arrival to neighboring stations and to identify correlated phases across the network. Spatial correlation is also found between the thunder source regions and regions of very high frequency (VHF) radiation as located by the New Mexico Lightning Mapping Array (LMA). Some of the misfit between the LMA and thunder locations is attributable to differences in excitation mechanisms of the respective radiation, which is related to current impulses in lightning channels (for thunder) and incremental ionization of the atmosphere (for VHF emissions).

Characteristics of Lightning Within Electrified Snowfall Events Using Lightning Mapping Arrays

NASA Astrophysics Data System (ADS)

Schultz, Christopher J.; Lang, Timothy J.; Bruning, Eric C.; Calhoun, Kristin M.; Harkema, Sebastian; Curtis, Nathan

2018-02-01

This study examined 34 lightning flashes within four separate thundersnow events derived from lightning mapping arrays (LMAs) in northern Alabama, central Oklahoma, and Washington DC. The goals were to characterize the in-cloud component of each lightning flash, as well as the correspondence between the LMA observations and lightning data taken from national lightning networks like the National Lightning Detection Network (NLDN). Individual flashes were examined in detail to highlight several observations within the data set. The study results demonstrated that the structures of these flashes were primarily normal polarity. The mean area encompassed by this set of flashes is 375 km2, with a maximum flash extent of 2,300 km2, a minimum of 3 km2, and a median of 128 km2. An average of 2.29 NLDN flashes were recorded per LMA-derived lightning flash. A maximum of 11 NLDN flashes were recorded in association with a single LMA-derived flash on 10 January 2011. Additionally, seven of the 34 flashes in the study contain zero NLDN-identified flashes. Eleven of the 34 flashes initiated from tall human-made objects (e.g., communication towers). In at least six lightning flashes, the NLDN detected a return stroke from the cloud back to the tower and not the initial upward leader. This study also discusses lightning's interaction with the human-built environment and provides an example of lightning within heavy snowfall observed by Geostationary Operational Environmental Satellite-16's Geostationary Lightning Mapper.

Characteristics of Lightning within Electrified Snowfall Events using Lightning Mapping Arrays.

PubMed

Schultz, Christopher J; Lang, Timothy J; Bruning, Eric C; Calhoun, Kristin M; Harkema, Sebastian; Curtis, Nathan

2018-02-27

This study examined 34 lightning flashes within four separate thundersnow events derived from lightning mapping arrays (LMAs) in northern Alabama, central Oklahoma, and Washington DC. The goals were to characterize the in-cloud component of each lightning flash, as well as the correspondence between the LMA observations and lightning data taken from national lightning networks like the National Lightning Detection Network (NLDN). Individual flashes were examined in detail to highlight several observations within the dataset. The study results demonstrated that the structures of these flashes were primarily normal polarity. The mean area encompassed by this set of flashes is 375 km 2 , with a maximum flash extent of 2300 km 2 , a minimum of 3 km 2 , and a median of 128 km 2 . An average of 2.29 NLDN flashes were recorded per LMA-derived lightning flash. A maximum of 11 NLDN flashes were recorded in association with a single LMA-derived flash on 10 January 2011. Additionally, seven of the 34 flashes in the study contain zero NLDN identified flashes. Eleven of the 34 flashes initiated from tall human-made objects (e.g., communication towers). In at least six lightning flashes, the NLDN detected a return stroke from the cloud back to the tower and not the initial upward leader. This study also discusses lightning's interaction with the human built environment and provides an example of lightning within heavy snowfall observed by GOES-16's Geostationary Lightning Mapper.

Lightning Location Using Acoustic Signals

NASA Astrophysics Data System (ADS)

Badillo, E.; Arechiga, R. O.; Thomas, R. J.

2013-05-01

In the summer of 2011 and 2012 a network of acoustic arrays was deployed in the Magdalena mountains of central New Mexico to locate lightning flashes. A Times-Correlation (TC) ray-tracing-based-technique was developed in order to obtain the location of lightning flashes near the network. The TC technique, locates acoustic sources from lightning. It was developed to complement the lightning location of RF sources detected by the Lightning Mapping Array (LMA) developed at Langmuir Laboratory, in New Mexico Tech. The network consisted of four arrays with four microphones each. The microphones on each array were placed in a triangular configuration with one of the microphones in the center of the array. The distance between the central microphone and the rest of them was about 30 m. The distance between centers of the arrays ranged from 500 m to 1500 m. The TC technique uses times of arrival (TOA) of acoustic waves to trace back the location of thunder sources. In order to obtain the times of arrival, the signals were filtered in a frequency band of 2 to 20 hertz and cross-correlated. Once the times of arrival were obtained, the Levenberg-Marquardt algorithm was applied to locate the spatial coordinates (x,y, and z) of thunder sources. Two techniques were used and contrasted to compute the accuracy of the TC method: Nearest-Neighbors (NN), between acoustic and LMA located sources, and standard deviation from the curvature matrix of the system as a measure of dispersion of the results. For the best case scenario, a triggered lightning event, the TC method applied with four microphones, located sources with a median error of 152 m and 142.9 m using nearest-neighbors and standard deviation respectively.; Results of the TC method in the lightning event recorded at 18:47:35 UTC, August 6, 2012. Black dots represent the results computed. Light color dots represent the LMA data for the same event. The results were obtained with the MGTM station (four channels). This figure shows a map of Altitude vs Longitude (in km).

GLM Validation Studies in Colorado

NASA Astrophysics Data System (ADS)

Rutledge, S. A.; Reimel, K.; Fuchs, B.; Xu, W.

2017-12-01

On 8 May 2017 the Geostationary Lightning Mapper (GLM) calibration/validation field campaign completed a mission over the domain of the Colorado Lightning Mapping Array (LMA). This "gold mine day" produced a mixture of normal polarity and anomalous storms of varying intensity. A case study analysis has been completed for a portion of three individual storms from this day. By utilizing a cell tracking algorithm and lightning flash attribution program, individual lightning flashes detected by the GLM, LMA, the National Lightning Detection Network (NLDN), and Earth Networks Total Lightning Network (ENTLN) are attributed to individual storm cells. The focus of this analysis is the detection efficiency of GLM. We will discuss how the GLM detection efficiency changes as a result of storm morphology and lightning flash characteristics. Lightning flash size, flash height, and the amount of ice present between the lightning flash altitude and the top of the cloud all appear to play a role in how well GLM detects lightning flashes. Since GLM shares the same concept as its predecessor TRMM LIS (optically-based lightning detection), the evaluation of TRMM LIS against LMA network-detected lightning provides insights into the GLM detection efficiency. We have collected observations by LIS and LMA coincident in time and space during 2008-2014. The sample includes 400 LIS overpasses with both LIS and LMA detecting flashes within 150 km radius of the center of the LMA array during the 120 second LIS observing time period (analysis presently confined to the Alabama LMA network). The overall LIS detection efficiency (DE, defined as the ratio of flash rates between LIS and LMA) is 0.45, with higher DE for lower flash rate cases. LIS showed a DE of nearly 100% for cases with flash rates < 10 fl/min, but had a DE of only 20-30% for high flash rates within intense storms (> 300 fl/min). We further separated the dataset into day and night, and found that the night-time DE (0.6) increased by 20% compared to day-time DE (0.5). LIS DE also increased as a function of LMA-derived flash size, possibly due to stronger radiance from larger flashes. LIS DE was the lowest ( 40%) for flashes with sizes smaller than a single LIS pixel (< 16 km2). These results may be applicable to GLM as well.

Adaptive lenticular microlens array based on voltage-induced waves at the surface of polyvinyl chloride/dibutyl phthalate gels.

PubMed

Xu, Miao; Jin, Boya; He, Rui; Ren, Hongwen

2016-04-18

We report a new approach to preparing a lenticular microlens array (LMA) using polyvinyl chloride (PVC)/dibutyl phthalate (DBP) gels. The PVD/DBP gels coated on a glass substrate form a membrane. With the aid of electrostatic repulsive force, the surface of the membrane can be reconfigured with sinusoidal waves by a DC voltage. The membrane with wavy surface functions as a LMA. By switching over the anode and cathode, the convex shape of each lenticular microlens in the array can be converted to the concave shape. Therefore, the LMA can present a large dynamic range. The response time is relatively fast and the driving voltage is low. With the advantages of compact structure, optical isotropy, and good mechanical stability, our LMA has potential applications in imaging, information processing, biometrics, and displays.

Total Lightning Observations within Electrified Snowfall using Polarimetric Radar, LMA, and NLDN Measurements

NASA Technical Reports Server (NTRS)

Schultz, Christopher J.; Carey, Lawerence D.; Brunning, Eric C.; Blakeslee, Richard

2013-01-01

Four electrified snowfall cases are examined using total lightning measurements from lightning mapping arrays (LMAs), and the National Lightning Detection Network (NLDN) from Huntsville, AL and Washington D.C. In each of these events, electrical activity was in conjunction with heavy snowfall rates, sometimes exceeding 5-8 cm hr-1. A combination of LMA, and NLDN data also indicate that many of these flashes initiated from tall communications towers and traveled over large horizontal distances. During events near Huntsville, AL, the Advanced Radar for Meteorological and Operational Research (ARMOR) C-band polarimetric radar was collecting range height indicators (RHIs) through regions of heavy snowfall. The combination of ARMOR polarimetric radar and VHF LMA observations suggested contiguous layer changes in height between sloping aggregate-dominated layers and horizontally-oriented crystals. These layers may have provided ideal conditions for the development of extensive regions of charge and resultant horizontal propagation of the lightning flashes over large distances.

Dynamic response of a lenticular microlens array using a polyvinyl chloride gel

NASA Astrophysics Data System (ADS)

Li, Xiaolong; Zhou, Zuowei; Ren, Hongwen

2017-12-01

We prepared a lenticular microlens array (LMA) using a polyvinyl chloride (PVC) gel and an interdigitated electrode. By applying a DC voltage to the electrode, the surface of the PVC gel can be waved with an LMA character. When the voltage is removed, the wavy PVC gel can recover its flat surface gradually. With the aid of a polarity-inverted voltage, the recovering time can be largely reduced. The LMA can present a stable dynamic response when it is repetitively impacted by a pulse voltage. The experimental results are given, and the mechanism of reducing the dynamic response time is explained. Our LMA with improved response time has potential applications in sensing, beam steering, biometrics, and displays.

Comparisons of GLM and LMA Observations

NASA Astrophysics Data System (ADS)

Thomas, R. J.; Krehbiel, P. R.; Rison, W.; Stanley, M. A.; Attanasio, A.

2017-12-01

Observations from 3-dimensional VHF lightning mapping arrays (LMAs) provide a valuable basis for evaluating the spatial accuracy and detection efficiencies of observations from the recently launched, optical-based Geosynchronous Lightning Mapper (GLM). In this presentation, we describe results of comparing the LMA and GLM observations. First, the observations are compared spatially and temporally at the individual event (pixel) level for sets of individual discharges. For LMA networks in Florida, Colorado, and Oklahoma, the GLM observations are well correlated time-wise with LMA observations but are systematically offset by one- to two pixels ( 10 to 15 or 20 km) in a southwesterly direction from the actual lightning activity. The graphical comparisons show a similar location uncertainty depending on the altitude at which the scattered light is emitted from the parent cloud, due to being observed at slant ranges. Detection efficiencies (DEs) can be accurately determined graphically for intervals where individual flashes in a storm are resolved time-wise, and DEs and false alarm rates can be automated using flash sorting algorithms for overall and/or larger storms. This can be done as a function of flash size and duration, and generally shows high detection rates for larger flashes. Preliminary results during the May 1 2017 ER-2 overflight of Colorado storms indicate decreased detection efficiency if the storm is obscured by an overlying cloud layer.

Flash propagation and inferred charge structure relative to radar-observed ice alignment signatures in a small Florida mesoscale convective system

NASA Astrophysics Data System (ADS)

Biggerstaff, Michael I.; Zounes, Zackery; Addison Alford, A.; Carrie, Gordon D.; Pilkey, John T.; Uman, Martin A.; Jordan, Douglas M.

2017-08-01

A series of vertical cross sections taken through a small mesoscale convective system observed over Florida by the dual-polarimetric SMART radar were combined with VHF radiation source locations from a lightning mapping array (LMA) to examine the lightning channel propagation paths relative to the radar-observed ice alignment signatures associated with regions of negative specific differential phase (KDP). Additionally, charge layers inferred from analysis of LMA sources were related to the ice alignment signature. It was found that intracloud flashes initiated near the upper zero-KDP boundary surrounding the negative KDP region. The zero-KDP boundary also delineated the propagation path of the lightning channel with the negative leaders following the upper boundary and positive leaders following the lower boundary. Very few LMA sources were found in the negative KDP region. We conclude that rapid dual-polarimetric radar observations can diagnose strong electric fields and may help identify surrounding regions of charge.

Lightning Mapping Observations During DC3 in Northern Colorado

NASA Astrophysics Data System (ADS)

Krehbiel, P. R.; Rison, W.; Thomas, R. J.

2012-12-01

The Deep Convective Clouds and Chemistry Experiment (DC3) was conducted in three regions covered by Lightning Mapping Arrays (LMAs): Oklahoma and west Texas, northern Alabama, and northern Colorado. In this and a companion presentation, we discuss results obtained from the newly-deployed North Colorado LMA. The CO LMA revealed a surprising variety of lightning-inferred electrical structures, ranging from classic tripolar, normal polarity storms to several variations of anomalously electrified systems. Storms were often characterized by a pronounced lack or deficit of cloud-to-ground discharges (negative or positive), both in relative and absolute terms compared to the large amount of intracloud activity revealed by the LMA. Anomalous electrification was observed in small, localized storms as well as in large, deeply convective and severe storms. Another surprising observation was the frequent occurrence of embedded convection in the downwind anvil/outflow region of large storm systems. Observations of discharges in low flash rate situations over or near the network are sufficiently detailed to enable branching algorithms to estimate total channel lengths for modeling NOx production. However, this will not be possible in large or distant storm systems where the lightning was essentially continuous and structurally complex, or spatially noisy. Rather, a simple empirical metric for characterizing the lightning activity can be developed based on the number of located VHF radiation sources, weighted for example by the peak source power, source altitude, and temporal duration.

The Colorado Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Rison, W.; Krehbiel, P. R.; Thomas, R. J.; Rodeheffer, D.; Fuchs, B.

2012-12-01

A fifteen station Lightning Mapping Array (LMA) was installed in northern Colorado in the spring of 2012. While the driving force for the array was to produce 3-dimensional lightning data to support the Deep Convective Clouds and Chemistry (DC3) Experiment (Barth, this conference), data from the array are being used for several other projects. These include: electrification studies in conjunction with the CSU CHILL radar (Lang et al, this conference); observations of the parent lightning discharges of sprites (Lyons et al, this conference); trying to detect upward discharges triggered by wind turbines, characterizing conditions in which aircraft flying through clouds produce discharges which can be detected by the LMA, and other opportunities, such as observations of lightning in pyrocumulus clouds produced by the High Park Fire west of Fort Collins, CO. All the COLMA stations are solar-powered, and use broadband cellular modems for data communications. This makes the stations completely self-contained and autonomous, allowing a station to be installed anywhere a cellular signal is available. Because most of the stations were installed well away from anthropogenic noise sources, the COLMA is very sensitive. This is evidenced by the numerous plane tracks detected in its the vicinity. The diameter, D, of the COLMA is about 100 km, significantly larger than other LMAs. Because the error in the radial distance r is proportional to (r/D)2, and the error in the altitude z is proportional to (z/D)2, the larger array diameter greatly expands the usable range of the COLMA. The COLMA is able to detect and characterize lighting flashes to a distance of about 350 km from the array center. In addition to a web-based display (lightning.nmt.edu/colma), geo-referenced images are produced and updated at one-minute intervals. These geo-referenced images can be used to overlay the real-time lightning data on Google Earth and other mapping software. These displays were used by the DC3 aircraft operations to guide the research aircraft to the best regions for sampling thunderstorm outflow chemistry, and to provide pilots information on regions to avoid due to lightning hazards.

Energy and Power Spectra of Thunder in the Magdalena Mountains, Central New Mexico

NASA Astrophysics Data System (ADS)

Johnson, R. L.; Johnson, J. B.; Arechiga, R. O.; Michnovicz, J. C.; Edens, H. E.; Rison, W.

2011-12-01

Thunder is generated primarily by heating and expansion of the atmosphere around a lightning channel and by charge relaxation within a cloud. Broadband acoustic studies are important for inferring dynamic charge behavior during and after lightning events. During the Summer monsoon seasons of 2009-2011, we deployed networks of 3-5 stations consisting of broadband (0.01 to 500 Hz) acoustic arrays and audio microphones in the Magdalena Mountains in central New Mexico. We utilize Lightning Mapping Array (LMA) data for accurate timing of lightning events within a 10 km radius of our network. Unlike the LMA, which detects VHF signals from breakdown processes, thunder signals may be used to observe charge dynamics and thermal shocking of the atmosphere. Previous investigations show that thunder spectral content may distinguish between electrostatic and thermal heating processes. We collected extensive datasets in terms of number of independent broadband sensors (up to 20), number of observed flashes (hundreds from multiple storms), and available coincident LMA data. We use infrasound and audio data to quantify total acoustic energy produced at lightning sources in various frequency bands. We attribute the spectral content and intensity of thunder signals to source characteristics, sensor locations, propagation effects, and noise. We observe variations in acoustic energy for both entire storm systems and individual lightning flashes. We propose that some variations may be related to the type of lightning flash and that spectral content is important for distinguishing between thunder generation mechanisms.

Monitoring the development of volcanic eruptions through volcanic lightning - Using a lightning mapping array, seismic and infrasound array, and visual plume analysis

NASA Astrophysics Data System (ADS)

Smith, C. M.; Thompson, G.; McNutt, S. R.; Behnke, S. A.; Edens, H. E.; Van Eaton, A. R.; Gaudin, D.; Thomas, R. J.

2017-12-01

The period of 28 May - 7 June 2015 at Sakurajima Volcano, Japan witnessed a multitude of Vulcanian eruptive events, which resulted in plumes reaching 500-3000m above the vent. These plumes varied from white, gas-rich plumes to dark grey and black ash-rich plumes, and were recorded on lowlight and infrared cameras. A nine-station lightning mapping array (LMA) was deployed to locate sources of VHF (67-73 MHz) radiation produced by lightning flashes and other types of electrical activity such as `continuous RF (radio frequency)'. Two Nanometrics Trillium broadband seismometers and six BSU infrasound sensors were deployed. Over this ten day period we recorded 1556 events that consisted of both seismic and infrasound signals, indicating explosive activity. There are an additional 1222 events that were recorded as only seismic or infrasound signals, which may be a result of precursory seismic signals or noise contamination. Plume discharge types included both distinct lightning flashes and `continuous RF'. The LMA ran continuously for the duration of the experiment. On 30 May 2015 at least seven lightning flashes were also detected by the Vaisala Global Lightning Detection 360 network, which detects VLF (3-30 kHz) radiation. However the University of Washington's World Wide Lightning Location Network, which also detects VLF radiation, detected no volcanic lightning flashes in this time period. This indicates that the electrical activity in Sakurajima's plume occurs near the lower limits of the VLF detection threshold. We investigate relationships between the plume dynamics, the geophysical signal and the corresponding electrical activity through: plume velocity and height; event waveform cross-correlation; volcano acoustic-seismic ratios; overall geophysical energy; RSAM records; and VHF sources detected by the LMA. By investigating these relationships we hope to determine the seismic/infrasound energy threshold required to generate measurable electrical activity. Seismic and infrasound are two of the most common volcanic monitoring methods. By developing the relationships between plume electrification and these geophysical methods we hope to expand the use of lightning for active volcano monitoring.

The North Alabama Lightning Mapping Array: Recent Severe Storm Observations and Future Prospects

NASA Technical Reports Server (NTRS)

Goodman, S. J.; Blakeslee, R.; Christian, H.; Koshak, W.; Bailey, J.; Hall, J.; McCaul, E.; Buechler, D.; Darden, C.; Burks, J.

2004-01-01

The North Alabama Lightning Mapping Array became operational in November 2001 as a principal component of a severe weather test bed to infuse new science and technology into the short-term forecasting of severe and hazardous weather, principally within nearby National Weather Service forecast offices. Since the installation of the LMA, it has measured the total lightning activity of a large number of severe weather events, including three supercell tornado outbreaks, two supercell hailstorm events, and numerous microburst-producing storms and ordinary non-severe thunderstorms. The key components of evolving storm morphology examined are the time rate-of-change (temporal trending) of storm convective and precipitation characteristics that can be diagnosed in real-time using NEXRAD WSR-88D Doppler radar (echo growth and decay, precipitation structures and velocity features, outflow boundaries), LMA (total lightning flash rate and its trend) and National Lightning Detection Network (cloud-to- ground lightning, its polarity and trends). For example, in a transitional season supercell tornado outbreak, peak total flash rates for typical supercells in Tennessee reached 70-100/min, and increases in the total flash rate occurred during storm intensification as much as 20-25 min prior to at least some of the tornadoes. The most intense total flash rate measured during this outbreak (over 800 flashes/min) occurred in a storm in Alabama. In the case of a severe summertime pulse thunderstorm in North Alabama, the peak total flash rate reached 300/min, with a strong increase in total lightning evident some 9 min before damaging winds were observed at the surface. In this paper we provide a sampling of LMA observations and products during severe weather events to illustrate the capability of the system, and discuss the prospects for improving the short-term forecasting of convective weather using total lightning data.

Kinematic and Microphysical Control of Lightning Flash Rate over Northern Alabama

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Bain, Anthony L.; Matthee, Retha; Schultz, Christopher J.; Schultz, Elise V.; Deierling, Wiebke; Petersen, Walter A.

2015-01-01

The Deep Convective Clouds and Chemistry (DC3) experiment seeks to examine the relationship between deep convection and the production of nitrogen oxides (NO (sub x)) via lightning (LNO (sub x)). A critical step in estimating LNO (sub x) production in a cloud-resolving model (CRM) without explicit lightning is to estimate the flash rate from available model parameters that are statistically and physically correlated. As such, the objective of this study is to develop, improve and evaluate lightning flash rate parameterizations in a variety of meteorological environments and storm types using radar and lightning mapping array (LMA) observations taken over Northern Alabama from 2005-2012, including during DC3. UAH's Advanced Radar for Meteorological and Operational Research (ARMOR) and the Weather Surveillance Radar - 1988 Doppler (WSR 88D) located at Hytop (KHTX) comprises the dual-Doppler and polarimetric radar network, which has been in operation since 2004. The northern Alabama LMA (NA LMA) in conjunction with Vaisala's National Lightning Detection Network (NLDN) allow for a detailed depiction of total lightning during this period. This study will integrate ARMOR-KHTX dual Doppler/polarimetric radar and NA LMA lightning observations from past and ongoing studies, including the more recent DC3 results, over northern Alabama to form a large data set of 15-20 case days and over 20 individual storms, including both ordinary multicell and supercell convection. Several flash rate parameterizations will be developed and tested, including those based on 1) graupel/small hail volume; 2) graupel/small hail mass, and 3) convective updraft volume. Sensitivity of the flash rate parameterizations to storm intensity, storm morphology and environmental conditions will be explored.

Lightning Behavior and its Dependence on Storm Kinematic and Precipitation Processes in Northern Alabama

NASA Technical Reports Server (NTRS)

Johnson, Elsie V.; Petersen, W. A,

2009-01-01

Numerous case studies and recent modeling studies have found that various metrics of updraft intensity appear to be reasonably well correlated to lightning production in thunderstorms, particularly severe thunderstorms. Indeed, the relationship between updraft and lightning flash rate is hypothesized to be the physical connection between a lightning "jump" signature and manifestations of severe weather such as tornadic activity. This study further examines this connection using a combination of dual Doppler wind retrievals made with the UAH ARMOR dual polarimetric and KHTX WSR 88D Doppler radar pair, together with northern Alabama Lightning Mapping Array (LMA) data. The dual Doppler data were used to construct three dimensional wind fields and the retrieved vertical velocity fields were subsequently compared to collocated total lightning flash rates observed by the LMA. Particular attention was paid to the timing of updraft pulses relative to changes in the flash rate, with the goal of assessing impacts on warning decision lead time. Results from the analysis of severe and non severe thunderstorms in Northern Alabama will be presented including the EF 4 tornado producing supercell on 6 February 2008.

The Lightning Nitrogen Oxides Model (LNOM): Status and Recent Applications

NASA Technical Reports Server (NTRS)

Koshak, William; Khan, Maudood; Peterson, Harold

2011-01-01

Improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) are discussed. Recent results from an August 2006 run of the Community Multiscale Air Quality (CMAQ) modeling system that employs LNOM lightning NOx (= NO + NO2) estimates are provided. The LNOM analyzes Lightning Mapping Array (LMA) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx. The latest LNOM estimates of (a) lightning channel length distributions, (b) lightning 1-m segment altitude distributions, and (c) the vertical profile of NOx are presented. The impact of including LNOM-estimates of lightning NOx on CMAQ output is discussed.

Photographic and LMA observations of a blue starter over a New Mexico thunderstorm

NASA Astrophysics Data System (ADS)

Edens, H. E.; Krehbiel, P. R.; Rison, W.; Hunyady, S. J.

2010-12-01

On the evening of August 3, 2010 we photographed a blue starter over an electrically active storm complex about 120 km to the WNW of Langmuir Laboratory in central New Mexico. The event occurred close to a broad overshooting top at an altitude of 15 km above MSL. It was also observed visually and detected by the Lightning Mapping Array (LMA) deployed around the mountaintop observatory. The blue starter appears as a white-blue leader channel propagating away from the storm top not straight upward but at a large angle from vertical, slightly curving upward and transitioning to an increasingly diffuse blue glow. In addition to this leader, a more diffuse glow of blue light from one or two additional leaders is seen in the background. The curved channel of the main leader and the fact that it did not propagate along a straight path upward indicates that a relatively strong local electric field near the storm top existed that dictated leader propagation and direction rather than the large-scale storm electric field. The visible part of the starter is estimated to have developed to about 1 km above the storm top. From the LMA data we infer that the blue starter was a screening layer discharge that initiated between upper positive charge and a negatively charged screening layer. A negative leader appears to initiate at 15 km altitude and propagates downward for 2 to 3 km, after which scattered and ill-defined activity occurred in the cloud between 10 to 15 km altitude. This indicates that the visible part of the blue starter emanating out of the storm top, which was photographed but not detected by the LMA, was positive breakdown. The event lasted for 100 ms in the LMA data. The storm where the starter occurred in was producing predominantly intracloud (IC) flashes at a rate of about 20 per minute. The starter itself occurred independently of other discharges in the storm about 4 seconds after a normal polarity IC flash. About 5 minutes after the first blue starter, a second luminous event was recorded further away above the cloud top, which was similar but smaller in extent both optically and as detected by the LMA. It too was preceded by a regular IC flash 5 seconds earlier.

High speed imaging, lightning mapping arrays and thermal imaging: a synergy for the monitoring of electrical discharges at the onset of volcanic explosions

NASA Astrophysics Data System (ADS)

Gaudin, Damien; Cimarelli, Corrado; Behnke, Sonja; Cigala, Valeria; Edens, Harald; McNutt, Stefen; Smith, Cassandra; Thomas, Ronald; Van Eaton, Alexa

2017-04-01

Volcanic lightning is being increasingly studied, due to its great potential for the detection and monitoring of ash plumes. Indeed, it is observed in a large number of ash-rich volcanic eruptions and it produces electromagnetic waves that can be detected remotely in all weather conditions. Electrical discharges in volcanic plume can also significantly change the structural, chemical and reactivity properties of the erupted material. Although electrical discharges are detected in various regions of the plume, those happening at the onset of an explosion are of particular relevance for the early warning and the study of volcanic jet dynamics. In order to better constrain the electrical activity of young volcanic plumes, we deployed at Sakurajima (Japan) in 2015 a multiparametric set-up including: i) a lightning mapping array (LMA) of 10 VHF antennas recording the electromagnetic waves produced by lightning at a sample rate of 25 Msps; ii) a visible-light high speed camera (5000 frames per second, 0.5 m pixel size, 300 m field of view) shooting short movies (approx. duration 1 s) at different stages of the plume evolution, showing the location of discharges in relation to the plume; and iii) a thermal camera (25 fps, 1.5 m pixel size, 800 m field of view) continuously recording the plume and allowing the estimation of its main source parameters (volume, rise velocity, mass eruption rate). The complementarity of these three setups is demonstrated by comparing and aggregating the data at various stages of the plume development. In the earliest stages, the high speed camera spots discrete small discharges, that appear on the LMA data as peaks superimposed to the continuous radio frequency (CRF) signal. At later stages, flashes happen less frequently and increase in length. The correspondence between high speed camera and LMA data allows to define a direct correlation between the length of the flash and the intensity of the electromagnetic signal. Such correlation is used to estimate the evolution of the total discharges within a volcanic plume, while the superimposition of thermal and high speed videos allows to contextualize the flashes location in the scope of the plume features and dynamics.

The North Alabama Lightning Warning Product

NASA Technical Reports Server (NTRS)

Buechler, Dennis E.; Blakeslee, R. J.; Stano, G. T.

2009-01-01

The North Alabama Lightning Mapping Array NALMA has been collecting total lightning data on storms in the Tennessee Valley region since 2001. Forecasters from nearby National Weather Service (NWS) offices have been ingesting this data for display with other AWIPS products. The current lightning product used by the offices is the lightning source density plot. The new product provides a probabalistic, short-term, graphical forecast of the probability of lightning activity occurring at 5 min intervals over the next 30 minutes . One of the uses of the current lightning source density product by the Huntsville National Weather Service Office is to identify areas of potential for cloud-to-ground flashes based on where LMA total lightning is occurring. This product quantifies that observation. The Lightning Warning Product is derived from total lightning observations from the Washington, D.C. (DCLMA) and North Alabama Lightning Mapping Arrays and cloud-to-ground lightning flashes detected by the National Lightning Detection Network (NLDN). Probability predictions are provided for both intracloud and cloud-to-ground flashes. The gridded product can be displayed on AWIPS workstations in a manner similar to that of the lightning source density product.

A transparent model of the human scala tympani cavity.

PubMed

Rebscher, S J; Talbot, N; Bruszewski, W; Heilmann, M; Brasell, J; Merzenich, M M

1996-01-01

A dimensionally accurate clear model of the human scala tympani has been produced to evaluate the insertion and position of clinically applied intracochlear electrodes for electrical stimulation. Replicates of the human scala tympani were made from low melting point metal alloy (LMA) and from polymethylmeth-acrylate (PMMA) resin. The LMA metal casts were embedded in blocks of epoxy and in clear silicone rubber. After removal of the metal alloy, a cavity was produced that accurately models the human scala tympani. Investment casting molds were made from the PMMA scala tympani casts to enable production of multiple LMA casts from which identical models were fabricated. Total dimensional distortion of the LMA casting process was less than 1% in length and 2% in diameter. The models have been successfully integrated into the design process for the iterative development of advanced intracochlear electrode arrays at UCSF. These fabrication techniques are applicable to a wide range of biomedical design problems that require modelling of visually obscured cavities.

Multicolor Photometric Observation of Lightning from Space: Comparison with Radio Measurements

NASA Technical Reports Server (NTRS)

Adachi, Toru; Cohen, Morris; Said, Ryan; Blakeslee, Richard J.; Cummer, Steven A.; Li, Jingbo; Lu, Geopeng; Hsu, Rue-Ron; Su, Han-Tzong; Chen, Alfred Bing-Chih;

VHF lightning mapping observations of a triggered lightning flash

NASA Astrophysics Data System (ADS)

Edens, H. E.; Eack, K. B.; Eastvedt, E. M.; Trueblood, J. J.; Winn, W. P.; Krehbiel, P. R.; Aulich, G. D.; Hunyady, S. J.; Murray, W. C.; Rison, W.; Behnke, S. A.; Thomas, R. J.

2012-10-01

On 3 August 2010 an extensive lightning flash was triggered over Langmuir Laboratory in New Mexico. The upward positive leader propagated into the storm's midlevel negative charge region, extending over a horizontal area of 13 × 13 km and 7.5 km altitude. The storm had a normal-polarity tripolar charge structure with upper positive charge over midlevel negative charge. Lightning Mapping Array (LMA) observations were used to estimate positive leader velocities along various branches, which were in the range of 1-3 × 104 m s-1, slower than in other studies. The upward positive leader initiated at 3.4 km altitude, but was mapped only above 4.0 km altitude after the onset of retrograde negative breakdown, indicating a change in leader propagation and VHF emissions. The observations suggest that both positive and negative breakdown produce VHF emissions that can be located by time-of-arrival systems, and that not all VHF emissions occurring along positive leader channels are associated with retrograde negative breakdown.

Sprite-producing Convective Storms within the Colorado Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Lyons, W. A.; Cummer, S. A.; Rison, W.; Krehbiel, P. R.; Lang, T. J.; Rutledge, S. A.; Lu, G.; Stanley, M. A.; Ashcraft, T.; Nelson, T. E.

2012-12-01

The multi-year, multi-institution effort entitled Physical Origins of Coupling to the Upper Atmosphere from Lightning (PhOCAL), has among its goals to qualitatively understand the meteorology and lightning flash characteristics that produce the unusual and/or very energetic lightning responsible for phenomena such as sprites, halos, elves, blue jets and gigantic jets, collectively known as Transient Luminous Events (TLEs). A key task is to obtain simultaneous video, ideally with a high-speed imager (HSI), of both a TLE and its parent lightning discharge, within the domain of a 3-D Lightning Mapping Array (LMA). While conceptually simple, this task is logistically quite complicated. In 2012, a new 15-station Colorado LMA (COLMA) became operational, covering northeastern Colorado, with the Yucca Ridge Field Station (YRFS) near its western edge. The National Charge Moment Change Network (CMCN), which since 2007 has been documenting sprite-class +CGs (those with impulse change moment changes >100 C km), indicates that a strong gradient of energetic +CGs exists west-to-east through the COLMA, with the most likely region for sprite-producing storms being in the COLMA eastern fringes (western Kansas and Nebraska). Yet, on 8 and 25 June, 2012, intense convective systems formed in the COLMA along and just east of the Front Range, producing severe weather and intense lightning. On the 8th, four sprite parent +CGs were captured at 3000 fps from YRFS with the sprites confirmed by dual (conventional speed) cameras in New Mexico. In a second storm on the 25th, viewing conditions prevented +CG video acquisition, but sprites were logged over the COLMA and detailed reconstructions of the discharges are being made. The parent discharges often began as upward negative leaders propagating into a mid-level positive charge layer at 8-10 km. They often originated within or near the convective core before expanding outward into a stratiform region and involving several hundred square kilometers, to be followed by +CG and strong continuing currents. LMA indications of recoil leaders appear confirmed by some high-speed video. These storms were somewhat smaller than the typical sprite-bearing MCS. The storm structures will be categorized using GOES IR, NEXRAD reflectivity, NLDN lightning data, CMCN impulse charge moment data, and full charge moment charge retrievals. The sprite parent CG discharges will be cataloged along with their points of origin, the height and volume from which charge is removed, the charge lowered to ground, and the continuing current characteristics. These CGs will be placed in the context of the storms' meteorological structure and evolution.

Automated analysis of lightning leader speed, local flash rates and electric charge structure in thunderstorms

NASA Astrophysics Data System (ADS)

Van Der Velde, O. A.; Montanya, J.; López, J. A.

2017-12-01

A Lightning Mapping Array (LMA) maps radio pulses emitted by lightning leaders, displaying lightning flash development in the cloud in three dimensions. Since the last 10 years about a dozen of these advanced systems have become operational in the United States and in Europe, often with the purpose of severe weather monitoring or lightning research. We introduce new methods for the analysis of complex three-dimensional lightning data produced by LMAs and illustrate them by cases of a mid-latitude severe weather producing thunderstorm and a tropical thunderstorm in Colombia. The method is based on the characteristics of bidrectional leader development as observed in LMA data (van der Velde and Montanyà, 2013, JGR-Atmospheres), where mapped positive leaders were found to propagate at characteristic speeds around 2 · 104 m s-1, while negative leaders typically propagate at speeds around 105 m s-1. Here, we determine leader speed for every 1.5 x 1.5 x 0.75 km grid box in 3 ms time steps, using two time intervals (e.g., 9 ms and 27 ms) and circles (4.5 km and 2.5 km wide) in which a robust Theil-Sen fitting of the slope is performed for fast and slow leaders. The two are then merged such that important speed characteristics are optimally maintained in negative and positive leaders, and labeled with positive or negative polarity according to the resulting velocity. The method also counts how often leaders from a lightning flash initiate or pass through each grid box. This "local flash rate" may be used in severe thunderstorm or NOx production studies and shall be more meaningful than LMA source density which is biased by the detection efficiency. Additionally, in each grid box the median x, y and z components of the leader propagation vectors of all flashes result in a 3D vector grid which can be compared to vectors in numerical models of leader propagation in response to cloud charge structure. Finally, the charge region altitudes, thickness and rates are summarized from vertical profiles of positive and negative leader rates where these exceed their 7-point averaged profiles. The summarized data can be used to follow charge structure evolution over time, and will be useful for climatological studies and statistical comparison against the parameters of the meteorological environment of storms.

Lightning mapping and dual-polarization radar observations of electrified storms at Langmuir Laboratory

NASA Astrophysics Data System (ADS)

Krehbiel, P. R.; Hyland, P. T.; Edens, H. E.; Rison, W.

2013-12-01

Observations being made at Langmuir Laboratory with the NM Tech Lightning Mapping Array (LMA) and the University of Oklahoma ARRC PX-1000 dual polarization X-band radar strongly confirm and expand upon the normal polarity tripolar electrical structure of central New Mexico storms. This is in sharp contrast with the anomalously electrified storm structures observed in northern Colorado during and subsequent to the 2012 DC3 field campaign, as seen with North Colorado LMA and CSU CHILL dual-polarization radar observations. In this presentation we focus on the New Mexico observations, and several modes in which the tripolar structure appears initially to develop and evolve with time. Central New Mexico storms are often prolific producers of negative cloud-to-ground (CG) flashes, but rarely produce positive CGs. By contrast, many or most north Colorado storms are CG-deficient, with the relatively few CG discharges being of predominantly positive polarity. In addition, NM storms commonly produce bolt-from-the-blue (BFB) negative CGs, whereas anomalously electrified Colorado storms produce none. The occurrence of BFBs is indicative of a relatively weak lower positive charge region, while the occurrence of normal downward -CGs is indicative of a somewhat stronger lower positive charge. The lack of -CGs in Colorado storms results from lower positive charge being a dominant storm charge that is elevated in altitude. These and other basic features of the electrically activity of storms, coupled with dual polarization and Doppler radar observations of hydrometeor types and motions, are leading to a better understanding of the storm electrification processes.

Location of acoustic radiators and inversion for energy density using radio-frequency sources and thunder recordings

NASA Astrophysics Data System (ADS)

Anderson, J.; Johnson, J. B.; Arechiga, R. O.; Edens, H. E.; Thomas, R. J.

2011-12-01

We use radio frequency (VHF) pulse locations mapped with the New Mexico Tech Lightning Mapping Array (LMA) to study the distribution of thunder sources in lightning channels. A least squares inversion is used to fit channel acoustic energy radiation with broadband (0.01 to 500 Hz) acoustic recordings using microphones deployed local (< 10 km) to the lightning. We model the thunder (acoustic) source as a superposition of line segments connecting the LMA VHF pulses. An optimum branching algorithm is used to reconstruct conductive channels delineated by VHF sources, which we discretize as a superposition of finely-spaced (0.25 m) acoustic point sources. We consider total radiated thunder as a weighted superposition of acoustic waves from individual channels, each with a constant current along its length that is presumed to be proportional to acoustic energy density radiated per unit length. Merged channels are considered as a linear sum of current-carrying branches and radiate proportionally greater acoustic energy. Synthetic energy time series for a given microphone location are calculated for each independent channel. We then use a non-negative least squares inversion to solve for channel energy densities to match the energy time series determined from broadband acoustic recordings across a 4-station microphone network. Events analyzed by this method have so far included 300-1000 VHF sources, and correlations as high as 0.5 between synthetic and recorded thunder energy were obtained, despite the presence of wind noise and 10-30 m uncertainty in VHF source locations.

Large-scale climatic and geophysical controls on the leaf economics spectrum.

PubMed

Asner, Gregory P; Knapp, David E; Anderson, Christopher B; Martin, Roberta E; Vaughn, Nicholas

2016-07-12

Leaf economics spectrum (LES) theory suggests a universal trade-off between resource acquisition and storage strategies in plants, expressed in relationships between foliar nitrogen (N) and phosphorus (P), leaf mass per area (LMA), and photosynthesis. However, how environmental conditions mediate LES trait interrelationships, particularly at large biospheric scales, remains unknown because of a lack of spatially explicit data, which ultimately limits our understanding of ecosystem processes, such as primary productivity and biogeochemical cycles. We used airborne imaging spectroscopy and geospatial modeling to generate, to our knowledge, the first biospheric maps of LES traits, here centered on 76 million ha of Andean and Amazonian forest, to assess climatic and geophysical determinants of LES traits and their interrelationships. Elevation and substrate were codominant drivers of leaf trait distributions. Multiple additional climatic and geophysical factors were secondary determinants of plant traits. Anticorrelations between N and LMA followed general LES theory, but topo-edaphic conditions strongly mediated and, at times, eliminated this classic relationship. We found no evidence for simple P-LMA or N-P trade-offs in forest canopies; rather, we mapped a continuum of N-P-LMA interactions that are sensitive to elevation and temperature. Our results reveal nested climatic and geophysical filtering of LES traits and their interrelationships, with important implications for predictions of forest productivity and acclimation to rapid climate change.

Charge rearrangement deduced from nearby electric field measurements of an intracloud flash with K‒changes

NASA Astrophysics Data System (ADS)

Hager, William W.; Feng, Wei

2013-09-01

An intracloud flash near Langmuir Laboratory is analyzed to determine the net rearrangement of charge. The analysis employed data from a balloon borne electric field sensor, or Esonde, that was within a few hundred meters of the lightning channel, data from a similar Esonde on a mountain about 6.4 km from the balloon, and data from the New Mexico Institute of Mining and Technology Lightning Mapping Array (LMA). The recovery of the charge transport required the solution of Poisson's equation over the mountainous terrain surrounding Langmuir Laboratory and the solution of a vastly under‒determined system of equations. The charge movement is analyzed using a new smooth charge transport model that incorporates constraints in the least squares fitting process through the use of penalty terms to smooth the charge movement and prevent data overfitting. The electric field measurements were consistent with about 26% of the negative charge being transported to the end of the channel, 36% deposited along the channel in the positive region, 8% deposited near the start of the channel in the positive region, and 30% deposited in another positive region several kilometers beneath the main channel. The transport of negative charge to a lower positive region occurred during the K‒processes when some negative charge was also deposited along the main channel in the upper positive region. Hence, the charge transport process during the K‒processes amounted to a tripolar charge rearrangement where the charge from the negative region was transported to two distinct positive regions, the positive region along the main channel and a lower positive region beneath the main channel. High altitude, widely scattered LMA sources beyond the end of the main channel could indicate the existence of streamers which transported the end‒of‒channel charge into the surrounding volume. Although the LMA showed the development of two upper channels, the charge transport analysis showed that measurable charge transport only occurred on one of the channels. The channel that did not transport charge was missing the high altitude, widely scattered LMA sources seen at the end of the channel that carried charge.

The NASA Lightning Nitrogen Oxides Model (LNOM): Recent Updates and Applications

NASA Technical Reports Server (NTRS)

Koshak, William; Peterson, Harold; Biazar, Arastoo; Khan, Maudood; Wang, Lihua; Park, Yee-Hun

2011-01-01

Improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) and its application to the Community Multiscale Air Quality (CMAQ) modeling system are presented. The LNOM analyzes Lightning Mapping Array (LMA) and National Lightning Detection Network(tm) (NLDN) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NOx (= NO + NO2). Lightning channel length distributions and lightning 10-m segment altitude distributions are also provided. In addition to NOx production from lightning return strokes, the LNOM now includes non-return stroke lightning NOx production due to: hot core stepped and dart leaders, stepped leader corona sheath, K-changes, continuing currents, and M-components. The impact of including LNOM-estimates of lightning NOx for an August 2006 run of CMAQ is discussed.

Learning from concurrent Lightning Imaging Sensor and Lightning Mapping Array observations in preparation for the MTG-LI mission

NASA Astrophysics Data System (ADS)

Defer, Eric; Bovalo, Christophe; Coquillat, Sylvain; Pinty, Jean-Pierre; Farges, Thomas; Krehbiel, Paul; Rison, William

2016-04-01

The upcoming decade will see the deployment and the operation of French, European and American space-based missions dedicated to the detection and the characterization of the lightning activity on Earth. For instance the Tool for the Analysis of Radiation from lightNIng and Sprites (TARANIS) mission, with an expected launch in 2018, is a CNES mission dedicated to the study of impulsive energy transfers between the atmosphere of the Earth and the space environment. It will carry a package of Micro Cameras and Photometers (MCP) to detect and locate lightning flashes and triggered Transient Luminous Events (TLEs). At the European level, the Meteosat Third Generation Imager (MTG-I) satellites will carry in 2019 the Lightning Imager (LI) aimed at detecting and locating the lightning activity over almost the full disk of Earth as usually observed with Meteosat geostationary infrared/visible imagers. The American community plans to operate a similar instrument on the GOES-R mission for an effective operation in early 2016. In addition NASA will install in 2016 on the International Space Station the spare version of the Lightning Imaging Sensor (LIS) that has proved its capability to optically detect the tropical lightning activity from the Tropical Rainfall Measuring Mission (TRMM) spacecraft. We will present concurrent observations recorded by the optical space-borne Lightning Imaging Sensor (LIS) and the ground-based Very High Frequency (VHF) Lightning Mapping Array (LMA) for different types of lightning flashes. The properties of the cloud environment will also be considered in the analysis thanks to coincident observations of the different TRMM cloud sensors. The characteristics of the optical signal will be discussed according to the nature of the parent flash components and the cloud properties. This study should provide some insights not only on the expected optical signal that will be recorded by LI, but also on the definition of the validation strategy of LI, and on the synergetic use of LI and ground-based VHF mappers like the SAETTA LMA network in Corsica for operational and research activities. Acknowledgements: this study is part of the SOLID-PREVALS project and is supported by CNES-TOSCA.

The NASA Severe Thunderstorm Observations and Regional Modeling (NASA STORM) Project

NASA Technical Reports Server (NTRS)

Schultz, Christopher J.; Gatlin, Patrick N.; Lang, Timothy J.; Srikishen, Jayanthi; Case, Jonathan L.; Molthan, Andrew L.; Zavodsky, Bradley T.; Bailey, Jeffrey; Blakeslee, Richard J.; Jedlovec, Gary J.

2016-01-01

The NASA Severe Storm Thunderstorm Observations and Regional Modeling(NASA STORM) project enhanced NASA’s severe weather research capabilities, building upon existing Earth Science expertise at NASA Marshall Space Flight Center (MSFC). During this project, MSFC extended NASA’s ground-based lightning detection capacity to include a readily deployable lightning mapping array (LMA). NASA STORM also enabled NASA’s Short-term Prediction and Research Transition (SPoRT) to add convection allowing ensemble modeling to its portfolio of regional numerical weather prediction (NWP) capabilities. As a part of NASA STORM, MSFC developed new open-source capabilities for analyzing and displaying weather radar observations integrated from both research and operational networks. These accomplishments enabled by NASA STORM are a step towards enhancing NASA’s capabilities for studying severe weather and positions them for any future NASA related severe storm field campaigns.

The LATEST Project: Operational Assessment of Total Lightning Data in the U.S.

NASA Technical Reports Server (NTRS)

Goodman, Steven

2004-01-01

A government, university, and industry alliance has joined forces to transition total lightning observations from ground-based research networks and NASA satellites (LIS/TRMM) to improve the short range prediction of severe weather. This interest builds on the desire of the U.S Weather Research Program to foster a national Nowcasting Test Bed, with this specific transition activity initiated through the NASA short-term Prediction Research and Transition (SPoRT) Center in Huntsville, AL. A kick-off national workshop sponsored by the SPoRT Center was held in Huntsville April 1-2 to identify the common goals and objectives of the research and operational community, and to assign roles and responsibilities within the alliance. The workshop agenda, presentations, and summary are available at the SPoRT Center Web site ( h h under the "Meetings" tab. The next national workshop is planned for 2005 in Dallas, TX. The NASA North Alabama regional Lightning Mapping Array &MA) has been operational in the Huntsville area for 3 years, and has continuously sampled a variety of severe weather systems during that period. A gridded version of the LMA total lightning data is currently being supplied to National Weather Service offices in Huntsville, Nashville and Birmingham through the NWS AWES decision support system, for the purposes of assessing the utility of the data in the nowcasting of severe weather such as tornadoes, damaging straight line winds, flash flooding and other weather hazards (lightning induced forest fires, microbursts). While the raw LMA data have been useful to NWS forecasters, even greater utility would be realized if higher-order data products could be supplied through AWIPS along with the gridded data over a larger domain. In 2003-2004 additional LMA systems have been deployed across the southern US. from Florida to New Mexico, providing an opportunity for more than 20 NWS forecast offices to evaluate the incremental value of total lightning data in the warning decision making process.

Ground-Based Observations of Terrestrial Gamma Ray Flashes Associated with Downward-Directed Lightning Leaders

NASA Astrophysics Data System (ADS)

Belz, J.; Abbasi, R.; Krehbiel, P. R.; LeVon, R.; Remington, J.; Rison, W.; Thomas, R. J.

2017-12-01

Terrestrial Gamma Flashes (TGFs) have been observed in satellite-borne gamma ray detectors for several decades, starting with the BATSE instrument on the Compton Gamma-Ray observatory in 1994. TGFs consist of bursts of upwards of 1018 primary gamma rays, with a duration of up to a few milliseconds, originating in the Earth's atmosphere. More recent observations have shown that satellite-observed TGFs are generated in upward-propagating negative leaders of intracloud lightning, suggesting that they may be sensitive to the processes responsible for the initial lightning breakdown. Here, we present the first evidence that TGFs are also produced at the beginning of negative cloud-to-ground flashes, and that they may provide a new window through which ground-based observatories may contribute to understanding the breakdown process. The Telescope Array Surface Detector (TASD) is a 700 square kilometer cosmic ray observatory, an array of 507 3m2 scintillators on a 1.2 km grid. The array is triggered and read out when at least three adjacent detectors observe activity within an 8 μs window. Following the observation of bursts of anomalous TASD triggers, lasting a few hundred microseconds and correlated with local lightning activity, a Lightning Mapping Array (LMA) and slow electric field antenna were installed at the TASD site in order to study the effect. From data obtained between 2014 and 2016, correlated observations were obtained for ten -CG flashes. In 9 out of 10 cases, bursts of up to five anomalous triggers were detected during the first ms of the flash, as negative breakdown was descending into lower positive storm charge. The triggers occurred when the LMA-detected VHF radiation sources were at altitudes between 1.5 to 4.5 km AGL. The tenth flash was initiated by an unusually energetic leader that reached the ground in 2.5 ms and produced increasingly powerful triggers down to about 500 m AGL. While the TASD is not optimized for individual gamma ray detection and energy measurement, simulation studies indicate that the fluxes and forward-beaming observed are consistent with production in processes such as the relativistic runaway electron avalanche. We conclude that the anomalous triggers observed by TA are most likely downward-directed Terrestrial Gamma Flashes.

The NASA Lightning Nitrogen Oxides Model (LNOM): Application to Air Quality Modeling

NASA Technical Reports Server (NTRS)

Koshak, William; Peterson, Harold; Khan, Maudood; Biazar, Arastoo; Wang, Lihua

2011-01-01

Recent improvements to the NASA Marshall Space Flight Center Lightning Nitrogen Oxides Model (LNOM) and its application to the Community Multiscale Air Quality (CMAQ) modeling system are discussed. The LNOM analyzes Lightning Mapping Array (LMA) and National Lightning Detection Network(TradeMark)(NLDN) data to estimate the raw (i.e., unmixed and otherwise environmentally unmodified) vertical profile of lightning NO(x) (= NO + NO2). The latest LNOM estimates of lightning channel length distributions, lightning 1-m segment altitude distributions, and the vertical profile of lightning NO(x) are presented. The primary improvement to the LNOM is the inclusion of non-return stroke lightning NOx production due to: (1) hot core stepped and dart leaders, (2) stepped leader corona sheath, K-changes, continuing currents, and M-components. The impact of including LNOM-estimates of lightning NO(x) for an August 2006 run of CMAQ is discussed.

Lightning: Nature's Probe of Severe Weather for Research and Operations

NASA Technical Reports Server (NTRS)

Blakeslee, R.J.

2007-01-01

Lightning, the energetic and broadband electrical discharge produced by thunderstorms, provides a natural remote sensing signal for the study of severe storms and related phenomena on global, regional and local scales. Using this strong signal- one of nature's own probes of severe weather -lightning measurements prove to be straightforward and take advantage of a variety of measurement techniques that have advanced considerably in recent years. We briefly review some of the leading lightning detection systems including satellite-based optical detectors such as the Lightning Imaging Sensor, and ground-based radio frequency systems such as Vaisala's National Lightning Detection Network (NLDN), long range lightning detection systems, and the Lightning Mapping Array (LMA) networks. In addition, we examine some of the exciting new research results and operational capabilities (e.g., shortened tornado warning lead times) derived from these observations. Finally we look forward to the next measurement advance - lightning observations from geostationary orbit.

Ground- and Space-based Observations of Horizontally-extensive Lightning Flashes

NASA Astrophysics Data System (ADS)

Zhang, D.; Cummins, K. L.; Bitzer, P. M.

2017-12-01

Horizontally-extensive lightning flashes occur frequently in association with mature and late phases of multicellular thunderstorms, both in trailing stratiform regions and horizontally-extensive anvils. The spatial relationship between these flashes and the parent cloud volume is of importance for space launch operational decision making, and is of broader scientific interest. Before this question can be accurately addressed, there is a need to understand the degree to which current lightning observation systems can depict the spatial extent of these long flashes. In this ongoing work, we will intercompare the depiction of horizontally-extensive flashes using several ground-based lightning locating systems (LLSs) located at Kennedy Space Center (KSC) with space-based observations observed by the recently-launched Geostationary Lightning Mapper (GLM) onboard the GOES-16 satellite. Ground-based datasets include the KSC Lightning Mapping Array (KSCLMA), the operational narrowband digital interferometer network MERLIN, and the combined cloud-to-ground and cloud lightning dataset produced by the U.S. National Lightning Detection Network (NLDN). The KSCLMA system is a network of VHF time-of-arrival sensors that preferentially report breakdown processes, and MERLIN is a network of VHF interferometers that point to the discharges in the horizontal plane. Observations to date indicate that MERLIN and the KSCSLMA provide similar overall descriptions of the spatial and temporal extent of these flashes, while the NLDN does not provide adequate spatial mapping of these flashes. The KSC LMA system has much better location accuracy, and provides excellent 3-dimensional representation within 100 km of KSC. It also has sufficient sensitivity to provide 2-dimensional flash mapping within 250 km of KSC. The MERLIN system provides a more-detailed representation of fast leader propagation (in 2 dimensions) with 100 km of KSC. Earlier work during the CHUVA campaign in Brazil with similar systems and the (orbital) Lightning Imaging System (LIS) has shown that the interferometric data correlated much better in space and time with the LIS optical observations. We are currently investigating this relationship at KSC, where both the LMA and interferometer perform much better than the systems used during CHUVA.

Observations of a bi-directional lightning leader producing an M-component

NASA Astrophysics Data System (ADS)

Kotovsky, D. A.; Uman, M. A.; Wilkes, R.; Carvalho, F. L.; Jordan, D. M.

2017-12-01

Lightning discharges to ground often exhibit millisecond-scale surges in the continuing currents following return strokes, called M-components. Relatively little is known regarding the source of M-component charge and the mechanisms by which that charge is transferred to ground. In this work, we seek to directly address these questions by presenting correlated high-speed video and Lightning Mapping Array (LMA) observations of a bi-directional leader that resulted in an M-component occurring in a rocket-and-wire triggered lightning flash. The observed leader initiated in the decayed remnants of a positive leader channel that had traversed virgin air approximately 90 msec prior. Three-dimensional locations and speeds of the photographed bi-directional leader and M-component processes are calculated by mapping video images to the observed LMA channel geometry. Both ends of the bi-directional leader exhibited speeds on the order of 2 x106 m sec-1 over 570 meters of the visible channel. Propagation of the luminosity wave from the in-cloud leader to ground ( 8.8 km channel length) exhibited appreciable dispersion, with rise-times (10-90%) increasing from 330 to 410 μsec and pulse-widths (half-maximum) increasing from 380 to 810 μsec - the M-component current pulse measured at ground-level exhibited a rise-time of 290 μsec and a pulse-width of 770 μsec. Group velocities of the luminosity wave have been calculated as a function of frequency, increasing from 2 x107 to 6 x107 m sec-1 over the dominant signal bandwidth (DC to 2 kHz). Additionally, multiple waves of luminosity are observed within the in-cloud channel, indicating nuanced wave phenomena possibly associated with reflection from the end of the leader channel and attachment with the main lightning channel carrying continuing current to ground.

Variability of electromagnetic signatures of lightning initiation observed in the West Mediterranean basin

NASA Astrophysics Data System (ADS)

Kolmasova, I.; Santolik, O.; Defer, E.; Stéphane, P.; Lan, R.; Uhlir, L.; Coquillat, S.; Lambert, D.; Pinty, J. P.; Prieur, S.

2016-12-01

Lightning discharges to ground often exhibit millisecond-scale surges in the continuing currents following return strokes, called M-components. Relatively little is known regarding the source of M-component charge and the mechanisms by which that charge is transferred to ground. In this work, we seek to directly address these questions by presenting correlated high-speed video and Lightning Mapping Array (LMA) observations of a bi-directional leader that resulted in an M-component occurring in a rocket-and-wire triggered lightning flash. The observed leader initiated in the decayed remnants of a positive leader channel that had traversed virgin air approximately 90 msec prior. Three-dimensional locations and speeds of the photographed bi-directional leader and M-component processes are calculated by mapping video images to the observed LMA channel geometry. Both ends of the bi-directional leader exhibited speeds on the order of 2 x106 m sec-1 over 570 meters of the visible channel. Propagation of the luminosity wave from the in-cloud leader to ground ( 8.8 km channel length) exhibited appreciable dispersion, with rise-times (10-90%) increasing from 330 to 410 μsec and pulse-widths (half-maximum) increasing from 380 to 810 μsec - the M-component current pulse measured at ground-level exhibited a rise-time of 290 μsec and a pulse-width of 770 μsec. Group velocities of the luminosity wave have been calculated as a function of frequency, increasing from 2 x107 to 6 x107 m sec-1 over the dominant signal bandwidth (DC to 2 kHz). Additionally, multiple waves of luminosity are observed within the in-cloud channel, indicating nuanced wave phenomena possibly associated with reflection from the end of the leader channel and attachment with the main lightning channel carrying continuing current to ground.

Do cosmic ray air showers initiate lightning?: A statistical analysis of cosmic ray air showers and lightning mapping array data

NASA Astrophysics Data System (ADS)

Hare, B. M.; Dwyer, J. R.; Winner, L. H.; Uman, M. A.; Jordan, D. M.; Kotovsky, D. A.; Caicedo, J. A.; Wilkes, R. A.; Carvalho, F. L.; Pilkey, J. T.; Ngin, T. K.; Gamerota, W. R.; Rassoul, H. K.

2017-08-01

It has been argued in the technical literature, and widely reported in the popular press, that cosmic ray air showers (CRASs) can initiate lightning via a mechanism known as relativistic runaway electron avalanche (RREA), where large numbers of high-energy and low-energy electrons can, somehow, cause the local atmosphere in a thundercloud to transition to a conducting state. In response to this claim, other researchers have published simulations showing that the electron density produced by RREA is far too small to be able to affect the conductivity in the cloud sufficiently to initiate lightning. In this paper, we compare 74 days of cosmic ray air shower data collected in north central Florida during 2013-2015, the recorded CRASs having primary energies on the order of 1016 eV to 1018 eV and zenith angles less than 38°, with Lightning Mapping Array (LMA) data, and we show that there is no evidence that the detected cosmic ray air showers initiated lightning. Furthermore, we show that the average probability of any of our detected cosmic ray air showers to initiate a lightning flash can be no more than 5%. If all lightning flashes were initiated by cosmic ray air showers, then about 1.6% of detected CRASs would initiate lightning; therefore, we do not have enough data to exclude the possibility that lightning flashes could be initiated by cosmic ray air showers.

Multiple Convective Cell Identification and Tracking Algorithm for documenting time-height evolution of measured polarimetric radar and lightning properties

NASA Astrophysics Data System (ADS)

Rosenfeld, D.; Hu, J.; Zhang, P.; Snyder, J.; Orville, R. E.; Ryzhkov, A.; Zrnic, D.; Williams, E.; Zhang, R.

2017-12-01

A methodology to track the evolution of the hydrometeors and electrification of convective cells is presented and applied to various convective clouds from warm showers to super-cells. The input radar data are obtained from the polarimetric NEXRAD weather radars, The information on cloud electrification is obtained from Lightning Mapping Arrays (LMA). The development time and height of the hydrometeors and electrification requires tracking the evolution and lifecycle of convective cells. A new methodology for Multi-Cell Identification and Tracking (MCIT) is presented in this study. This new algorithm is applied to time series of radar volume scans. A cell is defined as a local maximum in the Vertical Integrated Liquid (VIL), and the echo area is divided between cells using a watershed algorithm. The tracking of the cells between radar volume scans is done by identifying the two cells in consecutive radar scans that have maximum common VIL. The vertical profile of the polarimetric radar properties are used for constructing the time-height cross section of the cell properties around the peak reflectivity as a function of height. The LMA sources that occur within the cell area are integrated as a function of height as well for each time step, as determined by the radar volume scans. The result of the tracking can provide insights to the evolution of storms, hydrometer types, precipitation initiation and cloud electrification under different thermodynamic, aerosol and geographic conditions. The details of the MCIT algorithm, its products and their performance for different types of storm are described in this poster.

Coincident Observation of Lightning using Spaceborne Spectrophotometer and Ground-Level Electromagnetic Sensors

NASA Technical Reports Server (NTRS)

Adachi, Toru; Cohen, Morris; Li, Jingbo; Cummer, Steve; Blakeslee, Richard; Marshall, THomas; Stolzenberg, Maribeth; Karunarathne, Sumedhe; Hsu, Rue-Ron; Su, Han-Tzong;

Lightning Evolution In Two North Central Florida Summer Multicell Storms and Three Winter/Spring Frontal Storms

NASA Astrophysics Data System (ADS)

Caicedo, J. A.; Uman, M. A.; Pilkey, J. T.

2018-01-01

We present the first lightning evolution studies, via the Lightning Mapping Array (LMA) and radar, performed in North Central Florida. Parts of three winter/spring frontal storms (cold season) and two complete summer (warm season) multicell storms are studied. Storm parameters measured are as follows: total number of flashes, flash-type classification, first flashes, flash initiation altitude, flash initiation power, flash rate (flashes per minute), charge structure, altitude and temperature ranges of the inferred charge regions, atmospheric isotherm altitude, radar base reflectivity (dBZ), and radar echo tops (EET). Several differences were found between summer multicell and winter/spring frontal storms in North Central Florida: (1) in winter/spring storms, the range of altitudes that all charge regions occupy is up to 1 km lower in altitude than in summer storms, as are the 0°C, -10°C, and -20°C isotherms; (2) lightning activity in summer storms is highly correlated with changes in radar signatures, in particular, echo tops; and (3) the LMA average initiation power of all flash types in winter/frontal storms is about an order of magnitude larger than that for summer storms. In relation to storms in other geographical locations, North Central Florida seasonal storms were found to have similarities in most parameters studied with a few differences, examples in Florida being (1) colder initiation altitudes for intracloud flashes, (2) charge regions occupying larger ranges of atmospheric temperatures, and (3) winter/spring frontal storms not having much lightning activity in the stratiform region.

Video, LMA and ULF observations of a negative gigantic jet in North Texas

NASA Astrophysics Data System (ADS)

Bruning, E. C.; Cummer, S.; Palivec, K.; Lyons, W. A.; Chmielewski, V.; MacGorman, D. R.

2017-12-01

On 8 September 2016 at 0125:38 UTC video of a negative gigantic jet was captured from Hawley, TX. VHF Lightning Mapping Arrays in West Texas and Oklahoma also observed the parent flash (duration of about 1 s) and, for the first time, mapped dozens of points along ascending negative leaders, lasting about 50 ms, which extended well above cloud top to about 35 km MSL altitude. A few well-located VHF sources were also detected near 50 km. Together, the video and VHF observations provide additional confirmation of the altitude at which the leader-to-streamer transition takes place in gigantic jet discharges. ULF magnetic field data from the Duke iCMC network show a current excursion associated with the onset of the upward movement of negative charge and leaders in the VHF. As the gigantic jet reached its full height, current spiked to 80 kA, followed by several hundred milliseconds of continuing current of 10-20 kA. Total charge moment change was about 6000 C km. The storm complex produced predominantly negative large charge moment change events, which is characteristic of storms that produce negative gigantic jets.

Deriving leaf mass per area (LMA) from foliar reflectance across a variety of plant species using continuous wavelet analysis

NASA Astrophysics Data System (ADS)

Cheng, Tao; Rivard, Benoit; Sánchez-Azofeifa, Arturo G.; Féret, Jean-Baptiste; Jacquemoud, Stéphane; Ustin, Susan L.

2014-01-01

Leaf mass per area (LMA), the ratio of leaf dry mass to leaf area, is a trait of central importance to the understanding of plant light capture and carbon gain. It can be estimated from leaf reflectance spectroscopy in the infrared region, by making use of information about the absorption features of dry matter. This study reports on the application of continuous wavelet analysis (CWA) to the estimation of LMA across a wide range of plant species. We compiled a large database of leaf reflectance spectra acquired within the framework of three independent measurement campaigns (ANGERS, LOPEX and PANAMA) and generated a simulated database using the PROSPECT leaf optical properties model. CWA was applied to the measured and simulated databases to extract wavelet features that correlate with LMA. These features were assessed in terms of predictive capability and robustness while transferring predictive models from the simulated database to the measured database. The assessment was also conducted with two existing spectral indices, namely the Normalized Dry Matter Index (NDMI) and the Normalized Difference index for LMA (NDLMA). Five common wavelet features were determined from the two databases, which showed significant correlations with LMA (R2: 0.51-0.82, p < 0.0001). The best robustness (R2 = 0.74, RMSE = 18.97 g/m2 and Bias = 0.12 g/m2) was obtained using a combination of two low-scale features (1639 nm, scale 4) and (2133 nm, scale 5), the first being predominantly important. The transferability of the wavelet-based predictive model to the whole measured database was either better than or comparable to those based on spectral indices. Additionally, only the wavelet-based model showed consistent predictive capabilities among the three measured data sets. In comparison, the models based on spectral indices were sensitive to site-specific data sets. Integrating the NDLMA spectral index and the two robust wavelet features improved the LMA prediction. One of the bands used by this spectral index, 1368 nm, was located in a strong atmospheric water absorption region and replacing it with the next available band (1340 nm) led to lower predictive accuracies. However, the two wavelet features were not affected by data quality in the atmospheric absorption regions and therefore showed potential for canopy-level investigations. The wavelet approach provides a different perspective into spectral responses to LMA variation than the traditional spectral indices and holds greater promise for implementation with airborne or spaceborne imaging spectroscopy data for mapping canopy foliar dry biomass.

An ultrasound evaluation of laryngeal mask airway position in pediatric patients: an observational study.

PubMed

Kim, Jeongmin; Kim, Ji Young; Kim, Won Oak; Kil, Hae Keum

2015-02-01

In children, the laryngeal mask airway (LMA) is frequently displaced within the hypopharynx, resulting in repositioning of the device. When the tip of the LMA is placed in the esophageal inlet, the arytenoids are moved ventrally. When the LMA is rotated or deviated, the ventral movement of the arytenoids may result in asymmetric elevation of an arytenoid cartilage, which can be detected with ultrasound (US). In this study, we sought to estimate the incidence of LMA malposition detected with US in pediatric patients. The primary end point was to compare the incidence of LMA malposition between US and fiber optic bronchoscopy (FOB). The secondary end points were to find the interrelationship between US-detected and FOB-detected malposition of the LMA and to locate the diagnostic performance of US in detecting LMA malposition. In this observational study, 100 consecutive children were included. After anesthetic induction, US evaluation was performed before and after LMA insertion to obtain the glottic image on the anterior neck. FOB was performed to assess LMA position (FOB LMA grade and LMA rotation grade). With a post-LMA US image, the symmetry of the arytenoid cartilages was evaluated. Asymmetrical elevation of an arytenoid cartilage in reference to the glottic midline and the opposite arytenoid cartilage was graded as 0 to 3 (US arytenoid grade). The interrelationships between US arytenoid grade and FOB LMA grade or LMA rotation grade were assessed. The incidence of asymmetrical elevation of an arytenoid was 50% (95% confidence interval [CI], 40%-60%). On FOB, the incidence of LMA malposition was 78% (95% CI, 69%-86%), and that of LMA rotation was 43% (95% CI, 33%-53%). The incidence of LMA malposition was higher with FOB (P < 0.0001), but the incidence of rotation was similar (P = 0.395). US arytenoid grade did not correlate with FOB LMA grade (P = 0.611) but showed a significant correlation with LMA rotation grade (P < 0.0001; 95% CI, 60%-83%). To detect a rotated LMA, US had a sensitivity of 93% (95% CI, 81%-98%) and a specificity of 82% (95% CI, 70%-91%). The positive and negative predictive values were 80% (95% CI, 66%-90%) and 94% (95% CI, 83%-99%), respectively. The accuracy was 87% (95% CI, 79%-93%). Although US could not detect the suboptimal depth of an LMA, US has promise of being an accurate tool in detecting a rotated LMA.

Pharmacological profile of zacopride and new quaternarized fluorobenzamide analogues on mammalian α7 nicotinic acetylcholine receptor.

PubMed

Bourdin, Céline M; Lebreton, Jacques; Mathé-Allainmat, Monique; Thany, Steeve H

2015-08-15

From quaternarization of quinuclidine enantiomers of 2-fluoro benzamide LMA10203 in dichloromethane, the corresponding N-chloromethyl derivatives LMA10227 and LMA10228 were obtained. Here, we compared the agonist action of known zacopride and its 2-fluoro benzamide analogues, LMA10203, LMA10227 and LMA10228 against mammalian homomeric α7 nicotinic acetylcholine receptor expressed in Xenopus oocytes. We found that LMA10203 was a partial agonist of α7 receptor with a pEC50 value of 4.25 ± 0.06 μM whereas LMA10227 and LMA10228 were poorly active on α7 homomeric nicotinic receptor. LMA10227 and LMA10228 were identified as antagonists of acetylcholine-induced currents with IC50 values of 28.4 μM and 39.3 μM whereas LMA10203 and zacopride possessed IC50 values of 8.07 μM and 7.04 μM, respectively. Moreover, despite their IC50 values, LMA10227 was the most potent inhibitor of nicotine-induced current amplitudes (65.7 ± 2.1% inhibition). LMA10203 and LMA10228 had the same inhibitory effects (26.5 ± 7.5% and 33.2 ± 4.1%, respectively), whereas zacopride had no significant inhibitory effect (4.37 ± 4%) on nicotine-induced responses. Our results revealed different pharmacological properties between the four compounds on acetylcholine and nicotine currents. The mode of action of benzamide compounds may need to be reinterpreted with respect to the potential role of α7 receptor. Copyright © 2015 Elsevier Ltd. All rights reserved.

A Summary of the NASA Lightning Nitrogen Oxides Model (LNOM) and Recent Results

NASA Technical Reports Server (NTRS)

Koshak, William; Peterson, Harld

2011-01-01

The NASA Marshall Space Flight Center introduced the Lightning Nitrogen Oxides Model (LNOM) a couple of years ago to combine routine state-of-the-art measurements of lightning with empirical laboratory results of lightning NOx production. The routine measurements included VHF lightning source data [such as from the North Alabama Lightning Mapping Array (LMA)], and ground flash location, peak current, and stroke multiplicity data from the National Lightning Detection Network(TradeMark) (NLDN). Following these initial runs of LNOM, the model was updated to include several non-return stroke lightning NOx production mechanisms, and provided the impact of lightning NOx on an August 2006 run of CMAQ. In this study, we review the evolution of the LNOM in greater detail and discuss the model?s latest upgrades and applications. Whereas previous applications were limited to five summer months of data for North Alabama thunderstorms, the most recent LNOM analyses cover several years. The latest statistics of ground and cloud flash NOx production are provided.

Analysis of ELF Radio Atmospherics Radiated by Rocket-Triggered Lightning

NASA Astrophysics Data System (ADS)

Dupree, N. A.; Moore, R. C.; Pilkey, J. T.; Uman, M. A.; Jordan, D. M.; Caicedo, J. A.; Hare, B.; Ngin, T. K.

2014-12-01

Experimental observations of ELF radio atmospherics produced by rocket-triggered lightning flashes are used to analyze Earth-ionosphere waveguide excitation and propagation characteristics. Rocket-triggered lightning experiments are performed at the International Center for Lightning Research and Testing (ICLRT) located at Camp Blanding, Florida. Long-distance ELF observations are performed in California, Greenland, and Antarctica. The lightning current waveforms directly measured at the base of the lightning channel (at the ICLRT) along with pertinent Lightning Mapping Array (LMA) data are used together with the Long Wavelength Propagation Capability (LWPC) code to predict the radio atmospheric (sferic) waveform observed at the receiver locations under various ionospheric conditions. We identify fitted exponential electron density profiles that accurately describe the observed propagation delays, phase delays, and signal amplitudes. The ability to infer ionospheric characteristics using distant ELF observations greatly enhances ionospheric remote sensing capabilities, especially in regard to interpreting observations of transient luminous events (TLEs) and other ionospheric effects associated with lightning.

Triangulations of sprites relative to parent lighting near the Oklahoma Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Lu, G.; Cummer, S. A.; Li, J.; Lyons, W. A.; Stanley, M. A.; Krehbiel, P. R.; Rison, W.; Thomas, R. J.; Weiss, S. A.; Beasley, W. H.; Bruning, E. C.; MacGorman, D. R.; Palivec, K.; Samaras, T. M.

2012-12-01

Temporal and spatial development of sprite-producing lightning flashes is examined with coordinated observations over an asymmetric mesoscale convective system on June 29, 2011 near the Oklahoma Lightning Mapping Array (OK-LMA). About 30 sprites were mutually observed from Bennett, Colorado and Hawley, Texas, allowing us to triangulate sprite formation in comparison with spatial/temporal development of the parent lightning. Complementary measurements of broadband (<1 Hz to ~300 kHz) radio frequency lightning signals are available from several magnetic sensors across the United States. Our analyses indicate that although sprite locations can be significantly offset horizontally (up to 70 km) from the parent ground stroke, they are usually laterally within 30 km of the in-cloud lightning activity during the 100 ms time interval prior to the sprite production. This is true for short-delayed sprites produced within 20 ms after a causative stroke, and long-delayed sprites appearing up to more than 200 ms after the stroke. Multiple sprites appearing as dancing/jumping events can be produced during one single flash either in a single lightning channel, through series of current surges superposed on a long and intense continuing current, or in multiple lightning channels through distinct ground strokes of the flash. The burst of continuous very-low-frequency/low-frequency lightning sferics commonly observed in association with sprites is linked to the horizontal progression of multiple negative leaders through positive charged regions of the cloud, which are typically centered at altitudes ~1-2 km (or more) above the freezing level.

Using Total Lightning Observations to Enhance Lightning Safety

NASA Technical Reports Server (NTRS)

Stano, Geoffrey T.

2012-01-01

Lightning is often the underrated threat faced by the public when it comes to dangerous weather phenomena. Typically, larger scale events such as floods, hurricanes, and tornadoes receive the vast majority of attention by both the general population and the media. This comes from the fact that these phenomena are large, longer lasting, can impact a large swath of society at one time, and are dangerous events. The threat of lightning is far more isolated on a case by case basis, although millions of cloud-to-ground lightning strikes hit this United States each year. While attention is given to larger meteorological events, lightning is the second leading cause of weather related deaths in the United States. This information raises the question of what steps can be taken to improve lightning safety. Already, the meteorological community s understanding of lightning has increased over the last 20 years. Lightning safety is now better addressed with the National Weather Service s access to the National Lightning Detection Network data and enhanced wording in their severe weather warnings. Also, local groups and organizations are working to improve public awareness of lightning safety with easy phrases to remember, such as "When Thunder Roars, Go Indoors." The impacts can be seen in the greater array of contingency plans, from airports to sports stadiums, addressing the threat of lightning. Improvements can still be made and newer technologies may offer new tools as we look towards the future. One of these tools is a network of sensors called a lightning mapping array (LMA). Several of these networks exist across the United States. NASA s Short-term Prediction Research and Transition Center (SPoRT), part of the Marshall Spaceflight Center, has access to three of these networks from Huntsville, Alabama, the Kennedy Space Center, and Washington D.C. The SPoRT program s mission is to help transition unique products and observations into the operational forecast environment. SPoRT has been collaborating with the Huntsville National Weather Service (NWS) Office since 2003 and has since included several other offices to better implement LMA observations into real-time applications. Much of that work has focused on the LMA s ability to detect intra-cloud lightning in addition to cloud-to-ground lightning strikes. Combined, these observations are called total lightning. With total lightning observations, NWS offices can enhance their situational awareness and improve severe weather warnings. Just as importantly, the observed intra-cloud flashes often precede the first cloud-to-ground strike by a few minutes. SPoRT and its partner NWS offices are working to develop visualizations and applications to better utilize these data. However, there is a drawback. The LMAs have a short range of no more than 200 km. This is being addressed with the next generation geostationary satellite, GOES-R, which will boast the Geostationary Lightning Mapper (GLM). SPoRT, in conjunction with NOAA s GOES-R Proving Ground, is working to prepare the end user community for the GLM era using the LMA observations as a demonstration tool. Working collaboratively with our NWS partners, SPoRT is working to determine how best to integrate these future observations to improve both severe storm warnings and lightning safety.

Lightning NOx Production and Transport in the 29 May 2012 DC3 case: A Modeling Study Using Radar Data Assimilation and a Branched Lightning Simulation.

NASA Astrophysics Data System (ADS)

Allen, B. J.; Mansell, E. R.; Betten, D.

2014-12-01

Open questions exist regarding chemical transport by convection and the sensitivity of Lightning Nitrogen Oxide (LNOx) production to flash type (IC vs. CG), channel height, and channel length. To help answer these and other questions, the Deep Convective Clouds and Chemistry (DC3) field project was conducted during the spring of 2012. On 29 May 2012, observations of an Oklahoma supercell were collected by two mobile SMART-R radars, the mobile NOXP radar, multiple NEXRAD radars, the Oklahoma Lightning Mapping Array (LMA), and the NSF/NCAR HIAPER and NASA DC-8 aircraft. In this study, data from the mobile and NEXRAD radars are assimilated into the NSSL COMMAS model using the Ensemble Kalman Filter, beginning shortly after initiation of convection and ending when the aircraft made their final measurements of the storm's outflow. The model analyses produce a realistic representation of the kinematic character of the storm throughout this time period. COMMAS includes the NSSL multimoment microphysics, explicit cloud electrification, and a branched lightning discharge scheme, which is used to produce LNOx within the model via a method dependent upon air pressure and lightning channel length. Model results will be presented and compared to radar, lightning, and aircraft observations. Of particular importance, the vertical distribution of lightning, channel length of lightning, and LNOx production and transport in the model will be analyzed and compared to LMA observations and anvil-level outflow observations from the aircraft. In addition, to examine entrainment and detrainment of air by the storm and to provide a check on LNOx production and transport, trajectory analyses will be presented and the transport of inert trace gases such as carbon monoxide in the model will be analyzed and compared to aircraft measurements.

Lightning Jump Algorithm Development for the GOES·R Geostationary Lightning Mapper

NASA Technical Reports Server (NTRS)

Schultz. E.; Schultz. C.; Chronis, T.; Stough, S.; Carey, L.; Calhoun, K.; Ortega, K.; Stano, G.; Cecil, D.; Bateman, M.;

A Wrf-Chem Flash Rate Parameterization Scheme and LNO(x) Analysis of the 29-30 May 2012 Convective Event in Oklahoma During DC3

NASA Technical Reports Server (NTRS)

Cummings, Kristin A.; Pickering, Kenneth E.; Barth, M.; Weinheimer, A.; Bela, M.; Li, Y.; Allen, D.; Bruning, E.; MacGorman, D.; Rutledge, S.;

A WRF-Chem Flash Rate Parameterization Scheme and LNOx Analysis of the 29-30 May 2012 Convective Event in Oklahoma During DC3

NASA Technical Reports Server (NTRS)

Cummings, Kristin A.; Pickering, Kenneth E.; Barth, M.; Weinheimer, A.; Bela, M.; Li, Y.; Allen, D.; Bruning, E.; MacGorman, D.; Rutledge, S.;

A quantitative analysis of phenotypic variations of Metrosideros polymorpha within and across populations along environmental gradients on Mauna Loa, Hawaii.

PubMed

Tsujii, Yuki; Onoda, Yusuke; Izuno, Ayako; Isagi, Yuji; Kitayama, Kanehiro

2016-04-01

Metrosideros polymorpha, a dominant tree species in the Hawaiian Islands, shows an extreme phenotypic polymorphism both across gradients of climatic/edaphic conditions and within populations, making it a potentially useful model species for evolutionary study. In order to understand how the phenotypic diversity is maintained within populations as well as across populations, we examined the diversities of several leaf and stem functional traits across five elevations and two soil substrates on the volcanic mountain of Mauna Loa, on the island of Hawaii. Leaf dry mass per area (LMA), a key leaf functional trait, was particularly focused on and analyzed in relation to its underlying components-namely, tissue LMA and trichome LMA (LMA = tissue LMA + trichome LMA). Across populations, tissue LMA increased linearly with elevation while trichome LMA showed unimodal patterns with elevation, which were better correlated with temperature and rainfall, respectively. Substantial phenotypic variations were also found within populations. Interestingly, the variations of tissue LMA were often negatively correlated to trichome LMA within populations, which contrasts with the cross-populations pattern, where a strong positive correlation between tissue LMA and trichome LMA was found. This suggests that phenotypic variations within populations were substantially influenced by local ecological processes. Soil depth (an indicator of local water availability) and tree size (an indicator of colonized timing) modestly explained the within-population variations, implying other local environmental factors and/or random processes are also important in local phenotypic diversity. This study provides an insight about how phenotypic diversity of plant species is maintained from local to landscape levels.

Ethanol-induced locomotor activity in adolescent rats and the relationship with ethanol-induced conditioned place preference and conditioned taste aversion.

PubMed

Acevedo, María Belén; Nizhnikov, Michael E; Spear, Norman E; Molina, Juan C; Pautassi, Ricardo M

2013-05-01

Adolescent rats exhibit ethanol-induced locomotor activity (LMA), which is considered an index of ethanol's motivational properties likely to predict ethanol self-administration, but few studies have reported or correlated ethanol-induced LMA with conditioned place preference (CPP) by ethanol at this age. The present study assessed age-related differences in ethanol's motor stimulating effects and analyzed the association between ethanol-induced LMA and conventional measures of ethanol-induced reinforcement. Experiment 1 compared ethanol-induced LMA in adolescent and adult rats. Subsequent experiments analyzed ethanol-induced CPP and conditioned taste aversion (CTA) in adolescent rats evaluated for ethanol-induced LMA. Adolescent rats exhibit a robust LMA after high-dose ethanol. Ethanol-induced LMA was fairly similar across adolescents and adults. As expected, adolescents were sensitive to ethanol's aversive reinforcement, but they also exhibited CPP. These measures of ethanol reinforcement, however, were not related to ethanol-induced LMA. Spontaneous LMA in an open field was, however, negatively associated with ethanol-induced CTA. Copyright © 2012 Wiley Periodicals, Inc.

ETHANOL-INDUCED LOCOMOTOR ACTIVITY IN ADOLESCENT RATS AND THE RELATIONSHIP WITH ETHANOL-INDUCED CONDITIONED PLACE PREFERENCE AND CONDITIONED TASTE AVERSION

PubMed Central

Acevedo, María Belén; Nizhnikov, Michael E.; Spear, Norman E.; Molina, Juan C.; Pautassi, Ricardo Marcos

2012-01-01

Adolescent rats exhibit ethanol-induced locomotor activity (LMA), which is considered an index of ethanol’s motivational properties likely to predict ethanol self-administration, but few studies have reported or correlated ethanol-induced LMA with conditioned place preference by ethanol at this age. The present study assessed age-related differences in ethanol’s motor stimulating effects and analysed the association between ethanol-induced LMA and conventional measures of ethanol-induced reinforcement. Experiment 1 compared ethanol-induced LMA in adolescent and adult rats. Subsequent experiments analyzed ethanol-induced conditioned place preference and conditioned taste aversion in adolescent rats evaluated for ethanol-induced LMA. Adolescent rats exhibit a robust LMA after high-dose ethanol. Ethanol-induced LMA was fairly similar across adolescents and adults. As expected, adolescents were sensitive to ethanol’s aversive reinforcement, but they also exhibited conditioned place preference. These measures of ethanol reinforcement, however, were not related to ethanol-induced LMA. Spontaneous LMA in an open field was, however, negatively associated with ethanol-induced CTA. PMID:22592597

Lightning characterization through acoustic and electromagnetic measurements recorded during the HyMeX SOP1 and simulation of the acoustic nonlinear propagation in realistic thunderstorm meteorological conditions

NASA Astrophysics Data System (ADS)

Gallin, L.; Coulouvrat, F.; Farges, T.; Marchiano, R.; Defer, E.; Rison, W.; Schulz, W.; Nuret, M.

2013-12-01

The goal is to study the transformation of the thunder (amplitude, spectrum) during its travel from the lightning channel towards a detector (microphone, microbarometer), considering propagation distances of less than 50 km and complex local meteorological properties. Inside the European HyMeX project, the SOP1 campaign (2012) took place from September 2012 to November 2012 in South of France. An acoustic station (center: 4.39° E, 44.08° N) composed of a microphone array placed inside a microbarometer array was installed by CEA near city of Uzès. It was located in the center of an LMA network coming with two slow antennas. This network was deployed in France for the first time by the New Mexico Tech and LERMA laboratory. The detections from the European lightning location system EUCLID complete this dataset. During the SOP1 period several storms passed over the station. The post-processings of the records point out days with interesting thunderstorms. Especially during the 26th of October 2012 in the evening (around 8 pm) a thunderstorm passed just over the acoustic station. Not too many lightning strokes are detected by EUCLID, the corresponding flashes are then well characterized by the LMA network. Slow antennas present good electric field measurements. The acoustic records have excellent quality. We present for some selected flashes a comparative study of the different measurements (LMA, slow antenna, EUCLID, microphones, microbarometers): focusing on amplitude and spectrum of the thunder waveforms, and on propagation effects due to the meteorological conditions. To quantify the impact of these meteorological conditions on the propagating thunder (from the lightning sources to the acoustic array), a code named Flhoward is used [Dagrau et al., J. Acoust. Soc. Am., 130, 20-32, 2011][Coulouvrat, Wave Motion, 49, 50--63, 2012]. It is designed to simulate the nonlinear propagation of acoustic shock waves through a realistic atmosphere model (including temperature gradients, rigid ground, and wind flows). The meteorological conditions are extracted from the data calculated by Météo-France weather forecast model AROME-WMED for the chosen days. Some cases where numerical simulation helps to understand the observations are presented.

Development of the Langmuir Electric Field Array (LEFA)

NASA Astrophysics Data System (ADS)

Sonnenfeld, R. G.; Eack, K.; Eastvedt, E.; Edens, H. E.; Hager, W. W.; Hunyady, S.; Alvidrez, V.; Lapierre, J.; Morris, K.; Vaive, G.; Wang, T.; Zhang, J.

2009-12-01

An electric-field-change (ΔE) sensor (also called a ``slow antenna'') is a long proven instrument in atmospheric electricity research. While there is still value to be derived from single-station measurements of ΔE, multi-station measurements better constrain the data interpretation. Modern publications still cite the work of Krehbiel [et al] for the insights gleaned from the 8-station array they deployed in 1979. In particular, with four independent measurements, one can locate the center of charge discharged in a cloud-to-ground (CG) flash. With seven measurements, one can locate the two charge centers connected during an intra-cloud (IC) flash. The measurements become more interesting when multi-station ΔE data is combined with radio-frequency emission data from a lightning mapping array (LMA). The ΔE array allows an independent check of the assumptions about charge layers made in the interpretation of LMA data, as well as giving greater visibility into the effects of positive streamers. The Langmuir Electric Field Array (LEFA) is designed to accommodate the very large amplitude range of ΔE data characteristic of lightning. Such design is more important in an array than a single station, as the goal is explicitly to correlate data from ten stations spaced some kilometers apart. To address the dynamic range challenge, every ΔE sensor is a set of three independent sensors, integrated into a 19-inch-steel-mixing bowl. The electronic gain is a factor of 4 greater for the sensitive (S) channel than for the medium (M) channel, and 20X greater for the (S) channel compared to the insensitive (I) channel. Further, the electrode sensor areas decrease by factors of 5, moving from S, to M, to I, so that the (S) channel is hundreds of times more sensitive than the (I) channel. Since each channel is digitized with 16-bits of resolution, the ideal full range of the instrument is roughly equal to a single channel digitized at 24 bits. Digitizing the same signal at three sensitivities also turns out to be useful in identifying noise sources and separating unusual ΔE effects from instrumental noise. The LEFA was also designed for rapid data integration and processing. All three channels of ΔE data are continuously digitized with embedded PC-104 computers (along with timing data) at 50 kSamples/second and streamed to large hard-drives. Instruments are linked by a 802.11 wireless network, and a network broadcast protocol enables central control. During fair-weather, the controller tells all instruments to shut down and to do a first pass analysis of their own data, discarding periods of electrical inactivity, and imaging all interesting data. While the full precision data occupies 24~Mbytes/minute, the quick images are 20~kBytes/min, and are automatically uploaded to a web-server. We learned over a summer of operation that this method is workable, and allows one student to wrangle the data from the entire network. We are currently working toward a full deployment, hopefully before local electrical activity ends for the season.

High-Energy Particle Showers Observed at Ground Level in Coincidence with Downward Lightning Leaders at the Telescope Array Observatory

NASA Astrophysics Data System (ADS)

Belz, John; Abbasi, Rasha; Le Von, Ryan; Krehbiel, Paul; Remington, Jackson; Rison, William

Terrestrial Gamma Ray Flashes (TGFs) detected by satellite observations have been shown to be generated by upward propagating negative leaders at altitudes of about 10 to 12 km above Mean Sea Level (MSL), and have durations ranging between a few hundred microseconds and a few milliseconds. The Telescope Array Cosmic Ray observatory, designed to observe air showers induced by ultra high energy cosmic rays, includes a surface scintillator detector (SD) covering approximately 700 square kilometers on a 1.2 km grid. Following the observation of anomalous SD triggers correlated with local lightning activity, a Lightning Mapping Array (LMA) and slow electric field antenna were installed at the TA site in order to characterize the lightning associated with these anomalous triggers. In this talk, we present evidence that the anomalous triggers are produced during the initial breakdown phase of fast, downward propagating, negative leaders above the detectors which produced the triggers. The durations of the high energy radiation are a few hundred microseconds, similar to satellite observations of TGFs. The triggers were produced within a few hundred microseconds of the initiation of the leaders, when the leaders were at an altitude of about 3 to 4 km MSL. The TA scintillation detectors are not optimized for gamma ray detection, however we present the results of simulations demonstrating that the fluxes observed are consistent with this picture. We conclude that the anomalous triggers observed by TA are clearly due to high energy radiation produced by the fast downward propagating negative leaders, and are probably downward-directed TGFs.

Leaf density explains variation in leaf mass per area in rice between cultivars and nitrogen treatments.

PubMed

Xiong, Dongliang; Wang, Dan; Liu, Xi; Peng, Shaobing; Huang, Jianliang; Li, Yong

2016-05-01

Leaf mass per area (LMA) is an important leaf trait; however, correlations between LMA and leaf anatomical features and photosynthesis have not been fully investigated, especially in cereal crops. The objectives of this study were (a) to investigate the correlations between LMA and leaf anatomical traits; and (b) to clarify the response of LMA to nitrogen supply and its effect on photosynthetic nitrogen use efficiency (PNUE). In the present study, 11 rice varieties were pot grown under sufficient nitrogen (SN) conditions, and four selected rice cultivars were grown under low nitrogen (LN) conditions. Leaf anatomical traits, gas exchange and leaf N content were measured. There was large variation in LMA across selected rice varieties. Regression analysis showed that the variation in LMA was more closely related to leaf density (LD) than to leaf thickness (LT). LMA was positively related to the percentage of mesophyll tissue area (%mesophyll), negatively related to the percentage of epidermis tissue area (%epidermis) and unrelated to the percentage of vascular tissue area (%vascular). The response of LMA to N supplementation was dependent on the variety and was also mainly determined by the response of LD to N. Compared with SN, photosynthesis was significantly decreased under LN, while PNUE was increased. The increase in PNUE was more critical in rice cultivars with a higher LMA under SN supply. Leaf density is the major cause of the variation in LMA across rice varieties and N treatments, and an increase in LMA under high N conditions would aggravate the decrease in PNUE. © The Author 2016. Published by Oxford University Press on behalf of the Annals of Botany Company. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Technical note: the United States Department of Agriculture beef yield grade equation requires modification to reflect the current longissimus muscle area to hot carcass weight relationship.

PubMed

Lawrence, T E; Farrow, R L; Zollinger, B L; Spivey, K S

2008-06-01

With the adoption of visual instrument grading, the calculated yield grade can be used for payment to cattle producers selling on grid pricing systems. The USDA beef carcass grading standards include a relationship between required LM area (LMA) and HCW that is an important component of the final yield grade. As noted on a USDA yield grade LMA grid, a 272-kg (600-lb) carcass requires a 71-cm(2) (11.0-in.(2)) LMA and a 454-kg (1,000-lb) carcass requires a 102-cm(2) (15.8-in.(2)) LMA. This is a linear relationship, where required LMA = 0.171(HCW) + 24.526. If a beef carcass has a larger LMA than required, the calculated yield grade is lowered, whereas a smaller LMA than required increases the calculated yield grade. The objective of this investigation was to evaluate the LMA to HCW relationship against data on 434,381 beef carcasses in the West Texas A&M University (WTAMU) Beef Carcass Research Center database. In contrast to the USDA relationship, our data indicate a quadratic relationship [WTAMU LMA = 33.585 + 0.17729(HCW) -0.0000863(HCW(2))] between LMA and HCW whereby, on average, a 272-kg carcass has a 75-cm(2) (11.6-in.(2)) LMA and a 454-kg carcass has a 96-cm(2) (14.9-in.(2)) LMA, indicating a different slope and different intercept than those in the USDA grading standards. These data indicate that the USDA calculated yield grade equation favors carcasses lighter than 363 kg (800 lb) for having above average muscling and penalizes carcasses heavier than 363 kg (800 lb) for having below average muscling. If carcass weights continue to increase, we are likely to observe greater proportions of yield grade 4 and 5 carcasses because of the measurement bias that currently exists in the USDA yield grade equation.

Laminarin improves developmental competence of porcine early stage embryos by inhibiting oxidative stress.

PubMed

Jiang, Hao; Liang, Shuang; Yao, Xue-Rui; Jin, Yong-Xun; Shen, Xing-Hui; Yuan, Bao; Zhang, Jia-Bao; Kim, Nam-Hyung

2018-04-23

Laminarin (LMA), a β-glucan mixture with good biocompatibility, improves the growth performance and immune response when used as food additives and nutraceuticals. The aim of the present research was to explore the effects of LMA on porcine early stage embryo development, as well as the underlying mechanisms. The results showed that the developmental competence of porcine early stage embryos was dramatically improved after LMA supplementation during the in vitro culture period. The presence of 20 μg/mL LMA during the in vitro culture period significantly improved cleavage rate, blastocyst formation rates, hatching rate, and total cell number in the blastocyst compared to that in the control group. Notably, LMA attenuated the intracellular reactive oxygen species generation induced by H 2 O 2 . Furthermore, LMA not only increased intracellular glutathione levels, but also ameliorated mitochondrial membrane potential. In addition, the expression of a zygotic genome activation related gene (YAP1), pluripotency-related genes (OCT4, NANOG, and SOX2), and hatching-related genes (COX2, GATA4, and ITGA5) were up-regulated following LMA supplementation during porcine early stage embryo development. These results demonstrate that LMA has beneficial effects on the development of porcine early stage embryos via regulation of oxidative stress. This evidence provides a novel method for embryo development improvement associated with exposure to LMA. Copyright © 2018 Elsevier Inc. All rights reserved.

CART PEPTIDE IN THE NUCLEUS ACCUMBENS REGULATES PSYCHOSTIMULANTS: CORRELATIONS BETWEEN PSYCHOSTIMULANT AND CART PEPTIDE EFFECTS

PubMed Central

JOB, MARTIN O.; KUHAR, MICHAEL J.

2017-01-01

In this study, we reexamined the effect of CART peptide on psychostimulant (PS)-induced locomotor activity (LMA) in individual rats. The Methods utilized were as previously published. The PS-induced LMA was defined as the distance traveled after PS administration (intraperitoneal), and the CART peptide effect was defined as the change in the PS-induced activity after bilateral intra-NAc administration of CART peptide. The experiments included both male and female Sprague-Dawley rats, and varying the CART peptide dose and the PS dose. While the average effect of CART peptide was to inhibit PS-induced LMA, the effect of CART peptide on individual PS treated animals was not always inhibitory and sometimes even produced an increase or no change in PS-induced LMA. Upon further analysis, we observed a linear correlation, reported for the first time, between the magnitude of PS-induced LMA and the CART peptide effect. Because CART peptide inhibits PS-induced LMA when it is large, and increases PS-induced LMA when it is small, the peptide can be considered a homeostatic regulator of dopamine (DA)-induced LMA, which supports our earlier homeostatic hypothesis. PMID:28215744

Genetic, Hormonal, and Physiological Analysis of Late Maturity α-Amylase in Wheat1[W][OA

PubMed Central

Barrero, Jose M.; Mrva, Kolumbina; Talbot, Mark J.; White, Rosemary G.; Taylor, Jennifer; Gubler, Frank; Mares, Daryl J.

2013-01-01

Late maturity α-amylase (LMA) is a genetic defect that is commonly found in bread wheat (Triticum aestivum) cultivars and can result in commercially unacceptably high levels of α-amylase in harvest-ripe grain in the absence of rain or preharvest sprouting. This defect represents a serious problem for wheat farmers, and apart from the circumstantial evidence that gibberellins are somehow involved in the expression of LMA, the mechanisms or genes underlying LMA are unknown. In this work, we use a doubled haploid population segregating for constitutive LMA to physiologically analyze the appearance of LMA during grain development and to profile the transcriptomic and hormonal changes associated with this phenomenon. Our results show that LMA is a consequence of a very narrow and transitory peak of expression of genes encoding high-isoelectric point α-amylase during grain development and that the LMA phenotype seems to be a partial or incomplete gibberellin response emerging from a strongly altered hormonal environment. PMID:23321420

[The analysis of the causes of variability of the relationship between leaf dry mass and area in plants].

PubMed

Vasfilov, S P

2011-01-01

The lamina dry mass: area ratio (LMA - Leaf Mass per Area) is a quite variable trait. Leaf dry mass consists of symplast mass (a set of all leaf protoplasts) and apoplast mass (a set of all cell walls in a leaf). The ratio between symplast and apoplast masses is positively related to any functional trait of leaf calculated per unit of dry mass. The value of this ratio is defined by cells size and their number per unit of leaf area, number of mesophyll cells layers and their differentiation between palisade and spongy ones, and also by density of cells packing. The LMA value is defined by leaf thickness and density. The extent and direction of variability in both leaf traits define the extent and direction of variability in LMA. Negative correlation between leaf thickness and density reduces the level of LMA variability. As a consequence of this correlation the following pattern emerges: the thinner a leaf, the denser it is. Changes in the traits that define the LMA value take place both within a species under the influence of environmental factors and between species that differ in leaf structure and functions. Light is the most powerful environmental factor that influences the LMA, increase in illumination leading to increase in LMA. This effect occurs during leaf growth at the expense of structural changes associated with the reduction of symplast/apoplast mass ratio. Under conditions of intense illumination, LMA may increase due to accumulation of starch. With regard to the majority of leaf functions, the mass of starch may be ascribed to apoplast. Starch accumulation in leaves is observed also under conditions of elevated CO2 concentration in the air. Under high illumination, however, LMA increases also due to increased apoplast contribution to leaf dry mass. Scarce mineral nutrition leads to LMA increase due to lowering of growth zones demands for phothosyntates and, therefore, to increase in starch content of leaves. High level of mineral nutrition during leaf growth period leads to LMA increase at the expense of mesophyll thickening where components of photosynthesis system are located. When additional environmental factors are involved, starch accumulation may be partly responsible for increase in LMA. LMA increase at the expense of starch accumulation, unlike that at the expense of mesophyll thickening, is accompanied by increased leaf density. Under conditions of water deficiency LMA increases, which in mature leaf may be caused by starch accumulation. LMA increase during leaf growth period under conditions of water deficiency is associated with decrease in the symplast/apoplast mass ratio.

The GOES-R Lightning Mapper Sensor

NASA Technical Reports Server (NTRS)

Buechler, Dennis; Christian, Hugh; Goodman, Steve

2004-01-01

The Lightning Mapper Sensor on GOES-R builds on previous measurements of lightning from low earth orbit by the OTD (Optical Transient Detector) and LIS (Lightning Imaging Sensor) sensors. Unlike observations from low earth orbit, the GOES-R platform will allow continuous monitoring of lightning activity over the Continental United States and southern Canada, Central and South America, and portions of the Atlantic and Pacific Oceans. The LMS will detect total (cloud-to-ground and intracloud) lightning at storm scale resolution (approx. 8 km) using a highly sensitive Charge Coupled Device (CCD) detector array. Discrimination between lightning optical transients and a bright sunlit background scene is accomplished by employing spectral, spatial, and temporal filtering along with a background subtraction technique. The result is 24 hour detection capability of total lightning. These total lightning observations can be made available to users within about 20 seconds. Research indicates a number of ways that total lightning observations from LMS could benefit operational activities, including 1) potential increases in lead times and reduced false alarms for severe thunderstorm and tornado Warnings, 2) improved routing of &rail around thunderstorms, 3) support for spacecraft launches and landings, 4) improved ability to monitor tropical cyclone intensity, 5) ability to monitor thunderstorm intensification/weakening during radar outages or where radar coverage is poor, 6) better identification of deep convection for the initialization of numerical prediction models, 7) improved forest fire forecasts, 8) identification of convective initiation, 9) identification of heavy convective snowfall, and 10) enhanced temporal resolution of storm evolution (1 minute) than is available from radar observations. Total lightning data has been used in an operational environment since July 2003 at the Huntsville, Alabama National Weather Service office. Total lightning measurements are obtained by the North Alabama Lightning Mapping Array (LMA) and have successfully been used in warning decisions. Every 2 minutes, total lightning counts in 2 km by 2 km horizontal, 1 km vertical grids are available to forecasters on an AWIPS (Advanced Weather Interactive Processing System) workstation. Experience with the LMA total lightning data is used to illustrate the potential use of LMS data that would be available to forecasters across the US. This abstract is for submission as a presentation to the National Weather Association Annual Meeting to be held 16-21 October 2004 in Portland, OR. This abstract will be published in the conference proceedings.

Comparison of trapezius squeeze test and jaw thrust as clinical indicators for laryngeal mask airway insertion in spontaneously breathing children

PubMed Central

Dinesh Kumar, K. K.; Bhardwaj, Neerja; Yaddanapudi, Sandhya

2017-01-01

Background and Aims: It is not known whether trapezius squeeze test (TPZ) is a better clinical test than jaw thrust (JT) to assess laryngeal mask airway (LMA) insertion conditions in children under sevoflurane anesthesia. Material and Methods: After the Institutional Ethics Committee approval and written informed parental consent, 124 American Society of Anesthesiologists I and II children of 2–8 years of age undergoing minor surgical procedures were randomized into TPZ and JT groups. The children were induced with 8% sevoflurane in oxygen at a fresh gas flow of 4 L/min. TPZ or JT was performed after 1 min of start of sevoflurane and then every 20 s till the test was negative, when end-tidal (ET) sevoflurane concentration was noted. Classic LMA of requisite size was inserted by a blinded anesthetist and conditions at the insertion of LMA, insertion time, and the number of attempts of LMA insertion were recorded. Results: The mean LMA insertion time was significantly longer (P < 0.001) for TPZ (145 ± 28.7 sec) compared to JT group (111.8 ± 31.0 sec). ET sevoflurane concentration at the time of LMA insertion was comparable in the two groups. LMA insertion conditions were similar in the two groups. There was no difference between the two groups regarding total number of attempts of LMA insertion. Heart rate (HR) decreased in both groups after LMA insertion (P < 0.001) but TPZ group had significantly lower HR compared with the JT group up to 5 min after LMA insertion (P = 0.03). Conclusion: Both JT and TPZ are equivalent clinical indicators in predicting the optimal conditions of LMA insertion in spontaneously breathing children; however, it takes a longer time to achieve a negative TPZ squeeze test. PMID:28413275

Temperate rain forest species partition fine-scale gradients in light availability based on their leaf mass per area (LMA)

PubMed Central

Fajardo, Alex; Siefert, Andrew

2016-01-01

Background and Aims Ecologists are increasingly using plant functional traits to predict community assembly, but few studies have linked functional traits to species’ responses to fine-scale resource gradients. In this study, it was tested whether saplings of woody species partition fine-scale gradients in light availability based on their leaf mass per area (LMA) in three temperate rain forests and one Mediterranean forest in southern Chile. Methods LMA was measured under field conditions of all woody species contained in approx. 60 plots of 2 m2 in each site, and light availability, computed as the gap light index (GLI), was determined. For each site, species’ pairwise differences in mean LMA (Δ LMA) and abundance-weighted mean GLI (Δ light response) of 2 m2 plots were calculated and it was tested whether they were positively related using Mantel tests, i.e. if species with different LMA values differed in their response to light availability. Additionally linear models were fitted to the relationship between plot-level mean LMA and GLI across plots for each site. Key Results A positive and significant relationship was found between species’ pairwise differences in mean LMA and differences in light response across species for all temperate rain forests, but not for the Mediterranean forest. The results also indicated a significant positive interspecific link between LMA and light availability for all forests. This is in contrast to what is traditionally reported and to expectations from the leaf economics spectrum. Conclusions In environments subjected to light limitation, interspecific differences in a leaf trait (LMA) can explain the fine-scale partitioning of light availability gradients by woody plant species. This niche partitioning potentially facilitates species coexistence at the within-community level. The high frequency of evergreen shade-intolerant species in these forests may explain the positive correlation between light availability and LMA. PMID:27604280

Lightning NOx Statistics Derived by NASA Lightning Nitrogen Oxides Model (LNOM) Data Analyses

NASA Technical Reports Server (NTRS)

Koshak, William; Peterson, Harold

2013-01-01

What is the LNOM? The NASA Marshall Space Flight Center (MSFC) Lightning Nitrogen Oxides Model (LNOM) [Koshak et al., 2009, 2010, 2011; Koshak and Peterson 2011, 2013] analyzes VHF Lightning Mapping Array (LMA) and National Lightning Detection Network(TradeMark) (NLDN) data to estimate the lightning nitrogen oxides (LNOx) produced by individual flashes. Figure 1 provides an overview of LNOM functionality. Benefits of LNOM: (1) Does away with unrealistic "vertical stick" lightning channel models for estimating LNOx; (2) Uses ground-based VHF data that maps out the true channel in space and time to < 100 m accuracy; (3) Therefore, true channel segment height (ambient air density) is used to compute LNOx; (4) True channel length is used! (typically tens of kilometers since channel has many branches and "wiggles"); (5) Distinction between ground and cloud flashes are made; (6) For ground flashes, actual peak current from NLDN used to compute NOx from lightning return stroke; (7) NOx computed for several other lightning discharge processes (based on Cooray et al., 2009 theory): (a) Hot core of stepped leaders and dart leaders, (b) Corona sheath of stepped leader, (c) K-change, (d) Continuing Currents, and (e) M-components; and (8) LNOM statistics (see later) can be used to parameterize LNOx production for regional air quality models (like CMAQ), and for global chemical transport models (like GEOS-Chem).

Reconciling species-level vs plastic responses of evergreen leaf structure to light gradients: shade leaves punch above their weight.

PubMed

Lusk, Christopher H; Onoda, Yusuke; Kooyman, Robert; Gutiérrez-Girón, Alba

2010-04-01

*When grown in a common light environment, the leaves of shade-tolerant evergreen trees have a larger leaf mass per unit area (LMA) than their light-demanding counterparts, associated with differences in lifespan. Yet plastic responses of LMA run counter to this pattern: shade leaves have smaller LMA than sun leaves, despite often living longer. *We measured LMA and cell wall content, and conducted punch and shear tests, on sun and shade leaves of 13 rainforest evergreens of differing shade tolerance, in order to understand adaptation vs plastic responses of leaf structure and biomechanics to shade. *Species shade tolerance and leaf mechanical properties correlated better with cell wall mass per unit area than with LMA. Growth light environment had less effect on leaf mechanics than on LMA: shade leaves had, on average, 40% lower LMA than sun leaves, but differences in work-to-shear, and especially force-to-punch, were smaller. This was associated with a slightly larger cell wall fraction in shade leaves. *The persistence of shade leaves might reflect unattractiveness to herbivores because they yield smaller benefits (cell contents per area) per unit fracture force than sun leaves. In forest trees, cell wall fraction and force-to-punch are more robust correlates of species light requirements than LMA.

Efficient Buffering Scheme in the LMA for Seamless Handover in PMIPv6

NASA Astrophysics Data System (ADS)

Kim, Kwang-Ryoul; Lee, Hyo-Beom; Choi, Hyon-Young; Min, Sung-Gi; Han, Youn-Hee

Proxy Mobile IPv6 (PMIPv6) is proposed as a new network-based local mobility protocol which does not involve the Mobile Node (MN) in mobility management. PMIPv6, which uses link-layer attachment information, reduces the movement detection time and eliminates duplicate address detection procedures in order to provide faster handover than Mobile IPv6 (MIPv6). To eliminate packet loss during the handover period, the Local Mobility Anchor (LMA) buffering scheme is proposed. In this scheme, the LMA buffers lost packets of the Mobile Access Gateway (MAG) and the MN during the handover and recovers them after handover. A new Automatic Repeat reQuest (ARQ) handler is defined which efficiently manages the LMA buffer. The ARQ handler relays ARQ result between the MAG and the MN to the LMA. The LMA removes any buffered packets which have been successfully delivered to the MN. The ARQ handler recovers the packet loss during the handover using buffered packets in the LMA. The ARQ information, between the MAG and LMA, is inserted in the outer header of IP-in-IP encapsulated packets of a standard PMIPv6 tunnel. Since the proposed scheme simply adds information to the standard operation of an IP-in-IP tunnel between the LMA and the MAG, it can be implemented seamlessly without modification to the original PMIPv6 messages and signaling sequence. Unlike other Fast Handovers for Mobile IPv6 (FMIPv6) based enhancement for PMIPv6, the proposed scheme does not require any handover related information before the actual handover.

Further Research on the Electrification of Pyrocumulus Clouds

NASA Technical Reports Server (NTRS)

Lang, Timothy J.; Laroche, Kendell; Baum, Bryan; Bateman, Monte; Mach, Douglas

2015-01-01

Past research on pyrocumulus electrification has demonstrated that a variety of lightning types can occur, including cloud-to-ground (CG) flashes, sometimes of dominant positive polarity, as well as small intra-cloud (IC) discharges in the upper levels of the pyro-cloud. In Colorado during summer 2012, the first combined polarimetric radar, multi-Doppler radar, and three-dimensional lightning mapping array (LMA) observations of lightning-producing pyrocumulus were obtained. These observations suggested that the National Lightning Detection Network (NLDN) was not sensitive enough to detect the small IC flashes that appear to be the dominant mode of lightning in these clouds. However, after an upgrade to the network in late 2012, the NLDN began detecting some of this pyrocumulus lightning. Multiple pyrocumulus clouds documented by the University of Wisconsin for various fires in 2013 and 2014 (including over the Rim, West Fork Complex, Yarnell Hill, Hardluck, and several other incidents) are examined and reported on here. This study exploits the increased-sensitivity NLDN as well as the new nationwide U.S. network of polarimetric Next-generation Radars (NEXRADs). These observations document the common occurrence of a polarimetric "dirty ice" signature - modest reflectivities (20-40+ dBZ), near-zero differential reflectivity, and reduced correlation coefficient (less than 0.9) - prior to the production of lightning. This signature is indicative of a mixture of ash and ice particles in the upper levels of the pyro-cloud (less than -20 C), with the ice interpreted as being necessary for pyro-cloud electrification. Pseudo-Geostationary Lightning Mapper (GLM) data will be produced from the 2012 LMA observations, and the ability of GLM to detect small pyrocumulus ICs will be assessed. The utility of lightning and polarimetric radar for documenting rapid wildfire growth, as well as for documenting pyrocumulus impacts on the composition of the upper troposphere/lower stratosphere (UTLS), will be discussed.

High Speed Intensified Video Observations of TLEs in Support of PhOCAL

NASA Technical Reports Server (NTRS)

Lyons, Walter A.; Nelson, Thomas E.; Cummer, Steven A.; Lang, Timothy; Miller, Steven; Beavis, Nick; Yue, Jia; Samaras, Tim; Warner, Tom A.

2013-01-01

The third observing season of PhOCAL (Physical Origins of Coupling to the upper Atmosphere by Lightning) was conducted over the U.S. High Plains during the late spring and summer of 2013. The goal was to capture using an intensified high-speed camera, a transient luminous event (TLE), especially a sprite, as well as its parent cloud-to-ground (SP+CG) lightning discharge, preferably within the domain of a 3-D lightning mapping array (LMA). The co-capture of sprite and its SP+CG was achieved within useful range of an interferometer operating near Rapid City. Other high-speed sprite video sequences were captured above the West Texas LMA. On several occasions the large mesoscale convective complexes (MCSs) producing the TLE-class lightning were also generating vertically propagating convectively generated gravity waves (CGGWs) at the mesopause which were easily visible using NIR-sensitive color cameras. These were captured concurrent with sprites. These observations were follow-ons to a case on 15 April 2012 in which CGGWs were also imaged by the new Day/Night Band on the Suomi NPP satellite system. The relationship between the CGGW and sprite initiation are being investigated. The past year was notable for a large number of elve+halo+sprite sequences sequences generated by the same parent CG. And on several occasions there appear to be prominent banded modulations of the elves' luminosity imaged at >3000 ips. These stripes appear coincident with the banded CGGW structure, and presumably its density variations. Several elves and a sprite from negative CGs were also noted. New color imaging systems have been tested and found capable of capturing sprites. Two cases of sprites with an aurora as a backdrop were also recorded. High speed imaging was also provided in support of the UPLIGHTS program near Rapid City, SD and the USAFA SPRITES II airborne campaign over the Great Plains.

Evolutionarily stable strategy of carbon and nitrogen investments in forest leaves and its application in vegetation dynamic modeling

NASA Astrophysics Data System (ADS)

Weng, E.; Farrior, C.; Dybzinski, R.; Pacala, S. W.

2015-12-01

Leaf mass per area (LMA) and leaf lifespan (LL) are two highly correlated plant traits that are key to plant physiological and ecological properties. Usually, low LMA means short LL, high nitrogen (N) content per unit mass, and fast turnover rates of nutrients; high LMA leads to long LL, low N content, and slow turnover rates. Deciduous trees with low LMA and short lifespan leaves have low carbon cost but high nitrogen demand; and evergreen trees, with high LMA and long lifespan leaves, have high carbon cost but low nitrogen demand. These relationships lead to: 1) evergreen trees have higher leaf area index than deciduous trees; 2) evergreen trees' carbon use efficiency is lower than the deciduous trees' because of their thick leaves and therefore high maintenance respiration; 3) the advantage of evergreens trees brought by their extra leaves over deciduous trees diminishes with increase N in ecosystem. These facts determine who will win when trees compete with each other in a N-limited ecosystem. In this study, we formulate a mathematical model according to the relationships between LMA, LL, leaf nitrogen, and leaf building and maintenance cost, where LMA is the fundamental variable determining the other three. We analyze the evolutionarily stable strategies (ESSs) of LMA with this mathematical model by examining the benefits of carbon and nitrogen investments to leaves in ecosystems with different N. The model shows the ESS converges to low LMA at high N and high LMA at low N. At intermediate N, there are two ESSs at low and high ends of LMA, respectively. The ESS also leads to low forest productivity by outcompeting the possible high productive strategies. We design a simulation scheme in an individual-based competition model (LM3-PPA) to simulate forest dynamics as results of the competition between deciduous and evergreen trees in three different biomes, which are temperate deciduous forest, deciduous-evergreen mixed forest, and boreal evergreen forest. The simulated results are consistent with the actual forests. Our model and simulated results indicate the distribution of evergreen and deciduous forests can be explained by one single leaf trait (i.e., LMA) and associated physiological and biogeochemical processes.

PSW3 Poster Short Presentations, #2

NASA Astrophysics Data System (ADS)

Glover, Alexi; Trichtchenko, Larisa; Heynderickx, Daniel

2012-07-01

This slot will include 4 short summaries of the following PSW3 poster presentations: 1. A North-South Asymmetry in the Global Electron Content, Gulyaeva T., Arikan F. & Veselovsky I., Paper Number: PSW.3-0028-12 2. Operational mapping of the ionospheric W index maps, Stanislawska I. et al., Paper Number: PSW.3-0029-12 3. Space weather and human health: An investigation on aviators, Papailiou M.-C. et al., Paper Number PSW.3-0030-12 4. Castilla-La Mancha neutron monitor (CaLMa): status at June 2012, Medina J. et al., Paper Number: PSW.3-0031-12

LmaPA2G4, a Homolog of Human Ebp1, Is an Essential Gene and Inhibits Cell Proliferation in L. major

PubMed Central

Joyce, Michelle V.; Morales, Miguel A.

2014-01-01

We have identified LmaPA2G4, a homolog of the human proliferation-associated 2G4 protein (also termed Ebp1), in a phosphoproteomic screening. Multiple sequence alignment and cluster analysis revealed that LmaPA2G4 is a non-peptidase member of the M24 family of metallopeptidases. This pseudoenzyme is structurally related to methionine aminopeptidases. A null mutant system based on negative selection allowed us to demonstrate that LmaPA2G4 is an essential gene in Leishmania major. Over-expression of LmaPA2G4 did not alter cell morphology or the ability to differentiate into metacyclic and amastigote stages. Interestingly, the over-expression affected cell proliferation and virulence in mouse footpad analysis. LmaPA2G4 binds a synthetic double-stranded RNA polyriboinosinic polyribocytidylic acid [poly(I∶C)] as shown in an electrophoretic mobility shift assay (EMSA). Quantitative proteomics revealed that the over-expression of LmaPA2G4 led to accumulation of factors involved in translation initiation and elongation. Significantly, we found a strong reduction of de novo protein biosynthesis in transgenic parasites using a non-radioactive metabolic labeling assay. In conclusion, LmaPA2G4 is an essential gene and is potentially implicated in fundamental biological mechanisms, such as translation, making it an attractive target for therapeutic intervention. PMID:24421916

Light drives vertical gradients of leaf morphology in a sugar maple (Acer saccharum) forest.

PubMed

Coble, Adam P; Cavaleri, Molly A

2014-02-01

Leaf mass per area (LMA, g m(-2)) is an essential trait for modeling canopy function due to its strong association with photosynthesis, respiration and leaf nitrogen. Leaf mass per area, which is influenced by both leaf thickness and density (LMA = thickness × density), generally increases from the bottom to the top of tree canopies, yet the mechanisms behind this universal pattern are not yet resolved. For decades, the light environment was assumed to be the most influential driver of within-canopy variation in LMA, yet recent evidence has shown hydrostatic gradients to be more important in upper canopy positions, especially in tall evergreen trees in temperate and tropical forests. The aim of this study was to disentangle the importance of various environmental drivers on vertical LMA gradients in a mature sugar maple (Acer saccharum Marshall) forest. We compared LMA, leaf density and leaf thickness relationships with height, light and predawn leaf water potential (ΨPre) within a closed and an exposed canopy to assess leaf morphological traits at similar heights but different light conditions. Contrary to our expectations and recent findings in the literature, we found strong evidence that light was the primary driver of vertical gradients in leaf morphology. At similar heights (13-23 m), LMA was greater within the exposed canopy than the closed canopy, and light had a stronger influence over LMA compared with ΨPre. Light also had a stronger influence over both leaf thickness and density compared with ΨPre; however, the increase in LMA within both canopy types was primarily due to increasing leaf thickness with increasing light availability. This study provides strong evidence that canopy structure and crown exposure, in addition to height, should be considered as a parameter for determining vertical patterns in LMA and modeling canopy function.

Report on Mars Odyssey Independent Assessment Team Activities

NASA Technical Reports Server (NTRS)

Barto, R.; Day, John H. (Technical Monitor)

2001-01-01

During the week of March 26, 2001, I was asked by Rich Katz, NASA-GSFC, to participate on the Mars Odyssey Independent Assessment Team (IAT) that would investigate the implications of the failure of an Actel RP 1280 Field Programmable Gate Array (FPGA), which occurred on the Space Infrared Telescope Facility (SIRTF) spacecraft, on the Mars Odyssey spacecraft that was set to launch on April 7, 2001. We were provided with review materials from JPL and Lockheed Martin (LMA) that would be discussed at a meeting on April 2, 2001.

An Integrated 0-1 Hour First-Flash Lightning Nowcasting, Lightning Amount and Lightning Jump Warning Capability

NASA Technical Reports Server (NTRS)

Mecikalski, John; Jewett, Chris; Carey, Larry; Zavodsky, Brad; Stano, Geoffrey; Chronis, Themis

2015-01-01

Using satellite-based methods that provide accurate 0-1 hour convective initiation (CI) nowcasts, and rely on proven success coupling satellite and radar fields in the Corridor Integrated Weather System (CIWS; operated and developed at MIT-Lincoln Laboratory), to subsequently monitor for first-flash lightning initiation (LI) and later period lightning trends as storms evolve. Enhance IR-based methods within the GOES-R CI Algorithm (that must meet specific thresholds for a given cumulus cloud before the cloud is considered to have an increased likelihood of producing lightning next 90 min) that forecast LI. Integrate GOES-R CI and LI fields with radar thresholds (e.g., first greater than or equal to 40 dBZ echo at the -10 C altitude) and NWP model data within the WDSS-II system for LI-events from new convective storms. Track ongoing lightning using Lightning Mapping Array (LMA) and pseudo-Geostationary Lightning Mapper (GLM) data to assess per-storm lightning trends (e.g., as tied to lightning jumps) and outline threat regions. Evaluate the ability to produce LI nowcasts through a "lightning threat" product, and obtain feedback from National Weather Service forecasters on its value as a decision support tool.

Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease.

PubMed

Durkovic, Jaroslav; Canová, Ingrid; Lagana, Rastislav; Kucerová, Veronika; Moravcík, Michal; Priwitzer, Tibor; Urban, Josef; Dvorák, Milon; Krajnáková, Jana

2013-02-01

Previous studies have shown that Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), is able to colonize remote areas in infected plants of Ulmus such as the leaf midrib and secondary veins. The objective of this study was to compare the performances in leaf traits between two Dutch elm hybrids 'Groeneveld' and 'Dodoens' which possess a contrasting tolerance to DED. Trait linkages were also tested with leaf mass per area (LMA) and with the reduced Young's modulus of elasticity (MOE) as a result of structural, developmental or functional linkages. Measurements and comparisons were made of leaf growth traits, primary xylem density components, gas exchange variables and chlorophyll a fluorescence yields between mature plants of 'Groeneveld' and 'Dodoens' grown under field conditions. A recently developed atomic force microscopy technique, PeakForce quantitative nanomechanical mapping, was used to reveal nanomechanical properties of the cell walls of tracheary elements such as MOE, adhesion and dissipation. 'Dodoens' had significantly higher values for LMA, leaf tissue thickness variables, tracheary element lumen area (A), relative hydraulic conductivity (RC), gas exchange variables and chlorophyll a fluorescence yields. 'Groeneveld' had stiffer cell walls of tracheary elements, and higher values for water-use efficiency and leaf water potential. Leaves with a large carbon and nutrient investment in LMA tended to have a greater leaf thickness and a higher net photosynthetic rate, but LMA was independent of RC. Significant linkages were also found between the MOE and some vascular traits such as RC, A and the number of tracheary elements per unit area. Strong dissimilarities in leaf trait performances were observed between the examined Dutch elm hybrids. Both hybrids were clearly separated from each other in the multivariate leaf trait space. Leaf growth, vascular and gas exchange traits in the infected plants of 'Dodoens' were unaffected by the DED fungus. 'Dodoens' proved to be a valuable elm germplasm for further breeding strategies.

Anatomical basis of the change in leaf mass per area and nitrogen investment with relative irradiance within the canopy of eight temperate tree species

NASA Astrophysics Data System (ADS)

Aranda, I.; Pardo, F.; Gil, L.; Pardos, J. A.

2004-05-01

Changes in leaf mass per area (LMA), nitrogen content on a mass-basis (N m) and on an area basis (N a) with relative irradiance were assessed in leaves of eight temperate species harvested at different depths in a canopy. Relative irradiance (GSF) at the points of leaf sampling was estimated by hemispheric photographs. There was a strong species-dependent positive relationship between LMA and GSF for all species. Shade-tolerant species such as Fagus sylvatica showed lower LMA for the same GSF than less tolerant species as Quercus pyrenaica or Quercus petraea. The only evergreen species in the study, Ilex aquifollium, had the highest LMA, independent of light environment, with minimum values much higher than the rest of the broad-leaved species studied. There was no relation between N m and GSF for most species studied and only a very weak relation for the relative shade-intolerant species Q. pyrenaica. Within each species, the pattern of N a investment with regard to GSF was linked mainly to LMA. At the same relative irradiance, differences in N a among species were conditioned both by the LMA-GSF relationship and by the species N m value. The lowest N m value was measured in I. aquifollium (14.3 ± 0.6 mg g -1); intermediate values in Crataegus monogyna (16.9 ± 0.6 mg g -1) and Prunus avium (19.1 ± 0.6 mg g -1) and higher values, all in a narrow range (21.3 ± 0.6 to 23 ± 0.6 mg g -1), were measured for the other five species. Changes in LMA with the relative irradiance were linked both to lamina thickness (LT) and to palisade/spongy parenchyma ratio (PP/SP). In the second case, the LMA changes may be related to an increase in lamina density as palisade parenchyma involves higher cell packing than spongy parenchyma. However, since PP/SP ratio showed a weak species-specific relationship with LMA, the increase in LT should be the main cause of LMA variation.

Linear relations between leaf mass per area (LMA) and seasonal climate discovered through Linear Manifold Clustering (LMC)

NASA Astrophysics Data System (ADS)

Kiang, N. Y.; Haralick, R. M.; Diky, A.; Kattge, J.; Su, X.

2016-12-01

Leaf mass per area (LMA) is a critical variable in plant carbon allocation, correlates with leaf activity traits (photosynthetic activity, respiration), and is a controller of litterfall mass and hence carbon substrate for soil biogeochemistry. Recent advances in understanding the leaf economics spectrum (LES) show that LMA has a strong correlation with leaf life span, a trait that reflects ecological strategy, whereas physiological traits that control leaf activity scale with each other when mass-normalized (Osnas et al., 2013). These functional relations help reduce the number of independent variables in quantifying leaf traits. However, LMA is an independent variable that remains a challenge to specify in dynamic global vegetation models (DGVMs), when vegetation types are classified into a limited number of plant functional types (PFTs) without clear mechanistic drivers for LMA. LMA can range orders of magnitude across plant species, as well as vary within a single plant, both vertically and seasonally. As climate relations in combination with alternative ecological strategies have yet to be well identified for LMA, we have assembled 22,000 records of LMA spanning 0.004 - 33 mg/m2 from the numerous contributors to the TRY database (Kattge et al., 2011), with observations distributed over several climate zones and plant functional categories (growth form, leaf type, phenology). We present linear relations between LMA and climate variables, including seasonal temperature, precipitation, and radiation, as derived through Linear Manifold Clustering (LMC). LMC is a stochastic search technique for identifying linear dependencies between variables in high dimensional space. We identify a set of parsimonious classes of LMA-climate groups based on a metric of minimum description to identify structure in the data set, akin to data compression. The relations in each group are compared to Köppen-Geiger climate classes, with some groups revealing continuous linear relations between what might appear to be distinct classes. We discuss these results with regard to parameterization and evaluation of DGVMs with regard to plant diversity and representing the carbon cycle.

Decoupling of Local Metabolic Activity and Functional Connectivity Links to Amyloid in Alzheimer's Disease.

PubMed

Scherr, Martin; Pasquini, Lorenzo; Benson, Gloria; Nuttall, Rachel; Gruber, Martin; Neitzel, Julia; Brandl, Felix; Sorg, Christian

2018-05-19

Both ongoing local metabolic activity (LMA) and corresponding functional connectivity (FC) with remote brain regions are progressively impaired in Alzheimer's disease (AD), particularly in the posterior default mode network (pDMN); however, it is unknown how these impairments interact. It is well known that decreasing mean synaptic activity of a region, i.e., decreasing LMA, reduces the region's sensitivity to afferent input from other regions, i.e., FC. We hypothesized progressive decoupling between LMA and FC in AD, which is linked to amyloid-β pathology (Aβ). Healthy adults (n=20) and Aβ+patients without memory impairment (n=9), early MCI (n=21), late MCI (n=18) and AD (n=22) were assessed by resting-state fMRI, FDG-PET, and AV-45-PET to measure FC, LMA, and Aβ of the pDMN. Coupling between LMA and FC (rLA/FC) was estimated by voxelwise correlation. RLMA/FC decreased with disease severity (F=20.09, p<0.001). This decrease was specifically associated with pDMN Aβ (r=-0.273, p=0.029) but not global Aβ (r=-0.112, p=0.378) and with the impact of Aβ on FC (i.e., rAβ/FC,r=-0.339; p=0.006). In multiple regression models rLMA/FC was also associated with memory impairment, reduced cognitive speed and flexibility, outperforming global Aβ, pDMN Aβ, pDMN LMA, and pDMN FC, respectively. Results demonstrate increasing decoupling of LMA from its FC in AD. Data suggest that decoupling is driven by local Aβ and contributes to memory decline.

Comparison of postoperative complication between Laryngeal Mask Airway and endotracheal tube during low-flow anesthesia with controlled ventilation

PubMed Central

Peirovifar, Ali; Eydi, Mahmood; Mirinejhad, Mir Mousa; Mahmoodpoor, Ata; Mohammadi, Afsaneh; EJ Golzari, Samad

2013-01-01

Objective: To compare the postoperative complications between Laryngeal Mask Airway (LMA) and endotracheal tube (ETT) during low-flow anesthesia with controlled ventilation. Methodology: Eighty adult Patients with ASA class I or II were randomly allocated into two forty-patient groups (ETT or LMA). Cuff pressure was monitored during anesthesia. After high uptake period, fresh gas flow (FGF) was decreased to 1 lit/min and isoflurane set to 1%. Monitoring during anesthesia included non-invasive blood pressure, ECG, ETCO2 and pulse oximetry. System leakage (>100 ml/min), rebreathing and any attempt to increase FGF to overcome the leak were monitored during anesthesia. Later, patients were extubated and transferred to Post Anesthesia Care Unit (PACU). In PACU, the incidence of sore throat, cough, difficulty in swallowing and shivering was monitored for all patients. Results: Leakage was observed in two and three cases in ETT and LMA groups respectively (P>0.05). Postoperative cough, sore throat and difficulty in swallowing were significantly less in LMA than ETT group. No significant difference was observed regarding ETCo2 values between 2 groups. Conclusion: If careful measures regarding insertion techniques, correct LMA position and routine monitoring of LMA cuff pressure are taken, LMA can be used as a safe alternative with lower incidence of post operation complication compared with ETT during low-flow controlled anesthesia with modern anesthetic machines. PMID:24353586

Ultrasonic prediction of carcass merit in beef cattle: evaluation of technician effects on ultrasonic estimates of carcass fat thickness and longissimus muscle area.

PubMed

Perkins, T L; Green, R D; Hamlin, K E; Shepard, H H; Miller, M F

1992-09-01

The objective of this study was to determine technician effects of live animal ultrasonic estimates of fat thickness (FTU) and longissimus muscle area (LMAU). Steers (n = 36) representing four breed-types (Brown Swiss, Average Zebu-cross Mexican, Corriente Mexican, and typical British crossbred) of commercial slaughter cattle were isonified to estimate accuracy and repeatability of fat thickness (FT) and longissimus muscle area (LMA) measurements by two experienced technicians. Repeated measures of FTU and LMAU were taken by technicians on two consecutive days with an Aloka 500V ultrasound unit equipped with a 3.5-MHz, 172-mm scanning width, linear-array transducer. Ultrasonic estimates of fat thickness and LMAU were taken at the 12th and 13th rib interface 48 h before slaughter; carcass fat thickness (FTC) and longissimus muscle area (LMAC) were measured 48 h postmortem. Means for FTU, FTC, LMAU, and LMAC were .91 +/- .36 cm, .82 +/- .40 cm, 70.7 +/- 9.43 cm2, and 72.4 +/- 8.9 cm2, respectively. Ultrasound and carcass measures of FT and LMA were different (P less than .01) among breed-types but were not different (P greater than .10) between technicians or for technician x breed-type interactions. Pooled simple correlation coefficients (P less than .01) were .87 and .86 between FTU and FTC and .76 and .82 between LMAU and LMAC for Technicians 1 and 2, respectively. Repeatabilities estimated by intraclass correlation methods were .91 +/- .03 and .81 +/- .06 for images repeated over 2 d and .95 +/- .02 and .83 +/- .05 for images repeated by two technicians for FT and LMA, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

50 CFR 229.32 - Atlantic large whale take reduction plan regulations.

Code of Federal Regulations, 2010 CFR

2010-10-01

... South Channel Restricted Trap/Pot Area where it overlaps with Lobster Management Area (LMA) 2 and the... Trap/Pot Area overlaps with Lobster Management Area (LMA) 2 and the Outer Cape LMA (as defined in the... Offshore Management Area 3 (including the area known as the Area 2/3 Overlap and Area 3/5 Overlap as...

Comparison of the Supreme™ and ProSeal™ laryngeal mask airways in infants: a prospective randomised clinical study.

PubMed

Oba, Sibel; Turk, Hacer Sebnem; Isil, Canan Tulay; Erdogan, Huseyin; Sayin, Pinar; Dokucu, Ali Ihsan

2017-09-05

The Supreme™ and ProSeal™ laryngeal mask airways (LMAs) are widely used in paediatric anaesthesia; however, LMA use in infants is limited because many anaesthesiologists prefer to use tracheal intubation in infants. In this study, we compared the Supreme and ProSeal LMAs in infants by measuring their performance characteristics, including insertion features, ventilation parameters, induced changes in haemodynamics and rates of postoperative complications. Infants of ASA physical status I scheduled for elective, minor, lower abdominal surgery were divided into two groups: the Supreme LMA group and the ProSeal LMA group. Times and ease of LMA insertion were noted. The percentages of tidal volume leakage as well as peak, mean and leakage pressures for all infants were measured. Heart rate (HR), oxygen saturation (SpO2) and end tidal carbon dioxide (EtCO2) values were recorded before and after LMA insertion and before and after extubation. After extubation, complications and adverse effects were noted. Demographic and surgical data were similar between the two groups. LMA insertion times were shorter for the ProSeal group than for the Supreme group (P < 0.002). The mean HR value for the ProSeal group was lower than for the Supreme group (P < 0.011). Both the peak pressure and the leakage percentage for the ProSeal group were statistically lower than for the Supreme group. The leakage pressure for the ProSeal group was statistically higher than for the Supreme group (P < 0.001). The ProSeal LMA is superior to the Supreme LMA for use in infants due to the ease of insertion, high oropharyngeal leakage pressure and fewer induced changes in haemodynamics. ClinicalTrial.gov, NCT03251105 , retrospectively registered on 15 Aug 2017.

Effect-site concentration of propofol required for LMA-Supreme™ insertion with and without remifentanil: a randomized controlled trial.

PubMed

Zaballos, Matilde; Bastida, Emilia; Agustí, Salomé; Portas, Maite; Jiménez, Consuelo; López-Gil, Maite

2015-10-06

A new supraglottic device, the LMA-Supreme™, has recently become available for clinical use. Information on anaesthetic and co-adjuvant requirements for insertion of the LMA-Supreme™ is limited. The present study aimed to evaluate the optimal effect-site concentration of propofol in 50 % (EC50) of adults necessary for successful insertion of the LMA-Supreme™ and to examine remifentanil's effect on propofol requirements. Fifty-eight elective patients (aged 18-60 years; ASA (American Society Anaesthesiologists) physical status classification I and II) scheduled for day surgery were randomly assigned to one of two groups: propofol with saline or propofol with remifentanil. Anaesthesia was induced by target-controlled infusion according to predetermined effect-site concentrations of propofol and remifentanil (5 ng.mL(-1)). The EC50 was calculated using Dixon's up-and-down method. Ten minutes following drug administration, LMA-Supreme™ insertion was attempted without the use of muscle relaxant drugs. In the propofol + saline group, the EC50 of propofol required for LMA-Supreme™ insertion was 6.32 ± 0.67 μg.mL(-1) (95 % CI, 5.69-6.94 μg.mL(-1)). With the addition of remifentanil at an effect-site concentration of 5 ng.mL(-1), the EC50 of propofol required for LMA-Supreme™ insertion was 2.50 ± 0.80 μg.mL(-1) (95 % CI, 1.82-3.17 μg.mL(-1); p < 0.0001). The propofol requirement for smooth insertion of the LMA-Supreme™ was 60 % less when remifentanil (5 ng.mL(-1)) was co-administered. Identified as NCT01974648 at www.clinicaltrials.gov .

Laban Movement Analysis towards Behavior Patterns

NASA Astrophysics Data System (ADS)

Santos, Luís; Dias, Jorge

This work presents a study about the use of Laban Movement Analysis (LMA) as a robust tool to describe human basic behavior patterns, to be applied in human-machine interaction. LMA is a language used to describe and annotate dancing movements and is divided in components [1]: Body, Space, Shape and Effort. Despite its general framework is widely used in physical and mental therapy [2], it has found little application in the engineering domain. Rett J. [3] proposed to implement LMA using Bayesian Networks. However LMA component models have not yet been fully implemented. A study on how to approach behavior using LMA is presented. Behavior is a complex feature and movement chain, but we believe that most basic behavior primitives can be discretized in simple features. Correctly identifying Laban parameters and the movements the authors feel that good patterns can be found within a specific set of basic behavior semantics.

Height is more important than light in determining leaf morphology in a tropical forest.

PubMed

Cavaleri, Molly A; Oberbauer, Steven F; Clark, David B; Clark, Deborah A; Ryan, Michael G

2010-06-01

Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number of recent studies have provided evidence that water limitation in the upper canopy can constrain foliar morphological adaptations to higher light levels. We measured height, light, and LMA of all species encountered along 45 vertical canopy transects across a Costa Rican tropical rain forest. LMA was correlated with light levels in the lower canopy until approximately 18 m sample height and 22% diffuse transmittance. Height showed a remarkably linear relationship with LMA throughout the entire vertical canopy profile for all species pooled and for each functional group individually (except epiphytes), possibly through the influence of gravity on leaf water potential and turgor pressure. Models of forest function may be greatly simplified by estimating LMA-correlated leaf physiological parameters solely from foliage height profiles, which in turn can be assessed with satellite- and aircraft-based remote sensing.

Astronaut William Gregory activates Liquids Mixing Apparatus

NASA Technical Reports Server (NTRS)

2003-01-01

Experiments to seek solutions for a range of biomedical issues are at the heart of several investigations that will be hosted by the Commercial Instrumentation Technology Associates (ITA), Inc. Biomedical Experiments (CIBX-2) payload. CIBX-2 is unique, encompassing more than 20 separate experiments including cancer research, commercial experiments, and student hands-on experiments from 10 schools as part of ITA's ongoing University Among the Stars program. Astronaut William G. Gregory activates Liquids Mixing Apparatus (LMA) vials during STS-67. Other LMAs hang at top on the face of the middeck locker array. The experiments are sponsored under NASA's Space Product Development Program (SPD).

Space Product Development (SPD)

NASA Image and Video Library

2003-01-12

Experiments to seek solutions for a range of biomedical issues are at the heart of several investigations that will be hosted by the Commercial Instrumentation Technology Associates (ITA), Inc. Biomedical Experiments (CIBX-2) payload. CIBX-2 is unique, encompassing more than 20 separate experiments including cancer research, commercial experiments, and student hands-on experiments from 10 schools as part of ITA's ongoing University Among the Stars program. Astronaut William G. Gregory activates Liquids Mixing Apparatus (LMA) vials during STS-67. Other LMAs hang at top on the face of the middeck locker array. The experiments are sponsored under NASA's Space Product Development Program (SPD).

Early versus late removal of the laryngeal mask airway (LMA) for general anaesthesia.

PubMed

Mathew, Preethy J; Mathew, Joseph L

2015-08-10

The laryngeal mask airway (LMA) is a safe and effective modality to maintain the airway for general anaesthesia during surgical procedures. The LMA is removed at the end of surgery and anaesthesia, when the patient maintains an adequate respiratory rate and depth. This removal of the LMA can be done either when the patient is deep under anaesthesia (early removal) or only after the patient has regained consciousness (late removal). It is not clear which of these techniques is superior. The objective of this review was to compare the safety of LMA removal in the deep plane of anaesthesia (early removal) versus removal in the awake state (late removal) for participants undergoing general anaesthesia. We searched the Cochrane Central Register of Controlled Trials (CENTRAL; 2014, Issue 8); MEDLINE (1966 to August 2014); EMBASE (1980 to August 2014); LILACS (1982 to August 2014); CINAHL (WebSPIRS; 1984 to August 2014); and ISI Web of Science (1984 to August 2014). We searched for ongoing trials through various trial registration websites. In addition, we searched conference proceedings and reference lists of relevant articles. We included randomized controlled trials (RCTs) on adults and children undergoing elective general anaesthesia using the LMA, that compared early removal of the LMA (defined as removal of the LMA in the deep plane of anaesthesia) versus late removal of the LMA (defined as removal of the LMA after the patient is awake). Two authors independently assessed trial quality and extracted data. We contacted study authors for additional information. We used a random-effects model to generate forest plots from the data. We identified a total of 9188 citations and included 15 RCTs conducted on 2242 participants in this review. All trials used the LMA Classic in American Society of Anesthesiologists (ASA) physical status I or II for patients undergoing elective general anaesthesia. Children were enrolled in 11 trials and adults in five trials. None of the trials were of high methodological quality. Eight of the 15 studies had adequate generation of random sequence, whereas only one trial had adequate concealment of random sequence. Three trials had blinded the outcome assessor. Thus, the majority of the studies appeared to have a high risk of bias in the study design.Using the GRADE approach, we found low quality evidence that the risk of laryngospasm was similar with early removal of the LMA (3.3%) versus late removal (2.7%): risk ratio (RR) 1.23, 95% confidence interval (CI) 0.74 to 2.03; 11 trials, 1615 participants. The quality of evidence was very low that the risk of coughing was less after early removal (13.9%) than late removal (19.4%): RR 0.52, 95% CI 0.29 to 0.94; 11 trials, 1430 participants. The quality of evidence for the risk of desaturation was also very low; there was no difference between early removal (7.9%) and late removal (10.1%): RR 0.68, 95% CI 0.4 to 1.16; 13 trials, 2037 participants. We found low quality evidence that the risk of airway obstruction was higher with early removal (15.6%) compared to late removal of the LMA (4.6%): RR 2.69, 95% CI 1.32 to 5.5; eight trials, 1313 participants. This systematic review suggests that current best evidence comparing early versus late removal of the LMA in participants undergoing general anaesthesia does not demonstrate superiority of either intervention. However, the quality of evidence available is either low or very low. There is a paucity of well designed RCTs and a need for large scale RCTs to demonstrate whether early removal or late removal of the LMA is better after general anaesthesia.

Taxonomy and remote sensing of leaf mass per area (LMA) in humid tropical forests

Treesearch

Gregory P. Asner; Roberta E. Martin; Raul Tupayachi; Ruth Emerson; Paola Martinez; Felipe Sinca; George V.N. Powell; S. Joseph Wright; Ariel E. Lugo

2011-01-01

Leaf mass per area (LMA) is a trait of central importance to plant physiology and ecosystem function, but LMA patterns in the upper canopies of humid tropical forests have proved elusive due to tall species and high diversity. We collected top-of-canopy leaf samples from 2873 individuals in 57 sites spread across the Neotropics, Australasia, and Caribbean and Pacific...

[AWAKE CRANIOTOMY: IN SEARCH FOR OPTIMAL SEDATION].

PubMed

Kulikova, A S; Sel'kov, D A; Kobyakov, G L; Shmigel'skiy, A V; Lubnin, A Yu

2015-01-01

Awake craniotomy is a "gold standard"for intraoperative brain language mapping. One of the main anesthetic challenge of awake craniotomy is providing of optimal sedation for initial stages of intervention. The goal of this study was comparison of different technics of anesthesia for awake craniotomy. Materials and methods: 162 operations were divided in 4 groups: 76 cases with propofol sedation (2-4mg/kg/h) without airway protection; 11 cases with propofol sedation (4-5 mg/kg/h) with MV via LMA; 36 cases of xenon anesthesia; and 39 cases with dexmedetomidine sedation without airway protection. Results and discussion: brain language mapping was successful in 90% of cases. There was no difference between groups in successfulness of brain mapping. However in the first group respiratory complications were more frequent. Three other technics were more safer Xenon anesthesia was associated with ultrafast awakening for mapping (5±1 min). Dexmedetomidine sedation provided high hemodynamic and respiratory stability during the procedure.

Resonantly cladding-pumped Yb-free Er-doped LMA fiber laser with record high power and efficiency.

PubMed

Zhang, Jun; Fromzel, Viktor; Dubinskii, Mark

2011-03-14

We report the results of our power scaling experiments with resonantly cladding-pumped Er-doped eye-safe large mode area (LMA) fiber laser. While using commercial off-the-shelf LMA fiber we achieved over 88 W of continuous-wave (CW) single transverse mode power at ~1590 nm while pumping at 1532.5 nm. Maximum observed optical-to-optical efficiency was 69%. This result presents, to the best of our knowledge, the highest power reported from resonantly-pumped Yb-free Er-doped LMA fiber laser, as well as the highest efficiency ever reported for any cladding-pumped Er-doped laser, either Yb-co-doped or Yb-free.

Cocaine-and-Amphetamine-Regulated-Transcript (CART) peptide attenuates dopamine- and cocaine-mediated locomotor activity in both male and female rats: lack of sex differences

PubMed Central

Job, Martin O.; Perry, JoAnna; Shen, Li L.; Kuhar, Michael J.

2014-01-01

Cocaine-and-Amphetamine Regulated Transcript peptide (CART peptide) is known for having an inhibitory effect on dopamine (DA)- and cocaine-mediated actions and is postulated to be a homeostatic, regulatory factor in the nucleus accumbens (NAc). Some sex differences in cocaine-mediated LMA and in the expression and function of CART peptide have been reported. However, it is not known if the inhibitory effect of CART peptide on cocaine-mediated locomotor activity (LMA) is sexually dimorphic. In this study, the effect of CART 55-102 on LMA due to intra-NAc DA and i.p. cocaine were determined in male and female Sprague-Dawley rats. The results show that CART 55-102 blunted or reduced both the DA- and cocaine-induced LMA in both males and females. In conclusion, CART peptide is effective in blunting DA- and cocaine-mediated LMA in both males and females. PMID:24630272

An evolutionary perspective on leaf economics: phylogenetics of leaf mass per area in vascular plants

PubMed Central

Flores, Olivier; Garnier, Eric; Wright, Ian J; Reich, Peter B; Pierce, Simon; Dìaz, Sandra; Pakeman, Robin J; Rusch, Graciela M; Bernard-Verdier, Maud; Testi, Baptiste; Bakker, Jan P; Bekker, Renée M; Cerabolini, Bruno E L; Ceriani, Roberta M; Cornu, Guillaume; Cruz, Pablo; Delcamp, Matthieu; Dolezal, Jiri; Eriksson, Ove; Fayolle, Adeline; Freitas, Helena; Golodets, Carly; Gourlet-Fleury, Sylvie; Hodgson, John G; Brusa, Guido; Kleyer, Michael; Kunzmann, Dieter; Lavorel, Sandra; Papanastasis, Vasilios P; Pérez-Harguindeguy, Natalia; Vendramini, Fernanda; Weiher, Evan

2014-01-01

In plant leaves, resource use follows a trade-off between rapid resource capture and conservative storage. This “worldwide leaf economics spectrum” consists of a suite of intercorrelated leaf traits, among which leaf mass per area, LMA, is one of the most fundamental as it indicates the cost of leaf construction and light-interception borne by plants. We conducted a broad-scale analysis of the evolutionary history of LMA across a large dataset of 5401 vascular plant species. The phylogenetic signal in LMA displayed low but significant conservatism, that is, leaf economics tended to be more similar among close relatives than expected by chance alone. Models of trait evolution indicated that LMA evolved under weak stabilizing selection. Moreover, results suggest that different optimal phenotypes evolved among large clades within which extremes tended to be selected against. Conservatism in LMA was strongly related to growth form, as were selection intensity and phenotypic evolutionary rates: woody plants showed higher conservatism in relation to stronger stabilizing selection and lower evolutionary rates compared to herbaceous taxa. The evolutionary history of LMA thus paints different evolutionary trajectories of vascular plant species across clades, revealing the coordination of leaf trait evolution with growth forms in response to varying selection regimes. PMID:25165520

Eschmann introducer through laryngeal mask airway: a cadaveric trial of an alternate means of rescue intubation.

PubMed

Miller, Joel A; Levsky, Marc E; Givens, Melissa L; Miller, Michael A

2010-02-01

Laryngeal mask airways (LMAs) are often used as airway rescue devices where laryngoscopy is difficult. The LMA does not protect the airway and is preferably replaced with a cuffed endotracheal tube. There are reports of cases where an Eschmann tracheal tube introducer (ETTI) was successfully used to bridge between a standard LMA and an endotracheal tube. This project was designed to determine whether an Eschmann stylet can reliably be passed through an LMA into the trachea as a means of rescue intubation. Nineteen emergency medicine residents and attending physicians, who were participants in a cadaveric airway course, placed and inflated a size 4 LMA (The Laryngeal Mask Company Ltd., San Diego, CA) on each of six unembalmed human cadavers in the usual fashion. They then attempted to pass a lubricated, 15 Fr, reusable, coude-tipped ETTI (Portex, Smiths Medical, Keene, NH)) through the airspace/handle of the inflated LMA. The LMA was then deflated and removed while the ETTI was held in place. Investigators then determined the location of the ETTI by laryngoscopy. Of 114 attempts at the rescue procedure, 59 resulted in placement of the bougie into the trachea, yielding an overall success rate of 52% (95% CI 48%-56%). There were no significant differences in performance based on level of training of residents or years of experience of attending physicians. While not a primary difficult airway option, the use of a ETTI as a bridge device between LMA and endotracheal tube was successful about 50% of the time.

Air-Q® versus LMA Fastrach™ for fiberoptic-guided intubation: A randomized cross-over manikin trial.

PubMed

Portas, M; Canal, M I; Barrio, M; Alonso, M; Cabrerizo, P; López-Gil, M; Zaballos, M

2018-03-01

Airway management is still a major cause of anesthesia-associated morbidity and mortality. Supraglottic devices are recommended in difficult airway management guidelines. The aim of this study was to compare the performance of the Air-Q ® and the LMA Fastrach™ for fiberoptic guided tracheal intubation. Thirty-three anesthesia trainees participated in this randomized crossover study. Time to insert the dedicated airways (insertion of the airway into the manikin and delivery of two breaths), time to tracheal intubation (fiberoptic-guided tracheal intubation), time to remove the dedicated airway (removal of the Air-Q ® /LMA Fastrach™ over the tracheal tube) and the opinion of the ease of use of the anesthesia trainees were measured. There was 100% success rate for tracheal intubation with both devices on the first attempt. Time to insert the dedicated device and deliver two breaths was 10±3s for the Air-Q ® and 11±3s for the LMA Fastrach™, P=.07. Time taken to intubate the trachea was shorter with the air-Q ® , 38±15 s, than with the LMA Fastrach™, 47±19s, P=.017. Overall procedure time was significantly shorter with the Air-Q ® as compared with the LMA Fastrach™, with a mean time of 74±21s and 87±28s respectively, P=.002. Air-Q ® removal was considered easier than LMA Fastrach™ removal, P=.005. There were no tube dislodgements during the removal of the dedicated airways. Inexperienced anesthesia residents can perform fiberoptic-guided intubation through Air-Q ® and LMA Fastrach™ in a clinically acceptable time with high success. Copyright © 2017 Sociedad Española de Anestesiología, Reanimación y Terapéutica del Dolor. Publicado por Elsevier España, S.L.U. All rights reserved.

Leaf trait dissimilarities between Dutch elm hybrids with a contrasting tolerance to Dutch elm disease

PubMed Central

Ďurkovič, Jaroslav; Čaňová, Ingrid; Lagaňa, Rastislav; Kučerová, Veronika; Moravčík, Michal; Priwitzer, Tibor; Urban, Josef; Dvořák, Miloň; Krajňáková, Jana

2013-01-01

Background and Aims Previous studies have shown that Ophiostoma novo-ulmi, the causative agent of Dutch elm disease (DED), is able to colonize remote areas in infected plants of Ulmus such as the leaf midrib and secondary veins. The objective of this study was to compare the performances in leaf traits between two Dutch elm hybrids ‘Groeneveld’ and ‘Dodoens’ which possess a contrasting tolerance to DED. Trait linkages were also tested with leaf mass per area (LMA) and with the reduced Young's modulus of elasticity (MOE) as a result of structural, developmental or functional linkages. Methods Measurements and comparisons were made of leaf growth traits, primary xylem density components, gas exchange variables and chlorophyll a fluorescence yields between mature plants of ‘Groeneveld’ and ‘Dodoens’ grown under field conditions. A recently developed atomic force microscopy technique, PeakForce quantitative nanomechanical mapping, was used to reveal nanomechanical properties of the cell walls of tracheary elements such as MOE, adhesion and dissipation. Key Results ‘Dodoens’ had significantly higher values for LMA, leaf tissue thickness variables, tracheary element lumen area (A), relative hydraulic conductivity (RC), gas exchange variables and chlorophyll a fluorescence yields. ‘Groeneveld’ had stiffer cell walls of tracheary elements, and higher values for water-use efficiency and leaf water potential. Leaves with a large carbon and nutrient investment in LMA tended to have a greater leaf thickness and a higher net photosynthetic rate, but LMA was independent of RC. Significant linkages were also found between the MOE and some vascular traits such as RC, A and the number of tracheary elements per unit area. Conclusions Strong dissimilarities in leaf trait performances were observed between the examined Dutch elm hybrids. Both hybrids were clearly separated from each other in the multivariate leaf trait space. Leaf growth, vascular and gas exchange traits in the infected plants of ‘Dodoens’ were unaffected by the DED fungus. ‘Dodoens’ proved to be a valuable elm germplasm for further breeding strategies. PMID:23264236

Characteristics of NLDN-Reported Radio Frequency Emissions Associated with Terrestrial Gamma-ray Flashes

NASA Astrophysics Data System (ADS)

Mailyan, B. G.; Nag, A.; Murphy, M. J.; Briggs, M. S.; Dwyer, J. R.; Cramer, E.; Stanbro, M.; Roberts, O. J.; Rassoul, H.

2017-12-01

Electric and magnetic field signals in the radio frequency range associated with Terrestrial Gamma-ray Flashes (TGFs) have become important measurements for studying this high-energy atmospheric phenomenon. These signals can be used to geolocate the source of TGFs, but they also provide insights into the TGF production mechanism, and the relationship between particle fluxes and lightning. In this study, we analyze 32 TGFs detected by the Fermi Gamma-ray Burst Monitor (GBM) occurring in 2014-2016 in conjunction with data from the U.S. National Lightning Detection Network (NLDN). We examine the characteristics of magnetic field waveforms measured by NLDN sensors for 48 pulses occurring within 5 ms of the peak-time of the gamma-ray photon flux. The -3 dB bandwidth of the NLDN sensors are from about 400 Hz to 400 KHz. For 15 (out of 32) TGFs, the associated NLDN pulse occurred almost simultaneously with (that is, within 300 μs of) the TGF. It is possible that these near-simultaneous low frequency magnetic field pulses were produced by relativistic electron beams. The median time interval between the beginning of these near-simultaneous NLDN pulses and the peak-times of the TGF flux is 38 μs. 3 out of 16 ( 19%) of these pulses had negative initial polarity. The absolute value of NLDN-estimated peak currents, which can be viewed as a quantity proportional to the peak magnetic radiation field of these pulses, ranges from 17 kA to 166 kA, with the median being 32 kA. Twelve pulses had peak currents less than 50 kA. Additionally, we will compare the characteristics of GBM-reported gamma-ray signatures of the two categories of TGFs, those with a near-simultaneous NLDN-detected pulse and those with no such pulse (but with other pulses detected by the NLDN occurring within 5 ms of the TGF). Also, one of the TGFs occurred within the coverage region of the Kennedy Space Center Lightning Mapping Array (LMA). We will examine in detail the LMA, NLDN, and NEXRAD radar data for this TGF.

An Evaluation of Lightning Flash Rate Parameterizations Based on Observations of Colorado Storms during DC3

NASA Astrophysics Data System (ADS)

Basarab, B.; Fuchs, B.; Rutledge, S. A.

2013-12-01

Predicting lightning activity in thunderstorms is important in order to accurately quantify the production of nitrogen oxides (NOx = NO + NO2) by lightning (LNOx). Lightning is an important global source of NOx, and since NOx is a chemical precursor to ozone, the climatological impacts of LNOx could be significant. Many cloud-resolving models rely on parameterizations to predict lightning and LNOx since the processes leading to charge separation and lightning discharge are not yet fully understood. This study evaluates predicted flash rates based on existing lightning parameterizations against flash rates observed for Colorado storms during the Deep Convective Clouds and Chemistry Experiment (DC3). Evaluating lightning parameterizations against storm observations is a useful way to possibly improve the prediction of flash rates and LNOx in models. Additionally, since convective storms that form in the eastern plains of Colorado can be different thermodynamically and electrically from storms in other regions, it is useful to test existing parameterizations against observations from these storms. We present an analysis of the dynamics, microphysics, and lightning characteristics of two case studies, severe storms that developed on 6 and 7 June 2012. This analysis includes dual-Doppler derived horizontal and vertical velocities, a hydrometeor identification based on polarimetric radar variables using the CSU-CHILL radar, and insight into the charge structure using observations from the northern Colorado Lightning Mapping Array (LMA). Flash rates were inferred from the LMA data using a flash counting algorithm. We have calculated various microphysical and dynamical parameters for these storms that have been used in empirical flash rate parameterizations. In particular, maximum vertical velocity has been used to predict flash rates in some cloud-resolving chemistry simulations. We diagnose flash rates for the 6 and 7 June storms using this parameterization and compare to observed flash rates. For the 6 June storm, a preliminary analysis of aircraft observations of storm inflow and outflow is presented in order to place flash rates (and other lightning statistics) in the context of storm chemistry. An approach to a possibly improved LNOx parameterization scheme using different lightning metrics such as flash area will be discussed.

Laryngeal mask airway versus bag-mask ventilation or endotracheal intubation for neonatal resuscitation.

PubMed

Qureshi, Mosarrat J; Kumar, Manoj

2018-03-15

Providing effective positive pressure ventilation is considered to be the single most important component of successful neonatal resuscitation. Ventilation is frequently initiated manually with bag and face mask (BMV) followed by endotracheal intubation if respiratory depression continues. These techniques may be difficult to perform successfully resulting in prolonged resuscitation or neonatal asphyxia. The laryngeal mask airway (LMA) may achieve initial ventilation and successful resuscitation faster than a bag-mask device or endotracheal intubation. Among newborns requiring positive pressure ventilation for cardio-pulmonary resuscitation, is LMA more effective than BMV or endotracheal intubation for successful resuscitation? When BMV is either insufficient or ineffective, is effective positive pressure ventilation and successful resuscitation achieved faster with the LMA compared to endotracheal intubation? We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL 2017, Issue 1), MEDLINE via PubMed (1966 to 15 February 2017), Embase (1980 to 15 February 2017), and CINAHL (1982 to 15 February 2017). We also searched clinical trials registers, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials. We included randomised and quasi-randomised controlled trials that compared LMA for neonatal resuscitation with either BMV or endotracheal intubation and reported on any outcomes related to neonatal resuscitation specified in this review. Two review authors independently evaluated studies for risk of bias assessments, and extracted data using Cochrane Neonatal criteria. Categorical treatment effects were described as relative risks and continuous treatment effects were described as the mean difference, with 95% confidence intervals (95% CI) of estimates. We included seven trials that involved a total of 794 infants. Five studies compared LMA with BMV and three studies compared LMA with endotracheal intubation. We added six new studies for this update (754 infants).LMA was associated with less need for endotracheal intubation than BMV (typical risk ratio (RR) 0.24, 95% CI 0.12 to 0.47 and typical risk difference (RD) -0.14, 95% CI -0.14 to -0.06; 5 studies, 661 infants; moderate-quality evidence) and shorter ventilation time (mean difference (MD) -18.90 seconds, 95% CI -24.35 to -13.44; 4 studies, 610 infants). Babies resuscitated with LMA were less likely to require admission to neonatal intensive care unit (NICU) (typical RR 0.60, 95% CI 0.40 to 0.90 and typical RD -0.18, 95% CI -0.31 to -0.04; 2 studies,191 infants; moderate-quality evidence). There was no difference in deaths or hypoxic ischaemic encephalopathy (HIE) events.Compared to endotracheal intubation, there were no clinically significant differences in insertion time or failure to correctly insert the device (typical RR 0.95, 95% CI 0.17 to 5.42; 3 studies, 158 infants; very low-quality evidence). There was no difference in deaths or HIE events. LMA can achieve effective ventilation during neonatal resuscitation in a time frame consistent with current neonatal resuscitation guidelines. Compared to BMV, LMA is more effective in terms of shorter resuscitation and ventilation times, and less need for endotracheal intubation (low- to moderate-quality evidence). However, in trials comparing LMA with BMV, over 80% of infants in both trial arms responded to the allocated intervention. In studies that allowed LMA rescue of infants failing with BMV, it was possible to avoid intubation in the majority. It is important that the clinical community resorts to the use of LMA more proactively to provide effective ventilation when newborn is not responding to BMV before attempting intubation or initiating chest compressions.LMA was found to offer comparable efficacy to endotracheal intubation (very low- to low-quality evidence). It therefore offers an alternate airway device when attempts at inserting endotracheal intubation are unsuccessful during resuscitation.Most studies enrolled infants with birth weight over 1500 g or 34 or more weeks' gestation. As such, there is lack of evidence to support LMA use in more premature infants.

Optimal degree of mouth opening for laryngeal mask airway function during oral surgery.

PubMed

Sanuki, Takuro; Sugioka, Shingo; Hirokane, Motoko; Son, Hiroki; Uda, Rumiko; Akatsuka, Masafumi; Kotani, Junichiro

2011-04-01

This study was performed to determine the optimal degree of mouth opening in anesthetized patients requiring laryngeal mask airway (LMA) during oral surgery. A single, experienced LMA user inserted the LMA in 15 patients who were scheduled for elective oral surgery. Oropharyngeal leak pressure, intracuff pressure, and fiberoptic assessment of the LMA position were sequentially documented in 5 mouth conditions-opening of 1.4 (neutral position), 2, 3, 4, and 5 cm-and any resulting ventilatory difficulties were recorded. Oropharyngeal leak pressure with the mouth open 4 cm (21.8 ± 3.2 cm H(2)O, P = .025) and 5 cm (27.3 ± 7.2 cm H(2)O, P < .001) was significantly higher than in the neutral position (18.1 ± 1.5 cm H(2)O), as was intracuff pressure (neutral position, 60.0 ± 0 cm H(2)O; 4 cm, 72.6 ± 5.1 cm H(2)O [P < .001]; and 5 cm, 86.9 ± 14.4 cm H(2)O [P < .001]). LMA position, observed by fiberoptic bronchoscopy, was unchanged by mouth opening, being similar in the 5 mouth conditions (P = .999). In addition, ventilation difficulties (abnormal capnograph curves or inadequate tidal volume) occurred in 2 of 15 patients (13%) and 7 of 15 patients (53%) (P < .001) with the mouth opening of 4 and 5 cm, respectively. This study showed that a mouth opening over 4 cm led to substantial increases in oropharyngeal leak pressure and intracuff pressure of the LMA, warranting caution, because gastric insufflation, sore throat, and ventilation difficulties may occur. A mouth opening of 3 cm achieves acceptable airway conditions for anesthetized patients requiring LMA. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

Effects of L-methamphetamine treatment on cocaine- and food-maintained behavior in rhesus monkeys.

PubMed

Kohut, Stephen J; Bergman, Jack; Blough, Bruce E

2016-03-01

Monoamine releasers with prominent dopaminergic actions, e.g., D-methamphetamine (D-MA), significantly reduce cocaine use and craving in clinical and preclinical laboratory studies. However, D-MA and related drugs also display high abuse potential, which limits their acceptability as agonist replacement medications for the management of Cocaine Use Disorder. The L-isomer of methamphetamine (L-MA), unlike D-MA, has preferential noradrenergic actions and is used medicinally with low, if any, abuse liability. The present study was conducted to determine whether L-MA could serve as an agonist replacement medication by both mimicking interoceptive effects of cocaine and decreasing intravenous (IV) cocaine self-administration. Separate groups (N = 4-5) of rhesus monkeys were studied to determine whether L-MA could (1) substitute for cocaine in subjects that discriminated intramuscular (IM) cocaine (0.4 mg/kg) from saline and (2) decrease IV cocaine self-administration under a second-order FR2(VR16:S) schedule of reinforcement. L-MA, like D-MA but with approximately 5-fold lesser potency, substituted for cocaine in drug discrimination experiments in a dose-dependent manner. In IV self-administration studies, 5-10-day treatments with continuously infused L-MA (0.032-0.32 mg/kg/h, IV) dose-dependently decreased cocaine-maintained responding; the highest dosage reduced cocaine intake to levels of saline self-administration without appreciable effects on food-maintained responding. These results indicate that L-MA both shares discriminative stimulus effects with cocaine and reduces cocaine self-administration in a behaviorally selective manner. L-MA and other compounds with a similar pharmacological profile deserve further evaluation for the management of Cocaine Use Disorder.

A training program for novice paramedics provides initial laryngeal mask airway insertion skill and improves skill retention at 6 months.

PubMed

Hein, Cindy; Owen, Harry; Plummer, John

2010-02-01

Major resuscitation councils endorse the use of the laryngeal mask airway (LMA) by paramedics for lifesaving airway interventions. Learning and maintaining adequate skill level is important for patient safety. The aim of this project was to develop a training program that provides student paramedics with initial knowledge and experience in LMA insertion skills but equally important to provide ongoing skill retention. After ethics approval and informed consent, 55 first year Paramedic degree students watched a manufacturer's LMA instruction video and practiced insertion in three different part task trainers. Six months later, subjects were randomized to an intervention (reviewing the video and 10 minutes unsupervised practice) or control group before participating in a high-fidelity simulated clinical scenario. For equity of training, the control group received the intervention after the scenario. Main outcomes measured were time to insertion; success rate; and LMA skill retention (sum of LMA orientation; cuff inflation; bite block; securing; patient positioning; and overall subject performance). Fifty subjects completed the study. Those in the intervention group displayed significantly shorter insertion times (P = 0.029), fewer attempts to achieve success (P = 0.033), and had significantly higher LMA skill performance levels (P = 0.019) at 6 months. We devised a short intervention based on our training program using a video and practice in part task trainers. In an assessment using high-fidelity simulation, we demonstrated significant improvements in maintenance of LMA insertion skills in student paramedics at 6 months. Our model of just-in-time assessment and reinforcement of training prevents skill decay and has implications for healthcare skills training in general.

Effects of l-methamphetamine treatment on cocaine- and food-maintained behavior in rhesus monkeys

PubMed Central

Kohut, Stephen J.; Bergman, Jack; Blough, Bruce E.

2015-01-01

Rationale Monoamine releasers with prominent dopaminergic actions, e.g., d-methamphetamine (d-MA), significantly reduce cocaine use and craving in clinical and preclinical laboratory studies. However, d-MA and related drugs also display high abuse potential, which limits their acceptability as agonist replacement medications for the management of Cocaine Use Disorder. Objectives The l-isomer of methamphetamine (l-MA), unlike d-MA, has preferential noradrenergic actions and is used medicinally with low, if any, abuse liability. The present study was conducted to determine whether l-MA could serve as an agonist replacement medication by both mimicking interoceptive effects of cocaine and decreasing intravenous (IV) cocaine self-administration. Methods Separate groups (N=4-5) of rhesus monkeys were studied to determine whether l-MA could (1) substitute for cocaine in subjects that discriminated intramuscular (IM) cocaine (0.4 mg/kg) from saline and, (2) decrease IV cocaine self-administration under a second-order FR2(VR16:S) schedule of reinforcement. Results l-MA, like d-MA but with approximately 5-fold lesser potency, substituted for cocaine in drug discrimination experiments in a dose-dependent manner. In IV self-administration studies, 5-10 day treatments with continuously infused l-MA (0.032-0.32 mg/kg/hr, IV) dose-dependently decreased cocaine-maintained responding; the highest dosage reduced cocaine intake to levels of saline self-administration without appreciable effects on food-maintained responding. Conclusions These results indicate that l-MA both shares discriminative-stimulus effects with cocaine and reduces cocaine self-administration in a behaviorally selective manner. l-MA and other compounds with a similar pharmacological profile deserve further evaluation for the management of Cocaine Use Disorder. PMID:26713332

Amphiphilic HPMA-LMA copolymers increase the transport of Rhodamine 123 across a BBB model without harming its barrier integrity.

PubMed

Hemmelmann, Mirjam; Metz, Verena V; Koynov, Kaloian; Blank, Kerstin; Postina, Rolf; Zentel, Rudolf

2012-10-28

The successful non-invasive treatment of diseases associated with the central nervous system (CNS) is generally limited by poor brain permeability of various developed drugs. The blood-brain barrier (BBB) prevents the passage of therapeutics to their site of action. Polymeric drug delivery systems are promising solutions to effectively transport drugs into the brain. We recently showed that amphiphilic random copolymers based on the hydrophilic p(N-(2-hydroxypropyl)-methacrylamide), pHPMA, possessing randomly distributed hydrophobic p(laurylmethacrylate), pLMA, are able to mediate delivery of domperidone into the brain of mice in vivo. To gain further insight into structure-property relations, a library of carefully designed polymers based on p(HPMA) and p(LMA) was synthesized and tested applying an in vitro BBB model which consisted of human brain microvascular endothelial cells (HBMEC). Our model drug Rhodamine 123 (Rh123) exhibits, like domperidone, a low brain permeability since both substances are recognized by efflux transporters at the BBB. Transport studies investigating the impact of the polymer architecture in relation to the content of hydrophobic LMA revealed that random p(HPMA)-co-p(LMA) having 10mol% LMA is the most auspicious system. The copolymer significantly increased the permeability of Rh123 across the HBMEC monolayer whereas transcytosis of the polymer was very low. Further investigations on the mechanism of transport showed that integrity and barrier function of the BBB model were not harmed by the polymer. According to our results, p(HPMA)-co-p(LMA) copolymers are a promising delivery system for neurological therapeutics and their application might open alternative treatment strategies. Copyright © 2012 Elsevier B.V. All rights reserved.

The relationship of placement accuracy and insertion times for the laryngeal mask airway to the training of inexperienced dental students.

PubMed

Morse, Zac; Sano, Kimito; Kageyama, Ikuo; Kanri, Tomio

2002-01-01

Any health care professional can be faced with a medical emergency in which the patient needs ventilatory support. Bag-valve-mask ventilation with the assistance of an oropharyngeal airway that uses 100% oxygen is currently the preferred method for artificial ventilation. This procedure is generally performed ineffectively by most dentists inexperienced in airway management. We examined whether a short and simple period of training by dental students inexperienced in airway management would increase the speed and accuracy of the placement of the laryngeal mask airway (LMA), which may be a superior airway device to the bag-valve-mask and oropharyngeal airway. Thirty-five dental students inexperienced in airway management were divided into 3 groups. The first group received only a demonstration on how to use the LMA. The second and third groups received the demonstration plus practiced inserting the LMA 5 and 10 times, respectively. A dental anesthesiologist graded the placement of the LMA with a tracheobroncho-fiberscope (fiberoptic bronchoscope). Those who practiced inserting the LMA 5 times faired better than those who received no training; however, those who practiced 10 times did not do any better than the second group. The LMA can be inserted rapidly and effectively by dentists inexperienced in airway management after a short period of simple training that may be critical when personnel experienced in intubation are not readily available.

Cost-effective handoff scheme based on mobility-aware dual pointer forwarding in proxy mobile IPv6 networks.

PubMed

Son, Seungsik; Jeong, Jongpil

2014-01-01

In this paper, a mobility-aware Dual Pointer Forwarding scheme (mDPF) is applied in Proxy Mobile IPv6 (PMIPv6) networks. The movement of a Mobile Node (MN) is classified as intra-domain and inter-domain handoff. When the MN moves, this scheme can reduce the high signaling overhead for intra-handoff/inter-handoff, because the Local Mobility Anchor (LMA) and Mobile Access Gateway (MAG) are connected by pointer chains. In other words, a handoff is aware of low mobility between the previously attached MAG (pMAG) and newly attached MAG (nMAG), and another handoff between the previously attached LMA (pLMA) and newly attached LMA (nLMA) is aware of high mobility. Based on these mobility-aware binding updates, the overhead of the packet delivery can be reduced. Also, we analyse the binding update cost and packet delivery cost for route optimization, based on the mathematical analytic model. Analytical results show that our mDPF outperforms the PMIPv6 and the other pointer forwarding schemes, in terms of reducing the total cost of signaling.

Comparative life cycle assessment of disposable and reusable laryngeal mask airways.

PubMed

Eckelman, Matthew; Mosher, Margo; Gonzalez, Andres; Sherman, Jodi

2012-05-01

Growing awareness of the negative impacts from the practice of health care on the environment and public health calls for the routine inclusion of life cycle criteria into the decision-making process of device selection. Here we present a life cycle assessment of 2 laryngeal mask airways (LMAs), a one-time-use disposable Unique™ LMA and a 40-time-use reusable Classic™ LMA. In life cycle assessment, the basis of comparison is called the "functional unit." For this report, the functional unit of the disposable and reusable LMAs was taken to be maintenance of airway patency by 40 disposable LMAs or 40 uses of 1 reusable LMA. This was a cradle-to-grave study that included inputs and outputs for the manufacture, transport, use, and waste phases of the LMAs. The environmental impacts of the 2 LMAs were estimated using SimaPro life cycle assessment software and the Building for Environmental and Economic Sustainability impact assessment method. Sensitivity and simple life cycle cost analyses were conducted to aid in interpretation of the results. The reusable LMA was found to have a more favorable environmental profile than the disposable LMA as used at Yale New Haven Hospital. The most important sources of impacts for the disposable LMA were the production of polymers, packaging, and waste management, whereas for the reusable LMA, washing and sterilization dominated for most impact categories. The differences in environmental impacts between these devices strongly favor reusable devices. These benefits must be weighed against concerns regarding transmission of infection. Health care facilities can decrease their environmental impacts by using reusable LMAs, to a lesser extent by selecting disposable LMA models that are not made of certain plastics, and by ordering in bulk from local distributors. Certain practices would further reduce the environmental impacts of reusable LMAs, such as increasing the number of devices autoclaved in a single cycle to 10 (-25% GHG emissions) and improving the energy efficiency of the autoclaving machines by 10% (-8% GHG emissions). For both environmental and cost considerations, management and operating procedures should be put in place to ensure that reusable LMAs are not discarded prematurely.

Techniques for the insertion of the ProSeal laryngeal mask airway: comparison of the Foley airway stylet tool with the introducer tool in a prospective, randomized study.

PubMed

Chen, Mao-Kai; Hsu, Hung-Te; Lu, I-Cheng; Shih, Chih-Kai; Shen, Ya-Chun; Tseng, Kuang-Yi; Cheng, Kuang-I

2014-01-01

Many tools have been developed to facilitate the insertion of the ProSeal laryngeal mask airway (LMA) insertion, which can be impeded by folding of its soft cuff. The aim of this study was to compare the efficiency of ProSeal LMA insertion guided by a soft, direct optical Foley Airway Stylet Tool (FAST) with the standard introducer tool (IT). One hundred sixty patients undergoing general anesthesia using the ProSeal LMA as an airway management device were randomly allocated to either FAST-guided or IT-assisted groups. Following ProSeal LMA insertion, the glottic and esophageal openings were identified using a fiberoptic bronchoscope introduced through the airway and the drain tube. The primary outcomes were time taken to insert the ProSeal LMA and the success rate at the first attempt. Secondary end points included ease of insertion, hemodynamic response to insertion, and postoperative adverse events recorded in the recovery room and on the first postoperative morning. One hundred forty patients were included in the final analysis: 66 in the FAST-guided group and 74 in the IT-assisted group. The success rate of FAST device-guided ProSeal LMA insertion (95.7%) was broadly comparable with IT-assisted insertion (98.7%). However, the time taken to insert the ProSeal LMA was significantly longer when the FAST technique was used (p <0.001). The incidence of correct alignment of the airway tube and the drain tube did not differ significantly between the groups. There were no significant differences in ease of insertion or hemodynamic responses to insertion, except that the incidence of postoperative sore throat was significantly higher in the FAST group on the first postoperative day (22.2% compared with 6.8% in the IT group; p = 0.035). Both FAST-guided and IT-assisted techniques achieved correct ProSeal LMA positioning, but the IT technique was significantly quicker and less likely to cause a sore throat. ClinicalTrials.gov Identifier: NCT02048657.

The Relationship Between Nuclear DNA Content and Leaf Strategy in Seed Plants

PubMed Central

MORGAN, HUW D.; WESTOBY, MARK

2005-01-01

• Background and Aims Species' 2C-values (mass of DNA in G1 phase 2n nuclei) vary by at least four orders of magnitude among seed plants. The 2C-value has been shown to be co-ordinated with a number of other species traits, and with environmental variables. A prediction that species 2C-values are negatively related to leaf life span (LL) and leaf mass per area (LMA) is tested. These leaf traits are components of a major dimension of ecological variation among plant species. • Methods Flow cytometry was used to measure the 2C-values for 41 Australian seed plant species, 40 of which were new to the literature. Where possible, LL and LMA data from the global literature were combined with 2C-values from our data set and online C-value databases. • Key Results Across all species, weak positive relationships were found between 2C-values and both LL and LMA; however, these did not reflect the relationships within either angiosperms or gymnosperms. Across 59 angiosperm species, there were weak negative relationships between 2C-values and both LL (r2 = 0·13, P = 0·005) and LMA (r2 = 0·15, P = 0·002). These relationships were the result of shifts to longer LL and greater LMA in woody compared with herbaceous growth forms, with no relationships present within growth forms. It was not possible to explain a positive relationship between 2C-values and LMA (r2 = 0·30, P = 0·024) across 17 gymnosperm species. The 2C-value was not related to LL or LMA either across species within orders (except for LMA among Pinales), or as radiation divergences in a model phylogeny. • Conclusions Gymnosperms appear to vary along a spectrum different from angiosperms. Among angiosperms, weak negative cross-species relationships were associated with growth form differences, and traced to a few divergences deep in the model phylogeny. These results suggest that among angiosperms, nuclear DNA content and leaf strategy are unrelated. PMID:16230323

The pectic disaccharides lepidimoic acid and β-d-xylopyranosyl-(1→3)-d-galacturonic acid occur in cress-seed exudate but lack allelochemical activity

PubMed Central

Iqbal, Amjad; Miller, Janice G.; Murray, Lorna; Sadler, Ian H.; Fry, Stephen C.

2016-01-01

Background and aims Cress-seed (Lepidium sativum) exudate exerts an allelochemical effect, promoting excessive hypocotyl elongation and inhibiting root growth in neighbouring Amaranthus caudatus seedlings. We investigated acidic disaccharides present in cress-seed exudate, testing the proposal that the allelochemical is an oligosaccharin—lepidimoic acid (LMA; 4-deoxy-β-l-threo-hex-4-enopyranuronosyl-(1→2)-l-rhamnose). Methods Cress-seed exudate was variously treated [heating, ethanolic precipitation, solvent partitioning, high-voltage paper electrophoresis and gel-permeation chromatography (GPC)], and the products were bioassayed for effects on dark-grown Amaranthus seedlings. Two acidic disaccharides, including LMA, were isolated and characterized by electrophoresis, thin-layer chromatography (TLC) and nuclear magnetic resonance (NMR) spectroscopy, and then bioassayed. Key Results Cress-seed exudate contained low-Mr, hydrophilic, heat-stable material that strongly promoted Amaranthus hypocotyl elongation and inhibited root growth, but that separated from LMA on electrophoresis and GPC. Cress-seed exudate contained ∼250 µm LMA, whose TLC and electrophoretic mobilities, susceptibility to mild acid hydrolysis and NMR spectra are reported. A second acidic disaccharide, present at ∼120 µm, was similarly characterized, and shown to be β-d-xylopyranosyl-(1→3)-d-galacturonic acid (Xyl→GalA), a repeat unit of xylogalacturonan. Purified LMA and Xyl→GalA when applied at 360 and 740 µm, respectively, only slightly promoted Amaranthus hypocotyl growth, but equally promoted root growth and thus had no effect on the hypocotyl:root ratio, unlike total cress-seed exudate. Conclusions LMA is present in cress seeds, probably formed by rhamnogalacturonan lyase action on rhamnogalacturonan-I during seed development. Our results contradict the hypothesis that LMA is a cress allelochemical that appreciably perturbs the growth of potentially competing seedlings. Since LMA and Xyl→GalA slightly promoted both hypocotyl and root elongation, their effect could be nutritional. We conclude that rhamnogalacturonan-I and xylogalacturonan (pectin domains) are not sources of oligosaccharins with allelochemical activity, and the biological roles (if any) of the disaccharides derived from them are unknown. The main allelochemical principle in cress-seed exudate remains to be identified. PMID:26957370

[Comparison of jaw thrust and trapezius squeezing test as indicators for laryngeal mask airway insertion in infants and young children].

PubMed

Liu, J Z; Zhao, J; Zhang, Y J

2016-02-01

To compare the effectiveness of the jaw thrust and the trapezius squeezing test(TST) for laryngeal mask airway (LMA) insertion in infants and children under sevoflurane anesthesia. A total of 100 children aged from 6 month to 3 years, American Society of Anesthesiologists(ASA) Ⅰ-Ⅱ and undergoing minor operation were enrolled from January to June 2015 in Tianjin Children's Hospital. The patients were randomly divided into jaw thrusting group (Group J, n=50)and trapezius squeezing group(Group T, n=50). Anesthesia was induced with sevoflurane. When children's eyelash reflex lose, jaw thrust/trapezius squeeze was applied every 15 seconds.It's considered that the depth of anesthesia was not enough, and test reaction was positive if any movements of body, limbs or toes were found at the point of test. Sevoflurane should be keep on inhalation until negative test reaction was appeared. Then LMA was inserted immediately.The time required for the negative test, end-tidal sevoflurane concentrations (ETsev), the index of Narcotrend anesthesia monitor(NT), the occurrence of gross purposeful movements, coughing, gagging, breath-holding, laryngospasm or an SpO2 < 90% during LMA insertion in two groups of patients were observed and recorded. The condition of LMA insertion and the rate of successful insertion were evaluated. The blood pressure(BP), heart rate(HR) and SpO2 were also recorded before and after LMA insertion. In group J and group T, the time required for the negative test was (2.31±1.03) vs (2.85±0.97)min(t=-2.462, P<0.05), ETsev was(3.25±1.02)% vs (3.81±0.87) %(t=-2.361, P<0.05), the depth of anesthesia NT index was(50.41±5.38) vs (41.32±4.92)(t=3.021, all P<0.05). All of above results were significantly different. The successful rate of the first attempt LMA insertion was 78% vs 100%(χ(2)=12.36 , P<0.01), respectively. The differences had statistical significance. The conditions of LMA insertion in group T were superior to those in group J. The incidences of gross purposeful movements, coughing, gagging, breath-holding and SpO2<90% during LMA insertion in group J were 20%, 16%, 10%, 14% and 8%, which were higher than those in group T (2%, 2%, 0, 2%, 0), the differences were significant(χ(2)=8.27, 5.98, 5.26, 4.89, 4.17, all P<0.05). No significant change in blood pressure, heart rate and SpO2 were found before and after inserting LMA in two groups. The trapezius squeezing test is a superior indicator of adequate condition for LMA insertion compared to the jaw thrust in infants and young children under sevoflurane anesthesia.

Canopy gradients in leaf functional traits for species that differ in growth strategies and shade tolerance.

PubMed

Coble, Adam P; Fogel, Marilyn L; Parker, Geoffrey G

2017-10-01

In temperate deciduous forests, vertical gradients in leaf mass per area (LMA) and area-based leaf nitrogen (Narea) are strongly controlled by gradients in light availability. While there is evidence that hydrostatic constraints on leaf development may diminish LMA and Narea responses to light, inherent differences among tree species may also influence leaf developmental and morphological response to light. We investigated vertical gradients in LMA, Narea and leaf carbon isotope composition (δ13C) for three temperate deciduous species (Carpinus caroliniana Walter, Fagus grandifolia Ehrh., Liriodendron tulipifera L.) that differed in growth strategy (e.g., indeterminate and determinate growth), shade tolerance and leaf area to sapwood ratio (Al:As). Leaves were sampled across a broad range of light conditions within three vertical layers of tree crowns to maximize variation in light availability at each height and to minimize collinearity between light and height. All species displayed similar responses to light with respect to Narea and δ13C, but not for LMA. Light was more important for gradients in LMA for the shade-tolerant (C. caroliniana) and -intolerant (L. tulipifera) species with indeterminate growth, and height (e.g., hydrostatic gradients) and light were equally important for the shade-tolerant (F. grandifolia) species with determinate growth. Fagus grandifolia had a higher morphological plasticity in response to light, which may offer a competitive advantage in occupying a broader range of light conditions throughout the canopy. Differences in responses to light and height for the taller tree species, L. tulipifera and F. grandifolia, may be attributed to differences in growth strategy or Al:As, which may alter morphological and functional responses to light availability. While height was important in F. grandifolia, height was no more robust in predicting LMA than light in any of the species, confirming the strong role of light availability in determining LMA for temperate deciduous species. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Comparison of the Ambu AuraFlex with the laryngeal mask airway Flexible: a manikin study.

PubMed

Sanuki, Takuro; Nakatani, Gosuke; Sugioka, Shingo; Daigo, Erina; Kotani, Junichiro

2011-07-01

The present study compared the Ambu AuraFlex and the laryngeal mask airway (LMA) Flexible with regard to time required for and success rates of insertion on a manikin by dental students who had never used an LMA. In addition, participants' views on ease of insertion of each device were surveyed. Subjects consisted of 30 dental students who inserted each airway device in a manikin. The time required for and success rates of insertion were measured. Subjects were then asked to rate the ease of insertion of each device using the 100-mm visual analog scale (from 0 mm = extremely easy to 100 mm = extremely difficult). Insertion time was shorter with the Ambu AuraFlex (26.6 ± 7.1 seconds) than with the LMA Flexible (30.3 ± 6.8 seconds; P = .045). The rate of successful insertion using the Ambu AuraFlex (28 of 30 attempts, 93.3%) was greater than that with the LMA Flexible (23 of 30 attempts, 76.7%), although the difference was not statistically significant (P = .145). Ambu AuraFlex insertion was considered less difficult (median, 41 mm; 10th to 90th percentiles, 18 to 78 mm) than LMA Flexible insertion (60 mm; 42 to 82 mm; P = .004), as rated using the 100-mm visual analog scale. The Ambu AuraFlex appears to be useful for inexperienced users because it enables quicker and easier insertion than the LMA Flexible. Copyright © 2011 American Association of Oral and Maxillofacial Surgeons. Published by Elsevier Inc. All rights reserved.

The New Perilaryngeal Airway (CobraPLA™)1 Is as Efficient as the Laryngeal Mask Airway (LMA™)2, But Provides Better Airway Sealing Pressures

PubMed Central

Akça, Ozan; Wadhwa, Anupama; Sengupta, Papiya; Durrani, Jaleel; Hanni, Keith; Wenke, Mary; Yücel, Yüksel; Lenhardt, Rainer; Doufas, Anthony G.; Sessler, Daniel I.

2006-01-01

The Laryngeal Mask Airway (LMA) is a frequently-used efficient airway device, yet it sometimes seals poorly, thus reducing the efficacy of positive-pressure ventilation. The Perilaryngeal Airway (CobraPLA) is a novel airway device with a larger pharyngeal cuff (when inflated). We tested the hypothesis that the CobraPLA was superior to LMA with regard to insertion time and airway sealing pressure and comparable to LMA in airway adequacy and recovery characteristics. After midazolam and fentanyl, 81 ASA I-II outpatients having elective surgery were randomized to receive an LMA or CobraPLA. Anesthesia was induced with propofol (2.5 mg/kg, IV), and the airway inserted. We measured 1) insertion time; 2) adequacy of the airway (no leak at 15-cm-H2O peak pressure or tidal volume of 5 ml/kg); 3) airway sealing pressure; 4) number of repositioning attempts; and 5) sealing quality (no leak at tidal volume of 8 ml/kg). At the end of surgery, gastric insufflation, postoperative sore throat, dysphonia, and dysphagia were evaluated. Data were compared with unpaired t-tests, chi-square tests, or Fisher’s Exact tests; P<0.05 was significant. Patient characteristics, insertion times, airway adequacy, number of repositioning attempts, and recovery were similar in each group. Airway sealing pressure was significantly greater with CobraPLA (23±6 cm H2O) than LMA (18±5 cm H2O, P<0.001). The CobraPLA has insertion characteristics similar to LMA, but better airway sealing capabilities. PMID:15281543

Scaling, propagating and mapping uncertainty in spectroscopy-derived foliar traits from the leaf to the image

NASA Astrophysics Data System (ADS)

Singh, A.; Serbin, S. P.; Kingdon, C.; Townsend, P. A.

2013-12-01

A major goal of remote sensing, and imaging spectroscopy in particular, is the development of generalizable algorithms to repeatedly and accurately map ecosystem properties such as canopy chemistry across space and time. Existing methods must therefore be tested across a range of measurement approaches to identify and overcome limits to the consistent retrieval of such properties from spectroscopic imagery. Here we illustrate a general approach for the estimation of key foliar biochemical and morphological traits from spectroscopic imagery derived from the AVIRIS instrument and the propagation of errors from the leaf to the image scale using partial least squares regression (PLSR) techniques. Our method involves the integration of three types of data representing different scales of observation: At the image scale, the images were normalized for atmospheric, illumination and BRDF effects. Spectra from field plot locations were extracted from the 51AVIRIS images and were averaged when the field plot was larger than a single pixel. At the plot level, the scaling was conducted using multiple replicates (1000) derived from the leaf-level uncertainty estimates to generate plot-level estimates with their associated uncertainties. Leaf-level estimates of foliar traits (%N, %C, %Fiber, %Cellulose, %Lignin, LMA) were scaled to the canopy based on relative species composition of each plot. Image spectra were iteratively split into 50/50 randomized calibration-validation datasets and multiple (500) trait-predictive PLSR models were generated, this time sampling from within the plot-level uncertainty distribution. This allowed the propagation of uncertainty from the leaf-level dependent variables to the plot level, and finally to models built using AVIRIS image spectra. Moreover, this method allows us to generate spatially explicit maps of uncertainty in our sampled traits. Both LMA and %N PLSR models had a R2 greater than 0.8, root mean square errors (RMSEs) for both variables were less than 6% of the range of data. Fiber and lignin were predicted with R2 > 0.65 and carbon and cellulose greater than 0.5. Although R2 of these variables were lower than LMA and %N, their RMSE values were beneath 9% of the range of data. The comparatively lower R2 values for %C and cellulose in particular were related to the low amount of natural variability in these constituents. Further, coefficients from the randomized set of PLSR models were applied to imagery and aggregated to obtain pixel-wise predicted means and uncertainty estimates for each foliar trait. The resulting maps of nutritional and morphological properties together with their overall uncertainties represent a first-of-its-kind data product for examining the spatio-temporal patterns of forest functioning and nutrient cycling. These data are now being used to relate foliar traits with ecosystem processes such as streamwater nutrient export and insect herbivory. In addition, the ability to assign a retrieval uncertainty enables more efficient assimilation of these data products into ecosystem models to help constrain carbon and nutrient cycling projections.

A 2000 year varve-based climate record from the central Brooks Range, Alaska

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

Bird, BW; Abbott, MB; Finney, BP

Varved minerogenic sediments from glacial-fed Blue Lake, northern Alaska, are used to investigate late Holocene climate variability. Varve-thickness measurements track summer temperature recorded at Atigun Pass, located 41 km east at a similar elevation (r (2) = 0.31, P = 0.08). Results indicate that climate in the Brooks Range from 10 to 730 AD (varve year) was warm with precipitation inferred to be higher than during the twentieth century. The varvetemperature relationship for this period was likely compromised and not used in our temperature reconstruction because the glacier was greatly reduced, or absent, exposing sub-glacial sediments to erosion from enhancedmore » precipitation. Varve-inferred summer temperatures and precipitation decreased after 730 AD, averaging 0.4A degrees C above the last millennial average (LMA = 4.2A degrees C) from 730 to 850 AD, and 0.1A degrees C above the LMA from 850 to 980 AD. Cooling culminated between 980 and 1030 AD with temperatures 0.7A degrees C below the LMA. Varve-inferred summer temperatures increased between 1030 and 1620 AD to the LMA, though the period between 1260 and 1350 AD was 0.2A degrees C below the LMA. Although there is no equivalent to the European Medieval Warm Period in the Blue Lake record, two warm intervals occurred from 1350 to 1450 AD and 1500 to 1620 AD (0.4 and 0.3A degrees C above the LMA, respectively). During the Little Ice Age (LIA; 1620 to 1880 AD), inferred summer temperature averaged 0.2A degrees C below the LMA. After 1880 AD, inferred summer temperature increased to 0.8A degrees C above the LMA, glaciers retreated, but aridity persisted based on a number of regional paleoclimate records. Despite warming and glacial retreat, varve thicknesses have not achieved pre-730 AD levels. This reflects limited sediment availability and transport due to a less extensive retreat compared to the first millennium, and continued relative aridity. Overall, the Blue Lake record is similar to varve records from the eastern Canadian Arctic that document a cool LIA and twentieth century warming. However, the occurrence and timing of events, such as the LIA and Medieval Warm Period, varies considerably among records, suggesting heterogeneous climatic patterns across the North American Arctic.« less

Evaluation of Columbia, USMARC Composite, Suffolk, and Texel rams as terminal sires in an extensive rangeland production system: VII. Accuracy of ultrasound predictors and their association with carcass weight, yield, and value.

PubMed

Notter, D R; Mousel, M R; Leeds, T D; Zerby, H N; Moeller, S J; Lewis, G S; Taylor, J B

2014-06-01

Use of lamb BW or chilled carcass weights (CCW), live-animal ultrasound or direct carcass measurements of backfat thickness (BF; mm) and LM area (LMA; cm(2)), and carcass body wall thickness (BWall; mm) to predict carcass yield and value was evaluated using 512 crossbred lambs produced over 3 yr by mating Columbia, U.S. Meat Animal Research Center Composite, Suffolk, and Texel rams to adult Rambouillet ewes. Lambs were harvested at 3 BW endpoints within each year. The predictive value of 3 to 5 additional linear measurements of live-animal or carcass size and shape was also evaluated. Residual correlations (adjusted for effects of year, breed, and harvest group) between ultrasound and direct measurements were 0.69 for BF and 0.65 for LMA. Increasing ultrasound or carcass LMA had positive effects (P < 0.001) on yield of chilled carcass (i.e., on dressing percentage) and, at comparable CCW, on weight of high-value cuts (rack, loin, leg, and sirloin) before trimming (HVW), weight of trimmed high-value cuts (trimmed rack and loin and trimmed boneless leg and sirloin; TrHVW), and carcass value before (CVal) and after (TrCVal) trimming of high-value cuts. By contrast, ultrasound and direct measures of BF had positive effects on yields of CCW and on HVW and CVal but large negative effects on TrHVW and TrCVal. After adjusting for BW at scanning, increases of 1 mm in ultrasound BF or 1 cm(2) in ultrasound LMA were associated with changes of US$-0.32 (P < 0.10) and $1.62 (P < 0.001), respectively, in TrCVal. Carcass BWall was generally superior to carcass BF as a predictor of TrHVW and TrCVal. Carcass LMA was superior to ultrasound LMA but carcass BF was inferior to ultrasound BF for prediction of carcass yield and value. Increasing LMA thus would be expected to improve carcass yield and value. Addition of linear measurements of live-animal or carcass size and shape to the prediction model reduced residual SD (RSD) for TrHVW and TrCVal by 0.4 to 2.2%, but subsequent removal of ultrasound or direct measures of BF and LMA from the prediction model increased RSD by 7.4 to 12.2%. Measurements of CCW, LMA, BF, and BWall would thus be appropriate to support programs for value-based marketing of lamb carcasses and are superior to systems based only on measurements of size and shape in unribbed carcasses.

Low muscle attenuation is a prognostic factor for survival in metastatic breast cancer patients treated with first line palliative chemotherapy.

PubMed

Rier, Hánah N; Jager, Agnes; Sleijfer, Stefan; van Rosmalen, Joost; Kock, Marc C J M; Levin, Mark-David

2017-02-01

Low muscle mass (LMM) and low muscle attenuation (LMA) reflect low muscle quantity and low muscle quality, respectively. Both are associated with a poor outcome in several types of solid malignancies. This study determined the association of skeletal muscle measures with overall survival (OS) and time to next treatment (TNT). A skeletal muscle index (SMI) in cm 2 /m 2 and muscle attenuation (MA) in Hounsfield units (HU) were measured using abdominal CT-images of 166 patients before start of first-line chemotherapy for metastatic breast cancer. Low muscle mass (SMI <41 cm 2 /m 2 ), sarcopenic obesity (LMM and BMI ≥30 kg/m 2 ) and low muscle attenuation (MA <41 HU and BMI <25 kg/m2 or MA <33 HU and BMI ≥25 kg/m2) were related to OS and TNT. The prevalence of LMM, sarcopenic obesity and LMA were 66.9%, 7.2% and 59.6% respectively. LMM and sarcopenic obesity showed no significant association with OS and TNT, whereas LMA was associated with both lower OS (HR 2.04, 95% CI 1.34-3.12, p = 0.001) and shorter TNT (HR 1.72, 95% CI 1.14-2.62, p = 0.010). Patients with LMA had a median OS and TNT of 15 and 8 months respectively, compared to 23 and 10 months in patients with normal MA. LMA is a prognostic factor for OS and TNT in metastatic breast cancer patients receiving first-line palliative chemotherapy, whereas LMM and sarcopenic obesity are not. Further research is needed to establish what impact LMA should have in daily clinical practice. Copyright © 2016 Elsevier Ltd. All rights reserved.

Comparison of 2 cuff inflation methods of laryngeal mask airway Classic for safe use without cuff manometer in adults.

PubMed

Kim, Min-Soo; Lee, Jeong-Rim; Shin, Yang-Sik; Chung, Ji-Won; Lee, Kyu-Ho; Ahn, Ki Ryang

2014-03-01

This single-center, prospective, randomized, double-blind, 2-arm, parallel group comparison trial was performed to establish whether the adult-sized laryngeal mask airway (LMA) Classic (The Laryngeal Mask Company Ltd, Henley-on-Thames, UK) could be used safely without any consideration of cuff hyperinflation when a cuff of the LMA Classic was inflated using half the maximum inflation volume or the resting volume before insertion of device. Eighty patients aged 20 to 70 years scheduled for general anesthesia using the LMA Classic were included. Before insertion, the cuff was partially filled with half the maximum inflation volume in the half volume group or the resting volume created by opening the pilot balloon valve to equalize with atmospheric pressure in the resting volume group. Several parameters regarding insertion, intracuff pressure, airway leak pressure, and leakage volume/fraction were collected after LMA insertion. The LMA Classic with a partially inflated cuff was successfully inserted in all enrolled patients. Both groups had the same success rate of 95% at the first insertion attempt. The half volume group had a lower mean intracuff pressure compared with the resting volume group (54.5 ± 16.1 cm H2O vs 61.8 ± 16.1 cm H2O; P = .047). There was no difference in airway leak pressure or leakage volume/fraction between the 2 groups under mechanical ventilation. The partially inflated cuff method using half the maximum recommended inflation volume or the resting volume is feasible with the adult-sized LMA Classic, resulting in a high success rate of insertion and adequate range of intracuff pressures. Copyright © 2014 Elsevier Inc. All rights reserved.

The intuitive use of laryngeal airway tools by first year medical students.

PubMed

Bickenbach, Johannes; Schälte, Gereon; Beckers, Stefan; Fries, Michael; Derwall, Matthias; Rossaint, Rolf

2009-09-22

Providing a secured airway is of paramount importance in cardiopulmonary resuscitation. Although intubating the trachea is yet seen as gold standard, this technique is still reserved to experienced healthcare professionals. Compared to bag-valve facemask ventilation, however, the insertion of a laryngeal mask airway offers the opportunity to ventilate the patient effectively and can also be placed easily by lay responders. Obviously, it might be inserted without detailed background knowledge.The purpose of the study was to investigate the intuitive use of airway devices by first-year medical students as well as the effect of a simple, but well-directed training programme. Retention of skills was re-evaluated six months thereafter. The insertion of a LMA-Classic and a LMA-Fastrach performed by inexperienced medical students was compared in an airway model. The improvement on their performance after a training programme of overall two hours was examined afterwards. Prior to any instruction, mean time to correct placement was 55.5 +/- 29.6 s for the LMA-Classic and 38.1 +/- 24.9 s for the LMA-Fastrach. Following training, time to correct placement decreased significantly with 22.9 +/- 13.5 s for the LMA-Classic and 22.9 +/- 19.0 s for the LMA-Fastrach, respectively (p < 0.05). After six months, the results are comparable prior (55.6 +/- 29.9 vs 43.1 +/- 34.7 s) and after a further training period (23.5 +/- 13.2 vs 26.6 +/- 21.6, p < 0.05). Untrained laypersons are able to use different airway devices in a manikin and may therefore provide a secured airway even without having any detailed background knowledge about the tool. Minimal theoretical instruction and practical skill training can improve their performance significantly. However, refreshment of knowledge seems justified after six months.

Effects of adding liquid DL-methionine hydroxy analogue-free acid to drinking water on growth performance and small intestinal morphology of nursery pigs.

PubMed

Kaewtapee, C; Krutthai, N; Poosuwan, K; Poeikhampha, T; Koonawootrittriron, S; Bunchasak, C

2010-06-01

This study was conducted to evaluate the effect of adding liquid DL-methionine hydroxy analogue free acid (LMA) to drinking water on growth performance, small intestinal morphology and volatile fatty acids in the caecum of nursery pigs. Twenty-four crossbred pigs (Large White x Landrace, BW approximately 18 kg) were divided into three groups with four replications of two piglets each. The piglets received drinking water without (control), with 0.05 or 0.10% LMA. The results indicated that adding LMA at 0.10% to drinking water significantly increased their weight gain, average daily feed intake (p < 0.05) and tended to improve the feed conversion ratio. Adding LMA to drinking water significantly increased their water intake and significantly reduced the pH of drinking water (p < 0.01), thus total plate count (p < 0.01) and Escherichia coli in drinking water was reduced (p < 0.05), while the total number of bacteria in the caecum was not significantly affected. Liquid DL-methionine hydroxy analogue free acid supplementation in drinking water tended to decrease pH in the stomach, duodenum, jejunum, colon and rectum. Furthermore, adding LMA at 0.10% significantly increased villous height in the duodenum, jejunum and ileum (p < 0.05), and the villous height:crypt depth ratio in the jejunum and ileum (p < 0.01) was higher, whereas acetic acid concentration in the caecum was significantly lower than in the control group. It could be concluded that adding LMA to drinking water improved growth performance of the nursery pigs because of high water quality and high nutrient utilization caused by an improvement of small intestinal morphology (not from nutritional effect of methionine source).

Does cuff pressure monitoring reduce postoperative pharyngolaryngeal adverse events after LMA-ProSeal insertion? A parallel group randomised trial.

PubMed

Vasanth Karthik, R; Ranganathan, Priya; Kulkarni, Atul P; Sharma, Kailash S

2014-10-01

The incidence of postoperative pharyngolaryngeal complications after laryngeal mask airway (LMA) insertion can be as high as 50%. Over-inflation of the LMA cuff may be a causal factor. We conducted a single-centre parallel group randomised trial to determine whether maintaining LMA-ProSeal intra-cuff pressures below 60 cm H2O decreases postoperative pharyngolaryngeal complications. We recruited 120 adult patients who were scheduled to undergo elective surgery under general anaesthesia. Appropriate sized LMA-ProSeal was inserted and the cuff was inflated with air (to no more than the maximum recommended volume) until there was no audible leak. Patients were randomised to either the control group (n = 60), where the intra-cuff pressure was noted and no further action was taken, or to the pressure-monitored group (n = 60), where intra-cuff pressure was maintained below 60 cm H2O. Pharyngolaryngeal complications consisting of sore throat, dysphonia and dysphagia were assessed at 1, 2, and 24 h postoperatively. Patients, anaesthesiologists and assessors were blinded to group allocation. The primary outcome was a composite endpoint of any pharyngolaryngeal complication at any of the three time points. Secondary outcomes were the incidence of individual outcomes at each time point. The incidence of pharyngolaryngeal complications at any time point was 42% in the routine care group and 32% in the pressure-monitored group (95% CI for difference +28 to -7%, p = 0.26). There was no difference between groups for any of the secondary outcomes. Our study failed to demonstrate a statistically significant reduction in postoperative pharyngolaryngeal complications by limiting intra-cuff pressures in the LMA-Proseal.

Genome size evolution in relation to leaf strategy and metabolic rates revisited.

PubMed

Beaulieu, Jeremy M; Leitch, Ilia J; Knight, Charles A

2007-03-01

It has been proposed that having too much DNA may carry physiological consequences for plants. The strong correlation between DNA content, cell size and cell division rate could lead to predictable morphological variation in plants, including a negative relationship with leaf mass per unit area (LMA). In addition, the possible increased demand for resources in species with high DNA content may have downstream effects on maximal metabolic efficiency, including decreased metabolic rates. Tests were made for genome size-dependent variation in LMA and metabolic rates (mass-based photosynthetic rate and dark respiration rate) using our own measurements and data from a plant functional trait database (Glopnet). These associations were tested using two metrics of genome size: bulk DNA amount (2C DNA) and monoploid genome size (1Cx DNA). The data were analysed using an evolutionary framework that included a regression analysis and independent contrasts using a phylogenetic tree with estimates of molecular diversification times. A contribution index for the LMA data set was also calculated to determine which divergences have the greatest influence on the relationship between genome size and LMA. A significant negative association was found between bulk DNA amount and LMA in angiosperms. This was primarily a result of influential divergences that may represent early shifts in growth form. However, divergences in bulk DNA amount were positively associated with divergences in LMA, suggesting that the relationship may be indirect and mediated through other traits directly related to genome size. There was a significant negative association between genome size and metabolic rates that was driven by a basal divergence between angiosperms and gymnosperms; no significant independent contrast results were found. Therefore, it is concluded that genome size-dependent constraints acting on metabolic efficiency may not exist within seed plants.

How do different brands of size 1 laryngeal mask airway compare with face mask ventilation in a dedicated laryngeal mask airway teaching manikin?

PubMed

Tracy, Mark Brian; Priyadarshi, Archana; Goel, Dimple; Lowe, Krista; Huvanandana, Jacqueline; Hinder, Murray

2018-05-01

International neonatal resuscitation guidelines recommend the use of laryngeal mask airway (LMA) with newborn infants (≥34 weeks' gestation or >2 kg weight) when bag-mask ventilation (BMV) or tracheal intubation is unsuccessful. Previous publications do not allow broad LMA device comparison. To compare delivered ventilation of seven brands of size 1 LMA devices with two brands of face mask using self-inflating bag (SIB). 40 experienced neonatal staff provided inflation cycles using SIB with positive end expiratory pressure (PEEP) (5 cmH 2 O) to a specialised newborn/infant training manikin randomised for each LMA and face mask. All subjects received prior education in LMA insertion and BMV. 12 415 recorded inflations for LMAs and face masks were analysed. Leak detected was lowest with i-gel brand, with a mean of 5.7% compared with face mask (triangular 42.7, round 35.7) and other LMAs (45.5-65.4) (p<0.001). Peak inspiratory pressure was higher with i-gel, with a mean of 28.9 cmH 2 O compared with face mask (triangular 22.8, round 25.8) and other LMAs (14.3-22.0) (p<0.001). PEEP was higher with i-gel, with a mean of 5.1 cmH 2 O compared with face mask (triangular 3.0, round 3.6) and other LMAs (0.6-2.6) (p<0.001). In contrast to other LMAs examined, i-gel had no insertion failures and all users found i-gel easy to use. This study has shown dramatic performance differences in delivered ventilation, mask leak and ease of use among seven different brands of LMA tested in a manikin model. This coupled with no partial or complete insertion failures and ease of use suggests i-gel LMA may have an expanded role with newborn resuscitation as a primary resuscitation device. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Functional expression and characterization of a purine nucleobase transporter gene from Leishmania major.

PubMed

Sanchez, Marco A; Tryon, Rob; Pierce, Steven; Vasudevan, Gayatri; Landfear, Scott M

2004-01-01

Leishmania major, like all the other kinetoplastid protozoa, are unable to synthesize purines and rely on purine nucleobase and nucleoside acquisition across the parasite plasma membrane by specific permeases. Although, several genes have been cloned that encode nucleoside transporters in Leishmania and Trypanosoma brucei, much less progress has been made on nucleobase transporters, especially at the molecular level. The studies reported here have cloned and expressed the first gene for a L. major nucleobase transporter, designated LmaNT3. The LmaNT3 permease shows 33% identity to L. donovani nucleoside transporter 1.1 (LdNT1.1) and is, thus, a member of the equilibrative nucleoside transporter (ENT) family. ENT family members identified to date are nucleoside transporters, some of which also transport one or several nucleobases. Functional expression studies in Xenopus laevis oocytes revealed that LmaNT3 mediates high levels of uptake of hypoxanthine, xanthine, adenine and guanine. Moreover, LmaNT3 is an high affinity transporter with K(m) values for hypoxanthine, xanthine, adenine and guanine of 16.5 +/- 1.5, 8.5 +/- 0.6, 8.5 +/- 1.1, and 8.8 +/- 4.0 microM, respectively. LmaNT3 is, thus, the first member of the ENT family identified in any organism that functions as a nucleobase rather than nucleoside or nucleoside/nucleobase transporter.

The Severe Weather Outbreak of 10 November 2002: Lightning and Radar Analysis of Storms in the Deep South

NASA Technical Reports Server (NTRS)

Buechler, D. E.; McCaul, E. W., Jr.; Goodman, S. J.; Blakeslee, R. J.; Bailey, J. C.; Gatlin, P.

2004-01-01

On the afternoon and evening of 10 November 2002, the Midwest and Deep South were struck by a major outbreak of severe storms that produced some 80 tornadoes. In terms of number of tornadoes, this was the largest outbreak in the United States since November 1992. Some 32 of the tornadoes occurred in Tennessee, Mississippi, Alabama and Georgia, including several long-track killers. We use the North Alabama Lightning Mapping Array (LMA) and other data sources to perform a comprehensive analysis of the structure and evolution of the outbreak. Most of the Southern tornadoes occurred in isolated, fast-moving supercell storms that formed in warm, moist air ahead of a major cold front. Storms tended to form in lines parallel to storm cell motion, resulting in many communities being hit multiple times by severe storms that evening. Supercells in Tennessee produced numerous strong tornadoes with short to medium-length track paths, while the supercells further south produced several very long-track tornadoes. Radar data indicate that the Tennessee storms tended to split frequently, apparently limiting their ability to sustain long-lived tornadoes, while storms further south split at most one time. The differences between these storms appear to be related to the presence of stronger jetstream winds in Tennessee relative to those present in Mississippi, Alabama and Georgia. LMA-derived flash rates associated with most of the supercell storm cores were about 1-2 flashes per second. Rapid increases in lightning rates (or "jumps") occurred prior to tornado touchdown in many instances. Lightning "holes" (lightning-free regions associated with the echo-free vault) occurred in two of the Tennessee supercells. The complexity of the relationship between lightning and storm severity is revealed by the behavior of one Alabama supercell, which produced a peak flash rate of nearly 14 flashes per second, well after the end of its long-track tornado, while interacting and ultimately merging with a daughter supercell on its southwest flank. Close examination of this powerful storm indicates that its prodigious flash rate was the result of strong flash activity over an unusually large area, rather than a concentrated core of extremely high flash rate activity.

Anatomical basis of LMA variations drive to different photosynthetic and water storage strategies in two Sesleria species from mountain dry grasslands

NASA Astrophysics Data System (ADS)

Puglielli, Giacomo; Fiore Crescente, Maria; Frattaroli, Anna Rita; Gratani, Loretta

2016-04-01

Plant and leaf traits directly affect ecosystem processes ensuring carbon, nutrient and water exchanges between soil and atmosphere through the photosynthetic activity. Nevertheless, a great within sites variation in plant and leaf traits can be found resulting in different adaptive strategies in coexisting species. Leaf mass per unit of leaf area (LMA) is an important trait to understand plant functional ecology being the outcome of leaf anatomy and related to photosynthesis. We hypothesized that LMA was the main predictor of the adaptive strategies of Sesleria nitida (S1) and Sesleria juncifolia (S2), growing on the screes and on the crests of the summit area, respectively, on Mount Terminillo (Central Apennines, Loc. Sella di Leonessa, 1895 m a.s.l.). To test our hypothesis we broke LMA down into anatomical components, leaf tissue density (LTD) and thickness (LT) and then relating them to gas exchange parameters on twenty plants per species cultivated ex situ. LTD explained 69% of LMA variations in S1 while the relationship with LT was not significant. Moreover, LTD was negatively correlated with LT in S1 driving to a 17% higher volume of the intercellular air spaces, which increases the CO2 partial pressure at the carboxylation sites. This result was also attested by the significant relationship between LTD and both net photosynthesis per unit leaf area (Aa) and mass (Am) (R= 0.56 and -0.49, respectively), highlighting the role of LTD in determining the photosynthetic process in S1. LMA scaled with both LTD and LT explaining 82% and 70% of LMA variations in S2. Moreover, the positive relationship between LTD and LT (R2 = 0.52) highlighted a coordination between the variables in controlling the photosynthetic process. In particular, LTD and LT controlled the transactions of carbon and water through the leaf surface, being positively related to Aa (R= 0.93 and 0.79 for LTD and LT, respectively). Nevertheless, an increase in LT and LTD decreased Am (R = -0.9 and -0.8, respectively). This could be justified by the stronger control of water losses in S2 through a reduction of CO2 diffusion due to the increase in LT and LTD, attested by 6% and 30% lower sub stomatal CO2 concentration (Ci) and stomatal conductance (gs) compared to S1. By analyzing variations in LMA components we demonstrated that S. nitida maximizes carbon uptake mainly by LTD reduction while S. juncifolia reduces photosynthetic capacity and maximize water storage by increasing both LTD and LT. The analysis of the components for LMA provide better insight on uptake and storage strategies of resources such as CO2 and water by allowing the analysis of the relationship between physiological processes, leaf anatomy and environmental conditions.

Log-Multiplicative Association Models as Item Response Models

ERIC Educational Resources Information Center

Anderson, Carolyn J.; Yu, Hsiu-Ting

2007-01-01

Log-multiplicative association (LMA) models, which are special cases of log-linear models, have interpretations in terms of latent continuous variables. Two theoretical derivations of LMA models based on item response theory (IRT) arguments are presented. First, we show that Anderson and colleagues (Anderson & Vermunt, 2000; Anderson & Bockenholt,…

The effect of mathematics anxiety on the processing of numerical magnitude.

PubMed

Maloney, Erin A; Ansari, Daniel; Fugelsang, Jonathan A

2011-01-01

In an effort to understand the origins of mathematics anxiety, we investigated the processing of symbolic magnitude by high mathematics-anxious (HMA) and low mathematics-anxious (LMA) individuals by examining their performance on two variants of the symbolic numerical comparison task. In two experiments, a numerical distance by mathematics anxiety (MA) interaction was obtained, demonstrating that the effect of numerical distance on response times was larger for HMA than for LMA individuals. These data support the claim that HMA individuals have less precise representations of numerical magnitude than their LMA peers, suggesting that MA is associated with low-level numerical deficits that compromise the development of higher level mathematical skills.

Efficient Warm-ups: Creating a Warm-up That Works.

ERIC Educational Resources Information Center

Lauffenburger, Sandra Kay

1992-01-01

Proper warm-up is important for any activity, but designing an effective warm-up can be time consuming. An alternative approach is to take a cue from Laban Movement Analysis (LMA) and consider movement design from the perspective of space and planes of motion. Efficient warm-up exercises using LMA are described. (SM)

Failure of the Laryngeal Mask Airway Unique™ and Classic™ in the pediatric surgical patient: a study of clinical predictors and outcomes.

PubMed

Mathis, Michael R; Haydar, Bishr; Taylor, Emma L; Morris, Michelle; Malviya, Shobha V; Christensen, Robert E; Ramachandran, Satya-Krishna; Kheterpal, Sachin

2013-12-01

Although predictors of laryngeal mask airway failure in adults have been elucidated, there remains a paucity of data regarding laryngeal mask airway failure in children. The authors performed a retrospective database review of all pediatric patients who received a laryngeal mask anesthetic at their institution from 2006 to 2010. Device brands were restricted to LMA Unique™ (Cardinal Health, Dublin, OH) and LMA Classic™ (LMA North America, San Diego, CA), and primary outcome was laryngeal mask failure, defined as any airway event requiring device removal and tracheal intubation. Potential risk factors were analyzed with both univariate and multivariate techniques and included medical history, physical examination, surgical, and anesthetic characteristics. Of the 11,910 anesthesia cases performed in the study, 102 cases (0.86%) experienced laryngeal mask failure. Common presenting features of laryngeal mask failures included leak (25%), obstruction (48%), and patient intolerance such as intractable coughing/bucking (11%). Failures occurred before incision in 57% of cases and after incision in 43%. Independent clinical associations included ear/nose/throat surgical procedure, nonoutpatient admission status, prolonged surgical duration, congenital/acquired airway abnormality, and patient transport. The findings of the study support the use of the LMA Unique™ and LMA Classic™ as reliable pediatric supraglottic airway devices, demonstrating relatively low failure rates. Predictors of laryngeal mask airway failure in the pediatric surgical population do not overlap with those in the adult population and should therefore be independently considered.

A 12-month audit of laryngeal mask airway (LMA) use in a South Australian ambulance service.

PubMed

Hein, Cindy; Owen, Harry; Plummer, John

2008-11-01

The aim of the study was to provide an accurate account of current practice of laryngeal mask airway (LMA) use within SA Ambulance Service (SAAS) and identify issues that could lead to constructive training for paramedics and improve clinical care and patient safety. A clinical audit of LMA use within SAAS was registered with the Director of Clinical Governance at Flinders Medical Centre in South Australia. Data were collected prospectively in a state wide all inclusive study over 12 months (February 2006 to January 2007). The primary outcome variable we determined was successful insertion after one or two attempts. Secondary outcome measures were overall success rate and reasons for failure. Insertion of an LMA was attempted by 179 paramedical staff in 164 patients. Success after one or two attempts was obtained in 65% of patients (107/164). Overall success rate (any number of attempts) was 74% (121/164), of those 45% were on the first attempt, 20% on the second attempt and the remainder (9%) required three or more attempts to achieve successful insertion. Reported failures were ascribed to patient anatomy (13), technique (9), airway soiling (7), device (6), trismus (1), high Glasgow Coma Score (1), trauma (1) or unknown (5). This clinical audit provides a comprehensive account of LMA use within SA Ambulance Service. Although the current practice was found to be acceptable, these results are below those of comparable groups and should be improved upon.

Circadian rhythms of body temperature and locomotor activity in aging BALB/c mice: early and late life span predictors.

PubMed

Basso, Andrea; Del Bello, Giovanna; Piacenza, Francesco; Giacconi, Robertina; Costarelli, Laura; Malavolta, Marco

2016-08-01

Impairment of one or more parameters of circadian rhythms (CR) of body temperature (BT) and locomotor activity (LMA) are considered among the hallmarks of mammalian aging. These alterations are frequently used as markers for imminent death in laboratory mice. However, there are still contradictory data for particular strains and it is also uncertain which changes might predict senescence changes later in life, including the force of mortality. In the present paper we use telemetry to study LMA and CR of BT during aging of BALB/c mice. At our knowledge this is the first time that CR of BT and LMA are investigated in this strain in a range of age covering the whole lifespan, from young adult up to very old age. CR of BT was analyzed with a cosine model using a cross sectional approach and follow-up measurements. The results show that BT, LMA, amplitude, goodness-of-fit (GoF) to circadian cycle of temperature decrease with different shapes during chronological age. Moreover, we found that the % change of amplitude and BT in early life (5-19 months) can predict the remaining lifespan of the mice. Later in life (22-32 months), best predictors are single measurements of LMA and GoF. The results of this study also offer potential measures to rapidly identifying freely unrestrained mice with the worst longitudinal outcome and against which existing or novel biomarkers and treatments may be assessed.

Engineering high α-amylase levels in wheat grain lowers Falling Number but improves baking properties.

PubMed

Ral, Jean-Philippe; Whan, Alex; Larroque, Oscar; Leyne, Emmett; Pritchard, Jeni; Dielen, Anne-Sophie; Howitt, Crispin A; Morell, Matthew K; Newberry, Marcus

2016-01-01

Late maturity α-amylase (LMA) and preharvest sprouting (PHS) are genetic defects in wheat. They are both characterized by the expression of specific isoforms of α-amylase in particular genotypes in the grain prior to harvest. The enhanced expression of α-amylase in both LMA and PHS results in a reduction in Falling Number (FN), a test of gel viscosity, and subsequent downgrading of the grain, along with a reduced price for growers. The FN test is unable to distinguish between LMA and PHS; thus, both defects are treated similarly when grain is traded. However, in PHS-affected grains, proteases and other degradative process are activated, and this has been shown to have a negative impact on end product quality. No studies have been conducted to determine whether LMA is detrimental to end product quality. This work demonstrated that wheat in which an isoform α-amylase (TaAmy3) was overexpressed in the endosperm of developing grain to levels of up to 100-fold higher than the wild-type resulted in low FN similar to those seen in LMA- or PHS-affected grains. This increase had no detrimental effect on starch structure, flour composition and enhanced baking quality, in small-scale 10-g baking tests. In these small-scale tests, overexpression of TaAmy3 led to increased loaf volume and Maillard-related browning to levels higher than those in control flours when baking improver was added. These findings raise questions as to the validity of the assumption that (i) LMA is detrimental to end product quality and (ii) a low FN is always indicative of a reduction in quality. This work suggests the need for a better understanding of the impact of elevated expression of specific α-amylase on end product quality. © 2015 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.

Computational methods for reactive transport modeling: An extended law of mass-action, xLMA, method for multiphase equilibrium calculations

NASA Astrophysics Data System (ADS)

Leal, Allan M. M.; Kulik, Dmitrii A.; Kosakowski, Georg; Saar, Martin O.

2016-10-01

We present an extended law of mass-action (xLMA) method for multiphase equilibrium calculations and apply it in the context of reactive transport modeling. This extended LMA formulation differs from its conventional counterpart in that (i) it is directly derived from the Gibbs energy minimization (GEM) problem (i.e., the fundamental problem that describes the state of equilibrium of a chemical system under constant temperature and pressure); and (ii) it extends the conventional mass-action equations with Lagrange multipliers from the Gibbs energy minimization problem, which can be interpreted as stability indices of the chemical species. Accounting for these multipliers enables the method to determine all stable phases without presuming their types (e.g., aqueous, gaseous) or their presence in the equilibrium state. Therefore, the here proposed xLMA method inherits traits of Gibbs energy minimization algorithms that allow it to naturally detect the phases present in equilibrium, which can be single-component phases (e.g., pure solids or liquids) or non-ideal multi-component phases (e.g., aqueous, melts, gaseous, solid solutions, adsorption, or ion exchange). Moreover, our xLMA method requires no technique that tentatively adds or removes reactions based on phase stability indices (e.g., saturation indices for minerals), since the extended mass-action equations are valid even when their corresponding reactions involve unstable species. We successfully apply the proposed method to a reactive transport modeling problem in which we use PHREEQC and GEMS as alternative backends for the calculation of thermodynamic properties such as equilibrium constants of reactions, standard chemical potentials of species, and activity coefficients. Our tests show that our algorithm is efficient and robust for demanding applications, such as reactive transport modeling, where it converges within 1-3 iterations in most cases. The proposed xLMA method is implemented in Reaktoro, a unified open-source framework for modeling chemically reactive systems.

Post-operative atelectasis - a randomised trial investigating a ventilatory strategy and low oxygen fraction during recovery.

PubMed

Edmark, L; Auner, U; Lindbäck, J; Enlund, M; Hedenstierna, G

2014-07-01

Atelectasis is common during and after general anaesthesia. We hypothesized that a ventilation strategy with a combination of 1) continuous positive airway pressure (CPAP) or positive end-expiratory pressure (PEEP) and 2) a reduced end-expiratory oxygen concentration during recovery would reduce post-operative atelectasis. Sixty patients were randomized into two groups. During anaesthesia induction, inspiratory oxygen fraction (FIO2) was 1.0, and depending on weight, CPAP 6, 7 or 8 cmH2O was applied in both groups via facemask. During maintenance of anaesthesia, a laryngeal mask airway (LMA) was used, and PEEP was 6-8 cmH2O in both groups. Before removal of the LMA, FIO2 was set to 0.3 in the intervention group and 1.0 in the control group. Atelectasis was studied by computed tomography (CT) approximately 14 min post-operatively. In one patient in the group given an FIO2 of 0.3 before removal of the LMA a CT scan could not be performed so the patient was excluded. The area of atelectasis was 5.5, 0-16.9 cm(2) (median and range), and 6.8, 0-27.5 cm(2) in the groups given FIO2 0.3 or FIO2 1.0 before removal of the LMA, a difference that was not statistically significant (P = 0.48). Post-hoc analysis showed dependence of atelectasis on smoking (despite all were clinically lung healthy) and American Society of Anesthesiologists class (P = 0.038 and 0.015, respectively). Inducing anaesthesia with CPAP/PEEP and FIO2 1.0 and deliberately reducing FIO2 during recovery before removal of the LMA did not reduce post-operative atelectasis compared with FIO2 1.0 before removal of the LMA. © 2014 The Acta Anaesthesiologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

50 CFR 229.32 - Atlantic large whale take reduction plan regulations.

Code of Federal Regulations, 2011 CFR

2011-10-01

... South Channel Restricted Trap/Pot Area where it overlaps with Lobster Management Area (LMA) 2 and the Outer Cape LMA (as defined in the American Lobster Fishery regulations in 50 CFR 697.18), and the... defined in the American Lobster Fishery regulations in 50 CFR 697.18), and the Offshore Trap/Pot Waters...

System and method for generating a deselect mapping for a focal plane array

DOEpatents

Bixler, Jay V; Brandt, Timothy G; Conger, James L; Lawson, Janice K

2013-05-21

A method for generating a deselect mapping for a focal plane array according to one embodiment includes gathering a data set for a focal plane array when exposed to light or radiation from a first known target; analyzing the data set for determining which pixels or subpixels of the focal plane array to add to a deselect mapping; adding the pixels or subpixels to the deselect mapping based on the analysis; and storing the deselect mapping. A method for gathering data using a focal plane array according to another embodiment includes deselecting pixels or subpixels based on a deselect mapping; gathering a data set using pixels or subpixels in a focal plane array that are not deselected upon exposure thereof to light or radiation from a target of interest; and outputting the data set.

Project LMA: Learning Media Assessment of Students with Visual Impairments. Facilitator's Manual and Participant Workbook.

ERIC Educational Resources Information Center

Koenig, Alan J.; Holbrook, M. Cay

This document is comprised of the facilitator's manual and the participant's workbook for a 1- or 2-day workshop for inservice and preservice teachers on the process of learning media assessment (LMA) for students with visual impairments. The manual and workbook are intended for use in a complete program that also includes videotapes and…

What is happening to health in the economic downturn? A view of the Lisbon Metropolitan Area, Portugal.

PubMed

Nogueira, Helena

2016-01-01

The economic downturn has introduced new social risks in the most affected countries with foreseeable negative consequences for health. To analyse changes in health and its socioeconomic inequalities between 2001-2011 in the Lisbon Metropolitan Area (LMA), Portugal. This study, conducted in the LMA neighbourhoods (n = 207), examines the association between deprivation and premature mortality using standardised premature mortality ratios and a composite index of socioeconomic deprivation. The association was observed by analysing the whole range of values, quintiles and deciles of the LMA population. Pearson coefficients and ANOVA were used to assess associations and variability between quintiles/deciles. The findings show that people living in extreme deprivation conditions increased (5.45%) and that increasing deprivation is associated with health degradation in specific groups. Between 2001-2011, premature mortality became more unequally distributed, increasing in the richest (1%) and median (12%) areas, even though socioeconomic inequalities in mortality decreased. Health degradation is selective, affecting mainly the middle class living in LMA; these 'newly deprived' people experience an increased risk, while the 'traditionally deprived' show no decrease in premature mortality. Therefore, social inequalities in health tend to decrease, but without health gains.

Growth and optical properties of Co,Nd:LaMgAl11O19

NASA Astrophysics Data System (ADS)

Xu, Peng; Xia, Changtai; Di, Juqing; Xu, Xiaodong; Sai, Qinglin; Wang, Lulu

2012-12-01

Nd,Co:LaMgAl11O19 (abbreviated as Co,Nd:LMA) was grown using the Czochralski method. The structure, polarized absorption spectrum, fluorescence spectrum, and fluorescence decay time were analyzed. The as-grown crystal had very wide absorption bands at 794 nm, which can be pumped by GaAs laser diode without temperature stabilization. Two strong emission bands were present at 1056 nm and 1082 nm with full-width at half-maximum (FWHM) of 6 and 8 nm, respectively. The large FWHM is due to the inhomogeneity of the Nd ion sites. The lifetimes of the 4F3/2 manifold of Co,Nd:LMA at room temperature monitored at 905 nm, 1056 nm, and 1344 nm were 292, 288, and 350 μs, respectively, which was caused by the different contribution of the three different sites with D3h and C2v symmetry. The absorption band of Co is from 1.3 μm to 1.6 μm, and Co,Nd:LMA still has a strong emission around the 1.38 μm, indicating that the Co,Nd:LMA can be applied as a potential self-Q-switched material operating at 1.3 μm.

Remifentanil dose for laryngeal mask airway insertion with a single standard dose of propofol during emergency airway management in elderly patients.

PubMed

Ryu, Junghee; Oh, Ah Young; Baek, Ji-Seok; Kim, Jin-Hee; Park, Sang-Heon; Noh, Jae-Mun

2014-04-01

This study determined the dose of remifentanil to use during insertion of a Classic™ laryngeal mask airway (LMA, The Laryngeal Mask Co., Nicosia, Cyprus) in elderly patients during emergency airway management when combined with a single dose of propofol. Patients aged 65-80 years were enrolled. Anesthesia was induced with propofol 1 mg/kg, and then a blinded dose of remifentanil was infused over 30 s after confirming the patient's loss of consciousness. The dose of remifentanil was determined using Dixon's up-and-down method, starting at 0.5 µg/kg (a step size of 0.1 µg/kg). Insertion of the LMA was attempted 60 s after loss of consciousness. In total, 23 patients were recruited and the mean age ± standard deviation was 72 ± 3 years. The effective dose for successful LMA insertion in 50% of the patients (ED50) was 0.20 ± 0.05 µg/kg. No patient needed more than 0.3 µg/kg. Remifentanil 0.20 ± 0.05 µg/kg with propofol 1 mg/kg resulted in excellent LMA insertion in 50% of elderly patients without significant hemodynamic changes during emergency airway management.

Genetic parameters for yearling weight, carcass traits, and primal-cut yields of Hanwoo cattle.

PubMed

Choi, T J; Alam, M; Cho, C I; Lee, J G; Park, B; Kim, S; Koo, Y; Roh, S H

2015-04-01

Genetic parameters associated with yearling weight, carcass traits, and primal-cut yields of male Hanwoo cattle were investigated using univariate and bivariate animal models. The mean yearling weight (YWT), carcass weight (CWT), longissimus muscle area (LMA), backfat thickness (BFT), and marbling score (MS) were 352.47 ± 0.40 kg, 337.39 ± 0.64 kg, 78.28 ± 0.13 cm2, 8.45 ± 0.05 mm, and 3.25 ± 0.03, respectively. Total primal-cut yield (TPC) was 78.95 ± 0.10% of CWT, of which 42.3% was contributed by the forequarters (chuck, CHK; shoulder, SLD; ribs, RIB; and brisket and flank, BAF). Loins, top round (TRND), and round (RND) were associated with yields of 13.57%, 5.45 ± 0.01%, and 8.87 ± 0.02%, respectively. The largest cut studied was ribs (15.67 ± 0.03%). The estimated heritabilities (h2) of YWT, CWT, LMA, BFT, and MS were 0.18 ± 0.02, 0.29 ± 0.04, 0.38 ± 0.05, 0.45 ± 0.05, and 0.62 ± 0.07, respectively. Shoulder yield was highly heritable in Hanwoo steers (0.83 ± 0.13), followed by the yields of round (0.66 ± 0.12), striploin (0.64 ± 0.12), top round (0.62 ± 0.12), sirloin (0.60 ± 0.12), and total primal-cut yield (0.52 ± 0.11). The h2 values of CHK, BAF, RIB, and tenderloin (TLN) ranged from 0.19 ± 0.09 to 0.41 ± 0.11. Generally, the genetic CV was low for most traits (2.33%-6.15%), except for CHK, BFT, and MS. The genetic correlation (rg) was strong between YWT and CWT (0.77 ± 0.06). The greatest positive and negative rg among carcass traits were those between LMA and CWT (0.52 ± 0.08) and between LMA and BFT (-0.30 ± 0.09), respectively. The correlation between CHK and SLD (0.81 ± 0.14), and those between SLD, TLN, TRND, and RND, were mostly strong (0.77-0.87), but the rg between RIB and other traits were strongly negative. The TPC yield showed moderate to high rg with most primal cuts. The YWT, CWT, and LMA correlated notably with CHK, SLD, and loin yields, especially LMA. However, BFT and MS were negatively correlated with many primal cuts but RIB. Those rg estimates were also opposite of that of LMA and CWT with primal cuts. Phenotypic correlations (rp) were generally weaker than rg estimates. The rp of YWT, CWT, and LMA were either zero or moderately negative compared to those of the BFT and MS with primal cuts. Most primal cuts yielded positive rp estimates among them, except for RIB. Our results suggest that direct selection for YWT, various carcass traits, and primal-cut yields may increase the carcass value of Hanwoo males.

Converging patterns of vertical variability in leaf morphology and nitrogen across seven Eucalyptus plantations in Brazil and Hawaii, USA

Treesearch

Adam P. Coble; Alisha Autio; Molly A. Cavaleri; Dan Binkley; Michael G. Ryan

2014-01-01

Across sites in Brazil and Hawaii, LMA and Nmass were strongly correlated with height and shade index, respectively, which may help simplify canopy function modeling of Eucalyptus plantations. Abstract Within tree canopies, leaf mass per area (LMA) and leaf nitrogen per unit area (Narea) commonly increase with height. Previous research has suggested that these patterns...

Height is more important than light in determining leaf morphology in a tropical forest

Treesearch

Molly A. Cavaleri; Steven F. Oberbauer; David B. Clark; Deborah A. Clark; Michael G. Ryan

2010-01-01

Both within and between species, leaf physiological parameters are strongly related to leaf dry mass per area (LMA, g/m2), which has been found to increase from forest floor to canopy top in every forest where it has been measured. Although vertical LMA gradients in forests have historically been attributed to a direct phenotypic response to light, an increasing number...

Vertical leaf mass per area gradient of mature sugar maple reflects both height-driven increases in vascular tissue and light-driven increases in palisade layer thickness.

PubMed

Coble, Adam P; Cavaleri, Molly A

2017-10-01

A key trait used in canopy and ecosystem function modeling, leaf mass per area (LMA), is influenced by changes in both leaf thickness and leaf density (LMA = Thickness × Density). In tall trees, LMA is understood to increase with height through two primary mechanisms: (i) increasing palisade layer thickness (and thus leaf thickness) in response to light and/or (ii) reduced cell expansion and intercellular air space in response to hydrostatic constraints, leading to increased leaf density. Our objective was to investigate within-canopy gradients in leaf anatomical traits in order to understand environmental factors that influence leaf morphology in a sugar maple (Acer saccharum Marshall) forest canopy. We teased apart the effects of light and height on anatomical traits by sampling at exposed and closed canopies that had different light conditions at similar heights. As expected, palisade layer thickness responded strongly to cumulative light exposure. Mesophyll porosity, however, was weakly and negatively correlated with light and height (i.e., hydrostatic gradients). Reduced mesophyll porosity was not likely caused by limitations on cell expansion; in fact, epidermal cell width increased with height. Palisade layer thickness was better related to LMA, leaf density and leaf thickness than was mesophyll porosity. Vein diameter and fraction of vascular tissue also increased with height and LMA, density and thickness, revealing that greater investment in vascular and support tissue may be a third mechanism for increased LMA with height. Overall, decreasing mesophyll porosity with height was likely due to palisade cells expanding into the available air space and also greater investments in vascular and support tissue, rather than a reduction of cell expansion due to hydrostatic constraints. Our results provide evidence that light influences both palisade layer thickness and mesophyll porosity and indicate that hydrostatic gradients influence leaf vascular and support tissues in mature Acer saccharum trees. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Responses of leaf structure and photosynthetic properties to intra-canopy light gradients: a common garden test with four broadleaf deciduous angiosperm and seven evergreen conifer tree species.

PubMed

Wyka, Tomasz P; Oleksyn, J; Zytkowiak, R; Karolewski, P; Jagodziński, A M; Reich, P B

2012-09-01

Spectra of leaf traits in northern temperate forest canopies reflect major differences in leaf longevity between evergreen conifers and deciduous broadleaf angiosperms, as well as plastic modifications caused by within-crown shading. We investigated (1) whether long-lived conifer leaves exhibit similar intra-canopy plasticity as short-lived broadleaves, and (2) whether global interspecific relationships between photosynthesis, nitrogen, and leaf structure identified for sun leaves adequately describe leaves differentiated in response to light gradients. We studied structural and photosynthetic properties of intra-tree sun and shade foliage in adult trees of seven conifer and four broadleaf angiosperm species in a common garden in Poland. Shade leaves exhibited lower leaf mass-per-area (LMA) than sun leaves; however, the relative difference was smaller in conifers than in broadleaves. In broadleaves, LMA was correlated with lamina thickness and tissue density, while in conifers, it was correlated with thickness but not density. In broadleaves, but not in conifers, reduction of lamina thickness was correlated with a thinner palisade layer. The more conservative adjustment of conifer leaves could result from a combination of phylogenetic constraints, contrasting leaf anatomies and shoot geometries, but also from functional requirements of long-lived foliage. Mass-based nitrogen concentration (N(mass)) was similar between sun and shade leaves, and was lower in conifers than in deciduous broadleaved species. Given this, the smaller LMA in shade corresponded with a lower area-based N concentration (N(area)). In evergreen conifers, LMA and N(area) were less powerful predictors of area-based photosynthetic rate (A (max(area))) in comparison with deciduous broadleaved angiosperms. Multiple regression for sun and shade leaves showed that, in each group, A (max(mass)) was related to N(mass) but not to LMA, whereas LMA became a significant codeterminant of A (max(mass)) in analysis combining both groups. Thus, a fundamental mass-based relationship between photosynthesis, nitrogen, and leaf structure reported previously also exists in a dataset combining within-crown and across-functional type variation.

A simultaneous multichannel monophasic action potential electrode array for in vivo epicardial repolarization mapping.

PubMed

Sahakian, A V; Peterson, M S; Shkurovich, S; Hamer, M; Votapka, T; Ji, T; Swiryn, S

2001-03-01

While the recording of extracellular monophasic action potentials (MAPs) from single epicardial or endocardial sites has been performed for over a century, we are unaware of any previous successful attempt to record MAPs simultaneously from a large number of sites in vivo. We report here the design and validation of an array of MAP electrodes which records both depolarization and repolarization simultaneously at up to 16 epicardial sites in a square array on the heart in vivo. The array consists of 16 sintered Ag-AgCl electrodes mounted in a common housing with individual suspensions allowing each electrode to exert a controlled pressure on the epicardial surface. The electrodes are arranged in a square array, with each quadrant of four having an additional recessed sintered Ag-AgCl reference electrode at its center. A saline-soaked sponge establishes ionic contact between the reference electrodes and the tissue. The array was tested on six anesthetized open-chested pigs. Simultaneous diagnostic-quality MAP recordings were obtained from up to 13 out of 16 ventricular sites. Ventricular MAPs had amplitudes of 10-40 mV with uniform morphologies and stable baselines for up to 30 min. MAP duration at 90% repolarization was measured and shown to vary as expected with cycle length during sustained pacing. The relationship between MAP duration and effective refractory period was also confirmed. The ability of the array to detect local differences in repolarization was tested in two ways. Placement of the array straddling the atrioventricular (AV) junction yielded simultaneous atrial or ventricular recordings at corresponding sites during 1:1 and 2:1 AV conduction. Localized ischemia via constriction of a coronary artery branch resulted in shortening of the repolarization phase at the ischemic, but not the nonischemic, sites. In conclusion, these results indicate that the simultaneous multichannel MAP electrode array is a viable method for in vivo epicardial repolarization mapping. The array has the potential to be expanded to increase the number of sites and spatial resolution.

Metabolic adaptation to the aqueous leaf extract of Moringa oleifera Lam.-supplemented diet is related to the modulation of gut microbiota in mice.

PubMed

Gao, Xiaoyu; Xie, Qiuhong; Liu, Ling; Kong, Ping; Sheng, Jun; Xiang, Hongyu

2017-06-01

The aqueous leaf extract of Moringa oleifera Lam. (LM-A) is reported to have many health beneficial bioactivities and no obvious toxicity, but have mild adverse effects. Little is known about the mechanism of these reported adverse effects. Notably, there has been no report about the influence of LM-A on intestinal microecology. In this study, animal experiments were performed to explore the relationships between metabolic adaptation to an LM-A-supplemented diet and gut microbiota changes. After 8-week feeding with normal chow diet, the body weight of mice entered a stable period, and one of the group received daily doses of 750-mg/kg body weight LM-A by gavage for 4 weeks (assigned as LM); the other group received the vehicle (assigned as NCD). The liver weight to body weight ratio was enhanced, and the ceca were enlarged in the LM group compared with the NCD group. LM-A-supplemented-diet mice elicited a uniform metabolic adaptation, including slightly influenced fasting glucose and blood lipid profiles, significantly reduced liver triglycerides content, enhanced serum lipopolysaccharide level, activated inflammatory responses in the intestine and liver, compromised gut barrier function, and broken intestinal homeostasis. Many metabolic changes in mice were significantly correlated with altered specific gut bacteria. Changes in Firmicutes, Eubacterium rectale/Clostridium coccoides group, Faecalibacterium prausnitzii, Akkermansia muciniphila, segmented filamentous bacteria, Enterococcus spp., and Sutterella spp. may play an important role in the process of host metabolic adaptation to LM-A administration. Our research provides an explanation of the adverse effects of LM-A administration on normal adult individuals in the perspective of microecology.

History of labour market attachment as a determinant of health status: a 12-year follow-up of the Northern Swedish Cohort

PubMed Central

Waenerlund, Anna-Karin; Gustafsson, Per E; Hammarström, Anne; Virtanen, Pekka

2014-01-01

Objective The present study aims at using trajectory analysis to measure labour market attachment (LMA) over 12 years and at examining whether labour market tracks relate to perceived health status. Design Data were retrieved from a 26-year prospective cohort study, the Northern Swedish Cohort. Setting and participants All ninth grade students (n=1083) within the municipality of Luleå in northern Sweden were included in the baseline investigation in 1981. The vast majority (94%) of the original cohort participated at the fourth follow-up. In this study, 969 participants were included. Measures Perceived health status (psychological distress and non-optimal self-rated health) at age 42 and the data obtained from questionnaires. Results We have identified four tracks in relation to LMA across the 12-year period: ‘permanent’, ‘high level’, ‘strengthening’ and ‘poor level’ of attachment. LMA history relates to psychological distress. High level (OR 1.55 (95% CI 1.06 to 2.27)), strengthening (OR 1.95 (95% CI 1.29 to 2.93)) and poor attachment (OR 3.14 (95% CI 2.10 to 4.70) involve higher OR for psychological distress compared with permanent attachment. The overall p value remained significant in the final model (p=0.001). Analyses regarding non-optimal self-rated health displayed a similar pattern but this was not significant in the final model. Conclusions Our results suggest that health status in mid-life, particularly psychological distress, is related to patterns of LMA history, to a large part independently of other social risk factors and previous health. Consideration of heterogeneity and time in LMA might be important when analysing associations with perceived health. PMID:24531448

History of labour market attachment as a determinant of health status: a 12-year follow-up of the Northern Swedish Cohort.

PubMed

Waenerlund, Anna-Karin; Gustafsson, Per E; Hammarström, Anne; Virtanen, Pekka

2014-02-14

The present study aims at using trajectory analysis to measure labour market attachment (LMA) over 12 years and at examining whether labour market tracks relate to perceived health status. Data were retrieved from a 26-year prospective cohort study, the Northern Swedish Cohort. All ninth grade students (n=1083) within the municipality of Luleå in northern Sweden were included in the baseline investigation in 1981. The vast majority (94%) of the original cohort participated at the fourth follow-up. In this study, 969 participants were included. Perceived health status (psychological distress and non-optimal self-rated health) at age 42 and the data obtained from questionnaires. We have identified four tracks in relation to LMA across the 12-year period: 'permanent', 'high level', 'strengthening' and 'poor level' of attachment. LMA history relates to psychological distress. High level (OR 1.55 (95% CI 1.06 to 2.27)), strengthening (OR 1.95 (95% CI 1.29 to 2.93)) and poor attachment (OR 3.14 (95% CI 2.10 to 4.70) involve higher OR for psychological distress compared with permanent attachment. The overall p value remained significant in the final model (p=0.001). Analyses regarding non-optimal self-rated health displayed a similar pattern but this was not significant in the final model. Our results suggest that health status in mid-life, particularly psychological distress, is related to patterns of LMA history, to a large part independently of other social risk factors and previous health. Consideration of heterogeneity and time in LMA might be important when analysing associations with perceived health.

Genome-Wide Association Study for Carcass Traits in an Experimental Nelore Cattle Population

PubMed Central

Medeiros de Oliveira Silva, Rafael; Bonvino Stafuzza, Nedenia; de Oliveira Fragomeni, Breno; Miguel Ferreira de Camargo, Gregório; Matos Ceacero, Thaís; Noely dos Santos Gonçalves Cyrillo, Joslaine; Baldi, Fernando; Augusti Boligon, Arione; Zerlotti Mercadante, Maria Eugênia; Lino Lourenco, Daniela; Misztal, Ignacy; Galvão de Albuquerque, Lucia

2017-01-01

The purpose of this study was to identify genomic regions associated with carcass traits in an experimental Nelore cattle population. The studied data set contained 2,306 ultrasound records for longissimus muscle area (LMA), 1,832 for backfat thickness (BF), and 1,830 for rump fat thickness (RF). A high-density SNP panel (BovineHD BeadChip assay 700k, Illumina Inc., San Diego, CA) was used for genotyping. After genomic data quality control, 437,197 SNPs from 761 animals were available, of which 721 had phenotypes for LMA, 669 for BF, and 718 for RF. The SNP solutions were estimated using a single-step genomic BLUP approach (ssGWAS), which calculated the variance for windows of 50 consecutive SNPs and the regions that accounted for more than 0.5% of the additive genetic variance were used to search for candidate genes. The results indicated that 12, 18, and 15 different windows were associated to LMA, BF, and RF, respectively. Confirming the polygenic nature of the studied traits, 43, 65, and 53 genes were found in those associated windows, respectively for LMA, BF, and RF. Among the candidate genes, some of them, which already had their functions associated with the expression of energy metabolism, were found associated with fat deposition in this study. In addition, ALKBH3 and HSD17B12 genes, which are related in fibroblast death and metabolism of steroids, were found associated with LMA. The results presented here should help to better understand the genetic and physiologic mechanism regulating the muscle tissue deposition and subcutaneous fat cover expression of Zebu animals. The identification of candidate genes should contribute for Zebu breeding programs in order to consider carcass traits as selection criteria in their genetic evaluation. PMID:28118362

Light acclimation optimizes leaf functional traits despite height-related constraints in a canopy shading experiment.

PubMed

Coble, Adam P; Cavaleri, Molly A

2015-04-01

Within-canopy gradients of leaf functional traits have been linked to both light availability and vertical gradients in leaf water potential. While observational studies can reveal patterns in leaf traits, within-canopy experimental manipulations can provide mechanistic insight to tease apart multiple interacting drivers. Our objectives were to disentangle effects of height and light environment on leaf functional traits by experimentally shading branches along vertical gradients within a sugar maple (Acer saccharum) forest. Shading reduced leaf mass per area (LMA), leaf density, area-based leaf nitrogen (N(area)), and carbon:nitrogen (C:N) ratio, and increased mass-based leaf nitrogen (N(mass)), highlighting the importance of light availability on leaf morphology and chemistry. Early in the growing season, midday leaf water potential (Ψ(mid)), LMA, and N(area) were driven primarily by height; later in the growing season, light became the most important driver for LMA and Narea. Carbon isotope composition (δ(13)C) displayed strong, linear correlations with height throughout the growing season, but did not change with shading, implying that height is more influential than light on water use efficiency and stomatal behavior. LMA, leaf density, N(mass), C:N ratio, and δ(13)C all changed seasonally, suggesting that leaf ageing effects on leaf functional traits are equally as important as microclimatic conditions. Overall, our results indicate that: (1) stomatal sensitivity to vapor pressure deficit or Ψ(mid) constrains the supply of CO2 to leaves at higher heights, independent of light environment, and (2) LMA and N(area) distributions become functionally optimized through morphological acclimation to light with increasing leaf age despite height-related constraints.

Tile Drainage Management Influences on Surface-Water and Groundwater Quality following Liquid Manure Application.

PubMed

Frey, Steven K; Topp, Ed; Ball, Bonnie R; Edwards, Mark; Gottschall, Natalie; Sunohara, Mark; Zoski, Erin; Lapen, David R

2013-01-01

This study investigated the potential for controlled tile drainage (CD) to reduce bacteria and nutrient loading to surface water and groundwater from fall-season liquid manure application (LMA) on four macroporous clay loam plots, of which two had CD and two had free-draining (FD) tiles. Rhodamine WT (RWT) was mixed into the manure and monitored in the tile water and groundwater following LMA. Tile water and groundwater quality were influenced by drainage management. Following LMA on the FD plots, RWT, nutrients, and bacteria moved rapidly via tiles to surface water; at the CD plots, tiles did not flow until the first post-LMA rainfall, so the immediate risk of LMA-induced contamination of surface water was abated. During the 36-d monitoring period, flow-weighted average specific conductance, redox potential, and turbidity, as well as total Kjeldahl N (TKN), total P (TP), NH-N, reactive P, and RWT concentrations, were higher in the CD tile effluent; however, because of lower tile discharge from the CD plots, there was no significant ( ≤ 0.05) difference in surface water nutrient and RWT loading between the CD and FD plots when all tiles were flowing. The TKN, TP, and RWT concentrations in groundwater also tended to be higher at the CD plots. Bacteria behaved differently than nutrients and RWT, with no significant difference in total coliform, , fecal coliform, fecal streptococcus, and concentrations between the CD and FD tile effluent; however, for all but , hourly loading was higher from the FD plots. Results indicate that CD has potential for mitigating bacteria movement to surface water. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

[Photosynthetic physiological adaptabilities of Pinus tabulaeformis and Robinia pseudoacacia in the Loess Plateau].

PubMed

Zheng, Shu-xia; Shangguan, Zhou-ping

2007-01-01

With Yangling, Yongshou, Fuxian, Ansai, Mizhi and Shenmu, the s ix counties from the south to the north in the Loess Plateau as study sites, this paper studied thoe photosynthetic charac teristics and leaf traits of Pinus tabulaeformis and Robinia pseudoacacia. The results showed that among the six sites, there were significant differences in the photosynthetic rate (Pn), photosynthetic nitrogen use efficiency (PNUE), water use efficiency (WUE), leaf mass per area (LMA), nitrogen content (Nmass), and chlorophyll content (Chl) of P. tabulaeformis and R. pseudoacacia, suggesting that the photosynthetic capacity and leaf traits of the two species differed with sites. From the south to the north, the Pn, PNUE and WUE of P. tabulaeformis increased slightly while those of R. pseudoacacia decreased significantly, indicating that in drought habitat, P. tabulaef6rmis could still maintain high photosynthetic capacity, hut the photosynthetic capacity of R. pseudoacacia was greatly restrained. Also from the south to the north, the LMA of P. tabulaeformis and R. pseudoacacia had a slight increasing trend, while Nmass and Chl decreased slightly. The variation ranges of the three parameters were greater for R. pseudoacacia than for P. tabulaeformis, indicating that P. tabulaeformis had stronger drought-tolerant capability than R. pseudoacacia, which was not only exhibited in physiological metabolism, but also in leaf morphological acclimation. The correlation analysis between photosynthetic parameters and leaf traits of P. tabulaeformis and R. pseudoacacia in the six sites showed that there was a significant negative correlation between LMA and Nmass. The Pn and PNUE of both test species had no correlations with LMA and Nmass, but had significant positive correlation with Chl. The WUE of the species was negatively correlated with LMA, but positively correlated with Nmass.

[Usefullness of the StoneBreaker lithotripter for percutaneous nephrolithotomy].

PubMed

del Peso, Almudena Coloma; González, Inmaculada Fernández; Gálvez, Milagros Jiménez; Abad, Pablo Garrido; Fajardo, Gloria Bocardo; Fernández, Luis Miguel Herranz; Arjona, Manuel Fernández; Torres, Lorenzo Herrero; Sanz, Ignacio Pereira

2008-01-01

Throughout the history, many devices have been used for breaking urinary tract stones. StoneBreaker (LMA Urology, Gland, Switzerland) is a second generation of intracorporeal lithotripter, pneumatic and portable, which adds several new advantages, like effectiveness in stone fragmentation and easy handling, very useful during percutaneous lithotripsy. We report the case of a 40 year-old male patient, with a left kidney pyelic lithiasis, who was treated by percutaneous lithotripsy, under general anaesthesia, with StoneBreaker (LMA Urology, Gland, Switzerland) as lithotripter. StoneBreaker (LMA Urology, Gland, Switzerland) is a lithotripter usable with rigid and semirigid ureteroscopes, much more powerful than its predecessors. It is able to decrease the number of shocks necessary for stone fragmentation, without bigger tissue reaction. It also has a more comfortable design due to the absence of connections, and its power by replaceable carbon dioxide cartridges.

Rescue ventilation: resolving a "cannot mask ventilate, cannot intubate" situation during exchange of a Combitube for a definitive airway.

PubMed

Rich, James M; Mason, Andrew M; Tillmann, H A; Foreman, Michael

2009-10-01

Our anesthesia care team was called to care for a patient who was admitted to the emergency department with the esophageal-tracheal double-lumen airway device (Combitube, Tyco Healthcare, Nellcor, Pleasanton, California) in place, which needed to be exchanged for a definitive airway because the patient required an extended period of mechanical ventilation. Several techniques were attempted to exchange the esophageal-tracheal Combitube (ETC) without success. First, we attempted direct laryngoscopy with the ETC in place after deflation of the No. 1 proximal cuff and sweeping the ETC to the left. We were prepared to use bougie-assisted intubation but could not identify any airway anatomy. After removal of the ETC, we unsuccessfully attempted ventilation/intubation with a laryngeal mask airway (LMA Fastrach, LMA North America, San Diego, California). Our third attempt was insertion of another laryngeal mask airway (LMA Unique, LMA North America) with marginal ventilation, but we again experienced unsuccessful intubation using a fiberscope. The ETC was reinserted after each intubation attempt because mask ventilation was impossible. Before proceeding with cricothyrotomy, we repeated direct laryngoscopy but without the ETC in place. We identified the tip of the epiglottis, which allowed for bougie-assisted intubation. This obviated the need for emergency cricothyrotomy.

Design and analysis for a bend-resistant and large-mode-area photonic crystal fiber with hybrid cladding.

PubMed

Qin, Yan; Yang, Huajun; Jiang, Ping; Gui, Fengji; Caiyang, Weinan; Cao, Biao

2018-05-10

In this paper, an asymmetric large-mode-area photonic crystal fiber (LMA-PCF) with low bending loss at a smaller bending radius is designed. The finite-element method with a perfectly matched layer boundary is used to analyze the performance of the PCF. To achieve LMA-PCF with low bending loss, the air holes with double lattice constants and different sizes at the core are designed. Numerical results show that this structure can achieve low bending loss and LMA with a smaller bending radius at the wavelength of 1.55 μm. The effective mode area of the fundamental mode is larger than 1000  μm 2 when the bending radius is ≥10  cm. The bending loss of the fundamental mode is just 0.0113 dB/m, and the difference between the fundamental and high-order modes of the bending loss is larger than 10 3 when the bending radius is 10 cm. Simulation results show this novel PCF can achieve LMA and have effective single-mode operation when the bending orientation angle ranges in ±110°. This novel photonic crystal has potential application in high-power fiber lasers.

The solar neutrino problem after the first results from KamLAND

NASA Astrophysics Data System (ADS)

Bandyopadhyay, Abhijit; Choubey, Sandhya; Gandhi, Raj; Goswami, Srubabati; Roy, D. P.

2003-05-01

The first results from the KamLAND experiment have provided confirmational evidence for the Large Mixing Angle (LMA) Mikheyev-Smirnov-Wolfenstein (MSW) solution to the solar neutrino problem. We do a global analysis of solar and the recently announced KamLAND data (both rate and spectrum) and investigate its effect on the allowed region in the Δm2-tan2θ plane. The best-fit from a combined analysis which uses the KamLAND rate plus global solar data comes at Δm2=6.06×10-5 eV2 and tan2θ=0.42, very close to the global solar best-fit, leaving a large allowed region within the global solar LMA contour. The inclusion of the KamLAND spectral data in the global fit gives a best-fit Δm2=7.17×10-5 eV2 and tan2θ=0.43 and constrains the allowed areas within LMA, leaving essentially two allowed zones. Maximal mixing though allowed by the KamLAND data alone is disfavored by the global solar data and remains disallowed at about /3σ. The low Δm2 solution (LOW) is now ruled out at about 5/σ with respect to the LMA solution.

Photonic Lantern Adaptive Spatial Mode Control in LMA Fiber Amplifiers using SPGD

DTIC Science & Technology

2015-12-15

ll.mit.edu Abstract: We demonstrate adaptive-spatial mode control (ASMC) in few- moded double- clad large mode area (LMA) fiber amplifiers by using an...combination resulting in a single fundamental mode at the output is achieved. 2015 Optical Society of America OCIS codes: (140.3510) Lasers ...fiber; (140.3425) Laser stabilization; (060.2340) Fiber optics components; (110.1080) Active or adaptive optics; References and links 1. C

Photonic crystal fiber technology for high-performance all-fiber monolithic ultrafast fiber amplifiers

NASA Astrophysics Data System (ADS)

Papior, Sidsel R.; Weirich, Johannes; Johansen, Mette M.; Jakobsen, Christian; Michieletto, Mattia; Triches, Marco; Kristensen, Torben; Olesen, Anders S.; Petersen, Christian; Andersen, Thomas V.; Maack, Martin D.; Alkeskjold, Thomas T.

2018-02-01

Photonic crystal fiber (PCF) technology for ultrafast fiber amplifiers traditionally uses air holes as key elements for large mode area (LMA) fiber designs. These air holes are crucial for the performance of high-end LMA PCFs, but makes splicing and interfacing more complex. To reduce this complexity in mid-range amplifiers, we present single-mode polarization-maintaining Yb-doped LMA PCFs without air holes for easier splicing into monolithic all-fiber amplifier designs. A 30 μm core all-solid spliceable PCF is presented, and amplification of 1064 nm light above 50 W with an optical to optical efficiency of 80 % is demonstrated. Furthermore, to demonstrate the excellent reliability of PCF based monolithic amplifiers, we demonstrate ultra-longterm performance data of > 35 khrs on a 14 μm core step-index type PCF amplifier with low long-term power degradation slope of < 1.5 % / 10,000 h.

Leaf nitrogen from first principles: field evidence for adaptive variation with climate

NASA Astrophysics Data System (ADS)

Dong, Ning; Prentice, Iain Colin; Evans, Bradley J.; Caddy-Retalic, Stefan; Lowe, Andrew J.; Wright, Ian J.

2017-01-01

Nitrogen content per unit leaf area (Narea) is a key variable in plant functional ecology and biogeochemistry. Narea comprises a structural component, which scales with leaf mass per area (LMA), and a metabolic component, which scales with Rubisco capacity. The co-ordination hypothesis, as implemented in LPJ and related global vegetation models, predicts that Rubisco capacity should be directly proportional to irradiance but should decrease with increases in ci : ca and temperature because the amount of Rubisco required to achieve a given assimilation rate declines with increases in both. We tested these predictions using LMA, leaf δ13C, and leaf N measurements on complete species assemblages sampled at sites on a north-south transect from tropical to temperate Australia. Partial effects of mean canopy irradiance, mean annual temperature, and ci : ca (from δ13C) on Narea were all significant and their directions and magnitudes were in line with predictions. Over 80 % of the variance in community-mean (ln) Narea was accounted for by these predictors plus LMA. Moreover, Narea could be decomposed into two components, one proportional to LMA (slightly steeper in N-fixers), and the other to Rubisco capacity as predicted by the co-ordination hypothesis. Trait gradient analysis revealed ci : ca to be perfectly plastic, while species turnover contributed about half the variation in LMA and Narea. Interest has surged in methods to predict continuous leaf-trait variation from environmental factors, in order to improve ecosystem models. Coupled carbon-nitrogen models require a method to predict Narea that is more realistic than the widespread assumptions that Narea is proportional to photosynthetic capacity, and/or that Narea (and photosynthetic capacity) are determined by N supply from the soil. Our results indicate that Narea has a useful degree of predictability, from a combination of LMA and ci : ca - themselves in part environmentally determined - with Rubisco activity, as predicted from local growing conditions. This finding is consistent with a plant-centred approach to modelling, emphasizing the adaptive regulation of traits. Models that account for biodiversity will also need to partition community-level trait variation into components due to phenotypic plasticity and/or genotypic differentiation within species vs. progressive species replacement, along environmental gradients. Our analysis suggests that variation in Narea is about evenly split between these two modes.

Geographical accessibility to community pharmacies by the elderly in metropolitan Lisbon.

PubMed

Padeiro, Miguel

2018-07-01

In ageing societies, community pharmacies play an important role in delivering medicines, responsible advising, and other targeted services. Elderly people are among their main consumers, as they use more prescription drugs, need more specific health care, and experience more mobility issues than other age groups. This makes geographical accessibility a relevant concern for them. To measure geographical pedestrian accessibility to community pharmacies by elderly people in the Lisbon Metropolitan Area (LMA). The number of elderly people living within a 10- and 15-min walk was estimated based on the exploitation of population census data, the address-based location of 801 community pharmacies, and a Google Maps Application Programming Interface (API) method for calculating distances between pharmacies and the centroids of census statistical subsections. Results were compared to figures attained via traditional methods. In the LMA, 61.2% of the elderly live less than a 10 min walk from the nearest pharmacy and 76.9% live less than 15 min away. This opposes the common view that pharmacies are highly accessible in urban areas. In addition, results show a high spatial variability of proximity to pharmacies. Despite the illusion of good coverage suggested at the metropolitan scale, accessibility measures demonstrate the existence of pharmaceutical deprivation areas for the elderly. The findings indicate the need for more accuracy in both access measurements and redistribution policies. Measurement methods and population targets should be reconsidered. Copyright © 2017 Elsevier Inc. All rights reserved.

Mathematics Anxiety, Working Memory, and Mathematics Performance in Secondary-School Children.

PubMed

Passolunghi, Maria C; Caviola, Sara; De Agostini, Ruggero; Perin, Chiara; Mammarella, Irene C

2016-01-01

Mathematics anxiety (MA) has been defined as "a feeling of tension and anxiety that interferes with the manipulation of numbers and the solving of math problems in a wide variety of ordinary life and academic situations." Previous studies have suggested that a notable proportion of children in primary and secondary school suffer from MA, which is negatively correlated with calculation skills. The processing efficiency and attentional control theories suggest that working memory (WM) also plays an important part in such anxious feelings. The present study aimed to analyze the academic achievement and cognitive profiles of students with high math anxiety (HMA) and low math anxiety (LMA). Specifically, 32 students with HMA and 34 with LMA matched for age, gender, generalized anxiety, and vocabulary attending sixth to eighth grades were selected from a larger sample. The two groups were tested on reading decoding, reading comprehension, mathematics achievement, and on verbal short-term memory and WM. Our findings showed that HMA students were weak in several measures of mathematics achievement, but not in reading and writing skills, and that students with HMA reported lower scores on short-term memory and WM performances (with associated difficulties in inhibiting irrelevant information) than children with LMA. In addition, a logistic regression showed that weaknesses in inhibitory control and fact retrieval were the strongest variables for classifying children as having HMA or LMA.

Morphological findings in the tracheal epithelium of dogs exposed to the inhalation of poorly conditioned gases under use of an endotracheal tube or laryngeal mask airway.

PubMed

Dias, Norimar Hernandes; Braz, José Reinaldo Cerqueira; Defaveri, Júlio; Carvalho, Lídia Raquel; Martins, Regina Helena Garcia

2011-10-01

To study morphological findings in the tracheal epithelium of dogs exposed to the inhalation of poorly conditioned gases under use of an endotracheal tube (ET) or laryngeal mask airway (LMA). Twelve dogs randomly were allocated to two groups: ET group (n-6) and LMA group (n-6), anaesthetized and mechanically ventilated, without CO(2) reabsorption. Haemodynamic and ventilatory parameters, tympanic temperature, temperature, relative and absolute humidity of the ambient and inhaled gases were analyzed during three hours. The animals were submitted to euthanasia and biopsies were carried out along the tracheal segment to morphological study. Three healthy dogs were used to morphological control. Inhaled gas temperature was maintained between 24ºC and 26ºC, relative humidity between 10% and 12%, and absolute humidity between 2 - 3 mg H(2)O.L(-1) with no significant differences between groups. In both groups, histological analysis showed epithelial inflammation and congestion in the corion and scanning electron microscopy showed ciliary grouping and disorganization. Transmission electron microscopy showed higher alterations in ET group than LMA group as widening of cell junctions, ciliary disorientation, cytoplasmic vacuolization, nuclear abnormalities, picnosis and chromatin condensation. LMA determined less pronounced changes in the tracheal epithelium in dogs exposed to the inhalation of poorly conditioned gases.

Mathematics Anxiety, Working Memory, and Mathematics Performance in Secondary-School Children

PubMed Central

Passolunghi, Maria C.; Caviola, Sara; De Agostini, Ruggero; Perin, Chiara; Mammarella, Irene C.

2016-01-01

Mathematics anxiety (MA) has been defined as “a feeling of tension and anxiety that interferes with the manipulation of numbers and the solving of math problems in a wide variety of ordinary life and academic situations.” Previous studies have suggested that a notable proportion of children in primary and secondary school suffer from MA, which is negatively correlated with calculation skills. The processing efficiency and attentional control theories suggest that working memory (WM) also plays an important part in such anxious feelings. The present study aimed to analyze the academic achievement and cognitive profiles of students with high math anxiety (HMA) and low math anxiety (LMA). Specifically, 32 students with HMA and 34 with LMA matched for age, gender, generalized anxiety, and vocabulary attending sixth to eighth grades were selected from a larger sample. The two groups were tested on reading decoding, reading comprehension, mathematics achievement, and on verbal short-term memory and WM. Our findings showed that HMA students were weak in several measures of mathematics achievement, but not in reading and writing skills, and that students with HMA reported lower scores on short-term memory and WM performances (with associated difficulties in inhibiting irrelevant information) than children with LMA. In addition, a logistic regression showed that weaknesses in inhibitory control and fact retrieval were the strongest variables for classifying children as having HMA or LMA. PMID:26869951

Intraspecific trait variation and covariation in a widespread tree species (Nothofagus pumilio) in southern Chile.

PubMed

Fajardo, Alex; Piper, Frida I

2011-01-01

• The focus of the trait-based approach to study community ecology has mostly been on trait comparisons at the interspecific level. Here we quantified intraspecific variation and covariation of leaf mass per area (LMA) and wood density (WD) in monospecific forests of the widespread tree species Nothofagus pumilio to determine its magnitude and whether it is related to environmental conditions and ontogeny. We also discuss probable mechanisms controlling the trait variation found. • We collected leaf and stem woody tissues from 30-50 trees of different ages (ontogeny) from each of four populations at differing elevations (i.e. temperatures) and placed at each of three locations differing in soil moisture. • The total variation in LMA (coefficient of variation (CV) = 21.14%) was twice that of WD (CV = 10.52%). The total variation in traits was never less than 23% when compared with interspecific studies. Differences in elevation (temperature) for the most part explained variation in LMA, while differences in soil moisture and ontogeny explained the variation in WD. Traits covaried similarly in the altitudinal gradient only. • Functional traits of N. pumilio exhibited nonnegligible variation; LMA varied for the most part with temperature, while WD mostly varied with moisture and ontogeny. We demonstrate that environmental variation can cause important trait variation without species turnover. © The Authors (2010). Journal compilation © New Phytologist Trust (2010).

Daily energy balance in growth hormone receptor/binding protein (GHR -/-) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency.

PubMed

Longo, Kenneth A; Berryman, Darlene E; Kelder, Bruce; Charoenthongtrakul, Soratree; Distefano, Peter S; Geddes, Brad J; Kopchick, John J

2010-02-01

The goal of this study was to examine factors that contribute to energy balance in female GHR -/- mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (M(b)) changes and physical activity in 17month-old female GHR -/- mice and their age-matched wild type littermates. The GHR -/- mice were smaller, consumed more food per unit M(b), had greater EE per unit M(b) and had an increase in 24-h EE/M(b) that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR -/- mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, M(b) and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for M(b) and LMA, the GHR -/- mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR -/- mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR -/- mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final 3h of the dark phase. Therefore, we conclude that GHR -/- mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable M(b). Relative to wild type mice, the GHR -/- mice consumed more calories per unit M(b), which offset the disproportionate increase in their daily energy expenditure. While GHR -/- mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. Copyright 2009 Elsevier Ltd. All rights reserved.

How vertical patterns in leaf traits shift seasonally and the implications for modeling canopy photosynthesis in a temperate deciduous forest.

PubMed

Coble, Adam P; VanderWall, Brittany; Mau, Alida; Cavaleri, Molly A

2016-09-01

Leaf functional traits are used in modeling forest canopy photosynthesis (Ac) due to strong correlations between photosynthetic capacity, leaf mass per area (LMA) and leaf nitrogen per area (Narea). Vertical distributions of these traits may change over time in temperate deciduous forests as a result of acclimation to light, which may result in seasonal changes in Ac To assess both spatial and temporal variations in key traits, we measured vertical profiles of Narea and LMA from leaf expansion through leaf senescence in a sugar maple (Acer saccharum Marshall) forest. To investigate mechanisms behind coordinated changes in leaf morphology and function, we also measured vertical variation in leaf carbon isotope composition (δ(13)C), predawn turgor pressure, leaf water potential and osmotic potential. Finally, we assessed potential biases in Ac estimations by parameterizing models with and without vertical and seasonal Narea variations following leaf expansion. Our data are consistent with the hypothesis that hydrostatic constraints on leaf morphology drive the vertical increase in LMA with height early in the growing season; however, LMA in the upper canopy continued to increase over time during light acclimation, indicating that light is primarily driving gradients in LMA later in the growing season. Models with no seasonal variation in Narea overestimated Ac by up to 11% early in the growing season, while models with no vertical variation in Narea overestimated Ac by up to 60% throughout the season. According to the multilayer model, the upper 25% of leaf area contributed to over 50% of Ac, but when gradients of intercellular CO2, as estimated from δ(13)C, were accounted for, the upper 25% of leaf area contributed to 26% of total Ac Our results suggest that ignoring vertical variation of key traits can lead to considerable overestimation of Ac. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Daily energy balance in growth hormone receptor/binding protein (GHR−/−) gene-disrupted mice is achieved through an increase in dark-phase energy efficiency

PubMed Central

Longo, Kenneth A.; Berryman, Darlene E.; Kelder, Bruce; Charoenthongtrakul, Soratree; DiStefano, Peter S.; Geddes, Brad J.; Kopchick, John

2009-01-01

The goal of this study was to examine factors that contribute to energy balance in female GHR −/− mice. We measured energy intake, energy expenditure (EE), fuel utilization, body mass (Mb) changes and physical activity in 17 month-old female GHR −/− mice and their age-matched wild type littermates. The GHR −/− mice were smaller, consumed more food per unit Mb, had greater EE per unit Mb and had an increase in 24-h EE/Mb that was similar to the increase in their surface-area-to-volume ratio. Locomotor activity (LMA) was reduced in the GHR −/− mice, but the energetic cost associated with their LMA was greater than in wild type controls. Furthermore, Mb and LMA were independent explanatory covariates of most of the variance in EE, and when adjusted for Mb and LMA, the GHR −/− mice had higher EE during both the light and dark phases of the daily cycle. Respiratory quotient was lower in GHR −/− mice during the light phase, which indicated a greater utilization of lipid relative to carbohydrate in these mice. Additionally, GHR −/− mice had higher ratios of caloric intake to EE at several intervals during the dark phase, and this effect was greater and more sustained in the final three hours of the dark phase. Therefore, we conclude that GHR −/− mice are able to overcome the substantial energetic challenges of dwarfism through several mechanisms that promote stable Mb. Relative to wild type mice, the GHR −/− mice consumed more calories per unit Mb, which offset the disproportionate increase in their daily energy expenditure. While GHR −/− mice oxidized a greater proportion of lipid during the light phase in order to meet their energy requirements, they achieved greater energy efficiency and storage during the dark phase through a combination of higher energy consumption and lower LMA. PMID:19747867

Basic life support trained nurses ventilate more efficiently with laryngeal mask supreme than with facemask or laryngeal tube suction-disposable--a prospective, randomized clinical trial.

PubMed

Gruber, Elisabeth; Oberhammer, Rosmarie; Balkenhol, Karla; Strapazzon, Giacomo; Procter, Emily; Brugger, Hermann; Falk, Markus; Paal, Peter

2014-04-01

In some emergency situations resuscitation and ventilation may have to be performed by basic life support trained personnel, especially in rural areas where arrival of advanced life support teams can be delayed. The use of advanced airway devices such as endotracheal intubation has been deemphasized for basically-trained personnel, but it is unclear whether supraglottic airway devices are advisable over traditional mask-ventilation. In this prospective, randomized clinical single-centre trial we compared airway management and ventilation performed by nurses using facemask, laryngeal mask Supreme (LMA-S) and laryngeal tube suction-disposable (LTS-D). Basic life support trained nurses (n=20) received one-hour practical training with each device. ASA 1-2 patients scheduled for elective surgery were included (n=150). After induction of anaesthesia and neuromuscular block nurses had two 90-second attempts to manage the airway and ventilate the patient with volume-controlled ventilation. Ventilation failed in 34% of patients with facemask, 2% with LMA-S and 22% with LTS-D (P<0.001). In patients who could be ventilated successfully mean tidal volume was 240±210 ml with facemask, 470±120 ml with LMA-S and 470±140 ml with LTS-D (P<0.001). Leak pressure was lower with LMA-S (23.3±10.8 cm H2O, 95% CI 20.2-26.4) than with LTS-D (28.9±13.9 cm·H2O, 95% CI 24.4-33.4; P=0.047). After one hour of introductory training, nurses were able to use LMA-S more effectively than facemask and LTS-D. High ventilation failure rates with facemask and LTS-D may indicate that additional training is required to perform airway management adequately with these devices. High-level trials are needed to confirm these results in cardiac arrest patients. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Distribution of leaf characteristics in relation to orientation within the canopy of woody species

NASA Astrophysics Data System (ADS)

Escudero, Alfonso; Fernández, José; Cordero, Angel; Mediavilla, Sonia

2013-04-01

Over the last few decades considerable effort has been devoted to research of leaf adaptations to environmental conditions. Many studies have reported strong differences in leaf mass per unit area (LMA) within a single tree depending on the photosynthetic photon flux density (PPFD) incident on different locations in the crown. There are fewer studies, however, of the effects of differences in the timing of light incidence during the day on different crown orientations. Leaves from isolated trees of Quercus suber and Quercus ilex in a cold Mediterranean climate were sampled to analyze differences in LMA and other leaf traits among different crown orientations. Gas-exchange rates, leaf water potentials, leaf temperatures and PPFD incident on leaf surfaces in different crown orientations were also measured throughout one entire summer day for each species. Mean daily PPFD values were similar for the leaves from the eastern and western sides of the canopy. On the western side, PPFD reached maximum values during the afternoon. Maximum leaf temperatures were approximately 10-20% higher on the west side, whereas minimum leaf water potentials were between 10 and 24% higher on the east side. Maximum transpiration rates were approximately 22% greater on the west, because of the greater leaf-to-air vapor pressure deficits (LAVPD). Mean individual leaf area was around 10% larger on the east than on the west side of the trees. In contrast, there were no significant differences in LMA between east and west sides of the crown. Contrary to our expectations, more severe water stress on the west side did not result in increases in LMA, although it was associated with lower individual leaf area. We conclude that increases in LMA measured by other authors along gradients of water stress would be due to differences in light intensity between dry and humid sites.

Photonic lantern adaptive spatial mode control in LMA fiber amplifiers.

PubMed

Montoya, Juan; Aleshire, Chris; Hwang, Christopher; Fontaine, Nicolas K; Velázquez-Benítez, Amado; Martz, Dale H; Fan, T Y; Ripin, Dan

2016-02-22

We demonstrate adaptive-spatial mode control (ASMC) in few-moded double-clad large mode area (LMA) fiber amplifiers by using an all-fiber-based photonic lantern. Three single-mode fiber inputs are used to adaptively inject the appropriate superposition of input modes in a multimode gain fiber to achieve the desired mode at the output. By actively adjusting the relative phase of the single-mode inputs, near-unity coherent combination resulting in a single fundamental mode at the output is achieved.

[Difficult Ventilation Requiring Emergency Endotracheal Intubation during Awake Craniotomy Managed by Laryngeal Mask Airway].

PubMed

Matsuda, Asako; Mizota, Toshiyuki; Tanaka, Tomoharu; Segawa, Hajime; Fukuda, Kazuhiko

2016-04-01

We report a case of difficult ventilation requiring emergency endotracheal intubation during awake craniotomy managed by laryngeal mask airway (LMA). A 45-year-old woman was scheduled to receive awake craniotomy for brain tumor in the frontal lobe. After anesthetic induction, airway was secured using ProSeal LMA and patient was mechanically ventilated in pressure-control mode. Patient's head was fixed with head-pins at anteflex position, and the operation started. About one hour after the start of the operation, tidal volume suddenly decreased. We immediately started manual ventilation, but the airway resistance was extremely high and we could not adequately ventilate the patient. We administered muscle relaxant for suspected laryngospasm, but ventilatory status did not improve; so we decided to conduct emergency endotracheal intubation. We tried to intubate using Airwayscope or LMA-Fastrach, but they were not effective in our case. Finally trachea was intubated using transnasal fiberoptic bronchoscopy. We discuss airway management during awake craniotomy, focusing on emergency endotracheal intubation during surgery.

The effect of esophagogastroduodenoscopy probe insertion on the intracuff pressure of airway devices in children during general anesthesia.

PubMed

Balaban, Onur; Kamata, Mineto; Hakim, Mumin; Tumin, Dmitry; Tobias, Joseph D

2017-04-01

Given the size of the esophagogastroduodenoscopy (EGD) probe and the compressibility of the pediatric airway, the EGD probe may increase the intracuff pressure (IP) of an airway device. The current study evaluated IP changes during EGD examination under general anesthesia in pediatric patients. Following the induction of anesthesia, a laryngeal mask airway (LMA) or endotracheal tube (ETT) was placed without neuromuscular blockade. The IP was measured at baseline, during EGD probe insertion, while the EGD probe was in place, and after probe removal. The study cohort included 101 patients (mean age 11.3 years). The airway was secured with an LMA and an ETT in 88 and 13 patients, respectively. The IP increased from 27 ± 15 cmH 2 O at baseline to 34 ± 17 cmH 2 O during probe insertion (p < 0.001), remained at 33 ± 16 cmH 2 O while the probe was in place, and decreased to 26 ± 14 cmH 2 O after probe removal. The IP of the LMA or ETT increased during EGD probe insertion and remained elevated while the probe was in place. High IP may compromise mucosal perfusion resulting in a sore throat when using an LMA or the potential for airway damage if an ETT is used. Removal of air from the cuff and titration of the IP should be considered after EGD insertion.

A randomized non-crossover study comparing the ProSeal and Classic laryngeal mask airway in anaesthetized children.

PubMed

Lopez-Gil, M; Brimacombe, J; Garcia, G

2005-12-01

We tested the hypothesis that ease of insertion, oropharyngeal leak pressure, fibreoptic position, gastric insufflation, and the frequency of mucosal trauma differ between the ProSeal laryngeal mask airway (PLMA) and the classic laryngeal mask airway (cLMA) in anaesthetized children. For the PLMA, we also assessed the ease of gastric tube placement via the PLMA drain tube and measure residual gastric volume. 240 consecutive ASA I-III children aged 1-16 yr were randomized for airway management with the ProSeal or cLMA. The time taken to provide an effective airway, the number of insertion attempts, fibreoptic position of the airway tube and frequency of mucosal trauma were similar, but oropharyngeal leak pressure was higher (33 vs 26 cm H(2)O, P<0.0001) and gastric insufflation less common (0 vs 6%, P<0.01) for the PLMA. Gastric tube insertion was successful at the first attempt in 106 of 120, and at the second attempt in 14 of 120. The mean (sd; range) value for residual gastric volume was 2.2 (5.9; 0-30) ml. There were no differences in performance among sizes for the PLMA and the cLMA. We conclude that ease of insertion, fibreoptic position, and frequency of mucosal trauma are similar for the PLMA and cLMA in children, but oropharyngeal leak pressure is higher and gastric insufflation less common for the PLMA. Gastric tube insertion has a high success rate, provided the PLMA is correctly positioned.

Performance Analysis of Inter-Domain Handoff Scheme Based on Virtual Layer in PMIPv6 Networks for IP-Based Internet of Things.

PubMed

Cho, Chulhee; Choi, Jae-Young; Jeong, Jongpil; Chung, Tai-Myoung

2017-01-01

Lately, we see that Internet of things (IoT) is introduced in medical services for global connection among patients, sensors, and all nearby things. The principal purpose of this global connection is to provide context awareness for the purpose of bringing convenience to a patient's life and more effectively implementing clinical processes. In health care, monitoring of biosignals of a patient has to be continuously performed while the patient moves inside and outside the hospital. Also, to monitor the accurate location and biosignals of the patient, appropriate mobility management is necessary to maintain connection between the patient and the hospital network. In this paper, a binding update scheme on PMIPv6, which reduces signal traffic during location updates by Virtual LMA (VLMA) on the top original Local Mobility Anchor (LMA) Domain, is proposed to reduce the total cost. If a Mobile Node (MN) moves to a Mobile Access Gateway (MAG)-located boundary of an adjacent LMA domain, the MN changes itself into a virtual mode, and this movement will be assumed to be a part of the VLMA domain. In the proposed scheme, MAGs eliminate global binding updates for MNs between LMA domains and significantly reduce the packet loss and latency by eliminating the handoff between LMAs. In conclusion, the performance analysis results show that the proposed scheme improves performance significantly versus PMIPv6 and HMIPv6 in terms of the binding update rate per user and average handoff latency.

Development of a dense SNP-based linkage map of an apple rootstock progeny using the Malus Infinium whole genome genotyping array.

PubMed

Antanaviciute, Laima; Fernández-Fernández, Felicidad; Jansen, Johannes; Banchi, Elisa; Evans, Katherine M; Viola, Roberto; Velasco, Riccardo; Dunwell, Jim M; Troggio, Michela; Sargent, Daniel J

2012-05-25

A whole-genome genotyping array has previously been developed for Malus using SNP data from 28 Malus genotypes. This array offers the prospect of high throughput genotyping and linkage map development for any given Malus progeny. To test the applicability of the array for mapping in diverse Malus genotypes, we applied the array to the construction of a SNP-based linkage map of an apple rootstock progeny. Of the 7,867 Malus SNP markers on the array, 1,823 (23.2%) were heterozygous in one of the two parents of the progeny, 1,007 (12.8%) were heterozygous in both parental genotypes, whilst just 2.8% of the 921 Pyrus SNPs were heterozygous. A linkage map spanning 1,282.2 cM was produced comprising 2,272 SNP markers, 306 SSR markers and the S-locus. The length of the M432 linkage map was increased by 52.7 cM with the addition of the SNP markers, whilst marker density increased from 3.8 cM/marker to 0.5 cM/marker. Just three regions in excess of 10 cM remain where no markers were mapped. We compared the positions of the mapped SNP markers on the M432 map with their predicted positions on the 'Golden Delicious' genome sequence. A total of 311 markers (13.7% of all mapped markers) mapped to positions that conflicted with their predicted positions on the 'Golden Delicious' pseudo-chromosomes, indicating the presence of paralogous genomic regions or mis-assignments of genome sequence contigs during the assembly and anchoring of the genome sequence. We incorporated data for the 2,272 SNP markers onto the map of the M432 progeny and have presented the most complete and saturated map of the full 17 linkage groups of M. pumila to date. The data were generated rapidly in a high-throughput semi-automated pipeline, permitting significant savings in time and cost over linkage map construction using microsatellites. The application of the array will permit linkage maps to be developed for QTL analyses in a cost-effective manner, and the identification of SNPs that have been assigned erroneous positions on the 'Golden Delicious' reference sequence will assist in the continued improvement of the genome sequence assembly for that variety.

Lightning Activity Relative to the Microphysical and Kinematic Structure of Storms during a Thunder-Snow Episode on 29-30 November 2006

NASA Astrophysics Data System (ADS)

Emersic, C.; Macgorman, D.; Schuur, T.; Lund, N.; Payne, C.; Bruning, E.

2007-12-01

We have examined lightning activity relative to the microphysical and kinematic structure of a winter thunderstorm complex (a thunder-snow episode) observed east of Norman, Oklahoma during the evening of 29-30 November 2006. Polarimetric radar provided information about the type of particles present in various regions of the storms. The Lightning Mapping Array (LMA) recorded VHF signals produced by developing lightning channels. The times of arrival of these lightning signals across the array were then used to reconstruct the location and structure of lightning, and these reconstructions were overlaid with radar data to examine the relationship between lightning properties and storm particle types. Four storms in this winter complex have been examined. It was inferred from lightning structure that, in their mature stage, all cells we examined had a positive tripole electrical structure (an upper positive charge center, a midlevel negative charge center, and a lower positive charge center). The storms began with lightning activity in the lower dipole (lower positive and midlevel negative regions), but this evolved into lightning activity throughout the tripole structure within approximately 15-20 minutes. In the longer lived storms, the mature stage lasted for approximately 1.5-2 hours. During this stage, the lower positive charge region was situated less than 5 km above ground, the midlevel negative charge region was typically above 5 km, and the upper positive charge region was located at an altitude of less than 10 km in all the storm cells analyzed. The charge regions descended over approximately the last 30 minutes of lightning activity, the lower charge regions eventually reaching ground. This resulted in the loss of the lower positive charge center and the subsequent diminishment of the lower negative charge center. Lightning initiation usually coincided with the edges of regions of high reflectivity and was coincident with the presence of graupel and ice crystals in the lower dipole. Radar data suggest that ice crystals were the dominant charge carriers in the upper positive region.

Inspection design using 2D phased array, TFM and cueMAP software

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

McGilp, Ailidh; Dziewierz, Jerzy; Lardner, Tim

2014-02-18

A simulation suite, cueMAP, has been developed to facilitate the design of inspection processes and sparse 2D array configurations. At the core of cueMAP is a Total Focusing Method (TFM) imaging algorithm that enables computer assisted design of ultrasonic inspection scenarios, including the design of bespoke array configurations to match the inspection criteria. This in-house developed TFM code allows for interactive evaluation of image quality indicators of ultrasonic imaging performance when utilizing a 2D phased array working in FMC/TFM mode. The cueMAP software uses a series of TFM images to build a map of resolution, contrast and sensitivity of imagingmore » performance of a simulated reflector, swept across the inspection volume. The software takes into account probe properties, wedge or water standoff, and effects of specimen curvature. In the validation process of this new software package, two 2D arrays have been evaluated on 304n stainless steel samples, typical of the primary circuit in nuclear plants. Thick section samples have been inspected using a 1MHz 2D matrix array. Due to the processing efficiency of the software, the data collected from these array configurations has been used to investigate the influence sub-aperture operation on inspection performance.« less

Mapping Capacitive Coupling Among Pixels in a Sensor Array

NASA Technical Reports Server (NTRS)

Seshadri, Suresh; Cole, David M.; Smith, Roger M.

2010-01-01

An improved method of mapping the capacitive contribution to cross-talk among pixels in an imaging array of sensors (typically, an imaging photodetector array) has been devised for use in calibrating and/or characterizing such an array. The method involves a sequence of resets of subarrays of pixels to specified voltages and measurement of the voltage responses of neighboring non-reset pixels.

Methods of Real Time Image Enhancement of Flash LIDAR Data and Navigating a Vehicle Using Flash LIDAR Data

NASA Technical Reports Server (NTRS)

Vanek, Michael D. (Inventor)

2014-01-01

A method for creating a digital elevation map ("DEM") from frames of flash LIDAR data includes generating a first distance R(sub i) from a first detector i to a first point on a surface S(sub i). After defining a map with a mesh THETA having cells k, a first array S(k), a second array M(k), and a third array D(k) are initialized. The first array corresponds to the surface, the second array corresponds to the elevation map, and the third array D(k) receives an output for the DEM. The surface is projected onto the mesh THETA, so that a second distance R(sub k) from a second point on the mesh THETA to the detector can be found. From this, a height may be calculated, which permits the generation of a digital elevation map. Also, using sequential frames of flash LIDAR data, vehicle control is possible using an offset between successive frames.

The Washington DC Metro Area Lightning Mapping Array

NASA Technical Reports Server (NTRS)

Krehbiel, Paul; Rison, William; Edens, Harald; OConnor, Nicholas; Aulich, Graydon; Thomas, Ronald; Kieft, Sandra; Goodman, Steven; Blakeslee, Richard; Hall, John;

Design and Fabrication of an Experimental Microheater Array Powder Sintering Printer

NASA Astrophysics Data System (ADS)

Holt, Nicholas; Zhou, Wenchao

2018-03-01

Microheater array powder sintering (MAPS) is a novel additive manufacturing process that uses an array of microheaters to selectively sinter powder particles. MAPS shows great promise as a new method of printing flexible electronics by enabling digital curing of conductive inks on a variety of substrates. For MAPS to work effectively, a microscale air gap needs to be maintained between the heater array and the conductive ink. In this article, we present an experimental MAPS printer with air gap control for printing conductive circuits. First, we discuss design aspects necessary to implement MAPS. An analysis is performed to validate that the design can maintain the desired air gap between the microheaters and the sintering layer, which consists of a silver nanoparticle ink. The printer is tested by printing conductive lines on a flexible plastic substrate with silver nanoparticle ink. Results show MAPS performs on par with or better than the existing fabrication methods for printed electronics in terms of both the print quality (conductivity of the printed line) and print speed, which shows MAPS' great promise as a competitive new method for digital production of printed electronics.

Evaluation of SNP Data from the Malus Infinium Array Identifies Challenges for Genetic Analysis of Complex Genomes of Polyploid Origin.

PubMed

Troggio, Michela; Surbanovski, Nada; Bianco, Luca; Moretto, Marco; Giongo, Lara; Banchi, Elisa; Viola, Roberto; Fernández, Felicdad Fernández; Costa, Fabrizio; Velasco, Riccardo; Cestaro, Alessandro; Sargent, Daniel James

2013-01-01

High throughput arrays for the simultaneous genotyping of thousands of single-nucleotide polymorphisms (SNPs) have made the rapid genetic characterisation of plant genomes and the development of saturated linkage maps a realistic prospect for many plant species of agronomic importance. However, the correct calling of SNP genotypes in divergent polyploid genomes using array technology can be problematic due to paralogy, and to divergence in probe sequences causing changes in probe binding efficiencies. An Illumina Infinium II whole-genome genotyping array was recently developed for the cultivated apple and used to develop a molecular linkage map for an apple rootstock progeny (M432), but a large proportion of segregating SNPs were not mapped in the progeny, due to unexpected genotype clustering patterns. To investigate the causes of this unexpected clustering we performed BLAST analysis of all probe sequences against the 'Golden Delicious' genome sequence and discovered evidence for paralogous annealing sites and probe sequence divergence for a high proportion of probes contained on the array. Following visual re-evaluation of the genotyping data generated for 8,788 SNPs for the M432 progeny using the array, we manually re-scored genotypes at 818 loci and mapped a further 797 markers to the M432 linkage map. The newly mapped markers included the majority of those that could not be mapped previously, as well as loci that were previously scored as monomorphic, but which segregated due to divergence leading to heterozygosity in probe annealing sites. An evaluation of the 8,788 probes in a diverse collection of Malus germplasm showed that more than half the probes returned genotype clustering patterns that were difficult or impossible to interpret reliably, highlighting implications for the use of the array in genome-wide association studies.

Emergence times and airway reactions in general laryngeal mask airway anesthesia: study protocol for a randomized controlled trial.

PubMed

Stevanovic, Ana; Rossaint, Rolf; Keszei, András P; Fritz, Harald; Fröba, Gebhard; Pühringer, Friedrich; Coburn, Mark

2015-07-26

The use of a laryngeal mask airway (LMA) in appropriate patients supports fast-track anesthesia with a lower incidence of postoperative airway-connected adverse events. Data on the most favorable anesthetic in this context, with the lowest rate of upper airway complications and fast emergence times, are controversial and limited. Desflurane seems to match these criteria best, but large randomized controlled trials (RCTs) with a standardized study protocol are lacking. Therefore, we aim to compare desflurane with other commonly used anesthetics, sevoflurane and propofol, in a sufficiently powered RCT. We hypothesize that desflurane is noninferior regarding the frequency of upper airway events and superior regarding the emergence times to sevoflurane and propofol. A total of 351 patients undergoing surgery with an LMA will be included in this prospective, randomized, double-blind controlled, multicenter clinical trial. The patients will be randomly assigned to the three treatment arms: desflurane (n = 117), sevoflurane (n = 117), and propofol (n = 117). The emergence time (time to state the date of birth) will be the primary endpoint of this study. The secondary endpoints include further emergence times, such as time to open eyes, to remove LMA, to respond to command and to state name. Additionally, we will determine the frequency of cough and laryngospasm, measured intraoperatively and at emergence. We will assess the postoperative recovery on the first postoperative day via the Postoperative Quality Recovery Scale. Despite increasing importance of cost-effective and safe anesthesia application, we lack proof for the most advantageous anesthetic agent, when an LMA is used. There are only a few RCTs comparing desflurane to other commonly used anesthetics (sevoflurane, propofol and isoflurane) in patients with LMA. These RCTs were conducted with small sample sizes, huge interstudy variability, and some also showed strong biases. The present multicenter RCT will provide results from a large sample size with a standardized study protocol and minimized bias, which is feasible in the clinical routine. Furthermore, we will expand our knowledge regarding the most favorable recovery on the first postoperative day, which impacts patients' comfort after surgery. EudraCT Identifier: 2014-003810-96, 5 September 2014 ClinicalTrials.gov: NCT02322502, December 2014.

Relationship Between Respiratory Dynamics and Body Mass Index in Patients Undergoing General Anesthesia with Laryngeal Mask Airway (LMA) and Comparison Between Lithotomy and Supine Positions

PubMed Central

Zhao, Xiao; Huang, Shiwei; Wang, Zhaomin; Chen, Lianhua; Li, Shitong

2016-01-01

Background This study aimed to compare respiratory dynamics in patients undergoing general anesthesia with a laryngeal mask airway (LMA) in lithotomy and supine positions and to validate the impact of operational position on effectiveness of LMA ventilation. Material/Methods A total of 90 patients (age range, 18–65 years) who underwent general anesthesia were selected and divided into supine position (SP group) and lithotomy position groups (LP group). Vital signs and respiratory dynamic parameters of the 2 groups were measured at different time points and after implantation of an LMA. The arterial blood gas was monitored at 15 min after induction. The intraoperative changes of hemodynamic indexes and postoperative adverse reactions of LMA were recorded. The possible correlation between body mass index (BMI) and respiratory dynamic indexes was analyzed. Results With prolonged duration of the operation, the inspiratory plateau pressure (Pplat), inspiratory resistance (RI), and work of breathing (WOB) gradually increased, while chest-lung compliance (Compl) and partial pressure of carbon dioxide in end-expiratory gas (PetCO2) gradually decreased (all P value <0.05). The mean airway pressure (Pmean), Pplat, and expiratory resistance (Re) in the LP group were significantly higher than in the SP group (P<0.05), while the peak inspiratory flow (FImax), peak expiratory flow (FEmax), WOB, and Compl in the LP group were significantly lower than in the SP group (P<0.05). BMI was positively correlated with peak airway pressure (PIP/Ppeak), Pplat, and airway resistance (Raw) and was negatively correlated with Compl; the differences among patients in lithotomy position were more remarkable (P<0.05). Conclusions The inspiratory plateau pressure and airway resistance increased with prolonged duration of the operation, accompanied by decreased chest-lung compliance. Peak airway pressure and airway resistance were positively correlated with BMI, and chest-lung compliance was negatively correlated with BMI. Changes among patients in lithotomy position were more remarkable than those in supine position. PMID:27476762

Functional relationships between leaf hydraulics and leaf economic traits in response to nutrient addition in subtropical tree species.

PubMed

Villagra, Mariana; Campanello, Paula I; Bucci, Sandra J; Goldstein, Guillermo

2013-12-01

Leaves can be both a hydraulic bottleneck and a safety valve against hydraulic catastrophic dysfunctions, and thus changes in traits related to water movement in leaves and associated costs may be critical for the success of plant growth. A 4-year fertilization experiment with nitrogen (N) and phosphorus (P) addition was done in a semideciduous Atlantic forest in northeastern Argentina. Saplings of five dominant canopy species were grown in similar gaps inside the forests (five control and five N + P addition plots). Leaf lifespan (LL), leaf mass per unit area (LMA), leaf and stem vulnerability to cavitation, leaf hydraulic conductance (K(leaf_area) and K(leaf_mass)) and leaf turgor loss point (TLP) were measured in the five species and in both treatments. Leaf lifespan tended to decrease with the addition of fertilizers, and LMA was significantly higher in plants with nutrient addition compared with individuals in control plots. The vulnerability to cavitation of leaves (P50(leaf)) either increased or decreased with the nutrient treatment depending on the species, but the average P50(leaf) did not change with nutrient addition. The P50(leaf) decreased linearly with increasing LMA and LL across species and treatments. These trade-offs have an important functional significance because more expensive (higher LMA) and less vulnerable leaves (lower P50(leaf)) are retained for a longer period of time. Osmotic potentials at TLP and at full turgor became more negative with decreasing P50(leaf) regardless of nutrient treatment. The K(leaf) on a mass basis was negatively correlated with LMA and LL, indicating that there is a carbon cost associated with increased water transport that is compensated by a longer LL. The vulnerability to cavitation of stems and leaves were similar, particularly in fertilized plants. Leaves in the species studied may not function as safety valves at low water potentials to protect the hydraulic pathway from water stress-induced cavitation. The lack of rainfall seasonality in the subtropical forest studied probably does not act as a selective pressure to enhance hydraulic segmentation between leaves and stems.

Corona discharges from a windmill and its lightning protection tower in winter thunderstorms

NASA Astrophysics Data System (ADS)

Wu, Ting; Wang, Daohong; Rison, William; Thomas, Ronald J.; Edens, Harald E.; Takagi, Nobuyuki; Krehbiel, Paul R.

2017-05-01

This paper presents lightning mapping array (LMA) observations of corona discharges from a windmill and its lightning protection tower in winter thunderstorms in Japan. Corona discharges from the windmill, called windmill coronas, and those from the tower, called tower coronas, are distinctly different. Windmill coronas occur with periodic bursts, generally radiate larger power, and possibly develop to higher altitudes than tower coronas do. A strong negative electric field is necessary for the frequent production of tower coronas but is not apparently related with windmill coronas. These differences are due to the periodic rotation of the windmill and the moving blades which can escape space charges produced by corona discharges and sustain a large local electric field. The production period of windmill coronas is related with the rotation period of the windmill. Surprisingly, for one rotation of the windmill, only two out of the three blades produce detectable discharges and source powers of discharges from these two blades are different. The reason for this phenomenon is still unclear. For tower coronas, the source rate can get very high only when there is a strong negative electric field, and the source power can get very high only when the source rate is very low. The relationship between corona discharges and lightning flashes is investigated. There is no direct evidence that corona discharges can increase the chance of upward leader initiation, but nearby lightning flashes can increase the source rate of corona discharges right after the flashes. The peak of the source height distribution of corona discharges is about 100 m higher than the top of the windmill and the top of the tower. Possible reasons for this result are discussed.

Lightning Magnetic Field Measurements around Langmuir Laboratory

NASA Astrophysics Data System (ADS)

Stock, M.; Krehbiel, P. R.; Rison, W.; Aulich, G. D.; Edens, H. E.; Sonnenfeld, R. G.

2010-12-01

In the absence of artificial conductors, underground lightning transients are produced by diffusion of the horizontal surface magnetic field of a return stroke vertically downward into the conducting earth. The changing magnetic flux produces an orthogonal horizontal electric field, generating a dispersive, lossy transverse electromagnetic wave that penetrates a hundred meters or more into the ground according to the skin depth of the medium. In turn, the electric field produces currents that flow toward or away from the channel to ground depending on the stroke polarity. The underground transients can produce large radial horizontal potential gradients depending on the distance from the discharge and depth below the surface. In this study we focus on the surface excitation field. The goal of the work is to compare measurements of surface magnetic field waveforms B(t) at different distances from natural lightning discharges with simple and detailed models of the return stroke fields. In addition to providing input to the diffusion mechanism, the results should aid in further understanding return stroke field generation processes. The observational data are to be obtained using orthogonal sets of straightened Rogowski coils to measure magnetic field waveforms in N-S and E-W directions. The waveforms are sampled at 500 kS/s over 1.024 second time intervals and recorded directly onto secure digital cards. The instrument operates off of battery power for several days or weeks at a time in remote, unattended locations and measures magnetic field strengths of up to several tens of amperes/meter. The observations are being made in conjunction with collocated slow electric field change measurements and under good 3-D lightning mapping array (LMA) and fast electric field change coverage.

Satellite Proving Ground for the GOES-R Geostationary Lightning Mapper (GLM)

NASA Technical Reports Server (NTRS)

Goodman, Steven J.; Gurka, James; Bruning, E. C.; Blakeslee, J. R.; Rabin, Robert; Buechler, D.

2009-01-01

The key mission of the Satellite Proving Ground is to demonstrate new satellite observing data, products and capabilities in the operational environment to be ready on Day 1 to use the GOES-R suite of measurements. Algorithms, tools, and techniques must be tested, validated, and assessed by end users for their utility before they are finalized and incorporated into forecast operations. The GOES-R Proving Ground for the Geostationary Lightning Mapper (GLM) focuses on evaluating how the infusion of the new technology, algorithms, decision aids, or tailored products integrate with other available tools (weather radar and ground strike networks; nowcasting systems, mesoscale analysis, and numerical weather prediction models) in the hands of the forecaster responsible for issuing forecasts and warning products. Additionally, the testing concept fosters operation and development staff interactions which will improve training materials and support documentation development. Real-time proxy total lightning data from regional VHF lightning mapping arrays (LMA) in Northern Alabama, Central Oklahoma, Cape Canaveral Florida, and the Washington, DC Greater Metropolitan Area are the cornerstone for the GLM Proving Ground. The proxy data will simulate the 8 km Event, Group and Flash data that will be generated by GLM. Tailored products such as total flash density at 1-2 minute intervals will be provided for display in AWIPS-2 to select NWS forecast offices and national centers such as the Storm Prediction Center. Additional temporal / spatial combinations are being investigated in coordination with operational needs and case-study proxy data and prototype visualizations may also be generated from the NASA heritage Lightning Imaging Sensor and Optical Transient Detector data. End users will provide feedback on the utility of products in their operational environment, identify use cases and spatial/temporal scales of interest, and provide feedback to the developers for adjusted or new products.

Gap effects on leaf traits of tropical rainforest trees differing in juvenile light requirement.

PubMed

Houter, Nico C; Pons, Thijs L

2014-05-01

The relationships of 16 leaf traits and their plasticity with the dependence of tree species on gaps for regeneration (gap association index; GAI) were examined in a Neotropical rainforest. Young saplings of 24 species with varying GAI were grown under a closed canopy, in a medium-sized and in a large gap, thus capturing the full range of plasticity with respect to canopy openness. Structural, biomechanical, chemical and photosynthetic traits were measured. At the chloroplast level, the chlorophyll a/b ratio and plasticity in this variable were not related to the GAI. However, plasticity in total carotenoids per unit chlorophyll was larger in shade-tolerant species. At the leaf level, leaf mass per unit area (LMA) decreased with the GAI under the closed canopy and in the medium gap, but did not significantly decrease with the GAI in the large gap. This was a reflection of the larger plasticity in LMA and leaf thickness of gap-dependent species. The well-known opposite trends in LMA for adaptation and acclimation to high irradiance in evergreen tropical trees were thus not invariably found. Although leaf strength was dependent on LMA and thickness, plasticity in this trait was not related to the GAI. Photosynthetic capacity expressed on each basis increased with the GAI, but the large plasticity in these traits was not clearly related to the GAI. Although gap-dependent species tended to have a greater plasticity overall, as evident from a principle component analysis, leaf traits of gap-dependent species are thus not invariably more phenotypically plastic.

Is Corticosteroid of No Use for Pediatric Patients with Common Cold Undergoing Anesthesia? A Randomized, Double-Blind, Clinical Trial.

PubMed

Kamranmanesh, Mohammadreza; Gharaei, Babak

2017-06-01

Use of laryngeal mask airways (LMAs) has been advocated for children with upper respiratory tract infection (URI). However, no randomized trial has yet compared intravenous corticosteroids versus placebo in these patients. We hypothesized the lower incidence of postoperative cough (as the primary outcome) with intravenous corticosteroid versus placebo in pediatric patients with mild URI, who were anesthetized with LMA. A total of 210 patients with mild URI, aged 1 - 6 years, were included. The patients underwent full ophthalmic examination immediately (within few days). They were randomized to receive either intravenous corticosteroids (1 mg/kg of hydrocortisone and 0.1 mg/kg of dexamethasone 10 minutes prior to anesthesia induction) or placebo. Anesthesia was induced with sevoflurane. Following LMA insertion, the patients were maintained on anesthesia with spontaneous ventilation on N 2 O, O 2 , and 3% sevoflurane; LMA was removed under deep anesthesia. The outcomes were evaluated during anesthesia, recovery, and the first postoperative week. A total of 204 patients completed the trial. Cough, which was designated as the primary outcome, was not significantly different among patients receiving corticosteroids and placebo (31% vs. 34%; P = 0.7). Also, the incidence of laryngospasm (16% vs. 14%), apnea (9% VS 5%), desaturation (4% vs. 5%), bronchospasm (14% vs. 7%), vomiting (4% vs. 6%), and postoperative symptoms (8% vs. 7%) was not significantly different between the groups. Based on the present research, intravenous injection of corticosteroids has no beneficial effects for pediatric patients with minor uncomplicated URI (without a history of allergy), undergoing LMA anesthesia.

Performance Analysis of Inter-Domain Handoff Scheme Based on Virtual Layer in PMIPv6 Networks for IP-Based Internet of Things

PubMed Central

Choi, Jae-Young; Jeong, Jongpil; Chung, Tai-Myoung

2017-01-01

Lately, we see that Internet of things (IoT) is introduced in medical services for global connection among patients, sensors, and all nearby things. The principal purpose of this global connection is to provide context awareness for the purpose of bringing convenience to a patient’s life and more effectively implementing clinical processes. In health care, monitoring of biosignals of a patient has to be continuously performed while the patient moves inside and outside the hospital. Also, to monitor the accurate location and biosignals of the patient, appropriate mobility management is necessary to maintain connection between the patient and the hospital network. In this paper, a binding update scheme on PMIPv6, which reduces signal traffic during location updates by Virtual LMA (VLMA) on the top original Local Mobility Anchor (LMA) Domain, is proposed to reduce the total cost. If a Mobile Node (MN) moves to a Mobile Access Gateway (MAG)-located boundary of an adjacent LMA domain, the MN changes itself into a virtual mode, and this movement will be assumed to be a part of the VLMA domain. In the proposed scheme, MAGs eliminate global binding updates for MNs between LMA domains and significantly reduce the packet loss and latency by eliminating the handoff between LMAs. In conclusion, the performance analysis results show that the proposed scheme improves performance significantly versus PMIPv6 and HMIPv6 in terms of the binding update rate per user and average handoff latency. PMID:28129355

Development of a dense SNP-based linkage map of an apple rootstock progeny using the Malus Infinium whole genome genotyping array

PubMed Central

2012-01-01

Background A whole-genome genotyping array has previously been developed for Malus using SNP data from 28 Malus genotypes. This array offers the prospect of high throughput genotyping and linkage map development for any given Malus progeny. To test the applicability of the array for mapping in diverse Malus genotypes, we applied the array to the construction of a SNP-based linkage map of an apple rootstock progeny. Results Of the 7,867 Malus SNP markers on the array, 1,823 (23.2%) were heterozygous in one of the two parents of the progeny, 1,007 (12.8%) were heterozygous in both parental genotypes, whilst just 2.8% of the 921 Pyrus SNPs were heterozygous. A linkage map spanning 1,282.2 cM was produced comprising 2,272 SNP markers, 306 SSR markers and the S-locus. The length of the M432 linkage map was increased by 52.7 cM with the addition of the SNP markers, whilst marker density increased from 3.8 cM/marker to 0.5 cM/marker. Just three regions in excess of 10 cM remain where no markers were mapped. We compared the positions of the mapped SNP markers on the M432 map with their predicted positions on the ‘Golden Delicious’ genome sequence. A total of 311 markers (13.7% of all mapped markers) mapped to positions that conflicted with their predicted positions on the ‘Golden Delicious’ pseudo-chromosomes, indicating the presence of paralogous genomic regions or mis-assignments of genome sequence contigs during the assembly and anchoring of the genome sequence. Conclusions We incorporated data for the 2,272 SNP markers onto the map of the M432 progeny and have presented the most complete and saturated map of the full 17 linkage groups of M. pumila to date. The data were generated rapidly in a high-throughput semi-automated pipeline, permitting significant savings in time and cost over linkage map construction using microsatellites. The application of the array will permit linkage maps to be developed for QTL analyses in a cost-effective manner, and the identification of SNPs that have been assigned erroneous positions on the ‘Golden Delicious’ reference sequence will assist in the continued improvement of the genome sequence assembly for that variety. PMID:22631220

Synthesis of Eugenol–Lauryl Methacrylate Copolymers via Cationic Polymerization

NASA Astrophysics Data System (ADS)

Fajrin, A.; Marliana, SD; Handayani, D. S.

2018-04-01

Eugenol is one of the most abundant natural resources in Indonesia. The recently bio-based polymer resin is created based on eugenol because eugenol is functionalized with the polymerizable group. In order to improve the functional properties of eugenol, in this research Eugenol–Lauryl Methacrylate copolymers (co-poly(Eg-LMA)) were synthesized by cationic polymerization using H2SO4 as an initiator under the nitrogen atmosphere. Structure identification of the copolymer showed the absorption of the vinyl group from the monomers disappear at the analysis through FTIR at the wave number 1637-1639 and 985-995 cm-1 and also 1H-NMR on the chemical shift 5,97 and 5,08 ppm. The resulting copolymers obtained brown powder in 32.03 % yieldsand melting point at 96 – 97 °C. Solubility test of the co-poly(Eg-LMA) showed that the polymer couldnot soluble in water but soluble in chloroform, diethyl ether, and benzene. Average molecular weight of co-poly(Eg-LMA) Led Ostwald viscometry was obtained 42020 with the degree of polymerization by 200.

Development of a 63K SNP Array for Cotton and High-Density Mapping of Intraspecific and Interspecific Populations of Gossypium spp.

PubMed Central

Hulse-Kemp, Amanda M.; Lemm, Jana; Plieske, Joerg; Ashrafi, Hamid; Buyyarapu, Ramesh; Fang, David D.; Frelichowski, James; Giband, Marc; Hague, Steve; Hinze, Lori L.; Kochan, Kelli J.; Riggs, Penny K.; Scheffler, Jodi A.; Udall, Joshua A.; Ulloa, Mauricio; Wang, Shirley S.; Zhu, Qian-Hao; Bag, Sumit K.; Bhardwaj, Archana; Burke, John J.; Byers, Robert L.; Claverie, Michel; Gore, Michael A.; Harker, David B.; Islam, Md S.; Jenkins, Johnie N.; Jones, Don C.; Lacape, Jean-Marc; Llewellyn, Danny J.; Percy, Richard G.; Pepper, Alan E.; Poland, Jesse A.; Mohan Rai, Krishan; Sawant, Samir V.; Singh, Sunil Kumar; Spriggs, Andrew; Taylor, Jen M.; Wang, Fei; Yourstone, Scott M.; Zheng, Xiuting; Lawley, Cindy T.; Ganal, Martin W.; Van Deynze, Allen; Wilson, Iain W.; Stelly, David M.

2015-01-01

High-throughput genotyping arrays provide a standardized resource for plant breeding communities that are useful for a breadth of applications including high-density genetic mapping, genome-wide association studies (GWAS), genomic selection (GS), complex trait dissection, and studying patterns of genomic diversity among cultivars and wild accessions. We have developed the CottonSNP63K, an Illumina Infinium array containing assays for 45,104 putative intraspecific single nucleotide polymorphism (SNP) markers for use within the cultivated cotton species Gossypium hirsutum L. and 17,954 putative interspecific SNP markers for use with crosses of other cotton species with G. hirsutum. The SNPs on the array were developed from 13 different discovery sets that represent a diverse range of G. hirsutum germplasm and five other species: G. barbadense L., G. tomentosum Nuttal × Seemann, G. mustelinum Miers × Watt, G. armourianum Kearny, and G. longicalyx J.B. Hutchinson and Lee. The array was validated with 1,156 samples to generate cluster positions to facilitate automated analysis of 38,822 polymorphic markers. Two high-density genetic maps containing a total of 22,829 SNPs were generated for two F2 mapping populations, one intraspecific and one interspecific, and 3,533 SNP markers were co-occurring in both maps. The produced intraspecific genetic map is the first saturated map that associates into 26 linkage groups corresponding to the number of cotton chromosomes for a cross between two G. hirsutum lines. The linkage maps were shown to have high levels of collinearity to the JGI G. raimondii Ulbrich reference genome sequence. The CottonSNP63K array, cluster file and associated marker sequences constitute a major new resource for the global cotton research community. PMID:25908569

SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

NASA Astrophysics Data System (ADS)

Grelle, G.; Bonito, L.; Lampasi, A.; Revellino, P.; Guerriero, L.; Sappa, G.; Guadagno, F. M.

2015-06-01

SiSeRHMap is a computerized methodology capable of drawing up prediction maps of seismic response. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code-architecture composed of five interdependent modules. A GIS (Geographic Information System) Cubic Model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A metamodeling process confers a hybrid nature to the methodology. In this process, the one-dimensional linear equivalent analysis produces acceleration response spectra of shear wave velocity-thickness profiles, defined as trainers, which are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Spectra) is optimized on the above trainer acceleration response spectra by means of a dedicated Evolutionary Algorithm (EA) and the Levenberg-Marquardt Algorithm (LMA) as the final optimizer. In the final step, the GCM Maps Executor module produces a serial map-set of a stratigraphic seismic response at different periods, grid-solving the calibrated Spectra model. In addition, the spectra topographic amplification is also computed by means of a numerical prediction model. This latter is built to match the results of the numerical simulations related to isolate reliefs using GIS topographic attributes. In this way, different sets of seismic response maps are developed, on which, also maps of seismic design response spectra are defined by means of an enveloping technique.

Percutaneous Coronary Intervention for a Patient with Left Main Coronary Compression Syndrome.

PubMed

Ikegami, Ryutaro; Ozaki, Kazuyuki; Ozawa, Takuya; Hirono, Satoru; Ito, Masahiro; Minamino, Tohru

2018-05-15

Left main coronary compression syndrome rarely occurs in patients with severe pulmonary hypertension. A 65-year-old woman with severe pulmonary hypertension due to an atrial septal defect suffered from angina on effort. Cardiac computed-tomography and coronary angiography revealed considerable stenosis of the left main coronary artery (LMA) caused by compression between the dilated main pulmonary artery trunk and the sinus of valsalva. Stenting of the LMA under intravascular ultrasound imaging was effective for the treatment of angina. We herein report the diagnosis and management of this condition with a brief literature review.

Phased Array Ultrasonic Sound Field Mapping in Cast Austenitic Stainless Steel

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

Crawford, Susan L.; Prowant, Matthew S.; Cinson, Anthony D.

2014-05-31

This study maps the phased array-generated acoustic sound fields through three types of CASS microstructure in four specimens to quantitatively assess the beam formation effectiveness in these materials.

SiSeRHMap v1.0: a simulator for mapped seismic response using a hybrid model

NASA Astrophysics Data System (ADS)

Grelle, Gerardo; Bonito, Laura; Lampasi, Alessandro; Revellino, Paola; Guerriero, Luigi; Sappa, Giuseppe; Guadagno, Francesco Maria

2016-04-01

The SiSeRHMap (simulator for mapped seismic response using a hybrid model) is a computerized methodology capable of elaborating prediction maps of seismic response in terms of acceleration spectra. It was realized on the basis of a hybrid model which combines different approaches and models in a new and non-conventional way. These approaches and models are organized in a code architecture composed of five interdependent modules. A GIS (geographic information system) cubic model (GCM), which is a layered computational structure based on the concept of lithodynamic units and zones, aims at reproducing a parameterized layered subsoil model. A meta-modelling process confers a hybrid nature to the methodology. In this process, the one-dimensional (1-D) linear equivalent analysis produces acceleration response spectra for a specified number of site profiles using one or more input motions. The shear wave velocity-thickness profiles, defined as trainers, are randomly selected in each zone. Subsequently, a numerical adaptive simulation model (Emul-spectra) is optimized on the above trainer acceleration response spectra by means of a dedicated evolutionary algorithm (EA) and the Levenberg-Marquardt algorithm (LMA) as the final optimizer. In the final step, the GCM maps executor module produces a serial map set of a stratigraphic seismic response at different periods, grid solving the calibrated Emul-spectra model. In addition, the spectra topographic amplification is also computed by means of a 3-D validated numerical prediction model. This model is built to match the results of the numerical simulations related to isolate reliefs using GIS morphometric data. In this way, different sets of seismic response maps are developed on which maps of design acceleration response spectra are also defined by means of an enveloping technique.

Comparison of Computational and Experimental Microphone Array Results for an 18%-Scale Aircraft Model

NASA Technical Reports Server (NTRS)

Lockard, David P.; Humphreys, William M.; Khorrami, Mehdi R.; Fares, Ehab; Casalino, Damiano; Ravetta, Patricio A.

2015-01-01

An 18%-scale, semi-span model is used as a platform for examining the efficacy of microphone array processing using synthetic data from numerical simulations. Two hybrid RANS/LES codes coupled with Ffowcs Williams-Hawkings solvers are used to calculate 97 microphone signals at the locations of an array employed in the NASA LaRC 14x22 tunnel. Conventional, DAMAS, and CLEAN-SC array processing is applied in an identical fashion to the experimental and computational results for three different configurations involving deploying and retracting the main landing gear and a part span flap. Despite the short time records of the numerical signals, the beamform maps are able to isolate the noise sources, and the appearance of the DAMAS synthetic array maps is generally better than those from the experimental data. The experimental CLEAN-SC maps are similar in quality to those from the simulations indicating that CLEAN-SC may have less sensitivity to background noise. The spectrum obtained from DAMAS processing of synthetic array data is nearly identical to the spectrum of the center microphone of the array, indicating that for this problem array processing of synthetic data does not improve spectral comparisons with experiment. However, the beamform maps do provide an additional means of comparison that can reveal differences that cannot be ascertained from spectra alone.

Height-related changes in leaf photosynthetic traits in diverse Bornean tropical rain forest trees.

PubMed

Kenzo, Tanaka; Inoue, Yuta; Yoshimura, Mitsunori; Yamashita, Megumi; Tanaka-Oda, Ayumi; Ichie, Tomoaki

2015-01-01

Knowledge of variations in morphophysiological leaf traits with forest height is essential for quantifying carbon and water fluxes from forest ecosystems. Here, we examined changes in leaf traits with forest height in diverse tree species and their role in environmental acclimation in a tropical rain forest in Borneo that does not experience dry spells. Height-related changes in leaf physiological and morphological traits [e.g., maximum photosynthetic rate (Amax), stomatal conductance (gs), dark respiration rate (Rd), carbon isotope ratio (δ(13)C), nitrogen (N) content, and leaf mass per area (LMA)] from understory to emergent trees were investigated in 104 species in 29 families. We found that many leaf area-based physiological traits (e.g., A(max-area), Rd, gs), N, δ(13)C, and LMA increased linearly with tree height, while leaf mass-based physiological traits (e.g., A(max-mass)) only increased slightly. These patterns differed from other biomes such as temperate and tropical dry forests, where trees usually show decreased photosynthetic capacity (e.g., A(max-area), A(max-mass)) with height. Increases in photosynthetic capacity, LMA, and δ(13)C are favored under bright and dry upper canopy conditions with higher photosynthetic productivity and drought tolerance, whereas lower R d and LMA may improve shade tolerance in lower canopy trees. Rapid recovery of leaf midday water potential to theoretical gravity potential during the night supports the idea that the majority of trees do not suffer from strong drought stress. Overall, leaf area-based photosynthetic traits were associated with tree height and the degree of leaf drought stress, even in diverse tropical rain forest trees.

Agents for facilitation of laryngeal mask airway insertion: a comparative study between thiopentone sodium and propofol.

PubMed

Sengupta, Janmejoy; Sengupta, Mohua; Nag, Tulsi

2014-01-01

Development of endotracheal intubation to avoid deleterious effect on hemodynamic responses occurring during laryngoscopy and intubation compelled researchers to venture into alternative measures of airway management with subtle hemodynamic responses. This study was carried out to compare the conditions for laryngeal mask airways LMA insertion with widely used intravenous induction agents, thiopentone sodium and propofol, and also to compare the undesired responses occurring during LMA insertion with them. The study was prospective, randomized, and double blind. All patients selected were randomly allocated into two groups: Group 1 (propofol) and group II (thiopentone). Preinduction heart rate and blood pressure were recorded. Sixty healthy adult patients of either sex belonging to age group of 20-60 years and ASA grade I or II, to undergo surgery less than 1 h, were selected for the study-Patients were randomly allocated in two groups, 30 in each group. Premedication with midazolam 0.04 mg/kg and fentanyl 2 mg/kg done in both groups. Thereafter, group 1 was induced with 2 mg/kg of propofol and group 2 with 5 mg/kg of thiopentone sodium. The study revealed that, ease of insertion of LMA, was statistically significantly greater in group 1 when compared with group 2 (P 0.05). The time required for successful insertion of LMA was lesser in group 1 patients (53.8 ± 7.77 s) than in group 2 patients (84.7 ± 16.54 s) (P 0.001). Severity of undesired responses were more in group 2, as incremental boluses of respective induction agents were required in 20% patients in thiopentone group compared to only 6% patients in propofol group and 13% of patients in thiopentone group required rescue succinylcholine.

The effects of cleared larch canopy and nitrogen supply on gas exchange and leaf traits in deciduous broad-leaved tree seedlings.

PubMed

Kitaoka, Satoshi; Watanabe, Yoko; Koike, Takayoshi

2009-12-01

To understand the leaf-level responses of successional tree species to forest gap formation and nitrogen deposition, we performed canopy clearing and nitrogen-amendment treatments in larch plantations and investigated the changes in the light-use characteristics and the leaf structure of the invading deciduous broad-leaved tree seedlings. We hypothesized that the responses of the tree seedlings to clearing and nitrogen input would reflect specific traits in the shoot development that would be related to the species-specific successional characteristics. The gap phase species Magnolia hyporeuca Siebold et Zucc. and the mid-late successional tree species Quercus mongolica Fischer ex Ledeb. var. crispula (Blume) Ohashi., which grow in or near the forest gaps, had higher light-saturated photosynthetic rates (Psat), enhanced mesophyll surface area (Smes) and increased leaf mass per area (LMA) under both the clearing treatment and the clearing with nitrogen-amendment treatment. These two species therefore increased their Psat via an increase in Smes and LMA. The LMA values of the late successional tree species Prunus ssiori F. Schmidt and Carpinus cordata Blume, which grow in the forest understory, were enhanced by the clearing treatment. However, they displayed lesser responses to the clearing treatment under which there were no marked increases in Psat or Smes values in the second year. These results indicate distinct and varied responses to disturbance regimes among the four seral tree seedlings. The Psat value largely increased in line with the increase in Smes value during the second year in M. hyporeuca and Q. mongolica. The nitrogen supply accelerated the change in LMA and increased the Smes value in the leaves of Q. mongolica.

Disposable laryngeal mask airway (Soft Seal) for endotracheal intubation: FOB guidance technique and blind technique.

PubMed

Boonmak, S; Boonmak, P; Bunsaengjaroen, P; Srichaipanha, S

2006-05-01

To evaluate disposable LMA for endotracheal intubation using the FOB guidance and blind techniques. The authors included ASA class I-II patients between 15 and 60 years of age, with mouth opening more than 3 cm, scheduled for elective surgery. The authors excluded patients with any history of gastro-esophageal reflux, full stomach or a body weight < 30 kg. All of the patients received standard general anesthesia. After inducing anesthesia, a disposable LMA No. 3 or No. 4 (Soft Seal, Smiths Medical, Portex Inc, USA) was inserted while the patient was in the sniff position. The authors recorded the insertion time, the ease of insertion, the anatomic placement and position. The authors then inserted a flexible endotracheal tube (No. 6.5 for LMA No. 4 and No. 6 for LMA No. 3) and recorded the success rate and the ease of insertion. After three failures, the authors used FOB guidance. Sixty patients were enrolled (32 males). The mean +/- SD age and BMI was 43.2 +/- 13.4 years and 22.6 +/- 3.9, respectively. Most of the patients had a Mallampati of grade I. The mean +/- SD insertion time was 24.6 +/- 16.1 sec. After the FOB evaluation, only 27 patients had an anatomic placement in full view of the glottis. Eighteen patients had vocal cords in the middle part of the opening. The success rate of blind endotracheal intubation was 5 percent (95%CI 1.0-13.9) (3/60); while the success rate with FOB guidance was 85 percent (95%CI 73.4-92.9). A disposable laryngeal mask airway (Soft Seal) for blind endotracheal intubation had a low success rate, but it could be used more successfully with FOB guidance.

Efficacy of Combined Therapy with Liposome-Encapsulated Meglumine Antimoniate and Allopurinol in Treatment of Canine Visceral Leishmaniasis

PubMed Central

da Silva, Sydnei M.; Amorim, Izabela F. G.; Ribeiro, Raul R.; Azevedo, Erly G.; Demicheli, Cynthia; Melo, Maria N.; Tafuri, Wagner L.; Gontijo, Nelder F.; Michalick, Marilene S. M.

2012-01-01

An innovative liposomal formulation of meglumine antimoniate (LMA) was recently reported to promote both long-term parasite suppression and reduction of infectivity to sand flies in dogs with visceral leishmaniasis. However, 5 months after treatment, parasites were still found in the bone marrow of all treated dogs. In order to improve treatment with LMA, the present study aimed to evaluate its efficacy in combination with allopurinol. Mongrel dogs naturally infected with Leishmania infantum were treated with six doses of LMA (6.5 mg Sb/kg of body weight/dose) given at 4-day intervals, plus allopurinol (20 mg/kg/24 h per os) for 140 days. Comparison was made with groups treated with LMA, allopurinol, empty liposomes plus allopurinol, empty liposomes, and saline. Dogs remained without treatment from day 140 to 200 after the start of treatment. The drug combination promoted both clinical improvement of dogs and significant reduction in the parasitic load in bone marrow and spleen on days 140 and 200 compared to these parameters in the pretreatment period. This is in contrast with the other protocols, which did not result in significant reduction of the bone marrow parasite load on day 200. Strikingly, the combined treatment, in contrast to the other regimens, induced negative quantitative PCR (qPCR) results in the liver of 100% of the dogs. Both xenodiagnosis and skin parasite determination by qPCR indicated that the drug combination was effective in blocking the transmission of skin parasites to sand flies. Based on all of the parasitological tests performed on day 200, 50% of the animals that received the combined treatment were considered cured. PMID:22411610

Effects of structural complexity on within-canopy light environments and leaf traits in a northern mixed deciduous forest

NASA Astrophysics Data System (ADS)

Fotis, A. T.; Curtis, P.

2016-12-01

Canopy structure influences forest productivity through its effects on the distribution of radiation and the light-induced changes in leaf physiological traits. Due to the difficulty of accessing and measuring forest canopies, few field-based studies have quantitatively linked these divergent scales of canopy functioning. The objective of our study was to investigate how canopy structure affects light profiles within a forest canopy and whether leaves of mature trees adjust morphologically and biochemically to the light environments characteristic of canopies with different structural complexity. We used a combination of light detection and ranging (LiDAR) data and hemispherical photographs to quantify canopy structure and light environments, respectively, and a telescoping pole to sample leaves. Leaf mass per area (LMA), nitrogen on an area basis (Narea) and chlorophyll on a mass basis (Chlmass) were measured in four co-dominant species (Acer rubrum, Fagus grandifolia, Pinus strobus and Quercus rubra) at different heights in plots with similar leaf area index (LAI) but contrasting canopy complexity (rugosity). We found that more complex canopies had greater porosity and reduced light variability in the midcanopy while total light interception was unchanged relative to less complex canopies. Leaves of F. grandifolia, Q. rubra, and P. strobus shifted towards sun-acclimation phenotypes with increasing canopy complexity while leaves of A. rubrum became more shade-acclimated (lower LMA) in the upper canopy of more complex stands, despite no differences in total light interception. Broadleaf species showed further acclimation by increasing Narea and reducing Chlmass as LMA increased, while P. strobus showed no change in Narea and Chlmass with increasing LMA. Our results provide new insight on how light distribution and leaf acclimation in mature trees might be altered when natural and anthropogenic disturbances cause structural changes in the canopy.

Storm Physics and Lightning Properties over Northern Alabama during DC3

NASA Astrophysics Data System (ADS)

Matthee, R.; Carey, L. D.; Bain, A. L.

2013-12-01

The Deep Convective Clouds and Chemistry (DC3) experiment seeks to examine the relationship between deep moist convection (DMC) and the production of nitrogen oxides (NOx) via lightning (LNOx). The focus of this study will be to examine integrated storm microphysics and lightning properties of DMC across northern Alabama (NA) during the DC3 campaign through use of polarimetric radar [UAHuntsville's Advanced Radar for Meteorological and Operational Radar (ARMOR)] and lightning mapping [National Aeronautical and Space Administration's (NASA) north Alabama Lightning Mapping Array (NA LMA)] platforms. Specifically, ARMOR and NA LMA are being used to explore the ability of radar inferred microphysical (e.g., ice mass, graupel volume) measurements to parameterize flash rates (F) and flash area for estimation of LNOX production in cloud resolving models. The flash area was calculated by using the 'convex hull' method. This method essentially draws a polygon around all the sources that comprise a flash. From this polygon, the convex hull area that describes the minimum polygon that circumscribes the flash extent is calculated. Two storms have been analyzed so far; one on 21 May 2012 (S1) and another on 11 June 2012 (S2), both of which were aircraft-penetrated during DC3. For S1 and S2, radar reflectivity (Z) estimates of precipitation ice mass (M) within the mixed-phase zone (-10°C to -40°C) were well correlated to the trend of lightning flash rate. However, a useful radar-based F parameterization must provide accurate quantification of rates in addition to proper trends. The difference reflectivity was used to estimate Z associated with ice and then a single Z-M relation was employed to calculate M in the mixed-phase zone. Using this approach it was estimated that S1 produced an order of magnitude greater M, but produced about a third of the total amount of flashes compared to S2. Expectations based on the non-inductive charging (NIC) theory suggest that the M-to-F ratio (M/F) should be stable from storm-to-storm, amongst other factors, all else being equal. Further investigation revealed that the mean mixed-phase Z was 11 dB higher in S1 compared to S2, suggesting larger diameters and lower concentrations of ice particles in S1. Reduction by an order of magnitude of the intercept parameter (N0) of an assumed exponential ice particle size distribution within the Z-M relation for S1 resulted in a proportional reduction in S1's inferred M and therefore a more comparable M/F ratio between the storms. Flash statistics between S1 and S2 revealed the following: S1 produced 1.92 flashes/minute and a total of 102 flashes, while S2 produced 3.45 flashes/minute and a total of 307 flashes. On average, S1 (S2) produced 212 (78) sources per flash and an average flash area of 89.53 km2 (53.85 km2). Thus, S1 produced fewer flashes, a lower F, but more sources per flash and larger flash areas as compared to S2. Ongoing analysis is exploring the tuning of N0 within the Z-M relation by the mean Z in the mixed-phase zone. The suitability of various M estimates and other radar properties (graupel volume, ice fluxes, anvil ice mass) for parameterizing F, flash area and LNOX will be investigated on different storm types across NA.

Evaluation of SNP Data from the Malus Infinium Array Identifies Challenges for Genetic Analysis of Complex Genomes of Polyploid Origin

PubMed Central

Troggio, Michela; Šurbanovski, Nada; Bianco, Luca; Moretto, Marco; Giongo, Lara; Banchi, Elisa; Viola, Roberto; Fernández, Felicdad Fernández; Costa, Fabrizio; Velasco, Riccardo; Cestaro, Alessandro; Sargent, Daniel James

2013-01-01

High throughput arrays for the simultaneous genotyping of thousands of single-nucleotide polymorphisms (SNPs) have made the rapid genetic characterisation of plant genomes and the development of saturated linkage maps a realistic prospect for many plant species of agronomic importance. However, the correct calling of SNP genotypes in divergent polyploid genomes using array technology can be problematic due to paralogy, and to divergence in probe sequences causing changes in probe binding efficiencies. An Illumina Infinium II whole-genome genotyping array was recently developed for the cultivated apple and used to develop a molecular linkage map for an apple rootstock progeny (M432), but a large proportion of segregating SNPs were not mapped in the progeny, due to unexpected genotype clustering patterns. To investigate the causes of this unexpected clustering we performed BLAST analysis of all probe sequences against the ‘Golden Delicious’ genome sequence and discovered evidence for paralogous annealing sites and probe sequence divergence for a high proportion of probes contained on the array. Following visual re-evaluation of the genotyping data generated for 8,788 SNPs for the M432 progeny using the array, we manually re-scored genotypes at 818 loci and mapped a further 797 markers to the M432 linkage map. The newly mapped markers included the majority of those that could not be mapped previously, as well as loci that were previously scored as monomorphic, but which segregated due to divergence leading to heterozygosity in probe annealing sites. An evaluation of the 8,788 probes in a diverse collection of Malus germplasm showed that more than half the probes returned genotype clustering patterns that were difficult or impossible to interpret reliably, highlighting implications for the use of the array in genome-wide association studies. PMID:23826289

A low-frequency near-field interferometric-TOA 3-D Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Lyu, Fanchao; Cummer, Steven A.; Solanki, Rahulkumar; Weinert, Joel; McTague, Lindsay; Katko, Alex; Barrett, John; Zigoneanu, Lucian; Xie, Yangbo; Wang, Wenqi

2014-11-01

We report on the development of an easily deployable LF near-field interferometric-time of arrival (TOA) 3-D Lightning Mapping Array applied to imaging of entire lightning flashes. An interferometric cross-correlation technique is applied in our system to compute windowed two-sensor time differences with submicrosecond time resolution before TOA is used for source location. Compared to previously reported LF lightning location systems, our system captures many more LF sources. This is due mainly to the improved mapping of continuous lightning processes by using this type of hybrid interferometry/TOA processing method. We show with five station measurements that the array detects and maps different lightning processes, such as stepped and dart leaders, during both in-cloud and cloud-to-ground flashes. Lightning images mapped by our LF system are remarkably similar to those created by VHF mapping systems, which may suggest some special links between LF and VHF emission during lightning processes.

The first genetic map of pigeon pea based on diversity arrays technology (DArT) markers.

PubMed

Yang, Shi Ying; Saxena, Rachit K; Kulwal, Pawan L; Ash, Gavin J; Dubey, Anuja; Harper, John D I; Upadhyaya, Hari D; Gothalwal, Ragini; Kilian, Andrzej; Varshney, Rajeev K

2011-04-01

With an objective to develop a genetic map in pigeon pea (Cajanus spp.), a total of 554 diversity arrays technology (DArT) markers showed polymorphism in a pigeon pea F(2) mapping population of 72 progenies derived from an interspecific cross of ICP 28 (Cajanus cajan) and ICPW 94 (Cajanus scarabaeoides). Approximately 13% of markers did not conform to expected segregation ratio. The total number of DArT marker loci segregating in Mendelian manner was 405 with 73.1% (P > 0.001) of DArT markers having unique segregation patterns. Two groups of genetic maps were generated using DArT markers. While the maternal genetic linkage map had 122 unique DArT maternal marker loci, the paternal genetic linkage map has a total of 172 unique DArT paternal marker loci. The length of these two maps covered 270.0 cM and 451.6 cM, respectively. These are the first genetic linkage maps developed for pigeon pea, and this is the first report of genetic mapping in any grain legume using diversity arrays technology.

Low-NA single-mode LMA photonic crystal rod fiber amplifier

NASA Astrophysics Data System (ADS)

Alkeskjold, Thomas Tanggaard; Laurila, Marko; Scolari, Lara; Broeng, Jes

2011-02-01

Enabling Single-Mode (SM) operation in Large-Mode-Area (LMA) fiber amplifiers and lasers is critical, since a SM output ensures high beam quality and excellent pointing stability. In this paper, we demonstrate and test a new design approach for achieving ultra-low NA SM rod fibers by using a spatially Distributed Mode Filter (DMF). This approach achieves SM performance in a short and straight rod fiber and allows preform tolerances to be compensated during draw. A low-NA SM rod fiber amplifier having a mode field diameter of ~60μm at 1064nm and a pump absorption of 27dB/m at 976nm is demonstrated.

Convergent production and tolerance among 107 woody species and divergent production between shrubs and trees.

PubMed

He, Wei-Ming; Sun, Zhen-Kai

2016-02-08

Green leaves face two fundamental challenges (i.e., carbon fixation and stress tolerance) during their lifespan. However, the relationships between leaf production potential and leaf tolerance potential have not been explicitly tested with a broad range of plant species in the same environment. To do so, we conducted a field investigation based on 107 woody plants grown in a common garden and complementary laboratory measurements. The values, as measured by a chlorophyll meter, were significantly related to the direct measurements of chlorophyll content on a leaf area basis. Area-based chlorophyll content was positively correlated with root surface area, whole-plant biomass, leaf mass per area (LMA), and force to punch. Additionally, LMA had a positive correlation with force to punch. Shrubs had a higher leaf chlorophyll content than trees; however, shrubs and trees exhibited a similar leaf lifespan, force to punch, and LMA. These findings suggest that the production potential of leaves and their tolerance to stresses may be convergent in woody species and that the leaf production potential may differ between shrubs and trees. This study highlights the possibility that functional convergence and divergence might be linked to long-term selection pressures and genetic constraints.

Convergent production and tolerance among 107 woody species and divergent production between shrubs and trees

PubMed Central

He, Wei-Ming; Sun, Zhen-Kai

2016-01-01

Green leaves face two fundamental challenges (i.e., carbon fixation and stress tolerance) during their lifespan. However, the relationships between leaf production potential and leaf tolerance potential have not been explicitly tested with a broad range of plant species in the same environment. To do so, we conducted a field investigation based on 107 woody plants grown in a common garden and complementary laboratory measurements. The values, as measured by a chlorophyll meter, were significantly related to the direct measurements of chlorophyll content on a leaf area basis. Area-based chlorophyll content was positively correlated with root surface area, whole-plant biomass, leaf mass per area (LMA), and force to punch. Additionally, LMA had a positive correlation with force to punch. Shrubs had a higher leaf chlorophyll content than trees; however, shrubs and trees exhibited a similar leaf lifespan, force to punch, and LMA. These findings suggest that the production potential of leaves and their tolerance to stresses may be convergent in woody species and that the leaf production potential may differ between shrubs and trees. This study highlights the possibility that functional convergence and divergence might be linked to long-term selection pressures and genetic constraints. PMID:26854019

How well can spectroscopy predict leaf morphological traits in the seasonal neotropical savannas?

NASA Astrophysics Data System (ADS)

Streher, A. S.; McGill, B.; Morellato, P.; Silva, T. S. F.

2017-12-01

Variations in foliar morphological traits, quantified as leaf mass per area (LMA, g m-2) and leaf dry matter content (LDMC, g g-1), correspond to a tradeoff between investments in leaf construction costs and leaf life span. Leaf spectroscopy, the acquisition of reflected radiation along contiguous narrow spectral bands from leaves, has shown the potential to link leaf optical properties with a range of foliar traits. However, our knowledge is still limited on how well leaf traits from plants with different life forms and deciduousness strategies can be predicted from spectroscopy. To understand the relationships between leaf traits and optical properties, we investigated: 1) What are the spectral regions associated with leaf morphological traits? 2) How generalizable an optical trait model is across different life forms and leaf strategies? Five locations across cerrado and campo rupestre vegetation in Brazil were sampled during the growing season in 2017. Triplicate mature sun leaves were harvested from plants encompassing different life forms (grasses, perennial herbs, shrubs and trees), comprising 1650 individuals growing over a wide range of environmental conditions. For each individual, we determined LDMC and LMA, and took 30 spectral leaf measurements from 400 to 2500nm, using a spectrometer. We used the Random Forests (RF) algorithm to predict both morphological traits from leaf reflectance, and performed feature selection with a backward stepwise method, progressively removing variables with small importance at each iteration. Model performance was evaluated by using 10-fold cross-validation. LDMC values ranged from 0.12 to 0.67 g g-1, while LMA varied between 41.78 and 562 g m-2. The spectral bands that best explained trait variation were found within the SWIR, around 1397 nm for LDMC, and 2279 nm for LMA. Our general model explained 55.28% of LDMC variance and 55.64% of LMA variation, and the mean RMSE for the predicted values were 0.004 g g-1 and 36.99 g m-2, respectively. RF provided a consistent selection of spectral bands related to biophysical traits. This study highlighted the potential for estimation of key foliar traits from spectral information, while further efforts are necessary to disentangle the optical properties from a larger suite of vegetation types worldwide.

Comparison of the Force Required for Dislodgement Between Secured and Unsecured Airways.

PubMed

Davenport, Curtis; Martin-Gill, Christian; Wang, Henry E; Mayrose, James; Carlson, Jestin N

2018-05-01

Airway device placement and maintenance are of utmost importance when managing critically ill patients. The best method to secure airway devices is currently unknown. We sought to determine the force required to dislodge 4 types of airways with and without airway securing devices. We performed a prospective study using 4 commonly used airway devices (endotracheal tube [ETT], laryngeal mask airway [LMA], King laryngeal tube [King], and iGel) performed on 5 different mannequin models. All devices were removed twice per mannequin in random order, once unsecured and once secured as per manufacturers' recommendations; Thomas Tube Holder (Laerdal, Stavanger, Norway) for ETT, LMA, and King; custom tube holder for iGel. A digital force measuring device was attached to the exposed end of the airway device and gradually pulled vertically and perpendicular to the mannequin until the tube had been dislodged, defined as at least 4 cm of movement. Dislodgement force was reported as the maximum force recorded during dislodgement. We compared the relative difference in the secured and unsecured force for each device and between devices using a random-effects regression model accounting for variability in the manikins. The median dislodgment forces (interquartile range [IQR]) in pounds for each secured device were: ETT 13.3 (11.6, 14.1), LMA 16.6 (13.9, 18.3), King 21.7 (16.9, 25.1), and iGel 8 (6.8, 8.3). The median dislodgement forces for each unsecured device were: ETT 4.5 (4.3, 5), LMA 8.4 (6.8, 10.7), King 10.6 (8.2, 11.5), and iGel 3.9 (3.2, 4.2). The relative difference in dislodgement forces (95% confidence intervals) were higher for each device when secured: ETT 8.6 (6.2 to 11), LMA 8.8 (4.6 to 13), King 12.1 (7.2 to 16.6), iGel 4 (1.1 to 6.9). When compared to secured ETT, the King required greater dislodgement force (relative difference 8.6 [4.5-12.7]). The secured iGel required less force than the secured ETT (relative difference -4.8 [-8.9 to -0.8]). Compared with a secured device, an unsecured airway device requires only half the force to cause airway dislodgement. The secured King had the highest dislodgement force relative to the other studied devices.

The impact of airway management on quality of cardiopulmonary resuscitation: an observational study in patients during cardiac arrest.

PubMed

Yeung, Joyce; Chilwan, Mehboob; Field, Richard; Davies, Robin; Gao, Fang; Perkins, Gavin D

2014-07-01

Minimising interruptions in chest compressions is associated with improved survival from cardiac arrest. Current in-hospital guidelines recommend continuous chest compressions after the airway is secured on the premise that this will reduce no flow time. The aim of this study was to determine the effect of advanced airway use on the no flow ratio and other measures of CPR quality. Consecutive adult patients who sustained an in-hospital cardiac arrest were enrolled in this prospective observational study. The quality of CPR was measured using the Q-CPR device (Phillips, UK) before and after an advanced airway device (endotracheal tube [ET] or laryngeal mask airway [LMA]) was inserted. Patients receiving only bag-mask ventilation were used as the control cohort. The primary outcome was no flow ratio (NFR). Secondary outcomes were chest compression rate, depth, compressions too shallow, compressions with leaning, ventilation rate, inflation time, change in impedance and time required to successfully insert airway device. One hundred patients were enrolled in the study (2008-2011). Endotracheal tube and LMA placement took similar durations (median 15.8 s (IQR 6.8-19.4) vs. LMA median 8.0s (IQR 5.5-15.9), p=0.1). The use of an advanced airway was associated with improved no flow ratios (endotracheal tube placement (n=50) improved NFR from baseline median 0.24 IQR 0.17-0.40) to 0.15 to (IQR 0.09-0.28), p=0.012; LMA (n=25) from median 0.28 (IQR 0.23-0.40) to 0.13 (IQR 0.11- 0.19), p=0.0001). There was no change in NFR in patients managed solely with bag valve mask (BVM) (n=25) (median 0.29 (IQR 0.18-0.59) vs. median 0.26 (IQR 0.12-0.37), p=0.888). There was no significant difference in time taken to successfully insert the airway device between the two groups. The use of an advanced airway (ETT or LMA) during in-hospital cardiac arrest was associated with improved no flow ratio. Further studies are required to determine the effect of airway devices on overall patient outcomes. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Method for Enhancing a Three Dimensional Image from a Plurality of Frames of Flash LIDAR Data

NASA Technical Reports Server (NTRS)

Bulyshev, Alexander (Inventor); Vanek, Michael D. (Inventor); Amzajerdian, Farzin (Inventor)

2013-01-01

A method for enhancing a three dimensional image from frames of flash LIDAR data includes generating a first distance R(sub i) from a first detector i to a first point on a surface S(sub i). After defining a map with a mesh theta having cells k, a first array S(k), a second array M(k), and a third array D(k) are initialized. The first array corresponds to the surface, the second array corresponds to the elevation map, and the third array D(k) receives an output for the DEM. The surface is projected onto the mesh theta, so that a second distance R(sub k) from a second point on the mesh theta to the detector can be found. From this, a height may be calculated, which permits the generation of a digital elevation map. Also, using sequential frames of flash LIDAR data, vehicle control is possible using an offset between successive frames.

Thin-film sparse boundary array design for passive acoustic mapping during ultrasound therapy.

PubMed

Coviello, Christian M; Kozick, Richard J; Hurrell, Andrew; Smith, Penny Probert; Coussios, Constantin-C

2012-10-01

A new 2-D hydrophone array for ultrasound therapy monitoring is presented, along with a novel algorithm for passive acoustic mapping using a sparse weighted aperture. The array is constructed using existing polyvinylidene fluoride (PVDF) ultrasound sensor technology, and is utilized for its broadband characteristics and its high receive sensitivity. For most 2-D arrays, high-resolution imagery is desired, which requires a large aperture at the cost of a large number of elements. The proposed array's geometry is sparse, with elements only on the boundary of the rectangular aperture. The missing information from the interior is filled in using linear imaging techniques. After receiving acoustic emissions during ultrasound therapy, this algorithm applies an apodization to the sparse aperture to limit side lobes and then reconstructs acoustic activity with high spatiotemporal resolution. Experiments show verification of the theoretical point spread function, and cavitation maps in agar phantoms correspond closely to predicted areas, showing the validity of the array and methodology.

Map reading tools for map libraries.

USGS Publications Warehouse

Greenberg, G.L.

1982-01-01

Engineers, navigators and military strategists employ a broad array of mechanical devices to facilitate map use. A larger number of map users such as educators, students, tourists, journalists, historians, politicians, economists and librarians are unaware of the available variety of tools which can be used with maps to increase the speed and efficiency of their application and interpretation. This paper identifies map reading tools such as coordinate readers, protractors, dividers, planimeters, and symbol-templets according to a functional classification. Particularly, arrays of tools are suggested for use in determining position, direction, distance, area and form (perimeter-shape-pattern-relief). -from Author

CdS nanorods/organic hybrid LED array and the piezo-phototronic effect of the device for pressure mapping.

PubMed

Bao, Rongrong; Wang, Chunfeng; Dong, Lin; Shen, Changyu; Zhao, Kun; Pan, Caofeng

2016-04-21

As widely applied in light-emitting diodes and optical devices, CdS has attracted the attention of many researchers due to its nonlinear properties and piezo-electronic effect. Here, we demonstrate a LED array composed of PSS and CdS nanorods and research the piezo-photonic effect of the array device. The emission intensity of the device depends on the electron-hole recombination at the interface of the p-n junction which can be adjusted using the piezo-phototronic effect and can be used to map the pressure applied on the surface of the device with spatial resolution as high as 1.5 μm. A flexible LED device array has been prepared using a CdS nanorod array on a Au/Cr/kapton substrate. This device may be used in the field of strain mapping using its high pressure spatial-resolution and flexibility.

Utilizing Yagi antennas in Lightning Mapping Array to detect low-power VHF signals

NASA Astrophysics Data System (ADS)

Tilles, J.; Thomas, R. J.; Edens, H. E.; Krehbiel, P. R.; Rison, W.

2013-12-01

The New Mexico Tech VHF Lightning Mapping Array (LMA) being operated at Langmuir Laboratory in central New Mexico is comprised of 22 time-of-arrival stations spanning an area approximately 60 km north-south and 45 km east-west. Nine stations are at high altitude (3.1-3.3 km GPS) over a 3 x 4 km area around the mountain-top Laboratory, and 13 are on the surrounding plains and the Rio Grande valley, at altitudes between 1.4 and 2.2 km. Each station utilizes a vertical half-wave dipole antenna having about 2 dBi gain at horizontal incidence and providing omnidirectional azimuthal coverage. In 2012, four additional stations utilizing higher gain (11 dBi) Yagi antennas were co-located at four of the surrounding sites within 10-15 km of the laboratory, each pointed over the laboratory area. The purpose was to test if directional antennas would improve detection of low-power sources in the laboratory vicinity, such as those associated with positive breakdown or weak precursor events. The test involved comparing the number and quality of radiation sources obtained by processing data from two sets of stations: first for a 17-station network in which all stations were omnidirectional, and then for the same network with Yagi-based measurements substituted in place of the omni measurements at the four co-located stations. For radiation events located in both datasets, the indicated source power values from Yagi stations were typically 5-10 dB greater than their omnidirectional counterpart for sources over or near the laboratory, consistent with the 9 dB difference in on-axis gain values. The difference decreased through zero and to negative values with increasing distance from the laboratory, confirming that it was due to the directionality of the Yagi antennas. It was expected that a network having Yagi antennas at all outlying stations would improve the network's detection of lower power sources in its central region. Rather, preliminary results show that there is no significant difference in the number of located sources, and that there is no significant difference in flash structure details for either positive or negative breakdown channels. This may be due to a need for more outlying Yagi stations, but could also be the case if in fact the close, high altitude stations are primarily responsible for detection of low power sources, i.e. detection of low power sources does not require or does not benefit much from outlying stations. Furthermore, the ability to detect low power sources may be fundamentally limited due to masking by strongly radiating negative breakdown. Work is continuing on analyzing the measurements.

Whole genome sequences are required to fully resolve the linkage disequilibrium structure of human populations.

PubMed

Pengelly, Reuben J; Tapper, William; Gibson, Jane; Knut, Marcin; Tearle, Rick; Collins, Andrew; Ennis, Sarah

2015-09-03

An understanding of linkage disequilibrium (LD) structures in the human genome underpins much of medical genetics and provides a basis for disease gene mapping and investigating biological mechanisms such as recombination and selection. Whole genome sequencing (WGS) provides the opportunity to determine LD structures at maximal resolution. We compare LD maps constructed from WGS data with LD maps produced from the array-based HapMap dataset, for representative European and African populations. WGS provides up to 5.7-fold greater SNP density than array-based data and achieves much greater resolution of LD structure, allowing for identification of up to 2.8-fold more regions of intense recombination. The absence of ascertainment bias in variant genotyping improves the population representativeness of the WGS maps, and highlights the extent of uncaptured variation using array genotyping methodologies. The complete capture of LD patterns using WGS allows for higher genome-wide association study (GWAS) power compared to array-based GWAS, with WGS also allowing for the analysis of rare variation. The impact of marker ascertainment issues in arrays has been greatest for Sub-Saharan African populations where larger sample sizes and substantially higher marker densities are required to fully resolve the LD structure. WGS provides the best possible resource for LD mapping due to the maximal marker density and lack of ascertainment bias. WGS LD maps provide a rich resource for medical and population genetics studies. The increasing availability of WGS data for large populations will allow for improved research utilising LD, such as GWAS and recombination biology studies.

A Large Maize (Zea mays L.) SNP Genotyping Array: Development and Germplasm Genotyping, and Genetic Mapping to Compare with the B73 Reference Genome

PubMed Central

Ganal, Martin W.; Durstewitz, Gregor; Polley, Andreas; Bérard, Aurélie; Buckler, Edward S.; Charcosset, Alain; Clarke, Joseph D.; Graner, Eva-Maria; Hansen, Mark; Joets, Johann; Le Paslier, Marie-Christine; McMullen, Michael D.; Montalent, Pierre; Rose, Mark; Schön, Chris-Carolin; Sun, Qi; Walter, Hildrun; Martin, Olivier C.; Falque, Matthieu

2011-01-01

SNP genotyping arrays have been useful for many applications that require a large number of molecular markers such as high-density genetic mapping, genome-wide association studies (GWAS), and genomic selection. We report the establishment of a large maize SNP array and its use for diversity analysis and high density linkage mapping. The markers, taken from more than 800,000 SNPs, were selected to be preferentially located in genes and evenly distributed across the genome. The array was tested with a set of maize germplasm including North American and European inbred lines, parent/F1 combinations, and distantly related teosinte material. A total of 49,585 markers, including 33,417 within 17,520 different genes and 16,168 outside genes, were of good quality for genotyping, with an average failure rate of 4% and rates up to 8% in specific germplasm. To demonstrate this array's use in genetic mapping and for the independent validation of the B73 sequence assembly, two intermated maize recombinant inbred line populations – IBM (B73×Mo17) and LHRF (F2×F252) – were genotyped to establish two high density linkage maps with 20,913 and 14,524 markers respectively. 172 mapped markers were absent in the current B73 assembly and their placement can be used for future improvements of the B73 reference sequence. Colinearity of the genetic and physical maps was mostly conserved with some exceptions that suggest errors in the B73 assembly. Five major regions containing non-colinearities were identified on chromosomes 2, 3, 6, 7 and 9, and are supported by both independent genetic maps. Four additional non-colinear regions were found on the LHRF map only; they may be due to a lower density of IBM markers in those regions or to true structural rearrangements between lines. Given the array's high quality, it will be a valuable resource for maize genetics and many aspects of maize breeding. PMID:22174790

A novel isoform of MAP4 organises the paraxial microtubule array required for muscle cell differentiation

PubMed Central

Mogessie, Binyam; Roth, Daniel; Rahil, Zainab; Straube, Anne

2015-01-01

The microtubule cytoskeleton is critical for muscle cell differentiation and undergoes reorganisation into an array of paraxial microtubules, which serves as template for contractile sarcomere formation. In this study, we identify a previously uncharacterised isoform of microtubule-associated protein MAP4, oMAP4, as a microtubule organising factor that is crucial for myogenesis. We show that oMAP4 is expressed upon muscle cell differentiation and is the only MAP4 isoform essential for normal progression of the myogenic differentiation programme. Depletion of oMAP4 impairs cell elongation and cell–cell fusion. Most notably, oMAP4 is required for paraxial microtubule organisation in muscle cells and prevents dynein- and kinesin-driven microtubule–microtubule sliding. Purified oMAP4 aligns dynamic microtubules into antiparallel bundles that withstand motor forces in vitro. We propose a model in which the cooperation of dynein-mediated microtubule transport and oMAP4-mediated zippering of microtubules drives formation of a paraxial microtubule array that provides critical support for the polarisation and elongation of myotubes. DOI: http://dx.doi.org/10.7554/eLife.05697.001 PMID:25898002

Report on the Loss of the Mars Polar Lander and Deep Space 2 Missions

NASA Technical Reports Server (NTRS)

Albee, Arden; Battel, Steven; Brace, Richard; Burdick, Garry; Casani, John; Lavell, Jeffrey; Leising, Charles; MacPherson, Duncan; Burr, Peter; Dipprey, Duane

2000-01-01

NASA's Mars Surveyor Program (MSP) began in 1994 with plans to send spacecraft to Mars every 26 months. Mars Global Surveyor (MGS), a global mapping mission, was launched in 1996 and is currently orbiting Mars. Mars Surveyor '98 consisted of Mars Climate Orbiter (MCO) and Mars Polar Lander (MPL). Lockheed Martin Astronautics (LMA) was the prime contractor for Mars Surveyor '98. The Jet Propulsion Laboratory (JPL), California Institute of Technology, manages the Mars Surveyor Program for NASA's Office of Space Science. MPL was developed under very tight funding constraints. The combined development cost of MPL and MCO, including the cost of the two launch vehicles, was approximately the same as the development cost of the Mars Pathfinder mission, including the cost of its single launch vehicle. The MPL project accepted the challenge to develop effective implementation methodologies consistent with programmatic requirements.

Self-healing of the superhydrophobicity by ironing for the abrasion durable superhydrophobic cotton fabrics

PubMed Central

Wu, Jingxia; Li, Jingye; Deng, Bo; Jiang, Haiqing; Wang, Ziqiang; Yu, Ming; Li, Linfan; Xing, Chenyang; Li, Yongjin

2013-01-01

Self-healing of the superhydrophobic cotton fabric (SCF) obtained by the radiation-induced graft polymerization of lauryl methacrylate (LMA) and n-hexyl methacrylate (HMA), can be achieved by ironing. Through the steam ironing process, the superhydrophobicity of the SCFs will be regenerated even after the yarns are ruptured during the abrasion test under a load pressure of 44.8 kPa. SCFs made from LMA grafted cotton fabric can ultimately withstand at least 24,000 cycles of abrasion with periodic steam ironing. The FT-IR microscope results show that the migration of the polymethacrylates graft chains from the interior to the surface is responsible for the self-healing effect. PMID:24135813

Three-dimensional analysis of magnetometer array data

NASA Technical Reports Server (NTRS)

Richmond, A. D.; Baumjohann, W.

1984-01-01

A technique is developed for mapping magnetic variation fields in three dimensions using data from an array of magnetometers, based on the theory of optimal linear estimation. The technique is applied to data from the Scandinavian Magnetometer Array. Estimates of the spatial power spectra for the internal and external magnetic variations are derived, which in turn provide estimates of the spatial autocorrelation functions of the three magnetic variation components. Statistical errors involved in mapping the external and internal fields are quantified and displayed over the mapping region. Examples of field mapping and of separation into external and internal components are presented. A comparison between the three-dimensional field separation and a two-dimensional separation from a single chain of stations shows that significant differences can arise in the inferred internal component.

Diversity Arrays Technology (DArT) for whole-genome profiling of barley

PubMed Central

Wenzl, Peter; Carling, Jason; Kudrna, David; Jaccoud, Damian; Huttner, Eric; Kleinhofs, Andris; Kilian, Andrzej

2004-01-01

Diversity Arrays Technology (DArT) can detect and type DNA variation at several hundred genomic loci in parallel without relying on sequence information. Here we show that it can be effectively applied to genetic mapping and diversity analyses of barley, a species with a 5,000-Mbp genome. We tested several complexity reduction methods and selected two that generated the most polymorphic genomic representations. Arrays containing individual fragments from these representations generated DArT fingerprints with a genotype call rate of 98.0% and a scoring reproducibility of at least 99.8%. The fingerprints grouped barley lines according to known genetic relationships. To validate the Mendelian behavior of DArT markers, we constructed a genetic map for a cross between cultivars Steptoe and Morex. Nearly all polymorphic array features could be incorporated into one of seven linkage groups (98.8%). The resulting map comprised ≈385 unique DArT markers and spanned 1,137 centimorgans. A comparison with the restriction fragment length polymorphism-based framework map indicated that the quality of the DArT map was equivalent, if not superior, to that of the framework map. These results highlight the potential of DArT as a generic technique for genome profiling in the context of molecular breeding and genomics. PMID:15192146

SAETTA: fine-scale observation of the total lightning activity in the framework of the CORSiCA atmospheric observatory

NASA Astrophysics Data System (ADS)

Coquillat, Sylvain; Defer, Eric; Lambert, Dominique; Martin, Jean-Michel; Pinty, Jean-Pierre; Pont, Véronique; Prieur, Serge

2015-04-01

Located in the West Mediterranean basin, Corsica is strategically positioned for atmospheric studies referred by MISTRALS/HyMeX and MISTRALS/CHARMEX programs. The implementation of the project of atmospheric observatory CORSiCA (supported by the Collectivité Territoriale de Corse via CPER/FEDER funds) was an opportunity to strengthen the potential observation of convective events causing heavy rainfall and flash floods, by acquiring a total lightning activity detection system adapted to storm tracking at a regional scale. This detection system called SAETTA (Suivi de l'Activité Electrique Tridimensionnelle Totale de l'Atmosphère) is a network of 12 LMA stations (Lightning Mapping Array). Developed by New Mexico Tech (USA), the instrument allows observing lightning flashes in 3D and real time, at high temporal and spatial resolutions. It detects the radiations emitted by cloud discharges in the 60-66 MHz band, in a radius of about 300 km from the centre of the network, in passive mode and standalone (solar panel and battery). Each LMA station samples the signal at high rate (80 microseconds), records data on internal hard disk, and transmits a decimated signal in real-time via the 3G phone network. The decimated data are received on a server that calculates the position of the detected sources by the time-of-arrival method and manages a quasi real-time display on a website. The non decimated data intended for research applications are recovered later on the field. Deployed in May and June 2014, SAETTA operated nominally from July 13 to October 20, 2014. It is to be definitively re-installed in spring 2015 after a hardware updating. The operation of SAETTA is contractually scheduled until the end of 2019, but it is planned to continue well beyond to obtain longer-term observations for addressing issues related to climatic trends. SAETTA has great scientific potential in a broad range of topics: physics of discharge; monitoring and simulation of storm systems; climatology of convection in the western Mediterranean; production of nitrogen oxides by lightning; influence of pollution and aerosols on the electrical activity; synergy with operational lightning networks (EUCLID, ATDnet, Linet, ZEUS) and radar observations (ARAMIS). SAETTA should also become a validation tool for space observation of lightning (e.g. TARANIS mission and optical flash sensor on Meteosat Third Generation), but also for field campaigns. Acknowledgements are adressed to CORSiCA-SAETTA main sponsors (Collectivité Territoriale de Corse through the Fonds Européen de Développement Régional of the European Operational Program 2007-2013 and the Contrat de Plan Etat Région; HyMeX/MISTRALS; Observatoire Midi-Pyrénées; Laboratoire d'Aérologie) and many individuals and regional institutions in Corsica that host the 12 stations of the network or that helped us to find sites.

Endotracheal tube and laryngeal mask airway cuff volume changes with altitude: a rule of thumb for aeromedical transport.

PubMed

Mann, Catherine; Parkinson, Neil; Bleetman, Anthony

2007-03-01

Helicopters and light (unpressurised) aircraft are used increasingly for the transport of ventilated patients. Most of these patients are ventilated through endotracheal tubes (ETTs), others through laryngeal mask airways (LMAs). The cuffs of both ETTs and LMAs inflate with increases in altitude as barometric pressure decreases (30 mbar/1000 feet). Tracheal mucosa perfusion becomes compromised at a pressure of approximately 30 cm H2O; critical perfusion pressure is 50 cm H2O. The change in dimensions of the inflated cuffs of a size 8 ETT and a size 5 LMA were measured with digital callipers at 1000 feet intervals in the unpressurised cabin of an Agusta 109 helicopter used by the Warwickshire and Northamptonshire Air Ambulance. A linear expansion in cuff dimensions as a function of altitude increase was identified. For ETTs, a formula for removal of air from the cuff with increasing altitude was calculated and is recommended for use in aeromedical transfers. This is 1/17x1.1 = 0.06 ml/1000 foot ascent/ml initial cuff inflation. The data for LMA cuff expansion failed to show significant correlation with altitude change. Further work is required to determine a similar rule of thumb for LMA cuff deflation.

Leaf mass per area, not total leaf area, drives differences in above-ground biomass distribution among woody plant functional types.

PubMed

Duursma, Remko A; Falster, Daniel S

2016-10-01

Here, we aim to understand differences in biomass distribution between major woody plant functional types (PFTs) (deciduous vs evergreen and gymnosperm vs angiosperm) in terms of underlying traits, in particular the leaf mass per area (LMA) and leaf area per unit stem basal area. We used a large compilation of plant biomass and size observations, including observations of 21 084 individuals on 656 species. We used a combination of semiparametric methods and variance partitioning to test the influence of PFT, plant height, LMA, total leaf area, stem basal area and climate on above-ground biomass distribution. The ratio of leaf mass to above-ground woody mass (MF /MS ) varied strongly among PFTs. We found that MF /MS at a given plant height was proportional to LMA across PFTs. As a result, the PFTs did not differ in the amount of leaf area supported per unit above-ground biomass or per unit stem basal area. Climate consistently explained very little additional variation in biomass distribution at a given plant size. Combined, these results demonstrate consistent patterns in above-ground biomass distribution and leaf area relationships among major woody PFTs, which can be used to further constrain global vegetation models. © 2016 The Authors. New Phytologist © 2016 New Phytologist Trust.

Effects of tree height on branch hydraulics, leaf structure and gas exchange in California redwoods.

PubMed

Ambrose, Anthony R; Sillett, Stephen C; Dawson, Todd E

2009-07-01

We examined changes in branch hydraulic, leaf structure and gas exchange properties in coast redwood (Sequoia sempervirens) and giant sequoia (Sequoiadendron giganteum) trees of different sizes. Leaf-specific hydraulic conductivity (k(L)) increased with height in S. sempervirens but not in S. giganteum, while xylem cavitation resistance increased with height in both species. Despite hydraulic adjustments, leaf mass per unit area (LMA) and leaf carbon isotope ratios (delta(13)C) increased, and maximum mass-based stomatal conductance (g(mass)) and photosynthesis (A(mass)) decreased with height in both species. As a result, both A(mass) and g(mass) were negatively correlated with branch hydraulic properties in S. sempervirens and uncorrelated in S. giganteum. In addition, A(mass) and g(mass) were negatively correlated with LMA in both species, which we attributed to the effects of decreasing leaf internal CO(2) conductance (g(i)). Species-level differences in wood density, LMA and area-based gas exchange capacity constrained other structural and physiological properties, with S. sempervirens exhibiting increased branch water transport efficiency and S. giganteum exhibiting increased leaf-level water-use efficiency with increasing height. Our results reveal different adaptive strategies for the two redwoods that help them compensate for constraints associated with growing taller, and reflect contrasting environmental conditions each species faces in its native habitat.

Difficult airway management practice patterns among anesthesiologists practicing in the United States: have we made any progress?

PubMed

Ezri, Tiberiu; Szmuk, Peter; Warters, R David; Katz, Jeffrey; Hagberg, Carin A

2003-09-01

To determine the extent instruction and practice in the use of airway devices and techniques varies among anesthesiologists practicing in the United States. Survey questionnaire. University medical center. Questionnaires were completed by American-trained anesthesiologists who attended the 1999 American Society of Anesthesiologists (ASA) Annual Meeting. Data collected included demographics, education, skills with airway devices/techniques, management of clinical difficult airway scenarios, and the use of the ASA Difficult Airway Algorithm. 1) DEMOGRAPHICS: 452 questionnaires were correctly completed; 62% attending anesthesiologists, 70% <50 years, 81% males, 44% from academic institutions, 63% >10 years of practice, 81% night duty, 77% board certified. 2) Education: 71% had at least one educational modality: difficult airway rotation, workshops, conferences, books, and simulators. 3) Skills: Miller blade 61%, Bullard laryngoscope 32%, LMA 86%, Combitube 43%, bougie 43%, exchangers 47%, cuffed oropharyngeal airway (COPA) 34%, retrograde 41%, transtracheal needle jet ventilation 34%, cricothyrotomy 21%, fiberoptics 59%, and blind nasal intubation 78%. The average reported use of special airway devices/techniques was 47.5%. 4) Management choices: failed intubation/ventilation: LMA (81%) and for all other situations: fiberoptic intubation. Use of ASA Difficult Airway Algorithm in clinical practice (86%). Fiberoptic intubation and the LMA are most popular in management of the difficult airway.

Large-region acoustic source mapping using a movable array and sparse covariance fitting.

PubMed

Zhao, Shengkui; Tuna, Cagdas; Nguyen, Thi Ngoc Tho; Jones, Douglas L

2017-01-01

Large-region acoustic source mapping is important for city-scale noise monitoring. Approaches using a single-position measurement scheme to scan large regions using small arrays cannot provide clean acoustic source maps, while deploying large arrays spanning the entire region of interest is prohibitively expensive. A multiple-position measurement scheme is applied to scan large regions at multiple spatial positions using a movable array of small size. Based on the multiple-position measurement scheme, a sparse-constrained multiple-position vectorized covariance matrix fitting approach is presented. In the proposed approach, the overall sample covariance matrix of the incoherent virtual array is first estimated using the multiple-position array data and then vectorized using the Khatri-Rao (KR) product. A linear model is then constructed for fitting the vectorized covariance matrix and a sparse-constrained reconstruction algorithm is proposed for recovering source powers from the model. The user parameter settings are discussed. The proposed approach is tested on a 30 m × 40 m region and a 60 m × 40 m region using simulated and measured data. Much cleaner acoustic source maps and lower sound pressure level errors are obtained compared to the beamforming approaches and the previous sparse approach [Zhao, Tuna, Nguyen, and Jones, Proc. IEEE Intl. Conf. on Acoustics, Speech and Signal Processing (ICASSP) (2016)].

Ecological Impact of Climate Change on Leaf Economic Strategies Across the Paleocene- Eocene Thermal Maximum, Bighorn Basin, Wyoming

NASA Astrophysics Data System (ADS)

Royer, D. L.; Currano, E. D.; Wilf, P.; Wing, S. L.; Labandeira, C. C.; Lovelock, E. C.

2007-12-01

Deciphering the ecological impacts of climate change is a key priority for paleontologists and ecologists alike. An important ecological metric in vegetated settings is the leaf economics spectrum, which represents an adaptive continuum running from rapid resource acquisition to maximized resource retention. This spectrum is comprised of a large number of coordinated traits, including leaf mass per area (LMA), leaf lifespan, photosynthetic rate, nutrient concentration, and palatability to herbivores. Here we apply a recently developed technique for reconstructing LMA to a suite of four isotaphonomic fossil plant sites spanning the Paleocene-Eocene thermal maximum (PETM) in the Bighorn Basin, Wyoming, USA. This technique is based on the biomechanical scaling between petiole width and leaf mass, and it has been calibrated with 65 present-day sites from five continents and tested on two well-known Eocene fossil localities (Bonanza, Utah and Republic, Washington). There are no significant differences in LMA among plants across the PETM. This stasis is present despite a backdrop of extreme climate change during the PETM in this region, including a three-to-four-fold increase in atmospheric CO2, an ~5 °C rise in temperature, and possible drying. Moreover, quantitative measurements of insect herbivory show, on average, a two-fold increase during the PETM relative to before and after the event. We interpret our results to suggest that leaf-economic relationships can, in some situations, partially decouple. More specifically, our documented increase in insect herbivory during the PETM with no concomitant decrease in LMA implies that during this interval less carbon was being captured by plants per unit of investment. Because the rate and magnitude of climate change during the PETM is similar to present-day anthropogenic changes, our results may provide clues for predictions of ecological impacts in the near future.

Effects of structural complexity on within-canopy light environments and leaf traits in a northern mixed deciduous forest.

PubMed

Fotis, Alexander T; Curtis, Peter S

2017-10-01

Canopy structure influences forest productivity through its effects on the distribution of radiation and the light-induced changes in leaf physiological traits. Due to the difficulty of accessing and measuring forest canopies, few field-based studies have quantitatively linked these divergent scales of canopy functioning. The objective of our study was to investigate how canopy structure affects light profiles within a forest canopy and whether leaves of mature trees adjust morphologically and biochemically to the light environments characteristic of canopies with different structural complexity. We used a combination of light detection and ranging (LiDAR) data and hemispherical photographs to quantify canopy structure and light environments, respectively, and a telescoping pole to sample leaves. Leaf mass per area (LMA), nitrogen on an area basis (Narea) and chlorophyll on a mass basis (Chlmass) were measured in red maple (Acer rubrum), american beech (Fagus grandifolia), white pine (Pinus strobus), and northern red oak (Quercus rubra) at different heights in plots with similar leaf area index but contrasting canopy complexity (rugosity). We found that more complex canopies had greater porosity and reduced light variability in the midcanopy while total light interception was unchanged relative to less complex canopies. Leaf phenotypes of F. grandifolia, Q. rubra and P. strobus were more sun-acclimated in the midstory of structurally complex canopies while leaf phenotypes of A. rubrum were more shade-acclimated (lower LMA) in the upper canopy of more complex stands, despite no differences in total light interception. Broadleaf species showed further differences in acclimation with increased Narea and reduced Chlmass in leaves with higher LMA, while P. strobus showed no change in Narea and Chlmass with higher LMA. Our results provide new insight on how light distribution and leaf acclimation in mature trees might be altered when natural and anthropogenic disturbances cause structural changes in the canopy. © The Author 2017. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Electron transport efficiency at opposite leaf sides: effect of vertical distribution of leaf angle, structure, chlorophyll content and species in a forest canopy.

PubMed

Mänd, Pille; Hallik, Lea; Peñuelas, Josep; Kull, Olevi

2013-02-01

We investigated changes in chlorophyll a fluorescence from alternate leaf surfaces to assess the intraleaf light acclimation patterns in combination with natural variations in radiation, leaf angles, leaf mass per area (LMA), chlorophyll content (Chl) and leaf optical parameters. Measurements were conducted on bottom- and top-layer leaves of Tilia cordata Mill. (a shade-tolerant sub-canopy species, sampled at heights of 11 and 16 m) and Populus tremula L. (a light-demanding upper canopy species, sampled at canopy heights of 19 and 26 m). The upper canopy species P. tremula had a six times higher PSII quantum yield (Φ(II)) and ratio of open reaction centres (qP), and a two times higher LMA than T. cordata. These species-specific differences were also present when the leaves of both species were in similar light conditions. Leaf adaxial/abaxial fluorescence ratio was significantly larger in the case of more horizontal leaves. Populus tremula (more vertical leaves), had smaller differences in fluorescence parameters between alternate leaf sides compared with T. cordata (more horizontal leaves). However, optical properties on alternate leaf sides showed a larger difference for P. tremula. Intraspecifically, the measured optical parameters were better correlated with LMA than with leaf Chl. Species-specific differences in leaf anatomy appear to enhance the photosynthetic potential of leaf biochemistry by decreasing the interception of excess light in P. tremula and increasing the light absorptance in T. cordata. Our results indicate that intraleaf light absorption gradient, described here as leaf adaxial/abaxial side ratio of chlorophyll a fluorescence, varies significantly with changes in leaf light environment in a multi-layer multi-species tree canopy. However, this variation cannot be described merely as a simple function of radiation, leaf angle, Chl or LMA, and species-specific differences in light acclimation strategies should also be considered.

Brute-force mapmaking with compact interferometers: a MITEoR northern sky map from 128 to 175 MHz

NASA Astrophysics Data System (ADS)

Zheng, H.; Tegmark, M.; Dillon, J. S.; Liu, A.; Neben, A. R.; Tribiano, S. M.; Bradley, R. F.; Buza, V.; Ewall-Wice, A.; Gharibyan, H.; Hickish, J.; Kunz, E.; Losh, J.; Lutomirski, A.; Morgan, E.; Narayanan, S.; Perko, A.; Rosner, D.; Sanchez, N.; Schutz, K.; Valdez, M.; Villasenor, J.; Yang, H.; Zarb Adami, K.; Zelko, I.; Zheng, K.

2017-03-01

We present a new method for interferometric imaging that is ideal for the large fields of view and compact arrays common in 21 cm cosmology. We first demonstrate the method with the simulations for two very different low-frequency interferometers, the Murchison Widefield Array and the MIT Epoch of Reionization (MITEoR) experiment. We then apply the method to the MITEoR data set collected in 2013 July to obtain the first northern sky map from 128 to 175 MHz at ∼2° resolution and find an overall spectral index of -2.73 ± 0.11. The success of this imaging method bodes well for upcoming compact redundant low-frequency arrays such as Hydrogen Epoch of Reionization Array. Both the MITEoR interferometric data and the 150 MHz sky map are available at http://space.mit.edu/home/tegmark/omniscope.html.

High-resolution electrical mapping of porcine gastric slow-wave propagation from the mucosal surface.

PubMed

Angeli, T R; Du, P; Paskaranandavadivel, N; Sathar, S; Hall, A; Asirvatham, S J; Farrugia, G; Windsor, J A; Cheng, L K; O'Grady, G

2017-05-01

Gastric motility is coordinated by bioelectrical slow waves, and gastric dysrhythmias are reported in motility disorders. High-resolution (HR) mapping has advanced the accurate assessment of gastric dysrhythmias, offering promise as a diagnostic technique. However, HR mapping has been restricted to invasive surgical serosal access. This study investigates the feasibility of HR mapping from the gastric mucosal surface. Experiments were conducted in vivo in 14 weaner pigs. Reference serosal recordings were performed with flexible-printed-circuit (FPC) arrays (128-192 electrodes). Mucosal recordings were performed by two methods: (i) FPC array aligned directly opposite the serosal array, and (ii) cardiac mapping catheter modified for gastric mucosal recordings. Slow-wave propagation and morphology characteristics were quantified and compared between simultaneous serosal and mucosal recordings. Slow-wave activity was consistently recorded from the mucosal surface from both electrode arrays. Mucosally recorded slow-wave propagation was consistent with reference serosal activation pattern, frequency (P≥.3), and velocity (P≥.4). However, mucosally recorded slow-wave morphology exhibited reduced amplitude (65-72% reduced, P<.001) and wider downstroke width (18-31% wider, P≤.02), compared to serosal data. Dysrhythmias were successfully mapped and classified from the mucosal surface, accorded with serosal data, and were consistent with known dysrhythmic mechanisms in the porcine model. High-resolution gastric electrical mapping was achieved from the mucosal surface, and demonstrated consistent propagation characteristics with serosal data. However, mucosal signal morphology was attenuated, demonstrating necessity for optimized electrode designs and analytical algorithms. This study demonstrates feasibility of endoscopic HR mapping, providing a foundation for advancement of minimally invasive spatiotemporal gastric mapping as a clinical and scientific tool. © 2016 John Wiley & Sons Ltd.

Rapid recognition of volatile organic compounds with colorimetric sensor arrays for lung cancer screening.

PubMed

Zhong, Xianhua; Li, Dan; Du, Wei; Yan, Mengqiu; Wang, You; Huo, Danqun; Hou, Changjun

2018-06-01

Volatile organic compounds (VOCs) in breath can be used as biomarkers to identify early stages of lung cancer. Herein, we report a disposable colorimetric array that has been constructed from diverse chemo-responsive colorants. Distinguishable difference maps were plotted within 4 min for specifically targeted VOCs. Through the consideration of various chemical interactions with VOCs, the arrays successfully discriminate between 20 different volatile organic compounds in breath that are related to lung cancer. VOCs were identified either with the visualized difference maps or through pattern recognition with an accuracy of at least 90%. No uncertainties or errors were observed in the hierarchical cluster analysis (HCA). Finally, good reproducibility and stability of the array was achieved against changes in humidity. Generally, this work provides fundamental support for construction of simple and rapid VOC sensors. More importantly, this approach provides a hypothesis-free array method for breath testing via VOC profiling. Therefore, this small, rapid, non-invasive, inexpensive, and visualized sensor array is a powerful and promising tool for early screening of lung cancer. Graphical abstract A disposable colorimetric array has been developed with broadly chemo-responsive dyes to incorporate various chemical interactions, through which the arrays successfully discriminate 20 VOCs that are related to lung cancer via difference maps alone or chemometrics within 4 min. The hydrophobic porous matrix provides good stability against changes in humidity.

Highly scalable, resonantly cladding-pumped, Er-doped fiber laser with record efficiency.

PubMed

Dubinskii, M; Zhang, J; Ter-Mikirtychev, V

2009-05-15

We report the performance of a resonantly cladding-pumped, Yb-free, Er-doped fiber laser. We believe this is the first reported resonantly cladding-pumped fiber-Bragg-grating-based, Er-doped, large-mode-area (LMA) fiber laser. The laser, pumped by fiber-coupled InGaAsP/InP laser diode modules at 1,532.5 nm, delivers approximately 48 W of cw output at 1,590 nm. It is believed to be the highest power ever reported from a Yb-free Er-doped LMA fiber. This fully integrated laser also has the optical-to-optical efficiency of approximately 57%, to the best of our knowledge, the highest efficiency reported for cladding-pumped unidirectionally emitting Er-doped laser.

Rhesus monkeys (Macaca mulatta) map number onto space

PubMed Central

Drucker, Caroline B.; Brannon, Elizabeth M.

2014-01-01

Humans map number onto space. However, the origins of this association, and particularly the degree to which it depends upon cultural experience, are not fully understood. Here we provide the first demonstration of a number-space mapping in a non-human primate. We trained four adult male rhesus macaques (Macaca mulatta) to select the fourth position from the bottom of a five-element vertical array. Monkeys maintained a preference to choose the fourth position through changes in the appearance, location, and spacing of the vertical array. We next asked whether monkeys show a spatially-oriented number mapping by testing their responses to the same five-element stimulus array rotated ninety degrees into a horizontal line. In these horizontal probe trials, monkeys preferentially selected the fourth position from the left, but not the fourth position from the right. Our results indicate that rhesus macaques map number onto space, suggesting that the association between number and space in human cognition is not purely a result of cultural experience and instead has deep evolutionary roots. PMID:24762923

Magnetic field mapping of the UCNTau magneto-gravitational trap: design study

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

Libersky, Matthew Murray

2014-09-04

The beta decay lifetime of the free neutron is an important input to the Standard Model of particle physics, but values measured using different methods have exhibited substantial disagreement. The UCN r experiment in development at Los Alamos National Laboratory (LANL) plans to explore better methods of measuring the neutron lifetime using ultracold neutrons (UCNs). In this experiment, UCNs are confined in a magneto-gravitational trap formed by a curved, asymmetric Halbach array placed inside a vacuum vessel and surrounded by holding field coils. If any defects present in the Halbach array are sufficient to reduce the local field near themore » surface below that needed to repel the desired energy level UCNs, loss by material interaction can occur at a rate similar to the loss by beta decay. A map of the magnetic field near the surface of the array is necessary to identify any such defects, but the array's curved geometry and placement in a vacuum vessel make conventional field mapping methods difficult. A system consisting of computer vision-based tracking and a rover holding a Hall probe has been designed to map the field near the surface of the array, and construction of an initial prototype has begun at LANL. The design of the system and initial results will be described here.« less

Identification of Pyrus single nucleotide polymorphisms (SNPs) and evaluation for genetic mapping in European pear and interspecific Pyrus hybrids.

PubMed

Montanari, Sara; Saeed, Munazza; Knäbel, Mareike; Kim, YoonKyeong; Troggio, Michela; Malnoy, Mickael; Velasco, Riccardo; Fontana, Paolo; Won, KyungHo; Durel, Charles-Eric; Perchepied, Laure; Schaffer, Robert; Wiedow, Claudia; Bus, Vincent; Brewer, Lester; Gardiner, Susan E; Crowhurst, Ross N; Chagné, David

2013-01-01

We have used new generation sequencing (NGS) technologies to identify single nucleotide polymorphism (SNP) markers from three European pear (Pyrus communis L.) cultivars and subsequently developed a subset of 1096 pear SNPs into high throughput markers by combining them with the set of 7692 apple SNPs on the IRSC apple Infinium® II 8K array. We then evaluated this apple and pear Infinium® II 9K SNP array for large-scale genotyping in pear across several species, using both pear and apple SNPs. The segregating populations employed for array validation included a segregating population of European pear ('Old Home'×'Louise Bon Jersey') and four interspecific breeding families derived from Asian (P. pyrifolia Nakai and P. bretschneideri Rehd.) and European pear pedigrees. In total, we mapped 857 polymorphic pear markers to construct the first SNP-based genetic maps for pear, comprising 78% of the total pear SNPs included in the array. In addition, 1031 SNP markers derived from apple (13% of the total apple SNPs included in the array) were polymorphic and were mapped in one or more of the pear populations. These results are the first to demonstrate SNP transferability across the genera Malus and Pyrus. Our construction of high density SNP-based and gene-based genetic maps in pear represents an important step towards the identification of chromosomal regions associated with a range of horticultural characters, such as pest and disease resistance, orchard yield and fruit quality.

Toroidal sensor arrays for real-time photoacoustic imaging

NASA Astrophysics Data System (ADS)

Bychkov, Anton S.; Cherepetskaya, Elena B.; Karabutov, Alexander A.; Makarov, Vladimir A.

2017-07-01

This article addresses theoretical and numerical investigation of image formation in photoacoustic (PA) imaging with complex-shaped concave sensor arrays. The spatial resolution and the size of sensitivity region of PA and laser ultrasonic (LU) imaging systems are assessed using sensitivity maps and spatial resolution maps in the image plane. This paper also discusses the relationship between the size of high-sensitivity regions and the spatial resolution of real-time imaging systems utilizing toroidal arrays. It is shown that the use of arrays with toroidal geometry significantly improves the diagnostic capabilities of PA and LU imaging to investigate biological objects, rocks, and composite materials.

Lunar UV-visible-IR mapping interferometric spectrometer

NASA Technical Reports Server (NTRS)

Smith, W. Hayden; Haskin, L.; Korotev, R.; Arvidson, R.; Mckinnon, W.; Hapke, B.; Larson, S.; Lucey, P.

1992-01-01

Ultraviolet-visible-infrared mapping digital array scanned interferometers for lunar compositional surveys was developed. The research has defined a no-moving-parts, low-weight and low-power, high-throughput, and electronically adaptable digital array scanned interferometer that achieves measurement objectives encompassing and improving upon all the requirements defined by the LEXSWIG for lunar mineralogical investigation. In addition, LUMIS provides a new, important, ultraviolet spectral mapping, high-spatial-resolution line scan camera, and multispectral camera capabilities. An instrument configuration optimized for spectral mapping and imaging of the lunar surface and provide spectral results in support of the instrument design are described.

Development of a 63K SNP array for Gossypium and high-density mapping of intra- and inter-specific populations of cotton (G. hirsutum L.)

USDA-ARS?s Scientific Manuscript database

High-throughput genotyping arrays provide a standardized resource for crop research communities that are useful for a breadth of applications including high-density genetic mapping, genome-wide association studies (GWAS), genomic selection (GS), candidate marker and quantitative trait loci (QTL) ide...

Number Prompts Left-to-Right Spatial Mapping in Toddlerhood

ERIC Educational Resources Information Center

McCrink, Koleen; Perez, Jasmin; Baruch, Erica

2017-01-01

Toddlers performed a spatial mapping task in which they were required to learn the location of a hidden object in a vertical array and then transpose this location information 90° to a horizontal array. During the vertical training, they were given (a) no labels, (b) alphabetical labels, or (c) numerical labels for each potential spatial location.…

Materials Development for Next Generation Optical Fiber

PubMed Central

Ballato, John; Dragic, Peter

2014-01-01

Optical fibers, the enablers of the Internet, are being used in an ever more diverse array of applications. Many of the rapidly growing deployments of fibers are in high-power and, particularly, high power-per-unit-bandwidth systems where well-known optical nonlinearities have historically not been especially consequential in limiting overall performance. Today, however, nominally weak effects, most notably stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS) are among the principal phenomena restricting continued scaling to higher optical power levels. In order to address these limitations, the optical fiber community has focused dominantly on geometry-related solutions such as large mode area (LMA) designs. Since such scattering, and all other linear and nonlinear optical phenomena including higher order mode instability (HOMI), are fundamentally materials-based in origin, this paper unapologetically advocates material solutions to present and future performance limitations. As such, this paper represents a ‘call to arms’ for material scientists and engineers to engage in this opportunity to drive the future development of optical fibers that address many of the grand engineering challenges of our day. PMID:28788683

A Comparison of Cloud-to-Ground Lightning Characteristics and Observations from Multiple Networks and Videos during the 31 May 2013 El Reno, OK Tornadic Supercell Storm

NASA Astrophysics Data System (ADS)

Kuhlman, K. M.; Coy, J.; Seimon, A.

2015-12-01

Cloud-to-ground (CG) lightning flashes recorded by both the National Lightning Detection Network (NLDN) and Earth Networks Total Lightning Network (ENTLN) are compared with three-dimensional lightning mapping observations from the Oklahoma Lightning Mapping Array (OKLMA) and storm chaser video recorded of the 31 May 2013 El Reno tornadic supercell. The El Reno Survey Project (El-Reno-Survey.net) was created to crowd-source the abundance of storm chaser video from this event and provide open-access to the scientific community of the data. An initial comparison of CG lightning flashes captured on these videos with CG data from NLDN revealed a disagreement on the total number of flashes, with NLDN recording many negative CG flashes at lower peak amplitude not apparent in any of the videos. For this study, the area of the comparison was expanded to include the entire storm and data from both the ENTLN and LMA were added to compare the observations from each network in terms of timestamp, location detection, peak current, and polarity of each flash in the period 2230-2330 UTC. An initial comparison of 557 matched NLDN and ENLTN CG flashes, indicated predominately negative polairy CG flashes (58% NLDN/77% ENI) throughout the storm during this period. However, after a 15 kA peak current filter was applied, the NLDN indicated primarily positive polarity (84% +CG) while ENTLN still indicated primarily negative polarity (77% -CG) for the 264 remaining matched flashes. Before the filter was applied, the average distance between the two networks for the same flash was more than 2 km, but improved to approximately 1 km after the 15 kA filter was applied, likely removing some misidentified cloud flashes of uncertain location. This misclassification of IC flashes as CG at low peak current amplitudes for both networks is further evident when compared to video and the OKLMA data. Additionally, the charge analysis of OKLMA flashes revealed the NLDN-determined positive-polarity as correct every time the NLDN and ENTLN disagreed. For the 2013 El Reno supercell storm, there appears to be a major flaw in the ENTLN's ability to determine the polarity of CG flashes despite having roughly similar peak current magnitudes and location for most CG flash occurrences as the NLDN.

Alabama Ground Operations during the Deep Convective Clouds and Chemistry Experiment

NASA Technical Reports Server (NTRS)

Carey, Lawrence; Blakeslee, Richard; Koshak, William; Bain, Lamont; Rogers, Ryan; Kozlowski, Danielle; Sherrer, Adam; Saari, Matt; Bigelbach, Brandon; Scott, Mariana;

Modeling Allometric Relationships in Leaves of Young Rapeseed (Brassica napus L.) Grown at Different Temperature Treatments

PubMed Central

Tian, Tian; Wu, Lingtong; Henke, Michael; Ali, Basharat; Zhou, Weijun; Buck-Sorlin, Gerhard

2017-01-01

Functional–structural plant modeling (FSPM) is a fast and dynamic method to predict plant growth under varying environmental conditions. Temperature is a primary factor affecting the rate of plant development. In the present study, we used three different temperature treatments (10/14°C, 18/22°C, and 26/30°C) to test the effect of temperature on growth and development of rapeseed (Brassica napus L.) seedlings. Plants were sampled at regular intervals (every 3 days) to obtain growth data during the length of the experiment (1 month in total). Total leaf dry mass, leaf area, leaf mass per area (LMA), width-length ratio, and the ratio of petiole length to leaf blade length (PBR), were determined and statistically analyzed, and contributed to a morphometric database. LMA under high temperature was significantly smaller than LMA under medium and low temperature, while leaves at high temperature were significantly broader. An FSPM of rapeseed seedlings featuring a growth function used for leaf extension and biomass accumulation was implemented by combining measurement with literature data. The model delivered new insights into growth and development dynamics of winter oilseed rape seedlings. The present version of the model mainly focuses on the growth of plant leaves. However, future extensions of the model could be used in practice to better predict plant growth in spring and potential cold damage of the crop. PMID:28377775

Manipulation of the hypocotyl sink activity by reciprocal grafting of two Raphanus sativus varieties: its effects on morphological and physiological traits of source leaves and whole-plant growth.

PubMed

Sugiura, Daisuke; Betsuyaku, Eriko; Terashima, Ichiro

2015-12-01

To reveal whether hypocotyl sink activities are regulated by the aboveground parts, and whether physiology and morphology of source leaves are affected by the hypocotyl sink activities, we conducted grafting experiments using two Raphanus sativus varieties with different hypocotyl sink activities. Comet (C) and Leafy (L) varieties with high and low hypocotyl sink activities were reciprocally grafted and resultant plants were called by their scion and stock such as CC, LC, CL and LL. Growth, leaf mass per area (LMA), total non-structural carbohydrates (TNCs) and photosynthetic characteristics were compared among them. Comet hypocotyls in CC and LC grew well regardless of the scions, whereas Leafy hypocotyls in CL and LL did not. Relative growth rate was highest in LL and lowest in CC. Photosynthetic capacity was correlated with Rubisco (ribulose 1·5-bisphosphate carboxylase/oxygenase) content but unaffected by TNC. High C/N ratio and accumulation of TNC led to high LMA and structural LMA. These results showed that the hypocotyl sink activity was autonomously regulated by hypocotyl and that the down-regulation of photosynthesis was not induced by TNC. We conclude that the change in the sink activity alters whole-plant growth through the changes in both biomass allocation and leaf morphological characteristics in R. sativus. © 2015 John Wiley & Sons Ltd.

Comparison of Separation Shock for Explosive and Nonexplosive Release Actuators on a Small Spacecraft Panel

NASA Technical Reports Server (NTRS)

Lucy, M. H.; Buehrle, R. D.; Woolley, J. P.

1996-01-01

Functional shock, safety, overall system costs, and emergence of new technologies, have raised concerns regarding continued use of pyrotechnics on spacecraft. NASA Headquarters-Office of Chief Engineer requested Langley Research Center (LaRC) study pyrotechnic alternatives using non-explosive actuators (NEA's), and LARC participated with Lockheed Martin Missile and Space Co. (LMMSC)-Sunnyvale, CA in objectively evaluating applicability of some NEA mechanisms to reduce small spacecraft and booster separation event shock. Comparative tests were conducted on a structural simulator using five different separation nut mechanisms, consisting of three pyrotechnics from OEA-Aerospace and Hi-Shear Technology and two NEA's from G&H Technology and Lockheed Martin Astronautics (LMA)-Denver, CO. Multiple actuations were performed with preloads up to 7000 pounds, 7000 being the comparison standard. All devices except LMA's NEA rotary flywheel-nut concept were available units with no added provisions to attenuate shock. Accelerometer measurements were recorded, reviewed, processed into Shock Response Spectra (SRS), and comparisons performed. For the standard preload, pyrotechnics produced the most severe and the G&H NEA the least severe functional shock levels. Comparing all results, the LMA concept produced the lowest levels, with preload limited to approximately 4200 pounds. Testing this concept over a range of 3000 to 4200 pounds indicated no effect of preload on shock response levels. This report presents data from these tests and the comparative results.

Hyperspectral reflectance as a tool to measure biochemical and physiological traits in wheat

DOE PAGES

Silva-Perez, Viridiana; Molero, Gemma; Serbin, Shawn P.; ...

2017-12-22

Improving photosynthesis to raise wheat yield potential has emerged as a major target for wheat physiologists. Photosynthesis-related traits, such as nitrogen per unit leaf area (N area) and leaf dry mass per area (LMA), require laborious, destructive, laboratory-based methods, while physiological traits underpinning photosynthetic capacity, such as maximum Rubisco activity normalized to 25 °C (V cmax25) and electron transport rate (J), require time-consuming gas exchange measurements. The aim of this study was to assess whether hyperspectral reflectance (350–2500 nm) can be used to rapidly estimate these traits on intact wheat leaves. Predictive models were constructed using gas exchange and hyperspectralmore » reflectance data from 76 genotypes grown in glasshouses with different nitrogen levels and/or in the field under yield potential conditions. Models were developed using half of the observed data with the remainder used for validation, yielding correlation coefficients (R 2 values) of 0.62 for V cmax25, 0.7 for J, 0.81 for SPAD, 0.89 for LMA, and 0.93 for N area, with bias <0.7%. The models were tested on elite lines and landraces that had not been used to create the models. The bias varied between -2.3% and -5.5% while relative error of prediction was similar for SPAD but slightly greater for LMA and N area.« less

Arsenic in coal of the Thar coalfield, Pakistan, and its behavior during combustion.

PubMed

Ali, Jamshed; Kazi, Tasneem G; Baig, Jameel A; Afridi, Hassan I; Arain, Mariam S; Brahman, Kapil D; Naeemullah; Panhwar, Abdul H

2015-06-01

The aim of the current study is to evaluate the occurrence of arsenic in coal collected from Thar coalfield, Pakistan, and its behavior during the combustion. Fractionation of arsenic (As) in coal samples was carried out by Community Bureau of Reference sequential extraction scheme (BCR-SES) and single-step-based BCR method (BCR-SS). These methods are validated using the certified reference material of sediment BCR 701 and standard addition method. The stepwise fractions of As in laboratory-made ash (LMA) have been also investigated. The extractable As content associated with different phases in coal and LMA samples were analyzed by electrothermal atomic absorption spectrophotometer. The extraction efficiency of As by BCR-SS was slightly higher than BCR-SES, while the difference was not significant (p < 0.05). The BCR-SS method is a time-saving method because it can reduce the extraction time from 51 to 22 h. The As contents in LMA revealed that during combustion of the coal, >85 % of As may be released into atmosphere. The relative mobility of As in the coal samples was found in increasing order as follows: oxidizable fraction < reducible fraction < acid soluble fraction. The total and extractable As obtained by BCR-SES and BCR-SS were higher in coal samples of block III as compared to block V (p > 0.05).

Hyperspectral reflectance as a tool to measure biochemical and physiological traits in wheat

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

Silva-Perez, Viridiana; Molero, Gemma; Serbin, Shawn P.

Improving photosynthesis to raise wheat yield potential has emerged as a major target for wheat physiologists. Photosynthesis-related traits, such as nitrogen per unit leaf area (N area) and leaf dry mass per area (LMA), require laborious, destructive, laboratory-based methods, while physiological traits underpinning photosynthetic capacity, such as maximum Rubisco activity normalized to 25 °C (V cmax25) and electron transport rate (J), require time-consuming gas exchange measurements. The aim of this study was to assess whether hyperspectral reflectance (350–2500 nm) can be used to rapidly estimate these traits on intact wheat leaves. Predictive models were constructed using gas exchange and hyperspectralmore » reflectance data from 76 genotypes grown in glasshouses with different nitrogen levels and/or in the field under yield potential conditions. Models were developed using half of the observed data with the remainder used for validation, yielding correlation coefficients (R 2 values) of 0.62 for V cmax25, 0.7 for J, 0.81 for SPAD, 0.89 for LMA, and 0.93 for N area, with bias <0.7%. The models were tested on elite lines and landraces that had not been used to create the models. The bias varied between -2.3% and -5.5% while relative error of prediction was similar for SPAD but slightly greater for LMA and N area.« less

Performance Evaluation of Dsm Extraction from ZY-3 Three-Line Arrays Imagery

NASA Astrophysics Data System (ADS)

Xue, Y.; Xie, W.; Du, Q.; Sang, H.

2015-08-01

ZiYuan-3 (ZY-3), launched in January 09, 2012, is China's first civilian high-resolution stereo mapping satellite. ZY-3 is equipped with three-line scanners (nadir, backward and forward) for stereo mapping, the resolutions of the panchromatic (PAN) stereo mapping images are 2.1-m at nadir looking and 3.6-m at tilt angles of ±22° forward and backward looking, respectively. The stereo base-height ratio is 0.85-0.95. Compared with stereo mapping from two views images, three-line arrays images of ZY-3 can be used for DSM generation taking advantage of one more view than conventional photogrammetric methods. It would enrich the information for image matching and enhance the accuracy of DSM generated. The primary result of positioning accuracy of ZY-3 images has been reported, while before the massive mapping applications of utilizing ZY-3 images for DSM generation, the performance evaluation of DSM extraction from three-line arrays imagery of ZY-3 has significant meaning for the routine mapping applications. The goal of this research is to clarify the mapping performance of ZY-3 three-line arrays scanners on china's first civilian high-resolution stereo mapping satellite of ZY-3 through the accuracy evaluation of DSM generation. The comparison of DSM product in different topographic areas generated with three views images with different two views combination images of ZY-3 would be presented. Besides the comparison within different topographic study area, the accuracy deviation of the DSM products with different grid size including 25-m, 10-m and 5-m is delineated in order to clarify the impact of grid size on accuracy evaluation.

Towards on-chip time-resolved thermal mapping with micro-/nanosensor arrays

PubMed Central

2012-01-01

In recent years, thin-film thermocouple (TFTC) array emerged as a versatile candidate in micro-/nanoscale local temperature sensing for its high resolution, passive working mode, and easy fabrication. However, some key issues need to be taken into consideration before real instrumentation and industrial applications of TFTC array. In this work, we will demonstrate that TFTC array can be highly scalable from micrometers to nanometers and that there are potential applications of TFTC array in integrated circuits, including time-resolvable two-dimensional thermal mapping and tracing the heat source of a device. Some potential problems and relevant solutions from a view of industrial applications will be discussed in terms of material selection, multiplexer reading, pattern designing, and cold-junction compensation. We show that the TFTC array is a powerful tool for research fields such as chip thermal management, lab-on-a-chip, and other novel electrical, optical, or thermal devices. PMID:22931306

Development and Application of a Low Frequency Near-Field Interferometric-TOA 3D Lightning Mapping Array

NASA Astrophysics Data System (ADS)

Lyu, F.; Cummer, S. A.; Weinert, J. L.; McTague, L. E.; Solanki, R.; Barrett, J.

2014-12-01

Lightning processes radiated extremely wideband electromagnetic signals. Lightning images mapped by VHF interferometry and VHF time of arrival lightning mapping arrays enable us to understand the lightning in-cloud detail development during the extent of flash that can not always be captured by cameras because of the shield of cloud. Lightning processes radiate electromagnetically over an extremely wide bandwidth, offering the possibility of multispectral lightning radio imaging. Low frequency signals are often used for lightning detection, but usually only for ground point location or thunderstorm tracking. Some recent results have demonstrated lightning LF 3D mapping of discrete lightning pulses, but imaging of continuous LF emissions have not been shown. In this work, we report a GPS-synchronized LF near field interferometric-TOA 3D lightning mapping array applied to image the development of lightning flashes on second time scale. Cross-correlation, as used in broadband interferometry, is applied in our system to find windowed arrival time differences with sub-microsecond time resolution. However, because the sources are in the near field of the array, time of arrival processing is used to find the source locations with a typical precision of 100 meters. We show that this system images the complete lightning flash structure with thousands of LF sources for extensive flashes. Importantly, this system is able to map both continuous emissions like dart leaders, and bursty or discrete emissions. Lightning stepped leader and dart leader propagation speeds are estimated to 0.56-2.5x105 m/s and 0.8-2.0x106 m/s respectively, which are consistent with previous reports. In many aspects our LF images are remarkably similar to VHF lightning mapping array images, despite the 1000 times difference in frequency, which may suggest some special links between the LF and VHF emission during lightning processes.

Maps | Geospatial Data Science | NREL

Science.gov Websites

Maps Maps NREL develops an array of maps to support renewable energy development and generation resource in the United States by county Geothermal Maps of geothermal power plants, resources for enhanced geothermal systems, and hydrothermal sites in the United States Hydrogen Maps of hydrogen production

Mapping lightning in the sky with a mini array

NASA Astrophysics Data System (ADS)

Füllekrug, Martin; Liu, Zhongjian; Koh, Kuang; Mezentsev, Andrew; Pedeboy, Stéphane; Soula, Serge; Enno, Sven-Erik; Sugier, Jacqueline; Rycroft, Michael J.

2016-10-01

Mini arrays are commonly used for infrasonic and seismic studies. Here we report for the first time the detection and mapping of distant lightning discharges in the sky with a mini array. The array has a baseline to wavelength ratio ˜4.2·10-2 to record very low frequency electromagnetic waves from 2 to 18 kHz. It is found that the mini array detects ˜69 lightning pulses per second from cloud-to-ground and in-cloud discharges, even though the parent thunderstorms are ˜900-1100 km away and a rigorous selection criterion based on the quality of the wavefront across the array is used. In particular, lightning pulses that exhibit a clockwise phase progression are found at larger elevation angles in the sky as the result of a birefringent subionospheric wave propagation attributed to ordinary and extraordinary waves. These results imply that long range lightning detection networks might benefit from an exploration of the wave propagation conditions with mini arrays.

Identification of Pyrus Single Nucleotide Polymorphisms (SNPs) and Evaluation for Genetic Mapping in European Pear and Interspecific Pyrus Hybrids

PubMed Central

Troggio, Michela; Malnoy, Mickael; Velasco, Riccardo; Fontana, Paolo; Won, KyungHo; Durel, Charles-Eric; Perchepied, Laure; Schaffer, Robert; Wiedow, Claudia; Bus, Vincent; Brewer, Lester; Gardiner, Susan E.; Crowhurst, Ross N.; Chagné, David

2013-01-01

We have used new generation sequencing (NGS) technologies to identify single nucleotide polymorphism (SNP) markers from three European pear (Pyrus communis L.) cultivars and subsequently developed a subset of 1096 pear SNPs into high throughput markers by combining them with the set of 7692 apple SNPs on the IRSC apple Infinium® II 8K array. We then evaluated this apple and pear Infinium® II 9K SNP array for large-scale genotyping in pear across several species, using both pear and apple SNPs. The segregating populations employed for array validation included a segregating population of European pear (‘Old Home’בLouise Bon Jersey’) and four interspecific breeding families derived from Asian (P. pyrifolia Nakai and P. bretschneideri Rehd.) and European pear pedigrees. In total, we mapped 857 polymorphic pear markers to construct the first SNP-based genetic maps for pear, comprising 78% of the total pear SNPs included in the array. In addition, 1031 SNP markers derived from apple (13% of the total apple SNPs included in the array) were polymorphic and were mapped in one or more of the pear populations. These results are the first to demonstrate SNP transferability across the genera Malus and Pyrus. Our construction of high density SNP-based and gene-based genetic maps in pear represents an important step towards the identification of chromosomal regions associated with a range of horticultural characters, such as pest and disease resistance, orchard yield and fruit quality. PMID:24155917

Modeling thermo-optic effect in large mode area double cladding photonic crystal fibers

NASA Astrophysics Data System (ADS)

Coscelli, Enrico; Cucinotta, Annamaria

2014-02-01

The impact of thermally-induced refractive index changes on the single-mode (SM) properties of large mode area (LMA) photonic crystal fibers are thoroughly investigated by means of a full-vector modal solver with integrated thermal model. Three photonic crystal fiber designs are taken into account, namely the 19-cell core fiber, the large-pitch fiber (LPF) and the distributed modal filtering (DMF) fiber, to assess the effects of the interplay between thermal effects and the high-order mode (HOM) suppression mechanisms exploited in order to obtain effectively SM guiding. The results have shown significant differences in the way the SM regime is changed by the increase of heat load, providing useful hints for the design of LMA fibers for high power lasers.

Evaluation of realistic layouts for next generation on-scalp MEG: spatial information density maps.

PubMed

Riaz, Bushra; Pfeiffer, Christoph; Schneiderman, Justin F

2017-08-01

While commercial magnetoencephalography (MEG) systems are the functional neuroimaging state-of-the-art in terms of spatio-temporal resolution, MEG sensors have not changed significantly since the 1990s. Interest in newer sensors that operate at less extreme temperatures, e.g., high critical temperature (high-T c ) SQUIDs, optically-pumped magnetometers, etc., is growing because they enable significant reductions in head-to-sensor standoff (on-scalp MEG). Various metrics quantify the advantages of on-scalp MEG, but a single straightforward one is lacking. Previous works have furthermore been limited to arbitrary and/or unrealistic sensor layouts. We introduce spatial information density (SID) maps for quantitative and qualitative evaluations of sensor arrays. SID-maps present the spatial distribution of information a sensor array extracts from a source space while accounting for relevant source and sensor parameters. We use it in a systematic comparison of three practical on-scalp MEG sensor array layouts (based on high-T c SQUIDs) and the standard Elekta Neuromag TRIUX magnetometer array. Results strengthen the case for on-scalp and specifically high-T c SQUID-based MEG while providing a path for the practical design of future MEG systems. SID-maps are furthermore general to arbitrary magnetic sensor technologies and source spaces and can thus be used for design and evaluation of sensor arrays for magnetocardiography, magnetic particle imaging, etc.

Rhesus monkeys (Macaca mulatta) map number onto space.

PubMed

Drucker, Caroline B; Brannon, Elizabeth M

2014-07-01

Humans map number onto space. However, the origins of this association, and particularly the degree to which it depends upon cultural experience, are not fully understood. Here we provide the first demonstration of a number-space mapping in a non-human primate. We trained four adult male rhesus macaques (Macaca mulatta) to select the fourth position from the bottom of a five-element vertical array. Monkeys maintained a preference to choose the fourth position through changes in the appearance, location, and spacing of the vertical array. We next asked whether monkeys show a spatially-oriented number mapping by testing their responses to the same five-element stimulus array rotated ninety degrees into a horizontal line. In these horizontal probe trials, monkeys preferentially selected the fourth position from the left, but not the fourth position from the right. Our results indicate that rhesus macaques map number onto space, suggesting that the association between number and space in human cognition is not purely a result of cultural experience and instead has deep evolutionary roots. Copyright © 2014 Elsevier B.V. All rights reserved.

Demonstration Of Fast, Single-Shot Photocathode QE Mapping Method Using Mla Pattern Beam

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

Wisniewski, E. E.; Conde, M.; Doran, D. S.

Quantum efficiency (QE) is the chief figure of merit in the characterization of photocathodes. Semiconductor photocathodes, especially when used in high rep-rate photoinjectors, are known to show QE degradation over time and must be replaced. The totalQE is the basic diagnosticwhich is used widely and is easy to obtain. However, a QE map indicating variations of QE across the cathode surface has greater utility. It can quickly diagnose problems of QE inhomogeneity. Most QE mapping techniques require hours to complete and are thus disruptive to a user facility schedule. A fast, single-shot method has been proposed using a micro-lens arraymore » (MLA) generated QE map. In this paper we report the implementation of the method at Argonne Wakefield Accelerator facility. A micro-lens array (MLA) is used to project an array of beamlets onto the photocathode. The resulting photoelectron beam in the form of an array of electron beamlets is imaged at a YAG screen. Four synchronized measurements are made and the results used to produce a QE map of the photocathode.« less

Characterizing charge centroids from lightning using a slow antenna network and the Levenberg-Marquardt inverse method

NASA Astrophysics Data System (ADS)

Lapierre, J. L.; Sonnenfeld, R. G.; Hager, W. W.; Morris, K.

2011-12-01

Researchers have long studied the copious and complex electric field waveforms caused by lightning. By combining electric-field measurements taken at many different locations on the ground simultaneously [Krehbiel et al., 1979], we hope to learn more about charge sources for lightning flashes. The Langmuir Electric Field Array (LEFA) is a network of nine field-change measurement stations (slow-antennas) arranged around Langmuir Laboratory near Magdalena, New Mexico. Using a mathematical method called the Levenberg-Marquardt (LM) method, we can invert the electric field data to determine the magnitude and position of the charge centroid removed from the cloud. We analyzed three return strokes (RS) following a dart-leader from a storm occurring on October 21st 2011. RS 'A' occurred at 07:17:00.63 UT. The altitude of the charge centroid was estimated to be 5 km via LMA data. Because the LM method requires a prediction, the code was run with a wide range of values to verify the robustness of the method. Predictions varied from ±3 C for the charge magnitude and ±20 km N-S and E-W for the position (with the coordinate origin being the Langmuir Laboratory Annex). The LM method converged to a charge magnitude of -5.5 C and a centroid position of 3.3 km E-W and 12 km, N-S for that RS. RS 'B' occurred at 07:20:05.9 UT. With an altitude of 4 km, the predictions were again varied; ±3 C, ±15 km N-S and E-W. Most runs converged to -27.5 C, 4 km E-W, and 10.9 km N-S. Finally, while results seem best for events right over the array, success was had locating more distant events. RS 'C' occurred at 02:42:46.8 UT. Assuming an altitude of 5 km and varying the predictions as with RS 'A', the results converged to -9.2 C, 35.5 km E-W, and 9 km N-S. All of these results are broadly consistent with the LMA and the NLDN. By continuing this type of analysis, we hope to learn more about how lightning channels propagate and how the charges in the cloud respond to the sudden change in charge distribution after a CG flash. Reference Krehbiel, P.R., M. Brook, and R. A. McCrory (1979), An analysis of the charge structure of lightning discharges to ground, J. Geophys. Res., 84(C5), 2432-2456. We gratefully acknowledge support from the National Science Foundation Grant No. 0724771.

See Also:physica status solidi (a)physica status solidi (c)Copyright © 2004 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim