Estimation of tiger densities in India using photographic captures and recaptures

USGS Publications Warehouse

Karanth, U.; Nichols, J.D.

1998-01-01

Previously applied methods for estimating tiger (Panthera tigris) abundance using total counts based on tracks have proved unreliable. In this paper we use a field method proposed by Karanth (1995), combining camera-trap photography to identify individual tigers based on stripe patterns, with capture-recapture estimators. We developed a sampling design for camera-trapping and used the approach to estimate tiger population size and density in four representative tiger habitats in different parts of India. The field method worked well and provided data suitable for analysis using closed capture-recapture models. The results suggest the potential for applying this methodology for estimating abundances, survival rates and other population parameters in tigers and other low density, secretive animal species with distinctive coat patterns or other external markings. Estimated probabilities of photo-capturing tigers present in the study sites ranged from 0.75 - 1.00. The estimated mean tiger densities ranged from 4.1 (SE hat= 1.31) to 11.7 (SE hat= 1.93) tigers/100 km2. The results support the previous suggestions of Karanth and Sunquist (1995) that densities of tigers and other large felids may be primarily determined by prey community structure at a given site.

Wearable Wide-Range Strain Sensors Based on Ionic Liquids and Monitoring of Human Activities

PubMed Central

Zhang, Shao-Hui; Wang, Feng-Xia; Li, Jia-Jia; Peng, Hong-Dan; Yan, Jing-Hui; Pan, Ge-Bo

2017-01-01

Wearable sensors for detection of human activities have encouraged the development of highly elastic sensors. In particular, to capture subtle and large-scale body motion, stretchable and wide-range strain sensors are highly desired, but still a challenge. Herein, a highly stretchable and transparent stain sensor based on ionic liquids and elastic polymer has been developed. The as-obtained sensor exhibits impressive stretchability with wide-range strain (from 0.1% to 400%), good bending properties and high sensitivity, whose gauge factor can reach 7.9. Importantly, the sensors show excellent biological compatibility and succeed in monitoring the diverse human activities ranging from the complex large-scale multidimensional motions to subtle signals, including wrist, finger and elbow joint bending, finger touch, breath, speech, swallow behavior and pulse wave. PMID:29135928

Sequential assessment of prey through the use of multiple sensory cues by an eavesdropping bat

NASA Astrophysics Data System (ADS)

Page, Rachel A.; Schnelle, Tanja; Kalko, Elisabeth K. V.; Bunge, Thomas; Bernal, Ximena E.

2012-06-01

Predators are often confronted with a broad diversity of potential prey. They rely on cues associated with prey quality and palatability to optimize their hunting success and to avoid consuming toxic prey. Here, we investigate a predator's ability to assess prey cues during capture, handling, and consumption when confronted with conflicting information about prey quality. We used advertisement calls of a preferred prey item (the túngara frog) to attract fringe-lipped bats, Trachops cirrhosus, then offered palatable, poisonous, and chemically manipulated anurans as prey. Advertisement calls elicited an attack response, but as bats approached, they used additional sensory cues in a sequential manner to update their information about prey size and palatability. While both palatable and poisonous small anurans were readily captured, large poisonous toads were approached but not contacted suggesting the use of echolocation for assessment of prey size at close range. Once prey was captured, bats used chemical cues to make final, post-capture decisions about whether to consume the prey. Bats dropped small, poisonous toads as well as palatable frogs coated in toad toxins either immediately or shortly after capture. Our study suggests that echolocation and chemical cues obtained at close range supplement information obtained from acoustic cues at long range. Updating information about prey quality minimizes the occurrence of costly errors and may be advantageous in tracking temporal and spatial fluctuations of prey and exploiting novel food sources. These findings emphasize the sequential, complex nature of prey assessment that may allow exploratory and flexible hunting behaviors.

Gyroscopic effect in low-energy classical capture of a rotating quadrupolar diatom by an ion.

PubMed

Dashevskaya, Elena; Litvin, Iliya; Nikitin, Evgueni

2006-03-09

The low-energy capture of homonuclear diatoms by ions is due mainly to the long-range part of the interpartner potential with leading terms that correspond to charge-quadrupole interaction and charge-induced dipole interaction. The capture dynamics is described by the perturbed-rotor adiabatic potentials and the Coriolis interaction between manifold of states that belong to a given value of the intrinsic angular momentum. When the latter is large enough, it can noticeably affect the capture cross section calculated in the adiabatic channel approximation due to the gyroscopic property of a rotating diatom. This paper presents the low-energy (low-temperature) state-selected partial and mean capture cross sections (rate coefficients) for the charge-quadrupole interaction that include the gyroscopic effect (decoupling of intrinsic angular momentum from the collision axis), quantum correction for the diatom rotation, and the correction for the charge-induced dipole interaction. These results complement recent studies on the gyroscopic effect in the quantum regime of diatom-ion capture (Dashevskaya, E. I.; Litvin, I.; Nikitin, E. E.; Troe, J. J. Chem. Phys. 2004, 120, 9989-9997).

Spectroscopic Analyses of Neutron Capture Elements in Open Clusters

NASA Astrophysics Data System (ADS)

O'Connell, Julia E.

The evolution of elements as a function or age throughout the Milky Way disk provides strong constraints for galaxy evolution models, and on star formation epochs. In an effort to provide such constraints, we conducted an investigation into r- and s-process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 near infrared survey. To obtain data for neutron capture abundance analysis, we conducted a long-term observing campaign spanning three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-meter telescope and Sandiford Cass Echelle Spectrograph (SES, R(lambda/Deltalambda) ˜60,000). The SES provides a wavelength range of ˜1400 A, making it uniquely suited to investigate a number of other important chemical abundances as well as the neutron capture elements. For this study, we derive abundances for 18 elements covering four nucleosynthetic families- light, iron-peak, neutron capture and alpha-elements- for ˜30 open clusters within 6 kpc of the Sun with ages ranging from ˜80 Myr to ˜10 Gyr. Both equivalent width (EW) measurements and spectral synthesis methods were employed to derive abundances for all elements. Initial estimates for model stellar atmospheres- effective temperature and surface gravity- were provided by the APOGEE data set, and then re-derived for our optical spectra by removing abundance trends as a function of excitation potential and reduced width log(EW/lambda). With the exception of Ba II and Zr I, abundance analyses for all neutron capture elements were performed by generating synthetic spectra from the new stellar parameters. In order to remove molecular contamination, or blending from nearby atomic features, the synthetic spectra were modeled by a best-fit Gaussian to the observed data. Nd II shows a slight enhancement in all cluster stars, while other neutron capture elements follow solar abundance trends. Ba II shows a large cluster-to-cluster abundance spread, consistent with other open cluster abundance studies. From log(Age) ˜8.5, this large spread as a function of age appears to replicate the findings from an earlier, much debated study by Orazi et al. (2009) which found a linear trend of decreasing barium abundance with increasing age.

Nonintrusive iris image acquisition system based on a pan-tilt-zoom camera and light stripe projection

NASA Astrophysics Data System (ADS)

Yoon, Soweon; Jung, Ho Gi; Park, Kang Ryoung; Kim, Jaihie

2009-03-01

Although iris recognition is one of the most accurate biometric technologies, it has not yet been widely used in practical applications. This is mainly due to user inconvenience during the image acquisition phase. Specifically, users try to adjust their eye position within small capture volume at a close distance from the system. To overcome these problems, we propose a novel iris image acquisition system that provides users with unconstrained environments: a large operating range, enabling movement from standing posture, and capturing good-quality iris images in an acceptable time. The proposed system has the following three contributions compared with previous works: (1) the capture volume is significantly increased by using a pan-tilt-zoom (PTZ) camera guided by a light stripe projection, (2) the iris location in the large capture volume is found fast due to 1-D vertical face searching from the user's horizontal position obtained by the light stripe projection, and (3) zooming and focusing on the user's irises at a distance are accurate and fast using the estimated 3-D position of a face by the light stripe projection and the PTZ camera. Experimental results show that the proposed system can capture good-quality iris images in 2.479 s on average at a distance of 1.5 to 3 m, while allowing a limited amount of movement by the user.

Determining landscape extent for succession and disturbance simulation modeling

Treesearch

Eva C. Karau; Robert E. Keane

2007-01-01

Dividing regions into manageable landscape units presents special problems in landscape ecology and land management. Ideally, a landscape should be large enough to capture a broad range of vegetation, environmental and disturbance dynamics, but small enough to be useful for focused management objectives. The purpose of this study was to determine the optimal landscape...

Development of Affordable, Low-Carbon Hydrogen Supplies at an Industrial Scale

ERIC Educational Resources Information Center

Roddy, Dermot J.

2008-01-01

An existing industrial hydrogen generation and distribution infrastructure is described, and a number of large-scale investment projects are outlined. All of these projects have the potential to generate significant volumes of low-cost, low-carbon hydrogen. The technologies concerned range from gasification of coal with carbon capture and storage…

Electron Capture Supernovae from Close Binary Systems

NASA Astrophysics Data System (ADS)

Poelarends, Arend J. T.; Wurtz, Scott; Tarka, James; Cole Adams, L.; Hills, Spencer T.

2017-12-01

We present the first detailed study of the Electron Capture Supernova Channel (ECSN Channel) for a primary star in a close binary star system. Progenitors of ECSN occupy the lower end of the mass spectrum of supernova progenitors and are thought to form the transition between white dwarf progenitors and core-collapse progenitors. The mass range for ECSN from close binary systems is thought to be wider than the range for single stars, because of the effects of mass transfer on the helium core. Using the MESA stellar evolution code, we explored the parameter space of initial primary masses between 8 and 17 {M}⊙ , using a large grid of models. We find that the initial primary mass and the mass transfer evolution are important factors in the final fate of stars in this mass range. Mass transfer due to Roche lobe overflow during and after carbon burning causes the core to cool down so that it avoids neon ignition, even in helium-free cores with masses up to 1.52 {M}⊙ , which in single stars would ignite neon. If the core is able to contract to high enough densities for electron captures to commence, we find that, for the adopted Ledoux convection criterion, the initial mass range for the primary to evolve into an ECSN is between 13.5 and 17.6 {M}⊙ . The mass ratio, initial period, and mass-loss efficiency only marginally affect the predicted ranges.

The effect of split pixel HDR image sensor technology on MTF measurements

NASA Astrophysics Data System (ADS)

Deegan, Brian M.

2014-03-01

Split-pixel HDR sensor technology is particularly advantageous in automotive applications, because the images are captured simultaneously rather than sequentially, thereby reducing motion blur. However, split pixel technology introduces artifacts in MTF measurement. To achieve a HDR image, raw images are captured from both large and small sub-pixels, and combined to make the HDR output. In some cases, a large sub-pixel is used for long exposure captures, and a small sub-pixel for short exposures, to extend the dynamic range. The relative size of the photosensitive area of the pixel (fill factor) plays a very significant role in the output MTF measurement. Given an identical scene, the MTF will be significantly different, depending on whether you use the large or small sub-pixels i.e. a smaller fill factor (e.g. in the short exposure sub-pixel) will result in higher MTF scores, but significantly greater aliasing. Simulations of split-pixel sensors revealed that, when raw images from both sub-pixels are combined, there is a significant difference in rising edge (i.e. black-to-white transition) and falling edge (white-to-black) reproduction. Experimental results showed a difference of ~50% in measured MTF50 between the falling and rising edges of a slanted edge test chart.

Radio-triggered anesthetic-dart collar for recapturing large mammals

USGS Publications Warehouse

Mech, L.D.; Chapman, R.C.; Cochran, W.W.; Simmons, L.; Seal, U.S.

1984-01-01

A re-usable, radio-triggered, anesthetic-dart collar costing about $1,200 has been developed for recapturing large, free-ranging mammals. The collar was tested successfully on captive gray wolves, white-tailed deer, a mountain lion, a black bear, and a tiger, and on wild wolves, a bear, and deer after periods of up to 32 days. The main advantage of the capture collar is that it allows frequent recapture of individuals at will and thus enhances opportunities for new physiological monitoring of wild animals.

The Socio-Cultural and Learning Experiences of Music Students in a British University

ERIC Educational Resources Information Center

Dibben, Nicola

2006-01-01

Research into student experience in Higher Education has largely focused on students' role as learners. However, the student experience encompasses a much wider range of behaviours and beliefs than can be captured through a focus on teaching and learning alone. I report the findings of a research project which explored student experience in the…

Water Challenges for Geologic Carbon Capture and Sequestration

PubMed Central

Friedmann, Samuel J.; Carroll, Susan A.

2010-01-01

Carbon capture and sequestration (CCS) has been proposed as a means to dramatically reduce greenhouse gas emissions with the continued use of fossil fuels. For geologic sequestration, the carbon dioxide is captured from large point sources (e.g., power plants or other industrial sources), transported to the injection site and injected into deep geological formations for storage. This will produce new water challenges, such as the amount of water used in energy resource development and utilization and the “capture penalty” for water use. At depth, brine displacement within formations, storage reservoir pressure increases resulting from injection, and leakage are potential concerns. Potential impacts range from increasing water demand for capture to contamination of groundwater through leakage or brine displacement. Understanding these potential impacts and the conditions under which they arise informs the design and implementation of appropriate monitoring and controls, important both for assurance of environmental safety and for accounting purposes. Potential benefits also exist, such as co-production and treatment of water to both offset reservoir pressure increase and to provide local water for beneficial use. PMID:20127328

Neutron Capture Measurements on 97Mo with the DANCE Array

NASA Astrophysics Data System (ADS)

Walker, Carrie L.

Neutron capture is a process that is crucial to understanding nucleosynthesis, reactors, and nuclear weapons. Precise knowledge of neutron capture cross-sections and level densities is necessary in order to model these high-flux environments. High-confidence spin and parity assignments for neutron resonances are of critical importance to this end. For nuclei in the A=100 mass region, the p-wave neutron strength function is at a maximum, and the s-wave strength function is at a minimum, producing up to six possible Jpi combinations. Parity determination becomes important to assigning spins in this mass region, and the large number of spin groups adds complexity to the problem. In this work, spins and parities for 97Mo resonances are assigned, and best fit models for photon strength function and level density are determined. The neutron capture-cross section for 97Mo is also determined, as are resonance parameters for neutron energies ranging from 16 eV to 2 keV.

Targeted Capture Sequencing in Whitebark Pine Reveals Range-Wide Demographic and Adaptive Patterns Despite Challenges of a Large, Repetitive Genome.

PubMed

Syring, John V; Tennessen, Jacob A; Jennings, Tara N; Wegrzyn, Jill; Scelfo-Dalbey, Camille; Cronn, Richard

2016-01-01

Whitebark pine (Pinus albicaulis) inhabits an expansive range in western North America, and it is a keystone species of subalpine environments. Whitebark is susceptible to multiple threats - climate change, white pine blister rust, mountain pine beetle, and fire exclusion - and it is suffering significant mortality range-wide, prompting the tree to be listed as 'globally endangered' by the International Union for Conservation of Nature and 'endangered' by the Canadian government. Conservation collections (in situ and ex situ) are being initiated to preserve the genetic legacy of the species. Reliable, transferrable, and highly variable genetic markers are essential for quantifying the genetic profiles of seed collections relative to natural stands, and ensuring the completeness of conservation collections. We evaluated the use of hybridization-based target capture to enrich specific genomic regions from the 27 GB genome of whitebark pine, and to evaluate genetic variation across loci, trees, and geography. Probes were designed to capture 7,849 distinct genes, and screening was performed on 48 trees. Despite the inclusion of repetitive elements in the probe pool, the resulting dataset provided information on 4,452 genes and 32% of targeted positions (528,873 bp), and we were able to identify 12,390 segregating sites from 47 trees. Variations reveal strong geographic trends in heterozygosity and allelic richness, with trees from the southern Cascade and Sierra Range showing the greatest distinctiveness and differentiation. Our results show that even under non-optimal conditions (low enrichment efficiency; inclusion of repetitive elements in baits), targeted enrichment produces high quality, codominant genotypes from large genomes. The resulting data can be readily integrated into management and gene conservation activities for whitebark pine, and have the potential to be applied to other members of 5-needle pine group (Pinus subsect. Quinquefolia) due to their limited genetic divergence.

Size matters: large objects capture attention in visual search.

PubMed

Proulx, Michael J

2010-12-23

Can objects or events ever capture one's attention in a purely stimulus-driven manner? A recent review of the literature set out the criteria required to find stimulus-driven attentional capture independent of goal-directed influences, and concluded that no published study has satisfied that criteria. Here visual search experiments assessed whether an irrelevantly large object can capture attention. Capture of attention by this static visual feature was found. The results suggest that a large object can indeed capture attention in a stimulus-driven manner and independent of displaywide features of the task that might encourage a goal-directed bias for large items. It is concluded that these results are either consistent with the stimulus-driven criteria published previously or alternatively consistent with a flexible, goal-directed mechanism of saliency detection.

Broadcasts of wing-fanning vibrations recorded from calling male Ceratitis capitata (Diptera: Tephritidae) increase captures of females in traps.

PubMed

Mankin, R W; Anderson, J B; Mizrach, A; Epsky, N D; Shuman, D; Heath, R R; Mazor, M; Hetzroni, A; Grinshpun, J; Taylor, P W; Garrett, S L

2004-08-01

Female Mediterranean fruit flies, Ceratitis capitata (Wiedemann), from the sterile-male rearing facility in El Pino, Guatemala, were exposed to broadcasts of wing-fanning vibrations recorded from males engaged in calling behavior to investigate the feasibility of developing a female-selective acoustic trap. The recorded signals had frequent amplitude fluctuations and peak frequencies approximately 350 Hz, typical of signals observed in previous studies of Mediterranean fruit fly acoustic behavior. Females did not exhibit long-distance phonotaxis, but remained near a speaker significantly longer when the sounds were broadcast at 103-107 dB than when the speaker was silent. In addition, significantly higher percentages of females were captured by yellow adhesive traps next to a broadcasting speaker than by traps next to a silent mimic. Additional bioassays were conducted with synthetic, 350-Hz tones produced by a thermoacoustic tube as well as with silent mimics of the different sound sources to examine the relative responsiveness of female Mediterranean fruit flies to traps with different acoustic and visual features. The visual attributes of the different sound source assemblies significantly affected capture rates. The range over which the broadcast significantly increased the percentage of female captures was <0.5 m, which may limit the utility of these acoustic cues in large-scale trapping programs. However, the findings of this study do justify further testing of whether optimized short-range acoustic signals could be used to augment longer range pheromonal and visual cues to improve the efficacy of female-selective traps.

Experimental and Numerical Study of Ceramic Foam Filtration

NASA Astrophysics Data System (ADS)

Laé, E.; Duval, H.; Rivière, C.; Le Brun, P.; Guillot, J.-B.

Ceramic foam filtration is widely used to enable removal of non metallic inclusions from liquid aluminium. Its performances have been largely studied in the literature and some discrepancies remain amongst the published results. Consequently, a research program was deployed to evaluate the performances of a range of ceramic foam filters used under various conditions and to understand the inclusions capture mechanisms.

Influence of group size on the success of wolves hunting bison.

PubMed

MacNulty, Daniel R; Tallian, Aimee; Stahler, Daniel R; Smith, Douglas W

2014-01-01

An intriguing aspect of social foraging behaviour is that large groups are often no better at capturing prey than are small groups, a pattern that has been attributed to diminished cooperation (i.e., free riding) in large groups. Although this suggests the formation of large groups is unrelated to prey capture, little is known about cooperation in large groups that hunt hard-to-catch prey. Here, we used direct observations of Yellowstone wolves (Canis lupus) hunting their most formidable prey, bison (Bison bison), to test the hypothesis that large groups are more cooperative when hunting difficult prey. We quantified the relationship between capture success and wolf group size, and compared it to previously reported results for Yellowstone wolves hunting elk (Cervus elaphus), a prey that was, on average, 3 times easier to capture than bison. Whereas improvement in elk capture success levelled off at 2-6 wolves, bison capture success levelled off at 9-13 wolves with evidence that it continued to increase beyond 13 wolves. These results are consistent with the hypothesis that hunters in large groups are more cooperative when hunting more formidable prey. Improved ability to capture formidable prey could therefore promote the formation and maintenance of large predator groups, particularly among predators that specialize on such prey.

Influence of Group Size on the Success of Wolves Hunting Bison

PubMed Central

MacNulty, Daniel R.; Tallian, Aimee; Stahler, Daniel R.; Smith, Douglas W.

2014-01-01

An intriguing aspect of social foraging behaviour is that large groups are often no better at capturing prey than are small groups, a pattern that has been attributed to diminished cooperation (i.e., free riding) in large groups. Although this suggests the formation of large groups is unrelated to prey capture, little is known about cooperation in large groups that hunt hard-to-catch prey. Here, we used direct observations of Yellowstone wolves (Canis lupus) hunting their most formidable prey, bison (Bison bison), to test the hypothesis that large groups are more cooperative when hunting difficult prey. We quantified the relationship between capture success and wolf group size, and compared it to previously reported results for Yellowstone wolves hunting elk (Cervus elaphus), a prey that was, on average, 3 times easier to capture than bison. Whereas improvement in elk capture success levelled off at 2–6 wolves, bison capture success levelled off at 9–13 wolves with evidence that it continued to increase beyond 13 wolves. These results are consistent with the hypothesis that hunters in large groups are more cooperative when hunting more formidable prey. Improved ability to capture formidable prey could therefore promote the formation and maintenance of large predator groups, particularly among predators that specialize on such prey. PMID:25389760

Comparison of Congruence Judgment and Auditory Localization Tasks for Assessing the Spatial Limits of Visual Capture

PubMed Central

Bosen, Adam K.; Fleming, Justin T.; Brown, Sarah E.; Allen, Paul D.; O'Neill, William E.; Paige, Gary D.

2016-01-01

Vision typically has better spatial accuracy and precision than audition, and as a result often captures auditory spatial perception when visual and auditory cues are presented together. One determinant of visual capture is the amount of spatial disparity between auditory and visual cues: when disparity is small visual capture is likely to occur, and when disparity is large visual capture is unlikely. Previous experiments have used two methods to probe how visual capture varies with spatial disparity. First, congruence judgment assesses perceived unity between cues by having subjects report whether or not auditory and visual targets came from the same location. Second, auditory localization assesses the graded influence of vision on auditory spatial perception by having subjects point to the remembered location of an auditory target presented with a visual target. Previous research has shown that when both tasks are performed concurrently they produce similar measures of visual capture, but this may not hold when tasks are performed independently. Here, subjects alternated between tasks independently across three sessions. A Bayesian inference model of visual capture was used to estimate perceptual parameters for each session, which were compared across tasks. Results demonstrated that the range of audio-visual disparities over which visual capture was likely to occur were narrower in auditory localization than in congruence judgment, which the model indicates was caused by subjects adjusting their prior expectation that targets originated from the same location in a task-dependent manner. PMID:27815630

New insights on Ba overabundance in open clusters. Evidence for the intermediate neutron-capture process at play?

NASA Astrophysics Data System (ADS)

Mishenina, T.; Pignatari, M.; Carraro, G.; Kovtyukh, V.; Monaco, L.; Korotin, S.; Shereta, E.; Yegorova, I.; Herwig, F.

2015-02-01

Recently, an increasing number of studies were devoted to measure the abundances of neutron-capture elements heavier than iron in stars belonging to Galactic Open Clusters (OCs). OCs span a sizeable range in metallicity (-0.6 ≤ [Fe/H] ≤ +0.4), and they show abundances of light elements similar to disc stars of the same age. A different pattern is observed for heavy elements. A large scatter is observed for Ba, with most OCs showing [Ba/Fe] and [Ba/La] overabundant with respect to the Sun. The origin of this overabundance is not clearly understood. With the goal of providing new observational insights, we determined radial velocities, atmospheric parameters and chemical composition of 27 giant stars members of five OCs: Cr 110, Cr 261, NGC 2477, NGC 2506 and NGC 5822. We used high-resolution spectra obtained with the UVES spectrograph at European Southern Observatory Paranal. We perform a detailed spectroscopic analysis of these stars to measure the abundance of up to 22 elements per star. We study the dependence of element abundance on metallicity and age with unprecedented detail, complementing our analysis with data culled from the literature. We confirm the trend of Ba overabundance in OCs, and show its large dispersion for clusters younger than ˜4 Gyr. Finally, the implications of our results for stellar nucleosynthesis are discussed. We show in this work that the Ba enrichment compared to other neutron-capture elements in OCs cannot be explained by the contributions from the slow neutron-capture process and the rapid neutron-capture process. Instead, we argue that this anomalous signature can be explained by assuming an additional contribution by the intermediate neutron-capture process.

Estimating snow leopard population abundance using photography and capture-recapture techniques

USGS Publications Warehouse

Jackson, R.M.; Roe, J.D.; Wangchuk, R.; Hunter, D.O.

2006-01-01

Conservation and management of snow leopards (Uncia uncia) has largely relied on anecdotal evidence and presence-absence data due to their cryptic nature and the difficult terrain they inhabit. These methods generally lack the scientific rigor necessary to accurately estimate population size and monitor trends. We evaluated the use of photography in capture-mark-recapture (CMR) techniques for estimating snow leopard population abundance and density within Hemis National Park, Ladakh, India. We placed infrared camera traps along actively used travel paths, scent-sprayed rocks, and scrape sites within 16- to 30-km2 sampling grids in successive winters during January and March 2003-2004. We used head-on, oblique, and side-view camera configurations to obtain snow leopard photographs at varying body orientations. We calculated snow leopard abundance estimates using the program CAPTURE. We obtained a total of 66 and 49 snow leopard captures resulting in 8.91 and 5.63 individuals per 100 trap-nights during 2003 and 2004, respectively. We identified snow leopards based on the distinct pelage patterns located primarily on the forelimbs, flanks, and dorsal surface of the tail. Capture probabilities ranged from 0.33 to 0.67. Density estimates ranged from 8.49 (SE = 0.22; individuals per 100 km2 in 2003 to 4.45 (SE = 0.16) in 2004. We believe the density disparity between years is attributable to different trap density and placement rather than to an actual decline in population size. Our results suggest that photographic capture-mark-recapture sampling may be a useful tool for monitoring demographic patterns. However, we believe a larger sample size would be necessary for generating a statistically robust estimate of population density and abundance based on CMR models.

On the influences of key modelling constants of large eddy simulations for large-scale compartment fires predictions

NASA Astrophysics Data System (ADS)

Yuen, Anthony C. Y.; Yeoh, Guan H.; Timchenko, Victoria; Cheung, Sherman C. P.; Chan, Qing N.; Chen, Timothy

2017-09-01

An in-house large eddy simulation (LES) based fire field model has been developed for large-scale compartment fire simulations. The model incorporates four major components, including subgrid-scale turbulence, combustion, soot and radiation models which are fully coupled. It is designed to simulate the temporal and fluid dynamical effects of turbulent reaction flow for non-premixed diffusion flame. Parametric studies were performed based on a large-scale fire experiment carried out in a 39-m long test hall facility. Several turbulent Prandtl and Schmidt numbers ranging from 0.2 to 0.5, and Smagorinsky constants ranging from 0.18 to 0.23 were investigated. It was found that the temperature and flow field predictions were most accurate with turbulent Prandtl and Schmidt numbers of 0.3, respectively, and a Smagorinsky constant of 0.2 applied. In addition, by utilising a set of numerically verified key modelling parameters, the smoke filling process was successfully captured by the present LES model.

Using genic sequence capture in combination with a syntenic pseudo genome to map a deletion mutant in a wheat species.

PubMed

Gardiner, Laura-Jayne; Gawroński, Piotr; Olohan, Lisa; Schnurbusch, Thorsten; Hall, Neil; Hall, Anthony

2014-12-01

Mapping-by-sequencing analyses have largely required a complete reference sequence and employed whole genome re-sequencing. In species such as wheat, no finished genome reference sequence is available. Additionally, because of its large genome size (17 Gb), re-sequencing at sufficient depth of coverage is not practical. Here, we extend the utility of mapping by sequencing, developing a bespoke pipeline and algorithm to map an early-flowering locus in einkorn wheat (Triticum monococcum L.) that is closely related to the bread wheat genome A progenitor. We have developed a genomic enrichment approach using the gene-rich regions of hexaploid bread wheat to design a 110-Mbp NimbleGen SeqCap EZ in solution capture probe set, representing the majority of genes in wheat. Here, we use the capture probe set to enrich and sequence an F2 mapping population of the mutant. The mutant locus was identified in T. monococcum, which lacks a complete genome reference sequence, by mapping the enriched data set onto pseudo-chromosomes derived from the capture probe target sequence, with a long-range order of genes based on synteny of wheat with Brachypodium distachyon. Using this approach we are able to map the region and identify a set of deleted genes within the interval. © 2014 The Authors.The Plant Journal published by Society for Experimental Biology and John Wiley & Sons Ltd.

Simulation of aerosolized oil droplets capture in a range hood exhaust using coupled CFD-population balance method

NASA Astrophysics Data System (ADS)

Liu, Shuyuan; Zhang, Yong; Feng, Yu; Shi, Changbin; Cao, Yong; Yuan, Wei

2018-02-01

A coupled population balance sectional method (PBSM) coupled with computational fluid dynamics (CFD) is presented to simulate the capture of aerosolized oil droplets (AODs) in a range hood exhaust. The homogeneous nucleation and coagulation processes are modeled and simulated with this CFD-PBSM method. With the design angle, α of the range hood exhaust varying from 60° to 30°, the AODs capture increases meanwhile the pressure drop between the inlet and the outlet of the range hood also increases from 8.38Pa to 175.75Pa. The increasing inlet flow velocities also result in less AODs capture although the total suction increases due to higher flow rates to the range hood. Therefore, the CFD-PBSM method provides an insight into the formation and capture of AODs as well as their impact on the operation and design of the range hood exhaust.

Status and habitat relationships of northern flying squirrels on Mount Desert Island, Maine

USGS Publications Warehouse

O'Connell, A.F.; Servello, F.; Higgins, J.; Halteman, W.

2001-01-01

Northern (Glaucomys sabrinus) and southern (G. volans) flying squirrels occur in Maine, but there is uncertainty about range overlap in southcentral Maine where the southern flying squirrel reaches its geographic range limit. We surveyed flying squirrels on Mount Desert Island (MDI), located along the central Maine coast, to update the current status and distribution of these species. We captured only northern flying squirrels, and populations (> 2 individuals) were located in two conifer stands and one mixed conifer-hardwood stand. All three stands were located in relatively older forests, outside a large area burned in a 1947 fire. Tree diameters were similar between trap stations with and without captures, under-story density was low overall, and there was a trend of higher seedling density at capture locations. Low understory density may allow squirrels more effective gliding movements between trees, which may enhance predator avoidance. Although the southern flying squirrel was reported from MDI numerous times during the 20th century, no voucher specimens exist, and species identification and localities have been poorly documented. Future surveys on MDI should consider collection of voucher specimens to validate subsequent survey efforts and effectively document changes in local biodiversity.

Experimental study on rotating instability mode characteristics of axial compressor tip flow

NASA Astrophysics Data System (ADS)

Tian, Jie; Yao, Dan; Wu, Yadong; Ouyang, Hua

2018-04-01

This paper investigates the rotating instabilities that occurred on the single-stage axial compressor designed for aerodynamic performance validation, which was tested with two sets of circumferential measuring points in combination. Circumferential mode characteristics of compressors are usually too high to be captured experimentally, and aliasing of the circumferential mode order occurs when not enough sensors are used. A calibration and prediction method to capture the higher circumferential mode of unsteady flow in a compressor was proposed. Unsteady pressure fluctuations near the tip region in an axial compressor were studied, and high circumferential mode characteristics were captured on both the blade passing frequency (BPF) and the rotational instability frequency (RIF) under different flow rate conditions based on this novel method. The characteristic RI spectrum with a broadband hump was present in a large range of flow conditions. Both the frequency range and the dominant circumferential mode order decreased as the flow rate decreased. Based on the calibrated mode characteristics, a rotating aerodynamic source model is used to explain the side-by-side peak of RIF spectrum and rotating characteristics of RI. The calibration and prediction method of the high circumferential mode is beneficial for the research of unsteady flow in an axial compressor.

"Freshwater killer whales": beaching behavior of an alien fish to hunt land birds.

PubMed

Cucherousset, Julien; Boulêtreau, Stéphanie; Azémar, Frédéric; Compin, Arthur; Guillaume, Mathieu; Santoul, Frédéric

2012-01-01

The behavioral strategies developed by predators to capture and kill their prey are fascinating, notably for predators that forage for prey at, or beyond, the boundaries of their ecosystem. We report here the occurrence of a beaching behavior used by an alien and large-bodied freshwater predatory fish (Silurus glanis) to capture birds on land (i.e. pigeons, Columbia livia). Among a total of 45 beaching behaviors observed and filmed, 28% were successful in bird capture. Stable isotope analyses (δ(13)C and δ(15)N) of predators and their putative prey revealed a highly variable dietary contribution of land birds among individuals. Since this extreme behavior has not been reported in the native range of the species, our results suggest that some individuals in introduced predator populations may adapt their behavior to forage on novel prey in new environments, leading to behavioral and trophic specialization to actively cross the water-land interface.

Large perturbation flow field analysis and simulation for supersonic inlets

NASA Technical Reports Server (NTRS)

Varner, M. O.; Martindale, W. R.; Phares, W. J.; Kneile, K. R.; Adams, J. C., Jr.

1984-01-01

An analysis technique for simulation of supersonic mixed compression inlets with large flow field perturbations is presented. The approach is based upon a quasi-one-dimensional inviscid unsteady formulation which includes engineering models of unstart/restart, bleed, bypass, and geometry effects. Numerical solution of the governing time dependent equations of motion is accomplished through a shock capturing finite difference algorithm, of which five separate approaches are evaluated. Comparison with experimental supersonic wind tunnel data is presented to verify the present approach for a wide range of transient inlet flow conditions.

Generalized assorted pixel camera: postcapture control of resolution, dynamic range, and spectrum.

PubMed

Yasuma, Fumihito; Mitsunaga, Tomoo; Iso, Daisuke; Nayar, Shree K

2010-09-01

We propose the concept of a generalized assorted pixel (GAP) camera, which enables the user to capture a single image of a scene and, after the fact, control the tradeoff between spatial resolution, dynamic range and spectral detail. The GAP camera uses a complex array (or mosaic) of color filters. A major problem with using such an array is that the captured image is severely under-sampled for at least some of the filter types. This leads to reconstructed images with strong aliasing. We make four contributions in this paper: 1) we present a comprehensive optimization method to arrive at the spatial and spectral layout of the color filter array of a GAP camera. 2) We develop a novel algorithm for reconstructing the under-sampled channels of the image while minimizing aliasing artifacts. 3) We demonstrate how the user can capture a single image and then control the tradeoff of spatial resolution to generate a variety of images, including monochrome, high dynamic range (HDR) monochrome, RGB, HDR RGB, and multispectral images. 4) Finally, the performance of our GAP camera has been verified using extensive simulations that use multispectral images of real world scenes. A large database of these multispectral images has been made available at http://www1.cs.columbia.edu/CAVE/projects/gap_camera/ for use by the research community.

Face Value: Towards Robust Estimates of Snow Leopard Densities.

PubMed

Alexander, Justine S; Gopalaswamy, Arjun M; Shi, Kun; Riordan, Philip

2015-01-01

When densities of large carnivores fall below certain thresholds, dramatic ecological effects can follow, leading to oversimplified ecosystems. Understanding the population status of such species remains a major challenge as they occur in low densities and their ranges are wide. This paper describes the use of non-invasive data collection techniques combined with recent spatial capture-recapture methods to estimate the density of snow leopards Panthera uncia. It also investigates the influence of environmental and human activity indicators on their spatial distribution. A total of 60 camera traps were systematically set up during a three-month period over a 480 km2 study area in Qilianshan National Nature Reserve, Gansu Province, China. We recorded 76 separate snow leopard captures over 2,906 trap-days, representing an average capture success of 2.62 captures/100 trap-days. We identified a total number of 20 unique individuals from photographs and estimated snow leopard density at 3.31 (SE = 1.01) individuals per 100 km2. Results of our simulation exercise indicate that our estimates from the Spatial Capture Recapture models were not optimal to respect to bias and precision (RMSEs for density parameters less or equal to 0.87). Our results underline the critical challenge in achieving sufficient sample sizes of snow leopard captures and recaptures. Possible performance improvements are discussed, principally by optimising effective camera capture and photographic data quality.

Face Value: Towards Robust Estimates of Snow Leopard Densities

PubMed Central

2015-01-01

When densities of large carnivores fall below certain thresholds, dramatic ecological effects can follow, leading to oversimplified ecosystems. Understanding the population status of such species remains a major challenge as they occur in low densities and their ranges are wide. This paper describes the use of non-invasive data collection techniques combined with recent spatial capture-recapture methods to estimate the density of snow leopards Panthera uncia. It also investigates the influence of environmental and human activity indicators on their spatial distribution. A total of 60 camera traps were systematically set up during a three-month period over a 480 km2 study area in Qilianshan National Nature Reserve, Gansu Province, China. We recorded 76 separate snow leopard captures over 2,906 trap-days, representing an average capture success of 2.62 captures/100 trap-days. We identified a total number of 20 unique individuals from photographs and estimated snow leopard density at 3.31 (SE = 1.01) individuals per 100 km2. Results of our simulation exercise indicate that our estimates from the Spatial Capture Recapture models were not optimal to respect to bias and precision (RMSEs for density parameters less or equal to 0.87). Our results underline the critical challenge in achieving sufficient sample sizes of snow leopard captures and recaptures. Possible performance improvements are discussed, principally by optimising effective camera capture and photographic data quality. PMID:26322682

SPECS: Orbital debris removal

NASA Technical Reports Server (NTRS)

1991-01-01

The debris problem has reached a stage at which the risk to satellites and spacecraft has become substantial in low Earth orbit (LEO). This research discovered that small particles posed little threat to spacecraft because shielding can effectively prevent these particles from damaging the spacecraft. The research also showed that, even though collision with a large piece of debris could destroy the spacecraft, the large pieces of debris pose little danger because they can be tracked and the spacecraft can be maneuvered away from these pieces. Additionally, there are many current designs to capture and remove large debris particles from the space environment. From this analysis, it was decided to concentrate on the removal of medium-sized orbital debris, that is, those pieces ranging from 1 cm to 50 cm in size. The current design incorporates a transfer vehicle and a netting vehicle to capture the medium-sized debris. The system is based near an operational space station located at 28.5 deg inclination and 400 km altitude. The system uses ground-based tracking to determine the location of a satellite breakup or debris cloud. These data are uploaded to the transfer vehicle, which proceeds to rendezvous with the debris at a lower altitude parking orbit. Next, the netting vehicle is deployed, tracks the targeted debris, and captures it. After expending the available nets, the netting vehicle returns to the transfer vehicle for a new netting module and continues to capture more debris in the target area. Once all the netting modules are expended, the transfer vehicle returns to the space station's orbit where it is resupplied with new netting modules from a space shuttle load. The new modules are launched by the shuttle from the ground and the expended modules are taken back to Earth for removal of the captured debris, refueling, and repacking of the nets. Once the netting modules are refurbished, they are taken back into orbit for reuse. In a typical mission, the system has the ability to capture 50 pieces of orbital debris. One mission will take approximately six months and the system is designed to allow for a 30 deg inclination change on the outgoing and incoming trips of the transfer vehicle.

An Assessment of Stream Confluence Flow Dynamics using Large Scale Particle Image Velocimetry Captured from Unmanned Aerial Systems

NASA Astrophysics Data System (ADS)

Lewis, Q. W.; Rhoads, B. L.

2017-12-01

The merging of rivers at confluences results in complex three-dimensional flow patterns that influence sediment transport, bed morphology, downstream mixing, and physical habitat conditions. The capacity to characterize comprehensively flow at confluences using traditional sensors, such as acoustic Doppler velocimeters and profiles, is limited by the restricted spatial resolution of these sensors and difficulties in measuring velocities simultaneously at many locations within a confluence. This study assesses two-dimensional surficial patterns of flow structure at a small stream confluence in Illinois, USA, using large scale particle image velocimetry (LSPIV) derived from videos captured by unmanned aerial systems (UAS). The method captures surface velocity patterns at high spatial and temporal resolution over multiple scales, ranging from the entire confluence to details of flow within the confluence mixing interface. Flow patterns at high momentum ratio are compared to flow patterns when the two incoming flows have nearly equal momentum flux. Mean surface flow patterns during the two types of events provide details on mean patterns of surface flow in different hydrodynamic regions of the confluence and on changes in these patterns with changing momentum flux ratio. LSPIV data derived from the highest resolution imagery also reveal general characteristics of large-scale vortices that form along the shear layer between the flows during the high-momentum ratio event. The results indicate that the use of LSPIV and UAS is well-suited for capturing in detail mean surface patterns of flow at small confluences, but that characterization of evolving turbulent structures is limited by scale considerations related to structure size, image resolution, and camera instability. Complementary methods, including camera platforms mounted at fixed positions close to the water surface, provide opportunities to accurately characterize evolving turbulent flow structures in confluences.

Ion dipole capture cross sections at low ion and rotational energies - Comparison of integrated capture cross sections with reaction cross sections for NH3 and H2O parent-ion collisions.

NASA Technical Reports Server (NTRS)

Dugan, J. V., Jr.; Canright, R. B., Jr.

1972-01-01

The numerical capture cross section is calculated from the capture ratio, defined as the fraction of trajectories reaching a prescribed minimum separation of 3 A. The calculated capture cross sections for a rotational temperature of 77 K suggest large reaction cross sections in 80 K experiments for the large dipole-moment target, methyl cyanide.

Electron capture in collisions of Si3+ ions with atomic hydrogen from low to intermediate energies

NASA Astrophysics Data System (ADS)

Liu, C. H.; Liu, L.; Wang, J. G.

2014-07-01

The electron capture process for the Si3+(3s) + H(1s) collisions is investigated by the quantum-mechanical molecular orbital close-coupling (MOCC) method and by the two-center atomic orbital close-coupling (AOCC) method in the energy range of 10-5-10 keV/u and 0.8-200 keV/u, respectively. Total and state-selective cross sections are presented and compared with the available theoretical and experimental results. The present MOCC and AOCC results agree well with the experimental measurements, but show some discrepancy with the calculations of Wang et al. [Phys. Rev. A 74, 052709 (2006), 10.1103/PhysRevA.74.052709] at E > 40 eV/u because of the inclusion of rotational couplings, which play important roles in the electron capture process. At lower energies, the present results are about three to five times smaller than those of Wang et al. due to the difference in the molecular data at large internuclear distances. The energy behaviors of the electron capture cross sections are discussed on the basis of identified reaction mechanisms.

Clinical biochemistry in healthy manatees (Trichechus manatus latirostris).

PubMed

Harvey, John W; Harr, Kendal E; Murphy, David; Walsh, Michael T; Chittick, Elizabeth J; Bonde, Robert K; Pate, Melanie G; Deutsch, Charles J; Edwards, Holly H; Haubold, Elsa M

2007-06-01

Florida manatees (Trichechus manatus latirostris) are endangered aquatic mammals living in coastal and riverine waterways of Florida and adjacent states. Serum or plasma biochemical analyses are important tools in evaluating the health of free-ranging and captive manatees. The purpose of this study was to measure diagnostically important analytes in the plasma of healthy manatees and to determine whether there was significant variation with respect to location (free-ranging versus captive), age class (small calves, large calves, subadults, adults), and gender. No significant differences in plasma sodium, potassium, bilirubin, glucose, alanine aminotransferase, or creatine kinase were found among these classes of animals. Compared to free-ranging manatees, captive animals had significantly lower mean concentrations of plasma chloride, phosphate, magnesium, triglycerides, anion gap, and lactate. Captive manatees had significantly higher mean values of total CO2, calcium, urea, creatinine, alkaline phosphatase, gamma-glutamyltransferase, total protein, albumin, and albumin/globulin ratio than did free-ranging animals. Differences in the environments of these two groups, including diet, temperature, salinity, and stress, might account for some of these results. The higher plasma lactate and anion gap concentrations and lower total CO2 concentrations of free-ranging manatees were probably due to greater exertion during capture, but the lack of elevated plasma creatine kinase activity relative to captive animals indicates that there was no serious muscle injury associated with capture. Plasma phosphate decreased and total globulins increased with age. Plasma cholesterol and triglyceride concentrations were highest in small calves. Plasma aspartate aminotransferase was higher in large calves than in adults and subadults, and the albumin/ globulin ratio was higher in subadults than in adults. Plasma total CO2 was higher and chloride was slightly lower in females than in males.

Clinical biochemistry in healthy manatees (Trichechus manatus latirostris)

USGS Publications Warehouse

Harvey, J.W.; Harr, K.E.; Murphy, D.; Walsh, M.T.; Chittick, E.J.; Bonde, R.K.; Pate, M.G.; Deutsch, C.J.; Edwards, H.H.; Haubold, E.M.

2007-01-01

Florida manatees (Trichechus manatus latirostris) are endangered aquatic mammals living in coastal and riverine waterways of Florida and adjacent states. Serum or plasma biochemical analyses are important tools in evaluating the health of free-ranging and captive manatees. The purpose of this study was to measure diagnostically important analytes in the plasma of healthy manatees and to determine whether there was significant variation with respect to location (free-ranging versus captive), age class (small calves, large calves, subadults, adults), and gender. No significant differences in plasma sodium, potassium, bilirubin, glucose, alanine aminotransferase, or creatine kinase were found among these classes of animals. Compared to free-ranging manatees, captive animals had significantly lower mean concentrations of plasma chloride, phosphate, magnesium, triglycerides, anion gap, and lactate. Captive manatees had significantly higher mean values of total CO2, calcium, urea, creatinine, alkaline phosphatase, gamma-glutamyltransferase, total protein, albumin, and albumin/globulin ratio than did free-ranging animals. Differences in the environments of these two groups, including diet, temperature, salinity, and stress, might account for some of these results. The higher plasma lactate and anion gap concentrations and lower total CO2 concentrations of free-ranging manatees were probably due to greater exertion during capture, but the lack of elevated plasma creatine kinase activity relative to captive animals indicates that there was no serious muscle injury associated with capture. Plasma phosphate decreased and total globulins increased with age. Plasma cholesterol and triglyceride concentrations were highest in small calves. Plasma aspartate aminotransferase was higher in large calves than in adults and subadults, and the albumin/ globulin ratio was higher in subadults than in adults. Plasma total CO2 was higher and chloride was slightly lower in females than in males.

Modeling and Measurements of Multiphase Flow and Bubble Entrapment in Steel Continuous Casting

NASA Astrophysics Data System (ADS)

Jin, Kai; Thomas, Brian G.; Ruan, Xiaoming

2016-02-01

In steel continuous casting, argon gas is usually injected to prevent clogging, but the bubbles also affect the flow pattern, and may become entrapped to form defects in the final product. To investigate this behavior, plant measurements were conducted, and a computational model was applied to simulate turbulent flow of the molten steel and the transport and capture of argon gas bubbles into the solidifying shell in a continuous slab caster. First, the flow field was solved with an Eulerian k- ɛ model of the steel, which was two-way coupled with a Lagrangian model of the large bubbles using a discrete random walk method to simulate their turbulent dispersion. The flow predicted on the top surface agreed well with nailboard measurements and indicated strong cross flow caused by biased flow of Ar gas due to the slide-gate orientation. Then, the trajectories and capture of over two million bubbles (25 μm to 5 mm diameter range) were simulated using two different capture criteria (simple and advanced). Results with the advanced capture criterion agreed well with measurements of the number, locations, and sizes of captured bubbles, especially for larger bubbles. The relative capture fraction of 0.3 pct was close to the measured 0.4 pct for 1 mm bubbles and occurred mainly near the top surface. About 85 pct of smaller bubbles were captured, mostly deeper down in the caster. Due to the biased flow, more bubbles were captured on the inner radius, especially near the nozzle. On the outer radius, more bubbles were captured near to narrow face. The model presented here is an efficient tool to study the capture of bubbles and inclusion particles in solidification processes.

High Dynamic Range Digital Imaging of Spacecraft

NASA Technical Reports Server (NTRS)

Karr, Brian A.; Chalmers, Alan; Debattista, Kurt

2014-01-01

The ability to capture engineering imagery with a wide degree of dynamic range during rocket launches is critical for post launch processing and analysis [USC03, NNC86]. Rocket launches often present an extreme range of lightness, particularly during night launches. Night launches present a two-fold problem: capturing detail of the vehicle and scene that is masked by darkness, while also capturing detail in the engine plume.

Substrate-Mediated Laser Ablation under Ambient Conditions for Spatially-Resolved Tissue Proteomics

PubMed Central

Fatou, Benoit; Wisztorski, Maxence; Focsa, Cristian; Salzet, Michel; Ziskind, Michael; Fournier, Isabelle

2015-01-01

Numerous applications of ambient Mass Spectrometry (MS) have been demonstrated over the past decade. They promoted the emergence of various micro-sampling techniques such as Laser Ablation/Droplet Capture (LADC). LADC consists in the ablation of analytes from a surface and their subsequent capture in a solvent droplet which can then be analyzed by MS. LADC is thus generally performed in the UV or IR range, using a wavelength at which analytes or the matrix absorb. In this work, we explore the potential of visible range LADC (532 nm) as a micro-sampling technology for large-scale proteomics analyses. We demonstrate that biomolecule analyses using 532 nm LADC are possible, despite the low absorbance of biomolecules at this wavelength. This is due to the preponderance of an indirect substrate-mediated ablation mechanism at low laser energy which contrasts with the conventional direct ablation driven by sample absorption. Using our custom LADC system and taking advantage of this substrate-mediated ablation mechanism, we were able to perform large-scale proteomic analyses of micro-sampled tissue sections and demonstrated the possible identification of proteins with relevant biological functions. Consequently, the 532 nm LADC technique offers a new tool for biological and clinical applications. PMID:26674367

Systematic Tuning and Multifunctionalization of Covalent Organic Polymers for Enhanced Carbon Capture

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

Xiang, Zhonghua; Mercado, Rocio; Huck, Johanna M.

Porous covalent polymers are attracting increasing interest in the fields of gas adsorption, gas separation, and catalysis due to their fertile synthetic polymer chemistry, large internal surface areas, and ultrahigh hydrothermal stabilities. While precisely manipulating the porosities of porous organic materials for targeted applications remains challenging, we show how a large degree of diversity can be achieved in covalent organic polymers by incorporating multiple functionalities into a single framework, as is done for crystalline porous materials. Here, we synthesized 17 novel porous covalent organic polymers (COPs) with finely tuned porosities, a wide range of Brunauer–Emmett–Teller (BET) specific surface areas ofmore » 430–3624 m2 g–1, and a broad range of pore volumes of 0.24–3.50 cm3 g–1, all achieved by tailoring the length and geometry of building blocks. Furthermore, we are the first to successfully incorporate more than three distinct functional groups into one phase for porous organic materials, which has been previously demonstrated in crystalline metal–organic frameworks (MOFs). COPs decorated with multiple functional groups in one phase can lead to enhanced properties that are not simply linear combinations of the pure component properties. For instance, in the dibromobenzene-lined frameworks, the bi- and multifunctionalized COPs exhibit selectivities for carbon dioxide over nitrogen twice as large as any of the singly functionalized COPs. These multifunctionalized frameworks also exhibit a lower parasitic energy cost for carbon capture at typical flue gas conditions than any of the singly functionalized frameworks. Despite the significant improvement, these frameworks do not yet outperform the current state-of-art technology for carbon capture. Nonetheless, the tuning strategy presented here opens up avenues for the design of novel catalysts, the synthesis of functional sensors from these materials, and the improvement in the performance of existing covalent organic polymers by multifunctionalization.« less

Visibility through the gaseous smoke in airborne remote sensing using a DSLR camera

NASA Astrophysics Data System (ADS)

Chabok, Mirahmad; Millington, Andrew; Hacker, Jorg M.; McGrath, Andrew J.

2016-08-01

Visibility and clarity of remotely sensed images acquired by consumer grade DSLR cameras, mounted on an unmanned aerial vehicle or a manned aircraft, are critical factors in obtaining accurate and detailed information from any area of interest. The presence of substantial haze, fog or gaseous smoke particles; caused, for example, by an active bushfire at the time of data capture, will dramatically reduce image visibility and quality. Although most modern hyperspectral imaging sensors are capable of capturing a large number of narrow range bands of the shortwave and thermal infrared spectral range, which have the potential to penetrate smoke and haze, the resulting images do not contain sufficient spatial detail to enable locating important objects or assist search and rescue or similar applications which require high resolution information. We introduce a new method for penetrating gaseous smoke without compromising spatial resolution using a single modified DSLR camera in conjunction with image processing techniques which effectively improves the visibility of objects in the captured images. This is achieved by modifying a DSLR camera and adding a custom optical filter to enable it to capture wavelengths from 480-1200nm (R, G and Near Infrared) instead of the standard RGB bands (400-700nm). With this modified camera mounted on an aircraft, images were acquired over an area polluted by gaseous smoke from an active bushfire. Processed data using our proposed method shows significant visibility improvements compared with other existing solutions.

Comparing post-combustion CO2 capture operation at retrofitted coal-fired power plants in the Texas and Great Britain electric grids

NASA Astrophysics Data System (ADS)

Cohen, Stuart M.; Chalmers, Hannah L.; Webber, Michael E.; King, Carey W.

2011-04-01

This work analyses the carbon dioxide (CO2) capture system operation within the Electric Reliability Council of Texas (ERCOT) and Great Britain (GB) electric grids using a previously developed first-order hourly electricity dispatch and pricing model. The grids are compared in their 2006 configuration with the addition of coal-based CO2 capture retrofits and emissions penalties from 0 to 100 US dollars per metric ton of CO2 (USD/tCO2). CO2 capture flexibility is investigated by comparing inflexible CO2 capture systems to flexible ones that can choose between full- and zero-load CO2 capture depending on which operating mode has lower costs or higher profits. Comparing these two grids is interesting because they have similar installed capacity and peak demand, and both are isolated electricity systems with competitive wholesale electricity markets. However, differences in capacity mix, demand patterns, and fuel markets produce diverging behaviours of CO2 capture at coal-fired power plants. Coal-fired facilities are primarily base load in ERCOT for a large range of CO2 prices but are comparably later in the dispatch order in GB and consequently often supply intermediate load. As a result, the ability to capture CO2 is more important for ensuring dispatch of coal-fired facilities in GB than in ERCOT when CO2 prices are high. In GB, higher overall coal prices mean that CO2 prices must be slightly higher than in ERCOT before the emissions savings of CO2 capture offset capture energy costs. However, once CO2 capture is economical, operating CO2 capture on half the coal fleet in each grid achieves greater emissions reductions in GB because the total coal-based capacity is 6 GW greater than in ERCOT. The market characteristics studied suggest greater opportunity for flexible CO2 capture to improve operating profits in ERCOT, but profit improvements can be offset by a flexibility cost penalty.

Extending SME to Handle Large-Scale Cognitive Modeling.

PubMed

Forbus, Kenneth D; Ferguson, Ronald W; Lovett, Andrew; Gentner, Dedre

2017-07-01

Analogy and similarity are central phenomena in human cognition, involved in processes ranging from visual perception to conceptual change. To capture this centrality requires that a model of comparison must be able to integrate with other processes and handle the size and complexity of the representations required by the tasks being modeled. This paper describes extensions to Structure-Mapping Engine (SME) since its inception in 1986 that have increased its scope of operation. We first review the basic SME algorithm, describe psychological evidence for SME as a process model, and summarize its role in simulating similarity-based retrieval and generalization. Then we describe five techniques now incorporated into the SME that have enabled it to tackle large-scale modeling tasks: (a) Greedy merging rapidly constructs one or more best interpretations of a match in polynomial time: O(n 2 log(n)); (b) Incremental operation enables mappings to be extended as new information is retrieved or derived about the base or target, to model situations where information in a task is updated over time; (c) Ubiquitous predicates model the varying degrees to which items may suggest alignment; (d) Structural evaluation of analogical inferences models aspects of plausibility judgments; (e) Match filters enable large-scale task models to communicate constraints to SME to influence the mapping process. We illustrate via examples from published studies how these enable it to capture a broader range of psychological phenomena than before. Copyright © 2016 Cognitive Science Society, Inc.

Calculating hyperfine couplings in large ionic crystals containing hundreds of QM atoms: subsystem DFT is the key.

PubMed

Kevorkyants, Ruslan; Wang, Xiqiao; Close, David M; Pavanello, Michele

2013-11-14

We present an application of the linear scaling frozen density embedding (FDE) formulation of subsystem DFT to the calculation of isotropic hyperfine coupling constants (hfcc's) of atoms belonging to a guanine radical cation embedded in a guanine hydrochloride monohydrate crystal. The model systems range from an isolated guanine to a 15,000 atom QM/MM cluster where the QM region is comprised of 36 protonated guanine cations, 36 chlorine anions, and 42 water molecules. Our calculations show that the embedding effects of the surrounding crystal cannot be reproduced by small model systems nor by a pure QM/MM procedure. Instead, a large QM region is needed to fully capture the complicated nature of the embedding effects in this system. The unprecedented system size for a relativistic all-electron isotropic hfcc calculation can be approached in this work because the local nature of the electronic structure of the organic crystals considered is fully captured by the FDE approach.

Going nuts for nuts? The trace proteome of a Cola drink, as detected via combinatorial peptide ligand libraries.

PubMed

D'Amato, Alfonsina; Fasoli, Elisa; Kravchuk, Alexander V; Righetti, Pier Giorgio

2011-05-06

The "invisible" proteome of a Cola drink, stated to be produced with a kola nut extract, has been investigated via capture with combinatorial peptide ligand libraries (CPLL). Indeed, a few proteins in the M(r) 15-20 kDa range could be identified by treating large beverage volumes (1 L) and performing the capture with CPLLs at very acidic pH values (pH 2.2) under conditions mimicking reverse-phase adsorption. Ascertaining the presence of proteins deriving from plant extracts has confirmed the genuineness of such beverage and suggests the possibility of certifying whether soft drinks present on the market are indeed made with vegetable extracts or only with artificial chemical flavoring.

Echolocation behaviour adapted to prey in foraging Blainville's beaked whale (Mesoplodon densirostris)

PubMed Central

Johnson, M; Hickmott, L.S; Aguilar Soto, N; Madsen, P.T

2007-01-01

Toothed whales echolocating in the wild generate clicks with low repetition rates to locate prey but then produce rapid sequences of clicks, called buzzes, when attempting to capture prey. However, little is known about the factors that determine clicking rates or how prey type and behaviour influence echolocation-based foraging. Here we study Blainville's beaked whales foraging in deep water using a multi-sensor DTAG that records both outgoing echolocation clicks and echoes returning from mesopelagic prey. We demonstrate that the clicking rate at the beginning of buzzes is related to the distance between whale and prey, supporting the presumption that whales focus on a specific prey target during the buzz. One whale showed a bimodal relationship between target range and clicking rate producing abnormally slow buzz clicks while attempting to capture large echoic targets, probably schooling prey, with echo duration indicating a school diameter of up to 4.3 m. These targets were only found when the whale performed tight circling manoeuvres spending up to five times longer in water volumes with large targets than with small targets. The result indicates that toothed whales in the wild can adjust their echolocation behaviour and movement for capture of different prey on the basis of structural echo information. PMID:17986434

Large size biogas-fed Solid Oxide Fuel Cell power plants with carbon dioxide management: Technical and economic optimization

NASA Astrophysics Data System (ADS)

Curletti, F.; Gandiglio, M.; Lanzini, A.; Santarelli, M.; Maréchal, F.

2015-10-01

This article investigates the techno-economic performance of large integrated biogas Solid Oxide Fuel Cell (SOFC) power plants. Both atmospheric and pressurized operation is analysed with CO2 vented or captured. The SOFC module produces a constant electrical power of 1 MWe. Sensitivity analysis and multi-objective optimization are the mathematical tools used to investigate the effects of Fuel Utilization (FU), SOFC operating temperature and pressure on the plant energy and economic performances. FU is the design variable that most affects the plant performance. Pressurized SOFC with hybridization with a gas turbine provides a notable boost in electrical efficiency. For most of the proposed plant configurations, the electrical efficiency ranges in the interval 50-62% (LHV biogas) when a trade-off of between energy and economic performances is applied based on Pareto charts obtained from multi-objective plant optimization. The hybrid SOFC is potentially able to reach an efficiency above 70% when FU is 90%. Carbon capture entails a penalty of more 10 percentage points in pressurized configurations mainly due to the extra energy burdens of captured CO2 pressurization and oxygen production and for the separate and different handling of the anode and cathode exhausts and power recovery from them.

Neutron capture cross-section measurements for 238U between 0.4 and 1.4 MeV

NASA Astrophysics Data System (ADS)

Krishichayan, Fnu; Finch, S. W.; Howell, C. R.; Tonchev, A. P.; Tornow, W.

2017-09-01

Neutron-induced radiative-capture cross-section data of 238U are crucial for fundamental nuclear physics as well as for Stewardship Science, for advanced-fuel-cycle calculations, and for nuclear astrophysics. Based on different techniques, there are a large number of 238U(n, γ) 239U cross-section data available in the literature. However, there is a lack of systematic and consistent measurements in the 0.1 to 3.0 MeV energy range. The goal of the neutron-capture project at TUNL is to provide accurate 238U(n, γ) 239U cross-section data in this energy range. The 238U samples, sandwiched between gold foils of the same size, were irradiated for 8-14 hours with monoenergetic neutrons. To avoid any contribution from thermal neutrons, the 238U and 197Au targets were placed inside of a thin-walled pill-box made of 238U. Finally, the whole pill-box was wrapped in a gold foil as well. After irradiation, the samples were gamma-counted at the TUNL's low-background counting facility using high-efficient HPGe detectors. The 197Au monitor foils were used to calculate the neutron flux. The experimental technique and 238U(n, γ) 239U cross-section results at 6 energies will be discussed during the meeting.

Effects of water vapor pretreatment time and reaction temperature on CO(2) capture characteristics of a sodium-based solid sorbent in a bubbling fluidized-bed reactor.

PubMed

Seo, Yongwon; Jo, Sung-Ho; Ryu, Chong Kul; Yi, Chang-Keun

2007-10-01

CO(2) capture from flue gas using a sodium-based solid sorbent was investigated in a bubbling fluidized-bed reactor. Carbonation and regeneration temperature on CO(2) removal was determined. The extent of the chemical reactivity after carbonation or regeneration was characterized via (13)C NMR. In addition, the physical properties of the sorbent such as pore size, pore volume, and surface area after carbonation or regeneration were measured by gas adsorption method (BET). With water vapor pretreatment, near complete CO(2) removal was initially achieved and maintained for about 1-2min at 50 degrees C with 2s gas residence time, while without proper water vapor pretreatment CO(2) removal abruptly decreased from the beginning. Carbonation was effective at the lower temperature over the 50-70 degrees C temperature range, while regeneration more effective at the higher temperature over the 135-300 degrees C temperature range. To maintain the initial 90% CO(2) removal, it would be necessary to keep the regeneration temperature higher than about 135 degrees C. The results obtained in this study can be used as basic data for designing and operating a large scale CO(2) capture process with two fluidized-bed reactors.

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

Choi, K.; Itow, Y.; Rott, C., E-mail: koun@stelab.nagoya-u.ac.jp, E-mail: rott@skku.edu, E-mail: itow@stelab.nagoya-u.ac.jp

Dark matter could be captured in the Sun and self-annihilate, giving rise to an observable neutrino flux. Indirect searches for dark matter looking for this signal with neutrino telescopes have resulted in tight constraints on the interaction cross-section of dark matter with ordinary matter. We investigate how robust limits are against astro-physical uncertainties. We study the effect of the velocity distribution of dark matter in our Galaxy on capture rates in the Sun. We investigate four sources of uncertainties: orbital speed of the Sun, escape velocity of dark matter from the halo, dark matter velocity distribution functions and existence ofmore » a dark disc. We find that even extreme cases currently discussed do not decrease the sensitivity of indirect detection significantly because the capture is achieved over a broad range of the velocity distribution by integration over the velocity distribution. The effect of the uncertainty in the high-velocity tail of dark matter halo is very marginal as the capture process is rather inefficient at this region. The difference in capture rate in the Sun for various scenarios is compared to the expected change in event rates for direct detection. The possibility of co-rotating structure with the Sun can largely boost the signal and hence makes the interpretation of indirect detection conservative compared to direct detection.« less

Variation in capture efficiency of a beach seine for small fishes

USGS Publications Warehouse

Parsley, M.J.; Palmer, D.E.; Burkhardt, R.W.

1989-01-01

We determined the capture efficiency of a beach seine as a means of improving abundance estimates of small fishes in littoral areas. Capture efficiency for 14 taxa (individual species or species groups) was determined by seining within an enclosure at night over fine and coarse substrates in the John Day Reservoir, Oregon–Washington. Mean efficiency ranged from 12% for prickly sculpin Cottus asper captured over coarse substrates to 96% for peamouth Mylocheilus caurinus captured over fine substrates. Mean capture efficiency for a taxon (genus or species) was generally higher over fine substrates than over coarse substrates, although mean capture efficiencies over fine substrates were significantly greater for only 3 of 10 taxa. Capture efficiency generally was not influenced by fish density or by water temperature (range, 8–26°C). Conclusions about the relative abundance of taxa captured by seining can change substantially after capture efficiencies are taken into account.

Reliability and Validity of the Dyadic Observed Communication Scale (DOCS).

PubMed

Hadley, Wendy; Stewart, Angela; Hunter, Heather L; Affleck, Katelyn; Donenberg, Geri; Diclemente, Ralph; Brown, Larry K

2013-02-01

We evaluated the reliability and validity of the Dyadic Observed Communication Scale (DOCS) coding scheme, which was developed to capture a range of communication components between parents and adolescents. Adolescents and their caregivers were recruited from mental health facilities for participation in a large, multi-site family-based HIV prevention intervention study. Seventy-one dyads were randomly selected from the larger study sample and coded using the DOCS at baseline. Preliminary validity and reliability of the DOCS was examined using various methods, such as comparing results to self-report measures and examining interrater reliability. Results suggest that the DOCS is a reliable and valid measure of observed communication among parent-adolescent dyads that captures both verbal and nonverbal communication behaviors that are typical intervention targets. The DOCS is a viable coding scheme for use by researchers and clinicians examining parent-adolescent communication. Coders can be trained to reliably capture individual and dyadic components of communication for parents and adolescents and this complex information can be obtained relatively quickly.

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Galactic Neutron Capture Abundance Gradients

NASA Astrophysics Data System (ADS)

O'Connell, Julia; Frinchaboy, Peter M.; Shetrone, Matthew D.; Melendez, Matthew; Cunha, Katia M. L.; Majewski, Steven R.; Zasowski, Gail; APOGEE Team

2017-01-01

The evolution of elements, as a function or age, throughout the Milky Way disk provides a key constraint for galaxy evolution models. In an effort to provide these constraints, we have conducted an investigation into the r- and s- process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 survey. Stars were identified as cluster members by the Open Cluster Chemical Abundance & Mapping (OCCAM) survey, which culls member candidates by radial velocity, metallicity, and proper motion from the observed APOGEE sample. To obtain data for neutron capture elements in these clusters, we conducted a long-term observing campaign covering three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We present Galactic neutron-capture abundance gradients using 30+ clusters, within 6 kpc of the Sun, covering a range of ages from ~80 Myr to ~10 Gyr .

The Open Cluster Chemical Abundances and Mapping (OCCAM) Survey: Galactic Neutron CaptureAbundance Gradients

NASA Astrophysics Data System (ADS)

O'Connell, Julia; Frinchaboy, Peter M.; Shetrone, Matthew D.; Melendez, Matthew; Cunha, Katia; Majewski, Steven R.; Zasowski, Gail; APOGEE Team

2017-06-01

The evolution of elements, as a function or age, throughout the Milky Way disk provides a key constraint for galaxy evolution models. In an effort to provide these constraints, we have conducted an investigation into the r- and s- process elemental abundances for a large sample of open clusters as part of an optical follow-up to the SDSS-III/APOGEE-1 survey. Stars were identified as cluster members by the Open Cluster Chemical Abundance & Mapping (OCCAM) survey, which culls member candidates by radial velocity, metallicity and proper motion from the observed APOGEE sample. To obtain data for neutron capture elements in these clusters, we conducted a long-term observing campaign covering three years (2013-2016) using the McDonald Observatory Otto Struve 2.1-m telescope and Sandiford Cass Echelle Spectrograph (R ~ 60,000). We present Galactic neutron capture abundance gradients using 30+ clusters, within 6 kpc of the Sun, covering a range of ages from ~80 Myr to ~10 Gyr .

Habitat use and spatial structure of a barking frog (Eleutherodactylus augusti) population in southeastern Arizona

USGS Publications Warehouse

Goldberg, C.S.; Schwalbe, C.R.

2004-01-01

Barking Frogs (Eleutherodactylus augusti) are the northernmost ranging member of the large tropical family Leptodactylidae. We investigated the ecology of this saxicolous species at the northern edge of its range in a canyon in southern Arizona. We captured 54 frogs on discontinuous rock outcrops; eight of nine females and 39 of 45 males were on limestone outcrops. The remaining frogs were closer to limestone outcrops by more than 200 m than would be expected if they were distributed randomly with respect to limestone formations. Seven of 10 frogs radio-tracked had core home ranges (50% fixed kernel) from 94 to 100% on limestone; the other three frogs did not have any part of their home range on limestone outcrops. During five years of mark-recapture efforts, no frogs were found on a different outcrop from the one where they were originally captured; no radio-tracked frogs moved between outcrops during the breeding season. We estimated that four to 20 Barking Frogs occupied each outcrop; these groups probably are connected primarily by juvenile dispersal. As an organism living at the edge of its range, Barking Frogs in Arizona may rely heavily on extensive underground areas such as those found in limestone to protect them from a physiologically challenging environment. To manage for the persistence of Barking Frogs in southern Arizona, we must identify and protect habitat patches and movement pathways among them.

Large Eddy Simulation in the Computation of Jet Noise

NASA Technical Reports Server (NTRS)

Mankbadi, R. R.; Goldstein, M. E.; Povinelli, L. A.; Hayder, M. E.; Turkel, E.

1999-01-01

Noise can be predicted by solving Full (time-dependent) Compressible Navier-Stokes Equation (FCNSE) with computational domain. The fluctuating near field of the jet produces propagating pressure waves that produce far-field sound. The fluctuating flow field as a function of time is needed in order to calculate sound from first principles. Noise can be predicted by solving the full, time-dependent, compressible Navier-Stokes equations with the computational domain extended to far field - but this is not feasible as indicated above. At high Reynolds number of technological interest turbulence has large range of scales. Direct numerical simulations (DNS) can not capture the small scales of turbulence. The large scales are more efficient than the small scales in radiating sound. The emphasize is thus on calculating sound radiated by large scales.

A successful trap design for capturing large terrestrial snakes

Treesearch

Shirley J. Burgdorf; D. Craig Rudolph; Richard N. Conner; Daniel Saenz; Richard R. Schaefer

2005-01-01

Large scale trapping protocols for snakes can be expensive and require large investments of personnel and time. Typical methods, such as pitfall and small funnel traps, are not useful or suitable for capturing large snakes. A method was needed to survey multiple blocks of habitat for the Louisiana Pine Snake (Pituophis ruthveni), throughout its...

Viability of Carbon Capture and Sequestration Retrofits for Existing Coal-Fired Power Plants under an Emission Trading Scheme.

PubMed

Talati, Shuchi; Zhai, Haibo; Morgan, M Granger

2016-12-06

Using data on the coal-fired electric generating units (EGUs) in Texas we assess the economic feasibility of retrofitting existing units with carbon capture and sequestration (CCS) in order to comply with the Clean Power Plan's rate-based emission standards under an emission trading scheme. CCS with 90% capture is shown to be more economically attractive for a range of existing units than purchasing emission rate credits (ERCs) from a trading market at an average credit price above $28 per MWh under the final state standard and $35 per MWh under the final national standard. The breakeven ERC trading prices would decrease significantly if the captured CO 2 were sold for use in enhanced oil recovery, making CCS retrofits viable at lower trading prices. The combination of ERC trading and CO 2 use can greatly reinforce economic incentives and market demands for CCS and hence accelerate large-scale deployment, even under scenarios with high retrofit costs. Comparing the levelized costs of electricity generation between CCS retrofits and new renewable plants under the ERC trading scheme, retrofitting coal-fired EGUs with CCS may be significantly cheaper than new solar plants under some market conditions.

Captured metagenomics: large-scale targeting of genes based on ‘sequence capture’ reveals functional diversity in soils

PubMed Central

Manoharan, Lokeshwaran; Kushwaha, Sandeep K.; Hedlund, Katarina; Ahrén, Dag

2015-01-01

Microbial enzyme diversity is a key to understand many ecosystem processes. Whole metagenome sequencing (WMG) obtains information on functional genes, but it is costly and inefficient due to large amount of sequencing that is required. In this study, we have applied a captured metagenomics technique for functional genes in soil microorganisms, as an alternative to WMG. Large-scale targeting of functional genes, coding for enzymes related to organic matter degradation, was applied to two agricultural soil communities through captured metagenomics. Captured metagenomics uses custom-designed, hybridization-based oligonucleotide probes that enrich functional genes of interest in metagenomic libraries where only probe-bound DNA fragments are sequenced. The captured metagenomes were highly enriched with targeted genes while maintaining their target diversity and their taxonomic distribution correlated well with the traditional ribosomal sequencing. The captured metagenomes were highly enriched with genes related to organic matter degradation; at least five times more than similar, publicly available soil WMG projects. This target enrichment technique also preserves the functional representation of the soils, thereby facilitating comparative metagenomics projects. Here, we present the first study that applies the captured metagenomics approach in large scale, and this novel method allows deep investigations of central ecosystem processes by studying functional gene abundances. PMID:26490729

Low energy scattering cross section ratios of 14N(p ,p ) 14N

NASA Astrophysics Data System (ADS)

deBoer, R. J.; Bardayan, D. W.; Görres, J.; LeBlanc, P. J.; Manukyan, K. V.; Moran, M. T.; Smith, K.; Tan, W.; Uberseder, E.; Wiescher, M.; Bertone, P. F.; Champagne, A. E.; Islam, M. S.

2015-04-01

Background: The slowest reaction in the first CNO cycle is 14N(p ,γ ) 15O , therefore its rate determines the overall energy production efficiency of the entire cycle. The cross section presents several strong resonance contributions, especially for the ground-state transition. Some of the properties of the corresponding levels in the 15O compound nucleus remain uncertain, which affects the uncertainty in extrapolating the capture cross section to the low energy range of astrophysical interest. Purpose: The 14N(p ,γ ) 15O cross section can be described by using the phenomenological R matrix. Over the energy range of interest, only the proton and γ -ray channels are open. Since resonance capture makes significant contributions to the 14N(p ,γ ) 15O cross section, resonant proton scattering data can be used to provide additional constraints on the R -matrix fit of the capture data. Methods: A 4 MV KN Van de Graaff accelerator was used to bombard protons onto a windowless gas target containing enriched 14N gas over the proton energy range from Ep=1.0 to 3.0 MeV. Scattered protons were detected at θlab=90 , 120∘, 135∘, 150∘, and 160∘ using ruggedized silicon detectors. In addition, a 10 MV FN Tandem Van de Graaff accelerator was used to accelerate protons onto a solid Adenine (C5H5N5 ) target, of natural isotopic abundance, evaporated onto a thin self-supporting carbon backing, over the energy range from Ep=1.8 to 4.0 MeV. Scattered protons were detected at 28 angles between θlab=30 .4∘ and 167 .7∘ by using silicon photodiode detectors. Results: Relative cross sections were extracted from both measurements. While the relative cross sections do not provide as much constraint as absolute measurements, they greatly reduce the dependence of the data on otherwise significant systematic uncertainties, which are more difficult to quantify. The data are fit simultaneously using an R -matrix analysis and level energies and proton widths are extracted. Even with relative measurements, the statistics and large angular coverage of the measurements result in more confident values for the energies and proton widths of several levels; in particular, the broad resonance at Ec.m.=2.21 MeV, which corresponds to the 3 /2+ level at Ex=9.51 MeV in 15O . In particular, the s - and d -wave angular-momentum channels are separated. Conclusion: The relative cross sections provide a consistent set of data that can be used to better constrain a full multichannel R -matrix extrapolation of the capture data. It has been demonstrated how the scattering data reduce the uncertainty through a preliminary Monte Carlo uncertainty analysis, but several other issues remain that make large contributions to the uncertainty, which must be addressed by further capture and lifetime measurements.

Optimizing Radiometric Fidelity to Enhance Aerial Image Change Detection Utilizing Digital Single Lens Reflex (DSLR) Cameras

NASA Astrophysics Data System (ADS)

Kerr, Andrew D.

Determining optimal imaging settings and best practices related to the capture of aerial imagery using consumer-grade digital single lens reflex (DSLR) cameras, should enable remote sensing scientists to generate consistent, high quality, and low cost image data sets. Radiometric optimization, image fidelity, image capture consistency and repeatability were evaluated in the context of detailed image-based change detection. The impetus for this research is in part, a dearth of relevant, contemporary literature, on the utilization of consumer grade DSLR cameras for remote sensing, and the best practices associated with their use. The main radiometric control settings on a DSLR camera, EV (Exposure Value), WB (White Balance), light metering, ISO, and aperture (f-stop), are variables that were altered and controlled over the course of several image capture missions. These variables were compared for their effects on dynamic range, intra-frame brightness variation, visual acuity, temporal consistency, and the detectability of simulated cracks placed in the images. This testing was conducted from a terrestrial, rather than an airborne collection platform, due to the large number of images per collection, and the desire to minimize inter-image misregistration. The results point to a range of slightly underexposed image exposure values as preferable for change detection and noise minimization fidelity. The makeup of the scene, the sensor, and aerial platform, influence the selection of the aperture and shutter speed which along with other variables, allow for estimation of the apparent image motion (AIM) motion blur in the resulting images. The importance of the image edges in the image application, will in part dictate the lowest usable f-stop, and allow the user to select a more optimal shutter speed and ISO. The single most important camera capture variable is exposure bias (EV), with a full dynamic range, wide distribution of DN values, and high visual contrast and acuity occurring around -0.7 to -0.3EV exposure bias. The ideal values for sensor gain, was found to be ISO 100, with ISO 200 a less desirable. This study offers researchers a better understanding of the effects of camera capture settings on RSI pairs and their influence on image-based change detection.

Accuracy of human motion capture systems for sport applications; state-of-the-art review.

PubMed

van der Kruk, Eline; Reijne, Marco M

2018-05-09

Sport research often requires human motion capture of an athlete. It can, however, be labour-intensive and difficult to select the right system, while manufacturers report on specifications which are determined in set-ups that largely differ from sport research in terms of volume, environment and motion. The aim of this review is to assist researchers in the selection of a suitable motion capture system for their experimental set-up for sport applications. An open online platform is initiated, to support (sport)researchers in the selection of a system and to enable them to contribute and update the overview. systematic review; Method: Electronic searches in Scopus, Web of Science and Google Scholar were performed, and the reference lists of the screened articles were scrutinised to determine human motion capture systems used in academically published studies on sport analysis. An overview of 17 human motion capture systems is provided, reporting the general specifications given by the manufacturer (weight and size of the sensors, maximum capture volume, environmental feasibilities), and calibration specifications as determined in peer-reviewed studies. The accuracy of each system is plotted against the measurement range. The overview and chart can assist researchers in the selection of a suitable measurement system. To increase the robustness of the database and to keep up with technological developments, we encourage researchers to perform an accuracy test prior to their experiment and to add to the chart and the system overview (online, open access).

Micrometeoroid and Lunar Secondary Ejecta Flux Measurements: Comparison of Three Acoustic Systems

NASA Technical Reports Server (NTRS)

Corsaro, R. D.; Giovane, F.; Liou, Jer-Chyi; Burtchell, M.; Pisacane, V.; Lagakos, N.; Williams, E.; Stansbery, E.

2010-01-01

This report examines the inherent capability of three large-area acoustic sensor systems and their applicability for micrometeoroids (MM) and lunar secondary ejecta (SE) detection and characterization for future lunar exploration activities. Discussion is limited to instruments that can be fabricated and deployed with low resource requirements. Previously deployed impact detection probes typically have instrumented capture areas less than 0.2 square meters. Since the particle flux decreases rapidly with increased particle size, such small-area sensors rarely encounter particles in the size range above 50 microns, and even their sampling the population above 10 microns is typically limited. Characterizing the sparse dust population in the size range above 50 microns requires a very large-area capture instrument. However it is also important that such an instrument simultaneously measures the population of the smaller particles, so as to provide a complete instantaneous snapshot of the population. For lunar or planetary surface studies, the system constraints are significant. The instrument must be as large as possible to sample the population of the largest MM. This is needed to reliably assess the particle impact risks and to develop cost-effective shielding designs for habitats, astronauts, and critical instrument. The instrument should also have very high sensitivity to measure the flux of small and slow SE particles. is the SE environment is currently poorly characterized, and possess a contamination risk to machinery and personnel involved in exploration. Deployment also requires that the instrument add very little additional mass to the spacecraft. Three acoustic systems are being explored for this application.

Characterization and minimization of the stress response to trapping in free-ranging wolves (Canis lupus): insights from physiology and behavior.

PubMed

Santos, Nuno; Rio-Maior, Helena; Nakamura, Mónia; Roque, Sara; Brandão, Ricardo; Álvares, Francisco

2017-09-01

Wildlife capture is an essential management tool that induces a reactive homeostasis response in the captured animals. The aim of this study was to characterize the reactive homeostatic response to trapping in free-ranging wolves and assess the mitigation achieved by reducing the duration of restraint. Making use of wolves captured for ecological research as a model for wildlife acute stress, we characterize 25 reactive homeostasis mediators and we assess the effect on these mediators of reducing the duration of restraint in trap by using remote trap activation alarms. Free-ranging wolves trapped by leg-hold snares (n = 15) showed higher stress leukogram, tissue injury and hematocrit; while lower glucose, ions and cardiac rate compared with captive wolves. They also showed higher leukocyte count and creatine kinase; but lower hematocrit, cardiac rate and rectal body temperature compared to wolves captured by darting from a helicopter. Daily distance travelled was significantly lower up to day 12 post-capture compared to the remainder of the telemetry follow-up and this effect was more noticeable on the nocturnal distance travelled. Reducing the duration of restraint on trap significantly lowered the stress leukogram and dehydration. Daily distance travelled during the night by wolves captured using trap-alarms was significantly lower only up to day 4 post-capture compared to up to day 28 for wolves captured without trap-alarms. The capture method and duration of restraint influence the reactive homeostasis response of free-ranging wolves. Technological solutions that reduce the duration of restraint on trap significantly dampen this influence. Wildlife trapping actions should strive to minimize the delay from capture to manipulation.

Electrochemical force microscopy

DOEpatents

Kalinin, Sergei V.; Jesse, Stephen; Collins, Liam F.; Rodriguez, Brian J.

2017-01-10

A system and method for electrochemical force microscopy are provided. The system and method are based on a multidimensional detection scheme that is sensitive to forces experienced by a biased electrode in a solution. The multidimensional approach allows separation of fast processes, such as double layer charging, and charge relaxation, and slow processes, such as diffusion and faradaic reactions, as well as capturing the bias dependence of the response. The time-resolved and bias measurements can also allow probing both linear (small bias range) and non-linear (large bias range) electrochemical regimes and potentially the de-convolution of charge dynamics and diffusion processes from steric effects and electrochemical reactivity.

Predator size and the suitability of a common prey.

PubMed

Erickson, Kristin S; Morse, D H

1997-02-01

 Although a predator's mass should influence the suitability of its prey, this subject has received little direct attention. We studied the capture and processing of an abundant syrphid fly Toxomerus marginatus (c. 4 mg) by 0.6- to 40-mg juvenile crab spiders Misumena vatia (Thomisidae) to determine how profitability, relative profitability (profitability/predator mass), overall gain in mass, and relative gain in mass differed with predator mass, and whether foraging changed concurrently. In multi-prey experiments, the smallest successful spiders (0.6-3.0 mg) extracted less mass from flies, and did so more slowly, than large spiders. This gain was proportionately similar to that of 10- to 40-mg spiders with access to many Toxomerus. However, many small spiders failed to capture flies. When we gave spiders only a single Toxomerus, the smallest ones again extracted mass more slowly than the large ones and increased in mass less than the large ones, but increased in mass proportionately more than large ones. Relative gain in mass from a single prey decreased with increasing spider mass. Spiders larger than 10 mg all extracted similar amounts of mass from a single Toxomerus at similar rates, but varied in time spent between captures. Thus, Toxomerus changes with spider mass from a large, hard-to-capture bonanza to a small, easy-to-capture item of low per capita value. However, Toxomerus is common enough that large spiders can capture it en masse, thereby compensating for its decline in per capita value.

A blended continuous–discontinuous finite element method for solving the multi-fluid plasma model

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

Sousa, E.M., E-mail: sousae@uw.edu; Shumlak, U., E-mail: shumlak@uw.edu

The multi-fluid plasma model represents electrons, multiple ion species, and multiple neutral species as separate fluids that interact through short-range collisions and long-range electromagnetic fields. The model spans a large range of temporal and spatial scales, which renders the model stiff and presents numerical challenges. To address the large range of timescales, a blended continuous and discontinuous Galerkin method is proposed, where the massive ion and neutral species are modeled using an explicit discontinuous Galerkin method while the electrons and electromagnetic fields are modeled using an implicit continuous Galerkin method. This approach is able to capture large-gradient ion and neutralmore » physics like shock formation, while resolving high-frequency electron dynamics in a computationally efficient manner. The details of the Blended Finite Element Method (BFEM) are presented. The numerical method is benchmarked for accuracy and tested using two-fluid one-dimensional soliton problem and electromagnetic shock problem. The results are compared to conventional finite volume and finite element methods, and demonstrate that the BFEM is particularly effective in resolving physics in stiff problems involving realistic physical parameters, including realistic electron mass and speed of light. The benefit is illustrated by computing a three-fluid plasma application that demonstrates species separation in multi-component plasmas.« less

Estimating Common Growth Patterns in Juvenile Chinook Salmon (Oncorhynchus tshawytscha) from Diverse Genetic Stocks and a Large Spatial Extent.

PubMed

Goertler, Pascale A L; Scheuerell, Mark D; Simenstad, Charles A; Bottom, Daniel L

2016-01-01

Life history variation in Pacific salmon (Oncorhynchus spp.) supports species resilience to natural disturbances and fishery exploitation. Within salmon species, life-history variation often manifests during freshwater and estuarine rearing, as variation in growth. To date, however, characterizing variability in growth patterns within and among individuals has been difficult via conventional sampling methods because of the inability to obtain repeated size measurements. In this study we related otolith microstructures to growth rates of individual juvenile Chinook salmon (O. tshawytscha) from the Columbia River estuary over a two-year period (2010-2012). We used dynamic factor analysis to determine whether there were common patterns in growth rates within juveniles based on their natal region, capture location habitat type, and whether they were wild or of hatchery origin. We identified up to five large-scale trends in juvenile growth rates depending on month and year of capture. We also found that hatchery fish had a narrower range of trend loadings for some capture groups, suggesting that hatchery fish do not express the same breadth of growth variability as wild fish. However, we were unable to resolve a relationship between specific growth patterns and habitat transitions. Our study exemplifies how a relatively new statistical analysis can be applied to dating or aging techniques to summarize individual variation, and characterize aspects of life history diversity.

Estimating Common Growth Patterns in Juvenile Chinook Salmon (Oncorhynchus tshawytscha) from Diverse Genetic Stocks and a Large Spatial Extent

PubMed Central

Scheuerell, Mark D.; Simenstad, Charles A.; Bottom, Daniel L.

2016-01-01

Life history variation in Pacific salmon (Oncorhynchus spp.) supports species resilience to natural disturbances and fishery exploitation. Within salmon species, life-history variation often manifests during freshwater and estuarine rearing, as variation in growth. To date, however, characterizing variability in growth patterns within and among individuals has been difficult via conventional sampling methods because of the inability to obtain repeated size measurements. In this study we related otolith microstructures to growth rates of individual juvenile Chinook salmon (O. tshawytscha) from the Columbia River estuary over a two-year period (2010–2012). We used dynamic factor analysis to determine whether there were common patterns in growth rates within juveniles based on their natal region, capture location habitat type, and whether they were wild or of hatchery origin. We identified up to five large-scale trends in juvenile growth rates depending on month and year of capture. We also found that hatchery fish had a narrower range of trend loadings for some capture groups, suggesting that hatchery fish do not express the same breadth of growth variability as wild fish. However, we were unable to resolve a relationship between specific growth patterns and habitat transitions. Our study exemplifies how a relatively new statistical analysis can be applied to dating or aging techniques to summarize individual variation, and characterize aspects of life history diversity. PMID:27695094

Computational domain length and Reynolds number effects on large-scale coherent motions in turbulent pipe flow

NASA Astrophysics Data System (ADS)

Feldmann, Daniel; Bauer, Christian; Wagner, Claus

2018-03-01

We present results from direct numerical simulations (DNS) of turbulent pipe flow at shear Reynolds numbers up to Reτ = 1500 using different computational domains with lengths up to ?. The objectives are to analyse the effect of the finite size of the periodic pipe domain on large flow structures in dependency of Reτ and to assess a minimum ? required for relevant turbulent scales to be captured and a minimum Reτ for very large-scale motions (VLSM) to be analysed. Analysing one-point statistics revealed that the mean velocity profile is invariant for ?. The wall-normal location at which deviations occur in shorter domains changes strongly with increasing Reτ from the near-wall region to the outer layer, where VLSM are believed to live. The root mean square velocity profiles exhibit domain length dependencies for pipes shorter than 14R and 7R depending on Reτ. For all Reτ, the higher-order statistical moments show only weak dependencies and only for the shortest domain considered here. However, the analysis of one- and two-dimensional pre-multiplied energy spectra revealed that even for larger ?, not all physically relevant scales are fully captured, even though the aforementioned statistics are in good agreement with the literature. We found ? to be sufficiently large to capture VLSM-relevant turbulent scales in the considered range of Reτ based on our definition of an integral energy threshold of 10%. The requirement to capture at least 1/10 of the global maximum energy level is justified by a 14% increase of the streamwise turbulence intensity in the outer region between Reτ = 720 and 1500, which can be related to VLSM-relevant length scales. Based on this scaling anomaly, we found Reτ⪆1500 to be a necessary minimum requirement to investigate VLSM-related effects in pipe flow, even though the streamwise energy spectra does not yet indicate sufficient scale separation between the most energetic and the very long motions.

Sculpting Mountains: Interactive Terrain Modeling Based on Subsurface Geology.

PubMed

Cordonnier, Guillaume; Cani, Marie-Paule; Benes, Bedrich; Braun, Jean; Galin, Eric

2018-05-01

Most mountain ranges are formed by the compression and folding of colliding tectonic plates. Subduction of one plate causes large-scale asymmetry while their layered composition (or stratigraphy) explains the multi-scale folded strata observed on real terrains. We introduce a novel interactive modeling technique to generate visually plausible, large scale terrains that capture these phenomena. Our method draws on both geological knowledge for consistency and on sculpting systems for user interaction. The user is provided hands-on control on the shape and motion of tectonic plates, represented using a new geologically-inspired model for the Earth crust. The model captures their volume preserving and complex folding behaviors under collision, causing mountains to grow. It generates a volumetric uplift map representing the growth rate of subsurface layers. Erosion and uplift movement are jointly simulated to generate the terrain. The stratigraphy allows us to render folded strata on eroded cliffs. We validated the usability of our sculpting interface through a user study, and compare the visual consistency of the earth crust model with geological simulation results and real terrains.

Effects of capture and handling on survival of female northern pintails

USGS Publications Warehouse

Cox, R.R.; Afton, A.D.

1998-01-01

Identification of capture and handling procedures that influence survival of waterfowl has important research and management implications. We captured 347 female Northern Pintails (Anas acuta) using rocket nets, fitted them with harness (backpack-type) radio transmitters, and monitored their survival during the first 10 d following release. Females were 16 times more likely to die during the first 4 d of exposure than during days 5-10. Survival of females captured with small numbers of waterfowl (n < 172) was not related to holding time (time from capture until release), but survival of females captured with large numbers of waterfowl (n = 594) declined as holding time increased. Survival did not vary with age (immature or adult) or body condition (body mass adjusted for body size) of females. Survival was positively related to flight quality (scored as poor, moderate, or good) of females upon release; poor and moderate fliers were twice as likely to die as those scored in the next higher level of flight quality. Flight quality of females captured with small numbers of waterfowl was unrelated to holding time, but that of females captured with large numbers of waterfowl declined as holding time increased. In all cases where cause of mortalities could be determined (n = 12), we attributed proximate cause of death to predation. We recommend that holding time of ducks be minimized, particularly for those captured with large numbers of waterfowl in rocket nets.

Movements and use of space by Mangrove Cuckoos (Coccyzus minor) in Florida, USA.

PubMed

Lloyd, John David

2017-01-01

I used radio-telemetry to track the movements of Mangrove Cuckoos ( Coccyzus minor ) captured in southwest Florida. Relatively little is known about the natural history of Mangrove Cuckoos, and my goal was to provide an initial description of how individuals use space, with a focus on the size and placement of home ranges. I captured and affixed VHF radio-transmitters to 32 individuals between 2012 and 2015, and obtained a sufficient number of relocations from 16 of them to estimate home-range boundaries and describe patterns of movement. Home-range area varied widely among individuals, but in general was roughly four times larger than expected based on the body size of Mangrove Cuckoos. The median core area (50% isopleth) of a home range was 42 ha (range: 9-91 ha), and the median overall home range (90% isopleth) was 128 ha (range: 28-319 ha). The median distance between estimated locations recorded on subsequent days was 298 m (95% CI [187 m-409 m]), but variation within and among individuals was substantial, and it was not uncommon to relocate individuals >1 km from their location on the previous day. Site fidelity by individual birds was low; although Mangrove Cuckoos were present year-round within the study area, I did not observe any individuals that remained on a single home range throughout the year. Although individual birds showed no evidence of avoiding anthropogenic edges, they did not incorporate developed areas into their daily movements and home ranges consisted almost entirely of mangrove forest. The persistence of the species in the study area depended on a network of conserved lands-mostly public, but some privately conserved land as well-because large patches of mangrove forest did not occur on tracts left unprotected from development.

Implanted neural network potentials: Application to Li-Si alloys

NASA Astrophysics Data System (ADS)

Onat, Berk; Cubuk, Ekin D.; Malone, Brad D.; Kaxiras, Efthimios

2018-03-01

Modeling the behavior of materials composed of elements with different bonding and electronic structure character for large spatial and temporal scales and over a large compositional range is a challenging problem. Cases in point are amorphous alloys of Si, a prototypical covalent material, and Li, a prototypical metal, which are being considered as anodes for high-energy-density batteries. To address this challenge, we develop a methodology based on neural networks that extends the conventional training approach to incorporate pre-trained parts that capture the character of different components, into the overall network; we refer to this model as the "implanted neural network" method. We show that this approach works well for the Si-Li amorphous alloys for a wide range of compositions, giving good results for key quantities like the diffusion coefficients. The method is readily generalizable to more complicated situations that involve two or more different elements.

Integrating resource selection into spatial capture-recapture models for large carnivores

Treesearch

K. M. Proffitt; J. F. Goldberg; M. Hebblewhite; R. Russell; B. S. Jimenez; H. S. Robinson; Kristine Pilgrim; Michael Schwartz

2015-01-01

Wildlife managers need reliable methods to estimate large carnivore densities and population trends; yet large carnivores are elusive, difficult to detect, and occur at low densities making traditional approaches intractable. Recent advances in spatial capture-recapture (SCR) models have provided new approaches for monitoring trends in wildlife abundance and...

Field Testing of Cryogenic Carbon Capture

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

Sayre, Aaron; Frankman, Dave; Baxter, Andrew

Sustainable Energy Solutions has been developing Cryogenic Carbon Capture™ (CCC) since 2008. In that time two processes have been developed, the External Cooling Loop and Compressed Flue Gas Cryogenic Carbon Capture processes (CCC ECL™ and CCC CFG™ respectively). The CCC ECL™ process has been scaled up to a 1TPD CO2 system. In this process the flue gas is cooled by an external refrigerant loop. SES has tested CCC ECL™ on real flue gas slip streams from subbituminous coal, bituminous coal, biomass, natural gas, shredded tires, and municipal waste fuels at field sites that include utility power stations, heating plants, cementmore » kilns, and pilot-scale research reactors. The CO2 concentrations from these tests ranged from 5 to 22% on a dry basis. CO2 capture ranged from 95-99+% during these tests. Several other condensable species were also captured including NO2, SO2 and PMxx at 95+%. NO was also captured at a modest rate. The CCC CFG™ process has been scaled up to a .25 ton per day system. This system has been tested on real flue gas streams including subbituminous coal, bituminous coal and natural gas at field sites that include utility power stations, heating plants, and pilot-scale research reactors. CO2 concentrations for these tests ranged from 5 to 15% on a dry basis. CO2 capture ranged from 95-99+% during these tests. Several other condensable species were also captured including NO2, SO2 and PMxx at 95+%. NO was also captured at 90+%. Hg capture was also verified and the resulting effluent from CCC CFG™ was below a 1ppt concentration. This paper will focus on discussion of the capabilities of CCC, the results of field testing and the future steps surrounding the development of this technology.« less

Fully automated corneal endothelial morphometry of images captured by clinical specular microscopy

NASA Astrophysics Data System (ADS)

Bucht, Curry; Söderberg, Per; Manneberg, Göran

2010-02-01

The corneal endothelium serves as the posterior barrier of the cornea. Factors such as clarity and refractive properties of the cornea are in direct relationship to the quality of the endothelium. The endothelial cell density is considered the most important morphological factor of the corneal endothelium. Pathological conditions and physical trauma may threaten the endothelial cell density to such an extent that the optical property of the cornea and thus clear eyesight is threatened. Diagnosis of the corneal endothelium through morphometry is an important part of several clinical applications. Morphometry of the corneal endothelium is presently carried out by semi automated analysis of pictures captured by a Clinical Specular Microscope (CSM). Because of the occasional need of operator involvement, this process can be tedious, having a negative impact on sampling size. This study was dedicated to the development and use of fully automated analysis of a very large range of images of the corneal endothelium, captured by CSM, using Fourier analysis. Software was developed in the mathematical programming language Matlab. Pictures of the corneal endothelium, captured by CSM, were read into the analysis software. The software automatically performed digital enhancement of the images, normalizing lights and contrasts. The digitally enhanced images of the corneal endothelium were Fourier transformed, using the fast Fourier transform (FFT) and stored as new images. Tools were developed and applied for identification and analysis of relevant characteristics of the Fourier transformed images. The data obtained from each Fourier transformed image was used to calculate the mean cell density of its corresponding corneal endothelium. The calculation was based on well known diffraction theory. Results in form of estimated cell density of the corneal endothelium were obtained, using fully automated analysis software on 292 images captured by CSM. The cell density obtained by the fully automated analysis was compared to the cell density obtained from classical, semi-automated analysis and a relatively large correlation was found.

A search for energetic ion directivity in large solar flares

NASA Astrophysics Data System (ADS)

Vestrand, W. Thomas

One of the key observational questions for solar flare physics is: What is the number, the energy spectrum, and the angular distribution of flare accelerated ions? The standard method for deriving ion spectral shape employs the ratio of influences observed on the 4-7 MeV band to the narrow neutron capture line at 2.223 MeV. The 4-7 MeV band is dominated by the principal nuclear de-excitation lines from C-12 and O-16 which are generated in the low chromosphere by the direct excitation or spallation of nuclei by energetic ions. In contrast, the narrow 2.223 MeV line is produced by the capture of thermal neutrons on protons in the photosphere. These capture neutrons are generated by energetic ion interactions and thermalized by scattering in the solar atmosphere. In a series of papers, Ramaty, Lingenfelter, and their collaborators have calculated the expected ratio of fluence in the 4-7 MeV band to the 2.223 MeV line for a wide range of energetic ion spectral shapes (see, e.g. Hua and Lingenfelter 1987). Another technique for deriving ion spectral shapes and angular distributions uses the relative strength of the Compton tail associated with the 2.223 MeV neutron capture line (Vestrand 1988, 1990). This technique can independently constrain both the angular and the energy distribution of the energetic parent ions. The combination of this tail/line strength diagnostic with the line/(4-7) MeV fluence ratio can allow one to constrain both properties of the energetic ion distributions. The primary objective of our Solar Maximum Mission (SMM) guest investigator program was to study measurements of neutron capture line emission and prompt nuclear de-excitation for large flares detected by the Solar Maximum Mission/ Gamma-Ray Spectrometer (SMM/GRS) and to use these established line diagnostics to study the properties of flare accelerated ions.

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.

Effects of environmental covariates and density on the catchability of fish populations and interpretation of catch per unit effort trends

USGS Publications Warehouse

Korman, Josh; Yard, Mike

2017-01-01

Article for outlet: Fisheries Research. Abstract: Quantifying temporal and spatial trends in abundance or relative abundance is required to evaluate effects of harvest and changes in habitat for exploited and endangered fish populations. In many cases, the proportion of the population or stock that is captured (catchability or capture probability) is unknown but is often assumed to be constant over space and time. We used data from a large-scale mark-recapture study to evaluate the extent of spatial and temporal variation, and the effects of fish density, fish size, and environmental covariates, on the capture probability of rainbow trout (Oncorhynchus mykiss) in the Colorado River, AZ. Estimates of capture probability for boat electrofishing varied 5-fold across five reaches, 2.8-fold across the range of fish densities that were encountered, 2.1-fold over 19 trips, and 1.6-fold over five fish size classes. Shoreline angle and turbidity were the best covariates explaining variation in capture probability across reaches and trips. Patterns in capture probability were driven by changes in gear efficiency and spatial aggregation, but the latter was more important. Failure to account for effects of fish density on capture probability when translating a historical catch per unit effort time series into a time series of abundance, led to 2.5-fold underestimation of the maximum extent of variation in abundance over the period of record, and resulted in unreliable estimates of relative change in critical years. Catch per unit effort surveys have utility for monitoring long-term trends in relative abundance, but are too imprecise and potentially biased to evaluate population response to habitat changes or to modest changes in fishing effort.

Light-mediated predation by northern squawfish on juvenile Chinook salmon

USGS Publications Warehouse

Petersen, James H.; Gadomski, Dena M.

1994-01-01

Northern squawfish Ptychocheilus oregonensis cause significant mortality of juvenile salmon in the lower Columbia River Basin (U.S.A.). The effects of light intensity on this predator-prey interaction were examined with laboratory experiments and modelling studies. In laboratory experiments, the rate of capture of subyearling chinook salmon Oncorhynchus tshawytscha by northern squawfish was inversely related to light intensity. In a large raceway, about five times more salmon were captured during 4 h periods of relative darkness (0–03 Ix) than during periods with high light intensity (160 Ix). The rate of predation could be manipulated by increasing or decreasing light intensity.A simulation model was developed for visual predators that encounter, attack, and capture juvenile salmon, whose schooling behaviour was light-sensitive. The model was fitted to laboratory results using a Monte Carlo filtering procedure. Model-predicted predation rate was especially sensitive to the visual range of predators at low light intensity and to predator search speed at high light. Modelling results also suggested that predation by northern squawfish on juvenile salmon may be highest across a narrow window of fight intensity.

Naming games in two-dimensional and small-world-connected random geometric networks.

PubMed

Lu, Qiming; Korniss, G; Szymanski, B K

2008-01-01

We investigate a prototypical agent-based model, the naming game, on two-dimensional random geometric networks. The naming game [Baronchelli, J. Stat. Mech.: Theory Exp. (2006) P06014] is a minimal model, employing local communications that captures the emergence of shared communication schemes (languages) in a population of autonomous semiotic agents. Implementing the naming games with local broadcasts on random geometric graphs, serves as a model for agreement dynamics in large-scale, autonomously operating wireless sensor networks. Further, it captures essential features of the scaling properties of the agreement process for spatially embedded autonomous agents. Among the relevant observables capturing the temporal properties of the agreement process, we investigate the cluster-size distribution and the distribution of the agreement times, both exhibiting dynamic scaling. We also present results for the case when a small density of long-range communication links are added on top of the random geometric graph, resulting in a "small-world"-like network and yielding a significantly reduced time to reach global agreement. We construct a finite-size scaling analysis for the agreement times in this case.

Capture efficiency and injury rates of band-tailed pigeons using whoosh nets

USGS Publications Warehouse

Coxen, Christopher L.; Collins, Daniel P.; Carleton, Scott A.

2018-01-01

Catching ground feeding birds has typically been accomplished through small, walk-in funnel-style traps. This approach is limited because it requires a bird to find its way into the trap, is biased toward less wary birds, and does not allow targeted trapping of individual birds. As part of a large study on Band-tailed Pigeons (Patagioenas fasciata) in New Mexico, we needed a trapping method that would allow more control over the number of birds we could trap at one time, when a trap was deployed, and target trapping of specific individuals. We adopted a relatively novel trapping technique used primarily for shorebirds, whoosh nets, to trap Band-tailed Pigeons at 3 different sites where birds were being fed by local landowners. During 2013–2015, whoosh nets were used to trap 702 Band-tailed Pigeons at 3 different locations in New Mexico. We captured 12.54 ± 8.19 pigeons per shot over 56 capture events across 3 locations (range: 2–39). Some superficial injuries occurred using this technique and typically involved damage to the primary and secondary wing coverts. In 2013, 24% of captured birds had an injury of this nature, but after modifying the net speed, injury rates in 2014 and 2015 dropped to 8% and 7%, respectively. Recaptured previously injured birds showed new feather growth within 2 weeks and showed no signs of injury after 4 weeks. Whoosh nets proved to be a highly effective solution for trapping large numbers of pigeons at baited sites. These systems are easily transported, quickly deployed, and easily adapted to a variety of site conditions. 

Neutron-capture element abundances in the planetary nebula NGC 5315 from deep optical and near-infrared spectrophotometry★†

NASA Astrophysics Data System (ADS)

Madonna, S.; García-Rojas, J.; Sterling, N. C.; Delgado-Inglada, G.; Mesa-Delgado, A.; Luridiana, V.; Roederer, I. U.; Mashburn, A. L.

2017-10-01

We analyse the chemical composition of the planetary nebula (PN) NGC 5315, through high-resolution (R ˜ 40000) optical spectroscopy with Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope, and medium-resolution (R ˜ 4800) near-infrared spectroscopy with Folded-port InfraRed Echellette at Magellan Baade Telescope, covering a wide spectral range from 0.31 to 2.50 μm. The main aim of this work is to investigate neutron (n)-capture element abundances to study the operation of the slow n-capture ('s-process') in the asymptotic giant branch (AGB) progenitor of NGC 5315. We detect more than 700 emission lines, including ions of the n-capture elements Se, Kr, Xe and possibly Br. We compute physical conditions from a large number of diagnostic line ratios, and derive ionic abundances for species with available atomic data. The total abundances are computed using recent ionization correction factors (ICFs) or by summing ionic abundances. Total abundances of common elements are in good agreement with previous work on this object. Based on our abundance analysis of NGC 5315, including the lack of s-process enrichment, we speculate that the most probable evolutionary scenario is that the progenitor star is in a binary system as hinted at by radial velocity studies, and interactions with its companion truncated the AGB before s-process enrichment could occur. However there are other two possible scenarios for its evolution, that cannot be ruled out: (I) the progenitor is a low-mass single star that did not undergo third dredge-up; (II) the progenitor star of NGC 5315 had an initial mass of 3-5 M⊙, and any s-process enhancements were heavily diluted by the massive envelope during the AGB phase.

Peromyscus ranges at high and low population densities

USGS Publications Warehouse

Stickel, L.F.

1960-01-01

Live-trapping studies at the Patuxent Wildlife Research Center, Maryland, showed that the ranges of wood mice were larger when the population density was lower and smaller when the population density was higher. When the population density was about 1.3 male mice per acre in June 1954, the average distance recorded between traps after four or more captures was 258 feet. When the population density was about 4.1 male mice per acre in June 1957, the average distance was 119 feet. Differences were statistically significant. Females were so scarce at the low that comparisons could not be made for them. Examples from the literature also show that home range of a species may vary with population density. Other examples show that the range may vary with habitat, breeding condition and food supply. These variations in range size reduce the reliability of censuses in which relative methods are used: Lines of traps sample the population of a larger area when ranges are large than they do when ranges are small. Direct comparisons therefore will err in some degree. Error may be introduced also when line-trap data are transformed to per acre figures on the basis of home-range estimates made by area-trapping at another place or time. Variation in range size also can make it necessary to change area-trapping plans, for larger quadrants are needed when ranges are larger. It my be necessary to set traps closer together when ranges are small than when ranges are large.

New measurement of the 242Pu(n,γ) cross section at n_TOF

NASA Astrophysics Data System (ADS)

Lerendegui-Marco, J.; Guerrero, C.; Cortés-Giraldo, M. A.; Quesada, J. M.; Mendoza, E.; Cano-Ott, D.; Eberhardt, K.; Junghans, A.

2016-03-01

The use of MOX fuel (mixed-oxide fuel made of UO2 and PuO2) in nuclear reactors allows substituting a large fraction of the enriched Uranium by Plutonium reprocessed from spent fuel. With the use of such new fuel composition rich in Pu, a better knowledge of the capture and fission cross sections of the Pu isotopes becomes very important. In particular, a new series of cross section evaluations have been recently carried out jointly by the European (JEFF) and United States (ENDF) nuclear data agencies. For the case of 242Pu, the two only neutron capture time-of-flight measurements available, from 1973 and 1976, are not consistent with each other, which calls for a new time-of flight capture cross section measurement. In order to contribute to a new evaluation, we have perfomed a neutron capture cross section measurement at the n_TOF-EAR1 facility at CERN using four C6D6 detectors, using a high purity target of 95 mg. The preliminary results assessing the quality and limitations (background, statistics and γ-flash effects) of this new experimental data are presented and discussed, taking into account that the aimed accuracy of the measurement ranges between 7% and 12% depending on the neutron energy region.

Surface modification of poly(dimethylsiloxane) (PDMS) microchannels with DNA capture-probes for potential use in microfluidic DNA analysis systems

NASA Astrophysics Data System (ADS)

Khodakov, Dmitriy A.; Thredgold, Leigh D.; Lenehan, Claire E.; Andersson, Gunther A.; Kobus, Hilton; Ellis, Amanda V.

2011-12-01

Poly(dimethylsiloxane) (PDMS) is an elastomeric material used for microfluidic devices and is especially suited to medical and forensic applications. This is due to its relatively low cost, ease of fabrication, excellent optical transmission characteristics and its ability to support electroosmotic flow, required during electrophoretic separations. These aspects combined with its large range of surface modification chemistries, make PDMS an attractive substrate in microfluidic devices for, in particular, DNA separation. Here, we report the successful wet chemical surface modification of PDMS microchannels using a simple three step method to produce an isothiocyanate-terminated surface. Initially, PDMS was oxygen plasma treated to produce a silanol-terminated surface, this was then reacted with 3-aminopropyltriethoxysilane with subsequent reaction of the now amine-terminated surface with p-phenylenediisothiocyanate. Water contact angle measurements both before and after modification showed a reduction in hydrophobicity from 101o for native PDMS to 94o for the isothiocyante-terminated PDMS. The isothiocyanate-terminated surface was then coupled with an amineterminated single-stranded DNA (ssDNA) oligonucleotide capture probe via a thiourea linkage. Confirmation of capture probe attachment was observed using fluorescent microscopy after hybridization of the capture probes with fluorescently labeled complimentary ssDNA oligonucleotides.

Evaluation of three elevated mist-net systems for sampling birds

USGS Publications Warehouse

Meyers, J.M.; Pardieck, K.L.

1993-01-01

Three light-weight, low-canopy mist-net systems were developed and tested in dry tropical scrub, mangrove and forest habitats. One plastic (polyvinyl chloride) and two aluminum pole systems (with and without pulleys) were used to support mist nets to heights of up to 7.3 m. Although the aluminum telescoping-pole system (without pulleys) was expensive initially ( 79-141/unit (US)), its use reduced capture of nontarget species and may have increased capture of target species when compared with ground-level netting. In one year, its use also reduced labor costs by 756, which completely offset the higher cost of the aluminum telescoping-pole system when compared to the plastic-pole system ( 19/unit). Unlike the plastic-pole system, the aluminum telescoping-pole system was adjustable to any height within its range of 1.8 to 7.3 m, was 1.5 m higher, was more efficient to operate in the field, and was easily moved to new locations. For capture of psittacines, the pulleys of the aluminum telescoping-pole system were not necessary, but their use may assist in efficiently retrieving large numbers of birds from the nets. The aluminum telescoping-pole system was efficient in capturing psittacines, columbids, passerines and possibly chiropterans in habitats with canopies lt 10 m or in the forest subcanopy.

Optical cell monitoring system for underwater targets

NASA Astrophysics Data System (ADS)

Moon, SangJun; Manzur, Fahim; Manzur, Tariq; Demirci, Utkan

2008-10-01

We demonstrate a cell based detection system that could be used for monitoring an underwater target volume and environment using a microfluidic chip and charge-coupled-device (CCD). This technique allows us to capture specific cells and enumerate these cells on a large area on a microchip. The microfluidic chip and a lens-less imaging platform were then merged to monitor cell populations and morphologies as a system that may find use in distributed sensor networks. The chip, featuring surface chemistry and automatic cell imaging, was fabricated from a cover glass slide, double sided adhesive film and a transparent Polymethlymetacrylate (PMMA) slab. The optically clear chip allows detecting cells with a CCD sensor. These chips were fabricated with a laser cutter without the use of photolithography. We utilized CD4+ cells that are captured on the floor of a microfluidic chip due to the ability to address specific target cells using antibody-antigen binding. Captured CD4+ cells were imaged with a fluorescence microscope to verify the chip specificity and efficiency. We achieved 70.2 +/- 6.5% capturing efficiency and 88.8 +/- 5.4% specificity for CD4+ T lymphocytes (n = 9 devices). Bright field images of the captured cells in the 24 mm × 4 mm × 50 μm microfluidic chip were obtained with the CCD sensor in one second. We achieved an inexpensive system that rapidly captures cells and images them using a lens-less CCD system. This microfluidic device can be modified for use in single cell detection utilizing a cheap light-emitting diode (LED) chip instead of a wide range CCD system.

Satellite Monitoring of Long Term Changes in Intertidal Thermal Conditions

NASA Astrophysics Data System (ADS)

Purvis, C. L.; Lakshmi, V.; Helmuth, B.

2006-12-01

Documented trends of global climate change have implications for species dynamics, range boundaries and mortality rates. A generalized assumption about global warming is that species will shift poleward in response to the increased temperatures, thereby displacing pre-existing species at higher latitudes. However, studies such as those conducted along the rocky shorelines of the U.S. have shown that such a simplified ecosystem response is unrealistic. Habitat alterations due to climate change are greatly influenced by local conditions, resulting in a patchwork of varying responses to temperature changes all along the intertidal. In order to capture these spatially- and temporally-dependent dynamics, satellite observations of land and sea surface temperatures (LST and SST) have been assimilated for the Pacific coast from Vancouver Island to southern California. Images from three satellite sensors were included in the study: MODIS/Terra, MODIS/Aqua and ASTER/Terra. MODIS has a spatial resolution of 1km (LST) and 4km (SST), daily coverage and overpass times of 10:30am and 1:30pm. ASTER has a spatial resolution of 90m (LST), sporadic temporal coverage due to an on-demand status and a 10:30am crossing time. The remotely sensed data were statistically compared to nearly 10 years of in situ measurements of body temperature of the California mussel along the Pacific coast. This species is prevalent among the rocky intertidal areas, physiologically well studied in terms of heat response and situated in a thermally harsh environment which demonstrates strong responses to climate change. A regression was performed to account for noise such as tidal signals, changes in latitude among sites as well as seasonal fluctuations in body temperature. Comparisons show that while the satellite data are unable to capture many of the daily maximum body temperatures (due to overpass times), they do offer a fairly accurate method of capturing high temporal resolution temperatures over large areas. In addition, satellite measurements were utilized to investigate the spatial distribution of intertidal mussels in Humboldt Bay, CA. In situ measurements are not prevalent enough to explain the potentially heat-driven range of mussels in this critical habitat, and therefore remotely sensed data will be used to gather new insight into thermally-regulated range boundaries of this species. By incorporating satellite measurements into in-depth habitat studies, long term thermal variations due to climate change can be monitored over large regions and aid in capturing larger-scale impacts which cannot be accomplished by tedious, site-specific in situ studies.

Convenient and large-scale synthesis of nitrogen-rich hierarchical porous carbon spheres for supercapacitors and CO2 capture

NASA Astrophysics Data System (ADS)

Chang, Binbin; Zhang, Shouren; Yin, Hang; Yang, Baocheng

2017-08-01

Herein, considering the great potential of nitrogen-doped hierarchical porous carbons in energy storage and CO2 capture, we designed a convenient and easily large-scale production strategy for preparing nitrogen-doped hierarchical porous carbon sphere (NHPCS) materials. In this synthesis route, spherical resorcinol-formaldehyde (RF) resins were selected as carbon precursor, and then the ZnCl2-impregnated RF resin spheres were carbonized in a NH3 atmosphere at a temperature range of 600-800 °C. During the one-step heat-treatment process, nitrogen atom could be efficiently incorporated into the carbon skeleton, and the interconnected and hierarchical pore structure with different micro/mesopore proportion could be generated and tuned by adjusting the activating agent ZnCl2 dosage and carbonization temperature. The resultant nitrogen-doped hierarchical porous carbon sphere materials exhibited a satisfactory charge storage capacity, and the optimal sample of NHPCS-2-8 with a high mesopore proportion obtained at 800 °C with a ZnCl2/RF mass ratio of 2:1 presented a specific capacitance of 273.8 F g-1 at a current density of 0.5 A g-1. More importantly, the assembled NHPCS-2-8-based symmetric capacitor displayed a high energy density of 17.2 Wh kg-1 at a power density of 178.9 W kg-1 within a voltage window of 0 ∼ 1.8 V in 0.5 M Na2SO4 aqueous electrolyte. In addition, the CO2 capture application of these NHPCS materials was also explored, and the optimal sample of NHPCS-0-8 with a large micropore proportion prepared at 800 °C exhibited an exceptional CO2 uptake capacity at ambient pressures of up to 4.23 mmol g-1 at 0 °C.

Phylogenetic and functional diversity in large carnivore assemblages

PubMed Central

Dalerum, F.

2013-01-01

Large terrestrial carnivores are important ecological components and prominent flagship species, but are often extinction prone owing to a combination of biological traits and high levels of human persecution. This study combines phylogenetic and functional diversity evaluations of global and continental large carnivore assemblages to provide a framework for conservation prioritization both between and within assemblages. Species-rich assemblages of large carnivores simultaneously had high phylogenetic and functional diversity, but species contributions to phylogenetic and functional diversity components were not positively correlated. The results further provide ecological justification for the largest carnivore species as a focus for conservation action, and suggests that range contraction is a likely cause of diminishing carnivore ecosystem function. This study highlights that preserving species-rich carnivore assemblages will capture both high phylogenetic and functional diversity, but that prioritizing species within assemblages will involve trade-offs between optimizing contemporary ecosystem function versus the evolutionary potential for future ecosystem performance. PMID:23576787

A Broadband High Dynamic Range Digital Receiving System for Electromagnetic Signals

DTIC Science & Technology

2010-08-26

dB. [0014] In Steinbrecher (United States Patent No. 7,250,920), an air interface metasurface is described that efficiently captures incident...broadband electromagnetic energy and provides a method for segmenting the total metasurface capture area into a plurality of smaller capture areas...such that the sum of the capture areas is equal to the total capture area of the metasurface . The segmentation of the electromagnetic capture area is

A method for rapid 3D scanning and replication of large paleontological specimens

PubMed Central

Das, Anshuman J.; Murmann, Denise C.; Cohrn, Kenneth; Raskar, Ramesh

2017-01-01

We demonstrate a fast and cost-effective technique to perform three dimensional (3D) scanning and replication of large paleontological specimens, in this case the entire skull of a Tyrannosaurus rex (T.rex) with a volume in the range of 2 m3. The technique involves time-of-flight (TOF) depth sensing using the Kinect scanning module commonly used in gesture recognition in gaming. Raw data from the Kinect sensor was captured using open source software and the reconstruction was done rapidly making this a viable method that can be adopted by museums and researchers in paleontology. The current method has the advantage of being low-cost as compared to industrial scanners and photogrammetric methods but also of accurately scanning a substantial volume range which is well suited for large specimens. The depth resolution from the Kinect sensor was measured to be around 0.6 mm which is ideal for scanning large specimens with reasonable structural detail. We demonstrate the efficacy of this method on the skull of FMNH PR 2081, also known as SUE, a near complete T.rex at the Field Museum of Natural History. PMID:28678817

A method for rapid 3D scanning and replication of large paleontological specimens.

PubMed

Das, Anshuman J; Murmann, Denise C; Cohrn, Kenneth; Raskar, Ramesh

2017-01-01

We demonstrate a fast and cost-effective technique to perform three dimensional (3D) scanning and replication of large paleontological specimens, in this case the entire skull of a Tyrannosaurus rex (T.rex) with a volume in the range of 2 m3. The technique involves time-of-flight (TOF) depth sensing using the Kinect scanning module commonly used in gesture recognition in gaming. Raw data from the Kinect sensor was captured using open source software and the reconstruction was done rapidly making this a viable method that can be adopted by museums and researchers in paleontology. The current method has the advantage of being low-cost as compared to industrial scanners and photogrammetric methods but also of accurately scanning a substantial volume range which is well suited for large specimens. The depth resolution from the Kinect sensor was measured to be around 0.6 mm which is ideal for scanning large specimens with reasonable structural detail. We demonstrate the efficacy of this method on the skull of FMNH PR 2081, also known as SUE, a near complete T.rex at the Field Museum of Natural History.

The influence of large woody debris and a bankfull flood on movement of adult resident coastal cutthroat trout (Oncorhynchus clarki) during fall and winter

Treesearch

Bret C. Harvey; Rodney J. Nakamoto; Jason L. White

1999-01-01

Abstract - To improve understanding of the significance of large woody debris to stream fishes, we examined the influence of woody debris on fall and winter movement by adult coastal cutthroat trout (Oncorhynchus clarki) using radiotelemetry. Fish captured in stream pools containing large woody debris moved less than fish captured in pools lacking large woody debris or...

Relative sampling efficiency and movements of subadult Lake Sturgeon in the Lower Wolf River, Wisconsin

USGS Publications Warehouse

Snobl, Zachary R.; Isermann, Daniel A.; Koenigs, Ryan P.; Raabe, Joshua K.

2017-01-01

Understanding sampling efficiency and movements of subadult Lake Sturgeon Acipenser fulvescens is necessary to facilitate population rehabilitation and recruitment monitoring in large systems with extensive riverine and lacustrine habitats. We used a variety of sampling methods to capture subadult Lake Sturgeon (i.e., fish between 75 and 130 cm TL that had not reached sexual maturity) and monitored their movements using radio telemetry in the lower Wolf River, a tributary to the Lake Winnebago system in Wisconsin. Our objectives were to determine whether (1) capture efficiency (expressed in terms of sampling time) of subadult Lake Sturgeon using multiple sampling methods was sufficient to justify within-river sampling as part of a basin-wide recruitment survey targeting subadults, (2) linear home ranges varied in relation to season or sex, and (3) subadult Lake Sturgeon remained in the lower Wolf River. From 2013 to 2014, 628 h of combined sampling effort that included gill nets, trotlines, electrofishing, and scuba capture was required to collect 18 subadult sturgeon, which were then implanted with radio transmitters and tracked by boat and plane. Linear home ranges did not differ in relation to sex but did vary among seasons, and the majority of movement occurred in spring. Seven of the 18 (39%) Lake Sturgeon left the river and were not detected in the river again during the study. Between 56% and 70% of subadult fish remaining in the river made definitive movements to, or near, known spawning locations when adult Lake Sturgeon were actively spawning. Our results suggest only a small proportion of subadult Lake Sturgeon in the Lake Winnebago population use the lower Wolf River, indicating that riverine sampling may not always be warranted when targeting subadults in large lake–river complexes. More information is needed on distribution of subadult Lake Sturgeon to develop sampling protocols for this population segment.

Measurement Of Trailing Edge Noise using Directional Array and Coherent Output Power Methods

NASA Technical Reports Server (NTRS)

Hutcheson, Florence V.; Brooks, Thomas F.

2002-01-01

The use of a directional array of microphones for the measurement of trailing edge (TE) noise is described. The capabilities of this method are evaluated via measurements of TE noise from a NACA 63-215 airfoil model and from a cylindrical rod. This TE noise measurement approach is compared to one that is based on the cross spectral analysis of output signals from a pair of microphones (COP method). Advantages and limitations of both methods are examined. It is shown that the microphone array can accurately measures TE noise and captures its two-dimensional characteristic over a large frequency range for any TE configuration as long as noise contamination from extraneous sources is within bounds. The COP method is shown to also accurately measure TE noise but over a more limited frequency range that narrows for increased TE thickness. Finally, the applicability and generality of an airfoil self-noise prediction method was evaluated via comparison to the experimental data obtained using the COP and array measurement methods. The predicted and experimental results are shown to agree over large frequency ranges.

Capture success and efficiency of dragonflies pursuing different types of prey.

PubMed

Combes, S A; Salcedo, M K; Pandit, M M; Iwasaki, J M

2013-11-01

The dynamics of predator-prey interactions vary enormously, due both to the heterogeneity of natural environments and to wide variability in the sensorimotor systems of predator and prey. In addition, most predators pursue a range of different types of prey, and most organisms are preyed upon by a variety of predators. We do not yet know whether predators employ a general kinematic and behavioral strategy, or whether they tailor their pursuits to each type of prey; nor do we know how widely prey differ in their survival strategies and sensorimotor capabilities. To gain insight into these questions, we compared aerial predation in 4 species of libelluid dragonflies pursuing 4 types of dipteran prey, spanning a range of sizes. We quantified the proportion of predation attempts that were successful (capture success), as well as the total time spent and the distance flown in pursuit of prey (capture efficiency). Our results show that dragonfly prey-capture success and efficiency both decrease with increasing size of prey, and that average prey velocity generally increases with size. However, it is not clear that the greater distances and times required for capturing larger prey are due solely to the flight performance (e.g., speed or evasiveness) of the prey, as predicted. Dragonflies initiated pursuits of large prey when they were located farther away, on average, as compared to small prey, and the total distance flown in pursuit was correlated with initial distance to the prey. The greater initial distances observed during pursuits of larger prey may arise from constraints on dragonflies' visual perception; dragonflies typically pursued prey subtending a visual angle of 1°, and rarely pursued prey at visual angles greater than 3°. Thus, dragonflies may be unable to perceive large prey flying very close to their perch (subtending a visual angle greater than 3-4°) as a distinct target. In comparing the performance of different dragonfly species that co-occur in the same habitat, we found significant differences that are not explained by body size, suggesting that some dragonflies may be specialized for pursuing particular types of prey. Our results underscore the importance of performing comparative studies of predator-prey interactions with freely behaving subjects in natural settings, to provide insight into how the behavior of both participants influences the dynamics of the interaction. In addition, it is clear that gaining a full understanding of predator-prey interactions requires detailed knowledge not only of locomotory mechanics and behavior, but also of the sensory capabilities and constraints of both predator and prey.

Dynamics of Coronal Structures Captured During the 2012 and 2013 Total Solar Eclipses

NASA Astrophysics Data System (ADS)

Alzate, N.; Habbal, S. R.; Druckmuller, M.

2017-12-01

White light eclipse images taken during total solar eclipses provide a very high dynamic range spanning tens of solar radii starting from the solar surface. They capture the instantaneous state of the corona, including dynamic events. We present observations of the 2012 November 13 and 2013 November 3 total solar eclipses, taken by Constantinos Emmanouilidis, in which we captured high latitude tethered prominences accompanied by CMEs, as well as several `atypical' large scale structures, spanning a few solar radii above the solar surface. By complementing the eclipse observations with co-temporaneous SDO/AIA, STEREO/EUVI and SOHO/LASCO observations, we show how the shape of the atypical structures outlines the shape of faint CME shock fronts, driven by flaring activities. The tethered prominences were imaged from their anchor at the solar surface out to several solar radii. The SDO/AIA 30.4, 17.1 and 19.3 nm emission clearly show how a direct link between the cool (104 - 105 K) filamentary emission from prominence material, and the filamentary structures emitting at coronal temperatures (> 106 K), is unmistakably present. The observed survival of these tethered systems out to the field of view of LASCO C3, establishes the likely origin of counter-streaming electrons associated with CMEs observed in interplanetary space (ICMEs). They also provide new insights for CME-initiation models associated with prominence eruptions. Our work highlights the uniqueness of eclipse observations in identifying the impact of transit events on large-scale coronal structures.

Assessing tiger population dynamics using photographic capture-recapture sampling

USGS Publications Warehouse

Karanth, K.U.; Nichols, J.D.; Kumar, N.S.; Hines, J.E.

2006-01-01

Although wide-ranging, elusive, large carnivore species, such as the tiger, are of scientific and conservation interest, rigorous inferences about their population dynamics are scarce because of methodological problems of sampling populations at the required spatial and temporal scales. We report the application of a rigorous, noninvasive method for assessing tiger population dynamics to test model-based predictions about population viability. We obtained photographic capture histories for 74 individual tigers during a nine-year study involving 5725 trap-nights of effort. These data were modeled under a likelihood-based, ?robust design? capture?recapture analytic framework. We explicitly modeled and estimated ecological parameters such as time-specific abundance, density, survival, recruitment, temporary emigration, and transience, using models that incorporated effects of factors such as individual heterogeneity, trap-response, and time on probabilities of photo-capturing tigers. The model estimated a random temporary emigration parameter of =K' =Y' 0.10 ? 0.069 (values are estimated mean ? SE). When scaled to an annual basis, tiger survival rates were estimated at S = 0.77 ? 0.051, and the estimated probability that a newly caught animal was a transient was = 0.18 ? 0.11. During the period when the sampled area was of constant size, the estimated population size Nt varied from 17 ? 1.7 to 31 ? 2.1 tigers, with a geometric mean rate of annual population change estimated as = 1.03 ? 0.020, representing a 3% annual increase. The estimated recruitment of new animals, Bt, varied from 0 ? 3.0 to 14 ? 2.9 tigers. Population density estimates, D, ranged from 7.33 ? 0.8 tigers/100 km2 to 21.73 ? 1.7 tigers/100 km2 during the study. Thus, despite substantial annual losses and temporal variation in recruitment, the tiger density remained at relatively high levels in Nagarahole. Our results are consistent with the hypothesis that protected wild tiger populations can remain healthy despite heavy mortalities because of their inherently high reproductive potential. The ability to model the entire photographic capture history data set and incorporate reduced-parameter models led to estimates of mean annual population change that were sufficiently precise to be useful. This efficient, noninvasive sampling approach can be used to rigorously investigate the population dynamics of tigers and other elusive, rare, wide-ranging animal species in which individuals can be identified from photographs or other means.

Assessing tiger population dynamics using photographic capture-recapture sampling.

PubMed

Karanth, K Ullas; Nichols, James D; Kumar, N Samba; Hines, James E

2006-11-01

Although wide-ranging, elusive, large carnivore species, such as the tiger, are of scientific and conservation interest, rigorous inferences about their population dynamics are scarce because of methodological problems of sampling populations at the required spatial and temporal scales. We report the application of a rigorous, noninvasive method for assessing tiger population dynamics to test model-based predictions about population viability. We obtained photographic capture histories for 74 individual tigers during a nine-year study involving 5725 trap-nights of effort. These data were modeled under a likelihood-based, "robust design" capture-recapture analytic framework. We explicitly modeled and estimated ecological parameters such as time-specific abundance, density, survival, recruitment, temporary emigration, and transience, using models that incorporated effects of factors such as individual heterogeneity, trap-response, and time on probabilities of photo-capturing tigers. The model estimated a random temporary emigration parameter of gamma" = gamma' = 0.10 +/- 0.069 (values are estimated mean +/- SE). When scaled to an annual basis, tiger survival rates were estimated at S = 0.77 +/- 0.051, and the estimated probability that a newly caught animal was a transient was tau = 0.18 +/- 0.11. During the period when the sampled area was of constant size, the estimated population size N(t) varied from 17 +/- 1.7 to 31 +/- 2.1 tigers, with a geometric mean rate of annual population change estimated as lambda = 1.03 +/- 0.020, representing a 3% annual increase. The estimated recruitment of new animals, B(t), varied from 0 +/- 3.0 to 14 +/- 2.9 tigers. Population density estimates, D, ranged from 7.33 +/- 0.8 tigers/100 km2 to 21.73 +/- 1.7 tigers/100 km2 during the study. Thus, despite substantial annual losses and temporal variation in recruitment, the tiger density remained at relatively high levels in Nagarahole. Our results are consistent with the hypothesis that protected wild tiger populations can remain healthy despite heavy mortalities because of their inherently high reproductive potential. The ability to model the entire photographic capture history data set and incorporate reduced-parameter models led to estimates of mean annual population change that were sufficiently precise to be useful. This efficient, noninvasive sampling approach can be used to rigorously investigate the population dynamics of tigers and other elusive, rare, wide-ranging animal species in which individuals can be identified from photographs or other means.

Membrane-based systems for carbon capture and hydrogen purification

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

Berchtold, Kathryn A

2010-11-24

This presentation describes the activities being conducted at Los Alamos National Laboratory to develop carbon capture technologies for power systems. This work is aimed at continued development and demonstration of a membrane based pre- and post-combustion carbon capture technology and separation schemes. Our primary work entails the development and demonstration of an innovative membrane technology for pre-combustion capture of carbon dioxide that operates over a broad range of conditions relevant to the power industry while meeting the US DOE's Carbon Sequestration Program goals of 90% CO{sub 2} capture at less than a 10% increase in the cost of energy services.more » Separating and capturing carbon dioxide from mixed gas streams is a first and critical step in carbon sequestration. To be technically and economically viable, a successful separation method must be applicable to industrially relevant gas streams at realistic temperatures and pressures as well as be compatible with large gas volumes. Our project team is developing polymer membranes based on polybenzimidazole (PBI) chemistries that can purify hydrogen and capture CO{sub 2} at industrially relevant temperatures. Our primary objectives are to develop and demonstrate polymer-based membrane chemistries, structures, deployment platforms, and sealing technologies that achieve the critical combination of high selectivity, high permeability, chemical stability, and mechanical stability all at elevated temperatures (> 150 C) and packaged in a scalable, economically viable, high area density system amenable to incorporation into an advanced Integrated Gasification Combined-Cycle (IGCC) plant for pre-combustion CO{sub 2} capture. Stability requirements are focused on tolerance to the primary synthesis gas components and impurities at various locations in the IGCC process. Since the process stream compositions and conditions (temperature and pressure) vary throughout the IGCC process, the project is focused on the optimization of a technology that could be positioned upstream or downstream of one or more of the water-gas-shift reactors (WGSRs) or integrated with a WGSR.« less

Mach Number effects on turbulent superstructures in wall bounded flows

NASA Astrophysics Data System (ADS)

Kaehler, Christian J.; Bross, Matthew; Scharnowski, Sven

2017-11-01

Planer and three-dimensional flow field measurements along a flat plat boundary layer in the Trisonic Wind Tunnel Munich (TWM) are examined with the aim to characterize the scaling, spatial organization, and topology of large scale turbulent superstructures in compressible flow. This facility is ideal for this investigation as the ratio of boundary layer thickness to test section spanwise extent ratio is around 1/25, ensuring minimal sidewall and corner effects on turbulent structures in the center of the test section. A major difficulty in the experimental investigation of large scale features is the mutual size of the superstructures which can extend over many boundary layer thicknesses. Using multiple PIV systems, it was possible to capture the full spatial extent of large-scale structures over a range of Mach numbers from Ma = 0.3 - 3. To calculate the average large-scale structure length and spacing, the acquired vector fields were analyzed by statistical multi-point methods that show large scale structures with a correlation length of around 10 boundary layer thicknesses over the range of Mach numbers investigated. Furthermore, the average spacing between high and low momentum structures is on the order of a boundary layer thicknesses. This work is supported by the Priority Programme SPP 1881 Turbulent Superstructures of the Deutsche Forschungsgemeinschaft.

Electron capture by Ne3+ ions from atomic hydrogen

NASA Astrophysics Data System (ADS)

Rejoub, R.; Bannister, M. E.; Havener, C. C.; Savin, D. W.; Verzani, C. J.; Wang, J. G.; Stancil, P. C.

2004-05-01

Using the Oak Ridge National Laboratory ion-atom merged-beam apparatus, absolute total electron-capture cross sections have been measured for collisions of Ne3+ ions with hydrogen (deuterium) atoms at energies between 0.07 and 826 eV/u . Comparison to previous measurements shows large discrepancies between 50 and 400 eV/u . Previously published molecular-orbital close-coupling (MOCC) calculations were performed over limited energy ranges, but show good agreement with the present measurements. Here MOCC calculations are presented for energies between 0.01 and 1000 eV/u for collisions with both H and D. For energies below ˜1 eV/u , an enhancement in the magnitude of both the experimental and theoretical cross sections is observed which is attributed to the ion-induced dipole attraction between the reactants. Below ˜4 eV/u , the present calculations show a significant target isotope effect.

Soft x-ray emission from solar wind charge exchange in the laboratory

NASA Astrophysics Data System (ADS)

Shimaya, H.; Ishida, T.; Ishikawa, S.; Suda, S.; Tanuma, H.; Akamatsu, H.; Ohashi, H.; Ijima, N.; Inoue, M.; Ezoe, Y.; Ishisaki, Y.; Ohashi, T.; Shinozaki, K.; Mitsuda, K.; Liu, L.; Wang, J.

2013-09-01

We have observed the emission spectra in collisions of bare oxygen ions with a helium gas target in the soft x-ray region with a window-less silicon drift detector at the collision energy range of 48-80 keV. The dominant soft x-ray emission corresponds to the 1s-2p transition of hydrogen-like oxygen O7+ produced by the single-electron charge exchange reaction. Other emission lines are the 1s-3p, 1s-4p and 1s-5p transitions of O7+, and also the 1s2-1s2p transition of O6+ produced by the true double-electron capture. The cascades from the upper states result in a large population of the 2p state, even though the direct capture into the 2p state is extremely scarcer than those into the 3p, 4p and 5p states.

BioStar models of clinical and genomic data for biomedical data warehouse design

PubMed Central

Wang, Liangjiang; Ramanathan, Murali

2008-01-01

Biomedical research is now generating large amounts of data, ranging from clinical test results to microarray gene expression profiles. The scale and complexity of these datasets give rise to substantial challenges in data management and analysis. It is highly desirable that data warehousing and online analytical processing technologies can be applied to biomedical data integration and mining. The major difficulty probably lies in the task of capturing and modelling diverse biological objects and their complex relationships. This paper describes multidimensional data modelling for biomedical data warehouse design. Since the conventional models such as star schema appear to be insufficient for modelling clinical and genomic data, we develop a new model called BioStar schema. The new model can capture the rich semantics of biomedical data and provide greater extensibility for the fast evolution of biological research methodologies. PMID:18048122

Obstacle Detection and Avoidance of a Mobile Robotic Platform Using Active Depth Sensing

DTIC Science & Technology

2014-06-01

price of nearly one tenth of a laser range finder, the Xbox Kinect uses an infrared projector and camera to capture images of its environment in three...inception. At the price of nearly one tenth of a laser range finder, the Xbox Kinect uses an infrared projector and camera to capture images of its...cropped between 280 and 480 pixels. ........11 Figure 9. RGB image captured by the camera on the Xbox Kinect. ...............................12 Figure

Image Alignment for Multiple Camera High Dynamic Range Microscopy.

PubMed

Eastwood, Brian S; Childs, Elisabeth C

2012-01-09

This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera.

Image Alignment for Multiple Camera High Dynamic Range Microscopy

PubMed Central

Eastwood, Brian S.; Childs, Elisabeth C.

2012-01-01

This paper investigates the problem of image alignment for multiple camera high dynamic range (HDR) imaging. HDR imaging combines information from images taken with different exposure settings. Combining information from multiple cameras requires an alignment process that is robust to the intensity differences in the images. HDR applications that use a limited number of component images require an alignment technique that is robust to large exposure differences. We evaluate the suitability for HDR alignment of three exposure-robust techniques. We conclude that image alignment based on matching feature descriptors extracted from radiant power images from calibrated cameras yields the most accurate and robust solution. We demonstrate the use of this alignment technique in a high dynamic range video microscope that enables live specimen imaging with a greater level of detail than can be captured with a single camera. PMID:22545028

Cosmogenic effects on Cu isotopes in IVB iron meteorites

NASA Astrophysics Data System (ADS)

Chen, Heng; Moynier, Frédéric; Humayun, Munir; Bishop, M. Cole; Williams, Jeffrey T.

2016-06-01

We measured Cu isotope compositions of 12 out of the 14 known IVB iron meteorites. Our results show that IVB iron meteorites display a very large range of δ65Cu values (-5.84‰ < δ65Cu < -0.24‰; defined as per mil deviation of the 65Cu/63Cu ratio from the NIST-976 standard). These Cu isotopic data display clear correlations with W, Pt, and Os isotope ratios, which are very sensitive to secondary neutron capture due to galactic cosmic ray (GCR) irradiation. This demonstrates that δ65Cu in IVB irons is majorly modified by neutron capture by the reaction 62Ni(n,γ)63Ni followed by beta decay to 63Cu. Using correlations with Pt and Os neutron dosimeters, we calculated a pre-exposure δ65Cu of -0.3 ± 0.8‰ (95% conf.) of IVB irons that agrees well with the Cu isotopic compositions of other iron meteorite groups and falls within the range of chondrites. This shows that the volatile depletion of the IVB parent body is not due to evaporation that should have enriched IVB irons in the heavy Cu isotopes.

Patterns of spatial distribution of golden eagles across North America: How do they fit into existing landscape-scale mapping systems?

USGS Publications Warehouse

Brown, Jessi L.; Bedrosian, Bryan; Bell, Douglas A.; Braham, Melissa A.; Cooper, Jeff; Crandall, Ross H.; DiDonato, Joe; Domenech, Robert; Duerr, Adam E.; Katzner, Todd; Lanzone, Michael J.; LaPlante, David W.; McIntyre, Carol L.; Miller, Tricia A.; Murphy, Robert K.; Shreading, Adam; Slater, Steven J.; Smith, Jeff P.; Smith, Brian W.; Watson, James W.; Woodbridge, Brian

2017-01-01

Conserving wide-ranging animals requires knowledge about their year-round movements and resource use. Golden Eagles (Aquila chrysaetos) exhibit a wide range of movement patterns across North America. We combined tracking data from 571 Golden Eagles from multiple independent satellite-telemetry projects from North America to provide a comprehensive look at the magnitude and extent of these movements on a continental scale. We compared patterns of use relative to four alternative administrative and ecological mapping systems, namely Bird Conservation Regions (BCRs), U.S. administrative migratory bird flyways, Migratory Bird Joint Ventures, and Landscape Conservation Cooperatives. Our analyses suggested that eagles initially captured in eastern North America used space differently than those captured in western North America. Other groups of eagles that exhibited distinct patterns in space use included long-distance migrants from northern latitudes, and southwestern and Californian desert residents. There were also several groupings of eagles in the Intermountain West. Using this collaborative approach, we have identified large-scale movement patterns that may not have been possible with individual studies. These results will support landscape-scale conservation measures for Golden Eagles across North America.

Results from the HARP Experiment

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

Catanesi, M. G.

2008-02-21

Hadron production is a key ingredient in many aspects of {nu} physics. Precise prediction of atmospheric {nu} fluxes, characterization of accelerator {nu} beams, quantification of {pi} production and capture for {nu}-factory designs, all of these would profit from hadron production measurements. HARP at the CERN PS was the first hadron production experiment designed on purpose to match all these requirements. It combines a large, full phase space acceptance with low systematic errors and high statistics. HARP was operated in the range from 3 GeV to 15 GeV. We briefly describe here the most recent results.

Spatial heterogeneity in ecologically important climate variables at coarse and fine scales in a high-snow mountain landscape.

PubMed

Ford, Kevin R; Ettinger, Ailene K; Lundquist, Jessica D; Raleigh, Mark S; Hille Ris Lambers, Janneke

2013-01-01

Climate plays an important role in determining the geographic ranges of species. With rapid climate change expected in the coming decades, ecologists have predicted that species ranges will shift large distances in elevation and latitude. However, most range shift assessments are based on coarse-scale climate models that ignore fine-scale heterogeneity and could fail to capture important range shift dynamics. Moreover, if climate varies dramatically over short distances, some populations of certain species may only need to migrate tens of meters between microhabitats to track their climate as opposed to hundreds of meters upward or hundreds of kilometers poleward. To address these issues, we measured climate variables that are likely important determinants of plant species distributions and abundances (snow disappearance date and soil temperature) at coarse and fine scales at Mount Rainier National Park in Washington State, USA. Coarse-scale differences across the landscape such as large changes in elevation had expected effects on climatic variables, with later snow disappearance dates and lower temperatures at higher elevations. However, locations separated by small distances (∼20 m), but differing by vegetation structure or topographic position, often experienced differences in snow disappearance date and soil temperature as great as locations separated by large distances (>1 km). Tree canopy gaps and topographic depressions experienced later snow disappearance dates than corresponding locations under intact canopy and on ridges. Additionally, locations under vegetation and on topographic ridges experienced lower maximum and higher minimum soil temperatures. The large differences in climate we observed over small distances will likely lead to complex range shift dynamics and could buffer species from the negative effects of climate change.

Spatial Heterogeneity in Ecologically Important Climate Variables at Coarse and Fine Scales in a High-Snow Mountain Landscape

PubMed Central

Ford, Kevin R.; Ettinger, Ailene K.; Lundquist, Jessica D.; Raleigh, Mark S.; Hille Ris Lambers, Janneke

2013-01-01

Climate plays an important role in determining the geographic ranges of species. With rapid climate change expected in the coming decades, ecologists have predicted that species ranges will shift large distances in elevation and latitude. However, most range shift assessments are based on coarse-scale climate models that ignore fine-scale heterogeneity and could fail to capture important range shift dynamics. Moreover, if climate varies dramatically over short distances, some populations of certain species may only need to migrate tens of meters between microhabitats to track their climate as opposed to hundreds of meters upward or hundreds of kilometers poleward. To address these issues, we measured climate variables that are likely important determinants of plant species distributions and abundances (snow disappearance date and soil temperature) at coarse and fine scales at Mount Rainier National Park in Washington State, USA. Coarse-scale differences across the landscape such as large changes in elevation had expected effects on climatic variables, with later snow disappearance dates and lower temperatures at higher elevations. However, locations separated by small distances (∼20 m), but differing by vegetation structure or topographic position, often experienced differences in snow disappearance date and soil temperature as great as locations separated by large distances (>1 km). Tree canopy gaps and topographic depressions experienced later snow disappearance dates than corresponding locations under intact canopy and on ridges. Additionally, locations under vegetation and on topographic ridges experienced lower maximum and higher minimum soil temperatures. The large differences in climate we observed over small distances will likely lead to complex range shift dynamics and could buffer species from the negative effects of climate change. PMID:23762277

Temperature Insensitivity and Behavioural Reduction of the Physiological Stress Response to Longline Capture by the Gummy Shark, Mustelus antarcticus.

PubMed

Guida, Leonardo; Walker, Terence I; Reina, Richard D

2016-01-01

Many factors influence the physiological stress response to fisheries capture in elasmobranchs. However, the influence of sea surface temperatures (SST) and behaviour are unknown and crucial considering global fishing pressures. We investigated the effect of SST and behaviour on the physiological stress response to capture of the gummy shark, Mustelus antarcticus, and compared our results to a laboratory study using similar conditions to test whether stress responses of in situ capture are consistent with those from laboratory simulations. Capture time for 23 M. antarcticus ranged 32-241 min as measured by hook timers or time depth recorders (TDR) in SSTs ranging 12-20°C. TDR data from 13 M. antarcticus were analysed to quantify capture behaviour as the percentage of time spent moving during capture. Several physiological variables measured from blood samples obtained immediately upon the animals' landing indicated that although warmer SSTs increased metabolic rate, the stress response to capture was not exacerbated by capture duration. During capture movement occurred for an average of 10% of the time and since M. antarcticus can respire whilst stationary, restricted movement probably mitigated potential influences of increased SSTs and capture duration on the stress response. Previous laboratory findings were also shown to be indicative of in situ conditions and we thus advise that studies control for water temperature given the influence it has on variables (e.g. lactate) used to measure capture stress in elasmobranchs. We highlight the importance of seasonal water temperatures and capture behaviour when assessing the resilience to fisheries capture and the implementation of appropriate fisheries management strategies.

Digital Moiré based transient interferometry and its application in optical surface measurement

NASA Astrophysics Data System (ADS)

Hao, Qun; Tan, Yifeng; Wang, Shaopu; Hu, Yao

2017-10-01

Digital Moiré based transient interferometry (DMTI) is an effective non-contact testing methods for optical surfaces. In DMTI system, only one frame of real interferogram is experimentally captured for the transient measurement of the surface under test (SUT). When combined with partial compensation interferometry (PCI), DMTI is especially appropriate for the measurement of aspheres with large apertures, large asphericity or different surface parameters. Residual wavefront is allowed in PCI, so the same partial compensator can be applied to the detection of multiple SUTs. Excessive residual wavefront aberration results in spectrum aliasing, and the dynamic range of DMTI is limited. In order to solve this problem, a method based on wavelet transform is proposed to extract phase from the fringe pattern with spectrum aliasing. Results of simulation demonstrate the validity of this method. The dynamic range of Digital Moiré technology is effectively expanded, which makes DMTI prospective in surface figure error measurement for intelligent fabrication of aspheric surfaces.

Arsenic speciation and sorption in natural environments

USGS Publications Warehouse

Campbell, Kate M.; Nordstrom, D. Kirk

2014-01-01

Aqueous arsenic speciation, or the chemical forms in which arsenic exists in water, is a challenging, interesting, and complicated aspect of environmental arsenic geochemistry. Arsenic has the ability to form a wide range of chemical bonds with carbon, oxygen, hydrogen, and sulfur, resulting in a large variety of compounds that exhibit a host of chemical and biochemical properties. Besides the intriguing chemical diversity, arsenic also has the rare capacity to capture our imaginations in a way that few elements can duplicate: it invokes images of foul play that range from sinister to comedic (e.g., “inheritance powder” and arsenic-spiked elderberry wine). However, the emergence of serious large-scale human health problems from chronic arsenic exposure in drinking water has placed a high priority on understanding environmental arsenic mobility, toxicity, and bioavailability, and chemical speciation is key to these important questions. Ultimately, the purpose of arsenic speciation research is to predict future occurrences, mitigate contamination, and provide successful management of water resources.

Short-Range Temporal Interactions in Sleep; Hippocampal Spike Avalanches Support a Large Milieu of Sequential Activity Including Replay

PubMed Central

Mahoney, J. Matthew; Titiz, Ali S.; Hernan, Amanda E.; Scott, Rod C.

2016-01-01

Hippocampal neural systems consolidate multiple complex behaviors into memory. However, the temporal structure of neural firing supporting complex memory consolidation is unknown. Replay of hippocampal place cells during sleep supports the view that a simple repetitive behavior modifies sleep firing dynamics, but does not explain how multiple episodes could be integrated into associative networks for recollection during future cognition. Here we decode sequential firing structure within spike avalanches of all pyramidal cells recorded in sleeping rats after running in a circular track. We find that short sequences that combine into multiple long sequences capture the majority of the sequential structure during sleep, including replay of hippocampal place cells. The ensemble, however, is not optimized for maximally producing the behavior-enriched episode. Thus behavioral programming of sequential correlations occurs at the level of short-range interactions, not whole behavioral sequences and these short sequences are assembled into a large and complex milieu that could support complex memory consolidation. PMID:26866597

Capture mechanism in Palaeotropical pitcher plants (Nepenthaceae) is constrained by climate

PubMed Central

Moran, Jonathan A.; Gray, Laura K.; Clarke, Charles; Chin, Lijin

2013-01-01

Background and Aims Nepenthes (Nepenthaceae, approx. 120 species) are carnivorous pitcher plants with a centre of diversity comprising the Philippines, Borneo, Sumatra and Sulawesi. Nepenthes pitchers use three main mechanisms for capturing prey: epicuticular waxes inside the pitcher; a wettable peristome (a collar-shaped structure around the opening); and viscoelastic fluid. Previous studies have provided evidence suggesting that the first mechanism may be more suited to seasonal climates, whereas the latter two might be more suited to perhumid environments. In this study, this idea was tested using climate envelope modelling. Methods A total of 94 species, comprising 1978 populations, were grouped by prey capture mechanism (large peristome, small peristome, waxy, waxless, viscoelastic, non-viscoelastic, ‘wet’ syndrome and ‘dry’ syndrome). Nineteen bioclimatic variables were used to model habitat suitability at approx. 1 km resolution for each group, using Maxent, a presence-only species distribution modelling program. Key Results Prey capture groups putatively associated with perhumid conditions (large peristome, waxless, viscoelastic and ‘wet’ syndrome) had more restricted areas of probable habitat suitability than those associated putatively with less humid conditions (small peristome, waxy, non-viscoelastic and‘dry’ syndrome). Overall, the viscoelastic group showed the most restricted area of modelled suitable habitat. Conclusions The current study is the first to demonstrate that the prey capture mechanism in a carnivorous plant is constrained by climate. Nepenthes species employing peristome-based and viscoelastic fluid-based capture are largely restricted to perhumid regions; in contrast, the wax-based mechanism allows successful capture in both perhumid and more seasonal areas. Possible reasons for the maintenance of peristome-based and viscoelastic fluid-based capture mechanisms in Nepenthes are discussed in relation to the costs and benefits associated with a given prey capture strategy. PMID:23975653

Capture mechanism in Palaeotropical pitcher plants (Nepenthaceae) is constrained by climate.

PubMed

Moran, Jonathan A; Gray, Laura K; Clarke, Charles; Chin, Lijin

2013-11-01

Nepenthes (Nepenthaceae, approx. 120 species) are carnivorous pitcher plants with a centre of diversity comprising the Philippines, Borneo, Sumatra and Sulawesi. Nepenthes pitchers use three main mechanisms for capturing prey: epicuticular waxes inside the pitcher; a wettable peristome (a collar-shaped structure around the opening); and viscoelastic fluid. Previous studies have provided evidence suggesting that the first mechanism may be more suited to seasonal climates, whereas the latter two might be more suited to perhumid environments. In this study, this idea was tested using climate envelope modelling. A total of 94 species, comprising 1978 populations, were grouped by prey capture mechanism (large peristome, small peristome, waxy, waxless, viscoelastic, non-viscoelastic, 'wet' syndrome and 'dry' syndrome). Nineteen bioclimatic variables were used to model habitat suitability at approx. 1 km resolution for each group, using Maxent, a presence-only species distribution modelling program. Prey capture groups putatively associated with perhumid conditions (large peristome, waxless, viscoelastic and 'wet' syndrome) had more restricted areas of probable habitat suitability than those associated putatively with less humid conditions (small peristome, waxy, non-viscoelastic and'dry' syndrome). Overall, the viscoelastic group showed the most restricted area of modelled suitable habitat. The current study is the first to demonstrate that the prey capture mechanism in a carnivorous plant is constrained by climate. Nepenthes species employing peristome-based and viscoelastic fluid-based capture are largely restricted to perhumid regions; in contrast, the wax-based mechanism allows successful capture in both perhumid and more seasonal areas. Possible reasons for the maintenance of peristome-based and viscoelastic fluid-based capture mechanisms in Nepenthes are discussed in relation to the costs and benefits associated with a given prey capture strategy.

A volume-filtered formulation to capture particle-shock interactions in multiphase compressible flows

NASA Astrophysics Data System (ADS)

Shallcross, Gregory; Capecelatro, Jesse

2017-11-01

Compressible particle-laden flows are common in engineering systems. Applications include but are not limited to water injection in high-speed jet flows for noise suppression, rocket-plume surface interactions during planetary landing, and explosions during coal mining operations. Numerically, it is challenging to capture these interactions due to the wide range of length and time scales. Additionally, there are many forms of the multiphase compressible flow equations with volume fraction effects, some of which are conflicting in nature. The purpose of this presentation is to develop the capability to accurately capture particle-shock interactions in systems with a large number of particles from dense to dilute regimes. A thorough derivation of the volume filtered equations is presented. The volume filtered equations are then implemented in a high-order, energy-stable Eulerian-Lagrangian framework. We show this framework is capable of decoupling the fluid mesh from the particle size, enabling arbitrary particle size distributions in the presence of shocks. The proposed method is then assessed against particle-laden shock tube data. Quantities of interest include fluid-phase pressure profiles and particle spreading rates. The effect of collisions in 2D and 3D are also evaluated.

Energetic neutrinos from heavy-neutralino annihilation in the Sun. Ph.D. Thesis

NASA Technical Reports Server (NTRS)

Kamionkowski, Marc

1991-01-01

Neutralinos may be captured in the sun and annihilated therein producing high-energy neutrinos. Present limits on the flux of such neutrinos from underground detectors such as IMB and Kamiokande 2 may be used to rule out certain supersymmetric dark matter candidates, while in many other supersymmetric models the rates are large enough that if neutralinos do reside in the galactic halo, observation of a neutrino signal may be possible in the near future. Neutralinos that are either nearly pure Higgsino or a Higgsino/gaugino combination are generally captured in the sun by coherent scattering off nuclei via exchange of the lightest Higgs boson. If the squark mass is not much greater than the neutralino mass, then capture of neutralinos that are primarily gaugino occurs predominantly by spin-dependent scattering off hydrogen in the sun. The neutrino signal from annihilation of WIMPs with masses in the range of 80 to 1000 GeV in the sun should generally be stronger than that from weakly interacting massive particle (WIMP) annihilation in the earth, and detection rates for mixed-state neutralinos are generally higher than those for Higgsinos or gauginos.

Acoustic source signal and directivity for explosive sources in complex environments

NASA Astrophysics Data System (ADS)

Waxler, R.; Bonner, J. L.; Reinke, R.; Talmadge, C. L.; Kleinert, D. E.; Alberts, W.; Lennox, E.

2012-12-01

Much work has gone into characterizing the blast wave, and ultimate acoustic pulse, produced by an explosion in flat, open land. Recently, an experiment was performed to study signals produced by explosions in more complex environments, both above and below ground. Explosive charges, ranging in weight from 200 to 2000 lbs., were detonated in a variety of configurations in and around tubes and culverts as well as buried in alluvium and limestone. A large number of acoustic sensors were deployed to capture the signals from the explosions. The deployment included two concentric rings of eighteen sensors each, spaced roughly every twenty degrees at radii of 300 and 1000 meters and surrounding the explosions. These captured the acoustic source function and directivity. In addition, a network of sensors, including sensors mounted on an aerostat and elevated to 300 meters altitude, were deployed throughout the area to capture the signals as they propagated. The meteorological state was monitored with a variety of instruments including a tethersonde, radiosonde and sodar. Significant directivity was observed in the signals from many of the shots, including those from charges that were detonated underground, but not near any structure. Results from the experiment will be presented.

Temporal Topic Modeling to Assess Associations between News Trends and Infectious Disease Outbreaks.

PubMed

Ghosh, Saurav; Chakraborty, Prithwish; Nsoesie, Elaine O; Cohn, Emily; Mekaru, Sumiko R; Brownstein, John S; Ramakrishnan, Naren

2017-01-19

In retrospective assessments, internet news reports have been shown to capture early reports of unknown infectious disease transmission prior to official laboratory confirmation. In general, media interest and reporting peaks and wanes during the course of an outbreak. In this study, we quantify the extent to which media interest during infectious disease outbreaks is indicative of trends of reported incidence. We introduce an approach that uses supervised temporal topic models to transform large corpora of news articles into temporal topic trends. The key advantages of this approach include: applicability to a wide range of diseases and ability to capture disease dynamics, including seasonality, abrupt peaks and troughs. We evaluated the method using data from multiple infectious disease outbreaks reported in the United States of America (U.S.), China, and India. We demonstrate that temporal topic trends extracted from disease-related news reports successfully capture the dynamics of multiple outbreaks such as whooping cough in U.S. (2012), dengue outbreaks in India (2013) and China (2014). Our observations also suggest that, when news coverage is uniform, efficient modeling of temporal topic trends using time-series regression techniques can estimate disease case counts with increased precision before official reports by health organizations.

Temporal Topic Modeling to Assess Associations between News Trends and Infectious Disease Outbreaks

NASA Astrophysics Data System (ADS)

Ghosh, Saurav; Chakraborty, Prithwish; Nsoesie, Elaine O.; Cohn, Emily; Mekaru, Sumiko R.; Brownstein, John S.; Ramakrishnan, Naren

2017-01-01

In retrospective assessments, internet news reports have been shown to capture early reports of unknown infectious disease transmission prior to official laboratory confirmation. In general, media interest and reporting peaks and wanes during the course of an outbreak. In this study, we quantify the extent to which media interest during infectious disease outbreaks is indicative of trends of reported incidence. We introduce an approach that uses supervised temporal topic models to transform large corpora of news articles into temporal topic trends. The key advantages of this approach include: applicability to a wide range of diseases and ability to capture disease dynamics, including seasonality, abrupt peaks and troughs. We evaluated the method using data from multiple infectious disease outbreaks reported in the United States of America (U.S.), China, and India. We demonstrate that temporal topic trends extracted from disease-related news reports successfully capture the dynamics of multiple outbreaks such as whooping cough in U.S. (2012), dengue outbreaks in India (2013) and China (2014). Our observations also suggest that, when news coverage is uniform, efficient modeling of temporal topic trends using time-series regression techniques can estimate disease case counts with increased precision before official reports by health organizations.

Neutron-capture element abundances in the planetary nebula NGC 5315 from deep high-resolution optical and near-IR spectrophotometry

NASA Astrophysics Data System (ADS)

Madonna, S.; García-Rojas, J.; Sterling, N. C.; Luridiana, V.

2017-03-01

We have done a spectroscopical analysis of the type I planetary nebula (PN) NGC 5315, through high-resolution (R ˜ 40000) optical spectroscopy with UVES at the 8.2m Very Large Telescope, and medium-resolution (R ˜ 4800) near-IR spectroscopy with FIRE at the 6.5m Magellan Baade telescope, covering a wide spectral range from 0.31 μm to 2.50μm. The main aim of this work is to investigate the slow neutron(n)-capture process (the s-process) in the Asymptotic Giant Branch (AGB) star progenitor of a type I PNe. We detected and identified about 700 features, including lines from the n-capture elements Kr, Se, and possibly Br and Xe. We compute physical conditions using line ratios of common ions. Ionic abundances are computed for the species with available atomic data. We calculate total abundances using recent ionization correction factors (ICFs) or by summing ionic abundances. Our results for common elements are in good agreement with previous works on the same object. We do not find a substantial s-process enrichment in NGC 5315, which is typical for type I PNe.

Capturing reflected cladding modes from a fiber Bragg grating with a double-clad fiber coupler.

PubMed

Baiad, Mohamad Diaa; Gagné, Mathieu; Lemire-Renaud, Simon; De Montigny, Etienne; Madore, Wendy-Julie; Godbout, Nicolas; Boudoux, Caroline; Kashyap, Raman

2013-03-25

We present a novel measurement scheme using a double-clad fiber coupler (DCFC) and a fiber Bragg grating (FBG) to resolve cladding modes. Direct measurement of the optical spectra and power in the cladding modes is obtained through the use of a specially designed DCFC spliced to a highly reflective FBG written into slightly etched standard photosensitive single mode fiber to match the inner cladding diameter of the DCFC. The DCFC is made by tapering and fusing two double-clad fibers (DCF) together. The device is capable of capturing backward propagating low and high order cladding modes simply and efficiently. Also, we demonstrate the capability of such a device to measure the surrounding refractive index (SRI) with an extremely high sensitivity of 69.769 ± 0.035 μW/RIU and a resolution of 1.433 × 10(-5) ± 8 × 10(-9) RIU between 1.37 and 1.45 RIU. The device provides a large SRI operating range from 1.30 to 1.45 RIU with sufficient discrimination for all individual captured cladding modes. The proposed scheme can be adapted to many different types of bend, temperature, refractive index and other evanescent wave based sensors.

Temporal Topic Modeling to Assess Associations between News Trends and Infectious Disease Outbreaks

PubMed Central

Ghosh, Saurav; Chakraborty, Prithwish; Nsoesie, Elaine O.; Cohn, Emily; Mekaru, Sumiko R.; Brownstein, John S.; Ramakrishnan, Naren

2017-01-01

In retrospective assessments, internet news reports have been shown to capture early reports of unknown infectious disease transmission prior to official laboratory confirmation. In general, media interest and reporting peaks and wanes during the course of an outbreak. In this study, we quantify the extent to which media interest during infectious disease outbreaks is indicative of trends of reported incidence. We introduce an approach that uses supervised temporal topic models to transform large corpora of news articles into temporal topic trends. The key advantages of this approach include: applicability to a wide range of diseases and ability to capture disease dynamics, including seasonality, abrupt peaks and troughs. We evaluated the method using data from multiple infectious disease outbreaks reported in the United States of America (U.S.), China, and India. We demonstrate that temporal topic trends extracted from disease-related news reports successfully capture the dynamics of multiple outbreaks such as whooping cough in U.S. (2012), dengue outbreaks in India (2013) and China (2014). Our observations also suggest that, when news coverage is uniform, efficient modeling of temporal topic trends using time-series regression techniques can estimate disease case counts with increased precision before official reports by health organizations. PMID:28102319

Enhanced low-energy γ -decay strength of 70Ni and its robustness within the shell model

NASA Astrophysics Data System (ADS)

Larsen, A. C.; Midtbø, J. E.; Guttormsen, M.; Renstrøm, T.; Liddick, S. N.; Spyrou, A.; Karampagia, S.; Brown, B. A.; Achakovskiy, O.; Kamerdzhiev, S.; Bleuel, D. L.; Couture, A.; Campo, L. Crespo; Crider, B. P.; Dombos, A. C.; Lewis, R.; Mosby, S.; Naqvi, F.; Perdikakis, G.; Prokop, C. J.; Quinn, S. J.; Siem, S.

2018-05-01

Neutron-capture reactions on very neutron-rich nuclei are essential for heavy-element nucleosynthesis through the rapid neutron-capture process, now shown to take place in neutron-star merger events. For these exotic nuclei, radiative neutron capture is extremely sensitive to their γ -emission probability at very low γ energies. In this work, we present measurements of the γ -decay strength of 70Ni over the wide range 1.3 ≤Eγ≤8 MeV. A significant enhancement is found in the γ -decay strength for transitions with Eγ<3 MeV. At present, this is the most neutron-rich nucleus displaying this feature, proving that this phenomenon is not restricted to stable nuclei. We have performed E 1 -strength calculations within the quasiparticle time-blocking approximation, which describe our data above Eγ≃5 MeV very well. Moreover, large-scale shell-model calculations indicate an M 1 nature of the low-energy γ strength. This turns out to be remarkably robust with respect to the choice of interaction, truncation, and model space, and we predict its presence in the whole isotopic chain, in particular the neutron-rich Ni 72 ,74 ,76 .

Repeats, returns, and estimated flight ranges of neotropical migratory birds in Utah riparian habitat

Treesearch

Dan A. Roberts; Jimmie R. Parrish; Frank P. Howe

2005-01-01

We present data on capture and recapture of neotropical migrants at constant-effort mist net sampling locations in Utah between 1994 and 2002. Data were collected in accordance with MAPS (Monitoring Avian Productivity and Survivorship) protocols. Since 1994, a total of 23,789 birds have been captured (i.e., total captures include new captures, recaptures, and unbanded...

Simultaneous high efficiency capture of CO.sub.2 and H.sub.2S from pressurized gas

DOEpatents

Gal, Eli; Krishnan, Gopala N.; Jayaweera, Indira S.

2016-10-11

Low-cost and energy-efficient CO.sub.2 and H.sub.2S capture is provided obtaining greater than 99.9% capture efficiency from pressurized gas. The acid species are captured in an ammonia solution, which is then regenerated by stripping the absorbed species. The solution can capture as much as 330 grams of CO.sub.2 and H.sub.2S per 1000 gram of water and when regenerated it produces pure pressurized acid gas containing more than 99.7% CO.sub.2 and H2S. The absorption of the acid species is accomplished in two absorbers in-series, each having multiple stages. More than 95% of the acid species are captured in the first absorber and the balance is captured in the second absorber to below 10 ppm concentration in the outlet gas. The two absorbers operate at temperatures ranging from 20-70 degrees Celsius. The two absorbers and the main stripper of the alkaline solution operate at similar pressures ranging from 5-200 bara.

Visualizing Ebolavirus Particles Using Single-Particle Interferometric Reflectance Imaging Sensor (SP-IRIS).

PubMed

Carter, Erik P; Seymour, Elif Ç; Scherr, Steven M; Daaboul, George G; Freedman, David S; Selim Ünlü, M; Connor, John H

2017-01-01

This chapter describes an approach for the label-free imaging and quantification of intact Ebola virus (EBOV) and EBOV viruslike particles (VLPs) using a light microscopy technique. In this technique, individual virus particles are captured onto a silicon chip that has been printed with spots of virus-specific capture antibodies. These captured virions are then detected using an optical approach called interference reflectance imaging. This approach allows for the detection of each virus particle that is captured on an antibody spot and can resolve the filamentous structure of EBOV VLPs without the need for electron microscopy. Capture of VLPs and virions can be done from a variety of sample types ranging from tissue culture medium to blood. The technique also allows automated quantitative analysis of the number of virions captured. This can be used to identify the virus concentration in an unknown sample. In addition, this technique offers the opportunity to easily image virions captured from native solutions without the need for additional labeling approaches while offering a means of assessing the range of particle sizes and morphologies in a quantitative manner.

BSM (+BMM) Data Emulator Dynamic Interrogative Data Capture (DIDC) Assessment Report: Impacts of DIDC

DOT National Transportation Integrated Search

2016-04-01

The objective of the Dynamic Interrogative Data Capture (DIDC) algorithms and software is to optimize the capture and transmission of vehicle-based data under a range of dynamically configurable messaging strategies. The key hypothesis of DIDC is tha...

On mechanics and material length scales of failure in heterogeneous interfaces using a finite strain high performance solver

NASA Astrophysics Data System (ADS)

Mosby, Matthew; Matouš, Karel

2015-12-01

Three-dimensional simulations capable of resolving the large range of spatial scales, from the failure-zone thickness up to the size of the representative unit cell, in damage mechanics problems of particle reinforced adhesives are presented. We show that resolving this wide range of scales in complex three-dimensional heterogeneous morphologies is essential in order to apprehend fracture characteristics, such as strength, fracture toughness and shape of the softening profile. Moreover, we show that computations that resolve essential physical length scales capture the particle size-effect in fracture toughness, for example. In the vein of image-based computational materials science, we construct statistically optimal unit cells containing hundreds to thousands of particles. We show that these statistically representative unit cells are capable of capturing the first- and second-order probability functions of a given data-source with better accuracy than traditional inclusion packing techniques. In order to accomplish these large computations, we use a parallel multiscale cohesive formulation and extend it to finite strains including damage mechanics. The high-performance parallel computational framework is executed on up to 1024 processing cores. A mesh convergence and a representative unit cell study are performed. Quantifying the complex damage patterns in simulations consisting of tens of millions of computational cells and millions of highly nonlinear equations requires data-mining the parallel simulations, and we propose two damage metrics to quantify the damage patterns. A detailed study of volume fraction and filler size on the macroscopic traction-separation response of heterogeneous adhesives is presented.

Discriminating the Drivers of Edge Effects on Nest Predation: Forest Edges Reduce Capture Rates of Ship Rats (Rattus rattus), a Globally Invasive Nest Predator, by Altering Vegetation Structure

PubMed Central

Ruffell, Jay; Didham, Raphael K.; Barrett, Paul; Gorman, Nic; Pike, Rhonda; Hickey-Elliott, Andrée; Sievwright, Karin; Armstrong, Doug P.

2014-01-01

Forest edges can strongly affect avian nest success by altering nest predation rates, but this relationship is inconsistent and context dependent. There is a need for researchers to improve the predictability of edge effects on nest predation rates by examining the mechanisms driving their occurrence and variability. In this study, we examined how the capture rates of ship rats, an invasive nest predator responsible for avian declines globally, varied with distance from the forest edge within forest fragments in a pastoral landscape in New Zealand. We hypothesised that forest edges would affect capture rates by altering vegetation structure within fragments, and that the strength of edge effects would depend on whether fragments were grazed by livestock. We measured vegetation structure and rat capture rates at 488 locations ranging from 0–212 m from the forest edge in 15 forest fragments, seven of which were grazed. Contrary to the vast majority of previous studies of edge effects on nest predation, ship rat capture rates increased with increasing distance from the forest edge. For grazed fragments, capture rates were estimated to be 78% lower at the forest edge than 118 m into the forest interior (the farthest distance for grazed fragments). This relationship was similar for ungrazed fragments, with capture rates estimated to be 51% lower at the forest edge than 118 m into the forest interior. A subsequent path analysis suggested that these ‘reverse’ edge effects were largely or entirely mediated by changes in vegetation structure, implying that edge effects on ship rats can be predicted from the response of vegetation structure to forest edges. We suggest the occurrence, strength, and direction of edge effects on nest predation rates may depend on edge-driven changes in local habitat when the dominant predator is primarily restricted to forest patches. PMID:25412340

Discriminating the drivers of edge effects on nest predation: forest edges reduce capture rates of ship rats (Rattus rattus), a globally invasive nest predator, by altering vegetation structure.

PubMed

Ruffell, Jay; Didham, Raphael K; Barrett, Paul; Gorman, Nic; Pike, Rhonda; Hickey-Elliott, Andrée; Sievwright, Karin; Armstrong, Doug P

2014-01-01

Forest edges can strongly affect avian nest success by altering nest predation rates, but this relationship is inconsistent and context dependent. There is a need for researchers to improve the predictability of edge effects on nest predation rates by examining the mechanisms driving their occurrence and variability. In this study, we examined how the capture rates of ship rats, an invasive nest predator responsible for avian declines globally, varied with distance from the forest edge within forest fragments in a pastoral landscape in New Zealand. We hypothesised that forest edges would affect capture rates by altering vegetation structure within fragments, and that the strength of edge effects would depend on whether fragments were grazed by livestock. We measured vegetation structure and rat capture rates at 488 locations ranging from 0-212 m from the forest edge in 15 forest fragments, seven of which were grazed. Contrary to the vast majority of previous studies of edge effects on nest predation, ship rat capture rates increased with increasing distance from the forest edge. For grazed fragments, capture rates were estimated to be 78% lower at the forest edge than 118 m into the forest interior (the farthest distance for grazed fragments). This relationship was similar for ungrazed fragments, with capture rates estimated to be 51% lower at the forest edge than 118 m into the forest interior. A subsequent path analysis suggested that these 'reverse' edge effects were largely or entirely mediated by changes in vegetation structure, implying that edge effects on ship rats can be predicted from the response of vegetation structure to forest edges. We suggest the occurrence, strength, and direction of edge effects on nest predation rates may depend on edge-driven changes in local habitat when the dominant predator is primarily restricted to forest patches.

Capture of terrestrial-sized moons by gas giant planets.

PubMed

Williams, Darren M

2013-04-01

Terrestrial moons with masses >0.1 M (symbol in text) possibly exist around extrasolar giant planets, and here we consider the energetics of how they might form. Binary-exchange capture can occur if a binary-terrestrial object (BTO) is tidally disrupted during a close encounter with a giant planet and one of the binary members is ejected while the other remains as a moon. Tidal disruption occurs readily in the deep gravity wells of giant planets; however, the large encounter velocities in the wells make binary exchange more difficult than for planets of lesser mass. In addition, successful capture favors massive binaries with large rotational velocities and small component mass ratios. Also, since the interaction tends to leave the captured moons on highly elliptical orbits, permanent capture is only possible around planets with sizable Hill spheres that are well separated from their host stars.

Temperature Insensitivity and Behavioural Reduction of the Physiological Stress Response to Longline Capture by the Gummy Shark, Mustelus antarcticus

PubMed Central

Guida, Leonardo; Walker, Terence I.; Reina, Richard D.

2016-01-01

Many factors influence the physiological stress response to fisheries capture in elasmobranchs. However, the influence of sea surface temperatures (SST) and behaviour are unknown and crucial considering global fishing pressures. We investigated the effect of SST and behaviour on the physiological stress response to capture of the gummy shark, Mustelus antarcticus, and compared our results to a laboratory study using similar conditions to test whether stress responses of in situ capture are consistent with those from laboratory simulations. Capture time for 23 M. antarcticus ranged 32–241 min as measured by hook timers or time depth recorders (TDR) in SSTs ranging 12–20°C. TDR data from 13 M. antarcticus were analysed to quantify capture behaviour as the percentage of time spent moving during capture. Several physiological variables measured from blood samples obtained immediately upon the animals’ landing indicated that although warmer SSTs increased metabolic rate, the stress response to capture was not exacerbated by capture duration. During capture movement occurred for an average of 10% of the time and since M. antarcticus can respire whilst stationary, restricted movement probably mitigated potential influences of increased SSTs and capture duration on the stress response. Previous laboratory findings were also shown to be indicative of in situ conditions and we thus advise that studies control for water temperature given the influence it has on variables (e.g. lactate) used to measure capture stress in elasmobranchs. We highlight the importance of seasonal water temperatures and capture behaviour when assessing the resilience to fisheries capture and the implementation of appropriate fisheries management strategies. PMID:26886126

Two Wheels are Better than One: The Importance of Capturing the Home Literacy Environment in Large-Scale Assessments of Reading

ERIC Educational Resources Information Center

Dowd, Amy Jo; Pisani, Lauren

2013-01-01

Children's reading skill development is influenced by availability of reading materials, reading habits and opportunity to read. Save the Children's Literacy Boost data have replicated this finding across numerous developing contexts. Meanwhile international large-scale reading assessments do not capture detail on current home literacy. The…

Full-color digitized holography for large-scale holographic 3D imaging of physical and nonphysical objects.

PubMed

Matsushima, Kyoji; Sonobe, Noriaki

2018-01-01

Digitized holography techniques are used to reconstruct three-dimensional (3D) images of physical objects using large-scale computer-generated holograms (CGHs). The object field is captured at three wavelengths over a wide area at high densities. Synthetic aperture techniques using single sensors are used for image capture in phase-shifting digital holography. The captured object field is incorporated into a virtual 3D scene that includes nonphysical objects, e.g., polygon-meshed CG models. The synthetic object field is optically reconstructed as a large-scale full-color CGH using red-green-blue color filters. The CGH has a wide full-parallax viewing zone and reconstructs a deep 3D scene with natural motion parallax.

Towards the computation of time-periodic inertial range dynamics

NASA Astrophysics Data System (ADS)

van Veen, L.; Vela-Martín, A.; Kawahara, G.

2018-04-01

We explore the possibility of computing simple invariant solutions, like travelling waves or periodic orbits, in Large Eddy Simulation (LES) on a periodic domain with constant external forcing. The absence of material boundaries and the simple forcing mechanism make this system a comparatively simple target for the study of turbulent dynamics through invariant solutions. We show, that in spite of the application of eddy viscosity the computations are still rather challenging and must be performed on GPU cards rather than conventional coupled CPUs. We investigate the onset of turbulence in this system by means of bifurcation analysis, and present a long-period, large-amplitude unstable periodic orbit that is filtered from a turbulent time series. Although this orbit is computed on a coarse grid, with only a small separation between the integral scale and the LES filter length, the periodic dynamics seem to capture a regeneration process of the large-scale vortices.

Large poroelastic deformation of a soft material

NASA Astrophysics Data System (ADS)

MacMinn, Christopher W.; Dufresne, Eric R.; Wettlaufer, John S.

2014-11-01

Flow through a porous material will drive mechanical deformation when the fluid pressure becomes comparable to the stiffness of the solid skeleton. This has applications ranging from hydraulic fracture for recovery of shale gas, where fluid is injected at high pressure, to the mechanics of biological cells and tissues, where the solid skeleton is very soft. The traditional linear theory of poroelasticity captures this fluid-solid coupling by combining Darcy's law with linear elasticity. However, linear elasticity is only volume-conservative to first order in the strain, which can become problematic when damage, plasticity, or extreme softness lead to large deformations. Here, we compare the predictions of linear poroelasticity with those of a large-deformation framework in the context of two model problems. We show that errors in volume conservation are compounded and amplified by coupling with the fluid flow, and can become important even when the deformation is small. We also illustrate these results with a laboratory experiment.

Whole-exome sequencing for mutation detection in pediatric disorders of insulin secretion: Maturity onset diabetes of the young and congenital hyperinsulinism.

PubMed

Johnson, S R; Leo, P J; McInerney-Leo, A M; Anderson, L K; Marshall, M; McGown, I; Newell, F; Brown, M A; Conwell, L S; Harris, M; Duncan, E L

2018-06-01

To assess the utility of whole-exome sequencing (WES) for mutation detection in maturity-onset diabetes of the young (MODY) and congenital hyperinsulinism (CHI). MODY and CHI are the two commonest monogenic disorders of glucose-regulated insulin secretion in childhood, with 13 causative genes known for MODY and 10 causative genes identified for CHI. The large number of potential genes makes comprehensive screening using traditional methods expensive and time-consuming. Ten subjects with MODY and five with CHI with known mutations underwent WES using two different exome capture kits (Nimblegen SeqCap EZ Human v3.0 Exome Enrichment Kit, Nextera Rapid Capture Exome Kit). Analysis was blinded to previously identified mutations, and included assessment for large deletions. The target capture of five exome capture technologies was also analyzed using sequencing data from >2800 unrelated samples. Four of five MODY mutations were identified using Nimblegen (including a large deletion in HNF1B). Although targeted, one mutation (in INS) had insufficient coverage for detection. Eleven of eleven mutations (six MODY, five CHI) were identified using Nextera Rapid (including the previously missed mutation). On reconciliation, all mutations concorded with previous data and no additional variants in MODY genes were detected. There were marked differences in the performance of the capture technologies. WES can be useful for screening for MODY/CHI mutations, detecting both point mutations and large deletions. However, capture technologies require careful selection. © 2018 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Consumer Views: Fuel Economy, Plug-in Electric Vehicle Battery Range, and Willingness to Pay for Vehicle Technology

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

Singer, Mark

This presentation includes data captured by the National Renewable Energy Laboratory (NREL) to support the U.S. Department of Energy's Vehicle Technologies Office (VTO) research efforts. The data capture consumer views on fuel economy, plug-in electric vehicle battery range, and willingness to pay for advanced vehicle technologies.

Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system.

PubMed

Seinfeld, John H; Bretherton, Christopher; Carslaw, Kenneth S; Coe, Hugh; DeMott, Paul J; Dunlea, Edward J; Feingold, Graham; Ghan, Steven; Guenther, Alex B; Kahn, Ralph; Kraucunas, Ian; Kreidenweis, Sonia M; Molina, Mario J; Nenes, Athanasios; Penner, Joyce E; Prather, Kimberly A; Ramanathan, V; Ramaswamy, Venkatachalam; Rasch, Philip J; Ravishankara, A R; Rosenfeld, Daniel; Stephens, Graeme; Wood, Robert

2016-05-24

The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth's clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty.

Improving Our Fundamental Understanding of the Role of Aerosol Cloud Interactions in the Climate System

NASA Technical Reports Server (NTRS)

Seinfeld, John H.; Bretherton, Christopher; Carslaw, Kenneth S.; Coe, Hugh; DeMott, Paul J.; Dunlea, Edward J.; Feingold, Graham; Ghan, Steven; Guenther, Alex B.; Kahn, Ralph;

Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system

DOE PAGES

Seinfeld, John H.; Bretherton, Christopher; Carslaw, Kenneth S.; ...

2016-05-24

The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth’s clouds is the most uncertain component of the overall global radiative forcing from pre-industrial time. General Circulation Models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions but significant challengesmore » exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. Lastly, we suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty.« less

Improving our fundamental understanding of the role of aerosol−cloud interactions in the climate system

PubMed Central

Seinfeld, John H.; Bretherton, Christopher; Carslaw, Kenneth S.; Coe, Hugh; DeMott, Paul J.; Dunlea, Edward J.; Feingold, Graham; Ghan, Steven; Guenther, Alex B.; Kraucunas, Ian; Molina, Mario J.; Nenes, Athanasios; Penner, Joyce E.; Prather, Kimberly A.; Ramanathan, V.; Ramaswamy, Venkatachalam; Rasch, Philip J.; Ravishankara, A. R.; Rosenfeld, Daniel; Stephens, Graeme; Wood, Robert

2016-01-01

The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth’s clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol−cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol−cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol−cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty. PMID:27222566

Measurement of Trailing Edge Noise Using Directional Array and Coherent Output Power Methods

NASA Technical Reports Server (NTRS)

Hutcheson, Florence V.; Brooks, Thomas F.

2002-01-01

The use of a directional (or phased) array of microphones for the measurement of trailing edge (TE) noise is described and tested. The capabilities of this method arc evaluated via measurements of TE noise from a NACA 63-215 airfoil model and from a cylindrical rod. This TE noise measurement approach is compared to one that is based on thc cross spectral analysis of output signals from a pair of microphones placed on opposite sides of an airframe model (COP method). Advantages and limitations of both methods arc examined. It is shown that the microphone array can accurately measures TE noise and captures its two-dimensional characteristic over a large frequency range for any TE configuration as long as noise contamination from extraneous sources is within bounds. The COP method is shown to also accurately measure TE noise but over a more limited frequency range that narrows for increased TE thickness. Finally, the applicability and generality of an airfoil self-noise prediction method was evaluated via comparison to the experimental data obtained using the COP and array measurement methods. The predicted and experimental results are shown to agree over large frequency ranges.

Estimation of density of mongooses with capture-recapture and distance sampling

USGS Publications Warehouse

Corn, J.L.; Conroy, M.J.

1998-01-01

We captured mongooses (Herpestes javanicus) in live traps arranged in trapping webs in Antigua, West Indies, and used capture-recapture and distance sampling to estimate density. Distance estimation and program DISTANCE were used to provide estimates of density from the trapping-web data. Mean density based on trapping webs was 9.5 mongooses/ha (range, 5.9-10.2/ha); estimates had coefficients of variation ranging from 29.82-31.58% (X?? = 30.46%). Mark-recapture models were used to estimate abundance, which was converted to density using estimates of effective trap area. Tests of model assumptions provided by CAPTURE indicated pronounced heterogeneity in capture probabilities and some indication of behavioral response and variation over time. Mean estimated density was 1.80 mongooses/ha (range, 1.37-2.15/ha) with estimated coefficients of variation of 4.68-11.92% (X?? = 7.46%). Estimates of density based on mark-recapture data depended heavily on assumptions about animal home ranges; variances of densities also may be underestimated, leading to unrealistically narrow confidence intervals. Estimates based on trap webs require fewer assumptions, and estimated variances may be a more realistic representation of sampling variation. Because trap webs are established easily and provide adequate data for estimation in a few sample occasions, the method should be efficient and reliable for estimating densities of mongooses.

Solar System Exploration Augmented by Lunar and Outer Planet Resource Utilization: Historical Perspectives and Future Possibilities

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2014-01-01

Establishing a lunar presence and creating an industrial capability on the Moon may lead to important new discoveries for all of human kind. Historical studies of lunar exploration, in-situ resource utilization (ISRU) and industrialization all point to the vast resources on the Moon and its links to future human and robotic exploration. In the historical work, a broad range of technological innovations are described and analyzed. These studies depict program planning for future human missions throughout the solar system, lunar launched nuclear rockets, and future human settlements on the Moon, respectively. Updated analyses based on the visions presented are presented. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal propulsion, nuclear surface power, as well as advanced chemical propulsion can significantly enhance these scenarios. Robotic and human outer planet exploration options are described in many detailed and extensive studies. Nuclear propulsion options for fast trips to the outer planets are discussed. To refuel such vehicles, atmospheric mining in the outer solar system has also been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as Helium 3 (3He) and hydrogen can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and hydrogen (deuterium, etc.) were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses have investigated resource capturing aspects of atmospheric mining in the outer solar system. These analyses included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. With these two additional gases, the potential for fueling small and large fleets of additional exploration and exploitation vehicles exists.

Solar System Exploration Augmented by Lunar and Outer Planet Resource Utilization: Historical Perspectives and Future Possibilities

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2014-01-01

Establishing a lunar presence and creating an industrial capability on the Moon may lead to important new discoveries for all of human kind. Historical studies of lunar exploration, in-situ resource utilization (ISRU) and industrialization all point to the vast resources on the Moon and its links to future human and robotic exploration. In the historical work, a broad range of technological innovations are described and analyzed. These studies depict program planning for future human missions throughout the solar system, lunar launched nuclear rockets, and future human settlements on the Moon, respectively. Updated analyses based on the visions presented are presented. While advanced propulsion systems were proposed in these historical studies, further investigation of nuclear options using high power nuclear thermal propulsion, nuclear surface power, as well as advanced chemical propulsion can significantly enhance these scenarios. Robotic and human outer planet exploration options are described in many detailed and extensive studies. Nuclear propulsion options for fast trips to the outer planets are discussed. To refuel such vehicles, atmospheric mining in the outer solar system has also been investigated as a means of fuel production for high energy propulsion and power. Fusion fuels such as helium 3 (3He) and hydrogen (H2) can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. Helium 3 and H2 (deuterium, etc.) were the primary gases of interest with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses have investigated resource capturing aspects of atmospheric mining in the outer solar system. These analyses included the gas capturing rate, storage options, and different methods of direct use of the captured gases. While capturing 3He, large amounts of hydrogen and 4He are produced. With these two additional gases, the potential for fueling small and large fleets of additional exploration and exploitation vehicles exists.

Small fishes crossed a large mountain range: Quaternary stream capture events and freshwater fishes on both sides of the Taebaek Mountains.

PubMed

Kim, Daemin; Hirt, M Vincent; Won, Yong-Jin; Simons, Andrew M

2017-07-01

The Taebaek Mountains in Korea serve as the most apparent biogeographic barrier for Korean freshwater fishes, resulting in 2 distinct ichthyofaunal assemblages on the eastern (East/Japan Sea slope) and western (Yellow Sea and Korea Strait slopes) sides of the mountain range. Of nearly 100 species of native primary freshwater fishes in Korea, only 18 species occur naturally on both sides of the mountain range. Interestingly, there are 5 rheophilic species (Phoxinus phoxinus, Coreoleuciscus splendidus, Ladislavia taczanowskii, Iksookimia koreensis and Koreocobitis rotundicaudata) found on both sides of the Taebaek Mountains that are geographically restricted to the Osip River (and several neighboring rivers, for L. taczanowskii and I. koreensis) on the eastern side of the mountain range. The Osip River and its neighboring rivers also shared a rheophilic freshwater fish, Liobagrus mediadiposalis, with the Nakdong River on the western side of the mountain range. We assessed historical biogeographic hypotheses on the presence of these rheophilic fishes, utilizing DNA sequence data from the mitochondrial cytochrome b gene. Results of our divergence time estimation indicate that ichthyofaunal transfers into the Osip River (and several neighboring rivers in East Sea slope) have occurred from the Han (Yellow Sea slope) and Nakdong (Korea Strait slope) Rivers since the Late Pleistocene. The inferred divergence times for the ichthyofaunal transfer across the Taebaek Mountains were consistent with the timing of hypothesized multiple reactivations of the Osip River Fault (Late Pleistocene), suggesting that the Osip River Fault reactivations may have caused stream capture events, followed by ichthyofaunal transfer, not only between the Osip and Nakdong Rivers, but also between the Osip and Han Rivers. © 2016 International Society of Zoological Sciences, Institute of Zoology/Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

Economic and energetic analysis of capturing CO2 from ambient air

PubMed Central

House, Kurt Zenz; Baclig, Antonio C.; Ranjan, Manya; van Nierop, Ernst A.; Wilcox, Jennifer; Herzog, Howard J.

2011-01-01

Capturing carbon dioxide from the atmosphere (“air capture”) in an industrial process has been proposed as an option for stabilizing global CO2 concentrations. Published analyses suggest these air capture systems may cost a few hundred dollars per tonne of CO2, making it cost competitive with mainstream CO2 mitigation options like renewable energy, nuclear power, and carbon dioxide capture and storage from large CO2 emitting point sources. We investigate the thermodynamic efficiencies of commercial separation systems as well as trace gas removal systems to better understand and constrain the energy requirements and costs of these air capture systems. Our empirical analyses of operating commercial processes suggest that the energetic and financial costs of capturing CO2 from the air are likely to have been underestimated. Specifically, our analysis of existing gas separation systems suggests that, unless air capture significantly outperforms these systems, it is likely to require more than 400 kJ of work per mole of CO2, requiring it to be powered by CO2-neutral power sources in order to be CO2 negative. We estimate that total system costs of an air capture system will be on the order of $1,000 per tonne of CO2, based on experience with as-built large-scale trace gas removal systems. PMID:22143760

Conversion of a Capture ELISA to a Luminex xMAP Assay using a Multiplex Antibody Screening Method

PubMed Central

Baker, Harold N.; Murphy, Robin; Lopez, Erica; Garcia, Carlos

2012-01-01

The enzyme-linked immunosorbent assay (ELISA) has long been the primary tool for detection of analytes of interest in biological samples for both life science research and clinical diagnostics. However, ELISA has limitations. It is typically performed in a 96-well microplate, and the wells are coated with capture antibody, requiring a relatively large amount of sample to capture an antigen of interest . The large surface area of the wells and the hydrophobic binding of capture antibody can also lead to non-specific binding and increased background. Additionally, most ELISAs rely upon enzyme-mediated amplification of signal in order to achieve reasonable sensitivity. Such amplification is not always linear and can thus skew results. In the past 15 years, a new technology has emerged that offers the benefits of the ELISA, but also enables higher throughput, increased flexibility, reduced sample volume, and lower cost, with a similar workflow 1, 2. Luminex xMAP Technology is a microsphere (bead) array platform enabling both monoplex and multiplex assays that can be applied to both protein and nucleic acid applications 3-5. The beads have the capture antibody covalently immobilized on a smaller surface area, requiring less capture antibody and smaller sample volumes, compared to ELISA, and non-specific binding is significantly reduced. Smaller sample volumes are important when working with limiting samples such as cerebrospinal fluid, synovial fluid, etc. 6. Multiplexing the assay further reduces sample volume requirements, enabling multiple results from a single sample. Recent improvements by Luminex include: the new MAGPIX system, a smaller, less expensive, easier-to-use analyzer; Low-Concentration Magnetic MagPlex Microspheres which eliminate the need for expensive filter plates and come in a working concentration better suited for assay development and low-throughput applications; and the xMAP Antibody Coupling (AbC) Kit, which includes a protocol, reagents, and consumables necessary for coupling beads to the capture antibody of interest. (See Materials section for a detailed list of kit contents.) In this experiment, we convert a pre-optimized ELISA assay for TNF-alpha cytokine to the xMAP platform and compare the performance of the two methods 7-11. TNF-alpha is a biomarker used in the measurement of inflammatory responses in patients with autoimmune disorders. We begin by coupling four candidate capture antibodies to four different microsphere sets or regions. When mixed together, these four sets allow for the simultaneous testing of all four candidates with four separate detection antibodies to determine the best antibody pair, saving reagents, sample and time. Two xMAP assays are then constructed with the two most optimal antibody pairs and their performance is compared to that of the original ELISA assay in regards to signal strength, dynamic range, and sensitivity. PMID:22806215

On the Value-Dependence of Value-Driven Attentional Capture

PubMed Central

Anderson, Brian A.; Halpern, Madeline

2017-01-01

Findings from an increasingly large number of studies have been used to argue that attentional capture can be dependent on the learned value of a stimulus, or value-driven. However, under certain circumstances attention can be biased to select stimuli that previously served as targets, independent of reward history. Value-driven attentional capture, as studied using the training phase-test phase design introduced by Anderson and colleagues, is widely presumed to reflect the combined influence of learned value and selection history. However, the degree to which attentional capture is at all dependent on value learning in this paradigm has recently been questioned. Support for value-dependence can be provided through one of two means: (1) greater attentional capture by prior targets following rewarded training than following unrewarded training, and (2) greater attentional capture by prior targets previously associated with high compared to low value. Using a variant of the original value-driven attentional capture paradigm, Sha and Jiang (2016) failed to find evidence of either, and raised criticisms regarding the adequacy of evidence provided by prior studies using this particular paradigm. To address this disparity, here we provided a stringent test of the value-dependence hypothesis using the traditional value-driven attentional capture paradigm. With a sufficiently large sample size, value-dependence was observed based on both criteria, with no evidence of attentional capture without rewards during training. Our findings support the validity of the traditional value-driven attentional capture paradigm in measuring what its name purports to measure. PMID:28176215

Successful treatment of capture myopathy in three wild greater sandhill cranes (Grus canadensis tabida).

PubMed

Businga, Nancy K; Langenberg, Julie; Carlson, LaVinda

2007-12-01

Two adult and 1 juvenile free-flying greater sandhill cranes (Grus canadensis tabida) were diagnosed with capture myopathy after alpha-chloralose baiting and physical capture during a banding and feeding ecologic study. Blood samples were collected for serum biochemical analysis at the time of capture for the 2 adults, and at 24 hours postcapture, at various intervals during treatment, and at the time of release for all 3 birds. Concentrations of creatine kinase, aspartate transaminase, and lactate dehydrogenase were high within 1 hour of capture and peaked approximately 3 days after capture. By days 10-17 after capture, creatine kinase and lactate dehydrogenase concentrations both decreased to within the reference range measured for cranes at capture, but aspartate transaminase concentrations remained 2-5 times higher than the measured reference range. Treatment consisted of corticosteroids, selenium/vitamin E, parenteral fluids, and gavage feedings. Physical therapy consisted of assisting the cranes to stand and walk 2-8 times a day, massaging leg muscles, and moving limbs manually through the range of motion. The adults were released when they were able to stand up independently and were pacing in the pen. The juvenile was released 12 hours after it was able to stand independently but was returned to the pen when it fell and could not rise. It was treated supportively for an additional 3 days and then successfully released. Both adult cranes were observed on their territories with their original mates after release and returned to their territories for the subsequent 8 years, raising chicks most years. After release, the juvenile was observed in a flock of cranes near its natal territory for the next 2 days.

Optimizing local capture of atrial fibrillation by rapid pacing: study of the influence of tissue dynamics.

PubMed

Uldry, Laurent; Virag, Nathalie; Jacquemet, Vincent; Vesin, Jean-Marc; Kappenberger, Lukas

2010-12-01

While successful termination by pacing of organized atrial tachycardias has been observed in patients, rapid pacing of AF can induce a local capture of the atrial tissue but in general no termination. The purpose of this study was to perform a systematic evaluation of the ability to capture AF by rapid pacing in a biophysical model of the atria with different dynamics in terms of conduction velocity (CV) and action potential duration (APD). Rapid pacing was applied during 30 s at five locations on the atria, for pacing cycle lengths in the range 60-110% of the mean AF cycle length (AFCL(mean)). Local AF capture could be achieved using rapid pacing at pacing sites located distal to major anatomical obstacles. Optimal pacing cycle lengths were found in the range 74-80% AFCL(mean) (capture window width: 14.6 ± 3% AFCL(mean)). An increase/decrease in CV or APD led to a significant shrinking/stretching of the capture window. Capture did not depend on AFCL, but did depend on the atrial substrate as characterized by an estimate of its wavelength, a better capture being achieved at shorter wavelengths. This model-based study suggests that a proper selection of the pacing site and cycle length can influence local capture results and that atrial tissue properties (CV and APD) are determinants of the response to rapid pacing.

A Multiscale Survival Process for Modeling Human Activity Patterns.

PubMed

Zhang, Tianyang; Cui, Peng; Song, Chaoming; Zhu, Wenwu; Yang, Shiqiang

2016-01-01

Human activity plays a central role in understanding large-scale social dynamics. It is well documented that individual activity pattern follows bursty dynamics characterized by heavy-tailed interevent time distributions. Here we study a large-scale online chatting dataset consisting of 5,549,570 users, finding that individual activity pattern varies with timescales whereas existing models only approximate empirical observations within a limited timescale. We propose a novel approach that models the intensity rate of an individual triggering an activity. We demonstrate that the model precisely captures corresponding human dynamics across multiple timescales over five orders of magnitudes. Our model also allows extracting the population heterogeneity of activity patterns, characterized by a set of individual-specific ingredients. Integrating our approach with social interactions leads to a wide range of implications.

Pixel detectors for use in retina neurophysiology studies

NASA Astrophysics Data System (ADS)

Cunningham, W.; Mathieson, K.; Horn, M.; Melone, J.; McEwan, F. A.; Blue, A.; O'Shea, V.; Smith, K. M.; Litke, A.; Chichilnisky, E. J.; Rahman, M.

2003-08-01

One area of major inter-disciplinary co-operation is between the particle physics and bio-medical communities. The type of large detector arrays and fast electronics developed in laboratories like CERN are becoming used for a wide range of medical and biological experiments. In the present work fabrication technology developed for producing semiconductor radiation detectors has been applied to produce arrays which have been used in neuro-physiological experiments on retinal tissue. We have exploited UVIII, a low molecular weight resist, that has permitted large area electron beam lithography. This allows the resolution to go below that of conventional photolithography and hence the production of densely packed ˜500 electrode arrays with feature sizes down to below 2 μm. The neural signals from significant areas of the retina may thus be captured.

Large Eddy Simulation of a Film Cooling Flow Injected from an Inclined Discrete Cylindrical Hole into a Crossflow with Zero-Pressure Gradient Turbulent Boundary Layer

NASA Technical Reports Server (NTRS)

Johnson, Perry L.; Shyam, Vikram

2012-01-01

A Large Eddy Simulation (LES) is performed of a high blowing ratio (M = 1.7) film cooling flow with density ratio of unity. Mean results are compared with experimental data to show the degree of fidelity achieved in the simulation. While the trends in the LES prediction are a noticeable improvement over Reynolds-Averaged Navier-Stokes (RANS) predictions, there is still a lack a spreading on the underside of the lifted jet. This is likely due to the inability of the LES to capture the full range of influential eddies on the underside of the jet due to their smaller structure. The unsteady structures in the turbulent coolant jet are also explored and related to turbulent mixing characteristics

Microfluidic separation of magnetic nanoparticles on an ordered array of magnetized micropillars

NASA Astrophysics Data System (ADS)

Orlandi, G.; Kuzhir, P.; Izmaylov, Y.; Alves Marins, J.; Ezzaier, H.; Robert, L.; Doutre, F.; Noblin, X.; Lomenech, C.; Bossis, G.; Meunier, A.; Sandoz, G.; Zubarev, A.

2016-06-01

Microfluidic separation of magnetic particles is based on their capture by magnetized microcollectors while the suspending fluid flows past the microcollectors inside a microchannel. Separation of nanoparticles is often challenging because of strong Brownian motion. Low capture efficiency of nanoparticles limits their applications in bioanalysis. However, at some conditions, magnetic nanoparticles may undergo field-induced aggregation that amplifies the magnetic attractive force proportionally to the aggregate volume and considerably increases nanoparticle capture efficiency. In this paper, we have demonstrated the role of such aggregation on an efficient capture of magnetic nanoparticles (about 80 nm in diameter) in a microfluidic channel equipped with a nickel micropillar array. This array was magnetized by an external uniform magnetic field, of intensity as low as 6-10 kA/m, and experiments were carried out at flow rates ranging between 0.3 and 30 μ L /min . Nanoparticle capture is shown to be mostly governed by the Mason number Ma, while the dipolar coupling parameter α does not exhibit a clear effect in the studied range, 1.4 < α < 4.5. The capture efficiency Λ shows a strongly decreasing Mason number behavior, Λ ∝M a-1.78 within the range 32 ≤ Ma ≤ 3250. We have proposed a simple theoretical model which considers destructible nanoparticle chains and gives the scaling behavior, Λ ∝M a-1.7 , close to the experimental findings.

Variance associated with walking velocity during force platform gait analysis of a heterogeneous sample of clinically normal dogs.

PubMed

Piazza, Alexander M; Binversie, Emily E; Baker, Lauren A; Nemke, Brett; Sample, Susannah J; Muir, Peter

2017-04-01

OBJECTIVE To determine whether walking at specific ranges of absolute and relative (V*) velocity would aid efficient capture of gait trial data with low ground reaction force (GRF) variance in a heterogeneous sample of dogs. ANIMALS 17 clinically normal dogs of various breeds, ages, and sexes. PROCEDURES Each dog was walked across a force platform at its preferred velocity, with controlled acceleration within 0.5 m/s 2 . Ranges in V* were created for height at the highest point of the shoulders (withers; WHV*). Variance effects from 8 walking absolute velocity ranges and associated WHV* ranges were examined by means of repeated-measures ANCOVA. RESULTS The individual dog effect provided the greatest contribution to variance. Narrow velocity ranges typically resulted in capture of a smaller percentage of valid trials and were not consistently associated with lower variance. The WHV* range of 0.33 to 0.46 allowed capture of valid trials efficiently, with no significant effects on peak vertical force and vertical impulse. CONCLUSIONS AND CLINICAL RELEVANCE Dogs with severe lameness may be unable to trot or may have a decline in mobility with gait trial repetition. Gait analysis involving evaluation of individual dogs at their preferred absolute velocity, such that dogs are evaluated at a similar V*, may facilitate efficient capture of valid trials without significant effects on GRF. Use of individual velocity ranges derived from a WHV* range of 0.33 to 0.46 can account for heterogeneity and appears suitable for use in clinical trials involving dogs at a walking gait.

The origin of facet selectivity and alignment in anatase TiO 2 nanoparticles in electrolyte solutions: implications for oriented attachment in metal oxides

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

Sushko, M. L.; Rosso, K. M.

Atomic-to-mesoscale simulations were used to reveal the origin of oriented attachment between anatase TiO2 nanoparticles in aqueous HCl solutions. Analysis of the distance and pH dependence of interparticle interactions demonstrates that ion correlation forces are responsible for facet-specific attraction and rotation into lattice co-alignment at long-range. These forces give rise to a metastable solvent separated capture minimum on the disjoining pressure-distance curve, with the barrier to attachment largely due to steric hydration forces from structured intervening solvent.

Real-time terahertz near-field microscope.

PubMed

Blanchard, F; Doi, A; Tanaka, T; Hirori, H; Tanaka, H; Kadoya, Y; Tanaka, K

2011-04-25

We report a terahertz near-field microscope with a high dynamic range that can capture images of a 370 x 740 μm2 area at 35 frames per second. We achieve high spatial resolution (14 μm corresponding to λ/30 for a center frequency at 0.7 THz) on a large area by combining two novel techniques: terahertz generation by tilted-pulse-front excitation and electro-optic balanced imaging detection using a thin crystal. To demonstrate the microscope capability, we reveal the field enhancement at the gap position of a dipole antenna after the irradiation of a terahertz pulse.

Towards the mass production of slow, trappable molecules

NASA Astrophysics Data System (ADS)

McCarron, Daniel J.

2018-05-01

The Fast Track Communication by Petzold et al (2018 New J. Phys. 20 042001) demonstrates the first Zeeman slowing scheme for species with type-II optical cycling transitions. This new approach is directly applicable to those 2Σ molecules that have recently been captured and cooled in molecular magneto-optical traps (MOTs) and has the potential to efficiently and continuously load these traps for the first time. This advance could produce molecular MOTs with populations comparable to their atomic counterparts and realize an ideal platform for a wide range of studies using large, dense samples of ultracold molecules.

Meteorological impact assessment of possible large scale irrigation in Southwest Saudi Arabia

NASA Astrophysics Data System (ADS)

Ter Maat, H. W.; Hutjes, R. W. A.; Ohba, R.; Ueda, H.; Bisselink, B.; Bauer, T.

2006-11-01

On continental to regional scales feedbacks between landuse and landcover change and climate have been widely documented over the past 10-15 years. In the present study we explore the possibility that also vegetation changes over much smaller areas may affect local precipitation regimes. Large scale (˜ 10 5 ha) irrigated plantations in semi-arid environments under particular conditions may affect local circulations and induce additional rainfall. Capturing this rainfall 'surplus' could then reduce the need for external irrigation sources and eventually lead to self-sustained water cycling. This concept is studied in the coastal plains in South West Saudi Arabia where the mountains of the Asir region exhibit the highest rainfall of the peninsula due to orographic lifting and condensation of moisture imported with the Indian Ocean monsoon and with disturbances from the Mediterranean Sea. We use a regional atmospheric modeling system (RAMS) forced by ECMWF analysis data to resolve the effect of complex surface conditions in high resolution (Δ x = 4 km). After validation, these simulations are analysed with a focus on the role of local processes (sea breezes, orographic lifting and the formation of fog in the coastal mountains) in generating rainfall, and on how these will be affected by large scale irrigated plantations in the coastal desert. The validation showed that the model simulates the regional and local weather reasonably well. The simulations exhibit a slightly larger diurnal temperature range than those captured by the observations, but seem to capture daily sea-breeze phenomena well. Monthly rainfall is well reproduced at coarse resolutions, but appears more localized at high resolutions. The hypothetical irrigated plantation (3.25 10 5 ha) has significant effects on atmospheric moisture, but due to weakened sea breezes this leads to limited increases of rainfall. In terms of recycling of irrigation gifts the rainfall enhancement in this particular setting is rather insignificant.

Novel myosin mutations for hereditary hearing loss revealed by targeted genomic capture and massively parallel sequencing

PubMed Central

Brownstein, Zippora; Abu-Rayyan, Amal; Karfunkel-Doron, Daphne; Sirigu, Serena; Davidov, Bella; Shohat, Mordechai; Frydman, Moshe; Houdusse, Anne; Kanaan, Moien; Avraham, Karen B

2014-01-01

Hereditary hearing loss is genetically heterogeneous, with a large number of genes and mutations contributing to this sensory, often monogenic, disease. This number, as well as large size, precludes comprehensive genetic diagnosis of all known deafness genes. A combination of targeted genomic capture and massively parallel sequencing (MPS), also referred to as next-generation sequencing, was applied to determine the deafness-causing genes in hearing-impaired individuals from Israeli Jewish and Palestinian Arab families. Among the mutations detected, we identified nine novel mutations in the genes encoding myosin VI, myosin VIIA and myosin XVA, doubling the number of myosin mutations in the Middle East. Myosin VI mutations were identified in this population for the first time. Modeling of the mutations provided predicted mechanisms for the damage they inflict in the molecular motors, leading to impaired function and thus deafness. The myosin mutations span all regions of these molecular motors, leading to a wide range of hearing phenotypes, reinforcing the key role of this family of proteins in auditory function. This study demonstrates that multiple mutations responsible for hearing loss can be identified in a relatively straightforward manner by targeted-gene MPS technology and concludes that this is the optimal genetic diagnostic approach for identification of mutations responsible for hearing loss. PMID:24105371

Spatial and temporal variation in reef-scale carbonate storage of large benthic foraminifera: a case study on One Tree Reef

NASA Astrophysics Data System (ADS)

Doo, Steve S.; Hamylton, Sarah; Finfer, Joshua; Byrne, Maria

2017-03-01

Large benthic foraminifera (LBFs) are a vital component of coral reef carbonate production, often overlooked due to their small size. These super-abundant calcifiers are crucial to reef calcification by generation of lagoon and beach sands. Reef-scale carbonate production by LBFs is not well understood, and seasonal fluctuations in this important process are largely unquantified. The biomass of five LBF species in their algal flat habitat was quantified in the austral winter (July 2013), spring (October 2013), and summer (February 2014) at One Tree Reef. WorldView-2 satellite images were used to characterize and create LBF habitat maps based on ground-referenced photographs of algal cover. Habitat maps and LBF biomass measurements were combined to estimate carbonate storage across the entire reef flat. Total carbonate storage of LBFs on the reef flat ranged from 270 tonnes (winter) to 380 tonnes (summer). Satellite images indicate that the habitat area used by LBFs ranged from 0.6 (winter) to 0.71 km2 (spring) of a total possible area of 0.96 km2. LBF biomass was highest in the winter when algal habitat area was lowest, but total carbonate storage was the highest in the summer, when algal habitat area was intermediate. Our data suggest that biomass measurements alone do not capture total abundance of LBF populations (carbonate storage), as the area of available habitat is variable. These results suggest LBF carbonate production studies that measure biomass in discrete locations and single time points fail to capture accurate reef-scale production by not incorporating estimates of the associated algal habitat. Reef-scale measurements in this study can be incorporated into carbonate production models to determine the role of LBFs in sedimentary landforms (lagoons, beaches, etc.). Based on previous models of entire reef metabolism, our estimates indicate that LBFs contribute approximately 3.9-5.4% of reef carbonate budgets, a previously underappreciated carbon sink.

A cascade of warming impacts brings bluefin tuna to Greenland waters.

PubMed

MacKenzie, Brian R; Payne, Mark R; Boje, Jesper; Høyer, Jacob L; Siegstad, Helle

2014-08-01

Rising ocean temperatures are causing marine fish species to shift spatial distributions and ranges, and are altering predator-prey dynamics in food webs. Most documented cases of species shifts so far involve relatively small species at lower trophic levels, and consider individual species in ecological isolation from others. Here, we show that a large highly migratory top predator fish species has entered a high latitude subpolar area beyond its usual range. Bluefin tuna, Thunnus thynnus Linnaeus 1758, were captured in waters east of Greenland (65°N) in August 2012 during exploratory fishing for Atlantic mackerel, Scomber scombrus Linnaeus 1758. The bluefin tuna were captured in a single net-haul in 9-11 °C water together with 6 tonnes of mackerel, which is a preferred prey species and itself a new immigrant to the area. Regional temperatures in August 2012 were historically high and contributed to a warming trend since 1985, when temperatures began to rise. The presence of bluefin tuna in this region is likely due to a combination of warm temperatures that are physiologically more tolerable and immigration of an important prey species to the region. We conclude that a cascade of climate change impacts is restructuring the food web in east Greenland waters. © 2014 John Wiley & Sons Ltd.

Early opportunities of CO₂ geological storage deployment in coal chemical industry in China

DOE PAGES

Wei, Ning; Li, Xiaochun; Liu, Shengnan; ...

2014-12-31

Carbon dioxide capture and geological storage (CCS) is regarded as a promising option for climate change mitigation; however, the high capture cost is the major barrier to large-scale deployment of CCS technologies. High-purity CO₂ emission sources can reduce or even avoid the capture requirements and costs. Among these high-purity CO₂ sources, certain coal chemical industry processes are very important, especially in China. In this paper, the basic characteristics of coal chemical industries in China is investigated and analyzed. As of 2013 there were more than 100 coal chemical plants in operation. These emission sources together emit 430 million tons CO₂more » per year, of which about 30% are emit high-purity and pure CO₂ (CO₂ concentration >80% and >98.5% respectively). Four typical source-sink pairs are chosen for techno-economic evaluation, including site screening and selection, source-sink matching, concept design, and economic evaluation. The technical-economic evaluation shows that the levelized cost of a CO₂ capture and aquifer storage project in the coal chemistry industry ranges from 14 USD/t to 17 USD/t CO₂. When a 15USD/t CO₂ tax and 20USD/t for CO₂ sold to EOR are considered, the levelized cost of CCS project are negative, which suggests a benefit from some of these CCS projects. This might provide China early opportunities to deploy and scale-up CCS projects in the near future.« less

Resonant Capture and Tidal Evolution in Circumbinary Systems: Testing the Case of Kepler-38

NASA Astrophysics Data System (ADS)

Zoppetti, F. A.; Beaugé, C.; Leiva, A. M.

2018-04-01

Circumbinary planets are thought to form far from the central binary and migrate inwards by interactions with the circumbinary disk, ultimately stopping near their present location either by a planetary trap near the disk inner edge or by resonance capture. Here, we analyze the second possibility, presenting a detailed numerical study on the capture process, resonant dynamics and tidal evolution of circumbinary planets in high-order mean-motion resonances (MMRs). Planetary migration was modeled as an external acceleration in an N-body code, while tidal effects were incorporated with a weak-friction equilibrium tide model. As a working example we chose Kepler-38, a highly evolved system with a planet in the vicinity of the 5/1 MMR. Our simulations show that resonance capture is a high-probability event under a large range of system parameters, although several different resonant configuration are possible. We identified three possible outcomes: aligned librations, anti-aligned librations and chaotic solutions. All were found to be dynamically stable, even after the dissipation of the disk, for time-spans of the order of the system's age. We found that while tidal evolution decreases the binary's separation, the semimajor axis of the planet is driven outwards. Although the net effect is a secular increase in the mean-motion ratio, the system requires a planetary tidal parameter of the order of unity to reproduce the observed orbital configuration. The results presented here open an interesting outlook into the complex dynamics of high-order resonances in circumbinary systems.

Resonant capture and tidal evolution in circumbinary systems: testing the case of Kepler-38

NASA Astrophysics Data System (ADS)

Zoppetti, F. A.; Beaugé, C.; Leiva, A. M.

2018-07-01

Circumbinary planets are thought to form far from the central binary and migrate inwards by interactions with the circumbinary disc, ultimately stopping near their present location either by a planetary trap near the disc inner edge or by resonance capture. Here, we analyse the second possibility, presenting a detailed numerical study on the capture process, resonant dynamics, and tidal evolution of circumbinary planets in high-order mean-motion resonances (MMRs). Planetary migration was modelled as an external acceleration in an N-body code, while tidal effects were incorporated with a weak-friction equilibrium tide model. As a working example, we chose Kepler-38, a highly evolved system with a planet in the vicinity of the 5/1 MMR. Our simulations show that resonance capture is a high-probability event under a large range of system parameters, although several different resonant configuration are possible. We identified three possible outcomes: aligned librations, anti-aligned librations, and chaotic solutions. All were found to be dynamically stable, even after the dissipation of the disc, for time spans of the order of the system's age. We found that while tidal evolution decreases the binary's separation, the semimajor axis of the planet is driven outwards. Although the net effect is a secular increase in the mean-motion ratio, the system requires a planetary tidal parameter of the order of unity to reproduce the observed orbital configuration. The results presented here open an interesting outlook into the complex dynamics of high-order resonances in circumbinary systems.

Sustainable microalgae for the simultaneous synthesis of carbon quantum dots for cellular imaging and porous carbon for CO2 capture.

PubMed

Guo, Li-Ping; Zhang, Yan; Li, Wen-Cui

2017-05-01

Microalgae biomass is a sustainable source with the potential to produce a range of products. However, there is currently a lack of practical and functional processes to enable the high-efficiency utilization of the microalgae. We report here a hydrothermal process to maximize the utilizability of microalgae biomass. Specifically, our concept involves the simultaneous conversion of microalgae to (i) hydrophilic and stable carbon quantum dots and (ii) porous carbon. The synthesis is easily scalable and eco-friendly. The microalgae-derived carbon quantum dots possess a strong two-photon fluorescence property, have a low cytotoxicity and an efficient cellular uptake, and show potential for high contrast bioimaging. The microalgae-based porous carbons show excellent CO 2 capture capacities of 6.9 and 4.2mmolg -1 at 0 and 25°C respectively, primarily due to the high micropore volume (0.59cm 3 g -1 ) and large specific surface area (1396m 2 g -1 ). Copyright © 2017 Elsevier Inc. All rights reserved.

Slow swimming, fast strikes: effects of feeding behavior on scaling of anaerobic metabolism in epipelagic squid.

PubMed

Trueblood, Lloyd A; Seibel, Brad A

2014-08-01

Many pelagic fishes engage prey at high speeds supported by high metabolic rates and anaerobic metabolic capacity. Epipelagic squids are reported to have among the highest metabolic rates in the oceans as a result of demanding foraging strategies and the use of jet propulsion, which is inherently inefficient. This study examined enzymatic proxies of anaerobic metabolism in two species of pelagic squid, Dosidicus gigas and Doryteuthis pealeii (Lesueur 1821), over a size range of six orders of magnitude. We hypothesized that activity of the anaerobically poised enzymes would be high and increase with size as in ecologically similar fishes. In contrast, we demonstrate that anaerobic metabolic capacity in these organisms scales negatively with body mass. We explored several cephalopod-specific traits, such as the use of tentacles to capture prey, body morphology and reduced relative prey size of adult squids, that may create a diminished reliance on anaerobically fueled burst activity during prey capture in large animals. © 2014. Published by The Company of Biologists Ltd.

A compressible multiphase framework for simulating supersonic atomization

NASA Astrophysics Data System (ADS)

Regele, Jonathan D.; Garrick, Daniel P.; Hosseinzadeh-Nik, Zahra; Aslani, Mohamad; Owkes, Mark

2016-11-01

The study of atomization in supersonic combustors is critical in designing efficient and high performance scramjets. Numerical methods incorporating surface tension effects have largely focused on the incompressible regime as most atomization applications occur at low Mach numbers. Simulating surface tension effects in high speed compressible flow requires robust numerical methods that can handle discontinuities caused by both material interfaces and shocks. A shock capturing/diffused interface method is developed to simulate high-speed compressible gas-liquid flows with surface tension effects using the five-equation model. This includes developments that account for the interfacial pressure jump that occurs in the presence of surface tension. A simple and efficient method for computing local interface curvature is developed and an acoustic non-dimensional scaling for the surface tension force is proposed. The method successfully captures a variety of droplet breakup modes over a range of Weber numbers and demonstrates the impact of surface tension in countering droplet deformation in both subsonic and supersonic cross flows.

How many atoms are required to characterize accurately trajectory fluctuations of a protein?

NASA Astrophysics Data System (ADS)

Cukier, Robert I.

2010-06-01

Large molecules, whose thermal fluctuations sample a complex energy landscape, exhibit motions on an extended range of space and time scales. Principal component analysis (PCA) is often used to extract dominant motions that in proteins are typically domain motions. These motions are captured in the large eigenvalue (leading) principal components. There is also information in the small eigenvalues, arising from approximate linear dependencies among the coordinates. These linear dependencies suggest that instead of using all the atom coordinates to represent a trajectory, it should be possible to use a reduced set of coordinates with little loss in the information captured by the large eigenvalue principal components. In this work, methods that can monitor the correlation (overlap) between a reduced set of atoms and any number of retained principal components are introduced. For application to trajectory data generated by simulations, where the overall translational and rotational motion needs to be eliminated before PCA is carried out, some difficulties with the overlap measures arise and methods are developed to overcome them. The overlap measures are evaluated for a trajectory generated by molecular dynamics for the protein adenylate kinase, which consists of a stable, core domain, and two more mobile domains, referred to as the LID domain and the AMP-binding domain. The use of reduced sets corresponding, for the smallest set, to one-eighth of the alpha carbon (CA) atoms relative to using all the CA atoms is shown to predict the dominant motions of adenylate kinase. The overlap between using all the CA atoms and all the backbone atoms is essentially unity for a sum over PCA modes that effectively capture the exact trajectory. A reduction to a few atoms (three in the LID and three in the AMP-binding domain) shows that at least the first principal component, characterizing a large part of the LID-binding and AMP-binding motion, is well described. Based on these results, the overlap criterion should be applicable as a guide to postulating and validating coarse-grained descriptions of generic biomolecular assemblies.

A method for modeling contact dynamics for automated capture mechanisms

NASA Technical Reports Server (NTRS)

Williams, Philip J.

1991-01-01

Logicon Control Dynamics develops contact dynamics models for space-based docking and berthing vehicles. The models compute contact forces for the physical contact between mating capture mechanism surfaces. Realistic simulation requires proportionality constants, for calculating contact forces, to approximate surface stiffness of contacting bodies. Proportionality for rigid metallic bodies becomes quite large. Small penetrations of surface boundaries can produce large contact forces.

On the value-dependence of value-driven attentional capture.

PubMed

Anderson, Brian A; Halpern, Madeline

2017-05-01

Findings from an increasingly large number of studies have been used to argue that attentional capture can be dependent on the learned value of a stimulus, or value-driven. However, under certain circumstances attention can be biased to select stimuli that previously served as targets, independent of reward history. Value-driven attentional capture, as studied using the training phase-test phase design introduced by Anderson and colleagues, is widely presumed to reflect the combined influence of learned value and selection history. However, the degree to which attentional capture is at all dependent on value learning in this paradigm has recently been questioned. Support for value-dependence can be provided through one of two means: (1) greater attentional capture by prior targets following rewarded training than following unrewarded training, and (2) greater attentional capture by prior targets previously associated with high compared to low value. Using a variant of the original value-driven attentional capture paradigm, Sha and Jiang (Attention, Perception, and Psychophysics, 78, 403-414, 2016) failed to find evidence of either, and raised criticisms regarding the adequacy of evidence provided by prior studies using this particular paradigm. To address this disparity, here we provided a stringent test of the value-dependence hypothesis using the traditional value-driven attentional capture paradigm. With a sufficiently large sample size, value-dependence was observed based on both criteria, with no evidence of attentional capture without rewards during training. Our findings support the validity of the traditional value-driven attentional capture paradigm in measuring what its name purports to measure.

Lead and mercury in fall migrant golden eagles from western North America.

PubMed

Langner, Heiko W; Domenech, Robert; Slabe, Vincent A; Sullivan, Sean P

2015-07-01

Lead exposure from ingestion of bullet fragments is a serious environmental hazard to eagles. We determined blood lead levels (BLL) in 178 golden eagles (Aquila chrysaetos) captured during fall migration along a major North American flyway. These eagles spent the breeding season distributed over a large range and are the best currently available representation of free flying golden eagles on the continent. We found 58 % of these eagles containing increased BLL > 0.1 mg/L; 10 % were clinically lead poisoned with BLL > 0.6 mg/L; and 4 % were lethally exposed with BLL > 1.2 mg/L. No statistical difference in BLL existed between golden and bald eagles (Haliaeetus leucocephalus). Golden eagles captured on carrion had higher BLL than those captured using live bait suggesting differences in feeding habits among individuals. Median BLL increased with age class. We propose a conceptual model for the long-term increase in BLL after ingestion of lead particles. The mean blood mercury level in golden eagles was 0.023 mg/L. We evaluate a field test for BLL that is based on anodic stripping voltammetry. This cost-effective and immediate method correlated well with results from inductively coupled plasma-mass spectrometry, although results needed to be corrected for each calibration of the test kit.

The solar maximum satellite capture cell: Impact features and orbital debris and micrometeoritic projectile materials

NASA Technical Reports Server (NTRS)

Mckay, D. S.; Rietmeijer, F. J. M.; Schramm, L. S.; Barrett, R. A.; Zook, H. A.; Blanford, G. E.

1986-01-01

The physical properties of impact features observed in the Solar Max main electronics box (MEB) thermal blanket generally suggest an origin by hypervelocity impact. The chemistry of micrometeorite material suggests that a wide variety of projectile materials have survived impact with retention of varying degrees of pristinity. Impact features that contain only spacecraft paint particles are on average smaller than impact features caused by micrometeorite impacts. In case both types of materials co-occur, it is belevied that the impact feature, generally a penetration hole, was caused by a micrometeorite projectile. The typically smaller paint particles were able to penetrate though the hole in the first layer and deposit in the spray pattern on the second layer. It is suggested that paint particles have arrived with a wide range of velocities relative to the Solar Max satellite. Orbiting paint particles are an important fraction of materials in the near-Earth environment. In general, the data from the Solar Max studies are a good calibration for the design of capture cells to be flown in space and on board Space Station. The data also suggest that development of multiple layer capture cells in which the projectile may retain a large degree of pristinity is a feasible goal.

Boron neutron capture therapy of malignant brain tumors at the Brookhaven Medical Research Reactor

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

Joel, D.D.; Coderre, J.A.; Chanana, A.D.

1996-12-31

Boron neutron capture therapy (BNCT) is a bimodal form of radiation therapy for cancer. The first component of this treatment is the preferential localization of the stable isotope {sup 10}B in tumor cells by targeting with boronated compounds. The tumor and surrounding tissue is then irradiated with a neutron beam resulting in thermal neutron/{sup 10}B reactions ({sup 10}B(n,{alpha}){sup 7}Li) resulting in the production of localized high LET radiation from alpha and {sup 7}Li particles. These products of the neutron capture reaction are very damaging to cells, but of short range so that the majority of the ionizing energy released ismore » microscopically confined to the vicinity of the boron-containing compound. In principal it should be possible with BNCT to selectively destroy small nests or even single cancer cells located within normal tissue. It follows that the major improvements in this form of radiation therapy are going to come largely from the development of boron compounds with greater tumor selectivity, although there will certainly be advances made in neutron beam quality as well as the possible development of alternative sources of neutron beams, particularly accelerator-based epithermal neutron beams.« less

Data processing workflows from low-cost digital survey to various applications: three case studies of Chinese historic architecture

NASA Astrophysics Data System (ADS)

Sun, Z.; Cao, Y. K.

2015-08-01

The paper focuses on the versatility of data processing workflows ranging from BIM-based survey to structural analysis and reverse modeling. In China nowadays, a large number of historic architecture are in need of restoration, reinforcement and renovation. But the architects are not prepared for the conversion from the booming AEC industry to architectural preservation. As surveyors working with architects in such projects, we have to develop efficient low-cost digital survey workflow robust to various types of architecture, and to process the captured data for architects. Although laser scanning yields high accuracy in architectural heritage documentation and the workflow is quite straightforward, the cost and portability hinder it from being used in projects where budget and efficiency are of prime concern. We integrate Structure from Motion techniques with UAV and total station in data acquisition. The captured data is processed for various purposes illustrated with three case studies: the first one is as-built BIM for a historic building based on registered point clouds according to Ground Control Points; The second one concerns structural analysis for a damaged bridge using Finite Element Analysis software; The last one relates to parametric automated feature extraction from captured point clouds for reverse modeling and fabrication.

Coriolis effect on dynamic stall in a vertical axis wind turbine

NASA Astrophysics Data System (ADS)

Tsai, Hsieh-Chen; Colonius, Tim

2013-11-01

The immersed boundary method is used to simulate the flow around a two-dimensional rotating NACA 0018 airfoil at moderate (sub-scale) Reynolds number in order to investigate separated flow occurring on a vertical-axis wind turbine (VAWT). The influence of dynamic stall on the forces is characterized as a function of tip-speed ratio. The influence of the Coriolis effect is also investigated by comparing the rotating airfoil to one undergoing a surging and pitching motion that produces an equivalent speed and angle-of-attack variation over the cycle. While the Coriolis force produces only small differences in the averaged forces, it plays an important role during dynamic stall. Due to the fact that the Coriolis force deflects the fluid and propagates the vortices differently, the wake-capturing phenomenon of the trailing edge vortex is observed in the flow around the rotating airfoil during a certain range of azimuthal angle. This wake-capturing of the trailing edge vortex leads to a large decrease in lift. However, because of the phase difference between each wake-capturing, there are only small differences in the average forces. The simulations are also compared to results from companion water-tunnel experiments at Caltech. This project is supported by the Gordon and Betty Moore Foundation.

Development of the focal plane system for the SEparator for CApture Reactions

NASA Astrophysics Data System (ADS)

Hood, A. A. D.; Blackmon, J. C.; Cottingham, R.; Deibel, C. M.; Good, E.; Joerres, K.; Laminack, A.; Garrity, A.; Secar Collaboration

2017-09-01

The SEparator for CApture Reactions (SECAR) is currently under construction for the National Superconducting Cyclotron Laboratory and future Facility for Rare Isotope Beams. SECAR is designed to conduct sensitive measurements of capture reactions critical to understanding stellar explosions. We have developed a versatile focal plane system that will differentiate reaction recoils from unreacted scattered beam particles in measurements covering a large range of energies and masses. The elements of the focal plane system include two metal-foil, micro-channel plate (MCP) detectors, a variety of diagnostics, and two alternative recoil stopping detectors. The MCP detectors will measure the time-of-flight (and therefore velocity) as well as the position of the recoils. Our primary heavy ion recoil detector is a gas ionization chamber that measures position, total energy and relative energy loss and provides good atomic number discrimination at energies greater than about 0.5 MeV/u. For some cases, this gas counter will be replaced by silicon strip detectors to provide superior energy resolution. We will describe the overall design and report on construction and testing of the detector systems. Supported by the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Awards DE-SC0014384 and DE-FG02-96ER40978.

Suitability of digital camcorders for virtual reality image data capture

NASA Astrophysics Data System (ADS)

D'Apuzzo, Nicola; Maas, Hans-Gerd

1998-12-01

Today's consumer market digital camcorders offer features which make them appear quite interesting devices for virtual reality data capture. The paper compares a digital camcorder with an analogue camcorder and a machine vision type CCD camera and discusses the suitability of these three cameras for virtual reality applications. Besides the discussion of technical features of the cameras, this includes a detailed accuracy test in order to define the range of applications. In combination with the cameras, three different framegrabbers are tested. The geometric accuracy potential of all three cameras turned out to be surprisingly large, and no problems were noticed in the radiometric performance. On the other hand, some disadvantages have to be reported: from the photogrammetrists point of view, the major disadvantage of most camcorders is the missing possibility to synchronize multiple devices, limiting the suitability for 3-D motion data capture. Moreover, the standard video format contains interlacing, which is also undesirable for all applications dealing with moving objects or moving cameras. Further disadvantages are computer interfaces with functionality, which is still suboptimal. While custom-made solutions to these problems are probably rather expensive (and will make potential users turn back to machine vision like equipment), this functionality could probably be included by the manufacturers at almost zero cost.

Interactions between ecology, demography, capture stress, and profiles of corticosterone and glucose in a free-living population of Australian freshwater crocodiles.

PubMed

Jessop, Tim S; Tucker, Anton D; Limpus, Colin J; Whittier, Joan M

2003-06-01

In this study we examined three aspects pertaining to adrenocortical responsiveness in free-ranging Australian freshwater crocodiles (Crocodylus johnstoni). First, we examined the ability of freshwater crocodiles to produce corticosterone in response to a typical capture-stress protocol. A second objective addressed the relationship between capture stress, plasma glucose and corticosterone. Next we examined if variation in basal and capture-stress-induced levels of plasma corticosterone was linked to ecological or demographic factors for individuals in this free-ranging population. Blood samples obtained on three field trips were taken from a cross-sectional sample of the population. Crocodiles were bled once during four time categories at 0, 0.5, 6, and 10h post-capture. Plasma corticosterone increased significantly with time post-capture. Plasma glucose also significantly increased with duration of capture-stress and exhibited a positive and significant relationship with plasma corticosterone. Significant variation in basal or stress induced levels of corticosterone in crocodiles was not associated with any ecological or demographic factors including sex, age class or the year of capture that the crocodiles were sampled from. However, three immature males had basal levels of plasma corticosterone greater than 2 standard deviations above the mean. While crocodiles exhibited a pronounced adrenocortical and hyperglycaemic response to capture stress, limited variation in adrenocortical responsiveness due to ecological and demographic factors was not evident. This feature could arise in part because this population was sampled during a period of environmental benigness.

Silica Aerogel Captures Cosmic Dust Intact

NASA Technical Reports Server (NTRS)

Tsou, P.

1994-01-01

The mesostructure of silica aerogel resembles stings of grapes, ranging in size from 10 to 100 angstrom. This fine mesostructure transmits nearly 90 percent of incident light in the visible, while providing sufficiently gentle dissipation of the kinetric energy of hypervelocity cosmic dust particles to permit their intact capture. We introduced silica aerogel in 1987 as capture medium to take advantage of its low density, fine mesostruicture and most importantly, its transparency, allowing optical location of captured micron sized particles.

Jumpstarting commercial-scale CO 2 capture and storage with ethylene production and enhanced oil recovery in the US Gulf

DOE PAGES

Middleton, Richard S.; Levine, Jonathan S.; Bielicki, Jeffrey M.; ...

2015-04-27

CO 2 capture, utilization, and storage (CCUS) technology has yet to be widely deployed at a commercial scale despite multiple high-profile demonstration projects. We suggest that developing a large-scale, visible, and financially viable CCUS network could potentially overcome many barriers to deployment and jumpstart commercial-scale CCUS. To date, substantial effort has focused on technology development to reduce the costs of CO 2 capture from coal-fired power plants. Here, we propose that near-term investment could focus on implementing CO 2 capture on facilities that produce high-value chemicals/products. These facilities can absorb the expected impact of the marginal increase in the costmore » of production on the price of their product, due to the addition of CO 2 capture, more than coal-fired power plants. A financially viable demonstration of a large-scale CCUS network requires offsetting the costs of CO 2 capture by using the CO 2 as an input to the production of market-viable products. As a result, we demonstrate this alternative development path with the example of an integrated CCUS system where CO 2 is captured from ethylene producers and used for enhanced oil recovery in the U.S. Gulf Coast region.« less

A global/local affinity graph for image segmentation.

PubMed

Xiaofang Wang; Yuxing Tang; Masnou, Simon; Liming Chen

2015-04-01

Construction of a reliable graph capturing perceptual grouping cues of an image is fundamental for graph-cut based image segmentation methods. In this paper, we propose a novel sparse global/local affinity graph over superpixels of an input image to capture both short- and long-range grouping cues, and thereby enabling perceptual grouping laws, including proximity, similarity, continuity, and to enter in action through a suitable graph-cut algorithm. Moreover, we also evaluate three major visual features, namely, color, texture, and shape, for their effectiveness in perceptual segmentation and propose a simple graph fusion scheme to implement some recent findings from psychophysics, which suggest combining these visual features with different emphases for perceptual grouping. In particular, an input image is first oversegmented into superpixels at different scales. We postulate a gravitation law based on empirical observations and divide superpixels adaptively into small-, medium-, and large-sized sets. Global grouping is achieved using medium-sized superpixels through a sparse representation of superpixels' features by solving a ℓ0-minimization problem, and thereby enabling continuity or propagation of local smoothness over long-range connections. Small- and large-sized superpixels are then used to achieve local smoothness through an adjacent graph in a given feature space, and thus implementing perceptual laws, for example, similarity and proximity. Finally, a bipartite graph is also introduced to enable propagation of grouping cues between superpixels of different scales. Extensive experiments are carried out on the Berkeley segmentation database in comparison with several state-of-the-art graph constructions. The results show the effectiveness of the proposed approach, which outperforms state-of-the-art graphs using four different objective criteria, namely, the probabilistic rand index, the variation of information, the global consistency error, and the boundary displacement error.

Electronic archival tags provide first glimpse of bathythermal habitat use by free-ranging adult lake sturgeon Acipenser fulvescens

USGS Publications Warehouse

Briggs, Andrew S.; Hondorp, Darryl W.; Quinlan, Henry R.; Boase, James C.; Mohr, Lloyd C.

2016-01-01

Information on lake sturgeon (Acipenser fulvescens) depth and thermal habitat use during non-spawning periods is unavailable due to the difficulty of observing lake sturgeon away from shallow water spawning sites. In 2002 and 2003, lake sturgeon captured in commercial trap nets near Sarnia, Ontario were implanted with archival tags and released back into southern Lake Huron. Five of the 40 tagged individuals were recaptured and were at large for 32, 57, 286, 301, and 880 days. Temperatures and depths recorded by archival tags ranged from 0 to 23.5 ºC and 0.1 to 42.4 m, respectively. For the three lake sturgeon that were at large for over 200 days, temperatures occupied emulated seasonal fluctuations. Two of these fish occupied deeper waters during winter than summer while the other occupied similar depths during non-spawning periods. This study provides important insight into depth and thermal habitat use of lake sturgeon throughout the calendar year along with exploring the feasibility of using archival tags to obtain important physical habitat attributes during non-spawning periods.

Fusion and quasifission studies for the 40Ca+186W,192Os reactions

NASA Astrophysics Data System (ADS)

Prasad, E.; Hinde, D. J.; Williams, E.; Dasgupta, M.; Carter, I. P.; Cook, K. J.; Jeung, D. Y.; Luong, D. H.; Palshetkar, C. S.; Rafferty, D. C.; Ramachandran, K.; Simenel, C.; Wakhle, A.

2017-09-01

Background: All elements above atomic number 113 have been synthesized using hot fusion reactions with calcium beams on statically deformed actinide target nuclei. Quasifission and fusion-fission are the two major mechanisms responsible for the very low production cross sections of superheavy elements. Purpose: To achieve a quantitative measurement of capture and quasifission characteristics as a function of beam energy in reactions forming heavy compound systems using calcium beams as projectiles. Methods: Fission fragment mass-angle distributions were measured for the two reactions 40Ca+186W and 40C+192Os, populating 226Pu and 232Cm compound nuclei, respectively, using the Heavy Ion Accelerator Facility and CUBE spectrometer at the Australian National University. Mass ratio distributions, angular distributions, and total fission cross sections were obtained from the experimental data. Simulations to match the features of the experimental mass-angle distributions were performed using a classical phenomenological approach. Results: Both 40Ca+186W and 40C+192Os reactions show strong mass-angle correlations at all energies measured. A maximum fusion probability of 60 -70 % is estimated for the two reactions in the energy range of the present study. Coupled-channels calculations assuming standard Woods-Saxon potential parameters overpredict the capture cross sections. Large nuclear potential diffuseness parameters ˜1.5 fm are required to fit the total capture cross sections. The presence of a weak mass-asymmetric quasifission component attributed to the higher angular momentum events can be reproduced with a shorter average sticking time but longer mass-equilibration time constant. Conclusions: The deduced above-barrier capture cross sections suggest that the dissipative processes are already occurring outside the capture barrier. The mass-angle correlations indicate that a compact shape is not achieved for deformation aligned collisions with lower capture barriers. The average sticking time of fast quasifission events is 10-20 s.

Capture and decay of electroweak WIMPonium

NASA Astrophysics Data System (ADS)

Asadi, Pouya; Baumgart, Matthew; Fitzpatrick, Patrick J.; Krupczak, Emmett; Slatyer, Tracy R.

2017-02-01

The spectrum of Weakly-Interacting-Massive-Particle (WIMP) dark matter generically possesses bound states when the WIMP mass becomes sufficiently large relative to the mass of the electroweak gauge bosons. The presence of these bound states enhances the annihilation rate via resonances in the Sommerfeld enhancement, but they can also be produced directly with the emission of a low-energy photon. In this work we compute the rate for SU(2) triplet dark matter (the wino) to bind into WIMPonium—which is possible via single-photon emission for wino masses above 5 TeV for relative velocity v < O(10-2) —and study the subsequent decays of these bound states. We present results with applications beyond the wino case, e.g. for dark matter inhabiting a nonabelian dark sector; these include analytic capture and transition rates for general dark sectors in the limit of vanishing force carrier mass, efficient numerical routines for calculating positive and negative-energy eigenstates of a Hamiltonian containing interactions with both massive and massless force carriers, and a study of the scaling of bound state formation in the short-range Hulth&apos{e}n potential. In the specific case of the wino, we find that the rate for bound state formation is suppressed relative to direct annihilation, and so provides only a small correction to the overall annihilation rate. The soft photons radiated by the capture process and by bound state transitions could permit measurement of the dark matter's quantum numbers; for wino-like dark matter, such photons are rare, but might be observable by a future ground-based gamma-ray telescope combining large effective area and a low energy threshold.

Modelling foraging movements of diving predators: a theoretical study exploring the effect of heterogeneous landscapes on foraging efficiency

PubMed Central

Bartoń, Kamil A.; Scott, Beth E.; Travis, Justin M.J.

2014-01-01

Foraging in the marine environment presents particular challenges for air-breathing predators. Information about prey capture rates, the strategies that diving predators use to maximise prey encounter rates and foraging success are still largely unknown and difficult to observe. As well, with the growing awareness of potential climate change impacts and the increasing interest in the development of renewable sources it is unknown how the foraging activity of diving predators such as seabirds will respond to both the presence of underwater structures and the potential corresponding changes in prey distributions. Motivated by this issue we developed a theoretical model to gain general understanding of how the foraging efficiency of diving predators may vary according to landscape structure and foraging strategy. Our theoretical model highlights that animal movements, intervals between prey capture and foraging efficiency are likely to critically depend on the distribution of the prey resource and the size and distribution of introduced underwater structures. For multiple prey loaders, changes in prey distribution affected the searching time necessary to catch a set amount of prey which in turn affected the foraging efficiency. The spatial aggregation of prey around small devices (∼ 9 × 9 m) created a valuable habitat for a successful foraging activity resulting in shorter intervals between prey captures and higher foraging efficiency. The presence of large devices (∼ 24 × 24 m) however represented an obstacle for predator movement, thus increasing the intervals between prey captures. In contrast, for single prey loaders the introduction of spatial aggregation of the resources did not represent an advantage suggesting that their foraging efficiency is more strongly affected by other factors such as the timing to find the first prey item which was found to occur faster in the presence of large devices. The development of this theoretical model represents a useful starting point to understand the energetic reasons for a range of potential predator responses to spatial heterogeneity and environmental uncertainties in terms of search behaviour and predator–prey interactions. We highlight future directions that integrated empirical and modelling studies should take to improve our ability to predict how diving predators will be impacted by the deployment of manmade structures in the marine environment. PMID:25250211

Drainage capture and discharge variations driven by glaciation in the Southern Alps, New Zealand

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

Ann V. Rowan; Mitchell A. Plummer; Simon H. Brocklehurst

Sediment flux in proglacial fluvial settings is primarily controlled by discharge, which usually varies predictably over a glacial–interglacial cycle. However, glaciers can flow against the topographic gradient to cross drainage divides, reshaping fluvial drainage networks and dramatically altering discharge. In turn, these variations in discharge will be recorded by proglacial stratigraphy. Glacial-drainage capture often occurs in alpine environments where ice caps straddle range divides, and more subtly where shallow drainage divides cross valley floors. We investigate discharge variations resulting from glacial-drainage capture over the past 40 k.y. for the adjacent Ashburton, Rangitata, and Rakaia basins in the Southern Alps, Newmore » Zealand. Although glacial-drainage capture has previously been inferred in the range, our numerical glacier model provides the first quantitative demonstration that this process drives larger variations in discharge for a longer duration than those that occur due to climate change alone. During the Last Glacial Maximum, the effective drainage area of the Ashburton catchment increased to 160% of the interglacial value with drainage capture, driving an increase in discharge exceeding that resulting from glacier recession. Glacial-drainage capture is distinct from traditional (base level–driven) drainage capture and is often unrecognized in proglacial deposits, complicating interpretation of the sedimentary record of climate change.« less

Ab initio thermodynamic approach to identify mixed solid sorbents for CO 2 capture technology

DOE PAGES

Duan, Yuhua

2015-10-15

Because the current technologies for capturing CO 2 are still too energy intensive, new materials must be developed that can capture CO 2 reversibly with acceptable energy costs. At a given CO 2 pressure, the turnover temperature (T t) of the reaction of an individual solid that can capture CO 2 is fixed. Such T t may be outside the operating temperature range (ΔT o) for a practical capture technology. To adjust T t to fit the practical ΔT o, in this study, three scenarios of mixing schemes are explored by combining thermodynamic database mining with first principles density functionalmore » theory and phonon lattice dynamics calculations. Our calculated results demonstrate that by mixing different types of solids, it’s possible to shift T t to the range of practical operating temperature conditions. According to the requirements imposed by the pre- and post- combustion technologies and based on our calculated thermodynamic properties for the CO 2 capture reactions by the mixed solids of interest, we were able to identify the mixing ratios of two or more solids to form new sorbent materials for which lower capture energy costs are expected at the desired pressure and temperature conditions.« less

DUST CAPTURE AND LONG-LIVED DENSITY ENHANCEMENTS TRIGGERED BY VORTICES IN 2D PROTOPLANETARY DISKS

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

Surville, Clément; Mayer, Lucio; Lin, Douglas N. C., E-mail: clement.surville@physik.uzh.ch

We study dust capture by vortices and its long-term consequences in global two-fluid inviscid disk simulations using a new polar grid code RoSSBi. We perform the longest integrations so far, several hundred disk orbits, at the highest resolution attainable in global disk simulations with dust, namely, 2048 × 4096 grid points. We vary a wide range of dust parameters, most notably the initial dust-to-gas ratio ϵ varies in the range of 10{sup −4}–10{sup −2}. Irrespective of the value of ϵ , we find rapid concentration of the dust inside vortices, reaching dust-to-gas ratios of the order of unity inside themore » vortex. We present an analytical model that describes this dust capture process very well, finding consistent results for all dust parameters. A vortex streaming instability develops, which invariably causes vortex destruction. After vortex dissipation large-scale dust rings encompassing a disk annulus form in most cases, which sustain very high dust concentration, approaching ratios of the order of unity; they persist as long as the duration of the simulations. They are sustained by a streaming instability, which manifests itself in high-density dust clumps at various scales. When vortices are particularly long-lived, rings do not form but dust clumps inside vortices can survive a long time and would likely undergo collapse by gravitational instability. Rings encompass almost an Earth mass of solid material, while even larger masses of dust do accumulate inside vortices in the earlier stage. We argue that rapid planetesimal formation would occur in the dust clumps inside the vortices as well as in the post-vortex rings.« less

Dust Capture and Long-lived Density Enhancements Triggered by Vortices in 2D Protoplanetary Disks

NASA Astrophysics Data System (ADS)

Surville, Clément; Mayer, Lucio; Lin, Douglas N. C.

2016-11-01

We study dust capture by vortices and its long-term consequences in global two-fluid inviscid disk simulations using a new polar grid code RoSSBi. We perform the longest integrations so far, several hundred disk orbits, at the highest resolution attainable in global disk simulations with dust, namely, 2048 × 4096 grid points. We vary a wide range of dust parameters, most notably the initial dust-to-gas ratio ɛ varies in the range of 10-4-10-2. Irrespective of the value of ɛ, we find rapid concentration of the dust inside vortices, reaching dust-to-gas ratios of the order of unity inside the vortex. We present an analytical model that describes this dust capture process very well, finding consistent results for all dust parameters. A vortex streaming instability develops, which invariably causes vortex destruction. After vortex dissipation large-scale dust rings encompassing a disk annulus form in most cases, which sustain very high dust concentration, approaching ratios of the order of unity they persist as long as the duration of the simulations. They are sustained by a streaming instability, which manifests itself in high-density dust clumps at various scales. When vortices are particularly long-lived, rings do not form but dust clumps inside vortices can survive a long time and would likely undergo collapse by gravitational instability. Rings encompass almost an Earth mass of solid material, while even larger masses of dust do accumulate inside vortices in the earlier stage. We argue that rapid planetesimal formation would occur in the dust clumps inside the vortices as well as in the post-vortex rings.

Combined use of vancomycin-modified Ag-coated magnetic nanoparticles and secondary enhanced nanoparticles for rapid surface-enhanced Raman scattering detection of bacteria.

PubMed

Wang, Chongwen; Gu, Bing; Liu, Qiqi; Pang, Yuanfeng; Xiao, Rui; Wang, Shengqi

2018-01-01

Pathogenic bacteria have always been a significant threat to human health. The detection of pathogens needs to be rapid, accurate, and convenient. We present a sensitive surface-enhanced Raman scattering (SERS) biosensor based on the combination of vancomycin-modified Ag-coated magnetic nanoparticles (Fe 3 O 4 @Ag-Van MNPs) and Au@Ag nanoparticles (NPs) that can effectively capture and discriminate bacterial pathogens from solution. The high-performance Fe 3 O 4 @Ag MNPs were modified with vancomycin and used as bacteria capturer for magnetic separation and enrichment. The modified MNPS were found to exhibit strong affinity with a broad range of Gram-positive and Gram-negative bacteria. After separating and rinsing bacteria, Fe 3 O 4 @Ag-Van MNPs and Au@Ag NPs were synergistically used to construct a very large number of hot spots on bacteria cells, leading to ultrasensitive SERS detection. The dominant merits of our dual enhanced strategy included high bacterial-capture efficiency (>65%) within a wide pH range (pH 3.0-11.0), a short assay time (<30 min), and a low detection limit (5×10 2 cells/mL). Moreover, the spiked tests show that this method is still valid in milk and blood samples. Owing to these capabilities, the combined system enabled the sensitive and specific discrimination of different pathogens in complex solution, as verified by its detection of Gram-positive bacterium Escherichia coli , Gram-positive bacterium Staphylococcus aureus , and methicillin-resistant S. aureus . This method has great potential for field applications in food safety, environmental monitoring, and infectious disease diagnosis.

Combined use of vancomycin-modified Ag-coated magnetic nanoparticles and secondary enhanced nanoparticles for rapid surface-enhanced Raman scattering detection of bacteria

PubMed Central

Pang, Yuanfeng; Xiao, Rui; Wang, Shengqi

2018-01-01

Background Pathogenic bacteria have always been a significant threat to human health. The detection of pathogens needs to be rapid, accurate, and convenient. Methods We present a sensitive surface-enhanced Raman scattering (SERS) biosensor based on the combination of vancomycin-modified Ag-coated magnetic nanoparticles (Fe3O4@Ag-Van MNPs) and Au@Ag nanoparticles (NPs) that can effectively capture and discriminate bacterial pathogens from solution. The high-performance Fe3O4@Ag MNPs were modified with vancomycin and used as bacteria capturer for magnetic separation and enrichment. The modified MNPS were found to exhibit strong affinity with a broad range of Gram-positive and Gram-negative bacteria. After separating and rinsing bacteria, Fe3O4@Ag-Van MNPs and Au@Ag NPs were synergistically used to construct a very large number of hot spots on bacteria cells, leading to ultrasensitive SERS detection. Results The dominant merits of our dual enhanced strategy included high bacterial-capture efficiency (>65%) within a wide pH range (pH 3.0–11.0), a short assay time (<30 min), and a low detection limit (5×102 cells/mL). Moreover, the spiked tests show that this method is still valid in milk and blood samples. Owing to these capabilities, the combined system enabled the sensitive and specific discrimination of different pathogens in complex solution, as verified by its detection of Gram-positive bacterium Escherichia coli, Gram-positive bacterium Staphylococcus aureus, and methicillin-resistant S. aureus. Conclusion This method has great potential for field applications in food safety, environmental monitoring, and infectious disease diagnosis. PMID:29520142

Intrinsic stream-capture control of stepped fan pediments in the High Atlas piedmont of Ouarzazate (Morocco)

NASA Astrophysics Data System (ADS)

Pastor, A.; Babault, J.; Teixell, A.; Arboleya, M. L.

2012-11-01

The Ouarzazate basin is a Cenozoic foreland basin located to the south of the High Atlas Mountains. The basin has been externally drained during the Quaternary, with fluvial dynamics dominated by erosive processes from a progressive base level drop. The current drainage network is composed of rivers draining the mountain and carrying large amounts of coarse sediments and by piedmont streams with smaller catchments eroding the soft Cenozoic rocks of the Ouarzazate basin. The coarse-grained sediments covering the channel beds of main rivers cause the steepening of the channel gradient and act as a shield inhibiting bedrock incision. Under such circumstances, piedmont streams that incise to lower gradients evolve to large, depressed pediments at lower elevations and threaten to capture rivers originating in the mountain. Much of the current surface of the Ouarzazate basin is covered by coarse sediments forming large systems of stepped fan pediments that developed by the filling of low elevation pediments after a capture event. We identified 14 capture events, and previously published geochronology support an ~ 100 ka frequency for fan pediment formation. Our study indicates that the reorganization of the fluvial network in the Ouarzazate basin during the late Pleistocene and Holocene has been controlled by the piedmont-stream piracy process, a process ultimately controlled by the cover effect. The stream capture is influenced by erosion, sediment supply and transport, and therefore may not be entirely decoupled from tectonic and climatic forcing. Indeed, we show that at least two capture events may have occurred during climate changes, and local tectonic structures control at most the spatial localization of capture events.

Carbon capture and sequestration (CCS)

DOT National Transportation Integrated Search

2009-06-19

Carbon capture and sequestration (or storage)known as CCShas attracted interest as a : measure for mitigating global climate change because large amounts of carbon dioxide (CO2) : emitted from fossil fuel use in the United States are potentiall...

A comparison of certain methods of measuring ranges of small mammals

USGS Publications Warehouse

Stickel, L.F.

1954-01-01

SUMMARY: A comparison is made of different methods of determining size of home range from grid trapping data. Studies of artificial populations show that a boundary strip method of measuring area and an adjusted range length give sizes closer to the true range than do minimum area or observed range length methods. In simulated trapping of artificial populations, the known range size increases with successive captures until a level is reached that approximates the true range. The same general pattern is followed whether traps are visited at random or traps nearer the center of the range are favored; but when central traps are favored the curve levels more slowly. Range size is revealed with fewer captures when traps are far apart than when they are close together. The curve levels more slowly for oblong ranges than for circular ranges of the same area. Fewer captures are required to determine range length than to determine range area. Other examples of simulated trapping in artificial populations are used to provide measurements of distances from the center of activity and distances between successive captures. These are compared with similar measurements taken from Peromyscus trapping data. The similarity of range sizes found in certain field comparisons of area trapping, colored scat collections, and trailing is cited. A comparison of home range data obtained by area trapping and nest box studies is discussed. It is shown that when traps are set too far apart to include two or more in the range of each animal, calculation of average range size gives biased results. The smaller ranges are not expressed and cannot be included in the averages. The result is that range estimates are smaller at closer spacings and greater at wider spacings, purely as a result of these erroneous calculations and not reflecting any varying behavior of the animals. The problem of variation in apparent home range with variation in trap spacing is considered further by trapping in an artificial population. It is found that trap spacing can alter the apparent size of range even when biological factors are excluded and trap visiting is random. The desirability of excluding travels outside the normal range from home range calculations is discussed. Effects of varying the trapping plan by setting alternate rows of traps, or setting two traps per site, are discussed briefly.

A versatile technique for capturing urban gulls during winter

USGS Publications Warehouse

Clark, Daniel E.; Koenen, Kiana K. G.; MacKenzie, Kenneth G.; Pereira, Jillian W.; DeStefano, Stephen

2014-01-01

The capture of birds is a common part of many avian studies but often requires large investments of time and resources. We developed a novel technique for capturing gulls during the non-breeding season using a net launcher that was effective and efficient. The technique can be used in a variety of habitats and situations, including urban areas. Using this technique, we captured 1,326 gulls in 125 capture events from 2008 to 2012 in Massachusetts, USA. On average, 10 ring-billed gulls (Larus delawarensis; range = 1–37) were captured per trapping event. Capture rate (the number of birds captured per trapping event) was influenced by the type of bait used and also the time of the year (greatest in autumn, lowest in winter). Our capture technique could be adapted to catch a variety of urban or suburban birds and mammals that are attracted to bait.

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

Middleton, Richard S.; Levine, Jonathan S.; Bielicki, Jeffrey M.

CO 2 capture, utilization, and storage (CCUS) technology has yet to be widely deployed at a commercial scale despite multiple high-profile demonstration projects. We suggest that developing a large-scale, visible, and financially viable CCUS network could potentially overcome many barriers to deployment and jumpstart commercial-scale CCUS. To date, substantial effort has focused on technology development to reduce the costs of CO 2 capture from coal-fired power plants. Here, we propose that near-term investment could focus on implementing CO 2 capture on facilities that produce high-value chemicals/products. These facilities can absorb the expected impact of the marginal increase in the costmore » of production on the price of their product, due to the addition of CO 2 capture, more than coal-fired power plants. A financially viable demonstration of a large-scale CCUS network requires offsetting the costs of CO 2 capture by using the CO 2 as an input to the production of market-viable products. As a result, we demonstrate this alternative development path with the example of an integrated CCUS system where CO 2 is captured from ethylene producers and used for enhanced oil recovery in the U.S. Gulf Coast region.« less

Spatial capture-recapture

USGS Publications Warehouse

Royle, J. Andrew; Chandler, Richard B.; Sollmann, Rahel; Gardner, Beth

2013-01-01

Spatial Capture-Recapture provides a revolutionary extension of traditional capture-recapture methods for studying animal populations using data from live trapping, camera trapping, DNA sampling, acoustic sampling, and related field methods. This book is a conceptual and methodological synthesis of spatial capture-recapture modeling. As a comprehensive how-to manual, this reference contains detailed examples of a wide range of relevant spatial capture-recapture models for inference about population size and spatial and temporal variation in demographic parameters. Practicing field biologists studying animal populations will find this book to be a useful resource, as will graduate students and professionals in ecology, conservation biology, and fisheries and wildlife management.

Theoretical and experimental study on fiber-optic displacement sensor with bowknot bending modulation

NASA Astrophysics Data System (ADS)

Zheng, Yong; Huang, Da; Zhu, Zheng-Wei

2018-03-01

A novel and simple fiber-optic sensor for measuring a large displacement range in civil engineering has been developed. The sensor incorporates an extremely simple bowknot bending modulation that increases its sensitivity in bending, light source and detector. In this paper, to better understand the working principle and improve the performance of the sensor, the transduction of displacement to light loss is described analytically by using the geometry of sensor and principle of optical fiber loss. Results of the calibration tests show a logarithmic function relationship between light loss and displacement with two calibrated parameters. The sensor has a response over a wide displacement range of 44.7 mm with an initial accuracy of 2.65 mm, while for a small displacement range of 34 mm it shows a more excellent accuracy of 0.98 mm. The direct shear tests for the six models with the same dimensions were conducted to investigate the application of the sensor for warning the shear and sliding failure in civil engineering materials or geo-materials. Results address that the sliding displacement of sliding body can be relatively accurately captured by the theory logarithmic relation between sliding distance and optical loss in a definite structure, having a large dynamic range of 22.32 mm with an accuracy of 0.99 mm, which suggests that the sensor has a promising prospect in monitoring civil engineering, especially for landslides.

Interacting star clusters in the Large Magellanic Cloud. Overmerging problem solved by cluster group formation

NASA Astrophysics Data System (ADS)

Leon, Stéphane; Bergond, Gilles; Vallenari, Antonella

1999-04-01

We present the tidal tail distributions of a sample of candidate binary clusters located in the bar of the Large Magellanic Cloud (LMC). One isolated cluster, SL 268, is presented in order to study the effect of the LMC tidal field. All the candidate binary clusters show tidal tails, confirming that the pairs are formed by physically linked objects. The stellar mass in the tails covers a large range, from 1.8x 10(3) to 3x 10(4) \\msun. We derive a total mass estimate for SL 268 and SL 356. At large radii, the projected density profiles of SL 268 and SL 356 fall off as r(-gamma ) , with gamma = 2.27 and gamma =3.44, respectively. Out of 4 pairs or multiple systems, 2 are older than the theoretical survival time of binary clusters (going from a few 10(6) years to 10(8) years). A pair shows too large age difference between the components to be consistent with classical theoretical models of binary cluster formation (Fujimoto & Kumai \\cite{fujimoto97}). We refer to this as the ``overmerging'' problem. A different scenario is proposed: the formation proceeds in large molecular complexes giving birth to groups of clusters over a few 10(7) years. In these groups the expected cluster encounter rate is larger, and tidal capture has higher probability. Cluster pairs are not born together through the splitting of the parent cloud, but formed later by tidal capture. For 3 pairs, we tentatively identify the star cluster group (SCG) memberships. The SCG formation, through the recent cluster starburst triggered by the LMC-SMC encounter, in contrast with the quiescent open cluster formation in the Milky Way can be an explanation to the paucity of binary clusters observed in our Galaxy. Based on observations collected at the European Southern Observatory, La Silla, Chile}

Lightning electromagnetic radiation field spectra in the interval from 0.2 to 20 MHz

NASA Technical Reports Server (NTRS)

Willett, J. C.; Bailey, J. C.; Leteinturier, C.; Krider, E. P.

1990-01-01

New Fourier transforms of wideband time-domain electric fields (E) produced by lightning (recorded at the Kennedy Space Center during the summers of 1985 and 1987) were recorded in such a way that several different events in each lightning flash could be captured. Average HF spectral amplitudes for first return strokes, stepped-leader steps, and 'characteristic pulses' are given for significantly more events, at closer ranges, and with better spectral resolution than in previous literature reports. The method of recording gives less bias toward the first large event in the flash and thus yields a large sample of a wide variety of lightning processes. As a result, reliable composite spectral amplitudes are obtained for a number of different processes in cloud-to-ground lightning over the frequency interval from 0.2 to 20 MHz.

A high-throughput microRNA expression profiling system.

PubMed

Guo, Yanwen; Mastriano, Stephen; Lu, Jun

2014-01-01

As small noncoding RNAs, microRNAs (miRNAs) regulate diverse biological functions, including physiological and pathological processes. The expression and deregulation of miRNA levels contain rich information with diagnostic and prognostic relevance and can reflect pharmacological responses. The increasing interest in miRNA-related research demands global miRNA expression profiling on large numbers of samples. We describe here a robust protocol that supports high-throughput sample labeling and detection on hundreds of samples simultaneously. This method employs 96-well-based miRNA capturing from total RNA samples and on-site biochemical reactions, coupled with bead-based detection in 96-well format for hundreds of miRNAs per sample. With low-cost, high-throughput, high detection specificity, and flexibility to profile both small and large numbers of samples, this protocol can be adapted in a wide range of laboratory settings.

Optics and Nonlinear Buckling Mechanics in Large-Area, Highly Stretchable Arrays of Plasmonic Nanostructures.

PubMed

Gao, Li; Zhang, Yihui; Zhang, Hui; Doshay, Sage; Xie, Xu; Luo, Hongying; Shah, Deesha; Shi, Yan; Xu, Siyi; Fang, Hui; Fan, Jonathan A; Nordlander, Peter; Huang, Yonggang; Rogers, John A

2015-06-23

Large-scale, dense arrays of plasmonic nanodisks on low-modulus, high-elongation elastomeric substrates represent a class of tunable optical systems, with reversible ability to shift key optical resonances over a range of nearly 600 nm at near-infrared wavelengths. At the most extreme levels of mechanical deformation (strains >100%), nonlinear buckling processes transform initially planar arrays into three-dimensional configurations, in which the nanodisks rotate out of the plane to form linear arrays with "wavy" geometries. Analytical, finite-element, and finite-difference time-domain models capture not only the physics of these buckling processes, including all of the observed modes, but also the quantitative effects of these deformations on the plasmonic responses. The results have relevance to mechanically tunable optical systems, particularly to soft optical sensors that integrate on or in the human body.

Child Schooling in Ethiopia: The Role of Maternal Autonomy.

PubMed

Gebremedhin, Tesfaye Alemayehu; Mohanty, Itismita

2016-01-01

This paper examines the effects of maternal autonomy on child schooling outcomes in Ethiopia using a nationally representative Ethiopian Demographic and Health survey for 2011. The empirical strategy uses a Hurdle Negative Binomial Regression model to estimate years of schooling. An ordered probit model is also estimated to examine age grade distortion using a trichotomous dependent variable that captures three states of child schooling. The large sample size and the range of questions available in this dataset allow us to explore the influence of individual and household level social, economic and cultural factors on child schooling. The analysis finds statistically significant effects of maternal autonomy variables on child schooling in Ethiopia. The roles of maternal autonomy and other household-level factors on child schooling are important issues in Ethiopia, where health and education outcomes are poor for large segments of the population.

Defining Constellation Suit Helmet Field of View Requirements Employing a Mission Segment Based Reduction Process

NASA Technical Reports Server (NTRS)

McFarland, Shane

2009-01-01

Field of view has always been a design feature paramount to helmets, and in particular space suits, where the helmet must provide an adequate field of view for a large range of activities, environments, and body positions. For Project Constellation, a different approach to helmet requirement maturation was utilized; one that was less a direct function of body position and suit pressure and more a function of the mission segment in which the field of view will be required. Through taxonimization of various parameters that affect suited field of view, as well as consideration for possible nominal and contingency operations during that mission segment, a reduction process was employed to condense the large number of possible outcomes to only six unique field of view angle requirements that still captured all necessary variables while sacrificing minimal fidelity.

Navigating aerial transects with a laptop computer

USGS Publications Warehouse

Anthony, R. Michael; Stehn, R.A.

1994-01-01

SUMMARY: A comparison is made of different methods of determining size of home range from grid trapping data. Studies of artificial populations show that a boundary strip method of measuring area and an adjusted range length give sizes closer to the true range than do minimum area or observed range length methods. In simulated trapping of artificial populations, the known range size increases with successive captures until a level is reached that approximates the true range. The same general pattern is followed whether traps are visited at random or traps nearer the center of the range are favored; but when central traps are favored the curve levels more slowly. Range size is revealed with fewer captures when traps are far apart than when they are close together. The curve levels more slowly for oblong ranges than for circular ranges of the same area. Fewer captures are required to determine range length than to determine range area. Other examples of simulated trapping in artificial populations are used to provide measurements of distances from the center of activity and distances between successive captures. These are compared with similar measurements taken from Peromyscus trapping data. The similarity of range sizes found in certain field comparisons of area trapping, colored scat collections, and trailing is cited. A comparison of home range data obtained by area trapping and nest box studies is discussed. It is shown that when traps are set too far apart to include two or more in the range of each animal, calculation of average range size gives biased results. The smaller ranges are not expressed and cannot be included in the averages. The result is that range estimates are smaller at closer spacings and greater at wider spacings, purely as a result of these erroneous calculations and not reflecting any varying behavior of the animals. The problem of variation in apparent home range with variation in trap spacing is considered further by trapping in an artificial population. It is found that trap spacing can alter the apparent size of range even when biological factors are excluded and trap visiting is random. The desirability of excluding travels outside the normal range from home range calculations is discussed. Effects of varying the trapping plan by setting alternate rows of traps, or setting two traps per site, are discussed briefly.

Reproducibility of combinatorial peptide ligand libraries for proteome capture evaluated by selected reaction monitoring.

PubMed

Di Girolamo, Francesco; Righetti, Pier Giorgio; Soste, Martin; Feng, Yuehan; Picotti, Paola

2013-08-26

Systems biology studies require the capability to quantify with high precision proteins spanning a broad range of abundances across multiple samples. However, the broad range of protein expression in cells often precludes the detection of low-abundance proteins. Different sample processing techniques can be applied to increase proteome coverage. Among these, combinatorial (hexa)peptide ligand libraries (CPLLs) bound to solid matrices have been used to specifically capture and detect low-abundance proteins in complex samples. To assess whether CPLL capture can be applied in systems biology studies involving the precise quantitation of proteins across a multitude of samples, we evaluated its performance across the whole range of protein abundances in Saccharomyces cerevisiae. We used selected reaction monitoring assays for a set of target proteins covering a broad abundance range to quantitatively evaluate the precision of the approach and its capability to detect low-abundance proteins. Replicated CPLL-isolates showed an average variability of ~10% in the amount of the isolated proteins. The high reproducibility of the technique was not dependent on the abundance of the protein or the amount of beads used for the capture. However, the protein-to-bead ratio affected the enrichment of specific proteins. We did not observe a normalization effect of CPLL beads on protein abundances. However, CPLLs enriched for and depleted specific sets of proteins and thus changed the abundances of proteins from a whole proteome extract. This allowed the identification of ~400 proteins otherwise undetected in an untreated sample, under the experimental conditions used. CPLL capture is thus a useful tool to increase protein identifications in proteomic experiments, but it should be coupled to the analysis of untreated samples, to maximize proteome coverage. Our data also confirms that CPLL capture is reproducible and can be confidently used in quantitative proteomic experiments. Combinatorial hexapeptide ligand libraries (CPLLs) bound to solid matrices have been proposed to specifically capture and detect low-abundance proteins in complex samples. To assess whether the CPLL capture can be confidently applied in systems biology studies involving the precise quantitation of proteins across a broad range of abundances and a multitude of samples, we evaluated its reproducibility and performance features. Using selected reaction monitoring assays for proteins covering the whole range of abundances we show that the technique is reproducible and compatible with quantitative proteomic studies. However, the protein-to-bead ratio affects the enrichment of specific proteins and CPLLs depleted specific sets of proteins from a whole proteome extract. Our results suggest that CPLL-based analyses should be coupled to the analysis of untreated samples, to maximize proteome coverage. Overall, our data confirms the applicability of CPLLs in systems biology research and guides the correct use of this technique. Copyright © 2013 Elsevier B.V. All rights reserved.

The intact capture of hypervelocity dust particles using underdense foams

NASA Technical Reports Server (NTRS)

Maag, Carl R.; Borg, J.; Tanner, William G.; Stevenson, T. J.; Bibring, J.-P.

1994-01-01

The impact of a hypervelocity projectile (greater than 3 km/s) is a process that subjects both the impactor and the impacted material to a large transient pressure distribution. The resultant stresses cause a large degree of fragmentation, melting, vaporization, and ionization (for normal densities). The pressure regime magnitude, however, is directly related to the density relationship between the projectile and target materials. As a consequence, a high-density impactor on a low-density target will experience the lowest level of damage. Historically, there have been three different approaches toward achieving the lowest possible target density. The first employs a projectile impinging on a foil or film of moderate density, but whose thickness is much less than the particle diameter. This results in the particle experiencing a pressure transient with both a short duration and a greatly reduced destructive effect. A succession of these films, spaced to allow nondestructive energy dissipation between impacts, will reduce the impactor's kinetic energy without allowing its internal energy to rise to the point where destruction of the projectile mass will occur. An added advantage to this method is that it yields the possibility of regions within the captured particle where a minimum of thermal modification has taken place. Polymer foams have been employed as the primary method of capturing particles with minimum degradation. The manufacture of extremely low bulk density materials is usually achieved by the introduction of voids into the material base. It must be noted, however, that a foam structure only has a true bulk density of the mixture at sizes much larger than the cell size, since for impact processes this is of paramount importance. The scale at which the bulk density must still be close to that of the mixture is approximately equal to the impactor. When this density criterion is met, shock pressures during impact are minimized, which in turn maximizes the probability of survival for the impacting particle. The primary objectives of the experiment are to (1) Examine the morphology of primary and secondary hypervelocity impact craters. Primary attention will be paid to craters caused by ejecta during hypervelocity impacts of different substrates. (2) Determine the size distribution of ejecta by means of witness plates and collect fragments of ejecta from craters by means of momentum-sensitive mcropore foam. (3) Assess the directionality of the flux by means of penetration-hole alignment of thin films placed above the cells. (4) Capture intact the particles that perforated the thin film and entered the cell. Capture media consisted of both previously flight-tested micropore foams and aerogel. The foams had different latent heats of fusion and, accordingly, will capture particles over a range of momenta. Aerogel was incorporated into the cells to determine the minimum diameter than can be captured intact.

Search for neutrinoless double-electron capture of 156Dy

NASA Astrophysics Data System (ADS)

Finch, S. W.; Tornow, W.

2015-12-01

Background: Multiple large collaborations are currently searching for neutrinoless double-β decay, with the ultimate goal of differentiating the Majorana-Dirac nature of the neutrino. Purpose: Investigate the feasibility of resonant neutrinoless double-electron capture, an experimental alternative to neutrinoless double-β decay. Method: Two clover germanium detectors were operated underground in coincidence to search for the de-excitation γ rays of 156Gd following the neutrinoless double-electron capture of 156Dy. 231.95 d of data were collected at the Kimballton underground research facility with a 231.57 mg enriched 156Dy sample. Results: No counts were seen above background and half-life limits are set at O (1016-1018) yr for the various decay modes of 156Dy. Conclusion: Low background spectra were efficiently collected in the search for neutrinoless double-electron capture of 156Dy, although the low natural abundance and associated lack of large quantities of enriched samples hinders the experimental reach.

Measurement of gamma-ray production from thermal neutron capture on gadolinium for neutrino experiments

NASA Astrophysics Data System (ADS)

Yano, Takatomi; 2012B0025 Collaboration; 2014B0126 Collaboration

2017-02-01

Recently, several scientific applications of gadolinium are found in neutrino physics experiments. Gadolinium-157 is the nucleus, which has the largest thermal neutron capture cross-section among all stable nuclei. Gadolinium-155 also has the large cross-section. These neutron capture reactions provide the gamma-ray cascade with the total energy of about 8 MeV. This reaction is applied for several neutrino experiments, e.g. reactor neutrino experiments and Gd doped large water Cherenkov detector experiments, to recognize inverse-beta-decay reaction. A good Gd(n,γ) simulation model is needed to evaluate the detection efficiency of the neutron capture reaction, i.e. the efficiency of IBD detection. In this presentation, we will report the development and study status of a Gd(n,γ) calculation model and comparison with our experimental data taken at ANNRI/MLF beam line, J-PARC.

On the dependence on inclination of capture probability of short-period comets

NASA Astrophysics Data System (ADS)

Yabushita, S.; Tsujii, T.

1990-06-01

Calculation is made of probability of capture whereby a nearly parabolic comet with perihelion near the Jovian orbit comes to have a perihelion distance less than 2.5 AU and a period less than 200 yr. The probability is found to depend strongly on the inclination, in accordance with earlier results of Everhart and of Stagg and Bailey. It is large for orbits close to the ecliptic but decreases drastically for large inclinations. The overall probability of capture from randomly distributed orbits is 0.00044, which shows that either the presently observed short-period comets are not in a steady state or the source flux may be in the Uranus-Neptune zone.

Large scale genomic reorganization of topological domains at the HoxD locus.

PubMed

Fabre, Pierre J; Leleu, Marion; Mormann, Benjamin H; Lopez-Delisle, Lucille; Noordermeer, Daan; Beccari, Leonardo; Duboule, Denis

2017-08-07

The transcriptional activation of HoxD genes during mammalian limb development involves dynamic interactions with two topologically associating domains (TADs) flanking the HoxD cluster. In particular, the activation of the most posterior HoxD genes in developing digits is controlled by regulatory elements located in the centromeric TAD (C-DOM) through long-range contacts. To assess the structure-function relationships underlying such interactions, we measured compaction levels and TAD discreteness using a combination of chromosome conformation capture (4C-seq) and DNA FISH. We assessed the robustness of the TAD architecture by using a series of genomic deletions and inversions that impact the integrity of this chromatin domain and that remodel long-range contacts. We report multi-partite associations between HoxD genes and up to three enhancers. We find that the loss of native chromatin topology leads to the remodeling of TAD structure following distinct parameters. Our results reveal that the recomposition of TAD architectures after large genomic re-arrangements is dependent on a boundary-selection mechanism in which CTCF mediates the gating of long-range contacts in combination with genomic distance and sequence specificity. Accordingly, the building of a recomposed TAD at this locus depends on distinct functional and constitutive parameters.

Estimating abundance of mountain lions from unstructured spatial sampling

USGS Publications Warehouse

Russell, Robin E.; Royle, J. Andrew; Desimone, Richard; Schwartz, Michael K.; Edwards, Victoria L.; Pilgrim, Kristy P.; Mckelvey, Kevin S.

2012-01-01

Mountain lions (Puma concolor) are often difficult to monitor because of their low capture probabilities, extensive movements, and large territories. Methods for estimating the abundance of this species are needed to assess population status, determine harvest levels, evaluate the impacts of management actions on populations, and derive conservation and management strategies. Traditional mark–recapture methods do not explicitly account for differences in individual capture probabilities due to the spatial distribution of individuals in relation to survey effort (or trap locations). However, recent advances in the analysis of capture–recapture data have produced methods estimating abundance and density of animals from spatially explicit capture–recapture data that account for heterogeneity in capture probabilities due to the spatial organization of individuals and traps. We adapt recently developed spatial capture–recapture models to estimate density and abundance of mountain lions in western Montana. Volunteers and state agency personnel collected mountain lion DNA samples in portions of the Blackfoot drainage (7,908 km2) in west-central Montana using 2 methods: snow back-tracking mountain lion tracks to collect hair samples and biopsy darting treed mountain lions to obtain tissue samples. Overall, we recorded 72 individual capture events, including captures both with and without tissue sample collection and hair samples resulting in the identification of 50 individual mountain lions (30 females, 19 males, and 1 unknown sex individual). We estimated lion densities from 8 models containing effects of distance, sex, and survey effort on detection probability. Our population density estimates ranged from a minimum of 3.7 mountain lions/100 km2 (95% Cl 2.3–5.7) under the distance only model (including only an effect of distance on detection probability) to 6.7 (95% Cl 3.1–11.0) under the full model (including effects of distance, sex, survey effort, and distance x sex on detection probability). These numbers translate to a total estimate of 293 mountain lions (95% Cl 182–451) to 529 (95% Cl 245–870) within the Blackfoot drainage. Results from the distance model are similar to previous estimates of 3.6 mountain lions/100 km2 for the study area; however, results from all other models indicated greater numbers of mountain lions. Our results indicate that unstructured spatial sampling combined with spatial capture–recapture analysis can be an effective method for estimating large carnivore densities.

Assessment of Solid Sorbent Systems for Post-Combustion Carbon Dioxide Capture at Coal-Fired Power Plants

NASA Astrophysics Data System (ADS)

Glier, Justin C.

In an effort to lower future CO2 emissions, a wide range of technologies are being developed to scrub CO2 from the flue gases of fossil fuel-based electric power and industrial plants. This thesis models one of several early-stage post-combustion CO2 capture technologies, solid sorbent-based CO2 capture process, and presents performance and cost estimates of this system on pulverized coal power plants. The spreadsheet-based software package Microsoft Excel was used in conjunction with AspenPlus modelling results and the Integrated Environmental Control Model to develop performance and cost estimates for the solid sorbent-based CO2 capture technology. A reduced order model also was created to facilitate comparisons among multiple design scenarios. Assumptions about plant financing and utilization, as well as uncertainties in heat transfer and material design that affect heat exchanger and reactor design were found to produce a wide range of cost estimates for solid sorbent-based systems. With uncertainties included, costs for a supercritical power plant with solid sorbent-based CO2 capture ranged from 167 to 533 per megawatt hour for a first-of-a-kind installation (with all costs in constant 2011 US dollars) based on a 90% confidence interval. The median cost was 209/MWh. Post-combustion solid sorbent-based CO2 capture technology is then evaluated in terms of the potential cost for a mature system based on historic experience as technologies are improved with sequential iterations of the currently available system. The range costs for a supercritical power plant with solid sorbent-based CO2 capture was found to be 118 to 189 per megawatt hour with a nominal value of 163 per megawatt hour given the expected range of technological improvement in the capital and operating costs and efficiency of the power plant after 100 GW of cumulative worldwide experience. These results suggest that the solid sorbent-based system will not be competitive with currently available liquid amine-systems in the absence of significant new improvements in solid sorbent properties and process system design to reduce the heat exchange surface area in the regenerator and cross-flow heat exchanger. Finally, the importance of these estimates for policy makers is discussed.

Otorhinolaryngological aspects of sleep-related breathing disorders

PubMed Central

Virk, Jagdeep S.

2016-01-01

Snoring and obstructive sleep apnoea (OSA) are disorders within a wide spectrum of sleep-related breathing disorders (SRBD). Given the obesity epidemic, these conditions will become increasingly prevalent and continue to serve as a large economic burden. A thorough clinical evaluation and appropriate investigations will allow stratification of patients into appropriate treatment groups. A multidisciplinary team is required to manage these patients. Patient selection is critical in ensuring successful surgical and non-surgical outcomes. A wide range of options are available and further long term prospective studies, with standardised data capture and outcome goals, are required to evaluate the most appropriate techniques and long term success rates. PMID:26904262

Technologies and Concepts for Reducing the Fuel Burn of Subsonic Transport Aircraft

NASA Technical Reports Server (NTRS)

Nickol, Craig L.

2012-01-01

There are many technologies under development that have the potential to enable large fuel burn reductions in the 2025 timeframe for subsonic transport aircraft relative to the current fleet. This paper identifies a potential technology suite and analyzes the fuel burn reduction potential of these technologies when integrated into advanced subsonic transport concepts. Advanced tube-and-wing concepts are developed in the single aisle and large twin aisle class, and a hybrid-wing-body concept is developed for the large twin aisle class. The resulting fuel burn reductions for the advanced tube-and-wing concepts range from a 42% reduction relative to the 777-200 to a 44% reduction relative to the 737-800. In addition, the hybrid-wingbody design resulted in a 47% fuel burn reduction relative to the 777-200. Of course, to achieve these fuel burn reduction levels, a significant amount of technology and concept maturation is required between now and 2025. A methodology for capturing and tracking concept maturity is also developed and presented in this paper.

Transmission Geometry Laser Ablation into a Non-Contact Liquid Vortex Capture Probe for Mass Spectrometry Imaging

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

Ovchinnikova, Olga S; Bhandari, Deepak; Lorenz, Matthias

2014-01-01

RATIONALE: Capture of material from a laser ablation plume into a continuous flow stream of solvent provides the means for uninterrupted sampling, transport and ionization of collected material for coupling with mass spectral analysis. Reported here is the use of vertically aligned transmission geometry laser ablation in combination with a new non-contact liquid vortex capture probe coupled with electrospray ionization for spot sampling and chemical imaging with mass spectrometry. Methods: A vertically aligned continuous flow liquid vortex capture probe was positioned directly underneath a sample surface in a transmission geometry laser ablation (355 nm, 10 Hz, 7 ns pulse width)more » setup to capture into solution the ablated material. The outlet of the vortex probe was coupled to the Turbo V ion source of an AB SCIEX TripleTOF 5600+ mass spectrometer. System operation and performance metrics were tested using inked patterns and thin tissue sections. Glass slides and slides designed especially for laser capture microdissection, viz., DIRECTOR slides and PEN 1.0 (polyethylene naphthalate) membrane slides, were used as sample substrates. Results: The estimated capture efficiency of laser ablated material was 24%, which was enabled by the use of a probe with large liquid surface area (~ 2.8 mm2) and with gravity to help direct ablated material vertically down towards the probe. The swirling vortex action of the liquid surface potentially enhanced capture and dissolution of not only particulates, but also gaseous products of the laser ablation. The use of DIRECTOR slides and PEN 1.0 (polyethylene naphthalate) membrane slides as sample substrates enabled effective ablation of a wide range of sample types (basic blue 7, polypropylene glycol, insulin and cyctochrome c) without photodamage using a UV laser. Imaging resolution of about 6 m was demonstrated for stamped ink on DIRECTOR slides based on the ability to distinguish features present both in the optical and in the chemical image. This imaging resolution was 20 times better than the previous best reported results with laser ablation/liquid sample capture mass spectrometry imaging. Using thin sections of brain tissue the chemical image of a selected lipid was obtained with an estimated imaging resolution of about 50 um. Conclusions: A vertically aligned, transmission geometry laser ablation liquid vortex capture probe, electrospray ionization mass spectrometry system provides an effective means for spatially resolved spot sampling and imaging with mass spectrometry.« less

Transmission geometry laser ablation into a non-contact liquid vortex capture probe for mass spectrometry imaging.

PubMed

Ovchinnikova, Olga S; Bhandari, Deepak; Lorenz, Matthias; Van Berkel, Gary J

2014-08-15

Capture of material from a laser ablation plume into a continuous flow stream of solvent provides the means for uninterrupted sampling, transport and ionization of collected material for coupling with mass spectral analysis. Reported here is the use of vertically aligned transmission geometry laser ablation in combination with a new non-contact liquid vortex capture probe coupled with electrospray ionization for spot sampling and chemical imaging with mass spectrometry. A vertically aligned continuous flow liquid vortex capture probe was positioned directly underneath a sample surface in a transmission geometry laser ablation (355 nm, 10 Hz, 7 ns pulse width) set up to capture into solution the ablated material. The outlet of the vortex probe was coupled to the Turbo V™ ion source of an AB SCIEX TripleTOF 5600+ mass spectrometer. System operation and performance metrics were tested using inked patterns and thin tissue sections. Glass slides and slides designed especially for laser capture microdissection, viz., DIRECTOR(®) slides and PEN 1.0 (polyethylene naphthalate) membrane slides, were used as sample substrates. The estimated capture efficiency of laser-ablated material was 24%, which was enabled by the use of a probe with large liquid surface area (~2.8 mm(2) ) and with gravity to help direct ablated material vertically down towards the probe. The swirling vortex action of the liquid surface potentially enhanced capture and dissolution not only of particulates, but also of gaseous products of the laser ablation. The use of DIRECTOR(®) slides and PEN 1.0 (polyethylene naphthalate) membrane slides as sample substrates enabled effective ablation of a wide range of sample types (basic blue 7, polypropylene glycol, insulin and cyctochrome c) without photodamage using a UV laser. Imaging resolution of about 6 µm was demonstrated for stamped ink on DIRECTOR(®) slides based on the ability to distinguish features present both in the optical and in the chemical image. This imaging resolution was 20 times better than the previous best reported results with laser ablation/liquid sample capture mass spectrometry imaging. Using thin sections of brain tissue the chemical image of a selected lipid was obtained with an estimated imaging resolution of about 50 µm. A vertically aligned, transmission geometry laser ablation liquid vortex capture probe, electrospray ionization mass spectrometry system provides an effective means for spatially resolved spot sampling and imaging with mass spectrometry. Published in 2014. This article is a U.S. Government work and is in the public domain in the USA.

Catch of channel catfish with tandem-set hoop nets and gill nets in lentic systems of Nebraska

USGS Publications Warehouse

Richters, Lindsey K.; Pope, Kevin L.

2011-01-01

Twenty-six Nebraska water bodies representing two ecosystem types (small standing waters and large standing waters) were surveyed during 2008 and 2009 with tandem-set hoop nets and experimental gill nets to determine if similar trends existed in catch rates and size structures of channel catfish Ictalurus punctatus captured with these gears. Gear efficiency was assessed as the number of sets (nets) that would be required to capture 100 channel catfish given observed catch per unit effort (CPUE). Efficiency of gill nets was not correlated with efficiency of hoop nets for capturing channel catfish. Small sample sizes prohibited estimation of proportional size distributions in most surveys; in the four surveys for which sample size was sufficient to quantify length-frequency distributions of captured channel catfish, distributions differed between gears. The CPUE of channel catfish did not differ between small and large water bodies for either gear. While catch rates of hoop nets were lower than rates recorded in previous studies, this gear was more efficient than gill nets at capturing channel catfish. However, comparisons of size structure between gears may be problematic.

Range expansion of the Mayan cichlid, cichlasoma urophthalmus (pisces, cichlidae), above 28°N in Florida

USGS Publications Warehouse

Paperno, R.; Ruiz-Carus, R.; Krebs, J.M.; McIvor, C.C.

2008-01-01

Introduced exotic species are a well-recognized problem in Florida's subtropical ecosystems. The presence of the exotic Mayan cichlid (Cichlasoma urophthalmus) was first confirmed in Florida in 1983, when numerous individuals were found in the northeastern Florida Bay. Since then, this species has continued to expand its range northward. The capture, beginning in October 2004 to present, of large numbers of Mayan cichlids from central Florida's east- and west-coast mangrove systems north of 28°N latitude is documented here. Mayan cichlids in a wide range of sizes (estimated ages 0-7 years) at both east- and west-coast sites were collected. In addition, macroscopic examination of gonads showed the presence of developing eggs. The occurrence of multiple age-classes, maturing individuals, cichlid nests, and juveniles, plus repeated collections over a four-year period, indicates that the Mayan cichlid is successfully reproducing and surviving the average winter temperatures in some estuarine waters in central Florida.

Predicting commuter flows in spatial networks using a radiation model based on temporal ranges

NASA Astrophysics Data System (ADS)

Ren, Yihui; Ercsey-Ravasz, Mária; Wang, Pu; González, Marta C.; Toroczkai, Zoltán

2014-11-01

Understanding network flows such as commuter traffic in large transportation networks is an ongoing challenge due to the complex nature of the transportation infrastructure and human mobility. Here we show a first-principles based method for traffic prediction using a cost-based generalization of the radiation model for human mobility, coupled with a cost-minimizing algorithm for efficient distribution of the mobility fluxes through the network. Using US census and highway traffic data, we show that traffic can efficiently and accurately be computed from a range-limited, network betweenness type calculation. The model based on travel time costs captures the log-normal distribution of the traffic and attains a high Pearson correlation coefficient (0.75) when compared with real traffic. Because of its principled nature, this method can inform many applications related to human mobility driven flows in spatial networks, ranging from transportation, through urban planning to mitigation of the effects of catastrophic events.

Global carbon management using air capture and geosequestration at remote locations

NASA Astrophysics Data System (ADS)

Lackner, K. S.; Goldberg, D.

2014-12-01

CO2 emissions need not only stop; according the IPCC, emissions need to turn negative. This requires means to remove CO2 from air and store it safely and permanently. We outline a combination of secure geosequestration and direct capture of CO2 from ambient air to create negative emissions at remote locations. Operation at remote sites avoids many difficulties associated with capture at the source, where space for added equipment is limited, good storage sites are in short supply, and proximity to private property engenders resistance. Large Igneous Provinces have been tested as secure CO2 reservoirs. CO2 and water react with reservoir rock to form stable carbonates, permanently sequestering the carbon. Outfitting reservoirs in large igneous provinces far from human habitation with ambient air capture systems creates large CO2 sequestration sites. Their remoteness offers advantages in environmental security and public acceptance and, thus, can smooth the path toward CO2 stabilization. Direct capture of CO2 from ambient air appears energetically and economically viable and could be scaled up quickly. Thermodynamic energy requirements are very small and a number of approaches have shown to be energy efficient in practice. Sorbent technologies include supported organoamines, alkaline brines, and quaternary ammonium based ion-exchange resins. To demonstrate that the stated goals of low cost and low energy consumption can be reached at scale, public research and demonstration projects are essential. We suggest co-locating air capture and geosequestration at sites where renewable energy resources can power both activities. Ready renewable energy would also allow for the co-production of synthetic fuels. Possible locations with large wind and basalt resources include Iceland and Greenland, the north-western United States, the Kerguelen plateau, Siberia and Morocco. Capture and sequestration in these reservoirs could recover all of the emissions of the 20th century and still contribute to a carbon neutral economy throughout the 21st century. Mobilizing industrial infrastructure to these areas poses a challenge. However, the urgency of the climate problem requires immediate action, with economic incentives and commitments to site evaluation and engineering development.

Application of a High-Throughput Analyzer in Evaluating Solid Adsorbents for Post-Combustion Carbon Capture via Multicomponent Adsorption of CO2, N-2, and H2O

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

Mason, JA; McDonald, TM; Bae, TH

Despite the large number of metal-organic frameworks that have been studied in the context of post-combustion carbon capture, adsorption equilibria of gas mixtures including CO2, N-2, and H2O, which are the three biggest components of the flue gas emanating from a coal- or natural gas-fired power plant, have never been reported. Here, we disclose the design and validation of a high-throughput multicomponent adsorption instrument that can measure equilibrium adsorption isotherms for mixtures of gases at conditions that are representative of an actual flue gas from a power plant. This instrument is used to study 15 different metal-organic frameworks, zeolites, mesoporousmore » silicas, and activated carbons representative of the broad range of solid adsorbents that have received attention for CO2 capture. While the multicomponent results presented in this work provide many interesting fundamental insights, only adsorbents functionalized with alkylamines are shown to have any significant CO2 capacity in the presence of N-2 and H2O at equilibrium partial pressures similar to those expected in a carbon capture process. Most significantly, the amine-appended metal organic framework mmen-Mg-2(dobpdc) (mmen = N,N'-dimethylethylenediamine, dobpdc (4-) = 4,4'-dioxido-3,3'-biphenyldicarboxylate) exhibits a record CO2 capacity of 4.2 +/- 0.2 mmol/g (16 wt %) at 0.1 bar and 40 degrees C in the presence of a high partial pressure of H2O.« less

Application of a high-throughput analyzer in evaluating solid adsorbents for post-combustion carbon capture via multicomponent adsorption of CO2, N2, and H2O.

PubMed

Mason, Jarad A; McDonald, Thomas M; Bae, Tae-Hyun; Bachman, Jonathan E; Sumida, Kenji; Dutton, Justin J; Kaye, Steven S; Long, Jeffrey R

2015-04-15

Despite the large number of metal-organic frameworks that have been studied in the context of post-combustion carbon capture, adsorption equilibria of gas mixtures including CO2, N2, and H2O, which are the three biggest components of the flue gas emanating from a coal- or natural gas-fired power plant, have never been reported. Here, we disclose the design and validation of a high-throughput multicomponent adsorption instrument that can measure equilibrium adsorption isotherms for mixtures of gases at conditions that are representative of an actual flue gas from a power plant. This instrument is used to study 15 different metal-organic frameworks, zeolites, mesoporous silicas, and activated carbons representative of the broad range of solid adsorbents that have received attention for CO2 capture. While the multicomponent results presented in this work provide many interesting fundamental insights, only adsorbents functionalized with alkylamines are shown to have any significant CO2 capacity in the presence of N2 and H2O at equilibrium partial pressures similar to those expected in a carbon capture process. Most significantly, the amine-appended metal organic framework mmen-Mg2(dobpdc) (mmen = N,N'-dimethylethylenediamine, dobpdc (4-) = 4,4'-dioxido-3,3'-biphenyldicarboxylate) exhibits a record CO2 capacity of 4.2 ± 0.2 mmol/g (16 wt %) at 0.1 bar and 40 °C in the presence of a high partial pressure of H2O.

Early opportunities of CO2 geological storage deployment in coal chemical industry in China

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

Wei, Ning; Li, Xiaochun; Liu, Shengnan

2014-11-12

Abstract: Carbon dioxide capture and geological storage (CCS) is regarded as a promising option for climate change mitigation; however, the high capture cost is the major barrier to large-scale deployment of CCS technologies. High-purity CO2 emission sources can reduce or even avoid the capture requirements and costs. Among these high-purity CO2 sources, certain coal chemical industry processes are very important, especially in China. In this paper, the basic characteristics of coal chemical industries in China is investigated and analyzed. As of 2013 there were more than 100 coal chemical plants in operation or in late planning stages. These emission sourcesmore » together emit 430 million tons CO2 per year, of which about 30% are emit high-purity and pure CO2 (CO2 concentration >80% and >99% respectively).Four typical source-sink pairs are studied by a techno-economic evaluation, including site screening and selection, source-sink matching, concept design, and experienced economic evaluation. The technical-economic evaluation shows that the levelized cost of a CO2 capture and aquifer storage project in the coal chemistry industry ranges from 14 USD/t to 17 USD/t CO2. When a 15USD/t CO2 tax and 15USD/t for CO2 sold to EOR are considered, the levelized cost of CCS project are negative, which suggests a net economic benefit from some of these CCS projects. This might provide China early opportunities to deploy and scale-up CCS projects in the near future.« less

Pulling out the 1%: Whole-Genome Capture for the Targeted Enrichment of Ancient DNA Sequencing Libraries

PubMed Central

Carpenter, Meredith L.; Buenrostro, Jason D.; Valdiosera, Cristina; Schroeder, Hannes; Allentoft, Morten E.; Sikora, Martin; Rasmussen, Morten; Gravel, Simon; Guillén, Sonia; Nekhrizov, Georgi; Leshtakov, Krasimir; Dimitrova, Diana; Theodossiev, Nikola; Pettener, Davide; Luiselli, Donata; Sandoval, Karla; Moreno-Estrada, Andrés; Li, Yingrui; Wang, Jun; Gilbert, M. Thomas P.; Willerslev, Eske; Greenleaf, William J.; Bustamante, Carlos D.

2013-01-01

Most ancient specimens contain very low levels of endogenous DNA, precluding the shotgun sequencing of many interesting samples because of cost. Ancient DNA (aDNA) libraries often contain <1% endogenous DNA, with the majority of sequencing capacity taken up by environmental DNA. Here we present a capture-based method for enriching the endogenous component of aDNA sequencing libraries. By using biotinylated RNA baits transcribed from genomic DNA libraries, we are able to capture DNA fragments from across the human genome. We demonstrate this method on libraries created from four Iron Age and Bronze Age human teeth from Bulgaria, as well as bone samples from seven Peruvian mummies and a Bronze Age hair sample from Denmark. Prior to capture, shotgun sequencing of these libraries yielded an average of 1.2% of reads mapping to the human genome (including duplicates). After capture, this fraction increased substantially, with up to 59% of reads mapped to human and enrichment ranging from 6- to 159-fold. Furthermore, we maintained coverage of the majority of regions sequenced in the precapture library. Intersection with the 1000 Genomes Project reference panel yielded an average of 50,723 SNPs (range 3,062–147,243) for the postcapture libraries sequenced with 1 million reads, compared with 13,280 SNPs (range 217–73,266) for the precapture libraries, increasing resolution in population genetic analyses. Our whole-genome capture approach makes it less costly to sequence aDNA from specimens containing very low levels of endogenous DNA, enabling the analysis of larger numbers of samples. PMID:24568772

The weaker effects of First-order mean motion resonances in intermediate inclinations

NASA Astrophysics Data System (ADS)

Chen, YuanYuan; Quillen, Alice C.; Ma, Yuehua; Chinese Scholar Council, the National Natural Science Foundation of China, the Natural Science Foundation of Jiangsu Province, the Minor Planet Foundation of the Purple Mountain Observatory

2017-10-01

During planetary migration, a planet or planetesimal can be captured into a low-order mean motion resonance with another planet. Using a second-order expansion of the disturbing function in eccentricity and inclination, we explore the sensitivity of the capture probability of first-order mean motion resonances to orbital inclination. We find that second-order inclination contributions affect the resonance strengths, reducing them at intermediate inclinations of around 10-40° for major first-order resonances. We also integrated the Hamilton's equations with arbitrary initial arguments, and provided the varying tendencies of resonance capture probabilities versus orbital inclinations for different resonances and different particle or planetary eccentricities. Resonance-weaker ranges in inclinations generally appear at the places where resonance strengths are low, around 10-40° in general. The weaker ranges disappear with a higher particle eccentricity (≳0.05) or planetary eccentricity (≳0.05). These resonance-weaker ranges in inclinations implies that intermediate-inclination objects are less likely to be disturbed or captured into the first-order resonances, which would make them entering into the chaotic area around Neptune with a larger fraction than those with low inclinations, during the epoch of Neptune's outward migration. The privilege of high-inclination particles leave them to be more likely captured into Neptune Trojans, which might be responsible for the unexpected high fraction of high-inclination Neptune Trojans.

Affinity+: Semi-Structured Brainstorming on Large Displays

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

Burtner, Edwin R.; May, Richard A.; Scarberry, Randall E.

2013-04-27

Affinity diagraming is a powerful method for encouraging and capturing lateral thinking in a group environment. The Affinity+ Concept was designed to improve the collaborative brainstorm process through the use of large display surfaces in conjunction with mobile devices like smart phones and tablets. The system works by capturing the ideas digitally and allowing users to sort and group them on a large touch screen manually. Additionally, Affinity+ incorporates theme detection, topic clustering, and other processing algorithms that help bring structured analytic techniques to the process without requiring explicit leadership roles and other overhead typically involved in these activities.

SO 2-Resistant Immobilized Amine Sorbents for CO 2 Capture

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

Tumuluri, Uma

2014-01-01

The solid amine sorbent for CO 2 capture process has advantages of simplicity and low operating cost compared to the MEA (monoethanolamine) process. Solid amine sorbents reported so far suffered from either low CO 2 capture capacity or low stability in the flue gas environment. This project is aimed at developing a SO 2-resistant solid amine sorbent for capturing CO 2 from coal–fired power plants with SCR/FGD which emits SO 2ranging from 15 to 30 ppm and NO ranging from 5 to 10 ppm. The amine sorbent we developed in a previous project degraded rapidly with 65% decrease in themore » initial capture capacity in presence of 1% SO 2. This amine sorbent was further modified by coating with polyethyleneglycol (PEG) to increase the SO 2-resistance. Polyethylene glycol (PEG) was found to decrease the SO 2-amine interaction, resulting in the decrease in the maximum SO desorption temperature (Tmax ) of amine sorbent. The PEG-coated amine sorbent exhibited higher stability with only 40% decrease in the initial capture capacity compared to un-coated amine sorbents. The cost of the solid amine sorbent developed in this project is estimated to be less than $7.00/lb; the sorbent exhibited CO 2 capture capacity more than 2.3 mmol/g. The results of this study provided the scientific basis for further development of SO 2-resistant sorbents.« less

Comparison of magnetic resonance imaging-compatible optical detectors for in-magnet tissue spectroscopy: photodiodes versus silicon photomultipliers

PubMed Central

El-Ghussein, Fadi; Jiang, Shudong; Pogue, Brian W.; Paulsen, Keith D.

2014-01-01

Abstract. Tissue spectroscopy inside the magnetic resonance imaging (MRI) system adds a significant value by measuring fast vascular hemoglobin responses or completing spectroscopic identification of diagnostically relevant molecules. Advances in this type of spectroscopy instrumentation have largely focused on fiber coupling into and out of the MRI; however, nonmagnetic detectors can now be placed inside the scanner with signal amplification performed remotely to the high field environment for optimized light detection. In this study, the two possible detector options, such as silicon photodiodes (PD) and silicon photomultipliers (SiPM), were systematically examined for dynamic range and wavelength performance. Results show that PDs offer 108 (160 dB) dynamic range with sensitivity down to 1 pW, whereas SiPMs have 107 (140 dB) dynamic range and sensitivity down to 10 pW. A second major difference is the spectral sensitivity of the two detectors. Here, wavelengths in the 940 nm range are efficiently captured by PDs (but not SiPMs), likely making them the superior choice for broadband spectroscopy guided by MRI. PMID:25006986

A reduced basis method for molecular dynamics simulation

NASA Astrophysics Data System (ADS)

Vincent-Finley, Rachel Elisabeth

In this dissertation, we develop a method for molecular simulation based on principal component analysis (PCA) of a molecular dynamics trajectory and least squares approximation of a potential energy function. Molecular dynamics (MD) simulation is a computational tool used to study molecular systems as they evolve through time. With respect to protein dynamics, local motions, such as bond stretching, occur within femtoseconds, while rigid body and large-scale motions, occur within a range of nanoseconds to seconds. To capture motion at all levels, time steps on the order of a femtosecond are employed when solving the equations of motion and simulations must continue long enough to capture the desired large-scale motion. To date, simulations of solvated proteins on the order of nanoseconds have been reported. It is typically the case that simulations of a few nanoseconds do not provide adequate information for the study of large-scale motions. Thus, the development of techniques that allow longer simulation times can advance the study of protein function and dynamics. In this dissertation we use principal component analysis (PCA) to identify the dominant characteristics of an MD trajectory and to represent the coordinates with respect to these characteristics. We augment PCA with an updating scheme based on a reduced representation of a molecule and consider equations of motion with respect to the reduced representation. We apply our method to butane and BPTI and compare the results to standard MD simulations of these molecules. Our results indicate that the molecular activity with respect to our simulation method is analogous to that observed in the standard MD simulation with simulations on the order of picoseconds.

Designing large-scale conservation corridors for pattern and process.

PubMed

Rouget, Mathieu; Cowling, Richard M; Lombard, Amanda T; Knight, Andrew T; Kerley, Graham I H

2006-04-01

A major challenge for conservation assessments is to identify priority areas that incorporate biological patterns and processes. Because large-scale processes are mostly oriented along environmental gradients, we propose to accommodate them by designing regional-scale corridors to capture these gradients. Based on systematic conservation planning principles such as representation and persistence, we identified large tracts of untransformed land (i.e., conservation corridors) for conservation that would achieve biodiversity targets for pattern and process in the Subtropical Thicket Biome of South Africa. We combined least-cost path analysis with a target-driven algorithm to identify the best option for capturing key environmental gradients while considering biodiversity targets and conservation opportunities and constraints. We identified seven conservation corridors on the basis of subtropical thicket representation, habitat transformation and degradation, wildlife suitability, irreplaceability of vegetation types, protected area networks, and future land-use pressures. These conservation corridors covered 21.1% of the planning region (ranging from 600 to 5200 km2) and successfully achieved targets for biological processes and to a lesser extent for vegetation types. The corridors we identified are intended to promote the persistence of ecological processes (gradients and fixed processes) and fulfill half of the biodiversity pattern target. We compared the conservation corridors with a simplified corridor design consisting of a fixed-width buffer along major rivers. Conservation corridors outperformed river buffers in seven out of eight criteria. Our corridor design can provide a tool for quantifying trade-offs between various criteria (biodiversity pattern and process, implementation constraints and opportunities). A land-use management model was developed to facilitate implementation of conservation actions within these corridors.

Mercury in Pacific bluefin tuna (Thunnus orientalis):bioaccumulation and trans-Pacific Ocean migration

USGS Publications Warehouse

Colman, John A.; Nogueira, Jacob I.; Pancorbo, Oscar C.; Batdorf, Carol A.; Block, Barbara A.

2015-01-01

Pacific bluefin tuna (Thunnus orientalis) have the largest home range of any tuna species and are well known for the capacity to make transoceanic migrations. We report the measurement of mercury (Hg) concentrations in wild Pacific bluefin tuna (PBFT), the first reported with known size-of-fish and capture location. The results indicate juvenile PBFT that are recently arrived in the California Current from the western Pacific Ocean have significantly higher Hg concentrations in white muscle (0.51 ug/g wet mass, wm) than PBFT of longer California Current residency (0.41 ug/g wm). These new arrivals are also higher in Hg concentration than PBFT in farm pens (0.43 ug/g wm) that were captured on arrival in the California Current and raised in pens on locally derived feed. Analysis by direct Hg analyzer and attention to Hg by tissue type and location on the fish allowed precise comparisons of mercury among wild and captive fish populations. Analysis of migration and nearshore residency, determined through extensive archival tagging, bioaccumulation models, trophic investigations, and potential coastal sources of methylmercury, indicates Hg bioaccumulation is likely greater for PBFT juvenile habitats in the western Pacific Ocean (East China Sea, Yellow Sea) than in the eastern Pacific Ocean (California Current). Differential bioaccumulation may be a trophic effect or reflect methylmercury availability, with potential sources for coastal China (large hypoxic continental shelf receiving discharge of three large rivers, and island-arc volcanism) different from those for coastal Baja California (small continental shelf, no large rivers, spreading-center volcanism).

Comparison of Hi-C results using in-solution versus in-nucleus ligation.

PubMed

Nagano, Takashi; Várnai, Csilla; Schoenfelder, Stefan; Javierre, Biola-Maria; Wingett, Steven W; Fraser, Peter

2015-08-26

Chromosome conformation capture and various derivative methods such as 4C, 5C and Hi-C have emerged as standard tools to analyze the three-dimensional organization of the genome in the nucleus. These methods employ ligation of diluted cross-linked chromatin complexes, intended to favor proximity-dependent, intra-complex ligation. During development of single-cell Hi-C, we devised an alternative Hi-C protocol with ligation in preserved nuclei rather than in solution. Here we directly compare Hi-C methods employing in-nucleus ligation with the standard in-solution ligation. We show in-nucleus ligation results in consistently lower levels of inter-chromosomal contacts. Through chromatin mixing experiments we show that a significantly large fraction of inter-chromosomal contacts are the result of spurious ligation events formed during in-solution ligation. In-nucleus ligation significantly reduces this source of experimental noise, and results in improved reproducibility between replicates. We also find that in-nucleus ligation eliminates restriction fragment length bias found with in-solution ligation. These improvements result in greater reproducibility of long-range intra-chromosomal and inter-chromosomal contacts, as well as enhanced detection of structural features such as topologically associated domain boundaries. We conclude that in-nucleus ligation captures chromatin interactions more consistently over a wider range of distances, and significantly reduces both experimental noise and bias. In-nucleus ligation creates higher quality Hi-C libraries while simplifying the experimental procedure. We suggest that the entire range of 3C applications are likely to show similar benefits from in-nucleus ligation.

Effects of chemical immobilization on survival of African buffalo in the Kruger National Park

USGS Publications Warehouse

Oosthuizen, W.C.; Cross, P.C.; Bowers, J.A.; Hay, C.; Ebinger, M.R.; Buss, P.; Hofmeyr, M.; Cameron, E.Z.

2009-01-01

Capturing, immobilizing, and fitting radiocollars are common practices in studies of large mammals, but success is based on the assumptions that captured animals are representative of the rest of the population and that the capture procedure has negligible effects. We estimated effects of chemical immobilization on mortality rates of African buffalo (Syncerus caffer) in the Kruger National Park, South Africa. We used a Cox proportional hazards approach to test for differences in mortality among age, sex, and capture classes of repeatedly captured radiocollared buffalo. Capture variables did not improve model fit and the Cox regression did not indicate increased risk of death for captured individuals up to 90 days postcapture [exp (??) = 1.07]. Estimated confidence intervals, however, span from a halving to a doubling of the mortality rate (95% CI = 0.56-2.02). Therefore, capture did not influence survival of captured individuals using data on 875 captures over a 5-year period. Consequently, long-term research projects on African buffalo involving immobilization, such as associated with research on bovine tuberculosis, should result in minimal capture mortality, but monitoring of possible effects should continue.

Capturing Pressure Oscillations in Numerical Simulations of Internal Combustion Engines

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

Gubba, Sreenivasa Rao; Jupudi, Ravichandra S.; Pasunurthi, Shyam Sundar

In an earlier publication, the authors compared numerical predictions of the mean cylinder pressure of diesel and dual-fuel combustion, to that of measured pressure data from a medium-speed, large-bore engine. In these earlier comparisons, measured data from a flush-mounted in-cylinder pressure transducer showed notable and repeatable pressure oscillations which were not evident in the mean cylinder pressure predictions from computational fluid dynamics (CFD). In this paper, the authors present a methodology for predicting and reporting the local cylinder pressure consistent with that of a measurement location. Such predictions for large-bore, medium-speed engine operation demonstrate pressure oscillations in accordance with thosemore » measured. The temporal occurrences of notable pressure oscillations were during the start of combustion and around the time of maximum cylinder pressure. With appropriate resolutions in time steps and mesh sizes, the local cell static pressure predicted for the transducer location showed oscillations in both diesel and dual-fuel combustion modes which agreed with those observed in the experimental data. Fast Fourier transform (FFT) analysis on both experimental and calculated pressure traces revealed that the CFD predictions successfully captured both the amplitude and frequency range of the oscillations. Furthermore, resolving propagating pressure waves with the smaller time steps and grid sizes necessary to achieve these results required a significant increase in computer resources.« less

Analysis of benchmark critical experiments with ENDF/B-VI data sets

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

Hardy, J. Jr.; Kahler, A.C.

1991-12-31

Several clean critical experiments were analyzed with ENDF/B-VI data to assess the adequacy of the data for U{sup 235}, U{sup 238} and oxygen. These experiments were (1) a set of homogeneous U{sup 235}-H{sub 2}O assemblies spanning a wide range of hydrogen/uranium ratio, and (2) TRX-1, a simple, H{sub 2}O-moderated Bettis lattice of slightly-enriched uranium metal rods. The analyses used the Monte Carlo program RCP01, with explicit three-dimensional geometry and detailed representation of cross sections. For the homogeneous criticals, calculated k{sub crit} values for large, thermal assemblies show good agreement with experiment. This supports the evaluated thermal criticality parameters for U{supmore » 235}. However, for assemblies with smaller H/U ratios, k{sub crit} values increase significantly with increasing leakage and flux-spectrum hardness. These trends suggest that leakage is underpredicted and that the resonance eta of the ENDF/B-VI U{sup 235} is too large. For TRX-1, reasonably good agreement is found with measured lattice parameters (reaction-rate ratios). Of primary interest is rho28, the ratio of above-thermal to thermal U{sup 238} capture. Calculated rho28 is 2.3 ({+-} 1.7) % above measurement, suggesting that U{sup 238} resonance capture remains slightly overpredicted with ENDF/B-VI. However, agreement is better than observed with earlier versions of ENDF/B.« less

Capturing Pressure Oscillations in Numerical Simulations of Internal Combustion Engines

DOE PAGES

Gubba, Sreenivasa Rao; Jupudi, Ravichandra S.; Pasunurthi, Shyam Sundar; ...

2018-04-09

In an earlier publication, the authors compared numerical predictions of the mean cylinder pressure of diesel and dual-fuel combustion, to that of measured pressure data from a medium-speed, large-bore engine. In these earlier comparisons, measured data from a flush-mounted in-cylinder pressure transducer showed notable and repeatable pressure oscillations which were not evident in the mean cylinder pressure predictions from computational fluid dynamics (CFD). In this paper, the authors present a methodology for predicting and reporting the local cylinder pressure consistent with that of a measurement location. Such predictions for large-bore, medium-speed engine operation demonstrate pressure oscillations in accordance with thosemore » measured. The temporal occurrences of notable pressure oscillations were during the start of combustion and around the time of maximum cylinder pressure. With appropriate resolutions in time steps and mesh sizes, the local cell static pressure predicted for the transducer location showed oscillations in both diesel and dual-fuel combustion modes which agreed with those observed in the experimental data. Fast Fourier transform (FFT) analysis on both experimental and calculated pressure traces revealed that the CFD predictions successfully captured both the amplitude and frequency range of the oscillations. Furthermore, resolving propagating pressure waves with the smaller time steps and grid sizes necessary to achieve these results required a significant increase in computer resources.« less

Forming Giant Planet Cores by Pebble Accretion -- Why Slow and Steady wins the Race

NASA Astrophysics Data System (ADS)

Kretke, Katherine A.; Levison, Harold F.

2014-05-01

In recent years there has been a radical new solution proposed to solve the problem of giant planet core formation. "Pebbles", particles ranging from centimeters to meters in size, have been shown to accrete extremely efficiently due to aerodynamic drag. Large capture cross-sections combined with fast pebble drift rates can allow a single planetesimal to grow from Ceres size to 10s of Earth masses well within the lifetime of gaseous circumstellar disks. However, at large sizes, the the capture-cross section of pebbles goes with the Hill sphere, forcing pebble accretion to becomes a fundamentally "oligarchic-like" process. This makes it difficult to form a few giant planet cores; instead a more generic result is many 10s to 100s of competing oligarchs. In this work, we present a way to get around this oligarchic dilemma If pebbles are assumed to form slowly over a long period of time, then the planetesimal growth rates are slow enough for the planetesimals to dynamically excite each other. As the larger planetisimals/proto-planets stir their smaller companions, these smaller bodies are excited to such a degree that they spend only a small fraction of their orbits embedded in the cooler pebble disk. This allows the larger bodies to starve their neighbors and maintain a relative runaway growth rate to high mass, effectively forming the cores of giant planets.

High-resolution CCD imaging alternatives

NASA Astrophysics Data System (ADS)

Brown, D. L.; Acker, D. E.

1992-08-01

High resolution CCD color cameras have recently stimulated the interest of a large number of potential end-users for a wide range of practical applications. Real-time High Definition Television (HDTV) systems are now being used or considered for use in applications ranging from entertainment program origination through digital image storage to medical and scientific research. HDTV generation of electronic images offers significant cost and time-saving advantages over the use of film in such applications. Further in still image systems electronic image capture is faster and more efficient than conventional image scanners. The CCD still camera can capture 3-dimensional objects into the computing environment directly without having to shoot a picture on film develop it and then scan the image into a computer. 2. EXTENDING CCD TECHNOLOGY BEYOND BROADCAST Most standard production CCD sensor chips are made for broadcast-compatible systems. One popular CCD and the basis for this discussion offers arrays of roughly 750 x 580 picture elements (pixels) or a total array of approximately 435 pixels (see Fig. 1). FOR. A has developed a technique to increase the number of available pixels for a given image compared to that produced by the standard CCD itself. Using an inter-lined CCD with an overall spatial structure several times larger than the photo-sensitive sensor areas each of the CCD sensors is shifted in two dimensions in order to fill in spatial gaps between adjacent sensors.

A 3D metrology system for the GMT

NASA Astrophysics Data System (ADS)

Rakich, A.; Dettmann, Lee; Leveque, S.; Guisard, S.

2016-08-01

The Giant Magellan Telescope (GMT)1 is a 25 m telescope composed of seven 8.4 m "unit telescopes", on a common mount. Each primary and conjugated secondary mirror segment will feed a common instrument interface, their focal planes co-aligned and co-phased. During telescope operation, the alignment of the optical components will deflect due to variations in thermal environment and gravity induced structural flexure of the mount. The ultimate co-alignment and co-phasing of the telescope is achieved by a combination of the Acquisition Guiding and Wavefront Sensing system and two segment edge-sensing systems2. An analysis of the capture range of the wavefront sensing system indicates that it is unlikely that that system will operate efficiently or reliably with initial mirror positions provided by open-loop corrections alone3. The project is developing a Telescope Metrology System (TMS) which incorporates a large number of absolute distance measuring interferometers. The system will align optical components of the telescope to the instrument interface to (well) within the capture range of the active optics wavefront sensing systems. The advantages offered by this technological approach to a TMS, over a network of laser trackers, are discussed. Initial investigations of the Etalon Absolute Multiline Technology™ by Etalon Ag4 show that a metrology network based on this product is capable of meeting requirements. A conceptual design of the system is presented and expected performance is discussed.

Affinity proteomics to study endogenous protein complexes: Pointers, pitfalls, preferences and perspectives

PubMed Central

LaCava, John; Molloy, Kelly R.; Taylor, Martin S.; Domanski, Michal; Chait, Brian T.; Rout, Michael P.

2015-01-01

Dissecting and studying cellular systems requires the ability to specifically isolate distinct proteins along with the co-assembled constituents of their associated complexes. Affinity capture techniques leverage high affinity, high specificity reagents to target and capture proteins of interest along with specifically associated proteins from cell extracts. Affinity capture coupled to mass spectrometry (MS)-based proteomic analyses has enabled the isolation and characterization of a wide range of endogenous protein complexes. Here, we outline effective procedures for the affinity capture of protein complexes, highlighting best practices and common pitfalls. PMID:25757543

Long-range Self-interacting Dark Matter in the Sun

NASA Astrophysics Data System (ADS)

Chen, Jing; Liang, Zheng-Liang; Wu, Yue-Liang; Zhou, Yu-Feng

2015-12-01

We investigate the implications of the long-rang self-interaction on both the self-capture and the annihilation of the self-interacting dark matter (SIDM) trapped in the Sun. Our discussion is based on a specific SIDM model in which DM particles self-interact via a light scalar mediator, or Yukawa potential, in the context of quantum mechanics. Within this framework, we calculate the self-capture rate across a broad region of parameter space. While the self-capture rate can be obtained separately in the Born regime with perturbative method, and in the classical limits with the Rutherford formula, our calculation covers the gap between in a non-perturbative fashion. Besides, the phenomenology of both the Sommerfeld-enhanced s- and p-wave annihilation of the solar SIDM is also involved in our discussion. Moreover, by combining the analysis of the Super-Kamiokande (SK) data and the observed DM relic density, we constrain the nuclear capture rate of the DM particles in the presence of the dark Yukawa potential. The consequence of the long-range dark force on probing the solar SIDM turns out to be significant if the force-carrier is much lighter than the DM particle, and a quantitative analysis is provided.

Winter and summer home ranges of American White Pelicans (Pelecanus erythrorhynchos) captured at loafing sites in the southeastern United States

USGS Publications Warehouse

King, D. Tommy; Fischer, Justin W.; Strickland, Bronson K.; Walter, W. David; Cunningham, Fred L.; Wang, Guiming

2016-01-01

Satellite telemetry was used to investigate summer and winter home ranges for resident and migrant American White Pelicans (Pelecanus erythrorhynchos) captured in the southeastern United States between 2002 and 2007. Home range utilization distributions were calculated using 50% and 95% kernel density estimators with the plug-in bandwidth selector. Mean summer home ranges (95%) varied from 177 to 4,710 km2 and mean winter home ranges (95%) ranged from 185 to 916 km2. Mean 50% and 95% home ranges of adult American White Pelicans during summer tended to be larger than those during winter, whereas mean 50% and 95% home ranges of immature pelicans during summer tended to be smaller than those during winter. Home ranges for all American White Pelicans encompassed the latitude range of 24°–55° N, including wintering, stop over, and nesting habitat. These data provide baseline movement and home range data for future studies of American White Pelican ecology.

Registration of Large Motion Blurred Images

DTIC Science & Technology

2016-05-09

in handling the dynamics of the capturing system, for example, a drone. CMOS sensors , used in recent times, when employed in these cameras produce...handling the dynamics of the capturing system, for example, a drone. CMOS sensors , used in recent times, when employed in these cameras produce two types...blur in the captured image when there is camera motion during exposure. However, contemporary CMOS sensors employ an electronic rolling shutter (RS

Asteroid Redirect Robotic Mission: Robotic Boulder Capture Option Overview

NASA Technical Reports Server (NTRS)

Mazanek, Daniel D.; Merrill, Raymond G.; Belbin, Scott P.; Reeves, David M.; Earle, Kevin D.; Naasz, Bo J.; Abell, Paul A.

2014-01-01

The National Aeronautics and Space Administration (NASA) is currently studying an option for the Asteroid Redirect Robotic Mission (ARRM) that would capture a multi-ton boulder (typically 2-4 meters in size) from the surface of a large (is approximately 100+ meter) Near-Earth Asteroid (NEA) and return it to cislunar space for subsequent human and robotic exploration. This alternative mission approach, designated the Robotic Boulder Capture Option (Option B), has been investigated to determine the mission feasibility and identify potential differences from the initial ARRM concept of capturing an entire small NEA (4-10 meters in size), which has been designated the Small Asteroid Capture Option (Option A). Compared to the initial ARRM concept, Option B allows for centimeter-level characterization over an entire large NEA, the certainty of target NEA composition type, the ability to select the boulder that is captured, numerous opportunities for mission enhancements to support science objectives, additional experience operating at a low-gravity planetary body including extended surface contact, and the ability to demonstrate future planetary defense strategies on a hazardous-size NEA. Option B can leverage precursor missions and existing Agency capabilities to help ensure mission success by targeting wellcharacterized asteroids and can accommodate uncertain programmatic schedules by tailoring the return mass.

Incorporation of Automated ISR Systems by the 75th Ranger Regiment

DTIC Science & Technology

2003-06-06

Intelligence, describes the intelligence challenges faced by a commander, the command estimate process, military intelligence unit capabilities...feed- capture stills INTERVIEW SUBJECT #2 Strategic Range N/S N/S N/S Voice Recognitio n for TGT/Comb at ID INTERVIEW SUBJECT #3 100- 1000+ N/S...intercept- monitor- jam freqs. Send live feed- capture stills INTERVIEW SUBJECT #2 Strategic Range N/S N/S N/S Voice Recognitio n for TGT/Comb at ID

Multi-exposure high dynamic range image synthesis with camera shake correction

NASA Astrophysics Data System (ADS)

Li, Xudong; Chen, Yongfu; Jiang, Hongzhi; Zhao, Huijie

2017-10-01

Machine vision plays an important part in industrial online inspection. Owing to the nonuniform illuminance conditions and variable working distances, the captured image tends to be over-exposed or under-exposed. As a result, when processing the image such as crack inspection, the algorithm complexity and computing time increase. Multiexposure high dynamic range (HDR) image synthesis is used to improve the quality of the captured image, whose dynamic range is limited. Inevitably, camera shake will result in ghost effect, which blurs the synthesis image to some extent. However, existed exposure fusion algorithms assume that the input images are either perfectly aligned or captured in the same scene. These assumptions limit the application. At present, widely used registration based on Scale Invariant Feature Transform (SIFT) is usually time consuming. In order to rapidly obtain a high quality HDR image without ghost effect, we come up with an efficient Low Dynamic Range (LDR) images capturing approach and propose a registration method based on ORiented Brief (ORB) and histogram equalization which can eliminate the illumination differences between the LDR images. The fusion is performed after alignment. The experiment results demonstrate that the proposed method is robust to illumination changes and local geometric distortion. Comparing with other exposure fusion methods, our method is more efficient and can produce HDR images without ghost effect by registering and fusing four multi-exposure images.

Improved methods for nightside time domain Lunar Electromagnetic Sounding

NASA Astrophysics Data System (ADS)

Fuqua-Haviland, H.; Poppe, A. R.; Fatemi, S.; Delory, G. T.; De Pater, I.

2017-12-01

Time Domain Electromagnetic (TDEM) Sounding isolates induced magnetic fields to remotely deduce material properties at depth. The first step of performing TDEM Sounding at the Moon is to fully characterize the dynamic plasma environment, and isolate geophysically induced currents from concurrently present plasma currents. The transfer function method requires a two-point measurement: an upstream reference measuring the pristine solar wind, and one downstream near the Moon. This method was last performed during Apollo assuming the induced fields on the nightside of the Moon expand as in an undisturbed vacuum within the wake cavity [1]. Here we present an approach to isolating induction and performing TDEM with any two point magnetometer measurement at or near the surface of the Moon. Our models include a plasma induction model capturing the kinetic plasma environment within the wake cavity around a conducting Moon, and a geophysical forward model capturing induction in a vacuum. The combination of these two models enable the analysis of magnetometer data within the wake cavity. Plasma hybrid models use the upstream plasma conditions and interplanetary magnetic field (IMF) to capture the wake current systems formed around the Moon. The plasma kinetic equations are solved for ion particles with electrons as a charge-neutralizing fluid. These models accurately capture the large scale lunar wake dynamics for a variety of solar wind conditions: ion density, temperature, solar wind velocity, and IMF orientation [2]. Given the 3D orientation variability coupled with the large range of conditions seen within the lunar plasma environment, we characterize the environment one case at a time. The global electromagnetic induction response of the Moon in a vacuum has been solved numerically for a variety of electrical conductivity models using the finite-element method implemented within the COMSOL software. This model solves for the geophysically induced response in vacuum to any driving transient event for any specified 3D conductivity profile. Our models fit the analytic solutions to a Root-Mean-Square Error of better than 1%. Solutions are non-unique, however, serve to better understand and constrain the global interior composition and 3D structure of the Moon. [1] Dyal & Parkin (1971) JGR; [2] Fatemi et al. (2013) GRL.

Effects of nanopillar array diameter and spacing on cancer cell capture and cell behaviors

NASA Astrophysics Data System (ADS)

Wang, Shunqiang; Wan, Yuan; Liu, Yaling

2014-10-01

While substrates with nanopillars (NPs) have emerged as promising platforms for isolation of circulating tumor cells (CTCs), the influence of diameter and spacing of NPs on CTC capture is still unclear. In this paper, CTC-capture yield and cell behaviors have been investigated by using antibody functionalized NPs of various diameters (120-1100 nm) and spacings (35-800 nm). The results show a linear relationship between the cell capture yield and effective contact area of NP substrates where a NP array of small diameter and reasonable spacing is preferred; however, spacing that is too small or too large adversely impairs the capture efficiency and specificity, respectively. In addition, the formation of pseudopodia between captured cells and the substrate is found to be dependent not only on cell adhesion status but also on elution strength and shear direction. These findings provide essential guidance in designing NP substrates for more efficient capture of CTCs and manipulation of cytomorphology in future.While substrates with nanopillars (NPs) have emerged as promising platforms for isolation of circulating tumor cells (CTCs), the influence of diameter and spacing of NPs on CTC capture is still unclear. In this paper, CTC-capture yield and cell behaviors have been investigated by using antibody functionalized NPs of various diameters (120-1100 nm) and spacings (35-800 nm). The results show a linear relationship between the cell capture yield and effective contact area of NP substrates where a NP array of small diameter and reasonable spacing is preferred; however, spacing that is too small or too large adversely impairs the capture efficiency and specificity, respectively. In addition, the formation of pseudopodia between captured cells and the substrate is found to be dependent not only on cell adhesion status but also on elution strength and shear direction. These findings provide essential guidance in designing NP substrates for more efficient capture of CTCs and manipulation of cytomorphology in future. Electronic supplementary information (ESI) available: Additional details about calculation of maximal displacement of an individual NP; additional study of substrate wettability through Cassie's Law; additional details about selection of incubation time and shaking speeds. See DOI: 10.1039/c4nr02854f

In situ observation of penetration process in silica aerogel: Deceleration mechanism of hard spherical projectiles

NASA Astrophysics Data System (ADS)

Niimi, Rei; Kadono, Toshihiko; Arakawa, Masahiko; Yasui, Minami; Dohi, Koji; Nakamura, Akiko M.; Iida, Yosuke; Tsuchiyama, Akira

2011-02-01

A large number of cometary dust particles were captured with low-density silica aerogels by NASA's Stardust Mission. Knowledge of the details of the capture mechanism of hypervelocity particles in silica aerogel is needed in order to correctly derive the original particle features from impact tracks. However, the mechanism has not been fully understood yet. We shot hard spherical projectiles of several different materials into silica aerogel of density 60 mg cm -3 and observed their penetration processes using an image converter or a high-speed video camera. In order to observe the deceleration of projectiles clearly, we carried out impact experiments at two velocity ranges; ˜4 km s -1 and ˜200 m s -1. From the movies we took, it was indicated that the projectiles were decelerated by hydrodynamic force which was proportional to v2 ( v: projectile velocity) during the faster penetration process (˜4 km s -1) and they were merely overcoming the aerogel crushing strength during the slower penetration process (˜200 m s -1). We applied these deceleration mechanisms for whole capture process to calculate the track length. Our model well explains the track length in the experimental data set by Burchell et al. (Burchell, M.J., Creighton, J.A., Cole, M.J., Mann, J., Kearsley, A.T. [2001]. Meteorit. Planet. Sci. 36, 209-221).

tranSMART-XNAT Connector tranSMART-XNAT connector-image selection based on clinical phenotypes and genetic profiles.

PubMed

He, Sijin; Yong, May; Matthews, Paul M; Guo, Yike

2017-03-01

TranSMART has a wide range of functionalities for translational research and a large user community, but it does not support imaging data. In this context, imaging data typically includes 2D or 3D sets of magnitude data and metadata information. Imaging data may summarise complex feature descriptions in a less biased fashion than user defined plain texts and numeric numbers. Imaging data also is contextualised by other data sets and may be analysed jointly with other data that can explain features or their variation. Here we describe the tranSMART-XNAT Connector we have developed. This connector consists of components for data capture, organisation and analysis. Data capture is responsible for imaging capture either from PACS system or directly from an MRI scanner, or from raw data files. Data are organised in a similar fashion as tranSMART and are stored in a format that allows direct analysis within tranSMART. The connector enables selection and download of DICOM images and associated resources using subjects' clinical phenotypic and genotypic criteria. tranSMART-XNAT connector is written in Java/Groovy/Grails. It is maintained and available for download at https://github.com/sh107/transmart-xnat-connector.git. sijin@ebi.ac.uk. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com

The efficacy of the Microsoft KinectTM to assess human bimanual coordination.

PubMed

Liddy, Joshua J; Zelaznik, Howard N; Huber, Jessica E; Rietdyk, Shirley; Claxton, Laura J; Samuel, Arjmand; Haddad, Jeffrey M

2017-06-01

The Microsoft Kinect has been used in studies examining posture and gait. Despite the advantages of portability and low cost, this device has not been used to assess interlimb coordination. Fundamental insights into movement control, variability, health, and functional status can be gained by examining coordination patterns. In this study, we investigated the efficacy of the Microsoft Kinect to capture bimanual coordination relative to a research-grade motion capture system. Twenty-four healthy adults performed coordinated hand movements in two patterns (in-phase and antiphase) at eight movement frequencies (1.00-3.33 Hz). Continuous relative phase (CRP) and discrete relative phase (DRP) were used to quantify the means (mCRP and mDRP) and variability (sdCRP and sdDRP) of coordination patterns. Between-device agreement was assessed using Bland-Altman bias with 95 % limits of agreement, concordance correlation coefficients (absolute agreement), and Pearson correlation coefficients (relative agreement). Modest-to-excellent relative and absolute agreements were found for mCRP in all conditions. However, mDRP showed poor agreement for the in-phase pattern at low frequencies, due to large between-device differences in a subset of participants. By contrast, poor absolute agreement was observed for both sdCRP and sdDRP, while relative agreement ranged from poor to excellent. Overall, the Kinect captures the macroscopic patterns of bimanual coordination better than coordination variability.

Atmospheric Infrasound during a Large Wildfire

NASA Astrophysics Data System (ADS)

Vance, Alexis; Elbing, Brian

2017-11-01

Numerous natural and manmade sources generate infrasound, including tornado producing storms, human heart, hurricanes, and volcanoes. Infrasound is currently being studied as part of Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUD MAP), which is a multi-university collaboration focused on development and implementation of unmanned aircraft systems (UAS) and integration with sensors for atmospheric measurements. To support this effort a fixed infrasonic microphone located in Stillwater, Oklahoma has been monitoring atmospheric emissions since September of 2016. While severe storm systems is the primary focus of this work, the system also captures a wide range of infrasonic sources from distances in excess of 300 miles due to an acoustic ceiling and weak atmospheric absorption. The current presentation will focus on atmospheric infrasound observations during a large wildfire on the Kansas-Oklahoma border that occurred between March 6-22, 2017. This work was supported by NSF Grant 1539070.

High-rate real-time GPS network at Parkfield: Utility for detecting fault slip and seismic displacements

USGS Publications Warehouse

Langbein, J.; Bock, Y.

2004-01-01

A network of 13 continuous GPS stations near Parkfield, California has been converted from 30 second to 1 second sampling with positions of the stations estimated in real-time relative to a master station. Most stations are near the trace of the San Andreas fault, which exhibits creep. The noise spectra of the instantaneous 1 Hz positions show flicker noise at high frequencies and change to frequency independence at low frequencies; the change in character occurs between 6 to 8 hours. Our analysis indicates that 1-second sampled GPS can estimate horizontal displacements of order 6 mm at the 99% confidence level from a few seconds to a few hours. High frequency GPS can augment existing measurements in capturing large creep events and postseismic slip that would exceed the range of existing creepmeters, and can detect large seismic displacements. Copyright 2004 by the American Geophysical Union.

Child Schooling in Ethiopia: The Role of Maternal Autonomy

PubMed Central

Mohanty, Itismita

2016-01-01

This paper examines the effects of maternal autonomy on child schooling outcomes in Ethiopia using a nationally representative Ethiopian Demographic and Health survey for 2011. The empirical strategy uses a Hurdle Negative Binomial Regression model to estimate years of schooling. An ordered probit model is also estimated to examine age grade distortion using a trichotomous dependent variable that captures three states of child schooling. The large sample size and the range of questions available in this dataset allow us to explore the influence of individual and household level social, economic and cultural factors on child schooling. The analysis finds statistically significant effects of maternal autonomy variables on child schooling in Ethiopia. The roles of maternal autonomy and other household-level factors on child schooling are important issues in Ethiopia, where health and education outcomes are poor for large segments of the population. PMID:27942039

Evidence of a High Density Population of Harvested Leopards in a Montane Environment

PubMed Central

Chase Grey, Julia N.; Kent, Vivien T.; Hill, Russell A.

2013-01-01

Populations of large carnivores can persist in mountainous environments following extensive land use change and the conversion of suitable habitat for agriculture and human habitation in lower lying areas of their range. The significance of these populations is poorly understood, however, and little attention has focussed on why certain mountainous areas can hold high densities of large carnivores and what the conservation implications of such populations might be. Here we use the leopard (Panthera pardus) population in the western Soutpansberg Mountains, South Africa, as a model system and show that montane habitats can support high numbers of leopards. Spatially explicit capture-recapture (SECR) analysis recorded the highest density of leopards reported outside of state-protected areas in sub-Saharan Africa. This density represents a temporally high local abundance of leopards and we explore the explanations for this alongside some of the potential conservation implications. PMID:24349375

Diffusion and interactions of interstitials in hard-sphere interstitial solid solutions

NASA Astrophysics Data System (ADS)

van der Meer, Berend; Lathouwers, Emma; Smallenburg, Frank; Filion, Laura

2017-12-01

Using computer simulations, we study the dynamics and interactions of interstitial particles in hard-sphere interstitial solid solutions. We calculate the free-energy barriers associated with their diffusion for a range of size ratios and densities. By applying classical transition state theory to these free-energy barriers, we predict the diffusion coefficients, which we find to be in good agreement with diffusion coefficients as measured using event-driven molecular dynamics simulations. These results highlight that transition state theory can capture the interstitial dynamics in the hard-sphere model system. Additionally, we quantify the interactions between the interstitials. We find that, apart from excluded volume interactions, the interstitial-interstitial interactions are almost ideal in our system. Lastly, we show that the interstitial diffusivity can be inferred from the large-particle fluctuations alone, thus providing an empirical relationship between the large-particle fluctuations and the interstitial diffusivity.

Selective capture of iodide from solutions by microrosette-like δ-Bi₂O₃.

PubMed

Liu, Long; Liu, Wei; Zhao, Xiaoliang; Chen, Daimei; Cai, Rongsheng; Yang, Weiyou; Komarneni, Sridhar; Yang, Dongjiang

2014-09-24

Radioactive iodine isotopes that are produced in nuclear power plants and used in medical research institutes could be a serious threat to the health of many people if accidentally released to the environment because the thyroid gland can absorb and concentrate them from a liquid. For this reason, uptake of iodide anions was investigated on microrosette-like δ-Bi2O3 (MR-δ-Bi2O3). The MR-δ-Bi2O3 adsorbent showed a very high uptake capacity of 1.44 mmol g(-1) by forming insoluble Bi4I2O5 phase. The MR-δ-Bi2O3 also displayed fast uptake kinetics and could be easily separated from a liquid after use because of its novel morphology. In addition, the adsorbent showed excellent selectivity for I(-) anions in the presence of large concentrations of competitive anions such as Cl(-) and CO3(2-), and could work in a wide pH range of 4-11. This study led to a new and highly efficient Bi-based adsorbent for iodide capture from solutions.

Determination of iodopropynyl butylcarbamate in cosmetic formulations utilizing pulsed splitless injection, gas chromatography with electron capture detector.

PubMed

Palmer, Kevin B; LaFon, William; Burford, Mark D

2017-09-22

Current analytical methodology for iodopropynyl butylcarbamate (IPBC) analysis focuses on the use of liquid chromatography and mass spectrometer (LC-MS), but the high instrumentation and operator investment required has resulted in the need for a cost effective alternative methodology. Past publications investigating gas chromatography with electron capture detector (GC-ECD) for IPBC quantitation proved largely unsuccessful, likely due to the preservatives limited thermal stability. The use of pulsed injection techniques commonly used for trace analysis of thermally labile pharmaceutical compounds was successfully adapted for IPBC analysis and utilizes the selectivity of GC-ECD analysis. System optimization and sample preparation improvements resulted in substantial performance and reproducibility gains. Cosmetic formulations preserved with IPBC (50-100ppm) were solvated in toluene/isopropyl alcohol and quantified over the 0.3-1.3μg/ml calibration range. The methodology was robust (relative standard deviation 4%), accurate (98% recovery), and sensitive (limit of detection 0.25ng/ml) for use in routine testing of cosmetic formulation preservation. Copyright © 2017 Elsevier B.V. All rights reserved.

Data Standards for Flow Cytometry

PubMed Central

SPIDLEN, JOSEF; GENTLEMAN, ROBERT C.; HAALAND, PERRY D.; LANGILLE, MORGAN; MEUR, NOLWENN LE; OCHS, MICHAEL F.; SCHMITT, CHARLES; SMITH, CLAYTON A.; TREISTER, ADAM S.; BRINKMAN, RYAN R.

2009-01-01

Flow cytometry (FCM) is an analytical tool widely used for cancer and HIV/AIDS research, and treatment, stem cell manipulation and detecting microorganisms in environmental samples. Current data standards do not capture the full scope of FCM experiments and there is a demand for software tools that can assist in the exploration and analysis of large FCM datasets. We are implementing a standardized approach to capturing, analyzing, and disseminating FCM data that will facilitate both more complex analyses and analysis of datasets that could not previously be efficiently studied. Initial work has focused on developing a community-based guideline for recording and reporting the details of FCM experiments. Open source software tools that implement this standard are being created, with an emphasis on facilitating reproducible and extensible data analyses. As well, tools for electronic collaboration will assist the integrated access and comprehension of experiments to empower users to collaborate on FCM analyses. This coordinated, joint development of bioinformatics standards and software tools for FCM data analysis has the potential to greatly facilitate both basic and clinical research—impacting a notably diverse range of medical and environmental research areas. PMID:16901228

Methods of analysis by the U.S. Geological Survey National Water Quality Laboratory; determination of organochlorine pesticides and polychlorinated biphenyls in bottom sediment by dual capillary-column gas chromatography with electron-capture detection

USGS Publications Warehouse

Foreman, William T.; Connor, Brooke F.; Furlong, Edward T.; Vaught, Deborah G.; Merten, Leslie M.

1995-01-01

A method for the determination of 30 individual organochlorine pesticides, total toxaphene, and total polychlorinated biphenyls (PCBs) in bottom sediment is described. The method isolates the pesticides and PCBs by solvent extraction with dichlorobenzene, removes inorganic sulfur, large naturally occurring molecules, and other unwanted interferences by gel permeation chromatography, and further cleans up and class fractionates the extract using adsorption chromatography. The com- pounds then are instrumentally determined using dual capillary-column gas chromatography with electron-capture detection. Reporting limits range from 1 to 5 micrograms per kilogram for 30 individual pesticides, 50 micrograms per kilogram for total PCBs, and 200 micrograms per kilogram for total toxaphene. The method also is designed to allow the simultaneous isolation of 79 other semivolatile organic compounds from the sediment, which are separately quantified using gas chromatography with mass spectrometric detection. The method was developed in support of the U.S. Geological Survey's National Water-Quality Assessment program.

Gradient-based interpolation method for division-of-focal-plane polarimeters.

PubMed

Gao, Shengkui; Gruev, Viktor

2013-01-14

Recent advancements in nanotechnology and nanofabrication have allowed for the emergence of the division-of-focal-plane (DoFP) polarization imaging sensors. These sensors capture polarization properties of the optical field at every imaging frame. However, the DoFP polarization imaging sensors suffer from large registration error as well as reduced spatial-resolution output. These drawbacks can be improved by applying proper image interpolation methods for the reconstruction of the polarization results. In this paper, we present a new gradient-based interpolation method for DoFP polarimeters. The performance of the proposed interpolation method is evaluated against several previously published interpolation methods by using visual examples and root mean square error (RMSE) comparison. We found that the proposed gradient-based interpolation method can achieve better visual results while maintaining a lower RMSE than other interpolation methods under various dynamic ranges of a scene ranging from dim to bright conditions.

Quantitative X-ray - UV Line and Continuum Spectroscopy with Application to AGN: State-Specific Hydrogenic Recombination Cooling Coefficients for a Wide Range of Conditions

NASA Technical Reports Server (NTRS)

LaMothe, J.; Ferland, Gary J.

2002-01-01

Recombination cooling, in which a free electron emits light while being captured to an ion, is an important cooling process in photoionized clouds that are optically thick or have low metallicity. State specific rather than total recombination cooling rates are needed since the hydrogen atom tends to become optically thick in high-density regimes such as Active Galactic Nuclei. This paper builds upon previous work to derive the cooling rate over the full temperature range where the process can be a significant contributor in a photoionized plasma. We exploit the fact that the recombination and cooling rates are given by intrinsically similar formulae to express the cooling rate in terms of the closely related radiative recombination rate. We give an especially simple but accurate approximation that works for any high hydrogenic level and can be conveniently employed in large-scale numerical simulations.

Memory is relevant in the symmetric phase of the minority game

NASA Astrophysics Data System (ADS)

Ho, K. H.; Man, W. C.; Chow, F. K.; Chau, H. F.

2005-06-01

Minority game is a simple-mined econophysical model capturing the cooperative behavior among selfish players. Previous investigations, which were based on numerical simulations up to about 100 players for a certain parameter α in the range 0.1≲α≲1 , suggested that memory is irrelevant to the cooperative behavior of the minority game in the so-called symmetric phase. Here using a large scale numerical simulation up to about 3000 players in the parameter range 0.01≲α≲1 , we show that the mean variance of the attendance in the minority game actually depends on the memory in the symmetric phase. We explain such dependence in the framework of crowd-anticrowd theory. Our findings conclude that one should not overlook the feedback mechanism buried under the correlation in the history time series in the study of minority game.

Multiplexed direct genomic selection (MDiGS): a pooled BAC capture approach for highly accurate CNV and SNP/INDEL detection.

PubMed

Alvarado, David M; Yang, Ping; Druley, Todd E; Lovett, Michael; Gurnett, Christina A

2014-06-01

Despite declining sequencing costs, few methods are available for cost-effective single-nucleotide polymorphism (SNP), insertion/deletion (INDEL) and copy number variation (CNV) discovery in a single assay. Commercially available methods require a high investment to a specific region and are only cost-effective for large samples. Here, we introduce a novel, flexible approach for multiplexed targeted sequencing and CNV analysis of large genomic regions called multiplexed direct genomic selection (MDiGS). MDiGS combines biotinylated bacterial artificial chromosome (BAC) capture and multiplexed pooled capture for SNP/INDEL and CNV detection of 96 multiplexed samples on a single MiSeq run. MDiGS is advantageous over other methods for CNV detection because pooled sample capture and hybridization to large contiguous BAC baits reduces sample and probe hybridization variability inherent in other methods. We performed MDiGS capture for three chromosomal regions consisting of ∼ 550 kb of coding and non-coding sequence with DNA from 253 patients with congenital lower limb disorders. PITX1 nonsense and HOXC11 S191F missense mutations were identified that segregate in clubfoot families. Using a novel pooled-capture reference strategy, we identified recurrent chromosome chr17q23.1q23.2 duplications and small HOXC 5' cluster deletions (51 kb and 12 kb). Given the current interest in coding and non-coding variants in human disease, MDiGS fulfills a niche for comprehensive and low-cost evaluation of CNVs, coding, and non-coding variants across candidate regions of interest. © The Author(s) 2014. Published by Oxford University Press on behalf of Nucleic Acids Research.

Photographic images captured while sampling for bald eagles near the Davis Pond freshwater diversion structure in Barataria Bay, Louisiana (2009-10)

USGS Publications Warehouse

Jenkins, Jill A.; Jeske, Clinton W.; Allain, Larry K.

2011-01-01

The implementation of freshwater diversions in large-scale coastal restoration schemes presents several scientific and management considerations. Large-scale environmental restructuring necessitates aquatic biomonitoring, and during such field studies, photographs that document animals and habitat may be captured. Among the biomonitoring studies performed in conjunction with the Davis Pond freshwater diversion structure south of New Orleans, Louisiana, only postdiversion study images are readily available, and these are presented here.

Estimation of weapon-radius versus maneuverability trade-off for air-to-air combat

NASA Technical Reports Server (NTRS)

Kelley, H. J.; Lefton, L.

1977-01-01

A chase in a horizontal plane between a pursuer with a large capture radius and a more maneuverable evading vehicle is examined with constant-speed vehicle models. An approximation to the 'sidestepping' maneuver of the Homicidal Chauffeur Game is modified to account for the effect of evader turning rate, and an estimate of capture radius required is so obtained which agrees remarkably well with Cockayne's point-capture result. The maneuver assumes central importance for barrier surfaces appearing in the Game of Two Cars. Results are given for required weapon capture-radius in terms of the maneuverability of the two vehicles. Some calculations of capture radius are presented.

Program SPACECAP: software for estimating animal density using spatially explicit capture-recapture models

USGS Publications Warehouse

Gopalaswamy, Arjun M.; Royle, J. Andrew; Hines, James E.; Singh, Pallavi; Jathanna, Devcharan; Kumar, N. Samba; Karanth, K. Ullas

2012-01-01

1. The advent of spatially explicit capture-recapture models is changing the way ecologists analyse capture-recapture data. However, the advantages offered by these new models are not fully exploited because they can be difficult to implement. 2. To address this need, we developed a user-friendly software package, created within the R programming environment, called SPACECAP. This package implements Bayesian spatially explicit hierarchical models to analyse spatial capture-recapture data. 3. Given that a large number of field biologists prefer software with graphical user interfaces for analysing their data, SPACECAP is particularly useful as a tool to increase the adoption of Bayesian spatially explicit capture-recapture methods in practice.

Efficient data management in a large-scale epidemiology research project.

PubMed

Meyer, Jens; Ostrzinski, Stefan; Fredrich, Daniel; Havemann, Christoph; Krafczyk, Janina; Hoffmann, Wolfgang

2012-09-01

This article describes the concept of a "Central Data Management" (CDM) and its implementation within the large-scale population-based medical research project "Personalized Medicine". The CDM can be summarized as a conjunction of data capturing, data integration, data storage, data refinement, and data transfer. A wide spectrum of reliable "Extract Transform Load" (ETL) software for automatic integration of data as well as "electronic Case Report Forms" (eCRFs) was developed, in order to integrate decentralized and heterogeneously captured data. Due to the high sensitivity of the captured data, high system resource availability, data privacy, data security and quality assurance are of utmost importance. A complex data model was developed and implemented using an Oracle database in high availability cluster mode in order to integrate different types of participant-related data. Intelligent data capturing and storage mechanisms are improving the quality of data. Data privacy is ensured by a multi-layered role/right system for access control and de-identification of identifying data. A well defined backup process prevents data loss. Over the period of one and a half year, the CDM has captured a wide variety of data in the magnitude of approximately 5terabytes without experiencing any critical incidents of system breakdown or loss of data. The aim of this article is to demonstrate one possible way of establishing a Central Data Management in large-scale medical and epidemiological studies. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Large Prominence Eruption [video

NASA Image and Video Library

2014-10-07

The STEREO (Behind) spacecraft captured this large prominence and corona mass ejection as they erupted into space (Sept. 26, 2014). By combining images from three instruments, scientists can see the eruption itself (in extreme UV light) as well as follow its progression over the period of about 13 hours with its two coronagraphs. Credit: NASA/Goddard/STEREO The STEREO (Behind) spacecraft captured this large prominence and corona mass ejection as they erupted into space (Sept. 26, 2014). By combining images from three instruments, scientists can see the eruption itself (in extreme UV light) as well as follow its progression over the period of about 13 hours with its two coronagraphs.

Large Prominence Eruption (October 3, 2014)

NASA Image and Video Library

2017-12-08

The STEREO (Behind) spacecraft captured this large prominence and corona mass ejection as they erupted into space (Sept. 26, 2014). By combining images from three instruments, scientists can see the eruption itself (in extreme UV light) as well as follow its progression over the period of about 13 hours with its two coronagraphs. Credit: NASA/Goddard/STEREO The STEREO (Behind) spacecraft captured this large prominence and corona mass ejection as they erupted into space (Sept. 26, 2014). By combining images from three instruments, scientists can see the eruption itself (in extreme UV light) as well as follow its progression over the period of about 13 hours with its two coronagraphs.

Tidal capture of stars by a massive black hole

NASA Technical Reports Server (NTRS)

Novikov, I. D.; Pethick, C. J.; Polnarev, A. G.

1992-01-01

The processes leading to tidal capture of stars by a massive black hole and the consequences of these processes in a dense stellar cluster are discussed in detail. When the amplitude of a tide and the subsequent oscillations are sufficiently large, the energy deposited in a star after periastron passage and formation of a bound orbit cannot be estimated directly using the linear theory of oscillations of a spherical star, but rather numerical estimates must be used. The evolution of a star after tidal capture is discussed. The maximum ratio R of the cross-section for tidal capture to that for tidal disruption is about 3 for real systems. For the case of a stellar system with an empty capture loss cone, even in the case when the impact parameter for tidal capture only slightly exceeds the impact parameter for direct tidal disruption, tidal capture would be much more important than tidal disruption.

Stitching of near-nulled subaperture measurements

NASA Technical Reports Server (NTRS)

Devries, Gary (Inventor); Brophy, Christopher (Inventor); Forbes, Greg (Inventor); Murphy, Paul (Inventor)

2012-01-01

A metrology system for measuring aspheric test objects by subaperture stitching. A wavefront-measuring gauge having a limited capture range of wavefront shapes collects partially overlapping subaperture measurements over the test object. A variable optical aberrator reshapes the measurement wavefront with between a limited number of the measurements to maintain the measurement wavefront within the capture range of the wavefront-measuring gauge. Various error compensators are incorporated into a stitching operation to manage residual errors associated with the use of the variable optical aberrator.

Large Eddy Simulations of Electromagnetic Braking Effects on Argon Bubble Transport and Capture in a Steel Continuous Casting Mold

NASA Astrophysics Data System (ADS)

Jin, Kai; Vanka, Surya P.; Thomas, Brian G.

2018-02-01

In continuous casting of steel, argon gas is often injected to prevent clogging of the nozzle, but the bubbles affect the flow pattern, and may become entrapped to form defects in the final product. Further, an electromagnetic field is frequently applied to induce a braking effect on the flow field and modify the inclusion transport. In this study, a previously validated GPU-based in-house code CUFLOW is used to investigate the effect of electromagnetic braking on turbulent flow, bubble transport, and capture. Well-resolved large eddy simulations are combined with two-way coupled Lagrangian computations of the bubbles. The drag coefficient on the bubbles is modified to account for the effects of the magnetic field. The distribution of the argon bubbles, capture, and escape rates, are presented and compared with and without the magnetic field. The bubble capture patterns are also compared with results of a previous RANS model as well as with plant measurements.

Large Eddy Simulations of Electromagnetic Braking Effects on Argon Bubble Transport and Capture in a Steel Continuous Casting Mold

NASA Astrophysics Data System (ADS)

Jin, Kai; Vanka, Surya P.; Thomas, Brian G.

2018-06-01

In continuous casting of steel, argon gas is often injected to prevent clogging of the nozzle, but the bubbles affect the flow pattern, and may become entrapped to form defects in the final product. Further, an electromagnetic field is frequently applied to induce a braking effect on the flow field and modify the inclusion transport. In this study, a previously validated GPU-based in-house code CUFLOW is used to investigate the effect of electromagnetic braking on turbulent flow, bubble transport, and capture. Well-resolved large eddy simulations are combined with two-way coupled Lagrangian computations of the bubbles. The drag coefficient on the bubbles is modified to account for the effects of the magnetic field. The distribution of the argon bubbles, capture, and escape rates, are presented and compared with and without the magnetic field. The bubble capture patterns are also compared with results of a previous RANS model as well as with plant measurements.

Mahanaxar: quality of service guarantees in high-bandwidth, real-time streaming data storage

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

Bigelow, David; Bent, John; Chen, Hsing-Bung

2010-04-05

Large radio telescopes, cyber-security systems monitoring real-time network traffic, and others have specialized data storage needs: guaranteed capture of an ultra-high-bandwidth data stream, retention of the data long enough to determine what is 'interesting,' retention of interesting data indefinitely, and concurrent read/write access to determine what data is interesting, without interrupting the ongoing capture of incoming data. Mahanaxar addresses this problem. Mahanaxar guarantees streaming real-time data capture at (nearly) the full rate of the raw device, allows concurrent read and write access to the device on a best-effort basis without interrupting the data capture, and retains data as long asmore » possible given the available storage. It has built in mechanisms for reliability and indexing, can scale to meet arbitrary bandwidth requirements, and handles both small and large data elements equally well. Results from our prototype implementation shows that Mahanaxar provides both better guarantees and better performance than traditional file systems.« less

Air Force/Industry F-35/F-22 Technology Interchange Workshop for Small Business Innovation Research (SBIR): Plenary Session

DTIC Science & Technology

2007-11-28

order to optimize pilot performance in the JSF tactical maneuvering environment • Binaural Capture and Synthesis of Ambient Soundscapes –Create a...technique for capturing and replicating ambient soundscapes , and use the technique to statistically model ambient soundscapes for a wide range of...Actuator (HTCA) • Binaural Capture and Synthesis of Ambient Soundscapes • High Temperature PM Actuator Motor • Manufacturing of New Active Noise

Live HDR video streaming on commodity hardware

NASA Astrophysics Data System (ADS)

McNamee, Joshua; Hatchett, Jonathan; Debattista, Kurt; Chalmers, Alan

2015-09-01

High Dynamic Range (HDR) video provides a step change in viewing experience, for example the ability to clearly see the soccer ball when it is kicked from the shadow of the stadium into sunshine. To achieve the full potential of HDR video, so-called true HDR, it is crucial that all the dynamic range that was captured is delivered to the display device and tone mapping is confined only to the display. Furthermore, to ensure widespread uptake of HDR imaging, it should be low cost and available on commodity hardware. This paper describes an end-to-end HDR pipeline for capturing, encoding and streaming high-definition HDR video in real-time using off-the-shelf components. All the lighting that is captured by HDR-enabled consumer cameras is delivered via the pipeline to any display, including HDR displays and even mobile devices with minimum latency. The system thus provides an integrated HDR video pipeline that includes everything from capture to post-production, archival and storage, compression, transmission, and display.

Low-cost floating emergence net and bottle trap: Comparison of two designs

USGS Publications Warehouse

Cadmus, Pete; Pomeranz, Justin; Kraus, Johanna M.

2016-01-01

Sampling emergent aquatic insects is of interest to many freshwater ecologists. Many quantitative emergence traps require the use of aspiration for collection. However, aspiration is infeasible in studies with large amounts of replication that is often required in large biomonitoring projects. We designed an economic, collapsible pyramid-shaped floating emergence trap with an external collection bottle that avoids the need for aspiration. This design was compared experimentally to a design of similar dimensions that relied on aspiration to ensure comparable results. The pyramid-shaped design captured twice as many total emerging insects. When a preservative was used in bottle collectors, >95% of the emergent abundance was collected in the bottle. When no preservative was used, >81% of the total insects were collected from the bottle. In addition to capturing fewer emergent insects, the traps that required aspiration took significantly longer to sample. Large studies and studies sampling remote locations could benefit from the economical construction, speed of sampling, and capture efficiency.

Scaling properties of weakly nonlinear coefficients in the Faraday problem.

PubMed

Skeldon, A C; Porter, J

2011-07-01

Interesting and exotic surface wave patterns have regularly been observed in the Faraday experiment. Although symmetry arguments provide a qualitative explanation for the selection of some of these patterns (e.g., superlattices), quantitative analysis is hindered by mathematical difficulties inherent in a time-dependent, free-boundary Navier-Stokes problem. More tractable low viscosity approximations are available, but these do not necessarily capture the moderate viscosity regime of the most interesting experiments. Here we focus on weakly nonlinear behavior and compare the scaling results derived from symmetry arguments in the low viscosity limit with the computed coefficients of appropriate amplitude equations using both the full Navier-Stokes equations and a reduced set of partial differential equations due to Zhang and Vinãls. We find the range of viscosities over which one can expect "low viscosity" theories to hold. We also find that there is an optimal viscosity range for locating superlattice patterns experimentally-large enough that the region of parameters giving stable patterns is not impracticably small, yet not so large that crucial resonance effects are washed out. These results help explain some of the discrepancies between theory and experiment.

Mechanical Behavior of a Low-Cost Ti-6Al-4V Alloy

NASA Astrophysics Data System (ADS)

Casem, D. T.; Weerasooriya, T.; Walter, T. R.

2018-01-01

Mechanical compression tests were performed on an economical Ti-6Al-4V alloy over a range of strain-rates and temperatures. Low rate experiments (0.001-0.1/s) were performed with a servo-hydraulic load frame and high rate experiments (1000-80,000/s) were performed with the Kolsky bar (Split Hopkinson pressure bar). Emphasis is placed on the large strain, high-rate, and high temperature behavior of the material in an effort to develop a predictive capability for adiabatic shear bands. Quasi-isothermal experiments were performed with the Kolsky bar to determine the large strain response at elevated rates, and bars with small diameters (1.59 mm and 794 µm, instrumented optically) were used to study the response at the higher strain-rates. Experiments were also conducted at temperatures ranging from 81 to 673 K. Two constitutive models are used to represent the data. The first is the Zerilli-Armstrong recovery strain model and the second is a modified Johnson-Cook model which uses the recovery strain term from the Zerilli-Armstrong model. In both cases, the recovery strain feature is critical for capturing the instability that precedes localization.

The Multi-Scale Network Landscape of Collaboration.

PubMed

Bae, Arram; Park, Doheum; Ahn, Yong-Yeol; Park, Juyong

2016-01-01

Propelled by the increasing availability of large-scale high-quality data, advanced data modeling and analysis techniques are enabling many novel and significant scientific understanding of a wide range of complex social, natural, and technological systems. These developments also provide opportunities for studying cultural systems and phenomena--which can be said to refer to all products of human creativity and way of life. An important characteristic of a cultural product is that it does not exist in isolation from others, but forms an intricate web of connections on many levels. In the creation and dissemination of cultural products and artworks in particular, collaboration and communication of ideas play an essential role, which can be captured in the heterogeneous network of the creators and practitioners of art. In this paper we propose novel methods to analyze and uncover meaningful patterns from such a network using the network of western classical musicians constructed from a large-scale comprehensive Compact Disc recordings data. We characterize the complex patterns in the network landscape of collaboration between musicians across multiple scales ranging from the macroscopic to the mesoscopic and microscopic that represent the diversity of cultural styles and the individuality of the artists.

3-D trajectory model for MDT using micro-spheres implanted within large blood vessels

NASA Astrophysics Data System (ADS)

Choomphon-anomakhun, Natthaphon; Natenapit, Mayuree

2016-09-01

Implant assisted magnetic drug targeting (IA-MDT) using ferromagnetic spherical targets implanted within large blood vessels and subjected to a uniform externally applied magnetic field (H0) has been investigated and reported for the first time. The capture areas (As) of magnetic drug carrier particles (MDCPs) were determined from the analysis of particle trajectories simulated from equations of motion. Then, the effects of various parameters, such as types of ferromagnetic materials in the targets and MDCPs, blood flow rates, mass fraction of the ferromagnetic material in the MDCPs, average radii of MDCPs (Rp) and the strength of H0 on the As were obtained. Furthermore, the effects of saturation magnetization of the ferromagnetic materials in the MDCPs and within the targets on the As were analyzed. After this, the suitable strengths of H0 and Rp for IA-MDT designs were reported. Dimensionless As, ranging from 2 to 7, was obtained with Rp ranging from 500 to 2500 nm, μ0H0 less than 0.8 T and a blood flow rate of 0.1 m s-1. The target-MDCP materials considered are iron-iron, iron-magnetite and SS409-magnetite, respectively.

Absorption and scattering by fractal aggregates and by their equivalent coated spheres

NASA Astrophysics Data System (ADS)

Kandilian, Razmig; Heng, Ri-Liang; Pilon, Laurent

2015-01-01

This paper demonstrates that the absorption and scattering cross-sections and the asymmetry factor of randomly oriented fractal aggregates of spherical monomers can be rapidly estimated as those of coated spheres with equivalent volume and average projected area. This was established for fractal aggregates with fractal dimension ranging from 2.0 to 3.0 and composed of up to 1000 monodisperse or polydisperse monomers with a wide range of size parameter and relative complex index of refraction. This equivalent coated sphere approximation was able to capture the effects of both multiple scattering and shading among constituent monomers on the integral radiation characteristics of the aggregates. It was shown to be superior to the Rayleigh-Debye-Gans approximation and to the equivalent coated sphere approximation proposed by Latimer. However, the scattering matrix element ratios of equivalent coated spheres featured large angular oscillations caused by internal reflection in the coating which were not observed in those of the corresponding fractal aggregates. Finally, the scattering phase function and the scattering matrix elements of aggregates with large monomer size parameter were found to have unique features that could be used in remote sensing applications.

The Multi-Scale Network Landscape of Collaboration

PubMed Central

Ahn, Yong-Yeol; Park, Juyong

2016-01-01

Propelled by the increasing availability of large-scale high-quality data, advanced data modeling and analysis techniques are enabling many novel and significant scientific understanding of a wide range of complex social, natural, and technological systems. These developments also provide opportunities for studying cultural systems and phenomena—which can be said to refer to all products of human creativity and way of life. An important characteristic of a cultural product is that it does not exist in isolation from others, but forms an intricate web of connections on many levels. In the creation and dissemination of cultural products and artworks in particular, collaboration and communication of ideas play an essential role, which can be captured in the heterogeneous network of the creators and practitioners of art. In this paper we propose novel methods to analyze and uncover meaningful patterns from such a network using the network of western classical musicians constructed from a large-scale comprehensive Compact Disc recordings data. We characterize the complex patterns in the network landscape of collaboration between musicians across multiple scales ranging from the macroscopic to the mesoscopic and microscopic that represent the diversity of cultural styles and the individuality of the artists. PMID:26990088

Flow characteristics and spillage mechanisms of an inclined quad-vortex range hood subject to influence from draft.

PubMed

Huang, Rong Fung; Chen, Jia-Kun; Lin, Jyun-Hua

2015-01-01

The flow and spillage characteristics of an inclined quad-vortex (IQV) range hood subject to the influence of drafts from various directions were studied. The laser-assisted smoke flow visualization technique was used to reveal the flow characteristics, and the tracer-gas (sulfur hexafluoride) concentration detection method was used to indicate the quantitative values of the capture efficiency of the hood. It was found that the leakage mechanisms of the IQV range hood are closely related to the flow characteristics. A critical draft velocity of about 0.5 m/s and a critical face velocity of about 0.25 m/s for the IQV range hood were found. When the IQV range hood was influenced by a draft with a velocity larger than the critical draft velocity, the spillage of pollutants became significant and the pollutant spillage rate increased with increasing draft velocity. At draft velocities less than or equal to the critical value, no containment leakages induced by the turbulence diffusion, reverse flow, or boundary-layer separation were observed, and the capture efficiency was about 100%. The IQV range hood exhibited a high ability to resist the influences of lateral and frontal drafts. The capture efficiency of the IQV range hood operated at the suction flow rate 5 to 9 m(3)/min is higher than that of the conventional range hood operated at 11 to 15 m(3)/min.

Fingerprinting captured CO2 using natural tracers: Determining CO2 fate and proving ownership

NASA Astrophysics Data System (ADS)

Flude, Stephanie; Gilfillan, Stuart; Johnston, Gareth; Stuart, Finlay; Haszeldine, Stuart

2016-04-01

In the long term, captured CO2 will most likely be stored in large saline formations and it is highly likely that CO2 from multiple operators will be injected into a single saline formation. Understanding CO2 behavior within the reservoir is vital for making operational decisions and often uses geochemical techniques. Furthermore, in the event of a CO2 leak, being able to identify the owner of the CO2 is of vital importance in terms of liability and remediation. Addition of geochemical tracers to the CO2 stream is an effective way of tagging the CO2 from different power stations, but may become prohibitively expensive at large scale storage sites. Here we present results from a project assessing whether the natural isotopic composition (C, O and noble gas isotopes) of captured CO2 is sufficient to distinguish CO2 captured using different technologies and from different fuel sources, from likely baseline conditions. Results include analytical measurements of CO2 captured from a number of different CO2 capture plants and a comprehensive literature review of the known and hypothetical isotopic compositions of captured CO2 and baseline conditions. Key findings from the literature review suggest that the carbon isotope composition will be most strongly controlled by that of the feedstock, but significant fractionation is possible during the capture process; oxygen isotopes are likely to be controlled by the isotopic composition of any water used in either the industrial process or the capture technology; and noble gases concentrations will likely be controlled by the capture technique employed. Preliminary analytical results are in agreement with these predictions. Comparison with summaries of likely storage reservoir baseline and shallow or surface leakage reservoir baseline data suggests that C-isotopes are likely to be valuable tracers of CO2 in the storage reservoir, while noble gases may be particularly valuable as tracers of potential leakage.

The power of structural modeling of sub-grid scales - application to astrophysical plasmas

NASA Astrophysics Data System (ADS)

Georgiev Vlaykov, Dimitar; Grete, Philipp

2015-08-01

In numerous astrophysical phenomena the dynamical range can span 10s of orders of magnitude. This implies more than billions of degrees-of-freedom and precludes direct numerical simulations from ever being a realistic possibility. A physical model is necessary to capture the unresolved physics occurring at the sub-grid scales (SGS).Structural modeling is a powerful concept which renders itself applicable to various physical systems. It stems from the idea of capturing the structure of the SGS terms in the evolution equations based on the scale-separation mechanism and independently of the underlying physics. It originates in the hydrodynamics field of large-eddy simulations. We apply it to the study of astrophysical MHD.Here, we present a non-linear SGS model for compressible MHD turbulence. The model is validated a priori at the tensorial, vectorial and scalar levels against of set of high-resolution simulations of stochastically forced homogeneous isotropic turbulence in a periodic box. The parameter space spans 2 decades in sonic Mach numbers (0.2 - 20) and approximately one decade in magnetic Mach number ~(1-8). This covers the super-Alfvenic sub-, trans-, and hyper-sonic regimes, with a range of plasma beta from 0.05 to 25. The Reynolds number is of the order of 103.At the tensor level, the model components correlate well with the turbulence ones, at the level of 0.8 and above. Vectorially, the alignment with the true SGS terms is encouraging with more than 50% of the model within 30° of the data. At the scalar level we look at the dynamics of the SGS energy and cross-helicity. The corresponding SGS flux terms have median correlations of ~0.8. Physically, the model represents well the two directions of the energy cascade.In comparison, traditional functional models exhibit poor local correlations with the data already at the scalar level. Vectorially, they are indifferent to the anisotropy of the SGS terms. They often struggle to represent the energy backscatter from small to large scales as well as the turbulent dynamo mechanism.Overall, the new model surpasses the traditional ones in all tests by a large margin.

Propagation, cascades, and agreement dynamics in complex communication and social networks

NASA Astrophysics Data System (ADS)

Lu, Qiming

Many modern and important technological, social, information and infrastructure systems can be viewed as complex systems with a large number of interacting components. Models of complex networks and dynamical interactions, as well as their applications are of fundamental interests in many aspects. Here, several stylized models of multiplex propagation and opinion dynamics are investigated on complex and empirical social networks. We first investigate cascade dynamics in threshold-controlled (multiplex) propagation on random geometric networks. We find that such local dynamics can serve as an efficient, robust, and reliable prototypical activation protocol in sensor networks in responding to various alarm scenarios. We also consider the same dynamics on a modified network by adding a few long-range communication links, resulting in a small-world network. We find that such construction can further enhance and optimize the speed of the network's response, while keeping energy consumption at a manageable level. We also investigate a prototypical agent-based model, the Naming Game, on two-dimensional random geometric networks. The Naming Game [A. Baronchelli et al., J. Stat. Mech.: Theory Exp. (2006) P06014.] is a minimal model, employing local communications that captures the emergence of shared communication schemes (languages) in a population of autonomous semiotic agents. Implementing the Naming Games with local broadcasts on random geometric graphs, serves as a model for agreement dynamics in large-scale, autonomously operating wireless sensor networks. Further, it captures essential features of the scaling properties of the agreement process for spatially-embedded autonomous agents. Among the relevant observables capturing the temporal properties of the agreement process, we investigate the cluster-size distribution and the distribution of the agreement times, both exhibiting dynamic scaling. We also present results for the case when a small density of long-range communication links are added on top of the random geometric graph, resulting in a "small-world"-like network and yielding a significantly reduced time to reach global agreement. We construct a finite-size scaling analysis for the agreement times in this case. When applying the model of Naming Game on empirical social networks, this stylized agent-based model captures essential features of agreement dynamics in a network of autonomous agents, corresponding to the development of shared classification schemes in a network of artificial agents or opinion spreading and social dynamics in social networks. Our study focuses on the impact that communities in the underlying social graphs have on the outcome of the agreement process. We find that networks with strong community structure hinder the system from reaching global agreement; the evolution of the Naming Game in these networks maintains clusters of coexisting opinions indefinitely. Further, we investigate agent-based network strategies to facilitate convergence to global consensus.

Mapping mitochondrial heteroplasmy in a Leydig tumor by laser capture micro-dissection and cycling temperature capillary electrophoresis.

PubMed

Refinetti, Paulo; Arstad, Christian; Thilly, William G; Morgenthaler, Stephan; Ekstrøm, Per Olaf

2017-01-01

The growth of tumor cells is accompanied by mutations in nuclear and mitochondrial genomes creating marked genetic heterogeneity. Tumors also contain non-tumor cells of various origins. An observed somatic mitochondrial mutation would have occurred in a founding cell and spread through cell division. Micro-anatomical dissection of a tumor coupled with assays for mitochondrial point mutations permits new insights into this growth process. More generally, the ability to detect and trace, at a histological level, somatic mitochondrial mutations in human tissues and tumors, makes these mutations into markers for lineage tracing. A tumor was first sampled by a large punch biopsy and scanned for any significant degree of heteroplasmy in a set of sequences containing known mutational hotspots of the mitochondrial genome. A heteroplasmic tumor was sliced at a 12 μm thickness and placed on membranes. Laser capture micro-dissection was used to take 25000 μm 2 subsamples or spots. After DNA amplification, cycling temperature capillary electrophoresis (CTCE) was used on the laser captured samples to quantify mitochondrial mutant fractions. Of six testicular tumors studied, one, a Leydig tumor, was discovered to carry a detectable degree of heteroplasmy for two separate point mutations: a C → T mutation at bp 64 and a T → C mutation found at bp 152. From this tumor, 381 spots were sampled with laser capture micro-dissection. The ordered distribution of spots exhibited a wide range of fractions of the mutant sequences from 0 to 100% mutant copies. The two mutations co-distributed in the growing tumor indicating they were present on the same genome copies in the founding cell. Laser capture microdissection of sliced tumor samples coupled with CTCE-based point mutation assays provides an effective and practical means to obtain maps of mitochondrial mutational heteroplasmy within human tumors.

A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer

PubMed Central

Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

2015-01-01

Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10−4 to 102 ng/mL). PMID:26007739

A Highly Sensitive Porous Silicon (P-Si)-Based Human Kallikrein 2 (hK2) Immunoassay Platform toward Accurate Diagnosis of Prostate Cancer.

PubMed

Lee, Sang Wook; Hosokawa, Kazuo; Kim, Soyoun; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas; Maeda, Mizuo

2015-05-22

Levels of total human kallikrein 2 (hK2), a protein involved the pathology of prostate cancer (PCa), could be used as a biomarker to aid in the diagnosis of this disease. In this study, we report on a porous silicon antibody immunoassay platform for the detection of serum levels of total hK2. The surface of porous silicon has a 3-dimensional macro- and nanoporous structure, which offers a large binding capacity for capturing probe molecules. The tailored pore size of the porous silicon also allows efficient immobilization of antibodies by surface adsorption, and does not require chemical immobilization. Monoclonal hK2 capture antibody (6B7) was dispensed onto P-Si chip using a piezoelectric dispenser. In total 13 × 13 arrays (169 spots) were spotted on the chip with its single spot volume of 300 pL. For an optimization of capture antibody condition, we firstly performed an immunoassay of the P-Si microarray under a titration series of hK2 in pure buffer (PBS) at three different antibody densities (75, 100 and 145 µg/mL). The best performance of the microarray platform was seen at 100 µg/mL of the capture antibody concentration (LOD was 100 fg/mL). The platform then was subsequently evaluated for a titration series of serum-spiked hK2 samples. The developed platform utilizes only 15 µL of serum per test and the total assay time is about 3 h, including immobilization of the capture antibody. The detection limit of the hK2 assay was 100 fg/mL in PBS buffer and 1 pg/mL in serum with a dynamic range of 106 (10(-4) to 10(2) ng/mL).

Small Angle Neutron Scattering Observation of Chain Retraction after a Large Step Deformation

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

Blanchard, A.; Heinrich, M.; Pyckhout-Hintzen, W.

The process of retraction in entangled linear chains after a fast nonlinear stretch was detected from time-resolved but quenched small angle neutron scattering (SANS) experiments on long, well-entangled polyisoprene chains. The statically obtained SANS data cover the relevant time regime for retraction, and they provide a direct, microscopic verification of this nonlinear process as predicted by the tube model. Clear, quantitative agreement is found with recent theories of contour length fluctuations and convective constraint release, using parameters obtained mainly from linear rheology. The theory captures the full range of scattering vectors once the crossover to fluctuations on length scales belowmore » the tube diameter is accounted for.« less

Estimating Animal Abundance in Ground Beef Batches Assayed with Molecular Markers

PubMed Central

Hu, Xin-Sheng; Simila, Janika; Platz, Sindey Schueler; Moore, Stephen S.; Plastow, Graham; Meghen, Ciaran N.

2012-01-01

Estimating animal abundance in industrial scale batches of ground meat is important for mapping meat products through the manufacturing process and for effectively tracing the finished product during a food safety recall. The processing of ground beef involves a potentially large number of animals from diverse sources in a single product batch, which produces a high heterogeneity in capture probability. In order to estimate animal abundance through DNA profiling of ground beef constituents, two parameter-based statistical models were developed for incidence data. Simulations were applied to evaluate the maximum likelihood estimate (MLE) of a joint likelihood function from multiple surveys, showing superiority in the presence of high capture heterogeneity with small sample sizes, or comparable estimation in the presence of low capture heterogeneity with a large sample size when compared to other existing models. Our model employs the full information on the pattern of the capture-recapture frequencies from multiple samples. We applied the proposed models to estimate animal abundance in six manufacturing beef batches, genotyped using 30 single nucleotide polymorphism (SNP) markers, from a large scale beef grinding facility. Results show that between 411∼1367 animals were present in six manufacturing beef batches. These estimates are informative as a reference for improving recall processes and tracing finished meat products back to source. PMID:22479559

Characterization of Four Multidrug Resistance Plasmids Captured from the Sediments of an Urban Coastal Wetland

PubMed Central

Botts, Ryan T.; Apffel, Brooke A.; Walters, C. J.; Davidson, Kelly E.; Echols, Ryan S.; Geiger, Michael R.; Guzman, Victoria L.; Haase, Victoria S.; Montana, Michal A.; La Chat, Chip A.; Mielke, Jenna A.; Mullen, Kelly L.; Virtue, Cierra C.; Brown, Celeste J.; Top, Eva M.; Cummings, David E.

2017-01-01

Self-transmissible and mobilizable plasmids contribute to the emergence and spread of multidrug-resistant bacteria by enabling the horizontal transfer of acquired antibiotic resistance. The objective of this study was to capture and characterize self-transmissible and mobilizable resistance plasmids from a coastal wetland impacted by urban stormwater runoff and human wastewater during the rainy season. Four plasmids were captured, two self-transmissible and two mobilizable, using both mating and enrichment approaches. Plasmid genomes, sequenced with either Illumina or PacBio platforms, revealed representatives of incompatibility groups IncP-6, IncR, IncN3, and IncF. The plasmids ranged in size from 36 to 144 kb and encoded known resistance genes for most of the major classes of antibiotics used to treat Gram-negative infections (tetracyclines, sulfonamides, β-lactams, fluoroquinolones, aminoglycosides, and amphenicols). The mobilizable IncP-6 plasmid pLNU-11 was discovered in a strain of Citrobacter freundii enriched from the wetland sediments with tetracycline and nalidixic acid, and encodes a novel AmpC-like β-lactamase (blaWDC-1), which shares less than 62% amino acid sequence identity with the PDC class of β-lactamases found in Pseudomonas aeruginosa. Although the IncR plasmid pTRE-1611 was captured by mating wetland bacteria with P. putida KT2440 as recipient, it was found to be mobilizable rather than self-transmissible. Two self-transmissible multidrug-resistance plasmids were also captured: the small (48 kb) IncN3 plasmid pTRE-131 was captured by mating wetland bacteria with Escherichia coli HY842 where it is seemed to be maintained at nearly 240 copies per cell, while the large (144 kb) IncF plasmid pTRE-2011, which was isolated from a cefotaxime-resistant environmental strain of E. coli ST744, exists at just a single copy per cell. Furthermore, pTRE-2011 bears the globally epidemic blaCTX-M-55 extended-spectrum β-lactamase downstream of ISEcp1. Our results indicate that urban coastal wetlands are reservoirs of diverse self-transmissible and mobilizable plasmids of relevance to human health. PMID:29067005

Modeling and optimal design of CO2 Direct Air Capture systems in large arrays

NASA Astrophysics Data System (ADS)

Sadri Irani, Samaneh; Luzzatto-Fegiz, Paolo

2017-11-01

As noted by the 2014 IPCC report, while the rise in atmospheric CO2 would be slowed by emissions reductions, removing atmospheric CO2 is an important part of possible paths to climate stabilization. Direct Air Capture of CO2 with chemicals (DAC) is one of several proposed carbon capture technologies. There is an ongoing debate on whether DAC is an economically viable approach to alleviate climate change. In addition, like all air capture strategies, DAC is strongly constrained by the net-carbon problem, namely the need to control CO2 emissions associated with the capture process (for example, if DAC not powered by renewables). Research to date has focused on the chemistry and economics of individual DAC devices. However, the fluid mechanics of their large-scale deployment has not been examined in the literature, to the best of our knowledge. In this presentation, we develop a model for flow through an array of DAC devices, varying their lateral extent and their separation. We build on a recent theory of canopy flows, introducing terms for CO2 entrainment into the array boundary layer, and transport into the farm. In addition, we examine the possibility of driving flow passively by wind, thereby reducing energy consumption. The optimal operational design is established considering the total cost, drag force, energy consumption and total CO2 capture.

Camera trap placement and the potential for bias due to trails and other features

PubMed Central

Forrester, Tavis D.

2017-01-01

Camera trapping has become an increasingly widespread tool for wildlife ecologists, with large numbers of studies relying on photo capture rates or presence/absence information. It is increasingly clear that camera placement can directly impact this kind of data, yet these biases are poorly understood. We used a paired camera design to investigate the effect of small-scale habitat features on species richness estimates, and capture rate and detection probability of several mammal species in the Shenandoah Valley of Virginia, USA. Cameras were deployed at either log features or on game trails with a paired camera at a nearby random location. Overall capture rates were significantly higher at trail and log cameras compared to their paired random cameras, and some species showed capture rates as much as 9.7 times greater at feature-based cameras. We recorded more species at both log (17) and trail features (15) than at their paired control cameras (13 and 12 species, respectively), yet richness estimates were indistinguishable after 659 and 385 camera nights of survey effort, respectively. We detected significant increases (ranging from 11–33%) in detection probability for five species resulting from the presence of game trails. For six species detection probability was also influenced by the presence of a log feature. This bias was most pronounced for the three rodents investigated, where in all cases detection probability was substantially higher (24.9–38.2%) at log cameras. Our results indicate that small-scale factors, including the presence of game trails and other features, can have significant impacts on species detection when camera traps are employed. Significant biases may result if the presence and quality of these features are not documented and either incorporated into analytical procedures, or controlled for in study design. PMID:29045478

Camera trap placement and the potential for bias due to trails and other features.

PubMed

Kolowski, Joseph M; Forrester, Tavis D

2017-01-01

Camera trapping has become an increasingly widespread tool for wildlife ecologists, with large numbers of studies relying on photo capture rates or presence/absence information. It is increasingly clear that camera placement can directly impact this kind of data, yet these biases are poorly understood. We used a paired camera design to investigate the effect of small-scale habitat features on species richness estimates, and capture rate and detection probability of several mammal species in the Shenandoah Valley of Virginia, USA. Cameras were deployed at either log features or on game trails with a paired camera at a nearby random location. Overall capture rates were significantly higher at trail and log cameras compared to their paired random cameras, and some species showed capture rates as much as 9.7 times greater at feature-based cameras. We recorded more species at both log (17) and trail features (15) than at their paired control cameras (13 and 12 species, respectively), yet richness estimates were indistinguishable after 659 and 385 camera nights of survey effort, respectively. We detected significant increases (ranging from 11-33%) in detection probability for five species resulting from the presence of game trails. For six species detection probability was also influenced by the presence of a log feature. This bias was most pronounced for the three rodents investigated, where in all cases detection probability was substantially higher (24.9-38.2%) at log cameras. Our results indicate that small-scale factors, including the presence of game trails and other features, can have significant impacts on species detection when camera traps are employed. Significant biases may result if the presence and quality of these features are not documented and either incorporated into analytical procedures, or controlled for in study design.

Stardust impact analogs: Resolving pre- and postimpact mineralogy in Stardust Al foils

NASA Astrophysics Data System (ADS)

Wozniakiewicz, Penelope J.; Ishii, Hope A.; Kearsley, Anton T.; Burchell, Mark J.; Bradley, John P.; Price, Mark C.; Teslich, Nick; Lee, Martin R.; Cole, Mike J.

2012-04-01

The grains returned by NASA's Stardust mission from comet 81P/Wild 2 represent a valuable sample set that is significantly advancing our understanding of small solar system bodies. However, the grains were captured via impact at ˜6.1 km s-1 and have experienced pressures and temperatures that caused alteration. To ensure correct interpretations of comet 81P/Wild 2 mineralogy, and therefore preaccretional or parent body processes, an understanding of the effects of capture is required. Using a two-stage light-gas gun, we recreated Stardust encounter conditions and generated a series of impact analogs for a range of minerals of cometary relevance into flight spare Al foils. Through analyses of both preimpact projectiles and postimpact analogs by transmission electron microscopy, we explore the impact processes occurring during capture and distinguish between those materials inherent to the impactor and those that are the product of capture. We review existing and present additional data on olivine, diopside, pyrrhotite, and pentlandite. We find that surviving crystalline material is observed in most single grain impactor residues. However, none is found in that of a relatively monodisperse aggregate. A variety of impact-generated components are observed in all samples. Al incorporation into melt-derived phases allows differentiation between melt and shock-induced phases. In single grain impactor residues, impact-generated phases largely retain original (nonvolatile) major element ratios. We conclude that both surviving and impact-generated phases in residues of single grain impactors provide valuable information regarding the mineralogy of the impacting grain whilst further studies are required to fully understand aggregate impacts and the role of subgrain interactions during impact.

Algal Energy Conversion and Capture

NASA Astrophysics Data System (ADS)

Hazendonk, P.

2015-12-01

We address the potential for energy conversions and capture for: energy generation; reduction in energy use; reduction in greenhouse gas emissions; remediation of water and air pollution; protection and enhancement of soil fertility. These processes have the potential to sequester carbon at scales that may have global impact. Energy conversion and capture strategies evaluate energy use and production from agriculture, urban areas and industries, and apply existing and emerging technologies to reduce and recapture energy embedded in waste products. The basis of biocrude production from Micro-algal feedstocks: 1) The nutrients from the liquid fraction of waste streams are concentrated and fed into photo bioreactors (essentially large vessels in which microalgae are grown) along with CO2 from flue gasses from down stream processes. 2) The algae are processed to remove high value products such as proteins and beta-carotenes. The advantage of algae feedstocks is the high biomass productivity is 30-50 times that of land based crops and the remaining biomass contains minimal components that are difficult to convert to biocrude. 3) The remaining biomass undergoes hydrothermal liquefaction to produces biocrude and biochar. The flue gasses of this process can be used to produce electricity (fuel cell) and subsequently fed back into the photobioreactor. The thermal energy required for this process is small, hence readily obtained from solar-thermal sources, and furthermore no drying or preprocessing is required keeping the energy overhead extremely small. 4) The biocrude can be upgraded and refined as conventional crude oil, creating a range of liquid fuels. In principle this process can be applied on the farm scale to the municipal scale. Overall, our primary food production is too dependent on fossil fuels. Energy conversion and capture can make food production sustainable.

Long-range Self-interacting Dark Matter in the Sun

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

Chen, Jing; State Key Laboratory of Theoretical Physics, Kavli Institute for Theoretical Physics China,Institute of Theoretical Physics, Chinese Academy of Science,Zhong Guan Cun East Street 55#, Beijing, 100190; Liang, Zheng-Liang

2015-12-10

We investigate the implications of the long-rang self-interaction on both the self-capture and the annihilation of the self-interacting dark matter (SIDM) trapped in the Sun. Our discussion is based on a specific SIDM model in which DM particles self-interact via a light scalar mediator, or Yukawa potential, in the context of quantum mechanics. Within this framework, we calculate the self-capture rate across a broad region of parameter space. While the self-capture rate can be obtained separately in the Born regime with perturbative method, and in the classical limits with the Rutherford formula, our calculation covers the gap between in amore » non-perturbative fashion. Besides, the phenomenology of both the Sommerfeld-enhanced s- and p-wave annihilation of the solar SIDM is also involved in our discussion. Moreover, by combining the analysis of the Super-Kamiokande (SK) data and the observed DM relic density, we constrain the nuclear capture rate of the DM particles in the presence of the dark Yukawa potential. The consequence of the long-range dark force on probing the solar SIDM turns out to be significant if the force-carrier is much lighter than the DM particle, and a quantitative analysis is provided.« less

Mercury content of the Springfield coal, Indiana and Kentucky

USGS Publications Warehouse

Hower, J.C.; Mastalerz, Maria; Drobniak, A.; Quick, J.C.; Eble, C.F.; Zimmerer, M.J.

2005-01-01

With pending regulation of mercury emissions in United States power plants, its control at every step of the combustion process is important. An understanding of the amount of mercury in coal at the mine is the first step in this process. The Springfield coal (Middle Pennsylvanian) is one of the most important coal resources in the Illinois Basin. In Indiana and western Kentucky, Hg contents range from 0.02 to 0.55 ppm. The variation within small areas is comparable to the variation on a basin basis. Considerable variation also exists within the coal column, ranging from 0.04 to 0.224 ppm at one Kentucky site. Larger variations likely exist, since that site does not represent the highest whole-seam Hg nor was the collection of samples done with optimization of trace element variations in mind. Estimates of Hg capture by currently installed pollution control equipment range from 9-53% capture by cold-side electrostatic precipitators (ESP) and 47-81% Hg capture for ESP + flue-gas desulfurization (FGD). The high Cl content of many Illinois basin coals and the installation of Selective Catalytic Reduction of NOx enhances the oxidation of Hg species, improving the ability of ESPs and FGDs to capture Hg. ?? 2005 Elsevier B.V. All rights reserved.

Development of a long-gauge vibration sensor

NASA Astrophysics Data System (ADS)

Kung, Peter; Comanici, Maria I.; Li, Qian; Zhang, Yiwei

2014-11-01

Recently, we found that by terminating a long length of fiber of up to 1 km with an in-fiber cavity structure, the entire structure can detect vibrations over a frequency range from 5 Hz to 100 Hz. We want to determine whether the structure (including packaging) can be optimized to detect vibrations at even higher frequencies. The structure can be used as a distributed vibration sensor mounted on large motors and other rotating machines to capture the entire frequency spectrum of the associated vibration signals, and therefore, replace the many accelerometers, which add to the maintenance cost. Similarly, it will help detect in-slot vibrations which cause intermittent contact leading to sparking under high voltages inside air-cooled generators. However, that will require the sensor to detect frequencies associated with vibration sparking, ranging from 6 kHz to 15 kHz. Then, at even higher frequencies, the structure can be useful to detect acoustic vibrations (30 kHz to 150 kHz) associated with partial discharge (PD) in generators and transformers. Detecting lower frequencies in the range 2 Hz to 200 Hz makes the sensor suitable for seismic studies and falls well into the vibrations associated with rotating machines. Another application of interest is corrosion detection in large reenforced concrete structures by inserting the sensor along a long hole drilled around structures showing signs of corrosion. The frequency response for the proposed long-gauge vibration sensor depends on packaging.

Development of a long-gauge vibration sensor

NASA Astrophysics Data System (ADS)

Kung, Peter; Comanici, Maria I.; Li, Qian; Zhang, Yiwei

2015-03-01

We have recently found that a long length of fiber of up to 1 km terminated with an in-fiber cavity structure can detect vibrations over a frequency range from 5 Hz to 2 kHz. We want to determine whether the sensor (including packaging) can be optimized to detect vibrations at even higher frequencies. The structure can be used as a distributed vibration sensor mounted on large motors and other rotating machines to capture the entire frequency spectrum of the associated vibration signals, and therefore, replace the many accelerometers, which add to maintenance cost. The sensor may also help detect in-slot vibrations which cause intermittent contact leading to sparking under high voltages inside air-cooled generators. However, that requires the sensor to detect frequencies associated with vibration sparking, ranging from 6 kHz to 15 kHz. Acoustic vibration monitoring may need sensing at even higher frequencies (30 kHz to 150 kHz) associated with partial discharge (PD) in generators and transformers. Detecting lower frequencies in the range 2 Hz to 200 Hz makes the sensor suitable for seismic studies and falls well into the vibrations associated with rotating machines. Another application of interest is corrosion detection in large re-enforced concrete structures by inserting the sensor along a long hole drilled around structures showing signs of corrosion. The frequency response for the proposed longgauge vibration sensor depends on packaging.

The influence of leaf size and shape on leaf thermal dynamics: does theory hold up under natural conditions?

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

Leigh, A.; Sevanto, Sanna Annika; Close, J. D.

Laboratory studies on artificial leaves suggest that leaf thermal dynamics are strongly influenced by the two-dimensional size and shape of leaves and associated boundary layer thickness. Hot environments are therefore said to favour selection for small, narrow or dissected leaves. Empirical evidence from real leaves under field conditions is scant and traditionally based on point measurements that do not capture spatial variation in heat load. Here in this study, we used thermal imagery under field conditions to measure the leaf thermal time constant (τ) in summer and the leaf-to-air temperature difference (ΔT) and temperature range across laminae (T range) duringmore » winter, autumn and summer for 68 Proteaceae species. We investigated the influence of leaf area and margin complexity relative to effective leaf width (w e), the latter being a more direct indicator of boundary layer thickness. Normalized difference of margin complexity had no or weak effects on thermal dynamics, but w e strongly predicted τ and ΔT, whereas leaf area influenced T range. Unlike artificial leaves, however, spatial temperature distribution in large leaves appeared to be governed largely by structural variation. Therefore, we agree that small size, specifically we, has adaptive value in hot environments but not with the idea that thermal regulation is the primary evolutionary driver of leaf dissection.« less

The influence of leaf size and shape on leaf thermal dynamics: does theory hold up under natural conditions?

DOE PAGES

Leigh, A.; Sevanto, Sanna Annika; Close, J. D.; ...

2016-11-05

Laboratory studies on artificial leaves suggest that leaf thermal dynamics are strongly influenced by the two-dimensional size and shape of leaves and associated boundary layer thickness. Hot environments are therefore said to favour selection for small, narrow or dissected leaves. Empirical evidence from real leaves under field conditions is scant and traditionally based on point measurements that do not capture spatial variation in heat load. Here in this study, we used thermal imagery under field conditions to measure the leaf thermal time constant (τ) in summer and the leaf-to-air temperature difference (ΔT) and temperature range across laminae (T range) duringmore » winter, autumn and summer for 68 Proteaceae species. We investigated the influence of leaf area and margin complexity relative to effective leaf width (w e), the latter being a more direct indicator of boundary layer thickness. Normalized difference of margin complexity had no or weak effects on thermal dynamics, but w e strongly predicted τ and ΔT, whereas leaf area influenced T range. Unlike artificial leaves, however, spatial temperature distribution in large leaves appeared to be governed largely by structural variation. Therefore, we agree that small size, specifically we, has adaptive value in hot environments but not with the idea that thermal regulation is the primary evolutionary driver of leaf dissection.« less

Simultaneous measurement of polymerization stress and curing kinetics for photo-polymerized composites with high filler contents.

PubMed

Wang, Zhengzhi; Landis, Forrest A; Giuseppetti, Anthony A M; Lin-Gibson, Sheng; Chiang, Martin Y M

2014-12-01

Photopolymerized composites are used in a broad range of applications with their performance largely directed by reaction kinetics and contraction accompanying polymerization. The present study was to demonstrate an instrument capable of simultaneously collecting multiple kinetics parameters for a wide range of photopolymerizable systems: degree of conversion (DC), reaction exotherm, and polymerization stress (PS). Our system consisted of a cantilever beam-based instrument (tensometer) that has been optimized to capture a large range of stress generated by lightly-filled to highly-filled composites. The sample configuration allows the tensometer to be coupled to a fast near infrared (NIR) spectrometer collecting spectra in transmission mode. Using our instrument design, simultaneous measurements of PS and DC are performed, for the first time, on a commercial composite with ≈80% (by mass) silica particle fillers. The in situ NIR spectrometer collects more than 10 spectra per second, allowing for thorough characterization of reaction kinetics. With increased instrument sensitivity coupled with the ability to collect real time reaction kinetics information, we show that the external constraint imposed by the cantilever beam during polymerization could affect the rate of cure and final degree of polymerization. The present simultaneous measurement technique is expected to provide new insights into kinetics and property relationships for photopolymerized composites with high filler content such as dental restorative composites. Published by Elsevier Ltd.

Simultaneous Measurement of Polymerization Stress and Curing Kinetics for Photo-polymerized Composites with High Filler Contents

PubMed Central

Wang, Zhengzhi; Landis, Forrest A.; Giuseppetti, Anthony A.M.; Lin-Gibson, Sheng; Chiang, Martin Y.M.

2015-01-01

Objectives Photopolymerized composites are used in a broad range of applications with their performance largely directed by reaction kinetics and contraction accompanying polymerization. The present study was to demonstrate an instrument capable of simultaneously collecting multiple kinetics parameters for a wide range of photopolymerizable systems: degree of conversion (DC), reaction exotherm, and polymerization stress (PS). Methods Our system consisted of a cantilever beam-based instrument (tensometer) that has been optimized to capture a large range of stress generated by lightly-filled to highly-filled composites. The sample configuration allows the tensometer to be coupled to a fast near infrared (NIR) spectrometer collecting spectra in transmission mode. Results Using our instrument design, simultaneous measurements of PS and DC are performed, for the first time, on a commercial composite with ≈ 80 % (by mass) silica particle fillers. The in situ NIR spectrometer collects more than 10 spectra per second, allowing for thorough characterization of reaction kinetics. With increased instrument sensitivity coupled with the ability to collect real time reaction kinetics information, we show that the external constraint imposed by the cantilever beam during polymerization could affect the rate of cure and final degree of polymerization. Significance The present simultaneous measurement technique is expected to provide new insights into kinetics and property relationships for photopolymerized composites with high filler content such as dental restorative composites. PMID:25443160

Bench-Scale Process for Low-Cost Carbon Dioxide (CO2) Capture Using a Phase-Changing Absorbent

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

Westendorf, Tiffany; Caraher, Joel; Chen, Wei

2015-03-31

The objective of this project is to design and build a bench-scale process for a novel phase-changing aminosilicone-based CO2-capture solvent. The project will establish scalability and technical and economic feasibility of using a phase-changing CO2-capture absorbent for post-combustion capture of CO2 from coal-fired power plants with 90% capture efficiency and 95% CO2 purity at a cost of $40/tonne of CO2 captured by 2025 and a cost of <$10/tonne of CO2 captured by 2035. In the first budget period of this project, the bench-scale phase-changing CO2 capture process was designed using data and operating experience generated under a previous project (ARPA-emore » project DE-AR0000084). Sizing and specification of all major unit operations was completed, including detailed process and instrumentation diagrams. The system was designed to operate over a wide range of operating conditions to allow for exploration of the effect of process variables on CO2 capture performance.« less

Exploring incomplete fusion fraction in 6,7Li induced nuclear reactions

NASA Astrophysics Data System (ADS)

Parkar, V. V.; Jha, V.; Kailas, S.

2017-11-01

We have included breakup effects explicitly to simultaneously calculate the measured cross-sections of the complete fusion, incomplete fusion, and total fusion for 6,7Li projectiles on various targets using the Continuum Discretized Coupled Channels method. The breakup absorption cross-sections obtained with different choices of short range imaginary potentials are utilized to evaluate the individual α-capture and d/t-capture cross-sections and compare with the measured data. It is interesting to note, while in case of 7Li projectile the cross-sections for triton-ICF/triton-capture is far more dominant than α-ICF/α-capture at all energies, similar behavior is not observed in case of 6Li projectile for the deuteron-ICF/deuteron-capture and α-ICF/α-capture. Both these observations are also corroborated by the experimental data for all the systems studied.

Study of 3-D Dynamic Roughness Effects on Flow Over a NACA 0012 Airfoil Using Large Eddy Simulations at Low Reynolds Numbers

NASA Astrophysics Data System (ADS)

Guda, Venkata Subba Sai Satish

There have been several advancements in the aerospace industry in areas of design such as aerodynamics, designs, controls and propulsion; all aimed at one common goal i.e. increasing efficiency --range and scope of operation with lesser fuel consumption. Several methods of flow control have been tried. Some were successful, some failed and many were termed as impractical. The low Reynolds number regime of 104 - 105 is a very interesting range. Flow physics in this range are quite different than those of higher Reynolds number range. Mid and high altitude UAV's, MAV's, sailplanes, jet engine fan blades, inboard helicopter rotor blades and wind turbine rotors are some of the aerodynamic applications that fall in this range. The current study deals with using dynamic roughness as a means of flow control over a NACA 0012 airfoil at low Reynolds numbers. Dynamic 3-D surface roughness elements on an airfoil placed near the leading edge aim at increasing the efficiency by suppressing the effects of leading edge separation like leading edge stall by delaying or totally eliminating flow separation. A numerical study of the above method has been carried out by means of a Large Eddy Simulation, a mathematical model for turbulence in Computational Fluid Dynamics, owing to the highly unsteady nature of the flow. A user defined function has been developed for the 3-D dynamic roughness element motion. Results from simulations have been compared to those from experimental PIV data. Large eddy simulations have relatively well captured the leading edge stall. For the clean cases, i.e. with the DR not actuated, the LES was able to reproduce experimental results in a reasonable fashion. However DR simulation results show that it fails to reattach the flow and suppress flow separation compared to experiments. Several novel techniques of grid design and hump creation are introduced through this study.

Collecting verbal autopsies: improving and streamlining data collection processes using electronic tablets.

PubMed

Flaxman, Abraham D; Stewart, Andrea; Joseph, Jonathan C; Alam, Nurul; Alam, Sayed Saidul; Chowdhury, Hafizur; Mooney, Meghan D; Rampatige, Rasika; Remolador, Hazel; Sanvictores, Diozele; Serina, Peter T; Streatfield, Peter Kim; Tallo, Veronica; Murray, Christopher J L; Hernandez, Bernardo; Lopez, Alan D; Riley, Ian Douglas

2018-02-01

There is increasing interest in using verbal autopsy to produce nationally representative population-level estimates of causes of death. However, the burden of processing a large quantity of surveys collected with paper and pencil has been a barrier to scaling up verbal autopsy surveillance. Direct electronic data capture has been used in other large-scale surveys and can be used in verbal autopsy as well, to reduce time and cost of going from collected data to actionable information. We collected verbal autopsy interviews using paper and pencil and using electronic tablets at two sites, and measured the cost and time required to process the surveys for analysis. From these cost and time data, we extrapolated costs associated with conducting large-scale surveillance with verbal autopsy. We found that the median time between data collection and data entry for surveys collected on paper and pencil was approximately 3 months. For surveys collected on electronic tablets, this was less than 2 days. For small-scale surveys, we found that the upfront costs of purchasing electronic tablets was the primary cost and resulted in a higher total cost. For large-scale surveys, the costs associated with data entry exceeded the cost of the tablets, so electronic data capture provides both a quicker and cheaper method of data collection. As countries increase verbal autopsy surveillance, it is important to consider the best way to design sustainable systems for data collection. Electronic data capture has the potential to greatly reduce the time and costs associated with data collection. For long-term, large-scale surveillance required by national vital statistical systems, electronic data capture reduces costs and allows data to be available sooner.

Vehicle-triggered video compression/decompression for fast and efficient searching in large video databases

NASA Astrophysics Data System (ADS)

Bulan, Orhan; Bernal, Edgar A.; Loce, Robert P.; Wu, Wencheng

2013-03-01

Video cameras are widely deployed along city streets, interstate highways, traffic lights, stop signs and toll booths by entities that perform traffic monitoring and law enforcement. The videos captured by these cameras are typically compressed and stored in large databases. Performing a rapid search for a specific vehicle within a large database of compressed videos is often required and can be a time-critical life or death situation. In this paper, we propose video compression and decompression algorithms that enable fast and efficient vehicle or, more generally, event searches in large video databases. The proposed algorithm selects reference frames (i.e., I-frames) based on a vehicle having been detected at a specified position within the scene being monitored while compressing a video sequence. A search for a specific vehicle in the compressed video stream is performed across the reference frames only, which does not require decompression of the full video sequence as in traditional search algorithms. Our experimental results on videos captured in a local road show that the proposed algorithm significantly reduces the search space (thus reducing time and computational resources) in vehicle search tasks within compressed video streams, particularly those captured in light traffic volume conditions.

Fusion of Terrestrial and Airborne Laser Data for 3D modeling Applications

NASA Astrophysics Data System (ADS)

Mohammed, Hani Mahmoud

This thesis deals with the 3D modeling phase of the as-built large BIM projects. Among several means of BIM data capturing, such as photogrammetric or range tools, laser scanners have been one of the most efficient and practical tool for a long time. They can generate point clouds with high resolution for 3D models that meet nowadays' market demands. The current 3D modeling projects of as-built BIMs are mainly focused on using one type of laser scanner data, such as Airborne or Terrestrial. According to the literatures, no significant (few) efforts were made towards the fusion of heterogeneous laser scanner data despite its importance. The importance of the fusion of heterogeneous data arises from the fact that no single type of laser data can provide all the information about BIM, especially for large BIM projects that are existing on a large area, such as university buildings, or Heritage places. Terrestrial laser scanners are able to map facades of buildings and other terrestrial objects. However, they lack the ability to map roofs or higher parts in the BIM project. Airborne laser scanner on the other hand, can map roofs of the buildings efficiently and can map only small part of the facades. Short range laser scanners can map the interiors of the BIM projects, while long range scanners are used for mapping wide exterior areas in BIM projects. In this thesis the long range laser scanner data obtained in the Stop-and-Go mapping mode, the short range laser scanner data, obtained in a fully static mapping mode, and the airborne laser data are all fused together to bring a complete effective solution for a large BIM project. Working towards the 3D modeling of BIM projects, the thesis framework starts with the registration of the data, where a new fast automatic registration algorithm were developed. The next step is to recognize the different objects in the BIM project (classification), and obtain 3D models for the buildings. The last step is the development of an occlusion removal algorithm to efficiently retain parts of the buildings occluded by surrounding objects such as trees, vehicles, or street poles.

Cine-servo lens technology for 4K broadcast and cinematography

NASA Astrophysics Data System (ADS)

Nurishi, Ryuji; Wakazono, Tsuyoshi; Usui, Fumiaki

2015-09-01

Central to the rapid evolution of 4K image capture technology in the past few years, deployment of large-format cameras with Super35mm Single Sensors is increasing in TV production for diverse shows such as dramas, documentaries, wildlife, and sports. While large format image capture has been the standard in the cinema world for quite some time, the recent experiences within the broadcast industry have revealed a variety of requirement differences for large format lenses compared to those of the cinema industry. A typical requirement for a broadcast lens is a considerably higher zoom ratio in order to avoid changing lenses in the middle of a live event, which is mostly not the case for traditional cinema productions. Another example is the need for compact size, light weight, and servo operability for a single camera operator shooting in a shoulder-mount ENG style. On the other hand, there are new requirements that are common to both worlds, such as smooth and seamless change in angle of view throughout the long zoom range, which potentially offers new image expression that never existed in the past. This paper will discuss the requirements from the two industries of cinema and broadcast, while at the same time introducing the new technologies and new optical design concepts applied to our latest "CINE-SERVO" lens series which presently consists of two models, CN7x17KAS-S and CN20x50IAS-H. It will further explain how Canon has realized 4K optical performance and fast servo control while simultaneously achieving compact size, light weight and high zoom ratio, by referring to patent-pending technologies such as the optical power layout, lens construction, and glass material combinations.

Determination of habitat requirements for Apache Trout

USGS Publications Warehouse

Petre, Sally J.; Bonar, Scott A.

2017-01-01

The Apache Trout Oncorhynchus apache, a salmonid endemic to east-central Arizona, is currently listed as threatened under the U.S. Endangered Species Act. Establishing and maintaining recovery streams for Apache Trout and other endemic species requires determination of their specific habitat requirements. We built upon previous studies of Apache Trout habitat by defining both stream-specific and generalized optimal and suitable ranges of habitat criteria in three streams located in the White Mountains of Arizona. Habitat criteria were measured at the time thought to be most limiting to juvenile and adult life stages, the summer base flow period. Based on the combined results from three streams, we found that Apache Trout use relatively deep (optimal range = 0.15–0.32 m; suitable range = 0.032–0.470 m) pools with slow stream velocities (suitable range = 0.00–0.22 m/s), gravel or smaller substrate (suitable range = 0.13–2.0 [Wentworth scale]), overhead cover (suitable range = 26–88%), and instream cover (large woody debris and undercut banks were occupied at higher rates than other instream cover types). Fish were captured at cool to moderate temperatures (suitable range = 10.4–21.1°C) in streams with relatively low maximum seasonal temperatures (optimal range = 20.1–22.9°C; suitable range = 17.1–25.9°C). Multiple logistic regression generally confirmed the importance of these variables for predicting the presence of Apache Trout. All measured variables except mean velocity were significant predictors in our model. Understanding habitat needs is necessary in managing for persistence, recolonization, and recruitment of Apache Trout. Management strategies such as fencing areas to restrict ungulate use and grazing and planting native riparian vegetation might favor Apache Trout persistence and recolonization by providing overhead cover and large woody debris to form pools and instream cover, shading streams and lowering temperatures.

Bibliography of Intelligence Literature. A Critical and Annotated Bibliography of Open-Source Literature.

DTIC Science & Technology

1985-01-01

outlooks in a continuing, important battlefield. HAREL, Isser. The House on Garibaldi Street: The First Full Account of the Capture of Adolf Eichmann ...Israeli Service, MOSSAD, describes in detailed fashion the long-range, in-depth planning and operation for the Eichmann capture by Israeli agents in

Single-click beam patterns suggest dynamic changes to the field of view of echolocating Atlantic spotted dolphins (Stenella frontalis) in the wild.

PubMed

Jensen, Frants H; Wahlberg, Magnus; Beedholm, Kristian; Johnson, Mark; de Soto, Natacha Aguilar; Madsen, Peter T

2015-05-01

Echolocating animals exercise an extensive control over the spectral and temporal properties of their biosonar signals to facilitate perception of their actively generated auditory scene when homing in on prey. The intensity and directionality of the biosonar beam defines the field of view of echolocating animals by affecting the acoustic detection range and angular coverage. However, the spatial relationship between an echolocating predator and its prey changes rapidly, resulting in different biosonar requirements throughout prey pursuit and capture. Here, we measured single-click beam patterns using a parametric fit procedure to test whether free-ranging Atlantic spotted dolphins (Stenella frontalis) modify their biosonar beam width. We recorded echolocation clicks using a linear array of receivers and estimated the beam width of individual clicks using a parametric spectral fit, cross-validated with well-established composite beam pattern estimates. The dolphins apparently increased the biosonar beam width, to a large degree without changing the signal frequency, when they approached the recording array. This is comparable to bats that also expand their field of view during prey capture, but achieve this by decreasing biosonar frequency. This behaviour may serve to decrease the risk that rapid escape movements of prey take them outside the biosonar beam of the predator. It is likely that shared sensory requirements have resulted in bats and toothed whales expanding their acoustic field of view at close range to increase the likelihood of successfully acquiring prey using echolocation, representing a case of convergent evolution of echolocation behaviour between these two taxa. © 2015. Published by The Company of Biologists Ltd.

CO2 Extraction from Ambient Air Using Alkali-Metal Hydroxide Solutions Derived from Concrete Waste and Steel Slag

NASA Astrophysics Data System (ADS)

Stolaroff, J. K.; Lowry, G. V.; Keith, D. W.

2003-12-01

To mitigate global climate change, deep reductions in CO2 emissions are required in the coming decades. Carbon sequestration will play a crucial role in this reduction. Early adoption of carbon sequestration in low-cost niche markets will help develop the technology and experience required for large-scale deployment. One such niche may be the use of alkali metals from industrial waste streams to form carbonate minerals, a safe and stable means of sequestering carbon. In this research, the potential of using two industrial waste streams---concrete and steel slag---for sequestering carbon is assessed. The scheme is outlined as follows: Ca and Mg are leached with water from a finely ground bed of steel slag or concrete. The resulting solution is sprayed through air, capturing CO2 and forming solid carbonates, and collected. The feasibility of this scheme is explored with a combination of experiments, theoretical calculations, cost accounting, and literature review. The dissolution kinetics of steel slag and concrete as a function of particle size and pH is examined. In stirred batch reactors, the majority of Ca which dissolved did so within the first hour, yielding between 50 and 250 (mg; Ca)/(g; slag) and between 10 and 30 (mg; Ca)/(g; concrete). The kinetics of dissolution are thus taken to be sufficiently fast to support the type of scheme described above. As proof-of-concept, further experiments were performed where water was dripped slowly through a stagnant column of slag or concrete and collected at the bottom. Leachate Ca concentrations in the range of 15 mM were achieved --- sufficient to support the scheme. Using basic physical principles and numerical methods, the quantity of CO2 captured by falling droplets is estimated. Proportion of water loss and required pumping energy is similarly estimated. The results indicate that sprays are capable of capturing CO2 from the air and that the water and energy requirements are tractable. An example system for enacting the scheme is presented, along with capital and operational cost estimates. The system is found to be profitable for carbon credits above \\5/ton; C. Many findings in this research apply to a more general set of systems which capture CO_2$ from the air for sequestration. The metal-hydroxide solution in these systems is regenerated on site, allowing application of this scheme on as large a scale as needed. Implications of this study's findings for these more general carbon-capture systems is discussed.

New research discovery may mean less radioactive contamination, safer nuclear power plants

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

Murph, S.

Murph has now made another nanoparticle breakthrough that could benefit various work environments such as nuclear power plants. Murph and her team have created nanoparticle treated stainless steel filters that are capable to capturing radioactive vapor materials. Just like air filters capture dust and dirt, these filters are capable of capturing large amounts of radioactive vapors. The new research may one day mean that nuclear power plant workers, and other workers in related fields, will have a safer working environment.

Do different attention capture paradigms measure different types of capture?

PubMed

Roque, Nelson A; Wright, Timothy J; Boot, Walter R

2016-10-01

When something captures our attention, why does it do so? This topic has been hotly debated, with some arguing that attention is captured only by salient stimuli (bottom-up view) and others arguing capture is always due to a match between a stimulus and our goals (top-down view). Many different paradigms have provided evidence for 1 view or the other. If either of these strong views are correct, then capture represents a unitary phenomenon, and there should be a high correlation between capture in these paradigms. But if there are different types of capture (top-down, bottom-up), then some attention capture effects should be correlated and some should not. In 2 studies, we collected data from several paradigms used in support of claims of top-down and bottom-up capture in relatively large samples of participants. Contrary to either prediction, measures of capture were not strongly correlated. Results suggest that capture may in fact be strongly determined by idiosyncratic task demands and strategies. Relevant to this lack of relations among tasks, we observed that classic measures of attention capture demonstrated low reliability, especially among measures used to support bottom-up capture. Implications for the low reliability of capture measures are discussed. We also observed that the proportion of participants demonstrating a pattern of responses consistent with capture varied widely among classic measures of capture. Overall, results demonstrate that, even for relatively simple laboratory measures of attention, there are still important gaps in knowledge regarding what these paradigms measure and how they are related.

Local birefringence of the anterior segment of the human eye in a single capture with a full range polarisation-sensitive optical coherence tomography

NASA Astrophysics Data System (ADS)

Li, Qingyun; Karnowski, Karol; Villiger, Martin; Sampson, David D.

2017-04-01

A fibre-based full-range polarisation-sensitive optical coherence tomography system is developed to enable complete capture of the structural and birefringence properties of the anterior segment of the human eye in a single acquisition. The system uses a wavelength swept source centered at 1.3 μm, passively depth-encoded, orthogonal polarisation states in the illumination path and polarisation-diversity detection. Off-pivot galvanometer scanning is used to extend the imaging range and compensate for sensitivity drop-off. A Mueller matrix-based method is used to analyse data. We demonstrate the performance of the system and discuss issues relating to its optimisation.

Development of ROACH firmware for microwave multiplexed X-ray TES microcalorimeters

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

Madden, T. J.; Cecil, T. W.; Gades, L. M.

We are developing room temperature electronics based upon the ROACH platform for reading out microwave multiplexed X-ray TES. ROACH is an open-source hardware and software platform featuring a large Xilinx Field Programmable Gate Array (FPGA), Power PC processor, several 10GB Ethernet SFP+ interfaces, and a collection of daughter boards for analog signal generation and acquisition. The combination of a ROACH board, ADC/DAC conversion daughter boards, and hardware for RF mixing allows for the generation and capture of multiple RF tones for reading out microwave multiplexed x-ray TES microcalorimeters. The FPGA is used to generate multiple tones in base band, frommore » 10MHz to 250MHz, which are subsequently mixed to RF in the multiple GHz range and sent through the microwave multiplexer. The tones are generated in the FPGA by storing a large lookup table in Quad Data Rate (QDR) SRAM modules and playing out the waveform to a DAC board. Once the signal has been modulated to RF, passed through the microwave multiplexer, and has been modulated back to base band, the signal is digitized by an ADC board. The tones are modulated to 0Hz by using a FPGA circuit consisting of a polyphase filter bank, several Xilinx FFT blocks, Xilinx CORDIC blocks (for converting to magnitude and phase), and special phase accumulator circuit for mixing to exactly 0Hz. Upwards of 256 channels can be simultaneously captured and written into a bank of 256 First-In-First-Out (FIFO) memories, with each FIFO corresponding to a channel. Individual channel data can be further processed in the FPGA before being streamed through a 10GB Ethernet fiber-optic interface to a Linux system. The Linux system runs software written in Python and QT C++ for controlling the ROACH system, capturing data, and processing data.« less

The cost of getting CCS wrong: Uncertainty, infrastructure design, and stranded CO 2

DOE PAGES

Middleton, Richard Stephen; Yaw, Sean Patrick

2018-01-11

Carbon capture, and storage (CCS) infrastructure will require industry—such as fossil-fuel power, ethanol production, and oil and gas extraction—to make massive investment in infrastructure. The cost of getting these investments wrong will be substantial and will impact the success of CCS technology. Multiple factors can and will impact the success of commercial-scale CCS, including significant uncertainties regarding capture, transport, and injection-storage decisions. Uncertainties throughout the CCS supply chain include policy, technology, engineering performance, economics, and market forces. In particular, large uncertainties exist for the injection and storage of CO 2. Even taking into account upfront investment in site characterization, themore » final performance of the storage phase is largely unknown until commercial-scale injection has started. We explore and quantify the impact of getting CCS infrastructure decisions wrong based on uncertain injection rates and uncertain CO 2 storage capacities using a case study managing CO 2 emissions from the Canadian oil sands industry in Alberta. We use SimCCS, a widely used CCS infrastructure design framework, to develop multiple CCS infrastructure scenarios. Each scenario consists of a CCS infrastructure network that connects CO 2 sources (oil sands extraction and processing) with CO 2 storage reservoirs (acid gas storage reservoirs) using a dedicated CO 2 pipeline network. Each scenario is analyzed under a range of uncertain storage estimates and infrastructure performance is assessed and quantified in terms of cost to build additional infrastructure to store all CO 2. We also include the role of stranded CO 2, CO 2 that a source was expecting to but cannot capture due substandard performance in the transport and storage infrastructure. Results show that the cost of getting the original infrastructure design wrong are significant and that comprehensive planning will be required to ensure that CCS becomes a successful climate mitigation technology. Here, we show that the concept of stranded CO 2 can transform a seemingly high-performing infrastructure design into the worst case scenario.« less

The cost of getting CCS wrong: Uncertainty, infrastructure design, and stranded CO 2

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

Middleton, Richard Stephen; Yaw, Sean Patrick

Carbon capture, and storage (CCS) infrastructure will require industry—such as fossil-fuel power, ethanol production, and oil and gas extraction—to make massive investment in infrastructure. The cost of getting these investments wrong will be substantial and will impact the success of CCS technology. Multiple factors can and will impact the success of commercial-scale CCS, including significant uncertainties regarding capture, transport, and injection-storage decisions. Uncertainties throughout the CCS supply chain include policy, technology, engineering performance, economics, and market forces. In particular, large uncertainties exist for the injection and storage of CO 2. Even taking into account upfront investment in site characterization, themore » final performance of the storage phase is largely unknown until commercial-scale injection has started. We explore and quantify the impact of getting CCS infrastructure decisions wrong based on uncertain injection rates and uncertain CO 2 storage capacities using a case study managing CO 2 emissions from the Canadian oil sands industry in Alberta. We use SimCCS, a widely used CCS infrastructure design framework, to develop multiple CCS infrastructure scenarios. Each scenario consists of a CCS infrastructure network that connects CO 2 sources (oil sands extraction and processing) with CO 2 storage reservoirs (acid gas storage reservoirs) using a dedicated CO 2 pipeline network. Each scenario is analyzed under a range of uncertain storage estimates and infrastructure performance is assessed and quantified in terms of cost to build additional infrastructure to store all CO 2. We also include the role of stranded CO 2, CO 2 that a source was expecting to but cannot capture due substandard performance in the transport and storage infrastructure. Results show that the cost of getting the original infrastructure design wrong are significant and that comprehensive planning will be required to ensure that CCS becomes a successful climate mitigation technology. Here, we show that the concept of stranded CO 2 can transform a seemingly high-performing infrastructure design into the worst case scenario.« less

Rapid microscopy measurement of very large spectral images.

PubMed

Lindner, Moshe; Shotan, Zav; Garini, Yuval

2016-05-02

The spectral content of a sample provides important information that cannot be detected by the human eye or by using an ordinary RGB camera. The spectrum is typically a fingerprint of the chemical compound, its environmental conditions, phase and geometry. Thus measuring the spectrum at each point of a sample is important for a large range of applications from art preservation through forensics to pathological analysis of a tissue section. To date, however, there is no system that can measure the spectral image of a large sample in a reasonable time. Here we present a novel method for scanning very large spectral images of microscopy samples even if they cannot be viewed in a single field of view of the camera. The system is based on capturing information while the sample is being scanned continuously 'on the fly'. Spectral separation implements Fourier spectroscopy by using an interferometer mounted along the optical axis. High spectral resolution of ~5 nm at 500 nm could be achieved with a diffraction-limited spatial resolution. The acquisition time is fairly high and takes 6-8 minutes for a sample size of 10mm x 10mm measured under a bright-field microscope using a 20X magnification.

Stable isotope time-series in mammalian teeth: In situ δ18O from the innermost enamel layer

NASA Astrophysics Data System (ADS)

Blumenthal, Scott A.; Cerling, Thure E.; Chritz, Kendra L.; Bromage, Timothy G.; Kozdon, Reinhard; Valley, John W.

2014-01-01

Stable carbon and oxygen isotope ratios in mammalian tooth enamel are commonly used to understand the diets and environments of modern and fossil animals. Isotope variation during the period of enamel formation can be recovered by intra-tooth microsampling along the direction of growth. However, conventional sampling of the enamel surface provides highly time-averaged records in part due to amelogenesis. We use backscattered electron imaging in the scanning electron microscope (BSE-SEM) to evaluate enamel mineralization in developing teeth from one rodent and two ungulates. Gray levels from BSE-SEM images suggest that the innermost enamel layer, <20 μm from the enamel-dentine junction, is highly mineralized early in enamel maturation and therefore may record a less attenuated isotopic signal than other layers. We sampled the right maxillary incisor from a woodrat subjected to an experimentally induced water-switch during the period of tooth development, and demonstrate that secondary ion mass spectrometry (SIMS) can be used to obtain δ18O values with 4-5-μm spots from mammalian tooth enamel. We also demonstrate that SIMS can be used to discretely sample the innermost enamel layer, which is too narrow for conventional microdrilling or laser ablation. An abrupt δ18O switch of 16.0‰ was captured in breath CO2, a proxy for body water, while a laser ablation enamel surface intra-tooth profile of the left incisor captured a δ18O range of 12.1‰. The innermost enamel profile captured a δ18O range of 15.7‰, which approaches the full magnitude of δ18O variation in the input signal. This approach will likely be most beneficial in taxa such as large mammalian herbivores, whose teeth are characterized by less rapid mineralization and therefore greater attenuation of the enamel isotope signal.

Microbial community analysis using MEGAN.

PubMed

Huson, Daniel H; Weber, Nico

2013-01-01

Metagenomics, the study of microbes in the environment using DNA sequencing, depends upon dedicated software tools for processing and analyzing very large sequencing datasets. One such tool is MEGAN (MEtaGenome ANalyzer), which can be used to interactively analyze and compare metagenomic and metatranscriptomic data, both taxonomically and functionally. To perform a taxonomic analysis, the program places the reads onto the NCBI taxonomy, while functional analysis is performed by mapping reads to the SEED, COG, and KEGG classifications. Samples can be compared taxonomically and functionally, using a wide range of different charting and visualization techniques. PCoA analysis and clustering methods allow high-level comparison of large numbers of samples. Different attributes of the samples can be captured and used within analysis. The program supports various input formats for loading data and can export analysis results in different text-based and graphical formats. The program is designed to work with very large samples containing many millions of reads. It is written in Java and installers for the three major computer operating systems are available from http://www-ab.informatik.uni-tuebingen.de. © 2013 Elsevier Inc. All rights reserved.

Statistical Compression of Wind Speed Data

NASA Astrophysics Data System (ADS)

Tagle, F.; Castruccio, S.; Crippa, P.; Genton, M.

2017-12-01

In this work we introduce a lossy compression approach that utilizes a stochastic wind generator based on a non-Gaussian distribution to reproduce the internal climate variability of daily wind speed as represented by the CESM Large Ensemble over Saudi Arabia. Stochastic wind generators, and stochastic weather generators more generally, are statistical models that aim to match certain statistical properties of the data on which they are trained. They have been used extensively in applications ranging from agricultural models to climate impact studies. In this novel context, the parameters of the fitted model can be interpreted as encoding the information contained in the original uncompressed data. The statistical model is fit to only 3 of the 30 ensemble members and it adequately captures the variability of the ensemble in terms of seasonal internannual variability of daily wind speed. To deal with such a large spatial domain, it is partitioned into 9 region, and the model is fit independently to each of these. We further discuss a recent refinement of the model, which relaxes this assumption of regional independence, by introducing a large-scale component that interacts with the fine-scale regional effects.

Cationized Magnetoferritin Enables Rapid Labeling and Concentration of Gram-Positive and Gram-Negative Bacteria in Magnetic Cell Separation Columns

PubMed Central

Spencer, J.; Schwarzacher, W.

2016-01-01

ABSTRACT In order to identify pathogens rapidly and reliably, bacterial capture and concentration from large sample volumes into smaller ones are often required. Magnetic labeling and capture of bacteria using a magnetic field hold great promise for achieving this goal, but the current protocols have poor capture efficiency. Here, we present a rapid and highly efficient approach to magnetic labeling and capture of both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria using cationized magnetoferritin (cat-MF). Magnetic labeling was achieved within a 1-min incubation period with cat-MF, and 99.97% of the labeled bacteria were immobilized in commercially available magnetic cell separation (MACS) columns. Longer incubation times led to more efficient capture, with S. aureus being immobilized to a greater extent than E. coli. Finally, low numbers of magnetically labeled E. coli bacteria (<100 CFU per ml) were immobilized with 100% efficiency and concentrated 7-fold within 15 min. Therefore, our study provides a novel protocol for rapid and highly efficient magnetic labeling, capture, and concentration of both Gram-positive and Gram-negative bacteria. IMPORTANCE Antimicrobial resistance (AMR) is a significant global challenge. Rapid identification of pathogens will retard the spread of AMR by enabling targeted treatment with suitable agents and by reducing inappropriate antimicrobial use. Rapid detection methods based on microfluidic devices require that bacteria are concentrated from large volumes into much smaller ones. Concentration of bacteria is also important to detect low numbers of pathogens with confidence. Here, we demonstrate that magnetic separation columns capture small amounts of bacteria with 100% efficiency. Rapid magnetization was achieved by exposing bacteria to cationic magnetic nanoparticles, and magnetized bacteria were concentrated 7-fold inside the column. Thus, bacterial capture and concentration were achieved within 15 min. This approach could be extended to encompass the capture and concentration of specific pathogens, for example, by functionalizing magnetic nanoparticles with antibodies or small molecule probes. PMID:27060124

Cationized Magnetoferritin Enables Rapid Labeling and Concentration of Gram-Positive and Gram-Negative Bacteria in Magnetic Cell Separation Columns.

PubMed

Correia Carreira, S; Spencer, J; Schwarzacher, W; Seddon, A M

2016-06-15

In order to identify pathogens rapidly and reliably, bacterial capture and concentration from large sample volumes into smaller ones are often required. Magnetic labeling and capture of bacteria using a magnetic field hold great promise for achieving this goal, but the current protocols have poor capture efficiency. Here, we present a rapid and highly efficient approach to magnetic labeling and capture of both Gram-negative (Escherichia coli) and Gram-positive (Staphylococcus aureus) bacteria using cationized magnetoferritin (cat-MF). Magnetic labeling was achieved within a 1-min incubation period with cat-MF, and 99.97% of the labeled bacteria were immobilized in commercially available magnetic cell separation (MACS) columns. Longer incubation times led to more efficient capture, with S. aureus being immobilized to a greater extent than E. coli Finally, low numbers of magnetically labeled E. coli bacteria (<100 CFU per ml) were immobilized with 100% efficiency and concentrated 7-fold within 15 min. Therefore, our study provides a novel protocol for rapid and highly efficient magnetic labeling, capture, and concentration of both Gram-positive and Gram-negative bacteria. Antimicrobial resistance (AMR) is a significant global challenge. Rapid identification of pathogens will retard the spread of AMR by enabling targeted treatment with suitable agents and by reducing inappropriate antimicrobial use. Rapid detection methods based on microfluidic devices require that bacteria are concentrated from large volumes into much smaller ones. Concentration of bacteria is also important to detect low numbers of pathogens with confidence. Here, we demonstrate that magnetic separation columns capture small amounts of bacteria with 100% efficiency. Rapid magnetization was achieved by exposing bacteria to cationic magnetic nanoparticles, and magnetized bacteria were concentrated 7-fold inside the column. Thus, bacterial capture and concentration were achieved within 15 min. This approach could be extended to encompass the capture and concentration of specific pathogens, for example, by functionalizing magnetic nanoparticles with antibodies or small molecule probes. Copyright © 2016 Correia Carreira et al.

Stability analysis of chalk sea cliffs using UAV photogrammetry

NASA Astrophysics Data System (ADS)

Barlow, John; Gilham, Jamie

2017-04-01

Cliff erosion and instability poses a significant hazard to communities and infrastructure located is coastal areas. We use point cloud and spectral data derived from close range digital photogrammetry to assess the stability of chalk sea cliffs located at Telscombe, UK. Data captured from an unmanned aerial vehicle (UAV) were used to generate dense point clouds for a 712 m section of cliff face which ranges from 20 to 49 m in height. Generated models fitted our ground control network within a standard error of 0.03 m. Structural features such as joints, bedding planes, and faults were manually mapped and are consistent with results from other studies that have been conducted using direct measurement in the field. Kinematic analysis of these data was used to identify the primary modes of failure at the site. Our results indicate that wedge failure is by far the most likely mode of slope instability. An analysis of sequential surveys taken from the summer of 2016 to the winter of 2017 indicate several large failures have occurred at the site. We establish the volume of failure through change detection between sequential data sets and use back analysis to determine the strength of shear surfaces for each failure. Our results show that data capture through UAV photogrammetry can provide useful information for slope stability analysis over long sections of cliff. The use of this technology offers significant benefits in equipment costs and field time over existing methods.

Performance assessment of a single-pixel compressive sensing imaging system

NASA Astrophysics Data System (ADS)

Du Bosq, Todd W.; Preece, Bradley L.

2016-05-01

Conventional electro-optical and infrared (EO/IR) systems capture an image by measuring the light incident at each of the millions of pixels in a focal plane array. Compressive sensing (CS) involves capturing a smaller number of unconventional measurements from the scene, and then using a companion process known as sparse reconstruction to recover the image as if a fully populated array that satisfies the Nyquist criteria was used. Therefore, CS operates under the assumption that signal acquisition and data compression can be accomplished simultaneously. CS has the potential to acquire an image with equivalent information content to a large format array while using smaller, cheaper, and lower bandwidth components. However, the benefits of CS do not come without compromise. The CS architecture chosen must effectively balance between physical considerations (SWaP-C), reconstruction accuracy, and reconstruction speed to meet operational requirements. To properly assess the value of such systems, it is necessary to fully characterize the image quality, including artifacts and sensitivity to noise. Imagery of the two-handheld object target set at range was collected using a passive SWIR single-pixel CS camera for various ranges, mirror resolution, and number of processed measurements. Human perception experiments were performed to determine the identification performance within the trade space. The performance of the nonlinear CS camera was modeled with the Night Vision Integrated Performance Model (NV-IPM) by mapping the nonlinear degradations to an equivalent linear shift invariant model. Finally, the limitations of CS modeling techniques will be discussed.

Home ranges and movements of arctic fox (Alopex lagopus) in western Alaska

USGS Publications Warehouse

Anthony, R. Michael

1997-01-01

During the period from 1985 to 1990, radio collars were attached to 61 arctic foxes (Alopex lagopus) in the coastal region of the Yukon-Kuskokwim Delta in western Alaska. Radio tracking using hand-held receivers from aircraft, and from fixed towers was conducted to determine daily and seasonal movements of foxes. Intensive radio tracking of 18 foxes from May through July indicated that males used larger areas (x=10.22i??6.18 km2) than females (x=4.57i??1.94 km2) regardless of breeding status. Generally foxes were relocated near (x=3.4i??2.4 km) their summer home ranges during other seasons of the year. There were no complex social groups of foxes among the marked population. Foxes did not have a definitive preference for any plant community, probably because of the even distribution and abundance of prey throughout all communities. Thirty foxes were relocated repeatedly during a period of at least 10 months, which included the denning season of one year and the breeding season of the next. Of 24 confirmed deaths of collared foxes, 16 were caused by shooting or trapping by local residents and 8 had unidentified causes. Maximum distance moved between relocations was 48.4 km. Males moved farther from initial capture sites in the winter following capture than did females, largely because of greater than 20 km movements by two foxes. There were no seasonal differences in movements between males and females.

Haptoglobin concentrations in free-range and temporarily captive juvenile steller sea lions.

PubMed

Thomton, Jamie D; Mellish, Jo-Ann E

2007-04-01

Haptoglobin (Hp) is an acute-phase protein synthesized in the liver that circulates at elevated concentrations in response to tissue damage caused by inflammation, infection, and trauma. As part of a larger study, sera Hp concentrations were measured in temporarily captive (n = 21) and free-range (n = 38) western stock juvenile Steller sea lions (Eumetopias jubatus) sampled from 2003 to 2006. Baseline Hp concentration at time of capture was 133.3 +/- 17.4 mg/dl. Temporarily captive animals exhibited a 3.2-fold increase in Hp concentrations during the first 4 wk of captivity, followed by a return to entry levels by week 5. Haptoglobin levels were not influenced by age, season, or parasite load. There was a significant positive correlation between Hp concentrations and white blood cell count (P < 0.001) and globulin levels (P < 0.001) and a negative correlation to red blood cell count and hematocrit (P < 0.001 for both). There was no correlation between Hp levels and platelet count (P = 0.095) or hemoglobin (P = 0.457). Routine blubber biopsies collected under gas anesthesia did not produce a measurable Hp response. One animal with a large abscess had an Hp spike of 1,006.0 mg/dl that returned to entry levels after treatment. In conclusion, serum Hp levels correlate to the stable clinical health status observed during captivity, with moderate Hp response during capture and initial acclimation to captivity and acute response to inflammation and infection.

An Intraoperative Visualization System Using Hyperspectral Imaging to Aid in Brain Tumor Delineation

PubMed Central

Ortega, Samuel; M. Callicó, Gustavo; Juárez, Eduardo; Bulters, Diederik; Szolna, Adam; Piñeiro, Juan F.; Sosa, Coralia; J. O’Shanahan, Aruma; Bisshopp, Sara; Hernández, María; Morera, Jesús; Ravi, Daniele; Kiran, B. Ravi; Vega, Aurelio; Báez-Quevedo, Abelardo; Yang, Guang-Zhong; Stanciulescu, Bogdan; Sarmiento, Roberto

2018-01-01

Hyperspectral imaging (HSI) allows for the acquisition of large numbers of spectral bands throughout the electromagnetic spectrum (within and beyond the visual range) with respect to the surface of scenes captured by sensors. Using this information and a set of complex classification algorithms, it is possible to determine which material or substance is located in each pixel. The work presented in this paper aims to exploit the characteristics of HSI to develop a demonstrator capable of delineating tumor tissue from brain tissue during neurosurgical operations. Improved delineation of tumor boundaries is expected to improve the results of surgery. The developed demonstrator is composed of two hyperspectral cameras covering a spectral range of 400–1700 nm. Furthermore, a hardware accelerator connected to a control unit is used to speed up the hyperspectral brain cancer detection algorithm to achieve processing during the time of surgery. A labeled dataset comprised of more than 300,000 spectral signatures is used as the training dataset for the supervised stage of the classification algorithm. In this preliminary study, thematic maps obtained from a validation database of seven hyperspectral images of in vivo brain tissue captured and processed during neurosurgical operations demonstrate that the system is able to discriminate between normal and tumor tissue in the brain. The results can be provided during the surgical procedure (~1 min), making it a practical system for neurosurgeons to use in the near future to improve excision and potentially improve patient outcomes. PMID:29389893

An Intraoperative Visualization System Using Hyperspectral Imaging to Aid in Brain Tumor Delineation.

PubMed

Fabelo, Himar; Ortega, Samuel; Lazcano, Raquel; Madroñal, Daniel; M Callicó, Gustavo; Juárez, Eduardo; Salvador, Rubén; Bulters, Diederik; Bulstrode, Harry; Szolna, Adam; Piñeiro, Juan F; Sosa, Coralia; J O'Shanahan, Aruma; Bisshopp, Sara; Hernández, María; Morera, Jesús; Ravi, Daniele; Kiran, B Ravi; Vega, Aurelio; Báez-Quevedo, Abelardo; Yang, Guang-Zhong; Stanciulescu, Bogdan; Sarmiento, Roberto

2018-02-01

Hyperspectral imaging (HSI) allows for the acquisition of large numbers of spectral bands throughout the electromagnetic spectrum (within and beyond the visual range) with respect to the surface of scenes captured by sensors. Using this information and a set of complex classification algorithms, it is possible to determine which material or substance is located in each pixel. The work presented in this paper aims to exploit the characteristics of HSI to develop a demonstrator capable of delineating tumor tissue from brain tissue during neurosurgical operations. Improved delineation of tumor boundaries is expected to improve the results of surgery. The developed demonstrator is composed of two hyperspectral cameras covering a spectral range of 400-1700 nm. Furthermore, a hardware accelerator connected to a control unit is used to speed up the hyperspectral brain cancer detection algorithm to achieve processing during the time of surgery. A labeled dataset comprised of more than 300,000 spectral signatures is used as the training dataset for the supervised stage of the classification algorithm. In this preliminary study, thematic maps obtained from a validation database of seven hyperspectral images of in vivo brain tissue captured and processed during neurosurgical operations demonstrate that the system is able to discriminate between normal and tumor tissue in the brain. The results can be provided during the surgical procedure (~1 min), making it a practical system for neurosurgeons to use in the near future to improve excision and potentially improve patient outcomes.

Conformational switching upon phosphorylation: a predictive framework based on energy landscape principles.

PubMed

Lätzer, Joachim; Shen, Tongye; Wolynes, Peter G

2008-02-19

We investigate how post-translational phosphorylation modifies the global conformation of a protein by changing its free energy landscape using two test proteins, cystatin and NtrC. We first examine the changes in a free energy landscape caused by phosphorylation using a model containing information about both structural forms. For cystatin the free energy cost is fairly large indicating a low probability of sampling the phosphorylated conformation in a perfectly funneled landscape. The predicted barrier for NtrC conformational transition is several times larger than the barrier for cystatin, indicating that the switch protein NtrC most probably follows a partial unfolding mechanism to move from one basin to the other. Principal component analysis and linear response theory show how the naturally occurring conformational changes in unmodified proteins are captured and stabilized by the change of interaction potential. We also develop a partially guided structure prediction Hamiltonian which is capable of predicting the global structure of a phosphorylated protein using only knowledge of the structure of the unphosphorylated protein or vice versa. This algorithm makes use of a generic transferable long-range residue contact potential along with details of structure short range in sequence. By comparing the results obtained with this guided transferable potential to those from the native-only, perfectly funneled Hamiltonians, we show that the transferable Hamiltonian correctly captures the nature of the global conformational changes induced by phosphorylation and can sample substantially correct structures for the modified protein with high probability.

Spatial occupancy models applied to atlas data show Southern Ground Hornbills strongly depend on protected areas.

PubMed

Broms, Kristin M; Johnson, Devin S; Altwegg, Res; Conquest, Loveday L

2014-03-01

Determining the range of a species and exploring species--habitat associations are central questions in ecology and can be answered by analyzing presence--absence data. Often, both the sampling of sites and the desired area of inference involve neighboring sites; thus, positive spatial autocorrelation between these sites is expected. Using survey data for the Southern Ground Hornbill (Bucorvus leadbeateri) from the Southern African Bird Atlas Project, we compared advantages and disadvantages of three increasingly complex models for species occupancy: an occupancy model that accounted for nondetection but assumed all sites were independent, and two spatial occupancy models that accounted for both nondetection and spatial autocorrelation. We modeled the spatial autocorrelation with an intrinsic conditional autoregressive (ICAR) model and with a restricted spatial regression (RSR) model. Both spatial models can readily be applied to any other gridded, presence--absence data set using a newly introduced R package. The RSR model provided the best inference and was able to capture small-scale variation that the other models did not. It showed that ground hornbills are strongly dependent on protected areas in the north of their South African range, but less so further south. The ICAR models did not capture any spatial autocorrelation in the data, and they took an order, of magnitude longer than the RSR models to run. Thus, the RSR occupancy model appears to be an attractive choice for modeling occurrences at large spatial domains, while accounting for imperfect detection and spatial autocorrelation.

Coefficient of variation for use in crop area classification across multiple climates

NASA Astrophysics Data System (ADS)

Whelen, Tracy; Siqueira, Paul

2018-05-01

In this study, the coefficient of variation (CV) is introduced as a unitless statistical measurement for the classification of croplands using synthetic aperture radar (SAR) data. As a measurement of change, the CV is able to capture changing backscatter responses caused by cycles of planting, growing, and harvesting, and thus is able to differentiate these areas from a more static forest or urban area. Pixels with CV values above a given threshold are classified as crops, and below the threshold are non-crops. This paper uses cross-polarized L-band SAR data from the ALOS PALSAR satellite to classify eleven regions across the United States, covering a wide range of major crops and climates. Two separate sets of classification were done, with the first targeting the optimum classification thresholds for each dataset, and the second using a generalized threshold for all datasets to simulate a large-scale operationalized situation. Overall accuracies for the first phase of classification ranged from 66%-81%, and 62%-84% for the second phase. Visual inspection of the results shows numerous possibilities for improving the classifications while still using the same classification method, including increasing the number and temporal frequency of input images in order to better capture phenological events and mitigate the effects of major precipitation events, as well as more accurate ground truth data. These improvements would make the CV method a viable tool for monitoring agriculture throughout the year on a global scale.

Landscape-scale forest disturbance regimes in southern Peruvian Amazonia.

PubMed

Boyd, Doreen S; Hill, Ross A; Hopkinson, Chris; Baker, Timothy R

2013-10-01

Landscape-scale gap-size frequency distributions in tropical forests are a poorly studied but key ecological variable. Currently, a scale gap currently exists between local-scale field-based studies and those employing regional-scale medium-resolution satellite data. Data at landscape scales but of fine resolution would, however, facilitate investigation into a range of ecological questions relating to gap dynamics. These include whether canopy disturbances captured in permanent sample plots (PSPs) are representative of those in their surrounding landscape, and whether disturbance regimes vary with forest type. Here, therefore, we employ airborne LiDAR data captured over 142.5 km2 of mature, swamp, and regenerating forests in southeast Peru to assess the landscape-scale disturbance at a sampling resolution of up to 2 m. We find that this landscape is characterized by large numbers of small gaps; large disturbance events are insignificant and infrequent. Of the total number of gaps that are 2 m2 or larger in area, just 0.45% were larger than 100 m2, with a power-law exponent (alpha) value of the gap-size frequency distribution of 2.22. However, differences in disturbance regimes are seen among different forest types, with a significant difference in the alpha value of the gap-size frequency distribution observed for the swamp/regenerating forests compared with the mature forests at higher elevations. Although a relatively small area of the total forest of this region was investigated here, this study presents an unprecedented assessment of this landscape with respect to its gap dynamics. This is particularly pertinent given the range of forest types present in the landscape and the differences observed. The coupling of detailed insights into forest properties and growth provided by PSPs with the broader statistics of disturbance events using remote sensing is recommended as a strong basis for scaling-up estimates of landscape and regional-scale carbon balance.

Encapsulated liquid sorbents for carbon dioxide capture

NASA Astrophysics Data System (ADS)

Vericella, John J.; Baker, Sarah E.; Stolaroff, Joshuah K.; Duoss, Eric B.; Hardin, James O.; Lewicki, James; Glogowski, Elizabeth; Floyd, William C.; Valdez, Carlos A.; Smith, William L.; Satcher, Joe H.; Bourcier, William L.; Spadaccini, Christopher M.; Lewis, Jennifer A.; Aines, Roger D.

2015-02-01

Drawbacks of current carbon dioxide capture methods include corrosivity, evaporative losses and fouling. Separating the capture solvent from infrastructure and effluent gases via microencapsulation provides possible solutions to these issues. Here we report carbon capture materials that may enable low-cost and energy-efficient capture of carbon dioxide from flue gas. Polymer microcapsules composed of liquid carbonate cores and highly permeable silicone shells are produced by microfluidic assembly. This motif couples the capacity and selectivity of liquid sorbents with high surface area to facilitate rapid and controlled carbon dioxide uptake and release over repeated cycles. While mass transport across the capsule shell is slightly lower relative to neat liquid sorbents, the surface area enhancement gained via encapsulation provides an order-of-magnitude increase in carbon dioxide absorption rates for a given sorbent mass. The microcapsules are stable under typical industrial operating conditions and may be used in supported packing and fluidized beds for large-scale carbon capture.

ARC-1989-A89-7041

NASA Image and Video Library

1989-07-30

P-34540 Range: 37.3 million kilometers (23.6 million miles) This image captured by the Voyager 2 spacecraft was used to confirm the discovery of three new satellites orbiting Neptune. The 46-second exposure was taken with the narrow angle camera and shows the large globe of the planet to be severely overexposed and almost pure white in appearance. The image has been computer-processed to accentuate the new moons, which otherwise would be hard to distinguish from background noise. The satellite 1989N1, at right in this frame, was discovered by Voyager 2 in early July 1989. The new satellites confirmed later are 1989N2, 1989N3 and 1989N4. Each of the moons appears as a small streak, an effect caused by movement of the spacecraft during the long exposure. The new moons occupy nearly circular and equatorial orbits ranging from about 27,300 to 48,300 kilometers (17,000 to 30,000 miles) from Neptunes's cloud tops, and are estimated to range in diameter from about 100 to 200 kilometers (about 60 to 125 miles).

Red-tailed Hawk movements and use of habitat in the Luquillo Mountains of Puerto Rico

USGS Publications Warehouse

Vilella, Francisco; Nimitz, Wyatt F.

2012-01-01

The Red-tailed Hawk (Buteo jamaicensis) is a top predator of upland ecosystems in the Greater Antilles. Little information exists on the ecology of the insular forms of this widely distributed species. We studied movements and resource use of the Red-tailed Hawk from 2000 to 2002 in the montane forests of northeastern Puerto Rico. We captured 32 and used 21 radio-marked Red-tailed Hawks to delineate home range, core area shifts, and macrohabitat use in the Luquillo Mountains. Red-tailed Hawks in the Luquillo Mountains frequently perched near the top of canopy emergent trees and were characterized by wide-ranging capabilities and extensive spatial overlap. Home range size averaged 5,022.6 6 832.1 ha (305–11,288 ha) and core areas averaged 564.8 6 90.7 ha (150–1,230 ha). This species had large mean weekly movements (3,286.2 6 348.5 m) and a preference for roadside habitats. Our findings suggest fragmentation of contiguous forest outside protected areas in Puerto Rico may benefit the Red-tailed Hawk

Crowdsourcing-based evaluation of privacy in HDR images

NASA Astrophysics Data System (ADS)

Korshunov, Pavel; Nemoto, Hiromi; Skodras, Athanassios; Ebrahimi, Touradj

2014-05-01

The ability of High Dynamic Range imaging (HDRi) to capture details in high-contrast environments, making both dark and bright regions clearly visible, has a strong implication on privacy. However, the extent to which HDRi affects privacy when it is used instead of typical Standard Dynamic Range imaging (SDRi) is not yet clear. In this paper, we investigate the effect of HDRi on privacy via crowdsourcing evaluation using the Microworkers platform. Due to the lack of HDRi standard privacy evaluation dataset, we have created such dataset containing people of varying gender, race, and age, shot indoor and outdoor and under large range of lighting conditions. We evaluate the tone-mapped versions of these images, obtained by several representative tone-mapping algorithms, using subjective privacy evaluation methodology. Evaluation was performed using crowdsourcing-based framework, because it is a popular and effective alternative to traditional lab-based assessment. The results of the experiments demonstrate a significant loss of privacy when even tone-mapped versions of HDR images are used compared to typical SDR images shot with a standard exposure.

The Mexican American Biculturalism Scale: Bicultural Comfort, Facility, and Advantages for Adolescents and Adults

PubMed Central

Basilio, Camille D.; Knight, George P.; O'Donnell, Megan; Roosa, Mark W.; Gonzales, Nancy A.; Umaña-Taylor, Adriana J.; Torres, Marisela

2014-01-01

Empirical research on biculturalism is limited, in part because of the lack of quality measures of biculturalism. The currently available measures have limitations due to scoring procedures and sampling of only a narrow range of behaviors and attitudes. We present a measure of biculturalism that captures a broader range of the bicultural experience and uses a scoring system that better represents the wide ranging levels of biculturalism that exist in the diverse population of Mexican American adolescents, mothers, and fathers born either in Mexico or the United States. The Mexican American Biculturalism Scale (MABS; 27 items) includes 3 subscales: bicultural comfort (9 items), bicultural facility (9 items), and bicultural advantages (9 items). We report on the reliability and construct validity of test scores, and confirmatory factor analyses findings for a diverse sample of 316 Mexican American families from a large southwestern metropolitan city. The MABS is available both in English and Spanish (see Appendix). The use of the scale has implications for future research studying how biculturalism is related to psychological outcomes for Mexicans/Mexican Americans. PMID:24548151

Application and comparison of large-scale solution-based DNA capture-enrichment methods on ancient DNA

PubMed Central

Ávila-Arcos, María C.; Cappellini, Enrico; Romero-Navarro, J. Alberto; Wales, Nathan; Moreno-Mayar, J. Víctor; Rasmussen, Morten; Fordyce, Sarah L.; Montiel, Rafael; Vielle-Calzada, Jean-Philippe; Willerslev, Eske; Gilbert, M. Thomas P.

2011-01-01

The development of second-generation sequencing technologies has greatly benefitted the field of ancient DNA (aDNA). Its application can be further exploited by the use of targeted capture-enrichment methods to overcome restrictions posed by low endogenous and contaminating DNA in ancient samples. We tested the performance of Agilent's SureSelect and Mycroarray's MySelect in-solution capture systems on Illumina sequencing libraries built from ancient maize to identify key factors influencing aDNA capture experiments. High levels of clonality as well as the presence of multiple-copy sequences in the capture targets led to biases in the data regardless of the capture method. Neither method consistently outperformed the other in terms of average target enrichment, and no obvious difference was observed either when two tiling designs were compared. In addition to demonstrating the plausibility of capturing aDNA from ancient plant material, our results also enable us to provide useful recommendations for those planning targeted-sequencing on aDNA. PMID:22355593

Scheimpflug with computational imaging to extend the depth of field of iris recognition systems

NASA Astrophysics Data System (ADS)

Sinharoy, Indranil

Despite the enormous success of iris recognition in close-range and well-regulated spaces for biometric authentication, it has hitherto failed to gain wide-scale adoption in less controlled, public environments. The problem arises from a limitation in imaging called the depth of field (DOF): the limited range of distances beyond which subjects appear blurry in the image. The loss of spatial details in the iris image outside the small DOF limits the iris image capture to a small volume-the capture volume. Existing techniques to extend the capture volume are usually expensive, computationally intensive, or afflicted by noise. Is there a way to combine the classical Scheimpflug principle with the modern computational imaging techniques to extend the capture volume? The solution we found is, surprisingly, simple; yet, it provides several key advantages over existing approaches. Our method, called Angular Focus Stacking (AFS), consists of capturing a set of images while rotating the lens, followed by registration, and blending of the in-focus regions from the images in the stack. The theoretical underpinnings of AFS arose from a pair of new and general imaging models we developed for Scheimpflug imaging that directly incorporates the pupil parameters. The model revealed that we could register the images in the stack analytically if we pivot the lens at the center of its entrance pupil, rendering the registration process exact. Additionally, we found that a specific lens design further reduces the complexity of image registration making AFS suitable for real-time performance. We have demonstrated up to an order of magnitude improvement in the axial capture volume over conventional image capture without sacrificing optical resolution and signal-to-noise ratio. The total time required for capturing the set of images for AFS is less than the time needed for a single-exposure, conventional image for the same DOF and brightness level. The net reduction in capture time can significantly relax the constraints on subject movement during iris acquisition, making it less restrictive.

Comparison of taxon-specific versus general locus sets for targeted sequence capture in plant phylogenomics.

PubMed

Chau, John H; Rahfeldt, Wolfgang A; Olmstead, Richard G

2018-03-01

Targeted sequence capture can be used to efficiently gather sequence data for large numbers of loci, such as single-copy nuclear loci. Most published studies in plants have used taxon-specific locus sets developed individually for a clade using multiple genomic and transcriptomic resources. General locus sets can also be developed from loci that have been identified as single-copy and have orthologs in large clades of plants. We identify and compare a taxon-specific locus set and three general locus sets (conserved ortholog set [COSII], shared single-copy nuclear [APVO SSC] genes, and pentatricopeptide repeat [PPR] genes) for targeted sequence capture in Buddleja (Scrophulariaceae) and outgroups. We evaluate their performance in terms of assembly success, sequence variability, and resolution and support of inferred phylogenetic trees. The taxon-specific locus set had the most target loci. Assembly success was high for all locus sets in Buddleja samples. For outgroups, general locus sets had greater assembly success. Taxon-specific and PPR loci had the highest average variability. The taxon-specific data set produced the best-supported tree, but all data sets showed improved resolution over previous non-sequence capture data sets. General locus sets can be a useful source of sequence capture targets, especially if multiple genomic resources are not available for a taxon.

High-throughput screening of metal-porphyrin-like graphenes for selective capture of carbon dioxide

PubMed Central

Bae, Hyeonhu; Park, Minwoo; Jang, Byungryul; Kang, Yura; Park, Jinwoo; Lee, Hosik; Chung, Haegeun; Chung, ChiHye; Hong, Suklyun; Kwon, Yongkyung; Yakobson, Boris I.; Lee, Hoonkyung

2016-01-01

Nanostructured materials, such as zeolites and metal-organic frameworks, have been considered to capture CO2. However, their application has been limited largely because they exhibit poor selectivity for flue gases and low capture capacity under low pressures. We perform a high-throughput screening for selective CO2 capture from flue gases by using first principles thermodynamics. We find that elements with empty d orbitals selectively attract CO2 from gaseous mixtures under low CO2 pressures (~10−3 bar) at 300 K and release it at ~450 K. CO2 binding to elements involves hybridization of the metal d orbitals with the CO2 π orbitals and CO2-transition metal complexes were observed in experiments. This result allows us to perform high-throughput screening to discover novel promising CO2 capture materials with empty d orbitals (e.g., Sc– or V–porphyrin-like graphene) and predict their capture performance under various conditions. Moreover, these findings provide physical insights into selective CO2 capture and open a new path to explore CO2 capture materials. PMID:26902156

High-throughput screening of metal-porphyrin-like graphenes for selective capture of carbon dioxide.

PubMed

Bae, Hyeonhu; Park, Minwoo; Jang, Byungryul; Kang, Yura; Park, Jinwoo; Lee, Hosik; Chung, Haegeun; Chung, ChiHye; Hong, Suklyun; Kwon, Yongkyung; Yakobson, Boris I; Lee, Hoonkyung

2016-02-23

Nanostructured materials, such as zeolites and metal-organic frameworks, have been considered to capture CO2. However, their application has been limited largely because they exhibit poor selectivity for flue gases and low capture capacity under low pressures. We perform a high-throughput screening for selective CO2 capture from flue gases by using first principles thermodynamics. We find that elements with empty d orbitals selectively attract CO2 from gaseous mixtures under low CO2 pressures (~10(-3) bar) at 300 K and release it at ~450 K. CO2 binding to elements involves hybridization of the metal d orbitals with the CO2 π orbitals and CO2-transition metal complexes were observed in experiments. This result allows us to perform high-throughput screening to discover novel promising CO2 capture materials with empty d orbitals (e.g., Sc- or V-porphyrin-like graphene) and predict their capture performance under various conditions. Moreover, these findings provide physical insights into selective CO2 capture and open a new path to explore CO2 capture materials.

High-throughput screening of metal-porphyrin-like graphenes for selective capture of carbon dioxide

NASA Astrophysics Data System (ADS)

Bae, Hyeonhu; Park, Minwoo; Jang, Byungryul; Kang, Yura; Park, Jinwoo; Lee, Hosik; Chung, Haegeun; Chung, Chihye; Hong, Suklyun; Kwon, Yongkyung; Yakobson, Boris I.; Lee, Hoonkyung

2016-02-01

Nanostructured materials, such as zeolites and metal-organic frameworks, have been considered to capture CO2. However, their application has been limited largely because they exhibit poor selectivity for flue gases and low capture capacity under low pressures. We perform a high-throughput screening for selective CO2 capture from flue gases by using first principles thermodynamics. We find that elements with empty d orbitals selectively attract CO2 from gaseous mixtures under low CO2 pressures (~10-3 bar) at 300 K and release it at ~450 K. CO2 binding to elements involves hybridization of the metal d orbitals with the CO2 π orbitals and CO2-transition metal complexes were observed in experiments. This result allows us to perform high-throughput screening to discover novel promising CO2 capture materials with empty d orbitals (e.g., Sc- or V-porphyrin-like graphene) and predict their capture performance under various conditions. Moreover, these findings provide physical insights into selective CO2 capture and open a new path to explore CO2 capture materials.

A comparative analysis of exome capture.

PubMed

Parla, Jennifer S; Iossifov, Ivan; Grabill, Ian; Spector, Mona S; Kramer, Melissa; McCombie, W Richard

2011-09-29

Human exome resequencing using commercial target capture kits has been and is being used for sequencing large numbers of individuals to search for variants associated with various human diseases. We rigorously evaluated the capabilities of two solution exome capture kits. These analyses help clarify the strengths and limitations of those data as well as systematically identify variables that should be considered in the use of those data. Each exome kit performed well at capturing the targets they were designed to capture, which mainly corresponds to the consensus coding sequences (CCDS) annotations of the human genome. In addition, based on their respective targets, each capture kit coupled with high coverage Illumina sequencing produced highly accurate nucleotide calls. However, other databases, such as the Reference Sequence collection (RefSeq), define the exome more broadly, and so not surprisingly, the exome kits did not capture these additional regions. Commercial exome capture kits provide a very efficient way to sequence select areas of the genome at very high accuracy. Here we provide the data to help guide critical analyses of sequencing data derived from these products.

Multiple-predators-based capture process on complex networks

NASA Astrophysics Data System (ADS)

Ramiz Sharafat, Rajput; Pu, Cunlai; Li, Jie; Chen, Rongbin; Xu, Zhongqi

2017-03-01

The predator/prey (capture) problem is a prototype of many network-related applications. We study the capture process on complex networks by considering multiple predators from multiple sources. In our model, some lions start from multiple sources simultaneously to capture the lamb by biased random walks, which are controlled with a free parameter $\\alpha$. We derive the distribution of the lamb's lifetime and the expected lifetime $\\left\\langle T\\right\\rangle $. Through simulation, we find that the expected lifetime drops substantially with the increasing number of lions. We also study how the underlying topological structure affects the capture process, and obtain that locating on small-degree nodes is better than large-degree nodes to prolong the lifetime of the lamb. Moreover, dense or homogeneous network structures are against the survival of the lamb.

Astronaut Dale Gardner using MMU to travel to Westar VI satellite

NASA Technical Reports Server (NTRS)

1984-01-01

Astronaut Dale A. Gardner, wearing the manned maneuvering unit (MMU) approaching the spinng Westar VI satellite over Bahama Banks. Gardner uses a large tool called the apogee kick motor capture device (ACD) to enter the nozzle of the spent Westar engine and stabilize the satellite to capture it for return to Earth.

Evaluating the Use of Lecture Capture Using a Revealed Preference Approach

ERIC Educational Resources Information Center

Elliott, Caroline; Neal, David

2016-01-01

This article discusses the introduction of lecture capture technology on a large undergraduate module with diverse student cohorts. The literature has, so far, relied on surveying students to discover their use of the technology or attempted to quantify the impact of watching lecture recordings on assessment performance. Alternatively, the…

Wheat yield loss attributable to heat waves, drought and water excess at the global, national and subnational scales

NASA Astrophysics Data System (ADS)

Zampieri, M.; Ceglar, A.; Dentener, F.; Toreti, A.

2017-06-01

Heat waves and drought are often considered the most damaging climatic stressors for wheat. In this study, we characterize and attribute the effects of these climate extremes on wheat yield anomalies (at global and national scales) from 1980 to 2010. Using a combination of up-to-date heat wave and drought indexes (the latter capturing both excessively dry and wet conditions), we have developed a composite indicator that is able to capture the spatio-temporal characteristics of the underlying physical processes in the different agro-climatic regions of the world. At the global level, our diagnostic explains a significant portion (more than 40%) of the inter-annual production variability. By quantifying the contribution of national yield anomalies to global fluctuations, we have found that just two concurrent yield anomalies affecting the larger producers of the world could be responsible for more than half of the global annual fluctuations. The relative importance of heat stress and drought in determining the yield anomalies depends on the region. Moreover, in contrast to common perception, water excess affects wheat production more than drought in several countries. We have also performed the same analysis at the subnational level for France, which is the largest wheat producer of the European Union, and home to a range of climatic zones. Large subnational variability of inter-annual wheat yield is mostly captured by the heat and water stress indicators, consistently with the country-level result.

Spatial and temporal Brook Trout density dynamics: Implications for conservation, management, and monitoring

USGS Publications Warehouse

Wagner, Tyler; Jefferson T. Deweber,; Jason Detar,; Kristine, David; John A. Sweka,

2014-01-01

Many potential stressors to aquatic environments operate over large spatial scales, prompting the need to assess and monitor both site-specific and regional dynamics of fish populations. We used hierarchical Bayesian models to evaluate the spatial and temporal variability in density and capture probability of age-1 and older Brook Trout Salvelinus fontinalis from three-pass removal data collected at 291 sites over a 37-year time period (1975–2011) in Pennsylvania streams. There was high between-year variability in density, with annual posterior means ranging from 2.1 to 10.2 fish/100 m2; however, there was no significant long-term linear trend. Brook Trout density was positively correlated with elevation and negatively correlated with percent developed land use in the network catchment. Probability of capture did not vary substantially across sites or years but was negatively correlated with mean stream width. Because of the low spatiotemporal variation in capture probability and a strong correlation between first-pass CPUE (catch/min) and three-pass removal density estimates, the use of an abundance index based on first-pass CPUE could represent a cost-effective alternative to conducting multiple-pass removal sampling for some Brook Trout monitoring and assessment objectives. Single-pass indices may be particularly relevant for monitoring objectives that do not require precise site-specific estimates, such as regional monitoring programs that are designed to detect long-term linear trends in density.

The Chemical Route to a Carbon Dioxide Neutral World.

PubMed

Martens, Johan A; Bogaerts, Annemie; De Kimpe, Norbert; Jacobs, Pierre A; Marin, Guy B; Rabaey, Korneel; Saeys, Mark; Verhelst, Sebastian

2017-03-22

Excessive CO 2 emissions in the atmosphere from anthropogenic activity can be divided into point sources and diffuse sources. The capture of CO 2 from flue gases of large industrial installations and its conversion into fuels and chemicals with fast catalytic processes seems technically possible. Some emerging technologies are already being demonstrated on an industrial scale. Others are still being tested on a laboratory or pilot scale. These emerging chemical technologies can be implemented in a time window ranging from 5 to 20 years. The massive amounts of energy needed for capturing processes and the conversion of CO 2 should come from low-carbon energy sources, such as tidal, geothermal, and nuclear energy, but also, mainly, from the sun. Synthetic methane gas that can be formed from CO 2 and hydrogen gas is an attractive renewable energy carrier with an existing distribution system. Methanol offers advantages as a liquid fuel and is also a building block for the chemical industry. CO 2 emissions from diffuse sources is a difficult problem to solve, particularly for CO 2 emissions from road, water, and air transport, but steady progress in the development of technology for capturing CO 2 from air is being made. It is impossible to ban carbon from the entire energy supply of mankind with the current technological knowledge, but a transition to a mixed carbon-hydrogen economy can reduce net CO 2 emissions and ultimately lead to a CO 2 -neutral world. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Isotope separation by photoselective dissociative electron capture

DOEpatents

Stevens, C.G.

1978-08-29

Disclosed is a method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, [sup 235]UF[sub 6] is separated from a UF[sub 6] mixture by selective excitation followed by dissociative electron capture into [sup 235]UF[sub 5]- and F. 2 figs.

Isotope separation by photoselective dissociative electron capture

DOEpatents

Stevens, Charles G. [Pleasanton, CA

1978-08-29

A method of separating isotopes based on photoselective electron capture dissociation of molecules having an electron capture cross section dependence on the vibrational state of the molecule. A molecular isotope source material is irradiated to selectively excite those molecules containing a desired isotope to a predetermined vibrational state having associated therewith an electron capture energy region substantially non-overlapping with the electron capture energy ranges associated with the lowest vibration states of the molecules. The isotope source is also subjected to electrons having an energy corresponding to the non-overlapping electron capture region whereby the selectively excited molecules preferentially capture electrons and dissociate into negative ions and neutrals. The desired isotope may be in the negative ion product or in the neutral product depending upon the mechanism of dissociation of the particular isotope source used. The dissociation product enriched in the desired isotope is then separated from the reaction system by conventional means. Specifically, .sup.235 UF.sub.6 is separated from a UF.sub.6 mixture by selective excitation followed by dissociative electron capture into .sup.235 UF.sub.5 - and F.

Study on launch scheme of space-net capturing system.

PubMed

Gao, Qingyu; Zhang, Qingbin; Feng, Zhiwei; Tang, Qiangang

2017-01-01

With the continuous progress in active debris-removal technology, scientists are increasingly concerned about the concept of space-net capturing system. The space-net capturing system is a long-range-launch flexible capture system, which has great potential to capture non-cooperative targets such as inactive satellites and upper stages. In this work, the launch scheme is studied by experiment and simulation, including two-step ejection and multi-point-traction analyses. The numerical model of the tether/net is based on finite element method and is verified by full-scale ground experiment. The results of the ground experiment and numerical simulation show that the two-step ejection and six-point traction scheme of the space-net system is superior to the traditional one-step ejection and four-point traction launch scheme.

The Atlantic Seaduck Project: Medical Aspects

USGS Publications Warehouse

Olsen, Glenn H.; Perry, M.C.; Wells, A.M.; Lohnes, E.J.R.; Osenton, P.C.

2005-01-01

Some populations of seaducks, especially scoters along the Atlantic Coast, have been declining over recent decades. A joint US-Canadian tearn has been working to capture and surgically implant satellite radio transmitters in these ducks. Black scoters (Melanitta nigra) captured on the Restigouche River in New Brunswick, Canada and surf scoters (M. perspicilata) captured on Chesapeake Bay, Maryland, USA have been tracked by the use of Argos/NOAA polar orbiting operational environmental satellites to their breeding and molting areas and back south to their wintering ranges. Successful capture techniques included night-lighting and a capture net gun. A captive colony of seaducks has been maintained for feeding habits and nutritional studies. Veterinary medicine has played a key role in the surgical implantation of the satellite transmitters and in developing heath procedures for the captive seaduck colony.

Study on launch scheme of space-net capturing system

PubMed Central

Zhang, Qingbin; Feng, Zhiwei; Tang, Qiangang

2017-01-01

With the continuous progress in active debris-removal technology, scientists are increasingly concerned about the concept of space-net capturing system. The space-net capturing system is a long-range-launch flexible capture system, which has great potential to capture non-cooperative targets such as inactive satellites and upper stages. In this work, the launch scheme is studied by experiment and simulation, including two-step ejection and multi-point-traction analyses. The numerical model of the tether/net is based on finite element method and is verified by full-scale ground experiment. The results of the ground experiment and numerical simulation show that the two-step ejection and six-point traction scheme of the space-net system is superior to the traditional one-step ejection and four-point traction launch scheme. PMID:28877187

Captures of Crawford's gray shrews (Notiosorex crawfordi) along the Rio Grande in central New Mexico

Treesearch

Alice Chung-MacCoubrey; Heather L. Bateman; Deborah M. Finch

2009-01-01

We captured >2000 Crawford's gray shrews (Notiosorex crawfordi) in a riparian forest mainly consisting of cottonwoods (Populus deltoides) along the Rio Grande in central New Mexico. Little has been published about abundance and habitat of Crawford's gray shrew throughout its distributional range. During 7 summers, we...

Improved porous silicon (P-Si) microarray based PSA (prostate specific antigen) immunoassay by optimized surface density of the capture antibody

PubMed Central

Lee, SangWook; Kim, Soyoun; Malm, Johan; Jeong, Ok Chan; Lilja, Hans; Laurell, Thomas

2014-01-01

Enriching the surface density of immobilized capture antibodies enhances the detection signal of antibody sandwich microarrays. In this study, we improved the detection sensitivity of our previously developed P-Si (porous silicon) antibody microarray by optimizing concentrations of the capturing antibody. We investigated immunoassays using a P-Si microarray at three different capture antibody (PSA - prostate specific antigen) concentrations, analyzing the influence of the antibody density on the assay detection sensitivity. The LOD (limit of detection) for PSA was 2.5ngmL−1, 80pgmL−1, and 800fgmL−1 when arraying the PSA antibody, H117 at the concentration 15µgmL−1, 35µgmL−1 and 154µgmL−1, respectively. We further investigated PSA spiked into human female serum in the range of 800fgmL−1 to 500ngmL−1. The microarray showed a LOD of 800fgmL−1 and a dynamic range of 800 fgmL−1 to 80ngmL−1 in serum spiked samples. PMID:24016590

The influence of seine capture efficiency on fish abundance estimates in the upper Mississippi River

USGS Publications Warehouse

Holland Bartels, L. E.; Dewey, M.R.

1997-01-01

The effects of season, presence of vegetation, and time of day on seine capture efficiency for fish were evaluated using test enclosures in the upper Mississippi River. Overall capture efficiency of the seine haul was 49% (53% during the day and 43% at night). During daytime tests, the efficiency ranged from 39% to 74% but did not differ statistically between sites or among dates. At night, the efficiency was higher at the vegetated than at the nonvegetated site (55% vs 32%) and declined through time from 56% in May to 28% in October. Although susceptibility to capture differed among taxa, we could not predict either total catch efficiency or efficiency within a given taxon for a given sample. Adjustment of catch data with various estimates of efficiency reduced the mean absolute error for all sampling dates from 51% to 24%, but the error of the adjusted data still ranged from -58% to +54% on any given sampling date. These results indicate that it is difficult to make accurate adjustment of catch data to compensate for gear bias in studies of seasonal habitat use.

High dynamic range adaptive real-time smart camera: an overview of the HDR-ARTiST project

NASA Astrophysics Data System (ADS)

Lapray, Pierre-Jean; Heyrman, Barthélémy; Ginhac, Dominique

2015-04-01

Standard cameras capture only a fraction of the information that is visible to the human visual system. This is specifically true for natural scenes including areas of low and high illumination due to transitions between sunlit and shaded areas. When capturing such a scene, many cameras are unable to store the full Dynamic Range (DR) resulting in low quality video where details are concealed in shadows or washed out by sunlight. The imaging technique that can overcome this problem is called HDR (High Dynamic Range) imaging. This paper describes a complete smart camera built around a standard off-the-shelf LDR (Low Dynamic Range) sensor and a Virtex-6 FPGA board. This smart camera called HDR-ARtiSt (High Dynamic Range Adaptive Real-time Smart camera) is able to produce a real-time HDR live video color stream by recording and combining multiple acquisitions of the same scene while varying the exposure time. This technique appears as one of the most appropriate and cheapest solution to enhance the dynamic range of real-life environments. HDR-ARtiSt embeds real-time multiple captures, HDR processing, data display and transfer of a HDR color video for a full sensor resolution (1280 1024 pixels) at 60 frames per second. The main contributions of this work are: (1) Multiple Exposure Control (MEC) dedicated to the smart image capture with alternating three exposure times that are dynamically evaluated from frame to frame, (2) Multi-streaming Memory Management Unit (MMMU) dedicated to the memory read/write operations of the three parallel video streams, corresponding to the different exposure times, (3) HRD creating by combining the video streams using a specific hardware version of the Devebecs technique, and (4) Global Tone Mapping (GTM) of the HDR scene for display on a standard LCD monitor.

David and Goliath: potent venom of an ant-eating spider (Araneae) enables capture of a giant prey.

PubMed

Pekár, Stano; Šedo, Onřej; Líznarová, Eva; Korenko, Stanislav; Zdráhal, Zdeněk

2014-07-01

It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey.

David and Goliath: potent venom of an ant-eating spider (Araneae) enables capture of a giant prey

NASA Astrophysics Data System (ADS)

Pekár, Stano; Šedo, Onřej; Líznarová, Eva; Korenko, Stanislav; Zdráhal, Zdeněk

2014-07-01

It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey.

Atmospheric inverse modeling via sparse reconstruction

NASA Astrophysics Data System (ADS)

Hase, Nils; Miller, Scot M.; Maaß, Peter; Notholt, Justus; Palm, Mathias; Warneke, Thorsten

2017-10-01

Many applications in atmospheric science involve ill-posed inverse problems. A crucial component of many inverse problems is the proper formulation of a priori knowledge about the unknown parameters. In most cases, this knowledge is expressed as a Gaussian prior. This formulation often performs well at capturing smoothed, large-scale processes but is often ill equipped to capture localized structures like large point sources or localized hot spots. Over the last decade, scientists from a diverse array of applied mathematics and engineering fields have developed sparse reconstruction techniques to identify localized structures. In this study, we present a new regularization approach for ill-posed inverse problems in atmospheric science. It is based on Tikhonov regularization with sparsity constraint and allows bounds on the parameters. We enforce sparsity using a dictionary representation system. We analyze its performance in an atmospheric inverse modeling scenario by estimating anthropogenic US methane (CH4) emissions from simulated atmospheric measurements. Different measures indicate that our sparse reconstruction approach is better able to capture large point sources or localized hot spots than other methods commonly used in atmospheric inversions. It captures the overall signal equally well but adds details on the grid scale. This feature can be of value for any inverse problem with point or spatially discrete sources. We show an example for source estimation of synthetic methane emissions from the Barnett shale formation.

Angular Distributions of Differential Electron Capture Cross Sections in Collisions Between Low-Velocity Highly-Charged Ions and Neutral Targets.

NASA Astrophysics Data System (ADS)

Waggoner, William Tracy

1990-01-01

Experimental capture cross sections d sigma / dtheta versus theta , are presented for various ions incident on neutral targets. First, distributions are presented for Ar ^{rm 8+} ions incident on H_{rm 2}, D _{rm 2}, and Ar targets. Energy gain studies indicate that capture occurs to primarily a 5d,f final state of Ar^{rm 7+} with some contributions from transfer ionization (T.I.) channels. Angular distribution spectra for all three targets are similar, with spectra having a main peak located at forward angles which is attributed to single capture events, and a secondary structure occurring at large angles which is attributed to T.I. contributions. A series of Ar^{rm 8+} on Ar spectra were collected using a retarding grid system as a low resolution energy spectrometer to resolve single capture events from T.I. events. The resulting single capture and T.I. angular distributions are presented. Results are discussed in terms of a classical deflection function employing a simple two state curve crossing model. Angular distributions for electron capture from He by C, N, O, F, and Ne ions with charge states from 5 ^+-8^+ are presented for projectile energies between 1.2 and 2.0 kV. Distributions for the same charge state but different ion species are simlar, but not identical with distributions for the 5 ^+ and 7^+ ions being strongly forward peaked, the 6^+ distributions are much less forward peaked with the O^{6+} distributions showing structure, the Ne^{8+} ion distribution appears to be an intermediate case between forward peaking and large angle scattering. These results are discussed in terms of classical deflection functions which utilize two state Coulomb diabatic curve crossing models. Finally, angular distributions are presented for electron capture from He by Ar^{rm 6+} ions at energies between 1287 eV and 296 eV. At large projectile energies the distribution is broad. As the energy decreases below 523 eV, distributions shift to forward angles with a second peak appearing outside the Coulomb angle, theta_{c} = Q/2E, which continues to grow in magnitude as the projectile energy decreases further. Results are compared with a model calculation employing a two state diabatic Coulomb curve crossing model and the classical deflection function.

Capture, anesthesia, and disturbance of free-ranging brown bears (Ursus arctos) during hibernation.

PubMed

Evans, Alina L; Sahlén, Veronica; Støen, Ole-Gunnar; Fahlman, Åsa; Brunberg, Sven; Madslien, Knut; Fröbert, Ole; Swenson, Jon E; Arnemo, Jon M

2012-01-01

We conducted thirteen immobilizations of previously collared hibernating two- to four-year-old brown bears (Ursus arctos) weighing 21-66 kg in central Sweden in winter 2010 and 2011 for comparative physiology research. Here we report, for the first time, an effective protocol for the capture and anesthesia of free-ranging brown bears during hibernation and an assessment of the disturbance the captures caused. Bears were darted in anthill, soil, or uprooted tree dens on eleven occasions, but two bears in rock dens fled and were darted outside the den. We used medetomidine at 0.02-0.06 mg/kg and zolazepam-tiletamine at 0.9-2.8 mg/kg for anesthesia. In addition, ketamine at 1.5 mg/kg was hand-injected intramuscularly in four bears and in six it was included in the dart at 1.1-3.0 mg/kg. Once anesthetized, bears were removed from the dens. In nine bears, arterial blood samples were analyzed immediately with a portable blood gas analyzer. We corrected hypoxemia in seven bears (PaO(2) 57-74 mmHg) with supplemental oxygen. We placed the bears back into the dens and antagonized the effect of medetomidine with atipamezole. Capturing bears in the den significantly increased the risk of den abandonment. One of twelve collared bears that were captured remained at the original den until spring, and eleven, left their dens (mean ± standard deviation) 3.2±3.6 (range 0.5-10.5) days after capture. They used 1.9±0.9 intermediate resting sites, during 6.2±7.8 days before entering a new permanent den. The eleven new permanent dens were located 730±589 m from the original dens. We documented that it was feasible and safe to capture hibernating brown bears, although they behaved differently than black bears. When doing so, researchers should use 25% of the doses used for helicopter darting during the active period and should consider increased energetic costs associated with den abandonment.

Seasonal and year-round use of the Kushiro Wetland, Hokkaido, Japan by sika deer (Cervus nippon yesoensis).

PubMed

Takafumi, Hino; Kamii, Tatsuya; Murai, Takunari; Yoshida, Ryoto; Sato, Atsuki; Tachiki, Yasuyuki; Akamatsu, Rika; Yoshida, Tsuyoshi

2017-01-01

The sika deer ( Cervus nippon yesoensis ) population in the Ramsar-listed Kushiro Wetland has increased in recent years, and the Ministry of the Environment of Japan has decided to take measures to reduce the impact of deer on the ecosystem. However, seasonal movement patterns of the deer (i.e., when and where the deer inhabit the wetland) remain unclear. We examined the seasonal movement patterns of sika deer in the Kushiro Wetland from 2013 to 2015 by analyzing GPS location data for 28 hinds captured at three sites in the wetland. Seasonal movement patterns were quantitatively classified as seasonal migration, mixed, dispersal, nomadic, resident, or atypical, and the degree of wetland utilization for each individual was estimated. The area of overlap for each individual among intra-capture sites and inter-capture sites was calculated for the entire year and for each season. Our results showed that the movement patterns of these deer were classified not only as resident but also as seasonal migration, dispersal, and atypical. Approximately one-third of the individuals moved into and out of the wetland during the year as either seasonal migrants or individuals with atypical movement. Some of the individuals migrated to farmland areas outside the wetland (the farthest being 69.9 km away). Half of the individuals inhabited the wetland all or most of the year, i.e., 81-100% of their annual home range was within the wetland area. Even among individuals captured at the same site, different seasonal movement patterns were identified. The overlap areas of the home ranges of individuals from the same capture sites were larger than those for individuals from different capture sites (e.g., mean of annual home range overlap with intra-capture sites: 47.7% vs. inter-sites: 1.3%). To achieve more effective ecosystem management including deer management in the wetland, management plans should cover inside and outside of the wetland and separate the population into multiple management units to address the different movement patterns and wetland utilization of the population.

Seasonal and year-round use of the Kushiro Wetland, Hokkaido, Japan by sika deer (Cervus nippon yesoensis)

PubMed Central

Takafumi, Hino; Kamii, Tatsuya; Murai, Takunari; Yoshida, Ryoto; Sato, Atsuki; Tachiki, Yasuyuki; Akamatsu, Rika

2017-01-01

The sika deer (Cervus nippon yesoensis) population in the Ramsar-listed Kushiro Wetland has increased in recent years, and the Ministry of the Environment of Japan has decided to take measures to reduce the impact of deer on the ecosystem. However, seasonal movement patterns of the deer (i.e., when and where the deer inhabit the wetland) remain unclear. We examined the seasonal movement patterns of sika deer in the Kushiro Wetland from 2013 to 2015 by analyzing GPS location data for 28 hinds captured at three sites in the wetland. Seasonal movement patterns were quantitatively classified as seasonal migration, mixed, dispersal, nomadic, resident, or atypical, and the degree of wetland utilization for each individual was estimated. The area of overlap for each individual among intra-capture sites and inter-capture sites was calculated for the entire year and for each season. Our results showed that the movement patterns of these deer were classified not only as resident but also as seasonal migration, dispersal, and atypical. Approximately one-third of the individuals moved into and out of the wetland during the year as either seasonal migrants or individuals with atypical movement. Some of the individuals migrated to farmland areas outside the wetland (the farthest being 69.9 km away). Half of the individuals inhabited the wetland all or most of the year, i.e., 81–100% of their annual home range was within the wetland area. Even among individuals captured at the same site, different seasonal movement patterns were identified. The overlap areas of the home ranges of individuals from the same capture sites were larger than those for individuals from different capture sites (e.g., mean of annual home range overlap with intra-capture sites: 47.7% vs. inter-sites: 1.3%). To achieve more effective ecosystem management including deer management in the wetland, management plans should cover inside and outside of the wetland and separate the population into multiple management units to address the different movement patterns and wetland utilization of the population. PMID:29038752

A checklist of macroparasites of Liza haematocheila (Temminck & Schlegel) (Teleostei: Mugilidae)

PubMed Central

Kostadinova, Aneta

2008-01-01

Background The mugilid fish Liza haematocheila (syn. Mugil soiuy), native to the Western North Pacific, provides opportunities to examine the changes of its parasite fauna after its translocation to the Sea of Azov and subsequent establishment in the Black Sea. However, the information on macroparasites of this host in both ranges of its current distribution comes from isolated studies published in difficult-to-access literature sources. Materials and methods Data from 53 publications, predominantly in Chinese, Russian and Ukrainian, were compiled from an extensive search of the literature and the Host-Parasite Database maintained up to 2005 at the Natural History Museum, London. Results The complete checklist of the metazoan parasites of L. haematocheila throughout its distributional range comprises summarised information for 69 nominal species of helminth and ectoparasitic crustacean parasites, from 45 genera and 27 families (370 host-parasite records in total) and includes the name of the parasite species, the area/locality of the host capture, and the author and date of the published record. The taxonomy is updated and the validity of the records and synonymies are critically evaluated. A comparison of the parasite faunas based on the records in the native and introduced/invasive range of L. haematocheila suggests that a large number of parasite species was 'lost' in the new distributional range whereas an even greater number was 'gained'. Conclusion Although the present checklist provides information that will facilitate future studies, the interesting question of macroparasite faunal diversity in L. haematocheila in its natural and introduced/invasive ranges cannot be dealt with the current data because of unreliability associated with the large number of non-documented and questionable records. This stresses the importance of data quality analysis in using host-parasite database and checklist data. PMID:19117506

A checklist of macroparasites of Liza haematocheila (Temminck & Schlegel) (Teleostei: Mugilidae).

PubMed

Kostadinova, Aneta

2008-12-31

The mugilid fish Liza haematocheila (syn. Mugil soiuy), native to the Western North Pacific, provides opportunities to examine the changes of its parasite fauna after its translocation to the Sea of Azov and subsequent establishment in the Black Sea. However, the information on macroparasites of this host in both ranges of its current distribution comes from isolated studies published in difficult-to-access literature sources. Data from 53 publications, predominantly in Chinese, Russian and Ukrainian, were compiled from an extensive search of the literature and the Host-Parasite Database maintained up to 2005 at the Natural History Museum, London. The complete checklist of the metazoan parasites of L. haematocheila throughout its distributional range comprises summarised information for 69 nominal species of helminth and ectoparasitic crustacean parasites, from 45 genera and 27 families (370 host-parasite records in total) and includes the name of the parasite species, the area/locality of the host capture, and the author and date of the published record. The taxonomy is updated and the validity of the records and synonymies are critically evaluated. A comparison of the parasite faunas based on the records in the native and introduced/invasive range of L. haematocheila suggests that a large number of parasite species was 'lost' in the new distributional range whereas an even greater number was 'gained'. Although the present checklist provides information that will facilitate future studies, the interesting question of macroparasite faunal diversity in L. haematocheila in its natural and introduced/invasive ranges cannot be dealt with the current data because of unreliability associated with the large number of non-documented and questionable records. This stresses the importance of data quality analysis in using host-parasite database and checklist data.

Evaluation of bias associated with capture maps derived from nonlinear groundwater flow models

USGS Publications Warehouse

Nadler, Cara; Allander, Kip K.; Pohll, Greg; Morway, Eric D.; Naranjo, Ramon C.; Huntington, Justin

2018-01-01

The impact of groundwater withdrawal on surface water is a concern of water users and water managers, particularly in the arid western United States. Capture maps are useful tools to spatially assess the impact of groundwater pumping on water sources (e.g., streamflow depletion) and are being used more frequently for conjunctive management of surface water and groundwater. Capture maps have been derived using linear groundwater flow models and rely on the principle of superposition to demonstrate the effects of pumping in various locations on resources of interest. However, nonlinear models are often necessary to simulate head-dependent boundary conditions and unconfined aquifers. Capture maps developed using nonlinear models with the principle of superposition may over- or underestimate capture magnitude and spatial extent. This paper presents new methods for generating capture difference maps, which assess spatial effects of model nonlinearity on capture fraction sensitivity to pumping rate, and for calculating the bias associated with capture maps. The sensitivity of capture map bias to selected parameters related to model design and conceptualization for the arid western United States is explored. This study finds that the simulation of stream continuity, pumping rates, stream incision, well proximity to capture sources, aquifer hydraulic conductivity, and groundwater evapotranspiration extinction depth substantially affect capture map bias. Capture difference maps demonstrate that regions with large capture fraction differences are indicative of greater potential capture map bias. Understanding both spatial and temporal bias in capture maps derived from nonlinear groundwater flow models improves their utility and defensibility as conjunctive-use management tools.

A Double-Blinded, Randomized Comparison of Medetomidine-Tiletamine-Zolazepam and Dexmedetomidine-Tiletamine-Zolazepam Anesthesia in Free-Ranging Brown Bears (Ursus Arctos)

PubMed Central

Cattet, Marc; Zedrosser, Andreas; Stenhouse, Gordon B.; Küker, Susanne; Evans, Alina L.; Arnemo, Jon M.

2017-01-01

We compared anesthetic features, blood parameters, and physiological responses to either medetomidine-tiletamine-zolazepam or dexmedetomidine-tiletamine-zolazepam using a double-blinded, randomized experimental design during 40 anesthetic events of free-ranging brown bears (Ursus arctos) either captured by helicopter in Sweden or by culvert trap in Canada. Induction was smooth and predictable with both anesthetic protocols. Induction time, the need for supplemental drugs to sustain anesthesia, and capture-related stress were analyzed using generalized linear models, but anesthetic protocol did not differentially affect these variables. Arterial blood gases and acid-base status, and physiological responses were examined using linear mixed models. We documented acidemia (pH of arterial blood < 7.35), hypoxemia (partial pressure of arterial oxygen < 80 mmHg), and hypercapnia (partial pressure of arterial carbon dioxide ≥ 45 mmHg) with both protocols. Arterial pH and oxygen partial pressure were similar between groups with the latter improving markedly after oxygen supplementation (p < 0.001). We documented dose-dependent effects of both anesthetic protocols on induction time and arterial oxygen partial pressure. The partial pressure of arterial carbon dioxide increased as respiratory rate increased with medetomidine-tiletamine-zolazepam, but not with dexmedetomidine-tiletamine-zolazepam, demonstrating a differential drug effect. Differences in heart rate, respiratory rate, and rectal temperature among bears could not be attributed to the anesthetic protocol. Heart rate increased with increasing rectal temperature (p < 0.001) and ordinal day of capture (p = 0.002). Respiratory rate was significantly higher in bears captured by helicopter in Sweden than in bears captured by culvert trap in Canada (p < 0.001). Rectal temperature significantly decreased over time (p ≤ 0.05). Overall, we did not find any benefit of using dexmedetomidine-tiletamine-zolazepam instead of medetomidine-tiletamine-zolazepam in the anesthesia of brown bears. Both drug combinations appeared to be safe and reliable for the anesthesia of free-ranging brown bears captured by helicopter or by culvert trap. PMID:28118413

Relative abundance and distribution of fishes and crayfish at Ash Meadows National Wildlife Refuge, Nye County, Nevada, 2007-08

USGS Publications Warehouse

Scoppettone, G. Gary; Rissler, Peter; Johnson, Danielle; Hereford, Mark

2011-01-01

This study provides baseline data of native and non-native fish populations in Ash Meadows National Wildlife Refuge (NWR), Nye County, Nevada, that can serve as a gauge in native fish enhancement efforts. In support of Carson Slough restoration, comprehensive surveys of Ash Meadows NWR fishes were conducted seasonally from fall 2007 through summer 2008. A total of 853 sampling stations were created using Geographic Information Systems and National Agricultural Imagery Program. In four seasons of sampling, Amargosa pupfish (genus Cyprinodon) was captured at 388 of 659 stations. The number of captured Amargosa pupfish ranged from 5,815 (winter 2008) to 8,346 (summer 2008). The greatest success in capturing Amargosa pupfish was in warm water spring-pools with temperature greater than 25 degrees C, headwaters of warm water spring systems, and shallow (depths less than 10 centimeters) grassy marshes. In four seasons of sampling, Ash Meadows speckled dace (Rhinichthys osculus nevadesis) was captured at 96 of 659 stations. The number of captured Ash Meadows speckled dace ranged from 1,009 (summer 2008) to 1,552 (winter 2008). The greatest success in capturing Ash Meadows speckled dace was in cool water spring-pools with temperature less than 20 degrees C and in the high flowing water outflows. Among 659 sampling stations within the range of Amargosa pupfish, red swamp crayfish (Procambarus clarkii) was collected at 458 stations, western mosquitofish (Gambusia affinis) at 374 stations, and sailfin molly (Poecilia latipinna) at 128 stations. School Springs was restored during the course of this study. Prior to restoration of School Springs, maximum Warm Springs Amargosa pupfish (Cyprinodon nevadensis pectoralis) captured from the six springs of the Warm Springs Complex was 765 (fall 2007). In four seasons of sampling, Warm Springs Amargosa pupfish were captured at 85 of 177 stations. The greatest success in capturing Warm Springs Amargosa pupfish when co-occurring with red swamp crayfish and western mosquitofish was in water with temperature greater than 26 degrees C near the springhead, and in shallow (depths less than 10 centimeters) grassy marshes. Among 177 sampling stations within the range of Warm Springs Amargosa pupfish, red swamp crayfish were collected at 96 stations and western mosquitofish were collected at 49 stations. Removal of convict cichlid (Amatitlania nigrofasciata) from Fairbanks Spring was followed by a substantial increase in Ash Meadows Amargosa pupfish (Cyprinodon nevadensis mionectes) captures from 910 pre-removal to 3,056 post-removal. Red swamp crayfish was continually removed from Bradford 1 Spring, which seemed to cause an increase in the speckled dace population. Restoration of Kings Pool and Jackrabbit Springs promoted the success of native fishes with the greatest densities in restored reaches. Ongoing restoration of Carson Slough and its tributaries, as well as control and elimination of invasive species, is expected to increase abundance and distribution of Ash Meadows' native fish populations. Further analysis of data from this study will help determine the habitat characteristic(s) that promote native species and curtail non-native species.

Room-temperature ionic liquids and composite materials: platform technologies for CO(2) capture.

PubMed

Bara, Jason E; Camper, Dean E; Gin, Douglas L; Noble, Richard D

2010-01-19

Clean energy production has become one of the most prominent global issues of the early 21st century, prompting social, economic, and scientific debates regarding energy usage, energy sources, and sustainable energy strategies. The reduction of greenhouse gas emissions, specifically carbon dioxide (CO(2)), figures prominently in the discussions on the future of global energy policy. Billions of tons of annual CO(2) emissions are the direct result of fossil fuel combustion to generate electricity. Producing clean energy from abundant sources such as coal will require a massive infrastructure and highly efficient capture technologies to curb CO(2) emissions. Current technologies for CO(2) removal from other gases, such as those used in natural gas sweetening, are also capable of capturing CO(2) from power plant emissions. Aqueous amine processes are found in the vast majority of natural gas sweetening operations in the United States. However, conventional aqueous amine processes are highly energy intensive; their implementation for postcombustion CO(2) capture from power plant emissions would drastically cut plant output and efficiency. Membranes, another technology used in natural gas sweetening, have been proposed as an alternative mechanism for CO(2) capture from flue gas. Although membranes offer a potentially less energy-intensive approach, their development and industrial implementation lags far behind that of amine processes. Thus, to minimize the impact of postcombustion CO(2) capture on the economics of energy production, advances are needed in both of these areas. In this Account, we review our recent research devoted to absorptive processes and membranes. Specifically, we have explored the use of room-temperature ionic liquids (RTILs) in absorptive and membrane technologies for CO(2) capture. RTILs present a highly versatile and tunable platform for the development of new processes and materials aimed at the capture of CO(2) from power plant flue gas and in natural gas sweetening. The desirable properties of RTIL solvents, such as negligible vapor pressures, thermal stability, and a large liquid range, make them interesting candidates as new materials in well-known CO(2) capture processes. Here, we focus on the use of RTILs (1) as absorbents, including in combination with amines, and (2) in the design of polymer membranes. RTIL amine solvents have many potential advantages over aqueous amines, and the versatile chemistry of imidazolium-based RTILs also allows for the generation of new types of CO(2)-selective polymer membranes. RTIL and RTIL-based composites can compete with, or improve upon, current technologies. Moreover, owing to our experience in this area, we are developing new imidazolium-based polymer architectures and thermotropic and lyotropic liquid crystals as highly tailorable materials based on and capable of interacting with RTILs.

A Gamma Polarimeter for Neutron Polarization Measurement in a Liquid Deuterium Target for Parity Violation in Polarized Neutron Capture on Deuterium.

PubMed

Komives, A; Sint, A K; Bowers, M; Snow, M

2005-01-01

A measurement of the parity-violating gamma asymmetry in n-D capture would yield information on N-N parity violation independent of the n-p system. Since cold neutrons will depolarize in a liquid deuterium target in which the scattering cross section is much larger than the absorption cross section, it will be necessary to quantify the loss of polarization before capture. One way to do this is to use the large circular polarization of the gamma from n-D capture and analyze the circular polarization of the gamma in a gamma polarimeter. We describe the design of this polarimeter.

The urgency of the development of CO2 capture from ambient air

PubMed Central

Lackner, Klaus S.; Brennan, Sarah; Matter, Jürg M.; Park, A.-H. Alissa; Wright, Allen; van der Zwaan, Bob

2012-01-01

CO2 capture and storage (CCS) has the potential to develop into an important tool to address climate change. Given society’s present reliance on fossil fuels, widespread adoption of CCS appears indispensable for meeting stringent climate targets. We argue that for conventional CCS to become a successful climate mitigation technology—which by necessity has to operate on a large scale—it may need to be complemented with air capture, removing CO2 directly from the atmosphere. Air capture of CO2 could act as insurance against CO2 leaking from storage and furthermore may provide an option for dealing with emissions from mobile dispersed sources such as automobiles and airplanes. PMID:22843674

Contributions of Microtubule Dynamic Instability and Rotational Diffusion to Kinetochore Capture.

PubMed

Blackwell, Robert; Sweezy-Schindler, Oliver; Edelmaier, Christopher; Gergely, Zachary R; Flynn, Patrick J; Montes, Salvador; Crapo, Ammon; Doostan, Alireza; McIntosh, J Richard; Glaser, Matthew A; Betterton, Meredith D

2017-02-07

Microtubule dynamic instability allows search and capture of kinetochores during spindle formation, an important process for accurate chromosome segregation during cell division. Recent work has found that microtubule rotational diffusion about minus-end attachment points contributes to kinetochore capture in fission yeast, but the relative contributions of dynamic instability and rotational diffusion are not well understood. We have developed a biophysical model of kinetochore capture in small fission-yeast nuclei using hybrid Brownian dynamics/kinetic Monte Carlo simulation techniques. With this model, we have studied the importance of dynamic instability and microtubule rotational diffusion for kinetochore capture, both to the lateral surface of a microtubule and at or near its end. Over a range of biologically relevant parameters, microtubule rotational diffusion decreased capture time, but made a relatively small contribution compared to dynamic instability. At most, rotational diffusion reduced capture time by 25%. Our results suggest that while microtubule rotational diffusion can speed up kinetochore capture, it is unlikely to be the dominant physical mechanism for typical conditions in fission yeast. In addition, we found that when microtubules undergo dynamic instability, lateral captures predominate even in the absence of rotational diffusion. Counterintuitively, adding rotational diffusion to a dynamic microtubule increases the probability of end-on capture. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

On Spurious Numerics in Solving Reactive Equations

NASA Technical Reports Server (NTRS)

Kotov, D. V; Yee, H. C.; Wang, W.; Shu, C.-W.

2013-01-01

The objective of this study is to gain a deeper understanding of the behavior of high order shock-capturing schemes for problems with stiff source terms and discontinuities and on corresponding numerical prediction strategies. The studies by Yee et al. (2012) and Wang et al. (2012) focus only on solving the reactive system by the fractional step method using the Strang splitting (Strang 1968). It is a common practice by developers in computational physics and engineering simulations to include a cut off safeguard if densities are outside the permissible range. Here we compare the spurious behavior of the same schemes by solving the fully coupled reactive system without the Strang splitting vs. using the Strang splitting. Comparison between the two procedures and the effects of a cut off safeguard is the focus the present study. The comparison of the performance of these schemes is largely based on the degree to which each method captures the correct location of the reaction front for coarse grids. Here "coarse grids" means standard mesh density requirement for accurate simulation of typical non-reacting flows of similar problem setup. It is remarked that, in order to resolve the sharp reaction front, local refinement beyond standard mesh density is still needed.

Performance assessment of U.S. residential cooking exhaust hoods.

PubMed

Delp, William W; Singer, Brett C

2012-06-05

This study assessed the performance of seven new residential cooking exhaust hoods representing common U.S. designs. Laboratory tests were conducted to determine fan curves relating airflow to duct static pressure, sound levels, and exhaust gas capture efficiency for front and back cooktop burners and the oven. Airflow rate sensitivity to duct flow resistance was higher for axial fan devices than for centrifugal fan devices. Pollutant capture efficiency (CE) ranged from <15% to >98%, varying across hoods and with airflow and burner position for each hood. CE was higher for back burners relative to front burners, presumably because most hoods covered only part of the front burners. Open hoods had higher CE than those with grease screen and metal-covered bottoms. The device with the highest CE--exceeding 80% for oven and front burners--had a large, open hood that covered most of the front burners. The airflow rate for this hood surpassed the industry-recommended level of 118 L·s(-1) (250 cfm) and produced sound levels too high for normal conversation. For hoods meeting the sound and fan efficacy criteria for Energy Star, CE was <30% for front and oven burners.

Phycobilisome truncation causes widespread proteome changes in Synechocystis sp. PCC 6803

DOE PAGES

Liberton, Michelle; Chrisler, William B.; Nicora, Carrie D.; ...

2017-03-02

Here, cyanobacteria, such as Synechocystis sp. PCC 6803, utilize large antenna systems to optimize light harvesting and energy transfer to reaction centers. Understanding the structure and function of these complexes, particularly when altered, will help direct bio-design efforts to optimize biofuel production. Three specific phycobilisome (PBS) complex truncation mutants were studied, ranging from progressive truncation of phycocyanin rods in the CB and CK strains, to full removal of all phycocyanin and allophycocyanin cores in the PAL mutant. We applied comprehensive proteomic analyses to investigate both direct and downstream molecular systems implications of each truncation. Results showed that PBS truncation inmore » Synechocystis sp. PCC 6803 dramatically alters core cellular mechanisms beyond energy capture and electron transport, placing constraints upon cellular processes that dramatically altered phenotypes. This included primarily membrane associated functions and altered regulation of cellular resources (i.e., iron, nitrite/nitrate, bicarbonate). Additionally, each PBS truncation, though progressive in nature, exhibited unique phenotypes compare to WT, and hence we assert that in the current realm of extensive bioengineering and bio-design, there remains a continuing need to assess systems-wide protein based abundances to capture potential indirect phenotypic effects.« less

Phycobilisome truncation causes widespread proteome changes in Synechocystis sp. PCC 6803

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

Liberton, Michelle; Chrisler, William B.; Nicora, Carrie D.

Here, cyanobacteria, such as Synechocystis sp. PCC 6803, utilize large antenna systems to optimize light harvesting and energy transfer to reaction centers. Understanding the structure and function of these complexes, particularly when altered, will help direct bio-design efforts to optimize biofuel production. Three specific phycobilisome (PBS) complex truncation mutants were studied, ranging from progressive truncation of phycocyanin rods in the CB and CK strains, to full removal of all phycocyanin and allophycocyanin cores in the PAL mutant. We applied comprehensive proteomic analyses to investigate both direct and downstream molecular systems implications of each truncation. Results showed that PBS truncation inmore » Synechocystis sp. PCC 6803 dramatically alters core cellular mechanisms beyond energy capture and electron transport, placing constraints upon cellular processes that dramatically altered phenotypes. This included primarily membrane associated functions and altered regulation of cellular resources (i.e., iron, nitrite/nitrate, bicarbonate). Additionally, each PBS truncation, though progressive in nature, exhibited unique phenotypes compare to WT, and hence we assert that in the current realm of extensive bioengineering and bio-design, there remains a continuing need to assess systems-wide protein based abundances to capture potential indirect phenotypic effects.« less

An Investigation of Surge in a High-Speed Centrifugal Compressor Using Digital PIV

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Bright, Michelle M.; Skoch, Gary J.

2001-01-01

Compressor stall is a catastrophic breakdown of the flow in a compressor, which con lead to a loss of engine power, large pressure transients in the inlet/nacelle, and engine flameout. The implementation of active or passive strategies for controlling rotating stall and surge can significantly extend the stable operating range of a compressor without substantially sacrificing performance. It is crucial to identify the dynamic changes occurring in the flow field prior to rotating stall and surge in order to control these events successfully. Generally, pressure transducer measurements are made to capture the transient response of a compressor prior to rotating stall. In this investigation, Digital Particle Imaging Velocimetry (DPIV) is used in conjunction with dynamic pressure transducers to capture transient velocity and pressure measurements simultaneously in the nonstationary flow field during compressor surge. DPIV is an instantaneous, planar measurement technique that is ideally suited for studying transient flow phenomena in highspeed turbomachinery and has been used previously to map the stable operating point flow field in the diffuser of a high-speed centrifugal compressor. Through the acquisition of both DPIV images and transient pressure data, the time evolution of the unsteady flow during surge is revealed.

Rethinking work-health models for the new global economy: a qualitative analysis of emerging dimensions of work.

PubMed

Polanyi, Michael; Tompa, Emile

2004-01-01

Technology change, rising international trade and investment, and increased competition are changing the organization, distribution and nature of work in industrialized countries. To enhance productivity, employers are striving to increase innovation while minimizing costs. This is leading to an intensification of work demands on core employees and the outsourcing or casualization of more marginal tasks, often to contingent workers. The two prevailing models of work and health - demand-control and effort-reward imbalance - may not capture the full range of experiences of workers in today's increasingly flexible and competitive economies. To explore this proposition, we conducted a secondary qualitative analysis of interviews with 120 American workers [6]. Our analysis identifies aspects of work affecting the quality of workers' experiences that are largely overlooked by popular work-health models: the nature of social interactions with customers and clients; workers' belief in, and perception of, the importance of the product of their work. We suggest that the quality of work experiences is partly determined by the objective characteristics of the work environment, but also by the fit of the work environment with the worker's needs, interests, desires and personality, something not adequately captured in current models.

Evolution of Altimetry Calibration and Future Challenges

NASA Technical Reports Server (NTRS)

Fu, Lee-Lueng; Haines, Bruce J.

2012-01-01

Over the past 20 years, altimetry calibration has evolved from an engineering-oriented exercise to a multidisciplinary endeavor driving the state of the art. This evolution has been spurred by the developing promise of altimetry to capture the large-scale, but small-amplitude, changes of the ocean surface containing the expression of climate change. The scope of altimeter calibration/validation programs has expanded commensurately. Early efforts focused on determining a constant range bias and verifying basic compliance of the data products with mission requirements. Contemporary investigations capture, with increasing accuracies, the spatial and temporal characteristics of errors in all elements of the measurement system. Dedicated calibration sites still provide the fundamental service of estimating absolute bias, but also enable long-term monitoring of the sea-surface height and constituent measurements. The use of a network of island and coastal tide gauges has provided the best perspective on the measurement stability, and revealed temporal variations of altimeter measurement system drift. The cross-calibration between successive missions provided fundamentally new information on the performance of altimetry systems. Spatially and temporally correlated errors pose challenges for future missions, underscoring the importance of cross-calibration of new measurements against the established record.

An Investigation of Surge in a High-Speed Centrifugal Compressor Using Digital PIV

NASA Technical Reports Server (NTRS)

Wernet, Mark P.; Bright, Michelle M.; Skoch, Gary J.

2002-01-01

Compressor stall is a catastrophic breakdown of the flow in a compressor, which can lead to a loss of engine power, large pressure transients in the inlet/nacelle and engine flameout. The implementation of active or passive strategies for controlling rotating stall and surge can significantly extend the stable operating range of a compressor without substantially sacrificing performance. It is crucial to identify the dynamic changes occurring in the flow field prior to rotating stall and surge in order to successfully control these events. Generally, pressure transducer measurements are made to capture the transient response of a compressor prior to rotating stall. In this investigation, Digital Particle Imaging Velocimetry (DPIV) is used in conjunction with dynamic pressure transducers to simultaneously capture transient velocity and pressure measurements in the non-stationary flow field during compressor surge. DPIV is an instantaneous, planar measurement technique which is ideally suited for studying transient flow phenomena in high speed turbomachinery and has been used previously to successfully map the stable operating point flow field in the diffuser of a high speed centrifugal compressor. Through the acquisition of both DPIV images and transient pressure data, the time evolution of the unsteady flow during surge is revealed.

Towards Integration of Environmental and Health Impact Assessments for Wild Capture Fishing and Farmed Fish with Particular Reference to Public Health and Occupational Health Dimensions

PubMed Central

Watterson, Andrew; Little, David; Young, James A.; Boyd, Kathleen; Azim, Ekram; Murray, Francis

2008-01-01

The paper offers a review and commentary, with particular reference to the production of fish from wild capture fisheries and aquaculture, on neglected aspects of health impact assessments which are viewed by a range of international and national health bodies and development agencies as valuable and necessary project tools. Assessments sometimes include environmental health impact assessments but rarely include specific occupational health and safety impact assessments especially integrated into a wider public health assessment. This is in contrast to the extensive application of environmental impact assessments to fishing and the comparatively large body of research now generated on the public health effects of eating fish. The value of expanding and applying the broader assessments would be considerable because in 2004 the United Nations Food and Agriculture Organization reports there were 41,408,000 people in the total ‘fishing’ sector including 11,289,000 in aquaculture. The paper explores some of the complex interactions that occur with regard to fishing activities and proposes the wider adoption of health impact assessment tools in these neglected sectors through an integrated public health impact assessment tool. PMID:19190356

Contemporary Impact Analysis Methodology for Planetary Sample Return Missions

NASA Technical Reports Server (NTRS)

Perino, Scott V.; Bayandor, Javid; Samareh, Jamshid A.; Armand, Sasan C.

2015-01-01

Development of an Earth entry vehicle and the methodology created to evaluate the vehicle's impact landing response when returning to Earth is reported. NASA's future Mars Sample Return Mission requires a robust vehicle to return Martian samples back to Earth for analysis. The Earth entry vehicle is a proposed solution to this Mars mission requirement. During Earth reentry, the vehicle slows within the atmosphere and then impacts the ground at its terminal velocity. To protect the Martian samples, a spherical energy absorber called an impact sphere is under development. The impact sphere is composed of hybrid composite and crushable foam elements that endure large plastic deformations during impact and cause a highly nonlinear vehicle response. The developed analysis methodology captures a range of complex structural interactions and much of the failure physics that occurs during impact. Numerical models were created and benchmarked against experimental tests conducted at NASA Langley Research Center. The postimpact structural damage assessment showed close correlation between simulation predictions and experimental results. Acceleration, velocity, displacement, damage modes, and failure mechanisms were all effectively captured. These investigations demonstrate that the Earth entry vehicle has great potential in facilitating future sample return missions.

Development of anaerobic digestion methods for palm oil mill effluent (POME) treatment.

PubMed

Poh, P E; Chong, M F

2009-01-01

Palm oil mill effluent (POME) is a highly polluting wastewater that pollutes the environment if discharged directly due to its high chemical oxygen demand (COD) and biochemical oxygen demand (BOD) concentration. Anaerobic digestion has been widely used for POME treatment with large emphasis placed on capturing the methane gas released as a product of this biodegradation treatment method. The anaerobic digestion method is recognized as a clean development mechanism (CDM) under the Kyoto protocol. Certified emission reduction (CER) can be obtained by using methane gas as a renewable energy. This review aims to discuss the various anaerobic treatments of POME and factors that influence the operation of anaerobic treatment. The POME treatment at both mesophilic and thermophilic temperature ranges are also analyzed.

Gravity's Rainbow

NASA Image and Video Library

2018-04-23

Saturn's rings display their subtle colors in this view captured on Aug. 22, 2009, by NASA's Cassini spacecraft. The particles that make up the rings range in size from smaller than a grain of sand to as large as mountains, and are mostly made of water ice. The exact nature of the material responsible for bestowing color on the rings remains a matter of intense debate among scientists. Images taken using red, green and blue spectral filters were combined to create this natural color view. Cassini's narrow-angle camera took the images at a distance of approximately 1.27 million miles (2.05 million kilometers) from the center of the rings. The Cassini spacecraft ended its mission on Sept. 15, 2017 https://photojournal.jpl.nasa.gov/catalog/PIA22418

Entrapment of metal clusters in metal-organic framework channels by extended hooks anchored at open metal sites.

PubMed

Zheng, Shou-Tian; Zhao, Xiang; Lau, Samuel; Fuhr, Addis; Feng, Pingyun; Bu, Xianhui

2013-07-17

Reported here are the new concept of utilizing open metal sites (OMSs) for architectural pore design and its practical implementation. Specifically, it is shown here that OMSs can be used to run extended hooks (isonicotinates in this work) from the framework walls to the channel centers to effect the capture of single metal ions or clusters, with the concurrent partitioning of the large channel spaces into multiple domains, alteration of the host-guest charge relationship and associated guest-exchange properties, and transfer of OMSs from the walls to the channel centers. The concept of the extended hook, demonstrated here in the multicomponent dual-metal and dual-ligand system, should be generally applicable to a range of framework types.

Distributed Sensing and Processing for Multi-Camera Networks

NASA Astrophysics Data System (ADS)

Sankaranarayanan, Aswin C.; Chellappa, Rama; Baraniuk, Richard G.

Sensor networks with large numbers of cameras are becoming increasingly prevalent in a wide range of applications, including video conferencing, motion capture, surveillance, and clinical diagnostics. In this chapter, we identify some of the fundamental challenges in designing such systems: robust statistical inference, computationally efficiency, and opportunistic and parsimonious sensing. We show that the geometric constraints induced by the imaging process are extremely useful for identifying and designing optimal estimators for object detection and tracking tasks. We also derive pipelined and parallelized implementations of popular tools used for statistical inference in non-linear systems, of which multi-camera systems are examples. Finally, we highlight the use of the emerging theory of compressive sensing in reducing the amount of data sensed and communicated by a camera network.

Software Review: A program for testing capture-recapture data for closure

USGS Publications Warehouse

Stanley, Thomas R.; Richards, Jon D.

2005-01-01

Capture-recapture methods are widely used to estimate population parameters of free-ranging animals. Closed-population capture-recapture models, which assume there are no additions to or losses from the population over the period of study (i.e., the closure assumption), are preferred for population estimation over the open-population models, which do not assume closure, because heterogeneity in detection probabilities can be accounted for and this improves estimates. In this paper we introduce CloseTest, a new Microsoft® Windows-based program that computes the Otis et al. (1978) and Stanley and Burnham (1999) closure tests for capture-recapture data sets. Information on CloseTest features and where to obtain the program are provided.

In silico discovery of metal-organic frameworks for precombustion CO2 capture using a genetic algorithm

PubMed Central

Chung, Yongchul G.; Gómez-Gualdrón, Diego A.; Li, Peng; Leperi, Karson T.; Deria, Pravas; Zhang, Hongda; Vermeulen, Nicolaas A.; Stoddart, J. Fraser; You, Fengqi; Hupp, Joseph T.; Farha, Omar K.; Snurr, Randall Q.

2016-01-01

Discovery of new adsorbent materials with a high CO2 working capacity could help reduce CO2 emissions from newly commissioned power plants using precombustion carbon capture. High-throughput computational screening efforts can accelerate the discovery of new adsorbents but sometimes require significant computational resources to explore the large space of possible materials. We report the in silico discovery of high-performing adsorbents for precombustion CO2 capture by applying a genetic algorithm to efficiently search a large database of metal-organic frameworks (MOFs) for top candidates. High-performing MOFs identified from the in silico search were synthesized and activated and show a high CO2 working capacity and a high CO2/H2 selectivity. One of the synthesized MOFs shows a higher CO2 working capacity than any MOF reported in the literature under the operating conditions investigated here. PMID:27757420

Genotyping by Sequencing Using Specific Allelic Capture to Build a High-Density Genetic Map of Durum Wheat

PubMed Central

Holtz, Yan; Ardisson, Morgane; Ranwez, Vincent; Besnard, Alban; Leroy, Philippe; Poux, Gérard; Roumet, Pierre; Viader, Véronique; Santoni, Sylvain; David, Jacques

2016-01-01

Targeted sequence capture is a promising technology which helps reduce costs for sequencing and genotyping numerous genomic regions in large sets of individuals. Bait sequences are designed to capture specific alleles previously discovered in parents or reference populations. We studied a set of 135 RILs originating from a cross between an emmer cultivar (Dic2) and a recent durum elite cultivar (Silur). Six thousand sequence baits were designed to target Dic2 vs. Silur polymorphisms discovered in a previous RNAseq study. These baits were exposed to genomic DNA of the RIL population. Eighty percent of the targeted SNPs were recovered, 65% of which were of high quality and coverage. The final high density genetic map consisted of more than 3,000 markers, whose genetic and physical mapping were consistent with those obtained with large arrays. PMID:27171472

Bedrock river networks of the Sierra Nevada, USA record westward tilting, large-scale drainage area loss, and distinct patterns and causes of stream incision between the northern and southern Sierra

NASA Astrophysics Data System (ADS)

Beeson, H. W.; McCoy, S. W.

2017-12-01

The timing, rates, and spatial patterns of elevation change in the Sierra Nevada, California, USA, has been the subject of vigorous debate with multiple lines of evidence supporting the contrasting hypotheses that (1) the Sierra has been topographically high throughout the Cenozoic and (2) that the range has experienced a pulse of late Cenozoic uplift. We combined 2-D landscape evolution modeling with topographic analysis of the Sierra Nevada to investigate whether river networks dissecting the range record a change in tectonic forcing during the late Cenozoic. Specifically, we quantify basin geometry, including its area-channel length scaling relationship, fluvial channel steepness, and the spatial distributions of knickzones. We show that, throughout the Sierra, short equilibrated reaches near the mountain front are consistent with an ongoing westward tilt. However, the disequilibrium forms of river profiles north of the Kaweah River reflect large-scale drainage area loss due to network beheading by the Sierra Frontal Fault and/or reestablishment of a fluvial network on an inclined planar surface. Despite these similarities along the length of the range, river network analysis reveals striking differences north and south of approximately 37° N. In the northern Sierra, topographic asymmetry of drainage divides and large differences in cross-divide steady-state elevation suggest mobile divides. Additionally, the broad distribution of normalized knickzone locations, variability in channel steepness and basin shape, and the prevalence of anomalous topology, narrow basins, unadjusted captured reaches, and wind gaps is consistent with large-scale drainage reorganization following incision into an inclined planar surface. In contrast, in the southern Sierra, drainage divides appear more stable and knickzone locations are tightly distributed. We suggest that, although the northern Sierra may currently be tilting westward, the presence of large knickzones and deeply incised valleys in the northern Sierra does not require a recent increase in uplift, but rather could largely reflect the reestablishment of a fluvial network after mid-late Miocene volcanism filled and smoothed preexisting topography. In contrast, it appears that the southern Sierras are responding to a pulse of localized rapid uplift.

Electron capture into large-l Rydberg states of multiply charged ions escaping from solid surfaces

NASA Astrophysics Data System (ADS)

Nedeljković, N.; Nedeljković, Lj.; Mirković, M.

2003-07-01

We have investigated the electron capture into large-l Rydberg states of multiply charged ionic projectiles (e.g., the core charges Z=6, 7, and 8) escaping solid surfaces with intermediate velocities (v≈1 a.u.) in the normal emergence geometry. A model of the nonresonant electron capture from the solid conduction band into the moving large angular-momentum Rydberg states of the ions is developed through a generalization of our results obtained previously for the low-l cases (l=0, 1, and 2). The model is based on the two-wave-function dynamics of the Demkov-Ostrovskii type. The electron exchange process is described by a mixed flux through a moving plane (“Firsov plane”), placed between the solid surface and the ionic projectile. Due to low eccentricities of the large-l Rydberg systems, the mixed flux must be evaluated through the whole Firsov plane. It is for this purpose that a suitable asymptotic method is developed. For intermediate ionic velocities and for all relevant values of the principal quantum number n≈Z, the population probability Pnl is obtained as a nonlinear l distribution. The theoretical predictions concerning the ions S VI, Cl VII, and Ar VIII are compared with the available results of the beam-foil experiments.

Use of Lecture Capture in Undergraduate Biological Science Education

ERIC Educational Resources Information Center

Wiese, Candace; Newton, Genevieve

2013-01-01

This study examined the use of lecture capture in students in a large 3rd year undergraduate biological science course at the University of Guelph. Data regarding viewing behaviour, academic performance, and attendance were analyzed in relation to student learning approach (as assessed by the R-SPQ-2F), gender, and year of post-secondary…

A new method for digital video documentation in surgical procedures and minimally invasive surgery.

PubMed

Wurnig, P N; Hollaus, P H; Wurnig, C H; Wolf, R K; Ohtsuka, T; Pridun, N S

2003-02-01

Documentation of surgical procedures is limited to the accuracy of description, which depends on the vocabulary and the descriptive prowess of the surgeon. Even analog video recording could not solve the problem of documentation satisfactorily due to the abundance of recorded material. By capturing the video digitally, most problems are solved in the circumstances described in this article. We developed a cheap and useful digital video capturing system that consists of conventional computer components. Video images and clips can be captured intraoperatively and are immediately available. The system is a commercial personal computer specially configured for digital video capturing and is connected by wire to the video tower. Filming was done with a conventional endoscopic video camera. A total of 65 open and endoscopic procedures were documented in an orthopedic and a thoracic surgery unit. The median number of clips per surgical procedure was 6 (range, 1-17), and the median storage volume was 49 MB (range, 3-360 MB) in compressed form. The median duration of a video clip was 4 min 25 s (range, 45 s to 21 min). Median time for editing a video clip was 12 min for an advanced user (including cutting, title for the movie, and compression). The quality of the clips renders them suitable for presentations. This digital video documentation system allows easy capturing of intraoperative video sequences in high quality. All possibilities of documentation can be performed. With the use of an endoscopic video camera, no compromises with respect to sterility and surgical elbowroom are necessary. The cost is much lower than commercially available systems, and setting changes can be performed easily without trained specialists.

Effect of captivity on the blood composition of Spanish ibex (Capra pyrenaica hispanica).

PubMed

Peinado, V I; Fernandez-Arias, A; Zabala, J L; Palomeque, J

1995-12-02

Blood analyses of seven free-ranging Spanish ibex (Capra pyrenaica hispanica) captured from the wild and then held in captivity were used to determine the physiological changes in some haematological parameters and serum chemistry values during captivity. The captive animals had a higher haematocrit and haemoglobin concentration and larger numbers of erythrocytes than the same animals when they were captured. In addition, the absolute numbers of leucocytes and lymphocytes decreased progressively during captivity. Significant differences were found for some of the biochemical variables between the captive ibex and free-ranging animals.

Robust detection of chromosomal interactions from small numbers of cells using low-input Capture-C

PubMed Central

Oudelaar, A. Marieke; Davies, James O.J.; Downes, Damien J.; Higgs, Douglas R.

2017-01-01

Abstract Chromosome conformation capture (3C) techniques are crucial to understanding tissue-specific regulation of gene expression, but current methods generally require large numbers of cells. This hampers the investigation of chromatin architecture in rare cell populations. We present a new low-input Capture-C approach that can generate high-quality 3C interaction profiles from 10 000–20 000 cells, depending on the resolution used for analysis. We also present a PCR-free, sequencing-free 3C technique based on NanoString technology called C-String. By comparing C-String and Capture-C interaction profiles we show that the latter are not skewed by PCR amplification. Furthermore, we demonstrate that chromatin interactions detected by Capture-C do not depend on the degree of cross-linking by performing experiments with varying formaldehyde concentrations. PMID:29186505

Morphology of seahorse head hydrodynamically aids in capture of evasive prey.

PubMed

Gemmell, Brad J; Sheng, Jian; Buskey, Edward J

2013-01-01

Syngnathid fish (seahorses, pipefish and sea dragons) are slow swimmers yet capture evasive prey (copepods) using a technique known as the 'pivot' feeding, which involves rapid movement to overcome prey escape capabilities. However, this feeding mode functions only at short range and requires approaching very closely to hydrodynamically sensitive prey without triggering an escape. Here we investigate the role of head morphology on prey capture using holographic and particle image velocimetry (PIV). We show that head morphology functions to create a reduced fluid deformation zone, minimizing hydrodynamic disturbance where feeding strikes occur (above the end of the snout), and permits syngnathid fish to approach highly sensitive copepod prey (Acartia tonsa) undetected. The results explain how these animals can successfully employ short range 'pivot' feeding effectively on evasive prey. The need to approach prey with stealth may have selected for a head shape that produces lower deformation rates than other fish.

Virginia big-eared bats (Corynorhinus townsendii virginianus) roosting in abandoned coal mines in West Virginia

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

Johnson, J.B.; Edwards, J.W.; Wood, P.B.

We surveyed bats at 36 abandoned coal mines during summer 2002 and 47 mines during fall 2002 at New River Gorge National River and Gauley River National Recreation Area, WV. During summer, we captured three federally endangered Virginia big-eared bats at two mine entrances, and 25 were captured at 12 mine entrances during fall. These represent the first documented captures of this species at coal mines in West Virginia. Future survey efforts conducted throughout the range of the Virginia big-eared bat should include abandoned coal mines.

Shallow Processing and Attention Capture in Written and Spoken Discourse

ERIC Educational Resources Information Center

Sanford, Alison J. S.; Sanford, Anthony J.; Molle, Jo; Emmott, Catherine

2006-01-01

Processing of discourse seems to be far from uniform with much evidence indicating that it can be quite shallow. The question is then what modulates depth of processing? A range of discourse devices exist that we believe may lead to more detailed processing of language input (Attention Capturers), thus serving as modulators of processing enabling…

Evaluating population expansion of black bears using spatial capture-recapture

USGS Publications Warehouse

Sun, Catherine C.; Fuller, Angela K.; Hare, Matthew P.; Hurst, Jeremy E.

2017-01-01

The population of American black bears (Ursus americanus) in southern New York, USA has been growing and expanding in range since the 1990s. This has motivated a need to anticipate future patterns of range expansion. We conducted a non-invasive, genetic, spatial capture-recapture (SCR) study to estimate black bear density and identify spatial patterns of population density that are potentially associated with range expansion. We collected hair samples in a 2,519-km2 study area in southern New York with barbed-wire hair snares and identified individuals and measured genetic diversity using 7 microsatellite loci and 1 sex-linked marker. We estimated a mean density of black bears in the region of 13.7 bears/100 km2, and detected a slight latitudinal gradient in density consistent with the documented range expansion. However, elevation and the amounts of forest, crop, and developed landcover types did not influence density, suggesting that bears are using a diversity of resources in this heterogeneous landscape outside their previously described distribution. These results provide the first robust baseline estimates for population density and distribution associated with different landcover types in the expanded bear range. Further, genetic diversity was comparable to that of non-expanding black bear populations in the eastern United States, and in combination with the latitudinal density gradient, suggest that the study area is not at the colonizing front of the range expansion. In addition, the diversity of landcover types used by bears in the study area implies a possible lack of constraints for further northern expansion of the black bear range. Our non-invasive, genetic, spatial capture-recapture approach has utility for studying populations of other species that may be expanding in range because SCR allows for the testing of explicit, spatial ecological hypotheses. 

Effective sampling range of a synthetic protein-based attractant for Ceratitis capitata (Diptera: Tephritidae).

PubMed

Epsky, Nancy D; Espinoza, Hernán R; Kendra, Paul E; Abernathy, Robert; Midgarden, David; Heath, Robert R

2010-10-01

Studies were conducted in Honduras to determine effective sampling range of a female-targeted protein-based synthetic attractant for the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae). Multilure traps were baited with ammonium acetate, putrescine, and trimethylamine lures (three-component attractant) and sampled over eight consecutive weeks. Field design consisted of 38 traps (over 0.5 ha) placed in a combination of standard and high-density grids to facilitate geostatistical analysis, and tests were conducted in coffee (Coffea arabica L.),mango (Mangifera indica L.),and orthanique (Citrus sinensis X Citrus reticulata). Effective sampling range, as determined from the range parameter obtained from experimental variograms that fit a spherical model, was approximately 30 m for flies captured in tests in coffee or mango and approximately 40 m for flies captured in orthanique. For comparison, a release-recapture study was conducted in mango using wild (field-collected) mixed sex C. capitata and an array of 20 baited traps spaced 10-50 m from the release point. Contour analysis was used to document spatial distribution of fly recaptures and to estimate effective sampling range, defined by the area that encompassed 90% of the recaptures. With this approach, effective range of the three-component attractant was estimated to be approximately 28 m, similar to results obtained from variogram analysis. Contour maps indicated that wind direction had a strong influence on sampling range, which was approximately 15 m greater upwind compared with downwind from the release point. Geostatistical analysis of field-captured insects in appropriately designed trapping grids may provide a supplement or alternative to release-recapture studies to estimate sampling ranges for semiochemical-based trapping systems.

Laser-based structural sensing and surface damage detection

NASA Astrophysics Data System (ADS)

Guldur, Burcu

Damage due to age or accumulated damage from hazards on existing structures poses a worldwide problem. In order to evaluate the current status of aging, deteriorating and damaged structures, it is vital to accurately assess the present conditions. It is possible to capture the in situ condition of structures by using laser scanners that create dense three-dimensional point clouds. This research investigates the use of high resolution three-dimensional terrestrial laser scanners with image capturing abilities as tools to capture geometric range data of complex scenes for structural engineering applications. Laser scanning technology is continuously improving, with commonly available scanners now capturing over 1,000,000 texture-mapped points per second with an accuracy of ~2 mm. However, automatically extracting meaningful information from point clouds remains a challenge, and the current state-of-the-art requires significant user interaction. The first objective of this research is to use widely accepted point cloud processing steps such as registration, feature extraction, segmentation, surface fitting and object detection to divide laser scanner data into meaningful object clusters and then apply several damage detection methods to these clusters. This required establishing a process for extracting important information from raw laser-scanned data sets such as the location, orientation and size of objects in a scanned region, and location of damaged regions on a structure. For this purpose, first a methodology for processing range data to identify objects in a scene is presented and then, once the objects from model library are correctly detected and fitted into the captured point cloud, these fitted objects are compared with the as-is point cloud of the investigated object to locate defects on the structure. The algorithms are demonstrated on synthetic scenes and validated on range data collected from test specimens and test-bed bridges. The second objective of this research is to combine useful information extracted from laser scanner data with color information, which provides information in the fourth dimension that enables detection of damage types such as cracks, corrosion, and related surface defects that are generally difficult to detect using only laser scanner data; moreover, the color information also helps to track volumetric changes on structures such as spalling. Although using images with varying resolution to detect cracks is an extensively researched topic, damage detection using laser scanners with and without color images is a new research area that holds many opportunities for enhancing the current practice of visual inspections. The aim is to combine the best features of laser scans and images to create an automatic and effective surface damage detection method, which will reduce the need for skilled labor during visual inspections and allow automatic documentation of related information. This work enables developing surface damage detection strategies that integrate existing condition rating criteria for a wide range damage types that are collected under three main categories: small deformations already existing on the structure (cracks); damage types that induce larger deformations, but where the initial topology of the structure has not changed appreciably (e.g., bent members); and large deformations where localized changes in the topology of the structure have occurred (e.g., rupture, discontinuities and spalling). The effectiveness of the developed damage detection algorithms are validated by comparing the detection results with the measurements taken from test specimens and test-bed bridges.

Large tree diameter distribution modelling using sparse airborne laser scanning data in a subtropical forest in Nepal

NASA Astrophysics Data System (ADS)

Rana, Parvez; Vauhkonen, Jari; Junttila, Virpi; Hou, Zhengyang; Gautam, Basanta; Cawkwell, Fiona; Tokola, Timo

2017-12-01

Large-diameter trees (taking DBH > 30 cm to define large trees) dominate the dynamics, function and structure of a forest ecosystem. The aim here was to employ sparse airborne laser scanning (ALS) data with a mean point density of 0.8 m-2 and the non-parametric k-most similar neighbour (k-MSN) to predict tree diameter at breast height (DBH) distributions in a subtropical forest in southern Nepal. The specific objectives were: (1) to evaluate the accuracy of the large-tree fraction of the diameter distribution; and (2) to assess the effect of the number of training areas (sample size, n) on the accuracy of the predicted tree diameter distribution. Comparison of the predicted distributions with empirical ones indicated that the large tree diameter distribution can be derived in a mixed species forest with a RMSE% of 66% and a bias% of -1.33%. It was also feasible to downsize the sample size without losing the interpretability capacity of the model. For large-diameter trees, even a reduction of half of the training plots (n = 250), giving a marginal increase in the RMSE% (1.12-1.97%) was reported compared with the original training plots (n = 500). To be consistent with these outcomes, the sample areas should capture the entire range of spatial and feature variability in order to reduce the occurrence of error.

Modelling of photodegradation effect on elastic-viscoplastic behaviour of amorphous polylactic acid films

NASA Astrophysics Data System (ADS)

Belbachir, S.; Zaïri, F.; Ayoub, G.; Maschke, U.; Naït-Abdelaziz, M.; Gloaguen, J. M.; Benguediab, M.; Lefebvre, J. M.

2010-02-01

Polylactic acid (PLA) films were subjected to accelerated ultra-violet (UV) ageing. The UV irradiation leads to the alteration of the chemical structure which influences directly the mechanical response of the polymer. The chemical modification of the polymer was followed by gel permeation chromatography. Uniaxial tension tests were conducted at 50 °C and for different strain rates in order to characterize the large deformation response of PLA. The influence of UV irradiation on the alteration of the large deformation response of PLA was examined. A physically based elastic-viscoplastic model was used to describe the mechanical response of virgin PLA. The photodegradation effect was incorporated into the constitutive model to capture the stress-strain behaviour up to failure of aged PLA. To that end, the measured molecular weight was used as a direct input into the model. The model is shown to be in good agreement with experimental results over a wide range of UV irradiation doses.

Statistical analysis of Hasegawa-Wakatani turbulence

NASA Astrophysics Data System (ADS)

Anderson, Johan; Hnat, Bogdan

2017-06-01

Resistive drift wave turbulence is a multipurpose paradigm that can be used to understand transport at the edge of fusion devices. The Hasegawa-Wakatani model captures the essential physics of drift turbulence while retaining the simplicity needed to gain a qualitative understanding of this process. We provide a theoretical interpretation of numerically generated probability density functions (PDFs) of intermittent events in Hasegawa-Wakatani turbulence with enforced equipartition of energy in large scale zonal flows, and small scale drift turbulence. We find that for a wide range of adiabatic index values, the stochastic component representing the small scale turbulent eddies of the flow, obtained from the autoregressive integrated moving average model, exhibits super-diffusive statistics, consistent with intermittent transport. The PDFs of large events (above one standard deviation) are well approximated by the Laplace distribution, while small events often exhibit a Gaussian character. Furthermore, there exists a strong influence of zonal flows, for example, via shearing and then viscous dissipation maintaining a sub-diffusive character of the fluxes.

Process configuration of Liquid-nitrogen Energy Storage System (LESS) for maximum turnaround efficiency

NASA Astrophysics Data System (ADS)

Dutta, Rohan; Ghosh, Parthasarathi; Chowdhury, Kanchan

2017-12-01

Diverse power generation sector requires energy storage due to penetration of variable renewable energy sources and use of CO2 capture plants with fossil fuel based power plants. Cryogenic energy storage being large-scale, decoupled system with capability of producing large power in the range of MWs is one of the options. The drawback of these systems is low turnaround efficiencies due to liquefaction processes being highly energy intensive. In this paper, the scopes of improving the turnaround efficiency of such a plant based on liquid Nitrogen were identified and some of them were addressed. A method using multiple stages of reheat and expansion was proposed for improved turnaround efficiency from 22% to 47% using four such stages in the cycle. The novelty here is the application of reheating in a cryogenic system and utilization of waste heat for that purpose. Based on the study, process conditions for a laboratory-scale setup were determined and presented here.

Vibroacoustic Response of the NASA ACTS Spacecraft Antenna to Launch Acoustic Excitation

NASA Technical Reports Server (NTRS)

Larko, Jeffrey M.; Cotoni, Vincent

2008-01-01

The Advanced Communications Technology Satellite was an experimental NASA satellite launched from the Space Shuttle Discovery. As part of the ground test program, the satellite s large, parabolic reflector antennas were exposed to a reverberant acoustic loading to simulate the launch acoustics in the Shuttle payload bay. This paper describes the modelling and analysis of the dynamic response of these large, composite spacecraft antenna structure subjected to a diffuse acoustic field excitation. Due to the broad frequency range of the excitation, different models were created to make predictions in the various frequency regimes of interest: a statistical energy analysis (SEA) model to capture the high frequency response and a hybrid finite element-statistical energy (hybrid FE-SEA) model for the low to mid-frequency responses. The strengths and limitations of each of the analytical techniques are discussed. The predictions are then compared to the measured acoustic test data and to a boundary element (BEM) model to evaluate the performance of the hybrid techniques.

Generative diffeomorphic modelling of large MRI data sets for probabilistic template construction.

PubMed

Blaiotta, Claudia; Freund, Patrick; Cardoso, M Jorge; Ashburner, John

2018-02-01

In this paper we present a hierarchical generative model of medical image data, which can capture simultaneously the variability of both signal intensity and anatomical shapes across large populations. Such a model has a direct application for learning average-shaped probabilistic tissue templates in a fully automated manner. While in principle the generality of the proposed Bayesian approach makes it suitable to address a wide range of medical image computing problems, our work focuses primarily on neuroimaging applications. In particular we validate the proposed method on both real and synthetic brain MR scans including the cervical cord and demonstrate that it yields accurate alignment of brain and spinal cord structures, as compared to state-of-the-art tools for medical image registration. At the same time we illustrate how the resulting tissue probability maps can readily be used to segment, bias correct and spatially normalise unseen data, which are all crucial pre-processing steps for MR imaging studies. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Networks with fourfold connectivity in two dimensions.

PubMed

Tessier, Frédéric; Boal, David H; Discher, Dennis E

2003-01-01

The elastic properties of planar, C4-symmetric networks under stress and at nonzero temperature are determined by simulation and mean field approximations. Attached at fourfold coordinated junction vertices, the networks are self-avoiding in that their elements (or bonds) may not intersect each other. Two different models are considered for the potential energy of the elements: either Hooke's law springs or flexible tethers (square well potential). For certain ranges of stress and temperature, the properties of the networks are captured by one of several models: at large tensions, the networks behave like a uniform system of square plaquettes, while at large compressions or high temperatures, they display many characteristics of an ideal gas. Under less severe conditions, mean field models with more general shapes (parallelograms) reproduce many essential features of both networks. Lastly, the spring network expands without limit at a two-dimensional tension equal to the force constant of the spring; however, it does not appear to collapse under compression, except at zero temperature.

Do Offshore Wind Farms Influence Marine Primary Production?

NASA Astrophysics Data System (ADS)

Tweddle, J. F.; Murray, R. B. O.; Gubbins, M.; Scott, B. E.

2016-02-01

Primary producers (phytoplankton) form the basis of marine food-webs, supporting production of higher trophic levels, and act as a sink of CO2. We considered the impact of proposed large scale offshore wind farms in moderately deep waters (> 45 m) off the east coast of Scotland on rates of primary production. A 2 stage modelling process was used, employing state-of-the-art 3-D hydrographic models with the ability to capture flow at the spatial resolution of 10 m combined with 1-D vertical modelling using 7 years of local forcing data. Through influencing the strength of stratification via changes in current flow, large (100 m) modelled wind turbine foundations had a significant effect on primary producers, consistently reducing total annual primary production, although within the range of natural interannual variability. The percentage reduction was largest over submarine banks less than 54 m in depth, and was outside the range of natural interannual variability. Smaller (10 m) turbine foundations had no discernible effect on total annual primary production. The results indicate that smaller foundations should be favored as a mitigation measure, in terms of effects on primary production, and this type of analysis should be considered within sectoral planning and licensing processes for future renewable energy developments.

Generalized-active-space pair-density functional theory: an efficient method to study large, strongly correlated, conjugated systems.

PubMed

Ghosh, Soumen; Cramer, Christopher J; Truhlar, Donald G; Gagliardi, Laura

2017-04-01

Predicting ground- and excited-state properties of open-shell organic molecules by electronic structure theory can be challenging because an accurate treatment has to correctly describe both static and dynamic electron correlation. Strongly correlated systems, i.e. , systems with near-degeneracy correlation effects, are particularly troublesome. Multiconfigurational wave function methods based on an active space are adequate in principle, but it is impractical to capture most of the dynamic correlation in these methods for systems characterized by many active electrons. We recently developed a new method called multiconfiguration pair-density functional theory (MC-PDFT), that combines the advantages of wave function theory and density functional theory to provide a more practical treatment of strongly correlated systems. Here we present calculations of the singlet-triplet gaps in oligoacenes ranging from naphthalene to dodecacene. Calculations were performed for unprecedently large orbitally optimized active spaces of 50 electrons in 50 orbitals, and we test a range of active spaces and active space partitions, including four kinds of frontier orbital partitions. We show that MC-PDFT can predict the singlet-triplet splittings for oligoacenes consistent with the best available and much more expensive methods, and indeed MC-PDFT may constitute the benchmark against which those other models should be compared, given the absence of experimental data.

Using the Fe/Mn Ratio of FeO-Rich Olivine In WILD 2, Chondrite Matrix, and Type IIA Chondrules to Disentangle Their Histories

NASA Technical Reports Server (NTRS)

Frank, David R.; Le, L.; Zolensky, M. E.

2012-01-01

The Stardust Mission returned a large abundance of impactors from Comet 81P/Wild2 in the 5-30 m range. The preliminary examination of just a limited number of these particles showed that the collection captured abundant crystalline grains with a diverse mineralogy [1,2]. Many of these grains resemble those found in chondrite matrix and even contain fragments of chondrules and CAIs [1-3]. In particular, the olivine found in Wild 2 exhibits a wide compositional range (Fa0-97) with minor element abundances similar to the matrix olivine found in many carbonaceous chondrites (CCs) and unequilibrated ordinary chondrites (UOCs). Despite the wide distribution of Fa content, the olivine found in the matrices of CCs, UOCs, and Wild 2 can be roughly lumped into two types based solely on fayalite content. In fact, in some cases, a distinct bi-modal distribution is observed.

A study of infrasound propagation based on high-order finite difference solutions of the Navier-Stokes equations.

PubMed

Marsden, O; Bogey, C; Bailly, C

2014-03-01

The feasibility of using numerical simulation of fluid dynamics equations for the detailed description of long-range infrasound propagation in the atmosphere is investigated. The two dimensional (2D) Navier Stokes equations are solved via high fidelity spatial finite differences and Runge-Kutta time integration, coupled with a shock-capturing filter procedure allowing large amplitudes to be studied. The accuracy of acoustic prediction over long distances with this approach is first assessed in the linear regime thanks to two test cases featuring an acoustic source placed above a reflective ground in a homogeneous and weakly inhomogeneous medium, solved for a range of grid resolutions. An atmospheric model which can account for realistic features affecting acoustic propagation is then described. A 2D study of the effect of source amplitude on signals recorded at ground level at varying distances from the source is carried out. Modifications both in terms of waveforms and arrival times are described.

Hybrid micro-scale photovoltaics for enhanced energy conversion across all irradiation conditions

NASA Astrophysics Data System (ADS)

Agrawal, Gautam

A novel hybrid photovoltaics (HPV) architecture is presented that integrates high-performance micro-optics-based concentrator photovoltaics (CPV) array technology with a 1-sun photovoltaic (PV) cell within a low-profile panel structure. The approach simultaneously captures the direct solar radiation components with arrayed high-efficiency CPV cells and the diffuse solar components with an underlying wide-area PV cell. Performance analyses predict that the hybrid approach will significantly enhance the average energy produced per unit area for the full range of diffuse/direct radiation patterns across the USA. Furthermore, cost analyses indicate that the hybrid concept may be financially attractive for a wide range of locations. Indoor and outdoor experimental evaluation of a micro-optical system designed for use in a hybrid architecture verified that a large proportion of the direct radiation component was concentrated onto emulated micro-cell regions while most of the diffuse radiation and the remaining direct radiation was collected in the 1-sun cell area.

High dynamic range bio-molecular ion microscopy with the Timepix detector.

PubMed

Jungmann, Julia H; MacAleese, Luke; Visser, Jan; Vrakking, Marc J J; Heeren, Ron M A

2011-10-15

Highly parallel, active pixel detectors enable novel detection capabilities for large biomolecules in time-of-flight (TOF) based mass spectrometry imaging (MSI). In this work, a 512 × 512 pixel, bare Timepix assembly combined with chevron microchannel plates (MCP) captures time-resolved images of several m/z species in a single measurement. Mass-resolved ion images from Timepix measurements of peptide and protein standards demonstrate the capability to return both mass-spectral and localization information of biologically relevant analytes from matrix-assisted laser desorption ionization (MALDI) on a commercial ion microscope. The use of a MCP-Timepix assembly delivers an increased dynamic range of several orders of magnitude. The Timepix returns defined mass spectra already at subsaturation MCP gains, which prolongs the MCP lifetime and allows the gain to be optimized for image quality. The Timepix peak resolution is only limited by the resolution of the in-pixel measurement clock. Oligomers of the protein ubiquitin were measured up to 78 kDa. © 2011 American Chemical Society

Highly sensitive detection of target molecules using a new fluorescence-based bead assay

NASA Astrophysics Data System (ADS)

Scheffler, Silvia; Strauß, Denis; Sauer, Markus

2007-07-01

Development of immunoassays with improved sensitivity, specificity and reliability are of major interest in modern bioanalytical research. We describe the development of a new immunomagnetic fluorescence detection (IM-FD) assay based on specific antigen/antibody interactions and on accumulation of the fluorescence signal on superparamagnetic PE beads in combination with the use of extrinsic fluorescent labels. IM-FD can be easily modified by varying the order of coatings and assay conditions. Depending on the target molecule, antibodies (ABs), entire proteins, or small protein epitopes can be used as capture molecules. The presence of target molecules is detected by fluorescence microscopy using fluorescently labeled secondary or detection antibodies. Here, we demonstrate the potential of the new assay detecting the two tumor markers IGF-I and p53 antibodies in the clinically relevant concentration range. Our data show that the fluorescence-based bead assay exhibits a large dynamic range and a high sensitivity down to the subpicomolar level.

Depletion and capture: revisiting “The source of water derived from wells"

USGS Publications Warehouse

Konikow, Leonard F.; Leake, Stanley A.

2014-01-01

A natural consequence of groundwater withdrawals is the removal of water from subsurface storage, but the overall rates and magnitude of groundwater depletion and capture relative to groundwater withdrawals (extraction or pumpage) have not previously been well characterized. This study assesses the partitioning of long-term cumulative withdrawal volumes into fractions derived from storage depletion and capture, where capture includes both increases in recharge and decreases in discharge. Numerical simulation of a hypothetical groundwater basin is used to further illustrate some of Theis' (1940) principles, particularly when capture is constrained by insufficient available water. Most prior studies of depletion and capture have assumed that capture is unconstrained through boundary conditions that yield linear responses. Examination of real systems indicates that capture and depletion fractions are highly variable in time and space. For a large sample of long-developed groundwater systems, the depletion fraction averages about 0.15 and the capture fraction averages about 0.85 based on cumulative volumes. Higher depletion fractions tend to occur in more arid regions, but the variation is high and the correlation coefficient between average annual precipitation and depletion fraction for individual systems is only 0.40. Because 85% of long-term pumpage is derived from capture in these real systems, capture must be recognized as a critical factor in assessing water budgets, groundwater storage depletion, and sustainability of groundwater development. Most capture translates into streamflow depletion, so it can detrimentally impact ecosystems.

Development of a long-gauge vibration sensor

NASA Astrophysics Data System (ADS)

Kung, Peter; Comanici, Maria I.

2014-06-01

Recently, we found that by terminating a long length of fiber of up to 2 km with an in-fiber cavity structure, the entire structure can detect vibrations over a frequency range from 5 Hz to 100 Hz. We want to determine whether the structure (including packaging) can be optimized to detect vibrations at even higher frequencies. The structure can be used as a distributed vibration sensor mounted on large motors and other rotating machines to capture the entire frequency spectrum of the associated vibration signals, and therefore, replace the many accelerometers, which add to the maintenance cost. Similarly, it will help detect in-slot vibrations which cause intermittent contact leading to sparking under high voltages inside air-cooled generators. However, that will require the sensor to detect frequencies associated with vibration sparking, ranging from 6 kHz to 15 kHz. Then, at even higher frequencies, the structure can be useful to detect acoustic vibrations (30 kHz to 150 kHz) associated with partial discharge (PD) in generators and transformers. Detecting lower frequencies in the range 2 Hz to 200 Hz makes the sensor suitable for seismic studies and falls well into the vibrations associated with rotating machines. Another application of interest is corrosion detection in large re-enforced concrete structures by inserting the sensor along a long hole drilled around structures showing signs of corrosion. The frequency response for the proposed long-gauge vibration sensor depends on packaging.

Characterization of the Gamma Response of a Cadmium Capture-gated Neutron Spectrometer

NASA Astrophysics Data System (ADS)

Hogan, Nathaniel; Rees, Lawrence; Czirr, Bart; Bastola, Suraj

2010-10-01

We have studied the gamma response of a newly developed capture-gated neutron spectrometer. Such spectrometers detect a dual signal from incoming neutrons, allowing for differentiation between other particles, such as gamma rays. The neutron provides a primary light pulse in either plastic or liquid scintillator through neutron-proton collisions. A capture material then delivers a second pulse as the moderated neutron captures in the intended material, which then de-excites with the release of gamma energy. The presented spectrometer alternates one centimeter thick plastic scintillators with sheets of cadmium inserted in between for neutron capture. The neutron capture in cadmium offers a release of gamma energy ˜ 9 MeV. To verify that the interaction was caused by a neutron, the response functions of both events must be well known. Due to the prior existence of many capture-gated neutron spectrometers, the proton recoil pulse has already been studied, but the capture pulse is unique to each spectrometer and must be measured. Experimental results agree with theoretical Monte-Carlo code, both suggesting that the optics and geometry of the spectrometer play a large role in its efficiency. Results prove promising for the efficiency of the spectrometer.

Oculomotor capture during real-world scene viewing depends on cognitive load.

PubMed

Matsukura, Michi; Brockmole, James R; Boot, Walter R; Henderson, John M

2011-03-25

It has been claimed that gaze control during scene viewing is largely governed by stimulus-driven, bottom-up selection mechanisms. Recent research, however, has strongly suggested that observers' top-down control plays a dominant role in attentional prioritization in scenes. A notable exception to this strong top-down control is oculomotor capture, where visual transients in a scene draw the eyes. One way to test whether oculomotor capture during scene viewing is independent of an observer's top-down goal setting is to reduce observers' cognitive resource availability. In the present study, we examined whether increasing observers' cognitive load influences the frequency and speed of oculomotor capture during scene viewing. In Experiment 1, we tested whether increasing observers' cognitive load modulates the degree of oculomotor capture by a new object suddenly appeared in a scene. Similarly, in Experiment 2, we tested whether increasing observers' cognitive load modulates the degree of oculomotor capture by an object's color change. In both experiments, the degree of oculomotor capture decreased as observers' cognitive resources were reduced. These results suggest that oculomotor capture during scene viewing is dependent on observers' top-down selection mechanisms. Copyright © 2011 Elsevier Ltd. All rights reserved.

Computational Investigations of Inboard Flow Separation and Mitigation Techniques on Multi-Megawatt Wind Turbines

NASA Astrophysics Data System (ADS)

Chow, Raymond

The aerodynamic characteristics of the NREL 5-MW rotor have been examined using a Reynolds-averaged Navier-Stokes method, OVERFLOW2. A comprehensive off-body grid independence study has been performed. A strong dependence on the size of the near-body wake grid has been found. Rapid diffusion of the wake appears to generate an overprediction of power and thrust. A large, continuous near-wake grid at minimum of two rotor diameters downstream of the rotor appears to be necessary for accurate predictions of near-body forces. The NREL 5-MW rotor demonstrates significant inboard flow separation up to 30% of span. This separation appears to be highly three-dimensional, with a significant amount of radial flow increasing the size of the separated region outboard. Both integrated aerodynamic coefficients and detailed wake structures for the baseline NREL 5-MW rotor are in excellent agreement with results by Riso at Uinfinity = 8 and 11 m/s. A simple, continuous full-chord fence was applied at the maximum chord location of the blade, within the region of separation. This non-optimized device reduced the boundary-layer cross-flow and resulting separation, and increased rotor power capture by 0.9% and 0.6% at U infinity = 8 and 11 m/s, respectively. Suction side only fences perform similarly in terms of power capture but reduce the increase in rotor thrust. Fence heights from 0.5% to 17.5% of the maximum chord all demonstrate some level of effectiveness, with fences (1-2.5%cmax) showing similar performance gains to taller fences with smaller penalties in thrust. Performance in terms of power capture is not very sensitive to spanwise location when placed within the separation region. Blunt trailing edge modifications to the inboard region of the blade showed a relatively significant effect on rotor power. Over a large range of trailing edge thicknesses from hTE = 10 to 25%c, power was found to increase by 1.4%. Thrust increased proportionally with the thicknesses examined, reaching a comparable increase of 1.4% by a trailing edge thickness of 15%c. Decreasing inboard twist only acted to increase thrust without increasing power capture any further at U infinity = 11 m/s. While increasing inboard blade twist decreased power, but decreased thrust at even a higher rate. Vortex generators were not successively configured to significantly improve power capture in this study. Two of the three configurations examined actually decreased power capture and increased the separation region. The results found in this study are not believed to be representative of a properly sized and located array of VGs. The presence of the nose cone and nacelle body at the hub of the rotor is found to have a minimal effect on the power and thrust of the overall rotor. The downstream wake structure however is changed by the nacelle, potentially useful for wake tailoring when turbines are closely spaced together.

Atmospheric Mining in the Outer Solar System: Resource Capturing, Exploration, and Exploitation

NASA Technical Reports Server (NTRS)

Palaszewski, Bryan

2015-01-01

Atmospheric mining in the outer solar system (AMOSS) has been investigated as a means of fuel production for high-energy propulsion and power. Fusion fuels such as helium 3 (He-3) and hydrogen can be wrested from the atmospheres of Uranus and Neptune and either returned to Earth or used in-situ for energy production. 3He and hydrogen (deuterium, etc.) were the primary gases of interest, with hydrogen being the primary propellant for nuclear thermal solid core and gas core rocket-based atmospheric flight. A series of analyses were undertaken to investigate resource capturing aspects of AMOSS. These analyses included the gas capturing rate, storage options, and different methods of direct use of the captured gases. Additional supporting analyses were conducted to illuminate vehicle sizing and orbital transportation issues. While capturing 3He, large amounts of hydrogen and helium 4 (He-4) are produced. With these two additional gases, the potential exists for fueling small and large fleets of additional exploration and exploitation vehicles. Additional aerospacecraft or other aerial vehicles (UAVs, balloons, rockets, etc.) could fly through the outer-planet atmosphere to investigate cloud formation dynamics, global weather, localized storms or other disturbances, wind speeds, the poles, and so forth. Deep-diving aircraft (built with the strength to withstand many atmospheres of pressure) powered by the excess hydrogen or 4He may be designed to probe the higher density regions of the gas giants.

Minimally invasive percutaneous management of large bladder stones with a laparoscopic entrapment bag.

PubMed

Tan, Yung K; Gupta, Dilan M; Weinberg, Aaron; Matteis, August J; Kotwal, Sunny; Gupta, Mantu

2014-01-01

The treatment of large volume bladder stones is a management conundrum. Transurethral methods are plagued by long operative times, trauma to the bladder mucosa, and the need for a postoperative urethral catheter. Open cystolithotomy has higher morbidity. We present the percutaneous management of bladder stones with the novel use of a laparoscopic entrapment bag. Twenty-five patients (mean age 65.7), including 22 men and 3 women, 4 with a neurogenic bladder and 21 with a prior diagnosis of benign prostatic hyperplasia, underwent our novel technique. The mean number of stones was 6.8±8.0 (range, 1 to 30) and total stone burden 10.4±10.5 cm (range, 3.0 to 50.0 cm). Using regional or general anesthesia and flexible cystoscopic guidance, percutaneous bladder access was achieved. The tract was balloon dilated to 30F and stones captured in a laparoscopic entrapment bag. The bag's opening was exteriorized and stone fragmentation and comminution were achieved using a nephroscope and pneumatic or ultrasonic lithotripters. The bag was extracted and a 22F suprapubic catheter was inserted into the bladder; the patient was discharged the next day after a voiding trial. The procedure was done without fluoroscopy. No foley catheter was necessary. All patients were rendered stone free. The mean estimated blood loss was 11.1±3.93 mL (range, 10 to 25 mL). The mean operative time was 102.3 minutes. There was minimal trauma to the bladder mucosa and no complications of fluid extravasation, hematuria, or urethral trauma were noted. All patients were discharged within 24 hours of the operation. Percutaneous cystolithotomy with the use of an entrapment bag is an efficient, safe technique for treating large volume bladder calculi. We recommend this technique as an alternative to open surgery for patients with too large a stone burden to remove transurethrally.

Independent measurement of the neutrino mixing angle θ 13 via neutron capture on hydrogen at Daya Bay

DOE PAGES

Jaffe, D. E.

2014-10-03

A new measurement of the θ 13 mixing angle has been obtained at the Daya Bay Reactor Neutrino Experiment via the detection of inverse beta decays tagged by neutron capture on hydrogen. The antineutrino events for hydrogen capture are distinct from those for gadolinium capture with largely different systematic uncertainties, allowing a determination independent of the gadolinium-capture result and an improvement on the precision of the θ 13 measurement. With a 217-day antineutrino data set obtained with six antineutrino detectors and from six 2.9 GW th reactors, the rate deficit observed at the far hall is interpreted as sin 22θmore » 13=0.083±0.018 in the three-flavor oscillation model. When combined with the gadolinium-capture result from Daya Bay, we obtain sin 22θ 13=0.089±0.008 as the final result for the six-antineutrino-detector configuration of the Daya Bay experiment.« less

Heavy Element Abundances in Planetary Nebulae from Deep Optical Echelle Spectroscopy

NASA Astrophysics Data System (ADS)

Mashburn, Amanda; Sterling, Nicholas C.; Dinerstein, Harriet L.; Garofali, Kristen; Jensema, Rachael; Turbyfill, Amanda; Wieser, Hannah-Marie N.; Reed, Evan C.; Redfield, Seth

2016-01-01

We present the abundances of neutron(n)-capture elements (atomic number Z > 30) and iron determined from deep optical echelle spectroscopy of 14 Galactic planetary nebulae (PNe). The spectra were obtained with the 2D-coudé spectrograph on the 2.7-m Harlan J. Smith telescope at McDonald Observatory. The abundances of n-capture elements can be enhanced in PNe due to slow n-capture nucleosynthesis in the progenitor asymptotic giant branch (AGB) stars. The high spectral resolution of these data (R = 36,700) allow most n-capture element emission lines to be resolved from other nebular and telluric features. We detect Kr in all of the observed PNe (with multiple ions detected in several objects), while Br, Rb, and Xe were each detected in 4--5 objects. Using the new Kr ionization correction factors (ICFs) of Sterling et al. (2015, ApJS, 218, 25), we find [Kr/O] abundances ranging from 0.05 to 1.1 dex. We utilize approximate ICFs for the other n-capture elements, and find slightly lower enrichments for Br and Rb (-0.1 to 0.7 dex), while Xe is enhanced relative to solar by factors of two to 30. The [Xe/Kr] ratios range from -0.3 to 1.4 dex, indicating a significant range in neutron exposures in PN progenitor stars. Interestingly, the largest [Xe/Kr] ratio is found in the thick-disk PN NGC 6644, which has a lower metallicity than the other observed PNe. We detect iron emission lines in all but one target. Fe can be depleted into dust grains in ionized nebulae, and its abundance thus provides key information regarding dust-to-gas ratios and grain destruction processes. We find that [Fe/O] ranges from -1.3 to -0.7 dex in the observed PNe, a smaller spread of depletion factors than found in recent studies (Delgado-Inglada & Rodriguez 2014, ApJ, 784, 173) though this may be due in part to our smaller sample. These data are part of a larger study of heavy elements in PNe, which will provide more accurate determinations of n-capture element abundances than previous estimates in several PNe, thereby providing key new constraints to models of AGB nucleosynthesis and Galactic chemical evolution. This work was supported by NSF awards AST-0708245 and AST-901432.

Sampling the stream landscape: Improving the applicability of an ecoregion-level capture probability model for stream fishes

USGS Publications Warehouse

Mollenhauer, Robert; Mouser, Joshua B.; Brewer, Shannon K.

2018-01-01

Temporal and spatial variability in streams result in heterogeneous gear capture probability (i.e., the proportion of available individuals identified) that confounds interpretation of data used to monitor fish abundance. We modeled tow-barge electrofishing capture probability at multiple spatial scales for nine Ozark Highland stream fishes. In addition to fish size, we identified seven reach-scale environmental characteristics associated with variable capture probability: stream discharge, water depth, conductivity, water clarity, emergent vegetation, wetted width–depth ratio, and proportion of riffle habitat. The magnitude of the relationship between capture probability and both discharge and depth varied among stream fishes. We also identified lithological characteristics among stream segments as a coarse-scale source of variable capture probability. The resulting capture probability model can be used to adjust catch data and derive reach-scale absolute abundance estimates across a wide range of sampling conditions with similar effort as used in more traditional fisheries surveys (i.e., catch per unit effort). Adjusting catch data based on variable capture probability improves the comparability of data sets, thus promoting both well-informed conservation and management decisions and advances in stream-fish ecology.

Monitoring gully change: A comparison of airborne and terrestrial laser scanning using a case study from Aratula, Queensland

NASA Astrophysics Data System (ADS)

Goodwin, Nicholas R.; Armston, John D.; Muir, Jasmine; Stiller, Issac

2017-04-01

Airborne laser scanning (ALS) and terrestrial laser scanning (TLS) technologies capture spatially detailed estimates of surface topography and when collected multi-temporally can be used to assess geomorphic change. The sensitivity and repeatability of ALS measurements to characterise geomorphic change in topographically complex environments such as gullies; however, remains an area lacking quantitative research. In this study, we captured coincident ALS and TLS datasets to assess their ability and synergies to detect geomorphic change for a gully located in Aratula, southeast Queensland, Australia. We initially used the higher spatial density and ranging accuracy of TLS to provide an assessment of the Digital Elevation Models (DEM) derived from ALS within a gully environment. Results indicated mean residual errors of 0.13 and 0.09 m along with standard deviation (SD) of residual errors of 0.20 and 0.16 m using pixel sizes of 0.5 and 1.0 m, respectively. The positive mean residual errors confirm that TLS data consistently detected deeper sections of the gully than ALS. We also compared the repeatability of ALS and TLS for characterising gully morphology. This indicated that the sensitivity to detect change using ALS is substantially lower than TLS, as expected, and that the ALS survey characteristics influence the ability to detect change. Notably, we found that using one ALS transect (mean density of 5 points / m2) as opposed to three transects increased the SD of residual error by approximately 30%. The supplied classification of ALS ground points was also demonstrated to misclassify gully features as non-ground, with minimum elevation filtering found to provide a more accurate DEM of the gully. The number and placement of terrestrial laser scans were also found to influence the derived DEMs. Furthermore, we applied change detection using two ALS data captures over a four year period and four TLS field surveys over an eight month period. This demonstrated that ALS can detect large scale erosional changes with head cutting of gully branches migrating approximately 10 m upslope. In comparison, TLS captured smaller scale intra-annual erosional patterns largely undetectable by the ALS dataset with a large rainfall event coinciding with the highest volumetric change (net change > 46 m3). Overall, these findings reaffirm the importance of quantifying DEM errors and demonstrate that ALS is unlikely to detect subtle geomorphic changes (< 0.45 m) potentially missing significant sediment change. TLS was able to detect more subtle intra-annual changes but was limited in its spatial coverage. This suggests TLS and ALS surveys are complementary technologies and when used together can provide a more detailed understanding of gully processes at different temporal and spatial scales, provided the inherent errors are taken into account.

Back-pack unit for capturing waterfowl and upland game by night-lighting

USGS Publications Warehouse

Drewien, R.C.; Reeves, H.M.; Springer, P.F.; Kuck, T.L.

1967-01-01

A night-lighting unit, designed as a light weight back-pack, proved successful for capturing waterfowl pairs, pheasants (Phasianus colchicus), and cottontail rabbits (Sylvilagus floridanus) during the spring and summer when most breeding populations are widely dispersed. Eighty ducks of seven species were captured in 48 hours (1.7 ducks per hour) of night-lighting in marsh habitat. Similarly, 30 pheasants were trapped in 25 hours (1.2 birds per hour) and 63 cottontail rabbits were either observed at close range (6-12 ft) or captured during night-lighting operations in upland habitat. Catch per hour of effort increased for all species as their night habitat requirements and reaction to night-lights became known. The mobile unit proved well suited for intensive use on small areas where other methods of capture were unfeasible and where representative coverage of various habitat types was desired. Besides its utility for capturing animals, the unit provided a method for studying nocturnal movements, behavior, and habitat use of marked animals.

Neutron Capture Rates and the r-Process Abundance Pattern in Shocked Neutrino-Driven Winds

NASA Astrophysics Data System (ADS)

Barringer, Daniel; Surman, Rebecca

2009-10-01

The r-process is an important process in nucleosynthesis in which nuclei will undergo rapid neutron captures. Models of the r-process require nuclear data such as neutron capture rates for thousands of individual nuclei, many of which lie far from stability. Among the potential sites for the r-process, and the one that we investigate, is the shocked neutrino-driven wind in core-collapse supernovae. Here we examine the importance of the neutron capture rates of specific, individual nuclei in the second r-process abundance peak occurring at A ˜ 130 for a range of parameterized neutrino-driven wind trajectories. Of specific interest are the nuclei whose capture rates affect the abundances of nuclei outside of the A ˜ 130 peak. We found that increasing the neutron capture rate for a number of nuclei including ^135In, ^132Sn, ^133Sb, ^137Sb, and ^136Te can produce changes in the resulting abundance pattern of up to 13%.

Phase-Change Aminopyridines as Carbon Dioxide Capture Solvents

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

Malhotra, Deepika; Page, Jordan P.; Bowden, Mark E.

Carbon dioxide is the main atmospheric greenhouse gas released from industrial point sources. In order to mitigate adverse environmental effects of these emissions, carbon capture, storage and utilization is required. To this end, several CO2 capture technologies are being developed for application in carbon capture, which include aqueous amines and water-lean solvents. Herein we report new aminopyridine solvents with the potential for CO2 capture from coal-fired power plants. These four solvents 2-picolylamine, 3-picolylamine, 4-picolylamine and N’-(pyridin-4-ylmethyl)ethane-1,2-diamine are liquids that rapidly bind CO2 to form crystalline solids at standard room temperature and pressure. These solvents have displayed high CO2 capture capacitymore » (11 - 20 wt%) and can be regenerated at temperatures in the range of 120 - 150 C. The advantage of these primary aminopyridine solvents is that crystalline salt product can be separated, making it possible to regenerate only the CO2-rich solid ultimately resulting in reduced energy penalty.« less

A new proportion measure of the treatment effect captured by candidate surrogate endpoints.

PubMed

Kobayashi, Fumiaki; Kuroki, Manabu

2014-08-30

The use of surrogate endpoints is expected to play an important role in the development of new drugs, as they can be used to reduce the sample size and/or duration of randomized clinical trials. Biostatistical researchers and practitioners have proposed various surrogacy measures; however, (i) most of these surrogacy measures often fall outside the range [0,1] without any assumptions, (ii) these surrogacy measures do not provide a cut-off value for judging a surrogacy level of candidate surrogate endpoints, and (iii) most surrogacy measures are highly variable; thus, the confidence intervals are often unacceptably wide. In order to solve problems (i) and (ii), we propose a new surrogacy measure, a proportion of the treatment effect captured by candidate surrogate endpoints (PCS), on the basis of the decomposition of the treatment effect into parts captured and non-captured by the candidate surrogate endpoints. In order to solve problem (iii), we propose an estimation method based on the half-range mode method with the bootstrap distribution of the estimated surrogacy measures. Finally, through numerical experiments and two empirical examples, we show that the PCS with the proposed estimation method overcomes these difficulties. The results of this paper contribute to the reliable evaluation of how much of the treatment effect is captured by candidate surrogate endpoints. Copyright © 2014 John Wiley & Sons, Ltd.

Genomic prediction in contrast to a genome-wide association study in explaining heritable variation of complex growth traits in breeding populations of Eucalyptus.

PubMed

Müller, Bárbara S F; Neves, Leandro G; de Almeida Filho, Janeo E; Resende, Márcio F R; Muñoz, Patricio R; Dos Santos, Paulo E T; Filho, Estefano Paludzyszyn; Kirst, Matias; Grattapaglia, Dario

2017-07-11

The advent of high-throughput genotyping technologies coupled to genomic prediction methods established a new paradigm to integrate genomics and breeding. We carried out whole-genome prediction and contrasted it to a genome-wide association study (GWAS) for growth traits in breeding populations of Eucalyptus benthamii (n =505) and Eucalyptus pellita (n =732). Both species are of increasing commercial interest for the development of germplasm adapted to environmental stresses. Predictive ability reached 0.16 in E. benthamii and 0.44 in E. pellita for diameter growth. Predictive abilities using either Genomic BLUP or different Bayesian methods were similar, suggesting that growth adequately fits the infinitesimal model. Genomic prediction models using ~5000-10,000 SNPs provided predictive abilities equivalent to using all 13,787 and 19,506 SNPs genotyped in the E. benthamii and E. pellita populations, respectively. No difference was detected in predictive ability when different sets of SNPs were utilized, based on position (equidistantly genome-wide, inside genes, linkage disequilibrium pruned or on single chromosomes), as long as the total number of SNPs used was above ~5000. Predictive abilities obtained by removing relatedness between training and validation sets fell near zero for E. benthamii and were halved for E. pellita. These results corroborate the current view that relatedness is the main driver of genomic prediction, although some short-range historical linkage disequilibrium (LD) was likely captured for E. pellita. A GWAS identified only one significant association for volume growth in E. pellita, illustrating the fact that while genome-wide regression is able to account for large proportions of the heritability, very little or none of it is captured into significant associations using GWAS in breeding populations of the size evaluated in this study. This study provides further experimental data supporting positive prospects of using genome-wide data to capture large proportions of trait heritability and predict growth traits in trees with accuracies equal or better than those attainable by phenotypic selection. Additionally, our results document the superiority of the whole-genome regression approach in accounting for large proportions of the heritability of complex traits such as growth in contrast to the limited value of the local GWAS approach toward breeding applications in forest trees.

Spacesuit and Space Vehicle Comparative Ergonomic Evaluation

NASA Technical Reports Server (NTRS)

England, Scott; Benson, Elizabeth; Cowley, Matthew; Harvill, Lauren; Blackledge, Christopher; Perez, Esau; Rajulu, Sudhakar

2011-01-01

With the advent of the latest manned spaceflight objectives, a series of prototype launch and reentry spacesuit architectures were evaluated for eventual down selection by NASA based on the performance of a set of designated tasks. A consolidated approach was taken to testing, concurrently collecting suit mobility data, seat-suit-vehicle interface clearances and movement strategies within the volume of a Multi-Purpose Crew Vehicle mockup. To achieve the objectives of the test, a requirement was set forth to maintain high mockup fidelity while using advanced motion capture technologies. These seemingly mutually exclusive goals were accommodated with the construction of an optically transparent and fully adjustable frame mockup. The mockup was constructed such that it could be dimensionally validated rapidly with the motion capture system. This paper will describe the method used to create a motion capture compatible space vehicle mockup, the consolidated approach for evaluating spacesuits in action, as well as the various methods for generating hardware requirements for an entire population from the resulting complex data set using a limited number of test subjects. Kinematics, hardware clearance, suited anthropometry, and subjective feedback data were recorded on fifteen unsuited and five suited subjects. Unsuited subjects were selected chiefly by anthropometry, in an attempt to find subjects who fell within predefined criteria for medium male, large male and small female subjects. The suited subjects were selected as a subset of the unsuited subjects and tested in both unpressurized and pressurized conditions. Since the prototype spacesuits were fabricated in a single size to accommodate an approximately average sized male, the findings from the suit testing were systematically extrapolated to the extremes of the population to anticipate likely problem areas. This extrapolation was achieved by first performing population analysis through a comparison of suited subjects performance to their unsuited performance and then applying the results to the entire range of population. The use of a transparent space vehicle mockup enabled the collection of large amounts of data during human-in-the-loop testing. Mobility data revealed that most of the tested spacesuits had sufficient ranges of motion for tasks to be performed successfully. A failed tasked by a suited subject most often stemmed from a combination of poor field of view while seated and poor dexterity of the gloves when pressurized or from suit/vehicle interface issues. Seat ingress/egress testing showed that problems with anthropometric accommodation does not exclusively occur with the largest or smallest subjects, but rather specific combinations of measurements that lead to narrower seat ingress/egress clearance.

Hydrodynamic Capture and Release of Passively Driven Particles by Active Particles Under Hele-Shaw Flows

NASA Astrophysics Data System (ADS)

Mishler, Grant; Tsang, Alan Cheng Hou; Pak, On Shun

2018-03-01

The transport of active and passive particles plays central roles in diverse biological phenomena and engineering applications. In this paper, we present a theoretical investigation of a system consisting of an active particle and a passive particle in a confined micro-fluidic flow. The introduction of an external flow is found to induce the capture of the passive particle by the active particle via long-range hydrodynamic interactions among the particles. This hydrodynamic capture mechanism relies on an attracting stable equilibrium configuration formed by the particles, which occurs when the external flow intensity exceeds a certain threshold. We evaluate this threshold by studying the stability of the equilibrium configurations analytically and numerically. Furthermore, we study the dynamics of typical capture and non-capture events and characterize the basins of attraction of the equilibrium configurations. Our findings reveal a critical dependence of the hydrodynamic capture mechanism on the external flow intensity. Through adjusting the external flow intensity across the stability threshold, we demonstrate that the active particle can capture and release the passive particle in a controllable manner. Such a capture-and-release mechanism is desirable for biomedical applications such as the capture and release of therapeutic payloads by synthetic micro-swimmers in targeted drug delivery.

The environmental and economic sustainability of carbon capture and storage.

PubMed

Hardisty, Paul E; Sivapalan, Mayuran; Brooks, Peter

2011-05-01

For carbon capture and storage (CCS) to be a truly effective option in our efforts to mitigate climate change, it must be sustainable. That means that CCS must deliver consistent environmental and social benefits which exceed its costs of capital, energy and operation; it must be protective of the environment and human health over the long term; and it must be suitable for deployment on a significant scale. CCS is one of the more expensive and technically challenging carbon emissions abatement options available, and CCS must first and foremost be considered in the context of the other things that can be done to reduce emissions, as a part of an overall optimally efficient, sustainable and economic mitigation plan. This elevates the analysis beyond a simple comparison of the cost per tonne of CO(2) abated--there are inherent tradeoffs with a range of other factors (such as water, NOx, SOx, biodiversity, energy, and human health and safety, among others) which must also be considered if we are to achieve truly sustainable mitigation. The full life-cycle cost of CCS must be considered in the context of the overall social, environmental and economic benefits which it creates, and the costs associated with environmental and social risks it presents. Such analysis reveals that all CCS is not created equal. There is a wide range of technological options available which can be used in a variety of industries and applications-indeed CCS is not applicable to every industry. Stationary fossil-fuel powered energy and large scale petroleum industry operations are two examples of industries which could benefit from CCS. Capturing and geo-sequestering CO(2) entrained in natural gas can be economic and sustainable at relatively low carbon prices, and in many jurisdictions makes financial sense for operators to deploy now, if suitable secure disposal reservoirs are available close by. Retrofitting existing coal-fired power plants, however, is more expensive and technically challenging, and the economic sustainability of post-combustion capture retrofit needs to be compared on a portfolio basis to the relative overall net benefit of CCS on new-build plants, where energy efficiency can be optimised as a first step, and locations can be selected with sequestration sites in mind. Examples from the natural gas processing, liquefied natural gas (LNG), and coal-fired power generation sectors, illustrate that there is currently a wide range of financial costs for CCS, depending on how and where it is applied, but equally, environmental and social benefits of emissions reduction can be considerable. Some CCS applications are far more economic and sustainable than others. CCS must be considered in the context of the other things that a business can do to eliminate emissions, such as far-reaching efforts to improve energy efficiency.

The Environmental and Economic Sustainability of Carbon Capture and Storage

PubMed Central

Hardisty, Paul E.; Sivapalan, Mayuran; Brooks, Peter

2011-01-01

For carbon capture and storage (CCS) to be a truly effective option in our efforts to mitigate climate change, it must be sustainable. That means that CCS must deliver consistent environmental and social benefits which exceed its costs of capital, energy and operation; it must be protective of the environment and human health over the long term; and it must be suitable for deployment on a significant scale. CCS is one of the more expensive and technically challenging carbon emissions abatement options available, and CCS must first and foremost be considered in the context of the other things that can be done to reduce emissions, as a part of an overall optimally efficient, sustainable and economic mitigation plan. This elevates the analysis beyond a simple comparison of the cost per tonne of CO2 abated—there are inherent tradeoffs with a range of other factors (such as water, NOx, SOx, biodiversity, energy, and human health and safety, among others) which must also be considered if we are to achieve truly sustainable mitigation. The full life-cycle cost of CCS must be considered in the context of the overall social, environmental and economic benefits which it creates, and the costs associated with environmental and social risks it presents. Such analysis reveals that all CCS is not created equal. There is a wide range of technological options available which can be used in a variety of industries and applications—indeed CCS is not applicable to every industry. Stationary fossil-fuel powered energy and large scale petroleum industry operations are two examples of industries which could benefit from CCS. Capturing and geo-sequestering CO2 entrained in natural gas can be economic and sustainable at relatively low carbon prices, and in many jurisdictions makes financial sense for operators to deploy now, if suitable secure disposal reservoirs are available close by. Retrofitting existing coal-fired power plants, however, is more expensive and technically challenging, and the economic sustainability of post-combustion capture retrofit needs to be compared on a portfolio basis to the relative overall net benefit of CCS on new-build plants, where energy efficiency can be optimised as a first step, and locations can be selected with sequestration sites in mind. Examples from the natural gas processing, liquefied natural gas (LNG), and coal-fired power generation sectors, illustrate that there is currently a wide range of financial costs for CCS, depending on how and where it is applied, but equally, environmental and social benefits of emissions reduction can be considerable. Some CCS applications are far more economic and sustainable than others. CCS must be considered in the context of the other things that a business can do to eliminate emissions, such as far-reaching efforts to improve energy efficiency. PMID:21655130

Determination of 20Ne(p ,γ )21Na cross sections from Ep=500 -2000 keV

NASA Astrophysics Data System (ADS)

Lyons, S.; Görres, J.; deBoer, R. J.; Stech, E.; Chen, Y.; Gilardy, G.; Liu, Q.; Long, A. M.; Moran, M.; Robertson, D.; Seymour, C.; Vande Kolk, B.; Wiescher, M.; Best, A.

2018-06-01

Background: The reaction 20Ne(p ,γ )21Na influences the nucleosynthesis of Ne, Na, and Mg isotopes while contributing to hydrogen burning in several stellar sites, such as red giants, asymptotic giant branch (AGB) stars, massive stars, and oxygen-neon (ONe) novae. In the relevant temperature range for these environments (T = 0.05-0.5 GK), the main contributions to this reaction rate are from the direct capture process as well as the high-energy tail of a subthreshold resonance in the ground-state transition at Ex = 2425 keV in the 21Na compound nucleus. Purpose: The previous measurement of this reaction reports cross sections with large uncertainties for the ground-state transition. At higher energies, where the subthreshold resonance makes a smaller contribution to the total cross section, only upper limits are provided. This work aims to reduce the uncertainty in the cross section where direct capture dominates, as well as provide cross-section data in previously unmeasured regions. Method: The 20Ne(p ,γ )21Na reaction was measured over a wide proton energy range (Ep = 0.5-2.0 MeV) at θlab = 90∘. Transitions to the ground state and to the 332 and 2425 keV excited states were observed. The primary transitions to these three bound states were utilized in an R -matrix analysis to determine the contributions of the direct capture and the subthreshold resonance to the total cross section. Results: The cross sections of the present measurements have been found to be in good agreement with the previous data at low energy. Significantly improved cross-section measurements have been obtained over the Ep = 1300-1900 keV region. The narrow resonance at Ec.m. = 1113 keV (Ex = 3544.3 keV) has also been remeasured and its strength has been found to be in good agreement with previous measurements. Conclusions: An extrapolation of the S factor of 20Ne(p ,γ )21Na has been made to low energies using the R -matrix fit. The reaction rate from the subthreshold resonance was found to be the main contributor to the reaction rate at temperatures below about 0.1 GK. The present rate is lower in the temperature range of interest than those presented in current reaction rate libraries by up to 20%.

Magnetic bead-quantum dot assay for detection of a biomarker for traumatic brain injury

NASA Astrophysics Data System (ADS)

Kim, Chloe; Searson, Peter C.

2015-10-01

Current diagnostic methods for traumatic brain injury (TBI), which accounts for 15% of all emergency room visits, are limited to neuroimaging modalities. The challenges of accurate diagnosis and monitoring of TBI have created the need for a simple and sensitive blood test to detect brain-specific biomarkers. Here we report on an assay for detection of S100B, a putative biomarker for TBI, using antibody-conjugated magnetic beads for capture of the protein, and antibody-conjugated quantum dots for optical detection. From Western Blot, we show efficient antigen capture and concentration by the magnetic beads. Using magnetic bead capture and quantum dot detection in serum samples, we show a wide detection range and detection limit below the clinical cut-off level.Current diagnostic methods for traumatic brain injury (TBI), which accounts for 15% of all emergency room visits, are limited to neuroimaging modalities. The challenges of accurate diagnosis and monitoring of TBI have created the need for a simple and sensitive blood test to detect brain-specific biomarkers. Here we report on an assay for detection of S100B, a putative biomarker for TBI, using antibody-conjugated magnetic beads for capture of the protein, and antibody-conjugated quantum dots for optical detection. From Western Blot, we show efficient antigen capture and concentration by the magnetic beads. Using magnetic bead capture and quantum dot detection in serum samples, we show a wide detection range and detection limit below the clinical cut-off level. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr05608j

Democratisation or Management and Corporate Capture?: Theses on the Governance Crisis of Australia's Semi-Privatised Public Universities

ERIC Educational Resources Information Center

Bonnell, Andrew G.

2016-01-01

This paper proceeds from the view that managerial capture has already become a fundamental problem after a couple of decades of largely untrammelled managerialism in our public universities, and that this problem is likely to be compounded by further shifts towards deregulation and de facto privatisation, which is the direction that current…

Flying MOFs: polyamine-containing fluidized MOF/SiO 2 hybrid materials for CO 2 capture from post-combustion flue gas

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

Luz, Ignacio; Soukri, Mustapha; Lail, Marty

Solid-state synthesis ensures a high loading and well dispersed growth of a large collection of metal–organic framework (MOF) nanostructures within a series of commercially available mesoporous silica allowing to render MOFs into fluidized solid sorbents for CO 2 capture from post-combustion flue gas in a fluidized-bed reactor.

Flying MOFs: polyamine-containing fluidized MOF/SiO 2 hybrid materials for CO 2 capture from post-combustion flue gas

DOE PAGES

Luz, Ignacio; Soukri, Mustapha; Lail, Marty

2018-01-01

Solid-state synthesis ensures a high loading and well dispersed growth of a large collection of metal–organic framework (MOF) nanostructures within a series of commercially available mesoporous silica allowing to render MOFs into fluidized solid sorbents for CO 2 capture from post-combustion flue gas in a fluidized-bed reactor.

Amine enriched solid sorbents for carbon dioxide capture

DOEpatents

Gray, McMahan L.; Soong, Yee; Champagne, Kenneth J.

2003-04-15

A new method for making low-cost CO.sub.2 sorbents that can be used in large-scale gas-solid processes. The new method entails treating a solid substrate with acid or base and simultaneous or subsequent treatment with a substituted amine salt. The method eliminates the need for organic solvents and polymeric materials for the preparation of CO.sub.2 capture systems.

Large Pilot Scale Testing of Linde/BASF Post-Combustion CO 2 Capture Technology at the Abbott Coal-Fired Power Plant

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

O'Brien, Kevin C.

The work summarized in this report is the first step towards a project that will re-train and create jobs for personnel in the coal industry and continue regional economic development to benefit regions impacted by previous downturns. The larger project is aimed at capturing ~300 tons/day (272 metric tonnes/day) CO 2 at a 90% capture rate from existing coal- fired boilers at the Abbott Power Plant on the campus of University of Illinois (UI). It will employ the Linde-BASF novel amine-based advanced CO 2 capture technology, which has already shown the potential to be cost-effective, energy efficient and compact atmore » the 0.5-1.5 MWe pilot scales. The overall objective of the project is to design and install a scaled-up system of nominal 15 MWe size, integrate it with the Abbott Power Plant flue gas, steam and other utility systems, and demonstrate the viability of continuous operation under realistic conditions with high efficiency and capacity. The project will also begin to build a workforce that understands how to operate and maintain the capture plants by including students from regional community colleges and universities in the operation and evaluation of the capture system. This project will also lay the groundwork for follow-on projects that pilot utilization of the captured CO 2 from coal-fired power plants. The net impact will be to demonstrate a replicable means to (1) use a standardized procedure to evaluate power plants for their ability to be retrofitted with a pilot capture unit; (2) design and construct reliable capture systems based on the Linde-BASF technology; (3) operate and maintain these systems; (4) implement training programs with local community colleges and universities to establish a workforce to operate and maintain the systems; and (5) prepare to evaluate at the large pilot scale level various methods to utilize the resulting captured CO 2. Towards the larger project goal, the UI-led team, together with Linde, has completed a preliminary design for the carbon capture pilot plant with basic engineering and cost estimates, established permitting needs, identified approaches to address Environmental, Health, and Safety concerns related to pilot plant installation and operation, developed approaches for long-term use of the captured carbon, and established strategies for workforce development and job creation that will re-train coal operators to operate carbon capture plants. This report describes Phase I accomplishments and demonstrates that the project team is well-prepared for full implementation of Phase 2, to design, build, and operate the carbon capture pilot plant.« less

Evaluation of various models of propane-powered mosquito traps.

PubMed

Kline, Daniel L

2002-06-01

Large cage and field studies were conducted to determine the efficacy of various models of propane-powered mosquito traps. These traps utilized counterflow technology in conjunction with catalytic combustion to produce attractants (carbon dioxide, water vapor, and heat) and a thermoelectric generator that converted excess heat into electricity for stand-alone operation. The cage studies showed that large numbers of Aedes aegypti and Ochlerotatus taeniorhynchus were captured and that each progressive model resulted in increased trapping efficiency. In several field studies against natural populations of mosquitoes two different propane traps were compared against two other trap systems, the professional (PRO) and counterflow geometry (CFG) traps. In these studies the propane traps consistently caught more mosquitoes than the PRO trap and significantly fewer mosquitoes than the CFG traps. The difference in collection size between the CFG and propane traps was due mostly to Anopheles crucians. In spring 1997 the CFG trap captured 3.6X more An. crucians than the Portable Propane (PP) model and in spring 1998 it captured 6.3X more An. crucians than the Mosquito Magnet Beta-1 (MMB-1) trap. Both the PP and MMB-1 captured slightly more Culex spp. than the CFG trap.

System for clinical photometric stereo endoscopy

NASA Astrophysics Data System (ADS)

Durr, Nicholas J.; González, Germán.; Lim, Daryl; Traverso, Giovanni; Nishioka, Norman S.; Vakoc, Benjamin J.; Parot, Vicente

2014-02-01

Photometric stereo endoscopy is a technique that captures information about the high-spatial-frequency topography of the field of view simultaneously with a conventional color image. Here we describe a system that will enable photometric stereo endoscopy to be clinically evaluated in the large intestine of human patients. The clinical photometric stereo endoscopy system consists of a commercial gastroscope, a commercial video processor, an image capturing and processing unit, custom synchronization electronics, white light LEDs, a set of four fibers with diffusing tips, and an alignment cap. The custom pieces that come into contact with the patient are composed of biocompatible materials that can be sterilized before use. The components can then be assembled in the endoscopy suite before use. The resulting endoscope has the same outer diameter as a conventional colonoscope (14 mm), plugs into a commercial video processor, captures topography and color images at 15 Hz, and displays the conventional color image to the gastroenterologist in real-time. We show that this system can capture a color and topographical video in a tubular colon phantom, demonstrating robustness to complex geometries and motion. The reported system is suitable for in vivo evaluation of photometric stereo endoscopy in the human large intestine.

Pre-capture multiplexing improves efficiency and cost-effectiveness of targeted genomic enrichment.

PubMed

Shearer, A Eliot; Hildebrand, Michael S; Ravi, Harini; Joshi, Swati; Guiffre, Angelica C; Novak, Barbara; Happe, Scott; LeProust, Emily M; Smith, Richard J H

2012-11-14

Targeted genomic enrichment (TGE) is a widely used method for isolating and enriching specific genomic regions prior to massively parallel sequencing. To make effective use of sequencer output, barcoding and sample pooling (multiplexing) after TGE and prior to sequencing (post-capture multiplexing) has become routine. While previous reports have indicated that multiplexing prior to capture (pre-capture multiplexing) is feasible, no thorough examination of the effect of this method has been completed on a large number of samples. Here we compare standard post-capture TGE to two levels of pre-capture multiplexing: 12 or 16 samples per pool. We evaluated these methods using standard TGE metrics and determined the ability to identify several classes of genetic mutations in three sets of 96 samples, including 48 controls. Our overall goal was to maximize cost reduction and minimize experimental time while maintaining a high percentage of reads on target and a high depth of coverage at thresholds required for variant detection. We adapted the standard post-capture TGE method for pre-capture TGE with several protocol modifications, including redesign of blocking oligonucleotides and optimization of enzymatic and amplification steps. Pre-capture multiplexing reduced costs for TGE by at least 38% and significantly reduced hands-on time during the TGE protocol. We found that pre-capture multiplexing reduced capture efficiency by 23 or 31% for pre-capture pools of 12 and 16, respectively. However efficiency losses at this step can be compensated by reducing the number of simultaneously sequenced samples. Pre-capture multiplexing and post-capture TGE performed similarly with respect to variant detection of positive control mutations. In addition, we detected no instances of sample switching due to aberrant barcode identification. Pre-capture multiplexing improves efficiency of TGE experiments with respect to hands-on time and reagent use compared to standard post-capture TGE. A decrease in capture efficiency is observed when using pre-capture multiplexing; however, it does not negatively impact variant detection and can be accommodated by the experimental design.

Enabling CCS via Low-temperature Geothermal Energy Integration for Fossil-fired Power Generation

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

Davidson, Casie L.; Heldebrant, D. J.; Bearden, M. D.

Here, among the key barriers to commercial scale deployment is the cost associated with CO 2 capture. This is particularly true for existing large, fossil-fired assets that account for a large fraction of the electricity generation fleet in developed nations, including the U.S. Fitting conventional combustion technologies with CO 2 capture systems can carry an energy penalty of thirty percent or more, resulting in an increased price of power to the grid, as well as an overall decrease in net plant output. Taken together with the positive growth in demand for electricity, this implies a need for accelerated capital build-outmore » in the power generation markets to accommodate both demand growth and decreased output at retrofitted plants. In this paper, the authors present the results of a study to assess the potential to use geothermal energy to provide boiler feedwater preheating, capturing efficiency improvements designed to offset the losses associated with CO 2 capture. Based on NETL benchmark cases and subsequent analysis of the application using site-specific data from the North Valmy power plant, several cases for CO 2 capture were evaluated. These included geothermally assisted MEA capture, CO2BOLs capture, and stand-alone hybrid power generation, compared with a baseline, no-geothermal case. Based on Case 10, and assuming 2.7 MMlb/h of geothermally sourced 150 ºC water, the parasitic power load associated with MEA capture could be offset by roughly seven percent, resulting in a small (~1 percent) overall loss to net power generation, but at levelized costs of electricity similar to the no-geothermal CCS case. For the CO 2BOLs case, the availability of 150°C geothermal fluid could allow the facility to not only offset the net power decrease associated with CO 2BOLs capture alone, but could increase nameplate capacity by two percent. The geothermally coupled CO 2BOLs case also decreases LCOE by 0.75 ¢/kWh relative to the non-hybrid CO 2BOLs case, with the improved performance over the MEA case driven by the lower regeneration temperature and associated duty for CO 2BOLs relative to MEA.« less

Developing High-Affinity Protein Capture Agents and Nanotechnology-Based Platforms for In Vitro Diagnostics

NASA Astrophysics Data System (ADS)

Rohde, Rosemary Dyane

In this thesis, I describe projects that were aimed at improving ways to capture proteins for clinical diagnostics. Nanoelectronic sensors, such as silicon nanowires (SiNWs), can provide label-free quantitative measurements of protein biomarkers in real time. One technical challenge for SiNWs is to develop chemistry that can be applied for selectively encoding the nanowire surfaces with capture agents, thus making them sensors that have selectivity for specific proteins. Furthermore, because of the nature of how the sensor works, it is desirable to achieve this spatially selective chemical functionalization without having the silicon undergo oxidation. This method is described here and provides a general platform that can incorporate organic and biological molecules on Si (111) with minimal oxidation of the silicon surface. The development of these devices is, in part, driven by early diagnosis, treatment, monitoring, and personalized medicine---all of which are increasingly requiring quantitative, rapid, and multiparameter measurements. To begin achieving this goal, a large number of protein biomarkers need to be captured and quantitatively measured to create a diagnostic panel. One of the greatest challenges towards making protein-biomarker-based in vitro diagnostics inexpensive involves developing capture agents to detect the proteins. A major thrust of this thesis is to develop multi-valent, high-affinity and high-selectivity protein capture agents using in situ click chemistry. In situ click chemistry is a tool that utilizes the protein itself to catalyze the formation of a biligand from individual azide and alkyne ligands that are co-localized. Large one-bead one-compound (OBOC) libraries of peptides are used to form the body of these ligands, also providing high chemical diversity with minimal synthetic effort. This process can be repeated to identify a triligand, tetraligand, and so forth. Moreover, the resulting multiligand protein capture agents can be produced in gram-scale quantities with designed control over chemical and biochemical stability and water solubility. This is a general and robust method for inexpensive, high-throughput capture agent discovery that can be utilized to capture the relevant biomarker proteins for blood protein diagnostics.

Elliptic Capture Orbits for Missions to the Near Planets

NASA Technical Reports Server (NTRS)

Casal, Federico G.; Swenson, Byron L.; Mascy, Alfred C.

1968-01-01

Elliptic capture orbits around Mars and Venus have often been considered as means for reducing arrival and departure energy requirements for two-way missions. It had also generally been feared that the energy savings obtained by capturing a spacecraft into a highly elliptical orbit (rather than a near circular orbit of the same periapsis) would largely be offset by the penalties incurred in aligning the semi-major axis of the ellipse in such a way as to obtain the proper orientation of the departure hyperbola. This paper, presents the results of an analysis which takes into consideration the penalties arising from the requirement to match the orientation of the elliptical orbit with the asymptote of the departure hyperbola. The scientific aspects of elliptical orbits around the target planet are discussed, and it is shown that such orbits exhibit characteristics which may be considered advantageous or disadvantageous depending on the purpose of the mission. Alignment of ' the semi-major axis of the capture, ellipse relative to the, asymptote of the escape hyperbola was found not to be a critical requirement since the kinetic energy remains high over a substantial portion of the elliptical capture orbit. This 'means that the escape stage can operate efficiently even when ignited at some angle from the true periapsis point. Considerable freedom in choosing this angle is available at little propulsive cost. The resulting latitude in the choice of angles between arrival and escape asymptotes makes it possible to consider a wide variety of interplanetary transfers and planetary staytimes without the need for separate propulsive maneuvers to realign the capture ellipse before departure., Special consideration has also been g1ven to plane change maneuvers around the planet. These may be required for reasons of orbit dynamics or scientific experimentation and are not uniquely tied to elliptical captures. The sensitivity of the mass of the excursion module to the eccentricity of the capture orbit is discussed and mass-penalty diagrams are presented. It is shown that these penalties do not materially offset the large gains obtained through the use of the elliptical capture mode.

Enabling CCS via Low-temperature Geothermal Energy Integration for Fossil-fired Power Generation

DOE PAGES

Davidson, Casie L.; Heldebrant, D. J.; Bearden, M. D.; ...

2017-08-18

Here, among the key barriers to commercial scale deployment is the cost associated with CO 2 capture. This is particularly true for existing large, fossil-fired assets that account for a large fraction of the electricity generation fleet in developed nations, including the U.S. Fitting conventional combustion technologies with CO 2 capture systems can carry an energy penalty of thirty percent or more, resulting in an increased price of power to the grid, as well as an overall decrease in net plant output. Taken together with the positive growth in demand for electricity, this implies a need for accelerated capital build-outmore » in the power generation markets to accommodate both demand growth and decreased output at retrofitted plants. In this paper, the authors present the results of a study to assess the potential to use geothermal energy to provide boiler feedwater preheating, capturing efficiency improvements designed to offset the losses associated with CO 2 capture. Based on NETL benchmark cases and subsequent analysis of the application using site-specific data from the North Valmy power plant, several cases for CO 2 capture were evaluated. These included geothermally assisted MEA capture, CO2BOLs capture, and stand-alone hybrid power generation, compared with a baseline, no-geothermal case. Based on Case 10, and assuming 2.7 MMlb/h of geothermally sourced 150 ºC water, the parasitic power load associated with MEA capture could be offset by roughly seven percent, resulting in a small (~1 percent) overall loss to net power generation, but at levelized costs of electricity similar to the no-geothermal CCS case. For the CO 2BOLs case, the availability of 150°C geothermal fluid could allow the facility to not only offset the net power decrease associated with CO 2BOLs capture alone, but could increase nameplate capacity by two percent. The geothermally coupled CO 2BOLs case also decreases LCOE by 0.75 ¢/kWh relative to the non-hybrid CO 2BOLs case, with the improved performance over the MEA case driven by the lower regeneration temperature and associated duty for CO 2BOLs relative to MEA.« less

Co-location of air capture, sub-ocean CO2 storage and energy production on the Kerguelen plateau

NASA Astrophysics Data System (ADS)

Goldberg, D.; Han, P.; Lackner, K.; Wang, T.

2011-12-01

How can carbon capture and storage activities be sustained from an energy perspective while keeping the entire activity out of sight and away from material risk and social refrain near populated areas? In light of reducing the atmospheric CO2 level to mitigate its effect on climate change, the combination of new air-capture technologies and large offshore storage reservoirs, supplemented by carbon neutral renewable energy, could address both of these engineering and public policy concerns. Because CO2 mixes rapidly in the atmosphere, air capture scrubbers could be located anywhere in the world. Although the power requirements for this technology may reduce net efficiencies, the local availability of carbon-neutral renewable energy for this purpose would eliminate some net energy loss. Certain locations where wind speeds are high and steady, such as those observed at high latitude and across the open ocean, appeal as carbon-neutral energy sources in close proximity to immense and secure reservoirs for geological sequestration of captured CO2. In particular, sub-ocean basalt flows are vast and carry minimal risks of leakage and damages compared to on-land sites. Such implementation of a localized renewable energy source coupled with carbon capture and storage infrastructure could result in a global impact of lowered CO2 levels. We consider an extreme location on the Kerguelen plateau in the southern Indian Ocean, where high wind speeds and basalt storage reservoirs are both plentiful. Though endowed with these advantages, this mid-ocean location incurs clear material and economic challenges due to its remoteness and technological challenges for CO2 capture due to constant high humidity. We study the wind energy-air capture power balance and consider related factors in the feasibility of this location for carbon capture and storage. Other remote oceanic sites where steady winds blow and near large geological reservoirs may be viable as well, although all would require extensive research. Using these mitigation technologies in combination may offer a pivotal option for reducing atmospheric carbon to pre-industrial levels with minimal human risk or inconvenience.

Representation of natural vegetation in protected areas: Capturing the geographic range

USGS Publications Warehouse

Scott, J.M.; Murray, M.; Wright, R.G.; Csuti, B.; Morgan, P.; Pressey, R.L.

2001-01-01

Current conservation strategies for plant and animal species rarely address the need to protect the species throughout its geographic range thereby capturing potential genetic and ecological variation. We examined the degree that existing protected areas in the western United States satisfied this goal for four widespread vegetation cover types. We used latitude and longitude to stratify the distribution of these types into 16 cells, each of which was further stratified by up to five elevation classes. While protection of some vegetation types was high in parts of their range, it was minimal to nonexistent in other parts. While it is yet to be shown that protecting a given species throughout its geographic range is essential for its long-term existence, in the face of often unpredictable environmental changes, it seems a prudent course to follow. Our results suggest that if full range protection is a conservation goal, the existing network of protected areas may be inadequate for the task.

TARGETED CAPTURE IN EVOLUTIONARY AND ECOLOGICAL GENOMICS

PubMed Central

Jones, Matthew R.; Good, Jeffrey M.

2016-01-01

The rapid expansion of next-generation sequencing has yielded a powerful array of tools to address fundamental biological questions at a scale that was inconceivable just a few years ago. Various genome partitioning strategies to sequence select subsets of the genome have emerged as powerful alternatives to whole genome sequencing in ecological and evolutionary genomic studies. High throughput targeted capture is one such strategy that involves the parallel enrichment of pre-selected genomic regions of interest. The growing use of targeted capture demonstrates its potential power to address a range of research questions, yet these approaches have yet to expand broadly across labs focused on evolutionary and ecological genomics. In part, the use of targeted capture has been hindered by the logistics of capture design and implementation in species without established reference genomes. Here we aim to 1) increase the accessibility of targeted capture to researchers working in non-model taxa by discussing capture methods that circumvent the need of a reference genome, 2) highlight the evolutionary and ecological applications where this approach is emerging as a powerful sequencing strategy, and 3) discuss the future of targeted capture and other genome partitioning approaches in light of the increasing accessibility of whole genome sequencing. Given the practical advantages and increasing feasibility of high-throughput targeted capture, we anticipate an ongoing expansion of capture-based approaches in evolutionary and ecological research, synergistic with an expansion of whole genome sequencing. PMID:26137993

FlyCap: Markerless Motion Capture Using Multiple Autonomous Flying Cameras.

PubMed

Xu, Lan; Liu, Yebin; Cheng, Wei; Guo, Kaiwen; Zhou, Guyue; Dai, Qionghai; Fang, Lu

2017-07-18

Aiming at automatic, convenient and non-instrusive motion capture, this paper presents a new generation markerless motion capture technique, the FlyCap system, to capture surface motions of moving characters using multiple autonomous flying cameras (autonomous unmanned aerial vehicles(UAVs) each integrated with an RGBD video camera). During data capture, three cooperative flying cameras automatically track and follow the moving target who performs large-scale motions in a wide space. We propose a novel non-rigid surface registration method to track and fuse the depth of the three flying cameras for surface motion tracking of the moving target, and simultaneously calculate the pose of each flying camera. We leverage the using of visual-odometry information provided by the UAV platform, and formulate the surface tracking problem in a non-linear objective function that can be linearized and effectively minimized through a Gaussian-Newton method. Quantitative and qualitative experimental results demonstrate the plausible surface and motion reconstruction results.

Neutron capture by hook or by crook

NASA Astrophysics Data System (ADS)

Mosby, Shea

2016-03-01

The neutron capture reaction is a topic of fundamental interest for both heavy element (A>60) nucleosynthesis and applications in such fields as nuclear energy and defense. The full suite of interesting isotopes ranges from stable nuclei to the most exotic, and it is not possible to directly measure all the relevant reaction rates. The DANCE instrument at Los Alamos provides direct access to the neutron capture reaction for stable and long-lived nuclei, while Apollo coupled to HELIOS at Argonne has been developed as an indirect probe for cases where a direct measurement is impossible. The basic techniques and their implications will be presented, and the status of ongoing experimental campaigns to address neutron capture in the A=60 and A=100 mass regions will be discussed.

Variable pressure ionization detector for gas chromatography

DOEpatents

Buchanan, Michelle V.; Wise, Marcus B.

1988-01-01

Method and apparatus for differentiating organic compounds based on their electron affinity. An electron capture detector cell (ECD) is operated at pressures ranging from atmospheric to less than 1 torr. Through variation of the pressure within the ECD cell, the organic compounds are induced to either capture or emit electrons. Differentiation of isomeric compounds can be obtianed when, at a given pressure, one isomer is in the emission mode and the other is in the capture mode. Output of the ECD is recorded by chromatogram. The invention also includes a method for obtaining the zero-crossing pressure of a compound, defined as the pressure at which the competing emission and capture reactions are balanced and which may be correlated to the electron affinity of a compound.