Relative and seasonal abundance of Temnochila chlorodia (Mannerheim) (Coleoptera: Trogossitidae) collected in western pine beetle pheromone-baited traps in northern California

Treesearch

Christopher J. Fettig; Christopher P. Dabney

2006-01-01

Bark beetles (Coleoptera: Scolytidae) are commonly recognized as the most important mortality agent in western coniferous forests. In this study, we describe the abundance of bark beetle predators collected in multiple-funnel traps baited with exo-brevicomin, frontalin and myrcene in northern California during 2003 and 2004. A total of 32,903 Temnochila chlorodia (...

Dose-Dependent and Species-Specific Responses of Pine Bark Beetles (Coeoptera: Scolytidae) to Monoterpenes in Association with Phermones

Treesearch

Daniel R. Miller; John H. Borden

2000-01-01

Monoterpenes affected the attraction of three sympatric species of bark beetles (Coleoptera: Scolytidae) to pheromone-baited multiple-funnel traps in stands of lodgepole pine. Catches of Ips pini(Say) in traps baited with its pheromone, ipsdienol, were directly related to the release rates of 3-carene, ß-pphellandrene, and ß-pinene. Catches of

Encapsulated Essential Oils as an Alternative to Insecticides in Funnel Traps.

PubMed

Pascual-Villalobos, M J; López, M D; Castañé, C; Soler, A; Riudavets, J

2015-08-01

Pheromone-lured funnel traps are widely used for pest monitoring and mass trapping in agricultural fields and stores. DDVP vapona (dichlorvos), the insecticide of choice as a killing agent inside traps, has been banned, and research on new products is being pursued. Essential oils (EO) could be an alternative if properly formulated. To test their potential, beads of encapsulated coriander and basil EO were tested in funnel traps in stores of almonds and pet foods during 2 mo. The number of adult moth (Plodia interpunctella (Hübner) and Ephestia kuehniella Zeller) dead captures was similar with either coriander or basil EO beads and with vapona tablets while there were more insects alive in the control. These preliminary results indicate a good potential for the development of such natural products as an alternative to synthetic insecticides to include them inside funnel traps. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Evaluation of funnel traps for estimating tree mortality and associated population phase of spruce beetle in Utah

Treesearch

E. Matthew Hansen; Barbara J. Bentz; A. Steven Munson; James C. Vandygriff; David L. Turner

2006-01-01

Although funnel traps are routinely used to manage bark beetles, little is known regarding the relationship between trap captures of spruce beetle (Dendroctonus rufipennis Kirby) and mortality of Engelmann spruce (Picea engelmannii Parry ex Engelm.) within a 10 ha block of the trap. Using recursive partitioning tree analyses, rules...

Ipsenol, ipsdienol, ethanol, and á-pinene: trap lure blend for Cerambycidae and Buprestidae (Coleoptera) in pine forests of eastern North America

Treesearch

D. R. Miller; C. M. Crowe; K. J. Dodds; L. D. Galligan; P. de Groot; E. R. Hoebeke; A. E. Mayfield; T. M. Poland; K. F. Raffa; J. D. Sweeney

2015-01-01

In 2007-2008, we examined the flight responses of wood-boring beetles (Coleoptera: Cerambycidae and Buprestidae) to multiple-funnel traps baited with the pine volatiles, ethanol, and apinene [85% (–)], and the bark beetle pheromones, racemic ipsenol and racemic ipsdienol. Experiments were conducted in mature pine stands in Canada (Ontario and New Brunswick) and the...

Disruption Of Secondary Attraction Of The Spruce Beetle, Dendroctonus rufipennis, By Pheromones Of Two Sympatric Spcies

Treesearch

Therese M. Poland; J. H. Borden

1998-01-01

Capture of spruce beetles, Dendroctonus rufipennis, in multiple-funnel traps baited with frontalin and -pinene was reduced by up to 42% in the presence of synthetic (+)-exo- and (+)-endo-brevicomin, aggregation pheromones of the sympatric species Dryocoetes affaber. (+)-endo-...

Ion funnel ion trap and process

DOEpatents

Belov, Mikhail E [Richland, WA; Ibrahim, Yehia M [Richland, WA; Clowers, Biran H [West Richland, WA; Prior, David C [Hermiston, OR; Smith, Richard D [Richland, WA

2011-02-15

An ion funnel trap is described that includes a inlet portion, a trapping portion, and a outlet portion that couples, in normal operation, with an ion funnel. The ion trap operates efficiently at a pressure of .about.1 Torr and provides for: 1) removal of low mass-to-charge (m/z) ion species, 2) ion accumulation efficiency of up to 80%, 3) charge capacity of .about.10,000,000 elementary charges, 4) ion ejection time of 40 to 200 .mu.s, and 5) optimized variable ion accumulation times. Ion accumulation with low concentration peptide mixtures has shown an increase in analyte signal-to-noise ratios (SNR) of a factor of 30, and a greater than 10-fold improvement in SNR for multiply charged analytes.

Verbenone: Dose-Dependent Interruption of Pheromone-Based Attraction of Three Sympatric Species of Pine Bark Beetles (Coleoptera: Scolytidae)

Treesearch

Daniel R. Miller; John H. Borden; B. Staffan Lindgren

1995-01-01

Verbenone significantly reduced catches of Ips latidens (LeConte), I. pini (Say), and Dendroctonus ponderosae Hopkins in multiple-funnel traps, baited with aggregation pheromones, in stands of lodgepole pine in southern British Columbia. Interruption of attraction was dose dependent for all three species. There...

Dose-dependent pheromone responses of mountain pine beetle in stands of lodgepole pine

Treesearch

Daniel R. Miller; B. Staffan Lindgren; John H. Borden

2005-01-01

We conducted seven behavioral choice tests with Lindgren multiple-funnel traps in stands of mature lodgepole pine in British Columbia, from 1988 to 1994, to determine the dosedependent responses of the mountain pine beetle, Dendroctonus ponderosae Hopkins, to its pheromones. Amultifunctional dose-dependent response was exhibited by D. ...

Use of semiochemicals of secondary bark beetles to disrupt spruce beetle attraction and survival in Alaska.

Treesearch

Richard A. Werner; Edward H. Holsten

2002-01-01

Field experiments using baited multiple-funnel traps and baited felled trees were conducted to test the hypothesis that semiochemicals from secondary species of scolytids could be used to disrupt spruce beetle (Dendroctonus rufipennis (Kirby)) attraction. Semiochemicals from three secondary species of scolytids, (Ips perturbatus...

Effect of verbenone on attraction of predatory and woodboring beetles (Coleoptera) to kairomones in Lodgepole pine forests

Treesearch

B. Staffan Lindgren; Daniel R. Miller

2002-01-01

The response of bark beetle predators and woodboring beetles to the bark beetle anti-aggregation pheromone, verbenone, was tested in the field with multiple-funnel traps baited with attractant kairomones. Catches of the predators Thanasimus undatulus (Say), Enoclerus sphegeus (F.), Enocleris lecontei (Wolcott) (...

Comparison of a -pinene and myrcene on attraction of mountain pine beetle, Dendroctonus ponderosae (Coleoptera: Scolytidae) to pheromones in stands of western white pine

Treesearch

Daniel R. Miller; B. Staffan Lindgren

2000-01-01

Multiple-funnel traps baited with exo-brevicomin and a mixture of cis- and trans-verbenol were used to test the relative attractiveness of myrcene and (-)-a -pinene to the mountain pine beetle, Dendroctonus ponderosae Hopkins, in a stand...

Attraction of Pissodes affinis and P. fasciatus (Coleoptera: Curculionidae) to pityol and a-pinene in a Coastal Stand of Western White Pine and Douglas-fir

Treesearch

Daniel R. Miller; Don Heppner

1999-01-01

Lindgren multiple-funnel traps, baited with (-)-a-pinene and (±)-pityol, captured significant numbers of the weevils, Pissodes affinis Randall and P. fasciatus LeConte, in a coastal stand of Douglas-fir and western white pine.

The Use of Monoterpenes as Kairomones by Ips latidens (LeConte) (Coleoptera: Scolytidae)

Treesearch

D.R. Miller; J.H. Borden

1990-01-01

The responses of Ips lutidens (LeConte) to multiple-funnel traps baited with various monoterpenes were determined in stands of lodgepole pine in British Columbia. ß-Phellandrene was attractive to I. lutidens in the absence of the pheromone ipsenol ß-Phellandrene increased the attraction of I. lutidens to...

ß-Phellandrene: Kairomone for Pine Engraver, Ips pini (Say) (Coleoptera: Scolytidae)

Treesearch

Daniel R. Miller; John H. Borden

1990-01-01

The responses of Ips pini (Scolytidae) to multiple-funnel traps baited with the pheromone, ipsdienol, and various monoterpenes were determined in stands of lodgepole pine in southern and central British Columbia. Ips pini was attracted to both ipsdienol and ß-phellandrene, demonstrating that ß-phellandrene is a kairomone for this...

Evaluation of capture techniques on lesser prairie-chicken trap injury and survival

USGS Publications Warehouse

Grisham, Blake A.; Boal, Clint W.; Mitchell, Natasia R.; Gicklhorn, Trevor S.; Borsdorf, Philip K.; Haukos, David A.; Dixon, Charles

2015-01-01

Ethical treatment of research animals is required under the Animal Welfare Act. This includes trapping methodologies that reduce unnecessary pain and duress. Traps used in research should optimize animal welfare conditions within the context of the proposed research study. Several trapping techniques are used in the study of lesser prairie-chickens, despite lack of knowledge of trap injury caused by the various methods. From 2006 to 2012, we captured 217, 40, and 144 lesser prairie-chickens Tympanuchus pallidicinctus using walk-in funnel traps, rocket nets, and drop nets, respectively, in New Mexico and Texas, to assess the effects of capture technique on injury and survival of the species. We monitored radiotagged, injured lesser prairie-chickens 7–65 d postcapture to assess survival rates of injured individuals. Injuries occurred disproportionately among trap type, injury type, and sex. The predominant injuries were superficial cuts to the extremities of males captured in walk-in funnel traps. However, we observed no mortalities due to trapping, postcapture survival rates of injured birds did not vary across trap types, and the daily survival probability of an injured and uninjured bird was ≥99%. Frequency and intensity of injuries in walk-in funnel traps are due to the passive nature of these traps (researcher cannot select specific individuals for capture) and incidental capture of individuals not needed for research. Comparatively, rocket nets and drop nets allow observers to target birds for capture and require immediate removal of captured individuals from the trap. Based on our results, trap injuries would be reduced if researchers monitor and immediately remove birds from walk-in funnels before they injure themselves; move traps to target specific birds and reduce recaptures; limit the number of consecutive trapping days on a lek; and use proper netting techniques that incorporate quick, efficient, trained handling procedures.

Abundance and species richness of snakes along the Middle Rio Grande riparian forest in New Mexico

Treesearch

Heather L. Bateman; Alice Chung-MacCoubrey; Howard L. Snell; Deborah M. Finch

2009-01-01

To understand the effects of removal of non-native plants and fuels on wildlife in the riparian forest of the Middle Rio Grande in New Mexico, we monitored snakes from 2000 to 2006 using trap arrays of drift fences, pitfalls, and funnel traps. We recorded 158 captures of 13 species of snakes from 12 study sites. We captured more snakes in funnel traps than in pitfalls...

Attraction of bark beetle predator, Thanasimus undatulus (Coleoptera: Cleridae), to pheromones of the spruce beetle and two secondary bark beetles (Coleoptera: Scolytidae)

Treesearch

Therese M. Poland; John H. Borden

1997-01-01

The bark beetle predator Thanasimus undatulus Say was captured in statistically significant numbers (total catch = 470, 713, and 137) in three field experiments using multiple-funnel traps baited with various combinations of pheromones for the spruce beetle, Dendroctonus rufipennis Kirby, and the secondary bark beetles ...

E-Myrcenol: A New Pheromone for the Pine Engraver, Ips Pini (Say) (Coleoptera: Scolytidae)

Treesearch

D.R. Miller; G. Gries; J.H. Borden

1990-01-01

E-Myrcenol reduced catches of the pine engraver, Ips pini (Say), to ipsdienol-baited, multiple-funnel traps in a dose-dependent fashion. The sex ratio was unaffected by E-myrcenol treatments. Lures containing E-myrcenol in ethanol solution failed to protect freshly cut logs of lodgepole pine from attack by

Light Trapping with Silicon Light Funnel Arrays

PubMed Central

Nissan, Yuval; Gabay, Tamir; Shalev, Gil

2018-01-01

Silicon light funnels are three-dimensional subwavelength structures in the shape of inverted cones with respect to the incoming illumination. Light funnel (LF) arrays can serve as efficient absorbing layers on account of their light trapping capabilities, which are associated with the presence of high-density complex Mie modes. Specifically, light funnel arrays exhibit broadband absorption enhancement of the solar spectrum. In the current study, we numerically explore the optical coupling between surface light funnel arrays and the underlying substrates. We show that the absorption in the LF array-substrate complex is higher than the absorption in LF arrays of the same height (~10% increase). This, we suggest, implies that a LF array serves as an efficient surface element that imparts additional momentum components to the impinging illumination, and hence optically excites the substrate by near-field light concentration, excitation of traveling guided modes in the substrate, and mode hybridization. PMID:29562685

Association between severity of prescribed burns and subsequent activity of conifer-infesting beetles in stands of longleaf pine

Treesearch

Brian T. Sullivan; Christopher J. Fettig; William J. Otrosina; Mark J. Dalusky; C. Wayne Berisford

2003-01-01

A randomized complete block experiment was performed to measure the effect of prescribed, dormant-season burns of three different levels of severity (measured as fuel consumption and soil surface heating) on subsequent insect infestation and mortality of mature longleaf pine (Pinus palustris Mill.). Multiple-funnel traps baited with a low release...

Visual and semiochemical disruption of host finding in the southern pine beetle

Treesearch

B.L. Strom; L.M. Roton; R.A. Goyer; J.R. Meeker

1999-01-01

The importance of visual silhouettes for host finding by the southern pine beetle (SPB), Dendroctonus frontalis (Coleoptera: Scolytidae), and the potential for disruption of this process using visual deterrents were evaluated with multiple-funnel traps, painted white or black, and with clear, white or black Plexiglas sticky panel.The results show that both SPB and T....

Ethanol and (-)-a-pinene: attractant kairomones for some large wood-boring beetles in Southeastern USA

Treesearch

Daniel R. Miller

2006-01-01

Ethanol and a-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002-2004. Multiple-funnel traps baited with (-)-a-pinene (released at about 2 g/d at 25-28°C) were attractive to the following Cerambycidae: Acanthocinus nodosus, A. obsoletus, Arhopalus...

Pine shoot beetle, Tomicus piniperda (Col., Scolytidae), responses to commn green leaf volatiles

Treesearch

Therese M. Poland; Robert A. Haack

2000-01-01

We tested the hypothesis that green leaf volatiles (GLVs) disrupt the response of overwintered pine shoot beetles, Tomicus piniperda (L.) to multiple-funnel traps baited with the attractive host volatile -pinene. A combination of four GLV alcohols, 1-hexanol (E)-2-hexen-l-ol (Z)-2-hexen-l-ol, and (Z)-3-hexen-l-ol...

Summary from Working Group on Multiple Beams and Funneling

NASA Technical Reports Server (NTRS)

Wangler, T. P.

1985-01-01

The working group on Multiple Beams and Funneling discussed various topics related to multiple beams and funneling, including (1) design considerations for multiple-beam accelerators; (2) scaling of current, emittance, and brightness for multiple-beam systems; (3) funneling lines using either discrete components or a radiofrequency quadrupole (RFQ) funneling structure; and (4) alternatives to funneling.

Ethanol and (-)-α-Pinene: Attractant Kairomones for Some Large Wood-Boring Beetles in Southeastern USA

Treesearch

Daniel R. Miller

2006-01-01

Ethanol and α-pinene were tested as attractants for large wood-boring pine beetles in Alabama, Florida, Georgia, North Carolina, and South Carolina in 2002 –2004. Multiple-funnel traps baited with (-)-α-pinene (released at about 2 g/d at 25–28 degrees C) were attractive to the following Cerambycidae: Acanthocinus nodosus,

A simple technique for trapping Siren lacertina, Amphiuma means, and other aquatic vertebrates

USGS Publications Warehouse

Johnson, S.A.; Barichivich, W.J.

2004-01-01

We describe a commercially-available funnel trap for sampling aquatic vertebrates. The traps can be used in heavily vegetated wetlands and can be set in water up to 60 cm deep without concern for drowning the animals. They were especially useful for capturing the aquatic salamanders Siren lacertina and Amphiuma means, which have been difficult to capture with traditional sampling methods. They also were effective for sampling small fishes, particularly centrarchids, and larval anurans. In total, 14 species of amphibians, nine species of aquatic reptiles, and at least 32 fish species were captured. The trap we describe differs significantly from traditional funnel traps (e.g., minnow traps) and holds great promise for studies of small, aquatic vertebrates, in particular Siren and Amphiuma species.

Bark Beetle pheromones and pine volatiles: Attractant Kairomone Lure Blend for Longhorn Beetles (Cerambycidae) in pine stands of the southeastern United States.

Treesearch

Dan Miller; Chris Asaro; Christopher Crowe; Donald Duerr

2011-01-01

In 2006,weexamined the ßight responses of 43 species of longhorn beetles (Coleoptera: Cerambycidae) to multiple-funnel traps baited with binary lure blends of 1) ipsenol + ipsdienol, 2) ethanol + α-pinene, and a quaternary lure blend of 3) ipsenol + ipsdienol + ethanol + αpinene in the southeastern United States. In addition, we monitored responses of...

Captures of Ostrinia furnacalis (Lepidoptera: Crambidae) With Sex Pheromone Traps in NE China Corn and Soybeans.

PubMed

Chen, Ri-Zhao; Li, Lian-Bing; Klein, Michael G; Li, Qi-Yun; Li, Peng-Pei; Sheng, Cheng-Fa

2016-02-01

Ostrinia furnacalis (Guenée) (Lepidoptera: Crambidae), commonly referred to as the Asian corn borer, is the most important corn pest in Asia. Although capturing males with pheromone traps has recently been the main monitoring tool and suppression technique, the best trap designs remain unclear. Commercially available Delta and funnel traps, along with laboratory-made basin and water traps, and modified Delta traps, were evaluated in corn and soybean fields during 2013-2014 in NE China. The water trap was superior for capturing first-generation O. furnacalis (1.37 times the Delta trap). However, the basin (8.3 ± 3.2 moths/trap/3 d), Delta (7.9 ± 2.5), and funnel traps (7.0 ± 2.3) were more effective than water traps (1.4 ± 0.4) during the second generation. Delta traps gave optimal captures when deployed at ca. 1.57 × the highest corn plants, 1.36× that of average soybean plants, and at the field borders. In Delta traps modified by covering 1/3 of their ends, captures increased by ca. 15.7 and 8.1% in the first and second generations, respectively. After 35 d in the field, pheromone lures were still ca. 50% as attractive as fresh lures, and retained this level of attraction for ca. 25 more days. Increased captures (first and second generation: 90.9 ± 9.5%; 78.3 ± 9.3%) were obtained by adding a lure exposed for 5 d to funnel traps baited with a 35-d lure. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A Comparison of the Pitfall Trap, Winkler Extractor and Berlese Funnel for Sampling Ground-Dwelling Arthropods in Tropical Montane Cloud Forests

PubMed Central

Sabu, Thomas K.; Shiju, Raj T.; Vinod, KV.; Nithya, S.

2011-01-01

Little is known about the ground-dwelling arthropod diversity in tropical montane cloud forests (TMCF). Due to unique habitat conditions in TMCFs with continuously wet substrates and a waterlogged forest floor along with the innate biases of the pitfall trap, Berlese funnel and Winkler extractor are certain to make it difficult to choose the most appropriate method to sample the ground-dwelling arthropods in TMCFs. Among the three methods, the Winkler extractor was the most efficient method for quantitative data and pitfall trapping for qualitative data for most groups. Inclusion of floatation method as a complementary method along with the Winkler extractor would enable a comprehensive quantitative survey of ground-dwelling arthropods. Pitfall trapping is essential for both quantitative and qualitative sampling of Diplopoda, Opiliones, Orthoptera, and Diptera. The Winkler extractor was the best quantitative method for Psocoptera, Araneae, Isopoda, and Formicidae; and the Berlese funnel was best for Collembola and Chilopoda. For larval forms of different insect orders and the Acari, all the three methods were equally effective. PMID:21529148

Nesting bird "host funnel" increases mosquito-bird contact rate.

PubMed

Caillouët, Kevin A; Riggan, Anna E; Bulluck, Lesley P; Carlson, John C; Sabo, Roy T

2013-03-01

Increases in vector-host contact rates can enhance arbovirus transmission intensity. We investigated weekly fluctuations in contact rates between mosquitoes and nesting birds using the recently described Nest Mosquito Trap (NMT). The number of mosquitoes per nestling increased from < 1 mosquito per trap night to 36.2 in the final 2 wk of the nesting season. Our evidence suggests the coincidence of the end of the avian nesting season and increasing mosquito abundances may have caused a "host funnel," concentrating host-seeking mosquitoes to the few remaining nestlings. The relative abundance of mosquitoes collected by the NMT suggests that significantly more Aedes albopictus (Skuse) and Culex pipiens (L.) /restuans (Theobald) sought nesting bird bloodmeals than were predicted by their relative abundances in CO2-baited Centers for Disease Control and Prevention light and gravid traps. Culex salinarius (Coquillett) and Culex erraticus Dyar and Knab were collected in NMTs in proportion to their relative abundances in the generic traps. Temporal host funnels and nesting bird host specificity may enhance arbovirus amplification and explain observed West Nile virus and St. Louis encephalitis virus amplification periods.

Efficacy of trap modifications for increasing capture rates of aquatic snakes in floating aquatic funnel traps

USGS Publications Warehouse

Halstead, Brian J.; Wylie, Glenn D.; Casazza, Michael L.

2013-01-01

Increasing detection and capture probabilities of rare or elusive herpetofauna of conservation concern is important to inform the scientific basis for their management and recovery. The Giant Gartersnake (Thamnophis gigas) is an example of a secretive, wary, and generally difficult-to-sample species about which little is known regarding its patterns of occurrence and demography. We therefore evaluated modifications to existing traps to increase the detection and capture probabilities of the Giant Gartersnake to improve the precision with which occurrence, abundance, survival, and other demographic parameters are estimated. We found that adding a one-way valve constructed of cable ties to the small funnel opening of traps and adding hardware cloth extensions to the wide end of funnels increased capture rates of the Giant Gartersnake by 5.55 times (95% credible interval = 2.45–10.51) relative to unmodified traps. The effectiveness of these modifications was insensitive to the aquatic habitat type in which they were deployed. The snout-vent length of the smallest and largest captured snakes did not vary among trap modifications. These trap modifications are expected to increase detection and capture probabilities of the Giant Gartersnake, and show promise for increasing the precision with which demographic parameters can be estimated for this species. We anticipate that the trap modifications found effective in this study will be applicable to a variety of aquatic and semi-aquatic reptiles and amphibians and improve conservation efforts for these species.

Environmentally friendly tool to control mosquito populations without risk of insecticide resistance: the Lehmann’s funnel entry trap

PubMed Central

2013-01-01

Background Current malaria control strategies have cut down the malaria burden in many endemic areas, however the emergence and rapid spread of insecticide and drug resistance undermine the success of these efforts. There is growing concern that malaria eradication will not be achieved without the introduction of novel control tools. One approach that has been developed in the last few years is based on house screening to reduce indoor mosquito vector densities and consequently decrease malaria transmission. Here screening and trapping were combined in one tool to control mosquito populations. The trap does not require an insecticide or even an attractant, yet it effectively collects incoming resistant and susceptible mosquitoes and kills them. Results Performance of the funnel entry trap was tested in low and high malaria vector density areas. An overall reduction of 70 to 80% of mosquito density was seen in both. Species and molecular forms of Anopheles gambiae identification indicated no variation in the number of Anopheles arabiensis and the molecular forms of An. gambiae between houses and traps. Mosquitoes collected in the traps and in houses were highly resistant to pyrethroids (0.9 kdr-based mechanism). Conclusion There is a global consensus that new intervention tools are needed to cross the last miles in malaria elimination/eradication. The funnel entry trap showed excellent promise in suppressing mosquito densities even in area of high insecticide resistance. It requires no chemicals and is self-operated. PMID:23758904

Comparison of naturally and synthetically baited spruce beetle trapping systems in the central Rocky Mountains

Treesearch

E. Matthew Hansen; Jim C. Vandygriff; Robert J. Cain; David Wakarchuk

2006-01-01

We compared naturally baited trapping systems to synthetically baited funnel traps and fallen trap trees for suppressing preoutbreak spruce beetle, Dendroctonus rufipennis Kirby, populations. Lures for the traps were fresh spruce (Picea spp.) bolts or bark sections, augmented by adding female spruce beetles to create secondary attraction. In 2003, we...

Magneto-optical trapping of potassium isotopes

NASA Astrophysics Data System (ADS)

Williamson, Robert Sylvester, III

1997-12-01

We have demonstrated a magneto-optical trap (scMOT) suitable for capturing radioactive potassium produced on- line with the UW-Madison 12MeV tandem electrostatic accelerator. To do this, we made and characterized the first scMOT for potassium, measured the potassium ultracold collision rate, and developed a numerical trap- loading rate model that makes useful quantitative predictions. We have created a cold beam of collimated potassium atoms using a pyramidal magneto-optical funnel and used it to load a long-lifetime scMOT operating at ultrahigh vacuum. We have also built a target that produces a beam of radioactive 37K and 38K and coupled it to the magneto-optical funnel and trap. Once a trap of radioactive 38K has been demonstrated, the primary goal of this project is to measure the beta-asymmetry parameter in the decay of 38K, performing a sensitive test of the Standard Model of weak interactions.

Infrared laser dissociation of single megadalton polymer ions in a gated electrostatic ion trap: the added value of statistical analysis of individual events.

PubMed

Halim, Mohammad A; Clavier, Christian; Dagany, Xavier; Kerleroux, Michel; Dugourd, Philippe; Dunbar, Robert C; Antoine, Rodolphe

2018-05-07

In this study, we report the unimolecular dissociation mechanism of megadalton SO 3 -containing poly(2-acrylamido-2-methyl-1-propanesulfonic acid) (PAMPS) polymer cations and anions with the aid of infrared multiphoton dissociation coupled to charge detection ion trap mass spectrometry. A gated electrostatic ion trap ("Benner trap") is used to store and detect single gaseous polymer ions generated by positive and negative polarity in an electrospray ionization source. The trapped ions are then fragmented due to the sequential absorption of multiple infrared photons produced from a continuous-wave CO 2 laser. Several fragmentation pathways having distinct signatures are observed. Highly charged parent ions characteristically adopt a distinctive "stair-case" pattern (assigned to the "fission" process) whereas low charge species take on a "funnel like" shape (assigned to the "evaporation" process). Also, the log-log plot of the dissociation rate constants as a function of laser intensity between PAMPS positive and negative ions is significantly different.

Intercept™ Panel Trap (INT PT) effective in management of forest Coleoptera

Treesearch

D. Czokajlo; J. McLaughlin; L. I. Abu Ayyash; S. Teale; J. Wickham; J. Warren; R. Hoffman; B. Aukema; K. Raffa; P. Kirsch

2003-01-01

Trap efficacy in capturing economically important forest Coleoptera was measured in field trials comparing the Intercept Panel Trap (INT PT) with the Multi-Funnel Trap. The INT PT was designed to provide a better option for the monitoring of forest Coleoptera. The trap is made of corrugated plastic and is very robust under rigorous field conditions, but still...

Efficacy of Fluon conditioning for capturing cerambycid beetles in different trap designs and rersistence on panel traps over time

Treesearch

Elizabeth E. Graham; Therese M. Poland

2012-01-01

Fluon PTFE is a fluoropolymer dispersion applied as a surface conditioner to cross-vane panel traps to enhance trap efficiency for cerambycid beetles. We describe the results of three experiments to further optimize cerambycid traps of different designs and to test the effect of Fluon over time. We tested Fluon with Lindgren funnel and panel traps fitted with either...

A method for trapping prairie grouse hens on display grounds

Treesearch

John E. Toepfer; Jay A. Newell; John Monarch

1988-01-01

This paper describes a method for trapping prairie grouse hens on display grounds. The basic principle of the trap is a drift fence which funnels visiting hens into traps. The trap has been used successfully in at least 6 states and 2 provinces and on 4 species of prairie grouse. This method is less expensive and less disruptive than rocket or cannon nets.

A Trap For Capturing Arthropods Crawling up Tree Boles

Treesearch

James L. Hanula; Kirsten C.P. New

1996-01-01

A simple trap is described that captures arthropods as they crawl up tree boles. Constructed from metal funnels, plastic sandwich containers, and specimen cups, the traps can be assembled by one person at a rate of 5 to 6 per hour and installed in 2 to 3 minutes. Specimen collection required 15 to 20 seconds per trap. In 1993, three traps were placed on each tree. In...

Building Double-decker Traps for Early Detection of Emerald Ash Borer.

PubMed

McCullough, Deborah G; Poland, Therese M

2017-10-04

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire), the most destructive forest insect to have invaded North America, has killed hundreds of millions of forest and landscape ash (Fraxinus spp.) trees. Several artificial trap designs to attract and capture EAB beetles have been developed to detect, delineate, and monitor infestations. Double-decker (DD) traps consist of two corrugated plastic prisms, one green and one purple, attached to a 3 m tall polyvinyl chloride (PVC) pipe supported by a t-post. The green prism at the top of the PVC pipe is baited with cis-3-hexenol, a compound produced by ash foliage. Surfaces of both prisms are coated with sticky insect glue to capture adult EAB beetles. Double-decker traps should be placed near ash trees but in open areas, exposed to sun. Double-decker trap construction and placement are presented here, along with a summary of field experiments demonstrating the efficacy of DD traps in capturing EAB beetles. In a recent study in sites with relatively low EAB densities, double-decker traps captured significantly more EAB than green or purple prism traps or green funnel traps, all of which are designed to be suspended from a branch in the canopy of ash trees. A greater percentage of double decker traps were positive, i.e., captured at least one EAB, than the prism traps or funnel traps that were hung in ash tree canopies.

The Technical and Performance Characteristics of a Low-Cost, Simply Constructed, Black Light Moth Trap

PubMed Central

White, Peter J. T.; Glover, Katharine; Stewart, Joel; Rice, Amanda

2016-01-01

The universal mercury vapor black light trap is an effective device used for collecting moth specimens in a wide variety of habitats; yet, they can present challenges for researchers. The mercury vapor trap is often powered by a heavy automotive battery making it difficult to conduct extensive surveys in remote regions. The mercury vapor trap also carries a considerable financial cost per trap unit, making trapping challenging with low research budgets. Here, we describe the development and trapping properties of a lighter, simply constructed, and less expensive trap. The LED funnel trap consists of a funnel, soda bottles with plastic vanes, and is powered by rechargeable 9-V batteries. Two strips of low-wavelength LEDs are used as attractants. We tested the trapping parameters of this trap design compared to a standard mercury vapor trap over 10 trap nights in a suburban woodlot in the summer of 2015. The mercury vapor trap caught significantly more moth individuals than the LED trap (average of 78 vs 40 moths per trap night; P < 0.05), and significantly more species than the LED trap (23 vs 15 per trap night; P < 0.05); the mercury vapor trap caught a total of 104 macromoth species over the duration of the study, compared to a total of 87 by the LED trap. Despite the lower yields, the low cost of the LED trap (<$30 ea.) makes it superior to the mercury vapor trap in cost-acquisition per moth species and per moth individual trapped. The LED trap may be a viable alternative to the standard mercury vapor trap, facilitating insect trapping in more diverse settings. PMID:26936923

Microchip and wedge ion funnels and planar ion beam analyzers using same

DOEpatents

Shvartsburg, Alexandre A; Anderson, Gordon A; Smith, Richard D

2012-10-30

Electrodynamic ion funnels confine, guide, or focus ions in gases using the Dehmelt potential of oscillatory electric field. New funnel designs operating at or close to atmospheric gas pressure are described. Effective ion focusing at such pressures is enabled by fields of extreme amplitude and frequency, allowed in microscopic gaps that have much higher electrical breakdown thresholds in any gas than the macroscopic gaps of present funnels. The new microscopic-gap funnels are useful for interfacing atmospheric-pressure ionization sources to mass spectrometry (MS) and ion mobility separation (IMS) stages including differential IMS or FAIMS, as well as IMS and MS stages in various configurations. In particular, "wedge" funnels comprising two planar surfaces positioned at an angle and wedge funnel traps derived therefrom can compress ion beams in one dimension, producing narrow belt-shaped beams and laterally elongated cuboid packets. This beam profile reduces the ion density and thus space-charge effects, mitigating the adverse impact thereof on the resolving power, measurement accuracy, and dynamic range of MS and IMS analyzers, while a greater overlap with coplanar light or particle beams can benefit spectroscopic methods.

Optimized coupling of cold atoms into a fiber using a blue-detuned hollow-beam funnel

NASA Astrophysics Data System (ADS)

Poulin, Jerome; Light, Philip S.; Kashyap, Raman; Luiten, Andre N.

2011-11-01

We theoretically investigate the process of coupling cold atoms into the core of a hollow-core photonic-crystal optical fiber using a blue-detuned Laguerre-Gaussian beam. In contrast to the use of a red-detuned Gaussian beam to couple the atoms, the blue-detuned hollow beam can confine cold atoms to the darkest regions of the beam, thereby minimizing shifts in the internal states and making the guide highly robust to heating effects. This single optical beam is used as both a funnel and a guide to maximize the number of atoms into the fiber. In the proposed experiment, Rb atoms are loaded into a magneto-optical trap (MOT) above a vertically oriented optical fiber. We observe a gravito-optical trapping effect for atoms with high orbital momentum around the trap axis, which prevents atoms from coupling to the fiber: these atoms lack the kinetic energy to escape the potential and are thus trapped in the laser funnel indefinitely. We find that by reducing the dipolar force to the point at which the trapping effect just vanishes, it is possible to optimize the coupling of atoms into the fiber. Our simulations predict that by using a low-power (2.5 mW) and far-detuned (300 GHz) Laguerre-Gaussian beam with a 20-μm-radius core hollow fiber, it is possible to couple 11% of the atoms from a MOT 9 mm away from the fiber. When the MOT is positioned farther away, coupling efficiencies over 50% can be achieved with larger core fibers.

Traps and attractants for wood-boring insects in ponderosa pine stands in the Black Hills, South Dakota.

PubMed

Costello, Sheryl L; Negrón, José F; Jacobi, William R

2008-04-01

Recent large-scale wildfires have increased populations of wood-boring insects in the Black Hills of South Dakota. Because little is known about possible impacts of wood-boring insects in the Black Hills, land managers are interested in developing monitoring techniques such as flight trapping with semiochemical baits. Two trap designs and four semiochemical attractants were tested in a recently burned ponderosa pine, Pinus ponderosa Dougl. ex Laws., forest in the Black Hills. Modified panel and funnel traps were tested in combination with the attractants, which included a woodborer standard (ethanol and alpha-pinene), standard plus 3-carene, standard plus ipsenol, and standard plus ipsdienol. We found that funnel traps were equally efficient or more efficient in capturing wood-boring insects than modified panel traps. Trap catches of cerambycids increased when we added the Ips spp. pheromone components (ipsenol or ipsdienol) or the host monoterpene (3-carene) to the woodborer standard. During the summers of 2003 and 2004, 18 cerambycid, 14 buprestid, and five siricid species were collected. One species of cerambycid, Monochamus clamator (LeConte), composed 49 and 40% of the 2003 and 2004 trap catches, respectively. Two other cerambycids, Acanthocinus obliquus (LeConte) and Acmaeops proteus (Kirby), also were frequently collected. Flight trap data indicated that some species were present throughout the summer, whereas others were caught only at the beginning or end of the summer.

Sirex noctilio, the New York story

Treesearch

Carolyn Klass; E. Richard Hoebeke

2007-01-01

Sirex wood wasp, (Sirex noctilio Fabricius), was first identified in February 2005 from a Lindgren funnel trap taken September 7, 2004 in Fulton, NY (Oswego County). We followed the development of the events in New York chronologically from this first identification to the results of an expanded trapping program in 2005.

Straight-line drift fences and pitfall traps

USGS Publications Warehouse

Corn, Paul Stephen

1994-01-01

Straight-line drift fences typically are short barriers (5-15 m) that direct animals traveling on the substrate surface into traps places at the ends of or beside the barriers. Traps (described below) can be pitfalls, funnel traps, or a combination of the two. Drift fences with pitfall or funnel traps and pitfall traps without fences are used commonly to inventory and monitor populations of amphibians and reptiles. For example, 9 of 17 field studies reported for management of terrestrial vertebrates (Sarzo et al. 1988) used these techniques to sample amphibians. Drift fences with pitfall traps can be used to determine species richness at a site and to detect the presence of rare species. They also can yield data on relative abundances and habitat use of selected species. Pitfall traps arrayed in a grid without fences can also be used to study the population ecology and habitat use of selected species. Population density can be estimated with this latter technique if used in conjunction with mark-recapture techniques (see Chapter 8). Drift fence arrays or pitfall grids can be left in place for long-term monitoring. In this section, I discuss the use of this technique to obtain data on amphibians away from breeding ponds. Use of drift fences and traps to monitory amphibian activity at breeding ponds is discussed in the section "Drift Fences Encircling Breeding Sits", below (technique 9). Some materials and procedures are common to both techniques. Investigators contemplating the use of drift fences and traps in any context should read both accounts.

An electrodynamic ion funnel for electrospray ionization source based time-of-flight mass spectrometry

NASA Astrophysics Data System (ADS)

Bhushan, K. G.; Rao, K. C.; Sule, U.; Reddy, P.; Rodrigues, S. M.; Gaikwad, D. T.; Mukundhan, R.; Gupta, S. K.

2016-04-01

An electrodynamic ion funnel has been developed for improving the sensitivity of electrospray ionization sources widely used in the mass spectrometric study of proteins and other biological macromolecules. The ion funnel consists of 52 electrodes and works under the combined influence of RF and DC voltages in the pressure range of 0.1 to 5 mbar. A novel feature of this ion funnel is the specific shape of the exit electrode that improves transmission of lower mass ions by reducing the depth of effective trapping potentials. In this paper, we report on the optimization of the ion funnel design using ion trajectory simulation software SIMION 8.0 especially in the mass range 500-5000 amu, followed by experimental observations of the ion transmission from the electrospray interface. It is seen that the electrospray-ion funnel combination greatly enhances the transmission when compared with an electrospray-skimmer interface. Ion currents > 1 nA could be obtained at the exit of the ion funnel for dilute Streptomycin Sulphate (~ 1500 amu) solution with the ion funnel operating in the 500-900 kHz frequency range, amplitude of 70 Vp-p, under a DC gradient of about 20 Volts/cm at a background pressure of 0.3 mbar. Details of the construction of the ion funnel along with the experimental results are presented.

Rectangular Ion Funnel: A New Ion Funnel Interface for Structures for Lossless Ion Manipulations

DOE PAGES

Chen, Tsung-Chi; Webb, Ian K.; Prost, Spencer A.; ...

2014-11-19

A recent achievement in Structures for Lossless Ion Manipulations (SLIM) is the ability for near lossless ion focusing, transfer, and trapping in sub-atmospheric pressure regions. While lossless ion manipulations are advantageously applied to the applications of ion mobility separations and gas phase reactions, ion introduction through ring electrode ion funnels or more conventional ion optics to SLIM can involve discontinuities in electric fields or other perturbations that result in ion losses. In this work, we investigated a new funnel design that aims to seamlessly couple to SLIM at the funnel exit. This rectangular ion funnel (RIF) was initially evaluated bymore » ion simulations, fabricated utilizing printed circuit board technology and tested experimentally. The RIF was integrated to a SLIM-TOFMS system, and the operating parameters, including RF, DC bias of the RIF electrodes, and electric fields for effectively interfacing with a SLIM were characterized. The RIF provided a 2-fold sensitivity increase without significant discrimination over a wide m/z range along with greatly improved SLIM operational stability.« less

Gallery productivity, emergence, and flight activity of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)

Treesearch

M. Lake Maner; James Hanula; S. Kristine Braman

2013-01-01

Flight and emergence of the redbay ambrosia beetle, Xyleborus glabratus Eichhoff, were monitored from March 2011 through August 2012 using Lindgren funnel traps baited with manuka oil and emergence traps attached over individual beetle galleries on infested redbay (Persea borbonia (L.) Sprengel) trees. Of the 432 gallery entrances...

Impacts of silvicultural thinning treatments on beetle trap captures and tree attacks during low bark beetle populations in ponderosa pine forests of northern Arizona.

PubMed

Gaylord, M L; Hofstetter, R W; Wagner, M R

2010-10-01

Our research used a combination of passive traps, funnel traps with lures, baited trees, and surveys of long-term thinning plots to assess the impacts of different levels of stand basal area (BA) on bark beetle tree attack and on trap captures of Ips spp., Dendroctonus spp., and their predators. The study occurred at two sites in ponderosa pine, Pinus ponderosa Dougl. ex Laws., forests, from 2004 to 2007 during low bark beetle populations. Residual stand BA ranged from 9.0 to 37.0 m2/ha. More predators and bark beetles were collected in passive traps in stands of lower BA than in stands of higher BA; however, significance varied by species and site, and total number of beetles collected was low. Height of the clear panel passive traps affected trap catches for some species at some sites and years. When pheromone lures were used with funnel traps [Ips pini (Say) lure: lanierone, +03/-97 ipsdienol], we found no significant difference in trap catches among basal area treatments for bark beetles and their predators. Similarly, when trees were baited (Dendroctonus brevicomis LeConte lure: myrcene, exo-brevicomin and frontalin), we found no significant difference for days to first bark beetle attack. Surveys of long-term thinning treatments found evidence of bark beetle attacks only in unthinned plots (approximately 37 m2/ha basal area). We discuss our results in terms of management implications for bark beetle trapping and control.

Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

DOE PAGES

Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; ...

2015-06-24

The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher pressure regions (e.g. ion source interfaces) of mass spectrometers, and thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to charge ratios. In this study a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadruple mass spectrometer was developed and characterized. An orthogonal ionmore » injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at 9-10 Torr pressure. Several critical factors for the HPIF were characterized, including the effects of RF amplitude, DC gradient and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. Lastly, the sensitivity enhancement in liquid chromatography selected reaction monitoring (SRM) analyses of low abundance peptides spiked into a highly complex mixture was also compared with that obtained using a both commercial s-lens interface and a in-line dual ion funnel interface.« less

Orthogonal Injection Ion Funnel Interface Providing Enhanced Performance for Selected Reaction Monitoring-Triple Quadrupole Mass Spectrometry

PubMed Central

Chen, Tsung-Chi; Fillmore, Thomas L.; Prost, Spencer A.; Moore, Ronald J.; Ibrahim, Yehia M.; Smith, Richard D.

2016-01-01

The electrodynamic ion funnel facilitates efficient focusing and transfer of charged particles in the higher-pressure regions (e.g., ion source interfaces) of mass spectrometers, thus providing increased sensitivity. An “off-axis” ion funnel design has been developed to reduce the source contamination and interferences from, e.g. ESI droplet residue and other poorly focused neutral or charged particles with very high mass-to-charge ratios. In this study, a dual ion funnel interface consisting of an orthogonal higher pressure electrodynamic ion funnel (HPIF) and an ion funnel trap combined with a triple quadrupole mass spectrometer was developed and characterized. An orthogonal ion injection inlet and a repeller plate electrode was used to direct ions to an ion funnel HPIF at a pressure of 9–10 Torr. Key factors for the HPIF performance characterized included the effects of RF amplitude, the DC gradient, and operating pressure. Compared to the triple quadrupole standard interface more than 4-fold improvement in the limit of detection for the direct quantitative MS analysis of low abundance peptides was observed. The sensitivity enhancement in liquid chromatography selected reaction monitoring (LC-SRM) analyses of low-abundance peptides spiked into a highly complex mixture was also compared with that obtained using both a commercial S-lens interface and an in-line dual-ion funnel interface. PMID:26107611

Ethanol and (-)-?-pinene: attratant kairomones for bark ad ambrosia beetles in the Southeastern US

Treesearch

Daniel R. Miller; Robert J. Rabaglia

2009-01-01

In 2002–2004, we examined the flight responses of 49 species of native and exotic bark and ambrosia beetles (Coleoptera: Scolytidae and Platypodidae) to traps baited with ethanol and/or (?)-?-pinene in the southeastern US. Eight field trials were conducted in mature pine stands in Alabama, Florida, Georgia, North Carolina, and South Carolina. Funnel traps baited with...

Variation in effects of Conophthorin on catches of ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in ethanol-baited traps in the United States.

Treesearch

Dan Miller; K.J. Dodds; E.R. Hoebeke; T.M. Poland; E.A. Willhite

2015-01-01

In 2013, we examined the effects of conophthorin on flight responses of ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) tomultiple-funnel traps baited with ethanol in Georgia,Michigan, New Hampshire, and Oregon. Adventive species (¼exotic, nonnative, immigrant, introduced) accounted for 91.4% of total catches of ambrosia beetles. Conophthorin increased catches...

Development of the gravid Aedes trap for the capture of adult female container-exploiting mosquitoes (Diptera: Culicidae).

PubMed

Eiras, Alvaro E; Buhagiar, Tamara S; Ritchie, Scott A

2014-01-01

Monitoring dengue vector control by sampling adult Aedes aegypti (L.) recently has been used to replace both larval and pupal surveys. We have developed and evaluated the Gravid Aedes Trap (GAT) through a sequential behavioral study. The GAT does not require electricity to function, and trapped mosquitoes are identified easily during trap inspections. The GAT concept relies on visual and olfactory cues to lure gravid Ae. aegypti and an insecticide to kill trapped mosquitoes. Gravid mosquitoes are lured to a black bucket base containing oviposition attractant (infusion) and are trapped in a translucent chamber impregnated with a pyrethroid insecticide where they are killed within 3-15 min. In semifield observations, the GAT captured a significantly higher proportion of gravid mosquitoes than the double sticky ovitrap. We also demonstrated that the visual cues of the prototype GAT-LgBF (large black base bucket with a black funnel at the top of the translucent chamber) captured a significantly higher proportion of gravid mosquitoes than the other prototypes. The visual contrast created by the addition of a white lid to the top of the black funnel significantly increased the number of captured gravid mosquitoes when compared with the GAT-LgBF in semifield trials. We conclude that the GAT is more efficient in recapturing gravid Ae. aegypti when compared with sticky ovitraps. The GAT is an effective, practical, low cost, and easily transportable trap, features that are essential in large-scale monitoring programs, particularly in areas where funding is limited.

1-Octen-3-ol is repellent to Ips pini (Coleoptera: Curculionidae: Scolytinae) in the midwestern United States

Treesearch

Therese M. Poland; Tina M. Pureswaran Deepa S. Ciaramitaro; John H. Borden

2009-01-01

In field experiments at three sites in Michigan and Ohio we tested the activity of 1-octen-3-ol in combination with ipsdienol, the aggregation pheromone of the pine engraver, Ips pini (Say). When 1-octen-3-ol was added to funnel traps baited with ipsdienol, significantly fewer beetles of either sex were captured than in traps baited with ipsdienol...

Disruption by conophthorin of the kairomonal response of sawyer beetles to bark beetle pheromones.

PubMed

Morewood, W D; Simmonds, K E; Gries, R; Allison, J D; Borden, J H

2003-09-01

Antennally active nonhost angiosperm bark volatiles were tested for their ability to reduce the response of three common species of coniferophagous wood-boring Cerambycidae to attractant-baited multiple funnel traps in the southern interior of British Columbia. Of the nonhost volatiles tested, only conophthorin was behaviorally active, disrupting the attraction of sawyer beetles, Monochamus spp., to traps baited with the host volatiles alpha-pinene and ethanol and the bark beetle pheromones ipsenol and ipsdienol. Conophthorin did not affect the attraction of sawyer beetles to the host kairomones alpha-pinene and ethanol in the absence of bark beetle pheromones, nor did it have any behavioral effect on adults of Xylotrechus longitarsis, which were not attracted to bark beetle pheromones. These results indicate that conophthorin does not act as a general repellent for coniferophagous Cerambycidae, as it seems to do for many species of Scolytidae, but has the specific activity of disrupting the kairomonal response of sawyer beetles to bark beetle pheromones.

Disruptant effects of 4-allylanisole and verbenone on Tomicus piniperda (Coleoptera: Scolitidae) response to baited traps and logs

Treesearch

Robert A. Haack; Robert K. Lawrence; Toby R. Petrice; Therese M. Poland

2004-01-01

We assessed the inhibitory effects of the host compound 4-allylanisole (release rates = 1 and 2 mg/d in 1994, and 1 and 10 mg/d in 2001) on the response of the pine shoot beetle, Tomicus piniperda (L.), adults to funnel traps baited with the attractant host compound α-pinene (release rate = 150 mg/d) in two pine Christmas tree...

Realized detection and capture probabilities for giant gartersnakes (Thamnophis gigas) using modified floating aquatic funnel traps

USGS Publications Warehouse

Halstead, Brian J.; Skalos, Shannon M.; Casazza, Michael L.; Wylie, Glenn D.

2015-01-01

Detection and capture probabilities for giant gartersnakes (Thamnophis gigas) are very low, and successfully evaluating the effects of variables or experimental treatments on giant gartersnake populations will require greater detection and capture probabilities than those that had been achieved with standard trap designs. Previous research identified important trap modifications that can increase the probability of snakes entering traps and help prevent the escape of captured snakes. The purpose of this study was to quantify detection and capture probabilities obtained using the most successful modification to commercially available traps to date (2015), and examine the ability of realized detection and capture probabilities to achieve benchmark levels of precision in occupancy and capture-mark-recapture studies.

Deployable micro-traps to sequester motile bacteria

NASA Astrophysics Data System (ADS)

di Giacomo, Raffaele; Krödel, Sebastian; Maresca, Bruno; Benzoni, Patrizia; Rusconi, Roberto; Stocker, Roman; Daraio, Chiara

2017-04-01

The development of strategies to reduce the load of unwanted bacteria is a fundamental challenge in industrial processing, environmental sciences and medical applications. Here, we report a new method to sequester motile bacteria from a liquid, based on passive, deployable micro-traps that confine bacteria using micro-funnels that open into trapping chambers. Even in low concentrations, micro-traps afford a 70% reduction in the amount of bacteria in a liquid sample, with a potential to reach >90% as shown by modelling improved geometries. This work introduces a new approach to contain the growth of bacteria without chemical means, an advantage of particular importance given the alarming growth of pan-drug-resistant bacteria.

Deployable micro-traps to sequester motile bacteria

PubMed Central

Di Giacomo, Raffaele; Krödel, Sebastian; Maresca, Bruno; Benzoni, Patrizia; Rusconi, Roberto; Stocker, Roman; Daraio, Chiara

2017-01-01

The development of strategies to reduce the load of unwanted bacteria is a fundamental challenge in industrial processing, environmental sciences and medical applications. Here, we report a new method to sequester motile bacteria from a liquid, based on passive, deployable micro-traps that confine bacteria using micro-funnels that open into trapping chambers. Even in low concentrations, micro-traps afford a 70% reduction in the amount of bacteria in a liquid sample, with a potential to reach >90% as shown by modelling improved geometries. This work introduces a new approach to contain the growth of bacteria without chemical means, an advantage of particular importance given the alarming growth of pan-drug-resistant bacteria. PMID:28378786

Deployable micro-traps to sequester motile bacteria.

PubMed

Di Giacomo, Raffaele; Krödel, Sebastian; Maresca, Bruno; Benzoni, Patrizia; Rusconi, Roberto; Stocker, Roman; Daraio, Chiara

2017-04-05

The development of strategies to reduce the load of unwanted bacteria is a fundamental challenge in industrial processing, environmental sciences and medical applications. Here, we report a new method to sequester motile bacteria from a liquid, based on passive, deployable micro-traps that confine bacteria using micro-funnels that open into trapping chambers. Even in low concentrations, micro-traps afford a 70% reduction in the amount of bacteria in a liquid sample, with a potential to reach >90% as shown by modelling improved geometries. This work introduces a new approach to contain the growth of bacteria without chemical means, an advantage of particular importance given the alarming growth of pan-drug-resistant bacteria.

Plasmonic Circuit Theory for Multiresonant Light Funneling to a Single Spatial Hot Spot.

PubMed

Hughes, Tyler W; Fan, Shanhui

2016-09-14

We present a theoretical framework, based on plasmonic circuit models, for generating a multiresonant field intensity enhancement spectrum at a single "hot spot" in a plasmonic device. We introduce a circuit model, consisting of an array of coupled LC resonators, that directs current asymmetrically in the array, and we show that this circuit can funnel energy efficiently from each resonance to a single element. We implement the circuit model in a plasmonic nanostructure consisting of a series of metal bars of differing length, with nearest neighbor metal bars strongly coupled electromagnetically through air gaps. The resulting nanostructure resonantly traps different wavelengths of incident light in separate gap regions, yet it funnels the energy of different resonances to a common location, which is consistent with our circuit model. Our work is important for a number of applications of plasmonic nanoantennas in spectroscopy, such as in single-molecule fluorescence spectroscopy or Raman spectroscopy.

Responses of Cerambycidae and Other Insects to Traps Baited With Ethanol, 2,3-Hexanediol, and 3,2-Hydroxyketone Lures in North-Central Georgia.

PubMed

Miller, D R; Crowe, C M; Mayo, P D; Silk, P J; Sweeney, J D

2015-10-01

In north-central Georgia, 13 species of woodboring beetles (Coleoptera: Cerambycidae: Cerambycinae) were attracted to multiple-funnel traps baited with ethanol and one of the following pheromones: (1) racemic 3-hydroxyhexan-2-one; (2) racemic 3-hydroxyoctan-2-one; and (3) syn-2,3-hexanediol. The following species were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one: Anelaphus pumilus (Newman), Eburia quadrigeminata (Say), Euderces pini (Olivier), Knulliana cincta (Drury), Neoclytus mucronatus (F.), Neoclytus scutellaris (Olivier), and Xylotrechus colonus (F.). Clytus marginicollis Castelnau & Gory, and Anelaphus parallelus (Newman) were attracted to traps baited with ethanol and 3-hydroxyoctan-2-one, whereas traps baited with ethanol and syn-2,3-hexanediol were attractive to Anelaphus villosus (F.), A. parallelus, Neoclytus acuminatus (F.), Neoclytus jouteli jouteli Davis, and Megacyllene caryae (Gahan). Ethanol enhanced catches of seven cerambycid species in traps baited with syn-2,3-hexanediol and 3,2-hydroxyketones. Catches of bark and ambrosia beetles (Curculionidae: Scolytinae) in ethanol-baited traps were largely unaffected by the addition of syn-2,3-hexanediol and 3,2-hydroxyketone lures, except for two species. The mean catches of Hypothenemus rotundicollis Wood & Bright and Dryoxylon onoharaensum (Murayama) in ethanol-baited traps increased and decreased, respectively, with the addition of racemic 3-hydroxyoctan-2-one. Traps baited with ethanol and syn-2,3-hexanediol were attractive to Xylobiops basilaris (Say) (Bostrichidae) and Chariessa pilosa (Forster) (Cleridae), whereas Temnoscheila virescens (F.) (Trogossitidae) were attracted to traps baited with ethanol and 3-hydroxyhexan-2-one. The assassin bug, Apiomerus crassipes (F.) (Hemiptera: Reduviidae), was attracted to traps baited with ethanol and 3,2-hydroxyketones. Published by Oxford University Press on behalf of Entomological Society of America 2015. This work is written by US Government employees and is in the public domain in the US.

Magnetocentrifugally Driven Flows from Young Stars and Disks. IV. The Accretion Funnel and Dead Zone

NASA Astrophysics Data System (ADS)

Ostriker, Eve C.; Shu, Frank H.

1995-07-01

We formulate the time-steady, axisymmetric problem of stellar magnetospheric inflow of gas from a surrounding accretion disk. The computational domain is bounded on the outside by a surface of given shape containing the open field lines associated with an induced disk wind. The mechanism for this wind has been investigated in previous publications in this journal. Our zeroth-order solution incorporates an acceptable accounting of the pressure balance between the magnetic field lines loaded with accreting gas (funnel flow) and those empty of matter (dead zone). In comparison with previous models, our funnel-flow/dead-zone solution has the following novel features: (1) Because of a natural tendency for the trapped stellar magnetic flux to pinch toward the corotation radius Rx (X-point of the effective potential), most of the interesting magnetohydrodynamics is initiated within a small neighborhood of Rx (X-region), where the Keplerian angular speed of rotation in the disk equals the spin rate of the star. (2) Unimpeded funnel flow from the inner portion of the X-region to the star can occur when the amount of trapped magnetic flux equals or exceeds 1.5 times the unperturbed dipole flux that would lie outside Rx in the absence of an accretion disk. (3). Near the equatorial plane, radial infall from the X-point is terminated at a "kink" point Rk = 0.74Rx that deflects the flow away from the midplane, mediating thereby between the field topology imposed by a magnetic fan of trapped flux at Rx and the geometry of a strong stellar dipole. (4) The excess angular momentum of accretion that would otherwise spin up the star rapidly is deposited by the magnetic torques of the funnel flow into the inner portion of the X-region of the disk. (5) An induced disk wind arises in the outer portion of the .X-region, where the stellar field lines have been blown open, and removes whatever excess angular momentum that viscous torques do not transport to the outer disk. (6) The interface between open field lines loaded with outflowing matter (connected to the disk) and those not loaded (connected to the star) forms a "helmet streamer," along which major mass-ejection and reconnection events may arise in response to changing boundary conditions (e.g., stellar magnetic cycles), much the way that such events occur in the active Sun. (7) Pressure balance across the dead-zone/wind interface will probably yield an asymptotically vertical (i.e., "jetlike") trajectory for the matter ejected along the helmet streamer, but mathematical demonstration of this fact is left for future studies. (8) In steady state the overall balance of angular momentum in the star/disk/ magnetosphere system fixes the fractions, f and 1 - f, of the disk mass accretion rate into the X-region carried away, respectively, by the wind and funnel flows.

Attractant semiochemicals of the engraver beetle, Ips perturbatus, in south-central and interior Alaska.

Treesearch

Edward H. Holsten; Roger E. Burnside; Steven J. Seybold

2000-01-01

From 1996 through 1999, field tests of various engraver beetle (Ips perturbatus (Eichhoff)) semiochemicals in funnel traps were conducted in south-central and interior Alaska in stands of Lutz (Picea xlutzii Little) and white spruce (P.glauca (Moench) Voss). The European spruce beetle (I....

Herpetological Habitat Relations in the Ouachita Mountains, Arkansas

Treesearch

Doyle L. Crosswhite; Stanley F Fox; Ronald E. Thill

2004-01-01

Abstract - We studied habitat relationships of the herpetofauna inhabiting managed pine-oak woodlands of the Ouachita Mountains, Arkansas. We used drift fence arrays with pitfall and double-ended funnel traps to sample two replications each of three treatments: young clearcuts, selectively harvested stands, and late-rotation untreated controls. Our...

Seasonal dispersal of the oak wilt fungus by Colopterus truncatus and Carpophilus sayi in Minnesota

Treesearch

Angie K. Ambourn; Jennifer Juzwik; Roger D. Moon

2005-01-01

Sap beetles (Nitidulidae) are considered important overland vectors of the oak wilt pathogen, Ceratocystis fagacearum, in the north central United States. Colopterus truncatus and Carpophilus sayi are thought to be the principal sap beetle vectors in Minnesota. Field studies using wind-oriented funnel traps...

Compression Ratio Ion Mobility Programming (CRIMP) Accumulation and Compression of Billions of Ions for Ion Mobility-Mass Spectrometry Using Traveling Waves in Structures for Lossless Ion Manipulations (SLIM)

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

Deng, Liulin; Garimella, Sandilya V. B.; Hamid, Ahmed M.

We report on the implementation of a traveling wave (TW) based compression ratio ion mobility programming (CRIMP) approach within Structures for Lossless Ion Manipulations (SLIM) that enables both greatly enlarged trapped ion charge capacities and also their subsequent efficient compression for use in ion mobility (IM) separations. Ion accumulation is conducted in a long serpentine path TW SLIM region after which CRIMP allows the large ion populations to be ‘squeezed’. The compression process occurs at an interface between two SLIM regions, one operating conventionally and the second having an intermittently pausing or ‘stuttering’ TW, allowing the contents of multiple binsmore » of ions from the first region to be merged into a single bin in the second region. In this initial work stationary voltages in the second region were used to block ions from exiting the first (trapping) region, and the resumption of TWs in the second region allows ions to exit, and the population to also be compressed if CRIMP is applied. In our initial evaluation we show that the number of charges trapped for a 40 s accumulation period was ~5×109, more than two orders of magnitude greater than the previously reported charge capacity using an ion funnel trap. We also show that over 1×109 ions can be accumulated with high efficiency in the present device, and that the extent of subsequent compression is only limited by the space charge capacity of the trapping region. Lower compression ratios allow increased IM peak heights without significant loss of signal, while excessively large compression ratios can lead to ion losses and other artifacts. Importantly, we show that extended ion accumulation in conjunction with CRIMP and multiple passes provides the basis for a highly desirable combination of ultra-high sensitivity and ultra-high resolution IM separations using SLIM.« less

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

Werner, R.A.

Field tests on the efficacy of various scolytid bark beetle pheromones to attract Ips perturbatus (Eichhoff) were conducted from 1977 through 1992 in stands of white spruce (Picea glauca (Moench) Voss) in interior Alaska. Several pheromones attracted high numbers of I. perturbatus and species of the predator Thanasimus to baited funnel traps. Test results also indicated that attacks by I. perturbatus may be deferred by certain semiochemicals.

Spatio-temporal dynamics of pond use and recruitment in Florida gopher frogs (Rana capito aesopus)

Treesearch

Cathryn H. Greenberg

2001-01-01

This study examines spatio-temporal dynamics of Florida gopher frog (Rang capito aesopus) breeding and juvenile recruitment. Ponds were situated within a hardwood-invaded or a savanna-like longleaf pine-wiregrass upland matrix. Movement (N = 1444) was monitored using intermittent drift fences with pitfall and funnel traps at eight...

Improving detection tools for emerald ash borer (Coleoptera: Buprestidae): comparison of multifunnel traps, prism traps, and lure types at varying population densities.

PubMed

Crook, Damon J; Francese, Joseph A; Rietz, Michael L; Lance, David R; Hull-Sanders, Helen M; Mastro, Victor C; Silk, Peter J; Ryall, Krista L

2014-08-01

The emerald ash borer, Agrilus planipennis Fairmaire (Coleoptera: Buprestidae), is a serious invasive pest of North American ash (Fraxinus spp.) that has caused devastating mortality since it was first identified in North America in 2002. In 2012, we conducted field trapping assays that tested the efficacy of purple prism and fluon-coated green multifunnel (Lindgren funnel) traps. Traps were baited with combinations of several lures that were previously shown to be attractive to A. planipennis: manuka oil--a sesquiterpene-rich oil, (3Z)-hexenol--a green leaf volatile, or (3Z)-dodecen-12-olide [= (3Z)-lactone], a sex pheromone. Eighty-nine blocks (trap lines) were tested throughout nine states along the outer edges of the currently known A. planipennis infestation in North America. Trap catch was highest on fluon-coated green multifunnel traps, and trap detections at sites with low A. planipennis population density ranged from 72 to 76% for all trap and lure types tested. (3Z)-hexenol and (3Z)-lactone baited traps functioned as well as (3Z)-hexenol and manuka oil-baited traps. Independent of the lure used, detection rates on green fluon-coated multifunnel traps were comparable with glued purple prism traps in areas with low A. planipennis population densities.

Identification of failed fuel element

DOEpatents

Fryer, Richard M.; Matlock, Robert G.

1976-06-22

A passive fission product gas trap is provided in the upper portion of each fuel subassembly in a nuclear reactor. The gas trap consists of an inverted funnel of less diameter than the subassembly having a valve at the apex thereof. An actuating rod extends upwardly from the valve through the subassembly to a point where it can be contacted by the fuel handling mechanism for the reactor. Interrogation of the subassembly for the presence of fission products is accomplished by lowering the fuel handling machine onto the subassembly to press down on the actuating rod and open the valve.

Direct sampling during multiple sediment density flows reveals dynamic sediment transport and depositional environment in Monterey submarine canyon

NASA Astrophysics Data System (ADS)

Maier, K. L.; Gales, J. A.; Paull, C. K.; Gwiazda, R.; Rosenberger, K. J.; McGann, M.; Lundsten, E. M.; Anderson, K.; Talling, P.; Xu, J.; Parsons, D. R.; Barry, J.; Simmons, S.; Clare, M. A.; Carvajal, C.; Wolfson-Schwehr, M.; Sumner, E.; Cartigny, M.

2017-12-01

Sediment density flows were directly sampled with a coupled sediment trap-ADCP-instrument mooring array to evaluate the character and frequency of turbidity current events through Monterey Canyon, offshore California. This novel experiment aimed to provide links between globally significant sediment density flow processes and their resulting deposits. Eight to ten Anderson sediment traps were repeatedly deployed at 10 to 300 meters above the seafloor on six moorings anchored at 290 to 1850 meters water depth in the Monterey Canyon axial channel during 6-month deployments (October 2015 - April 2017). Anderson sediment traps include a funnel and intervalometer (discs released at set time intervals) above a meter-long tube, which preserves fine-scale stratigraphy and chronology. Photographs, multi-sensor logs, CT scans, and grain size analyses reveal layers from multiple sediment density flow events that carried sediment ranging from fine sand to granules. More sediment accumulation from sediment density flows, and from between flows, occurred in the upper canyon ( 300 - 800 m water depth) compared to the lower canyon ( 1300 - 1850 m water depth). Sediment accumulated in the traps during sediment density flows is sandy and becomes finer down-canyon. In the lower canyon where sediment directly sampled from density flows are clearly distinguished within the trap tubes, sands have sharp basal contacts, normal grading, and muddy tops that exhibit late-stage pulses. In at least two of the sediment density flows, the simultaneous low velocity and high backscatter measured by the ADCPs suggest that the trap only captured the collapsing end of a sediment density flow event. In the upper canyon, accumulation between sediment density flow events is twice as fast compared to the lower canyon; it is characterized by sub-cm-scale layers in muddy sediment that appear to have accumulated with daily to sub-daily frequency, likely related to known internal tidal dynamics also measured in the experiment. The comprehensive scale of the Monterey Coordinated Canyon Experiment allows us to integrate sediment traps with ADCP instrument data and seafloor core samples, which provides important new data to constrain how, when, and what sediment is transported through submarine canyons and how this is archived in seafloor deposits.

Mushroom Emergence Detected by Combining Spore Trapping with Molecular Techniques.

PubMed

Castaño, Carles; Oliva, Jonàs; Martínez de Aragón, Juan; Alday, Josu G; Parladé, Javier; Pera, Joan; Bonet, José Antonio

2017-07-01

Obtaining reliable and representative mushroom production data requires time-consuming sampling schemes. In this paper, we assessed a simple methodology to detect mushroom emergence by trapping the fungal spores of the fruiting body community in plots where mushroom production was determined weekly. We compared the performance of filter paper traps with that of funnel traps and combined these spore trapping methods with species-specific quantitative real-time PCR and Illumina MiSeq to determine the spore abundance. Significantly more MiSeq proportional reads were generated for both ectomycorrhizal and saprotrophic fungal species using filter traps than were obtained using funnel traps. The spores of 37 fungal species that produced fruiting bodies in the study plots were identified. Spore community composition changed considerably over time due to the emergence of ephemeral fruiting bodies and rapid spore deposition (lasting from 1 to 2 weeks), which occurred in the absence of rainfall events. For many species, the emergence of epigeous fruiting bodies was followed by a peak in the relative abundance of their airborne spores. There were significant positive relationships between fruiting body yields and spore abundance in time for five of seven fungal species. There was no relationship between fruiting body yields and their spore abundance at plot level, indicating that some of the spores captured in each plot were arriving from the surrounding areas. Differences in fungal detection capacity by spore trapping may indicate different dispersal ability between fungal species. Further research can help to identify the spore rain patterns for most common fungal species. IMPORTANCE Mushroom monitoring represents a serious challenge in economic and logistical terms because sampling approaches demand extensive field work at both the spatial and temporal scales. In addition, the identification of fungal taxa depends on the expertise of experienced fungal taxonomists. Similarly, the study of fungal dispersal has been constrained by technological limitations, especially because the morphological identification of spores is a challenging and time-consuming task. Here, we demonstrate that spores from ectomycorrhizal and saprotrophic fungal species can be identified using simple spore traps together with either MiSeq fungus-specific amplicon sequencing or species-specific quantitative real-time PCR. In addition, the proposed methodology can be used to characterize the airborne fungal community and to detect mushroom emergence in forest ecosystems. Copyright © 2017 American Society for Microbiology.

Mushroom Emergence Detected by Combining Spore Trapping with Molecular Techniques

PubMed Central

Oliva, Jonàs; Martínez de Aragón, Juan; Alday, Josu G.; Parladé, Javier; Pera, Joan; Bonet, José Antonio

2017-01-01

ABSTRACT Obtaining reliable and representative mushroom production data requires time-consuming sampling schemes. In this paper, we assessed a simple methodology to detect mushroom emergence by trapping the fungal spores of the fruiting body community in plots where mushroom production was determined weekly. We compared the performance of filter paper traps with that of funnel traps and combined these spore trapping methods with species-specific quantitative real-time PCR and Illumina MiSeq to determine the spore abundance. Significantly more MiSeq proportional reads were generated for both ectomycorrhizal and saprotrophic fungal species using filter traps than were obtained using funnel traps. The spores of 37 fungal species that produced fruiting bodies in the study plots were identified. Spore community composition changed considerably over time due to the emergence of ephemeral fruiting bodies and rapid spore deposition (lasting from 1 to 2 weeks), which occurred in the absence of rainfall events. For many species, the emergence of epigeous fruiting bodies was followed by a peak in the relative abundance of their airborne spores. There were significant positive relationships between fruiting body yields and spore abundance in time for five of seven fungal species. There was no relationship between fruiting body yields and their spore abundance at plot level, indicating that some of the spores captured in each plot were arriving from the surrounding areas. Differences in fungal detection capacity by spore trapping may indicate different dispersal ability between fungal species. Further research can help to identify the spore rain patterns for most common fungal species. IMPORTANCE Mushroom monitoring represents a serious challenge in economic and logistical terms because sampling approaches demand extensive field work at both the spatial and temporal scales. In addition, the identification of fungal taxa depends on the expertise of experienced fungal taxonomists. Similarly, the study of fungal dispersal has been constrained by technological limitations, especially because the morphological identification of spores is a challenging and time-consuming task. Here, we demonstrate that spores from ectomycorrhizal and saprotrophic fungal species can be identified using simple spore traps together with either MiSeq fungus-specific amplicon sequencing or species-specific quantitative real-time PCR. In addition, the proposed methodology can be used to characterize the airborne fungal community and to detect mushroom emergence in forest ecosystems. PMID:28432095

An Open-source Low-cost Portable Apparatus for Soil Fauna Sampling

NASA Astrophysics Data System (ADS)

Daliakopoulos, Ioannis; Wagner, Karl; Grillakis, Manolis; Apostolakis, Antonios; Tsanis, Ioannis

2016-04-01

A low-cost apparatus for the extraction of living soil animals from soil or litter samples is presented. The main unit consists of a modular bank system with three horizontal shelves designed to accommodate lamps and soil samples over funnel and jar systems for animal collection, thus serving as a practical and standardized modification of the well-documented Berlese-Tullgren funnel. Shelves are vertically adjustable, sliding on 5 mm threaded rods and securing with wing nuts for easy assembly/disassembly and stability. Shelf material is 4 mm plywood (or similar), laser-cut (or similar) to accommodate lamp sockets, tubes and funnels at respective levels. Soil samples are inserted in 10 cm tubes from standard Ø50 mm PVC piping that can also function as direct collection corers for softer soils. Tubes are fitted in the tube bank shelf, each directly under a 25 W reflector lamp and over a funnel and jar system. Lamps are located 25 mm over the tubes' top creating a relatively constant 10 oC temperature gradient that drives soil animals away from heat and light, and towards the bottom end of the tube which is fitted with a suitable fabric mesh. Standard 106 ml panelled jars, filled with a safe-to-handle preservative (e.g. propylene glycol) to the lower end of the funnel fitted in them, trap and preserve soil organisms until identification. The apparatus offers flat-pack portability and scalability using low-cost standard material. Design specifications and Drawing eXchange Format (dxf) files for apparatus reproduction are provided.

Effect of verbenone on five species of bark beetles (Coleoptera: Scolytidae) in Lodgepole pine forests

Treesearch

B. Staffan Lindren; Daniel R. Miller

2002-01-01

The response by five species of bark beetles to a range of verbenone doses were tested in bioassays using Lindgren funnel traps baited with attractant semiochemicals. The objective was to determine how these bark beetles respond to verbenone, a purported anti-aggregation pheromone of several economically significant bark beetle species. Catches of Dendroctonus...

Height preference of Scolytus schevyrewi Semenov, the banded elm bark beetle of American elm, Ulmus americana

Treesearch

S. McElwey; J. F. Negron; J. Withrow

2007-01-01

Scolytus schevyrewi Semenov, the banded elm bark beetle, was first detected in North America in April 2003 in Colorado and Utah by the Rapid Detection and Response Pilot Project sponsored by APHIS and USDA Forest Service, Forest Health Protection. It was captured in Lindgren funnel traps baited with a-pinene, ethanol, and the Ips typographus...

Topography of funneled landscapes determines the thermodynamics and kinetics of protein folding

PubMed Central

Wang, Jin; Oliveira, Ronaldo J.; Chu, Xiakun; Whitford, Paul C.; Chahine, Jorge; Han, Wei; Wang, Erkang; Onuchic, José N.; Leite, Vitor B.P.

2012-01-01

The energy landscape approach has played a fundamental role in advancing our understanding of protein folding. Here, we quantify protein folding energy landscapes by exploring the underlying density of states. We identify three quantities essential for characterizing landscape topography: the stabilizing energy gap between the native and nonnative ensembles δE, the energetic roughness ΔE, and the scale of landscape measured by the entropy S. We show that the dimensionless ratio between the gap, roughness, and entropy of the system accurately predicts the thermodynamics, as well as the kinetics of folding. Large Λ implies that the energy gap (or landscape slope towards the native state) is dominant, leading to more funneled landscapes. We investigate the role of topological and energetic roughness for proteins of different sizes and for proteins of the same size, but with different structural topologies. The landscape topography ratio Λ is shown to be monotonically correlated with the thermodynamic stability against trapping, as characterized by the ratio of folding temperature versus trapping temperature. Furthermore, Λ also monotonically correlates with the folding kinetic rates. These results provide the quantitative bridge between the landscape topography and experimental folding measurements. PMID:23019359

Non-fluorescent nanoscopic monitoring of a single trapped nanoparticle via nonlinear point sources.

PubMed

Yoon, Seung Ju; Lee, Jungmin; Han, Sangyoon; Kim, Chang-Kyu; Ahn, Chi Won; Kim, Myung-Ki; Lee, Yong-Hee

2018-06-07

Detection of single nanoparticles or molecules has often relied on fluorescent schemes. However, fluorescence detection approaches limit the range of investigable nanoparticles or molecules. Here, we propose and demonstrate a non-fluorescent nanoscopic trapping and monitoring platform that can trap a single sub-5-nm particle and monitor it with a pair of floating nonlinear point sources. The resonant photon funnelling into an extremely small volume of ~5 × 5 × 7 nm 3 through the three-dimensionally tapered 5-nm-gap plasmonic nanoantenna enables the trapping of a 4-nm CdSe/ZnS quantum dot with low intensity of a 1560-nm continuous-wave laser, and the pumping of 1560-nm femtosecond laser pulses creates strong background-free second-harmonic point illumination sources at the two vertices of the nanoantenna. Under the stable trapping conditions, intermittent but intense nonlinear optical spikes are observed on top of the second-harmonic signal plateau, which is identified as the 3.0-Hz Kramers hopping of the quantum dot trapped in the 5-nm gap.

Optimization of multifunnel traps for emerald ash borer (Coleoptera: Buprestidae): influence of size, trap coating, and color.

PubMed

Francese, Joseph A; Rietz, Michael L; Mastro, Victor C

2013-12-01

Field assays were conducted in southeastern and south-central Michigan in 2011 and 2012 to optimize green and purple multifunnel (Lindgren funnel) traps for use as a survey tool for the emerald ash borer, Agrilus planipennis Fairmaire. Larger sized (12- and 16-unit) multifunnel traps caught more beetles than their smaller-sized (4- and 8-unit) counterparts. Green traps coated with untinted (white) fluon caught almost four times as many adult A. planipennis as Rain-X and tinted (green) fluon-coated traps and almost 33 times more beetles than untreated control traps. Purple multifunnel traps generally caught much lower numbers of A. planipennis adults than green traps, and trap catch on them was not affected by differences in the type of coating applied. However, trap coating was necessary as untreated control purple traps caught significantly less beetles than traps treated with Rain-X and untinted or tinted (purple) fluon. Proportions of male beetles captured were generally much higher on green traps than on purple traps, but sex ratios were not affected by trap coating. In 2012, a new shade of purple plastic, based on a better color match to an attractive purple paint than the previously used purple, was used for trapping assays. When multifunnel traps were treated with fluon, green traps caught more A. planipennis adults than both shades of purple and a prism trap that was manufactured based on the same color match. Trap catch was not affected by diluting the fluon concentration applied to traps to 50% (1:1 mixture in water). At 10%, trap catch was significantly lowered.

Response of reptile and amphibian communities to canopy gaps created by wind disturbance in the Southern Appalachians

Treesearch

Cathryn H. Greenberg

2001-01-01

Reptile and amphibian communities were sampled in intact gaps created by wind disturbance, salvage-logged gaps, and closed canopy mature forest (controls). Sampling was conducted during June–October in 1997 and 1998 using drift fences with pitfall and funnel traps. Basal area of live trees, shade, leaf litter coverage, and litter depth was highest in controls and...

Short-term response of reptiles and amphibians to prescribed fire and mechanical fuel reduction in a southern Appalachian upland hardwood forest

Treesearch

Cathryn H. Greenberg; Thomas A. Waldrop

2008-01-01

We compared the effects of three fuel reduction techniques and a control on the relative abundance and richness of reptiles and amphibians using drift fence arrays with pitfall and funnel traps. Three replicate blocks were established at the Green River Game Land, Polk County, North Carolina. Each replicate block contained four experimental units that were each...

A synthesized mating pheromone component increases adult sea lamprey (Petromyzon marinus) trap capture in management scenarios

USGS Publications Warehouse

Johnson, Nicholas S.; Siefkes, Michael J.; Wagner, C. Michael; Dawson, Heather; Wang, Huiyong; Steeves, Todd; Twohey, Michael; Li, Weiming

2013-01-01

Application of chemical cues to manipulate adult sea lamprey (Petromyzon marinus) behavior is among the options considered for new sea lamprey control techniques in the Laurentian Great Lakes. A male mating pheromone component, 7a,12a,24-trihydroxy-3-one-5a-cholan-24-sulfate (3kPZS), lures ovulated female sea lamprey upstream into baited traps in experimental contexts with no odorant competition. A critical knowledge gap is whether this single pheromone component influences adult sea lamprey behavior in management contexts containing free-ranging sea lampreys. A solution of 3kPZS to reach a final in-stream concentration of 10-12 mol·L-1 was applied to eight Michigan streams at existing sea lamprey traps over 3 years, and catch rates were compared between paired 3kPZS-baited and unbaited traps. 3kPZS-baited traps captured significantly more sexually immature and mature sea lampreys, and overall yearly trapping efficiency within a stream averaged 10% higher during years when 3kPZS was applied. Video analysis of a trap funnel showed that the likelihood of sea lamprey trap entry after trap encounter was higher when the trap was 3kPZS baited. Our approach serves as a model for the development of similar control tools for sea lamprey and other aquatic invaders.

A survey of reptiles and amphibians on Kinmen Island, Taiwan

Treesearch

Daniel Saenz; Heather V. Podlipny; Pei-Yu Tasi; D. Brent Burt; Hsiao-Wei Yuan

2009-01-01

Little is known about the reptiles and amphibians of Kinmen Island, Taiwan. Until recently, Kinmen had been off-limits to outsiders. It wasn’t until the mid 1990’s that civilian travel was allowed to and from the island. We surveyed 8 sites from 19 May through 18 July 2005, using 15 m drift fences with collapsible funnel traps on the ends. We documented encounters with...

Greatly Increasing Trapped Ion Populations for Mobility Separations Using Traveling Waves in Structures for Lossless Ion Manipulations

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

Deng, Liulin; Ibrahim, Yehia M.; Garimella, Sandilya V. B.

The initial use of traveling waves (TW) for ion mobility (IM) separations using a structures for lossless ion manipulations (SLIM) employed an ion funnel trap (IFT) to accumulate ions from a continuous electrospray ionization source, and limited to injected ion populations of ~106 charges due to the onset of space charge effects in the trapping region. Additional limitations arise due to the loss of resolution for the injection of ions over longer periods (e.g. in extended pulses). In this work a new SLIM ‘flat funnel’ (FF) module has been developed and demonstrated to enable the accumulation of much larger ionmore » populations and their injection for IM separations. Ion current measurements indicate a capacity of ~3.2×108 charges for the extended trapping volume, over an order of magnitude greater than the IFT. The orthogonal ion injection into a funnel shaped separation region can greatly reduce space charge effects during the initial IM separation stage, and the gradually reduced width of the path allows the ion packet to be increasingly compressed in the lateral dimension as the separation progresses, allowing e.g. efficient transmission through conductance limits or compatibility with subsequent ion manipulations. This work examined the TW, RF, and DC confining field SLIM parameters involved in ion accumulation, injection, transmission and separation in the FF IM module using both direct ion current and MS measurements. Wide m/z range ion transmission is demonstrated, along with significant increases in signal to noise (S/N) ratios due to the larger ion populations injected. Additionally, we observed a reduction in the chemical background, which was attributed to more efficient desolvation of solvent related clusters over the extended ion accumulation periods. The TW SLIM FF IM module is anticipated to be especially effective as a front end for long path SLIM IM separation modules.« less

Comparison of Data Acquisition Strategies on Quadrupole Ion Trap Instrumentation for Shotgun Proteomics

PubMed Central

Canterbury, Jesse D.; Merrihew, Gennifer E.; Goodlett, David R.; MacCoss, Michael J.; Shaffer, Scott A.

2015-01-01

A common strategy in mass spectrometry analyses of complex protein mixtures is to digest the proteins to peptides, separate the peptides by microcapillary liquid chromatography and collect tandem mass spectra (MS/MS) on the eluting, complex peptide mixtures, a process commonly termed “shotgun proteomics”. For years, the most common way of data collection was via data-dependent acquisition (DDA), a process driven by an automated instrument control routine that directs MS/MS acquisition from the highest abundant signals to the lowest, a process often leaving lower abundant signals unanalyzed and therefore unidentified in the experiment. Advances in both instrumentation duty cycle and sensitivity allow DDA to probe to lower peptide abundance and therefore enable mapping proteomes to a more significant depth. An alternative to acquiring data by DDA is by data-independent acquisition (DIA), in which a specified range in m/z is fragmented without regard to prioritization of a precursor ion or its relative abundance in the mass spectrum. As a consequence, DIA acquisition potentially offers more comprehensive analysis of peptides than DDA and in principle can yield tandem mass spectra of all ionized molecules following their conversion to the gas-phase. In this work, we evaluate both DDA and DIA on three different linear ion trap instruments: an LTQ, an LTQ modified in-house with an electrodynamic ion funnel, and an LTQ-Velos. These instruments were chosen as they are representative of both older (LTQ) and newer (LTQ-Velos) ion trap designs i.e., linear ion trap and dual ion traps, respectively, and allow direct comparison of peptide identification using both DDA and DIA analysis. Further, as the LTQ-Velos has an improved “S-lens” ion guide in the high-pressure region to improve ion flux, we found it logical to determine if the former LTQ model could be leveraged by improving sensitivity by modifying with an electrodynamic ion guide of significantly different design to the S-lens. We find that the ion funnel enabled LTQ identifies more proteins in the insoluble fraction of a yeast lysate than the other two instruments in DIA mode, while the faster scanning LTQ-Velos performs better in DDA mode. We explore reasons for these results, including differences in scan speed, source ion optics, and linear ion trap design. PMID:25261218

Resolving the problem of trapped water in binding cavities: prediction of host-guest binding free energies in the SAMPL5 challenge by funnel metadynamics

NASA Astrophysics Data System (ADS)

Bhakat, Soumendranath; Söderhjelm, Pär

2017-01-01

The funnel metadynamics method enables rigorous calculation of the potential of mean force along an arbitrary binding path and thereby evaluation of the absolute binding free energy. A problem of such physical paths is that the mechanism characterizing the binding process is not always obvious. In particular, it might involve reorganization of the solvent in the binding site, which is not easily captured with a few geometrically defined collective variables that can be used for biasing. In this paper, we propose and test a simple method to resolve this trapped-water problem by dividing the process into an artificial host-desolvation step and an actual binding step. We show that, under certain circumstances, the contribution from the desolvation step can be calculated without introducing further statistical errors. We apply the method to the problem of predicting host-guest binding free energies in the SAMPL5 blind challenge, using two octa-acid hosts and six guest molecules. For one of the hosts, well-converged results are obtained and the prediction of relative binding free energies is the best among all the SAMPL5 submissions. For the other host, which has a narrower binding pocket, the statistical uncertainties are slightly higher; longer simulations would therefore be needed to obtain conclusive results.

Cotton production in the presence of Helicoverpa armigera (Hb.) in Central Greece.

PubMed

Stavridis, D G; Gliatis, A; Deligeorgidis, P N; Giatropoulos, C; Giatropoulos, A; Deligeorgidis, N P; Ipsilandis, C G

2008-11-01

The present study was conducted in 10 different communities of prefecture of Larissa, one of the main cotton-productive areas of Greece. Monitoring of Helicoverpa armigera lasted four years from 2002 to 2005. The monitoring system included four locations within each community and three traps in each location. Traps were of the funnel type, a reusable injection-moulded kind of plastic trap. Pheromone was z-11-hexadecenyl aldehyde 0.36% w/w. Insecticide (Vapona) was used for all the four years, but for years 2003 and 2004 double traps were used additionally, without the presence of insecticide (only with pheromone). Traps containing a pheromone and an insecticide had significantly greater number of insects trapped than those containing no insecticide. Fluctuation of insect population was different from year to year. Correlations on data between years (insect populations and cotton production across all communities) revealed that, when cotton production was low, the number of adult male insects of H. armigera captured in pheromone traps was high (r = -0.69). There were no statistically significant correlations between cotton production and number of trapped insects when data from all communities (across the four years) were used. Local conditions within each area have been proved important and these results were completely different compared to data concerning specific years. Prediction models must be used for average estimations within great areas that include data from many locations.

Detecting small-study effects and funnel plot asymmetry in meta-analysis of survival data: A comparison of new and existing tests.

PubMed

Debray, Thomas P A; Moons, Karel G M; Riley, Richard D

2018-03-01

Small-study effects are a common threat in systematic reviews and may indicate publication bias. Their existence is often verified by visual inspection of the funnel plot. Formal tests to assess the presence of funnel plot asymmetry typically estimate the association between the reported effect size and their standard error, the total sample size, or the inverse of the total sample size. In this paper, we demonstrate that the application of these tests may be less appropriate in meta-analysis of survival data, where censoring influences statistical significance of the hazard ratio. We subsequently propose 2 new tests that are based on the total number of observed events and adopt a multiplicative variance component. We compare the performance of the various funnel plot asymmetry tests in an extensive simulation study where we varied the true hazard ratio (0.5 to 1), the number of published trials (N=10 to 100), the degree of censoring within trials (0% to 90%), and the mechanism leading to participant dropout (noninformative versus informative). Results demonstrate that previous well-known tests for detecting funnel plot asymmetry suffer from low power or excessive type-I error rates in meta-analysis of survival data, particularly when trials are affected by participant dropout. Because our novel test (adopting estimates of the asymptotic precision as study weights) yields reasonable power and maintains appropriate type-I error rates, we recommend its use to evaluate funnel plot asymmetry in meta-analysis of survival data. The use of funnel plot asymmetry tests should, however, be avoided when there are few trials available for any meta-analysis. © 2017 The Authors. Research Synthesis Methods Published by John Wiley & Sons, Ltd.

Pulsed Multiple Reaction Monitoring Approach to Enhancing Sensitivity of a Tandem Quadrupole Mass Spectrometer

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

Belov, Mikhail E.; Prasad, Satendra; Prior, David C.

2011-02-23

Liquid chromatography (LC)-triple quadrupole mass spectrometers operating in a Multiple Reaction Monitoring (MRM) mode are increasingly used for quantitative analysis of low abundance analytes in highly complex biochemical matrices. After development and selection of optimum MRM transition, sensitivity and data quality limitations are largely related to mass spectral peak interferences from sample or matrix constituents and statistical limitations at low number of ions reaching the detector. Herein, we report a new approach to enhancing MRM sensitivity by converting the continuous stream of ions from the ion source into a pulsed ion beam through the use of an Ion Funnel Trapmore » (IFT). Evaluation of the pulsed MRM approach was performed with a tryptic digest of Shewanella oneidensis strain MR-1 spiked with several reference peptides. The sensitivity improvement observed with the IFT coupled to the triple quadrupole instrument is based on several unique features. First, ion accumulation in the radio frequency (RF) ion trap facilitates improved droplet desolvation, which is manifested in the reduced background ion noise at the detector. Second, signal amplitude for a given transition is enhanced because of an order-of-magnitude increase in the ion charge density per unit time compared to a continuous mode of operation. Third, signal detection at the full duty cycle is obtained, as the trap use eliminates dead times between transitions, which are inevitable with continuous ion streams. In comparison with the conventional approach, the pulsed MRM signals showed up to 5-fold enhanced peak amplitude and 2-3 fold reduced chemical background, resulting in an improvement in the limit of detection (LOD) by a factor of ~ 4 to ~ 8.« less

The Laser Ablation Ion Funnel: Sampling for in situ Mass Spectrometry on Mars

NASA Technical Reports Server (NTRS)

Johnson, Paul V.; Hodyss, Robert; Tang, Keqi; Brinckerhoff, William B.; Smith, Richard D.

2011-01-01

A considerable investment has been made by NASA and other space agencies to develop instrumentation suitable for in situ analytical investigation of extra terrestrial bodies including various mass spectrometers (time-of-flight, quadrupole ion trap, quadrupole mass filters, etc.). However, the front-end sample handling that is needed to collect and prepare samples for interrogation by such instrumentation remains underdeveloped. Here we describe a novel approach tailored to the exploration of Mars where ions are created in the ambient atmosphere via laser ablation and then efficiently transported into a mass spectrometer for in situ analysis using an electrodynamic ion funnel. This concept would enable elemental and isotopic analysis of geological samples with the analysis of desorbed organic material a possibility as well. Such an instrument would be suitable for inclusion on all potential missions currently being considered such as the Mid-Range Rover, the Astrobiology Field Laboratory, and Mars Sample Return (i.e., as a sample pre-selection triage instrument), among others.

New insights into mechanistic photoisomerization of ethylene-bridged azobenzene from ab initio multiple spawning simulation.

PubMed

Liu, Lihong; Wang, Yating; Fang, Qiu

2017-02-14

Ethylene-bridged azobenzene (br-AB) has aroused broad interests due to its unique photoswitching properties. Numerous dynamical simulations have been performed for the br-AB photoisomerization, which focused mainly on the conformational effect and the funnel role of minimum-energy conical intersection (MECI) on the mechanism. In the present work, we use the "full quantum" ab initio multiple spawning method to simulate the br-AB photoisomerization, which provides new insights into the mechanism. Upon irradiation of br-AB to the first excited singlet state (S 1 ), most of the excess energies are trapped in the azo-moiety. Since the intramolecular vibrational energy redistribution is slower than the S 1 relaxation processes, the nonadiabatic transition from S 1 to the ground state (S 0 ) occurs in the vicinity of high-energy crossing seam and even the largest probabilities of the S 1 → S 0 transition are not distributed in the MECI regions. Once decaying to the S 0 state through the high-energy region, the subsequent isomerization and re-formation of the initial isomer are ultrafast processes in the S 0 state. It is the nonergodic behavior of the S 1 and S 0 dynamics that is mainly responsible for the unique photoswitching properties of the ethylene-bridged azobenzene, which will be discussed in detail.

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. 

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

Ulyshen, Michael D.; Hanula, James L.; Horn, Scott

Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and trap-shy species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce differentmore » results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.« less

Attraction of the larval predator Elater ferrugineus to the sex pheromone of its prey, Osmoderma eremita, and its implication for conservation biology.

PubMed

Svensson, Glenn P; Larsson, Mattias C; Hedin, Jonas

2004-02-01

Elater ferrugineus is a threatened click beetle inhabiting old hollow trees. Its larvae consume larvae of other saproxylic insects including the threatened scarab beetle Osmoderma eremita. Recently, (R)-(+)-gamma-decalactone was identified as a male-produced sex pheromone of O. eremita. Here we present evidence that E. ferrugineus adults use this odor as a kairomone for location of their prey. In field trapping experiments, significantly more trapping events of E. ferrugineus beetles were observed in Lindgren funnel traps baited with (R)-(+)-gamma-decalactone than in control traps (20 vs. 1, respectively). Analyses of headspace collections from E. ferrugineus beetles indicate that the predator itself does not produce the substance. Both sexes were attracted to the prey pheromone. suggesting that E. ferrugineus males use the odor as an indirect cue for location of mates or of the tree hollows, which make up their habitat. When compared to pitfall traps, the Lindgren system was significantly more effective in trapping E. ferragineus, and no difference could be established for O. eremita, showing the high potential to use odor-based systems to catch both species. We suggest that (R)-(+)-gamma-decalactone could be used as a master signal in monitoring programs for these vulnerable beetle species. which are both regarded as indicators of the associated insect fauna of the threatened habitat of old hollow trees.

The folding energy landscape and free energy excitations of cytochrome c.

PubMed

Weinkam, Patrick; Zimmermann, Jörg; Romesberg, Floyd E; Wolynes, Peter G

2010-05-18

The covalently bound heme cofactor plays a dominant role in the folding of cytochrome c. Because of the complicated inorganic chemistry of the heme, some might consider the folding of cytochrome c to be a special case, following principles different from those used to describe the folding of proteins without cofactors. Recent investigations, however, demonstrate that common models describing folding for many proteins work well for cytochrome c when heme is explicitly introduced, generally providing results that agree with experimental observations. In this Account, we first discuss results from simple native structure-based models. These models include attractive interactions between nonadjacent residues only if they are present in the crystal structure at pH 7. Because attractive nonnative contacts are not included in native structure-based models, their energy landscapes can be described as "perfectly funneled". In other words, native structure-based models are energetically guided towards the native state and contain no energetic traps that would hinder folding. Energetic traps are denoted sources of "frustration", which cause specific transient intermediates to be populated. Native structure-based models do, however, include repulsion between residues due to excluded volume. Nonenergetic traps can therefore exist if the chain, which cannot cross over itself, must partially unfold so that folding can proceed. The ability of native structure-based models to capture this kind of motion is partly responsible for their successful predictions of folding pathways for many types of proteins. Models without frustration describe the sequence of folding events for cytochrome c well (as inferred from hydrogen-exchange experiments), thereby justifying their use as a starting point. At low pH, the experimentally observed folding sequence of cytochrome c deviates from that at pH 7 and from models with perfectly funneled energy landscapes. Here, alternate folding pathways are a result of "chemical frustration". This frustration arises because some regions of the protein are destabilized more than others due to the heterogeneous distribution of titratable residues that are protonated at low pH. Beginning with native structure-based terms, we construct more complex models by adding chemical frustration. These more complex models only modestly perturb the energy landscape, which remains, overall, well funneled. These perturbed models can accurately describe how alternative folding pathways are used at low pH. At alkaline pH, cytochrome c populates distinctly different structural ensembles. For instance, lysine residues are deprotonated and compete for the heme ligation site. The same models that can describe folding at low pH also predict well the structures and relative stabilities of intermediates populated at alkaline pH. The success of models based on funneled energy landscapes suggest that cytochrome c folding is driven primarily by native contacts. The presence of heme appears to add chemical complexity to the folding process, but it does not require fundamental modification of the general principles used to describe folding. Moreover, its added complexity provides a valuable means of probing the folding energy landscape in greater detail than is possible with simpler systems.

Lead Selenide Colloidal Quantum Dot Solar Cells Achieving High Open-Circuit Voltage with One-Step Deposition Strategy.

PubMed

Zhang, Yaohong; Wu, Guohua; Ding, Chao; Liu, Feng; Yao, Yingfang; Zhou, Yong; Wu, Congping; Nakazawa, Naoki; Huang, Qingxun; Toyoda, Taro; Wang, Ruixiang; Hayase, Shuzi; Zou, Zhigang; Shen, Qing

2018-06-18

Lead selenide (PbSe) colloidal quantum dots (CQDs) are considered to be a strong candidate for high-efficiency colloidal quantum dot solar cells (CQDSCs) due to its efficient multiple exciton generation. However, currently, even the best PbSe CQDSCs can only display open-circuit voltage ( V oc ) about 0.530 V. Here, we introduce a solution-phase ligand exchange method to prepare PbI 2 -capped PbSe (PbSe-PbI 2 ) CQD inks, and for the first time, the absorber layer of PbSe CQDSCs was deposited in one step by using this PbSe-PbI 2 CQD inks. One-step-deposited PbSe CQDs absorber layer exhibits fast charge transfer rate, reduced energy funneling, and low trap assisted recombination. The champion large-area (active area is 0.35 cm 2 ) PbSe CQDSCs fabricated with one-step PbSe CQDs achieve a power conversion efficiency (PCE) of 6.0% and a V oc of 0.616 V, which is the highest V oc among PbSe CQDSCs reported to date.

An Adaptable Multiple Power Source for Mass Spectrometry and other Scientific Instruments

DOE PAGES

Lin, Tzu-Yung; Anderson, Gordon A.; Norheim, Randolph V.; ...

2015-09-18

Power supplies are commonly used in the operation of many types of scientific equipment, including mass spectrometers and ancillary instrumentation. A generic modern mass spectrometer comprises an ionization source, such as electrospray ionization (ESI), ion transfer devices such as ion funnels and multipole ion guides, and ion signal detection apparatus. Very often such platforms include, or are interfaced with ancillary elements in order to manipulate samples before or after ionization. In order to operate such scientific instruments, numerous direct current (DC) channels and radio frequency (RF) signals are required, along with other controls such as temperature regulation. In particular, DCmore » voltages in the range of ±400 V, along with MHz range RF signals with peak-to-peak amplitudes in the hundreds of volts range are commonly used to transfer ionized samples under vacuum. Additionally, an ESI source requires a high voltage (HV) DC source capable of producing several thousand volts and heaters capable of generating temperatures up to 300°C. All of these signals must be properly synchronized and managed in order to carry out ion trapping, accumulation and detection.« less

Implementation of Biotic Integrity Metrics to Identify the Effects of Land Use on the Diversity of Wetlands

NASA Astrophysics Data System (ADS)

Mills, L. D.; Hamilton, S. W.; Schiller, J. R.

2005-05-01

To identify critical biological measures of wetland health, we studied twelve wetlands in north-central Tennessee and south-central Kentucky, six impacted by row crop agriculture and six unimpacted. Aquatic macroinvertebrate were collected using 10.2 cm clear PVC pipe funnel traps and wire minnow traps. Seven samples were collected from each site between May 19 and August 8, 2004. Qualitative samples (one person-hour) were collected with dip nets from each wetland to correspond with the early July trap samples. Water quality parameters measured included dissolved oxygen, pH, temperature, specific conductance, and turbidity with multiparameter aquatic probe and nephlometer. Macroinvertebrates from three sets of samples for each site were identified, when possible, to genus. The number of organism collected per trap-period per site ranged from 43 to 2224. Fifty-six taxa were identified. Generally, natural areas showed greater species richness, diversity and evenness than agricultural sites. Dipterans, primarily chironomids, were the most dominant assemblages. The three most abundant predatory orders, Coleoptera, Odonata and Hemiptera, showed alternating patterns of dominance. Habitat stability and greater vegetative complexity, which are impacted by surrounding agricultural practices, appear to be strongly related to higher species diversity.

General mechanism of two-state protein folding kinetics.

PubMed

Rollins, Geoffrey C; Dill, Ken A

2014-08-13

We describe here a general model of the kinetic mechanism of protein folding. In the Foldon Funnel Model, proteins fold in units of secondary structures, which form sequentially along the folding pathway, stabilized by tertiary interactions. The model predicts that the free energy landscape has a volcano shape, rather than a simple funnel, that folding is two-state (single-exponential) when secondary structures are intrinsically unstable, and that each structure along the folding path is a transition state for the previous structure. It shows how sequential pathways are consistent with multiple stochastic routes on funnel landscapes, and it gives good agreement with the 9 order of magnitude dependence of folding rates on protein size for a set of 93 proteins, at the same time it is consistent with the near independence of folding equilibrium constant on size. This model gives estimates of folding rates of proteomes, leading to a median folding time in Escherichia coli of about 5 s.

Aquatic Plant Control Research Program. Large-Scale Operations Management Test of Use of the White Amur for Control of Problem Aquatic Plants. The Herpetofauna of Lake Conway: Species Accounts.

DTIC Science & Technology

1983-07-01

complex suite of physiological and 39 respiratory adaptations (Ultch 1976) enable this species to occupy both open water and littoral zone environments...be an adaptation to avoid fish predation on juveniles in open water and may explain the spring peak in funnel trap captures near shore (Fig. 10). 79...population of C. picta probably is not established on Lake Conway. The one collected individual 103 defecated gastropod (Viviparous sp.) shells and

New Coleoptera records from New Brunswick, Canada: Buprestidae

PubMed Central

Webster, Reginald P.; DeMerchant, Ian

2012-01-01

Abstract Nine species of Buprestidae; Agrilus bilineatus (Weber), Agrilus crinicornis Horn, Agrilus obsoletoguttatus Gory, Agrilus putillus putillus Say, Brachys ovatus (Weber), Buprestis sulcicollis (LeConte), Chalcophora liberta (Germar), Phaenops aeneola (Melsheimer), and Taphrocerus gracilis (Say) are newly recorded for New Brunswick, Canada. Agrilus bilineatus, A. crinicornis, A. obsoletoguttatus,and B. ovatus are also newly reported for the Maritime provinces. Lindgren 12-funnel traps do not appear to be an effective tool for sampling the Bupresidae. Collection, habitat notes, and distribution maps are presented for each species. PMID:22539885

Using malaise traps to sample ground beetles (Coleoptera: Carabidae).

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

Ulyshen, Michael D., James L. Hanula, and Scott Horn

2005-01-01

Pitfall traps provide an easy and inexpensive way to sample ground-dwelling arthropods (Spence and Niemela 1994; Spence et al. 1997; Abildsnes and Tommeras 2000) and have been used exclusively in many studies of the abundance and diversity of ground beetles (Coleoptera: Carabidae). Despite the popularity of this trapping technique, pitfall traps have many disadvantages. For example, they often fail to collect both small (Spence and Niemela 1994) and trap-shy species (Benest 1989), eventually deplete the local carabid population (Digweed et al. 1995), require a species to be ground-dwelling in order to be captured (Liebherr and Mahar 1979), and produce differentmore » results depending on trap diameter and material, type of preservative used, and trap placement (Greenslade 1964; Luff 1975; Work et al. 2002). Further complications arise from seasonal patterns of movement among the beetles themselves (Maelfait and Desender 1990), as well as numerous climatic factors, differences in plant cover, and variable surface conditions (Adis 1979). Because of these limitations, pitfall trap data give an incomplete picture of the carabid community and should be interpreted carefully. Additional methods, such as use of Berlese funnels and litter washing (Spence and Niemela 1994), collection from lights (Usis and MacLean 1998), and deployment of flight intercept devices (Liebherr and Mahar 1979; Paarmann and Stork 1987), should be incorporated in surveys to better ascertain the species composition and relative numbers of ground beetles. Flight intercept devices, like pitfall traps, have the advantage of being easy to use and replicate, but their value to carabid surveys is largely unknown. Here we demonstrate the effectiveness of Malaise traps for sampling ground beetles in a bottomland hardwood forest.« less

Coh-Metrix Measures Text Characteristics at Multiple Levels of Language and Discourse

ERIC Educational Resources Information Center

Graesser, Arthur C.; McNamara, Danielle S.; Cai, Zhiqiang; Conley, Mark; Li, Haiying; Pennebaker, James

2014-01-01

Coh-Metrix analyzes texts on multiple measures of language and discourse that are aligned with multilevel theoretical frameworks of comprehension. Dozens of measures funnel into five major factors that systematically vary as a function of types of texts (e.g., narrative vs. informational) and grade level: narrativity, syntactic simplicity, word…

Light funneling from a photonic crystal laser cavity to a nano-antenna: overcoming the diffraction limit in optical energy transfer down to the nanoscale.

PubMed

Mivelle, Mathieu; Viktorovitch, Pierre; Baida, Fadi I; El Eter, Ali; Xie, Zhihua; Vo, Than-Phong; Atie, Elie; Burr, Geoffrey W; Nedeljkovic, Dusan; Rauch, Jean-Yves; Callard, Ségolène; Grosjean, Thierry

2014-06-16

We show that the near-field coupling between a photonic crystal microlaser and a nano-antenna can enable hybrid photonic systems that are both physically compact (free from bulky optics) and efficient at transferring optical energy into the nano-antenna. Up to 19% of the laser power from a micron-scale photonic crystal laser cavity is experimentally transferred to a bowtie aperture nano-antenna (BNA) whose area is 400-fold smaller than the overall emission area of the microlaser. Instead of a direct deposition of the nano-antenna onto the photonic crystal, it is fabricated at the apex of a fiber tip to be accurately placed in the microlaser near-field. Such light funneling within a hybrid structure provides a path for overcoming the diffraction limit in optical energy transfer to the nanoscale and should thus open promising avenues in the nanoscale enhancement and confinement of light in compact architectures, impacting applications such as biosensing, optical trapping, local heating, spectroscopy, and nanoimaging.

A comparison of trapping techniques (Coleoptera: Carabidae, Buprestidae, Cerambycidae, and Curculionoidea excluding Scolytinae)

PubMed Central

Skvarla, Michael J.; Dowling, Ashley P. G.

2017-01-01

Beetles (Coleoptera) are a charismatic group of insects targeted by collectors and often used in biodiversity surveys. As part of a larger project, we surveyed a small (4 hectare) plot in the Boston Mountains of Arkansas using 70 traps of 12 trap types and Berlese–Tullgren extraction of leaf litter and identified all Buprestidae, Carabidae, Cerambycidae, and Curculionoidea (Anthribidae, Attelabidae, Brachyceridae, Brentidae, and Curculionidae excluding Scolytinae) to species. This resulted in the collection of 7,973 specimens representing 242 species arranged in 8 families. In a previous publication, we reported new state records and the number of specimens collected per species. In this publication, we used these data to determine the most effective collection method for four beetle groups: Carabidae, Cerambycidae, Curculionoidea (excluding Scolytinae), and Buprestidae. We found that the combination of pitfall and Malaise traps was most effective for Carabidae, Cerambycidae, and Curculionoidea, but that the combination of Malaise and green Lindgren funnel traps was most effective at collecting Buprestidae. Species accumulation curves did not become asymptotic and extrapolated rarefaction curves did not become asymptotic until 350–1,000 samples, suggesting that much more effort is required to completely inventory even a small site. Additionally, seasonal activity is presented for each species and the similarity and overlap between collecting dates and seasons is discussed for each family. PMID:28042105

Identifying sources of heterogeneity in capture probabilities: An example using the Great Tit Parus major

USGS Publications Warehouse

Senar, J.C.; Conroy, M.J.; Carrascal, L.M.; Domenech, J.; Mozetich, I.; Uribe, F.

1999-01-01

Heterogeneous capture probabilities are a common problem in many capture-recapture studies. Several methods of detecting the presence of such heterogeneity are currently available, and stratification of data has been suggested as the standard method to avoid its effects. However, few studies have tried to identify sources of heterogeneity, or whether there are interactions among sources. The aim of this paper is to suggest an analytical procedure to identify sources of capture heterogeneity. We use data on the sex and age of Great Tits captured in baited funnel traps, at two localities differing in average temperature. We additionally use 'recapture' data obtained by videotaping at feeder (with no associated trap), where the tits ringed with different colours were recorded. This allowed us to test whether individuals in different classes (age, sex and condition) are not trapped because of trap shyness or because o a reduced use of the bait. We used logistic regression analysis of the capture probabilities to test for the effects of age, sex, condition, location and 'recapture method. The results showed a higher recapture probability in the colder locality. Yearling birds (either males or females) had the highest recapture prob abilities, followed by adult males, while adult females had the lowest recapture probabilities. There was no effect of the method of 'recapture' (trap or video tape), which suggests that adult females are less often captured in traps no because of trap-shyness but because of less dependence on supplementary food. The potential use of this methodological approach in other studies is discussed.

The pros and cons of funnel plots as an aid to risk communication and patient decision making.

PubMed

Rakow, Tim; Wright, Rebecca J; Spiegelhalter, David J; Bull, Catherine

2015-05-01

Funnel plots, which simultaneously display a sample statistic and the corresponding sample size for multiple cases, have a range of applications. In medicine, they are used to display treatment outcome rates and caseload volume by institution, which can inform strategic decisions about health care delivery. We investigated lay people's understanding of such plots and explored their suitability as an aid to individual treatment decisions. In two studies, 172 participants answered objective questions about funnel plots representing the surgical outcomes (survival or mortality rates) of institutions varying in caseload, and indicated their preferred institutions. Accuracy for extracting objective information was high, unless question phrasing was inconsistent with the plot's survival/mortality framing, or participants had low numeracy levels. Participants integrated caseload-volume and outcome-rate data when forming preferences, but were influenced by reference lines on the plot to make inappropriate discriminations between institutions with similar outcome rates. With careful choice of accompanying language, funnel plots can be readily understood and are therefore a useful tool for communicating risk. However, they are less effective as a decision aid for individual patient's treatment decisions, and we recommend refinements to the standard presentation of the plots if they are to be used for that purpose. © 2014 The British Psychological Society.

Graphical augmentations to the funnel plot assess the impact of additional evidence on a meta-analysis.

PubMed

Langan, Dean; Higgins, Julian P T; Gregory, Walter; Sutton, Alexander J

2012-05-01

We aim to illustrate the potential impact of a new study on a meta-analysis, which gives an indication of the robustness of the meta-analysis. A number of augmentations are proposed to one of the most widely used of graphical displays, the funnel plot. Namely, 1) statistical significance contours, which define regions of the funnel plot in which a new study would have to be located to change the statistical significance of the meta-analysis; and 2) heterogeneity contours, which show how a new study would affect the extent of heterogeneity in a given meta-analysis. Several other features are also described, and the use of multiple features simultaneously is considered. The statistical significance contours suggest that one additional study, no matter how large, may have a very limited impact on the statistical significance of a meta-analysis. The heterogeneity contours illustrate that one outlying study can increase the level of heterogeneity dramatically. The additional features of the funnel plot have applications including 1) informing sample size calculations for the design of future studies eligible for inclusion in the meta-analysis; and 2) informing the updating prioritization of a portfolio of meta-analyses such as those prepared by the Cochrane Collaboration. Copyright © 2012 Elsevier Inc. All rights reserved.

The Folding Energy Landscape and Free Energy Excitations of Cytochrome c

PubMed Central

Weinkam, Patrick; Zimmermann, Jörg; Romesberg, Floyd E.

2014-01-01

The covalently bound heme cofactor plays a dominant role in the folding of cytochrome c. Due to the complicated inorganic chemistry of the heme, some might consider the folding of cytochrome c to be a special case that follows different principles than those used to describe folding of proteins without cofactors. Recent investigations, however, demonstrate that models which are commonly used to describe folding for many proteins work well for cytochrome c when heme is explicitly introduced and generally provide results that agree with experimental observations. We will first discuss results from simple native structure-based models. These models include attractive interactions between nonadjacent residues only if they are present in the crystal structure at pH 7. Since attractive nonnative contacts are not included in native structure-based models, their energy landscapes can be described as “perfectly funneled.” In other words, native structure-based models are energetically guided towards the native state and contain no energetic traps that would hinder folding. Energetic traps are sources of frustration which cause specific transient intermediates to be populated. Native structure-based models do include repulsion between residues due to excluded volume. Nonenergetic traps can therefore exist if the chain, which cannot cross over itself, must partially unfold in order for folding to proceed. The ability of native structure-based models to capture these type of motions is in part responsible for their successful predictions of folding pathways for many types of proteins. Models without frustration describe well the sequence of folding events for cytochrome c inferred from hydrogen exchange experiments thereby justifying their use as a starting point. At low pH, the folding sequence of cytochrome c deviates from that at pH 7 and from those predicted from models with perfectly funneled energy landscapes. Alternate folding pathways are a result of “chemical frustration.” This frustration arises because some regions of the protein are destabilized more than others due to the heterogeneous distribution of titratable residues that are protonated at low pH. We construct more complex models that include chemical frustration, in addition to the native structure-based terms. These more complex models only modestly perturb the energy landscape which remains overall well funneled. These perturbed models can accurately describe how alternative folding pathways are used at low pH. At alkaline pH, cytochrome c populates distinctly different structural ensembles. For instance, lysine residues are deprotonated and compete for the heme ligation site. The same models that can describe folding at low pH also predict well the structures and relative stabilities of intermediates populated at alkaline pH. PMID:20143816

General Mechanism of Two-State Protein Folding Kinetics

PubMed Central

Rollins, Geoffrey C.; Dill, Ken A.

2016-01-01

We describe here a general model of the kinetic mechanism of protein folding. In the Foldon Funnel Model, proteins fold in units of secondary structures, which form sequentially along the folding pathway, stabilized by tertiary interactions. The model predicts that the free energy landscape has a volcano shape, rather than a simple funnel, that folding is two-state (single-exponential) when secondary structures are intrinsically unstable, and that each structure along the folding path is a transition state for the previous structure. It shows how sequential pathways are consistent with multiple stochastic routes on funnel landscapes, and it gives good agreement with the 9 order of magnitude dependence of folding rates on protein size for a set of 93 proteins, at the same time it is consistent with the near independence of folding equilibrium constant on size. This model gives estimates of folding rates of proteomes, leading to a median folding time in Escherichia coli of about 5 s. PMID:25056406

Piezoelectric T-matrix approach and multiple scattering of electroacoustic waves in thin plates

NASA Astrophysics Data System (ADS)

Darabi, Amir; Ruzzene, Massimo; Leamy, Michael J.

2017-12-01

Metamaterial-enhanced harvesting (MEH) of wave energy in thin plates and other structures has appeared recently for powering small sensors and devices. To support continued MEH concept development, this paper proposes a fully coupled T-matrix formulation for analyzing scattering of incident wave energy from a piezoelectric patch attached to a thin plate. More generally, the T-matrix represents an input-output relationship between incident and reflected waves from inclusions in a host layer, and is introduced herein for a piezoelectric patch connected to an external circuit. The utility of a T-matrix formalism is most apparent in scenarios employing multiple piezoelectric harvesters, where it can be re-used with other T-matrices (such as those previously formulated for rigid, void, and elastic inclusions) in a multiple scattering context to compute the total wavefield and other response quantities, such as harvested power. Following development of the requisite T-matrix, harvesting in an example funnel-shaped metamaterial waveguide structure is predicted using the multiple scattering approach. Enhanced wave energy harvesting predictions are verified through comparisons to experimental results of a funnel-shaped waveguide formed by placing rigid aluminum inclusions in, and multiple piezoelectric harvesters on, a Lexan plate. Good agreement with predicted response quantities is noted.

Self-Field-Dominated Plasma

DTIC Science & Technology

1998-03-31

plasma focus discharges. Part of the tests summarized here address methods and means for achieving controlled variations of the current sheath (CS) structure via electrode geometry modifications. CS parameters are monitored with multiple magnetic probes in the case of cylindrical - and open-funnel electrode

Export fluxes in a naturally iron-fertilized area of the Southern Ocean - Part 1: Seasonal dynamics of particulate organic carbon export from a moored sediment trap

NASA Astrophysics Data System (ADS)

Rembauville, M.; Salter, I.; Leblond, N.; Gueneugues, A.; Blain, S.

2015-06-01

A sediment trap moored in the naturally iron-fertilized Kerguelen Plateau in the Southern Ocean provided an annual record of particulate organic carbon and nitrogen fluxes at 289 m. At the trap deployment depth, current speeds were typically low (~ 10 cm s-1) and primarily tidal-driven (M2 tidal component). Although advection was weak, the sediment trap may have been subject to hydrodynamical and biological (swimmer feeding on trap funnel) biases. Particulate organic carbon (POC) flux was generally low (< 0.5 mmol m-2 d-1), although two episodic export events (< 14 days) of 1.5 mmol m-2 d-1 were recorded. These increases in flux occurred with a 1-month time lag from peaks in surface chlorophyll and together accounted for approximately 40% of the annual flux budget. The annual POC flux of 98.2 ± 4.4 mmol m-2 yr-1 was low considering the shallow deployment depth but comparable to independent estimates made at similar depths (~ 300 m) over the plateau, and to deep-ocean (> 2 km) fluxes measured from similarly productive iron-fertilized blooms. Although undertrapping cannot be excluded in shallow moored sediment trap deployment, we hypothesize that grazing pressure, including mesozooplankton and mesopelagic fishes, may be responsible for the low POC flux beneath the base of the winter mixed layer. The importance of plankton community structure in controlling the temporal variability of export fluxes is addressed in a companion paper.

Analytical interferences of mercuric chloride preservative in environmental water samples: Determination of organic compounds isolated by continuous liquid-liquid extraction or closed-loop stripping

USGS Publications Warehouse

Foreman, W.T.; Zaugg, S.D.; Falres, L.M.; Werner, M.G.; Leiker, T.J.; Rogerson, P.F.

1992-01-01

Analytical interferences were observed during the determination of organic compounds in groundwater samples preserved with mercuric chloride. The nature of the interference was different depending on the analytical isolation technique employed. (1) Water samples extracted with dichloromethane by continuous liquid-liquid extraction (CLLE) and analyzed by gas chromatography/mass spectrometry revealed a broad HgCl2 'peak' eluting over a 3-5-min span which interfered with the determination of coeluting organic analytes. Substitution of CLLE for separatory funnel extraction in EPA method 508 also resulted in analytical interferences from the use of HgCl2 preservative. (2) Mercuric chloride was purged, along with organic contaminants, during closed-loop stripping (CLS) of groundwater samples and absorbed onto the activated charcoal trap. Competitive sorption of the HgCl2 by the trap appeared to contribute to the observed poor recoveries for spiked organic contaminants. The HgCl2 was not displaced from the charcoal with the dichloromethane elution solvent and required strong nitric acid to achieve rapid, complete displacement. Similar competitive sorption mechanisms might also occur in other purge and trap methods when this preservative is used.

Wind tunnel behavioural response and field trapping of the blowfly Calliphora vicina.

PubMed

Aak, A; Knudsen, G K; Soleng, A

2010-09-01

The attraction of the blowfly Calliphora vicina Robineau-Desvoidy, 1830 (Diptera: Calliphoridae) to single synthetic compounds, blends and authentic odours was investigated in a wind tunnel. A total of 1850 C. vicina (1750 females and 100 males) were tested. A comparison of male and female responses showed significant differences in attraction between the sexes. Females were more attracted than males to liver odour. The attraction of females lay in the ranges of 0-22% for single compounds, 26-64% for synthetic blends and 58-88% for authentic odours. Dimethyl trisulphide was the most attractive single compound. Significant improvement in attraction was achieved with blends and a three-component lure, consisting of dimethyl trisulphide, mercaptoethanol and o-cresol, was found to be the best solution for field trapping of C. vicina. Authentic odours from dead fish and mice were significantly more attractive than liver and the three-component blend, and the blend and liver were similarly effective as attractants. Field tests support the results of the wind tunnel study and a high number of C. vicina were caught in funnel traps. Overall, 99.1% of the specimens caught were females.

Funnel plots, performance variation and the Myocardial Infarction National Audit Project 2003-2004.

PubMed

Gale, Christopher P; Roberts, Anthony P; Batin, Phil D; Hall, Alistair S

2006-08-02

Clinical governance requires health care professionals to improve standards of care and has resulted in comparison of clinical performance data. The Myocardial Infarction National Audit Project (a UK cardiology dataset) tabulates its performance. However funnel plots are the display method of choice for institutional comparison. We aimed to demonstrate that funnel plots may be derived from MINAP data and allow more meaningful interpretation of data. We examined the attainment of National Service Framework standards for all hospitals (n = 230) and all patients (n = 99,133) in the MINAP database between 1st April 2003 and 31st March 2004. We generated funnel plots (with control limits at 3 sigma) of Door to Needle and Call to Needle thrombolysis times, and the use of aspirin, beta-blockers and statins post myocardial infarction. Only 87,427 patients fulfilled criteria for analysis of the use of secondary prevention drugs and 15,111 patients for analysis by Door to Needle and Call to Needle times (163 hospitals achieved the standards for Door to Needle times and 215 were within or above their control limits). One hundred and sixteen hospitals fell outside the 'within 25%' and 'more than 25%' standards for Call to Needle times, but 28 were below the lower control limits. Sixteen hospitals failed to reach the standards for aspirin usage post AMI and 24 remained below the lower control limits. Thirty hospitals were below the lower CL for beta-blocker usage and 49 outside the standard. Statin use was comparable. Funnel plots may be applied to a complex dataset and allow visual comparison of data derived from multiple health-care units. Variation is readily identified permitting units to appraise their practices so that effective quality improvement may take place.

Optimal management strategies for biodiversity within a powerline right-of-way

USGS Publications Warehouse

Perry, M.C.; Osenton, P.C.; Fallon, F.W.; Fallon, J.E.; Williams, James R.= (Randy); Goodrich-Mahoney, John W.; Wisniewski, Jan R.; Wisniewski, Joe

1997-01-01

Management techniques used to control vegetation along a new 8.5 km- (5.3 mile) long powerline right-of-way located at Patuxent Research Refuge are being evaluated to identify changes in habitat that affect wildlife. Techniques include: complete mow, strip mow, low volume foliar spray, selective basal spray, and tree topping. One hundred and one bird species were recorded during line transect sampling along the right-of-way. The eastern towhee had the highest frequency of occurrence followed by the field sparrow and the common yellowthroat. The field sparrow had the highest numbers per visit followed by the eastern towhee and eastern bluebird. Fifteen species were recorded in numbers greater than ten individuals per visit in at least one season of the year. Nine species of mammals were trapped in live traps during the study and four other mammal species were observed but not captured. Twelve species of amphibians and six species of reptiles were trapped in pitfall or funnel traps. Differences in the distribution of species seemed to be related to the physical and hydrological features of the right-of-way. Although no major differences in the distribution of wildlife species resulted from the vegetation management, differences are expected in the future as vegetation differences become more pronounced. Data from this study will be of value to resource managers attempting to provide optimal habitat for biodiversity.

Remediation of PCB contaminated soils in the Canadian Arctic: excavation and surface PRB technology.

PubMed

Kalinovich, Indra; Rutter, Allison; Poland, John S; Cairns, Graham; Rowe, R Kerry

2008-12-15

The site BAF-5 is located on the summit of Resolution Island, Nunavut, just southeast of Baffin Island at 61 degrees 35'N and 60 degrees 40'W. The site was part of a North American military defense system established in the 1950s that became heavily contaminated with PCBs during and subsequent, its operational years. Remediation through excavation of the PCB contaminated soil at Resolution Island began in 1999 and at its completion in 2006 approximately 5 tonnes of pure PCBs in approximately 20,000 m3 of soil were remediated. Remediation strategies were based on both quantity of soil and level of contamination in the soil. Excavation removed 96% of the PCB contaminated soil on site. In 2003, a surface funnel-and-gate permeable reactive barrier was design and constructed to treat the remaining contamination left in rock crevices and inaccessible areas of the site. Excavation had destabilized contaminated soil in the area, enabling contaminant migration through erosion and runoff pathways. The barrier was designed to maximize sedimentation through settling ponds. This bulk removal enabled the treatment of highly contaminated fines and water through a permeable gate. The increased sediment loading during excavation required both modifications to the funnel and a shift to a more permeable, granular system. Granulated activated charcoal was chosen for its ability to both act as a particle retention filter and adsorptive filter. The reduction in mass of PCB and volume of soils trapped by the funnel of the barrier indicate that soils are re-stabilizing. In 2007, nonwoven geotextiles were re-introduced back into the filtration system as fine filtering could be achieved without clogging. Monitoring sites downstream indicate that the barrier system is effective. This paper describes the field progress of PCB remediation at Resolution Island.

Funnel-web spider bite

MedlinePlus

... page: //medlineplus.gov/ency/article/002844.htm Funnel-web spider bite To use the sharing features on ... the effects of a bite from the funnel-web spider. Male funnel-web spiders are more poisonous ...

Reliability investigation of high-k/metal gate in nMOSFETs by three-dimensional kinetic Monte-Carlo simulation with multiple trap interactions

NASA Astrophysics Data System (ADS)

Li, Yun; Jiang, Hai; Lun, Zhiyuan; Wang, Yijiao; Huang, Peng; Hao, Hao; Du, Gang; Zhang, Xing; Liu, Xiaoyan

2016-04-01

Degradation behaviors in the high-k/metal gate stacks of nMOSFETs are investigated by three-dimensional (3D) kinetic Monte-Carlo (KMC) simulation with multiple trap coupling. Novel microscopic mechanisms are simultaneously considered in a compound system: (1) trapping/detrapping from/to substrate/gate; (2) trapping/detrapping to other traps; (3) trap generation and recombination. Interacting traps can contribute to random telegraph noise (RTN), bias temperature instability (BTI), and trap-assisted tunneling (TAT). Simulation results show that trap interaction induces higher probability and greater complexity in trapping/detrapping processes and greatly affects the characteristics of RTN and BTI. Different types of trap distribution cause largely different behaviors of RTN, BTI, and TAT. TAT currents caused by multiple trap coupling are sensitive to the gate voltage. Moreover, trap generation and recombination have great effects on the degradation of HfO2-based nMOSFETs under a large stress.

Free Energy Landscape - Settlements of Key Residues.

NASA Astrophysics Data System (ADS)

Aroutiounian, Svetlana

2007-03-01

FEL perspective in studies of protein folding transitions reflects notion that since there are ˜10^N conformations to scan in search of lowest free energy state, random search is beyond biological timescale. Protein folding must follow certain fel pathways and folding kinetics of evolutionary selected proteins dominates kinetic traps. Good model for functional robustness of natural proteins - coarse-grained model protein is not very accurate but affords bringing simulations closer to biological realm; Go-like potential secures the fel funnel shape; biochemical contacts signify the funnel bottleneck. Boltzmann-weighted ensemble of protein conformations and histogram method are used to obtain from MC sampling of protein conformational space the approximate probability distribution. The fel is F(rmsd) = -1/βLn[Hist(rmsd)], β=kBT and rmsd is root-mean-square-deviation from native conformation. The sperm whale myoglobin has rich dynamic behavior, is small and large - on computational scale, has a symmetry in architecture and unusual sextet of residue pairs. Main idea: there is a mathematical relation between protein fel and a key residues set providing stability to folding transition. Is the set evolutionary conserved also for functional reasons? Hypothesis: primary sequence determines the key residues positions conserved as stabilizers and the fel is the battlefield for the folding stability. Preliminary results: primary sequence - not the architecture, is the rule settler, indeed.

Sub-micron particle sampler apparatus and method for sampling sub-micron particles

DOEpatents

Gay, D.D.; McMillan, W.G.

1984-04-12

Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however, the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis. 6 figures.

Sub-micron particle sampler apparatus

DOEpatents

Gay, Don D.; McMillan, William G.

1987-01-01

Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar.RTM. and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis.

Method for sampling sub-micron particles

DOEpatents

Gay, Don D.; McMillan, William G.

1985-01-01

Apparatus and method steps for collecting sub-micron sized particles include a collection chamber and cryogenic cooling. The cooling is accomplished by coil tubing carrying nitrogen in liquid form, with the liquid nitrogen changing to the gas phase before exiting from the collection chamber in the tubing. Standard filters are used to filter out particles of diameter greater than or equal to 0.3 microns; however the present invention is used to trap particles of less than 0.3 micron in diameter. A blower draws air to said collection chamber through a filter which filters particles with diameters greater than or equal to 0.3 micron. The air is then cryogenically cooled so that moisture and sub-micron sized particles in the air condense into ice on the coil. The coil is then heated so that the ice melts, and the liquid is then drawn off and passed through a Buchner funnel where the liquid is passed through a Nuclepore membrane. A vacuum draws the liquid through the Nuclepore membrane, with the Nuclepore membrane trapping sub-micron sized particles therein. The Nuclepore membrane is then covered on its top and bottom surfaces with sheets of Mylar.RTM. and the assembly is then crushed into a pellet. This effectively traps the sub-micron sized particles for later analysis.

An artificial light-harvesting array constructed from multiple Bodipy dyes.

PubMed

Ziessel, Raymond; Ulrich, Gilles; Haefele, Alexandre; Harriman, Anthony

2013-07-31

An artificial light-harvesting array, comprising 21 discrete chromophores arranged in a rational manner, has been synthesized and characterized fully. The design strategy follows a convergent approach that leads to a molecular-scale funnel, having an effective chromophore concentration of 0.6 M condensed into ca. 55 nm(3), able to direct the excitation energy to a focal point. A cascade of electronic energy-transfer steps occurs from the rim to the focal point, with the rate slowing down as the exciton moves toward its ultimate target. Situated midway along each branch of the V-shaped array, two chromophoric relays differ only slightly in terms of their excitation energies, and this situation facilitates reverse energy transfer. Thus, the excitation energy becomes spread around the array, a situation reminiscent of a giant holding pattern for the photon that can sample many different chromophores before being trapped by the terminal acceptor. At high photon flux under conditions of relatively slow off-load to a device, such as a solar cell, electronic energy transfer encounters one or more barriers that hinder forward progress of the exciton and thereby delays arrival of the second photon. Preliminary studies have addressed the ability of the array to function as a sensitizer for amorphous silicon solar cells.

Note: Toward multiple addressable optical trapping

PubMed Central

Faustov, Alexei R.; Webb, Michael R.; Walt, David R.

2010-01-01

We describe a setup for addressable optical trapping in which a laser source is focused on a digital micromirror device and generates an optical trap in a microfluidic cell. In this paper, we report a proof-of-principle single beam∕single micromirror∕single three-dimensional trap arrangement that should serve as the basis for a multiple-trap instrument. PMID:20192526

DNA fingerprint similarity between female and juvenile brown-headed cowbirds trapped together

USGS Publications Warehouse

Hahn, D.C.; Fleischer, R.C.

1995-01-01

This DNA fingerprinting study investigates whether females of the brood parasite brown-headed cowbird, Molothrus ater, associate with their own juvenile offspring at feeding sites more often than would be expected by chance. Cowbirds lay their eggs in the nests of a variety of host species and, as far as is known, leave them to the care of foster parents. Using baited walk-in funnel traps, 36 adult female-juvenile pairs (or trios) of cowbirds were trapped. Blood samples were collected from these individuals to conduct DNA fingerprinting analyses, calculate similarity indices, and to compare S-values for the 11 comparisons of juveniles and the females with which they were caught with S-values of random pairings of juveniles and the females in adjacent gel lanes with which they were not caught. Overall band-sharing was significantly higher for the individuals trapped together than for the random pairings. These associations between juvenile cowbirds and their mothers could occur as a result of female cowbirds monitoring the development of their young in the nests where they have laid. Alternatively, nestling cowbirds in the nest could become familiar visually and locally with a female parent that is frequently in their territory and could follow her when she departs for feeding grounds. In either case these data suggest that adult cowbirds associate with juveniles, in some cases their own offspring, and that offspring may learn to function as cowbirds in part from this association.

High-Performance Ion Mobility Spectrometry Using Hourglass Electrodynamic Funnel And Internal Ion Funnel

DOEpatents

Smith, Richard D.; Tang, Keqi; Shvartsburg, Alexandre A.

2004-11-16

A method and apparatus enabling increased sensitivity in ion mobility spectrometry/mass spectrometry instruments which substantially reduces or eliminates the loss of ions in ion mobility spectrometer drift tubes utilizing an hourglass electrodynamic ion funnel at the entrance to the drift tube and/or an internal ion funnel at the exit of the drift tube. An hourglass electrodynamic funnel is formed of at least an entry element, a center element, and an exit element, wherein the aperture of the center element is smaller than the aperture of the entry element and the aperture of the exit elements. Ions generated in a relatively high pressure region by an ion source at the exterior of the hourglass electrodynamic funnel are transmitted to a relatively low pressure region at the entrance of the hourglass funnel through a conductance limiting orifice. Alternating and direct electrical potentials are applied to the elements of the hourglass electrodynamic funnel thereby drawing ions into and through the hourglass electrodynamic funnel thereby introducing relatively large quantities of ions into the drift tube while maintaining the gas pressure and composition at the interior of the drift tube as distinct from those at the entrance of the electrodynamic funnel and allowing a positive gas pressure to be maintained within the drift tube, if desired. An internal ion funnel is provided within the drift tube and is positioned at the exit of said drift tube. The advantage of the internal ion funnel is that ions that are dispersed away from the exit aperture within the drift tube, such as those that are typically lost in conventional drift tubes to any subsequent analysis or measurement, are instead directed through the exit of the drift tube, vastly increasing the amount of ions exiting the drift tube.

4-allylanisole as an inhibitor of bark beetle (Coleoptera: Scolytidae) aggregation

Treesearch

Jane L. Hayes; Brian L. Strom

1994-01-01

To assess the extent of inhibitory activity of the host compound 4-allylanisole, we conducted field studies with three scolytid species.These species are geographically widespread and economically important.Trials were completed with Dendroctonus brevicomis LeConte (California), D. ponderosae Hopkins (Oregon), and Ips pini (Say) (Wisconsin) by using multiple-funnel...

How Bacterial Population Soliton Waves Can Defeat a Funnel Ring

NASA Astrophysics Data System (ADS)

Austin, Robert; Morris, Ryan; Phan, Average; Black, Matthew; Lin, Ke-Chih; Bos, Julia

We have constructed using microfabrication a circular corral for bacteria made of rings of concentric funnels which channel motile bacteria outwards via non-hydrodynamic interactions with the funnel walls. Although initially bacteria do move rapidly outwards with the funnels, they are able with increasing cell density on the perimeter to defeat the physical constraints of the funnel by launching collective, soliton like waves of bacteria inwards against the funnel ring. We present the basic data and some non-linear modeling which can explain the basic way that bacterial population solitons propagate across a funnel landscape. There are three surprising aspects to the experiments: (1) The bifurcation of the population into motile bacteria which are pumped by the funnels and bacteria which are non-motile (i.e., not pumped); (2) The launching of a collective wave which rapidly circles the device and radiates inwards against the pumping action of the funnel; (3) the subsequent loss of motility by all the bacteria after this burst of very high motility. Engineering and Physical Sciences Research Council [EP/J007404/1], National Cancer Institute (Grant No U54CA143803), and NSF PoLS program NSF PHY1521553.

Opportunities and challenges in biological lignin valorization

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

Beckham, Gregg T.; Johnson, Christopher W.; Karp, Eric M.

Lignin is a primary component of lignocellulosic biomass that is an underutilized feedstock in the growing biofuels industry. Despite the fact that lignin depolymerization has long been studied, the intrinsic heterogeneity of lignin typically leads to heterogeneous streams of aromatic compounds, which in turn present significant technical challenges when attempting to produce lignin-derived chemicals where purity is often a concern. In Nature, microorganisms often encounter this same problem during biomass turnover wherein powerful oxidative enzymes produce heterogeneous slates of aromatics compounds. Some microbes have evolved metabolic pathways to convert these aromatic species via ‘upper pathways’ into central intermediates, which canmore » then be funneled through ‘lower pathways’ into central carbon metabolism in a process we dubbed ‘biological funneling’. This funneling approach offers a direct, biological solution to overcome heterogeneity problems in lignin valorization for the modern biorefinery. Coupled to targeted separations and downstream chemical catalysis, this concept offers the ability to produce a wide range of molecules from lignin. This perspective describes research opportunities and challenges ahead for this new field of research, which holds significant promise towards a biorefinery concept wherein polysaccharides and lignin are treated as equally valuable feedstocks. In particular, we discuss tailoring the lignin substrate for microbial utilization, host selection for biological funneling, ligninolytic enzyme–microbe synergy, metabolic engineering, expanding substrate specificity for biological funneling, and process integration, each of which presents key challenges. Ultimately, for biological solutions to lignin valorization to be viable, multiple questions in each of these areas will need to be addressed, making biological lignin valorization a multidisciplinary, co-design problem.« less

High Performance Ion Mobility Spectrometry Using Hourglass Electrodynamic Funnel And Internal Ion Funnel

DOEpatents

Smith, Richard D.; Tang, Keqi; Shvartsburg, Alexandre A.

2005-11-22

A method and apparatus enabling increased sensitivity in ion mobility spectrometry/mass spectrometry instruments which substantially reduces or eliminates the loss of ions in ion mobility spectrometer drift tubes utilizing a device for transmitting ions from an ion source which allows the transmission of ions without significant delay to an hourglass electrodynamic ion funnel at the entrance to the drift tube and/or an internal ion funnel at the exit of the drift tube. An hourglass electrodynamic funnel is formed of at least an entry element, a center element, and an exit element, wherein the aperture of the center element is smaller than the aperture of the entry element and the aperture of the exit elements. Ions generated in a relatively high pressure region by an ion source at the exterior of the hourglass electrodynamic funnel are transmitted to a relatively low pressure region at the entrance of the hourglass funnel through a conductance limiting orifice. Alternating and direct electrical potentials are applied to the elements of the hourglass electrodynamic funnel thereby drawing ions into and through the hourglass electrodynamic funnel thereby introducing relatively large quantities of ions into the drift tube while maintaining the gas pressure and composition at the interior of the drift tube as distinct from those at the entrance of the electrodynamic funnel and allowing a positive gas pressure to be maintained within the drift tube, if desired. An internal ion funnel is provided within the drift tube and is positioned at the exit of said drift tube. The advantage of the internal ion funnel is that ions that are dispersed away from the exit aperture within the drift tube, such as those that are typically lost in conventional drift tubes to any subsequent analysis or measurement, are instead directed through the exit of the drift tube, vastly increasing the amount of ions exiting the drift tube.

Modeling of reference operating scenario of GOL-NB multiple-mirror trap

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

Postupaev, V. V., E-mail: V.V.Postupaev@inp.nsk.su; Yurov, D. V.

Currently, the GOL-NB multiple-mirror trap is being developed at the Budker Institute of Nuclear Physics, Siberian Branch, Russian Academy of Sciences. The main scientific goal pursued by building GOL-NB is direct demonstration of suppression of longitudinal losses of particles and energy from the trap by using sections with a multiple-mirror magnetic field, which can be attached to the central gas-dynamic trap. Plasma heating in GOL-NB will be accomplished by neutral beam injection with a power of up to 1.5MW. The paper presents the first results of modeling the dynamics of the plasma parameters and fast ions under the reference operatingmore » scenario of the trap in which traditional short magnetic mirrors, rather than multiple-mirror sections, are attached to the central trap. In such a configuration, the plasma lifetime in the trap is expected to be minimal. The modeling was performed by using the DOL kinetic code. As a result, the initial conditions of the experiments are refined and the requirements to the system of maintaining the particle balance in the trap are determined.« less

Optimising the application of multiple-capture traps for invasive species management using spatial simulation.

PubMed

Warburton, Bruce; Gormley, Andrew M

2015-01-01

Internationally, invasive vertebrate species pose a significant threat to biodiversity, agricultural production and human health. To manage these species a wide range of tools, including traps, are used. In New Zealand, brushtail possums (Trichosurus vulpecula), stoats (Mustela ermine), and ship rats (Rattus rattus) are invasive and there is an ongoing demand for cost-effective non-toxic methods for controlling these pests. Recently, traps with multiple-capture capability have been developed which, because they do not require regular operator-checking, are purported to be more cost-effective than traditional single-capture traps. However, when pest populations are being maintained at low densities (as is typical of orchestrated pest management programmes) it remains uncertain if it is more cost-effective to use fewer multiple-capture traps or more single-capture traps. To address this uncertainty, we used an individual-based spatially explicit modelling approach to determine the likely maximum animal-captures per trap, given stated pest densities and defined times traps are left between checks. In the simulation, single- or multiple-capture traps were spaced according to best practice pest-control guidelines. For possums with maintenance densities set at the lowest level (i.e. 0.5/ha), 98% of all simulated possums were captured with only a single capacity trap set at each site. When possum density was increased to moderate levels of 3/ha, having a capacity of three captures per trap caught 97% of all simulated possums. Results were similar for stoats, although only two potential captures per site were sufficient to capture 99% of simulated stoats. For rats, which were simulated at their typically higher densities, even a six-capture capacity per trap site only resulted in 80% kill. Depending on target species, prevailing density and extent of immigration, the most cost-effective strategy for pest control in New Zealand might be to deploy several single-capture traps rather than investing in fewer, but more expense, multiple-capture traps.

Quadrupole ion traps and trap arrays: geometry, material, scale, performance.

PubMed

Ouyang, Z; Gao, L; Fico, M; Chappell, W J; Noll, R J; Cooks, R G

2007-01-01

Quadrupole ion traps are reviewed, emphasizing recent developments, especially the investigation of new geometries, guided by multiple particle simulations such as the ITSIM program. These geometries include linear ion traps (LITs) and the simplified rectilinear ion trap (RIT). Various methods of fabrication are described, including the use of rapid prototyping apparatus (RPA), in which 3D objects are generated through point-by-point laser polymerization. Fabrication in silicon using multilayer semi-conductor fabrication techniques has been used to construct arrays of micro-traps. The performance of instruments containing individual traps as well as arrays of traps of various sizes and geometries is reviewed. Two types of array are differentiated. In the first type, trap arrays constitute fully multiplexed mass spectrometers in which multiple samples are examined using multiple sources, analyzers and detectors, to achieve high throughput analysis. In the second, an array of individual traps acts collectively as a composite trap to increase trapping capacity and performance for a single sample. Much progress has been made in building miniaturized mass spectrometers; a specific example is a 10 kg hand-held tandem mass spectrometer based on the RIT mass analyzer. The performance of this instrument in air and water analysis, using membrane sampling, is described.

Funnel for fuel pin loading system

DOEpatents

Christiansen, D.W.; Steffen, J.M.; Brown, W.F.

1984-01-01

An enlarged funnel is described which is releasably mounted at the open end of a length of cladding by an encircling length of shrink tubing which securely engages outer surfaces of both the funnel and cladding. The shrink tubing overlaps an annular shoulder against which pulling force can be exerted to remove the tubing from the cladding. The shoulder can be provided on a separate collar or ring, or on the funnel itself.

Funnel for fuel pin loading system

DOEpatents

Christiansen, David W.; Steffen, Jim M.; Brown, William F.

1985-01-01

An enlarged funnel is releasably mounted at the open end of a length of cladding by an encircling length of shrink tubing which securely engages outer surfaces of both the funnel and cladding. The shrink tubing overlaps an annular shoulder against which pulling force can be exerted to remove the tubing from the cladding. The shoulder can be provided on a separate collar or ring, or on the funnel itself.

AC Electroosmotic Pumping in Nanofluidic Funnels.

PubMed

Kneller, Andrew R; Haywood, Daniel G; Jacobson, Stephen C

2016-06-21

We report efficient pumping of fluids through nanofluidic funnels when a symmetric AC waveform is applied. The asymmetric geometry of the nanofluidic funnel induces not only ion current rectification but also electroosmotic flow rectification. In the base-to-tip direction, the funnel exhibits a lower ion conductance and a higher electroosmotic flow velocity, whereas, in the tip-to-base direction, the funnel has a higher ion conductance and a lower electroosmotic flow velocity. Consequently, symmetric AC waveforms easily pump fluid through the nanofunnels over a range of frequencies, e.g., 5 Hz to 5 kHz. In our experiments, the nanofunnels were milled into glass substrates with a focused ion beam (FIB) instrument, and the funnel design had a constant 5° taper with aspect ratios (funnel tip width to funnel depth) of 0.1 to 1.0. We tracked ion current rectification by current-voltage (I-V) response and electroosmotic flow rectification by transport of a zwitterionic fluorescent probe. Rectification of ion current and electroosmotic flow increased with increasing electric field applied to the nanofunnel. Our results support three-dimensional simulations of ion transport and electroosmotic transport through nanofunnels, which suggest the asymmetric electroosmotic transport stems from an induced pressure at the junction of the nanochannel and nanofunnel tip.

Preparation of lead oxide nanoparticles from cathode-ray tube funnel glass by self-propagating method.

PubMed

Wang, Yu; Zhu, Jianxin

2012-05-15

This paper presents a novel process of extracting lead oxide nanoparticles from cathode-ray tube (CRT) funnel glass using self-propagating high-temperature synthesis (SHS) method. The impacts of added amount of funnel glass on the extraction ratio of lead, the lead extraction velocity and the micromorphology, as well as particle size of extracted nanoparticles were investigated. We found that self-propagating reaction in the presence of Mg and Fe(2)O(3) could separate lead preferentially and superfine lead oxide nanoparticles were obtained from a collecting chamber. The separation ratio was related closely to the amount of funnel glass added in the original mixture. At funnel glass addition of no more than 40wt.%, over 90wt.% of lead was recovered from funnel glass. High extraction yield reveals that the network structure of funnel glass was fractured due to the dramatic energy generated during the SHS melting process. The PbO nanoparticles collected show good dispersion and morphology with a mean grain size of 40-50nm. Copyright © 2012 Elsevier B.V. All rights reserved.

Cross-reactivity of Sydney funnel-web spider antivenom: neutralization of the in vitro toxicity of other Australian funnel-web (Atrax and Hadronyche) spider venoms.

PubMed

Graudins, A; Wilson, D; Alewood, P F; Broady, K W; Nicholson, G M

2002-03-01

Australian funnel-web spiders are recognized as one of the most venomous spiders to humans world-wide. Funnel-web spider antivenom (FWS AV) reverses clinical effects of envenomation from the bite of Atrax robustus and a small number of related Hadronyche species. This study assessed the in vitro efficacy of FWS AV in neutralization of the effects of funnel-web spider venoms, collected from various locations along the eastern seaboard of Australia, in an isolated chick biventer cervicis nerve-muscle preparation. Venoms were separated by SDS-PAGE electrophoresis to compare protein composition and transblotted for Western blotting and incubation with FWS AV.SDS-PAGE of venoms revealed similar low and high molecular weight protein bands. Western blotting with FWS AV showed similar antivenom binding with protein bands in all the venoms tested. Male funnel-web spider venoms (7/7) and female venoms (5/10) produced muscle contracture and fasciculation when applied to the nerve-muscle preparation. Venom effects were reversed by subsequent application of FWS AV or prevented by pretreatment of the preparation with antivenom.FWS AV appears to reverse the in vitro toxicity of a number of funnel-web spider venoms from the eastern seaboard of Australia. FWS AV should be effective in the treatment of envenomation from most, if not all, species of Australian funnel-web spiders.

Laser Ablation Electrodynamic Ion Funnel for In Situ Mass Spectrometry on Mars

NASA Technical Reports Server (NTRS)

Johnson, Paul V.; Hodyss, Robert P.; Tang, Keqi; Smith, Richard D.

2012-01-01

A front-end instrument, the laser ablation ion funnel, was developed, which would ionize rock and soil samples in the ambient Martian atmosphere, and efficiently transport the product ions into a mass spectrometer for in situ analysis. Laser ablation creates elemental ions from a solid with a high-power pulse within ambient Mars atmospheric conditions. Ions are captured and focused with an ion funnel into a mass spectrometer for analysis. The electrodynamic ion funnel consists of a series of axially concentric ring-shaped electrodes whose inside diameters (IDs) decrease over the length of the funnel. DC potentials are applied to each electrode, producing a smooth potential slope along the axial direction. Two radio-frequency (RF) AC potentials, equal in amplitude and 180 out of phase, are applied alternately to the ring electrodes. This creates an effective potential barrier along the inner surface of the electrode stack. Ions entering the funnel drift axially under the influence of the DC potential while being restricted radially by the effective potential barrier created by the applied RF. The net result is to effectively focus the ions as they traverse the length of the funnel.

Light funnel concentrator panel for solar power

NASA Technical Reports Server (NTRS)

1987-01-01

The solar concentrator design concept provides a theoretical concentration efficiency of 96 percent with power-to-weight ratios as high as 50 W/kg. Further, it eliminates the need for fragile reflective coatings and is very tolerant to pointing inaccuracies. The concept differs from conventional reflective mirrors and lens design in that is uses the principle of total internal reflection in order to funnel incident sunlight into a concentrator photovoltaic cell. The feasibility of the light funnel concentrator concept was determined through a balanced approach of analysis, development, and fabrication of prototypes, and testing of components. A three-dimensional optical model of the light funnel concentrator and photovoltaic cell was developed in order to assess the ultimate performance of such systems. In addition, a thermal and structural analysis of a typical unit was made. Techniques of fabricating the light funnel cones, optically coupling them to GaAs concentrator cells, bonding the funnels to GaAs cells, making electrical interconnects, and bonding substrates was explored and a prototype light funnel concentrator unit was fabricated and tested. Testing of the system included measurements of optical concentrating efficiency, optical concentrator to cell coupling efficiency, and electrical efficiency.

Note: An inexpensive square waveform ion funnel driver

NASA Astrophysics Data System (ADS)

Hoffman, Nathan M.; Opačić, Bojana; Reilly, Peter T. A.

2017-01-01

An inexpensive frequency variable square waveform generator (WFG) was developed to use with existing sinusoidal waveform driven ion funnels. The developed WFG was constructed using readily available low voltage DC power supplies and discrete components placed in printed circuit boards. As applied to ion funnels, this WFG represents considerable cost savings over commercially available products without sacrificing performance. Operation of the constructed pulse generator has been demonstrated for a 1 nF ion funnel at an operating frequency of 1 MHz while switching 48 Vp-p.

Note: An inexpensive square waveform ion funnel driver.

PubMed

Hoffman, Nathan M; Opačić, Bojana; Reilly, Peter T A

2017-01-01

An inexpensive frequency variable square waveform generator (WFG) was developed to use with existing sinusoidal waveform driven ion funnels. The developed WFG was constructed using readily available low voltage DC power supplies and discrete components placed in printed circuit boards. As applied to ion funnels, this WFG represents considerable cost savings over commercially available products without sacrificing performance. Operation of the constructed pulse generator has been demonstrated for a 1 nF ion funnel at an operating frequency of 1 MHz while switching 48 V p-p .

Lead recovery from scrap cathode ray tube funnel glass by hydrothermal sulphidisation.

PubMed

Yuan, Wenyi; Meng, Wen; Li, Jinhui; Zhang, Chenglong; Song, Qingbin; Bai, Jianfeng; Wang, Jingwei; Li, Yingshun

2015-10-01

This research focused on the application of the hydrothermal sulphidisation method to separate lead from scrap cathode ray tube funnel glass. Prior to hydrothermal treatment, the cathode ray tube funnel glass was pretreated by mechanical activation. Under hydrothermal conditions, hydroxyl ions (OH(-)) were generated through an ion exchange reaction between metal ions in mechanically activated funnel glass and water, to accelerate sulphur disproportionation; no additional alkaline compound was needed. Lead contained in funnel glass was converted to lead sulphide with high efficiency. Temperature had a significant effect on the sulphidisation rate of lead in funnel glass, which increased from 25% to 90% as the temperature increased from 100 °C to 300 °C. A sulphidisation rate of 100% was achieved at a duration of 8 h at 300 °C. This process of mechanical activation and hydrothermal sulphidisation is efficient and promising for the treatment of leaded glass. © The Author(s) 2015.

The GOL-NB program: further steps in multiple-mirror confinement research

NASA Astrophysics Data System (ADS)

Postupaev, V. V.; Batkin, V. I.; Beklemishev, A. D.; Burdakov, A. V.; Burmasov, V. S.; Chernoshtanov, I. S.; Gorbovsky, A. I.; Ivanov, I. A.; Kuklin, K. N.; Mekler, K. I.; Rovenskikh, A. F.; Sidorov, E. N.; Yurov, D. V.

2017-03-01

Physical and technical details of the GOL-NB project are presented. GOL-NB is a medium-scale multiple-mirror trap that is under development in the Budker Institute, Novosibirsk, Russia. This device will be created in several years as a deep conversion of the existing GOL-3 facility. It will consist of a central trap with two 0.75 MW neutral beams, two multiple-mirror solenoids, two expander tanks and a plasma gun that creates the start plasma. The central trap with the neutral beam injection-heated plasma is a compact gas-dynamic system. The multiple-mirror sections should decrease the power and particle losses along the magnetic field. The confinement improvement factor depends on plasma parameters and on the magnetic configuration in the multiple mirrors. The main physical task of GOL-NB is direct demonstration of the performance of multiple-mirror sections that will change equilibrium plasma parameters in the central trap. In this paper we discuss results of the scenario modeling and progress in the hardware.

Spectrally reconfigurable integrated multi-spot particle trap.

PubMed

Leake, Kaelyn D; Olson, Michael A B; Ozcelik, Damla; Hawkins, Aaron R; Schmidt, Holger

2015-12-01

Optical manipulation of small particles in the form of trapping, pushing, or sorting has developed into a vast field with applications in the life sciences, biophysics, and atomic physics. Recently, there has been increasing effort toward integration of particle manipulation techniques with integrated photonic structures on self-contained optofluidic chips. Here, we use the wavelength dependence of multi-spot pattern formation in multimode interference (MMI) waveguides to create a new type of reconfigurable, integrated optical particle trap. Interfering lateral MMI modes create multiple trapping spots in an intersecting fluidic channel. The number of trapping spots can be dynamically controlled by altering the trapping wavelength. This novel, spectral reconfigurability is utilized to deterministically move single and multiple particles between different trapping locations along the channel. This fully integrated multi-particle trap can form the basis of high throughput biophotonic assays on a chip.

Pseudo-Random Sequence Modifications for Ion Mobility Orthogonal Time of Flight Mass Spectrometry

PubMed Central

Clowers, Brian H.; Belov, Mikhail E.; Prior, David C.; Danielson, William F.; Ibrahim, Yehia; Smith, Richard D.

2008-01-01

Due to the inherently low duty cycle of ion mobility spectrometry (IMS) experiments that sample from continuous ion sources, a range of experimental advances have been developed to maximize ion utilization efficiency. The use of ion trapping mechanisms prior to the ion mobility drift tube has demonstrated significant gains over discrete sampling from continuous sources; however, these technologies have traditionally relied upon a signal averaging to attain analytically relevant signal-to-noise ratios (SNR). Multiplexed (MP) techniques based upon the Hadamard transform offer an alternative experimental approach by which ion utilization efficiency can be elevated to ∼ 50 %. Recently, our research group demonstrated a unique multiplexed ion mobility time-of-flight (MP-IMS-TOF) approach that incorporates ion trapping and can extend ion utilization efficiency beyond 50 %. However, the spectral reconstruction of the multiplexed signal using this experiment approach requires the use of sample-specific weighing designs. Though general weighing designs have been shown to significantly enhance ion utilization efficiency using this MP technique, such weighing designs cannot be applied to all samples. By modifying both the ion funnel trap and the pseudo random sequence (PRS) used for the MP experiment we have eliminated the need for complex weighing matrices. For both simple and complex mixtures SNR enhancements of up to 13 were routinely observed as compared to the SA-IMS-TOF experiment. In addition, this new class of PRS provides a two fold enhancement in ion throughput compared to the traditional HT-IMS experiment. PMID:18311942

Acoustically enriching, large-depth aquatic sampler.

PubMed

Jonsson, Jonas; Ogden, Sam; Johansson, Linda; Hjort, Klas; Thornell, Greger

2012-05-07

In marine biology, it is useful to collect water samples when exploring the distribution and diversity of microbial communities in underwater environments. In order to provide, e.g., a miniaturized submersible explorer with the capability of collecting microorganisms, a compact sample enrichment system has been developed. The sampler is 30 mm long, 15 mm wide, and just a few millimetres thick. Integrated in a multilayer steel, polyimide and glass construction is a microfluidic channel with piezoelectric transducers, where microorganism and particle samples are collected and enriched, using acoustic radiation forces for gentle and labelless trapping. High-pressure, latchable valves, using paraffin as the actuation material, at each end of the microfluidic channel keep the collected sample pristine. A funnel structure raised above the surface of the device directs water into the microfluidic channel as the vehicle propels itself or when there is a flow across its hull. The valves proved leak proof to a pressure of 2.1 MPa for 19 hours and momentary pressures of 12.5 MPa, corresponding to an ocean depth of more than 1200 metres. By reactivating the latching mechanism, small leakages through the valves could be remedied, which could thus increase the leak-less operational time. Fluorescent particles, 1.9 μm in diameter, were successfully trapped in the microfluidic channel at flow rates up to 15 μl min(-1), corresponding to an 18.5 cm s(-1) external flow rate of the sampler. In addition, liquid-suspended GFP-marked yeast cells were successfully trapped.

Optical Couplers

DTIC Science & Technology

1975-12-01

FUNNEL DIAMETER 250 DIA FUNNEL DIAMETER, Df SHOWN IN LIST 375 FUNNEL DIAMETER Df . 043 ,060 .173 .044 .062 .175 .045 .063 .176 .046...Physical Dimensions Nom . Size (mil) Fiber Count V (mi 1) d (mil) [ (nr ) 1) 1 (m- Df 1) 46 285 41 .58 2.463 45 79 46 .71 ^/2x46 570 58

The Enrollment Funnel

ERIC Educational Resources Information Center

Perna, Mark C.

2005-01-01

A smart marketing plan creates emotional attachment and loyalty in a school's prospective students, but how does a school go about creating this type of positive environment?. In this brief paper, the author describes a step-by-step approach that he created--the enrollment funnel. The enrollment funnel is a systematic method of moving…

Improving the Sensitivity of Mass Spectrometer using a High-Pressure Electrodynamic Ion Funnel Interface

PubMed Central

Ibrahim, Yehia; Tang, Keqi; Tolmachev, Aleksey V.; Shvartsburg, Alexandre A.

2006-01-01

We report on a new electrodynamic ion funnel that operates at a pressure of 30 Torr with no loss of ion transmission. The enhanced performance compared to previous ion funnel designs optimized for pressures of <5 Torr was achieved by reducing the ion funnel capacitance and increasing the RF drive frequency (1.7 MHz) and amplitude (100-170 V peak-to-peak). No degradation of ion transmission was observed for pressures from 2 - 30 Torr. The ability to operate at higher pressure enabled a new tandem ion funnel mass spectrometer (MS) interface design that can accommodate a greater gas load. When combined with a multicapillary inlet, the interface provided more efficient introduction of ions, resulting in a significant enhancement in MS sensitivity and detection limits. PMID:16839773

The effect of multimodal and enriched feedback on SMR-BCI performance.

PubMed

Sollfrank, T; Ramsay, A; Perdikis, S; Williamson, J; Murray-Smith, R; Leeb, R; Millán, J D R; Kübler, A

2016-01-01

This study investigated the effect of multimodal (visual and auditory) continuous feedback with information about the uncertainty of the input signal on motor imagery based BCI performance. A liquid floating through a visualization of a funnel (funnel feedback) provided enriched visual or enriched multimodal feedback. In a between subject design 30 healthy SMR-BCI naive participants were provided with either conventional bar feedback (CB), or visual funnel feedback (UF), or multimodal (visual and auditory) funnel feedback (MF). Subjects were required to imagine left and right hand movement and were trained to control the SMR based BCI for five sessions on separate days. Feedback accuracy varied largely between participants. The MF feedback lead to a significantly better performance in session 1 as compared to the CB feedback and could significantly enhance motivation and minimize frustration in BCI use across the five training sessions. The present study demonstrates that the BCI funnel feedback allows participants to modulate sensorimotor EEG rhythms. Participants were able to control the BCI with the funnel feedback with better performance during the initial session and less frustration compared to the CB feedback. The multimodal funnel feedback provides an alternative to the conventional cursorbar feedback for training subjects to modulate their sensorimotor rhythms. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Dynamics of submicron aerosol droplets in a robust optical trap formed by multiple Bessel beams

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

Thanopulos, Ioannis; Theoretical and Physical Chemistry Institute, National Hellenic Research Foundation, Athens 11635; Luckhaus, David

In this paper, we model the three-dimensional escape dynamics of single submicron-sized aerosol droplets in optical multiple Bessel beam traps. Trapping in counter-propagating Bessel beams (CPBBs) is compared with a newly proposed quadruple Bessel beam (QBB) trap, which consists of two perpendicularly arranged CPBB traps. Calculations are performed for perfectly and imperfectly aligned traps. Mie-theory and finite-difference time-domain methods are used to calculate the optical forces. The droplet escape kinetics are obtained from the solution of the Langevin equation using a Verlet algorithm. Provided the traps are perfectly aligned, the calculations indicate very long lifetimes for droplets trapped either inmore » the CPBB or in the QBB trap. However, minor misalignments that are hard to control experimentally already severely diminish the stability of the CPBB trap. By contrast, such minor misalignments hardly affect the extended droplet lifetimes in a QBB trap. The QBB trap is found to be a stable, robust optical trap, which should enable the experimental investigation of submicron droplets with radii down to 100 nm. Optical binding between two droplets and its potential role in preventing coagulation when loading a CPBB trap is briefly addressed.« less

High Precision Pressure Measurement with a Funnel

ERIC Educational Resources Information Center

Lopez-Arias, T.; Gratton, L. M.; Oss, S.

2008-01-01

A simple experimental device for high precision differential pressure measurements is presented. Its working mechanism recalls that of a hydraulic press, where pressure is supplied by insufflating air under a funnel. As an application, we measure air pressure inside a soap bubble. The soap bubble is inflated and connected to a funnel which is…

Automatic Gain Control in Mass Spectrometry using a Jet Disrupter Electrode in an Electrodynamic Ion Funnel

PubMed Central

Page, Jason S.; Bogdanov, Bogdan; Vilkov, Andrey N.; Prior, David C.; Buschbach, Michael A.; Tang, Keqi; Smith, Richard D.

2007-01-01

We report on the use of a jet disrupter electrode in an electrodynamic ion funnel as an electronic valve to regulate the intensity of the ion beam transmitted through the interface of a mass spectrometer in order to perform automatic gain control (AGC). The ion flux is determined by either directly detecting the ion current on the conductance limiting orifice of the ion funnel or using a short mass spectrometry acquisition. Based upon the ion flux intensity, the voltage of the jet disrupter is adjusted to alter the transmission efficiency of the ion funnel to provide a desired ion population to the mass analyzer. Ion beam regulation by an ion funnel is shown to provide control to within a few percent of a targeted ion intensity or abundance. The utility of ion funnel AGC was evaluated using a protein tryptic digest analyzed with liquid chromatography Fourier transform ion cyclotron resonance (LC-FTICR) mass spectrometry. The ion population in the ICR cell was accurately controlled to selected levels, which improved data quality and provided better mass measurement accuracy. PMID:15694774

Investigation of local evaporation flux and vapor-phase pressure at an evaporative droplet interface.

PubMed

Duan, Fei; Ward, C A

2009-07-07

In the steady-state experiments of water droplet evaporation, when the throat was heating at a stainless steel conical funnel, the interfacial liquid temperature was found to increase parabolically from the center line to the rim of the funnel with the global vapor-phase pressure at around 600 Pa. The energy conservation analysis at the interface indicates that the energy required for evaporation is maintained by thermal conduction to the interface from the liquid and vapor phases, thermocapillary convection at interface, and the viscous dissipation globally and locally. The local evaporation flux increases from the center line to the periphery as a result of multiple effects of energy transport at the interface. The local vapor-phase pressure predicted from statistical rate theory (SRT) is also found to increase monotonically toward the interface edge from the center line. However, the average value of the local vapor-phase pressures is in agreement with the measured global vapor-phase pressure within the measured error bar.

Flow generation by the corona ciliata in Chaetognatha - quantification and implications for current functional hypotheses.

PubMed

Bleich, Steffen; Müller, Carsten H G; Graf, Gerhard; Hanke, Wolf

2017-12-01

The corona ciliata of Chaetognatha (arrow worms) is a circular or elliptical groove lined by a rim from which multiple lines of cilia emanate, located dorsally on the head and/or trunk. Mechanoreception, chemosensation, excretion, respiration, and support of reproduction have been suggested to be its main functions. Here we provide the first experimental evidence that the cilia produce significant water flow, and the first visualisation and quantification of this flow. In Spadella cephaloptera, water is accelerated toward the corona ciliata from dorsal and anterior of the body in a funnel-shaped pattern, and expelled laterally and caudally from the corona, with part of the water being recirculated. Maximal flow speeds were approximately 140μms -1 in adult specimens. Volumetric flow rate was Q=0.0026μls -1 . The funnel-shaped directional flow can possibly enable directional chemosensation. The flow measurements demonstrate that the corona ciliata is well suited as a multifunctional organ. Copyright © 2017 Elsevier GmbH. All rights reserved.

Male adaptations to minimize sexual cannibalism during reproduction in the funnel-web spider Hololena curta.

PubMed

Xiao, Yong-Hong; Zunic-Kosi, Alenka; Zhang, Long-Wa; Prentice, Thomas R; McElfresh, J Steven; Chinta, Satya P; Zou, Yun-Fan; Millar, Jocelyn G

2015-12-01

Males of many spider species risk being attacked and cannibalized while searching for, courting, and mating with conspecific females. However, there are exceptions. We show that the funnel-web spider, Hololena curta, has 3 adaptations that minimize risk to males during courtship and mating, and enhance reproductive success. First, males detected chemical or tactile signals associated with webs of virgin females, and differentiated them from webs of mated females, enabling males to increase encounter rates with virgin females and avoid aggressive mated females. Second, males produced stereotyped vibrational signals during courting which induced female quiescence and suppressed female aggression. Third, when touched by males, sexually receptive females entered a cataleptic state, allowing males to safely approach and copulate. Because males can mate multiple times and the sex ratio in natural populations of H. curta is female biased, overall reproductive output is likely increased by males of this species avoiding sexual cannibalism. © 2015 Institute of Zoology, Chinese Academy of Sciences.

Solar cells using quantum funnels.

PubMed

Kramer, Illan J; Levina, Larissa; Debnath, Ratan; Zhitomirsky, David; Sargent, Edward H

2011-09-14

Colloidal quantum dots offer broad tuning of semiconductor bandstructure via the quantum size effect. Devices involving a sequence of layers comprised of quantum dots selected to have different diameters, and therefore bandgaps, offer the possibility of funneling energy toward an acceptor. Here we report a quantum funnel that efficiently conveys photoelectrons from their point of generation toward an intended electron acceptor. Using this concept we build a solar cell that benefits from enhanced fill factor as a result of this quantum funnel. This concept addresses limitations on transport in soft condensed matter systems and leverages their advantages in large-area optoelectronic devices and systems.

Exploiting intraspecific competitive mechanisms to control invasive cane toads (Rhinella marina)

PubMed Central

Crossland, Michael R.; Haramura, Takashi; Salim, Angela A.; Capon, Robert J.; Shine, Richard

2012-01-01

If invasive species use chemical weapons to suppress the viability of conspecifics, we may be able to exploit those species-specific chemical cues for selective control of the invader. Cane toads (Rhinella marina) are spreading through tropical Australia, with negative effects on native species. The tadpoles of cane toads eliminate intraspecific competitors by locating and consuming newly laid eggs. Our laboratory trials show that tadpoles find those eggs by searching for the powerful bufadienolide toxins (especially, bufogenins) that toads use to deter predators. Using those toxins as bait, funnel-traps placed in natural waterbodies achieved near-complete eradication of cane toad tadpoles with minimal collateral damage (because most native (non-target) species are repelled by the toads' toxins). More generally, communication systems that have evolved for intraspecific conflict provide novel opportunities for invasive-species control. PMID:22696528

Energy-efficient modification of reduction-melting for lead recovery from cathode ray tube funnel glass

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

Okada, Takashi, E-mail: t-okada@u-fukui.ac.jp; Yonezawa, Susumu

2013-08-15

Highlights: • We recovered Pb from cathode ray tube funnel glass using reduction melting process. • We modified the melting process to achieve Pb recovery with low energy consumption. • Pb in the funnel glass is efficiently recovered at 1000 °C by adding Na{sub 2}CO{sub 3}. • Pb remaining in the glass after reduction melting is extracted with 1 M HCl. • 98% of Pb in the funnel glass was recovered by reduction melting and HCl leaching. - Abstract: Lead can be recovered from funnel glass of waste cathode ray tubes via reduction melting. While low-temperature melting is necessary formore » reduced energy consumption, previously proposed methods required high melting temperatures (1400 °C) for the reduction melting. In this study, the reduction melting of the funnel glass was performed at 900–1000 °C using a lab-scale reactor with varying concentrations of Na{sub 2}CO{sub 3} at different melting temperatures and melting times. The optimum Na{sub 2}CO{sub 3} dosage and melting temperature for efficient lead recovery was 0.5 g per 1 g of the funnel glass and 1000 °C respectively. By the reduction melting with the mentioned conditions, 92% of the lead in the funnel glass was recovered in 60 min. However, further lead recovery was difficult because the rate of the lead recovery decreased as with the recovery of increasing quantity of the lead from the glass. Thus, the lead remaining in the glass after the reduction melting was extracted with 1 M HCl, and the lead recovery improved to 98%.« less

A randomized comparison between league tables and funnel plots to inform health care decision-making.

PubMed

Anell, Anders; Hagberg, Oskar; Liedberg, Fredrik; Ryden, Stefan

2016-12-01

Comparison of provider performance is commonly used to inform health care decision-making. Little attention has been paid to how data presentations influence decisions. This study analyzes differences in suggested actions by decision-makers informed by league tables or funnel plots. Decision-makers were invited to a survey and randomized to compare hospital performance using either league tables or funnel plots for four different measures within the area of cancer care. For each measure, decision-makers were asked to suggest actions towards 12-16 hospitals (no action, ask for more information, intervene) and provide feedback related to whether the information provided had been useful. Swedish health care. Two hundred and twenty-one decision-makers at administrative and clinical levels. Data presentations in the form of league tables or funnel plots. Number of actions suggested by participants. Proportion of appropriate actions. For all four measures, decision-makers tended to suggest more actions based on the information provided in league tables compared to funnel plots (44% vs. 21%, P < 0.001). Actions were on average more appropriate for funnel plots. However, when using funnel plots, decision-makers more often missed to react even when appropriate. The form of data presentation had an influence on decision-making. With league tables, decision-makers tended to suggest more actions compared to funnel plots. A difference in sensitivity and specificity conditioned by the form of presentation could also be identified, with different implications depending on the purpose of comparisons. Explanations and visualization aids are needed to support appropriate actions. © The Author 2016. Published by Oxford University Press in association with the International Society for Quality in Health Care. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com

Mechanistic insights on spider neurotoxins.

PubMed

Luch, Andreas

2010-01-01

In physiology research, animal neurotoxins historically have served as valuable tools for identification, purification, and functional characterization of voltage-dependent ion channels. In particular, toxins from scorpions, sea anemones and cone snails were at the forefront of work aimed at illuminating the three-dimensional architecture of sodium channels. To date, at least six different receptor binding sites have been identified and--most of them--structurally assigned in terms of protein sequence and spatial disposition. Recent work on Australian funnel-web spiders identified certain peptidic ingredients as being responsible for the neurotoxicity of the crude venom. These peptides, termed delta-atracotoxins (delta-ACTX), consist of 42 amino acids and bind to voltage-gated sodium channels in the same way as classical scorpion alpha-toxins. According to the 'voltage-sensor trapping model' proposed in the literature, delta-ACTX isoforms interact with the voltage sensor S4 transmembrane segment of alpha-subunit domain IV, thereby preventing its normal outward movement and concurrent conformational changes required for inactivation of the channel. As consequence prolonged action potentials at autonomic or somatic synapses induce massive transmitter release, resulting in clinical correlates of neuroexcitation (e.g., muscle fasciculation, spasms, paresthesia, tachycardia, diaphoresis, etc.). On the other hand, the major neurotoxin isolated from black widow spiders, alpha-latrotoxin (alpha-LTX), represents a 132 kDa protein consisting of a unique N-terminal sequence and a C-terminal part harboring multiple ankyrin-like repeats. Upon binding to one of its specific presynaptic receptors, alpha-LTX has been shown to tetramerize under physiological conditions to form Ca2+-permeable pores in presynaptic membranes. The molecular model worked out during recent years separates two distinguishable receptor-mediated effects. According to current knowledge, binding of the N terminus of alpha-LTX at one of its specific receptors either triggers intracellular signaling cascades, resulting in phospholipase C-mediated mobilization of presynaptic Ca2+ stores, or leads to the formation of tetrameric pore complexes, allowing extracellular Ca2+ to enter the presynaptic terminal. Alpha-LTX-triggered exocytosis and fulminant transmitter release at autonomic synapses may then provoke a clinical syndrome referred to as 'latrodectism', characterized by local and incapacitating pain, diaphoresis, muscle fasciculation, tremor, anxiety, and so forth. The present review aims at providing a short introduction into some of the exciting molecular effects induced by neurotoxins isolated from black widow and funnel-web spiders.

Energy landscape paving simulations of the trp-cage protein.

PubMed

Schug, Alexander; Wenzel, Wolfgang; Hansmann, Ulrich H E

2005-05-15

We evaluate the efficiency of multiple variants of energy landscape paving in all-atom simulations of the trp-cage protein using a recently developed new force field. Especially, we introduce a temperature-free variant of the method and demonstrate that it allows a fast scanning of the energy landscape. Nativelike structures are found in less time than by other techniques. The sampled low-energy configurations indicate a funnel-like energy landscape.

Broadband light funneling in ultrasubwavelength channels having periodic connected unfilled apertures

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

Subramania, Ganapathi Subramanian; Brener, Igal; Foteinopoulou, Stavroula

2017-08-01

A structure for broadband light funneling comprises a two-dimensional periodic array of connected ultrasubwavelength apertures, each aperture comprising a large sub-aperture that aids in the coupling of the incoming incident light and a small sub-aperture that funnels a significant fraction of the incident light power. The structure possesses all the capabilities of prior extraordinary optical transmission platforms, yet operates nonresonantly on a distinctly different mechanism. The structure demonstrates efficient ultrabroadband funneling of optical power confined in an area as small as .about.(.lamda./500).sup.2, where optical fields are enhanced, thus exhibiting functional possibilities beyond resonant platforms.

Ion funnel with extended mass range and reduced conductance limit aperture

DOEpatents

Tolmachev, Aleksey V [Richland, WA; Smith, Richard D [Richland, WA

2008-04-01

An improved ion funnel design is disclosed that decreases the axial RF (parasite) fields at the ion funnel exit. This is achieved by addition of one or more compensation electrodes after the conductance limit electrode. Various RF voltage profiles may be applied to the various electrodes minimizing the parasite axial potential wells. The smallest RF aperture that serves as the conductance limiting electrode is further reduced over standard designs. Overall, the ion funnel improves transmission ranges of both low m/z and high m/z ions, reducing RF activation of ions and decreasing the gas load to subsequent differential pumping stages.

Nano-funnels as electro-osmotic ``tweezers and pistons''

NASA Astrophysics Data System (ADS)

Wang, Yanqian; Panyukov, Sergey; Zhou, Jinsheng; Menard, Laurent D.; Ramsey, J. Michael; Rubinstien, Michael

2014-03-01

An electric field is used to force a DNA molecule into a nano-channel by compensating the free energy penalty that results from the reduced conformational entropy of the confined macromolecule. Narrow nano-channels require high critical electric fields to achieve DNA translocation, leading to short dwell times of DNA in these channels. We demonstrate that nano-funnels integrated with nano-channels reduce the free energy barrier and lower the critical electric field required for DNA translocation. A focused electric field within the funnel increases the electric force on the DNA, compresses the molecule, and increases the osmotic pressure at the nano-channel entrance. This ``electro-osmotic piston'' forces the molecule into the nano-channel at lower electric fields than those observed without the funnel. Appropirately designed nano-funnels can also function as tweezers that allow manipulation of the position of the DNA molecule. The predictions of our theory describing double-stranded DNA behavior in nano-funnel - nano-channel devices are consistent with experimental results. Thanks for the financial support from NSF (DMR-1309892, DMR-1121107, DMR-1122483), NIH (1-P50-HL107168, 1-P01-HL108808-01A1, R01HG02647), NHGRI and CF Foundation.

The role of gravity in the nutrition and formation of Bacillus colonies

NASA Astrophysics Data System (ADS)

Puzyr, A.; Tirranen, L.; Krylova, T.

The soil-like substrate is used to cultivate higher plants in man-made closed ecosystems. It allows increasing the closeness of the systems and decreasing the plant solid residues and human wastes. Unusual funnel-shaped bacterial colonies of Bacillus species have been observed during analysis of microflora of plant nutritional solution. The colonies have the following characteristics: a) the diameter of "funnel socket" (the biomass contacting with nutritional agar) is 10.0-15.0 mm; b) the thickness of "funnel socket" is 0.5-2.5 mm; c) the diameter of the middle part of the "funnel spout" (the biomass contacting with the gas phase) is 1,0-1,5 mm; d) the length of the "funnel spout" is 10.0-15.0 mm. In the socket and the middle part of the "funnel spout" there is a gas cavity which is most probably formed by bacterial gas metabolites. It has been shown that: i) the surface of these funnel-shaped colonies of Bacillus species is hydrophobic, as is the surface of other Bacillus species ( . brevis, B. cellulomonos, B. flavus, B.B formosus, B. subtilis); ii) the forms of colonies can be changed by varying the position of the growing biomass in relation to the gravitation forces. The experiment proved that the form of the "funnel sockets" and the length of the "funnel spouts" of the colonies are determined by hydrophobic air-contacting surface layer, which does not leak and stretches under the weight of accumulated water. A hypothesis has been suggested that the gravity force plays the role of a "pump" supplying and holding water within the colony. Thus, the water that comes under the gravity force contains dissolved nutrients and bacterial cells in the hydrophobic layer. These cells that are situated far away from the nutrient agar have no nutrient deficiency. The water accumulated by the colonies might be free water of agar media or it can be produced by metabolic disruption of medium fat. Hence, when growing a colony in agar media the water-soluble nutrient substances enter the growing colonies not only due to diffusion processes but also with the directional water flow under the gravity force.

The pollination mechanism in Trigonidium obtusum Lindl (Orchidaceae: Maxillariinae): sexual mimicry and trap-flowers.

PubMed

Singer, Rodrigo B

2002-02-01

The pollination process in Trigonidium obtusum Lindl. (Epidendroideae: Maxillariinae) is documented. The flowers are pollinated by sexually excited drones of Plebeia droryana (Meliponinae). When attempting to copulate either with sepals or petals, these bees slip on the waxy perianth surface and become trapped in the funnel-like flower tube. Bees trying to escape from the flowers may instead access the space between the column and lip, fixing the pollinarium on their scutellum. Pollinarium-bearing bees may pollinate the flowers when repeating the above-mentioned steps, leaving pollinia on the concave stigmatic surface, thus effecting pollination. Recently removed pollinaria are too broad to enter the stigma but they begin to dehydrate and within 40 min of removal are small enough to fit the stigmatic cavity. This mechanism prevents insect-mediated self-pollination and promotes cross-pollination. Preliminary evidence based on experiments with cultivated plants suggests that they are self-compatible but that fruit set is pollinator-dependent. The data obtained are discussed in a phylogenetic context. It is suggested that the pseudocopulatory syndrome in Trigonidium could have evolved from rewardless (food advertising) ancestors. Pseudocopulation in the context of the long flowering period of this orchid species (about 7 months) is understandable since the eusocial Plebeia bees produce fertile individuals several times a year.

Expanding the capability of reaction-diffusion codes using pseudo traps and temperature partitioning: Applied to hydrogen uptake and release from tungsten

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

Simmonds, M. J.; Yu, J. H.; Wang, Y. Q.

Simulating the implantation and thermal desorption evolution in a reaction-diffusion model requires solving a set of coupled differential equations that describe the trapping and release of atomic species in Plasma Facing Materials (PFMs). These fundamental equations are well outlined by the Tritium Migration Analysis Program (TMAP) which can model systems with no more than three active traps per atomic species. To overcome this limitation, we have developed a Pseudo Trap and Temperature Partition (PTTP) scheme allowing us to lump multiple inactive traps into one pseudo trap, simplifying the system of equations to be solved. For all temperatures, we show themore » trapping of atoms from solute is exactly accounted for when using a pseudo trap. However, a single effective pseudo trap energy can not well replicate the release from multiple traps, each with its own detrapping energy. However, atoms held in a high energy trap will remain trapped at relatively low temperatures, and thus there is a temperature range in which release from high energy traps is effectively inactive. By partitioning the temperature range into segments, a pseudo trap can be defined for each segment to account for multiple high energy traps that are actively trapping but are effectively not releasing atoms. With increasing temperature, as in controlled thermal desorption, the lowest energy trap is nearly emptied and can be removed from the set of coupled equations, while the next higher energy trap becomes an actively releasing trap. Each segment is thus calculated sequentially, with the last time step of a given segment solution being used as an initial input for the next segment as only the pseudo and actively releasing traps are modeled. This PTTP scheme is then applied to experimental thermal desorption data for tungsten (W) samples damaged with heavy ions, which display six distinct release peaks during thermal desorption. Without modifying the TMAP7 source code the PTTP scheme is shown to successfully model the D retention in all six traps. In conclusion, we demonstrate the full reconstruction from the plasma implantation phase through the controlled thermal desorption phase with detrapping energies near 0.9, 1.1, 1.4, 1.7, 1.9 and 2.1 eV for a W sample damaged at room temperature.« less

Expanding the capability of reaction-diffusion codes using pseudo traps and temperature partitioning: Applied to hydrogen uptake and release from tungsten

DOE PAGES

Simmonds, M. J.; Yu, J. H.; Wang, Y. Q.; ...

2018-06-04

Simulating the implantation and thermal desorption evolution in a reaction-diffusion model requires solving a set of coupled differential equations that describe the trapping and release of atomic species in Plasma Facing Materials (PFMs). These fundamental equations are well outlined by the Tritium Migration Analysis Program (TMAP) which can model systems with no more than three active traps per atomic species. To overcome this limitation, we have developed a Pseudo Trap and Temperature Partition (PTTP) scheme allowing us to lump multiple inactive traps into one pseudo trap, simplifying the system of equations to be solved. For all temperatures, we show themore » trapping of atoms from solute is exactly accounted for when using a pseudo trap. However, a single effective pseudo trap energy can not well replicate the release from multiple traps, each with its own detrapping energy. However, atoms held in a high energy trap will remain trapped at relatively low temperatures, and thus there is a temperature range in which release from high energy traps is effectively inactive. By partitioning the temperature range into segments, a pseudo trap can be defined for each segment to account for multiple high energy traps that are actively trapping but are effectively not releasing atoms. With increasing temperature, as in controlled thermal desorption, the lowest energy trap is nearly emptied and can be removed from the set of coupled equations, while the next higher energy trap becomes an actively releasing trap. Each segment is thus calculated sequentially, with the last time step of a given segment solution being used as an initial input for the next segment as only the pseudo and actively releasing traps are modeled. This PTTP scheme is then applied to experimental thermal desorption data for tungsten (W) samples damaged with heavy ions, which display six distinct release peaks during thermal desorption. Without modifying the TMAP7 source code the PTTP scheme is shown to successfully model the D retention in all six traps. In conclusion, we demonstrate the full reconstruction from the plasma implantation phase through the controlled thermal desorption phase with detrapping energies near 0.9, 1.1, 1.4, 1.7, 1.9 and 2.1 eV for a W sample damaged at room temperature.« less

Funnel for localizing biological cell placement and arrangement

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

Soscia, David; Benett, William J.; Mukerjee, Erik V.

2018-03-06

The present disclosure relates to a funnel apparatus for channeling cells onto a plurality of distinct, closely spaced regions of a seeding surface. The funnel apparatus has a body portion having an upper surface and a lower surface. The body portion forms a plurality of flow paths, at least one of which is shaped to have a decreasing cross-sectional area from the upper surface to the lower surface. The flow paths are formed at the lower surface to enable cells deposited into the flow paths at the upper surface of the funnel apparatus to be channeled into a plurality ofmore » distinct, closely spaced regions on the seeding surface positioned adjacent the lower surface.« less

Abnormal Multiple Charge Memory States in Exfoliated Few-Layer WSe2 Transistors.

PubMed

Chen, Mikai; Wang, Yifan; Shepherd, Nathan; Huard, Chad; Zhou, Jiantao; Guo, L J; Lu, Wei; Liang, Xiaogan

2017-01-24

To construct reliable nanoelectronic devices based on emerging 2D layered semiconductors, we need to understand the charge-trapping processes in such devices. Additionally, the identified charge-trapping schemes in such layered materials could be further exploited to make multibit (or highly desirable analog-tunable) memory devices. Here, we present a study on the abnormal charge-trapping or memory characteristics of few-layer WSe 2 transistors. This work shows that multiple charge-trapping states with large extrema spacing, long retention time, and analog tunability can be excited in the transistors made from mechanically exfoliated few-layer WSe 2 flakes, whereas they cannot be generated in widely studied few-layer MoS 2 transistors. Such charge-trapping characteristics of WSe 2 transistors are attributed to the exfoliation-induced interlayer deformation on the cleaved surfaces of few-layer WSe 2 flakes, which can spontaneously form ambipolar charge-trapping sites. Our additional results from surface characterization, charge-retention characterization at different temperatures, and density functional theory computation strongly support this explanation. Furthermore, our research also demonstrates that the charge-trapping states excited in multiple transistors can be calibrated into consistent multibit data storage levels. This work advances the understanding of the charge memory mechanisms in layered semiconductors, and the observed charge-trapping states could be further studied for enabling ultralow-cost multibit analog memory devices.

The initial rise method extended to multiple trapping levels in thermoluminescent materials.

PubMed

Furetta, C; Guzmán, S; Ruiz, B; Cruz-Zaragoza, E

2011-02-01

The well known Initial Rise Method (IR) is commonly used to determine the activation energy when only one glow peak is presented and analysed in the phosphor materials. However, when the glow peak is more complex, a wide peak and some holders appear in the structure. The application of the Initial Rise Method is not valid because multiple trapping levels are considered and then the thermoluminescent analysis becomes difficult to perform. This paper shows the case of a complex glow curve structure as an example and shows that the calculation is also possible using the IR method. The aim of the paper is to extend the well known Initial Rise Method (IR) to the case of multiple trapping levels. The IR method is applied to minerals extracted from Nopal cactus and Oregano spices because the thermoluminescent glow curve's shape suggests a trap distribution instead of a single trapping level. Copyright © 2010 Elsevier Ltd. All rights reserved.

Standardized mean differences cause funnel plot distortion in publication bias assessments.

PubMed

Zwetsloot, Peter-Paul; Van Der Naald, Mira; Sena, Emily S; Howells, David W; IntHout, Joanna; De Groot, Joris Ah; Chamuleau, Steven Aj; MacLeod, Malcolm R; Wever, Kimberley E

2017-09-08

Meta-analyses are increasingly used for synthesis of evidence from biomedical research, and often include an assessment of publication bias based on visual or analytical detection of asymmetry in funnel plots. We studied the influence of different normalisation approaches, sample size and intervention effects on funnel plot asymmetry, using empirical datasets and illustrative simulations. We found that funnel plots of the Standardized Mean Difference (SMD) plotted against the standard error (SE) are susceptible to distortion, leading to overestimation of the existence and extent of publication bias. Distortion was more severe when the primary studies had a small sample size and when an intervention effect was present. We show that using the Normalised Mean Difference measure as effect size (when possible), or plotting the SMD against a sample size-based precision estimate, are more reliable alternatives. We conclude that funnel plots using the SMD in combination with the SE are unsuitable for publication bias assessments and can lead to false-positive results.

Standardized mean differences cause funnel plot distortion in publication bias assessments

PubMed Central

Van Der Naald, Mira; Sena, Emily S; Howells, David W; IntHout, Joanna; De Groot, Joris AH; Chamuleau, Steven AJ; MacLeod, Malcolm R

2017-01-01

Meta-analyses are increasingly used for synthesis of evidence from biomedical research, and often include an assessment of publication bias based on visual or analytical detection of asymmetry in funnel plots. We studied the influence of different normalisation approaches, sample size and intervention effects on funnel plot asymmetry, using empirical datasets and illustrative simulations. We found that funnel plots of the Standardized Mean Difference (SMD) plotted against the standard error (SE) are susceptible to distortion, leading to overestimation of the existence and extent of publication bias. Distortion was more severe when the primary studies had a small sample size and when an intervention effect was present. We show that using the Normalised Mean Difference measure as effect size (when possible), or plotting the SMD against a sample size-based precision estimate, are more reliable alternatives. We conclude that funnel plots using the SMD in combination with the SE are unsuitable for publication bias assessments and can lead to false-positive results. PMID:28884685

Ejector device for direct injection fuel jet

DOEpatents

Upatnieks, Ansis [Livermore, CA

2006-05-30

Disclosed is a device for increasing entrainment and mixing in an air/fuel zone of a direct fuel injection system. The device comprises an ejector nozzle in the form of an inverted funnel whose central axis is aligned along the central axis of a fuel injector jet and whose narrow end is placed just above the jet outlet. It is found that effective ejector performance is achieved when the ejector geometry is adjusted such that it comprises a funnel whose interior surface diverges about 7.degree. to about 9.degree. away from the funnel central axis, wherein the funnel inlet diameter is about 2 to about 3 times the diameter of the injected fuel plume as the fuel plume reaches the ejector inlet, and wherein the funnel length equal to about 1 to about 4 times the ejector inlet diameter. Moreover, the ejector is most effectively disposed at a separation distance away from the fuel jet equal to about 1 to about 2 time the ejector inlet diameter.

The problem of natural funnel asymmetries: a simulation analysis of meta-analysis in macroeconomics.

PubMed

Callot, Laurent; Paldam, Martin

2011-06-01

Effect sizes in macroeconomic are estimated by regressions on data published by statistical agencies. Funnel plots are a representation of the distribution of the resulting regression coefficients. They are normally much wider than predicted by the t-ratio of the coefficients and often asymmetric. The standard method of meta-analysts in economics assumes that the asymmetries are because of publication bias causing censoring and adjusts the average accordingly. The paper shows that some funnel asymmetries may be 'natural' so that they occur without censoring. We investigate such asymmetries by simulating funnels by pairs of data generating processes (DGPs) and estimating models (EMs), in which the EM has the problem that it disregards a property of the DGP. The problems are data dependency, structural breaks, non-normal residuals, non-linearity, and omitted variables. We show that some of these problems generate funnel asymmetries. When they do, the standard method often fails. Copyright © 2011 John Wiley & Sons, Ltd. Copyright © 2011 John Wiley & Sons, Ltd.

Early Development and Orientation of the Acoustic Funnel Provides Insight into the Evolution of Sound Reception Pathways in Cetaceans

PubMed Central

Yamato, Maya; Pyenson, Nicholas D.

2015-01-01

Whales receive underwater sounds through a fundamentally different mechanism than their close terrestrial relatives. Instead of hearing through the ear canal, cetaceans hear through specialized fatty tissues leading to an evolutionarily novel feature: an acoustic funnel located anterior to the tympanic aperture. We traced the ontogenetic development of this feature in 56 fetal specimens from 10 different families of toothed (odontocete) and baleen (mysticete) whales, using X-ray computed tomography. We also charted ear ossification patterns through ontogeny to understand the impact of heterochronic developmental processes. We determined that the acoustic funnel arises from a prominent V-shaped structure established early in ontogeny, formed by the malleus and the goniale. In odontocetes, this V-formation develops into a cone-shaped funnel facing anteriorly, directly into intramandibular acoustic fats, which is likely functionally linked to the anterior orientation of sound reception in echolocation. In contrast, the acoustic funnel in balaenopterids rotates laterally, later in fetal development, consistent with a lateral sound reception pathway. Balaenids and several fossil mysticetes retain a somewhat anteriorly oriented acoustic funnel in the mature condition, indicating that a lateral sound reception pathway in balaenopterids may be a recent evolutionary innovation linked to specialized feeding modes, such as lunge-feeding. PMID:25760328

Funnel plot control limits to identify poorly performing healthcare providers when there is uncertainty in the value of the benchmark.

PubMed

Manktelow, Bradley N; Seaton, Sarah E; Evans, T Alun

2016-12-01

There is an increasing use of statistical methods, such as funnel plots, to identify poorly performing healthcare providers. Funnel plots comprise the construction of control limits around a benchmark and providers with outcomes falling outside the limits are investigated as potential outliers. The benchmark is usually estimated from observed data but uncertainty in this estimate is usually ignored when constructing control limits. In this paper, the use of funnel plots in the presence of uncertainty in the value of the benchmark is reviewed for outcomes from a Binomial distribution. Two methods to derive the control limits are shown: (i) prediction intervals; (ii) tolerance intervals Tolerance intervals formally include the uncertainty in the value of the benchmark while prediction intervals do not. The probability properties of 95% control limits derived using each method were investigated through hypothesised scenarios. Neither prediction intervals nor tolerance intervals produce funnel plot control limits that satisfy the nominal probability characteristics when there is uncertainty in the value of the benchmark. This is not necessarily to say that funnel plots have no role to play in healthcare, but that without the development of intervals satisfying the nominal probability characteristics they must be interpreted with care. © The Author(s) 2014.

Funnel-web spider bite: a systematic review of recorded clinical cases.

PubMed

Isbister, Geoffrey K; Gray, Michael R; Balit, Corrine R; Raven, Robert J; Stokes, Barrie J; Porges, Kate; Tankel, Alan S; Turner, Elizabeth; White, Julian; Fisher, Malcolm McD

2005-04-18

To investigate species-specific envenoming rates and spectrum of severity of funnel-web spider bites, and the efficacy and adverse effects of funnel-web spider antivenom. Cases were identified from a prospective study of spider bite presenting to four major hospitals and three state poisons information centres (1999-2003); museum records of spider specimens since 1926; NSW Poisons Information Centre database; MEDLINE and EMBASE search; clinical toxinology textbooks; the media; and the manufacturer's reports of antivenom use. Patient age and sex, geographical location, month, expert identification of the spider, clinical effects and management; envenoming was classified as severe, mild-moderate or minor/local effects. 198 potential funnel-web spider bites were identified: 138 were definite (spider expertly identified to species or genus), and 77 produced severe envenoming. All species-identified severe cases were attributed to one of six species restricted to NSW and southern Queensland. Rates of severe envenoming were: Hadronyche cerberea (75%), H. formidabilis (63%), Atrax robustus (17%), Hadronyche sp. 14 (17%), H. infensa (14%) and H. versuta (11%). Antivenom was used in 75 patients, including 22 children (median dose, 3 ampoules; range, 1-17), with a complete response in 97% of expertly identified cases. Three adverse reactions were reported, all in adults: two early allergic reactions (one mild and one with severe systemic effects requiring adrenaline), and one case of serum sickness. Severe funnel-web spider envenoming is confined to NSW and southern Queensland; tree-dwelling funnel webs (H. cerberea and H. formidabilis) have the highest envenoming rates. Funnel-web spider antivenom appears effective and safe; severe allergic reactions are uncommon.

Dynamic superconcentration at critical-point double-layer gates of conducting nanoporous granules due to asymmetric tangential fluxes

PubMed Central

Wang, Shau-Chun; Wei, Hsien-Hung; Chen, Hsiao-Ping; Tsai, Min-Hsuan; Yu, Chun-Ching; Chang, Hsueh-Chia

2008-01-01

A transient 106-fold concentration of double-layer counterions by a high-intensity electric field is demonstrated at the exit pole of a millimeter-sized conducting nanoporous granule that permits ion permeation. The phenomenon is attributed to a unique counterion screening dynamics that transforms half of the surface field into a converging one toward the ejecting pole. The resulting surface conduction flux then funnels a large upstream electro-osmotic convective counterion flux into the injecting hemisphere toward the zero-dimensional gate of the ejecting hemisphere to produce the superconcentration. As the concentrated counterion is ejected into the electroneutral bulk electrolyte, it attracts co-ions and produce a corresponding concentration of the co-ions. This mechanism is also shown to trap and concentrate co-ion microcolloids of micron sizes too (macroions) and hence has potential application in bead-based molecular assays. PMID:19693364

Near-field multiple traps of paraxial acoustic vortices with strengthened gradient force generated by sector transducer array

NASA Astrophysics Data System (ADS)

Wang, Qingdong; Li, Yuzhi; Ma, Qingyu; Guo, Gepu; Tu, Juan; Zhang, Dong

2018-01-01

In order to improve the capability of particle trapping close to the source plane, theoretical and experimental studies on near-field multiple traps of paraxial acoustic vortices (AVs) with a strengthened acoustic gradient force (AGF) generated by a sector transducer array were conducted. By applying the integration of point source radiation, numerical simulations for the acoustic fields generated by the sector transducer array were conducted and compared with those produced by the circular transducer array. It was proved that strengthened AGFs of near-field multiple AVs with higher peak pressures and smaller vortex radii could be produced by the sector transducer array with a small topological charge. The axial distributions of the equivalent potential gradient indicated that the AGFs of paraxial AVs in the near field were much higher than those in the far field, and the distances at the near-field vortex antinodes were also proved to be the ideal trapping positions with relatively higher AGFs. With the established 8-channel AV generation system, theoretical studies were also verified by the experimental measurements of pressure and phase for AVs with various topological charges. The formation of near-field multiple paraxial AVs was verified by the cross-sectional circular pressure distributions with perfect phase spirals around central pressure nulls, and was also proved by the vortex nodes and antinodes along the center axis. The favorable results demonstrated the feasibility of generating near-field multiple traps of paraxial AVs with strengthened AGF using the sector transducer array, and suggested the potential applications of close-range particle trapping in biomedical engineering.

Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping.

PubMed

Dickel, Timo; Plaß, Wolfgang R; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I; Geissel, Hans; Scheidenberger, Christoph

2017-06-01

A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. Graphical Abstract ᅟ.

Isobar Separation in a Multiple-Reflection Time-of-Flight Mass Spectrometer by Mass-Selective Re-Trapping

NASA Astrophysics Data System (ADS)

Dickel, Timo; Plaß, Wolfgang R.; Lippert, Wayne; Lang, Johannes; Yavor, Mikhail I.; Geissel, Hans; Scheidenberger, Christoph

2017-06-01

A novel method for (ultra-)high-resolution spatial mass separation in time-of-flight mass spectrometers is presented. Ions are injected into a time-of-flight analyzer from a radio frequency (rf) trap, dispersed in time-of-flight according to their mass-to-charge ratios and then re-trapped dynamically in the same rf trap. This re-trapping technique is highly mass-selective and after sufficiently long flight times can provide even isobaric separation. A theoretical treatment of the method is presented and the conditions for optimum performance of the method are derived. The method has been implemented in a multiple-reflection time-of-flight mass spectrometer and mass separation powers (FWHM) in excess of 70,000, and re-trapping efficiencies of up to 35% have been obtained for the protonated molecular ion of caffeine. The isobars glutamine and lysine (relative mass difference of 1/4000) have been separated after a flight time of 0.2 ms only. Higher mass separation powers can be achieved using longer flight times. The method will have important applications, including isobar separation in nuclear physics and (ultra-)high-resolution precursor ion selection in multiple-stage tandem mass spectrometry. [Figure not available: see fulltext.

Deep-level stereoscopic multiple traps of acoustic vortices

NASA Astrophysics Data System (ADS)

Li, Yuzhi; Guo, Gepu; Ma, Qingyu; Tu, Juan; Zhang, Dong

2017-04-01

Based on the radiation pattern of a planar piston transducer, the mechanisms underlying the generation of axially controllable deep-level stereoscopic multiple traps of acoustic vortices (AV) using sparse directional sources were proposed with explicit formulae. Numerical simulations for the axial and cross-sectional distributions of acoustic pressure and phase were conducted for various ka (product of the wave number and the radius of transducer) values at the frequency of 1 MHz. It was demonstrated that, for bigger ka, besides the main-AV (M-AV) generated by the main lobes of the sources, cone-shaped side-AV (S-AV) produced by the side lobes were closer to the source plane at a relatively lower pressure. Corresponding to the radiation angles of pressure nulls between the main lobe and the side lobes of the sources, vortex valleys with nearly pressure zero could be generated on the central axis to form multiple traps, based on Gor'kov potential theory. The number and locations of vortex valleys could be controlled accurately by the adjustment of ka. With the established eight-source AV generation system, the existence of the axially controllable multiple traps was verified by the measured M-AV and S-AVs as well as the corresponding vortex valleys. The favorable results provided the feasibility of deep-level stereoscopic control of AV and suggested potential application of multiple traps for particle manipulation in the area of biomedical engineering.

Modelling multiple sources of dissemination bias in meta-analysis.

PubMed

Bowden, Jack; Jackson, Dan; Thompson, Simon G

2010-03-30

Asymmetry in the funnel plot for a meta-analysis suggests the presence of dissemination bias. This may be caused by publication bias through the decisions of journal editors, by selective reporting of research results by authors or by a combination of both. Typically, study results that are statistically significant or have larger estimated effect sizes are more likely to appear in the published literature, hence giving a biased picture of the evidence-base. Previous statistical approaches for addressing dissemination bias have assumed only a single selection mechanism. Here we consider a more realistic scenario in which multiple dissemination processes, involving both the publishing authors and journals, are operating. In practical applications, the methods can be used to provide sensitivity analyses for the potential effects of multiple dissemination biases operating in meta-analysis.

People’s Republic of China Scientific Abstracts, Number 174

DTIC Science & Technology

1977-08-23

involving the gastric body. All cases showed filling defects, with elliptical, semilunar and cauliflower multiple polyps or funnel shaped narrowing. Minute...34Report 4 Cases of Rhabdomyosarcoma of the Ear , Nasal Sinus and Throat" SOURCE: Peking CHUNG-HUA I-HSUEH TSA-CHIH [CHINESE MEDICAL JOURNAL] No 3, 15 Mar...77 pp 161-162 ABSTRACT: Two cases of rhabdomyosarcoma of the ear , 1 each of the nasal sinus and throat were reported. All 4 cases died in a short

Apparatus for blending small particles

DOEpatents

Bradley, R.A.; Reese, C.R.; Sease, J.D.

1975-08-26

An apparatus is described for blending small particles and uniformly loading the blended particles in a receptacle. Measured volumes of various particles are simultaneously fed into a funnel to accomplish radial blending and then directed onto the apex of a conical splitter which collects the blended particles in a multiplicity of equal subvolumes. Thereafter the apparatus sequentially discharges the subvolumes for loading in a receptacle. A system for blending nuclear fuel particles and loading them into fuel rod molds is described in a preferred embodiment. (auth)

Exploring and accounting for publication bias in mental health: a brief overview of methods.

PubMed

Mavridis, Dimitris; Salanti, Georgia

2014-02-01

OBJECTIVE Publication bias undermines the integrity of published research. The aim of this paper is to present a synopsis of methods for exploring and accounting for publication bias. METHODS We discussed the main features of the following methods to assess publication bias: funnel plot analysis; trim-and-fill methods; regression techniques and selection models. We applied these methods to a well-known example of antidepressants trials that compared trials submitted to the Food and Drug Administration (FDA) for regulatory approval. RESULTS The funnel plot-related methods (visual inspection, trim-and-fill, regression models) revealed an association between effect size and SE. Contours of statistical significance showed that asymmetry in the funnel plot is probably due to publication bias. Selection model found a significant correlation between effect size and propensity for publication. CONCLUSIONS Researchers should always consider the possible impact of publication bias. Funnel plot-related methods should be seen as a means of examining for small-study effects and not be directly equated with publication bias. Possible causes for funnel plot asymmetry should be explored. Contours of statistical significance may help disentangle whether asymmetry in a funnel plot is caused by publication bias or not. Selection models, although underused, could be useful resource when publication bias and heterogeneity are suspected because they address directly the problem of publication bias and not that of small-study effects.

Speckle field as a multiple particle trap

NASA Astrophysics Data System (ADS)

Shvedov, V. G.; Rode, A. V.; Izdebskaya, Ya. V.; Desyatnikov, A. S.; Krolikowski, W.; Kivshar, Yu. S.

2010-04-01

We demonstrate that a speckle pattern in the spatially coherent laser field transmitted by a diffuser forms a multitude of three-dimensional bottle-shaped micro-traps. These multiple traps serve as a means for an effective trapping of large number of air-born absorbing particles. Confinement of up to a few thousand particles in air with a single beam has been achieved. The ability to capture light-absorbing particles suspended in gases by optical means opens up rich and diverse practical opportunities, including development of photonic shielding/fencing for environmental protection in nanotechnology industry and new methods of touch-free air transport of particles and small containers, which may hold dangerous substances, or viruses and living cells.

Lost lake - restoration of a Carolina bay

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

Hanlin, H.G.; McLendon, J.P.; Wike, L.D.

1994-09-01

Carolina bays are shallow wetland depressions found only on the Atlantic Coastal Plain. Although these isolated interstream wetlands support many types of communities, they share the common features of having a sandy margin, a fluctuating water level, an elliptical shape, and a northwest to southeast orientation. Lost Lake, an 11.3 hectare Carolina bay, was ditched and drained for agricultural production before establishment of the Savannah River Site in 1950. Later it received overflow from a seepage basin containing a variety of chemicals, primarily solvents and some heavy metals. In 1990 a plan was developed for the restoration of Lost Lake,more » and restoration activities were complete by mid-1991. Lost Lake is the first known project designed for the restoration and recovery of a Carolina bay. The bay was divided into eight soil treatment zones, allowing four treatments in duplicate. Each of the eight zones was planted with eight species of native wetland plants. Recolonization of the bay by amphibians and reptiles is being evaluated by using drift fences with pitfall traps and coverboard arrays in each of the treatment zones. Additional drift fences in five upland habitats were also established. Hoop turtle traps, funnel minnow traps, and dip nets were utilized for aquatic sampling. The presence of 43 species common to the region has been documented at Lost Lake. More than one-third of these species show evidence of breeding populations being established. Three species found prior to the restoration activity and a number of species common to undisturbed Carolina bays were not encountered. Colonization by additional species is anticipated as the wetland undergoes further succession.« less

Saproxylic community, guild and species responses to varying pheromone components of a pine bark beetle.

PubMed

Etxebeste, Iñaki; Lencina, José L; Pajares, Juan

2013-10-01

Some bark beetle species (Coleoptera: Scolytinae) produce aggregation pheromones that allow coordinated attack on their conifer hosts. As a new saproxylic habitat is founded, an assemblage of associated beetles kairomonally respond to bark beetle infochemicals. Ips sexdentatus is one of the major damaging insects of Pinus spp. in Southern Europe. Its response to varying ipsenol (Ie) percentages in relation to ipsdienol (Id) was studied in northwestern Spain, along with the entire saproxylic beetle assemblage captured at multiple-funnel traps. Response profile modeling was undertaken for I. sexdentatus sexes and sex-ratios, associated species and for selected trophic groups using a reference Gaussian model. In addition, the effects on the saproxylic assemblages were analyzed. I. sexdentatus response curve peaked at 22.7% Ie content, while remaining taxa that could be modeled, peaked above ca. 40% Ie. Predator guilds showed a linear relationship with Ie proportion, while competitors showed a delayed response peak. Consequently, species assemblages differed markedly between varying pheromone component mixtures. Given that the evaluated pheromonal proportions mimicked that of logs being colonized by I. sexdentatus, results suggested that the registered differential responses at different levels might provide I. sexdentatus with a temporal window that maximizes conspecific attraction while reducing interference with competitor and predatory guilds. Described responses might help improve the monitoring of the population status of target bark beetles and their associates, but also point toward the by-catch of many natural enemies, as well as rare saproxylic beetle species, interfering with the aims of sustainable forest management.

Funnel plots and choropleth maps in cancer risk communication: a comparison of tools for disseminating population-based incidence data to stakeholders

PubMed Central

Cusimano, Rosanna; Zarcone, Maurizio; Mazzola, Sergio; Vitale, Francesco

2017-01-01

Background Population-based cancer registries provide epidemiological cancer information, but the indicators are often too complex to be interpreted by local authorities and communities, due to numeracy and literacy limitations. The aim of this paper is to compare the commonly used visual formats to funnel plots to enable local public health authorities and communities to access valid and understandable cancer incidence data obtained at the municipal level. Methods A funnel plot representation of standardised incidence ratio (SIR) was generated for the 82 municipalities of the Palermo Province with the 2003–2011 data from the Palermo Province Cancer Registry (Sicily, Italy). The properties of the funnel plot and choropleth map methodologies were compared within the context of disseminating epidemiological data to stakeholders. Results The SIRs of all the municipalities remained within the control limits, except for Palermo city area (SIR=1.12), which was sited outside the upper control limit line of 99.8%. The Palermo Province SIRs funnel plot representation was congruent with the choropleth map generated from the same data, but the former resulted more informative as shown by the comparisons of the weaknesses and strengths of the 2 visual formats. Conclusions Funnel plot should be used as a complementary valuable tool to communicate epidemiological data of cancer registries to communities and local authorities, visually conveying an efficient and simple way to interpret cancer incidence data. PMID:28363917

Lateral charge transport from heavy-ion tracks in integrated circuit chips

NASA Technical Reports Server (NTRS)

Zoutendyk, J. A.; Schwartz, H. R.; Nevill, L. R.

1988-01-01

A 256K DRAM has been used to study the lateral transport of charge (electron-hole pairs) induced by direct ionization from heavy-ion tracks in an IC. The qualitative charge transport has been simulated using a two-dimensional numerical code in cylindrical coordinates. The experimental bit-map data clearly show the manifestation of lateral charge transport in the creation of adjacent multiple-bit errors from a single heavy-ion track. The heavy-ion data further demonstrate the occurrence of multiple-bit errors from single ion tracks with sufficient stopping power. The qualitative numerical simulation results suggest that electric-field-funnel-aided (drift) collection accounts for single error generated by an ion passing through a charge-collecting junction, while multiple errors from a single ion track are due to lateral diffusion of ion-generated charge.

Fluorescence polarization measures energy funneling in single light-harvesting antennas—LH2 vs conjugated polymers

NASA Astrophysics Data System (ADS)

Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J.; Sforazzini, Giuseppe; Anderson, Harry L.; Pullerits, Tõnu; Scheblykin, Ivan G.

2015-10-01

Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ɛ). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ɛ = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

Fluorescence polarization measures energy funneling in single light-harvesting antennas--LH2 vs conjugated polymers.

PubMed

Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J; Sforazzini, Giuseppe; Anderson, Harry L; Pullerits, Tõnu; Scheblykin, Ivan G

2015-10-19

Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ε). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ε = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET.

Lead recovery and the feasibility of foam glass production from funnel glass of dismantled cathode ray tube through pyrovacuum process.

PubMed

Chen, Mengjun; Zhang, Fu-Shen; Zhu, Jianxin

2009-01-30

Cathode ray tube (CRT) is the first and foremost problem that must be solved in electronic waste disposal, and the key of which lies in the detoxification and reutilization of lead-contained funnel glass. In this study, a novel and effective process for funnel glass of dismantled CRT treatment was developed. The key point of the process was to recover metallic lead from the funnel glass and to prepare foam glass synchronously. Experimental results showed that lead recovery rate increased first with the increase of temperature, carbon adding amount, and holding time, then reached a plateau value, but pressure was on the contrary. The optimum temperature, pressure, carbon adding amount and holding time for lead recovery were 1000 degrees C, 1000 Pa, 5% and 4h, respectively, and the maximum lead recovery rate was 98.6%. In the pyrovacuum process, lead in the funnel glass was firstly detached and changed to PbO, then reduced and evaporated, and was recovered in the form of pure metal with a purity of 99.3%. The residue porous glass was environmentally acceptable for construction application.

Variation in hospital mortality in an Australian neonatal intensive care unit network.

PubMed

Abdel-Latif, Mohamed E; Nowak, Gen; Bajuk, Barbara; Glass, Kathryn; Harley, David

2018-07-01

Studying centre-to-centre (CTC) variation in mortality rates is important because inferences about quality of care can be made permitting changes in practice to improve outcomes. However, comparisons between hospitals can be misleading unless there is adjustment for population characteristics and severity of illness. We sought to report the risk-adjusted CTC variation in mortality among preterm infants born <32 weeks and admitted to all eight tertiary neonatal intensive care units (NICUs) in the New South Wales and the Australian Capital Territory Neonatal Network (NICUS), Australia. We analysed routinely collected prospective data for births between 2007 and 2014. Adjusted mortality rates for each NICU were produced using a multiple logistic regression model. Output from this model was used to construct funnel plots. A total of 7212 live born infants <32 weeks gestation were admitted consecutively to network NICUs during the study period. NICUs differed in their patient populations and severity of illness.The overall unadjusted hospital mortality rate for the network was 7.9% (n=572 deaths). This varied from 5.3% in hospital E to 10.4% in hospital C. Adjusted mortality rates showed little CTC variation. No hospital reached the +99.8% control limit level on adjusted funnel plots. Characteristics of infants admitted to NICUs differ, and comparing unadjusted mortality rates should be avoided. Logistic regression-derived risk-adjusted mortality rates plotted on funnel plots provide a powerful visual graphical tool for presenting quality performance data. CTC variation is readily identified, permitting hospitals to appraise their practices and start timely intervention. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Halyomorpha halys (Hemiptera: Pentatomidae) response to pyramid traps baited with attractive light and pheromonal stimuli

USDA-ARS?s Scientific Manuscript database

Halyomorpha halys is an invasive insect that causes severe economic damage to multiple agricultural commodities. Several monitoring techniques have been developed to monitor H. halys including pheromone and light-baited black pyramid traps. Here, we evaluated the attractiveness of these traps bait...

[Comparative quality measurements part 3: funnel plots].

PubMed

Kottner, Jan; Lahmann, Nils

2014-02-01

Comparative quality measurements between organisations or institutions are common. Quality measures need to be standardised and risk adjusted. Random error must also be taken adequately into account. Rankings without consideration of the precision lead to flawed interpretations and enhances "gaming". Application of confidence intervals is one possibility to take chance variation into account. Funnel plots are modified control charts based on Statistical Process Control (SPC) theory. The quality measures are plotted against their sample size. Warning and control limits that are 2 or 3 standard deviations from the center line are added. With increasing group size the precision increases and so the control limits are forming a funnel. Data points within the control limits are considered to show common cause variation; data points outside special cause variation without the focus of spurious rankings. Funnel plots offer data based information about how to evaluate institutional performance within quality management contexts.

Adapting the buying funnel model of consumer behavior to the design of an online health research recruitment tool.

PubMed

Doshi, Aalap; Connally, Lisa; Spiroff, Meghan; Johnson, Anita; Mashour, George A

2017-08-01

UMHealthResearch is the University of Michigan's digital health research recruitment platform. It allows health researchers to connect efficiently with potentially eligible volunteers. In 2013, the UMHealthResearch team strategically adapted a consumer behavior model, the buying funnel, to create the Digital Health Research Participation Funnel. The Digital Health Research Participation Funnel was then used to design a more active way for potential participants to volunteer for research studies through UMHealthResearch. In the 5 years before the redesign (2007-2012), an average of 1844 new accounts were created every year, whereas in the completed years after the redesign (2013-2016) the annual average improved to 3906, an increase of 111%. Although a randomized design was not possible in this instance, these preintervention and postintervention data suggest that the focus on user experience is an effective strategy for improving web-based research recruitment platforms.

Cold Atom Source Containing Multiple Magneto-Optical Traps

NASA Technical Reports Server (NTRS)

Ramirez-Serrano, Jaime; Kohel, James; Kellogg, James; Lim, Lawrence; Yu, Nan; Maleki, Lute

2007-01-01

An apparatus that serves as a source of a cold beam of atoms contains multiple two-dimensional (2D) magneto-optical traps (MOTs). (Cold beams of atoms are used in atomic clocks and in diverse scientific experiments and applications.) The multiple-2D-MOT design of this cold atom source stands in contrast to single-2D-MOT designs of prior cold atom sources of the same type. The advantages afforded by the present design are that this apparatus is smaller than prior designs.

Free-energy landscapes from adaptively biased methods: Application to quantum systems

NASA Astrophysics Data System (ADS)

Calvo, F.

2010-10-01

Several parallel adaptive biasing methods are applied to the calculation of free-energy pathways along reaction coordinates, choosing as a difficult example the double-funnel landscape of the 38-atom Lennard-Jones cluster. In the case of classical statistics, the Wang-Landau and adaptively biased molecular-dynamics (ABMD) methods are both found efficient if multiple walkers and replication and deletion schemes are used. An extension of the ABMD technique to quantum systems, implemented through the path-integral MD framework, is presented and tested on Ne38 against the quantum superposition method.

Comparison of sampling methodologies and estimation of population parameters for a temporary fish ectoparasite.

PubMed

Artim, J M; Sikkel, P C

2016-08-01

Characterizing spatio-temporal variation in the density of organisms in a community is a crucial part of ecological study. However, doing so for small, motile, cryptic species presents multiple challenges, especially where multiple life history stages are involved. Gnathiid isopods are ecologically important marine ectoparasites, micropredators that live in substrate for most of their lives, emerging only once during each juvenile stage to feed on fish blood. Many gnathiid species are nocturnal and most have distinct substrate preferences. Studies of gnathiid use of habitat, exploitation of hosts, and population dynamics have used various trap designs to estimate rates of gnathiid emergence, study sensory ecology, and identify host susceptibility. In the studies reported here, we compare and contrast the performance of emergence, fish-baited and light trap designs, outline the key features of these traps, and determine some life cycle parameters derived from trap counts for the Eastern Caribbean coral-reef gnathiid, Gnathia marleyi. We also used counts from large emergence traps and light traps to estimate additional life cycle parameters, emergence rates, and total gnathiid density on substrate, and to calibrate the light trap design to provide estimates of rate of emergence and total gnathiid density in habitat not amenable to emergence trap deployment.

The complex folding pathways of protein A suggest a multiple-funnelled energy landscape

NASA Astrophysics Data System (ADS)

St-Pierre, Jean-Francois; Mousseau, Normand; Derreumaux, Philippe

2008-01-01

Folding proteins into their native states requires the formation of both secondary and tertiary structures. Many questions remain, however, as to whether these form into a precise order, and various pictures have been proposed that place the emphasis on the first or the second level of structure in describing folding. One of the favorite test models for studying this question is the B domain of protein A, which has been characterized by numerous experiments and simulations. Using the activation-relaxation technique coupled with a generic energy model (optimized potential for efficient peptide structure prediction), we generate more than 50 folding trajectories for this 60-residue protein. While the folding pathways to the native state are fully consistent with the funnel-like description of the free energy landscape, we find a wide range of mechanisms in which secondary and tertiary structures form in various orders. Our nonbiased simulations also reveal the presence of a significant number of non-native β and α conformations both on and off pathway, including the visit, for a non-negligible fraction of trajectories, of fully ordered structures resembling the native state of nonhomologous proteins.

The protein folding network

NASA Astrophysics Data System (ADS)

Rao, Francesco; Caflisch, Amedeo

2004-03-01

Networks are everywhere. The conformation space of a 20-residue antiparallel beta-sheet peptide [1], sampled by molecular dynamics simulations, is mapped to a network. Conformations are nodes of the network, and the transitions between them are links. As previously found for the World-Wide Web as well as for social and biological networks , the conformation space contains highly connected hubs like the native state which is the most populated free energy basin. Furthermore, the network shows a hierarchical modularity [2] which is consistent with the funnel mechanism of folding [3] and is not observed for a random heteropolymer lacking a native state. Here we show that the conformation space network describes the free energy landscape without requiring projections into arbitrarily chosen reaction coordinates. The network analysis provides a basis for understanding the heterogeneity of the folding transition state and the existence of multiple pathways. [1] P. Ferrara and A. Caflisch, Folding simulations of a three-stranded antiparallel beta-sheet peptide, PNAS 97, 10780-10785 (2000). [2] Ravasz, E. and Barabási, A. L. Hierarchical organization in complex networks. Phys. Rev. E 67, 026112 (2003). [3] Dill, K. and Chan, H From Levinthal to pathways to funnels. Nature Struct. Biol. 4, 10-19 (1997)

Refractive multiple optical tweezers for parallel biochemical analysis in micro-fluidics

NASA Astrophysics Data System (ADS)

Merenda, Fabrice; Rohner, Johann; Pascoal, Pedro; Fournier, Jean-Marc; Vogel, Horst; Salathé, René-Paul

2007-02-01

We present a multiple laser tweezers system based on refractive optics. The system produces an array of 100 optical traps thanks to a refractive microlens array, whose focal plane is imaged into the focal plane of a high-NA microscope objective. This refractive multi-tweezers system is combined to micro-fluidics, aiming at performing simultaneous biochemical reactions on ensembles of free floating objects. Micro-fluidics allows both transporting the particles to the trapping area, and conveying biochemical reagents to the trapped particles. Parallel trapping in micro-fluidics is achieved with polystyrene beads as well as with native vesicles produced from mammalian cells. The traps can hold objects against fluid flows exceeding 100 micrometers per second. Parallel fluorescence excitation and detection on the ensemble of trapped particles is also demonstrated. Additionally, the system is capable of selectively and individually releasing particles from the tweezers array using a complementary steerable laser beam. Strategies for high-yield particle capture and individual particle release in a micro-fluidic environment are discussed. A comparison with diffractive optical tweezers enhances the pros and cons of refractive systems.

Evolved Minimal Frustration in Multifunctional Biomolecules.

PubMed

Röder, Konstantin; Wales, David J

2018-05-25

Protein folding is often viewed in terms of a funnelled potential or free energy landscape. A variety of experiments now indicate the existence of multifunnel landscapes, associated with multifunctional biomolecules. Here, we present evidence that these systems have evolved to exhibit the minimal number of funnels required to fulfil their cellular functions, suggesting an extension to the principle of minimum frustration. We find that minimal disruptive mutations result in additional funnels, and the associated structural ensembles become more diverse. The same trends are observed in an atomic cluster. These observations suggest guidelines for rational design of engineered multifunctional biomolecules.

Nature of inclined growth in thin-layer electrodeposition under uniform magnetic fields.

PubMed

Soba, Alejandro; González, Graciela; Calivar, Lucas; Marshall, Guillermo

2012-11-01

Electrochemical deposition (ECD) in thin cells in a vertical position relative to gravity, subject to an external uniform magnetic field, yields a growth pattern formation with dense branched morphology with branches tilted in the direction of the magnetic force. We study the nature of the inclined growth through experiments and theory. Experiments in ECD, in the absence of magnetic forces, reveal that a branch grows by allowing fluid to penetrate its tip and to be ejected from the sides through a pair of symmetric vortices attached to the tip. The upper vortices zone defines an arch separating an inner zone ion depleted and an outer zone in a funnel-like form with a concentrated solution through which metal ions are carried into the tip. When a magnetic field is turned on, vortex symmetry is broken, one vortex becoming weaker than the other, inducing an inclination of the funnel. Consequently, particles entering the funnel give rise to branch growth tilted in the same direction. Theory predicts, in the absence of a magnetic force, funnel symmetry induced through symmetric vortices driven by electric and gravitational forces; when the magnetic force is on, it is composed with the pair of clockwise and counterclockwise vortices, reducing or amplifying one or the other. In turn, funnel tilting modifies particle trajectories, thus, growth orientation.

Fluorescence polarization measures energy funneling in single light-harvesting antennas—LH2 vs conjugated polymers

PubMed Central

Camacho, Rafael; Tubasum, Sumera; Southall, June; Cogdell, Richard J.; Sforazzini, Giuseppe; Anderson, Harry L.; Pullerits, Tõnu; Scheblykin, Ivan G.

2015-01-01

Numerous approaches have been proposed to mimic natural photosynthesis using artificial antenna systems, such as conjugated polymers (CPs), dendrimers, and J-aggregates. As a result, there is a need to characterize and compare the excitation energy transfer (EET) properties of various natural and artificial antennas. Here we experimentally show that EET in single antennas can be characterized by 2D polarization imaging using the single funnel approximation. This methodology addresses the ability of an individual antenna to transfer its absorbed energy towards a single pool of emissive states, using a single parameter called energy funneling efficiency (ε). We studied individual peripheral antennas of purple bacteria (LH2) and single CP chains of 20 nm length. As expected from a perfect antenna, LH2s showed funneling efficiencies close to unity. In contrast, CPs showed lower average funneling efficiencies, greatly varying from molecule to molecule. Cyclodextrin insulation of the conjugated backbone improves EET, increasing the fraction of CPs possessing ε = 1. Comparison between LH2s and CPs shows the importance of the protection systems and the protein scaffold of LH2, which keep the chromophores in functional form and at such geometrical arrangement that ensures excellent EET. PMID:26478272

Energy transfer dynamics in Light-Harvesting Dendrimers

NASA Astrophysics Data System (ADS)

Melinger, Joseph S.; McMorrow, Dale; Kleiman, Valeria D.

2002-03-01

We explore energy transfer dynamics in light-harvesting phenylacetylene symmetric and asymmetric dendrimers. Femtosecond pump-probe spectroscopy is used to probe the ultrafast dynamics of electronic excitations in these dendrimers. The backbone of the macromolecule consists of branches of increasing conjugation length, creating an energy gradient, which funnels energy to an accepting perylene trap. In the case of the symmetric dendrimer (nanostar), the energy transfer efficiency is known to approach nearly unity, although the nature and timescale of the energy transfer process is still unknown. For the asymmetric dendrimers, energy transfer efficiencies are very high, with the possibility of more complex transfer processes. We experimentally monitor the transport of excitons through the light-harvesting dendrimer. The transients show a number of components, with timescales ranging from <300fs to several tens of picoseconds, revealing the complex photophysics taking place in these macromolecules. We interpret our results in terms of the Förster mechanism in which energy transfer occurs through dipole-dipole interactions.

/sup 239/Pu contamination in snakes inhabiting the Rocky Flats Plant site

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

Geiger, R.A.; Winsor, T.F.

1975-01-01

For approximately four years studies have been under way at the Rocky Flats plant to determine contamination patterns and concentrations of Pu in the biota. Contamination of the Rocky Flats environs has resulted from at least three incidents, a September 1957 fire, a May 1969 fire, and leaking barrels containing plutonium-laden cutting oil. The latter incident was considered by far the major source of the plutonium contamination. Results are reported from a study conducted to determine whether snake tissues of the area contained detectable amounts of /sup 239/Pu and, if so, at what concentrations. Eastern yellow-bellied racers (Coluber constrictor flaviventris,more » bullsnakes (Pituophis melanoleucus sayi, and prairie rattlesnakes (Crotalus viridis viridis, were collected for /sup 239/Pu bioassay of lung, liver, and bone tissues. Snakes were captured using drift fences terminating in funnel traps and by opportunistic sampling. Results led to the conclusion that snakes are not an important organism in the redistribution of /sup 239/Pu. (CH)« less

Monodisperse self-assembly in a model with protein-like interactions

NASA Astrophysics Data System (ADS)

Wilber, Alex W.; Doye, Jonathan P. K.; Louis, Ard A.; Lewis, Anna C. F.

2009-11-01

We study the self-assembly behavior of patchy particles with "proteinlike" interactions that can be considered as a minimal model for the assembly of viral capsids and other shell-like protein complexes. We thoroughly explore the thermodynamics and dynamics of self-assembly as a function of the parameters of the model and find robust assembly of all target structures considered. Optimal assembly occurs in the region of parameter space where a free energy barrier regulates the rate of nucleation, thus preventing the premature exhaustion of the supply of monomers that can lead to the formation of incomplete shells. The interactions also need to be specific enough to prevent the assembly of malformed shells, but while maintaining kinetic accessibility. Free energy landscapes computed for our model have a funnel-like topography guiding the system to form the target structure and show that the torsional component of the interparticle interactions prevents the formation of disordered aggregates that would otherwise act as kinetic traps.

ABCluster: the artificial bee colony algorithm for cluster global optimization.

PubMed

Zhang, Jun; Dolg, Michael

2015-10-07

Global optimization of cluster geometries is of fundamental importance in chemistry and an interesting problem in applied mathematics. In this work, we introduce a relatively new swarm intelligence algorithm, i.e. the artificial bee colony (ABC) algorithm proposed in 2005, to this field. It is inspired by the foraging behavior of a bee colony, and only three parameters are needed to control it. We applied it to several potential functions of quite different nature, i.e., the Coulomb-Born-Mayer, Lennard-Jones, Morse, Z and Gupta potentials. The benchmarks reveal that for long-ranged potentials the ABC algorithm is very efficient in locating the global minimum, while for short-ranged ones it is sometimes trapped into a local minimum funnel on a potential energy surface of large clusters. We have released an efficient, user-friendly, and free program "ABCluster" to realize the ABC algorithm. It is a black-box program for non-experts as well as experts and might become a useful tool for chemists to study clusters.

Abiotic processes are insufficient for fertile island development: A 10-year artificial shrub experiment in a desert grassland

NASA Astrophysics Data System (ADS)

Li, Junran; Gilhooly, William P.; Okin, Gregory S.; Blackwell, John

2017-03-01

The relative importance of biotic and abiotic processes in the development of "fertile islands" in dryland systems has rarely been investigated. Here we approached this question by using artificial shrubs, which exclude plant litter production and soil nutrient uptake, but retain the functions of trapping windblown material, funneling of stemflow, and differential rain splash. We conducted a vegetation manipulation study more than a decade ago in the desert grassland of southern New Mexico and subsequently revisited the site in 2012 and 2015. The results show that no notable soil mounds were observed under the artificial shrubs; however, soil texture under the artificial shrubs has gradually changed to resemble the patterns of soil particle-size distribution under natural shrubs. Our results highlight that with the exclusion of direct biotic additions, soils captured by shrub canopies are not necessarily fertile and thus do not themselves contribute to the development of fertile islands.

Validation of the Berlese-funnel technique for thrips extraction.

PubMed

Casteels, H; Witters, J; De Bondt, G; Desamblanx, J

2009-01-01

In order to get the accreditation EN ISO/IEC 17025 for Thrips palmi the Berlese-funnel technique, which is used for the isolation of quarantine insects out of plant material, was validated. Following parameters were investigated: cleaning of the funnel, temperature during isolation, detection limit and duration of the isolation period. Thrips fuscipennis was collected from heavily infected rosehip and used as target organism. Besides orchids, artificially contaminated maple leaves (Acer pseudoplatanus) were used for the validation. Results showed that thrips and other organisms can be present alive or dead in the funnel after removing the treated plants and can contaminate the next sample or isolate. Cleaning of the funnel with a vacuum cleaner and compressed-air apparatus is necessary before running a new extraction. Contamination of the recipient is also possible from the environment. This can be avoided by closing the opening between the funnel and the recipient. To reach an optimal temperature for isolation of the thrips a 60 Watt bulb is necessary. The results showed that the maximum temperature doesn't reach a temperature above 51 degrees C, the average temperatures were situated between 35, 74 degrees C and 39, 38 degrees C. A 40 Watt bulb doesn't create enough heat to guarantee an efficient isolation of the thrips; the average temperature was 34, 74 degrees C and the maximum temperature 36, 80 degrees C. Based on the results we can conclude that an isolation time of 20 hours is necessary to obtain accurate data. Dependent on the number of thrips in the artificially infected samples 87 to 95% is isolated after 20 hours. The detection limit is 1 thrips with a probability of 95% being isolated after 20 hours.

A study of electrically active traps in AlGaN/GaN high electron mobility transistor

NASA Astrophysics Data System (ADS)

Yang, Jie; Cui, Sharon; Ma, T. P.; Hung, Ting-Hsiang; Nath, Digbijoy; Krishnamoorthy, Sriram; Rajan, Siddharth

2013-10-01

We have studied electron conduction mechanisms and the associated roles of the electrically active traps in the AlGaN layer of an AlGaN/GaN high electron mobility transistor structure. By fitting the temperature dependent I-V (Current-Voltage) curves to the Frenkel-Poole theory, we have identified two discrete trap energy levels. Multiple traces of I-V measurements and constant-current injection experiment all confirm that the main role of the traps in the AlGaN layer is to enhance the current flowing through the AlGaN barrier by trap-assisted electron conduction without causing electron trapping.

Experiments on the transportation of a magnetized plasma stream in the GOL-3 facility

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

Postupaev, V. V., E-mail: V.V.Postupaev@inp.nsk.su; Batkin, V. I.; Burdakov, A. V.

2016-04-15

The program of the deep upgrade of the GOL-3 multiple-mirror trap is presented. The upgrade is aimed at creating a new GOL-NB open trap located at the GOL-3 site and intended to directly demonstrate the efficiency of using multiple-mirror magnetic cells to improve longitudinal plasma confinement in a gasdynamic open trap. The GOL-NB device will consist of a new central trap, adjoint cells with a multiple-mirror magnetic field, and end tanks (magnetic flux expanders). Plasma in the central trap will be heated by neutral beam injection with a power of up to 1.5 MW and duration of 1 ms. Atmore » present, physical experiments directed at developing plasma technologies that are novel for this facility are being carried out using the 6-m-long autonomous part of the GOL-3 solenoid. The aim of this work was to develop a method for filling the central trap with a low-temperature start plasma. Transportation of a plasma stream from an arc source over a distance of 3 m in a uniform magnetic field with an induction of 0.5–4.5 T is demonstrated. In these experiments, the axial plasma density was (1–4) × 10{sup 20} m{sup –3} and the mirror ratio varied from 5 to 60. In general, the experiments confirmed the correctness of the adopted decisions for the start plasma source of the GOL-NB device.« less

Biomimetic light-harvesting funnels for re-directioning of diffuse light.

PubMed

Pieper, Alexander; Hohgardt, Manuel; Willich, Maximilian; Gacek, Daniel Alexander; Hafi, Nour; Pfennig, Dominik; Albrecht, Andreas; Walla, Peter Jomo

2018-02-14

Efficient sunlight harvesting and re-directioning onto small areas has great potential for more widespread use of precious high-performance photovoltaics but so far intrinsic solar concentrator loss mechanisms outweighed the benefits. Here we present an antenna concept allowing high light absorption without high reabsorption or escape-cone losses. An excess of randomly oriented pigments collects light from any direction and funnels the energy to individual acceptors all having identical orientations and emitting ~90% of photons into angles suitable for total internal reflection waveguiding to desired energy converters (funneling diffuse-light re-directioning, FunDiLight). This is achieved using distinct molecules that align efficiently within stretched polymers together with others staying randomly orientated. Emission quantum efficiencies can be >80% and single-foil reabsorption <0.5%. Efficient donor-pool energy funneling, dipole re-orientation, and ~1.5-2 nm nearest donor-acceptor transfer occurs within hundreds to ~20 ps. Single-molecule 3D-polarization experiments confirm nearly parallel emitters. Stacked pigment selection may allow coverage of the entire solar spectrum.

Particle injector for fluid systems

DOEpatents

Ruch, Jeffrey F.

1997-01-01

A particle injector device provides injection of particles into a liquid eam. The device includes a funnel portion comprising a conical member having side walls tapering from a top opening (which receives the particles) down to a relatively smaller exit opening. A funnel inlet receives a portion of the liquid stream and the latter is directed onto the side walls of the conical member so as to create a cushion of liquid against which the particles impact. A main section of the device includes an inlet port in communication with the exit opening of the funnel portion. A main liquid inlet receives the main portion of the liquid stream at high pressure and low velocity and a throat region located downstream of the main liquid inlet accelerates liquid received by this inlet from the low velocity to a higher velocity so as to create a low pressure area at the exit opening of the funnel portion. An outlet opening of the main section enables the particles and liquid stream to exit from the injector device.

The Solar Chromosphere/Corona Interface. I; FUV-EUV Observations and Modeling of Unresolved Coronal Funnels

NASA Technical Reports Server (NTRS)

Martinez-Galarce, D. S.; Walker, A. B. C.; Barbee, T. W., II; Hoover, R. B.

2003-01-01

A coronal funnel model, developed by Rabin (199l), was tested against a calibrated spectroheliogram recorded in 171 - 175 Angstrom bandpass. This image was recorded on board a sounding rocket experiment flown on 1994 November 3, called the Multi-Spectral Solar Telescope Array, II (MSSTA II), MSSTA, a joint project of Stanford University, the NASA Marshall Space Flight Center and the Lawrence Livermore National Laboratory, is an observing platform composed of a set of normal-incidence, multilayer-coated optics designed to obtain narrow bandpass, high resolution images (1 - 3 arc sec) at selected FUV, EUV and soft X-ray wavelengths (44 Angstroms - 1550 Angstroms). Using full-disk images centered at 1550 Angstroms (C IV) and 173 Angstroms (FE IX/X), the funnel model, which is based on coronal back-heating, was tested against the data incorporating observed constraints on global coverage and measured flux. Found, was a class of funnel models that could account for the quiescent, globally diffuse and unresolved emission seen in the 171 - 175 Angstrom bandpass, where the funnels are assumed to be rooted in the C IV supergranular network. These models, when incorporated with the Chianti spectral code, suggest that this emission is mostly of upper transition region origin and primarily composed of FE IX plasma. The funnels are found to have constrictions, Gamma approx. 6 - 20, which is in good agreement with the observations. Further, the fitted models simultaneously satisfy global areal constraints seen in both images; namely, that a global network of funnels must cover approx. 70 - 95 % of the total solar surface area seen in the 171 - 175 Angstrom image, and = 45 % of the disk area seen in the 1550 Angstrom bandpass. These findings support the configuration of the EUV magnetic network as suggested by Reeves et af. (1974) and put forth in more detail by Gabriel (1976). Furthermore, the models are in good agreement with differential emission measure estimates made of the transition region by Raymond & Doyle (1981) for temperatures, 250,000 K = T = 650,000 K, based on full-disk observations made on board by SkyLab.

The Solar Chromosphere/Corona Interface. I. Far-Ultraviolet to Extreme-Ultraviolet Observations and Modeling of Unresolved Coronal Funnels

NASA Technical Reports Server (NTRS)

Martinez-Galarce, Dennis S.; Walker, Arthur C., III; Barbee, Troy W., II; Hoover, Richard B.

2003-01-01

A coronal funnel model, developed by D. Rabin, was tested against a calibrated spectroheliogram recorded in the 170-1 75 A bandpass. This image was recorded on board a sounding-rocket experiment flown on 1994 November 3, called the Multi-Spectral Solar Telescope Array II (MSSTA II). MSSTA, a joint project of Stanford University, the NASA Marshall Space Flight Center, and the Lawrence Livermore National Laboratory' is an observing platform composed of a set of normal-incidence, multilayer-coated optics designed to obtain narrow-bandpass, high-resolution images (1 sec.- 3 sec.) at selected far-ultraviolet (FUV), extreme-ultraviolet (EUV), and soft X-ray wavelengths (44-1550 A). Using full disk images centered at 1550 A (C IV) and 173 A (Fe IX/X), the funnel model, which is based on coronal back-heating, was tested against the data incorporating observed constraints on global coverage and measured flux. Found was a class of funnel models that could account for the quiescent, globally diffuse and unresolved emission seen in the 171-175 A bandpass, where the funnels are assumed to be rooted in the C IV supergranular network. These models, when incorporated with the CHIANTI spectral code, suggest that this emission is mostly of upper transition region origin and primarily composed of Fe IX plasma. The funnels are found to have constrictions, Gamma approx. 6-20, which is in good agreement with the observations. Further, the fitted models simultaneously satisfy global areal constraints seen in both images; namely,that a global network of funnels must cover approx. 700 - 95% of the total solar surface area seen in the 171-175 A image, and a 5% of the disk area seen in the 1550 A bandpass. These findings support the configuration of the EUV magnetic network as suggested by Reeves et al. and put forth in more detail by Gabriel. Furthermore, the models are in good agreement with differential emission measure estimates made of the transition region by J. C. Raymond & J. G. Doyle for temperatures 250,000 K less than or = T less than or = 650,000 K, based on full-disk observations made on board Skylab.

Evaluation of border traps and interface traps in HfO2/MoS2 gate stacks by capacitance–voltage analysis

NASA Astrophysics Data System (ADS)

Zhao, Peng; Khosravi, Ava; Azcatl, Angelica; Bolshakov, Pavel; Mirabelli, Gioele; Caruso, Enrico; Hinkle, Christopher L.; Hurley, Paul K.; Wallace, Robert M.; Young, Chadwin D.

2018-07-01

Border traps and interface traps in HfO2/few-layer MoS2 top-gate stacks are investigated by C–V characterization. Frequency dependent C–V data shows dispersion in both the depletion and accumulation regions for the MoS2 devices. The border trap density is extracted with a distributed model, and interface traps are analyzed using the high-low frequency and multi-frequency methods. The physical origins of interface traps appear to be caused by impurities/defects in the MoS2 layers, performing as band tail states, while the border traps are associated with the dielectric, likely a consequence of the low-temperature deposition. This work provides a method of using multiple C–V measurements and analysis techniques to analyze the behavior of high-k/TMD gate stacks and deconvolute border traps from interface traps.

Ionization source utilizing a jet disturber in combination with an ion funnel and method of operation

DOEpatents

Smith, Richard D.; Kim, Taeman; Tang, Keqi; Udseth, Harold R.

2003-06-24

A jet disturber used in combination with an ion funnel to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of the ions and other charged particles. The jet disturber is positioned within an ion funnel and may be interfaced with a multi-capillary inlet juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure. The invention finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer.

Continuous-flow trapping and localized enrichment of micro- and nano-particles using induced-charge electrokinetics.

PubMed

Zhao, Cunlu; Yang, Chun

2018-02-14

In this work, we report an effective microfluidic technique for continuous-flow trapping and localized enrichment of micro- and nano-particles by using induced-charge electrokinetic (ICEK) phenomena. The proposed technique utilizes a simple microfluidic device that consists of a straight microchannel and a conducting strip attached to the bottom wall of the microchannel. Upon application of the electric field along the microchannel, the conducting strip becomes polarized to introduce two types of ICEK phenomena, the ICEK flow vortex and particle dielectrophoresis, and they are identified by a theoretical model formulated in this study to be jointly responsible for the trapping of particles over the edge of the conducting strip. Our experiments showed that successful trapping requires an AC/DC combined electric field: the DC component is mainly to induce electroosmotic flow for transporting particles to the trapping location; the AC component induces ICEK phenomena over the edge of the conducting strip for particle trapping. The performance of the technique is examined with respect to the applied electric voltage, AC frequency and the particle size. We observed that the trapped particles form a narrow band (nearly a straight line) defined by the edge of the conducting strip, thereby allowing localized particle enrichment. For instance, we found that under certain conditions a high particle enrichment ratio of 200 was achieved within 30 seconds. We also demonstrated that the proposed technique was able to trap particles from several microns down to several tens of nanometer. We believe that the proposed ICEK trapping would have great flexibility that the trapping location can be readily varied by controlling the location of the patterned conducting strip and multiple-location trapping can be expected with the use of multiple conducting strips.

Nanohystricidae n. fam., an unusual, plesiomorphic enarthronote mite family endemic to New Zealand (Acari, Oribatida).

PubMed

Norton, Roy A; Fuangarworn, Marut

2015-10-02

Nanohystrix hammerae n. gen., n. sp.--proposed on the basis of numerous adults and a few juveniles--is a new oribatid mite of the infraorder Enarthronota that appears to be phylogenetically relictual and endemic to northern New Zealand, in habitats ranging from native shrublands to native and semi-native forests. With an adult body length of 1-1.2 mm, the species is the largest known enarthronote mite outside Lohmanniidae, and it has an unusual combination of plesiomorphic and apomorphic traits. Plesiomorphies include: a well-formed median (naso) eye and pigmented lateral eyes; a bothridial seta with a simple, straight base; a vertically-oriented gnathosoma; a peranal segment; adanal sclerites partially incorporated in notogaster (uncertain polarity); three genu I solenidia and a famulus on tarsus II. Autapomorphies include: five pairs of pale cuticular disks on the notogaster, with unknown function; six pairs of long, erectile notogastral setae, including pair h2 incorporated in the second transverse scissure along with the f-row, and pair h1 in a third scissure; chelicerae that are unusually broad, creating a flat-faced appearance; legs I that are inferred to have an unusually wide range of motion. Further, it is the only enarthronote species known to have an elongated ovipositor, and one of few to have glassy, luminous notogastral setae. The gastronotum of juveniles lacks transverse scissures, but has isolated sclerites supporting setae, including erectile setae. The large character gaps between N. hammerae and other enarthronote taxa justifies proposal of a monotypic new family--Nanohystricidae n. fam.--which is tentatively grouped with several other relictual families in the paraphyletic Heterochthonioidea. Small muscles appear to be involved in the operation of all erectile setae, but seem to be only depressors, with erection effected by hysterosomal distension. Based on gut contents, its food is primarily fungal hyphae and spores, though ingestion of small arthropods also occurs (perhaps by necrophagy). Collections were made by Berlese-funnel samples of litter, by sweeping low vegetation, and (mainly) by pitfall traps; the latter two suggest that adults are surface-active. Tritonymphs were collected by pitfall traps, but earlier juveniles were collected only by Berlese-funnels. Adults are frequently infected with a eugregarine parasite, which can entirely fill the digestive caeca; immature trophozoites were also seen in tritonymphs. Adults also can serve as hosts for dispersal of secondary capilliconidia of the fungal genus Basidiobolus.

Lead recovery and glass microspheres synthesis from waste CRT funnel glasses through carbon thermal reduction enhanced acid leaching process.

PubMed

Mingfei, Xing; Yaping, Wang; Jun, Li; Hua, Xu

2016-03-15

In this study, a novel process for detoxification and reutilization of waste cathode ray tube (CRT) funnel glass was developed by carbon thermal reduction enhanced acid leaching process. The key to this process is removal of lead from the CRT funnel glass and synchronous preparation of glass microspheres. Carbon powder was used as an isolation agent and a reducing agent. Under the isolation of the carbon powder, the funnel glass powder was sintered into glass microspheres. In thermal reduction, PbO in the funnel glass was first reduced to elemental Pb by carbon monoxide and then located on the surface of glass microspheres which can be removed easily by acid leaching. Experimental results showed that temperature, carbon adding amount and holding time were the major parameters that controlled lead removal rate. The maximum lead removal rate was 94.80% and glass microspheres that measured 0.73-14.74μm were obtained successfully by setting the temperature, carbon adding amount and holding time at 1200°C, 10% and 30min, respectively. The prepared glass microspheres may be used as fillers in polymer materials and abrasive materials, among others. Accordingly, this study proposed a practical and economical process for detoxification and recycling of waste lead-containing glass. Copyright © 2015 Elsevier B.V. All rights reserved.

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

Cameron, Maria K., E-mail: cameron@math.umd.edu

We develop computational tools for spectral analysis of stochastic networks representing energy landscapes of atomic and molecular clusters. Physical meaning and some properties of eigenvalues, left and right eigenvectors, and eigencurrents are discussed. We propose an approach to compute a collection of eigenpairs and corresponding eigencurrents describing the most important relaxation processes taking place in the system on its way to the equilibrium. It is suitable for large and complex stochastic networks where pairwise transition rates, given by the Arrhenius law, vary by orders of magnitude. The proposed methodology is applied to the network representing the Lennard-Jones-38 cluster created bymore » Wales's group. Its energy landscape has a double funnel structure with a deep and narrow face-centered cubic funnel and a shallower and wider icosahedral funnel. However, the complete spectrum of the generator matrix of the Lennard-Jones-38 network has no appreciable spectral gap separating the eigenvalue corresponding to the escape from the icosahedral funnel. We provide a detailed description of the escape process from the icosahedral funnel using the eigencurrent and demonstrate a superexponential growth of the corresponding eigenvalue. The proposed spectral approach is compared to the methodology of the Transition Path Theory. Finally, we discuss whether the Lennard-Jones-38 cluster is metastable from the points of view of a mathematician and a chemical physicist, and make a connection with experimental works.« less

Observational Signatures of Mass-loading in Jets Launched by Rotating Black Holes

NASA Astrophysics Data System (ADS)

O’ Riordan, Michael; Pe’er, Asaf; McKinney, Jonathan C.

2018-01-01

It is widely believed that relativistic jets in X-ray binaries (XRBs) and active-galactic nuclei are powered by the rotational energy of black holes. This idea is supported by general-relativistic magnetohydrodynamic (GRMHD) simulations of accreting black holes, which demonstrate efficient energy extraction via the Blandford–Znajek mechanism. However, due to uncertainties in the physics of mass loading, and the failure of GRMHD numerical schemes in the highly magnetized funnel region, the matter content of the jet remains poorly constrained. We investigate the observational signatures of mass loading in the funnel by performing general-relativistic radiative transfer calculations on a range of 3D GRMHD simulations of accreting black holes. We find significant observational differences between cases in which the funnel is empty and cases where the funnel is filled with plasma, particularly in the optical and X-ray bands. In the context of Sgr A*, current spectral data constrains the jet filling only if the black hole is rapidly rotating with a ≳ 0.9. In this case, the limits on the infrared flux disfavor a strong contribution from material in the funnel. We comment on the implications of our models for interpreting future Event Horizon Telescope observations. We also scale our models to stellar-mass black holes, and discuss their applicability to the low-luminosity state in XRBs.

Prioritising the placement of riparian vegetation to reduce flood risk and end-of-catchment sediment yields: Important considerations in hydrologically-variable regions.

PubMed

Croke, Jacky; Thompson, Chris; Fryirs, Kirstie

2017-04-01

In perennial stream settings, there is abundant literature confirming that riparian vegetation affects flood hydrology by attenuating the flood wave, enhancing deposition and reducing bank erosion. In contrast, relatively little is known about the effectiveness of riparian vegetation during floods in hydrologically-variable regions. The dominant channel form in these settings is often referred to as a 'macrochannel' or compound channel-in-channel which displays multiple inundation surfaces where it is often difficult to identify the active channel bank and bank top. This study uses the inundation pattern of recent flood events in the Lockyer Valley of South East Queensland (SEQ), Australia to present a framework which specifically considers the interaction between inundation frequency and trapping potential on a range of inundation surfaces. Using hydrological modelling and a consistent definition of floodplains and within-channel features, it outlines five key priority areas for the placement of riparian vegetation to alleviate common flood problems within the catchment. The highest priority for the placement of riparian vegetation to ameliorate the effects of small-moderate floods is on within-channel benches. For out-of-macrochannel flows, riparian vegetation is most effective on genetic floodplains which occupy the largest spatial extent within the valley. In particular, it identifies the need for, and benefits of, revegetation in spill out zones (SOZ) which occur where upstream channel capacity is larger and flow is funnelled at high velocity onto the floodplain downstream. This study highlights the importance of understanding the key geomorphic processes occurring within a catchment and developing effective catchment management plans to suit these conditions. Copyright © 2016 Elsevier Ltd. All rights reserved.

Independent polarisation control of multiple optical traps

PubMed Central

Preece, Daryl; Keen, Stephen; Botvinick, Elliot; Bowman, Richard; Padgett, Miles; Leach, Jonathan

2009-01-01

We present a system which uses a single spatial light modulator to control the spin angular momentum of multiple optical traps. These traps may be independently controlled both in terms of spatial location and in terms of their spin angular momentum content. The system relies on a spatial light modulator used in a “split-screen” configuration to generate beams of orthogonal polarisation states which are subsequently combined at a polarising beam splitter. Defining the phase difference between the beams with the spatial light modulator enables control of the polarisation state of the light. We demonstrate the functionality of the system by controlling the rotation and orientation of birefringent vaterite crystals within holographic optical tweezers. PMID:18825226

Evidence from mixed hydrate nucleation for a funnel model of crystallization.

PubMed

Hall, Kyle Wm; Carpendale, Sheelagh; Kusalik, Peter G

2016-10-25

The molecular-level details of crystallization remain unclear for many systems. Previous work has speculated on the phenomenological similarities between molecular crystallization and protein folding. Here we demonstrate that molecular crystallization can involve funnel-shaped potential energy landscapes through a detailed analysis of mixed gas hydrate nucleation, a prototypical multicomponent crystallization process. Through this, we contribute both: (i) a powerful conceptual framework for exploring and rationalizing molecular crystallization, and (ii) an explanation of phenomenological similarities between protein folding and crystallization. Such funnel-shaped potential energy landscapes may be typical of broad classes of molecular ordering processes, and can provide a new perspective for both studying and understanding these processes.

Evidence from mixed hydrate nucleation for a funnel model of crystallization

PubMed Central

Hall, Kyle Wm.; Carpendale, Sheelagh; Kusalik, Peter G.

2016-01-01

The molecular-level details of crystallization remain unclear for many systems. Previous work has speculated on the phenomenological similarities between molecular crystallization and protein folding. Here we demonstrate that molecular crystallization can involve funnel-shaped potential energy landscapes through a detailed analysis of mixed gas hydrate nucleation, a prototypical multicomponent crystallization process. Through this, we contribute both: (i) a powerful conceptual framework for exploring and rationalizing molecular crystallization, and (ii) an explanation of phenomenological similarities between protein folding and crystallization. Such funnel-shaped potential energy landscapes may be typical of broad classes of molecular ordering processes, and can provide a new perspective for both studying and understanding these processes. PMID:27790987

Lead recovery from waste CRT funnel glass by high-temperature melting process.

PubMed

Hu, Biao; Hui, Wenlong

2018-02-05

In this research, a novel and effective process for waste CRT funnel glass treatment was developed. The key to this process is removal of lead from the CRT funnel glass by high-temperature melting process. Sodium carbonate powder was used as a fusion agent, sodium sulfide serves as a catalytic agent and carbon powder acts as reducing agent. Experimental results showed that lead recovery rate increased with an increase in the amount of added sodium carbonate, sodium sulfide, carbonate, temperature and holding time initially, and then reached a stable value. The maximum lead recovery rate was approximately 94%, when the optimum adding amount of sodium carbonate, sodium sulfide, carbonate, temperature and holding time were 25%, 8%, 3.6%, 1200°C and 120min, respectively. In the high-temperature melting process, lead silicate in the funnel glass was firstly reduced, and then removed. The glass slag can be made into sodium and potassium silicate by hydrolysis process. This study proposed a practical and economical process for recovery of lead and utilization of waste glass slag. Copyright © 2017 Elsevier B.V. All rights reserved.

Funnel metadynamics as accurate binding free-energy method

PubMed Central

Limongelli, Vittorio; Bonomi, Massimiliano; Parrinello, Michele

2013-01-01

A detailed description of the events ruling ligand/protein interaction and an accurate estimation of the drug affinity to its target is of great help in speeding drug discovery strategies. We have developed a metadynamics-based approach, named funnel metadynamics, that allows the ligand to enhance the sampling of the target binding sites and its solvated states. This method leads to an efficient characterization of the binding free-energy surface and an accurate calculation of the absolute protein–ligand binding free energy. We illustrate our protocol in two systems, benzamidine/trypsin and SC-558/cyclooxygenase 2. In both cases, the X-ray conformation has been found as the lowest free-energy pose, and the computed protein–ligand binding free energy in good agreement with experiments. Furthermore, funnel metadynamics unveils important information about the binding process, such as the presence of alternative binding modes and the role of waters. The results achieved at an affordable computational cost make funnel metadynamics a valuable method for drug discovery and for dealing with a variety of problems in chemistry, physics, and material science. PMID:23553839

[Pectus excavatum: what treatment in plastic surgery? About 10 cases].

PubMed

Poupon, M; Duteille, F; Casanova, D; Caye, N; Magalon, G; Pannier, M

2008-06-01

Several controversial issues concern pectus excavatum (funnel chest), the most common chest wall deformity. The pathogenesis of this deformity is uncertain, and there is no agreement as to its psychological, cardiac and pulmonary effects. An even more debatable point is the choice of surgical treatment among the more or less radical proposals made by different teams. No consensus exists concerning the indications for surgery, the technique to be used, or the suitable age of the patient. This retrospective study concerns 10 patients with funnel chest who underwent reconstruction surgery in our unit between 1989 and 2002. Nine patients received a silicone chest implant made to measure, and one a single breast implant. Each patient was interviewed and examined to obtain information and provide a basis for evaluation. The effects of possible associated abnormalities were evidenced by complementary cardiopulmonary examinations, and the severity of funnel chest was evaluated according to the Haller pectus index. The mean period after surgery was 5 years. The effects of funnel chest deformity were essentially psychological, relating to aesthetic disgrace. Although two-thirds of the deformities were considered severe, cardiopulmonary repercussions were minor. All 10 patients were satisfied with the repair performed, and this judgment was independent of surgical assessment. Acute complications concerned 5 seromas and one minimal scar separation. The indications for surgery and the means of surgical treatment for funnel chest are considered after comparison of our results with those in the literature and a survey of the different existing possibilities for treatment (implant, chondrosternoplasty, fat transplant).

An inhibitor of TRPV1 channels isolated from funnel Web spider venom.

PubMed

Kitaguchi, Tetsuya; Swartz, Kenton J

2005-11-29

Capsaicin receptor channels (TRPV1) are nonselective cation channels that integrate multiple noxious stimuli in sensory neurons. In an effort to identify new inhibitors of these channels we screened a venom library for activity against TRPV1 channels and found robust inhibitory activity in venom from Agelenopsis aperta, a north American funnel web spider. Fractionation of the venom using reversed-phase HPLC resulted in the purification of two acylpolyamine toxins, AG489 and AG505, which inhibit TRPV1 channels from the extracellular side of the membrane. The activity of AG489 was characterized further, and the toxin was found to inhibit TRPV1 channels with a K(i) of 0.3 microM at -40 mV. Inhibition of TRPV1 channels by AG489 is strongly voltage-dependent, with relief of inhibition at positive voltages, consistent with the toxin inhibiting the channel through a pore-blocking mechanism. We used scanning mutagenesis throughout the TM5-TM6 linker, a region thought to form the outer pore of TRPV1 channels, to identify pore mutations that alter toxin affinity. Four mutants dramatically decrease toxin affinity and several mutants increase toxin affinity, consistent with the notion that the TM5-TM6 linker forms the outer vestibule of TRPV1 channels and that AG489 is a pore blocker.

On the polymer physics origins of protein folding thermodynamics.

PubMed

Taylor, Mark P; Paul, Wolfgang; Binder, Kurt

2016-11-07

A remarkable feature of the spontaneous folding of many small proteins is the striking similarity in the thermodynamics of the folding process. This process is characterized by simple two-state thermodynamics with large and compensating changes in entropy and enthalpy and a funnel-like free energy landscape with a free-energy barrier that varies linearly with temperature. One might attribute the commonality of this two-state folding behavior to features particular to these proteins (e.g., chain length, hydrophobic/hydrophilic balance, attributes of the native state) or one might suspect that this similarity in behavior has a more general polymer-physics origin. Here we show that this behavior is also typical for flexible homopolymer chains with sufficiently short range interactions. Two-state behavior arises from the presence of a low entropy ground (folded) state separated from a set of high entropy disordered (unfolded) states by a free energy barrier. This homopolymer model exhibits a funneled free energy landscape that reveals a complex underlying dynamics involving competition between folding and non-folding pathways. Despite the presence of multiple pathways, this simple physics model gives the robust result of two-state thermodynamics for both the cases of folding from a basin of expanded coil states and from a basin of compact globule states.

On the polymer physics origins of protein folding thermodynamics

NASA Astrophysics Data System (ADS)

Taylor, Mark P.; Paul, Wolfgang; Binder, Kurt

2016-11-01

A remarkable feature of the spontaneous folding of many small proteins is the striking similarity in the thermodynamics of the folding process. This process is characterized by simple two-state thermodynamics with large and compensating changes in entropy and enthalpy and a funnel-like free energy landscape with a free-energy barrier that varies linearly with temperature. One might attribute the commonality of this two-state folding behavior to features particular to these proteins (e.g., chain length, hydrophobic/hydrophilic balance, attributes of the native state) or one might suspect that this similarity in behavior has a more general polymer-physics origin. Here we show that this behavior is also typical for flexible homopolymer chains with sufficiently short range interactions. Two-state behavior arises from the presence of a low entropy ground (folded) state separated from a set of high entropy disordered (unfolded) states by a free energy barrier. This homopolymer model exhibits a funneled free energy landscape that reveals a complex underlying dynamics involving competition between folding and non-folding pathways. Despite the presence of multiple pathways, this simple physics model gives the robust result of two-state thermodynamics for both the cases of folding from a basin of expanded coil states and from a basin of compact globule states.

The Sternocleidomastoid Muscle Flap: A Versatile Local Method for Repair of External Penetrating Injuries of Hypopharyngeal-Cervical Esophageal Funnel.

PubMed

Ellabban, Mohamed A

2016-04-01

A primary repair of external penetrating injury to hypopharyngeal-cervical esophageal (HP-CE) funnel without reinforcement has more complications if compared with muscle reinforcement. The aim of the present study was to assess the outcome of using sternocleidomastoid (SCM) muscle flap for reinforcement of primary repair of HP-CE funnel injury. The study proposed an algorithm for different uses of SCM flap repair according to site and size of funnel perforation. A prospective analysis of 12 patients, who had surgical treatment for external penetrating injuries of HP-CE funnel between January 2011 and September 2014, was recorded. The following factors were studied for each case: demographic data, Revised Trauma Score (RTS), mechanism of injury, time interval between injury and definitive surgical care, injury morphology, any associated injuries, technique of SCM flap used, length of hospital stay, and surgical outcome and complications. They were 10 males and 2 females and the mean age was 31.9 years. The cause of injury was stab wound in 5 (41.7 %) cases, gunshot injury in 4 (33.3 %) cases and 3 (25 %) cases after anterior cervical spine surgery. Isolated injury to HP and CE was recorded in 5 cases (41.7 %) for each site. However, 2 (16.7 %) cases had injury to both HP and CE. Cranially based SCM flap was mainly used in cases with HP injury and caudally based flap in CE cases with some limitations. The whole muscle flap was used in large (≥ 1 cm) defects while and the split muscle flap in small (<1 cm) defects. Oral intake started 7 days postoperatively with only one (8.3 %) case of small leakage, which was treated conservatively. The SCM flap is a very useful and versatile tool in reinforcement of HP-CE funnel injury with the advantages of high success rates of leakage prevention.

Completing the census of young stars near the Sun with the FunnelWeb spectroscopic survey

NASA Astrophysics Data System (ADS)

Lawson, Warrick; Murphy, Simon; Tinney, Christopher G.; Ireland, Michael; Bessell, Michael S.

2016-06-01

From late 2016, the Australian FunnelWeb survey will obtain medium-resolution (R~2000) spectra covering the full optical range for 2 million of the brightest stars (I<12) in the southern sky. It will do so using an upgraded UK Schmidt Telescope at Siding Spring Observatory, equipped with a revolutionary, parallelizable optical fibre positioner ("Starbugs") and spectrograph. The ability to reconfigure a multi-fibre plate in less than 5 minutes allows FunnelWeb to observe more stars per night than any other competing multi-fibre spectrograph and enables a range of previously inefficient bright star science not attempted since the completion of the HD catalogues in the 1940s. Among its key science aims, FunnelWeb will obtain spectra for thousands of young and adolescent (<1 Gyr) stars near the Sun (<200 pc) across a wide range of spectral types. These spectra will include well-studied youth and activity indicators such as H-alpha, Li I 6708A, Ca II H&K, as well as surface gravity diagnostics (e.g. Na I, K I). In addition, FunnelWeb will obtain stellar parameters (Teff, logg, vsini), abundances (Fe/H, alpha/Fe) and radial velocities to 1-2 km/s for every star in the survey. When combined with high precision parallaxes and proper motions from the Gaia mission expected from 2017, this dataset will provide a near-complete census of adolescent stars in the solar neighbourhood. It will help reveal the typical formation environments of young solar-type stars, how such stars move from their stellar nurseries to their adult lives in the field, and identifying thousands of high-priority targets for follow-up direct imaging (GPI, SPHERE), transit (including TESS) and radial velocity exoplanet studies. In this poster contribution we introduce the FunnelWeb survey, its science goals and input catalogue, as well as provide an update on the status of the fibre positioner and spectrograph commissioning at Siding Spring.

Septic tanks as larval habitats for the mosquitoes Aedes aegypti and Culex quinquefasciatus in Playa-Playita, Puerto Rico.

PubMed

Burke, R; Barrera, R; Lewis, M; Kluchinsky, T; Claborn, D

2010-06-01

Adult Aedes aegypti (Linnaeus) (Diptera: Culicidae) were previously recovered from emergence traps on septic tanks in southeastern Puerto Rico. In this study we quantified immature mosquito abundance and its relationship with structural variables of the septic tanks and chemical properties of the water containing raw sewage. A miniaturized floating funnel trap was used to sample 89 septic tanks for larvae in the Puerto Rican community of Playa-Playita. Aedes aegypti larvae were recovered from 18% of the sampled tanks (10.3 larvae per septic tank per day). Larval presence was positively associated with cracking of the septic tank walls and uncovered access ports. Larval abundance was positively associated with cracking of the septic tank walls and larger tank surface areas, and inversely associated with the total dissolved solids (TDS). Culex quinquefasciatus (Say) larvae were also recovered from 74% of the septic tanks (129.6 larvae per septic tank per day). Larval presence was negatively associated with TDS in the water and larval abundance was positively associated with cracking of the septic tank walls. A screened, plastic emergence trap was used to sample 93 septic tanks within the community for Ae. aegypti and Cx. quinquefasciatus adults. Aedes aegypti adults were recovered from 49% of the sampled tanks (8.7 adults per septic tank per day) and Cx. quinquefasciatus adults were recovered from 97% of the sampled tanks (155.5 adults per septic tank per day). Aedes aegypti adult presence was positively associated with cracking, uncapped openings and septic water pH. The Ae. aegypti adult counts were positively associated with cracking and inversely associated with TDS and conductivity. This study marks the first published record of the recovery of Ae. aegypti larvae from holding tanks containing raw sewage in the Caribbean region. Our study indicates that Ae. aegypti larvae are present in sewage water and that septic tanks have at least the potential to maintain dengue transmission during the dry season.

Echocolor Doppler morpho-functional study of the jugulo-subclavian confluence in chronic cerebro-spinal venous insufficiency and multiple sclerosis patients.

PubMed

Mandolesi, Sandro; d'Alessandro, Aldo; Desogus, Antonello Ignazio; Ciccone, Marco Matteo; Zito, Annapaola; Stammegna, Immacolata; Niglio, Tarcisio; Orsini, Augusto; Mandolesi, Dimitri; d'Alessandro, Alessandro; Revelli, Luca

2017-01-01

The aim of this work is to measure the mean diameter of the confluence jugulo- subclavian, the impact of different types of jugular confluences and the correlation between the types of confluences and the Valsalva maneuver (jugular reflux) in subjects with Chronic Cerebro-Spinal Venous Insufficiency (CCSVI) and Multiple Sclerosis. We investigated by Echo-Color-Doppler (ECD) 103 subjects (67 F 36M) of mean age 45 ± 12 years (a minimum of 22 to a maximum of 79 years, with a median of 44 and a modal value 42 years), mean EDSS of 4.7 and average disease duration of 12 years. The 103 right jugular veins investigated had an average diameter of 8.4 ± 2.4 mm (minimum 4.0, maximum 14.9 mm; median 7.9; modal value 7.6 mm). Three form types were found: 56 cylindrical, 29 conical and 18 funnel. Valsalva maneuver was positive in 30 patients. The 103 left jugular investigated had an average diameter of 8.9 ± 2.4 mm (minimum 2.8, maximum 14.4 mm; median of 8.8; modal value 8.7 mm). The form types were found: 42 cylindrical, 45 conical and 16 funnel. Valsalva maneuver was positive in 30 patients. The mean diameter of the jugular veins was 8.7 mm. Internal jugular veins with cylindrical morphology have a diameter smaller than other forms; this difference is statistically significant. The different morphology of the jugular vein confluence does not increase the possibility of a reflux because the positive Valsalva maneuvers are not statistically significant when compared to the various types. CCSVI, EchoColorDoppler Map, Jugulo-Subclavian Confluence Diameter.

Electrodynamic multiple-scattering method for the simulation of optical trapping atop periodic metamaterials

NASA Astrophysics Data System (ADS)

Yannopapas, Vassilios; Paspalakis, Emmanuel

2018-07-01

We present a new theoretical tool for simulating optical trapping of nanoparticles in the presence of an arbitrary metamaterial design. The method is based on rigorously solving Maxwell's equations for the metamaterial via a hybrid discrete-dipole approximation/multiple-scattering technique and direct calculation of the optical force exerted on the nanoparticle by means of the Maxwell stress tensor. We apply the method to the case of a spherical polystyrene probe trapped within the optical landscape created by illuminating of a plasmonic metamaterial consisting of periodically arranged tapered metallic nanopyramids. The developed technique is ideally suited for general optomechanical calculations involving metamaterial designs and can compete with purely numerical methods such as finite-difference or finite-element schemes.

Retooling the Enrollment Funnel: Strategies and Metrics for a New Era. Noel-Levitz White Paper

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2009

2009-01-01

For more than two decades, the enrollment funnel has shaped how enrollment managers planned their enrollment strategies. It was a reliable, effective model for enrollment behavior, and campuses could shape their strategies around it. In recent years, however, demographic changes as well as technological advances have rendered the traditional…

Non-contact fiber-optical trapping of motile bacteria: dynamics observation and energy estimation

PubMed Central

Xin, Hongbao; Liu, Qingyuan; Li, Baojun

2014-01-01

The dynamics and energy conversion of bacteria are strongly associated with bacterial activities, such as survival, spreading of bacterial diseases and their pathogenesis. Although different discoveries have been reported on trapped bacteria (i.e. immobilized bacteria), the investigation on the dynamics and energy conversion of motile bacteria in the process of trapping is highly desirable. Here, we report a non-contact optical trapping of motile bacteria using a modified tapered optical fiber. Using Escherichia coli as an example, both single and multiple motile bacteria have been trapped and manipulated in a non-contact manner. Bacterial dynamics has been observed and bacterial energy has been estimated in the trapping process. This non-contact optical trapping provides a new opportunity for better understanding the bacterial dynamics and energy conversion at the single cell level. PMID:25300713

ANALYSIS OF POLYCYCLIC AROMATIC HYDROCARBONS BY ION TRAP TANDEM MASS SPECTROMETRY

EPA Science Inventory

An ion-trap mass spectrometer with a wave board and tandem mass spectrometry software was used to analyze gas chromatographically separated polycyclic aromatic hydrocarbons (PAHs) by using collision-induced dissociation (CID). The nonresonant (multiple collision) mode was used to...

Sampling bees in tropical forests and agroecosystems: A review

USGS Publications Warehouse

Prado, Sara G.; Ngo, Hien T.; Florez, Jaime A.; Collazo, Jaime A.

2017-01-01

Bees are the predominant pollinating taxa, providing a critical ecosystem service upon which many angiosperms rely for successful reproduction. Available data suggests that bee populations worldwide are declining, but scarce data in tropical regions precludes assessing their status and distribution, impact on ecological services, and response to management actions. Herein, we reviewed >150 papers that used six common sampling methods (pan traps, baits, Malaise traps, sweep nets, timed observations and aspirators) to better understand their strengths and weaknesses, and help guide method selection to meet research objectives and development of multi-species monitoring approaches. Several studies evaluated the effectiveness of sweep nets, pan traps, and malaise traps, but only one evaluated timed observations, and none evaluated aspirators. Only five studies compared two or more of the remaining four sampling methods to each other. There was little consensus regarding which method would be most reliable for sampling multiple species. However, we recommend that if the objective of the study is to estimate abundance or species richness, malaise traps, pan traps and sweep nets are the most effective sampling protocols in open tropical systems; conversely, malaise traps, nets and baits may be the most effective in forests. Declining bee populations emphasize the critical need in method standardization and reporting precision. Moreover, we recommend reporting a catchability coefficient, a measure of the interaction between the resource (bee) abundance and catching effort. Melittologists could also consider existing methods, such as occupancy models, to quantify changes in distribution and abundance after modeling heterogeneity in trapping probability, and consider the possibility of developing monitoring frameworks that draw from multiple sources of data.

Origin of large dark current increase in InGaAs/InP avalanche photodiode

NASA Astrophysics Data System (ADS)

Wen, J.; Wang, W. J.; Chen, X. R.; Li, N.; Chen, X. S.; Lu, W.

2018-04-01

The large dark current increase near the breakdown voltage of an InGaAs/InP avalanche photodiode is observed and analyzed from the aspect of bulk defects in the device materials. The trap level information is extracted from the temperature-dependent electrical characteristics of the device and the low temperature photoluminescence spectrum of the materials. Simulation results with the extracted trap level taken into consideration show that the trap is in the InP multiplication layer and the trap assisted tunneling current induced by the trap is the main cause of the large dark current increase with the bias from the punch-through voltage to 95% breakdown voltage.

On biodiversity conservation and poverty traps.

PubMed

Barrett, Christopher B; Travis, Alexander J; Dasgupta, Partha

2011-08-23

This paper introduces a special feature on biodiversity conservation and poverty traps. We define and explain the core concepts and then identify four distinct classes of mechanisms that define important interlinkages between biodiversity and poverty. The multiplicity of candidate mechanisms underscores a major challenge in designing policy appropriate across settings. This framework is then used to introduce the ensuing set of papers, which empirically explore these various mechanisms linking poverty traps and biodiversity conservation.

On biodiversity conservation and poverty traps

PubMed Central

Barrett, Christopher B.; Travis, Alexander J.; Dasgupta, Partha

2011-01-01

This paper introduces a special feature on biodiversity conservation and poverty traps. We define and explain the core concepts and then identify four distinct classes of mechanisms that define important interlinkages between biodiversity and poverty. The multiplicity of candidate mechanisms underscores a major challenge in designing policy appropriate across settings. This framework is then used to introduce the ensuing set of papers, which empirically explore these various mechanisms linking poverty traps and biodiversity conservation. PMID:21873176

Specific Resistance. Operational Control Tests for Wastewater Facilities. Instructor's Manual [and] Student Workbook.

ERIC Educational Resources Information Center

Wooley, John F.

A commonly used test for determining filterability of conditioned sludge is the specific resistance (Buchner funnel) test. The sludge is filtered through filter paper using a Buchner funnel, and the time needed to obtain a given volume of filtrate (or for cake residue to begin to crack) is measured. The shorter the time, the better the…

Thermotropic Liquid Crystals with Nitrocinnamylidene Unit

DTIC Science & Technology

1988-10-14

added through dropping funnel. Stir for 2 hrs before precipitated from distilled water . The crude yellow product was redissolved in chloroform and dried...rate 1O*C/hr) for overnight. Filter through celite and ceramic filtration funnel before precipitating with distilled water . The crude product was...Table 1. Cinnamylidene-P-octyloxyaniline was synthesized primarily by reacting cinnamaldehyde with p-octyloxyaniline and exhibits no mesomorphic property

Admissions Funnel Benchmarks for Four-Year Public and Private Institutions, 2010. Noel-Levitz Report on Undergraduate Enrollment Trends

ERIC Educational Resources Information Center

Noel-Levitz, Inc, 2010

2010-01-01

To assist campuses with accurately forecasting enrollments, this report continues Noel-Levitz's long-standing research into admissions funnel conversion and yield rates. The report is based on a Web-based survey of college and university admissions officials in September and October, 2010, in which respondents reported fall 2010 and fall 2009…

Dynamics and thermodynamics of a tornado: Rotation effects

NASA Astrophysics Data System (ADS)

Ben-Amots, N.

2016-09-01

This paper investigates the relevant processes in the tornado including the dynamics of rotation and thermodynamics as well as condensation. The main novelty of this paper is the explanation of the phenomena occurring in the central downflow. The reduced pressure in the tornado's funnel sucks air and water vapor from the cloud above the tornado. The latent heat of condensation is released in the funnel. The centrifugal force drives the generated water drops out of the funnel. The latent heat of condensation released is also transferred out of the funnel, and supplies the helically ascending air flow surrounding the tornado with additional buoyancy energy. This process gives the tornado increased strength compared to the dust devil type of flow, thus explaining why tornadoes occur always under a cloud, and why the tornado pipe can reach a height of a kilometer and more. To sustain a tornado, the temperature of water vapor at the cloud's base should be higher than the surroundings by a certain minimal value. Remote infrared temperature measurements of clouds' bases may provide indications of the probability that a cloud can spawn a tornado, which may increase the lead time.

Biased Metropolis Sampling for Rugged Free Energy Landscapes

NASA Astrophysics Data System (ADS)

Berg, Bernd A.

2003-11-01

Metropolis simulations of all-atom models of peptides (i.e. small proteins) are considered. Inspired by the funnel picture of Bryngelson and Wolyness, a transformation of the updating probabilities of the dihedral angles is defined, which uses probability densities from a higher temperature to improve the algorithmic performance at a lower temperature. The method is suitable for canonical as well as for generalized ensemble simulations. A simple approximation to the full transformation is tested at room temperature for Met-Enkephalin in vacuum. Integrated autocorrelation times are found to be reduced by factors close to two and a similar improvement due to generalized ensemble methods enters multiplicatively.

An MPA-IO interface to HPSS

NASA Technical Reports Server (NTRS)

Jones, Terry; Mark, Richard; Martin, Jeanne; May, John; Pierce, Elsie; Stanberry, Linda

1996-01-01

This paper describes an implementation of the proposed MPI-IO (Message Passing Interface - Input/Output) standard for parallel I/O. Our system uses third-party transfer to move data over an external network between the processors where it is used and the I/O devices where it resides. Data travels directly from source to destination, without the need for shuffling it among processors or funneling it through a central node. Our distributed server model lets multiple compute nodes share the burden of coordinating data transfers. The system is built on the High Performance Storage System (HPSS), and a prototype version runs on a Meiko CS-2 parallel computer.

Alcoholism in cockchafers: orientation of male Melolontha melolontha towards green leaf alcohols

NASA Astrophysics Data System (ADS)

Reinecke, Andreas; Ruther, Joachim; Tolasch, Till; Francke, Wittko; Hilker, Monika

2002-03-01

Chemical orientation of the European cockchafer, Melolontha melolontha L., a serious pest in agriculture and horticulture, was investigated by field tests and electrophysiological experiments using plant volatiles. In total, 16 typical plant volatiles were shown to elicit electrophysiological responses in male cockchafers. Funnel trap field bioassays revealed that green leaf alcohols (i.e. (Z)-3-hexen-1-ol, (E)-2-hexen-1-ol and 1-hexanol) attracted males, whereas the corresponding aldehydes and acetates were behaviourally inactive. Furthermore, male cockchafers were attracted by volatiles from mechanically damaged leaves of Fagus sylvatica L., Quercus robur L. and Carpinus betulus L. However, volatiles emitted by damaged leaves of F. sylvatica attracted significantly more males than those from the other host plants. Odour from intact F. sylvatica leaves was not attractive to M. melolontha males. Females were not attracted by any of the tested volatile sources. The results suggest that plant volatiles play a similar role as a sexual kairomone in mate finding of M. melolontha, as has been shown for the forest cockchafer, Melolontha hippocastani F. Nevertheless, both species show remarkable differences in their reaction to green leaf alcohols.

Mass Spectrometric Imaging Using Laser Ablation and Solvent Capture by Aspiration (LASCA)

NASA Astrophysics Data System (ADS)

Brauer, Jonathan I.; Beech, Iwona B.; Sunner, Jan

2015-09-01

A novel interface for ambient, laser ablation-based mass spectrometric imaging (MSI) referred to as laser ablation and solvent capture by aspiration (LASCA) is presented and its performance demonstrated using selected, unaltered biological materials. LASCA employs a pulsed 2.94 μm laser beam for specimen ablation. Ablated materials in the laser plumes are collected on a hanging solvent droplet with electric field-enhanced trapping, followed by aspiration of droplets and remaining plume material in the form of a coarse aerosol into a collection capillary. The gas and liquid phases are subsequently separated in a 10 μL-volume separatory funnel, and the solution is analyzed with electrospray ionization in a high mass resolution Q-ToF mass spectrometer. The LASCA system separates the sampling and ionization steps in MSI and combines high efficiencies of laser plume sampling and of electrospray ionization (ESI) with high mass resolution MS. Up to 2000 different compounds are detected from a single ablation spot (pixel). Using the LASCA platform, rapid (6 s per pixel), high sensitivity, high mass-resolution ambient imaging of "as-received" biological material is achieved routinely and reproducibly.

TITAN's multiple-reflection time-of-flight isobar separator

NASA Astrophysics Data System (ADS)

Reiter, Moritz Pascal; Titan Collaboration

2016-09-01

At the ISAC facility located at TRIUMF exotic nuclei are produced by the ISOL method. Exotic nuclei are separated by a magnetic separator and transported to TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN). TITAN is a system of multiple ion traps for high precision mass measurements and in-trap decay spectroscopy. Although ISAC can deliver some of the highest yields for even many of the most exotic species many measurements suffer from a strong isobaric background. This background often prevents the high precision measurement of the species of interest. To overcome this limitation an additional isobar separator based on the Multiple-Reflection Time-Of-Flight Mass Spectrometry (MR-TOF-MS) technique has been developed for TITAN. Mass selection is achieved using dynamic re-trapping of the species of interest after a time-of-flight analysis in an electrostatic isochronous reflector system. Additionally the MR-TOF-MS will, on its own, enable mass measurements of very short-lived nuclides that are weakly produced. Being able to measure all isobars of a given mass number at the same time the MR-TOF-MS can be used for beam diagnostics or determination of beam compositions. Results from the offline commissioning showing mass resolving power and separation power will be presented.

Coaxial ion trap mass spectrometer: concentric toroidal and quadrupolar trapping regions.

PubMed

Peng, Ying; Hansen, Brett J; Quist, Hannah; Zhang, Zhiping; Wang, Miao; Hawkins, Aaron R; Austin, Daniel E

2011-07-15

We present the design and results for a new radio-frequency ion trap mass analyzer, the coaxial ion trap, in which both toroidal and quadrupolar trapping regions are created simultaneously. The device is composed of two parallel ceramic plates, the facing surfaces of which are lithographically patterned with concentric metal rings and covered with a thin film of germanium. Experiments demonstrate that ions can be trapped in either region, transferred from the toroidal to the quadrupolar region, and mass-selectively ejected from the quadrupolar region to a detector. Ions trapped in the toroidal region can be transferred to the quadrupole region using an applied ac signal in the radial direction, although it appears that the mechanism of this transfer does not involve resonance with the ion secular frequency, and the process is not mass selective. Ions in the quadrupole trapping region are mass analyzed using dipole resonant ejection. Multiple transfer steps and mass analysis scans are possible on a single population of ions, as from a single ionization/trapping event. The device demonstrates better mass resolving power than the radially ejecting halo ion trap and better sensitivity than the planar quadrupole ion trap.

An efficient, self-orienting, vertical-array, sand trap

NASA Astrophysics Data System (ADS)

Hilton, Michael; Nickling, Bill; Wakes, Sarah; Sherman, Douglas; Konlechner, Teresa; Jermy, Mark; Geoghegan, Patrick

2017-04-01

There remains a need for an efficient, low-cost, portable, passive sand trap, which can provide estimates of vertical sand flux over topography and within vegetation and which self-orients into the wind. We present a design for a stacked vertical trap that has been modelled (computational fluid dynamics, CFD) and evaluated in the field and in the wind tunnel. The 'swinging' trap orients to within 10° of the flow in the wind tunnel at 8 m s-1, and more rapidly in the field, where natural variability in wind direction accelerates orientation. The CFD analysis indicates flow is steered into the trap during incident wind flow. The trap has a low profile and there is only a small decrease in mass flow rate for multiple traps, poles and rows of poles. The efficiency of the trap was evaluated against an isokinetic sampler and found to be greater than 95%. The centre pole is a key element of the design, minimally decreasing trap efficiency. Finally, field comparisons with the trap of Sherman et al. (2014) yielded comparable estimates of vertical sand flux. The trap described in this paper provides accurate estimates of sand transport in a wide range of field conditions.

Generation of multiple Bessel beams for a biophotonics workstation.

PubMed

Cizmár, T; Kollárová, V; Tsampoula, X; Gunn-Moore, F; Sibbett, W; Bouchal, Z; Dholakia, K

2008-09-01

We present a simple method using an axicon and spatial light modulator to create multiple parallel Bessel beams and precisely control their individual positions in three dimensions. This technique is tested as an alternative to classical holographic beam shaping commonly used now in optical tweezers. Various applications of precise control of multiple Bessel beams are demonstrated within a single microscope giving rise to new methods for three-dimensional positional control of trapped particles or active sorting of micro-objects as well as "focus-free" photoporation of living cells. Overall this concept is termed a 'biophotonics workstation' where users may readily trap, sort and porate material using Bessel light modes in a microscope.

Ion funnel device

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

Ibrahim, Yehia M.; Chen, Tsung-Chi; Harrer, Marques B.

2017-11-21

An ion funnel device is disclosed. A first pair of electrodes is positioned in a first direction. A second pair of electrodes is positioned in a second direction. The device includes an RF voltage source and a DC voltage source. A RF voltage with a superimposed DC voltage gradient is applied to the first pair of electrodes, and a DC voltage gradient is applied to the second pair of electrodes.

Multiple components in narrow planetary rings.

PubMed

Benet, L; Merlo, O

2008-01-11

The phase-space volume of regions of regular or trapped motion, for bounded or scattering systems with 2 degrees of freedom, respectively, displays universal properties. In particular, drastic reductions in the volume (gaps) are observed at specific values of a control parameter. Using the stability resonances we show that they, and not the mean-motion resonances, account for the position of these gaps. For more degrees of freedom, exciting these resonances divides the regions of trapped motion. For planetary rings, we demonstrate that this mechanism yields rings with multiple components.

Linearized theory of inhomogeneous multiple 'water-bag' plasmas

NASA Technical Reports Server (NTRS)

Bloomberg, H. W.; Berk, H. L.

1973-01-01

Equations are derived for describing the inhomogeneous equilibrium and small deviations from the equilibrium, giving particular attention to systems with trapped particles. An investigation is conducted of periodic systems with a single trapped-particle water bag, taking into account the behavior of the perturbation equations at the turning points. An outline is provided concerning a procedure for obtaining the eigenvalues. The results of stability calculations connected with the sideband effects are considered along with questions regarding the general applicability of the multiple water-bag approach in stability calculations.

Fourier optics along a hybrid optical fiber for Bessel-like beam generation and its applications in multiple-particle trapping.

PubMed

Kim, Jongki; Jeong, Yoonseob; Lee, Sejin; Ha, Woosung; Shin, Jeon-Soo; Oh, Kyunghwan

2012-02-15

Highly efficient Bessel-like beam generation was achieved based on a new all-fiber method that implements Fourier transformation of a micro annular aperture along a concatenated composite optical fiber. The beam showed unique characteristics of tilted washboard optical potential in the transverse plane and sustained a nondiffracting length over 400 μm along the axial direction. Optical trapping of multiple dielectric particles and living Jurkat cells were successfully demonstrated along the axial direction of the beam in the water.

Systematic Studies using the UCN τ Magneto-Gravitational Trap

NASA Astrophysics Data System (ADS)

Seestrom, Susan; UCNτ Collaboration

2016-09-01

The UCN τ Experiment measures the neutron lifetime using Ultracold Neutrons (UCN) stored in a magneto-gravitational trap. The trap employs various techniques to remove neutrons whose energies are too high to be trapped. It has recently been instrumented with a novel in situ detector that can be lowered into the trap to measure the neutron population as a function of height within the trap. This has allowed us to perform a series of systematic studies aimed at understanding and quantifying potential systematic effects associated with quasi-bound neutrons and phase space evolution. We have obtained multiple sets of data each having a statistical uncertainty of about 3 sec. We will discuss the results of our studies of cleaning and phase space evolution as well as results from studies of backgrounds and normalization of the initial neutron loading.

Trapping and manipulation of microparticles using laser-induced convection currents and photophoresis.

PubMed

Flores-Flores, E; Torres-Hurtado, S A; Páez, R; Ruiz, U; Beltrán-Pérez, G; Neale, S L; Ramirez-San-Juan, J C; Ramos-García, R

2015-10-01

In this work we demonstrate optical trapping and manipulation of microparticles suspended in water due to laser-induced convection currents. Convection currents are generated due to laser light absorption in an hydrogenated amorphous silicon (a:Si-H) thin film. The particles are dragged towards the beam's center by the convection currents (Stokes drag force) allowing trapping with powers as low as 0.8 mW. However, for powers >3 mW trapped particles form a ring around the beam due to two competing forces: Stokes drag and thermo-photophoretic forces. Additionally, we show that dynamic beam shaping can be used to trap and manipulate multiple particles by photophotophoresis without the need of lithographically created resistive heaters.

Trapping and manipulation of microparticles using laser-induced convection currents and photophoresis

PubMed Central

Flores-Flores, E.; Torres-Hurtado, S. A.; Páez, R.; Ruiz, U.; Beltrán-Pérez, G.; Neale, S. L.; Ramirez-San-Juan, J. C.; Ramos-García, R.

2015-01-01

In this work we demonstrate optical trapping and manipulation of microparticles suspended in water due to laser-induced convection currents. Convection currents are generated due to laser light absorption in an hydrogenated amorphous silicon (a:Si-H) thin film. The particles are dragged towards the beam's center by the convection currents (Stokes drag force) allowing trapping with powers as low as 0.8 mW. However, for powers >3 mW trapped particles form a ring around the beam due to two competing forces: Stokes drag and thermo-photophoretic forces. Additionally, we show that dynamic beam shaping can be used to trap and manipulate multiple particles by photophotophoresis without the need of lithographically created resistive heaters. PMID:26504655

Multiple scattering and the density distribution of a Cs MOT.

PubMed

Overstreet, K; Zabawa, P; Tallant, J; Schwettmann, A; Shaffer, J

2005-11-28

Multiple scattering is studied in a Cs magneto-optical trap (MOT). We use two Abel inversion algorithms to recover density distributions of the MOT from fluorescence images. Deviations of the density distribution from a Gaussian are attributed to multiple scattering.

Ion transfer from an atmospheric pressure ion funnel into a mass spectrometer with different interface options: Simulation-based optimization of ion transmission efficiency.

PubMed

Mayer, Thomas; Borsdorf, Helko

2016-02-15

We optimized an atmospheric pressure ion funnel (APIF) including different interface options (pinhole, capillary, and nozzle) regarding a maximal ion transmission. Previous computer simulations consider the ion funnel itself and do not include the geometry of the following components which can considerably influence the ion transmission into the vacuum stage. Initially, a three-dimensional computer-aided design (CAD) model of our setup was created using Autodesk Inventor. This model was imported to the Autodesk Simulation CFD program where the computational fluid dynamics (CFD) were calculated. The flow field was transferred to SIMION 8.1. Investigations of ion trajectories were carried out using the SDS (statistical diffusion simulation) tool of SIMION, which allowed us to evaluate the flow regime, pressure, and temperature values that we obtained. The simulation-based optimization of different interfaces between an atmospheric pressure ion funnel and the first vacuum stage of a mass spectrometer require the consideration of fluid dynamics. The use of a Venturi nozzle ensures the highest level of transmission efficiency in comparison to capillaries or pinholes. However, the application of radiofrequency (RF) voltage and an appropriate direct current (DC) field leads to process optimization and maximum ion transfer. The nozzle does not hinder the transfer of small ions. Our high-resolution SIMION model (0.01 mm grid unit(-1) ) under consideration of fluid dynamics is generally suitable for predicting the ion transmission through an atmospheric-vacuum system for mass spectrometry and enables the optimization of operational parameters. A Venturi nozzle inserted between the ion funnel and the mass spectrometer permits maximal ion transmission. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

Surgeon-level reporting presented by funnel plot is understood by doctors but inaccurately interpreted by members of the public.

PubMed

Bhalla, Ashish; Mehrotra, Prerna; Amawi, Falah; Lund, Jonathan N

2015-01-01

Risk-adjusted outcome data for general surgeons practicing in the United Kingdom were published for the first time in 2013 with the aim of increasing transparency, improving standards, and providing the public with information to aid decision making. Most specialties used funnel plots to present their data. We assess the ability of members of the public (MoP), medical students, nonsurgical doctors (NSD), and surgeons to understand risk-adjusted surgical outcome data. A fictitious outcome dataset was created and presented in the form of a funnel plot to 10 participants from each of the aforementioned group. Standard explanatory text was provided. Each participant was given 5 minutes to review the funnel plot and complete a questionnaire. For each question, there was only 1 correct answer. Completion rate was 100% (n = 40). No difference existed between NSD and surgeons. A significant difference for identification of the "worst performing surgeon" was noted between surgeons and MoP (p < 0.01) and between NSD and MoP (p < 0.01). Half of medical students and MoP claimed they would use this information to aid decision making compared with 80% of doctors. MoP reported the funnel plot significantly "more difficult" to interpret than surgeons did (p < 0.01) and NSD (p < 0.01). MoP found these data significantly more "difficult to understand" and were less likely to both spot "outliers" and use this data to inform decisions than doctors. Surgeons should be aware that outcome data may require an alternative method of presentation to be understood by MoP. Copyright © 2015 Association of Program Directors in Surgery. Published by Elsevier Inc. All rights reserved.

Flux and accumulation of sedimentary particles off the continental slope of Pakistan: a comparison of water column and seafloor estimates from the oxygen minimum zone, NE Arabian Sea

NASA Astrophysics Data System (ADS)

Schulz, H.; von Rad, U.

2013-07-01

Due to the lack of bioturbation, the laminated muds from the oxygen-minimum zone (OMZ) off Pakistan provide a unique opportunity to precisely determine the vertical and lateral sediment fluxes in the near shore part of the northeastern Arabian Sea, and to explore the effects of the margin topography and the low oxygen conditions on the accumulation of organic matter and other particles. West of Karachi, in the Hab river area of EPT and WPT (Eastern and Western PAKOMIN Traps), 16 short sediment profiles from water depths between 250 m and 1970 m on a depth transect crossing the OMZ (~ 120 to ~ 1200 m water depth) were investigated, and correlated on the basis of a thick, light-gray- to reddish-colored turbidite layer. Varve counting yielded a date for this layer of AD 1905 to 1888. We adopted the young age which agrees with 210Pb- dating, and used this isochronous stratigraphic marker bed to calculate sediment accumulation rates, that we could directly compare with the flux rates from the sediment traps installed within the water column above. All traps in the area show exceptionally high, pulsed winter fluxes of up to 5000 mg m-2 d-1 in this margin environment. The lithic flux at the sea floor is as high as 4000 mg m-2 d-1 , and agrees remarkably well with the bulk winter flux of material. This holds as well for the individual bulk components (organic carbon, calcium carbonate, opal, lithic fraction). However, the high winter flux events (HFE) by their extreme mass of remobilized matter terminated the recording in the shallow traps by clogging the funnels. Based on our comparisons, we argue that HFE for the past 5000 yr most likely occurred as regular events within the upper OMZ off Pakistan. Coarse fraction and foraminiferal accumulation rates from sediment surface samples along the Hab transect show distribution patterns that seem to be a function of water depth and distance from the shelf. Some of these sediment fractions show sudden shifts at the lower boundary of the OMZ. However, the potential effect of the OMZ on carbon preservation in the area would by masked by high mass of fine-grained matter laterally advected, and by the pulsed nature of the resuspension events.

Absolute ion detection efficiencies of microchannel plates and funnel microchannel plates for multi-coincidence detection

NASA Astrophysics Data System (ADS)

Fehre, K.; Trojanowskaja, D.; Gatzke, J.; Kunitski, M.; Trinter, F.; Zeller, S.; Schmidt, L. Ph. H.; Stohner, J.; Berger, R.; Czasch, A.; Jagutzki, O.; Jahnke, T.; Dörner, R.; Schöffler, M. S.

2018-04-01

Modern momentum imaging techniques allow for the investigation of complex molecules in the gas phase by detection of several fragment ions in coincidence. For these studies, it is of great importance that the single-particle detection efficiency ɛ is as high as possible, as the overall efficiency scales with ɛn, i.e., the power of the number of detected particles. Here we present measured absolute detection efficiencies for protons of several micro-channel plates (MCPs), including efficiency enhanced "funnel MCPs." Furthermore, the relative detection efficiency for two-, three-, four-, and five-body fragmentation of CHBrClF has been examined. The "funnel" MCPs exhibit an efficiency of approximately 90%, gaining a factor of 24 (as compared to "normal" MCPs) in the case of a five-fold ion coincidence detection.

Chick cerebellar Purkinje cells express omega-conotoxin GVIA-sensitive rather than funnel-web spider toxin-sensitive calcium channels.

PubMed

Angulo, M C; Parra, P; Dieudonné, S

1998-03-01

Voltage-gated calcium channels form a complex family of distinct molecular entities which participate in multiple neuronal functions. In cerebellar Purkinje cells these channels contribute to the characteristic electrophysiological pattern of complex spikes, first described in birds and later in mammals. A specific calcium channel, the P-type channel, has been shown to mediate the majority of the voltage-gated calcium flux in mammalian Purkinje cells. P-type channels play an essential role in synaptic transmission of mammalian cerebellum. It is unclear whether the P-type calcium channel is present in birds. Studies in chick synaptosomal preparations show that the pharmacological profile of calcium channels is complex and suggest a minimal expression of the P-type channel in avian central nervous system. In the present work, we studied voltage-gated calcium channels in dissociated chick cerebellar Purkinje cells to examine the presence of different calcium channel types. Purkinje cells were used because, in mammals, they express predominantly P-type channels and because the morphology of these cells is thought to be phylogenetically conserved. We found that omega-conotoxin GVIA (omega-CgTx GVIA), a specific antagonist of N-type calcium channel, rather than the synthetic funnel-web spider toxin (sFTX), a P-type channel antagonist, blocks the majority of the barium current flowing through calcium channels in chick Purkinje neurons.

Assembly of microparticles by optical trapping with a photonic crystal nanocavity

NASA Astrophysics Data System (ADS)

Renaut, C.; Dellinger, J.; Cluzel, B.; Honegger, T.; Peyrade, D.; Picard, E.; de Fornel, F.; Hadji, E.

2012-03-01

In this work, we report the auto-assembly experiments of micrometer sized particles by optical trapping in the evanescent field of a photonic crystal nanocavity. The nanocavity is inserted inside an optofluidic cell designed to enable the real time control of the nanoresonator transmittance as well as the real time visualization of the particles motion in the vicinity of the nanocavity. It is demonstrated that the optical trap above the cavity enables the assembly of multiple particles in respect of different stable conformations.

Funnel Libraries for Real-Time Robust Feedback Motion Planning

DTIC Science & Technology

2016-07-21

motion plans for a robot that are guaranteed to suc- ceed despite uncertainty in the environment, parametric model uncertainty, and disturbances...resulting funnel library is then used to sequentially compose motion plans at runtime while ensuring the safety of the robot . A major advantage of...the work presented here is that by explicitly taking into account the effect of uncertainty, the robot can evaluate motion plans based on how vulnerable

Using maps and funnel plots to explore variation in place of death from cancer within London, 2002-2007.

PubMed

Madden, P; Coupland, Vh; Møller, H; Davies, Ea

2011-06-01

London has a high proportion of hospital deaths, which health policy seeks to reduce. We explore variation and trends in place of death from cancer within London between 2002 and 2007. Mortality data based on death certificates were used to define deaths from cancer at home, hospice, hospital and nursing home and examine trends over time for London. Proportions of deaths in each place were presented in maps for 31 London primary care trusts (PCTs). Funnel plots were used to identify consistent performance outside the control limits of three standard deviations. There was little overall change in place of death for London, but consistent variation between PCTs. Outer London PCTs had higher proportions of home deaths and inner London PCTs higher proportions of hospice deaths. Funnel plots identified consistent high outlying performance for home, hospice and hospital deaths. No PCT showed a change of 10% or more in home deaths, but five showed decreasing hospital deaths and three increasing hospice deaths. Maps and funnel plots appear useful for identifying areas with differing performance for home, hospital, nursing home and hospice deaths. These methods may help further investigation of how local services may successfully support deaths outside hospital. © The Author(s) 2011

Two-phase flows in the formed tornado funnel

NASA Astrophysics Data System (ADS)

Sinkevich, O. A.; Bortsova, A. A.

2017-10-01

At present, it is obvious that the problem of the tornado is important not only for our planetЮ to determine the conditions for the formation of a tornado, it is required to take into account a number of hydrodynamic and plasma processes [1 - 6]. Along to prediction of a tornado generation conditions [1 - 3] it is necessary to evaluate the characteristics of its quasi-stationary motion in a formed funnel: the mass of the moving moist air involved in the funnel and the size and form of the funnel. For a complete description of the phenomena, it is necessary to involve numerical calculations. We note that even for numerical calculations using powerful computers, the problem is very difficult because of the need to calculate multiphase turbulent flows with free, self-organizing boundaries [1, 6]. However, “strict” numerical calculations, it is impossible to do without the use of many, often mutually exclusive, models. For example, how to choice an adequate model of turbulence (algebraic, k-ε model, etc.) or the use of additional, often not accepted, hypotheses about certain processes used in calculations (mechanisms on the nature of moisture condensation, etc.). Therefore, along with numerical calculations of such flows, modeling problems that allow an exact solution and allow to determine the most important and observed characteristics of a tornado.

A theoretical analysis of steady-state photocurrents in simple silicon diodes

NASA Technical Reports Server (NTRS)

Edmonds, L.

1995-01-01

A theoretical analysis solves for the steady-state photocurrents produced by a given photo-generation rate function with negligible recombination in simple silicon diodes, consisting of a uniformly doped quasi-neutral region (called 'substrate' below) adjacent to a p-n junction depletion region (DR). Special attention is given to conditions that produce 'funneling' (a term used by the single-eventeffects community) under steady-state conditions. Funneling occurs when carriers are generated so fast that the DR becomes flooded and partially or completely collapses. Some or nearly all of the applied voltage, plus built-in potential normally across the DR, is now across the substrate. This substrate voltage drop affects substrate currents. The steady-state problem can provide some qualitative insights into the more difficult transient problem. First, it was found that funneling can be induced from a distance, i.e., from carriers generated at locations outside of the DR. Secondly, it was found that the substrate can divide into two subregions, with one controlling substrate resistance and the other characterized by ambipolar diffusion. Finally, funneling was found to be more difficult to induce in the p(sup +)/n diode than in the n(sup +)/p diode. The carrier density exceeding the doping density in the substrate and at the DR boundary is not a sufficient condition to collapse a DR.

Design and Performance of a High-Flux Electrospray Ionization Source for Ion Soft-Landing

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

Gunaratne, Kalupathirannehelage Don D.; Prabhakaran, Venkateshkumar; Ibrahim, Yehia M.

2015-01-01

We report the design and evaluation of a new high-intensity electrospray ionization source for ion soft-landing experiments. The source incorporates a dual ion funnel, which enables operation with a higher gas load through an expanded heated inlet into the additional first region of differential pumping. This capability allowed us to examine the effect of the inner diameter (ID) of the heated stainless steel inlet on the total ion current transmitted through the dual funnel interface and, more importantly, the mass-selected ion current delivered to the deposition target. The ion transmission of the dual funnel is similar to the transmission ofmore » the single funnel used in our previous soft landing studies. However, substantially higher ion currents were obtained using larger ID heated inlets and an orthogonal inlet geometry, in which the heated inlet is positioned perpendicular to the direction of ion propagation through the instrument. The highest ion currents were obtained using the orthogonal geometry and a 1.4 mm ID heated inlet. The corresponding stable deposition rate of ~1 μg of mass-selected ions per day will facilitate future studies focused on the controlled deposition of biological molecules on substrates and preparation of materials for studies in catalysis, energy storage, and self-assembly« less

A single-sampling hair trap for mesocarnivores

Treesearch

Jonathan N. Pauli; Matthew B. Hamilton; Edward B. Crain; Steven W. Buskirk

2007-01-01

Although techniques to analyze and quantifY DNA-based data have progressed, methods to noninvasively collect samples lag behind. Samples are generally collected from devices that permit coincident sampling of multiple individuals. Because of cross-contamination, substantive genotyping errors can arise. We developed a cost-effective (US$4.60/trap) single-capture hair...

Dynamical traps in Wang-Landau sampling of continuous systems: Mechanism and solution

NASA Astrophysics Data System (ADS)

Koh, Yang Wei; Sim, Adelene Y. L.; Lee, Hwee Kuan

2015-08-01

We study the mechanism behind dynamical trappings experienced during Wang-Landau sampling of continuous systems reported by several authors. Trapping is caused by the random walker coming close to a local energy extremum, although the mechanism is different from that of the critical slowing-down encountered in conventional molecular dynamics or Monte Carlo simulations. When trapped, the random walker misses the entire or even several stages of Wang-Landau modification factor reduction, leading to inadequate sampling of the configuration space and a rough density of states, even though the modification factor has been reduced to very small values. Trapping is dependent on specific systems, the choice of energy bins, and the Monte Carlo step size, making it highly unpredictable. A general, simple, and effective solution is proposed where the configurations of multiple parallel Wang-Landau trajectories are interswapped to prevent trapping. We also explain why swapping frees the random walker from such traps. The efficacy of the proposed algorithm is demonstrated.

Gravitational radiation from magnetically funneled supernova fallback onto a magnetar

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

Melatos, A.; Priymak, M., E-mail: amelatos@unimelb.edu.au, E-mail: m.priymak@pgrad.unimelb.edu.au

2014-10-20

Protomagnetars spun up to millisecond rotation periods by supernova fallback are predicted to radiate gravitational waves via hydrodynamic instabilities for ∼10{sup 2} s before possibly collapsing to form a black hole. It is shown that magnetic funneling of the accretion flow (1) creates a magnetically confined polar mountain, which boosts the gravitational wave signal, and (2) 'buries' the magnetic dipole moment, delaying the propeller phase and assisting black hole formation.

21 CFR Appendix A to Part 74 - The Procedure for Determining Ether Soluble Material in D&C Red Nos. 6 and 7

Code of Federal Regulations, 2010 CFR

2010-04-01

... throughout method.) Allow the funnel to stand until the layers have separated. Transfer the bottom (aqueous) layer to a 500 mL separatory funnel, add 100 mL of ether, stopper and shake for one minute. When the layers have separated, drain off the bottom layer into a waste beaker. Pour the ether layer in the 500 mL...

An Assembly Funnel Makes Biomolecular Complex Assembly Efficient

PubMed Central

Zenk, John; Schulman, Rebecca

2014-01-01

Like protein folding and crystallization, the self-assembly of complexes is a fundamental form of biomolecular organization. While the number of methods for creating synthetic complexes is growing rapidly, most require empirical tuning of assembly conditions and/or produce low yields. We use coarse-grained simulations of the assembly kinetics of complexes to identify generic limitations on yields that arise because of the many simultaneous interactions allowed between the components and intermediates of a complex. Efficient assembly occurs when nucleation is fast and growth pathways are few, i.e. when there is an assembly “funnel”. For typical complexes, an assembly funnel occurs in a narrow window of conditions whose location is highly complex specific. However, by redesigning the components this window can be drastically broadened, so that complexes can form quickly across many conditions. The generality of this approach suggests assembly funnel design as a foundational strategy for robust biomolecular complex synthesis. PMID:25360818

Evolution, Energy Landscapes and the Paradoxes of Protein Folding

PubMed Central

Wolynes, Peter G.

2014-01-01

Protein folding has been viewed as a difficult problem of molecular self-organization. The search problem involved in folding however has been simplified through the evolution of folding energy landscapes that are funneled. The funnel hypothesis can be quantified using energy landscape theory based on the minimal frustration principle. Strong quantitative predictions that follow from energy landscape theory have been widely confirmed both through laboratory folding experiments and from detailed simulations. Energy landscape ideas also have allowed successful protein structure prediction algorithms to be developed. The selection constraint of having funneled folding landscapes has left its imprint on the sequences of existing protein structural families. Quantitative analysis of co-evolution patterns allows us to infer the statistical characteristics of the folding landscape. These turn out to be consistent with what has been obtained from laboratory physicochemical folding experiments signalling a beautiful confluence of genomics and chemical physics. PMID:25530262

Apple Snail: a Bio Cleaner of the Water Free Surface.

NASA Astrophysics Data System (ADS)

Bassiri, Golnaz

2005-11-01

Oil spills from tankers represent a threat for shorelines and marine life. Despite continuing research, there has been little change in the fundamental technology for dealing with oil spills. An experimental investigation of the feeding strategy of Apple snails from the water free surface, called surface film feeding, is being studied motivated by the need to develop new techniques to recover oil spills. To feed on floating food (usually a thin layer of microorganisms), the apple snail forms a funnel with its foot and pulls the free surface toward the funnel. High speed imaging and particle image velocimetry were used in the present investigation to measure the free surface motion and to investigate the mechanism used by the apple snails to pull the free surface. The results suggest that the snail pulls the free surface via the wavy motion of the muscles in its funnel.

Line-Trapping of Codling Moth (Lepidoptera: Tortricidae): A Novel Approach to Improving the Precision of Capture Numbers in Traps Monitoring Pest Density.

PubMed

Adams, C G; McGhee, P S; Schenker, J H; Gut, L J; Miller, J R

2017-08-01

This field study of codling moth, Cydia pomonella (L.), response to single versus multiple monitoring traps baited with codlemone demonstrates that precision of a given capture number is alarmingly poor when the population is held constant by releasing moths. Captures as low as zero and as high as 12 males per single trap are to be expected where the catch mode is three. Here, we demonstrate that the frequency of false negatives and overestimated positives for codling moth trapping can be substantially reduced by employing the tactic of line-trapping, where five traps were deployed 4 m apart along a row of apple trees. Codling moth traps spaced closely competed only slightly. Therefore, deploying five traps closely in a line is a sampling technique nearly as good as deploying five traps spaced widely. But line trapping offers a substantial savings in time and therefore cost when servicing aggregated versus distributed traps. As the science of pest management matures by mastering the ability to translate capture numbers into estimates of absolute pest density, it will be important to employ a tactic like line-trapping so as to shrink the troublesome variability associated with capture numbers in single traps that thwarts accurate decisions about if and when to spray. Line-trapping might similarly increase the reliability and utility of density estimates derived from capture numbers in monitoring traps for various pest and beneficial insects. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America.

The Politics of Storytelling: Unfolding the Multiple Layers of Politics in (P)AR Publications

ERIC Educational Resources Information Center

Santos, Doris

2012-01-01

In the social sciences, inquiry into the relationship between storytelling and politics is based on a notion of historical continuity. One problem is the possible trap of inevitability inherent in this notion--that something which happened "had to happen". Hannah Arendt's conception of political theory as storytelling overcomes this trap,…

Fiber optical tweezers for microscale and nanoscale particle manipulation and force sensing

NASA Astrophysics Data System (ADS)

Liu, Yuxiang

2011-12-01

Optical tweezers have been an important tool in biology and physics for studying single molecules and colloidal systems. Most of current optical tweezers are built with microscope objectives, which are: i) expensive, ii) bulky and hard to integrate, iii) sensitive to environmental fluctuations, iv) limited in terms of working distances from the substrate, and v) rigid with the requirements on the substrate (transparent substrate made with glass and with a fixed thickness). These limitations of objective-based optical tweezers prevent them from being miniaturized. Fiber optical tweezers can provide a solution for cost reduction and miniaturization, and these optical tweezers can be potentially used in microfluidic systems. However, the existing fiber optical tweezers have the following limitations: i) low trapping efficiency due to weakly focused beams, ii) lack of the ability to control the positions of multiple particles simultaneously, and iii) limited functionalities. The overall objective of this dissertation work is to further the fundamental understanding of fiber optical tweezers through experimental study and modeling, and to develop novel fiber optical tweezers systems to enhance the capability and functionalities of fiber optical tweezers as microscale and nanoscale manipulators/sensors. The contributions of this dissertation work are summarized as follows. i) An enhanced understanding of the inclined dual-fiber optical tweezers (DFOTs) system has been achieved. Stable three dimensional (3D) optical trapping of a single micron-sized particle has been experimentally demonstrated. This is the first time that the trapping efficiency has been calibrated and the stiffness of the trap has been obtained in the experiments, which has been carried out by using two methods: the drag force method and power spectrum analysis. Such calibration enables the system to be used as a picoNewton-level force sensor in addition to a particle manipulator. The influence of system parameters on the trapping performance has been carefully investigated through both experimental and numerical studies. ii) Multiple traps have been created and carefully studied with the inclined DFOTs for the first time. Three traps, one 3D trap and two 2D traps, have been experimentally created at different vertical levels with adjustable separations and positions. iii) Multiple functionalities have been achieved and studied for the first time with the inclined DFOTs. Particle separation, grouping, stacking, rod alignment, rod rotation, and optical binding have been experimentally demonstrated. The multiple functionalities allow the inclined DFOTs to find applications in the study of interaction forces in colloidal systems as well as parallel particle manipulation in drug delivery systems. iv) Far-field superfocusing effect has been investigated and successfully demonstrated with a fiber-based surface plasmonic (SP) lens for the first time. A planar SP lens with a set of concentric nanoscale rings on a fiber endface has been developed. For the first time, a focus size that is comparable to the smallest achievable focus size of high NA objective lenses has been achieved with the fiber-based SP lens. The fiber-based SP lens can bridge the nanoscale particles/systems and the macroscale power sources/detectors, which has been a long standing challenge for nanophotonics. In addition to optical trapping, the fiber-based SP lens will impact many applications including high-resolution lithography, high-resolution fluorescence detection, and sub-wavelength imaging. v) Trapping ability enhanced with the fiber-based SP lens has been successfully demonstrated. With the help of the fiber-based SP lens, the trapping efficiency of fiber optical tweezers has been significantly enhanced, which is comparable with that of objective-based optical tweezers. A submicron-sized bacterium has been successfully trapped in three dimensions for the first time with optical tweezers based on single fibers.

Identification of two conformationally trapped n-propanol-water dimers in a supersonic expansion

NASA Astrophysics Data System (ADS)

Mead, Griffin J.; Alonso, Elena R.; Finneran, Ian A.; Carroll, P. Brandon; Blake, Geoffrey A.

2017-05-01

Two conformers of the n-propanol-water dimer have been observed in a supersonic expansion using chirped-pulse Fourier-transform microwave (CPFTMW) spectroscopy. Structural assignments reveal the n-propanol sub-unit is conformationally trapped, with its methyl group in both Gauche and Trans orientations. Despite different carbon backbone conformations, both dimers display the same water-donor/alcohol-acceptor hydrogen bonding motif. This work builds upon other reported alcohol-water dimers and upon previous work detailing the trapping of small molecules into multiple structural minima in rare gas supersonic expansions.

Multichannel microfluidic chip for rapid and reliable trapping and imaging plant-parasitic nematodes

NASA Astrophysics Data System (ADS)

Amrit, Ratthasart; Sripumkhai, Witsaroot; Porntheeraphat, Supanit; Jeamsaksiri, Wutthinan; Tangchitsomkid, Nuchanart; Sutapun, Boonsong

2013-05-01

Faster and reliable testing technique to count and identify nematode species resided in plant roots is therefore essential for export control and certification. This work proposes utilizing a multichannel microfluidic chip with an integrated flow-through microfilter to retain the nematodes in a trapping chamber. When trapped, it is rather simple and convenient to capture images of the nematodes and later identify their species by a trained technician. Multiple samples can be tested in parallel using the proposed microfluidic chip therefore increasing number of samples tested per day.

[Meta-analysis for correlation between multiple lung lobe lesions and prognostic influence on acquired pneumonia in hospitalized elderly patients].

PubMed

Huang, Wenjie; Feng, Wei; Li, Yang; Chen, Yu

2014-11-01

To explore the correlation regarding the prognostic influence between multiple lung lobe lesions and acquired pneumonia in hospitalized elderly patients by a Meta-analysis. We collected all studies which investigated the correlation regarding the prognostic effect between multiple lung lobe lesions and acquired pneumonia by searching China National Knowledge Infrastructure, Wanfang Database, Chinese Science and Technology Periodical Database, Chinese Biological Medical Literature Database, PubMed, and EMBase in accordance with the inclusion and exclusion criteria. Th e retrieval limit time of searches was from databases establishment to July 2014. Th e Meta-analysis was performed by using RevMan5.2 soft ware. We calculated the odds ratio (OR) and 95% confidence interval (95% CI) by using heterogeneous tests. Publication bias was assessed by Egger's test and funnel plot, and the sensitivity was analyzed. Ten studies involving 1 836 patients were finally included, with 487 cases (the dead group) and 1 349 controls (the survival group). The Meta-analysis demonstrated that multiple lung lobe lesions was highly correlated with the prognosis for the aged acquired pneumonia (OR=3.22, 95% CI 1.84 to 5.63). Multiple lung lobe lesions increase the risk of death in the prognosis of the aged patients with acquired pneumonia.

Guiding and focusing of fast electron beams produced by ultra-intense laser pulse using a double cone funnel target

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

Zhang, Wen-shuai; Cai, Hong-bo, E-mail: Cai-hongbo@iapcm.ac.cn; HEDPS, Center for Applied Physics and Technology, Peking University, Beijing 100871

A novel double cone funnel target design aiming at efficiently guiding and focusing fast electron beams produced in high intensity (>10{sup 19 }W/cm{sup 2}) laser-solid interactions is investigated via two-dimensional particle-in-cell simulations. The forward-going fast electron beams are shown to be directed and focused to a smaller size in comparison with the incident laser spot size. This plasma funnel attached on the cone target guides and focuses electrons in a manner akin to the control of liquid by a plastic funnel. Such device has the potential to add substantial design flexibility and prevent inefficiencies for important applications such as fast ignition.more » Two reasons account for the collimation of fast electron beams. First, the sheath electric fields and quasistatic magnetic fields inside the vacuum gap of the double cone provide confinement of the fast electrons in the laser-plasma interaction region. Second, the interface magnetic fields inside the beam collimator further guide and focus the fast electrons during the transport. The application of this technique to cone-guided fast ignition is considered, and it is shown that it can enhance the laser energy deposition in the compressed fuel plasma by a factor of 2 in comparison with the single cone target case.« less

Influence of elevation on bark beetle (Coleoptera: Curculionidae, Scolytinae) community structure and flight periodicity in ponderosa pine forests of Arizona.

PubMed

Williams, Kelly K; McMillin, Joel D; DeGomez, Tom E; Clancy, Karen M; Miller, Andy

2008-02-01

We examined abundance and flight periodicity of five Ips and six Dendroctonus species (Coleoptera: Curculionidae, Scolytinae) among three different elevation bands in ponderosa pine (Pinus ponderosa Douglas ex. Lawson) forests of northcentral Arizona. Bark beetle populations were monitored at 10 sites in each of three elevation bands (low: 1,600-1,736 m; middle: 2,058-2,230 m; high: 2,505-2,651 m) for 3 yr (2004-2006) using pheromone-baited Lindgren funnel traps. Trap contents were collected weekly from March to December. We also studied temperature differences among the elevation bands and what role this may play in beetle flight behavior. Bark beetles, regardless of species, showed no consistent elevational trend in abundance among the three bands. The higher abundances of Ips lecontei Swaine, I. calligraphus ponderosae Swaine, Dendroctonus frontalis Zimmerman, and D. brevicomis LeConte at low and middle elevations offset the greater abundance of I. knausi Swaine, D. adjunctus Blandford, D. approximatus Dietz, and D. valens LeConte at high elevations. I. pini (Say) and I. latidens LeConte were found in similar numbers across the three bands. Flight periodicity of several species varied among elevation bands. In general, the flight period shortened as elevation increased; flight initiated later and terminated earlier in the year. The timing, number, and magnitude of peaks in flight activity also varied among the elevation bands. These results suggest that abundance and flight seasonality of several bark beetles are related to elevation and the associated temperature differences. The implications of these results are discussed in relation to bark beetle management and population dynamics.

Integrated multiple patch-clamp array chip via lateral cell trapping junctions

NASA Astrophysics Data System (ADS)

Seo, J.; Ionescu-Zanetti, C.; Diamond, J.; Lal, R.; Lee, L. P.

2004-03-01

We present an integrated multiple patch-clamp array chip by utilizing lateral cell trapping junctions. The intersectional design of a microfluidic network provides multiple cell addressing and manipulation sites for efficient electrophysiological measurements at a number of patch sites. The patch pores consist of openings in the sidewall of a main fluidic channel, and a membrane patch is drawn into a smaller horizontal channel. This device geometry not only minimizes capacitive coupling between the cell reservoir and the patch channel, but also allows simultaneous optical and electrical measurements of ion channel proteins. Evidence of the hydrodynamic placement of mammalian cells at the patch sites as well as measurements of patch sealing resistance is presented. Device fabrication is based on micromolding of polydimethylsiloxane, thus allowing inexpensive mass production of disposable high-throughput biochips.

Combining optical trapping in a microfluidic channel with simultaneous micro-Raman spectroscopy and motion detection

NASA Astrophysics Data System (ADS)

Lawton, Penelope F.; Saunter, Christopher D.; Girkin, John M.

2014-03-01

Since their invention by Ashkin optical tweezers have demonstrated their ability and versatility as a non-invasive tool for micromanipulation. One of the most useful additions to the basic optical tweezers system is micro-Raman spectroscopy, which permits highly sensitive analysis of single cells or particles. We report on the development of a dual laser system combining two spatial light modulators to holographically manipulate multiple traps (at 1064nm) whilst undertaking Raman spectroscopy using a 532nm laser. We can thus simultaneously trap multiple particles and record their Raman spectra, without perturbing the trapping system. The dual beam system is built around micro-fluidic channels where crystallisation of calcium carbonate occurs on polymethylmethacrylate (PMMA) beads. The setup is designed to simulate at a microscopic level the reactions that occur on items in a dishwasher, where permanent filming of calcium carbonate on drinking glasses is a problem. Our system allows us to monitor crystal growth on trapped particles in which the Raman spectrum and changes in movement of the bead are recorded. Due to the expected low level of crystallisation on the bead surfaces this allows us to obtain results quickly and with high sensitivity. The long term goal is to study the development of filming on samples in-situ with the microfl.uidic system acting as a model dishwasher.

α-Copaene is an attractant, synergistic with quercivorol, for improved detection of Euwallacea nr. fornicatus (Coleoptera: Curculionidae: Scolytinae)

PubMed Central

Owens, David; Montgomery, Wayne S.; Narvaez, Teresa I.; Bauchan, Gary R.; Schnell, Elena Q.; Tabanca, Nurhayat; Carrillo, Daniel

2017-01-01

The tea shot-hole borer, Euwallacea fornicatus Eichhoff, is an ambrosia beetle endemic to Asia and a pest of commercial tea, Camellia sinensis (L.) Kuntze. Recently, a complex of species morphologically similar to E. fornicatus has been recognized, which includes new pests established in Israel and the USA, both in California and Florida. Collectively termed E. nr. fornicatus, these cryptic species carry symbiotic Fusarium spp. fungi, some of which cause dieback disease in susceptible hosts, which include avocado, Persea americana Miller. Due to the threat to this economically important crop, research was initiated to evaluate efficacy of kairomone-based lures for detection of the beetle in Florida (termed the Florida tea shot hole borer, FL-TSHB). A series of field tests were conducted in 2016 in commercial avocado groves known to have FL-TSHB at various population levels. All tests evaluated lures containing quercivorol (p-menth-2-en-1-ol) and α-copaene, presented separately and in combination; and one test evaluated effect of trap type on beetle captures. In addition, electroantennography (EAG) was used to quantify female olfactory responses to lure emissions. This study identified (-)-α-copaene as a new attractant for FL-TSHB, equivalent in efficacy to quercivorol (the standard lure for Euwallacea detection in the USA); however, the combination of lures captured significantly more FL-TSHB than either lure alone. This combination resulted in synergistic attraction at two field sites and additive attraction at a third site. Sticky panel traps captured more FL-TSHB than comparably-baited Lindgren funnel traps. Females engaged in host-seeking flight from 11:00 to 16:00 hr (EST), with peak numbers observed between 12:00 and 13:00 hr. EAG analyses confirmed olfactory chemoreception of both kairomones, with a higher response elicited with the combination of volatiles. Results indicate that detection of pest E. nr. fornicatus in Florida can be improved by using a two-component lure consisting of p-menth-2-en-1-ol and (-)-α-copaene. PMID:28609448

Safety of thoracic pedicle screw application using the funnel technique in Asians: a cadaveric evaluation.

PubMed

Chan, Chris Yin Wei; Kwan, Mun Keong; Saw, Lim Beng

2010-01-01

The objective of this cadaveric study is to determine the safety and outcome of thoracic pedicle screw placement in Asians using the funnel technique. Pedicle screws have superior biomechanical as well as clinical data when compared to other methods of instrumentation. However, misplacement in the thoracic spine can result in major neurological implications. There is great variability of the thoracic pedicle morphometry between the Western and the Asian population. The feasibility of thoracic pedicle screw insertion in Asians has not been fully elucidated yet. A pre-insertion radiograph was performed and surgeons were blinded to the morphometry of the thoracic pedicles. 240 pedicle screws were inserted in ten Asian cadavers from T1 to T12 using the funnel technique. 5.0 mm screws were used from T1 to T6 while 6.0 mm screws were used from T7 to T12. Perforations were detected by direct visualization via a wide laminectomy. The narrowest pedicles are found between T3 and T6. T5 pedicle width is smallest measuring 4.1 +/- 1.3 mm. There were 24 (10.0%) Grade 1 perforations and only 1 (0.4%) Grade 2 perforation. Grade 2 or worse perforation is considered significant perforation which would threaten the neural structures. There were twice as many lateral and inferior perforations compared to medial perforations. 48.0% of the perforations occurred at T1, T2 and T3 pedicles. Pedicle fracture occurred in 10.4% of pedicles. Intra-operatively, the absence of funnel was found in 24.5% of pedicles. In conclusion, thoracic pedicle screws using 5.0 mm at T1-T6 and 6.0 mm at T7-T12 can be inserted safely in Asian cadavers using the funnel technique despite having smaller thoracic pedicle morphometry.

Hydrodynamic trapping for rapid assembly and in situ electrical characterization of droplet interface bilayer arrays

DOE PAGES

Nguyen, Mary -Anne; Srijanto, Bernadeta; Collier, C. Patrick; ...

2016-08-02

The droplet interface bilayer (DIB) is a modular technique for assembling planar lipid membranes between water droplets in oil. The DIB method thus provides a unique capability for developing digital, droplet-based membrane platforms for rapid membrane characterization, drug screening and ion channel recordings. This paper demonstrates a new, low-volume microfluidic system that automates droplet generation, sorting, and sequential trapping in designated locations to enable the rapid assembly of arrays of DIBs. The channel layout of the device is guided by an equivalent circuit model, which predicts that a serial arrangement of hydrodynamic DIB traps enables sequential droplet placement and minimizesmore » the hydrodynamic pressure developed across filled traps to prevent squeeze-through of trapped droplets. Furthermore, the incorporation of thin-film electrodes fabricated via evaporation metal deposition onto the glass substrate beneath the channels allows for the first time in situ, simultaneous electrical interrogation of multiple DIBs within a sealed device. Combining electrical measurements with imaging enables measurements of membrane capacitance and resistance and bilayer area, and our data show that DIBs formed in different trap locations within the device exhibit similar sizes and transport properties. Simultaneous, single channel recordings of ion channel gating in multiple membranes are obtained when alamethicin peptides are incorporated into the captured droplets, qualifying the thin-film electrodes as a means for measuring stimuli-responsive functions of membrane-bound biomolecules. Furthermore, this novel microfluidic-electrophysiology platform provides a reproducible, high throughput method for performing electrical measurements to study transmembrane proteins and biomembranes in low-volume, droplet-based membranes.« less

Hydrodynamic trapping for rapid assembly and in situ electrical characterization of droplet interface bilayer arrays

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

Nguyen, Mary -Anne; Srijanto, Bernadeta; Collier, C. Patrick

The droplet interface bilayer (DIB) is a modular technique for assembling planar lipid membranes between water droplets in oil. The DIB method thus provides a unique capability for developing digital, droplet-based membrane platforms for rapid membrane characterization, drug screening and ion channel recordings. This paper demonstrates a new, low-volume microfluidic system that automates droplet generation, sorting, and sequential trapping in designated locations to enable the rapid assembly of arrays of DIBs. The channel layout of the device is guided by an equivalent circuit model, which predicts that a serial arrangement of hydrodynamic DIB traps enables sequential droplet placement and minimizesmore » the hydrodynamic pressure developed across filled traps to prevent squeeze-through of trapped droplets. Furthermore, the incorporation of thin-film electrodes fabricated via evaporation metal deposition onto the glass substrate beneath the channels allows for the first time in situ, simultaneous electrical interrogation of multiple DIBs within a sealed device. Combining electrical measurements with imaging enables measurements of membrane capacitance and resistance and bilayer area, and our data show that DIBs formed in different trap locations within the device exhibit similar sizes and transport properties. Simultaneous, single channel recordings of ion channel gating in multiple membranes are obtained when alamethicin peptides are incorporated into the captured droplets, qualifying the thin-film electrodes as a means for measuring stimuli-responsive functions of membrane-bound biomolecules. Furthermore, this novel microfluidic-electrophysiology platform provides a reproducible, high throughput method for performing electrical measurements to study transmembrane proteins and biomembranes in low-volume, droplet-based membranes.« less

Sociocultural perspectives of trapping revisited: a comparative analysis of activities and motives 1994 and 2000

Treesearch

Rodney R. Zwick; Ron Glass; Kim Royar; Tom Decker

2002-01-01

Vermont trappers are faced with multiple social, economic, and political factors that influence their harvest activities, the extent of their participation, and affect their motives for participating in trapping. The purpose of this study was to assess changes in participation and motives of Vermont trappers from 1994 to 2000. Data collected from 333 licensed Vermont...

Influence of trap distance from a source population and multiple traps on captures and attack densities of the redbay ambrosia beetle (Coleoptera: Curculionidae: Scolytinae)

Treesearch

James L. Hanula; Albert (Bud) Mayfield; Laurie S. Reid; Scott Horn

2016-01-01

The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is the principal vector of laurel wilt disease in North America. Lures incorporating essential oils of manuka plants (Leptospermum scoparium J. R. Forster & G. Forster) or cubeb seeds (Piper cubeba L.f.) are the most effective in-flight...

Use of unwounded ash trees for the detection of emerald ash borer adults: EAB landing behavior

Treesearch

Jordan M. Marshall; Melissa J. Porter; Andrew J. Storer

2011-01-01

Incorporation of multiple trapping techniques and sites within a survey program is essential to adequately identify the range of emerald ash borer (EAB) (Agrilus planipennis Fairmaire) infestation. Within natural forests, EAB lands on stick band traps wrapped around girdled ash trees at a rate similar to that on unwounded ash trees. The objective of...

Defensive Gin-Trap Closure Response of Tenebrionid Beetle, Zophobas atratus, Pupae

PubMed Central

Ichikawa, Toshio; Kurauchi, Toshiaki; Yamawaki, Yoshifumi

2012-01-01

Pupae of the beetle Zophobas atratus Fab. (Coleoptera: Tenebrionidae) have jaws called gin traps on the lateral margin of their jointed abdominal segments. When a weak tactile stimulation was applied to the intersegmental region between the two jaws of a gin trap in a resting pupa, the pupa rapidly closed and reopened single or multiple gin traps adjacent to the stimulated trap for 100200 ms. In response to a strong stimulation, a small or large rotation of the abdominal segments occurred after the rapid closure of the traps. Analyses of trajectory patterns of the last abdominal segment during the rotations revealed that the rotational responses were graded and highly variable with respect to the amplitudes of their horizontal and vertical components. The high variability of these rotational responses is in contrast with the low variability (or constancy) of abdominal rotations induced by the tactile stimulation of cephalic and thoracic appendages. Since the closed state of the gin traps lasts only for a fraction of a second, the response may mainly function to deliver a “painful” stimulus to an attacker rather than to cause serious damage. PMID:23448309

Defensive gin-trap closure response of tenebrionid beetle, Zophobas atratus, pupae.

PubMed

Ichikawa, Toshio; Kurauchi, Toshiaki; Yamawaki, Yoshifumi

2012-01-01

Pupae of the beetle Zophobas atratus Fab. (Coleoptera: Tenebrionidae) have jaws called gin traps on the lateral margin of their jointed abdominal segments. When a weak tactile stimulation was applied to the intersegmental region between the two jaws of a gin trap in a resting pupa, the pupa rapidly closed and reopened single or multiple gin traps adjacent to the stimulated trap for 100200 ms. In response to a strong stimulation, a small or large rotation of the abdominal segments occurred after the rapid closure of the traps. Analyses of trajectory patterns of the last abdominal segment during the rotations revealed that the rotational responses were graded and highly variable with respect to the amplitudes of their horizontal and vertical components. The high variability of these rotational responses is in contrast with the low variability (or constancy) of abdominal rotations induced by the tactile stimulation of cephalic and thoracic appendages. Since the closed state of the gin traps lasts only for a fraction of a second, the response may mainly function to deliver a "painful" stimulus to an attacker rather than to cause serious damage.

The long-term dissolution characteristics of a residually trapped BTX mixture in soil

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

Rixey, W.G.

1996-12-31

A mass transfer limited model is presented to describe the long-term dissolution of organic compounds from a benzene, toluene, and xylenes (BTX) mixture residually trapped in a sandy soil. The model is an extension of a previously presented equilibrium dissolution model which takes into consideration mass transfer limitations that develop later in the leaching process and is similar to that presented by Borden and Kao for modeling BTX dissolution from residually trapped gasoline. The residual nonaqueous phase liquid (NAPL) is divided into multiple regions: one region which undergoes equilibrium dissolution and additional regions in which mass transfer is progressively limited.more » Application of the model to BTX column effluent data indicates that the initial dissolution (exponential decay region) of BTX can be effectively described by equilibrium dissolution. When applied to later dissolution times (Asymptotic region) a multiple-region model is required to rationalize the data for all three components. This explanation of the observed tailing in leaching experiments form residually trapped hydrocarbons if offered as an alternative to the explanation of tailing due to rate-limited desorption from soils. 16 refs., 5 figs., 2 tabs.« less

Atomistic modeling trap-assisted tunneling in hole tunnel field effect transistors

NASA Astrophysics Data System (ADS)

Long, Pengyu; Huang, Jun Z.; Povolotskyi, Michael; Sarangapani, Prasad; Valencia-Zapata, Gustavo A.; Kubis, Tillmann; Rodwell, Mark J. W.; Klimeck, Gerhard

2018-05-01

Tunnel Field Effect Transistors (FETs) have the potential to achieve steep Subthreshold Swing (S.S.) below 60 mV/dec, but their S.S. could be limited by trap-assisted tunneling (TAT) due to interface traps. In this paper, the effect of trap energy and location on OFF-current (IOFF) of tunnel FETs is evaluated systematically using an atomistic trap level representation in a full quantum transport simulation. Trap energy levels close to band edges cause the highest leakage. Wave function penetration into the surrounding oxide increases the TAT current. To estimate the effects of multiple traps, we assume that the traps themselves do not interact with each other and as a whole do not modify the electrostatic potential dramatically. Within that model limitation, this numerical metrology study points to the critical importance of TAT in the IOFF in tunnel FETs. The model shows that for Dit higher than 1012/(cm2 eV) IO F F is critically increased with a degraded IO N/IO F F ratio of the tunnel FET. In order to have an IO N/IO F F ratio higher than 104, the acceptable Dit near Ev should be controlled to no larger than 1012/(cm2 eV) .

ECCENTRICITY TRAP: TRAPPING OF RESONANTLY INTERACTING PLANETS NEAR THE DISK INNER EDGE

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

Ogihara, Masahiro; Ida, Shigeru; Duncan, Martin J., E-mail: ogihara@geo.titech.ac.j, E-mail: ida@geo.titech.ac.j, E-mail: duncan@astro.queensu.c

2010-10-01

Using orbital integration and analytical arguments, we have found a new mechanism (an 'eccentricity trap') to halt type I migration of planets near the inner edge of a protoplanetary disk. Because asymmetric eccentricity damping due to disk-planet interaction on the innermost planet at the disk edge plays a crucial role in the trap, this mechanism requires continuous eccentricity excitation and hence works for a resonantly interacting convoy of planets. This trap is so strong that the edge torque exerted on the innermost planet can completely halt type I migrations of many outer planets through mutual resonant perturbations. Consequently, the convoymore » stays outside the disk edge, as a whole. We have derived a semi-analytical formula for the condition for the eccentricity trap and predict how many planets are likely to be trapped. We found that several planets or more should be trapped by this mechanism in protoplanetary disks that have cavities. It can be responsible for the formation of non-resonant, multiple, close-in super-Earth systems extending beyond 0.1 AU. Such systems are being revealed by radial velocity observations to be quite common around solar-type stars.« less

An adaptive strategy for reducing Feral Cat predation on endangered hawaiian birds

USGS Publications Warehouse

Hess, S.C.; Banko, P.C.; Hansen, H.

2009-01-01

Despite the long history of Feral Cats Felis catus in Hawai'i, there has been little research to provide strategies to improve control programmes and reduce depredation on endangered species. Our objective Was to develop a predictive model to determine how landscape features on Mauna Kea, such as habitat, elevation, and proximity to roads, may affect the number of Feral Cats captured at each trap. We used log-link generalized linear models and QAIC c model ranking criteria to determine the effect of these factors. We found that The number of cats captured per trap Was related to effort, habitat type, and Whether traps Were located on The West or North Slope of Mauna Kea. We recommend an adaptive management strategy to minimize trapping interference by non-target Small Indian Mongoose Herpestes auropunctatus with toxicants, to focus trapping efforts in M??mane Sophora chrysophylla habitat on the West slope of Mauna Kea, and to cluster traps near others that have previously captured multiple cats.

Assessment of Detection and Refinement Strategies for de novo Protein Structures using Force Field and Statistical Potentials

DTIC Science & Technology

2007-01-01

energy landscape of real proteins . As such, real proteins may have a subtle free energy gradient toward the native that requires long folding times...some leaning, however slight, toward the lowest free - energy basin .9 One caveat in the connection between the scoring funnel and the folding funnel is... protein sets. The average DFIRE-AA scores from each cluster were ranked, and the lowest- energy conformers from each of the top 16 clusters

Magnetic monopole search with the MoEDAL test trapping detector

NASA Astrophysics Data System (ADS)

Katre, Akshay

2016-11-01

IMoEDAL is designed to search for monopoles produced in high-energy Large Hadron Collider (LHC) collisions, based on two complementary techniques: nucleartrack detectors for high-ionisation signatures and other highly ionising avatars of new physics, and trapping volumes for direct magnetic charge measurements with a superconducting magnetometer. The MoEDAL test trapping detector array deployed in 2012, consisting of over 600 aluminium samples, was analysed and found to be consistent with zero trapped magnetic charge. Stopping acceptances are obtained from a simulation of monopole propagation in matter for a range of charges and masses, allowing to set modelindependent and model-dependent limits on monopole production cross sections. Multiples of the fundamental Dirac magnetic charge are probed for the first time at the LHC.

The dual-basin landscape in GFP folding

PubMed Central

Andrews, Benjamin T.; Gosavi, Shachi; Finke, John M.; Onuchic, José N.; Jennings, Patricia A.

2008-01-01

Recent experimental studies suggest that the mature GFP has an unconventional landscape composed of an early folding event with a typical funneled landscape, followed by a very slow search and rearrangement step into the locked, active chromophore-containing structure. As we have shown previously, the substantial difference in time scales is what generates the observed hysteresis in thermodynamic folding. The interconversion between locked and the soft folding structures at intermediate denaturant concentrations is so slow that it is not observed under the typical experimental observation time. Simulations of a coarse-grained model were used to describe the fast folding event as well as identify native-like intermediates on energy landscapes enroute to the fluorescent native fold. Interestingly, these simulations reveal structural features of the slow dynamic transition to chromophore activation. Experimental evidence presented here shows that the trapped, native-like intermediate has structural heterogeneity in residues previously linked to chromophore formation. We propose that the final step of GFP folding is a “locking” mechanism leading to chromophore formation and high stability. The combination of previous experimental work and current simulation work is explained in the context of a dual-basin folding mechanism described above. PMID:18713871

Influence of conservation programs on amphibians using seasonal wetlands in the Prairie Pothole Region

USGS Publications Warehouse

Balas, Caleb J.; Euliss, Ned H.; Mushnet, David M.

2012-01-01

Extensive modification of upland habitats surrounding wetlands to facilitate agricultural production has negatively impacted amphibian communities in the Prairie Pothole Region of North America. In attempts to mitigate ecosystem damage associated with extensive landscape alteration, vast tracks of upland croplands have been returned to perennial vegetative cover (i.e., conservation grasslands) under a variety of U.S. Department of Agriculture programs. We evaluated the influence of these conservation grasslands on amphibian occupancy of seasonal wetlands in the Prairie Pothole Region. Using automated call surveys, aquatic funnel traps, and visual encounter surveys, we detected eight amphibian species using wetlands within three land-use categories (farmed, conservation grasslands, and native prairie grasslands) during the summers of 2005 and 2006. Seasonal wetlands within farmlands were used less frequently by amphibians than those within conservation and native prairie grasslands, and wetlands within conservation grasslands were used less frequently than those within native prairie grasslands by all species and life-stages we successfully modeled. Our results suggest that, while not occupied as frequently as wetlands within native prairie, wetlands within conservation grasslands provide important habitat for maintaining amphibian biodiversity in the Prairie Pothole Region

Longer-term effects of selective thinning on carabid beetles and spiders in the Cascade Mountains of southern Oregon

USGS Publications Warehouse

Peck, R.; Niwa, C.G.

2005-01-01

Within late-successional forests of the Cascade Mountains of southern Oregon, abundances of carabid beetles (Carabidae) and spiders (Araneae) from pitfall traps were compared between stands thinned 16-41 years prior and nearby unthinned stands. Species richness of both taxa were moderate for coniferous forests of this region, with 12 carabid beetle species and >120 spider species collected. No differences in total abundance or species richness were found between stand types for carabid beetles, although abundances of four of the six most common species differed significantly. Pterostichus setosus, the most abundant species collected, was significantly more abundant in unthinned stands, while Omus cazieri, P. lama, and Carabus taedatus were more numerous in thinned stands. In contrast, both total spider abundance and species richness were significantly higher in thinned stands. Hunting spiders within the families Lycosidae and Gnaphosidae, and the funnel web-building Dictynidae were captured more often in thinned stands while sheet web spiders within Linyphiidae and Hahniidae were more abundant in unthinned stands. The forest floor within unthinned stands was structurally more diverse than in thinned stands, but this did not lead to greater overall abundance or diversity of either carabid beetles or spiders.

Further contributions to the Coleoptera fauna of New Brunswick with an addition to the fauna of Nova Scotia, Canada

PubMed Central

Webster, Reginald P.; Webster, Vincent L.; Alderson, Chantelle A.; Hughes, Cory C.; Sweeney, Jon D.

2016-01-01

Abstract This paper treats 134 new records of Coleoptera for the province of New Brunswick, Canada from the following 41 families: Gyrinidae, Carabidae, Dytiscidae, Histeridae, Leiodidae, Scarabaeidae, Scirtidae, Buprestidae, Elmidae, Limnichidae, Heteroceridae, Ptilodactylidae, Eucnemidae, Throscidae, Elateridae, Lampyridae, Cantharidae, Dermestidae, Bostrichidae, Ptinidae, Cleridae, Melyridae, Monotomidae, Cryptophagidae, Silvanidae, Laemophloeidae, Nitidulidae, Endomychidae, Coccinellidae, Corylophidae, Latridiidae, Tetratomidae, Melandryidae, Mordellidae, Tenebrionidae, Mycteridae, Pyrochroidae, Aderidae, Scraptiidae, Megalopodidae, and Chrysomelidae. Among these, the following four species are newly recorded from Canada: Dirrhagofarsus ernae Otto, Muona & McClarin (Eucnemidae), Athous equestris (LeConte) (Elateridae), Ernobius opicus Fall (Ptinidae), and Stelidota coenosa Erichson (Nitidulidae). The Family Limnichidae is newly reported for New Brunswick, and one species is added to the fauna of Nova Scotia. Stephostethus productus Rosenhauer (Latridiidae), Tetratoma (Abstrulia) variegata Casey (Tetratomidae), and Chauliognathus marginatus (Fabricius) (Cantharidae) are removed from the faunal list of New Brunswick, and additional records of Lacconotus punctatus LeConte (Mycteridae) are presented and discussed. Lindgren funnel traps provided specimens for 104 (78%) of the species and were the sole source of specimens for 89 (66%) of the species reported here, suggesting they are a very useful tool for sampling Coleoptera fauna in the forests of New Brunswick. PMID:27110171

Reversible ratchet effects for vortices in conformal pinning arrays

DOE PAGES

Reichhardt, Charles; Ray, Dipanjan; Reichhardt, Cynthia Jane Olson

2015-05-04

A conformal transformation of a uniform triangular pinning array produces a structure called a conformal crystal which preserves the sixfold ordering of the original lattice but contains a gradient in the pinning density. Here we use numerical simulations to show that vortices in type-II superconductors driven with an ac drive over gradient pinning arrays produce the most pronounced ratchet effect over a wide range of parameters for a conformal array, while square gradient or random gradient arrays with equivalent pinning densities give reduced ratchet effects. In the conformal array, the larger spacing of the pinning sites in the direction transversemore » to the ac drive permits easy funneling of interstitial vortices for one driving direction, producing the enhanced ratchet effect. In the square array, the transverse spacing between pinning sites is uniform, giving no asymmetry in the funneling of the vortices as the driving direction switches, while in the random array, there are numerous easy-flow channels present for either direction of drive. We find multiple ratchet reversals in the conformal arrays as a function of vortex density and ac amplitude, and correlate the features with a reversal in the vortex ordering, which is greater for motion in the ratchet direction. In conclusion, the enhanced conformal pinning ratchet effect can also be realized for colloidal particles moving over a conformal array, indicating the general usefulness of conformal structures for controlling the motion of particles.« less

Role of self-trapped holes in the photoconductive gain of β-gallium oxide Schottky diodes

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

Armstrong, Andrew M.; Crawford, Mary H.; Jayawardena, Asanka

Solar-blind photodetection and photoconductive gain > 50 corresponding to a responsivity > 8 A/W was observed for β-Ga 2O 3 Schottky photodiodes. We investigated the origin of photoconductive gain. Current-voltage characteristics of the diodes did not indicate avalanche breakdown, which excludes carrier multiplication by impact ionization as the source for gain. However, photocapacitance measurements indicated a mechanism for hole localization for above-band gap illumination, suggesting self-trapped hole formation. Comparison of photoconductivity and photocapacitance spectra indicated that self-trapped hole formation coincides with the strong photoconductive gain. We conclude that self-trapped hole formation near the Schottky diode lowers the effective Schottky barriermore » in reverse bias, producing photoconductive gain. Ascribing photoconductive gain to an inherent property like self-trapping of holes can explain the operation of a variety of β-Ga 2O 3 photodetectors.« less

Towards Non-Equilibrium Dynamics with Trapped Ions

NASA Astrophysics Data System (ADS)

Silbert, Ariel; Jubin, Sierra; Doret, Charlie

2016-05-01

Atomic systems are superbly suited to the study of non-equilibrium dynamics. These systems' exquisite isolation from environmental perturbations leads to long relaxation times that enable exploration of far-from-equilibrium phenomena. One example of particular relevance to experiments in trapped ion quantum information processing, metrology, and precision spectroscopy is the approach to thermal equilibrium of sympathetically cooled linear ion chains. Suitable manipulation of experimental parameters permits exploration of the quantum-to-classical crossover between ballistic transport and diffusive, Fourier's Law conduction, a topic of interest not only to the trapped ion community but also for the development of microelectronic devices and other nanoscale structures. We present progress towards trapping chains of multiple co-trapped calcium isotopes geared towards measuring thermal equilibration and discuss plans for future experiments in non-equilibrium statistical mechanics. This work is supported by Cottrell College Science Award from the Research Corporation for Science Advancement and by Williams College.

Microfluidic droplet trapping array as nanoliter reactors for gas-liquid chemical reaction.

PubMed

Zhang, Qingquan; Zeng, Shaojiang; Qin, Jianhua; Lin, Bingcheng

2009-09-01

This article presents a simple method for trapping arrays of droplets relying on the designed microstructures of the microfluidic device, and this has been successfully used for parallel gas-liquid chemical reaction. In this approach, the trapping structure is composed of main channel, lateral channel and trapping region. Under a negative pressure, array droplets can be generated and trapped in the microstructure simultaneously, without the use of surfactant and the precise control of the flow velocity. By using a multi-layer microdevice containing the microstructures, single (pH gradient) and multiple gas-liquid reactions (metal ion-NH3 complex reaction) can be performed in array droplets through the transmembrane diffusion of the gas. The droplets with quantitative concentration gradient can be formed by only replacing the specific membrane. The established method is simple, robust and easy to operate, demonstrating the potential of this device for droplet-based high-throughput screening.

Role of self-trapped holes in the photoconductive gain of β-gallium oxide Schottky diodes

DOE PAGES

Armstrong, Andrew M.; Crawford, Mary H.; Jayawardena, Asanka; ...

2016-03-10

Solar-blind photodetection and photoconductive gain > 50 corresponding to a responsivity > 8 A/W was observed for β-Ga 2O 3 Schottky photodiodes. We investigated the origin of photoconductive gain. Current-voltage characteristics of the diodes did not indicate avalanche breakdown, which excludes carrier multiplication by impact ionization as the source for gain. However, photocapacitance measurements indicated a mechanism for hole localization for above-band gap illumination, suggesting self-trapped hole formation. Comparison of photoconductivity and photocapacitance spectra indicated that self-trapped hole formation coincides with the strong photoconductive gain. We conclude that self-trapped hole formation near the Schottky diode lowers the effective Schottky barriermore » in reverse bias, producing photoconductive gain. Ascribing photoconductive gain to an inherent property like self-trapping of holes can explain the operation of a variety of β-Ga 2O 3 photodetectors.« less

Synchronization of a self-sustained cold-atom oscillator

NASA Astrophysics Data System (ADS)

Heimonen, H.; Kwek, L. C.; Kaiser, R.; Labeyrie, G.

2018-04-01

Nonlinear oscillations and synchronization phenomena are ubiquitous in nature. We study the synchronization of self-oscillating magneto-optically trapped cold atoms to a weak external driving. The oscillations arise from a dynamical instability due the competition between the screened magneto-optical trapping force and the interatomic repulsion due to multiple scattering of light. A weak modulation of the trapping force allows the oscillations of the cloud to synchronize to the driving. The synchronization frequency range increases with the forcing amplitude. The corresponding Arnold tongue is experimentally measured and compared to theoretical predictions. Phase locking between the oscillator and drive is also observed.

Trapped ion system for sympathetic cooling and non-equilibrium dynamics

NASA Astrophysics Data System (ADS)

Doret, Charlie; Jubin, Sierra; Stevenson, Sarah

2017-04-01

Atomic systems are superbly suited to the study of non-equilibrium dynamics. These systems' exquisite isolation from environmental perturbations leads to long relaxation times that enable exploration of far-from-equilibrium phenomena. We present progress towards trapping chains of multiple co-trapped calcium isotopes geared towards measuring thermal equilibration and sympathetic cooling rates. We also discuss plans for future experiments in non-equilibrium statistical mechanics, including exploration of the quantum-to-classical crossover between ballistic transport and diffusive, Fourier's Law conduction. This work is supported by Cottrell College Science Award from the Research Corporation for Science Advancement and by Williams College.

Manipulation of Micro Scale Particles in Optical Traps Using Programmable Spatial Light Modulation

NASA Technical Reports Server (NTRS)

Seibel, Robin E.; Decker, Arthur J. (Technical Monitor)

2003-01-01

1064 nm light, from an Nd:YAG laser, was polarized and incident upon a programmable parallel aligned liquid crystal spatial light modulator (PAL-SLM), where it was phase modulated according to the program controlling the PAL-SLM. Light reflected from the PAL-SLM was injected into a microscope and focused. At the focus, multiple optical traps were formed in which 9.975 m spheres were captured. The traps and the spheres were moved by changing the program of the PAL-SLM. The motion of ordered groups of micro particles was clearly demonstrated.

Method of measuring field funneling and range straggling in semiconductor charge-collecting junctions

NASA Technical Reports Server (NTRS)

Zoutendyk, John A. (Inventor); Malone, Carl J. (Inventor)

1987-01-01

Electric-field funneling length is measured while irradiating a semiconductor charge-collecting junction with electron-hole-pair generating charged particles at a first junction bias voltage. The bias voltage is then reduced to a second level in order to reduce the depth of the depletion region such that the total charge can no longer be collected by drift and measured in the energy band previously displayed in the multichannel analyzer. This is representative of the maximum electric field funnelling length which may be calculated by measuring the difference at the second bias voltage level of the depletion width and the ion penetration range. The bias voltage is further lowered to a third level at which the particles are collected over a spread of energy levels while at least some of the particles are still collected at the selected energy level. From this the different depths of penetration of the particles are determined while additional effects due to diffusion are minimized.

Method of measuring field funneling and range straggling in semiconductor charge-collecting junctions

NASA Technical Reports Server (NTRS)

Zoutendyk, J. A. (Inventor)

1985-01-01

Electric-field funneling length is measured while irradiating a semiconductor charge-collecting junction with electron-hole-pair generating charged particles at a first junction bias voltage. The bias voltage is then reduced to a second level in order to reduce the depth of the depletion region such that the total charge can no longer be collected by drift and measured in the energy band previously displayed in the multichannel analyzer. This is representative of the maximum electric field funneling length which may be calculated by measuring the difference at the second bias voltage level of the depletion width and the ion penetration range. The bias voltage is further lowered to a third level at which the particles are collected over a spread of energy levels while at least some of the particles are still collected at the selected energy level. From this the different depths of penetration of the particles are determined while additional effects due to diffusion are minimized.

Golf-course and funnel energy landscapes: Protein folding concepts in martensites

NASA Astrophysics Data System (ADS)

Shankaraiah, N.

2017-06-01

We use protein folding energy landscape concepts such as golf course and funnel to study re-equilibration in athermal martensites under systematic temperature quench Monte Carlo simulations. On quenching below a transition temperature, the seeded high-symmetry parent-phase austenite that converts to the low-symmetry product-phase martensite, through autocatalytic twinning or elastic photocopying, has both rapid conversions and incubation delays in the temperature-time-transformation phase diagram. We find the rapid (incubation delays) conversions at low (high) temperatures arises from the presence of large (small) size of golf-course edge that has the funnel inside for negative energy states. In the incubating state, the strain structure factor enters into the Brillouin-zone golf course through searches for finite transitional pathways which close off at the transition temperature with Vogel-Fulcher divergences that are insensitive to Hamiltonian energy scales and log-normal distributions, as signatures of dominant entropy barriers. The crossing of the entropy barrier is identified through energy occupancy distributions, Monte Carlo acceptance fractions, heat emission, and internal work.

Watching Electrons at Conical Intersections and Funnels

NASA Astrophysics Data System (ADS)

Jonas, David M.; Smith, Eric R.; Peters, William K.; Kitney, Katherine A.

2009-06-01

The electronic motion at conical intersections and funnels is probed after polarized excitation of aligned electronic wavepackets. The pulses have bandwidth sufficient to observe vibrations mainly through their effect on the electrons. Vibrational symmetry can be identified by the polarization anisotropy of vibrational quantum beats. The polarized transients show signatures of electronic wavepacket motion (due to the energy gaps) and of electron transfer between orbitals (due to the couplings) driven by the conical intersection. For a conical intersection in a four-fold symmetric symmetry silicon naphthalocyanine molecule, electronic motions on a 100 fs timescale are driven by couplings of 1 meV. In the lower symmetry free-base naphthalocyanine, the conical intersection may be missed or missing (conical funnel), and the motions are nearly as rapid, but electronic equilibration is incomplete for red-edge excitation. These experiments probe non-adiabatic electronic dynamics with near-zero nuclear momentum - the electronic motions are determined by the principal slopes of the conical intersection and the width of the vibrational wavepacket.

Blends of Pheromones, With and Without Host Plant Volatiles, Can Attract Multiple Species of Cerambycid Beetles Simultaneously

Treesearch

L.M. Hanks; J.A. Mongold-Diers; T.H. Atkinson; M.K. Fierke; M.D. Ginzel; E.E. Graham; T.M. Poland; A.B. Richards; M.L. Richardson; J.G. Millar

2018-01-01

Pheromone components of cerambycid beetles are often conserved, with a given compound serving as a pheromone component for multiple related species, including species native to different continents. Consequently, a single synthesized compound may attract multiple species to a trap simultaneously. Furthermore, our previous research in east-central Illinois had...

Paraquat detoxication with multiple emulsions.

PubMed

Frasca, S; Couvreur, P; Seiller, M; Pareau, D; Lacour, B; Stambouli, M; Grossiord, J L

2009-10-01

In this study, we show that detoxifying W/O/W multiple emulsions, prepared with an appropriate extractant/trapping couple, represent a promising technology for quick and safe poisoning treatments, with application to the highly toxic herbicide Paraquat, responsible of poisonings from low-dose exposure leading to several deaths every year. In vitro tests led to the choice of an appropriate extractant/trapping couple system with significant detoxication performance. In vivo tests showed (i) that rats receiving high doses of Paraquat, then a detoxifying emulsion, presented an increase from 50% to 100% of the MST (median survival time) and (ii) that no mortality was observed during 30 days with rats dosed with emulsions initially loaded with Paraquat at a concentration much higher than the lethal dose, proving the stability and the inocuity of the detoxifying multiple emulsion in the gastrointestinal tract.

Effects of prescribed fire and fire surrogates on Saproxylic coleoptera in the Southern Appalachians of North Carolina

Treesearch

Joshua W. Campbell; James L. Hanula; Thomas A. Waldrop

2008-01-01

We examined the effects of forest management practices (prescribed burning, mechanical, and prescribed burn plus mechanical) on saproxylic forest Coleoptera in the southern Appalachian Mountains of North Carolina. During the 2-yr study, we captured 37,191 Coleoptera with baited multiple- unnel traps and pipe traps, comprising 20 families and 122 species that were used...

Optimal quantum control of multimode couplings between trapped ion qubits for scalable entanglement.

PubMed

Choi, T; Debnath, S; Manning, T A; Figgatt, C; Gong, Z-X; Duan, L-M; Monroe, C

2014-05-16

We demonstrate entangling quantum gates within a chain of five trapped ion qubits by optimally shaping optical fields that couple to multiple collective modes of motion. We individually address qubits with segmented optical pulses to construct multipartite entangled states in a programmable way. This approach enables high-fidelity gates that can be scaled to larger qubit registers for quantum computation and simulation.

Multiple Optical Traps with a Single-Beam Optical Tweezer Utilizing Surface Micromachined Planar Curved Grating

NASA Astrophysics Data System (ADS)

Kuo, Ju-Nan; Chen, Kuan-Yu

2010-11-01

In this paper, we present a single-beam optical tweezer integrated with a planar curved diffraction grating for microbead manipulation. Various curvatures of the surface micromachined planar curved grating are systematically investigated. The planar curved grating was fabricated using multiuser micro-electro-mechanical-system (MEMS) processes (MUMPs). The angular separation and the number of diffracted orders were determined. Experimental results indicate that the diffraction patterns and curvature of the planar curved grating are closely related. As the curvature of the planar curved grating increases, the vertical diffraction angle increases, resulting in the strip patterns of the planar curved grating. A single-beam optical tweezer integrated with a planar curved diffraction grating was developed. We demonstrate a technique for creating multiple optical traps from a single laser beam using the developed planar curved grating. The strip patterns of the planar curved grating that resulted from diffraction were used to trap one row of polystyrene beads.

Risk-taking behavior in the presence of nonconvex asset dynamics.

PubMed

Lybbert, Travis J; Barrett, Christopher B

2011-01-01

The growing literature on poverty traps emphasizes the links between multiple equilibria and risk avoidance. However, multiple equilibria may also foster risk-taking behavior by some poor people. We illustrate this idea with a simple analytical model in which people with different wealth and ability endowments make investment and risky activity choices in the presence of known nonconvex asset dynamics. This model underscores a crucial distinction between familiar static concepts of risk aversion and forward-looking dynamic risk responses to nonconvex asset dynamics. Even when unobservable preferences exhibit decreasing absolute risk aversion, observed behavior may suggest that risk aversion actually increases with wealth near perceived dynamic asset thresholds. Although high ability individuals are not immune from poverty traps, they can leverage their capital endowments more effectively than lower ability types and are therefore less likely to take seemingly excessive risks. In general, linkages between behavioral responses and wealth dynamics often seem to run in both directions. Both theoretical and empirical poverty trap research could benefit from making this two-way linkage more explicit.

Annular beam with segmented phase gradients

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

Cheng, Shubo; Wu, Liang; Tao, Shaohua, E-mail: eshtao@csu.edu.cn

2016-08-15

An annular beam with a single uniform-intensity ring and multiple segments of phase gradients is proposed in this paper. Different from the conventional superposed vortices, such as the modulated optical vortices and the collinear superposition of multiple orbital angular momentum modes, the designed annular beam has a doughnut intensity distribution whose radius is independent of the phase distribution of the beam in the imaging plane. The phase distribution along the circumference of the doughnut beam can be segmented with different phase gradients. Similar to a vortex beam, the annular beam can also exert torques and rotate a trapped particle owingmore » to the orbital angular momentum of the beam. As the beam possesses different phase gradients, the rotation velocity of the trapped particle can be varied along the circumference. The simulation and experimental results show that an annular beam with three segments of different phase gradients can rotate particles with controlled velocities. The beam has potential applications in optical trapping and optical information processing.« less

Real-time interactive 3D manipulation of particles viewed in two orthogonal observation planes.

PubMed

Perch-Nielsen, Ivan; Rodrigo, Peter; Glückstad, Jesper

2005-04-18

The generalized phase contrast (GPC) method has been applied to transform a single TEM00 beam into a manifold of counterpropagating-beam traps capable of real-time interactive manipulation of multiple microparticles in three dimensions (3D). This paper reports on the use of low numerical aperture (NA), non-immersion, objective lenses in an implementation of the GPC-based 3D trapping system. Contrary to high-NA based optical tweezers, the GPC trapping system demonstrated here operates with long working distance (>10 mm), and offers a wider manipulation region and a larger field of view for imaging through each of the two opposing objective lenses. As a consequence of the large working distance, simultaneous monitoring of the trapped particles in a second orthogonal observation plane is demonstrated.

A compact multi-trap optical tweezer system based on CD-ROM technologies

NASA Astrophysics Data System (ADS)

McMenamin, T.; Lee, W. M.

2017-08-01

We implemented an integrated time sharing multiple optical trapping system through the synchronisation of high speed voice coil scanning lens and laser pulsing. The integration is achieved by using commonly available optical pickup unit (OPU) that exists inside optical drives. Scanning frequencies of up to 2 kHz were showed to achieve arbitrary distribution of optical traps within the one-dimensional scan range of the voice coil motor. The functions of the system were demonstrated by the imaging and trapping of 1 μm particles and giant unilamellar vesicles (GUVs). The new device circumvents existing bulky laser scanning systems (4f lens systems) with an integrated laser and lens steering platform that can be integrated on a variety of microscopy platforms (confocal, lightsheet, darkfield).

Matter-wave dark solitons in boxlike traps

NASA Astrophysics Data System (ADS)

Sciacca, M.; Barenghi, C. F.; Parker, N. G.

2017-01-01

Motivated by the experimental development of quasihomogeneous Bose-Einstein condensates confined in boxlike traps, we study numerically the dynamics of dark solitons in such traps at zero temperature. We consider the cases where the side walls of the box potential rise either as a power law or a Gaussian. While the soliton propagates through the homogeneous interior of the box without dissipation, it typically dissipates energy during a reflection from a wall through the emission of sound waves, causing a slight increase in the soliton's speed. We characterize this energy loss as a function of the wall parameters. Moreover, over multiple oscillations and reflections in the boxlike trap, the energy loss and speed increase of the soliton can be significant, although the decay eventually becomes stabilized when the soliton equilibrates with the ambient sound field.

Tempo-Spatial Dynamics of Adult Plum Curculio (Coleoptera: Curculionidae) Based on Semiochemical-Baited Trap Captures in Blueberries.

PubMed

Hernandez-Cumplido, Johnattan; Leskey, Tracy C; Holdcraft, Robert; Zaman, Faruque U; Hahn, Noel G; Rodriguez-Saona, Cesar

2017-06-01

Plum curculio, Conotrachelus nenuphar (Herbst), has become an important pest of highbush blueberries in the northeastern United States. Here, we conducted experiments in 2010-2013 to compare the efficacy of semiochemical-baited traps for C. nenuphar versus conventional (beating cloth) sampling methods in blueberries, and to understand the seasonal abundance and distribution of C. nenuphar adults within and among blueberry fields using these traps. Black pyramid traps baited with the C. nenuphar aggregation pheromone grandisoic acid and the fruit volatile benzaldehyde caught three to four times more adults than unbaited traps without causing an increase in injury to berries in neighboring bushes. Numbers of adult weevils caught in traps correlated with those on bushes (beating cloth samples), indicating that trap counts can predict C. nenuphar abundance in the field. Early in the season, traps placed 20 m from field edges near a forest caught higher C. nenuphar numbers than traps placed at farther distances, suggesting movement of overwintered weevils from outside fields. Using a trapping network across multiple fields in an organic farm, we found evidence of C. nenuphar aggregation in "hotspots"; early in the season, C. nenuphar numbers in traps were higher in the middle of fields, and there was a correlation between these numbers and distance from the forest in 2013 but not in 2012. These results show that semiochemical-baited traps are effective in capturing C. nenuphar adults in blueberries, and that these traps should be placed in the interior of fields preferably, but not exclusively, near wooded habitats to maximize their efficacy. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Shaping of nested potentials for electron cooling of highly-charged ions in a cooler Penning trap

NASA Astrophysics Data System (ADS)

Paul, Stefan; Kootte, Brian; Lascar, Daniel; Gwinner, Gerald; Dilling, Jens; Titan Collaboration

2016-09-01

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is dedicated to mass spectrometry and decay spectroscopy of short-lived radioactive nuclides in a series of ion traps including a precision Penning trap. In order to boost the achievable precision of mass measurements TITAN deploys an Electron Beam Ion Trap (EBIT) providing Highly-Charged Ions (HCI). However, the charge breeding process in the EBIT leads to an increase in the ion bunch's energy spread which is detrimental to the overall precision gain. To reduce this effect a new cylindrical Cooler PEnning Trap (CPET) is being commissioned to sympathetically cool the HCI via a simultaneously trapped electron plasma. Simultaneous trapping of ions and electrons requires a high level of control over the nested potential landscape and sophisticated switching schemes for the voltages on CPET's multiple ring electrodes. For this purpose, we are currently setting up a new experimental control system for multi-channel voltage switching. The control system employs a Raspberry Pi communicating with a digital-to-analog board via a serial peripheral interface. We report on the implementation of the voltage control system and its performance with respect to electron and ion manipulation in CPET. University of British Columbia, Vancouver, BC, Canada.

Pulse I-V characterization of a nano-crystalline oxide device with sub-gap density of states

NASA Astrophysics Data System (ADS)

Kim, Taeho; Hur, Ji-Hyun; Jeon, Sanghun

2016-05-01

Understanding the charge trapping nature of nano-crystalline oxide semiconductor thin film transistors (TFTs) is one of the most important requirements for their successful application. In our investigation, we employed a fast-pulsed I-V technique for understanding the charge trapping phenomenon and for characterizing the intrinsic device performance of an amorphous/nano-crystalline indium-hafnium-zinc-oxide semiconductor TFT with varying density of states in the bulk. Because of the negligible transient charging effect with a very short pulse, the source-to-drain current obtained with the fast-pulsed I-V measurement was higher than that measured by the direct-current characterization method. This is because the fast-pulsed I-V technique provides a charge-trap free environment, suggesting that it is a representative device characterization methodology of TFTs. In addition, a pulsed source-to-drain current versus time plot was used to quantify the dynamic trapping behavior. We found that the charge trapping phenomenon in amorphous/nano-crystalline indium-hafnium-zinc-oxide TFTs is attributable to the charging/discharging of sub-gap density of states in the bulk and is dictated by multiple trap-to-trap processes.

Pulse I-V characterization of a nano-crystalline oxide device with sub-gap density of states.

PubMed

Kim, Taeho; Hur, Ji-Hyun; Jeon, Sanghun

2016-05-27

Understanding the charge trapping nature of nano-crystalline oxide semiconductor thin film transistors (TFTs) is one of the most important requirements for their successful application. In our investigation, we employed a fast-pulsed I-V technique for understanding the charge trapping phenomenon and for characterizing the intrinsic device performance of an amorphous/nano-crystalline indium-hafnium-zinc-oxide semiconductor TFT with varying density of states in the bulk. Because of the negligible transient charging effect with a very short pulse, the source-to-drain current obtained with the fast-pulsed I-V measurement was higher than that measured by the direct-current characterization method. This is because the fast-pulsed I-V technique provides a charge-trap free environment, suggesting that it is a representative device characterization methodology of TFTs. In addition, a pulsed source-to-drain current versus time plot was used to quantify the dynamic trapping behavior. We found that the charge trapping phenomenon in amorphous/nano-crystalline indium-hafnium-zinc-oxide TFTs is attributable to the charging/discharging of sub-gap density of states in the bulk and is dictated by multiple trap-to-trap processes.

Where does the waiting list begin? A short review of the dynamics and organization of modern waiting lists.

PubMed

Rotstein, Dalia L; Alter, David A

2006-06-01

Waiting for medical care is the by-product of system rationing, where demand exceeds supply. In this short report we expand on the conventional concept of the queue, by focusing on the regulation of demand and by incorporating a funnel and spout analogy. Real-world examples are used to illustrate the infancy of funnel or demand-side reform initiatives targeting the queue, and the suggestion is made that policy needs to address the concept of 'waiting' much earlier in the treatment cycle.

Outdoor Weathering and Dissolution of TNT and Tritonal

DTIC Science & Technology

2009-01-01

ranged from 0.361 to 1.975 g and the Tritonal chunks ran- ged from 2.162 to 5.320 g. Each funnel was attached to a 1-L glass bottle with a #4 rubber ... stopper fitted with two holes, one hole for the funnel stem and the other for a bent copper tube that allows air exchange. The bottles fit snuggly into...dissolved mass averaged about one-third of the total TNT mass loss. This result was surprising because we have had excel- lent HE mass- closure during

Single Event Upset Rate Estimates for a 16-K CMOS (Complementary Metal Oxide Semiconductor) SRAM (Static Random Access Memory).

DTIC Science & Technology

1986-09-30

4 . ~**..ft.. ft . - - - ft SI TABLES 9 I. SA32~40 Single Event Upset Test, 1140-MeV Krypton, 9/l8/8~4. . .. .. .. .. .. .16 II. CRUP Simulation...cosmic ray interaction analysis described in the remainder of this report were calculated using the CRUP computer code 3 modified for funneling. The... CRUP code requires, as inputs, the size of a depletion region specified as a retangular parallel piped with dimensions a 9 b S c, the effective funnel

Advanced Development of Certified OS Kernels

DTIC Science & Technology

2015-06-01

It provides an infrastructure to map a physical page into multiple processes’ page maps in different address spaces. Their ownership mechanism ensures...of their shared memory infrastructure . Trap module The trap module specifies the behaviors of exception handlers and mCertiKOS system calls. In...layers), 1 pm for the shared memory infrastructure (3 layers), 3.5 pm for the thread management (10 layers), 1 pm for the process management (4 layers

Nanocomposite Gate Dielectrics With Nanoparticles for Organic Thin Film Transistors

DTIC Science & Technology

2006-09-15

gives rise to the larger transport activation energy and trap distribution width in pentacene TFTs, leading to a decrease of carrier mobility. On the...voltage, carrier mobility of pentacene TFTs increase. These phenomena can be explained by multiple trapping and release model. Therefore, a possible...the low charge carrier mobility of organic semiconductors. Hence, for the applications that require high current output, such as switching of organic

Optical Trapping of Ion Coulomb Crystals

NASA Astrophysics Data System (ADS)

Schmidt, Julian; Lambrecht, Alexander; Weckesser, Pascal; Debatin, Markus; Karpa, Leon; Schaetz, Tobias

2018-04-01

The electronic and motional degrees of freedom of trapped ions can be controlled and coherently coupled on the level of individual quanta. Assembling complex quantum systems ion by ion while keeping this unique level of control remains a challenging task. For many applications, linear chains of ions in conventional traps are ideally suited to address this problem. However, driven motion due to the magnetic or radio-frequency electric trapping fields sometimes limits the performance in one dimension and severely affects the extension to higher-dimensional systems. Here, we report on the trapping of multiple barium ions in a single-beam optical dipole trap without radio-frequency or additional magnetic fields. We study the persistence of order in ensembles of up to six ions within the optical trap, measure their temperature, and conclude that the ions form a linear chain, commonly called a one-dimensional Coulomb crystal. As a proof-of-concept demonstration, we access the collective motion and perform spectrometry of the normal modes in the optical trap. Our system provides a platform that is free of driven motion and combines advantages of optical trapping, such as state-dependent confinement and nanoscale potentials, with the desirable properties of crystals of trapped ions, such as long-range interactions featuring collective motion. Starting with small numbers of ions, it has been proposed that these properties would allow the experimental study of many-body physics and the onset of structural quantum phase transitions between one- and two-dimensional crystals.

Bone-seeking TRAP conjugates: surprising observations and their implications on the development of gallium-68-labeled bisphosphonates

PubMed Central

2012-01-01

Background Bisphosphonates possess strong affinity to bone. 99mTc bisphosphonate complexes are widely used for bone scintigraphy. For positron emission tomography (PET) bone imaging, Ga-68-based PET tracers based on bisphosphonates are highly desirable. Findings Two trimeric bisphosphonate conjugates of the triazacyclononane-phosphinate (TRAP) chelator were synthesized, labeled with Ga-68, and used for microPET imaging of bone in male Lewis rats. Both Ga-68 tracers show bone uptake and, thus, are suitable for PET bone imaging. Surprisingly, Ga-71 nuclear magnetic resonance data prove that Ga(III) is not located in the chelating cavity of TRAP and must therefore be bound by the conjugated bisphosphonate units. Conclusion The intrinsic Ga-68 chelating properties of TRAP are not needed for Ga-68 PET bone imaging with TRAP-bisphosphonate conjugates. Here, TRAP serves only as a trimeric scaffold. For preparation of Ga-68-based bone seekers for PET, it appears sufficient to equip branched scaffolds with multiple bisphosphonate units, which serve both Ga-68-binding and bone-targeting purposes. PMID:22464278

Truncated RAP-MUSIC (TRAP-MUSIC) for MEG and EEG source localization.

PubMed

Mäkelä, Niko; Stenroos, Matti; Sarvas, Jukka; Ilmoniemi, Risto J

2018-02-15

Electrically active brain regions can be located applying MUltiple SIgnal Classification (MUSIC) on magneto- or electroencephalographic (MEG; EEG) data. We introduce a new MUSIC method, called truncated recursively-applied-and-projected MUSIC (TRAP-MUSIC). It corrects a hidden deficiency of the conventional RAP-MUSIC algorithm, which prevents estimation of the true number of brain-signal sources accurately. The correction is done by applying a sequential dimension reduction to the signal-subspace projection. We show that TRAP-MUSIC significantly improves the performance of MUSIC-type localization; in particular, it successfully and robustly locates active brain regions and estimates their number. We compare TRAP-MUSIC and RAP-MUSIC in simulations with varying key parameters, e.g., signal-to-noise ratio, correlation between source time-courses, and initial estimate for the dimension of the signal space. In addition, we validate TRAP-MUSIC with measured MEG data. We suggest that with the proposed TRAP-MUSIC method, MUSIC-type localization could become more reliable and suitable for various online and offline MEG and EEG applications. Copyright © 2017 Elsevier Inc. All rights reserved.

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet

PubMed Central

Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2015-01-01

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles. PMID:26221197

Simultaneous diamagnetic and magnetic particle trapping in ferrofluid microflows via a single permanent magnet.

PubMed

Zhou, Yilong; Kumar, Dhileep Thanjavur; Lu, Xinyu; Kale, Akshay; DuBose, John; Song, Yongxin; Wang, Junsheng; Li, Dongqing; Xuan, Xiangchun

2015-07-01

Trapping and preconcentrating particles and cells for enhanced detection and analysis are often essential in many chemical and biological applications. Existing methods for diamagnetic particle trapping require the placement of one or multiple pairs of magnets nearby the particle flowing channel. The strong attractive or repulsive force between the magnets makes it difficult to align and place them close enough to the channel, which not only complicates the device fabrication but also restricts the particle trapping performance. This work demonstrates for the first time the use of a single permanent magnet to simultaneously trap diamagnetic and magnetic particles in ferrofluid flows through a T-shaped microchannel. The two types of particles are preconcentrated to distinct locations of the T-junction due to the induced negative and positive magnetophoretic motions, respectively. Moreover, they can be sequentially released from their respective trapping spots by simply increasing the ferrofluid flow rate. In addition, a three-dimensional numerical model is developed, which predicts with a reasonable agreement the trajectories of diamagnetic and magnetic particles as well as the buildup of ferrofluid nanoparticles.

Trap Design and Construction for High-Power Multinuclear Magnetic Resonance Experiments

PubMed Central

Rispoli, Joseph V.; Dimitrov, Ivan E.; Cheshkov, Sergey; Malloy, Craig; Wright, Steven M.; McDougall, Mary P.

2016-01-01

Performing multinuclear experiments requires one or more radiofrequency (RF) coils operating at both the proton and second-nucleus frequencies; however, inductive coupling between coils must be mitigated to retain proton sensitivity and coil tuning stability. The inclusion of trap circuits simplifies placement of multinuclear RF coils while maintaining inter-element isolation. Of the commonly investigated non-proton nuclei, perhaps the most technically demanding is carbon-13, particularly when applying a proton decoupling scheme to improve the resulting spectra. This work presents experimental data for trap circuits withstanding high-power broadband proton decoupling of carbon-13 at 7 T. The advantages and challenges of building trap circuits with various inductor and capacitor components are discussed. Multiple trap designs are evaluated on the bench and utilized on an RF coil at 7 T to detect broadband proton-decoupled carbon-13 spectra from a lipid phantom. A particular trap design, built from a coaxial stub inductor and high-voltage ceramic chip capacitors, is highlighted owing to both its performance and adaptability for planar array coil elements with diverse spatial orientations. PMID:28529464

Optical waveguide loop for planar trapping of blood cells and microspheres

NASA Astrophysics Data System (ADS)

Ahluwalia, Balpreet S.; Hellesø, Olav G.

2013-09-01

The evanescent field from a waveguide can be used to trap and propel a particle. An optical waveguide loop with an intentional gap at the center is used for planar transport and stable trapping of particles. The waveguide acts as a conveyor belt to trap and deliver spheres towards the gap. At the gap, the counter-diverging light fields hold the sphere at a fixed position. Numerical simulation based on the finite element method was performed in three dimensions using a computer cluster. The field distribution and optical forces for rib and strip waveguide designs are compared and discussed. The optical force on a single particle was computed for various positions of the particle in the gap. Simulation predicted stable trapping of particles in the gap. Depending on the gap separation (2-50 μm) a single or multiple spheres and red blood cells were trapped at the gap. Waveguides were made of tantalum pentaoxide material. The waveguides are only 180 nm thick and thus could be integrated with other functions on the chip.

Three-dimensional ultrasonic trapping of micro-particles in water with a simple and compact two-element transducer

NASA Astrophysics Data System (ADS)

Franklin, A.; Marzo, A.; Malkin, R.; Drinkwater, B. W.

2017-08-01

We report a simple and compact piezoelectric transducer capable of stably trapping single and multiple micro-particles in water. A 3D-printed Fresnel lens is bonded to a two-element kerfless piezoceramic disk and actuated in a split-piston mode to produce an acoustic radiation force trap that is stable in three-dimensions. Polystyrene micro-particles in the Rayleigh regime (radius λ/14 to λ/7) are trapped at the focus of the lens (F# = 0.4) and manipulated in two-dimensions on an acoustically transparent membrane with a peak trap stiffness of 0.43 mN/m. Clusters of Rayleigh particles are also trapped and manipulated in three-dimensions, suspended in water against gravity. This transducer represents a significant simplification over previous acoustic devices used for micro-particle manipulation in liquids as it operates at relatively low frequency (688 kHz) and only requires a single electrical drive signal. This simplified device has potential for widespread use in applications such as micro-scale manufacturing and handling of cells or drug capsules in biomedical assays.

Auroral-particle precipitation and trapping caused by electrostatic double layers in the ionosphere.

PubMed

Albert, R D; Lindstrom, P J

1970-12-25

Interpretation of high-resolution angular distribution measurements of the primary auroral electron flux detected by a rocket probe launched into a visible aurora from Fort Churchill in the fall of 1966 leads to the following conclusions. The auroral electron flux is nearly monoenergetic and has a quasi-trapped as well as a precipitating component. The quasi-trapped flux appears to be limited to a region defined by magnetic-mirror points and multiple electrostatic double layers in the ionosphere. The electrostatic field of the double-layer distribution enhances the aurora by lowering the magnetic-mirror points and supplying energy to the primary auroral electrons.

A minimalist model protein with multiple folding funnels

PubMed Central

Locker, C. Rebecca; Hernandez, Rigoberto

2001-01-01

Kinetic and structural studies of wild-type proteins such as prions and amyloidogenic proteins provide suggestive evidence that proteins may adopt multiple long-lived states in addition to the native state. All of these states differ structurally because they lie far apart in configuration space, but their stability is not necessarily caused by cooperative (nucleation) effects. In this study, a minimalist model protein is designed to exhibit multiple long-lived states to explore the dynamics of the corresponding wild-type proteins. The minimalist protein is modeled as a 27-monomer sequence confined to a cubic lattice with three different monomer types. An order parameter—the winding index—is introduced to characterize the extent of folding. The winding index has several advantages over other commonly used order parameters like the number of native contacts. It can distinguish between enantiomers, its calculation requires less computational time than the number of native contacts, and reduced-dimensional landscapes can be developed when the native state structure is not known a priori. The results for the designed model protein prove by existence that the rugged energy landscape picture of protein folding can be generalized to include protein “misfolding” into long-lived states. PMID:11470921

Emlen funnel experiments revisited: methods update for studying compass orientation in songbirds.

PubMed

Bianco, Giuseppe; Ilieva, Mihaela; Veibäck, Clas; Öfjäll, Kristoffer; Gadomska, Alicja; Hendeby, Gustaf; Felsberg, Michael; Gustafsson, Fredrik; Åkesson, Susanne

2016-10-01

Migratory songbirds carry an inherited capacity to migrate several thousand kilometers each year crossing continental landmasses and barriers between distant breeding sites and wintering areas. How individual songbirds manage with extreme precision to find their way is still largely unknown. The functional characteristics of biological compasses used by songbird migrants has mainly been investigated by recording the birds directed migratory activity in circular cages, so-called Emlen funnels. This method is 50 years old and has not received major updates over the past decades. The aim of this work was to compare the results from newly developed digital methods with the established manual methods to evaluate songbird migratory activity and orientation in circular cages.We performed orientation experiments using the European robin ( Erithacus rubecula ) using modified Emlen funnels equipped with thermal paper and simultaneously recorded the songbird movements from above. We evaluated and compared the results obtained with five different methods. Two methods have been commonly used in songbirds' orientation experiments; the other three methods were developed for this study and were based either on evaluation of the thermal paper using automated image analysis, or on the analysis of videos recorded during the experiment.The methods used to evaluate scratches produced by the claws of birds on the thermal papers presented some differences compared with the video analyses. These differences were caused mainly by differences in scatter, as any movement of the bird along the sloping walls of the funnel was recorded on the thermal paper, whereas video evaluations allowed us to detect single takeoff attempts by the birds and to consider only this behavior in the orientation analyses. Using computer vision, we were also able to identify and separately evaluate different behaviors that were impossible to record by the thermal paper.The traditional Emlen funnel is still the most used method to investigate compass orientation in songbirds under controlled conditions. However, new numerical image analysis techniques provide a much higher level of detail of songbirds' migratory behavior and will provide an increasing number of possibilities to evaluate and quantify specific behaviors as new algorithms will be developed.

Powerful radiative jets in supercritical accretion discs around non-spinning black holes

NASA Astrophysics Data System (ADS)

Sądowski, Aleksander; Narayan, Ramesh

2015-11-01

We describe a set of simulations of supercritical accretion on to a non-rotating supermassive black hole (BH). The accretion flow takes the form of a geometrically thick disc with twin low-density funnels around the rotation axis. For accretion rates {gtrsim } 10 dot{M}_Edd, there is sufficient gas in the funnel to make this region optically thick. Radiation from the disc first flows into the funnel, after which it accelerates the optically thick funnel gas along the axis. The resulting jet is baryon loaded and has a terminal density-weighted velocity ≈0.3c. Much of the radiative luminosity is converted into kinetic energy by the time the escaping gas becomes optically thin. These jets are not powered by BHrotation or magnetic driving, but purely by radiation. Their characteristic beaming angle is ˜0.2 rad. For an observer viewing down the axis, the isotropic equivalent luminosity of total energy is as much as 1048 erg s- 1 for a 107 M⊙ BH accreting at 103 Eddington. Therefore, energetically, the simulated jets are consistent with observations of the most powerful tidal disruption events, e.g. Swift J1644. The jet velocity is, however, too low to match the Lorentz factor γ > 2 inferred in J1644. There is no such conflict in the case of other tidal disruption events. Since favourably oriented observers see isotropic equivalent luminosities that are highly super-Eddington, the simulated models can explain observations of ultraluminous X-ray sources, at least in terms of luminosity and energetics, without requiring intermediate-mass BHs.

The simplest "field" methods for extractin of nematodes from plants, wood, insects and soil, with additional description how to keep extracted nematodes alive for a long time.

PubMed

Ryss, A Yu

2017-01-01

The simplest modification of the dynamic extraction method using cottonwool filter based on the Baermann funnel principle, is described. This modification excludes the funnel because a great share of Sticky worms attach to sloping walls of a funnel and thus do not reach the collector Eppendorf tube. But the main principle of the Baermann funnel is used, I. e. sinking down of actively moving heavy narrow bodies via wide holes of filter and thus separating the active worms from passive non-Brownian moving substrate particles, which do not pass the filter and remain above it. This principle is illustrated because it has never been described before. In the proposed modification any sloping walls in the extraction paths are excluded and thus the probability to attach sticky nemotodes to walls is also excluded; only cylindrical equipment with abrupt vertical walls is used; procedures are extremely simplified to be user-friendly for beginners: only filter (cotton pads), Eppendorf tubes, plastic glasses and narrow PVC tubing are applied. The new simplified modification allows one to collect nematodes by non-professional workers, e. g. in Polar expeditions without microscopic study of results. As an addition, an efficient method to maintain extracted nematodes alive is proposed, using the "effect of water film" in foam rubber inside the Eppendorf tube. To maintain nematodes alive during several months it is recommended to suppress bacteria via addition of 0.2-0.4% formaldehyde solution and then keep the tube with nematodes in a refrigerator.

Ultrastructure of the anterior organ and posterior funnel-shaped canal of Gyrocotyle urna Wagener, 1852 (Cestoda: Gyrocotylidea).

PubMed

Poddubnaya, Larisa G; Kuchta, Roman; Bristow, Glenn A; Scholz, Tomas

2015-05-22

Using scanning and transmission electron microscopy, ultrastructure of the anterior organ and posterior funnel-shaped canal of Gyrocotyle urna Wagener, 1852 (Cestoda: Gyrocotylidea) from ratfish, Chimaera monstrosa (Holocephali), was studied for the first time. The proper anterior organ is localised at a short distance (about 170 µm) from an apical pore surrounded by a receptor field, whereas its distal end is marked by a muscular sphincter. The tegumental surface of this organ is covered with short filitriches of irregular length; large area of muscle layers traverse beneath the tegumental layer. The funnel-shaped canal of G. urna (2.5-3.0 mm long) is a specialised, muscular part of the posterior attachment organ; it opens on the rounded elevation on the dorsal body surface. The tegumental layer bears conical sclerite-like structures (up to 1.5 µm long). It produces electron-dense bodies that are transported into a canal lumen and surrounded thick muscle area mixed with numerous nerve fibres. The present ultrastructural study of G. urna indicates that gyrocotylideans share some ultrastructural characters of the anterior organ with spathebothriidean cestodes with a single anterior attachment sucker-like organ. In contrast, the unique posterior rosette attachment organ with funnel-shaped canal of the Gyrocotylidea resembles the haptor of polyopisthocotylean monogeneans in its position at the posterior end of the body and presumed origin. The above-mentioned features add more clarity to support the basal position of the Gyrocotylidea Poche, 1926 among cestodes. In addition, they also indicate a possible relationship of gyrocotylidean ancestors with monogeneans.

Simulation of primary-slag melting behavior in the cohesive zone of a blast furnace, considering the effect of Al{sub 2}O{sub 3}, Fe{sub t}O, and basicity in the sinter ore

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

Hino, Mitsutaka; Nagasaka, Tetsuya; Katsumata, Akitoshi

1999-08-01

The alumina content in the iron ore imported to Japan is increasing year by year, and some problems in blast furnace operation, due to the use of the high-alumina-containing sinter, have already been reported. In order to clarify the mechanism of the harmful effect of alumina on the blast furnace operation, the behavior of the primary melt, which is formed in the sinter at the cohesive zone of the blast furnace, has been simulated by dripping slag through an iron or oxide funnel. The effects of basicity, Al{sub 2}O{sub 3}, and Fe{sub t}O contents in the five slag systems onmore » the dripping temperature and weight of slag remaining on the funnel have been discussed. It was found that the eutectic melt formed in the sinter would play an important role in the dripping behavior of the slag in the blast furnace through the fine porosity of the reduced iron and ore particles. Al{sub 2}O{sub 3} increased the weight of the slag remaining on the funnel, and its effect became very significant in the acidic and low-Fe{sub t}O-containing slag. It was estimated that the increase of the weight of the slag remaining on the funnel by Al{sub 2}O{sub 3} in the ore could result in a harmful effect on the permeability resistance and an indirect reduction rate of the sinter in the blast furnace.« less

Semiclassical theory of sub-Doppler forces in an asymmetric magneto-optical trap with unequal laser detunings

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

Noh, Heung-Ryoul; Jhe, Wonho

We present a semiclassical theory of the sub-Doppler forces in an asymmetric magneto-optical trap where the trap-laser frequencies are unequal to one another. To solve the optical Bloch equations, which contain explicit time dependence, unlike in the symmetric case of equal laser detunings, we have developed a convenient and efficient method to calculate the atomic forces at various oscillating frequencies for each atomic density matrix element. In particular, the theory provides a qualitative understanding of the array of sub-Doppler traps (SDTs) recently observed in such an asymmetric trap. We find that the distances between SDTs are proportional to the relativemore » detuning differences, in good agreement with experimental results. The theory presented here can be applied to a dynamic system with multiple laser frequencies involved; the number of coupled equations to solve is much reduced and the resulting numerical calculation can be performed rather simply and efficiently.« less

Rotation of an optically trapped vaterite microsphere measured using rotational Doppler effect

NASA Astrophysics Data System (ADS)

Chen, Xinlin; Xiao, Guangzong; Xiong, Wei; Yang, Kaiyong; Luo, Hui; Yao, Baoli

2018-03-01

The angular velocity of a vaterite microsphere spinning in the optical trap is measured using rotational Doppler effect. The perfectly spherical vaterite microspheres are synthesized via coprecipitation in the presence of silk fibroin nanospheres. When trapped by a circularly polarized beam, the vaterite microsphere is uniformly rotated in the trap center. The probe beams containing two Laguerre-Gaussian beams of opposite topological charge l = ± 7, l = ± 8, and l = ± 9 are illuminated on the spinning vaterite. By analyzing the backscattered light, a frequency shift is observed scaling with the rotation rate of the vaterite microsphere. The multiplicative enhancement of the frequency shift proportion to the topological charge has greatly improved the measurement precision. The reliability and practicability of this approach are verified through varying the topological charge of the probe beam and the trapping laser power. In consideration of the excellent measurement precision of the rotation frequency, this technique might be generally applicable in studying the torsional properties of micro-objects.

Optimization of a mirror-based neutron source using differential evolution algorithm

NASA Astrophysics Data System (ADS)

Yurov, D. V.; Prikhodko, V. V.

2016-12-01

This study is dedicated to the assessment of capabilities of gas-dynamic trap (GDT) and gas-dynamic multiple-mirror trap (GDMT) as potential neutron sources for subcritical hybrids. In mathematical terms the problem of the study has been formulated as determining the global maximum of fusion gain (Q pl), the latter represented as a function of trap parameters. A differential evolution method has been applied to perform the search. Considered in all calculations has been a configuration of the neutron source with 20 m long distance between the mirrors and 100 MW heating power. It is important to mention that the numerical study has also taken into account a number of constraints on plasma characteristics so as to provide physical credibility of searched-for trap configurations. According to the results obtained the traps considered have demonstrated fusion gain up to 0.2, depending on the constraints applied. This enables them to be used either as neutron sources within subcritical reactors for minor actinides incineration or as material-testing facilities.

Patrick Draw field, Wyoming - 1 seismic expression of subtle strat trap in Upper Cretaceous Almond

USGS Publications Warehouse

Ryder, Robert T.; Lee, Myung W.; Agena, Warren F.; Anderson, Robert C.

1990-01-01

The east flank of the Rock Springs uplift and the adjacent Wamsutter arch contain several large hydrocarbon accumulations. Among these accumulations are Patrick Draw field, which produces oil and gas from a stratigraphic trap in the Upper Cretaceous Almond formation, and Table Rock field, a faulted anticlinal trap that produces gas from multiple Tertiary, Mesozoic, and Paleozoic reservoirs. The principal petroleum reservoir in Patrick Draw field is a sandstone at the top of the Almond formation. This sandstone attains a maximum thickness of 35ft and piches out westward into relatively impervious silt-stone and shale that constitute the trapping facies. The objective of this investigation is to determine whether or not the stratigraphic trap at Patrick Draw can be detected on a 12 fold, common depth point seismic profile acquired by Forest Oil Corp. and its partners. The seismic line is 18.5 miles long and crosses Patrick Draw and Table Rock fields.

Fast selective trapping and release of picoliter droplets in a 3D microfluidic PDMS multi-trap system with bubbles.

PubMed

Rambach, Richard W; Biswas, Preetika; Yadav, Ashutosh; Garstecki, Piotr; Franke, Thomas

2018-02-12

The selective manipulation and incubation of individual picoliter drops in high-throughput droplet based microfluidic devices still remains challenging. We used a surface acoustic wave (SAW) to induce a bubble in a 3D designed multi-trap polydimethylsiloxane (PDMS) device to manipulate multiple droplets and demonstrate the selection, incubation and on-demand release of aqueous droplets from a continuous oil flow. By controlling the position of the acoustic actuation, individual droplets are addressed and selectively released from a droplet stream of 460 drops per s. A complete trapping and releasing cycle can be as short as 70 ms and has no upper limit for incubation time. We characterize the fluidic function of the hybrid device in terms of electric power, pulse duration and acoustic path.

Bacteria can mobilize nematode-trapping fungi to kill nematodes

PubMed Central

Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

2014-01-01

In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode–predatory form; this predacious form is characterized by formation of specialized cellular structures or ‘traps’. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator–prey interactions in prey defense mechanisms. PMID:25514608

In-Plane Heterostructures Enable Internal Stress Assisted Strain Engineering in 2D Materials.

PubMed

Liu, Feng; Wang, Tzu-Chiang; Tang, Qiheng

2018-04-01

Conventional methods to induce strain in 2D materials can hardly catch up with the sharp increase in requirements to design specific strain forms, such as the pseudomagnetic field proposed in graphene, funnel effect of excitons in MoS 2 , and also the inverse funnel effect reported in black phosphorus. Therefore, a long-standing challenge in 2D materials strain engineering is to find a feasible scheme that can be used to design given strain forms. In this article, combining the ability of experimentally synthetizing in-plane heterostructures and elegant Eshelby inclusion theory, the possibility of designing strain fields in 2D materials to manipulate physical properties, which is called internal stress assisted strain engineering, is theoretically demonstrated. Particularly, through changing the inclusion's size, the stress or strain gradient can be controlled precisely, which is never achieved. By taking advantage of it, the pseudomagnetic field as well as the funnel effect can be accurately designed, which opens an avenue to practical applications for strain engineering in 2D materials. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Interface and process for enhanced transmission of non-circular ion beams between stages at unequal pressure

DOEpatents

Tang, Keqi [Richland, WA; Shvartsburg, Alexandre A [Richland, WA; Smith, Richard D [Richland, WA

2008-03-04

The invention discloses a new interface with non-circular conductance limit aperture(s) useful for effective transmission of non-circular ion beams between stages with different gas pressure. In particular, the invention provides an improved coupling of field asymmetric waveform ion mobility spectrometry (FAIMS) analyzers of planar or side-to-side geometry to downstream stages such as mass spectrometry or ion mobility spectrometry. In this case, the non-circular aperture is rectangular; other geometries may be optimum in other applications. In the preferred embodiment, the non-circular aperture interface is followed by an electrodynamic ion funnel that may focus wide ion beams of any shape into tight circular beams with virtually no losses. The jet disrupter element of the funnel may also have a non-circular geometry, matching the shape of arriving ion beam. The improved sensitivity of planar FAIMS/MS has been demonstrated in experiments using a non-contiguous elongated aperture but other embodiments (e.g., with a contiguous slit aperture) may be preferable, especially in conjunction with an ion funnel operated at high pressures.

Towards a microscopic description of the free-energy landscape of water.

PubMed

Prada-Gracia, Diego; Shevchuk, Roman; Hamm, Peter; Rao, Francesco

2012-10-14

Free-energy landscape theory is often used to describe complex molecular systems. Here, a microscopic description of water structure and dynamics based on configuration-space-networks and molecular dynamics simulations of the TIP4P/2005 model is applied to investigate the free-energy landscape of water. The latter is built on top of a large set of water microstates describing the kinetic stability of local hydrogen-bond arrangements up to the second solvation shell. In temperature space, the landscape displays three different regimes. At around ambient conditions, the free-energy surface is characterized by many short-lived basins of attraction which are structurally well-defined (inhomogeneous regime). At lower temperatures instead, the liquid rapidly becomes homogeneous. In this regime, the free energy is funneled-like, with fully coordinated water arrangements at the bottom of the funnel. Finally, a third regime develops below the temperature of maximal compressibility (Widom line) where the funnel becomes steeper with few interconversions between microstates other than the fully coordinated ones. Our results present a way to manage the complexity of water structure and dynamics, connecting microscopic properties to its ensemble behavior.

Folding of the 25 residue Abeta(12-36) peptide in TFE/water: temperature-dependent transition from a funneled free-energy landscape to a rugged one.

PubMed

Kamiya, Narutoshi; Mitomo, Daisuke; Shea, Joan-Emma; Higo, Junichi

2007-05-17

The free-energy landscape of the Alzheimer beta-amyloid peptide Abeta(12-36) in a 40% (v/v) 2,2,2-trifluoroethanol (TFE)/water solution was determined by using multicanonical molecular dynamics simulations. Simulations using this enhanced conformational sampling technique were initiated from a random unfolded polypeptide conformation. Our simulations reliably folded the peptide to the experimental NMR structure, which consists of two linked helices. The shape of the free energy landscape for folding was found to be strongly dependent on temperature: Above 325 K, the overall shape was funnel-like, with the bottom of the funnel coinciding exactly with the NMR structure. Below 325 K, on the other hand, the landscape became increasingly rugged, with the emergence of new conformational clusters connected by low free-energy pathways. Finally, our simulations reveal that water and TFE solvate the polypeptide in different ways: The hydrogen bond formation between TFE and Abeta was enhanced with decreasing temperature, while that between water and Abeta was depressed.

Evaluation of lead recovery efficiency from waste CRT funnel glass by chlorinating volatilization process.

PubMed

Erzat, Aris; Zhang, Fu-Shen

2014-01-01

The current study was carried out to develop a novel process, namely chloride volatilization procedure for lead recovery from waste cathode ray tube (CRT) funnel glass. In the recovery system, the glass powder was first compressed into cylindrical pellet homogeneously with chlorinating agents, and then subjected to thermal treatment for solid-phase reaction. In this case, lead could be easily released from the silicon oxide network of the glass and it was recovered in the form of PbCl₂. It was found that CaCl2 was the most effective chlorinating agent, and the optimum operation temperature, holding time and system pressure were 1000 °C, 2 h, 600 ± 50 Pa, respectively. The evaporated PbCl₂could be easily recovered by a cooling device. The evaporation ratio of lead from waste CRT was 99.1% and the purity of the recovered PbCl₂product was 97.0%. The reaction routes and lead recovery mechanisms of the process were identified. This study provides an efficient and practical process for waste CRT funnel glass detoxification and recycling.

Integrating Recycled Glass Cullet in Asphalt Roof Shingles to Mitigate Heat Island Effect

DTIC Science & Technology

2014-05-01

polymer, 39.3% bituminous composition, 57.5% trap rock dust stabilizer. Using recycled rubber, the formula is 3.2% elastomeric polymer, 37.2...and then rock or slag granules with similar gradation for the headlap granules. Ideal top surface materials are either igneous or metamorphic ...inherently opaque, and must be resistant to multiple heat-thaw cycles. The granules most widely used are crushed slate, basalt, and trap rock (Pagen

Short-range phenotypic divergence among genetically distinct parapatric populations of an Australian funnel-web spider.

PubMed

Wong, Mark K L; Woodman, James D; Rowell, David M

2017-07-01

Speciation involves divergence at genetic and phenotypic levels. Where substantial genetic differentiation exists among populations, examining variation in multiple phenotypic characters may elucidate the mechanisms by which divergence and speciation unfold. Previous work on the Australian funnel-web spider Atrax sutherlandi Gray (2010; Records of the Australian Museum 62 , 285-392; Mygalomorphae: Hexathelidae: Atracinae) has revealed a marked genetic structure along a 110-kilometer transect, with six genetically distinct, parapatric populations attributable to past glacial cycles. In the present study, we explore variation in three classes of phenotypic characters (metabolic rate, water loss, and morphological traits) within the context of this phylogeographic structuring. Variation in metabolic and water loss rates shows no detectable association with genetic structure; the little variation observed in these rates may be due to the spiders' behavioral adaptations (i.e., burrowing), which buffer the effects of climatic gradients across the landscape. However, of 17 morphological traits measured, 10 show significant variation among genetic populations, in a disjunct manner that is clearly not latitudinal. Moreover, patterns of variation observed for morphological traits serving different organismic functions (e.g., prey capture, burrowing, and locomotion) are dissimilar. In contrast, a previous study of an ecologically similar sympatric spider with little genetic structure indicated a strong latitudinal response in 10 traits over the same range. The congruence of morphological variation with deep phylogeographic structure in Tallaganda's A. sutherlandi populations, as well as the inconsistent patterns of variation across separate functional traits, suggest that the spiders are likely in early stages of speciation, with parapatric populations independently responding to local selective forces.

Improving low-level plasma protein mass spectrometry-based detection for candidate biomarker discovery and validation

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

Page, Jason S.; Kelly, Ryan T.; Camp, David G.

2008-09-01

Methods. To improve the detection of low abundance protein candidate biomarker discovery and validation, particularly in complex biological fluids such as blood plasma, increased sensitivity is desired using mass spectrometry (MS)-based instrumentation. A key current limitation on the sensitivity of electrospray ionization (ESI) MS is due to the fact that many sample molecules in solution are never ionized, and the vast majority of the ions that are created are lost during transmission from atmospheric pressure to the low pressure region of the mass analyzer. Two key technologies, multi-nanoelectrospray emitters and the electrodynamic ion funnel have recently been developed and refinedmore » at Pacific Northwest National Laboratory (PNNL) to greatly improve the ionization and transmission efficiency of ESI MS based analyses. Multi-emitter based ESI enables the flow from a single source (typically a liquid chromatography [LC] column) to be divided among an array of emitters (Figure 1). The flow rate delivered to each emitter is thus reduced, allowing the well-documented benefits of nanoelectrospray 1 for both sensitivity and quantitation to be realized for higher flow rate separations. To complement the increased ionization efficiency afforded by multi-ESI, tandem electrodynamic ion funnels have also been developed at PNNL, and shown to greatly improve ion transmission efficiency in the ion source interface.2, 3 These technologies have been integrated into a triple quadrupole mass spectrometer for multiple reaction monitoring (MRM) of probable biomarker candidates in blood plasma and show promise for the identification of new species even at low level concentrations.« less

Sponge grade body fossil with cellular resolution dating 60 Myr before the Cambrian

PubMed Central

Yin, Zongjun; Zhu, Maoyan; Davidson, Eric H.; Bottjer, David J.; Zhao, Fangchen; Tafforeau, Paul

2015-01-01

An extraordinarily well preserved, 600-million-year (Myr)-old, three-dimensionally phosphatized fossil displaying multiple independent characters of modern adult sponges has been analyzed by SEM and synchrotron X-ray tomography. The fossilized animal (Eocyathispongia qiania gen. et sp. nov.) is slightly more than 1.2 mm wide and 1.1 mm tall, is composed of hundreds of thousands of cells, and has a gross structure consisting of three adjacent hollow tubes sharing a common base. The main tube is crowned with a large open funnel, and the others end in osculum-like openings to the exterior. The external surface is densely covered with flat tile-like cells closely resembling sponge pinacocytes, and this layer is punctuated with smaller pores. A dense patch of external structures that display the form of a lawn of sponge papillae has also survived. Within the main funnel, an area where features of the inner surface are preserved displays a regular pattern of uniform pits. Many of them are surrounded individually by distinct collars, mounted in a supporting reticulum. The possibility cannot be excluded that these pits are the remains of a field of choanocytes. The character set evinced by this specimen, ranging from general anatomy to cell type, uniquely indicates that this specimen is a fossil of probable poriferan affinity. So far, we have only this single specimen, and although its organized and complex cellular structure precludes any reasonable interpretation that its origin is abiogenic, confirmation that it is indeed a fossilized sponge will clearly require discovery of additional specimens. PMID:25775601

Isotopic composition and identification of the origins of individuals buried in a Neolithic collective grave at Bronocice (southern Poland).

PubMed

Szostek, K; Haduch, E; Stepańczak, B; Kruk, J; Szczepanek, A; Pawlyta, J; Głąb, H; Milisauskas, S

2014-04-01

The oxygen present in a human organism comes from numerous sources, but the major factor that causes variation in the isotopic composition of this element in a tissue is available drinking water. The isotopic ratio of oxygen in an organism's tissue, including that found in bones and teeth, reflects the isotopic oxygen composition typical for the area where a given individual developed and lived. Of particular interest with regard to this issue were a series of skeletons from the multiple grave discovered at the Funnel Beaker-Baden settlement at Bronocice (southern Poland). The question therefore arose whether the specimens buried in this grave were part of the local community. The oxygen isotope level was established using apatite isolated from bones or teeth. A femur and root dentine samples taken from permanent teeth were subjected to oxygen isotope analysis. The oxygen isotope level of the site was established on the basis of local water precipitation and measurements taken from the oxygen isotope concentration in apatite samples isolated from the bones of animals co-occurring with the studied human group. It has been found that the oxygen isotope levels in the bones and dentine of almost all the analysed specimens from the excavated site at Bronocice were within the established range for the area's environment, providing evidence for their local origin. Thus, it can be assumed that the analysed group inhabiting the macrosettlement at Bronocice during the Funnel Beaker phase of the Baden culture was most probably of local origin. Copyright © 2013 Elsevier GmbH. All rights reserved.

Stacking Multiple Ion Captures in The High Performance Antiproton Trap (HiPAT)

NASA Technical Reports Server (NTRS)

Martin, James J.; Lewis, Raymond A.; Sims, William H.; Chakrabarti, Suman; Pearson, Boise; Fant, Wallace E.

2004-01-01

The High performance Antiproton Trap (HiPAT) research project was initiated by the Marshall Space Flight Center's propulsion Research Center to examining the fundamental behavior of low energy antiprotons. Stored antiproton would ultimately be used for experimental demonstration of basic propulsive concepts. Matter-antimatter annihilation produces approximately 10(exp 8) MJ/g nearly 10 orders of magnitude more energy per unit mass than chemical based combustion, hence NASA's interest. To achieve containment, HiPAT utilizes a type of electromagnetic bottle know as a Penning trap positioned within an ultrahigh vacuum test section. Recently, the HiPAT hardware configuration has been enhanced to facilitate the capture of multiple normal matter ion burst. This endeavor is often referred to as "stacking" and used to increasing the number of captured particles. A prior normal matter experimental effort, successfully demonstrated the effectiveness of single burst capture. The stacking process is accomplished by manipulating the electric field generated by the confinement electrodes i.e. adjusting the well potential depth. These potential well values are initially configured to maximize the quantity of captured ions per burst; shallow wells with a depth of 100 volt or less (referenced to the incoming ion beam energy) are typically selected. Once captured, a cooling interval is required to reduce the energy of trapped particles below the lower extent of the "trap door" (or leading electrode) ion emitting potential. This is necessary such that a new burst of hot ions can be introduced while preventing those already inside from escaping. The cooling time is driven by a combination of mechanisms such as synchrotron radiation, background gas scattering, and resistive damping in a time scale on the order of minutes. A potential for reducing this hold period is to actively manipulate the electric field shape, using the power supply control system, to produce a deeper potential well. The trapped ions ride down the morphing well to a lower potential energy, leaving margin to once again cycle the "trap door" capturing a new burst while limiting the number of escaping ions. By adjusting the magnitude and timing of the potential well shaping, subsequent shots from the ion beam can be captured on a time scale shorter then that dictated by the standard inject, capture and cool technique. Currently, experimental tests are under way examining the functionally of this system for stacking multiple ions bursts within the HiPAT system.

Elastico-mechanoluminescence in CaZr(PO4)2:Eu2+ with multiple trap levels.

PubMed

Zhang, Jun-Cheng; Xu, Chao-Nan; Long, Yun-Ze

2013-06-03

We report on a novel elastico-mechanoluminescence (EML) phosphor of CaZr(PO4)2:Eu2+ for simultaneous luminescent sensing and imaging to mechanical load by the light-emitting of Eu2+ ions. The EML properties of CaZr(PO4)2:Eu2+ show an intense luminance (above 15 mcd m(-2)), a low load threshold (below 5 N), a broad measurement range for the dynamic load (up to 2000 N), and an accurate linear relationship of EML intensity against the applied load. The excellent EML characteristics are considered to originate from the piezoelectric crystal structure and the multiple trap levels with appropriate depths. An EML mechanism based on the electrons as the main charge carriers is proposed.

Multiple trapping on a comb structure as a model of electron transport in disordered nanostructured semiconductors

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

Sibatov, R. T., E-mail: ren-sib@bk.ru; Morozova, E. V., E-mail: kat-valezhanina@yandex.ru

2015-05-15

A model of dispersive transport in disordered nanostructured semiconductors has been proposed taking into account the percolation structure of a sample and joint action of several mechanisms. Topological and energy disorders have been simultaneously taken into account within the multiple trapping model on a comb structure modeling the percolation character of trajectories. The joint action of several mechanisms has been described within random walks with a mixture of waiting time distributions. Integral transport equations with fractional derivatives have been obtained for an arbitrary density of localized states. The kinetics of the transient current has been calculated within the proposed newmore » model in order to analyze time-of-flight experiments for nanostructured semiconductors.« less

Use of egg traps to investigate lake trout spawning in the Great Lakes

USGS Publications Warehouse

Schreiner, Donald R.; Bronte, Charles R.; Payne, N. Robert; Fitzsimons, John D.; Casselman, John M.

1995-01-01

Disk-shaped traps were used to examine egg deposition by lake trout (Salvelinus namaycush) at 29 sites in the Great Lakes. The main objectives were to; first, evaluate the disk trap as a device for sampling lake trout eggs in the Great Lakes, and second, summarize what has been learned about lake trout spawning through the use of disk traps. Of the 5,085 traps set, 60% were classified as functional when retrieved. Evidence of lake trout egg deposition was documented in each of the lakes studied at 14 of 29 sites. A total of 1,147 eggs were trapped. The percentage of traps functioning and catch per effort were compared among sites based on depth, timing of egg deposition, distance from shore, size of reef, and type of reef (artificial or natural). Most eggs were caught on small, shallow, protected reefs that were close to shore. Use of disk traps on large, shallow, unprotected offshore reefs or along unprotected shorelines was generally unsuccessful due to the effects of heavy wind and wave action. Making multiple lifts at short intervals, and retrieval before and re-deployment after storms are recommended for use in exposed areas. On large reefs, preliminary surveys to identify preferred lake trout spawning habitat may be required to deploy disk traps most effectively. Egg deposition by hatchery-reared fish was widespread throughout the Great Lakes, and the use of artificial structures by these fish was extensive.

Role of tumour necrosis factor (TNF)-α and TNFRSF1A R92Q mutation in the pathogenesis of TNF receptor-associated periodic syndrome and multiple sclerosis

PubMed Central

Caminero, A; Comabella, M; Montalban, X

2011-01-01

It has long been known that tumour necrosis factor (TNF)/TNFRSF1A signalling is involved in the pathophysiology of multiple sclerosis (MS). Different genetic and clinical findings over the last few years have generated renewed interest in this relationship. This paper provides an update on these recent findings. Genome-wide association studies have identified the R92Q mutation in the TNFRSF1A gene as a genetic risk factor for MS (odds ratio 1·6). This allele, which is also common in the general population and in other inflammatory conditions, therefore only implies a modest risk for MS and provides yet another piece of the puzzle that defines the multiple genetic risk factors for this disease. TNFRSF1A mutations have been associated with an autoinflammatory disease known as TNF receptor-associated periodic syndrome (TRAPS). Clinical observations have identified a group of MS patients carrying the R92Q mutation who have additional TRAPS symptoms. Hypothetically, the co-existence of MS and TRAPS or a co-morbidity relationship between the two could be mediated by this mutation. The TNFRSF1A R92Q mutation behaves as a genetic risk factor for MS and other inflammatory diseases, including TRAPS. Nevertheless, this mutation does not appear to be a severity marker of the disease, neither modifying the clinical progression of MS nor its therapeutic response. An alteration in TNF/TNFRS1A signalling may increase proinflammatory signals; the final clinical phenotype may possibly be determined by other genetic or environmental modifying factors that have not yet been identified. PMID:22059991

A simple estimate of funneling-assisted charge collection

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

Edmonds, L.D.

In this paper, funneling is qualitatively discussed in detail and quantitative analysis is given for the total (time-integrated) collected charge. It is shown that for an n{sup +}/p junction, the total collected charge Q{sub T} is given by Q{sub R} = (1 + {mu}{sub n}/{mu}{sub p})Q{sub D} + 2Q{sub diff} where Q{degrees}D is the charge initially liberated in the depletion region and Q{sub diff} is charge collected by diffusion. This equation does not apply to very short ion tracks or to device having a thin epilayer.

The optimal number of menu options per panel

NASA Technical Reports Server (NTRS)

Paap, Kenneth R.; Roske-Hofstrand, Renate J.

1986-01-01

An evaluation is made of the effects of the 'funneling' phenomenon, in an analysis of hierarchical menu structures' optimal search times which builds on the work of Lee and MacGregor (1985). Funneling is a reduction in the total number of options processed through the design of a system of greater choice 'depth' and correspondingly restricted choice 'breadth'. Both random and ordered menus are treated. The available evidence is found to support the general conclusion that randomly ordered menu panels should have only a few (4-8) options, while organized menus should contain as many options as 64.

Molecular phylogenetics and diversification of trap-jaw ants in the genera Anochetus and Odontomachus (Hymenoptera: Formicidae).

PubMed

Larabee, Fredrick J; Fisher, Brian L; Schmidt, Chris A; Matos-Maraví, Pável; Janda, Milan; Suarez, Andrew V

2016-10-01

Ants in the genera Anochetus and Odontomachus belong to one of the largest clades in the subfamily Ponerinae, and are one of four lineages of ants possessing spring-loaded "trap-jaws." Here we present results from the first global species-level molecular phylogenetic analysis of these trap-jaw ants, reconstructed from one mitochondrial, one ribosomal RNA, and three nuclear protein-coding genes. Bayesian and likelihood analyses strongly support reciprocal monophyly for the genera Anochetus and Odontomachus. Additionally, we found strong support for seven trap-jaw ant clades (four in Anochetus and three in Odontomachus) mostly concordant with geographic distribution. Ambiguity remains concerning the closest living non-trap-jaw ant relative of the Anochetus+Odontomachus clade, but Bayes factor hypothesis testing strongly suggests that trap-jaw ants evolved from a short mandible ancestor. Ponerine trap-jaw ants originated in the early Eocene (52.5Mya) in either South America or Southeast Asia, where they have radiated rapidly in the last 30million years, and subsequently dispersed multiple times to Africa and Australia. These results will guide future taxonomic work on the group and act as a phylogenetic framework to study the macroevolution of extreme ant mouthpart specialization. Copyright © 2016 Elsevier Inc. All rights reserved.

Degradation of the electrical characteristics of MOS structures with erbium, gadolinium, and dysprosium oxides under the effect of an electric field

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

Shalimova, M. B., E-mail: shamb@samsu.ru; Sachuk, N. V.

2015-08-15

The degradation of the characteristics of silicon metal-oxide-semiconductor (MOS) structures with oxides of rare-earth elements under the effect of electric fields with intensities of 0.1–4 MV/cm during the course of electroforming is studied. A specific feature of electroforming consists in the possibility of multiple switching of the structures from the insulating state to the low-resistivity one and back. The temporal characteristics of the degradation of MOS structures during the course of electroforming are exponential. The current-voltage characteristics follow the power law in the range of 0.2–3 V; the effect of an electric field brings about a variation in the distributionmore » of the energy density of traps responsible for currents limited by space charge. It is established that multiple cycles of electroforming lead to an increase in the density of surface states at the Si-oxide interface and to a variation in the energy position of the trap levels, which affects the charge state of the traps.« less

Trapped Ion Qubits

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

Maunz, Peter; Wilhelm, Lukas

Qubits can be encoded in clock states of trapped ions. These states are well isolated from the environment resulting in long coherence times [1] while enabling efficient high-fidelity qubit interactions mediated by the Coulomb coupled motion of the ions in the trap. Quantum states can be prepared with high fidelity and measured efficiently using fluorescence detection. State preparation and detection with 99.93% fidelity have been realized in multiple systems [1,2]. Single qubit gates have been demonstrated below rigorous fault-tolerance thresholds [1,3]. Two qubit gates have been realized with more than 99.9% fidelity [4,5]. Quantum algorithms have been demonstrated on systemsmore » of 5 to 15 qubits [6–8].« less

Magnetic polarons in a nonequilibrium polariton condensate

NASA Astrophysics Data System (ADS)

Mietki, Paweł; Matuszewski, Michał

2017-09-01

We consider a condensate of exciton polaritons in a diluted magnetic semiconductor microcavity. Such a system may exhibit magnetic self-trapping in the case of sufficiently strong coupling between polaritons and magnetic ions embedded in the semiconductor. We investigate the effect of the nonequilibrium nature of exciton polaritons on the physics of the resulting self-trapped magnetic polarons. We find that multiple polarons can exist at the same time, and we derive a critical condition for self-trapping that is different from the one predicted previously in the equilibrium case. Using the Bogoliubov-de Gennes approximation, we calculate the excitation spectrum and provide a physical explanation in terms of the effective magnetic attraction between polaritons, mediated by the ion subsystem.

Effects produced by iodine irradiation on high resistivity silicon

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

Lazanu, S.; Slav, A.; Lepadatu, A.-M.

2012-12-10

The effects of 5 Multiplication-Sign 10{sup 11} cm{sup -26+}I{sup 127} ions of 28 MeV kinetic energy on high resistivity (100) Si were studied. The profile of primary defects was simulated. The defects produced by irradiation which act as traps were investigated. Thermally stimulated current measurements without externally applied bias were used, and for this the traps were charged by illuminating samples with 1000, 800, and 400 nm wavelengths. The discharge currents were recorded and modeled, and therefore the parameters of the traps were determined. The presence of I ions, heavier than Si, stopped into the target was modeled as amore » temperature independent electric field.« less

Narrow-line magneto-optical cooling and trapping of strongly magnetic atoms.

PubMed

Berglund, Andrew J; Hanssen, James L; McClelland, Jabez J

2008-03-21

Laser cooling on weak transitions is a useful technique for reaching ultracold temperatures in atoms with multiple valence electrons. However, for strongly magnetic atoms a conventional narrow-line magneto-optical trap (MOT) is destabilized by competition between optical and magnetic forces. We overcome this difficulty in Er by developing an unusual narrow-line MOT that balances optical and magnetic forces using laser light tuned to the blue side of a narrow (8 kHz) transition. The trap population is spin polarized with temperatures reaching below 2 muK. Our results constitute an alternative method for laser cooling on weak transitions, applicable to rare-earth-metal and metastable alkaline earth elements.

Mode trap for absorbing transverse modes of an accelerated electron beam

DOEpatents

Chojnacki, Eric P.

1994-01-01

A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer.

Use of Compound-Specific Stable Isotope Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs

DTIC Science & Technology

2012-01-01

published, in all cases involving some form of preconcentration of VOCs from larger volumes of air on adsorbents or cryogenic traps. Researchers in...volumes of air in that case are collected in multiple stainless cylinders and the VOCs are recovered by cryogenic focusing. This approach is...Summa cylinders are directed into a second-stage concentrator (for example, a standard commercial purge and trap (P&T)) and then transferred into a

Use of Compound Specific Stable Isotope Analysis to Distinguish Between Vapor Intrusion and Indoor Sources of VOCs

DTIC Science & Technology

2012-01-01

published, in all cases involving some form of preconcentration of VOCs from larger volumes of air on adsorbents or cryogenic traps. Researchers in...volumes of air in that case are collected in multiple stainless cylinders and the VOCs are recovered by cryogenic focusing. This approach is...Summa cylinders are directed into a second-stage concentrator (for example, a standard commercial purge and trap (P&T)) and then transferred into a

Ion cyclotron resonance cell

DOEpatents

Weller, Robert R.

1995-01-01

An ion cyclotron resonance cell having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions.

Form follows function: morphological diversification and alternative trapping strategies in carnivorous Nepenthes pitcher plants.

PubMed

Bauer, Ulrike; Clemente, C J; Renner, T; Federle, W

2012-01-01

Carnivorous plants of the genus Nepenthes have evolved a striking diversity of pitcher traps that rely on specialized slippery surfaces for prey capture. With a comparative study of trap morphology, we show that Nepenthes pitcher plants have evolved specific adaptations for the use of either one of two distinct trapping mechanisms: slippery wax crystals on the inner pitcher wall and 'insect aquaplaning' on the wet upper rim (peristome). Species without wax crystals had wider peristomes with a longer inward slope. Ancestral state reconstructions identified wax crystal layers and narrow, symmetrical peristomes as ancestral, indicating that wax crystals have been reduced or lost multiple times independently. Our results complement recent reports of nutrient source specializations in Nepenthes and suggest that these specializations may have driven speciation and rapid diversification in this genus. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.

A versatile MOF-based trap for heavy metal ion capture and dispersion.

PubMed

Peng, Yaguang; Huang, Hongliang; Zhang, Yuxi; Kang, Chufan; Chen, Shuangming; Song, Li; Liu, Dahuan; Zhong, Chongli

2018-01-15

Current technologies for removing heavy metal ions are typically metal ion specific. Herein we report the development of a broad-spectrum heavy metal ion trap by incorporation of ethylenediaminetetraacetic acid into a robust metal-organic framework. The capture experiments for a total of 22 heavy metal ions, covering hard, soft, and borderline Lewis metal ions, show that the trap is very effective, with removal efficiencies of >99% for single-component adsorption, multi-component adsorption, or in breakthrough processes. The material can also serve as a host for metal ion loading with arbitrary selections of metal ion amounts/types with a controllable uptake ratio to prepare well-dispersed single or multiple metal catalysts. This is supported by the excellent performance of the prepared Pd 2+ -loaded composite toward the Suzuki coupling reaction. This work proposes a versatile heavy metal ion trap that may find applications in the fields of separation and catalysis.

Optical trapping and binding of particles in an optofluidic stable Fabry-Pérot resonator with single-sided injection.

PubMed

Gaber, Noha; Malak, Maurine; Marty, Frédéric; Angelescu, Dan E; Richalot, Elodie; Bourouina, Tarik

2014-07-07

In this article, microparticles are manipulated inside an optofluidic Fabry-Pérot cylindrical cavity embedding a fluidic capillary tube, taking advantage of field enhancement and multiple reflections within the optically-resonant cavity. This enables trapping of suspended particles with single-side injection of light and with low optical power. A Hermite-Gaussian standing wave is developed inside the cavity, forming trapping spots at the locations of the electromagnetic field maxima with a strong intensity gradient. The particles get arranged in a pattern related to the mechanism affecting them: either optical trapping or optical binding. This is proven to eventually translate into either an axial one dimensional (1D) particle array or a cluster of particles. Numerical simulations are performed to model the field distributions inside the cavity allowing a behavioral understanding of the phenomena involved in each case.

FDTD simulations of forces on particles during holographic assembly.

PubMed

Benito, David C; Simpson, Stephen H; Hanna, Simon

2008-03-03

We present finite-difference time-domain (FDTD) calculations of the forces and torques on dielectric particles of various shapes, held in one or many Gaussian optical traps, as part of a study of the physical limitations involved in the construction of micro- and nanostructures using a dynamic holographic assembler (DHA). We employ a full 3-dimensional FDTD implementation, which includes a complete treatment of optical anisotropy. The Gaussian beams are sourced using a multipole expansion of a fifth order Davis beam. Force and torques are calculated for pairs of silica spheres in adjacent traps, for silica cylinders trapped by multiple beams and for oblate silica spheroids and calcite spheres in both linearly and circularly polarized beams. Comparisons are drawn between the magnitudes of the optical forces and the Van der Waals forces acting on the systems. The paper also considers the limitations of the FDTD approach when applied to optical trapping.

Rare alluvial sands of El Monte Valley, California (San Diego County), support high herpetofaunal species richness and diversity, despite severe habitat disturbance

USGS Publications Warehouse

Richmond, Jonathan Q.; Rochester, Carlton J.; Smith, Nathan W.; Nordland, Jeffrey A.; Fisher, Robert N.

2016-01-01

We characterized the species richness, diversity, and distribution of amphibians and reptiles inhabiting El Monte Valley, a heavily disturbed, alluvium-filled basin within the lower San Diego River in Lakeside, California. This rare habitat type in coastal southern California is designated as a critical sand resource by the state of California and is currently under consideration for a large-scale sand mining operation with subsequent habitat restoration. We conducted field surveys from June 2015 to May 2016 using drift fence lines with funnel traps, coverboard arrays, walking transects, and road driving. We recorded 1,208 total captures, revealing high species richness and diversity, but with marked unevenness in species' abundances. Snakes were the most species-rich taxonomic group (13 species representing 11 genera), followed by lizards (11 species representing 9 genera). After the southern Pacific rattlesnake (Crotalus oreganus helleri), the California glossy snake (Arizona elegans occidentalis) was the second most frequently detected snake species (n = 23 captures). Amphibian species richness was limited to only three species in three genera. Despite the relatively limited 12-month sampling period, a longstanding drought, and severe habitat disturbance, our study demonstrates that El Monte Valley harbors a rich herpetofauna that includes many sensitive species.

Hierarchical folding free energy landscape of HP35 revealed by most probable path clustering.

PubMed

Jain, Abhinav; Stock, Gerhard

2014-07-17

Adopting extensive molecular dynamics simulations of villin headpiece protein (HP35) by Shaw and co-workers, a detailed theoretical analysis of the folding of HP35 is presented. The approach is based on the recently proposed most probable path algorithm which identifies the metastable states of the system, combined with dynamical coring of these states in order to obtain a consistent Markov state model. The method facilitates the construction of a dendrogram associated with the folding free-energy landscape of HP35, which reveals a hierarchical funnel structure and shows that the native state is rather a kinetic trap than a network hub. The energy landscape of HP35 consists of the entropic unfolded basin U, where the prestructuring of the protein takes place, the intermediate basin I, which is connected to U via the rate-limiting U → I transition state reflecting the formation of helix-1, and the native basin N, containing a state close to the NMR structure and a native-like state that exhibits enhanced fluctuations of helix-3. The model is in line with recent experimental observations that the intermediate and native states differ mostly in their dynamics (locked vs unlocked states). Employing dihedral angle principal component analysis, subdiffusive motion on a multidimensional free-energy surface is found.

Diffracted field distributions from the HE11 mode in a hollow optical fibre for an atomic funnel

NASA Astrophysics Data System (ADS)

Ni, Yun; Liu, Nanchun; Yin, Jianping

2003-06-01

The diffracted near field distribution from an LP01 mode in a hollow optical fibre was recently calculated using a scalar model based on the weakly waveguiding approximation (Yoo et al 1999 J. Opt. B: Quantum Semiclass. Opt. 1 364). It showed a dominant Gaussian-like distribution with an increased axial intensity in the central region (not a doughnut-like distribution), so the diffracted output beam from the hollow fibre cannot be used to form an atomic funnel. Using exact solutions of the Maxwell equations based on a vector model, however, we calculate the electric field and intensity distributions of the HE11 mode in the same hollow fibre and study the diffracted near- and far-field distributions of the HE11-mode output beam under the Fresnel approximation. We analyse and compare the differences between the output beams from the HE11 and LP01 modes. Our study shows that both the near- and far-field intensity distributions of the HE11-mode output beam are doughnut-like and can be used to form a simple atomic funnel. However, it is not suitable to use the weakly waveguiding approximation to calculate the diffracted near-field distribution of the hollow fibre due to the greater refractive-index difference between the hollow region (n0 = 1) and the core (n1 = 1.45 or 1.5). Finally, the 3D intensity distribution of the HE11-mode output beam is modelled and the corresponding optical potentials for cold atoms are calculated. Some potential applications of the HE11-mode output beam in an atomic guide and funnel are briefly discussed.

Photophysics of conjugated polymers: interplay between Förster energy migration and defect concentration in shaping a photochemical funnel in PPV.

PubMed

Saini, Sangeeta; Bagchi, Biman

2010-07-21

Recent single molecule experiments have suggested the existence of a photochemical funnel in the photophysics of conjugated polymers, like poly[2-methoxy-5-(2'-ethylhexyl)oxy-1,4-phenylenevinylene] (MEH-PPV). The funnel is believed to be a consequence of the presence of conformational or chemical defects along the polymer chain and efficient non-radiative energy transfer among different chromophore segments. Here we address the effect of the excitation energy dynamics on the photophysics of PPV. The PPV chain is modeled as a polymer with the length distribution of chromophores given either by a Gaussian or by a Poisson distribution. We observe that the Poisson distribution of the segment lengths explains the photophysics of PPV better than the Gaussian distribution. A recently proposed version of an extended 'particle-in-a-box' model is used to calculate the exciton energies and the transition dipole moments of the chromophores, and a master equation to describe the excitation energy transfer among different chromophores. The rate of energy transfer is assumed to be given here, as a first approximation, by the well-known Förster expression. The observed excitation population dynamics confirms the photochemical funneling of excitation energy from shorter to longer chromophores of the polymer chain. The time scale of spectral shift and energy transfer for our model polymer, with realistic values of optical parameters, is in the range of 200-300 ps. We find that the excitation energy may not always migrate towards the longest chromophore segments in the polymer chain as the efficiency of energy transfer between chromophores depends on the separation distance between the two and their relative orientation.

A new improved graphical and quantitative method for detecting bias in meta-analysis.

PubMed

Furuya-Kanamori, Luis; Barendregt, Jan J; Doi, Suhail A R

2018-04-04

Detection of publication and related biases remains suboptimal and threatens the validity and interpretation of meta-analytical findings. When bias is present, it usually differentially affects small and large studies manifesting as an association between precision and effect size and therefore visual asymmetry of conventional funnel plots. This asymmetry can be quantified and Egger's regression is, by far, the most widely used statistical measure for quantifying funnel plot asymmetry. However, concerns have been raised about both the visual appearance of funnel plots and the sensitivity of Egger's regression to detect such asymmetry, particularly when the number of studies is small. In this article, we propose a new graphical method, the Doi plot, to visualize asymmetry and also a new measure, the LFK index, to detect and quantify asymmetry of study effects in Doi plots. We demonstrate that the visual representation of asymmetry was better for the Doi plot when compared with the funnel plot. We also show that the diagnostic accuracy of the LFK index in discriminating between asymmetry due to simulated publication bias versus chance or no asymmetry was also better with the LFK index which had areas under the receiver operating characteristic curve of 0.74-0.88 with simulations of meta-analyses with five, 10, 15, and 20 studies. The Egger's regression result had lower areas under the receiver operating characteristic curve values of 0.58-0.75 across the same simulations. The LFK index also had a higher sensitivity (71.3-72.1%) than the Egger's regression result (18.5-43.0%). We conclude that the methods proposed in this article can markedly improve the ability of researchers to detect bias in meta-analysis.

Simple and Efficient Trap for Bark and Ambrosia Beetles (Coleoptera: Curculionidae) to Facilitate Invasive Species Monitoring and Citizen Involvement.

PubMed

Steininger, M S; Hulcr, J; Šigut, M; Lucky, A

2015-06-01

Bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae & Platypodinae) are among the most damaging forest pests worldwide, and monitoring is essential to damage prevention. Unfortunately, traps and attractants that are currently used are costly, and agencies rely on limited field personnel for deployment. The situation can be greatly aided by 1) the development of cost-effective trapping techniques, and 2) distribution of the effort through the Citizen Science approach. The goal of this study was to test a simple, effective trap that can be made and deployed by anyone interested in collecting bark and ambrosia beetles. Three trap types made from 2-liter soda bottles and, separately, four attractants were compared. Simple, one-window traps performed comparably at capturing species in traps painted or with multiple windows. A comparison of attractants in two-window traps found that 95% ethanol attracted the highest number of species but that Purell hand sanitizer (70% ethanol) and then Germ-X hand sanitizer (63% ethanol) were also effective. A perforated zip-top plastic bag containing Purell hanging over a trap filled with automobile antifreeze attracted the fewest species and individual specimens. Overall, >4,500 bark and ambrosia beetles, including 30 species were captured, representing a third of the regional species diversity. More than three quarters of the specimens were nonnative, representing nearly half of the known regional exotic species. These results suggest that simple one-window soda bottle traps baited with ethanol-based hand sanitizer will be effective and inexpensive tools for large-scale monitoring of bark and ambrosia beetles. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Sand fly fauna (Diptera, pcychodidae, phlebotominae) in different leishmaniasis-endemic areas of ecuador, surveyed using a newly named mini-shannon trap.

PubMed

Hashiguchi, Kazue; Velez N, Lenin; Kato, Hirotomo; Criollo F, Hipatia; Romero A, Daniel; Gomez L, Eduardo; Martini R, Luiggi; Zambrano C, Flavio; Calvopina H, Manuel; Caceres G, Abraham; Hashiguchi, Yoshihisa

2014-12-01

To study the sand fly fauna, surveys were performed at four different leishmaniasis-endemic sites in Ecuador from February 2013 to April 2014. A modified and simplified version of the conventional Shannon trap was named "mini-Shannon trap" and put to multiple uses at the different study sites in limited, forested and narrow spaces. The mini-Shannon, CDC light trap and protected human landing method were employed for sand fly collection. The species identification of sand flies was performed mainly based on the morphology of spermathecae and cibarium, after dissection of fresh samples. In this study, therefore, only female samples were used for analysis. A total of 1,480 female sand flies belonging to 25 Lutzomyia species were collected. The number of female sand flies collected was 417 (28.2%) using the mini-Shannon trap, 259 (17.5%) using the CDC light trap and 804 (54.3%) by human landing. The total number of sand flies per trap collected by the different methods was markedly affected by the study site, probably because of the various composition of species at each locality. Furthermore, as an additional study, the attraction of sand flies to mini-Shannon traps powered with LED white-light and LED black-light was investigated preliminarily, together with the CDC light trap and human landing. As a result, a total of 426 sand flies of nine Lutzomyia species, including seven man-biting and two non-biting species, were collected during three capture trials in May and June 2014 in an area endemic for leishmaniasis (La Ventura). The black-light proved relatively superior to the white-light with regard to capture numbers, but no significant statistical difference was observed between the two traps.

Coherent Multiple Light Scattering in Ultracold Atomic Rb

NASA Astrophysics Data System (ADS)

Kulatunga, Pasad; Sukenik, C. I.; Balik, Salim; Havey, M. D.; Kupriyanov, D. V.; Sokolov, I. M.

2003-05-01

Wave transport in mesoscopic systems can be strongly influenced by coherent multiple scattering,which can lead to novel magneto-optic, transmission, and backscattering effects of light in atomic vapors. Although related to traditional studies of radiation trapping, in ultracold vapors negligible frequency or phase redistribution takes place in the scattering, and high-order coherent light scattering occurs. Among other things, this leads to enhancement of the influence of otherwise small non-resonant terms in the scattering amplitudes. We report investigation of multiple coherent light scattering from ultracold Rb atoms confined in a magneto-optic trap (MOT). In experimental studies, measurements are made of the angular, spectral, and polarization-dependent coherent backscattering profile of a low-intensity probe beam tuned near the F = 3 - F' = 4 hyperfine transition. The influence of higher probe beam intensity is also studied. In a theoretical study of angular intensity enhancement of backscattered light, we consider scattering orders up to 10 and a realistic and asymmetric Gaussian atom distribution in the MOT. Supported by NSF, NATO, and RFBR.

Simultaneous and Sequential MS/MS Scan Combinations and Permutations in a Linear Quadrupole Ion Trap.

PubMed

Snyder, Dalton T; Szalwinski, Lucas J; Cooks, R Graham

2017-10-17

Methods of performing precursor ion scans as well as neutral loss scans in a single linear quadrupole ion trap have recently been described. In this paper we report methodology for performing permutations of MS/MS scan modes, that is, ordered combinations of precursor, product, and neutral loss scans following a single ion injection event. Only particular permutations are allowed; the sequences demonstrated here are (1) multiple precursor ion scans, (2) precursor ion scans followed by a single neutral loss scan, (3) precursor ion scans followed by product ion scans, and (4) segmented neutral loss scans. (5) The common product ion scan can be performed earlier in these sequences, under certain conditions. Simultaneous scans can also be performed. These include multiple precursor ion scans, precursor ion scans with an accompanying neutral loss scan, and multiple neutral loss scans. We argue that the new capability to perform complex simultaneous and sequential MS n operations on single ion populations represents a significant step in increasing the selectivity of mass spectrometry.

Complete structural characterization of ceramides as [M – H]− ions by multiple-stage linear ion trap mass spectrometry

PubMed Central

Hsu, Fong-Fu

2016-01-01

Ceramide is a huge lipid family consisting of diversified structures including various modifications in the fatty acyl chain and the long chain base (LCB). In this contribution, negative-ion ESI linear ion-trap multiple-stage mass spectrometric method (LIT MSn) towards complete structural determination of ceramides in ten major families characterized as the [M – H]− ions is described. Multiple sets of fragment ions reflecting the fatty acyl chain and LCB were observed in the CID MS2 spectrum, while the sequential MS3 and MS4 spectra contain structural information for locating the double bond and the functional groups, permitting realization of the fragmentation processes. Thereby, differentiation of ceramide molecules varied by chain length, the LCB (sphingosine, phytosphigosine, 6-hydroxy-sphingosine), and by the modification (α-hydroxy-, β-hydroxy-, ω-hydroxy-FA) can be achieved; and many isomeric structures in the biological specimen can be revealed in detail. PMID:27523779

Monitoring populations of saddled prominent (Lepidoptera: Notodontidae) with pheromone-baited traps.

PubMed

Spear-O'Mara, Jennifer; Allen, Douglas C

2007-04-01

Field trials with three types of pheromone traps were performed in eight northern hardwood stands in northern New York state to develop a population-monitoring tool for the saddled prominent, Heterocampa guttivitta (Walker) (Lepidoptera: Notodontidae). Lure specificity and the relationship between pheromone trap catch and subsequent egg density were examined. A study of moth emergence in relation to temperature was designed to determine whether moth activity throughout the flight season can be predicted using a growing degree-day (DD) model. Pherocon 1C wing traps were significantly more effective than the green Unitrap bucket style. Catch was not affected by position when traps were > or =20 m from an opening (road), and lures were specific to saddled prominent. Lure specificity was examined using green Multipher bucket traps, which effectively attracted and held moths. In the first year of the study, number of viable eggs per 10 leaf clusters was significantly correlated (r2 = 0.59) with average moth catch/trap in pheromone-baited Pherocon traps. When differences in stand density (basal area) and relative abundance of sugar maple (percentage of total stems per hectare), the principle host, were accounted for, the multiple regression model also was significant and r2 = 0. 83. Neither model, however, was significant the second year. Using a base temperature of 5.5 degrees C and on-site temperature data, the peak of moth flight occurred at 316 +/- 8 DD and end of flight occurred at 533 +/- 9 DD.

Unusual Case of Suicide With a Modified Trap Gun.

PubMed

Vadysinghe, Amal; Dassanayake, Prasanna; Wickramasinghe, Medhani

2017-06-01

Trap gun is an illegal, locally manufactured gun with a basic trip system used to hunt wild animals. The body of a 28-year-old man was found in the jungle in supine position with both legs apart. A trap gun was between the legs pointing toward the cranial side of the body. It had 2 free wires that were not connected together. There was no evidence of foul play.The body had a single-entry wound (2.5-cm diameter) in the anterior chest, with blackening, burning, and tattooing. Six metal particles and nylon clothing material were embedded into soft tissue. No exit wound was found. Toxicology analysis reported an alcohol level of 72 mg/dL. The cause of death was multiple shrapnel injury to the chest at close to intermediate range by a single discharge from a trap gun. Circumstance was concluded as suicide.Ballistic and firearm experts opined that an illegal, manually operated, battery-powered ignition device was used to ignite the gun powder. We report the first case of suicide by a modified trap gun in literature.

Effects of viscosity on sperm motility studied with optical tweezers

NASA Astrophysics Data System (ADS)

Hyun, Nicholas; Chandsawangbhuwana, Charlie; Zhu, Qingyuan; Shi, Linda Z.; Yang-Wong, Collin; Berns, Michael W.

2012-02-01

The purpose of this study is to analyze human sperm motility and energetics in media with different viscosities. Multiple experiments were performed to collect motility parameters using customized computer tracking software that measures the curvilinear velocity (VCL) and the minimum laser power (Pesc) necessary to hold an individual sperm in an optical trap. The Pesc was measured by using a 1064 nm Nd:YVO4 continuous wave laser that optically traps motile sperm at a power of 450 mW in the focused trap spot. The VCL was measured frame by frame before trapping. In order to study sperm energetics under different viscous conditions sperm were labeled with the fluorescent dye DiOC6(3) to measure membrane potentials of mitochondria in the sperm midpiece. Fluorescence intensity was measured before and during trapping. The results demonstrate a decrease in VCL but an increase in Pesc with increasing viscosity. Fluorescent intensity is the same regardless of the viscosity level indicating no change in sperm energetics. The results suggest that, under the conditions tested, viscosity physically affects the mechanical properties of sperm motility rather than the chemical pathways associated with energetics.

Modeling electronic trap state distributions in nanocrystalline anatase

NASA Astrophysics Data System (ADS)

Le, Nam; Schweigert, Igor

The charge transport properties of nanocrystalline TiO2 films, and thus the catalytic performance of devices that incorporate them, are affected strongly by the spatial and energetic distribution of localized electronic trap states. Such traps may arise from a variety of defects: Ti interstitials, O vacancies, step edges at surfaces, and grain boundaries. We have developed a procedure for applying density functional theory (DFT) and density functional tight binding (DFTB) calculations to characterize distributions of localized states arising from multiple types of defects. We have applied the procedure to investigate how the morphologies of interfaces between pairs of attached anatase nanoparticles determine the energies of trap states therein. Our results complement recent experimental findings that subtle changes in the morphology of highly porous TiO2 aerogel networks can have a dramatic effect on catalytic performance, which was attributed to changes in the distribution of trap states. This work was supported by the U.S. Naval Research Laboratory via the National Research Council and by the Office of Naval Research through the U.S. Naval Research Laboratory.

Simulation of a 3D MOT-Optical Molasses Hybrid for Potassium-41 Atoms

NASA Astrophysics Data System (ADS)

Peterson, W. A.; Wrubel, Jonathan

2017-04-01

We report a design and numerical model for a 3D magneto-optical trap (MOT)-optical molasses hybrid for potassium-41 atoms. In this arrangement, the usual quadrupole magnetic field is replaced by an octupole field. The octupole field has a central region of very low magnetic field where our simulations show that the atoms experience an optical molasses, resulting in sub-doppler cooling not possible in a quadrupole MOT. The simulations also show that the presence of the magneto-optical trapping force at the edge of the cooling beams provides a restoring force which cycles atoms through the molasses region. We plan to use this hybrid trap to directly load a far off-resonance optical dipole trap. Because the atoms are recycled for multiple passes through the molasses, we expect a higher phase-space density of atoms loaded into the dipole trap. Similar hybrid cooling schemes should be relevant for lithium-6 and lithium-7, which also have poorly resolved D2 hyperfine structure. Research Corporation for Science Advancement, Cottrell College Science Award.

Charge carrier transport in polycrystalline organic thin film based field effect transistors

NASA Astrophysics Data System (ADS)

Rani, Varsha; Sharma, Akanksha; Ghosh, Subhasis

2016-05-01

The charge carrier transport mechanism in polycrystalline thin film based organic field effect transistors (OFETs) has been explained using two competing models, multiple trapping and releases (MTR) model and percolation model. It has been shown that MTR model is most suitable for explaining charge carrier transport in grainy polycrystalline organic thin films. The energetic distribution of traps determined independently using Mayer-Neldel rule (MNR) is in excellent agreement with the values obtained by MTR model for copper phthalocyanine and pentacene based OFETs.

An energy-based perturbation and a taboo strategy for improving the searching ability of stochastic structural optimization methods

NASA Astrophysics Data System (ADS)

Cheng, Longjiu; Cai, Wensheng; Shao, Xueguang

2005-03-01

An energy-based perturbation and a new idea of taboo strategy are proposed for structural optimization and applied in a benchmark problem, i.e., the optimization of Lennard-Jones (LJ) clusters. It is proved that the energy-based perturbation is much better than the traditional random perturbation both in convergence speed and searching ability when it is combined with a simple greedy method. By tabooing the most wide-spread funnel instead of the visited solutions, the hit rate of other funnels can be significantly improved. Global minima of (LJ) clusters up to 200 atoms are found with high efficiency.

Long-term result after operative correction of funnel chest

PubMed Central

Borgeskov, Sven; Raahave, Dennis

1971-01-01

During the last decades it has been commonly accepted that funnel chest is such a serious cosmetic handicap that it deserves correction for this reason alone. A group of patients with this deformity, operated upon by the method of Paltia (transsternal fixation with metal struts), was re-examined 5 to 10 years postoperatively. In more than 50% of the cases the immediate acceptable cosmetic result had disappeared in contrast to the satisfaction expressed by almost all the patients. Because of the high incidence of recurrence and because of various risks involved in this operation, the authors do not advocate its performance. Images PMID:5101274

The progress of funnelling gun high voltage condition and beam test

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

Wang, E.; Ben-Zvi, I.; Gassner, D. M.

A prototype of a high average current polarized electron funneling gun as an eRHIC injector has been built at BNL. The gun was assembled and tested at Stangenes Incorporated. Two beams were generated from two GaAs photocathodes and combined by a switched combiner field. We observed the combined beams on a YAG crystal and measured the photocurrent by a Faraday cup. The gun has been shipped to Stony Brook University and is being tested there. In this paper we will describe the major components of the gun and recent beam test results. High voltage conditioning is discussed as well.

Ion funnel augmented Mars atmospheric pressure photoionization mass spectrometry for in situ detection of organic molecules.

PubMed

Johnson, Paul V; Hodyss, Robert; Beauchamp, J L

2014-11-01

Laser desorption is an attractive technique for in situ sampling of organics on Mars given its relative simplicity. We demonstrate that under simulated Martian conditions (~2.5 Torr CO(2)) laser desorption of neutral species (e.g., polycyclic aromatic hydrocarbons), followed by ionization with a simple ultraviolet light source such as a discharge lamp, offers an effective means of sampling organics for detection and identification with a mass spectrometer. An electrodynamic ion funnel is employed to provide efficient ion collection in the ambient Martian environment. This experimental methodology enables in situ sampling of Martian organics with minimal complexity and maximum flexibility.

Alternative theoretical method for motion of a sand-filled funnel experiment

NASA Astrophysics Data System (ADS)

Byrd, David; White, Gary

2001-11-01

In "Motion of a Sand-Filled Funnel," Peter Sullivan and Anna McLoon described how to use numerical methods and a Microsoft Excel spreadsheet to predict the motion of a variant of Atwood's machine with variable mass. They wrote for noncalculus-based physics classes, but we solve the same problem using the methods of calculus. Our method highlights the less-familiar but more accurate version of Newton's second law, ∑F =dp/dt. This can help introductory physics students understand a broader definition of Newton's second law and enhance their calculus skills. It also teaches students how to solve a variable-mass problem.

Evidence-based decision-making 7: Knowledge translation.

PubMed

Manns, Braden J

2015-01-01

There is a significant gap between what is known and what is implemented by key stakeholders in practice (the evidence to practice gap). The primary purpose of knowledge translation is to address this gap, bridging evidence to clinical practice. The knowledge to action cycle is one framework for knowledge translation that integrates policy-makers throughout the research cycle. The knowledge to action cycle begins with the identification of a problem (usually a gap in care provision). After identification of the problem, knowledge creation is undertaken, depicted at the center of the cycle as a funnel. Knowledge inquiry is at the wide end of the funnel, and moving down the funnel, the primary data is synthesized into knowledge products in the form of educational materials, guidelines, decision aids, or clinical pathways. The remaining components of the knowledge to action cycle refer to the action of applying the knowledge that has been created. This includes adapting knowledge to local context, assessing barriers to knowledge use, selecting, tailoring implementing interventions, monitoring knowledge use, evaluating outcomes, and sustaining knowledge use. Each of these steps is connected by bidirectional arrows and ideally involves healthcare decision-makers and key stakeholders at each transition.

Extraction of lead from waste CRT funnel glass by generating lead sulfide - An approach for electronic waste management.

PubMed

Hu, Biao; Hui, Wenlong

2017-09-01

Waste cathode ray tube (CRT) funnel glass is the key and difficult points in waste electrical and electronic equipment (WEEE) disposal. In this paper, a novel and effective process for the detoxification and reutilization of waste CRT funnel glass was developed by generating lead sulfide precipitate via a high-temperature melting process. The central function in this process was the generation of lead sulfide, which gathered at the bottom of the crucible and was then separated from the slag. Sodium carbonate was used as a flux and reaction agent, and sodium sulfide was used as a precipitating agent. The experimental results revealed that the lead sulfide recovery rate initially increased with an increase in the amount of added sodium carbonate, the amount of sodium sulfide, the temperature, and the holding time and then reached an equilibrium value. The maximum lead sulfide recovery rate was approximately 93%, at the optimum sodium carbonate level, sodium sulfide level, temperature, and holding time of 25%, 8%, 1200°C, and 2h, respectively. The glass slag can be made into sodium and potassium silicate by hydrolysis in an environmental and economical process. Copyright © 2017 Elsevier Ltd. All rights reserved.

MSSM A-funnel and the galactic center excess: prospects for the LHC and direct detection experiments

DOE PAGES

Freese, Katherine; López, Alejandro; Shah, Nausheen R.; ...

2016-04-11

The pseudoscalar resonance or “A-funnel” in the Minimal Supersymmetric Standard Model (MSSM) is a widely studied framework for explaining dark matter that can yield interesting indirect detection and collider signals. The well-known Galactic Center excess (GCE) at GeV energies in the gamma ray spectrum, consistent with annihilation of a ≲ 40 GeV dark matter particle, has more recently been shown to be compatible with significantly heavier masses following reanalysis of the background.For this study, we explore the LHC and direct detection implications of interpreting the GCE in this extended mass window within the MSSM A-funnel framework. We find that compatibilitymore » with relic density, signal strength, collider constraints, and Higgs data can be simultaneously achieved with appropriate parameter choices. The compatible regions give very sharp predictions of 200-600 GeV CP-odd/even Higgs bosons at low tan β at the LHC and spin-independent cross sections ≈ 10 -11 pb at direct detection experiments. Finally, regardless of consistency with the GCE, this study serves as a useful template of the strong correlations between indirect, direct, and LHC signatures of the MSSM A-funnel region.« less

Imaging MS Methodology for More Chemical Information in Less Data Acquisition Time Utilizing a Hybrid Linear Ion Trap-Orbitrap Mass Spectrometer

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

Perdian, D. C.; Lee, Young Jin

2010-11-15

A novel mass spectrometric imaging method is developed to reduce the data acquisition time and provide rich chemical information using a hybrid linear ion trap-orbitrap mass spectrometer. In this method, the linear ion trap and orbitrap are used in tandem to reduce the acquisition time by incorporating multiple linear ion trap scans during an orbitrap scan utilizing a spiral raster step plate movement. The data acquisition time was decreased by 43-49% in the current experiment compared to that of orbitrap-only scans; however, 75% or more time could be saved for higher mass resolution and with a higher repetition rate laser.more » Using this approach, a high spatial resolution of 10 {micro}m was maintained at ion trap imaging, while orbitrap spectra were acquired at a lower spatial resolution, 20-40 {micro}m, all with far less data acquisition time. Furthermore, various MS imaging methods were developed by interspersing MS/MS and MSn ion trap scans during orbitrap scans to provide more analytical information on the sample. This method was applied to differentiate and localize structural isomers of several flavonol glycosides from an Arabidopsis flower petal in which MS/MS, MSn, ion trap, and orbitrap images were all acquired in a single data acquisition.« less

Kinect the dots: 3D control of optical tweezers

NASA Astrophysics Data System (ADS)

Shaw, Lucy; Preece, Daryl; Rubinsztein-Dunlop, Halina

2013-07-01

Holographically generated optical traps confine micron- and sub-micron sized particles close to the center of focused light beams. They also provide a way of trapping multiple particles and moving them in three dimensions. However, in many systems the user interface is not always advantageous or intuitive especially for collaborative work and when depth information is required. We discuss and evaluate a set of multi-beam optical tweezers that utilize off the shelf gaming technology to facilitate user interaction. We use the Microsoft Kinect sensor bar as a way of getting the user input required to generate arbitrary optical force fields and control optically trapped particles. We demonstrate that the system can also be used for dynamic light control.

Mode trap for absorbing transverse modes of an accelerated electron beam

DOEpatents

Chojnacki, E.P.

1994-05-31

A mode trap to trap and absorb transverse modes formed by a beam in a linear accelerator includes a waveguide having a multiplicity of electrically conductive (preferably copper) irises and rings, each iris and ring including an aperture, and the irises and rings being stacked in a side-by-side, alternating fashion such that the apertures of the irises and rings are concentrically aligned. An absorbing material layer such as a dielectric is embedded in each iris and ring, and this absorbing material layer encircles, but is circumferentially spaced from its respective aperture. Each iris and ring includes a plurality of circumferentially spaced slots around its aperture and extending radially out toward its absorbing material layer. 9 figs.

Enzyme clustering accelerates processing of intermediates through metabolic channeling

PubMed Central

Castellana, Michele; Wilson, Maxwell Z.; Xu, Yifan; Joshi, Preeti; Cristea, Ileana M.; Rabinowitz, Joshua D.; Gitai, Zemer; Wingreen, Ned S.

2015-01-01

We present a quantitative model to demonstrate that coclustering multiple enzymes into compact agglomerates accelerates the processing of intermediates, yielding the same efficiency benefits as direct channeling, a well-known mechanism in which enzymes are funneled between enzyme active sites through a physical tunnel. The model predicts the separation and size of coclusters that maximize metabolic efficiency, and this prediction is in agreement with previously reported spacings between coclusters in mammalian cells. For direct validation, we study a metabolic branch point in Escherichia coli and experimentally confirm the model prediction that enzyme agglomerates can accelerate the processing of a shared intermediate by one branch, and thus regulate steady-state flux division. Our studies establish a quantitative framework to understand coclustering-mediated metabolic channeling and its application to both efficiency improvement and metabolic regulation. PMID:25262299

Maximizing Information Yield From Pheromone-Baited Monitoring Traps: Estimating Plume Reach, Trapping Radius, and Absolute Density of Cydia pomonella (Lepidoptera: Tortricidae) in Michigan Apple

PubMed Central

Adams, C. G.; Schenker, J. H.; McGhee, P. S.; Gut, L. J.; Brunner, J. F.

2017-01-01

Abstract Novel methods of data analysis were used to interpret codling moth (Cydia pomonella) catch data from central-trap, multiple-release experiments using a standard codlemone-baited monitoring trap in commercial apple orchards not under mating disruption. The main objectives were to determine consistency and reliability for measures of: 1) the trapping radius, composed of the trap’s behaviorally effective plume reach and the maximum dispersive distance of a responder population; and 2) the proportion of the population present in the trapping area that is caught. Two moth release designs were used: 1) moth releases at regular intervals in the four cardinal directions, and 2) evenly distributed moth releases across entire approximately 18-ha orchard blocks using both high and low codling moth populations. For both release designs, at high populations, the mean proportion catch was 0.01, and for the even release of low populations, that value was approximately 0.02. Mean maximum dispersive distance for released codling moth males was approximately 260 m. Behaviorally effective plume reach for the standard codling moth trap was < 5 m, and total trapping area for a single trap was approximately 21 ha. These estimates were consistent across three growing seasons and are supported by extraordinarily high replication for this type of field experiment. Knowing the trapping area and mean proportion caught, catch number per single monitoring trap can be translated into absolute pest density using the equation: males per trapping area = catch per trapping area/proportion caught. Thus, catches of 1, 3, 10, and 30 codling moth males per trap translate to approximately 5, 14, 48, and 143 males/ha, respectively, and reflect equal densities of females, because the codling moth sex ratio is 1:1. Combined with life-table data on codling moth fecundity and mortality, along with data on crop yield per trapping area, this fundamental knowledge of how to interpret catch numbers will enable pest managers to make considerably more precise projections of damage and therefore more precise and reliable decisions on whether insecticide applications are justified. The principles and methods established here for estimating absolute codling moth density may be broadly applicable to pests generally and thereby could set a new standard for integrated pest management decisions based on trapping. PMID:28131989

Tunable two-dimensional acoustic meta-structure composed of funnel-shaped unit cells with multi-band negative acoustic property

NASA Astrophysics Data System (ADS)

Cho, Sungjin; Kim, Boseung; Min, Dongki; Park, Junhong

2015-10-01

This paper presents a two-dimensional heat-exhaust and sound-proof acoustic meta-structure exhibiting tunable multi-band negative effective mass density. The meta-structure was composed of periodic funnel-shaped units in a square lattice. Each unit cell operates simultaneously as a Helmholtz resonator (HR) and an extended pipe chamber resonator (EPCR), leading to a negative effective mass density creating bandgaps for incident sound energy dissipation without transmission. This structure allowed large heat-flow through the cross-sectional area of the extended pipe since the resonance was generated by acoustic elements without using solid membranes. The pipes were horizontally directed to a flow source to enable small flow resistance for cooling. Measurements of the sound transmission were performed using a two-load, four-microphone method for a unit cell and small reverberation chamber for two-dimensional panel to characterize the acoustic performance. The effective mass density showed significant frequency dependent variation exhibiting negative values at the specific bandgaps, while the effective bulk modulus was not affected by the resonator. Theoretical models incorporating local resonances in the multiple resonator units were proposed to analyze the noise reduction mechanism. The acoustic meta-structure parameters to create broader frequency bandgaps were investigated using the theoretical model. The negative effective mass density was calculated to investigate the creation of the bandgaps. The effects of design parameters such as length, cross-sectional area, and volume of the HR; length and cross-sectional area of the EPCR were analyzed. To maximize the frequency band gap, the suggested acoustic meta-structure panel, small neck length, and cross-sectional area of the HR, large EPCR length was advantageous. The bandgaps became broader when the two resonant frequencies were similar.

Ion cyclotron resonance cell

DOEpatents

Weller, R.R.

1995-02-14

An ion cyclotron resonance cell is disclosed having two adjacent sections separated by a center trapping plate. The first section is defined by the center trapping plate, a first end trapping plate, and excitation and detector electrodes. The second section includes a second end trapping plate spaced apart from the center plate, a mirror, and an analyzer. The analyzer includes a wavelength-selective light detector, such as a detector incorporating an acousto-optical device (AOD) and a photodetector. One or more ion guides, grounded plates with holes for the ion beam, are positioned within the vacuum chamber of the mass spectrometer between the ion source and the cell. After ions are trapped and analyzed by ion cyclotron resonance techniques in the first section, the ions of interest are selected according to their mass and passed into the second section for optical spectroscopic studies. The trapped ions are excited by light from a laser and caused thereby to fluoresce. The fluorescent light emitted by the excited ions is reflected by the mirror and directed onto the detector. The AOD is scanned, and the photodetector output is recorded and analyzed. The ions remain in the second section for an extended period, enabling multiple studies to be carried out on the same ensemble of ions. 5 figs.

Visual outdoor response of multiple wild bee species: highly selective stimulation of a single photoreceptor type by sunlight-induced fluorescence.

PubMed

Rao, Sujaya; Ostroverkhova, Oksana

2015-07-01

Bees have ultraviolet (UV), blue and green photoreceptor types in their compound eyes with which they locate food sources in landscapes that change continuously in cues emanating from plants and backgrounds against which they are perceived. The complexity of bee vision has been elucidated through studies examining individual species under laboratory conditions. Here, we used a bee-attractive fluorescent blue trap as a model for analyzing visual signals in operation outdoors, and across bee species. We manipulated trap color (appearance to humans under light with weak UV component) and UV-induced fluorescence emission, and aligned field capture results with bee vision models. Our studies show that the bees were attracted to traps that under solar illumination exhibited strong fluorescence emission exclusively in the blue spectral region. Through quantitative analysis, we established that strong spectral overlap of trap emittance with the photosensitivity characteristic of the blue receptor type and minimal overlap with those of the other two receptor types is the most critical property of attractive traps. A parameter has been identified which predicts the degree of attractiveness of the traps and which captures trends in the field data across wild bee species and for a diversity of backgrounds.

Numerical study of the properties of optical vortex array laser tweezers.

PubMed

Kuo, Chun-Fu; Chu, Shu-Chun

2013-11-04

Chu et al. constructed a kind of Ince-Gaussian modes (IGM)-based vortex array laser beams consisting of p x p embedded optical vortexes from Ince-Gaussian modes, IG(e)(p,p) modes [Opt. Express 16, 19934 (2008)]. Such an IGM-based vortex array laser beams maintains its vortex array profile during both propagation and focusing, and is applicable to optical tweezers. This study uses the discrete dipole approximation (DDA) method to study the properties of the IGM-based vortex array laser tweezers while it traps dielectric particles. This study calculates the resultant force exerted on the spherical dielectric particles of different sizes situated at the IGM-based vortex array laser beam waist. Numerical results show that the number of trapping spots of a structure light (i.e. IGM-based vortex laser beam), is depended on the relation between the trapped particle size and the structure light beam size. While the trapped particle is small comparing to the beam size of the IGM-based vortex array laser beams, the IGM-based vortex array laser beams tweezers are suitable for multiple traps. Conversely, the tweezers is suitable for single traps. The results of this study is useful to the future development of the vortex array laser tweezers applications.

Multi-scale X-ray Microtomography Imaging of Immiscible Fluids After Imbibition

NASA Astrophysics Data System (ADS)

Garing, C.; de Chalendar, J.; Voltolini, M.; Ajo Franklin, J. B.; Benson, S. M.

2015-12-01

A major issue for CO2 storage security is the efficiency and long-term reliability of the trapping mechanisms occurring in the reservoir where CO2 is injected. Residual trapping is one of the key processes for storage security beyond the primary stratigraphic seal. Although classical conceptual models of residual fluid trapping assume that disconnected ganglia are permanently immobilized, multiple mechanisms exist which could allow the remobilization of residually trapped CO2. The aim of this study is to quantify fluid phases saturation, connectivity and morphology after imbibition using x-ray microtomography in order to evaluate potential changes in droplets organization due to differences in capillary pressure between disconnected ganglia. Particular emphasis is placed on the effect of image resolution. Synchrotron-based x-ray microtomographic datasets of air-water spontaneous imbibition were acquired in sintered glass beads and sandstone samples with voxel sizes varying from 0.64 to 4.44 μm. The results show that for both sandstones the residual air phase is homogeneously distributed within the entire pore space and consists of disconnected clusters of multiple sizes and morphologies. The multi-scale analysis of subsamples of few pores and throats imaged at the same location of the sample reveals significant variations in the estimation of connectivity, size and shape of the fluid phases. This is particularly noticeable when comparing the results from the images with voxel sizes above 1 μm with the results from the images acquired with voxel sizes below 1 μm.

Bathymetric controls on sediment transport in the Hudson River estuary: Lateral asymmetry and frontal trapping

USGS Publications Warehouse

Ralston, David K.; Geyer, W. Rockwell; Warner, John C.

2012-01-01

Analyses of field observations and numerical model results have identified that sediment transport in the Hudson River estuary is laterally segregated between channel and shoals, features frontal trapping at multiple locations along the estuary, and varies significantly over the spring-neap tidal cycle. Lateral gradients in depth, and therefore baroclinic pressure gradient and stratification, control the lateral distribution of sediment transport. Within the saline estuary, sediment fluxes are strongly landward in the channel and seaward on the shoals. At multiple locations, bottom salinity fronts form at bathymetric transitions in width or depth. Sediment convergences near the fronts create local maxima in suspended-sediment concentration and deposition, providing a general mechanism for creation of secondary estuarine turbidity maxima at bathymetric transitions. The lateral bathymetry also affects the spring-neap cycle of sediment suspension and deposition. In regions with broad, shallow shoals, the shoals are erosional and the channel is depositional during neap tides, with the opposite pattern during spring tides. Narrower, deeper shoals are depositional during neaps and erosional during springs. In each case, the lateral transfer is from regions of higher to lower bed stress, and depends on the elevation of the pycnocline relative to the bed. Collectively, the results indicate that lateral and along-channel gradients in bathymetry and thus stratification, bed stress, and sediment flux lead to an unsteady, heterogeneous distribution of sediment transport and trapping along the estuary rather than trapping solely at a turbidity maximum at the limit of the salinity intrusion.

Computational Modeling of Blood Flow in the TrapEase Inferior Vena Cava Filter

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

Singer, M A; Henshaw, W D; Wang, S L

To evaluate the flow hemodynamics of the TrapEase vena cava filter using three dimensional computational fluid dynamics, including simulated thrombi of multiple shapes, sizes, and trapping positions. The study was performed to identify potential areas of recirculation and stagnation and areas in which trapped thrombi may influence intrafilter thrombosis. Computer models of the TrapEase filter, thrombi (volumes ranging from 0.25mL to 2mL, 3 different shapes), and a 23mm diameter cava were constructed. The hemodynamics of steady-state flow at Reynolds number 600 was examined for the unoccluded and partially occluded filter. Axial velocity contours and wall shear stresses were computed. Flowmore » in the unoccluded TrapEase filter experienced minimal disruption, except near the superior and inferior tips where low velocity flow was observed. For spherical thrombi in the superior trapping position, stagnant and recirculating flow was observed downstream of the thrombus; the volume of stagnant flow and the peak wall shear stress increased monotonically with thrombus volume. For inferiorly trapped spherical thrombi, marked disruption to the flow was observed along the cava wall ipsilateral to the thrombus and in the interior of the filter. Spherically shaped thrombus produced a lower peak wall shear stress than conically shaped thrombus and a larger peak stress than ellipsoidal thrombus. We have designed and constructed a computer model of the flow hemodynamics of the TrapEase IVC filter with varying shapes, sizes, and positions of thrombi. The computer model offers several advantages over in vitro techniques including: improved resolution, ease of evaluating different thrombus sizes and shapes, and easy adaptation for new filter designs and flow parameters. Results from the model also support a previously reported finding from photochromic experiments that suggest the inferior trapping position of the TrapEase IVC filter leads to an intra-filter region of recirculating/stagnant flow with very low shear stress that may be thrombogenic.« less

Sand Fly Fauna (Diptera, Pcychodidae, Phlebotominae) in Different Leishmaniasis-Endemic Areas of Ecuador, Surveyed Using a Newly Named Mini-Shannon Trap

PubMed Central

Hashiguchi, Kazue; Velez N., Lenin; Kato, Hirotomo; Criollo F., Hipatia; Romero A., Daniel; Gomez L., Eduardo; Martini R., Luiggi; Zambrano C., Flavio; Calvopina H., Manuel; Caceres G., Abraham; Hashiguchi, Yoshihisa

2014-01-01

To study the sand fly fauna, surveys were performed at four different leishmaniasis-endemic sites in Ecuador from February 2013 to April 2014. A modified and simplified version of the conventional Shannon trap was named “mini-Shannon trap” and put to multiple uses at the different study sites in limited, forested and narrow spaces. The mini-Shannon, CDC light trap and protected human landing method were employed for sand fly collection. The species identification of sand flies was performed mainly based on the morphology of spermathecae and cibarium, after dissection of fresh samples. In this study, therefore, only female samples were used for analysis. A total of 1,480 female sand flies belonging to 25 Lutzomyia species were collected. The number of female sand flies collected was 417 (28.2%) using the mini-Shannon trap, 259 (17.5%) using the CDC light trap and 804 (54.3%) by human landing. The total number of sand flies per trap collected by the different methods was markedly affected by the study site, probably because of the various composition of species at each locality. Furthermore, as an additional study, the attraction of sand flies to mini-Shannon traps powered with LED white-light and LED black-light was investigated preliminarily, together with the CDC light trap and human landing. As a result, a total of 426 sand flies of nine Lutzomyia species, including seven man-biting and two non-biting species, were collected during three capture trials in May and June 2014 in an area endemic for leishmaniasis (La Ventura). The black-light proved relatively superior to the white-light with regard to capture numbers, but no significant statistical difference was observed between the two traps. PMID:25589880

Effects of multiple pathways on excited-state energy flow in self-assembled wheel-and-spoke light-harvesting architectures.

PubMed

Song, Hee-eun; Kirmaier, Christine; Schwartz, Jennifer K; Hindin, Eve; Yu, Lianhe; Bocian, David F; Lindsey, Jonathan S; Holten, Dewey

2006-10-05

Static and time-resolved optical measurements are reported for three cyclic hexameric porphyrin arrays and their self-assembled complexes with guest chromophores. The hexameric hosts contain zinc porphyrins and 0, 1, or 2 free base (Fb) porphyrins (denoted Zn(6), Zn(5)Fb, or Zn(4)Fb(2), respectively). The guest is a core-modified (O replacing one of the four N atoms) dipyridyl-substituted Fb porphyrin (DPFbO) that coordinates to zinc porphyrins of a host via pyridyl-zinc dative bonding. Each architecture is designed to have a gradient of excited-state energies for excitation funneling among the weakly coupled constituents of the host to the guest. Energy transfer to the lowest-energy chromophore(s) (coordinated zinc porphyrins or Fb porphyrins) within a hexameric host occurs primarily via a through-bond (TB) mechanism, is rapid ( approximately 40 ps), and is essentially quantitative (>or=98%). Energy transfer from a pyridyl-coordinated zinc porphyrin of the host to the guest in the Zn(6)*DPFbO complex has a yield of approximately 75%, a rate constant of approximately (0.7 ns)(-1), and significant Förster through-space (TS) character. In the case of Zn(5)Fb*DPFbO, which has an additional TS route via the Fb porphyrin with a rate constant of approximately (20 ns)(-1), the yield of energy transfer to the guest is somewhat lower ( approximately 50%) than that for Zn(6)*DPFbO. Complex Zn(4)Fb(2)*DPFbO has an identical TS pathway via the Fb porphyrin plus an additional TS pathway involving the second Fb porphyrin (closer to the guest) with a rate constant of approximately (0.5 ns)(-1). This complex exhibits an energy-transfer yield to the guest that is significantly enhanced over that for Zn(5)Fb*DPFbO and comparable to that for Zn(6)*DPFbO. Collectively, the results for the various arrays suggest designs for similar host-guest complexes that are expected to exhibit much more efficient light harvesting and excitation trapping at the central guest chromophore.

Structural distinction of diacyl-, alkylacyl, and alk-1-enylacyl glycerophosphocholines as [M - 15]⁻ ions by multiple-stage linear ion-trap mass spectrometry with electrospray ionization.

PubMed

Hsu, Fong-Fu; Lodhi, Irfan J; Turk, John; Semenkovich, Clay F

2014-08-01

We describe a linear ion-trap (LIT) multiple-stage (MS(n)) mass spectrometric approach towards differentiation of alkylacyl, alk-1-enylacyl- and diacyl-glycerophoscholines (PCs) as the [M - 15]⁻ ions desorbed by electrospray ionization (ESI) in the negative-ion mode. The MS⁴ mass spectra of the [M - 15 - R²'CH = CO]⁻ ions originated from the three PC subfamilies are readily distinguishable, resulting in unambiguous distinction of the lipid classes. This method is applied to two alkyl ether rich PC mixtures isolated from murine bone marrow neutrophils and kidney, respectively, to explore its utility in the characterization of complex PC mixture of biological origin, resulting in the realization of the detailed structures of the PC species, including various classes and many minor isobaric isomers.

Does Passive Sampling Accurately Reflect the Bee (Apoidea: Anthophila) Communities Pollinating Apple and Sour Cherry Orchards?

PubMed

Gibbs, Jason; Joshi, Neelendra K; Wilson, Julianna K; Rothwell, Nikki L; Powers, Karen; Haas, Mike; Gut, Larry; Biddinger, David J; Isaacs, Rufus

2017-06-01

During bloom of spring orchard crops, bees are the primary providers of pollination service. Monitoring these insects for research projects is often done by timed observations or by direct aerial netting, but there has been increasing interest in blue vane traps as an efficient passive approach to collecting bees. Over multiple spring seasons in Michigan and Pennsylvania, orchards were monitored for wild bees using timed netting from crop flowers and blue vane traps. This revealed a distinctly different community of wild bees captured using the two methods, suggesting that blue vane traps can complement but cannot replace direct aerial netting. The bee community in blue vane traps was generally composed of nonpollinating species, which can be of interest for broader biodiversity studies. In particular, blue vane traps caught Eucera atriventris (Smith), Eucera hamata (Bradley), Bombus fervidus (F.), and Agapostemon virescens (F.) that were never collected from the orchard crop flowers during the study period. Captures of bee species in nets was generally stable across the 3 yr, whereas we observed significant declines in the abundance of Lasioglossum pilosum (Smith) and Eucera spp. trapped using blue vane traps during the project, suggesting local overtrapping of reproductive individuals. We conclude that blue vane traps are a useful tool for expanding insights into bee communities within orchard crop systems, but they should be used with great caution to avoid local extirpation of these important insects. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

A surface-associated activity trap for capturing water surface and aquatic invertebrates in wetlands

USGS Publications Warehouse

Hanson, Mark A.; Roy, Christiane C.; Euliss, Ned H.; Zimmer, Kyle D.; Riggs, Michael R.; Butler, Malcolm G.

2000-01-01

We developed a surface-associated activity trap (SAT) for sampling aquatic invertebrates in wetlands. We compared performance of this trap with that of a conventional activity trap (AT) based on non-detection rates and relative abundance estimates for 13 taxa of common wetland invertebrates and for taxon richness using data from experiments in constructed wetlands. Taxon-specific non-detection rates for ATs generally exceeded those of SATs, and largest improvements using SATs were for Chironomidae and Gastropoda. SATs were efficient at capturing cladocera, Chironomidae, Gastropoda, total Crustacea, and multiple taxa (taxon richness) but were only slightly better than ATs at capturing Dytiscidae. Temporal differences in capture rates were observed only for cladocera, Chironomidae, Dytiscidae, and total Crustacea, with capture efficiencies of SATs usually decreasing from mid-June through mid-July for these taxa. We believe that SATs may be useful for characterizing wetland invertebrate communities and for developing improved measures of prey available to foraging waterfowl and other aquatic birds.

A surface-associated activity trap for capturing water-surface and aquatic invertebrates in wetlands

USGS Publications Warehouse

Hanson, M.A.; Roy, C.C.; Euliss, N.H.; Zimmer, K.D.; Riggs, M.R.; Butler, Malcolm G.

2000-01-01

We developed a surface-associated activity trap (SAT) for sampling aquatic invertebrates in wetlands. We compared performance of this trap with that of a conventional activity trap (AT) based on non-detection rates and relative abundance estimates for 13 taxa of common wetland invertebrates and for taxon richness using data from experiments in constructed wetlands. Taxon-specific non-detection rates for ATs generally exceeded those of SATs, and largest improvements using SATs were for Chironomidae and Gastropoda. SATs were efficient at capturing cladocera, Chironomidae, Gastropoda, total Crustacea, and multiple taxa (taxon richness) but were only slightly better than ATs at capturing Dytiscidae. Temporal differences in capture rates were observed only for cladocera, Chironomidae, Dytiscidae, and total Crustacea, with capture efficiencies of SATs usually decreasing from mid-June through mid-July for these taxa. We believe that SATs may be useful for characterizing wetland invertebrate communities and for developing improved measures of prey available to foraging waterfowl and other aquatic birds.

Carbon Flux Trapping: Highly Efficient Production of Polymer-Grade d-Lactic Acid with a Thermophilic d-Lactate Dehydrogenase.

PubMed

Li, Chao; Tao, Fei; Xu, Ping

2016-08-17

High production of polymer-grade d-lactic acid is urgently required, particularly for the synthesis of polylactic acid. High-temperature fermentation has multiple advantages, such as lower equipment requirement and energy consumption, which are essential for lowering operating costs. We identified and introduced a unique d-lactate dehydrogenase into a thermotolerant butane-2,3-diol-producing strain. Carbon flux "trapping" was achieved by a "trapping point" created by combination of the introduced enzyme and the host efflux pump, which afforded irreversible transport of d-lactic acid. The overall carbon flux of the engineered strain was significantly enhanced and was redistributed predominantly to d-lactic acid. Under optimized conditions at 50 °C, d-lactic acid reached the highest titer (226.6 g L(-1) ) reported to date. This discovery allows us to extend the carbon flux trapping strategy to engineering complex metabolic networks. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Method and apparatus for directing ions and other charged particles generated at near atmospheric pressures into a region under vacuum

DOEpatents

Smith, Richard D.; Shaffer, Scott A.

2000-01-01

A method and apparatus for focusing dispersed charged particles. More specifically, a series of elements within a region maintained at a pressure between 10.sup.-1 millibar and 1 bar, each having successively larger apertures forming an ion funnel, wherein RF voltages are applied to the elements so that the RF voltage on any element has phase, amplitude and frequency necessary to define a confinement zone for charged particles of appropriate charge and mass in the interior of the ion funnel, wherein the confinement zone has an acceptance region and an emmitance region and where the acceptance region area is larger than the emmitance region area.

Ionization source utilizing a multi-capillary inlet and method of operation

DOEpatents

Smith, Richard D.; Kim, Taeman; Udseth, Harold R.

2004-10-12

A multi-capillary inlet to focus ions and other charged particles generated at or near atmospheric pressure into a relatively low pressure region, which allows increased conductance of ions and other charged particles. The multi-capillary inlet is juxtaposed between an ion source and the interior of an instrument maintained at near atmospheric pressure, it finds particular advantages when deployed to improve the ion transmission between an electrospray ionization source and the first vacuum stage of a mass spectrometer, and finds its greatest advantages when deployed in conjunction with an electrodynamic (RF) ion funnel deployed within the interior of the mass spectrometer, particularly an ion funnel equipped with a jet disturber.

3-dimensional dark traps for low refractive index bio-cells using a single optical fiber Bessel beam.

PubMed

Zhang, Yu; Tang, Xiaoyun; Zhang, Yaxun; Su, Wenjie; Liu, Zhihai; Yang, Xinghua; Zhang, Jianzhong; Yang, Jun; Oh, Kyunghwan; Yuan, Libo

2018-06-15

We proposed and experimentally demonstrated 3-dimensional dark traps for low refractive index bio-cells using a single optical fiber Bessel beam. The Bessel beam was produced by concatenating single-mode fiber and a step index multimode fiber, which was then focused by a high refractive index glass microsphere integrated on the fiber end facet. The focused Bessel beam provided two dark fields along the axial direction, where stable trapping of low refractive index bio-cells was realized in a high refractive index liquid bath. The all-fiber and seamlessly integrated structure of the proposed scheme can find ample potential as a micro-optical probe in in situ characterization and manipulation of multiple bio-cells with refractive indices lower than that of the liquid bath.

A new ring-shape high-temperature superconducting trapped-field magnet

NASA Astrophysics Data System (ADS)

Sheng, Jie; Zhang, Min; Wang, Yawei; Li, Xiaojian; Patel, Jay; Yuan, Weijia

2017-09-01

This paper presents a new trapped-field magnet made of second-generation high-temperature superconducting (2G HTS) rings. This so-called ring-shape 2G HTS magnet has the potential to provide much stronger magnetic fields relative to existing permanent magnets. Compared to existing 2G HTS trapped- field magnets, e.g. 2G HTS bulks and stacks, this new ring-shape 2G HTS magnet is more flexible in size and can be made into magnets with large dimensions for industrial applications. Effective magnetization is the key to being able to use trapped-field magnets. Therefore, this paper focuses on the magnetization mechanism of this new magnet using both experimental and numerical methods. Unique features have been identified and quantified for this new type of HTS magnet in the field cooling and zero field cooling process. The magnetization mechanism can be understood by the interaction between shielding currents and the penetration of external magnetic fields. An accumulation in the trapped field was observed by using multiple pulse field cooling. Three types of demagnetization were studied to measure the trapped-field decay for practical applications. Our results show that this new ring-shape HTS magnet is very promising in the trapping of a high magnetic field. As a super-permanent magnet, it will have a significant impact on large-scale industrial applications, e.g. the development of HTS machines with a very high power density and HTS magnetic resonance imaging devices.

Clogging and transport of driven particles in asymmetric funnel arrays

NASA Astrophysics Data System (ADS)

Reichhardt, C. J. O.; Reichhardt, C.

2018-06-01

We numerically examine the flow and clogging of particles driven through asymmetric funnel arrays when the commensurability ratio of the number of particles per plaquette is varied. The particle–particle interactions are modeled with a soft repulsive potential that could represent vortex flow in type-II superconductors or driven charged colloids. The velocity-force curves for driving in the easy flow direction of the funnels exhibit a single depinning threshold; however, for driving in the hard flow direction, we find that there can be both negative mobility where the velocity decreases with increasing driving force as well as a reentrant pinning effect in which the particles flow at low drives but become pinned at intermediate drives. This reentrant pinning is associated with a transition from smooth 1D flow at low drives to a clogged state at higher drives that occurs when the particles cluster in a small number of plaquettes and block the flow. When the drive is further increased, particle rearrangements occur that cause the clog to break apart. We map out the regimes in which the pinned, flowing, and clogged states appear as a function of plaquette filling and drive. The clogged states remain robust at finite temperatures but develop intermittent bursts of flow in which a clog temporarily breaks apart but quickly reforms.

Three dimensional touch and vision for the micro-world

NASA Astrophysics Data System (ADS)

Bowman, Richard W.

This thesis describes advances in the holographic technology used to control multiple optical traps (and hence many trapped particles), and improved methods for monitoring the positions and forces involved. The speed with which multiple holographic optical traps can be moved has traditionally been limited by the time taken to calculate holograms, but by using consumer graphics cards and high speed Spatial Light Modulators (SLMs) I have implemented holographic systems fast enough to react to the Brownian motion of trapped particles. Brownian motion can, to some extent, be suppressed by this approach, and it also allows the trap's stiffness to be engineered to balance sensitivity against tight constraint of position. Feedback control using an SLM, rather than the other beam steering technologies that have been employed, is able to react to motion in three dimensions. This requires 3D position measurement, which is provided by the stereo microscopy technique described in Chapter 2. By illuminating and viewing the sample from two different angles it is possible to reconstruct the depth of objects. This is accomplished through a single high numerical aperture microscope objective, the same lens used to focus the trapping laser. In conjunction with a fast CMOS camera, it is possible to track particles with an accuracy of 2-3nm at several thousand frames per second. This allows measurement of forces and displacements within the control loop, that can be fed back to influence the position of the optical traps. This force information can also be relayed to the operator using a force-feedback joystick as detailed in Chapter 7. Interface design is an important part of making technology accessible to scientists from other disciplines; to this end I have also developed a multi-touch tablet application to control optical tweezers. By creating simple, reliable systems and coupling them to an intuitive interface, I have endeavoured to produce developments which are of use to the non-specialist as well as to experts in optical tweezers-a number of which are now available commercially (Section 8.7). These technologies form the basis of a toolkit for working with multi-part probes in optical tweezers, and they should bear fruit in the coming years as a new form of scanning-probe microscopy emerges.

A sea lamprey (Petromyzon marinus) sex pheromone mixture increases trap catch relative to a single synthesized component in specific environments

USGS Publications Warehouse

Johnson, Nicholas S.; Tix, John A.; Hlina, Benjamin L.; Wagner, C. Michael; Siefkes, Michael J.; Wang, Huiyong; Li, Weiming

2015-01-01

Spermiating male sea lamprey (Petromyzon marinus) release a sex pheromone, of which a component, 7α, 12α, 24-trihydoxy-3-one-5α-cholan-24-sulfate (3kPZS), has been identified and shown to induce long distance preference responses in ovulated females. However, other pheromone components exist, and when 3kPZS alone was used to control invasive sea lamprey populations in the Laurentian Great Lakes, trap catch increase was significant, but gains were generally marginal. We hypothesized that free-ranging sea lamprey populations discriminate between a partial and complete pheromone while migrating to spawning grounds and searching for mates at spawning grounds. As a means to test our hypothesis, and to test two possible uses of sex pheromones for sea lamprey control, we asked whether the full sex pheromone mixture released by males (spermiating male washings; SMW) is more effective than 3kPZS in capturing animals in traditional traps (1) en route to spawning grounds and (2) at spawning grounds. At locations where traps target sea lampreys en route to spawning grounds, SMW-baited traps captured significantly more sea lampreys than paired 3kPZS-baited traps (~10 % increase). At spawning grounds, no difference in trap catch was observed between 3kPZS and SMW-baited traps. The lack of an observed difference at spawning grounds may be attributed to increased pheromone competition and possible involvement of other sensory modalities to locate mates. Because fishes often rely on multiple and sometimes redundant sensory modalities for critical life history events, the addition of sex pheromones to traditionally used traps is not likely to work in all circumstances. In the case of the sea lamprey, sex pheromone application may increase catch when applied to specifically designed traps deployed in streams with low adult density and limited spawning habitat.

Stemflow-induced processes of soil water storage

NASA Astrophysics Data System (ADS)

Germer, Sonja

2013-04-01

Compared to stemflow production studies only few studies deal with the fate of stemflow at the near-stem soil. To investigate stemflow contribution to the root zone soil moisture by young and adult babassu palms (Attalea speciosa Mart.), I studied stemflow generation, subsequent soil water percolation and root distributions. Rainfall, stemflow and perched water tables were monitored on an event basis. Perched water tables were monitored next to adult palms at two depths and three stem distances. Dye tracer experiments monitored stemflow-induced preferential flow paths. Root distributions of fine and coarse roots were related to soil water redistribution. Average rainfall-collecting area per adult palm was 6.4 m², but variability between them was high. Funneling ratios ranged between 16-71 and 4-55 for adult and young palms, respectively. Nonetheless, even very small rainfall events of 1 mm can generate stemflow. On average, 9 liters of adult palm stemflow were intercepted and stemflow tended to decrease for-high intensity rainfall events. Young babassu palms funneled rainfall via their fronds, directly to their subterranean stems. The funneling of rainfall towards adult palm stems, in contrast, led to great stemflow fluxes down to the soil and induced initial horizontal water flows through the soil, leading to perched water tables next to palms, even after small rainfall events. The perched water tables extended, however, only a few decimeters from palm stems. After perched water tables became established, vertical percolation through the soil dominated. To my knowledge, this process has not been described before, and it can be seen as an addition to the two previously described stemflow-induced processes of Horton overland flow and fast, deep percolation along roots. This study has demonstrated that Babassu palms funnel water to their stems and subsequently store it in the soil next to their stems in areas where coarse root length density is very high. This might partly explain the competitive position of babassu palms on pastures or secondary forests.

The Time-Course of Sentence Meaning Composition. N400 Effects of the Interaction between Context-Induced and Lexically Stored Affordances

PubMed Central

Cosentino, Erica; Baggio, Giosuè; Kontinen, Jarmo; Werning, Markus

2017-01-01

Contemporary semantic theories can be classified along two dimensions: (i) the way and time-course in which contextual factors influence sentence truth-conditions; and (ii) whether and to what extent comprehension involves sensory, motor and emotional processes. In order to explore this theoretical space, our ERP study investigates the time-course of the interaction between the lexically specified telic component of a noun (the function of the object to which the noun refers to, e.g., a funnel is generally used to pour liquids into containers) and an ad-hoc affordance contextually induced by the situation described in the discourse. We found that, if preceded by a neutral discourse context, a verb incongruent with the noun's telic component as in “She uses the funnel to hang her coat” elicited an enhanced N400 compared to a congruent verb as in “She uses the funnel to pour water into a container.” However, if the situation introduced in the preceding discourse induced a new function for the object as an ad-hoc affordance (e.g., the funnel is glued to the wall and the agent wants to hang the coat), we observed a crossing-over regarding the direction of the N400 effect: comparing the ad-hoc affordance-inducing context with the neutral context, the N400 for the incongruent verb was significantly reduced, whereas the N400 for the congruent verb was significantly enhanced. We explain these results as a consequence of the incorporation of the contextually triggered ad-hoc affordance into the meaning of the noun. Combining these results with an analysis of semantic similarity values between test sentences and contexts, we argue that one possibility is that the incorporation of an ad-hoc affordance may be explained on the basis of the mental simulation of concurrent motor information. PMID:28603506

The Time-Course of Sentence Meaning Composition. N400 Effects of the Interaction between Context-Induced and Lexically Stored Affordances.

PubMed

Cosentino, Erica; Baggio, Giosuè; Kontinen, Jarmo; Werning, Markus

2017-01-01

Contemporary semantic theories can be classified along two dimensions: (i) the way and time-course in which contextual factors influence sentence truth-conditions; and (ii) whether and to what extent comprehension involves sensory, motor and emotional processes. In order to explore this theoretical space, our ERP study investigates the time-course of the interaction between the lexically specified telic component of a noun (the function of the object to which the noun refers to, e.g., a funnel is generally used to pour liquids into containers) and an ad-hoc affordance contextually induced by the situation described in the discourse. We found that, if preceded by a neutral discourse context, a verb incongruent with the noun's telic component as in "She uses the funnel to hang her coat" elicited an enhanced N400 compared to a congruent verb as in "She uses the funnel to pour water into a container." However, if the situation introduced in the preceding discourse induced a new function for the object as an ad-hoc affordance (e.g., the funnel is glued to the wall and the agent wants to hang the coat), we observed a crossing-over regarding the direction of the N400 effect: comparing the ad-hoc affordance-inducing context with the neutral context, the N400 for the incongruent verb was significantly reduced, whereas the N400 for the congruent verb was significantly enhanced. We explain these results as a consequence of the incorporation of the contextually triggered ad-hoc affordance into the meaning of the noun. Combining these results with an analysis of semantic similarity values between test sentences and contexts, we argue that one possibility is that the incorporation of an ad-hoc affordance may be explained on the basis of the mental simulation of concurrent motor information.

Water storage capacity, stemflow and water funneling in Mediterranean shrubs

NASA Astrophysics Data System (ADS)

Garcia-Estringana, P.; Alonso-Blázquez, N.; Alegre, J.

2010-08-01

SummaryTo predict water losses and other hydrological and ecological features of a given vegetation, its water storage capacity and stemflow need to be accurately determined. Vast areas of the Mediterranean region are occupied by shrublands yet there is scarce data available on their rainwater interception capacity. In this study, simulated rainfall tests were conducted in controlled conditions on nine Mediterranean shrubs of varying anatomic and morphological features to determine water storage capacity, stemflow and the funneling ratio. After assessing correlations between these hydrological variables and the biometric characteristics of the shrubs, we compared two methods of determining storage capacity: rainfall simulation and immersion. Mean water storage capacity was 1.02 mm (0.35-3.24 mm), stemflow was 16% (3.8-26.4%) and the funneling ratio was 104 (30-260). Per unit biomass, mean storage capacity was 0.66 ml g -1 and ranged from 0.23 ml g -1 for Cistus ladanifer to 2.26 ml g -1 for Lavandula latifolia. Despite their small size, shrubs may generate high water losses to the atmosphere when they form dense communities and this can have a significant impact in regions where water is scarce. When considered the whole shrubs in absolute terms (ml per plant), water storage capacity and stemflow were correlated to biomass and the dendrometric characteristics of the shrubs, yet in relative terms (expressed per surface area unit or as %), anatomic features such as pubescence, branch rigidity or leaf insertion angle emerged as determining factors. The use of a simple procedure to assess storage capacity was inefficient. The immersion method underestimated storage capacity to a different extent for each species. Some shrubs returned high stemflow values typical of their adaptation to the semiarid climate. In contrast, other shrubs seem to have structures that promote stemflow yet have developed other drought-adaptation mechanisms. In this report, we discuss the ecological and hydrological significance of stemflow and the funneling ratio.

Funneled potential and flux landscapes dictate the stabilities of both the states and the flow: Fission yeast cell cycle.

PubMed

Luo, Xiaosheng; Xu, Liufang; Han, Bo; Wang, Jin

2017-09-01

Using fission yeast cell cycle as an example, we uncovered that the non-equilibrium network dynamics and global properties are determined by two essential features: the potential landscape and the flux landscape. These two landscapes can be quantified through the decomposition of the dynamics into the detailed balance preserving part and detailed balance breaking non-equilibrium part. While the funneled potential landscape is often crucial for the stability of the single attractor networks, we have uncovered that the funneled flux landscape is crucial for the emergence and maintenance of the stable limit cycle oscillation flow. This provides a new interpretation of the origin for the limit cycle oscillations: There are many cycles and loops existed flowing through the state space and forming the flux landscapes, each cycle with a probability flux going through the loop. The limit cycle emerges when a loop stands out and carries significantly more probability flux than other loops. We explore how robustness ratio (RR) as the gap or steepness versus averaged variations or roughness of the landscape, quantifying the degrees of the funneling of the underlying potential and flux landscapes. We state that these two landscapes complement each other with one crucial for stabilities of states on the cycle and the other crucial for the stability of the flow along the cycle. The flux is directly related to the speed of the cell cycle. This allows us to identify the key factors and structure elements of the networks in determining the stability, speed and robustness of the fission yeast cell cycle oscillations. We see that the non-equilibriumness characterized by the degree of detailed balance breaking from the energy pump quantified by the flux is the cause of the energy dissipation for initiating and sustaining the replications essential for the origin and evolution of life. Regulating the cell cycle speed is crucial for designing the prevention and curing strategy of cancer.

Funneled potential and flux landscapes dictate the stabilities of both the states and the flow: Fission yeast cell cycle

PubMed Central

2017-01-01

Using fission yeast cell cycle as an example, we uncovered that the non-equilibrium network dynamics and global properties are determined by two essential features: the potential landscape and the flux landscape. These two landscapes can be quantified through the decomposition of the dynamics into the detailed balance preserving part and detailed balance breaking non-equilibrium part. While the funneled potential landscape is often crucial for the stability of the single attractor networks, we have uncovered that the funneled flux landscape is crucial for the emergence and maintenance of the stable limit cycle oscillation flow. This provides a new interpretation of the origin for the limit cycle oscillations: There are many cycles and loops existed flowing through the state space and forming the flux landscapes, each cycle with a probability flux going through the loop. The limit cycle emerges when a loop stands out and carries significantly more probability flux than other loops. We explore how robustness ratio (RR) as the gap or steepness versus averaged variations or roughness of the landscape, quantifying the degrees of the funneling of the underlying potential and flux landscapes. We state that these two landscapes complement each other with one crucial for stabilities of states on the cycle and the other crucial for the stability of the flow along the cycle. The flux is directly related to the speed of the cell cycle. This allows us to identify the key factors and structure elements of the networks in determining the stability, speed and robustness of the fission yeast cell cycle oscillations. We see that the non-equilibriumness characterized by the degree of detailed balance breaking from the energy pump quantified by the flux is the cause of the energy dissipation for initiating and sustaining the replications essential for the origin and evolution of life. Regulating the cell cycle speed is crucial for designing the prevention and curing strategy of cancer. PMID:28892489

Dynamics of multiple bodies in a corotation resonance

NASA Astrophysics Data System (ADS)

A'Hearn, Joseph; Hedman, Matthew

2018-04-01

The orbital evolution of multiple massive bodies trapped in the same corotation resonance site has not yet been studied in depth, but could be relevant to the origins and history of small moons like Saturn's moon Aegaeon. We conduct numerical simulations of multiple bodies trapped within a corotation resonance and examine what happens to these bodies when they have close encounters. Compared to simulations with equal mass bodies, simulations with one body more massive than the others may be more likely to feature an asymmetry in the phase space of semi-major axis and mean longitude. That is, bodies on one side of phase space have a slightly greater tendency to lose angular momentum, while bodies on the other side gain angular momentum. With this asymmetry, the transfer of angular momentum during gravitational encounters makes it more likely for the most massive body rather than other bodies to approach the center of the corotation site. More work is needed to determine if this sort of process can significantly affect the orbital evolution of small moons like Aegaeon.

Effects of surface and interface traps on exciton and multi-exciton dynamics in core/shell quantum dots

NASA Astrophysics Data System (ADS)

Bozio, Renato; Righetto, Marcello; Minotto, Alessandro

2017-08-01

Exciton interactions and dynamics are the most important factors determining the exceptional photophysical properties of semiconductor quantum dots (QDs). In particular, best performances have been obtained for ingeniously engineered core/shell QDs. We have studied two factors entering in the exciton decay dynamics with adverse effects for the luminescence efficiency: exciton trapping at surface and interface traps, and non-radiative Auger recombination in QDs carrying either net charges or multiple excitons. In this work, we present a detailed study into the optical absorption, fluorescence dynamics and quantum yield, as well as ultrafast transient absorption properties of CdSe/CdS, CdSe/Cd0.5Zn0.5S, and CdSe/ZnS QDs as a function of shell thickness. It turns out that de-trapping processes play a pivotal role in determining steady state emission properties. By studying the excitation dependent photoluminescence quantum yields (PLQY) in different CdSe/CdxZn1-xS (x = 0, 0.5, 1) QDs, we demonstrate the different role played by hot and cold carrier trapping rates in determining fluorescence quantum yields. Finally, the use of global analysis allows us untangling the complex ultrafast transient absorption signals. Smoothing of interface potential, together with effective surface passivation, appear to be crucial factors in slowing down both Auger-based and exciton trapping recombination processes.

Safety and Immunogenicity of Heterologous Prime-Boost Immunisation with Plasmodium falciparum Malaria Candidate Vaccines, ChAd63 ME-TRAP and MVA ME-TRAP, in Healthy Gambian and Kenyan Adults

PubMed Central

Kimani, Domtila; Jagne, Ya Jankey; Sheehy, Susanne H.; Bliss, Carly M.; Duncan, Christopher J. A.; Collins, Katharine A.; Garcia Knight, Miguel A.; Kimani, Eva; Anagnostou, Nicholas A.; Berrie, Eleanor; Moyle, Sarah; Gilbert, Sarah C.; Spencer, Alexandra J.; Soipei, Peninah; Mueller, Jenny; Okebe, Joseph; Colloca, Stefano; Cortese, Riccardo; Viebig, Nicola K.; Roberts, Rachel; Gantlett, Katherine; Lawrie, Alison M.; Nicosia, Alfredo; Imoukhuede, Egeruan B.; Bejon, Philip; Urban, Britta C.; Flanagan, Katie L.; Ewer, Katie J.; Chilengi, Roma; Hill, Adrian V. S.; Bojang, Kalifa

2013-01-01

Background Heterologous prime boost immunization with chimpanzee adenovirus 63 (ChAd63) and Modified vaccinia Virus Ankara (MVA) vectored vaccines is a strategy recently shown to be capable of inducing strong cell mediated responses against several antigens from the malaria parasite. ChAd63-MVA expressing the Plasmodium falciparum pre-erythrocytic antigen ME-TRAP (multiple epitope string with thrombospondin-related adhesion protein) is a leading malaria vaccine candidate, capable of inducing sterile protection in malaria naïve adults following controlled human malaria infection (CHMI). Methodology We conducted two Phase Ib dose escalation clinical trials assessing the safety and immunogenicity of ChAd63-MVA ME-TRAP in 46 healthy malaria exposed adults in two African countries with similar malaria transmission patterns. Results ChAd63-MVA ME-TRAP was shown to be safe and immunogenic, inducing high-level T cell responses (median >1300 SFU/million PBMC). Conclusions ChAd63-MVA ME-TRAP is a safe and highly immunogenic vaccine regimen in adults with prior exposure to malaria. Further clinical trials to assess safety and immunogenicity in children and infants and protective efficacy in the field are now warranted. Trial Registration Pactr.org PACTR2010020001771828 Pactr.org PACTR201008000221638 ClinicalTrials.gov NCT01373879 NCT01373879 ClinicalTrials.gov NCT01379430 NCT01379430 PMID:23526949

Comparison of BG-Sentinel® Trap and Oviposition Cups for Aedes aegypti and Aedes albopictus Surveillance in Jacksonville, Florida, USA.

PubMed

Wright, Jennifer A; Larson, Ryan T; Richardson, Alec G; Cote, Noel M; Stoops, Craig A; Clark, Marah; Obenauer, Peter J

2015-03-01

The BG-Sentinel® (BGS) trap and oviposition cups (OCs) have both proven effective in the surveillance of Aedes species. This study aimed to determine which of the 2 traps could best characterize the relative population sizes of Aedes albopictus and Aedes aegypti in an urban section of Jacksonville, FL. Until 1986, Ae. aegypti was considered the dominant container-breeding species in urban northeastern Florida. Since the introduction of Ae. albopictus, Ae. aegypti has become almost completely extirpated. In 2011, a resurgence of Ae. aegypti was detected in the urban areas of Jacksonville; thus this study initially set out to determine the extent of Ae. aegypti reintroduction to the area. We determined that the BGS captured a greater number of adult Ae. aegypti than Ae. albopictus, while OCs did not monitor significantly different numbers of either species, even in areas where the BGS traps suggested a predominance of one species over the other. Both traps were effective at detecting Aedes spp.; however, the BGS proved more diverse by detecting over 20 other species as well. Our results show that in order to accurately determine vectorborne disease threats and the impact of control operations on these 2 species, multiple trapping techniques should be utilized when studying Ae. aegypti and Ae. albopictus population dynamics.

Safety and immunogenicity of heterologous prime-boost immunisation with Plasmodium falciparum malaria candidate vaccines, ChAd63 ME-TRAP and MVA ME-TRAP, in healthy Gambian and Kenyan adults.

PubMed

Ogwang, Caroline; Afolabi, Muhammed; Kimani, Domtila; Jagne, Ya Jankey; Sheehy, Susanne H; Bliss, Carly M; Duncan, Christopher J A; Collins, Katharine A; Garcia Knight, Miguel A; Kimani, Eva; Anagnostou, Nicholas A; Berrie, Eleanor; Moyle, Sarah; Gilbert, Sarah C; Spencer, Alexandra J; Soipei, Peninah; Mueller, Jenny; Okebe, Joseph; Colloca, Stefano; Cortese, Riccardo; Viebig, Nicola K; Roberts, Rachel; Gantlett, Katherine; Lawrie, Alison M; Nicosia, Alfredo; Imoukhuede, Egeruan B; Bejon, Philip; Urban, Britta C; Flanagan, Katie L; Ewer, Katie J; Chilengi, Roma; Hill, Adrian V S; Bojang, Kalifa

2013-01-01

Heterologous prime boost immunization with chimpanzee adenovirus 63 (ChAd63) and Modified vaccinia Virus Ankara (MVA) vectored vaccines is a strategy recently shown to be capable of inducing strong cell mediated responses against several antigens from the malaria parasite. ChAd63-MVA expressing the Plasmodium falciparum pre-erythrocytic antigen ME-TRAP (multiple epitope string with thrombospondin-related adhesion protein) is a leading malaria vaccine candidate, capable of inducing sterile protection in malaria naïve adults following controlled human malaria infection (CHMI). We conducted two Phase Ib dose escalation clinical trials assessing the safety and immunogenicity of ChAd63-MVA ME-TRAP in 46 healthy malaria exposed adults in two African countries with similar malaria transmission patterns. ChAd63-MVA ME-TRAP was shown to be safe and immunogenic, inducing high-level T cell responses (median >1300 SFU/million PBMC). ChAd63-MVA ME-TRAP is a safe and highly immunogenic vaccine regimen in adults with prior exposure to malaria. Further clinical trials to assess safety and immunogenicity in children and infants and protective efficacy in the field are now warranted. Pactr.org PACTR2010020001771828 Pactr.org PACTR201008000221638 ClinicalTrials.gov NCT01373879 NCT01373879 ClinicalTrials.gov NCT01379430 NCT01379430.

Multiple seeding for the growth of bulk GdBCO-Ag superconductors with single grain behaviour

NASA Astrophysics Data System (ADS)

Shi, Y.; Durrell, J. H.; Dennis, A. R.; Huang, K.; Namburi, D. K.; Zhou, D.; Cardwell, D. A.

2017-01-01

Rare earth-barium-copper oxide bulk superconductors fabricated in large or complicated geometries are required for a variety of engineering applications. Initiating crystal growth from multiple seeds reduces the time taken to melt-process individual samples and can reduce the problem of poor crystal texture away from the seed. Grain boundaries between regions of independent crystal growth can reduce significantly the flow of current due to crystallographic misalignment and the agglomeration of impurity phases. Enhanced supercurrent flow at such boundaries has been achieved by minimising the depth of the boundary between A growth sectors generated during the melt growth process by reducing second phase agglomerations and by a new technique for initiating crystal growth that minimises the misalignment between different growth regions. The trapped magnetic fields measured for the resulting samples exhibit a single trapped field peak indicating they are equivalent to conventional single grains.

Lidar observation of marine mixed layer

NASA Technical Reports Server (NTRS)

Yamagishi, Susumu; Yamanouchi, Hiroshi; Tsuchiya, Masayuki

1992-01-01

Marine mixed layer is known to play an important role in the transportation of pollution exiting ship funnels. The application of a diffusion model is critically dependent upon a reliable estimate of a lid. However, the processes that form lids are not well understood, though considerable progress toward marine boundary layer has been achieved. This report describes observations of the marine mixed layer from the course Ise-wan to Nii-jima with the intention of gaining a better understanding of their structure by a shipboard lidar. These observations were made in the summer of 1991. One interesting feature of the observations was that the multiple layers of aerosols, which is rarely numerically modeled, was encountered. No attempt is yet made to present a systematic analysis of all the data collected. Instead we focus on observations that seem to be directly relevant to the structure of the mixed layer.

Development of Paper Products from Dried Sweetpotato Stems and Peanut Shells

NASA Technical Reports Server (NTRS)

McConnell, R.; Smith, R.; Jones, G.; Lu, J. Y.

1998-01-01

One of the goals of NASA's Advanced Life Support Program (ALS) for sustaining human life in space is to achieve a closed system in plant production and usage. That all inedible plant parts should be recycled or used in some way. A Tuskegee University team researching sweetpotato and peanut for ALS has developed paper products from dried sweet-potato stems and peanut shells. In this study, the sweet-potato stems and peanut shells were soaked separately in water for 48 hours. After 48 hours, researchers manually separated the pulp and the unusable parts. To form the paper, 160 g of pulp and water mixture was poured through a 15.1 cm (diameter) filtration funnel and the pulp was trapped on 15 cm (diameter) filter paper. The filter paper and pulp were dried in an air oven, and the filter paper was removed, An examination under a scanning electron microscope showed that the sweet-potato paper was composed of "fibers", whereas the peanut shell paper was composed of "blocks". Results of physical testing showed that the sweet-potato stem paper was stronger than the peanut shell paper. It is anticipated that there may be other uses of these products such as writing paper, bags and packaging material. Because of its biodegradability, it can be incorporated into the resource recycling system at the end of its use.

Structural analysis of N-linked carbohydrate chains of funnel web spider (Agelenopsis aperta) venom peptide isomerase.

PubMed

Shikata, Y; Ohe, H; Mano, N; Kuwada, M; Asakawa, N

1998-06-01

The structure of the N-linked carbohydrate chains of peptide isomerase from the venom of the funnel web spider (Agelenopsis aperta) has been analyzed. Carbohydrates were released from peptide isomerase by hydrazinolysis and reductively aminated with 2-aminopyridine. The fluorescent derivatives were purified by phenol/chloroform extraction, followed by size-exclusion HPLC. The structure of the purified pyridylamino (PA-) carbohydrate chains were analyzed by a combination of two-dimensional HPLC mapping, sugar composition analysis, sequential exoglycosidase digestions, and mass spectrometry. The peptide isomerase contains six kinds of N-linked carbohydrate chains of truncated high-mannose type, with a fucose alpha 1-6 linked to the reducing N-acetylglucosamine in approximately 80% of them.

Improved ion optics for introduction of ions into a 9.4-T Fourier transform ion cyclotron resonance mass spectrometer

DOE PAGES

Chen, Yu; Leach, Franklin E.; Kaiser, Nathan K.; ...

2015-01-19

Fourier transform ion cyclotron resonance (FT-ICR) mass spectrometry provides unparalleled mass accuracy and resolving power.[1],[2] With electrospray ionization (ESI), ions are typically transferred into the mass spectrometer through a skimmer, which serves as a conductance-limiting orifice. However, the skimmer allows only a small fraction of incoming ions to enter the mass spectrometer. An ion funnel, originally developed by Smith and coworkers at Pacific Northwest National Laboratory (PNNL)[3-5] provides much more efficient ion focusing and transfer. The large entrance aperture of the ion funnel allows almost all ions emanating from a heated capillary to be efficiently captured and transferred, resulting inmore » nearly lossless transmission.« less

Device for two-dimensional gas-phase separation and characterization of ion mixtures

DOEpatents

Tang, Keqi [Richland, WA; Shvartsburg, Alexandre A [Richland, WA; Smith, Richard D [Richland, WA

2006-12-12

The present invention relates to a device for separation and characterization of gas-phase ions. The device incorporates an ion source, a field asymmetric waveform ion mobility spectrometry (FAIMS) analyzer, an ion mobility spectrometry (IMS) drift tube, and an ion detector. In one aspect of the invention, FAIMS operating voltages are electrically floated on top of the IMS drift voltage. In the other aspect, the FAIMS/IMS interface is implemented employing an electrodynamic ion funnel, including in particular an hourglass ion funnel. The present invention improves the efficiency (peak capacity) and sensitivity of gas-phase separations; the online FAIMS/IMS coupling creates a fundamentally novel two-dimensional gas-phase separation technology with high peak capacity, specificity, and exceptional throughput.

Protein misfolding occurs by slow diffusion across multiple barriers in a rough energy landscape

PubMed Central

Yu, Hao; Dee, Derek R.; Liu, Xia; Brigley, Angela M.; Sosova, Iveta; Woodside, Michael T.

2015-01-01

The timescale for the microscopic dynamics of proteins during conformational transitions is set by the intrachain diffusion coefficient, D. Despite the central role of protein misfolding and aggregation in many diseases, it has proven challenging to measure D for these processes because of their heterogeneity. We used single-molecule force spectroscopy to overcome these challenges and determine D for misfolding of the prion protein PrP. Observing directly the misfolding of individual dimers into minimal aggregates, we reconstructed the energy landscape governing nonnative structure formation. Remarkably, rather than displaying multiple pathways, as typically expected for aggregation, PrP dimers were funneled into a thermodynamically stable misfolded state along a single pathway containing several intermediates, one of which blocked native folding. Using Kramers’ rate theory, D was found to be 1,000-fold slower for misfolding than for native folding, reflecting local roughening of the misfolding landscape, likely due to increased internal friction. The slow diffusion also led to much longer transit times for barrier crossing, allowing transition paths to be observed directly for the first time to our knowledge. These results open a new window onto the microscopic mechanisms governing protein misfolding. PMID:26109573

Protein misfolding occurs by slow diffusion across multiple barriers in a rough energy landscape.

PubMed

Yu, Hao; Dee, Derek R; Liu, Xia; Brigley, Angela M; Sosova, Iveta; Woodside, Michael T

2015-07-07

The timescale for the microscopic dynamics of proteins during conformational transitions is set by the intrachain diffusion coefficient, D. Despite the central role of protein misfolding and aggregation in many diseases, it has proven challenging to measure D for these processes because of their heterogeneity. We used single-molecule force spectroscopy to overcome these challenges and determine D for misfolding of the prion protein PrP. Observing directly the misfolding of individual dimers into minimal aggregates, we reconstructed the energy landscape governing nonnative structure formation. Remarkably, rather than displaying multiple pathways, as typically expected for aggregation, PrP dimers were funneled into a thermodynamically stable misfolded state along a single pathway containing several intermediates, one of which blocked native folding. Using Kramers' rate theory, D was found to be 1,000-fold slower for misfolding than for native folding, reflecting local roughening of the misfolding landscape, likely due to increased internal friction. The slow diffusion also led to much longer transit times for barrier crossing, allowing transition paths to be observed directly for the first time to our knowledge. These results open a new window onto the microscopic mechanisms governing protein misfolding.

Effects of emission layer doping on the spatial distribution of charge and host recombination rate density in organic light emitting devices: A numerical study

NASA Astrophysics Data System (ADS)

Li, Yanli; Zhou, Maoqing; Zheng, Tingcai; Yao, Bo; Peng, Yingquan

2013-12-01

Based on drift-diffusion theory, a numerical model of the doping of a single energy level trap in the emission layer of an organic light emitting device (OLED) was developed, and the effects of doping of this single energy level trap on the distribution of the charge density, the recombination rate density, and the electric field in single- and double-layer OLEDs were studied numerically. The results show that by doping the n-type (p-type) emission layer with single energy electron (hole) traps, the distribution of the recombination rate density can be tuned and shifted, which is useful for improvement of the device performance by reduced electrode quenching or for realization of desirable special functions, e.g., emission spectrum tuning in multiple dye-doped white OLEDs.

Inside the trap: gland morphologies, digestive enzymes, and the evolution of plant carnivory in the Caryophyllales⋆

PubMed Central

Renner, Tanya; Specht, Chelsea D

2013-01-01

The digestion of prey by carnivorous plants is determined in part by suites of enzymes that are associated with morphologically and anatomically diverse trapping mechanisms. Chitinases represent a group of enzymes known to be integral to effective plant carnivory. In non-carnivorous plants, chitinases commonly act as pathogenesis-related proteins, which are either induced in response to insect herbivory and fungal elicitors, or constitutively expressed in tissues vulnerable to attack. In the Caryophyllales carnivorous plant lineage, multiple classes of chitinases are likely involved in both pathogenic response and digestion of prey items. We review what is currently known about trap morphologies, provide an examination of the diversity, roles, and evolution of chitinases, and examine how herbivore and pathogen defense mechanisms may have been coopted for plant carnivory in the Caryophyllales. PMID:23830995

Multi-vortex crystal lattices in Bose-Einstein condensates with a rotating trap.

PubMed

Xie, Shuangquan; Kevrekidis, Panayotis G; Kolokolnikov, Theodore

2018-05-01

We consider vortex dynamics in the context of Bose-Einstein condensates (BECs) with a rotating trap, with or without anisotropy. Starting with the Gross-Pitaevskii (GP) partial differential equation (PDE), we derive a novel reduced system of ordinary differential equations (ODEs) that describes stable configurations of multiple co-rotating vortices (vortex crystals). This description is found to be quite accurate quantitatively especially in the case of multiple vortices. In the limit of many vortices, BECs are known to form vortex crystal structures, whereby vortices tend to arrange themselves in a hexagonal-like spatial configuration. Using our asymptotic reduction, we derive the effective vortex crystal density and its radius. We also obtain an asymptotic estimate for the maximum number of vortices as a function of rotation rate. We extend considerations to the anisotropic trap case, confirming that a pair of vortices lying on the long (short) axis is linearly stable (unstable), corroborating the ODE reduction results with full PDE simulations. We then further investigate the many-vortex limit in the case of strong anisotropic potential. In this limit, the vortices tend to align themselves along the long axis, and we compute the effective one-dimensional vortex density, as well as the maximum admissible number of vortices. Detailed numerical simulations of the GP equation are used to confirm our analytical predictions.

A semi-analytical method for near-trapped mode and fictitious frequencies of multiple scattering by an array of elliptical cylinders in water waves

NASA Astrophysics Data System (ADS)

Chen, Jeng-Tzong; Lee, Jia-Wei

2013-09-01

In this paper, we focus on the water wave scattering by an array of four elliptical cylinders. The null-field boundary integral equation method (BIEM) is used in conjunction with degenerate kernels and eigenfunctions expansion. The closed-form fundamental solution is expressed in terms of the degenerate kernel containing the Mathieu and the modified Mathieu functions in the elliptical coordinates. Boundary densities are represented by using the eigenfunction expansion. To avoid using the addition theorem to translate the Mathieu functions, the present approach can solve the water wave problem containing multiple elliptical cylinders in a semi-analytical manner by introducing the adaptive observer system. Regarding water wave problems, the phenomena of numerical instability of fictitious frequencies may appear when the BIEM/boundary element method (BEM) is used. Besides, the near-trapped mode for an array of four identical elliptical cylinders is observed in a special layout. Both physical (near-trapped mode) and mathematical (fictitious frequency) resonances simultaneously appear in the present paper for a water wave problem by an array of four identical elliptical cylinders. Two regularization techniques, the combined Helmholtz interior integral equation formulation (CHIEF) method and the Burton and Miller approach, are adopted to alleviate the numerical resonance due to fictitious frequency.