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Sample records for limulus polyphemus exhibits

  1. Simple photoreceptors in Limulus polyphemus.

    PubMed

    Millecchia, R; Bradbury, J; Mauro, A

    1966-12-01

    The "olfactory nerve," the endoparietal eye, and the rudimentary lateral eyes of Limulus (polyphemus) contain simple photoreceptor cells that duplicate many of the electrical responses of the retinular cells of the lateral eye; the responses are a receptor potential consisting of aninitial transient phase and a subsequent steady phase,low-amplitude fluctuations, and a small locally regenerative response to pulses of both light and current. Photic stimulation does not induce conducted action potentials, but does increase the membrane conductance. The receptor potentialrequires the presence of sodium ions in the external medium. Measurements of action and absorption spectra indicate a photopigment whose maximum absorption is of light with wavelength of 535 nanometers. The functional significance of these cells has not been ascertained. PMID:5921383

  2. Classroom Applications Using Limulus Polyphemus--The American Horseshoe Crab.

    ERIC Educational Resources Information Center

    Pearson, Frederick C., III; Weary, Marlys

    1981-01-01

    Provides examples of several classroom activities utilizing the American horseshoe crab (Limulus Polyphemus), including raising fertilized eggs, fertilizing eggs in vitro, and testing water samples. Includes background information on the natural history, life cycle, and breeding habits of this animal. (DS)

  3. Phagocytic activity of Limulus polyphemus amebocytes in vitro.

    PubMed

    Coates, Christopher J; Whalley, Tim; Nairn, Jacqueline

    2012-11-01

    Phagocytosis of invading microorganisms is a fundamental component of innate immunity. The Atlantic horseshoe crab, Limulus polyphemus, possesses a single immune cell type, the granular amebocyte. Amebocytes release a repertoire of potent immune effectors in the presence of pathogens, and function in hemostasis. In contrast to other arthropod immunocytes, the properties of amebocyte phagocytosis remain poorly characterised, restricted by the technical challenges associated with handling these labile cells. We have addressed these challenges and observed the internalisation of microbial and synthetic targets by amebocytes in vitro. Confirmation of target internalisation was achieved using a combination of fluorescent quenching and lipophilic membrane probes: R18 and FM 1-43. Viability, morphological integrity and functionality of extracted amebocytes appeared to be retained in vitro. The phagocytic properties of L. polyphemus amebocytes described here, in the absence of endotoxin, are similar to those observed for arthropod immunocytes and mammalian neutrophils. PMID:22910042

  4. Zoothamnium duplicatum infestation of cultured horseshoe crabs (Limulus polyphemus).

    PubMed

    Shinn, Andrew P; Mühlhölzl, Alexander P; Coates, Christopher J; Metochis, Christoforos; Freeman, Mark A

    2015-02-01

    An outbreak of the sessile peritrich Zoothamnium duplicatum in a pilot, commercial-scale Limulus polyphemus hatchery resulted in the loss of ∼96% (40,000) second/third instar larvae over a 61day period. peritrich growth was heavy, leading to mechanical obstruction of the gills and physical damage. The peritrichs were controlled without resultant loss of juvenile crabs by administering 10ppm chlorine in freshwater for 1h and the addition of aquarium grade sand; a medium into which the crabs could burrow and facilitate cleaning of the carapace. Peritrich identity was confirmed from a partial SSU rDNA contiguous sequence of 1343bp (99.7% similarity to Z. duplicatum). PMID:25499897

  5. Circalunidian clocks control tidal rhythms of locomotion in the American horseshoe crab, Limulus polyphemus

    PubMed Central

    Chabot, Christopher C.; Ramberg-Pihl, Nicole C.; Watson, Winsor H.

    2016-01-01

    While many intertidal animals exhibit circatidal rhythms, the nature of the underlying endogenous clocks that control these rhythms has been controversial. In this study American horseshoe crabs, Limulus polyphemus, were used to test the circalunidian hypothesis by exposing them to four different tidal regimes. Overall, the results obtained support the circalunidian hypothesis: each of the twice-daily rhythms of activity appears to be controlled by a separate clock, each with an endogenous period of approximately 24.8h. First, spontaneous “skipping” of one of the daily bouts was observed under several different conditions. Second, the presence of two bouts of activity/day, with different periods, was observed. Lastly, we were able to separately synchronize bouts of activity to two artificial tidal regimes with different periods. These results, taken together, argue in favor of two separate circalunidian clocks in Limulus, each of which controls one of the two bouts of their daily tidal activity rhythms. PMID:27559270

  6. Effects of Bunkers C oil on juvenile horseshoe crabs (Limulus polyphemus)

    SciTech Connect

    Strobel, C.J.; Brenowitz, A.H.

    1981-06-01

    Newly hatched horseshow crabs (Limulus polyphemus) were exposed to autoclaved Bunker C oil for 8 weeks. Autoclaving served to prevent bacterial degradation of stored oil and to drive off the volatile fraction of the oil. The oil was introduced in the form of a whole oil suspension. Minimum lethal dose was shown to be 2.25 mg per l. Concentrations greater than 0.25 mg per l caused a delay in molting.

  7. Isolation and expression of Pax6 and atonal homologues in the American Horseshoe Crab, Limulus polyphemus

    PubMed Central

    Blackburn, David C.; Conley, Kevin W.; Plachetzki, David C.; Kempler, Karen; Battelle, Barbara-Anne; Brown, Nadean L.

    2008-01-01

    Pax6 regulates eye development in many animals. In addition, Pax6 activates atonal transcription factors in both invertebrate and vertebrate eyes. Here we investigate the roles of Pax6 and atonal during embryonic development of Limulus polyphemus rudimentary lateral, medial and ventral eyes, and the initiation of lateral ommatidial eye and medial ocelli formation. Limulus eye development is of particular interest because these animals hold a unique position in arthropod phylogeny and possess multiple eye types. Furthermore, the molecular underpinnings of eye development have yet to be investigated in chelicerates. We characterized a Limulus Pax6 gene, with multiple splice products and predicted protein isoforms, and one atonal homologue. Unexpectedly, neither gene is expressed in the developing eye types examined, although both genes are present in the lateral sense organ, a structure of unknown function. PMID:18651657

  8. Identification of putative circadian clock genes in the American horseshoe crab, Limulus polyphemus.

    PubMed

    Chesmore, Kevin N; Watson, Winsor H; Chabot, Christopher C

    2016-09-01

    While the American horseshoe crab, Limulus polyphemus, has robust circadian and circatidal rhythms, virtually nothing is known about the molecular basis of these rhythms in this species or any other chelicerate. In this study, next generation sequencing was used to assemble transcriptomic reads and then putative homologs of known core and accessory circadian genes were identified in these databases. Homologous transcripts were discovered for one circadian clock input gene, five core genes, 22 accessory genes, and two possible output pathways. Alignments and functional domain analyses showed generally high conservation between the putative L. polyphemus clock genes and homologs from Drosophila melanogaster and Daphnia pulex. The presence of both cry1 and cry2 in the L. polyphemus transcriptome would classify its system as an "ancestral", type 2 clock system. In addition, a novel duplication of CYCLE, and a novel triplication of PERIOD were found. Investigations are currently underway to determine if any of these "circadian" genes also participate in the molecular processes that drive the Limulus circatidal clock. PMID:27341138

  9. Green algal infection of American horseshoe crab (Limulus polyphemus) exoskeletal structures.

    PubMed

    Braverman, Hillary; Leibovitz, Louis; Lewbart, Gregory A

    2012-09-15

    Degenerative lesions in the dorsum of the horseshoe crab (Limulus polyphemus) exoskeleton, eyes, arthrodial membrane, and base of the telson were documented in a population of wild caught laboratory animals. The disease can lead to loss of tissue structure and function, deformed shells, abnormal molting, loss of ocular structures, erosion of interskeletal membranes, and cardiac hemorrhage. Microscopy, histopathology, and in vitro culture confirmed the causative agent to be a green algae of the family Ulvaceae. Further research may explain how green algae overcome horseshoe crab innate immunity leading to external and internal damage. PMID:22709543

  10. Phenoloxidase activity and thermostability of Cancer pagurus and Limulus polyphemus hemocyanin.

    PubMed

    Idakieva, Krassimira; Raynova, Yuliana; Meersman, Filip; Gielens, Constant

    2013-03-01

    The intrinsic and inducible o-diphenoloxidase (o-diPO) activity of Cancer pagurus hemocyanin (CpH) and Limulus polyphemus hemocyanin (LpH) were studied using catechol, l-Dopa and dopamine as substrates. The kinetic analysis shows that dopamine is a more specific substrate for CpH than catechol and l-Dopa (K(m) value of 0.01 mM for dopamine versus 0.67 mM for catechol, and 2.14 mM for l-Dopa), while k(cat) is highest for catechol (2.44 min(-1) versus 0.67 min(-1) for l-Dopa and 0.71 min(-1) for dopamine). On treatment with 4mM sodium dodecyl sulfate (SDS) or by proteolysis the o-diPO activity of CpH increases about twofold. In contrast, native LpH shows no o-diPO activity, and exhibits only a slight activity after incubation with SDS. Neither CpH nor LpH show intrinsic mono-PO activity with l-tyrosine and tyramine as substrates. To explore the possible correlation between the degree of PO activity and protein stability of arthropod hemocyanins, the thermal stability of CpH and LpH was investigated by differential scanning calorimetry and Fourier transform infrared spectroscopy. CpH is found to be less thermostable (T(m)~80 °C), suggesting that the dicopper active sites are more accessible, thereby allowing the hemocyanin to show PO activity in the native state. The LpH, on the other hand, is more thermostable (T(m)~92 °C), suggesting the existence of a correlation between the thermal stability and the intrinsic PO activity of arthropod hemocyanins. PMID:23313741

  11. Genetic Variation and Geographic Differentiation in Mitochondrial DNA of the Horseshoe Crab, LIMULUS POLYPHEMUS

    PubMed Central

    Saunders, Nancy C.; Kessler, Louis G.; Avise, John C.

    1986-01-01

    Restriction site variation in mitochondrial DNA (mtDNA) of the horseshoe crab (Limulus polyphemus) was surveyed in populations ranging from New Hampshire to the Gulf Coast of Florida. MtDNA clonal diversity was moderately high, particularly in southern samples, and a major genetic "break" (nucleotide sequence divergence approximately 2%) distinguished all sampled individuals which were north vs. south of a region in northeastern Florida. The area of genotypic divergence in Limulus corresponds to a long-recognized zoogeographic boundary between warm-temperate and tropical marine faunas, and it suggests that selection pressures and/or gene flow barriers associated with water mass differences may also influence the evolution of species widely distributed across such transition zones. On the other hand, a comparison of the mtDNA divergence patterns in Limulus with computer models involving stochastic lineage extinction in species with limited gene flow demonstrates that deterministic explanations need not necessarily be invoked to account for the observations. Experiments to distinguish stochastic from deterministic possibilities are suggested. Overall, the pattern and magnitude of mtDNA differentiation in horseshoe crabs is very similar to that typically reported for freshwater and terrestrial species assayed over a comparable geographic range. Results demonstrate for the first time that, geographically, at least some continuously distributed marine organisms can show considerable mtDNA genetic differentiation. PMID:17246319

  12. Opsin Repertoire and Expression Patterns in Horseshoe Crabs: Evidence from the Genome of Limulus polyphemus (Arthropoda: Chelicerata)

    PubMed Central

    Battelle, Barbara-Anne; Ryan, Joseph F.; Kempler, Karen E.; Saraf, Spencer R.; Marten, Catherine E.; Warren, Wesley C.; Minx, Patrick J.; Montague, Michael J.; Green, Pamela J.; Schmidt, Skye A.; Fulton, Lucinda; Patel, Nipam H.; Protas, Meredith E.; Wilson, Richard K.; Porter, Megan L.

    2016-01-01

    Horseshoe crabs are xiphosuran chelicerates, the sister group to arachnids. As such, they are important for understanding the most recent common ancestor of Euchelicerata and the evolution and diversification of Arthropoda. Limulus polyphemus is the most investigated of the four extant species of horseshoe crabs, and the structure and function of its visual system have long been a major focus of studies critical for understanding the evolution of visual systems in arthropods. Likewise, studies of genes encoding Limulus opsins, the protein component of the visual pigments, are critical for understanding opsin evolution and diversification among chelicerates, where knowledge of opsins is limited, and more broadly among arthropods. In the present study, we sequenced and assembled a high quality nuclear genomic sequence of L. polyphemus and used these data to annotate the full repertoire of Limulus opsins. We conducted a detailed phylogenetic analysis of Limulus opsins, including using gene structure and synteny information to identify relationships among different opsin classes. We used our phylogeny to identify significant genomic events that shaped opsin evolution and therefore the visual system of Limulus. We also describe the tissue expression patterns of the 18 opsins identified and show that transcripts encoding a number, including a peropsin, are present throughout the central nervous system. In addition to significantly extending our understanding of photosensitivity in Limulus and providing critical insight into the genomic evolution of horseshoe crab opsins, this work provides a valuable genomic resource for addressing myriad questions related to xiphosuran physiology and arthropod evolution. PMID:27189985

  13. Opsin Repertoire and Expression Patterns in Horseshoe Crabs: Evidence from the Genome of Limulus polyphemus (Arthropoda: Chelicerata).

    PubMed

    Battelle, Barbara-Anne; Ryan, Joseph F; Kempler, Karen E; Saraf, Spencer R; Marten, Catherine E; Warren, Wesley C; Minx, Patrick J; Montague, Michael J; Green, Pamela J; Schmidt, Skye A; Fulton, Lucinda; Patel, Nipam H; Protas, Meredith E; Wilson, Richard K; Porter, Megan L

    2016-01-01

    Horseshoe crabs are xiphosuran chelicerates, the sister group to arachnids. As such, they are important for understanding the most recent common ancestor of Euchelicerata and the evolution and diversification of Arthropoda. Limulus polyphemus is the most investigated of the four extant species of horseshoe crabs, and the structure and function of its visual system have long been a major focus of studies critical for understanding the evolution of visual systems in arthropods. Likewise, studies of genes encoding Limulus opsins, the protein component of the visual pigments, are critical for understanding opsin evolution and diversification among chelicerates, where knowledge of opsins is limited, and more broadly among arthropods. In the present study, we sequenced and assembled a high quality nuclear genomic sequence of L. polyphemus and used these data to annotate the full repertoire of Limulus opsins. We conducted a detailed phylogenetic analysis of Limulus opsins, including using gene structure and synteny information to identify relationships among different opsin classes. We used our phylogeny to identify significant genomic events that shaped opsin evolution and therefore the visual system of Limulus We also describe the tissue expression patterns of the 18 opsins identified and show that transcripts encoding a number, including a peropsin, are present throughout the central nervous system. In addition to significantly extending our understanding of photosensitivity in Limulus and providing critical insight into the genomic evolution of horseshoe crab opsins, this work provides a valuable genomic resource for addressing myriad questions related to xiphosuran physiology and arthropod evolution. PMID:27189985

  14. Pharmacokinetics of cefovecin (Convenia) in white bamboo sharks (Chiloscyllium plagiosum) and Atlantic horseshoe crabs (Limulus polyphemus).

    PubMed

    Steeil, James C; Schumacher, Juergen; George, Robert H; Bulman, Frank; Baine, Katherine; Cox, Sherry

    2014-06-01

    Cefovecin was administered to six healthy adult white bamboo sharks (Chiloscyllium plagiosum) and six healthy adult Atlantic horseshoe crabs (Limulus polyphemus) to determine its pharmacokinetics in these species. A single dose of cefovecin at 8 mg/kg was administered subcutaneously in the epaxial region of the bamboo sharks and in the proximal articulation of the lateral leg of the horseshoe crabs. Blood and hemolymph samples were collected at various time points from bamboo sharks and Atlantic horseshoe crabs. High performance liquid chromatography was performed to determine plasma levels of cefovecin. The terminal halflife of cefovecin in Atlantic horseshoe crabs was 37.70 +/- 9.04 hr and in white bamboo sharks was 2.02 +/- 4.62 hr. Cefovecin concentrations were detected for 4 days in white bamboo sharks and for 14 days in Atlantic horseshoe crabs. No adverse effects associated with cefovecin administration were seen in either species. PMID:25000704

  15. Effects of known phenoloxidase inhibitors on hemocyanin-derived phenoloxidase from Limulus polyphemus.

    PubMed

    Wright, Jamie; Clark, William McCaskill; Cain, Jennifer A; Patterson, Alan; Coates, Christopher J; Nairn, Jacqueline

    2012-01-01

    Inhibitors of phenoloxidase are used routinely to characterise the structural and functional properties of phenoloxidases. Hemocyanin-derived phenoloxidase activity is also sensitive to standard phenoloxidase inhibitors. In this study, we characterise the effects of a number of phenoloxidase inhibitors on hemocyanin-derived phenoloxidase activity from the chelicerate, Limulus polyphemus. Both inhibition type and K(i) values were similar to those observed for hemocyanin-derived phenoloxidase from another chelicerate, Eurypelma californicum. In addition, substrate inhibition was observed at concentrations above 2mM dopamine. The conformation in which two of the inhibitors, namely tropolone and kojic acid, would bind near the Cu(II) centre of hemocyanin is proposed. PMID:22885403

  16. Chemical attractants in horseshoe crab, Limulus polyphemus, eggs: the potential for an artificial bait.

    PubMed

    Ferrari, Kirstin M; Targett, Nancy M

    2003-02-01

    Horseshoe crabs, Limulus polyphemus, are the preferred bait in the eel and conch fisheries along the east coast of the United States. However, recent management measures have restricted the availability of horseshoe crabs to commercial fisheries, creating the need for sustainable, alternative bait sources. In this study, we examined the chemistry underlying the predator-prey attraction to determine if specific, isolable attractant metabolites from the horseshoe crab could be identified and characterized for incorporation into an artifical bait. Initial assays with the mud snail, Hyanassa obsoleta, suggested that the chemoattractants were concentrated in L. polyphemus eggs. Chemical analyses and biological assays of the egg extract indicated the primary cue was a heat-stable, proteinaceous compound (>10 kDa). A carbohydrate-rich fraction of low molecular mass (< 10 kDa) also enhanced mud snail chemotaxis. Analysis of egg digests with SDS-PAGE confirmed the presence of glycoproteins or carbohydrate-binding proteins in the horseshoe crab egg extract. Because the attractant appears to be a complex protein or glycoprotein, conventional chemical synthesis is unlikely. However, the tools of modem biotechnology offer the potential to produce this attractant in a system independent of the horseshoe crab. Such an attractant could be incorporated into an artificial bait, providing an ecologically sound alternative for commercial eel and whelk fisheries. PMID:12737271

  17. Estimating tag loss of the Atlantic Horseshoe crab, Limulus polyphemus, using a multi-state model

    USGS Publications Warehouse

    Butler, Catherine Alyssa; McGowan, Conor P.; Grand, James B.; Smith, David

    2012-01-01

    The Atlantic Horseshoe crab, Limulus polyphemus, is a valuable resource along the Mid-Atlantic coast which has, in recent years, experienced new management paradigms due to increased concern about this species role in the environment. While current management actions are underway, many acknowledge the need for improved and updated parameter estimates to reduce the uncertainty within the management models. Specifically, updated and improved estimates of demographic parameters such as adult crab survival in the regional population of interest, Delaware Bay, could greatly enhance these models and improve management decisions. There is however, some concern that difficulties in tag resighting or complete loss of tags could be occurring. As apparent from the assumptions of a Jolly-Seber model, loss of tags can result in a biased estimate and underestimate a survival rate. Given that uncertainty, as a first step towards estimating an unbiased estimate of adult survival, we first took steps to estimate the rate of tag loss. Using data from a double tag mark-resight study conducted in Delaware Bay and Program MARK, we designed a multi-state model to allow for the estimation of mortality of each tag separately and simultaneously.

  18. Crossreactivity of IgE antibody against Dermatophagoides farinae with Limulus polyphemus agglutinin.

    PubMed

    Shibasaki, M; Isoyama, S; Sumazaki, R; Takita, H

    1994-04-01

    Crossreactivity of IgE antibody against Dermatophagoides farinae (Der f) with Limulus polyphemus agglutinin (LPA) was examined using RAST and immunoblot analysis. Of 40 Der f-sensitive asthmatic patients, 28 revealed a positive RAST reaction to LPA, while none of 20 Der f-insensitive hay fever patients showed this reaction. LPA-specific RAST levels of the 40 asthmatic patients correlated with their Der f-specific levels. The RAST reactivity to LPA was competitively inhibited by the addition of either soluble Der f or LPA, but not by the specific inhibitory sugar of sialic acid. LPA could also induce histamine release from leucocytes of Der f-sensitive asthmatic patients. IgE immunoblot analyses showed that the positive RAST sera for LPA had a strong IgE binding activity to the 30 kDa and 80 kDa components of Der f body extract, whereas gel filtration studies showed that the high molecular weight fractions above 150 kDa retained antigenic constituents associated with IgE reactivity to LPA. These results suggest that the antigenic materials of Dermatophagoides mites share some determinants with the haemagglutinin of horseshoe crabs. PMID:7518731

  19. Proximate causes of sexual size dimorphism in horseshoe crabs (Limulus Polyphemus) of the Delaware Bay

    USGS Publications Warehouse

    Smith, D.R.; Mandt, M.T.; Macdonald, P.D.M.

    2009-01-01

    The unresolved status of the proximate cause for sexual size dimorphism in horseshoe crabs has practical consequence, because harvest recommendations rely on assumptions about sex-specific growth and maturity. We propose and evaluate competing hypotheses for the proximate cause of sexual size dimorphism in horseshoe crabs (Limulus polyphemus) by comparing size and estimated age frequencies from spring-captured juveniles (n = 9,075) and adults (n = 36,274) to predictions from the competing hypotheses. We found that the number of identifiable juvenile size distributions was greater for females than males and the probability of remaining a juvenile was higher for females than males among older juveniles. These findings are consistent with males maturing earlier than females. Molt increments and mean sizes were similar for male and female juveniles, which is not consistent with differential growth. Among adults, one size distribution accounted for ???90% of females regardless of carapace wear. Also, size ratio of adult females to males was 1.26, and size ratio of the largest adult to largest juvenile female was 1.28. These observations are not consistent with females continuing to molt as adults. Differential-maturity is the most parsimonious explanation for sexual size dimorphism in Delaware Bay horseshoe crabs. In addition, because of a low frequency of juvenile females >195 mm relative to adult females and male-biased sex ratios starting at 105 mm, we hypothesize that females, more than males, migrate as older juveniles and mature in the ocean. Management implications include that (1) minimum size limits, as previously suggested, would not allocate harvest to older adults as intended because size does not indicate age among adult horseshoe crabs in the Delaware Bay population, and (2) the Shuster Horseshoe Crab Reserve, which has reduced harvest on the continental shelf, could be protecting older juveniles and newly mature females from harvest prior to their first

  20. Multiple-stressor interactions influence embryo development rate in the American horseshoe crab, Limulus polyphemus.

    PubMed

    Vasquez, M Christina; Murillo, Andrea; Brockmann, H Jane; Julian, David

    2015-08-01

    Fertilized eggs of the American horseshoe crab, Limulus polyphemus, are buried in shallow nests above the high tide line, where they are exposed to variations in abiotic conditions during early development. Using a multiple-stressors approach, we examined whether the rate of embryonic development is affected by exposure to combinations of three factors: temperature (25, 30 and 35°C), salinity (5, 15 and 34 ppt) and ambient O2 (5%, 13% and 21% O2). Newly fertilized eggs were incubated under 27 fully factorial stressor combinations for 14 days, then allowed to recover in control conditions (30°C, 34 ppt, 21% O2) for an additional 14 days. Growth rate was measured every 2 days throughout the experiment (N=1289). We found that the effect of isolated stressors (high temperature, low salinity or low O2) reduced developmental success by up to 72% (low salinity), and that stressor combinations showed stronger effects and evidence of complex interactions. For example, low O2 had little effect individually but was lethal in combination with high temperature, and low temperature in isolation slightly decreased the rate of development but reduced the negative effects of low salinity and low O2. Development was delayed under exposure to low O2 but resumed upon return to control conditions after a 10 day lag. These data demonstrate that complex, synergistic interactions among abiotic stressors can substantially alter the development of a coastal invertebrate in ways that may not be predicted from the effects of the stressors in isolation. PMID:26026044

  1. Comparative status and assessment of Limulus polyphemus with emphasis on the New England and Delaware Bay populations

    USGS Publications Warehouse

    Smith, David; Millard, Michael J.; Carmichael, Ruth H.

    2009-01-01

    Increases in harvest of the American horseshoe crab (Limulus polyphemus) during the 1990s, particularly for whelk bait, coupled with decreases in species that depend on their eggs has reduced horseshoe crab abundance, threatened their ecological relationships, and dictated precautionary management of the horseshoe crab resource. Accordingly, population assessments and monitoring programs have been developed throughout much of the horseshoe crab’s range. We review and discuss implications for several recent assessments of Delaware Bay and New England populations and a meta-analysis of region-specific trends. These assessments show that the western Atlantic distribution of the horseshoe crab is comprised of regional or estuarine-specific meta-populations, which exhibit distinct population dynamics and require management as separate units. Modeling of Delaware Bay and Cape Cod populations confirmed that overharvest caused declines, but indicated that some harvest levels are sustainable and consistent with population growth. Coast-wide harvest was reduced by 70% from 1998 to 2006, with the greatest reductions within Delaware Bay states. Harvest regulations in Delaware Bay starting in the late 1990s, such as harvest quotas, seasonal closures, male-only harvest, voluntary use of bait-saving devices, and establishment of the Carl N. Shuster Jr. Horseshoe Crab Reserve, were followed by stabilization and recent evidence of increase in abundance of horseshoe crabs in the region. However, decreased harvest of the Delaware Bay population has redirected harvest to outlying populations, particularly in New York and New England. While the recent Delaware Bay assessments indicate positive population growth, increased harvest elsewhere is believed to be unsustainable. Two important considerations for future assessments include (1) managing Delaware Bay horseshoe crab populations within a multi-species context, for example, to help support migratory shorebirds and (2

  2. An evaluation of Mississippi barrier islands as spawning and nesting habitat for the American horseshoe crab, Limulus polyphemus, with implications for island restoration

    EPA Science Inventory

    The American Horseshoe crab (HSC), Limulus polyphemus, is an economically and ecologically important species in the coastal ecosystem. Horseshoe crabs inhabit the continental shelf and estuaries from Maine to the central Gulf Coast and the Yucatán Peninsula. Although the presen...

  3. Sublethal behavioral and physiological effects of the biomedical bleeding process on the American horseshoe crab, Limulus polyphemus.

    PubMed

    Anderson, Rebecca L; Watson, Winsor H; Chabot, Christopher C

    2013-12-01

    The hemolymph of the American horseshoe crab, Limulus polyphemus, is harvested from over 500,000 animals annually to produce Limulus amebocyte lysate (LAL), a medically important product used to detect pathogenic bacteria. Declining abundance of spawning Limulus females in heavily harvested regions suggests deleterious effects of this activity, and while mortality rates of the harvest process are known to be 10%-30%, sublethal behavioral and physiological effects are not known. In this study, we determined the impact of the harvest process on locomotion and hemocyanin levels of 28 female horseshoe crabs. While mortality rates after bleeding (18%) were similar to previous studies, we found significant decreases in the linear and angular velocity of freely moving animals, as well as changes in their activity levels and expression of circatidal behavioral rhythms. Further, we found reductions in hemocyanin levels, which may alter immune function and cuticle integrity. These previously unrecognized behavioral and physiological deficits suggest that the harvest of LAL may decrease female fitness, and thus may contribute to the current population decline. PMID:24445440

  4. Mitochondrial gene arrangement of the horseshoe crab Limulus polyphemus L.: conservation of major features among arthropod classes

    NASA Technical Reports Server (NTRS)

    Staton, J. L.; Daehler, L. L.; Brown, W. M.; Jacobs, D. K. (Principal Investigator)

    1997-01-01

    Numerous complete mitochondrial DNA sequences have been determined for species within two arthropod groups, insects and crustaceans, but there are none for a third, the chelicerates. Most mitochondrial gene arrangements reported for crustaceans and insect species are identical or nearly identical to that of Drosophila yakuba. Sequences across 36 of the gene boundaries in the mitochondrial DNA (mtDNA) of a representative chelicerate. Limulus polyphemus L., also reveal an arrangement like that of Drosophila yakuba. Only the position of the tRNA(LEU)(UUR) gene differs; in Limulus it is between the genes for tRNA(LEU)(CUN) and ND1. This positioning is also found in onychophorans, mollusks, and annelids, but not in insects and crustaceans, and indicates that tRNA(LEU)(CUN)-tRNA(LEU)(UUR)-ND1 was the ancestral gene arrangement for these groups, as suggested earlier. There are no differences in the relative arrangements of protein-coding and ribosomal RNA genes between Limulus and Drosophila, and none have been observed within arthropods. The high degree of similarity of mitochondrial gene arrangements within arthropods is striking, since some taxa last shared a common ancestor before the Cambrian, and contrasts with the extensive mtDNA rearrangements occasionally observed within some other metazoan phyla (e.g., mollusks and nematodes).

  5. Isolation, cDNA cloning, and characterization of an 18-kDa hemagglutinin and amebocyte aggregation factor from Limulus polyphemus.

    PubMed

    Fujii, N; Minetti, C A; Nakhasi, H L; Chen, S W; Barbehenn, E; Nunes, P H; Nguyen, N Y

    1992-11-01

    An 18-kDa hemagglutinin which possesses the property of inducing both aggregation of amebocytes and agglutination of erythrocytes has been isolated from Limulus polyphemus amebocytes and purified by ion exchange chromatography. This nonglycosylated, single chain polypeptide with an M(r) of 18,506 and isoelectric point of 8.3 is stored exclusively in the large secretory granules of amebocytes. Based on the partial N-terminal amino acid sequence of 63 residues, DNA probes have been synthesized for screening a pBR322 cDNA library constructed from Limulus amebocytes. The cDNA coding for this protein reveals the presence of a 19-residue signal peptide preceding the 153-residue open reading frame. Northern blot analysis indicates the presence of a single mRNA species. The primary structure derived from the corresponding cDNA sequence reveals an internal homology consisting of two consensus sequences, Val-Asn-Asp/Ser-Trp-Asp and Glu-Asp-Arg-Arg-Trp. The formation of 5 disulfide bonds between 10 half-cysteines divides the molecule into three looped domains each containing the Glu-Asp-Arg-Arg-Trp repeating unit. One of the novel features of this protein is that it shares 37% identity with a 22-kDa mammalian extracellular matrix protein isolated from fetal bovine skin (Neame, P.J., Choi, H.U., and Rosenberg, L.C. (1989) J. Biol. Chem. 264, 5474-5479). The two proteins exhibit a similar pattern of looped domains, each domain containing a homologous consensus sequence (i.e. Glu-Asp-Arg-Arg-Trp). The overall structure of both proteins seems to be highly related, with the exception of an N-terminal tyrosine-rich region present only in the mammalian extracellular matrix protein. The functional properties of the two proteins are similar in that the Limulus 18-kDa protein agglutinates horse erythrocytes and aggregates Limulus amebocytes, and the mammalian 22-kDa protein is an effective adhesion promoter for dermal fibroblasts. On the basis of these unique properties, the newly

  6. Effects of copper and cadmium on development and superoxide dismutase levels in horseshoe crab (Limulus polyphemus) embryos.

    PubMed

    Hamilton, Mary G; Esposito, Christopher; Malin, Mia; Cusumano, Lucas R; Botton, Mark L

    2015-01-01

    Pollution by metals may adversely affect organisms through the generation of reactive oxygen species (ROS). In this study, we examined the sublethal effects of two metals, copper and cadmium, on horseshoe crab (Limulus polyphemus) embryos. Exposure to copper or cadmium at concentrations of 0.01-10 mg/L for periods of 4, 8, 16 and 24 h had minimal effect on embryo survival except at 100 mg/L Cu. However, metal-exposed embryos took significantly longer to hatch into first instar ("trilobite") larvae than seawater controls. Levels of superoxide dismutase (SOD), believed to be important in the response to oxidative stress, were determined by Western blotting. Both the Cu/Zn and Mn cofactor forms of SOD tended to be somewhat elevated in metal-exposed embryos, but the increases were neither dose nor time-dependent. Likewise, SOD enzymatic activity showed no significant differences comparing embryos exposed to metals with seawater controls. We conclude that the protective role of SOD's against ROS produced in response to metal exposure appears to be limited in horseshoe crab embryos, at least under our experimental conditions. PMID:26405624

  7. Fusarium solani species complex associated with carapace lesions and branchitis in captive American horseshoe crabs Limulus polyphemus.

    PubMed

    Tuxbury, Kathryn A; Shaw, Gillian C; Montali, Richard J; Clayton, Leigh Ann; Kwiatkowski, Nicole P; Dykstra, Michael J; Mankowski, Joseph L

    2014-07-01

    Captive American horseshoe crabs Limulus polyphemus housed at the National Aquarium presented with a variety of shell and gill lesions over a 3 yr period. Carapace lesions were located on both the dorsal and ventral prosoma and opisthosoma and included multifocal circular areas of tan discoloration, ulcerations, and/or pitting lesions, extending from superficial to full thickness. Gill lesions involved both the book gill cover (operculum) and individual book gill leaflets and included multifocal circular areas of tan discoloration, tan to off-white opaque proliferative lesions, and/or areas of black discoloration. Histopathology revealed fungal hyphae, with variable morphology throughout the thickened and irregular cuticle of the carapace and occasionally penetrating into subcuticular tissues, with associated amebocytic inflammation. Book gill leaflets were infiltrated by fungal hyphae and contained necrotic debris and amebocytes. Thirty-eight of 39 animals (97%) evaluated via histopathological examination had intralesional fungal hyphae. Fungal cultures of carapace and gill lesions were attempted in 26 tissue samples from 15 individuals and were positive in 13 samples (50%), with 10 cultures (77%) yielding identification to genus. Fusarium sp. was identified in 8 of the 10 cultures (80%) via culture morphology. The Fusarium solani species complex was confirmed in 6 of these 8 (75%) via polymerase chain reaction amplification of 2 different ribosomal-specific sequences of isolated fungal DNA. Ante-mortem systemic and topical treatments were performed on some affected individuals, but no appreciable change in lesions was observed. Mycotic dermatitis and branchitis are serious health issues for captive American horseshoe crabs. PMID:24991848

  8. Book gill development in embryos and first and second instars of the horseshoe crab Limulus polyphemus L. (Chelicerata, Xiphosura).

    PubMed

    Farley, Roger D

    2010-09-01

    The scanning electron microscope (SEM) was used to study the development of the opisthosomal appendages and book gills of the horseshoe crab, Limulus polyphemus. Later embryonic stages were examined as well as the first and second instars. The observations are compared with a much earlier light microscopic description of book gill development in the horseshoe crab and with book lung development in scorpion embryos and first and second instars in a recent study with SEM. After the third embryonic molt in the horseshoe crab, the opisthosomal appendages are of sufficient size so they could be fractured or dissected open so internal cells and other structures could be examined. The opisthosomal appendages and book gill lamellae of first and second instars were also opened. The observations support the earlier histological report that the gill lamellae are a hypodermal outgrowth from the posterior surface of the preceding branchial appendages. The genital operculum, branchial appendages and gill lamellae are very thin and consist of external cuticle, hypodermis and space holders. The latter help hold the cuticle walls in place so hemolymph can flow through the narrow channels. The space holders are formed from cell processes that extend into the lumen from the hypodermis just inside the external cuticle. In the recent SEM study in scorpion embryos and in some histological investigations in spider embryos, the book lung lamellae are formed by alignment of cells from an invaginated sac or mass of cells. This clearly differs from the mode of formation of gill lamellae as observed in this and earlier investigations. These reports of differences in embryology refine but do not preclude hypotheses about book gill/book lung homology since addition, deletion or modification of ancestral features often occur for the benefit of the embryos and larvae. PMID:20420937

  9. Biophysical characterization of the interaction of Limulus polyphemus endotoxin neutralizing protein with lipopolysaccharide.

    PubMed

    Andrä, Jörg; Garidel, Patrick; Majerle, Andreja; Jerala, Roman; Ridge, Richard; Paus, Erik; Novitsky, Tom; Koch, Michel H J; Brandenburg, Klaus

    2004-05-01

    Endotoxin-neutralizing protein (ENP) of the horseshoe crab is one of the most potent neutralizers of endotoxins [bacterial lipopolysaccharide (LPS)]. Here, we report on the interaction of LPS with recombinant ENP using a variety of physical and biological techniques. In biological assays (Limulus amebocyte lysate and tumour necrosis factor-alpha induction in human mononuclear cells), ENP causes a strong reduction of the immunostimulatory ability of LPS in a dose-dependent manner. Concomitantly, the accessible negative surface charges of LPS and lipid A (zeta potential) are neutralized and even converted into positive values. The gel to liquid crystalline phase transitions of LPS and lipid A shift to higher temperatures indicative of a rigidification of the acyl chains, however, the only slight enhancement of the transition enthalpy indicates that the hydrophobic moiety is not strongly disturbed. The aggregate structure of lipid A is converted from a cubic into a multilamellar phase upon ENP binding, whereas the secondary structure of ENP does not change due to the interaction with LPS. ENP contains a hydrophobic binding site to which the dye 1-anilino-8-sulfonic acid binds at a K(d) of 19 micro m, which is displaced by LPS. Because lipopolysaccharide-binding protein (LBP) is not able to bind to LPS when ENP and LPS are preincubated, tight binding of ENP to LPS can be deduced with a K(d) in the low nonomolar range. Importantly, ENP is able to incorporate by itself into target phospholipid liposomes, and is also able to mediate the intercalation of LPS into the liposomes thus acting as a transport protein in a manner similar to LBP. Thus, LPS-ENP complexes might enter target membranes of immunocompetent cells, but are not able to activate due to the ability of ENP to change LPS aggregates from an active into an inactive form. PMID:15128313

  10. Glucose and fructose uptake by Limulus polyphemus hepatopancreatic brush border and basolateral membrane vesicles: evidence for Na+-dependent sugar transport activity.

    PubMed

    Sterling, Kenneth M; Ahearn, Gregory A

    2011-05-01

    [(3)H]-fructose and [(3)H]-glucose transport activities were determined in brush border membrane vesicles (BBMV) and basolateral membrane vesicles (BLMV) from Limulus polyphemus (horseshoe crab) hepatopancreas. Glucose transport was equilibrative in the absence of sodium and sodium dependent in the presence of sodium in BBMV, suggesting GLUT-like and SGLT-like transport activity. Glucose transport by BLMV was equilibrative and sodium independent. Fructose uptake by BBMV and BLMV was equilibrative in the absence of sodium and sodium dependent in the presence of sodium. Western blot analysis using a rabbit anti-mouse SGLT-1 polyclonal antibody indicated the presence of a cross-reacting horseshoe crab BBMV protein of similar molecular weight to the mammalian SGLT1. Sequence alignment of the mouse SGLT-4 and SGLT1 with a translated, horseshoe crab-expressed sequence tag also indicated significant identity between species. Fructose and glucose uptake in the absence and presence of sodium by hepatopancreas BBMV and BLMV indicated the presence of sodium-dependent transport activity for each sugar that may result from the presence of transporters similar to those described for other species. PMID:21184084

  11. The effects of short- and long-term hypoxia on hemolymph gas values in the American horseshoe crab (Limulus polyphemus) using a point-of-care analyzer.

    PubMed

    Allender, Matthew C; Schumacher, Juergen; George, Robert; Milam, Jennifer; Odoi, Agricola

    2010-06-01

    Hemolymph gas parameters were evaluated using a point-of-care analyzer in healthy American horseshoe crabs (Limulus polyphemus) at rest and after short- and long-term removal from water. Baseline vascular pH, partial pressure of oxygen (PO2), partial pressure of carbon dioxide, bicarbonate, base excess, total carbon dioxide, and lactate concentrations were determined from hemolymph samples collected from 10 horseshoe crabs (group 1) submerged in water and were compared with values after removal from water for 5 min, and after recovery in water for 10 min and for longer than 60 min (range, 61-221 min). Hemolymph gas parameters were also determined in 12 horseshoe crabs (group 2) after shipment out of water for 24 hr and were compared with values obtained from group 1 animals. Baseline hemolymph gas values of the American horseshoe crab are within range for other aquatic vertebrates. After removal from water for 5 min, all group 1 crabs developed severe hypoxia, with PO2 levels falling below the detectable limit of the analyzer. Group 2 crabs had pronounced respiratory acidosis, and their PO2 values were significantly below baseline values of group 1 animals. PMID:20597209

  12. Detection of liposomal cholesterol and monophosphoryl lipid A by QS-21 saponin and Limulus polyphemus amebocyte lysate.

    PubMed

    Beck, Zoltan; Matyas, Gary R; Alving, Carl R

    2015-03-01

    Liposomes containing cholesterol (Chol) have long been used as an important membrane system for modeling the complex interactions of Chol with adjacent phospholipids or other lipids in a membrane environment. In this study we utilize a probe composed of QS-21, a saponin molecule that recognizes liposomal Chol and causes hemolysis of erythrocytes. The interaction of QS-21 with liposomal Chol results in a stable formulation which, after injection into the tissues of an animal, lacks toxic effects of QS-21 on neighboring cells that contain Chol, such as erythrocytes. Here we have used liposomes containing different saturated phospholipid fatty acyl groups and Chol, with or without monophosphoryl lipid A (MPLA), as model membranes. QS-21 is then employed as a probe to study the interactions of liposomal lipids on the visibility of membrane Chol. We demonstrate that changes either in the mole fraction of Chol in liposomes, or with different chain lengths of phospholipid fatty acyl groups, can have a substantial impact on the detection of Chol by the QS-21. We further show that liposomal MPLA can partially inhibit detection of the liposomal Chol by QS-21. The Limulus amebocyte lysate assay is used for binding to and detection of MPLA. Previous work has demonstrated that sequestration of MPLA into the liposomal lipid bilayer can block detection by the Limulus assay, but the binding site on the MPLA to which the Limulus protein binds is unknown. Changes in liposomal Chol concentration and phospholipid fatty acyl chain length influenced the detection of the liposome-embedded MPLA. PMID:25511587

  13. Physical and chemical changes in the foreshore of an estuarine beach: Implications for viability and development of horseshoe crab Limulus polyphemus eggs

    USGS Publications Warehouse

    Jackson, N.L.; Smith, D.R.; Nordstrom, K.F.

    2008-01-01

    Knowledge of conditions that favor development of eggs is important for management of species whose population growth is sensitive to early life history survival. Viability and development of the eggs of horseshoe crabs Limulus polyphemus on a sand and gravel beach were evaluated using data gathered on Delaware Bay, USA, from 18 May to 19 June 2004. Eggs were transplanted to pouches and buried in the foreshore for up to 6 wk. Viability and developmental stage were estimated as a function of oxygen and temperature gradients across the foreshore. These gradients were related to the characteristics of the intertidal foreshore sediments, beach water table changes, and frequency of inundation due to tide and swash/backwash processes. Results demonstrate the importance of interstitial temperature for development to larvae and the passive role of sediment characteristics on moisture retention and temperature. Percentage of eggs remaining in egg stage was similar across the foreshore, but more eggs developed to embryos at 0.45 of foreshore width, where moisture and gravel content were greater and interstitial temperature was lower. More eggs developed to larvae at 0.60 and 0.75 of foreshore width, where moisture and gravel content were less but interstitial temperature was higher. The beach above 0.75 of foreshore width came under the influence of wave action or full tidal inundation only during high wave heights or spring tides, and pouches at 0.75 of foreshore width were inundated only 19% of the time. Periodic wetting at this elevation did not reduce overall viability of the eggs. High wave energy events resulted in sediment activation depths to pouches at 0.30 of foreshore width, where loss of eggs due to wave activation was the most important control on the development of eggs. ?? Inter-Research 2008.

  14. Stable isotope and pen feeding trial studies confirm the value of horseshoe crab Limulus polyphemus eggs to spring migrant shorebirds in Delaware Bay

    USGS Publications Warehouse

    Haramis, G.M.; Link, W.A.; Osenton, P.C.; Carter, Daniel B.; Weber, R.G.; Clark, N.A.; Teece, M.A.; Mizrahi, D.S.

    2007-01-01

    We used stable isotope (SI) methods in combination with pen feeding trials to determine the importance of eggs of the Atlantic horseshoe crab Limulus polyphemus to migratory fattening of red knots Calidris canutus rufa and ruddy turnstones Arenaria interpres morinella during spring stopover in Delaware Bay. By manifesting measurable fractionation (ca +3?) and rapid turnover, blood plasma *15 nitrogen proved a functional marker for SI diet tracking during the short 3-week stopover. Blood samples from free-ranging knots (3 data sets) and turnstones (1 data set) produced similar convergence of plasma *15 N signatures with increasing body mass that indicated highly similar diets. Asymptotes deviated slightly (0.3? to 0.7?) from that of captive shorebirds fed a diet of only crab eggs during stopover, thus confirming a strong crab egg-shorebird linkage. The plasma *15N crab-egg diet asymptote was enriched ca +4.5? and therefore readily discriminated from that of either blue mussels Mytilus edulis or coquina clams Donax variabilis, the most likely alternative prey of knots in Delaware Bay. Crab eggs were highly palatable to captive knots and turnstones which achieved rates of mass gain (3?11 g/d) comparable to that of free-ranging birds. Peak consumption rates during hyperphagic events were 23,940 and 19,360 eggs/bird/d, respectively. The empirical conversions of eggs consumed to body mass gained (5,017 eggs/g for knots and 4,320 eggs/g for turnstones) indicate the large quantities of crab eggs required for the maintenance of these shorebird populations during stopover.

  15. Cytoskeletal F-actin polymerization from cytosolic G-actin occurs in the phagocytosing immunocytes of arthropods (Limulus polyphemus and Gromphadorhina portentosa): does [cAMP]i play any role?

    PubMed

    Gupta, A P; Campenot, E S

    1996-09-01

    Phagocytosis is a major defense reaction in arthropods and is accomplished by two blood cells (hemocytes), the granulocyte (GRs) and plasmatocytes (PLs), collectively called immunocytes. Immunocytes (principally the GRs) from two arthropods, Limulus polyphemus (horseshoe crab) and Gromphadorhina portentosa (Madagascar hissing cockroach) effectively phagocytose fluorescein isothiocyanate (FITC)-conjugated fluoresbrite microspheres (FITC-FM) and chicken (Gallus domesticus) erythrocytes within 1 hr of incubation. Although actin polymerization and changes in intracellular cAMP ([cAMP]i) levels occur during the early stages of phagocytosis in vertebrates, these two phenomena have not been studied in arthropod immunocytes. Using the DNase I inhibition assay, we found a decrease in cytosolic G-actin and an increase in the cytoskeletal F-actin in the phagocytosing immunocytes; the total actin in both resting and phagocytosing immunocytes remained constant. These results showed an 86% increase in F-actin in G. portentosa immunocytes and a 29% increase in those of L. polyphemus after 1 hr of initial incubation with FITC-FM. As in some vertebrates, the role of [cAMP]i in the early stages of phagocytosis in these two animals- and perhaps in arthropods in general-is variable; although we detected some negligible amounts of [cAMP]i (0.10-0.80 pmol/cell at different time intervals) in L. polyphemus immunocytes, it was inconclusive whether those in G. portentosa also contained [cAMP]i. Even in L. polyphemus, the difference in the amounts of [cAMP]i in resting and phagocytosing cells was insignificant (P > 0.05). It was also inconclusive whether [Ca2+]i and/or [Mg2+]i play any roles in the early stages of phagocytosis in the two arthropods in this study. These results suggest that the two phenomena (F-actin polymerization and levels of [cAMP]i in arthropods) are basically similar to those in vertebrate neutrophils and macrophages, which suggests that certain immunological

  16. Structure and stability of arthropodan hemocyanin Limulus polyphemus

    NASA Astrophysics Data System (ADS)

    Dolashka-Angelova, Pavlina; Dolashki, Alexander; Stevanovic, Stefan; Hristova, Rumijana; Atanasov, Boris; Nikolov, Peter; Voelter, Wolfgang

    2005-04-01

    In the hemolymph of many arthropodan species, respiratory copper proteins of high molecular weight, termed hemocyanins (Hcs) are dissolved. In this communication, we report on the protein stability of different hemocyanin species (Crustacea and Chelicerata) using fluorescence spectroscopy. Five to seven major electrophoretically separable protein chains (structural subunits) were purified by fast protein liquid chromatography (FPLC) ion exchange chromatography from different hemocyanins with very high sequence homology of the active site regions binding copper ions (CuA and CuB), and especially the relative sequence positions of histidine (His) and tryptophan (Trp) residues of these protein segments are in all cases identical. The conformational stabilities of the native dodecameric aggregates and their isolated structural subunits towards various denaturants (pH and guanidine hydrochloride (Gdn.HCl)) indicate that the quaternary structure is stabilized by hydrophilic and polar forces, whereby both, the oxy- and apo-forms of the protein are considered. These two classes of Crustacea and Chelicerata Hcs have the similar Trp-fluorescence quantum yields, but different values of λmax emission (about 325 and 337 nm, respectively). Differences in the quantum yields are observed of the oxy- and apo-forms, which must be attributed to the fluorescence quenching effect of the two copper ions (CuA and CuB) in the active site. The position of emission maximum indicates tryptophan side chains are situated in a non-polar environment. Denaturation studies of Hcs by Gdn.HCl indicate that the denaturation process consists of two steps: dissociation of the native molecule into its structural subunits and denaturation of the subunits at concentrations >1.5 M Gdn.HCl. Two steps of denaturation are also observed after keeping the protein in buffer solutions at different pH values with different pH-stability for holo-oxy and apo-Hc forms.

  17. The horseshoe crab of the genus Limulus: living fossil or stabilomorph?

    PubMed

    Kin, Adrian; Błażejowski, Błażej

    2014-01-01

    A new horseshoe crab species, Limulus darwini, is described from the uppermost Jurassic (ca. 148 Ma) near-shore sediments of the Kcynia Formation, central Poland. The only extant species Limulus polyphemus (Linnaeus) inhabits brackish-marine, shallow water environments of the east coast of the United States. Here it is shown that there are no important morphological differences between the Kcynia Formation specimens and extant juvenile representatives of the genus Limulus. The palaeoecological setting inhabited by the new species and the trophic relationships of extant horseshoe crabs are discussed in an attempt to determine the potential range of food items ingested by these Mesozoic xiphosurans. In this paper we propose the adoption of a new term stabilomorphism, this being: an effect of a specific formula of adaptative strategy among organisms whose taxonomic status does not exceed genus-level. A high effectiveness of adaptation significantly reduces the need for differentiated phenotypic variants in response to environmental changes and provides for long-term evolutionary success. PMID:25275563

  18. The Horseshoe Crab of the Genus Limulus: Living Fossil or Stabilomorph?

    PubMed Central

    Błażejowski, Błażej

    2014-01-01

    A new horseshoe crab species, Limulus darwini, is described from the uppermost Jurassic (ca. 148 Ma) near-shore sediments of the Kcynia Formation, central Poland. The only extant species Limulus polyphemus (Linnaeus) inhabits brackish-marine, shallow water environments of the east coast of the United States. Here it is shown that there are no important morphological differences between the Kcynia Formation specimens and extant juvenile representatives of the genus Limulus. The palaeoecological setting inhabited by the new species and the trophic relationships of extant horseshoe crabs are discussed in an attempt to determine the potential range of food items ingested by these Mesozoic xiphosurans. In this paper we propose the adoption of a new term stabilomorphism, this being: an effect of a specific formula of adaptative strategy among organisms whose taxonomic status does not exceed genus-level. A high effectiveness of adaptation significantly reduces the need for differentiated phenotypic variants in response to environmental changes and provides for long-term evolutionary success. PMID:25275563

  19. The ventral photoreceptor cells of Limulus. I. The microanatomy.

    PubMed

    Clark, A W; Millecchia, R; Mauro, A

    1969-09-01

    The ventral photoreceptor cells of Limulus polyphemus resemble the retinular cells of the lateral eyes both in electrical behavior and in morphology. Because of the great size of the ventral photoreceptor cells they are easy to impale with glass capillary micropipettes. Their location along the length of the ventral eye nerve makes them easy to dissect out and fix for electron microscopy. Each cell has a large, ellipsoidal soma that tapers into an axon whose length depends upon the distance of the cell from the brain. The cell body contains a rich variety of cytoplasmic organelles with an especially abundant endoplasmic reticulum. The most prominent structural feature is the microvillous rhabdomere, a highly modified infolding of the plasmalemma. The microvilli are tightly packed together within the rhabdomere, and quintuple-layered junctions are encountered wherever microvillar membranes touch each other. Glial cells cover the surface of the photoreceptor cell and send long, sheet-like projections of their cytoplasm into the cell body of the photoreceptor cell. Some of these projections penetrate the rhabdomere deep within the cell and form quintuple-layered junctions with the microvilli. Junctions between glial cells and the photoreceptor cell and between adjacent glial cells are rarely encountered elsewhere, indicating that there is an open pathway between the intermicrovillous space and the extracellular medium. The axon has a normal morphology but it is electrically inexcitable. PMID:5806591

  20. Opsins in Limulus eyes: characterization of three visible light-sensitive opsins unique to and co-expressed in median eye photoreceptors and a peropsin/RGR that is expressed in all eyes.

    PubMed

    Battelle, Barbara-Anne; Kempler, Karen E; Saraf, Spencer R; Marten, Catherine E; Dugger, Donald R; Speiser, Daniel I; Oakley, Todd H

    2015-02-01

    The eyes of the horseshoe crab Limulus polyphemus have long been used for studies of basic mechanisms of vision, and the structure and physiology of Limulus photoreceptors have been examined in detail. Less is known about the opsins Limulus photoreceptors express. We previously characterized a UV opsin (LpUVOps1) that is expressed in all three types of Limulus eyes (lateral compound eyes, median ocelli and larval eyes) and three visible light-sensitive rhabdomeric opsins (LpOps1, -2 and -5) that are expressed in Limulus lateral compound and larval eyes. Physiological studies showed that visible light-sensitive photoreceptors are also present in median ocelli, but the visible light-sensitive opsins they express were unknown. In the current study we characterize three newly identified, visible light-sensitive rhabdomeric opsins (LpOps6, -7 and -8) that are expressed in median ocelli. We show that they are ocellar specific and that all three are co-expressed in photoreceptors distinct from those expressing LpUVOps1. Our current findings show that the pattern of opsin expression in Limulus eyes is much more complex than previously thought and extend our previous observations of opsin co-expression in visible light-sensitive Limulus photoreceptors. We also characterize a Limulus peropsin/RGR (LpPerOps1). We examine the phylogenetic relationship of LpPerOps1 with other peropsins and RGRs, demonstrate that LpPerOps1 transcripts are expressed in each of the three types of Limulus eyes and show that the encoded protein is expressed in membranes of cells closely associated with photoreceptors in each eye type. These finding suggest that peropsin was in the opsin repertoire of euchelicerates. PMID:25524988

  1. Opsins in Limulus eyes: characterization of three visible light-sensitive opsins unique to and co-expressed in median eye photoreceptors and a peropsin/RGR that is expressed in all eyes

    PubMed Central

    Battelle, Barbara-Anne; Kempler, Karen E.; Saraf, Spencer R.; Marten, Catherine E.; Dugger, Donald R.; Speiser, Daniel I.; Oakley, Todd H.

    2015-01-01

    The eyes of the horseshoe crab Limulus polyphemus have long been used for studies of basic mechanisms of vision, and the structure and physiology of Limulus photoreceptors have been examined in detail. Less is known about the opsins Limulus photoreceptors express. We previously characterized a UV opsin (LpUVOps1) that is expressed in all three types of Limulus eyes (lateral compound eyes, median ocelli and larval eyes) and three visible light-sensitive rhabdomeric opsins (LpOps1, -2 and -5) that are expressed in Limulus lateral compound and larval eyes. Physiological studies showed that visible light-sensitive photoreceptors are also present in median ocelli, but the visible light-sensitive opsins they express were unknown. In the current study we characterize three newly identified, visible light-sensitive rhabdomeric opsins (LpOps6, -7 and -8) that are expressed in median ocelli. We show that they are ocellar specific and that all three are co-expressed in photoreceptors distinct from those expressing LpUVOps1. Our current findings show that the pattern of opsin expression in Limulus eyes is much more complex than previously thought and extend our previous observations of opsin co-expression in visible light-sensitive Limulus photoreceptors. We also characterize a Limulus peropsin/RGR (LpPerOps1). We examine the phylogenetic relationship of LpPerOps1 with other peropsins and RGRs, demonstrate that LpPerOps1 transcripts are expressed in each of the three types of Limulus eyes and show that the encoded protein is expressed in membranes of cells closely associated with photoreceptors in each eye type. These finding suggest that peropsin was in the opsin repertoire of euchelicerates. PMID:25524988

  2. Horseshoe crab (Limulus polyphemus) reproductive activity on Delaware Bay beaches: Interactions with beach characteristics

    USGS Publications Warehouse

    Smith, D.R.; Pooler, P.S.; Loveland, R.E.; Botton, M.L.; Michels, S.F.; Weber, R.G.; Carter, Daniel B.

    2002-01-01

    We used results from a survey of horseshoe crab reproductive activity that was conducted in 1999 throughout Delaware Bay to examine the relationship between estimates of spawning females and egg deposition and analyze how that relationship varies with geography, time within a spawning season, beach morphology, and wave energy. We found that beach morphology and wave energy interacted with density of spawning females to explain variation in the density and distribution of eggs and larvae. For example, the quantity of eggs in surface sediment (i.e., eggs that are potentially available to foraging shorebirds) was associated with the density of spawning females, beach morphology, and wave energy. The association between beach morphology and live eggs in surface sediment was strong especially in late May (Percent Reduction in Error = 86% from regression tree model) where egg density was an order of magnitude higher on beaches <15 m wide (3.38*105 m-2; 90% CI: 2.29*105, 4.47*105) compared to wider beaches (1.49*104 m-2; 90% CI: 4.47*103, 2.53*104). Results also indicate that, among bay-front beaches, horseshoe crabs prefer to spawn on narrow beaches, possibly because of reduced wave energy. At peak periods of spawning activity, density of spawning females was inversely related to foreshore width on mid-latitude beaches within Delaware Bay (t = -2.68, 7 df, p = 0.03). Because the distribution of eggs across the foreshore varied with beach morphology and widened as the spawning season progressed, methods used to sample eggs need to be robust to variation in beach morphology and applicable regardless of when the samples are taken. Because beach morphology and wave energy were associated with the quantity of eggs in surface sediment, certain beach types may be critical to the conservation of shorebird foraging habitat.

  3. Opsin expression in Limulus eyes: a UV opsin is expressed in each eye type and co-expressed with a visible light-sensitive opsin in ventral larval eyes

    PubMed Central

    Battelle, Barbara-Anne; Kempler, Karen E.; Harrison, Alexandra; Dugger, Donald R.; Payne, Richard

    2014-01-01

    The eyes of the horseshoe crab, Limulus polyphemus, are a model for studies of visual function and the visual systems of euarthropods. Much is known about the structure and function of L. polyphemus photoreceptors, much less about their photopigments. Three visible-light-sensitive L. polyphemus opsins were characterized previously (LpOps1, 2 and 5). Here we characterize a UV opsin (LpUVOps1) that is expressed in all three types of L. polyphemus eyes. It is expressed in most photoreceptors in median ocelli, the only L. polyphemus eyes in which UV sensitivity was previously detected, and in the dendrite of eccentric cells in lateral compound eyes. Therefore, eccentric cells, previously thought to be non-photosensitive second-order neurons, may actually be UV-sensitive photoreceptors. LpUVOps1 is also expressed in small photoreceptors in L. polyphemus ventral larval eyes, and intracellular recordings from these photoreceptors confirm that LpUVOps1 is an active, UV-sensitive photopigment. These photoreceptors also express LpOps5, which we demonstrate is an active, long-wavelength-sensitive photopigment. Thus small photoreceptors in ventral larval eyes, and probably those of the other larval eyes, have dual sensitivity to UV and visible light. Interestingly, the spectral tuning of small ventral photoreceptors may change day to night, because the level of LpOps5 in their rhabdoms is lower during the day than during the night, whereas LpUVOps1 levels show no diurnal change. These and previous findings show that opsin co-expression and the differential regulation of co-expressed opsins in rhabdoms is a common feature of L. polyphemus photoreceptors. PMID:24948643

  4. Opsin expression in Limulus eyes: a UV opsin is expressed in each eye type and co-expressed with a visible light-sensitive opsin in ventral larval eyes.

    PubMed

    Battelle, Barbara-Anne; Kempler, Karen E; Harrison, Alexandra; Dugger, Donald R; Payne, Richard

    2014-09-01

    The eyes of the horseshoe crab, Limulus polyphemus, are a model for studies of visual function and the visual systems of euarthropods. Much is known about the structure and function of L. polyphemus photoreceptors, much less about their photopigments. Three visible-light-sensitive L. polyphemus opsins were characterized previously (LpOps1, 2 and 5). Here we characterize a UV opsin (LpUVOps1) that is expressed in all three types of L. polyphemus eyes. It is expressed in most photoreceptors in median ocelli, the only L. polyphemus eyes in which UV sensitivity was previously detected, and in the dendrite of eccentric cells in lateral compound eyes. Therefore, eccentric cells, previously thought to be non-photosensitive second-order neurons, may actually be UV-sensitive photoreceptors. LpUVOps1 is also expressed in small photoreceptors in L. polyphemus ventral larval eyes, and intracellular recordings from these photoreceptors confirm that LpUVOps1 is an active, UV-sensitive photopigment. These photoreceptors also express LpOps5, which we demonstrate is an active, long-wavelength-sensitive photopigment. Thus small photoreceptors in ventral larval eyes, and probably those of the other larval eyes, have dual sensitivity to UV and visible light. Interestingly, the spectral tuning of small ventral photoreceptors may change day to night, because the level of LpOps5 in their rhabdoms is lower during the day than during the night, whereas LpUVOps1 levels show no diurnal change. These and previous findings show that opsin co-expression and the differential regulation of co-expressed opsins in rhabdoms is a common feature of L. polyphemus photoreceptors. PMID:24948643

  5. The ventral photoreceptor cells of Limulus. II. The basic photoresponse.

    PubMed

    Millecchia, R; Mauro, A

    1969-09-01

    The ventral photoreceptors of Limulus polyphemus are unipolar cells with large, ellipsoidal somas located long both "lateral olfactory nerves." As a consequence of their size and location, the cells are easily impaled with microelectrodes. The cells have an average resting potential of -48 mv. The resting potential is a function of the external concentration of K. When the cell is illuminated, it gives rise to the typical "receptor potential" seen in most invertebrate photoreceptors which consists of a transient phase followed by a maintained phase of depolarization. The amplitude of the transient phase depends on both the state of adaptation of the cell and the intensity of the illumination, while the amplitude of the maintained phase depends only on the intensity of the illumination. The over-all size of the receptor potential depends on the external concentration of Na, e.g. in sodium-free seawater the receptor potential is markedly reduced, but not abolished. On the other hand lowering the Ca concentration produces a marked enhancement of both components of the response, but predominantly of the steady-state component. Slow potential fluctuations are seen in the dark-adapted cell when it is illuminated with a low intensity light. A spike-like regenerative process can be evoked by either the receptor potential or a current applied via a microelectrode. No evidence of impulse activity has been found in the axons of these cells. The ventral photoreceptor cell has many properties in common with a variety of retinular cells and therefore should serve as a convenient model of the primary receptor cell in many invertebrate eyes. PMID:5806592

  6. Clicking caterpillars: acoustic aposematism in Antheraea polyphemus and other Bombycoidea.

    PubMed

    Brown, Sarah G; Boettner, George H; Yack, Jayne E

    2007-03-01

    Acoustic signals produced by caterpillars have been documented for over 100 years, but in the majority of cases their significance is unknown. This study is the first to experimentally examine the phenomenon of audible sound production in larval Lepidoptera, focusing on a common silkmoth caterpillar, Antheraea polyphemus (Saturniidae). Larvae produce airborne sounds, resembling ;clicks', with their mandibles. Larvae typically signal multiple times in quick succession, producing trains that last over 1 min and include 50-55 clicks. Individual clicks within a train are on average 24.7 ms in duration, often consisting of multiple components. Clicks are audible in a quiet room, measuring 58.1-78.8 dB peSPL at 10 cm. They exhibit a broadband frequency that extends into the ultrasound spectrum, with most energy between 8 and 18 kHz. Our hypothesis that clicks function as acoustic aposematic signals, was supported by several lines of evidence. Experiments with forceps and domestic chicks correlated sound production with attack, and an increase in attack rate was positively correlated with the number of signals produced. In addition, sound production typically preceded or accompanied defensive regurgitation. Bioassays with invertebrates (ants) and vertebrates (mice) revealed that the regurgitant is deterrent to would-be predators. Comparative evidence revealed that other Bombycoidea species, including Actias luna (Saturniidae) and Manduca sexta (Sphingidae), also produce airborne sounds upon attack, and that these sounds precede regurgitation. The prevalence and adaptive significance of warning sounds in caterpillars is discussed. PMID:17337712

  7. Spike firing pattern of output neurons of the Limulus circadian clock.

    PubMed

    Liu, Jiahui S; Passaglia, Christopher L

    2011-08-01

    The lateral eyes of the horseshoe crab (Limulus polyphemus) show a daily rhythm in visual sensitivity that is mediated by efferent nerve signals from a circadian clock in the crab's brain. How these signals communicate circadian messages is not known for this or other animals. Here the authors describe in quantitative detail the spike firing pattern of clock output neurons in living horseshoe crabs and discuss its possible significance to clock organization and function. Efferent fiber spike trains were recorded extracellularly for several hours to days, and in some cases, the electroretinogram was simultaneously acquired to monitor eye sensitivity. Statistical features of single- and multifiber recordings were characterized via interval distribution, serial correlation, and power spectral analysis. The authors report that efferent feedback to the eyes has several scales of temporal structure, consisting of multicellular bursts of spikes that group into clusters and packets of clusters that repeat throughout the night and disappear during the day. Except near dusk and dawn, the bursts occur every 1 to 2 sec in clusters of 10 to 30 bursts separated by a minute or two of silence. Within a burst, each output neuron typically fires a single spike with a preferred order, and intervals between bursts and clusters are positively correlated in length. The authors also report that efferent activity is strongly modulated by light at night and that just a brief flash has lasting impact on clock output. The multilayered firing pattern is likely important for driving circadian rhythms in the eye and other target organs. PMID:21775292

  8. Isopotentiality and an optical determination of series resistance in Limulus ventral photoreceptors.

    PubMed Central

    Brown, J E; Harary, H H; Waggoner, A

    1979-01-01

    1. Photoreceptor somas in the ventral rudimentary eye of Limulus polyphemus were impaled with three micropipettes. Two micropipettes were connected in a voltage-clamp circuit and the cells were stimulated by brief flashes. The third micropipette did not measure any significant deviations from the 'clamped' voltage during responses to the flashes, in several geometries of electrode placement, even for very bright flashes. Therefore using the described techniques there is no evidence for spatial non-uniformity of intracellular voltage in the soma of these photoreceptors. 2. A voltage-sensitive dye was used to monitor light-induced changes in membrane voltage while intracellular voltage was held clamped by a feed-back circuit. With a known series resistance connected between the bath and ground the dye recorded a light-induced change in membrane voltage. When there was no added series resistance, the light-induced change was smaller and often undetectable. From these data the naturally occurring series resistance was calculated to be less than or equal to 30 k omega. 3. From these measurements, as well as from calculations for a model spherical cell, we conclude that membrane potential can be controlled to within 2 mV using our micropipette 'point clamp' methods, for all but the brightest stimuli. PMID:529105

  9. Delivery and movement of horseshoe crab eggs (Limulus polyphemus) in the breaking waves and swash uprush of an estuarine foreshore

    NASA Astrophysics Data System (ADS)

    Jackson, Nancy L.; Nordstrom, Karl F.; Smith, David R.; Saini, Sherestha

    2014-01-01

    Knowledge of conditions for entrainment of eggs and larvae from beach spawning sites is critical in determining the likelihood that these food sources will be delivered to shorebirds. The exhumation of horseshoe crab eggs buried within the beach foreshore is a function of changes in wave and current velocities over a tidal cycle. This field study was conducted to evaluate the temporal constraints to egg release at two different locations across the foreshore of a sandy estuarine beach in Delaware Bay, New Jersey. Wind, wave, current characteristics, beach change and eggs in transport were sampled over two tidal cycles. Egg counts were determined using four colors of dyed-egg tracers placed as point sources 5 and 10 m bayward of the expected upper limit of swash. Tracer recovery varied from 1% to 18% of the tracer eggs buried. Wave heights were relatively low (instrumented Hs = 0.09-0.17 m) but with long periods (5.6-8.8 s). Results reveal that egg release is discontinuous and occurs in pulses when the swash and breakers migrate across the injection points on the rising tide and when the breakers migrate past the injection points during the falling tide. A lack of tracer at the upper (5 m) injection point after early stages of high tide is likely due to the maximum disturbance depth being achieved early, leaving no eggs within the swash boundary layer. Peaks in recovery of tracer initially buried at the lower (10 m) location after the breakers migrated up the foreshore well past the injection location are likely from eggs deposited in the wrack on the upper beach or reburied in the sediment near the upper limit of swash and remobilized by high swash uprushes. These results using point sources of tracer eggs suggest that the contribution of eggs from within the beach matrix is temporally variable across the foreshore. Most eggs are released during rising tide, but additional eggs can be released during falling tide if the depth of activation of the bed is greater than on the rise due to net erosion or change to higher wave-energy conditions. Successful shorebird foraging at other times in the falling tide appears due to transport of eggs released earlier in the tidal cycle and delivered alongshore and not due to eggs exhumed in-situ at that time.

  10. Molecular cloning of a cDNA for a putative choline co-transporter from Limulus CNS.

    PubMed

    Wang, Y; Cao, Z; Newkirk, R F; Ivy, M T; Townsel, J G

    2001-05-01

    It is well documented that the sodium dependent, hemicholinium-3 sensitive, high affinity choline co-transporter is rate limiting in the biosynthesis of acetylcholine and is essential to cholinergic transmission. Until recently this transporter had eluded cloning. Okuda et al. (2000. Nature Neurosci. 3, 120-125) recently reported the successful cloning of the choline co-transporter in Caenorhabditis elegans (CHO-1) and rat (CHT1). We report herein the cloning of the choline co-transporter in the horseshoe crab, Limulus polyphemus. Through the use of a series of degenerate primers selected from consensus sequences of CHO-1 and CHT1, we generated two probes that were used to search a Limulus cDNA library produced from central nervous system (CNS) tissue. The full length nucleotide sequence of the Limulus homolog consists of 3368 bp which includes an open reading frame (ORF) that predicts a protein of 579 amino acids and two non-translation regions (NTR), one at the 3' end and the other at the 5' end. The amino acid sequence has 46% identity with rat CHT1 and 50% identity with both CHO-1 in C. elegans and the recently cloned human co-transporter (hCHT; Apparsundaram et al., 2000. Biochem. Biophys. Res. Commun. 276, 862-867; Okuda and Haga, 2000. FEBS Lett. 484, 92-97). Hydropathy plot analysis predicts the Limulus choline co-transporter (LChCoT) to have thirteen transmembrane domains (TMD), with the N-terminus oriented extracellularly and the C-terminus oriented intracellularly. Northern blot analyses using cDNA probes designed from LChCoT cDNA sequences revealed its distribution specifically in central nervous system structures. On the other hand it was not found in non-nervous tissues. The successful cloning of LChCoT, which was shown to be a member of the sodium-dependent glucose transporter family (SLGT), should prove useful in the determination of its physiological regulation, including its intracellular trafficking. PMID:11368908

  11. Limulus psychophysics: spectral sensitivity of the ventral eye.

    PubMed

    Wasserman, G S

    1976-09-01

    The ventral eye of Limulus contains only one type of photoreceptor. Behaviors mediated by the ventral eye provide an unambiguous representation of the function of that single-receptor type. Such behaviors can be compared with the results of acute, single-cell investigations to assay for the contributions of candidate neural codes in the regulation of behavior (cf. Uttal, 1973). Using an unconditioned tail movement as the response, the psychophysical spectral sensitivity function mediated by the ventral eye of Limulus was measured. This psychophysical function peaked at 525 nm and showed evidence of strong absorption by the cuticle in the short-wavelength portion of the spectrum. Under the conditions of the present experiment, the threshold was 4.5 quanta absorbed per receptor per msec at 525 nm. The spectral transmission of the ventral eye cuticle was also measured. After correction for cuticle absorption, the psychophysical spectral sensitivity function was compared with previously reported spectral sensitivity functions obtained either from electrophysiologic (Millecchia, Bradbury, and Mauro, 1966; Nolte and Brown, 1970) or from microspectrophotometric (Murry, 1966) recordings from single, isolated ventral eye photoreceptor cells. All three functions exhibit a sensitivity peak near 525 nm; the corrected psychophysical and microspectrophotometric functions both display a second peak near 425 nm. A second experiment confirmed the reliability and validity of the 425-nm peak. The coding implications of these findings were explored. A preliminary finding is that, in dichromatic or trichromatic visual systems, two-peaked receptor spectral sensitivity functions produce central, opponent response systems that are qualitatively the same as those produced by single-peaked receptors. PMID:978142

  12. Internal dialysis of Limulus ventral photoreceptors.

    PubMed Central

    Stern, J H; Lisman, J E

    1982-01-01

    The internal dialysis technique has been applied to Limulus ventral photoreceptors. This method potentially allows quantitative control of the concentration of diffusible molecules within living cells. During dialysis, Limulus photoreceptors retained their ability to respond to light. Under conditions of dim illumination, responses were normal for close to an hour. In bright light, abnormalities developed more rapidly. The reversible effects of raising the dialysate Mg2+ concentration and the entrance of rhodamine-labeled albumin into cells shows that the dialysis method is useful for assaying the effects of small or large molecules on visual transduction. This method has been used to examine the effects of nucleotide triphosphates and cyclic nucleotides. The results show that nucleotide triphosphates (5-10 mM) are required to maintain a low rate of spontaneous quantum bumps. The importance of cyclic nucleotides in transduction is less clear; the light response was reduced by either cGMP or cAMP but only at very high concentrations (10 mM). Images PMID:6961434

  13. Mechanism of interaction of optimized Limulus-derived cyclic peptides with endotoxins: thermodynamic, biophysical and microbiological analysis

    PubMed Central

    Andrä, Jörg; Howe, Jörg; Garidel, Patrick; Rössle, Manfred; Richter, Walter; Leiva-León, José; Moriyon, Ignacio; Bartels, Rainer; Gutsmann, Thomas; Brandenburg, Klaus

    2007-01-01

    On the basis of formerly investigated peptides corresponding to the endotoxin-binding domain from LALF [Limulus anti-LPS (lipopolysaccharide) factor], a protein from Limulus polyphemus, we have designed and synthesized peptides of different lengths with the aim of obtaining potential therapeutic agents against septic shock syndrome. For an understanding of the mechanisms of action, we performed a detailed physicochemical and biophysical analysis of the interaction of rough mutant LPS with these peptides by applying FTIR (Fourier-transform infrared) spectroscopy, SAXS (small-angle X-ray scattering), calorimetric techniques [DSC (differential scanning calorimetry) and ITC (isothermal titration calorimetry)] and FFTEM (freeze-fracture transmission electron microscopy). Also, the action of the peptides on bacteria of different origin in microbial assays was investigated. Using FTIR and DSC, our results indicated a strong fluidization of the lipid A acyl chains due to peptide binding, with a decrease in the endothermic melting enthalpy change of the acyl chains down to a complete disappearance in the 1:0.5 to 1:2 [LPS]:[peptide] molar ratio range. Via ITC, it was deduced that the binding is a clearly exothermic process which becomes saturated at a 1:0.5 to 1:2 [LPS]:[peptide] molar ratio range. The results obtained with SAXS indicated a drastic change of the aggregate structures of LPS into a multilamellar stack, which was visualized in electron micrographs as hundreds of lamellar layers. This can be directly correlated with the inhibition of the LPS-induced production of tumour necrosis factor α in human mononuclear cells, but not with the action of the peptides on bacteria. PMID:17501719

  14. Multiple paternity and breeding system in the gopher tortoise, Gopherus polyphemus.

    PubMed

    Moon, Jamie C; McCoy, Earl D; Mushinsky, Henry R; Karl, Stephen A

    2006-01-01

    Little is known about the reproductive behaviors and the actual outcomes of mating attempts in the gopher tortoise (Gopherus polyphemus). We examined the mating system and reproductive behaviors of a population of gopher tortoises in central Florida. Using microsatellite markers, we assigned fathers to the offspring of seven clutches and determined that multiple fathers were present in two of the seven clutches examined. We found that gopher tortoises exhibited a promiscuous mating system with larger males fertilizing the majority of clutches. The advantage of larger males over smaller males in fertilizing females may be a result of larger males winning access to females in aggressive bouts with other males or larger males may be more attractive to females. Clutches produced by larger females tended to be sired by a single male, whereas clutches of smaller females tended to be sired by multiple males. PMID:16489146

  15. Abundance of adult horseshoe crabs (Limulus polylphemus) in Delaware Bay estimated from a bay-wide mark-recapture study

    USGS Publications Warehouse

    Smith, D.R.; Millard, M.J.; Eyler, S.

    2006-01-01

    Estimates of the abundance of American horseshoe crabs (Limulus polyphemus) are important to determine egg production and to manage populations for the energetic needs of shorebirds that feed on horseshoe crab eggs. In 2003, over 17,500 horseshoe crabs were tagged and released throughout Delaware Bay, and recaptured crabs came from spawning surveys that were conducted during peak spawning. We used two release cohorts to test for a temporary effect of tagging on spawning behavior and we adjusted the number of releases according to relocation rates from a telemetry study. The abundance estimate was 20 million horseshoe crabs (90% confidence interval: 13-28 million), of which 6.25 million (90% CI: 4.0-8.8 million) were females. The combined harvest rate for Delaware, New Jersey, Virginia, and Maryland in 2003 was 4% (90% CI: 3-6%) of the abundance estimate. Over-wintering of adults in Delaware Bay could explain, in part, differences in estimates from ocean-trawl surveys. Based on fecundity of 88,000 eggs per female, egg production was 5.5??1011 (90% CI: 3.5??1011, 7.7??1011), but egg availability for shorebirds also depended on overlap between horseshoe crab and shorebird migrations, density-dependent bioturbation, and wave-mediated vertical transport.

  16. Limulus vision in the marine environment.

    PubMed

    Barlow, R B; Hitt, J M; Dodge, F A

    2001-04-01

    Horseshoe crabs use vision to find mates. They can reliably detect objects resembling potential mates under a variety of lighting conditions. To understand how they achieve this remarkable performance, we constructed a cell based realistic model of the lateral eye to compute the ensembles of optic nerve activity ("neural images") it transmits to the brain. The neural images reveal a robust encocding of mate-like objects that move underwater during the day. The neural images are much less clear at night, even though the eyes undergo large circadian increases of sensitivity that nearly compensate for the millionfold decreasein underwater lighting after sundown. At night the neurral images are noisy, dominated by bursts of nerve impulses from random photon events that occur at low nighttime levels of illumination. Deciphering the eye's input to the brain begins at the first synaptic level with lowpass temporal and spatial filtering. Both neural filtering mechanisms improve the signal-to-noise properties of the eye's input, yielding clearer neural images of potential mates, especiallyat night. Insights about visual processing by the relatively simple visual system of Limulus may aid in the designof robotic sensors for the marine environment. PMID:11341579

  17. Salmonella from gopher tortoises (Gopherus polyphemus) in south Georgia.

    PubMed

    Lockhart, J Mitchell; Lee, Gregory; Turco, Jenifer; Chamberlin, Linda

    2008-10-01

    From 2002 to 2006, gopher tortoises (Gopherus polyphemus) were collected at Moody Air Force Base, Lowndes/Lanier counties, Georgia, USA, and opportunistically surveyed for the presence of Salmonella species. Four of 155 (2.6%) cloacal swabs collected from 80 tortoises were positive for the presence of Salmonella enterica, and the following serovars were identified: Give, Hartford, Javiana, and Luciana. Female tortoises (5%) were infected at a rate similar to male tortoises (5%). All isolates were obtained from adult tortoises (n = 73); subadults (n = 7) were all negative. Each isolated serovar is a potential human pathogen, suggesting appropriate precautions should be emphasized when handling these animals. PMID:18957656

  18. "Limulus" Psychophysics: Spectral Sensitivity of the Ventral Eye

    ERIC Educational Resources Information Center

    Wasserman, Gerald S.

    1976-01-01

    The ventral eye of "Limulus" (horseshoe crab) contains only one type of photoreceptor. Behaviors mediated by the ventral eye provide an unambiguous representation of the function of that single-receptor type. Compares such behaviors with results of acute, single-cell investigations to assay for the contributions of candidate neural codes in the…

  19. Biochemical principle of Limulus test for detecting bacterial endotoxins

    PubMed Central

    Iwanaga, Sadaaki

    2007-01-01

    A hemocyte lysate from horseshoe crab (Limulus) produced a gel, when exposed to Gram-negative bacterial endotoxins, lipopolysaccharides (LPS). This gelation reaction of the lysate, so-called Limulus test, has been widely employed as a simple and very sensitive assay method for endotoxins. Recent biochemical studies on the principle of Limulus test indicate that the hemocytes contain several serine protease zymogens, which constitute a coagulation cascade triggered by endotoxins, and that there is a (1,3)-β-D-glucan-mediated coagulation pathway which also results in the formation of gel. Up to now, six protein components, designated coagulogen, proclotting enzyme, factor B, factor C, and factor G, all of which are closely associated with the endotoxin-mediated coagulation pathway, have been purified and biochemically characterized. The molecular structures of these proteins have also been elucidated. Moreover, the reconstitution experiments using the isolated clotting factors, factor C, factor B, proclotting enzyme and coagulogen in the presence of endotoxin, leads to the formation of coagulin gel. Here, I will focus on the biochemical principle of Limulus test for detecting bacterial endotoxins, and its activation and regulation mechanism on the LPS-mediated coagulation cascade. PMID:24019589

  20. Opsin1-2, G(q)α and arrestin levels at Limulus rhabdoms are controlled by diurnal light and a circadian clock.

    PubMed

    Battelle, Barbara-Anne; Kempler, Karen E; Parker, Alexander K; Gaddie, Cristina D

    2013-05-15

    Dark and light adaptation in photoreceptors involve multiple processes including those that change protein concentrations at photosensitive membranes. Light- and dark-adaptive changes in protein levels at rhabdoms have been described in detail in white-eyed Drosophila maintained under artificial light. Here we tested whether protein levels at rhabdoms change significantly in the highly pigmented lateral eyes of wild-caught Limulus polyphemus maintained in natural diurnal illumination and whether these changes are under circadian control. We found that rhabdomeral levels of opsins (Ops1-2), the G protein activated by rhodopsin (G(q)α) and arrestin change significantly from day to night and that nighttime levels of each protein at rhabdoms are significantly influenced by signals from the animal's central circadian clock. Clock input at night increases Ops1-2 and G(q)α and decreases arrestin levels at rhabdoms. Clock input is also required for a rapid decrease in rhabdomeral Ops1-2 beginning at sunrise. We found further that dark adaptation during the day and the night are not equivalent. During daytime dark adaptation, when clock input is silent, the increase of Ops1-2 at rhabdoms is small and G(q)α levels do not increase. However, increases in Ops1-2 and G(q)α at rhabdoms are enhanced during daytime dark adaptation by treatments that elevate cAMP in photoreceptors, suggesting that the clock influences dark-adaptive increases in Ops1-2 and G(q)α at Limulus rhabdoms by activating cAMP-dependent processes. The circadian regulation of Ops1-2 and G(q)α levels at rhabdoms probably has a dual role: to increase retinal sensitivity at night and to protect photoreceptors from light damage during the day. PMID:23393287

  1. Fungal keratitis in a gopher tortoise (Gopherus polyphemus).

    PubMed

    Myers, Debbie A; Isaza, Ramiro; Ben-Shlomo, Gil; Abbott, Jeffrey; Plummer, Caryn E

    2009-09-01

    A free-ranging gopher tortoise (Gopherus polyphemus) presented for trauma and blindness. Fibrinous exudate obscured visualization of the globes. This exudative crust extended from the conjunctival fornices through the palpebral fissure and was manually removed. Ophthalmic examination revealed bilateral corneal ulcerations and scarring and phthisis bulbi of the left globe. Histology of the crust revealed a necrotic conjunctivitis with intralesional fungal hyphae. Culture of the corneal ulcer of the left eye isolated moderate growth of a mixed fungal flora consisting of Curvularia sp. and Aspergillus sp. Miconazole ophthalmic solution was administered and the ulcers in both eyes healed, but corneal edema continued. After 2 mo of treatment with miconazole, tramadol, acetylcysteine, hypertonic saline ointment, artificial tears, and hypertonic saline flushes, the right eye was normal with only a small scar. The left eye remained phthisical. This is the first report of fungal keratitis in a wild reptile and a gopher tortoise. PMID:19746878

  2. Looking like Limulus? – Retinula axons and visual neuropils of the median and lateral eyes of scorpions

    PubMed Central

    2013-01-01

    Background Despite ongoing interest in the neurophysiology of visual systems in scorpions, aspects of their neuroanatomy have received little attention. Lately sets of neuroanatomical characters have contributed important arguments to the discussion of arthropod ground patterns and phylogeny. In various attempts to reconstruct phylogeny (from morphological, morphological + molecular, or molecular data) scorpions were placed either as basalmost Arachnida, or within Arachnida with changing sister-group relationships, or grouped with the extinct Eurypterida and Xiphosura inside the Merostomata. Thus, the position of scorpions is a key to understanding chelicerate evolution. To shed more light on this, the present study for the first time combines various techniques (Cobalt fills, DiI / DiO labelling, osmium-ethyl gallate procedure, and AMIRA 3D-reconstruction) to explore central projections and visual neuropils of median and lateral eyes in Euscorpius italicus (Herbst, 1800) and E. hadzii Di Caporiacco, 1950. Results Scorpion median eye retinula cells are linked to a first and a second visual neuropil, while some fibres additionally connect the median eyes with the arcuate body. The lateral eye retinula cells are linked to a first and a second visual neuropil as well, with the second neuropil being partly shared by projections from both eyes. Conclusions Comparing these results to previous studies on the visual systems of scorpions and other chelicerates, we found striking similarities to the innervation pattern in Limulus polyphemus for both median and lateral eyes. This supports from a visual system point of view at least a phylogenetically basal position of Scorpiones in Arachnida, or even a close relationship to Xiphosura. In addition, we propose a ground pattern for the central projections of chelicerate median eyes. PMID:23842208

  3. A Stochastic Model for Discrete Waves in the Limulus Photoreceptor

    PubMed Central

    Srebro, Richard; Behbehani, Mahmood

    1971-01-01

    A stochastic model that links the absorption of a photon to the production of a discrete wave in the photoreceptor of the lateral eye of Limulus is proposed. By separating a discrete wave into an initial component due directly to the absorption of a photon, and a second quasi all-or-nothing component, a mathematical description of the latencies of discrete waves is deduced and some important features of their time courses are suggested. The predictions of the model are compared to observations from 60 different ommatidia. PMID:5095679

  4. Seasonal changes in sex and adrenal steroid hormones of gopher tortoises (Gopherus polyphemus).

    PubMed

    Ott, J A; Mendonça, M T; Guyer, C; Michener, W K

    2000-02-01

    We sampled a population of gopher tortoises (Gopherus polyphemus) from May to October 1997 to determine seasonal cycles of steroid hormones (testosterone, T; 17beta-estradiol, E; and progesterone, P) and related them to observations of mating behavior. In males, plasma T levels peaked in July and August and remained elevated through October. This coincides with the reported time of peak mating and spermatogenesis, indicating that males display an associated pattern of reproduction. In females, E levels were high in September and October. Plasma T levels in females were elevated in May, decreased to basal levels in June and July, and rose again in August and September. Elevated E and T levels correspond to the reported time of peak vitellogenic activity, indicating that females also display an associated cycle. Plasma P in females remained basal throughout the active season, suggesting that ovulation occurs in late winter. We also determined levels of corticosterone (B) to assess the influence of capture stress on tortoises and correlated B levels with tortoise activity patterns and sex steroid levels. We found no seasonal variation in levels of B in males or females. Plasma B levels were not correlated with levels of T or E, but were positively correlated with female P levels. Further, we found no relationship between plasma B levels in males and mean distance moved, mean number of burrows used, or mean home range size. However, there was a significant negative correlation between plasma B levels and male body size. In females, there was no relationship between B levels and mean distance moved, but B levels were significantly negatively correlated with the number of burrows females occupied. Lastly, there was no relationship between levels of B and the number of minutes required to obtain blood from an animal. However, B levels increased with the length of time that a tortoise spent in a trap, suggesting that trapped tortoises do exhibit capture stress. PMID

  5. CIRCUS MOVEMENTS OF LIMULUS AND THE TROPISM THEORY.

    PubMed

    Cole, W H

    1923-03-20

    1. Under laboratory conditions Limulus from 20 to 60 mm. in diameter are positively phototropic, and execute circus movements towards the normal side, when the median and the opposite lateral eyes are removed or covered. 2. The phototropism of Limulus may be modified or obliterated by (a) fright, (b) hunger, (c) stereotropism, (d) photokinesis, and (e) unknown stimuli. 3. Quantitative measurements of the paths of animals doing circus movements demonstrate that the amount of turning varies directly with the light intensity as follows: for 8,000 candle meters the degrees turned per centimeter were 6.73; for 2,000 candle meters, 5.23; and for 900 candle meters, 4.78. In other words, the diameter of the circle varies inversely with the light intensity. 4. The rate of locomotion per minute also varies directly with the light intensity, being 178 cm. for 8,000 candle meters, 167 for 2,000, and 157 for 900. 5. These reactions are satisfactorily explained by the tropism theory. PMID:19872007

  6. The thermal origin of spontaneous activity in the Limulus photoreceptor

    PubMed Central

    Srebro, Richard; Behbehani, Mahmood

    1972-01-01

    1. Discrete depolarizations of the photoreceptor cell membrane called discrete waves occur spontaneously and in response to illumination in the eye of the horseshoe crab, Limulus. Each light induced discrete wave is caused by the absorption of a single photon. 2. The frequencies of spontaneous and light induced discrete waves were studied at different temperatures from 0 to 25° C using a new method of counting them to avoid errors due to their temporal overlap. 3. The frequency of spontaneous discrete waves followed the Arrhenius relationship with activation energy equal to 48·6 kcal. 4. The frequency of the discrete waves caused by a fixed level of steady illumination was not significantly changed when the temperature of the cell was changed. 5. The relationship of the frequency of spontaneous discrete waves to temperature was compared to a prediction based on the relationship of the quantum relative spectral sensitivity of the Limulus eye to the temperature of the eye. The prediction was in good agreement with observation and suggests that spontaneous discrete waves result from thermally induced cis to trans isomerizations of visual pigment molecules. PMID:5071400

  7. The quantal source of area supralinearity of flash responses in Limulus photoreceptors

    PubMed Central

    1988-01-01

    The time integrals of the responses of dark-adapted Limulus ventral photoreceptors to flashes exhibit a supralinear dependence on intensity at intermediate intensities. By decomposing the responses into their elementary single-photon components ("bumps"), we are able to calculate the overall quantum efficiency and to display the time courses of the bump amplitude and rate of appearance. Since the time course of the flash response is not slow compared with that of the bump, it was necessary, in order to carry out the decomposition, to develop a new technique for noise analysis of dynamic signals. This new technique should have wide applications. Our main finding is that the supralinearity of the flash responses corresponds to an increase in bump amplitude, with little change in bump duration or quantum efficiency. The time courses of the bump rate and of the change in bump amplitude are peaked and have widths similar to that of the response itself. The peaks of the time courses of the bump rate and amplitude displayed against the starting times of the bumps do not coincide and occur approximately 80 and approximately 40 ms, respectively, before the peak of the response. The time from the start of a bump to its centroid is approximately 70 ms, which means that the time at which the bump centroid reaches its maximum follows the response peak by 30 ms. These results impose constraints on possible mechanisms for the amplitude enhancement. PMID:3418317

  8. 3',5'-cyclic adenosine monophosphate and adenylate cyclase in phototransduction by limulus ventral photoreceptors.

    PubMed Central

    Brown, J E; Kaupp, U B; Malbon, C C

    1984-01-01

    Biochemical and electrophysiological measurements were made on photoreceptor cells from Limulus ventral eyes to investigate the possible role of cyclic AMP and adenylate cyclase in the visual transduction mechanism. Cyclic AMP content in a photoreceptor-enriched fraction (the end organs) of Limulus ventral eyes was approximately 15 pmol/mg protein. The cyclic AMP content was increased by bathing eyes in 1-methyl-3-isobutyl xanthine or forskolin and was increased almost 100-fold when bathed in both. Illumination did not change cyclic AMP content significantly in any of these conditions. Discrete events that can be recorded electrophysiologically occur spontaneously in darkness. An increase in the frequency of discrete events is evoked by dim illumination. The discrete events are a sign of excitation of Limulus photoreceptor cells. Drug-induced changes in the rate of occurrence of discrete events recorded electrophysiologically in darkness were not correlated with changes in cyclic AMP content. Adenylate cyclase activity measured from a small number of pooled photoreceptor clusters was stimulated by fluoride and vanadate ions, hydrolysis-resistant analogues of GTP, cholera toxin and forskolin. The Limulus enzyme is similar pharmacologically to mammalian and avian adenylate cyclases. Activation of adenylate cyclase by drugs was not correlated with changes in the rate of occurrence of discrete events recorded electrophysiologically in darkness. A heat-treated Lubrol extract of membranes from Limulus ventral eyes reconstituted the adenylate cyclase activity of membranes from S49 mouse lymphoma cyc- mutant cells which lack a functional regulatory protein. These findings suggest that Limulus ventral eye photoreceptors contain a regulatory protein that mediates the activation of adenylate cyclase by guanine nucleotides, fluoride or cholera toxin. This regulatory protein is homologous with that found in mammalian and avian adenylate cyclases. Our findings suggest that

  9. A comparison of artificial incubation and natural incubation hatching success of gopher tortoise (Gopherus polyphemus) eggs in southern Mississippi

    USGS Publications Warehouse

    Noel, Krista M.; Qualls, Carl P.; Ennen, Joshua R.

    2012-01-01

    Recent studies have found that Gopher Tortoise, Gopherus polyphemus, populations in southern Mississippi exhibit low recruitment, due in part to very low hatching success of their eggs. We sought to determine if the cause(s) of this low hatching success was related to egg quality (intrinsic factors), unsuitability of the nest environment (extrinsic factors), or a combination of the two. In 2003, hatching success was monitored simultaneously for eggs from the same clutches that were incubated in the laboratory and left to incubate in nests. A subset of randomly chosen eggs from each clutch was incubated in the laboratory under physical conditions that were known to be conducive to successful hatching to estimate the proportion of eggs that were capable of hatching in a controlled setting. Hatching success in the laboratory was compared with that of eggs incubated in natural nests to estimate the proportion of eggs that failed to hatch presumably from extrinsic factors. Laboratory hatching success was 58.8%, suggesting that roughly 40% of the eggs were intrinsically incapable of hatching even when incubated under controlled conditions. Hatching success in natural nests, 16.7%, was significantly lower than hatching success in the laboratory, suggesting that approximately 42.1% of eggs were capable of hatching but failed to hatch due to some extrinsic aspect(s) of the nest environment. Thus, the low hatching success of Gopher Tortoise eggs in southern Mississippi appears to be attributable to a combination of intrinsic (egg quality) and extrinsic (nest environment) factors.

  10. Opsin co-expression in Limulus photoreceptors: differential regulation by light and a circadian clock.

    PubMed

    Katti, C; Kempler, K; Porter, M L; Legg, A; Gonzalez, R; Garcia-Rivera, E; Dugger, D; Battelle, B-A

    2010-08-01

    A long-standing concept in vision science has held that a single photoreceptor expresses a single type of opsin, the protein component of visual pigment. However, the number of examples in the literature of photoreceptors from vertebrates and invertebrates that break this rule is increasing. Here, we describe a newly discovered Limulus opsin, Limulus opsin5, which is significantly different from previously characterized Limulus opsins, opsins1 and 2. We show that opsin5 is co-expressed with opsins1 and 2 in Limulus lateral and ventral eye photoreceptors and provide the first evidence that the expression of co-expressed opsins can be differentially regulated. We show that the relative levels of opsin5 and opsin1 and 2 in the rhabdom change with a diurnal rhythm and that their relative levels are also influenced by the animal's central circadian clock. An analysis of the sequence of opsin5 suggests it is sensitive to visible light (400-700 nm) but that its spectral properties may be different from that of opsins1 and 2. Changes in the relative levels of these opsins may underlie some of the dramatic day-night changes in Limulus photoreceptor function and may produce a diurnal change in their spectral sensitivity. PMID:20639420

  11. Distinct lobes of Limulus ventral photoreceptors. II. Structure and ultrastructure

    PubMed Central

    1982-01-01

    The structure of Limulus ventral photoreceptors fixed in situ has been investigated using light and electron microscopy and computer-assisted reconstruction and planimetry. Photoreceptors occur singly and in clusters. All photoreceptors have two types of lobes. The rhabdomeral lobe (R lobe) appears to be specialized for light sensitivity, containing the rhabdomere, which completely covers its external surface and forms infoldings into the lobe. The structure of the external rhabdom differs from that within infoldings. The other main structures of the R lobe are the palisades along the rhabdom, multivesicular bodies, lamellar bodies, and mitochondria. The arhabdomeral lobe (A lobe) bears the axon and contains the nucleus, clusters of residual bodies, lamellar arrays of endoplasmic reticulum, masses of glycogen, lipid droplets, and Golgi complexes. The R lobe and A lobe are analogous to the outer and inner segments of vertebrae photoreceptors. In single photoreceptors A and R lobes are separated by an indentation filled with glial processes. Computer reconstructions of cell clusters reveal that each cell has both types of lobes and an axon. Most of the rhabdom is formed from abutting arrays of external rhabdom from the R lobes of different members of the cluster. Efferent fibers containing characteristic angular granules penetrate single cells and clusters in glial invaginations. The main, if not exclusive, target of the efferent fibers is the internal rhabdom. PMID:7175491

  12. Voltage-sensitive potassium channels in Limulus ventral photoreceptors

    PubMed Central

    1978-01-01

    The steady-state slope conductance of Limulus ventral photoreceptors increases markedly when the membrane is depolarized from rest. The ionic basis of this rectification has been examined with a voltage- clamp technique. Tail currents that occur when membrane potential is repolarized after having been depolarized have been identified. The tail currents reverse direction at a voltage that becomes more positive when Ko is increased. Rectification is reduced by extracellular 4- aminopyridine and by intracellular injection of tetra-ethyl-ammonium (TEA). These results indicate that the membrane rectification around resting potential is due primarily to voltage-sensitive K+ channels. The increase in gK caused by depolarization is not mediated by a voltage-dependent rise in in Cai++, since intracellular injection of Ca++ causes a decrease rather than an increase in slope conductance. TEA can be used to examine the functional role of the K+ channels because it blocks them without substantially affecting the light- activated Na+ conductance. The effect of TEA on response-intensity curves shows that the K+ channels serve to compress the voltage range of receptor potentials. PMID:621492

  13. Enhancement and phototransduction in the ventral eye of limulus

    PubMed Central

    Fein, A; Charlton, JS

    1977-01-01

    Limulus ventral photoreceptors were voltage clamped to the resting (dark) potential and stimulated by a 20-ms test flash and a 1-s conditioning flash. At a constant level of adaptation, we measured the response to the test flash given in the dark (control) and the incremental response produced when the test flash occurred within the duration of the conditioning flash. The incremental response is defined as the response to the conditioning and test flashes minus the response to the conditioning flash given alone. When the test flash was presented within 100 ms after the onset of the conditioning flash we observed that: (a) for dim conditioning flashes the incremental response equaled the control response; (b) for intermediate intensity conditioning flashes the incremental response was greater than the control response (we refer to this as enhancement); (c) for high intensity conditioning flashes the incremental response nearly equaled the control response. Using 10-μm diam spots of illumnination, we stimulated two spatially separate regions of one photoreceptor. When the test flash and the conditioning flash were presented to the same region, enhancement was present; but when the flashes were applied to separate regions, enhancement was nearly absent. This result indicates that enhancement is localized to the region of illumination. We discuss mechanisms that may account for enhancement. PMID:864432

  14. Electrophysiological Properties of Cells in the Median Ocellus of Limulus

    PubMed Central

    Nolte, John; Brown, Joel E.

    1972-01-01

    Two types of photoreceptors are found in the median ocellus of Limulus. One type is maximally sensitive to ultraviolet (UV) light, the other to green light; they are called UV and VIS cells, respectively. Biphasic receptor potentials, consisting of a small initial hyperpolarizing phase and a later slow depolarizing phase, can be recorded from both receptor types. These biphasic responses are elicited in UV cells in response to long-wavelength light, and in VIS cells in response to ultraviolet light. Another type of hyperpolarizing response can be recorded in UV cells: after a bright ultraviolet stimulus, the cell remains depolarized; long-wavelength light rapidly returns the membrane potential to its value preceding ultraviolet illumination (this long-wavelength-induced potential change is called a "repolarizing response"). Also, a long-wavelength stimulus superimposed during a UV stimulus elicits a sustained repolarizing response. A third cell type (arhabdomeric cell) found in the median ocellus generates large action potentials and is maximally sensitive to UV light. Biphasic responses and repolarizing responses also can be recorded from arhabdomeric cells. The retina is divided into groups of cells; both UV cells and VIS cells can occur in the same group. UV cells in the same group are electrically coupled to one another and to an arhabdomeric cell. PMID:5058473

  15. Voltage-dependent conductances in Limulus ventral photoreceptors

    PubMed Central

    1982-01-01

    The voltage-dependent conductances of Limulus ventral photoreceptors have been investigated using a voltage-clamp technique. Depolarization in the dark induces inward and outward currents. The inward current is reduced by removing Na+ or Ca2+ and is abolished by removing both ions. These results suggest that both Na+ and Ca2+ carry voltage-dependent inward current. Inward current is insensitive to tetrodotoxin but is blocked by external Ni2+. The outward current has a large transient component that is followed by a smaller maintained component. Intracellular tetraethylammonium preferentially reduces the maintained component, and extracellular 4-amino pyridine preferentially reduces the transient component. Neither component is strongly affected by removal of extracellular Ca2+ or by intracellular injection of EGTA. It is concluded that the photoreceptors contain at least three separate voltage-dependent conductances: 1) a conductance giving rise to inward currents; 2) a delayed rectifier giving rise to maintained outward K+ current; and 3) a rapidly inactivating K+ conductance similar to the A current of molluscan neurons. PMID:7057161

  16. Ion channels activated by light in Limulus ventral photoreceptors

    PubMed Central

    1986-01-01

    The light-activated conductance of Limulus ventral photoreceptors was studied using the patch-clamp technique. Channels (40 pS) were observed whose probability of opening was greatly increased by light. In some cells the latency of channel activation was nearly the same as that of the macroscopic response, while in other cells the channel latency was much greater. Like the macroscopic conductance, channel activity was reduced by light adaptation but enhanced by the intracellular injection of the calcium chelator EGTA. The latter observation indicates that channel activation was not a secondary result of the light-induced rise in intracellular calcium. A two-microelectrode voltage-clamp method was used to measure the voltage dependence of the light-activated macroscopic conductance. It was found that this conductance is constant over a wide voltage range more negative than zero, but it increases markedly at positive voltages. The single channel currents measured over this same voltage range show that the single channel conductance is independent of voltage, but that channel gating properties are dependent on voltage. Both the mean channel open time and the opening rate increase at positive voltages. These properties change in a manner consistent with the voltage dependence of the macroscopic conductance. The broad range of similarities between the macroscopic and single channel currents supports the conclusion that the 40-pS channel that we have observed is the principal channel underlying the response to light in these photoreceptors. PMID:2419481

  17. Light-induced changes of sensitivity in Limulus ventral photoreceptors

    PubMed Central

    1975-01-01

    The responses of Limulus ventral photoreceptors to brief test flashes and to longer adapting lights were measured under voltage clamp conditions. When the cell was dark adapted, there was a range of energy of the test flashes over which the peak amplitude of the responses (light-induced currents) was directly proportional to the flash energy. This was also true when test flashes were superposed on adapting stimuli but the proportionality constant (termed peak currently/photon) was reduced. The peak current/photon was attenuated more by brighter adapting stimuli than by less bright adapting stimuli. The peak current/photon is a measure of the sensitivity of the conductance- increase mechanism underlying the light response of the photo-receptor. The response elicited by an adapting stimulus had a large initial transient which declined to a smaller plateau. The peak current/photon decreased sharply during the declining phase of the transient and was relatively stable during the plateau. This indicates that the onset of light adaptation is delayed with respect to the onset of the response to the adapting stimulus. If the adaptational state just before the onset of each of a series of adapting stimuli was constant, the amplitude of the transient was a nearly linear function of intensity. When the total intensity was rapidly doubled (or halved) during a plateau response, the total current approximately doubled (or halved). We argue that the transition from transient to plateau, light-elicited changes of threshold, and the nonlinear function relating the plateau response to stimulus intensity all reflect changes of the responsiveness of the conductance-increase mechanism. PMID:1181378

  18. Flash photolysis of caged compounds in Limulus ventral photoreceptors

    PubMed Central

    1992-01-01

    Rapid concentration jumps of Ins(1,4,5)P3 or ATP were made inside Limulus ventral photoreceptors by flash photolysis of the parent caged compounds. In intact ventral photoreceptors, the photolysis flash evokes a maximum amplitude light-activated current; therefore, a procedure was developed for uncoupling phototransduction by blocking two of the initial reactions in the cascade, rhodopsin excitation and G protein activation. Rhodopsin was inactivated by exposure to hydroxylamine and bright light. This procedure abolished the early receptor potential and reduced the quantum efficiency by 325 +/- 90- fold (mean +/- SD). G protein activation was blocked by injection of guanosine-5'-O-(2-thiodiphosphate) (GDP beta S). GDP beta S injection reduced the quantum efficiency by 1,881 +/- 1,153-fold (mean +/- SD). Together hydroxylamine exposure and GDP beta S injection reduced the quantum efficiency by 870,000 +/- 650,000-fold (mean +/- SD). After the combined treatment, photoreceptors produced quantum bumps to light that was approximately 10(6) times brighter than the intensity that produced quantum bumps before treatment. Experiments were performed with caged compounds injected into photoreceptors in which phototransduction was largely uncoupled. Photolysis of one compound, myo-inositol 1,4,5- triphosphate P4(5)-1-(2-nitrophenyl)ethyl ester (caged IP3), increased the voltage clamp current in response to the flashlamp by more than twofold without changing the latency of the response. The effect was not seen with photolysis of either adenosine-5'-triphosphate P3-1-(2- nitrophenyl)ethyl ester (caged ATP) or caged IP3 in cells preloaded with either heparin or (1,2-bis-(o-amino-phenoxy)ethane-N-N-N'-N' tetraacetic acid tetrapotassium salt (BAPTA). The results suggest that photoreleased IP3 releases calcium ions from intracellular stores and the resulting increase in [Ca2+]i enhances the amplification of the phototransduction cascade. PMID:1431805

  19. Adapting bump model for ventral photoreceptors of Limulus

    PubMed Central

    1982-01-01

    Light-evoked current fluctuations have been recorded from ventral photoreceptors of Limulus for light intensity from threshold up to 10(5) times threshold. These data are analyzed in terms of the adapting bump noise model, which postulates that (a) the response to light is a summation of bumps; and (b) the average size of bump decreases with light intensity, and this is the major mechanism of light adaptation. It is shown here that this model can account for the data well. Furthermore, the model provides a convenient framework to characterize, in terms of bump parameters, the effects of calcium ions, which are known to affect photoreceptor functions. From responses to very dim light, it is found that the average impulse response (average of a large number of responses to dim flashes) can be predicted from knowledge of both the noise characteristics under steady light and the dispersion of latencies of individual bumps. Over the range of light intensities studied, it is shown that (a) the bump rate increases in strict proportionality to light intensity, up to approximately 10(5) bumps per second; and (b) the bump height decreases approximately as the -0.7 power of light intensity; at rates greater than 10(5) bumps per second, the conductance change associated with the single bump seems to reach a minimum value of approximately 10(-11) reciprocal ohms; (c) from the lowest to the highest light intensity, the bump duration decreases approximately by a factor of 2, and the time scale of the dispersion of latencies of individual bumps decreases approximately by a factor of 3; (d) removal of calcium ions from the bath lengthens the latency process and causes an increase in bump height but appears to have no effect on either the bump rate or the bump duration. PMID:7108487

  20. The ventral photoreceptor cells of Limulus. 3. A voltage-clamp study.

    PubMed

    Millecchia, R; Mauro, A

    1969-09-01

    In the dark, the ventral photoreceptor of Limulus exhibits time-variant currents under voltage-clamp conditions; that is, if the membrane potential of the cell is clamped to a depolarized value there is an initial large outward current which slowly declines to a steady level. The current-voltage relation of the cell in the dark is nonlinear. The only ion tested which has any effect on the current-voltage relation is potassium; high potassium shifts the reversal potential towards zero and introduces a negative slope-conductance region. When the cell is illuminated under voltage-clamp conditions, an additional current, the light-induced current, flows across the cell membrane. The time course of this current mimics the time course of the light response (receptor potential) in the unclamped cell; namely, an initial transient phase is followed by a steady-state phase. The amplitude of the peak transient current can be as large as 60 times the amplitude of the steady-state current, while in the unclamped cell the amplitude of the peak transient voltage never exceeds 4 times the amplitude of the steady-state voltage. The current-voltage relations of the additional light-induced current obtained for different instants of time are also nonlinear, but differ from the current-voltage relations of the dark current. The ions tested which have the greatest effect on the light-induced current are sodium and calcium; low sodium decreases the current, while low calcium increases the current. The data strongly support the hypothesis that two systems of electric current exist in the membrane. Thus the total ionic current which flows in the membrane is accounted for as the sum of a dark current and a light-induced current. PMID:5806593

  1. Saturation of the response to light in Limulus ventral photoreceptor.

    PubMed Central

    Brown, J E; Coles, J A

    1979-01-01

    1. Limulus ventral photoreceptor cells were voltage-clamped with two intracellular micro-electrodes. The light-induced membrane current was recorded for brief stimuli. From observation of discrete waves (quantum bumps) at low stimulus energies and the early receptor potential at high energies, the stimulus energy was related to the number of rhodopsin molecules photosiomerized. 2. In the dark-adapted cell the log (peak light-induced current) reached almost its maximum value when about 10(3) of the 10(9) rhodopsin molecules in the cell were photoisomerized. 3. The magnitude of the maximum light-induced current was not significantly altered after iontophoresis of EGTA into the cell. This treatment is known to counteract the Ca2+-mediated reduction in sensitivity to light. 4. Current pulses were injected into the unclamped cell during the receptor potential. The form of the voltage deflexion (a step followed by a curve) suggested that the effective electrical equivalent of the cell was a membrane capacitance in parallel with a light-dependent membrane resistance, Rm, and in series with another, light-invariant, resistance, Rs. Rs ranged from 7 to 24 k omega (five cells). 5. During a receptor potential the ratio Rm/Rs was never observed to fall below 1.7 no matter how intense the light flash. Hence, it is concluded that the light-induced current saturated essentially because Rm fell to a minimum value. 6. Charging curves gave a value for the capacitance, and hence the area, of the surface membrane. From this it was estimated that there were 10(5)-10(6) microvilli on each cell. 7. These results show that the light-induced increase in membrane conductance in a dark-adapted cell comes close to its maximum value when the number of photoisomerizations is about 1/1000 the total number of microvilli. We suggest that absorption of a photon by a rhodopsin molecule in a microvillus causes an increase in membrane conductance on parts of the surface membrane beyond that

  2. Estimating Occupancy of Gopher Tortoise (Gorpherus polyphemus) Burrows in Coastal Scrub and Slash Pine Flatwoods

    NASA Technical Reports Server (NTRS)

    Breininger, David R.; Schmalzer, Paul A.; Hinkle, C. Ross

    1991-01-01

    One hundred twelve plots were established in coastal scrub and slash pine flatwoods habitats on the John F. Kennedy Space Center (KSC) to evaluate relationships between the number of burrows and gopher tortoise (Gopherus polyphemus) density. All burrows were located within these plots and were classified according to tortoise activity. Depending on season, bucket trapping, a stick method, a gopher tortoise pulling device, and a camera system were used to estimate tortoise occupancy. Correction factors (% of burrows occupied) were calculated by season and habitat type. Our data suggest that less than 20% of the active and inactive burrows combined were occupied during seasons when gopher tortoises were active. Correction factors were higher in poorly-drained areas and lower in well-drained areas during the winter, when gopher tortoise activity was low. Correction factors differed from studies elsewhere, indicating that population estimates require correction factors specific to the site and season to accurately estimate population size.

  3. Intraspecific phylogeography of the gopher tortoise, Gopherus polyphemus: RFLP analysis of amplified mtDNA segments.

    PubMed

    Osentoski, M F; Lamb, T

    1995-12-01

    The slow rate of mtDNA evolution in turtles poses a limitation on the levels of intraspecific variation detectable by conventional restriction fragment surveys. We examined mtDNA variation in the gopher tortoise (Gopherus polyphemus) using an alternative restriction assay, one in which PCR-amplified segments of the mitochondrial genome were digested with tetranucleotide-site endonucleases. Restriction fragment polymorphisms representing four amplified regions were analysed to evaluate population genetic structure among 112 tortoises throughout the species' range. Thirty-six haplotypes were identified, and three major geographical assemblages (Eastern, Western, and Mid-Florida) were resolved by UPGMA and parsimony analyses. Eastern and Western assemblages abut near the Apalachicola drainage, whereas the Mid-Florida assemblage appears restricted to the Brooksville Ridge. The Eastern/Western assemblage boundary is remarkably congruent with phylogeographic profiles for eight additional species from the south-eastern U.S., representing both freshwater and terrestrial realms. PMID:8564009

  4. Intensity increases of actin layer-lines on activation of the Limulus muscle.

    PubMed Central

    Maéda, Y; Boulin, C; Gabriel, A; Sumner, I; Koch, M H

    1986-01-01

    Small angle x-ray diffraction patterns were recorded from isometrically contracting Limulus (horseshoe crab) telson levator muscle using a multiwire proportional-area detector on the storage ring DORIS. In the pattern a substantial increase in intensity is observed on the thin-filament-associated layer-line at 1/38 nm-1 (the first actin layer-line) with a maximum increase at a radial spacing of R = 0.07 nm-1 but there is a much smaller change in the intensity of the 5.9-nm layer-line, which also arises from the thin filament structure. The results suggest that during contraction the myosin heads, presumably being attached to the thin filaments, are arranged along the long-stranded helical tracks of the thin filaments but that the spatial relationship between the heads and the actin monomers varies. Intensity increases have also been observed (Maéda et al., manuscript in preparation) in the part of the patterns from frog muscle and barnacle muscle, which are attributable to the first actin layer-line. It is thus likely that the intensity increase of the first actin layer-line on the Limulus pattern is associated not with structural features which are special to Limulus muscle, but with the tension generating processes that are shared by muscles in general. Images FIGURE 1 FIGURE 2 PMID:3801566

  5. Isolation of an iron-binding protein from the hemolymph of the horseshoe crab (Limulus polyhemus)

    SciTech Connect

    Topham, R.; Cooper, B.; Tesh, S.; Bonaventura, C.

    1987-05-01

    The presence of an iron-binding protein in the hemolymph of Limulus was detected by gel-filtration of /sup 59/Fe-labeled hemolymph. This protein was easily separated from hemocyanin, the oxygen transport protein that constitutes greater than 90% of the protein of Limulus hemolymph. The amount of the Limulus iron-binding protein (LIBP) in hemolymph samples prepared under sterile and non-sterile conditions was identical. LIBP was purified to homogeneity by ion-exchange chromatography. The molecular weight of purified LIBP was estimated by gel-filtration to be 282,000 + 10,000. SDS-electrophoresis demonstrated that LIBP was an oligomeric protein composed of subunits with a molecular weight of 28,000 +/- 2000. The isoelectric point of LIBP was 6.5 as determined by electrofocusing. No /sup 49/Fe was removed from purified LIBP by extensive dialysis with EDTA or 2,2'-dipyridyl. Purified, unlabeled LIBP efficiently sequestered /sup 59/Fe in the absence of hemolymph indicating that no other hemolymph factors are required for the incorporation of iron into LIBP. The isolation of LIBP would support the proposal that the development of specific iron-binding and transport proteins was not necessarily coupled to the development of hemoglobin as a means to accomplish oxygen transport.

  6. Contributions of Private Landowners to the Conservation of the Gopher Tortoise ( Gopherus polyphemus)

    NASA Astrophysics Data System (ADS)

    Underwood, Vicki J.; Ober, Holly K.; Miller, Deborah L.; Munn, Ian A.

    2012-04-01

    Private landowners play a pivotal role in determining whether or not rare species persist in regions where privately owned land is extensive. The range of the gopher tortoise ( Gopherus polyphemus) is confined to the Southeastern U.S., a region predominantly under private ownership, and thus the status of this species is largely dependent upon land management decisions made by private landowners. We sent an anonymous mail survey to 2,584 individuals to examine factors affecting gopher tortoise occurrence on private lands in Mississippi (adjusted response rate of 23%). Few respondents (19%) reported currently having tortoises on their property, although many had them in the past (30%). Tortoises were persisting primarily on larger properties with longleaf pine that were not managed chiefly for timber production. In general, respondents were largely unaware of habitat requirements of tortoises or effects of various land management practices on them, and few reported using management techniques that benefit tortoises, such as prescribed burning. Most respondents (57%) knew of wildlife incentive programs, but were hesitant to enroll because they did not want to commit to managing their property in a particular manner (34%). We suggest actions that could improve the likelihood of tortoise persistence in this region, as well as changes that could be made to incentive programs to increase landowner participation. These suggestions should be relevant to the conservation of other rare species on private lands in other regions.

  7. Daily energy expenditure in free-ranging Gopher Tortoises (Gopherus polyphemus)

    USGS Publications Warehouse

    Jodice, P.G.R.; Epperson, D.M.; Visser, G.H.

    2006-01-01

    Studies of ecological energetics in chelonians are rare. Here, we report the first measurements of daily energy expenditure (DEE) and water influx rates (WIRs) in free-ranging adult Gopher Tortoises (Gopherus polyphemus). We used the doubly labeled water (DLW) method to measure DEE in six adult tortoises during the non-breeding season in south-central Mississippi, USA. Tortoise DEE ranged from 76.7-187.5 kj/day and WIR ranged from 30.6-93.1 ml H2O/day. Daily energy expenditure did not differ between the sexes, but DEE was positively related to body mass. Water influx rates varied with the interaction of sex and body mass. We used a log/log regression model to assess the allometric relationship between DEE and body mass for Gopher Tortoises, Desert Tortoises (Gopherus agassizii), and Box Turtles (Terrapene carolina), the only chelonians for which DEE has been measured. The slope of this allometric model (0.626) was less than that previously calculated for herbivorous reptiles (0.813), suggesting that chelonians may expend energy at a slower rate per unit of body mass compared to other herbivorous reptiles. We used retrospective power analyses and data from the DLW isotope analyses to develop guidelines for sample sizes and duration of measurement intervals, respectively, for larger-scale energetic studies in this species. ?? 2006 by the American Society of Ichthyologists and Herpetologists.

  8. Contributions of private landowners to the conservation of the gopher tortoise (Gopherus polyphemus).

    PubMed

    Underwood, Vicki J; Ober, Holly K; Miller, Deborah L; Munn, Ian A

    2012-04-01

    Private landowners play a pivotal role in determining whether or not rare species persist in regions where privately owned land is extensive. The range of the gopher tortoise (Gopherus polyphemus) is confined to the Southeastern U.S., a region predominantly under private ownership, and thus the status of this species is largely dependent upon land management decisions made by private landowners. We sent an anonymous mail survey to 2,584 individuals to examine factors affecting gopher tortoise occurrence on private lands in Mississippi (adjusted response rate of 23%). Few respondents (19%) reported currently having tortoises on their property, although many had them in the past (30%). Tortoises were persisting primarily on larger properties with longleaf pine that were not managed chiefly for timber production. In general, respondents were largely unaware of habitat requirements of tortoises or effects of various land management practices on them, and few reported using management techniques that benefit tortoises, such as prescribed burning. Most respondents (57%) knew of wildlife incentive programs, but were hesitant to enroll because they did not want to commit to managing their property in a particular manner (34%). We suggest actions that could improve the likelihood of tortoise persistence in this region, as well as changes that could be made to incentive programs to increase landowner participation. These suggestions should be relevant to the conservation of other rare species on private lands in other regions. PMID:22371129

  9. Intestinal parasites of the gopher tortoise (Gopherus polyphemus) from eight populations in Georgia.

    PubMed

    McGuire, Jessica L; Miller, Elizabeth A; Norton, Terry M; Raphael, Bonnie L; Spratt, Jeffrey S; Yabsley, Michael J

    2013-12-01

    The gopher tortoise (Gopherus polyphemus), one of five tortoise species endemic in the USA, was recently classified as a candidate for federal listing as a threatened species. Fecal samples collected from 117 tortoises from eight sites in Georgia were examined for endoparasites using a combination of sedimentation and flotation. Samples from an island population were examined for parasitic oocysts and ova only by flotation, protozoan cysts by trichrome-stained direct smear, and Cryptosporidium by direct immunofluorescence assay and ProSpecT rapid assay. A total of 99 tortoises (85, range 0-100%) was infected with pinworms (Alaeuris spp.), 47 (40, 0-86%) with cestodes (Oochorstica sp.), 34 (41, 0-74%) with Chapiniella spp., 2 (3, 0-33%) with Eimeria paynei, and a single tortoise each with a capillarid and ascarid (1%). On the island, Entamoeba was detected in one tortoise (2%) while Cryptosporidium oocysts were detected in eight (17%). In conclusion, at least eight species of parasites were detected including Cryptosporidium, a possible pathogen of tortoises. Interestingly, we detected spatial variation in the distribution of several parasites among populations suggesting additional work should be conducted across a gradient of tortoise densities, land use, and habitat characteristics. PMID:24072334

  10. Respiratory and pharyngo-esophageal iridovirus infection in a gopher tortoise (Gopherus polyphemus).

    PubMed

    Westhouse, R A; Jacobson, E R; Harris, R K; Winter, K R; Homer, B L

    1996-10-01

    A free-living adult male gopher tortoise (Gopherus polyphemus) was found on Sanibel Island, Florida (USA), on 18 February 1992 with signs of upper respiratory disease. On necropsy after euthanasia on 27 February 1992, severe, extensive necrotizing ulcerative tracheitis, multifocal necrotizing pneumonia, and multifocal necrotizing ulcerative pharyngitis and esophagitis were observed. Large ovoid to round intracytoplasmic basophilic inclusions, which appeared to displace the nucleus to the cell periphery, occurred within degenerate and necrotic epithelial cells of the above tissues. On transmission electron microscopy of formalin-fixed trachea and lung, intracytoplasmic viral particles were observed within necrotic cells in the tracheal lumen and epithelial cells of the lung. Most infected cells also had a roughly spherical granular cytoplasmic inclusion that contained clusters of viral particles. Viral particles had an electron dense spherical to icosahedral core surrounded by a less electron dense icosahedral capsid. Mature extracellular virions were surrounded by an envelope and were 150 to 220 nm in diameter. Virions and cytoplasmic inclusions were morphologically similar to those of the Family Iridoviridae. PMID:9359071

  11. Performance of two different Limulus amebocyte lysate assays for the quantitation of fungal glucan.

    PubMed

    Cherid, Hafsa; Foto, Mark; Miller, J David

    2011-09-01

    This study examined the response of various forms and sources of glucans toward two different Limulus amebocyte lysate (LAL) methods, the modified LAL, and Glucatell. The glucans studied were curdlan, laminarin, yeast glucan, barley glucan, paramylon, pullulan, pustulan, mannan, and pachyman (as part of the Glucatell kit). Both methods provided largely similar results for each of the glucans; however, the Glucatell method yielded slightly higher responses to certain structures that may not necessarily be of fungal origin, leading to falsely greater positive results. The performance of each method to measure fungal glucan concentration specifically was then assessed. PMID:21830869

  12. Interference of silica nanoparticles with the traditional Limulus amebocyte lysate gel clot assay.

    PubMed

    Kucki, Melanie; Cavelius, Christian; Kraegeloh, Annette

    2014-04-01

    Endotoxin contaminations of engineered nanomaterials can be responsible for observed biological responses, especially for misleading results in in vitro test systems, as well as in vivo studies. Therefore, endotoxin testing of nanomaterials is necessary to benchmark their influence on cells. Here, we tested the traditional Limulus amebocyte lysate gel clot assay for the detection of endotoxins in nanoparticle suspensions with a focus on possible interference of the particles with the test system. We systematically investigated the effects of nanomaterials made of, or covered by, the same material. Different types of bare or PEGylated silica nanoparticles, as well as iron oxide-silica core shell nanoparticles, were tested. Detailed inhibition/enhancement controls revealed enhanced activity in the Limulus coagulation cascade for all particles with bare silica surface. In comparison, PEGylation led to a lower degree of enhancement. These results indicate that the protein-particle interactions are the basis for the observed inhibition and enhancement effects. The enhancement activity of a particle type was positively related to the calculated particle surface area. For most silica particles tested, a dilution of the sample within the maximum valid dilution was sufficient to overcome non-valid enhancement, enabling semi-quantification of the endotoxin contamination. PMID:23884096

  13. Fast desensitization of the response to InsP3 in Limulus ventral photoreceptors.

    PubMed Central

    Levitan, I; Hillman, P; Payne, R

    1993-01-01

    In Limulus ventral photoreceptor cells the time-course of the desensitization of InsP3 response was measured by an injection-pair paradigm. Pressure pulses of InsP3 were delivered into the cell with various interpulse intervals. The desensitization of the response to the second injection of each pair approached totality at 200 ms, which is the duration of the response to a single pressure pulse of InsP3. Lowering extracellular calcium did not affect the time-course of the desensitization. Lowering the temperature slowed down both the time-course of the response to InsP3 and the time-course of the desensitization to the same extent. These findings suggest that the desensitization is powerful enough and its onset fast enough to contribute to the transience of the InsP3 response. The time-course of the desensitization suggests it may influence light adaptation. PMID:8494989

  14. Effects of removing extracellular Ca2+ on excitation and adaptation in Limulus ventral photoreceptors.

    PubMed Central

    Lisman, J E

    1976-01-01

    In Limulus ventral photoreceptors, removing extracellular calcium (Ca2+o) increases the median latency of light-evoked discrete waves. Removal greatly lengthens the time-to-peak of responses in the dark-adapted cell, but not in the light-adapted cell. Removal does not block light-adaptation or the light-induced rise in intracellular calcium (Ca2+i). These results are interpreted in terms of the hypothesis that both sensitivity and the kinetics of excitation are dependent on Ca2+i, and that Ca2+i is dependent on Ca2+o in the dark-adapted cell, but in the light is dependent largely on Ca2+ released from intracellular compartments. PMID:974224

  15. Outdoor Exhibits

    NASA Technical Reports Server (NTRS)

    1996-01-01

    The National Data Buoy Center (NDBC) at the John C. Stennis Space Center has exhibits located in front of the Visitors Center. These boat-shaped buoys are moored in areas of the ocean that experience hostile environmental conditions. The instruments installed gather information and relay it to the National Weather Service by satellite. Nomad buoys are 20 feet long and weigh 13,900 pounds. They provide information on wind speed and direction, humidity levels, air and sea surface temperature and air pressure. U.S. Coast Guard ships transport buoys to their mooring sites.

  16. Relative potencies of four reference endotoxin standards as measured by the Limulus amoebocyte lysate and USP rabbit pyrogen tests.

    PubMed Central

    Weary, M E; Donohue, G; Pearson, F C; Story, K

    1980-01-01

    Four commonly used reference endotoxin standards, Escherichia coli O113:H10:K0, E. coli O55:B5, Salmonella abortusequi, and Shigella dysenteriae were compared by the USP rabbit pyrogen and the Limulus amoebocyte lysate tests. By the rabbit pyrogen test, S. abortus equi was identified as the most potent endotoxin, followed closely by E. coli O113:H10:K0 and E. coli O55:B5. PMID:7006505

  17. Evidence for electrogenic Na+/Ca2+ exchange in Limulus ventral photoreceptors

    PubMed Central

    1989-01-01

    The Ca2+ indicator photoprotein, aequorin, was used to estimate and monitor intracellular Ca2+ levels in Limulus ventral photoreceptors during procedures designed to affect Na+/Ca2+ exchange. Dark levels of [Ca2+]i were estimated at 0.66 +/- 0.09 microM. Removal of extracellular Na+ caused [Ca2+]i to rise transiently from an estimated 0.5-0.6 microM in a typical cell to approximately 21 microM; [Ca2+]i approached a plateau level in 0-Na+ saline of approximately 5.5 microM; restoration of normal [Na+]o lowered [Ca2+]i to baseline with a time course of 1 log10 unit per 9 s. The apparent rate of Nao+-dependent [Ca2+]i decline decreased with decreasing [Ca2+]i. Reintroduction of Ca2+ to 0-Na+, 0-Ca2+ saline in a typical cell caused a transient rise in [Ca2+]i from an estimated 0.36 microM (or lower) to approximately 16.5 microM. This was followed by a decline in [Ca2+]i approaching a plateau of approximately 5 microM; subsequent removal of Cao2+ caused [Ca2+]i to decline slowly (1 log unit in approximately 110 s). Intracellular injection of Na+ in the absence of extracellular Na+ caused a transient rise in [Ca2+]i in the presence of normal [Ca2+]o; in 0-Ca2+ saline, however, no such rise in [Ca2+]i was detected. Under constant voltage clamp (-80 mV) inward currents were measured after the addition of Nao+ to 0-Na+ 0-Ca2+ saline and outward currents were measured after the addition of Cao2+ to 0-Na+ 0-Ca2+ saline. The results suggest the presence of an electrogenic Na+/Ca2+ exchange process in the plasma membrane of Limulus ventral photoreceptors that can operate in forward (Nao+-dependent Ca2+ extrusion) or reverse (Nai+- dependent Ca2+ influx) directions. PMID:2703822

  18. Effects of intracellular injection of calcium buffers on light adaptation in Limulus ventral photoreceptors

    PubMed Central

    1975-01-01

    The calcium sequestering agent, EGTA, was injected into Limulus ventral photoreceptors. Before injection, the inward membrane current induced by a long stimulus had a large initial transient which declined to a smaller plateau. Iontophoretic injection of EGTA tended to prevent the decline from transient to plateau. Before injection the plateau response was a nonlinear function of light intensity. After EGTA injection the response-intensity curves tended to become linear. Before injection, bright lights lowered the sensitivity as determined with subsequent test flashes. EGTA injection decreased the light-induced changes in sensitivity. Ca-EGTA buffers having different levels of free calcium were pressure-injected into ventral photoreceptors; the higher the level of free calcium, the lower the sensitivity measured after injection. The effects of inotophoretic injection of EGTA were not mimicked by injection or similar amounts of sulfate and the effects of pressure injection of EGTA buffer solutions were not mimicked by injection of similar volumes of pH buffer or mannitol. The data are consistent with the hypothesis that light adaptation is mediated by a rise of the intracellular free calcium concentration. PMID:810540

  19. Properties of visual cells in the lateral eye of Limulus in situ: intracellular recordings

    PubMed Central

    1977-01-01

    Two types of potential fluctuations, large and small, recorded intracellularly from photoreceptors in the dark-adapted Limulus eye in situ underlie the dual properties of the impulse discharge of the optic nerve fibers. The small potential fluctuations (SPFs)--the well-known quantum bumps--were normally less than 20 mV in amplitude. The large potential fluctuations (LPFs) were up to 80 mV in amplitude. LPFs appear to be regenerative events triggered by SPFs that enable single photon absorptions in retinular cells to fire off nerve impulses in the eccentric cell. In the dark, SPFs and LPFs occur spontaneously. At low light intensities, LPFs are the major components of the receptor potential. At high intensities, LPFs are suppressed and SPFs become the major components. SPFs and LPFs together enable single photoreceptor cells to encode approximately a 9-log unit range of light intensity. Excising the eye from the animal or cutting off its blood supply generally abolishes LPFs and thereby reduces the range of light intensity coded in the optic nerve discharge. PMID:839197

  20. Two Light-Induced Processes in the Photoreceptor Cells of Limulus Ventral Eye

    PubMed Central

    Lisman, J. E.; Brown, J. E.

    1971-01-01

    The dark-adapted current-voltage (I-V) curve of a ventral photoreceptor cell of Limulus, measured by a voltage-clamp technique, has a high slope-resistance region more negative than resting voltage, a lower slope-resistance region between resting voltage and zero, and a negative slope-resistance region more positive than 0 v. With illumination, we find no unique voltage at which there is no light-induced current. At the termination of illumination, the I-V curve changes quickly, then recovers very slowly to a dark-adapted configuration. The voltage-clamp currents during and after illumination can be interpreted to arise from two separate processes. One process (fast) changes quickly with change in illumination, has a reversal potential at +20 mv, and has an I-V curve with positive slope resistance at all voltages. These properties are consistent with a light-induced change in membrane conductance to sodium ions. The other process (slow) changes slowly with changes in illumination, generates light-activated current at +20 mv, and has an I-V curve with a large region of negative slope resistance. The mechanism of this process cannot as yet be identified. PMID:5122373

  1. Intracellular injection of heparin and polyamines. Effects on phototransduction in limulus ventral photoreceptors

    PubMed Central

    1993-01-01

    Heparin is thought to inhibit InsP3 binding to receptors involved in the intracellular release of Ca2+. Injection of heparin into Limulus ventral photoreceptors to high intracellular concentrations reduces the amplitude and slows the rate of rise of voltage-clamp currents induced by brief flashes, tends to make the responses to long flashes more "square," and tends to block the light-induced rise in [Ca2+]i detected by arsenazo III. In these ways, intracellular heparin mimics the effects of high concentrations of intracellular BAPTA or EGTA. In addition, the effects of heparin are attenuated by prior injection of BAPTA to high intracellular concentrations. Neomycin and spermine are thought to inhibit phospholipase C activity. Injections of spermine or neomycin to low intracellular concentrations largely mimic the effects of intracellular heparin. These findings suggest that the predominant effect of polyamines is to inhibit light-induced production of InsP3 by phospholipase C activity and thereby reduce the light-induced increase in [Ca2+]i. Our findings suggest that excitation can proceed in the absence of InsP3-induced increases in [Ca2+]i, but (a) the gain and speed of transduction are reduced and (b) adaptation is largely blocked. PMID:8331323

  2. Chemical excitation of Limulus photoreceptors. I. Phosphatase inhibitors induce discrete-wave production in the dark

    PubMed Central

    1983-01-01

    Molybdate, tungstate, fluoride, vanadate, and GTP-gamma-S [guanosine-5'- 0-(3-thiotriphosphate)] were injected into Limulus ventral photoreceptors by ionophoresis from microelectrodes. All of these drugs induce discrete waves of depolarization similar in waveform to, but smaller in amplitude than, those normally elicited by dim light. As for light-evoked waves, the amplitude of drug-induced waves decreases with light adaptation. For the compounds examined so far (fluoride, vanadate, GTP-gamma-S), the drug-induced waves share a reversal potential with light-induced discrete waves at about +15 mV. The induction of discrete waves by fluoride, vanadate, and molybdate was found to be reversible, whereas the induction of waves by GTP-gamma-S was not. Unlike fluoride and vanadate, which induce waves when added to the bath, molybdate appears to be ineffective when applied extracellularly. Because of the similarity of the drug-induced waves to light-induced discrete waves, we conclude that the drug-induced waves arise from a process similar or perhaps identical to visual excitation of the photoreceptor. However, the smaller size of drug-induced waves suggests that they arise at a stage of phototransduction subsequent to the isomerization of rhodopsin. On the basis of the chemical properties and action of the drugs, we suggest that discrete waves may arise through the activation of a GTP-binding protein. PMID:6315860

  3. Functional significance of voltage-dependent conductances in Limulus ventral photoreceptors

    PubMed Central

    1982-01-01

    The influence of voltage-dependent conductances on the receptor potential of Limulus ventral photoreceptors was investigated. During prolonged, bright illumination, the receptor potential consists of an initial transient phase followed by a smaller plateau phase. Generally, a spike appears on the rising edge of the transient phase, and often a dip occurs between the transient and plateau. Block of the rapidly inactivating outward current, iA, by 4-aminopyridine eliminates the dip under some conditions. Block of maintained outward current by internal tetraethylammonium increases the height of the plateau phase, but does not eliminate the dip. Block of the voltage-dependent Na+ and Ca2+ current by external Ni2+ eliminates the spike. The voltage-dependent Ca2+ conductance also influences the sensitivity of the photoreceptor to light as indicated by the following evidence: depolarizing voltage- clamp pulses reduce sensitivity to light. This reduction is blocked by removal of external Ca2+ or by block of inward Ca2+ current with Ni2+. The reduction of sensitivity depends on the amplitude of the pulse, reaching a maximum at or approximately +15 mV. The voltage dependence is consistent with the hypothesis that the desensitization results from passive Ca2+ entry through a voltage-dependent conductance. PMID:7057162

  4. Development of an electrochemical Limulus amebocyte lysate assay technique for portable and highly sensitive endotoxin sensor.

    PubMed

    Inoue, Kumi Y; Takahashi, Satoko; Ino, Kosuke; Shiku, Hitoshi; Matsue, Tomokazu

    2012-04-01

    Here, we report the development of an electrochemical detection method for endotoxin based on the Limulus amebocyte lysate (LAL) assay. A mixture of LAL reagent and endotoxin sample solution was incubated for 1 h. The endotoxin activated a cascade reaction of zymogens contained in the LAL to generate p-nitroaniline (pNA) which was then electrochemically detected by differential pulse voltammetry (DPV). The generated pNA gave a clear peak at -0.75 V vs. silver/silver chloride (Ag/AgCl), which increased with the concentration of endotoxin in the LAL assay solution. This DPV detection was performed using an electrode chip device fabricated from a diamond-like carbon-coated glass substrate. This chip device could detect as low as 10 endotoxin units l(-1) at room temperature within 1 h. This novel electrochemical method for the detection of endotoxin appears promising for the development of compact, low-cost and easy-to-use sensors for on-site monitoring of potentially contaminated medical supplies, including dialysis fluid, transplanted tissue and culture medium for assisted reproduction. PMID:21844129

  5. Modification of the Limulus amebocyte lysate assay for the analysis of glucan in indoor environments.

    PubMed

    Foto, Mark; Plett, Jonathan; Berghout, Joanne; Miller, J David

    2004-05-01

    beta-1,3- D-Glucan is a biologically active component mainly from fungi that has been shown in several studies to be related to respiratory health outcomes from damp building exposures. Here, we report the development and application of a method for the analysis of the glucan extracted in 0.5 N NaOH solution making use of an available preparation of Limulus amebocyte lysate (LAL). The method yields reproducible beta-1,3- D-glucan measurements from samples of outdoor air, yeast cells, fungal spore preparations and ragweed pollen, and is more sensitive than competing measurements. The LAL-based measurement compared favourably to that based on size-exclusion chromatography using UV and refractive index detection. Growth conditions of the fungi did not materially change the concentrations of glucan in spores indicating that this is a stable property. Glucan content was proportional to spore surface area; however, some species contain higher relative spore glucan contents. PMID:15042272

  6. Surveillance for upper respiratory tract disease and Mycoplasma in free-ranging gopher tortoises (Gopherus polyphemus) in Georgia, USA.

    PubMed

    McGuire, Jessica L; Smith, Lora L; Guyer, Craig; Lockhart, J Mitchell; Lee, Gregory W; Yabsley, Michael J

    2014-10-01

    Abstract Upper respiratory tract disease (URTD) in the gopher tortoise (Gopherus polyphemus) is highly contagious and has been implicated in the reduction of populations throughout the range. With the exception of a few limited studies, the prevalence of URTD in Georgia, USA tortoise populations is poorly known. We found that exposure to Mycoplasma agassizii and Mycoplasma testudineum, associated with URTD, varied geographically among 11 Georgia tortoise populations. The prevalence of antibodies to M. agassizii in individual populations was either very low (0-3%, n=7 populations) or very high (96-100%, n=4 populations), whereas there was variation in the prevalence of antibodies to M. testudineum among populations (20-61%, n=10) with only one site being negative. Five sites had tortoises with antibodies to both pathogens, and these were the only sites where we observed tortoises with clinical signs consistent with URTD. We did not find tortoises with clinical signs of URTD at sites with tortoises with antibodies only to M. testudineum, which provides evidence that this organism may be of limited pathogenicity for gopher tortoises. Collectively, these data indicate that both M. agassizii and M. testudineum are present in Georgia populations of gopher tortoises and that clinical disease is apparent in populations where both pathogens are present. Additional research is needed to better understand the role of these two pathogens, and other potential pathogens, in the overall health of tortoise populations, especially if future conservation efforts involve translocation of tortoises. PMID:25098305

  7. Calcium ion, an intracellular messenger of light adaptation, also participates in excitation of Limulus photoreceptors.

    PubMed Central

    Bolsover, S R; Brown, J E

    1985-01-01

    Photoreceptor cells of Limulus ventral eyes were bathed in artificial sea water (ASW) that contained 10 mM-EGTA and no added Ca2+ (EGTA-ASW). Test flashes elicited responses that increased to a maximum size within 10 min in EGTA-ASW but did not change further when dark-adapted cells were bathed for an additional 35 min in this solution. Light responses progressively declined from this maximum size if the cells were repetitively illuminated in EGTA-ASW. In this state of reduced responsiveness, response amplitudes were further reduced by intracellular ionophoretic injection of EGTA; response amplitudes were increased by intracellular ionophoretic injection of Ca2+. Both of these findings are opposite to what is normally observed for cells bathed in ASW. Also, after repetitive illumination in EGTA-ASW, both the slope of the response versus intensity relationship became steeper and light responses often had a delayed increase in amplitude. The light responses and the response versus intensity relation returned to normal when the bathing medium was changed back to ASW containing 10 mM-Ca2+. The light-induced rise in luminescence recorded from photoreceptors injected with the photoprotein aequorin (the 'aequorin response') declined by at most 50% after dark-adapted photoreceptors were bathed in EGTA-ASW for 45 min. However, the aequorin response progressively declined by 98% if cells were repetitively illuminated while bathed in EGTA-ASW. The total intracellular Ca content of whole end-organs was measured by atomic absorption spectroscopy. Total intracellular Ca content did not change significantly while photoreceptors were bathed in EGTA-ASW even after repetitive illumination. We suggest that cytosolic Ca2+ is required by one or more steps in the mechanisms that link rhodopsin isomerization to both (i) an increase in the conductance of the cell membrane to Na+ and (ii) a release of Ca2+ from a light-labile store. PMID:3928878

  8. Injection of guanosine and adenosine nucleotides into Limulus ventral photoreceptor cells

    PubMed Central

    Bolsover, S. R.; Brown, J. E.

    1982-01-01

    1. Several nucleotide and nucleotide analogues had striking effects when pressure-injected into Limulus ventral photoreceptor cells. The poorly hydrolysable GTP analogues guanosine 5′-0-(3-thiotriphosphate) (GTPγS), guanylyl imidodiphosphate (Gpp[NH]p) and guanylyl (β, γ methylene) diphosphonate (Gpp[CH2]p) produced large increases in the frequency of `discrete events' that were recorded from photoreceptors in darkness. This effect was only observed after the injected cell was exposed to light. Injection of the ATP analogue ATPγS had effects similar to those of the GTP analogues. 2. We conclude that GTPγS, Gpp[NH]p, Gpp[CH2]p and ATPγS act at a common site to cause a light-dependent, long-term activation of the excitation mechanism of the photoreceptor. 3. Injection of GTP or GDP at pH 4.8 was followed by a smooth, transient depolarization that was observed neither when GTP at pH 7.5 was injected nor when ATP, 5′GMP or 2-[N-morpholino] ethane sulphonic acid (MES) were injected at pH 4.8. The reversal potential of the current induced by GTP injection was significantly more positive than the reversal potential of the light-induced current. 4. We conclude that GTP injection induces changes of membrane conductance either in addition to, or different from, the light-induced change of membrane conductance. 5. Injection of the ATP analogue adenylyl imidodiphosphate (App[NH]p), and the pyrophosphate analogue imidodiphosphate (p[NH]p) produced a drastic decrease in the sensitivity of photoreceptors to light. This decrease in sensitivity was partially reversed when the concentration of calcium ions in the bathing medium was reduced. 6. We suggest that App[NH]p and p[NH]p injections act by increasing the cytoplasmic concentration of calcium ions. PMID:7153930

  9. Pressure injection of calcium both excites and adapts Limulus ventral photoreceptors

    PubMed Central

    1986-01-01

    Single pressure injections of 1-2 mM calcium aspartate into the light- sensitive region of Limulus ventral photoreceptors resulted in a rapid, 20-40-mV depolarization lasting approximately 2 s. The depolarization closely followed the rise in intracellular free calcium caused by the injection, as indicated by aequorin luminescence. The depolarization was followed by reversible desensitization (adaptation) of responses to both light and inositol 1,4,5 trisphosphate. Similar single injections of calcium into the light-insensitive region of the receptor were essentially without effect, even though aequorin luminescence indicated a large, rapid rise in intracellular free calcium. The depolarization caused by injection of calcium arose from the activation of an inward current with rectification characteristics and a reversal potential between +10 and +20 mV that were similar to those of the light- activated conductance, which suggests that the same channels were activated by light and by calcium. The reversal potentials of the light- and calcium-activated currents shifted similarly when three-fourths of the extracellular sodium was replaced by sucrose, but were not affected by a similar replacement of sodium by lithium. The current activated by calcium was abolished by prior injection of a calcium buffer solution containing EGTA. The responses of the same cells to brief light flashes were slowed and diminished in amplitude, but were not abolished after the injection of calcium buffer. Light adaptation and prior injection of calcium diminished the calcium-activated current much less than they diminished the light-activated current. PMID:3734748

  10. IrFC - An Ixodes ricinus injury-responsive molecule related to Limulus Factor C.

    PubMed

    Urbanová, Veronika; Hartmann, David; Grunclová, Lenka; Šíma, Radek; Flemming, Tina; Hajdušek, Ondřej; Kopáček, Petr

    2014-10-01

    Limulus Clotting Factor C is a multi-domain serine protease that triggers horseshoe crab hemolymph clotting in the presence of trace amounts of bacterial lipopolysaccharides. Here we describe and functionally characterize an homologous molecule, designated as IrFC, from the hard tick Ixodes ricinus. Tick Factor C consists of an N-terminal cysteine-rich domain, four complement control protein (sushi) modules, an LCCL domain, a truncated C-lectin domain and a C-terminal trypsin-type domain. Developmental expression profiling by quantitative real-time PCR revealed that the irfc mRNA is expressed in all stages including eggs. In tissues dissected from adult I. ricinus females, the irfc mRNA is present mainly in tick hemocytes and accordingly, indirect immunofluorescence microscopy localized IrFC intracellularly, in tick hemocytes. Irfc mRNA levels were markedly increased upon injection of sterile saline, or different microbes, demonstrating that the irfc gene transcription occurs in response to injury. This indicates a possible role of IrFC in hemolymph clotting and/or wound healing, although these defense mechanisms have not been yet definitely demonstrated in ticks. RNAi silencing of irfc expression resulted in a significant reduction in phagocytic activity of tick hemocytes against the Gram-negative bacteria Chryseobacterium indologenes and Escherichia coli, but not against the yeast, Candida albicans. This result suggests that IrFC plays a role in the tick primordial complement system and as such possibly mediates transmission of tick-borne pathogens. PMID:24924263

  11. An estimate of the number of G regulator proteins activated per excited rhodopsin in living Limulus ventral photoreceptors.

    PubMed Central

    Kirkwood, A; Weiner, D; Lisman, J E

    1989-01-01

    Previous work by others on Limulus photoreceptors has shown that application of a variety of guanine nucleotide-binding regulatory protein (G protein) activators produces discrete waves of depolarization similar to those generated by single photos, but smaller in size. We investigated whether these events might originate at a site other than the G protein. Initiation of the events did not depend on the state of the visual pigment, suggesting that the events do not originate at the pigment level. The events could be blocked by the G-protein blocker guanosine 5'-[beta-thio]diphosphate (GDP[betaS]) and thus support the conclusion that these discrete events are due to the activation of G protein itself. Quantitative measurements indicate that the average size of these events is approximately 8 times smaller than that evoked by single photons under the same conditions. Given certain reasonable assumptions, these results imply that the gain of the first stage of transduction in vivo is approximately 8, a value considerably lower than that measured in vitro in vertebrate rods (gain, 100-500). Furthermore, independent evidence for a low first-stage gain in Limulus is derived from the observation that GDP[betaS] barely affects the size of the response to single photons, but greatly reduces the probability that a photon evokes a response. These results can be explained if rhodopsin normally activates only a few G proteins. PMID:2498877

  12. Whole genome sequencing in Drosophila virilis identifies Polyphemus, a recently activated Tc1-like transposon with a possible role in hybrid dysgenesis

    PubMed Central

    2014-01-01

    Background Hybrid dysgenic syndromes in Drosophila have been critical for characterizing host mechanisms of transposable element (TE) regulation. This is because a common feature of hybrid dysgenesis is germline TE mobilization that occurs when paternally inherited TEs are not matched with a maternal pool of silencing RNAs that maintain transgenerational TE control. In the face of this imbalance TEs become activated in the germline and can cause F1 sterility. The syndrome of hybrid dysgenesis in Drosophila virilis was the first to show that the mobilization of one dominant TE, the Penelope retrotransposon, may lead to the mobilization of other unrelated elements. However, it is not known how many different elements contribute and no exhaustive search has been performed to identify additional ones. To identify additional TEs that may contribute to hybrid dysgenesis in Drosophila virilis, I analyzed repeat content in genome sequences of inducer and non-inducer lines. Results Here I describe Polyphemus, a novel Tc1-like DNA transposon, which is abundant in the inducer strain of D. virilis but highly degraded in the non-inducer strain. Polyphemus expression is also increased in the germline of progeny of the dysgenic cross relative to reciprocal progeny. Interestingly, like the Penelope element, it has experienced recent re-activation within the D. virilis lineage. Conclusions Here I present the results of a comprehensive search to identify additional factors that may cause hybrid dysgenesis in D. virilis. Polyphemus, a novel Tc1-like DNA transposon, has recently become re-activated in Drosophila virilis and likely contributes to the hybrid dysgenesis syndrome. It has been previously shown that the Penelope element has also been re-activated in the inducer strain. This suggests that TE co-reactivation within species may synergistically contribute to syndromes of hybrid dysgenesis. PMID:24555450

  13. Calcium and the control of discrete wave latency in the ventral photoreceptor of Limulus.

    PubMed Central

    Martinez, J M; Srebro, R

    1976-01-01

    1. Discrete, transient depolarization (discrete waves) of the ventral photoreceptor of the horseshoe crab, Limulus, occur spontaneously in the dark adapted photoreceptor and are also evoked by light. They form the basic events which comprise the receptor potential. A brief, low energy flash of light evokes variable numbers of discrete waves which have variable latencies. Evidence suggesting that discrete wave latency reflects the kinetics of the chemical reactions of phototransduction is reviewed. 2. The concentration of extracellular Ca influences both the average discrete wave latency and its variability. Lowering extracellular Ca prolongs the latency and increases its variability. Increasing extracellular Ca has the opposite effect. 3. Changes in discrete wave latency caused by changes in extracellular Ca require 10--15 min to become fully manifest, whereas when the concentration of extracellular K is increased the photoreceptor achieves a steady-state depolarization in 10-15 sec. 4. Iontophoresis of the Ca-chelating agent EGTA into the photoreceptor increases both the average discrete wave latency and its variability. Iontophoresis of Ca-EGTA mixtures may either increase or decrease discrete wave latency and its variability depending upon the proportion of Ca mixed with EGTA. 5. It is suggested that the concentration of intracellular rather than extracellular ionized Ca is the prime factor indicating discrete wave latency. The effects of changing extracellular Ca can be explained if the photoreceptor is permeable to Ca in the dark and if it maintains a low intracellular Ca concentration by virtue of active metabolic processes (a pump-leak system). 6. Lowering the temperature of the photoreceptor also has the dual effect of increasing discrete wave latency and its variability. However, effects of lowering temperature and Ca simultaneously are greater than the sum of the two effects in individually. This suggests that Ca may be a reactant in the chemical process

  14. Three components in the light-induced current of the Limulus ventral photoreceptor.

    PubMed Central

    Deckert, A; Nagy, K; Helrich, C S; Stieve, H

    1992-01-01

    1. Light-induced currents were measured in Limulus ventral nerve photoreceptors using a two-electrode voltage clamp. Three kinetically distinct components in the light-induced current could be distinguished by varying the light adaptation state of the photoreceptor and the intensity of the stimulus light. 2. The components could be partly separated by choosing appropriate stimulus intensities and dark adaptation time. Thus the properties of the components could be separately studied. The first component is the first to recover after a light adaptation, appears temporally first in the light-induced response, has the lowest activation threshold and is the smallest. The second component needs a longer time to recover after an adapting illumination and its kinetics differ from that of the other components. Applying a bright stimulus to a dark-adapted cell a third component can be observed late in the response. 3. The time to peak of the first and the third components depended on the stimulus intensity, but not on the dark adaptation time. The time to peak of the second component became shorter the longer the dark adaptation time. For a constant adaptation state the time to the maximum of component 2 was independent, but those of components 1 and 3 were dependent on the membrane voltage. 4. To exclude the possibility of the contribution of voltage-gated currents, light-activated currents were measured at clamp potentials more negative than -50 mV after adding 4-aminopyridine into the bath solution or injecting tetraethyl-ammonium chloride into the cell. The properties of the three components remained unchanged under these conditions. 5. The I-V curve of the first component was flat at negative membrane potentials and had a strong outward rectification at positive membrane potentials. The I-V curve of component 3 showed a negative resistance at potentials more negative than about -30 mV. In contrast, the I-V curve for the second component was always nearly linear. 6. No

  15. Endotoxin detection--from limulus amebocyte lysate to recombinant factor C.

    PubMed

    Ding, Jeak Ling; Ho, Bow

    2010-01-01

    Gram negative bacterial endotoxin is a biological pyrogen that causes fever when introduced intravenously. The endotoxin, also known as lipopolysaccharide (LPS), is found in the outer membrane of Gram-negative bacteria. During Gram-negative sepsis, endotoxin stimulates host macrophages to release inflammatory cytokines. However, excessive inflammation causes multiple organ failure and death. Endotoxins, which are ubiquitous pathogenic molecules, are a bane to the pharmaceutical industry and healthcare community. Thus early and sensitive detection of endotoxin is crucial to prevent endotoxaemia. The limulus amebocyte lysate (LAL) has been widely used for ~30 years for the detection of endotoxin in the quality assurance of injectable drugs and medical devices. The LAL constitutes a cascade of serine proteases which are triggered by trace levels of endotoxin, culminating in a gel clot at the end of the reaction. The Factor C, which normally exists as a zymogen, is the primer of this coagulation cascade. In vivo, Factor C is the perfect biosensor, which alerts the horseshoe crab of the presence of a Gram-negative invader. The hemostatic end-point entraps the invader, killing it and limiting further infection. However, as an in vitro endotoxin detection tool, variations in the sensitivity and specificity of LAL to endotoxin, and the dwindling supply of horseshoe crabs are posing increasing challenges to the biotechnology industry. This has necessitated the innovation of an alternative test for endotoxin. Thus, Factor C became the obvious, albeit tricky target for the recombinant technology effort. This chapter documents the backwater of mining the natural blood lysate of the endangered species to the monumental effort of genetic engineering, to produce recombinant Factor C (rFC). The rFC is a 132 kDa molecule, which was produced as a proenzyme inducible by the presence of trace levels of endotoxin. The rFC forms the basis of the "PyroGene" kit, which is a novel micro

  16. Detection of peptidoglycan and endotoxin in dialysate, using silkworm larvae plasma and limulus amebocyte lysate methods.

    PubMed

    Tsuchida, K; Takemoto, Y; Yamagami, S; Edney, H; Niwa, M; Tsuchiya, M; Kishimoto, T; Shaldon, S

    1997-01-01

    Silkworm larvae plasma (SLP) reagent is activated by peptidoglycan (PG), a fragment of both the gram-positive and gram-negative bacterial cell wall, as well as beta-glucan (BG), a component of fungi. It is possible to measure contamination of gram-positive bacteria quantitatively by combining the conventional limulus amebocyte lysate (LAL) and PG measurement methods. Therefore, a more highly accurate analysis of dialysate can be made using both SLP and LAL methods to detect endotoxin (ET) and/or PG contamination. We studied the effects of contaminated dialysate on human peripheral blood mononuclear cells (PBMC) by producing various cytokines in vitro. Muramyl dipeptide (MDP) was used as the biologically active minimum constituent of PG. A total of 54 dialysate samples were obtained under sterile conditions from 4 sites: (1) reverse osmosis water unit; (2) proportioning unit; (3) multiple dialysate preparation console, and (4) personal dialysate preparation console, at 9 dialysis facilities. To detect bacterial contamination, the samples were measured with LAL(C), LAL(G) and SLP methods. PBMC were collected from 10 healthy controls and from 10 hemodialysis patients and cultured for 24 h with ET, MDP, ET + MDP and contaminated dialysate. IL-1 receptor antagonist (IL-1Ra), IL-1 beta and TNF-alpha in the culture medium supernatants were measured using the ELISA method. PG was not detected in dialysate from sites 1 or 2. However, dialysate from the inlet of the dialyzer at the bedside monitor of the central supply and personal console showed 4.1 +/- 6.1 ng/ml for site 3 (in 7 of 18 samples) and 3.3 +/- 4.6 ng/ml for site 4 (in 3 of 18 samples). Contamination by PG alone and complex contamination by PG and ET were also detected. Furthermore, IL-1Ra, IL-1 beta and TNF-alpha production by PBMC increased in accordance with the concentrations of MDP. Cytokine production was enhanced 5-10 times more where MDP and ET coexisted than where either MDP or ET existed alone, showing

  17. Detection of light-induced changes of intracellular ionized calcium concentration in Limulus ventral photoreceptors using arsenazo III

    PubMed Central

    Brown, J. E.; Brown, P. K.; Pinto, L. H.

    1977-01-01

    1. The metallochromic indicator dye, arsenazo III, was injected intracellularly into Limulus ventral photoreceptor cells to concentrations greater than 1 mM. 2. The absorption spectrum (450-750 nm) of the dye in single dark-adapted cells was measured by a scanning microspectrophotometer. When a cell was light-adapted, the absorption of the dye changed; the difference spectrum had two maxima at about 610 and 660 nm, a broad minimum at about 540 nm and an isosbestic point at about 585 nm. 3. When intracellular calcium concentration was raised in dark-adapted cells previously injected with arsenazo III, the difference spectum had two maxima at about 610 and 660 nm, a broad minimum at about 530 nm and an isosbestic point at about 585 nm. The injection of Mg2+ into dark-adapted cells previously injected with the dye induced a difference spectrum that had a single maximum at about 620 nm. Also, decreasing the intracellular pH of cells previously injected with the dye induced a difference spectrum that had a minimum at about 620 nm. The evidence suggests that there is a rise of intracellular ionized calcium when a Limulus ventral photoreceptor is light-adapted. 4. The intracellular calcium concentration, [Ca2+]1, in light-adapted photoreceptors was estimated to reach at least 10-4 M by compaing the light-induced difference spectra measured in ventral photoreceptors with a standard curve determined in microcuvettes containing 2mM arsenazo III in 400 mM-KCl, 1 mM-MgCl2 and 25 mM MOPS at pH 7·0. 5. In cells injected to less than 3 mM arsenazo III, light induced a transient decrease in optical transmission at 660 nm (T660). This decrease in T660 indicates that illumination of a ventral photoreceptor normally causes a transient increase of [Ca2+]1. 6. Arsenazo III was found to be sensitive, selective and rapid enough to measure light-induced changes of intracellular ionized calcium in Limulus ventral photoreceptor cells. PMID:17732

  18. A quantitative comparison of the effects of intracellular calcium injection and light adaptation on the photoresponse of Limulus ventral photoreceptors

    PubMed Central

    1977-01-01

    Calcium ions were iontophoretically injected into ventral photoreceptors of Limulus by passing current between two intracellular pipettes. Changes in sensitivity and photoresponse time course were measured for both light adaptation and Ca++ injection. We found for some photoreceptors that there was no significant difference in the photoresponse time course for desensitization produced by light adaptation or by Ca++ injection. In other photoreceptors, the time delay of photoresponse for Ca++ injection was slightly longer than for light adaptation. The variability of threshold response amplitude and time delay decreases when the photoreceptor is desensitized by either light adaptation or Ca++ injection. The peak amplitude versus log stimulus intensity relationships for controls, light adaptation, and Ca++ injection all could be described very closely by a single template curve shifted along the log intensity axis. A 40- to 50-fold change in sensitivity is associated with a 2-fold change in photoresponse time delay for both light adaptation and Ca++ injection. PMID:591913

  19. The Effects of Intracellular Iontophoretic Injection of Calcium and Sodium Ions on the Light Response of Limulus Ventral Photoreceptors

    PubMed Central

    Lisman, J. E.; Brown, J. E.

    1972-01-01

    During intracellular iontophoretic injection of Ca++ into Limulus ventral photoreceptor cells, there is a progressive diminution of the light response. Following Ca++ injection, the size of the light response slowly recovers. Similarly, there is a progressive diminution of the light response during intracellular injection of Na+ and recovery after the injection is stopped. The rate of diminution during Na+ injection is greater for higher [Ca++]out. In solutions which contain 0.1 mM Ca++, there is nearly no progressive decrease in the size of the light response during Na+ injection. Intracellular injections of Li+ or K+ do not progressively decrease the size of the light response. We propose that an increase in [Na+]in leads to an increase in [Ca++]in and that an increase in [Ca++]in by any means leads to a reduction in responsiveness to light. PMID:5025746

  20. The effects of isolation on the demography and genetic diversity of long-lived species: Implications for conservation and management of the gopher tortoise (Gopherus polyphemus)

    USGS Publications Warehouse

    Ennen, J.R.; Birkhead, R.D.; Kreiser, B.R.; Gaillard, D.L.; Qualls, C.P.; Lovich, J.E.

    2011-01-01

    In the southeastern United States, habitat loss has fragmented the landscape and isolated many populations of this region's flora and fauna, which has presumably resulted in smaller population sizes and reduced levels of genetic diversity. For example, forestry practices and anthropogenic disturbances are both cited as factors fragmenting the once extensive range of Gopherus polyphemus. One localized, but extreme, source of fragmentation was the impoundment of the Chattahoochee River in 1963 to form Walter F. George Reservoir along the border of Georgia and Alabama. The formation of this reservoir isolated populations of G. polyphemus on two newly created islands providing a natural laboratory to explore the demographics and genetic effects of fragmentation on a long-lived species. These populations were first surveyed in 1984 and, 21 years later, we revisited them to collect demographic data and tissue samples for genetic analysis. We genotyped all individuals for 10 microsatellite loci, and we tested these data for bottlenecks and compared them to levels of genetic diversity for populations from other portions of the range. We found 45 and two individuals on the larger and smaller islands, respectively. On the large island, however, the population size was identical to the 1984 survey. Only the population structure based on estimated age differed between the 1984 and 2004 surveys, while population size structure based on carapace length, sex ratio, and sex-specific growth rates did not differ. The population of the large island showed genetic evidence of a past bottleneck. The genetic diversity indices from the population of the large island, however, were comparable to or greater than those found at mainland sites, in particular from western populations.

  1. Development and use of an indirect enzyme-linked immunosorbent assay for detection of iridovirus exposure in gopher tortoises (Gopherus polyphemus) and eastern box turtles (Terrapene carolina carolina).

    PubMed

    Johnson, April J; Wendland, Lori; Norton, Terry M; Belzer, Bill; Jacobson, Elliott R

    2010-05-19

    Iridoviruses, pathogens typically associated with fish and amphibians, have recently been shown to cause acute respiratory disease in chelonians including box turtles, red-eared sliders, gopher tortoises, and Burmese star tortoises. Case reports of natural infections in several chelonian species in the United States have been reported, however the prevalence remains unknown in susceptible populations of free-ranging chelonians. To determine the prevalence of iridovirus exposure in free-ranging gopher tortoises (Gopherus polyphemus) in the southeast United States, an indirect enzyme-linked immunosorbent assay (ELISA) was developed and used to evaluate plasma samples from wild gopher tortoises (G. polyphemus) from: Alabama (n=9); Florida (n=658); Georgia (n=225); Louisiana (n=12); Mississippi (n=28); and unknown locations (68) collected between 2001 and 2006. Eight (1.2%) seropositive tortoises were identified from Florida and seven (3.1%) from Georgia for an overall prevalence of 1.5%. Additionally, a population of eastern box turtles was sampled from a private nature sanctuary in Pennsylvania that experienced an outbreak of iridovirus the previous year, which killed 16 turtles. Only 1 turtle out of 55 survivors tested positive (1.8%). Results suggest a low exposure rate in chelonians to this pathogen; however, it is suspected that this is an underestimate of the true prevalence. Since experimental transmission studies and past outbreaks have shown a high rate of mortality in infected turtles, turtles may die before they develop an antibody response. Further, the duration of the antibody response is unknown and may also cause an underestimate of the true prevalence. PMID:19931321

  2. Application of WRF/Chem-MADRID and WRF/Polyphemus in Europe - Part 2: Evaluation of chemical concentrations and sensitivity simulations

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Sartelet, K.; Zhu, S.; Wang, W.; Wu, S.-Y.; Zhang, X.; Wang, K.; Tran, P.; Seigneur, C.; Wang, Z.-F.

    2013-07-01

    An offline-coupled model (WRF/Polyphemus) and an online-coupled model (WRF/Chem-MADRID) are applied to simulate air quality in July 2001 at horizontal grid resolutions of 0.5° and 0.125° over Western Europe. The model performance is evaluated against available surface and satellite observations. The two models simulate different concentrations in terms of domainwide performance statistics, spatial distribution, temporal variations, and column abundance. WRF/Chem-MADRID at 0.5° gives higher values than WRF/Polyphemus for the domainwide mean and over polluted regions in Central and southern Europe for all surface concentrations and column variables except for the tropospheric ozone residual (TOR). Compared with observations, WRF/Polyphemus gives better statistical performance for daily HNO3, SO2, and NO2 at the European Monitoring and Evaluation Programme (EMEP) sites, maximum 1 h O3 at the AirBase sites, PM2.5 at the AirBase sites, maximum 8 h O3 and PM10 composition at all sites, column abundance of CO, NO2, TOR, and aerosol optical depth (AOD), whereas WRF/Chem-MADRID gives better statistical performance for NH3, hourly SO2, NO2, and O3 at the AirBase and BDQA (Base de données de la qualité de l'air) sites, maximum 1 h O3 at the BDQA and EMEP sites, and PM10 at all sites. WRF/Chem-MADRID generally reproduces well the observed high hourly concentrations of SO2 and NO2 at most sites except for extremely high episodes at a few sites, and WRF/Polyphemus performs well for hourly SO2 concentrations at most rural or background sites where pollutant levels are relatively low, but it underpredicts the observed hourly NO2 concentrations at most sites. Both models generally capture well the daytime maximum 8 h O3 concentrations and diurnal variations of O3 with more accurate peak daytime and minimal nighttime values by WRF/Chem-MADRID, but neither model reproduces extremely low nighttime O3 concentrations at several urban and suburban sites due to underpredictions of

  3. Application of WRF/Chem-MADRID and WRF/Polyphemus in Europe - Part 2: Evaluation of chemical concentrations, sensitivity simulations, and aerosol-meteorology interactions

    NASA Astrophysics Data System (ADS)

    Zhang, Y.; Sartelet, K.; Zhu, S.; Wang, W.; Wu, S.-Y.; Zhang, X.; Wang, K.; Tran, P.; Seigneur, C.; Wang, Z.-F.

    2013-02-01

    An offline-coupled model (WRF/Polyphemus) and an online-coupled model (WRF/Chem-MADRID) are applied to simulate air quality in July 2001 at horizontal grid resolutions of 0.5° and 0.125° over western Europe. The model performance is evaluated against available surface and satellite observations. The two models simulate different concentrations in terms of domainwide performance statistics, spatial distribution, temporal variations, and column abundance. WRF/Chem-MADRID at 0.5° gives higher values than WRF/Polyphemus for the domainwide mean and over polluted regions in central and southern Europe for all surface concentrations and column variables except for TOR. Compared with observations, WRF/Polyphemus gives better statistical performance for daily HNO3, SO2, and NO2 at the EMEP sites, max 1-h O3 at the AirBase sites, PM2.5 at the AirBase sites, max 8-h O3 and PM10 composition at all sites, column abundance of CO, NO2, TOR, and AOD, whereas WRF/Chem-MADRID gives better statistical performance for NH3, hourly SO2, NO2, and O3 at the AirBase and BDQA sites, max 1-h O3 at the BDQA and EMEP sites, and PM10 at all sites. WRF/Chem-MADRID generally reproduces well the observed high hourly concentrations of SO2 and NO2 at most sites except for extremely high episodes at a few sites, and WRF/Polyphemus performs well for hourly SO2 concentrations at most rural or background sites where pollutant levels are relatively low, but it underpredicts the observed hourly NO2 concentrations at most sites. Both models generally capture well the daytime max 8-h O3 concentrations and diurnal variations of O3 with more accurate peak daytime and minimal nighttime values by WRF/Chem-MADRID, but neither models reproduce extremely low nighttime O3 concentrations at several urban and suburban sites due to underpredictions of NOx and thus insufficient titration of O3 at night. WRF/Polyphemus gives more accurate concentrations of PM2.5, and WRF/Chem-MADRID reproduces better the observations

  4. Quantitative lipopolysaccharide analysis using HPLC/MS/MS and its combination with the limulus amebocyte lysate assay.

    PubMed

    Pais de Barros, Jean-Paul; Gautier, Thomas; Sali, Wahib; Adrie, Christophe; Choubley, Hélène; Charron, Emilie; Lalande, Caroline; Le Guern, Naig; Deckert, Valérie; Monchi, Mehran; Quenot, Jean-Pierre; Lagrost, Laurent

    2015-07-01

    Quantitation of plasma lipopolysaccharides (LPSs) might be used to document Gram-negative bacterial infection. In the present work, LPS-derived 3-hydroxymyristate was extracted from plasma samples with an organic solvent, separated by reversed phase HPLC, and quantitated by MS/MS. This mass assay was combined with the limulus amebocyte lysate (LAL) bioassay to monitor neutralization of LPS activity in biological samples. The described HPLC/MS/MS method is a reliable, practical, accurate, and sensitive tool to quantitate LPS. The combination of the LAL and HPLC/MS/MS analyses provided new evidence for the intrinsic capacity of plasma lipoproteins and phospholipid transfer protein to neutralize the activity of LPS. In a subset of patients with systemic inflammatory response syndrome, with documented infection but with a negative plasma LAL test, significant amounts of LPS were measured by the HPLC/MS/MS method. Patients with the highest plasma LPS concentration were more severely ill. HPLC/MS/MS is a relevant method to quantitate endotoxin in a sample, to assess the efficacy of LPS neutralization, and to evaluate the proinflammatory potential of LPS in vivo. PMID:26023073

  5. The initial response of Limulus ventral photoreceptors to bright flashes. Released calcium as a synergist to excitation

    PubMed Central

    Payne, R; Fein, A

    1986-01-01

    The leading edge of the response of Limulus ventral photoreceptors to brief flashes was investigated using a voltage clamp. The leading edge of responses increases linearly with flash intensity when dim flashes produce less than one photoisomerization per square micron of cell surface. Brighter flashes accelerate the initial portion of the response, resulting in a fourth-power relationship between the magnitude of the response at brief times after the flash and the flash intensity. The onset of this nonlinearity with increasing flash intensity is determined by the local density of photoisomerizations within the receptor. Responses to bright 10-15-mum-diam spots therefore rise faster than responses to diffuse flashes producing the same number of photoisomerizations within the receptor. Background illumination shortens the response latency and suppresses the initial nonlinearity. These phenomena can be explained by a model of transduction in which light activates two parallel cascades of reactions. Particles released by the first of these cascades open ionic channels, while the second produces an agent that accelerates the rate of production of particles by the first. Injection of the calcium buffer EGTA slows the initial portion of the response to bright flashes and suppresses its nonlinearity, which suggests that the accelerating agent released by the second cascade is calcium. PMID:3081681

  6. Increased intracellular sodium mimics some but not all aspects of photoreceptor adaptation in the ventral eye of Limulus

    PubMed Central

    1977-01-01

    The effects of the intracellular iontophoretic injection of Na+ ions have been quantitatively compared with adaptation in ventral photoreceptors of Limulus. We find that: (a) both light adaptation and sodium injection are associated with a decrease in the variability of the threshold response amplitued; (b) both light adaptation and sodium injection are associated with a decrease in the absolute value of the temporal dispersion of the threshold response time delay; (c) the same template curve adequately fits the intensity response relationships measured under light adaptation and Na+ injection; (d) both light adaptation and Na+ injection produce a fourfold decrease in response time delay for a desensitization of 3 log units; (e) the time coures of light adaptation and dark adaptation is significantly faster than the onset of and recovery from desensitization produced by Na+ injection; (f) unlike local illumination, Na+ injection does not produce localized desensitization of the photoreceptor. These findings suggest that a rise in intracellular Na+ concentration makes at most only a minor contribution (probably less than 5%) to the total adaptation of these receptors in the intensity range we have examined (up to 3 log units above absolute threshold). However, changes in intracellular Na+ concentration may contribute to certain components of light and dark adaptation in these receptors. PMID:591914

  7. Quantitative lipopolysaccharide analysis using HPLC/MS/MS and its combination with the limulus amebocyte lysate assay[S

    PubMed Central

    Pais de Barros, Jean-Paul; Gautier, Thomas; Sali, Wahib; Adrie, Christophe; Choubley, Hélène; Charron, Emilie; Lalande, Caroline; Le Guern, Naig; Deckert, Valérie; Monchi, Mehran; Quenot, Jean-Pierre; Lagrost, Laurent

    2015-01-01

    Quantitation of plasma lipopolysaccharides (LPSs) might be used to document Gram-negative bacterial infection. In the present work, LPS-derived 3-hydroxymyristate was extracted from plasma samples with an organic solvent, separated by reversed phase HPLC, and quantitated by MS/MS. This mass assay was combined with the limulus amebocyte lysate (LAL) bioassay to monitor neutralization of LPS activity in biological samples. The described HPLC/MS/MS method is a reliable, practical, accurate, and sensitive tool to quantitate LPS. The combination of the LAL and HPLC/MS/MS analyses provided new evidence for the intrinsic capacity of plasma lipoproteins and phospholipid transfer protein to neutralize the activity of LPS. In a subset of patients with systemic inflammatory response syndrome, with documented infection but with a negative plasma LAL test, significant amounts of LPS were measured by the HPLC/MS/MS method. Patients with the highest plasma LPS concentration were more severely ill. HPLC/MS/MS is a relevant method to quantitate endotoxin in a sample, to assess the efficacy of LPS neutralization, and to evaluate the proinflammatory potential of LPS in vivo. PMID:26023073

  8. Ethics on Exhibit

    ERIC Educational Resources Information Center

    Vick, Randy M.

    2011-01-01

    This article discusses ethical questions raised by an exhibition of work by an artist with a history of mental illness and the exhibition's relevance to art therapy and “outsider art” discourse on the subject. Considerations for how such an exhibit could be handled had the circumstances included an art therapist and art therapy client are…

  9. An Exhibit for Touching.

    ERIC Educational Resources Information Center

    Hunt, Susan

    1979-01-01

    An exhibit designed for visually handicapped persons presented by the Kalamazoo (Michigan) Institute of Art included bronze sculptures and oil paintings from the institute's permanent collection. (CL)

  10. A quantitative comparison of the time-course of sensitivity changes produced by calcium injection and light adaptation in Limulus ventral photoreceptors.

    PubMed Central

    Fein, A; Charlton, J S

    1978-01-01

    The time-course of light and dark adaptation was quantitatively compared with the time-course of the onset of and recovery from desensitization produced by intracellular calcium injection in Limulus ventral photoreceptors. The onset of light adaptation tended to be faster (by 60-90 s) than the onset of desensitization produced by intracellular Ca++ injection. The initial portion of the time-course of dark adaptation was faster (about 10-20 s) than the time-course of recovery from desensitization produced by intracellular Ca++ injection. The final portion of recovery from Ca++ injection had the same time-course as a comparable dark adaptation. PMID:638219

  11. San Rafael Schools Exhibit.

    ERIC Educational Resources Information Center

    San Rafael City Schools, CA.

    The San Rafael City Schools' exhibit which was displayed at the 1983 Marin County Fair (California) is described. The exhibit, entitled "Education - A Real Winner," consisted of 12 display panels illustrating the following aspects of the school system: (1) early history from 1861; (2) present board and administration; (3) present schools and…

  12. A Teaching Aids Exhibition.

    ERIC Educational Resources Information Center

    Mahanja, Salah

    1985-01-01

    Describes an exhibition for the benefit of teachers of English in Arab Primary Schools, which was prepared by third-year students at the Teachers College for Arab Teachers. The exhibition included games, songs, audiovisual aids, crossword puzzles, vocabulary, spelling booklets, preposition aids, and worksheet and lesson planning aids. (SED)

  13. Visitors Center Exhibits

    NASA Technical Reports Server (NTRS)

    1997-01-01

    A child enjoys building his own LEGO model at a play table which was included in the exhibit 'Travel in Space' World Show. The exhibit consisted of 21 displays designed to teach children about flight and space travel from the Wright brothers to future generations of space vehicles.

  14. [Usefulness of endotoxin-specific limulus test for the measurement of endotoxin in cerebrospinal fluid in diagnosis of bacterial meningitis].

    PubMed

    Ichinohe, S; Inada, K; Nemoto, T; Murata, A; Ichinohe, N; Fujiwara, T; Yoshida, M

    1995-11-01

    Using a new endotoxin-specific chromogneic limulus assay (Endoscopy test), endotoxin concentrations were measured in 93 specimens of cerebrospinal fluid (CSF) from 66 pediatric patients. Eighteen patients were diagnosed as having menigitios. Of these, 6 cases (group A) with gram-negative meningitis proven by culture had high CSF endotoxin concentrations of 115.3, (82-133) (median, range) pg/ml. Ten cases (group B) with gram-positive or aseptic meningitis had endotoxin concentrations of 2.15 (0.1-3.6) pg ml. Other 2 cases with bacterial meningitis (group C), in whom no pathogen was detected, had CSF endotoxin concentrations of more than 100 pg/ml. Four cases with encephalitis (group D) and 45 cases with non-meningitis or non- encephalitis (group E), had CSF endotoxin concentrations of less than 5 pg/ml. Despite a negative culture after antibiotic treatment in group A patients, endotoxin was cleared slowly from the CSF. A clearing of endotoxin from CSF was followed by alleviation of fever with a more gradual decline in CRP values. In 2 cases of group C, the negative bacterial culture appeared to be attributable to the previous treatment with antibiotics. However, these patients had high CSF endotoxin levels, indicating gram negative bacterial meningitis. In 17 CSF specimens from 5 patients of group A, in whom Haemophilus influenzae was detected on admission, an additional a latex agglutination test for the detection of H. influenzae polysaccharide antigen was performed. Only 3 specimens from 3 patients with CSF endotoxin concentrations of more than 80 pg/ml had a positive agglutination test. These results suggest that quantitation of endotoxin concentrations is useful for the diagnosis of gram-negative meningitis. And also, the clearance of endotoxin from CSF during treatment appears to be useful in determining the timing of when antibiotic should be stopped. PMID:8708402

  15. Human endothelial cell-based assay for endotoxin as sensitive as the conventional Limulus Amebocyte Lysate assay.

    PubMed

    Unger, Ronald E; Peters, Kirsten; Sartoris, Anne; Freese, Christian; Kirkpatrick, C James

    2014-03-01

    Endotoxin, also known as lipopolysaccharide (LPS) produced by bacteria can be present in any liquid or on any biomaterial even if the material is sterile. Endotoxin in mammals can cause fever, inflammation, cell and tissue damage and irreversible septic shock and death. In the body, endothelial cells making up the blood vasculature and endothelial cells in vitro rapidly react to minute amounts of endotoxin resulting in a rapid induction of the cell adhesion molecule E-selectin. In this study we have used immunofluorescent staining to evaluate the expression of E-selectin on human microvascular endothelial cells from the skin (HDMEC) and human umbilical vein endothelial cells (HUVEC) exposed to various concentrations of LPS. In addition, the sensitivity of detection was compared with the most widely used assay for the presence of endotoxin, the Limulus Amebocyte Lysate assay (LAL). The detection of E-selectin on endothelial cells in the presence of LPS for 4 h was found to be at least as sensitive in detecting the same concentration using the LAL assay. A cell adhesion molecule-enzyme immunosorbent assay was also developed and used to quantify LPS using the endothelial cell model. A comparison of LAL and the immunofluorescent staining method was carried out with solutions, nanoparticles, biomaterial extracts and endothelial cells grown directly on biomaterials. Under all conditions, the endothelial/E-selectin model system was positive for the test samples that were positive by LAL. Thus, we propose the use of this highly sensitive, rapid, reproducible assay for the routine testing of endotoxin in all steps in the manufacturing process of materials destined for use in humans. This can give a rapid feedback and localization of bacterial contamination sources with the LAL being reserved for the testing of the final product. PMID:24456607

  16. Multiple conductance states of the light-activated channel of Limulus ventral photoreceptors. Alteration of conductance state during light

    PubMed Central

    1991-01-01

    The properties of light-dependent channels in Limulus ventral photoreceptors have been studied in cell-attached patches. Two sizes of single-channel events are seen during illumination. Previous work has characterized the large (40 pS) events; the goal of the current work was to characterize the small (15 pS) events and determine their relationship to the large events. The small events are activated by light rather than as a secondary result of the change in membrane voltage during light. The mean open time of the small events is 1.34 +/- 0.49 ms (mean +/- SD, n = 15), approximately 50% of that of the large events. The large and small events have the same reversal potential and a similar dependence of open-state probability on voltage. Evidence that these events are due to different conductance states of the same channel comes from analysis of relatively infrequent events showing a direct transition between the 15 and 40-pS levels. Furthermore, large and small events do not superpose, even at positive voltages when the probability of being open is very high, as would be predicted if the two-sized events were due to independent channels. Expression of the different conductance states is not random; during steady illumination there are alternating periods of several hundred milliseconds in which there are consecutive, sequential large events followed by periods in which there are consecutive, sequential small events. At early times during the response to a step of light, the large conductance state is preferentially expressed. At later times, there is an increase in the relative contribution of the low conductance state. These findings indicate that there is a process that changes the preferred conductance state of the channel. This alteration has functional importance in the process of light adaptation. PMID:1875187

  17. Evaluation of the endotoxin binding efficiency of clay minerals using the Limulus Amebocyte lysate test: an in vitro study

    PubMed Central

    2014-01-01

    Endotoxins are part of the cell wall of Gram-negative bacteria. They are potent immune stimulators and can lead to death if present in high concentrations. Feed additives, which bind endotoxins in the gastrointestinal tract of animals, could help to prevent their negative impact. The objective of our study was to determine the potential of a bentonite (Bentonite 1), a sodium bentonite (Bentonite 2), a chemically treated smectite (Organoclay 1) and a modified attapulgite (Organoclay 2) to bind endotoxins in vitro. Polymyxin B served as positive control. The kinetic chromogenic Limulus Amebocyte lysate test was adapted to measure endotoxin activity. Firstly, a single sorption experiment (10 endotoxin units/mL (EU/mL)) was performed. Polymyxin B and organoclays showed 100% binding efficiency. Secondly, the adsorption efficiency of sorbents in aqueous solution with increasing endotoxin concentrations (2,450 – 51,700 EU/mL) was investigated. Organoclay 1 (0.1%) showed a good binding efficiency in aqueous solution (average 81%), whereas Bentonite 1 (0.1%) obtained a lower binding efficiency (21-54%). The following absorbent capacities were calculated in highest endotoxin concentration: 5.59 mg/g (Organoclay 1) > 3.97 mg/g (Polymyxin B) > 2.58mg/g (Organoclay 2) > 1.55 mg/g (Bentonite 1) > 1.23 mg/g (Bentonite 2). Thirdly, a sorption experiment in artificial intestinal fluid was conducted. Especially for organoclays, which are known to be unspecific adsorbents, the endotoxin binding capacity was significantly reduced. In contrast, Bentonite 1 showed comparable results in artificial intestinal fluid and aqueous solution. Based on the results of this in vitro study, the effect of promising clay minerals will be investigated in in vivo trials. PMID:24383578

  18. Communicating Science through Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P.; Harold, J.; Morrow, C.

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. There are many ways for scientists to help develop science exhibitions. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). Two of its exhibitions, Space Weather Center and MarsQuest, are currently on tour. Another exhibition, Alien Earths, is in development. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. MarsQuest is a 5000 square-foot traveling exhibition. The exhibit's second 3-year tour began this January at the Detroit Science Center. It is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. The 3,000 square-foot traveling exhibition, called Alien Earths, will bring origins-related research and discoveries to students and the American public. Alien Earths has four interrelated exhibit areas: Our Place in Space, Star Birth, PlanetQuest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in ``habitable zones'' around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. Besides the exhibits, SSI is also developing interactive web sites based on exhibit themes. New technologies are transforming the Web from a static medium to an interactive environment with tremendous

  19. New Hurricane Exhibit

    NASA Technical Reports Server (NTRS)

    2007-01-01

    A new exhibit in StenniSphere depicting NASA's role in hurricane prediction and research and SSC's role in helping the region recover from Hurricane Katrina. The cyclone-shaped exhibit focuses on the effects of the Aug. 29, 2005 storm and outlines how NASA is working to improve weather forecasting. Through photos, 3-D models and digital animations, the exhibit tells the story of what happened inside the storm and how NASA's scientific research can increase the accuracy of hurricane tracking and modeling.

  20. Communicating Science through Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, Paul

    2005-04-01

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. Science exhibitions also provide a marvelous opportunity for scientists to become engaged in the exhibit development process. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). The focus of this presentation will be on two of its exhibit projects: MarsQuest (on tour for four years) and Alien Earths (its tour began early in 2005). MarsQuest is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. Alien Earths will bring origins-related research and discoveries to students and the American public. It has four interrelated exhibit areas: Our Place in Space, Star Birth, Planet Quest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in ``habitable zones'' around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. SSI is also developing interactive web sites based on exhibit themes. New technologies are transforming the Web from a static medium to an interactive environment with tremendous potential for informal education and inquiry-based investigations. This talk will focus on the role informal science projects play in effectively communicating science to a broad, public audience.

  1. Test Control Center exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Have you ever wondered how the engineers at John C. Stennis Space Center in Hancock County, Miss., test fire a Space Shuttle Main Engine? The Test Control Center exhibit at StenniSphere can answer your questions by simulating the test firing of a Space Shuttle Main Engine. A recreation of one of NASA's test control centers, the exhibit explains and portrays the 'shake, rattle and roar' that happens during a real test firing.

  2. Swamp to Space exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The menacing-looking alligator is really harmless. It is one of the realistic props to help convince visitors that the feel of the swamp is real in StenniSphere's Swamp to Space exhibit at John C. Stennis Space Center in Hancock County, Miss. The historical section of the Swamp to Space exhibit tells the story of why and how Stennis Space Center came to be. It also pays tribute to the families who moved their homes to make way for the space age in Mississippi.

  3. A Palaeozoic Puzzle in Cenozoic Science.

    ERIC Educational Resources Information Center

    Mikkelsen, Tom

    1982-01-01

    The sword-tailed horseshoe crab (Limulus polyphemus) has developed its own defense against bacteria surrounding it. This defense system, under the name "Limulus test," now provides medicine and hygiene with a valuable means of detecting bacterial endotoxins at extremely low levels. (Author/JN)

  4. Limulus ventral eye. Physiological properties of photoreceptor cells in an organ culture medium

    PubMed Central

    1978-01-01

    Ventral photoreceptor cells bathed in an organ culture medium typically have resting potentials of -85 mV and membrane resistances of 35 Momega and, when dark-adapted, exhibit large potential fluctuations (LPFs) of 60 mV and small potential fluctuations (SPFs) of less than 30 mV. LPFs appear to be regenerative events triggered by SPFs, the well-known quantum bumps. In the dark, SPFs and LPFs occur spontaneously. At intensities near threshold, the rate of occurrence is directly proportional to light intensity, indicating that SPFs and LPFs are elicited by single photon events. At higher intensities, SPFs and LPFs sum to produce a receptor potential that is graded over approximately a 9-log-unit range of light intensity. Amplitude histograms of the discrete potential waves are bimodal, reflecting the SPF and LPF populations. Histograms of current waves are unimodal. SPFs and LPFs are insensitive to 1 microgram tetrodotoxin. I-V characteristics show initial inward currents of approximately 15 nA for voltage clamps to - 40 mV and steady-state outward currents for all clamp potentials. Photoreceptor cells bathed in organ culture medium retain these properties for periods of at least 75 days. PMID:722278

  5. 1989 Architectural Exhibition Winners.

    ERIC Educational Resources Information Center

    School Business Affairs, 1990

    1990-01-01

    Winners of the 1989 Architectural Exhibition sponsored annually by the ASBO International's School Facilities Research Committee include the Brevard Performing Arts Center (Melbourne, Florida), the Capital High School (Santa Fe, New Mexico), Gage Elementary School (Rochester, Minnesota), the Lakewood (Ohio) High School Natatorium, and three other…

  6. Exhibitions in Sight

    ERIC Educational Resources Information Center

    Wasserman, Burton

    1978-01-01

    During this past year a vast number of art shows have been exhibited across the United States. Their most striking features were their range and diversity. Here are some comments on Ben Shahn's paintings and photography focusing on social realism, some works by the Polish Constructivists, interested in redefining form in relation to space, the…

  7. Electrogenic Na(+)-Ca2+ exchanger, the link between intra- and extracellular calcium in the Limulus ventral photoreceptor.

    PubMed Central

    Deckert, A; Stieve, H

    1991-01-01

    1. Limulus ventral photoreceptors were injected with Arsenazo III and the internal change in the calcium concentration, [Ca2+]i, was measured under voltage clamp conditions. It is shown that in response to a light flash the rising phase of the [Ca2+]i is independent of the clamp voltage, Vm. This observation is contrary to other results reported in the literature. Experiments are reported that resolve this contradiction (see paragraph 4). 2. The relaxation of the [Ca2+]i after a bright light flash was observed to have a fast and slow phase. A function consisting of the sum of an exponential and a ramp was fitted to the relaxation. The fast phase, characterized by the time constant of the exponential, was observed not to depend on Vm, while the slow phase, characterized by the slope of the ramp, was strongly dependent on Vm. Furthermore the slope of the slow phase is shown to depend on the external Na+ concentration, but not the time constant of the fast phase. 3. In the dark the [Ca2+]i was observed to increase when the cell was depolarized and to decrease when the cell was hyperpolarized. This observation was more pronounced when the cell was continuously illuminated. 4. When the cell was clamped to a depolarizing voltage before illumination of the cell, the maximum of the calcium indicator signal was observed to depend on how long the cell had been clamped before applying the light stimulus. This experiment resolves the contradiction mentioned in paragraph 1. 5. The results presented here are consistent with the interpretation that a Na(+)-Ca2+ exchanger with a stoichiometry greater than 2:1 is the predominant link between intra- and extracellular calcium. Secondly that the light-induced intracellular calcium increase comes from a release by intracellular stores. Finally a measurable uptake of calcium occurs after a light-induced release, possibly by the internal calcium stores. The two-phase recovery of [Ca2+]i after a light flash is interpreted as being a

  8. Skylab Exhibit Ribbon Cutting

    NASA Technical Reports Server (NTRS)

    1976-01-01

    A metal strap became tangled over one of the folded solar array panels when Skylab lost its micro meteoroid shield during its launch. Cutters like the ones used to free the solar array were used to cut the ribbon opening to the public a new full-scale Skylab cluster exhibit at the Alabama Space and Rocket Center in Huntsville, Alabama. Wielding the cutters are (left to right): Alabama Senator James B. Allen; Marshall Space Flight Center director, Dr. William R. Lucas, Huntsville Mayor, Joe Davis; Madison County Commission Chairman, James Record (standing behind Mayor Davis); and chairman of the Alabama Space Science Exhibit Commission, Jack Giles. Astronauts Conrad and Kerwin used the same type of tool in Earth orbit to cut the aluminum strap which jammed the Skylab solar array.

  9. Starship 2040 Exhibit

    NASA Technical Reports Server (NTRS)

    2002-01-01

    This photograph shows Justin Varnadore, son of a Marshall TV employee, at the controls of one of the many displays within the Starship 2040 exhibit on display at Joe Davis Stadium in Huntsville, Alabama. Developed by the Space Transportation Directorate at Marshall Space Flight Center (MSFC), the Starship 2040 exhibit is housed in a 48-ft (14.6-m) tractor and trailer rig, permitting it to travel around the Nation, demonstrating NASA's vision of what commercial spaceflight might be like 40 years from now. All the irnovations suggested aboard the exhibit (automated vehicle health monitoring systems, high-energy propulsion drive, navigational aids, and emergency and safety systems) are based on concepts and technologies now being studied at NASA Centers and partner institutions around the Nation. NASA is the Nation's premier agency for development of the space transportation system, including future-generation reusable launch vehicles. Such systems, the keys to a 'real' Starship 2040, require revolutionary advances in critical aerospace technologies, from thermal, magnetic, chemical, and propellantless propulsion systems to new energy sources such as space solar power or antimatter propulsion. These and other advances are now being studied, developed, and tested at NASA field centers and partner institutions all over the Nation.

  10. Online Exhibits & Concept Maps

    NASA Astrophysics Data System (ADS)

    Douma, M.

    2009-12-01

    Presenting the complexity of geosciences to the public via the Internet poses a number of challenges. For example, utilizing various - and sometimes redundant - Web 2.0 tools can quickly devour limited time. Do you tweet? Do you write press releases? Do you create an exhibit or concept map? The presentation will provide participants with a context for utilizing Web 2.0 tools by briefly highlighting methods of online scientific communication across several dimensions. It will address issues of: * breadth and depth (e.g. from narrow topics to well-rounded views), * presentation methods (e.g. from text to multimedia, from momentary to enduring), * sources and audiences (e.g. for experts or for the public, content developed by producers to that developed by users), * content display (e.g. from linear to non-linear, from instructive to entertaining), * barriers to entry (e.g. from an incumbent advantage to neophyte accessible, from amateur to professional), * cost and reach (e.g. from cheap to expensive), and * impact (e.g. the amount learned, from anonymity to brand awareness). Against this backdrop, the presentation will provide an overview of two methods of online information dissemination, exhibits and concept maps, using the WebExhibits online museum (www.webexhibits.org) and SpicyNodes information visualization tool (www.spicynodes.org) as examples, with tips on how geoscientists can use either to communicate their science. Richly interactive online exhibits can serve to engage a large audience, appeal to visitors with multiple learning styles, prompt exploration and discovery, and present a topic’s breadth and depth. WebExhibits, which was among the first online museums, delivers interactive information, virtual experiments, and hands-on activities to the public. While large, multidisciplinary exhibits on topics like “Color Vision and Art” or “Calendars Through the Ages” require teams of scholars, user interface experts, professional writers and editors

  11. Effects of mycoplasmal upper-respiratory-tract disease on movement and thermoregulatory behavior of gopher tortoises (Gopherus polyphemus) in Georgia, USA.

    PubMed

    McGuire, Jessica L; Smith, Lora L; Guyer, Craig; Yabsley, Michael J

    2014-10-01

    Abstract From 2011-12, we studied a gopher tortoise (Gopherus polyphemus) population with a historically high prevalence of antibodies to Mycoplasma agassizii to assess long-term effects of upper-respiratory-tract disease (URTD) on tortoise behavior. We radiotracked 30 adult tortoises (16 males, 14 females) from a long-term study site with the use of mark-recapture methods to determine site fidelity and to compare home-range size to that of a study in 1997. An additional 10 tortoises (six males, four females) with severe clinical signs of URTD from elsewhere in the study area were radiotracked and compared to tortoises that were asymptomatic or had only mild clinical signs. We also monitored thermoregulatory behavior of tortoises with the use of data loggers affixed to the carapace. There was no significant difference in home-range size between the asymptomatic tortoises and those with mild symptoms. Home ranges of tortoises with severe URTD were significantly larger than asymptomatic or mildly affected tortoises. Tortoises with severe clinical signs moved long distances over short periods, contradicting a hypothesis that chronically infected tortoises are less likely to emigrate. Prevalence of M. agassizii antibodies was similar among the three groups (98% overall), but prevalence of antibodies to a second pathogen associated with URTD, Mycoplasma testudineum, was lower in the asymptomatic (n=14, 7%) and mild-symptoms (n=7, 14%) groups than the severe-symptoms group (n=8, 50%). Variation in the average carapacial temperatures of tortoises with severe URTD was significantly different from carapacial temperatures of mild and asymptomatic tortoises, suggesting differences in thermoregulatory behavior of severely ill tortoises. Our 15-yr recapture data suggest that, despite high prevalence of M. agassizii, population density has not decreased over time. However, emigration, especially of tortoises with severe clinical disease, may play an important role in dispersal

  12. Space Shuttle Cockpit exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Want to sit in the cockpit of the Space Shuttle and watch astronauts work in outer space? At StenniSphere, you can do that and much more. StenniSphere, the visitor center at John C. Stennis Space Center in Hancock County, Miss., presents 14,000-square-feet of interactive exhibits that depict America's race for space as well as a glimpse of the future. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  13. Crystal structure of an endotoxin-neutralizing protein from the horseshoe crab, Limulus anti-LPS factor, at 1.5 A resolution.

    PubMed Central

    Hoess, A; Watson, S; Siber, G R; Liddington, R

    1993-01-01

    Lipopolysaccharide (LPS), or endotoxin, is the major mediator of septic shock, a serious complication of Gram-negative bacterial infections in humans. Molecules that bind LPS and neutralize its biological effects or enhance its clearance could have important clinical applications. Limulus anti-LPS factor (LALF) binds LPS tightly, and, in animal models, reduces mortality when administered before or after LPS challenge or bacterial infection. Here we present the high resolution structure of a recombinant LALF. It has a single domain consisting of three alpha-helices packed against a four-stranded beta-sheet. The wedge-shaped molecule has a striking charge distribution and amphipathicity that suggest how it can insert into membranes. The binding site for LPS probably involves an extended amphipathic loop, and we propose that two mammalian LPS-binding proteins will have a similar loop. The amphipathic loop structure may be used in the design of molecules with therapeutic properties against septic shock. Images PMID:8253062

  14. Simplified preparation of crude and functional coagulogen by thermal inactivation of serine proteases in Limulus amebocyte lysate and its application for rapid endotoxin determination.

    PubMed

    Yabusaki, Katsumi; Aoyagi, Hideki

    2012-03-01

    The effects of thermal treatment on Limulus amebocyte lysate (LAL) reagent were studied. Thermal resistances of enzymes and coagulogen in LAL reagent were evaluated by aggregometry and SDS-PAGE. Although enzyme activities of LAL reagent were completely lost after heating at temperatures above 60 °C for 10 min, gelating activities of coagulogen were retained even over 80 °C. Phenylmethanesulfonyl fluoride (PMSF; 1 mmol/mL), a strong non-specific serine-protease inhibitor, did not completely inactivate serine-protease activities of LAL. As a result, complete hydrolysis of coagulogen to coagulin was unexpectedly obtained. Solvent treatment of LAL was similar in effect to thermal treatment of LAL, but there were 2 problems: complete removal of solvent from samples and increased solution turbidity during preparation. To study the application of thermal-treated LAL, we conjugated it with titania particles. LAL-conjugated titania particles were obtained as small aggregates between titania nanoparticles and thermal-treated LAL (LAL-conjugated microbeads; LCM). When the mixture of LCMs and fresh LAL reagent was reacted with endotoxin an acute aggregation of LCMs was induced prior to the aggregate formation of LAL as monitored by stirring turbidimetry. This method, endotoxin microbeads aggregometry (EMA) may provide a rapid and sensitive method for endotoxin determination. PMID:22143069

  15. Application of quartz tuning forks for detection of endotoxins and Gram-negative bacterial cells by monitoring of Limulus Amebocyte Lysate coagulation.

    PubMed

    Chałupniak, Andrzej; Waszczuk, Karol; Hałubek-Głuchowska, Katarzyna; Piasecki, Tomasz; Gotszalk, Teodor; Rybka, Jacek

    2014-08-15

    Endotoxins, pyrogens of bacterial origin, are a significant threat in many areas of life. Currently, the test most commonly used for endotoxin level determination is LAL (Limulus Amebocyte Lysate) assay. This paper presents application of commercially available low-frequency piezoelectric tuning forks (QTFs) for endotoxin detection. Measurement of the decrease in the QTF oscillation amplitude provides information about the viscosity changes, occurring in the tested sample upon addition of LAL. That method was used to determine the concentrations of endotoxins and bacterial cells (E. coli O157:H19). The relevance of the obtained results was confirmed using a commercially available colorimetric LAL assay. The constructed system can detect bacterial endotoxins in the range of 0.001-5EU/ml and bacterial cells in the range of 10(2)-10(7)CFU/ml. The presented technique requires very simple sample preparation and the sensor response is obtained using compact, portable readout electronics. The single test cost is low compared to commercial endotoxin assays and other novel systems based on micromechanical sensors. PMID:24632139

  16. A screen-printed endotoxin sensor based on amperometry using a novel p-aminophenol conjugated substrate for a Limulus amebocyte lysate protease reaction.

    PubMed

    Inoue, Kumi Y; Takano, Shinichiro; Takahashi, Satoko; Ishida, Yosuke; Ino, Kosuke; Shiku, Hitoshi; Matsue, Tomokazu

    2013-11-01

    We developed a novel protease detection method based on amperometry using a p-aminophenol (pAP) conjugated substrate. We prepared Boc-Leu-Gly-Arg-pAP (LGR-pAP) as a novel substrate for a clotting enzyme, which is a protease activated by an endotoxin-induced Limulus amebocyte lysate (LAL) cascade reaction. The basic study using cyclic voltammetry revealed that the oxidation peak potentials of LGR-pAP and pAP were sufficiently separated from each other (0.25 V) to conduct amperometric detection of protease activity. We combined simple amperometric detection with a screen-printed electrode chip to produce a practical protease sensor. As an application of the sensor, we demonstrated quantitative endotoxin sensing. The endotoxin activated zymogens contained in the LAL to generate pAP, which was then electrochemically detected by potential step chronoamperometry (PSCA). The observed oxidation current increased with the concentration of endotoxin in the LAL assay solution. This PSCA detection was performed with a disposable chip sensor consisting of a screen-printed electrode and a fluidic channel with a hydrophilic cover. This chip sensor successfully detected 10-1000 EU L(-1) endotoxin within 60 min. This novel amperometric measurement with a screen-printed electrode not only provides compact, low-cost, and easy-to-use sensors for on-site monitoring of endotoxin, but also shows promise for use in other in vitro protease assays for biochemical research, diagnosis, and drug development. PMID:23978902

  17. Traveling Exhibitions: translating current science into effective science exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P.; Morrow, C.; Harold, J.

    The Space Science Institute (SSI) of Boulder, Colorado has recently developed two museum exhibits called the Space Weather Center and MarsQuest. It is currently planning to develop two other exhibitions called Cosmic Origins and InterActive Earth. Museum exhibitions provide research scientists the opportunity to engage in a number of activities that are vital to the success of earth and space outreach programs. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. The focus of the presentation will be on the Institute's MarsQuest exhibition. This project is a 5000 square-foot, 2.5M, traveling exhibition that is now touring the country. The exhibit's 3-year tour is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and learn more about their own planet in the process. The associated planetarium show and education program will also be described, with particular emphasis on workshops to orient host museum staff (e.g. museum educators and docents). The workshops make innovative connections between the exhibitions interactive experiences and lesson plans aligned with the National Science Education Standards. SSI is also developing an interactive web site called MarsQuest On-line. The linkage between the web site, education program and exhibit will be discussed. MarsQuest and SSI's other exhibitions are good models for actively involving scientists and their discoveries to help improve informal science education in the museum community and for forging a stronger connection between formal and informal education.

  18. Exhibitions: Facing Outward, Pointing Inward

    ERIC Educational Resources Information Center

    McDonald, Joseph P.

    2007-01-01

    The Coalition of Essential Schools (CES) Exhibitions Project of the early 1990s produced a range of work that continues to inform the practice of using exhibitions as a "360 degree" method of transforming teaching and learning, community connections, school design, and assessment. Among that work was this paper coupling the origins of exhibitions…

  19. Evaluation of the limulus amoebocyte lysate test in conjunction with a gram negative bacterial plate count for detecting irradiation of chicken

    NASA Astrophysics Data System (ADS)

    Scotter, Susan L.; Wood, Roger; McWeeny, David J.

    A study to evaluate the potential of the Limulus amoebocyte lysate (LAL) test in conjuction with a Gram negative bacteria (GNB) plate count for detecting the irradiation of chicken is described. Preliminary studies demonstrated that chickens irradiated at an absorbed dose of 2.5 kGy could be differentiated from unirradiated birds by measuring levels of endotoxin and of numbers of GNB on chicken skin. Irradiated birds were found to have endotoxin levels similar to those found in unirradiated birds but significantly lower numbers of GNB. In a limited study the test was found to be applicable to birds from different processors. The effect of temperature abuse on the microbiological profile, and thus the efficacy of the test, was also investigated. After temperature abuse, the irradiated birds were identifiable at worst up to 3 days after irradiation treatment at the 2.5 kGy level and at best some 13 days after irradiation. Temperature abuse at 15°C resulted in rapid recovery of surviving micro-organisms which made differentiation of irradiated and unirradiated birds using this test unreliable. The microbiological quality of the bird prior to irradiation treatment also affected the test as large numbers of GNB present on the bird prior to irradiation treatment resulted in larger numbers of survivors. In addition, monitoring the developing flora after irradiation treatment and during subsequent chilled storage also aided differentiation of irradiated and unirradiated birds. Large numbers of yeasts and Gram positive cocci were isolated from irradiated carcasses whereas Gram negative oxidative rods were the predominant spoilage flora on unirradiated birds.

  20. Measurement of β-(1,3)-glucan in household dust samples using Limulus amebocyte assay and enzyme immunoassays: an inter-laboratory comparison.

    PubMed

    Brooks, Collin R; Siebers, Rob; Crane, Julian; Noss, Ilka; Wouters, Inge M; Sander, Ingrid; Raulf-Heimsoth, Monika; Thorne, Peter S; Metwali, Nervana; Douwes, Jeroen

    2013-02-01

    Environmental levels of β-(1,3)-glucan, an inflammatory fungal cell wall component, have been suggested to be related to respiratory symptoms. However there is currently little data comparing β-(1,3)-glucan detection methods and/or results obtained in different laboratories. The aim of this study was to compare levels of β-(1,3)-glucans detected in household dust samples (n = 40) using different extraction/detection methods (Limulus amebocyte assay (LAL), inhibition enzyme immunoassay (EIA) and sandwich EIA) in five different laboratories. Dust sample aliquots were sent to participating centres, extracted and analysed for β-(1,3)-glucan according to standard in-house procedures. Significant differences in the levels of β-(1,3)-glucan were observed between all laboratories (geometric mean levels ranging from 15.4 μg g (-1) to 4754 μg g(-1) dust; p < 0.0001) with the exception of those using a similar LAL method. The inhibition EIA used in laboratory D produced mean β-(1,3)-glucan measurements 80-100 times higher than the LAL assays, 4 times higher than the sandwich EIA in the same lab, 17.6 times those obtained with the EIA in lab E and 363 times those obtained in the EIA in laboratory C. Pearson's correlations generally showed significant associations between methods and laboratories, particularly those using similar methodology (R ranging from 0.5 to 0.8; p < 0.001), although some poor and even inverse correlations were observed. Bland-Altman analyses showed moderate to good agreement between most assays, although clear absolute differences were observed. In conclusion, although results obtained with different methods were often significantly correlated and therefore comparable in relative terms, direct comparison of results between laboratories and assays may be inappropriate. PMID:25208705

  1. Against the Odds Exhibition Opens

    MedlinePlus

    ... the National Institutes of Health in Bethesda, Md. Photo courtesy of Bill Branson NIH Director Dr. Elias ... addresses visitors to the opening of the exhibition. Photo courtesy of Bill Branson Brothers Niko and Theo ...

  2. Against the Odds Exhibition Opens

    MedlinePlus

    ... Bar Home Current Issue Past Issues Special Section Against the Odds Exhibition Opens Past Issues / Spring 2008 ... Research in Bethesda. Photo courtesy of Bill Branson "Against the Odds" is a remarkable story of achievement ...

  3. Greenhouse Earth: A Traveling Exhibition

    SciTech Connect

    Booth, W.H.; Caesar, S.

    1992-09-01

    The Franklin Institute Science Museum provided an exhibit entitled the Greenhouse Earth: A Traveling Exhibition. This 3500 square-foot exhibit on global climate change was developed in collaboration with the Association of Science-Technology Centers. The exhibit opened at The Franklin Institute on February 14, 1992, welcoming 291,000 visitors over its three-month stay. During its three-year tour, Greenhouse Earth will travel to ten US cities, reaching two million visitors. Greenhouse Earth aims to deepen public understanding of the scientific issues of global warming and the conservation measures that can be taken to slow its effects. The exhibit features hands-on exhibitry, interactive computer programs and videos, a theater production, a demonstration cart,'' guided tours, and lectures. supplemental educational programs at the Institute included a teachers preview, a symposium on climate change, and a satellite field trip.'' The development of Greenhouse Earth included front-end and formative evaluation procedures. Evaluation includes interviews with visitors, prototypes, and summative surveys for participating museums. During its stay in Philadelphia, Greenhouse Earth was covered by the local and national press, with reviews in print and broadcast media. Greenhouse Earth is the first large-scale museum exhibit to address global climate change.

  4. Considering High-Tech Exhibits?

    ERIC Educational Resources Information Center

    Routman, Emily

    1994-01-01

    Discusses a variety of high-tech exhibit media used in The Living World, an educational facility operated by The Saint Louis Zoo. Considers the strengths and weaknesses of holograms, video, animatronics, video-equipped microscopes, and computer interactives. Computer interactives are treated with special attention. (LZ)

  5. Relationship between light sensitivity and intracellular free Ca concentration in Limulus ventral photoreceptors. A quantitative study using Ca-selective microelectrodes

    PubMed Central

    1985-01-01

    The possible role of Ca ions in mediating the drop in sensitivity associated with light adaptation in Limulus ventral photoreceptors was assessed by simultaneously measuring the sensitivity to light and the intracellular free Ca concentration (Cai); the latter was measured by using Ca-selective microelectrodes. In dark-adapted photoreceptors, the mean resting Cai was 3.5 +/- 2.5 microM SD (n = 31). No correlation was found between resting Cai and absolute sensitivity from cell to cell. Typically, photoreceptors are not uniformly sensitive to light; the Cai rise evoked by uniform illumination was 20-40 times larger and faster in the most sensitive region of the cell (the rhabdomeral lobe) than it was away from it. In response to a brief flash, the Cai rise was barely detectable when 10(2) photons were absorbed, and it was saturated when approximately 10(5) photons were absorbed. During maintained illumination, starting near the threshold of light adaptation, steady Cai increases were associated with steady desensitizations over several log units of light intensity: a 100-fold desensitization was associated with a 2.5-fold increase in Cai. After a bright flash, sensitivity and Cai recovered with different time courses: the cell was still desensitized by approximately 0.5 log units when Cai had already recovered to the prestimulus level, which suggests that under those conditions Cai is not the rate-limiting step of dark adaptation. Ionophoretic injection of EGTA markedly decreased the light-induced Cai rise and increased the time to peak of the light response, but did not alter the resting Cai, which suggests that the time to peak is affected by a change in the capacity to bind Ca2+ and not by resting Cai. Lowering the extracellular Ca2+ concentration (Cao) first decreased Cai and increased sensitivity. Longer exposure to low Cao resulted in a further decrease of Cai but decreased rather than increased sensitivity, which suggests that under certain conditions it is

  6. Longwall - USA: International exhibition & conference

    SciTech Connect

    1996-12-31

    The Longwall-USA International Exhibition and Conference was held June 4-6, 1996 in Pittsburgh, PA. Seventeen papers are included in the proceedings that covered such topics as health and safety, development of gate roads, telemetry monitoring systems, fires, longwall miners, roof support technologies, dust control, moving car bunker systems, reducing longwall noise, vibration of longwall equipment, and the USBM`s strategic structures testing laboratory. A separate abstract with indexing was prepared for each paper for inclusion in the Energy Science and Technology Database.

  7. Collaborative virtual environments art exhibition

    NASA Astrophysics Data System (ADS)

    Dolinsky, Margaret; Anstey, Josephine; Pape, Dave E.; Aguilera, Julieta C.; Kostis, Helen-Nicole; Tsoupikova, Daria

    2005-03-01

    This panel presentation will exhibit artwork developed in CAVEs and discuss how art methodologies enhance the science of VR through collaboration, interaction and aesthetics. Artists and scientists work alongside one another to expand scientific research and artistic expression and are motivated by exhibiting collaborative virtual environments. Looking towards the arts, such as painting and sculpture, computer graphics captures a visual tradition. Virtual reality expands this tradition to not only what we face, but to what surrounds us and even what responds to our body and its gestures. Art making that once was isolated to the static frame and an optimal point of view is now out and about, in fully immersive mode within CAVEs. Art knowledge is a guide to how the aesthetics of 2D and 3D worlds affect, transform, and influence the social, intellectual and physical condition of the human body through attention to psychology, spiritual thinking, education, and cognition. The psychological interacts with the physical in the virtual in such a way that each facilitates, enhances and extends the other, culminating in a "go together" world. Attention to sharing art experience across high-speed networks introduces a dimension of liveliness and aliveness when we "become virtual" in real time with others.

  8. Crows spontaneously exhibit analogical reasoning.

    PubMed

    Smirnova, Anna; Zorina, Zoya; Obozova, Tanya; Wasserman, Edward

    2015-01-19

    Analogical reasoning is vital to advanced cognition and behavioral adaptation. Many theorists deem analogical thinking to be uniquely human and to be foundational to categorization, creative problem solving, and scientific discovery. Comparative psychologists have long been interested in the species generality of analogical reasoning, but they initially found it difficult to obtain empirical support for such thinking in nonhuman animals (for pioneering efforts, see [2, 3]). Researchers have since mustered considerable evidence and argument that relational matching-to-sample (RMTS) effectively captures the essence of analogy, in which the relevant logical arguments are presented visually. In RMTS, choice of test pair BB would be correct if the sample pair were AA, whereas choice of test pair EF would be correct if the sample pair were CD. Critically, no items in the correct test pair physically match items in the sample pair, thus demanding that only relational sameness or differentness is available to support accurate choice responding. Initial evidence suggested that only humans and apes can successfully learn RMTS with pairs of sample and test items; however, monkeys have subsequently done so. Here, we report that crows too exhibit relational matching behavior. Even more importantly, crows spontaneously display relational responding without ever having been trained on RMTS; they had only been trained on identity matching-to-sample (IMTS). Such robust and uninstructed relational matching behavior represents the most convincing evidence yet of analogical reasoning in a nonprimate species, as apes alone have spontaneously exhibited RMTS behavior after only IMTS training. PMID:25532894

  9. Cystamine preparations exhibit anticoagulant activity.

    PubMed

    Aleman, Maria M; Holle, Lori A; Stember, Katherine G; Devette, Christa I; Monroe, Dougald M; Wolberg, Alisa S

    2015-01-01

    Transglutaminases are a superfamily of isoenzymes found in cells and plasma. These enzymes catalyze the formation of ε-N-(γ-glutamyl)-lysyl crosslinks between proteins. Cystamine blocks transglutaminase activity and is used in vitro in human samples and in vivo in mice and rats in studies of coagulation, immune dysfunction, and inflammatory disease. These studies have suggested cystamine blocks fibrin crosslinking and has anti-inflammatory effects, implicating transglutaminase activity in the pathogenesis of several diseases. We measured the effects of cystamine on fibrin crosslinking, tissue factor-triggered plasma clot formation and thrombin generation, and coagulation factor enzymatic activity. At concentrations that blocked fibrin crosslinking, cystamine also inhibited plasma clot formation and reduced thrombin generation. Cystamine inhibited the amidolytic activity of coagulation factor XI and thrombin towards chromogenic substrates. These findings demonstrate that cystamine exhibits anticoagulant activity during coagulation. Given the close relationship between coagulation and inflammation, these findings suggest prior studies that used cystamine to implicate transglutaminase activity in disease pathogenesis warrant re-examination. PMID:25915545

  10. Cystamine Preparations Exhibit Anticoagulant Activity

    PubMed Central

    Aleman, Maria M.; Holle, Lori A.; Stember, Katherine G.; Devette, Christa I.; Monroe, Dougald M.; Wolberg, Alisa S.

    2015-01-01

    Transglutaminases are a superfamily of isoenzymes found in cells and plasma. These enzymes catalyze the formation of ε-N-(γ-glutamyl)-lysyl crosslinks between proteins. Cystamine blocks transglutaminase activity and is used in vitro in human samples and in vivo in mice and rats in studies of coagulation, immune dysfunction, and inflammatory disease. These studies have suggested cystamine blocks fibrin crosslinking and has anti-inflammatory effects, implicating transglutaminase activity in the pathogenesis of several diseases. We measured the effects of cystamine on fibrin crosslinking, tissue factor-triggered plasma clot formation and thrombin generation, and coagulation factor enzymatic activity. At concentrations that blocked fibrin crosslinking, cystamine also inhibited plasma clot formation and reduced thrombin generation. Cystamine inhibited the amidolytic activity of coagulation factor XI and thrombin towards chromogenic substrates. These findings demonstrate that cystamine exhibits anticoagulant activity during coagulation. Given the close relationship between coagulation and inflammation, these findings suggest prior studies that used cystamine to implicate transglutaminase activity in disease pathogenesis warrant re-examination. PMID:25915545

  11. 29 CFR 2200.70 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... separate file designated for rejected exhibits. (e) Return of physical exhibits. A party may on motion request the return of a physical exhibit within 30 days after expiration of the time for filing a petition... proceeding. (f) Request for custody of physical exhibit. Any person may on motion to the Executive...

  12. 29 CFR 2200.70 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... separate file designated for rejected exhibits. (e) Return of physical exhibits. A party may on motion request the return of a physical exhibit within 30 days after expiration of the time for filing a petition... proceeding. (f) Request for custody of physical exhibit. Any person may on motion to the Executive...

  13. 29 CFR 2200.70 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... separate file designated for rejected exhibits. (e) Return of physical exhibits. A party may on motion request the return of a physical exhibit within 30 days after expiration of the time for filing a petition... proceeding. (f) Request for custody of physical exhibit. Any person may on motion to the Executive...

  14. Exhibits Enhanced by Stand-Alone Computers.

    ERIC Educational Resources Information Center

    Van Rennes, Eve C.

    Both the development and evaluation of one of a set of computer programs designed for use by visitors as adjuncts to museum exhibits are described. Museum displays used were (1) a static, behind-glass exhibit on evolution; (2) a hands-on primitive stone age tools exhibit; and (3) a Foucault pendulum. A computer placed next to each exhibit served…

  15. An Astrobiology Microbes Exhibit and Education Module

    NASA Astrophysics Data System (ADS)

    Lindstrom, M. M.; Allen, J. S.; Mortillaro, C.; Ducceschi, C.; Rawlings, P.; Stocco, K.; Tobola, K.; Olendzenski, L.; Angermiller, L.

    2001-03-01

    A JSC-SCH team has produced an astrobiology exhibit and education module to augment the 'Microbes!' traveling exhibit. The astrobiology section focuses on life in extreme environments and considers the possibility of extraterrestrrial life.

  16. Learning by Doing, Creating a Museum Exhibit.

    ERIC Educational Resources Information Center

    Main, Sarah; Kallquist, Dierdre

    2000-01-01

    Describes an exhibit called Kid's Kitchen, built within a major exhibit called Biodiversity: Life Supporting Life, in order to discuss environmental prompts hidden within the kitchen designed to surprise students and get them thinking. (ASK)

  17. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  18. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  19. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  20. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  1. 49 CFR 1114.7 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... practical the sheets of each exhibit and the lines of each sheet should be numbered. If the exhibit consists of five or more sheets, the first sheet or title-page should be confined to a brief statement of what the exhibit purports to show with reference by sheet and line to illustrative or typical...

  2. Superconductive microstrip exhibiting negative differential resistivity

    DOEpatents

    Huebener, R.P.; Gallus, D.E.

    1975-10-28

    A device capable of exhibiting negative differential electrical resistivity over a range of values of current and voltage is formed by vapor- depositing a thin layer of a material capable of exhibiting superconductivity on an insulating substrate, establishing electrical connections at opposite ends of the deposited strip, and cooling the alloy into its superconducting range. The device will exhibit negative differential resistivity when biased in the current- induced resistive state.

  3. Encountering Nanotechnology in an Interactive Exhibition

    ERIC Educational Resources Information Center

    Murriello, Sandra E.; Knobel, Marcelo

    2008-01-01

    This article offers findings from a learning sciences-informed evaluation of a nanoscience and nanotechnology exhibition called Nano-Aventura (NanoAdventure), based on four interactive-collaborative games and two narrated videos. This traveling exhibition was developed in Brazil by the Museu Exploratorio de Ciencias for children and teenagers…

  4. Science Fiction Exhibits as STEM Gateways

    NASA Astrophysics Data System (ADS)

    Robie, Samantha

    Women continue to hold less than a quarter of all STEM jobs in the United States, prompting many museums to develop programs and exhibits with the express goal of interesting young girls in scientific fields. At the same time, a number of recent museum exhibits have harnessed the popularity of pop culture and science fiction in order to interest general audiences in STEM subject matter, as well as using the exhibits as springboards to expand or shift mission goals and focus. Because science fiction appears to be successful at raising interest in STEM fields, it may be an effective way to garner the interest of young girls in STEM in particular. This research seeks to describe the ways in which museums are currently using science fiction exhibits to interest young girls in STEM fields and careers. Research focused on four institutions across the country hosting three separate exhibits, and included staff interviews and content analysis of exhibit descriptions, promotional materials, a summative evaluation and supplementary exhibit productions. In some ways, science fiction exhibits do serve young girls, primarily through the inclusion of female role models, staff awareness, and prototype testing to ensure interactives are attractive to girls as well as to boys. However, STEM appears to be underutilized, which may be partly due to a concern within the field that the outcome of targeting a specific gender could be construed as "stereotyping".

  5. Strategies for Determining Exhibit Effectiveness. Final Report.

    ERIC Educational Resources Information Center

    Shettel, Harris H.; And Others

    This project was designed to develop research strategies and hypotheses for evaluating the effectiveness of exhibits. An exhibit on the role of the Federal Government in science and technology was used as the subject matter. Two basic groups of viewers were used, casual viewers and paid experimental viewers. Both were tested on knowledge gained…

  6. An Attention Model for Museum Exhibits.

    ERIC Educational Resources Information Center

    Lightner, John W.

    A qualitative study determined which factors in the museum exhibit environment or within the museum visitor may influence the visitor to attend an exhibit. Observations and interviews were conducted of 14 groups that visited a Chesapeake & Ohio steam locomotive at the Henry Ford Museum in Dearborn, Michigan. An inductive or grounded theory…

  7. Learning4Life on the Exhibit Floor

    ERIC Educational Resources Information Center

    Sullivan, Margaret

    2009-01-01

    The exhibit floor is a wealth of knowledge. One can read, view, and listen to information presented in many formats. Somewhere on the exhibit floor there are experts on every topic, ready and waiting for one's questions. But like any research topic, frequently a structured search is required to find the best answers. This article discusses how to…

  8. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... (respondent) necessary for the rendition of service requested by the applicant. (6) Exhibit G—Flow diagram showing daily design capacity and reflecting operation with proposed transmission facilities. A flow...—Flow diagram reflecting maximum capabilities. If Exhibit G does not reflect the maximum deliveries...

  9. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... (respondent) necessary for the rendition of service requested by the applicant. (6) Exhibit G—Flow diagram showing daily design capacity and reflecting operation with proposed transmission facilities. A flow...—Flow diagram reflecting maximum capabilities. If Exhibit G does not reflect the maximum deliveries...

  10. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  11. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 14 2013-01-01 2013-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  12. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  13. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 14 2014-01-01 2014-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  14. 7 CFR Exhibit G to Subpart E of... - Exhibit G to Subpart E of Part 1980

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 14 2012-01-01 2012-01-01 false Exhibit G to Subpart E of Part 1980 G Exhibit G to Subpart E of Part 1980 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING... Program Pt. 1980, Subpt. E, Exh. G Exhibit G to Subpart E of Part 1980 Note: The Exhibit is not...

  15. Museum Exhibitions: Optimizing Development Using Evaluation

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.

    2002-12-01

    The Space Science Institute (SSI) of Boulder, Colorado, has recently developed two museum exhibits called the Space Weather Center and MarsQuest. It is currently planning to develop a third exhibit called InterActive Earth. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. The development of these exhibitions included a comprehensive evaluation plan. I will report on the important role evaluation plays in exhibit design and development using MarsQuest and InterActive Earth as models. The centerpiece of SSI's Mars Education Program is the 5,000-square-foot traveling exhibition, MarsQuest: Exploring the Red Planet, which was developed with support from the National Science Foundation (NSF), NASA, and several corporate donors. The MarsQuest exhibit is nearing the end of a highly successful, fully-booked three-year tour. The Institute plans to send an enhanced and updated MarsQuest on a second three-year tour and is also developing Destination: Mars, a mini-version of MarsQuest designed for smaller venues. They are designed to inspire and empower participants to extend the excitement and science content of the exhibitions into classrooms and museum-based education programs in an ongoing fashion. The centerpiece of the InterActive Earth project is a traveling exhibit that will cover about 4,000 square feet. The major goal of the proposed exhibit is to introduce students and the public to the complexity of the interconnections in the Earth system, and thereby, to inspire them to better understand planet Earth. Evaluation must be an integral part of the exhibition development process. For MarsQuest, a 3-phase evaluation (front end, formative and summative) was conducted by Randi Korn and Associates in close association with the development team. Sampling procedures for all three evaluation phases ensured the participation of all audiences, including family groups, students, and adults. Each phase of

  16. The Making of a Museum Exhibition.

    ERIC Educational Resources Information Center

    Bleecker, Samuel E.

    1979-01-01

    Discusses the preparation of the Reptile and Amphibian exhibition at the American Museum of Natural History. Various steps involved in developing the ten showcases in a six-year period are presented. (SA)

  17. 18 CFR 32.2 - Required exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... of operating such facilities. Exhibit B. A general or key map on a scale not greater than 20 miles to... facilities used for the generation and transmission of electric energy, indicating on said map the...

  18. 32 CFR 705.24 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... tractor-trailer transportation should be forwarded prior to November 15th previous to the year desired. A... time for which an exhibit is authorized will be determined by the nature of the event and the type...

  19. 32 CFR 705.24 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... tractor-trailer transportation should be forwarded prior to November 15th previous to the year desired. A... time for which an exhibit is authorized will be determined by the nature of the event and the type...

  20. Exhibit of School Architecture, 1996. Special Section.

    ERIC Educational Resources Information Center

    Texas Architect, 1997

    1997-01-01

    Presents selected winners of the Texas 1996 Exhibit of School Architecture Design Competition. The Caudill and honor award-winning projects are listed along with facility photos, brief descriptions, project credits, and the names of the construction companies used. (GR)

  1. Exhibit of School Architecture, 1997. Special Section.

    ERIC Educational Resources Information Center

    Texas Architect, 1998

    1998-01-01

    Presents selected winners of the Texas 1997 Exhibit of School Architecture Design Competition. The Caudill and honor award winning projects are listed along with facility photos, brief descriptions, project credits, and the names of the construction companies used. (GR)

  2. When Do Children Exhibit a "Yes" Bias?

    ERIC Educational Resources Information Center

    Okanda, Mako; Itakura, Shoji

    2010-01-01

    This study investigated whether one hundred and thirty-five 3- to 6-year-old children exhibit a yes bias to various yes-no questions and whether their knowledge status affects the production of a yes bias. Three-year-olds exhibited a yes bias to all yes-no questions such as "preference-object" and "knowledge-object" questions pertaining to…

  3. Reaching the Public through Traveling Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.; Harold, J. B.; Morrow, C. A.

    2004-11-01

    The Space Science Institute (SSI) of Boulder, Colorado has recently developed two museum exhibits called Alien Earths and MarsQuest. It has just started to develop another exhibit called Giant Planets. These exhibitions provide research scientists the opportunity to engage in a number of activities that are vital to the success of these major outreach programs. Alien Earths was developed in partnership with various research missions. The focus of the presentation will be on MarsQuest and Giant Planets. MarsQuest is a 5000 square-foot, \\$3M, traveling exhibition that is now touring the country. The exhibit's second 3-year tour will enable millions of Americans to share in the excitement of the scientific exploration of Mars and learn more about their own planet in the process. The associated planetarium show and education program will also be described, with particular emphasis on workshops to orient museum staff (e.g. museum educators and docents) and workshops for master educators near host museums and science centers. The workshops make innovative connections between the exhibition's interactive experiences and lesson plans aligned with the National Science Education Standards. These exhibit programs are good models for actively involving scientists and their discoveries to help improve informal science education in the museum community and for forging a stronger connection between formal and informal education. The presentation will also discuss how Giant Planets, a proposed 3500 square-foot traveling exhibition on the mysteries and discoveries of the outer planets, will be able to take advantage of the connections and resources that have been developed by the MarsQuest project.

  4. An Astrobiology Microbes Exhibit and Education Module

    NASA Technical Reports Server (NTRS)

    Lindstrom, Marilyn M.; Allen, Jaclyn S.; Stocco, Karen; Tobola, Kay; Olendzenski, Lorraine

    2001-01-01

    Telling the story of NASA-sponsored scientific research to the public in exhibits is best done by partnerships of scientists and museum professionals. Likewise, preparing classroom activities and training teachers to use them should be done by teams of teachers and scientists. Here we describe how we used such partnerships to develop a new astrobiology augmentation to the Microbes! traveling exhibit and a companion education module. "Additional information is contained in the original extended abstract."

  5. Sex differences in science museum exhibit attraction

    NASA Astrophysics Data System (ADS)

    Arámbula Greenfield, Teresa

    This study examines the relative attraction of hands-on, interactive science museum exhibits for females and males. Studies have demonstrated that such exhibits can be effective learning experiences for children, with both academic and affective benefits. Other studies have shown that girls and boys do not always experience the same science-related educational opportunities and that, even when they do, they do not necessarily receive the same benefits from them. These early differences can lead to more serious educational and professional disparities later in life. As interactive museum exhibits represent a science experience that is-readily available to both girls and boys, the question arose as to whether they were being used similarly by the two groups as well as by adult women and men. It was found that both girls and boys used all types of exhibits, but that girls were more likely than boys to use puzzles and exhibits focusing on the human body; boys were more likely than girls to use computers and exhibits illustrating physical science principles. However, this was less true of children accompanied by adults (parents) than it was of unaccompanied children on school field trips who roamed the museum more freely.Received: 16 February 1994; Revised: 3 February 1995;

  6. Using Comparative Planetology in Exhibit Development

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.; Harold, J. B.; Morrow, C. A.

    2004-12-01

    It is critically important for the public to better understand the scientific process. Museum exhibitions are an important part of informal science education that can effectively reach public audiences as well as school groups. They provide an important gateway for the public to learn about compelling scientific endeavors. The Space Science Institute (SSI) is a national leader in producing traveling science exhibitions and their associated educational programming (i.e. interactive websites, educator workshops, public talks, instructional materials). The focus of this presentation will be on three of its exhibit projects: MarsQuest (currently on tour), Alien Earths (in fabrication), and Giant Planets (in development). MarsQuest is enabling millions of Americans to share in the excitement of the scientific exploration of Mars and to learn more about their own planet in the process. Alien Earths will bring origins-related research and discoveries to students and the American public. It has four interrelated exhibit areas: Our Place in Space, Star Birth, PlanetQuest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in "habitable zones" around other stars; and finally they will be able to learn about how scientists are looking for signs of life beyond Earth. Giant Planets: Exploring the Outer Solar System will take advantage of the excitement generated by the Cassini mission and bring planetary and origins research and discoveries to students and the public. It will be organized around four thematic areas: Our Solar System; Colossal Worlds; Moons, Rings, and Fields; and Make Space for Kids. Giant Planets will open in 2007. This talk will focus on the importance of making Earth comparisons in the conceptual design of each exhibit and will show several examples of how these comparisons were manifested in

  7. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... engineering design data in explanation and support of the diagrams and the proposed project, setting forth: (i... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Exhibits. 156.5 Section 156.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT...

  8. 10 CFR 205.303 - Required exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... pertinent Federal and State laws. (c) Exhibit C. A general map showing the applicant's overall electric system and a detailed map highlighting the location of the facilities or the proposed facilities to be used for the generation and transmission of the electric energy to be exported. The detailed map...

  9. 10 CFR 205.303 - Required exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... pertinent Federal and State laws. (c) Exhibit C. A general map showing the applicant's overall electric system and a detailed map highlighting the location of the facilities or the proposed facilities to be used for the generation and transmission of the electric energy to be exported. The detailed map...

  10. 18 CFR 34.4 - Required exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... stockholders has been obtained. (c) Exhibit C. The Balance Sheet and attached notes for the most recent 12... computation of interest coverage Actual for the year ended mm-dd-yy OMB control No. 1902-0043, pro forma for the year ended mm-dd-yy Net income Add: Interest on Long-Term Debt, Interest on Short-Term Debt,...

  11. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Exhibits. 156.5 Section 156.5 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF... outlet connections at each compressor station. (iv) Pressures and volumes of gas at each intake...

  12. After Terror Charges, Artist Exhibits Academic Freedom

    ERIC Educational Resources Information Center

    Wilson, Robin

    2008-01-01

    Steven Kurtz, a professor of visual studies at the State University of New York, has been working with various bacteria as part of his counterculture exhibit artworks for nearly 20 years. Four years ago, federal agents raided his home in a bioterrorism investigation. The federal agents had been called to the house by local police officers…

  13. Do Online Students Exhibit Different Learning Styles

    ERIC Educational Resources Information Center

    Hausler, Joel; Sanders, John W.; Young, Barbara

    2007-01-01

    We examined the relationship between learning styles and student type. This research seeks to examine if online students exhibit different learning styles from onsite students; and, if so, what accommodations relating to learning style differences may be made for online students? Students (N = 80) were asked to complete an online survey in order…

  14. The medial prefrontal cortex exhibits money illusion

    PubMed Central

    Weber, Bernd; Rangel, Antonio; Wibral, Matthias; Falk, Armin

    2009-01-01

    Behavioral economists have proposed that money illusion, which is a deviation from rationality in which individuals engage in nominal evaluation, can explain a wide range of important economic and social phenomena. This proposition stands in sharp contrast to the standard economic assumption of rationality that requires individuals to judge the value of money only on the basis of the bundle of goods that it can buy—its real value—and not on the basis of the actual amount of currency—its nominal value. We used fMRI to investigate whether the brain's reward circuitry exhibits money illusion. Subjects received prizes in 2 different experimental conditions that were identical in real economic terms, but differed in nominal terms. Thus, in the absence of money illusion there should be no differences in activation in reward-related brain areas. In contrast, we found that areas of the ventromedial prefrontal cortex (vmPFC), which have been previously associated with the processing of anticipatory and experienced rewards, and the valuation of goods, exhibited money illusion. We also found that the amount of money illusion exhibited by the vmPFC was correlated with the amount of money illusion exhibited in the evaluation of economic transactions. PMID:19307555

  15. 49 CFR 250.2 - Required exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    .... (8) As Exhibit 8, a copy of applicant's most recent year-end general balance sheet certified by... general balance sheet as of a date no less recent than the end of the third month preceding the date of the filing of the application. The unaudited balance sheet shall be presented in account form...

  16. 49 CFR 250.2 - Required exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    .... (8) As Exhibit 8, a copy of applicant's most recent year-end general balance sheet certified by... general balance sheet as of a date no less recent than the end of the third month preceding the date of the filing of the application. The unaudited balance sheet shall be presented in account form...

  17. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 18 Conservation of Power and Water Resources 1 2011-04-01 2011-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE INTERSTATE ELECTRIC TRANSMISSION FACILITIES §...

  18. 32 CFR 705.24 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... favorably only when not in conflict with recruiting requirements. (i) Requests for exhibits must be... among the Armed Forces, or with other agencies of the Federal Government. (i) All Navy activities will... concerned, via the chain of command. (3) The official OASD(PA) Request Form for Armed Forces...

  19. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 18 Conservation of Power and Water Resources 1 2013-04-01 2013-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE...

  20. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 18 Conservation of Power and Water Resources 1 2012-04-01 2012-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE...

  1. 18 CFR 50.7 - Applications: exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 18 Conservation of Power and Water Resources 1 2014-04-01 2014-04-01 false Applications: exhibits. 50.7 Section 50.7 Conservation of Power and Water Resources FEDERAL ENERGY REGULATORY COMMISSION, DEPARTMENT OF ENERGY REGULATIONS UNDER THE FEDERAL POWER ACT APPLICATIONS FOR PERMITS TO SITE...

  2. 18 CFR 153.8 - Required exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... facilities in the United States and Canada or Mexico; (5) Exhibit E. If the proposal is to import or export... Seismic Risk Map of the United States, or where there is a risk of surface faulting or ground liquefaction... the Seismic Review of LNG Facilities,” NBSIR 84-2833. This document may be obtained from the...

  3. 18 CFR 156.5 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... such enterprises or operations, a detailed explanation of each such relationship, including the... relationship. (5) Exhibit F—Location of facilities. A geographical map of suitable scale and detail showing all...—Construction, operation, and management. A concise statement setting forth arrangements for...

  4. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... explanation of each such relationship, including the percentage of voting strength represented by such... detailed explanation of each such relationship. (5) Exhibit E—Other pending applications and filings. A... abandoned. This map, or an additional map, shall clearly show the relationship of the new facilities to...

  5. 10 CFR 205.303 - Required exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...; Applications; Administrative Procedures and Sanctions Application for Authorization to Transmit Electric Energy... used for the generation and transmission of the electric energy to be exported. The detailed map shall... or fixing of rates for the purchase, sale or transmission of electric energy. (f) Exhibit F....

  6. 24 CFR 180.645 - Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Exhibits. 180.645 Section 180.645... OPPORTUNITY CONSOLIDATED HUD HEARING PROCEDURES FOR CIVIL RIGHTS MATTERS Procedures at Hearing § 180.645... evidence could not reasonably be anticipated at that time. (c) Authenticity. The authenticity of...

  7. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... Act (42 U.S.C. 7101-7352); E.O. 12009, 3 CFR 142) Editorial Note: For Federal Register citations affecting § 157.14, see the List of CFR Sections Affected, which appears in the Finding Aids section of the...) Exhibit G—Flow diagrams showing daily design capacity and reflecting operation with and without...

  8. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... Act (42 U.S.C. 7101-7352); E.O. 12009, 3 CFR 142) Editorial Note: For Federal Register citations affecting § 157.14, see the List of CFR Sections Affected, which appears in the Finding Aids section of the...) Exhibit G—Flow diagrams showing daily design capacity and reflecting operation with and without...

  9. 18 CFR 157.14 - Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... Act (42 U.S.C. 7101-7352); E.O. 12009, 3 CFR 142) Editorial Note: For Federal Register citations affecting § 157.14, see the List of CFR Sections Affected, which appears in the Finding Aids section of the...) Exhibit G—Flow diagrams showing daily design capacity and reflecting operation with and without...

  10. MarsQuest: A National Traveling Exhibition

    NASA Astrophysics Data System (ADS)

    Lee, S. W.; Dusenbery, P. B.

    1998-09-01

    With the successful landing of Mars Pathfinder and the arrival of Mars Global Surveyor, a new decade of Mars exploration has commenced. MarsQuest, a 5000 square foot traveling exhibition, is being developed to further bring the excitement and discoveries of this "Decade of Mars Exploration" to the public. MarsQuest is partially funded by the Informal Science Education Program of the National Science Foundation and NASA's Office of Space Science. The Space Science Institute (SSI) in Boulder, CO, is leading the project. Scientific and educational advisors from many different universities and government laboratories, most of whom are directly involved in the active and planned Mars missions, will ensure the scientific accuracy, timeliness, and relevance of the key concepts presented in the exhibition and accompanying programs. The traveling exhibit is the primary element of the MarsQuest project. The exhibition experience, carefully keyed to current events in Mars exploration, will transport visitors to the surface of the Red Planet via large murals, dioramas, and numerous interactive displays. There they will have the opportunity to share in the spirit and thrill of exploration, and come to appreciate the similarities and differences between Earth and Mars. A planetarium show, geared to the goals of the MarsQuest project, will be an important sensory addition to the traveling exhibit. The planetarium/star-theater venue presents a unique environment where audience members can literally be surrounded by Mars images. Education and outreach programs comprise the remainder of the MarsQuest project. The goal of these is to make scientific concepts and scientific and engineering processes understandable to students via Mars-inspired curricula. MarsQuest will open in late-1999, traveling to about nine sites throughout the United States and reaching an estimated two to three million children and adults during its planned three-year tour. Mars - coming soon to a museum near

  11. Multimodal audio guide for museums and exhibitions

    NASA Astrophysics Data System (ADS)

    Gebbensleben, Sandra; Dittmann, Jana; Vielhauer, Claus

    2006-02-01

    In our paper we introduce a new Audio Guide concept for exploring buildings, realms and exhibitions. Actual proposed solutions work in most cases with pre-defined devices, which users have to buy or borrow. These systems often go along with complex technical installations and require a great degree of user training for device handling. Furthermore, the activation of audio commentary related to the exhibition objects is typically based on additional components like infrared, radio frequency or GPS technology. Beside the necessity of installation of specific devices for user location, these approaches often only support automatic activation with no or limited user interaction. Therefore, elaboration of alternative concepts appears worthwhile. Motivated by these aspects, we introduce a new concept based on usage of the visitor's own mobile smart phone. The advantages in our approach are twofold: firstly the Audio Guide can be used in various places without any purchase and extensive installation of additional components in or around the exhibition object. Secondly, the visitors can experience the exhibition on individual tours only by uploading the Audio Guide at a single point of entry, the Audio Guide Service Counter, and keeping it on her or his personal device. Furthermore, since the user usually is quite familiar with the interface of her or his phone and can thus interact with the application device easily. Our technical concept makes use of two general ideas for location detection and activation. Firstly, we suggest an enhanced interactive number based activation by exploiting the visual capabilities of modern smart phones and secondly we outline an active digital audio watermarking approach, where information about objects are transmitted via an analog audio channel.

  12. Naval Meteorology and Oceanography Command exhibit entrance

    NASA Technical Reports Server (NTRS)

    2000-01-01

    StenniSphere at NASA's John C. Stennis Space Center in Hancock County, Miss., invites visitors to discover why America comes to Stennis Space Center before going into space. Designed to entertain while educating, StenniSphere includes informative displays and exhibits from NASA and other agencies located at Stennis, such as this one from the Naval Meteorology and Oceanography Command. Visitors can 'travel' three-dimensionally under the sea and check on the weather back home in the Weather Center.

  13. Naval Meteorology and Oceanography Command exhibit

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Designed to entertain while educating, StenniSphere at the John C. Stennis Space Center in Hancock County, Miss., includes informative displays and exhibits from NASA and other agencies located at Stennis, such as this one from the Naval Meteorology and Oceanography Command. Visitors can 'travel' three-dimensionally under the sea and check on the weather back home in the Weather Center. StenniSphere is open free of charge from 9 a.m. to 5 p.m. daily.

  14. The E = mc{sup 2} exhibition

    SciTech Connect

    Henderson, D.; Peshkin, M.

    1995-08-01

    The goal of this DOE-supported exhibition is to demystify Einstein`s formula E = mc{sup 2} by illustrating the interchangeability of matter (m) and energy (E), c{sup 2} being the exchange rate. The exhibition has two major parts, {open_quotes}matter into energy{close_quotes} and {open_quotes}energy into matter{close_quotes}, plus a video to connect them. {open_quotes}Matter into energy{close_quotes} has now been completed and has been placed on the museum floor. Positrons from a {sup 22}Na source are annihilated to produce gamma rays that are caught in NaI detectors. The viewer can alter the alignment of the detectors and observe the consequences for the rates of single and coincident counts. The viewer can also observe the effects of placing absorbers in front of the counters. Prototype explanatory graphics were placed around the exhibit and those will probably be changed after we have some experience with their effectiveness. The connecting video is in the process of being produced in collaboration with Fermilab. A cloud chamber for {open_quotes}energy into matter{close_quotes}, where gamma rays from a small Th source will produce observable pairs, was purchased and work to make the pairs visible has commenced.

  15. Art exhibit focuses on African astronomy

    NASA Astrophysics Data System (ADS)

    Showstack, Randy

    2012-07-01

    Connections between Africans and astronomy are the focus of a new exhibition in the National Museum of African Art in Washington, D. C. "African Cosmos: Stellar Arts," which includes artwork, cultural items, and scientific displays from ancient to contemporary times, is the first major exhibit "that brings together arts and science focused on Africa's contribution to keen observations of the heavens over time," curator Christine Mullen Kreamer said at a 20 June news briefing. Among the exhibit's nearly 100 objects are an ancient Egyptian mummy board that includes a representation of the sky goddess Nut, sculptures by the Dogon people of Mali depicting figures in relation to the cosmos, a video that uses data from two square degrees of the Hubble Space Telescope Cosmic Evolution Survey, and a nearly floor-to-ceiling "Rainbow Serpent" constructed of plastic containers by Benin artist Hazoume. An untitled acrylic painting (Figure 1) by South African Gavin Jantjes evokes a myth of the Khoi San people of southern Africa, as it portrays a girl throwing evening fire embers into the night sky, where they remained as the Milky Way.

  16. Bumblebees exhibit the memory spacing effect

    NASA Astrophysics Data System (ADS)

    Toda, Nicholas R. T.; Song, Jeremy; Nieh, James C.

    2009-10-01

    Associative learning is key to how bees recognize and return to rewarding floral resources. It thus plays a major role in pollinator floral constancy and plant gene flow. Honeybees are the primary model for pollinator associative learning, but bumblebees play an important ecological role in a wider range of habitats, and their associative learning abilities are less well understood. We assayed learning with the proboscis extension reflex (PER), using a novel method for restraining bees (capsules) designed to improve bumblebee learning. We present the first results demonstrating that bumblebees exhibit the memory spacing effect. They improve their associative learning of odor and nectar reward by exhibiting increased memory acquisition, a component of long-term memory formation, when the time interval between rewarding trials is increased. Bombus impatiens forager memory acquisition (average discrimination index values) improved by 129% and 65% at inter-trial intervals (ITI) of 5 and 3 min, respectively, as compared to an ITI of 1 min. Memory acquisition rate also increased with increasing ITI. Encapsulation significantly increases olfactory memory acquisition. Ten times more foragers exhibited at least one PER response during training in capsules as compared to traditional PER harnesses. Thus, a novel conditioning assay, encapsulation, enabled us to improve bumblebee-learning acquisition and demonstrate that spaced learning results in better memory consolidation. Such spaced learning likely plays a role in forming long-term memories of rewarding floral resources.

  17. A metafluid exhibiting strong optical magnetism.

    PubMed

    Sheikholeslami, Sassan N; Alaeian, Hadiseh; Koh, Ai Leen; Dionne, Jennifer A

    2013-09-11

    Advances in the field of metamaterials have enabled unprecedented control of light-matter interactions. Metamaterial constituents support high-frequency electric and magnetic dipoles, which can be used as building blocks for new materials capable of negative refraction, electromagnetic cloaking, strong visible-frequency circular dichroism, and enhancing magnetic or chiral transitions in ions and molecules. While all metamaterials to date have existed in the solid-state, considerable interest has emerged in designing a colloidal metamaterial or "metafluid". Such metafluids would combine the advantages of solution-based processing with facile integration into conventional optical components. Here we demonstrate the colloidal synthesis of an isotropic metafluid that exhibits a strong magnetic response at visible frequencies. Protein-antibody interactions are used to direct the solution-phase self-assembly of discrete metamolecules comprised of silver nanoparticles tightly packed around a single dielectric core. The electric and magnetic response of individual metamolecules and the bulk metamaterial solution are directly probed with optical scattering and spectroscopy. Effective medium calculations indicate that the bulk metamaterial exhibits a negative effective permeability and a negative refractive index at modest fill factors. This metafluid can be synthesized in large-quantity and high-quality and may accelerate development of advanced nanophotonic and metamaterial devices. PMID:23919764

  18. Nematic liquid crystals exhibiting high birefringence

    NASA Astrophysics Data System (ADS)

    Thingujam, Kiranmala; Bhattacharjee, Ayon; Choudhury, Basana; Dabrowski, Roman

    2016-06-01

    Two fluorinated isothiocyanato nematic liquid crystalline compounds, 4'-butylcyclohexyl-3, 5-difluoro-4-isothiocyanatobiphenyl and 4'-pentylcyclohexyl-3, 5-difluoro-4-isothiocynatobiphenyl are studied in detail to obtain their different physical parameters. Optical polarizing microscopy, differential scanning calorimetry, density and dielectric studies have been carried out for the two samples. Both the samples were found to have high clearing temperature (>100 °C) and exhibit small enthalpy of transition. The two samples exhibit high optical birefringence (Δ n > 0.2). The values of order parameters for the two samples were obtained using different approaches, namely, Vuks', Neugebauer's, modified Vuks' and direct extrapolation method from birefringence data. Experimentally obtained values of order parameters have also been compared with theoretical Maier-Saupe values. The parallel and perpendicular components of dielectric permittivity values of the two compounds were also calculated and their anisotropy values were found to be small. The effect of temperature on the molecular dipole moment μ and the angle of inclination β of the dipole axis with the director have also been investigated in this work.

  19. Shape-Memory PVDF Exhibiting Switchable Piezoelectricity.

    PubMed

    Hoeher, Robin; Raidt, Thomas; Novak, Nikola; Katzenberg, Frank; Tiller, Joerg C

    2015-12-01

    In this study, a material is designed which combines the properties of shape-memory and electroactive polymers. This is achieved by covalent cross-linking of polyvinylidene fluoride. The resulting polymer network exhibits excellent shape-memory properties with a storable strain of 200%, and fixity as well as recovery values of 100%. Programming upon rolling induces the transformation from the nonelectroactive α-phase to the piezoelectric β-phase. The highest β-phase content is found to be 83% for a programming strain of 200% affording a d33 value of -30 pm V(-1). This is in good accordance with literature known values for piezoelectric properties. Thermal triggering this material does not only result in a shape change but also renders the material nonelectroactive. PMID:26332996

  20. Supercomputing meets seismology in earthquake exhibit

    ScienceCinema

    Blackwell, Matt; Rodger, Arthur; Kennedy, Tom

    2014-07-22

    When the California Academy of Sciences created the "Earthquake: Evidence of a Restless Planet" exhibit, they called on Lawrence Livermore to help combine seismic research with the latest data-driven visualization techniques. The outcome is a series of striking visualizations of earthquakes, tsunamis and tectonic plate evolution. Seismic-wave research is a core competency at Livermore. While most often associated with earthquakes, the research has many other applications of national interest, such as nuclear explosion monitoring, explosion forensics, energy exploration, and seismic acoustics. For the Academy effort, Livermore researchers simulated the San Andreas and Hayward fault events at high resolutions. Such calculations require significant computational resources. To simulate the 1906 earthquake, for instance, visualizing 125 seconds of ground motion required over 1 billion grid points, 10,000 time steps, and 7.5 hours of processor time on 2,048 cores of Livermore's Sierra machine.

  1. Nanoporous frameworks exhibiting multiple stimuli responsiveness

    NASA Astrophysics Data System (ADS)

    Kundu, Pintu K.; Olsen, Gregory L.; Kiss, Vladimir; Klajn, Rafal

    2014-04-01

    Nanoporous frameworks are polymeric materials built from rigid molecules, which give rise to their nanoporous structures with applications in gas sorption and storage, catalysis and others. Conceptually new applications could emerge, should these beneficial properties be manipulated by external stimuli in a reversible manner. One approach to render nanoporous frameworks responsive to external signals would be to immobilize molecular switches within their nanopores. Although the majority of molecular switches require conformational freedom to isomerize, and switching in the solid state is prohibited, the nanopores may provide enough room for the switches to efficiently isomerize. Here we describe two families of nanoporous materials incorporating the spiropyran molecular switch. These materials exhibit a variety of interesting properties, including reversible photochromism and acidochromism under solvent-free conditions, light-controlled capture and release of metal ions, as well reversible chromism induced by solvation/desolvation.

  2. New Monolayered Materials Exhibiting Unusual Electronic Properties

    NASA Astrophysics Data System (ADS)

    Lopez-Bezanilla, Alejandro; Martin, Ivar; Littlewood, Peter B.

    Computationally based approaches are allowing to progress in the discovery and design of nano-scaled materials. Here we propose a series of new mono-layered compounds with exotic properties. By means of density functional theory calculations we demonstrate that the pentagonal arrangement of SiC2 yields an inverted distribution of the p-bands which leads to an unusual electronic behaviour of the material under strain [J. Phys. Chem. C, 2015, 119 (33), pp 19469]. A different pentagonal arrangement of C atoms enables the formation of Dirac cones which, unlike graphene, exhibit a strain-mediated tunable band gap. This work is supported by DOE-BES under Contract No. DE-AC02-06CH11357.

  3. Supercomputing meets seismology in earthquake exhibit

    SciTech Connect

    Blackwell, Matt; Rodger, Arthur; Kennedy, Tom

    2013-10-03

    When the California Academy of Sciences created the "Earthquake: Evidence of a Restless Planet" exhibit, they called on Lawrence Livermore to help combine seismic research with the latest data-driven visualization techniques. The outcome is a series of striking visualizations of earthquakes, tsunamis and tectonic plate evolution. Seismic-wave research is a core competency at Livermore. While most often associated with earthquakes, the research has many other applications of national interest, such as nuclear explosion monitoring, explosion forensics, energy exploration, and seismic acoustics. For the Academy effort, Livermore researchers simulated the San Andreas and Hayward fault events at high resolutions. Such calculations require significant computational resources. To simulate the 1906 earthquake, for instance, visualizing 125 seconds of ground motion required over 1 billion grid points, 10,000 time steps, and 7.5 hours of processor time on 2,048 cores of Livermore's Sierra machine.

  4. Application of an imaging system to a museum exhibition for developing interactive exhibitions

    NASA Astrophysics Data System (ADS)

    Miyata, Kimiyoshi; Inoue, Yuka; Takiguchi, Takahiro; Tsumura, Norimichi; Nakaguchi, Toshiya; Miyake, Yoichi

    2009-10-01

    In the National Museum of Japanese History, 215,759 artifacts are stored and used for research and exhibitions. In museums, due to the limitation of space in the galleries, a guidance system is required to satisfy visitors' needs and to enhance their understanding of the artifacts. We introduce one exhibition using imaging technology to improve visitors' understanding of a kimono (traditional Japanese clothing) exhibition. In the imaging technology introduced, one data projector, one display with touch panel interface, and magnifiers were used as exhibition tools together with a real kimono. The validity of this exhibition method was confirmed by results from a visitors' interview survey. Second, to further develop the interactive guidance system, an augmented reality system that consisted of cooperation between the projector and a digital video camera was also examined. A white paper board in the observer's hand was used as a projection screen and also as an interface to control the images projected on the board. The basic performance of the proposed system was confirmed; however continuous development was necessary for applying the system to actual exhibitions.

  5. A Traveling Exhibit of Cassini Image Science

    NASA Astrophysics Data System (ADS)

    Burns, Joseph A.; Hedman, M. M.; Tiscareno, M. S.; Ebel, D.; Mac Low, M.; Lovett, L. E.; Burns, J. K.; Schaff, N.; Bilson, E. M.

    2007-10-01

    An exhibit of Cassini's images will open at NYC's American Museum of Natural History in March 2008 and then visit the Johnson Art Museum (Cornell) throughout fall 2008, including during next year's DPS. It is under consideration by several other venues in the States and overseas. The exhibit will feature 40-50 images, ranging from letter size to large posters, taken by remote-sensing instruments aboard Cassini and Huygens. Photos will be organized into a half-dozen thematic clusters (e.g., organized by celestial target or by physical process); a panel will introduce each grouping with individual images identified briefly. The Saturn system is a perfect vehicle to educate citizens about planetary science and origins. The images’ beauty should capture the public's attention, allowing us to then engage their curiosity about the relevant science. Among the Saturn system's broad suite of objects are Enceladus and Titan, two satellites of astrobiological interest; moreover, the rings display many processes active in other astrophysical disks. Several auxiliary ideas will be implemented. In Ithaca, we will project images at night against the museum's sand-colored exterior walls. A 10-12 minute musical composition has been commissioned from Roberto Sierra to open the show. We will encourage school children to participate in a human orrery circling the museum and will seek volunteers to participate in several Saturnalia. At Cornell we will involve the university and local communities, by taping their reactions to the images’ exquisite beauty as well as to their scientific content. Cassini will be the E/PO focus of next year's DPS meeting; those materials will be employed throughout the fall at New York schools and be available to travel with the show. We intend to work with NYC partners to offer teacher credits for associated weekend courses. We will produce classroom materials, including a DVD, for teacher use.

  6. Extract from Ceratonia siliqua Exhibits Depigmentation Properties.

    PubMed

    Lall, Namrita; Kishore, Navneet; Momtaz, Saeideh; Hussein, Ahmed; Naidoo, Sanushka; Nqephe, Mabatho; Crampton, Bridget

    2015-11-01

    Skin hyper-pigmentation is a condition initiated by the overproduction of melanin existing in the melanocytes. Melanin pigment is responsible for the colour of skin in humans. It is formed through a series of oxidative reactions involving the amino acid tyrosine in the presence of the key enzyme tyrosinase. In continuation with our efforts to identify tyrosinase inhibitors from plants sources, the methanol extract from leaf, bark and fruit of Ceratonia siliqua were screened for tyrosinase inhibition and diphenolase activity. The bark extract exhibited significant inhibition on mushroom tyrosinase using L-tyrosine as a substrate and showed diphenolase activity. The extract further significantly lowered tyrosinase mRNA levels in B16-F10 mouse melanocytes. Bioassay-guided fractionation led to the isolation of six compounds. Compounds (-)-epicatechin-3-O-gallate, 1,2,3,6-tetra-O-galloyl-ß-D-glucose and gallocatechin-3-O-gallate showed tyrosinase inhibitions with the IC50 values of 27.52, 83.30 and 28.30 µg/mL, respectively. These compounds also exhibited L-DOPA activities with IC50 values of >200, 150 and 200 µg/mL, respectively. A clinical study was conducted using 20 volunteers in a patch testing trial for irritancy potential and skin depigmentation. The clinical results showed the sample to be non-irritant with irritancy potential of -34.21 and depigmentation trial showed an improvement in the even skin tone of UV induced pigmentation at 3% after 28 days of application. PMID:26201055

  7. Quiescent Fibroblasts Exhibit High Metabolic Activity

    PubMed Central

    Lemons, Johanna M. S.; Feng, Xiao-Jiang; Bennett, Bryson D.; Legesse-Miller, Aster; Johnson, Elizabeth L.; Raitman, Irene; Pollina, Elizabeth A.; Rabitz, Herschel A.; Rabinowitz, Joshua D.; Coller, Hilary A.

    2010-01-01

    Many cells in mammals exist in the state of quiescence, which is characterized by reversible exit from the cell cycle. Quiescent cells are widely reported to exhibit reduced size, nucleotide synthesis, and metabolic activity. Much lower glycolytic rates have been reported in quiescent compared with proliferating lymphocytes. In contrast, we show here that primary human fibroblasts continue to exhibit high metabolic rates when induced into quiescence via contact inhibition. By monitoring isotope labeling through metabolic pathways and quantitatively identifying fluxes from the data, we show that contact-inhibited fibroblasts utilize glucose in all branches of central carbon metabolism at rates similar to those of proliferating cells, with greater overflow flux from the pentose phosphate pathway back to glycolysis. Inhibition of the pentose phosphate pathway resulted in apoptosis preferentially in quiescent fibroblasts. By feeding the cells labeled glutamine, we also detected a “backwards” flux in the tricarboxylic acid cycle from α-ketoglutarate to citrate that was enhanced in contact-inhibited fibroblasts; this flux likely contributes to shuttling of NADPH from the mitochondrion to cytosol for redox defense or fatty acid synthesis. The high metabolic activity of the fibroblasts was directed in part toward breakdown and resynthesis of protein and lipid, and in part toward excretion of extracellular matrix proteins. Thus, reduced metabolic activity is not a hallmark of the quiescent state. Quiescent fibroblasts, relieved of the biosynthetic requirements associated with generating progeny, direct their metabolic activity to preservation of self integrity and alternative functions beneficial to the organism as a whole. PMID:21049082

  8. Circular dichroism study of the hemocyanin thermostability

    NASA Astrophysics Data System (ADS)

    Nikolova Georgieva, Dessislava; Stoeva, Stanka; Abid Ali, Syed; Abbasi, Atiya; Genov, Nicolay; Voelter, Wolfgang

    1998-05-01

    Circular dichroism spectroscopy is used to investigate the thermostability of six arthropod hemocyanins (Hcs), representatives of the subphyla Crustacea (infraorder Brachyura) and Chelicerate (infraorders Xiphosura and Arachnida), and three molluscan Hcs from gastropod organisms. Melting points ( Tm) are determined from the temperature dependence of ellipticity of dioxygen-binding proteins from Maia squinado, Callinectes sapidus, Carcinus maenas, Limulus polyphemus, Buthus sindicus, Androctonus australis, Megathura crenulata, Haliotis tuberculata, and Rapana thomasiana. Both, arthropod and molluscan Hcs, are thermostable proteins with melting temperatures in the region 68-91°C. Binuclear dioxygen-binding sites contribute significantly to the thermostability and increase the Tm values of the apo-forms by 3-16°C. An elevated thermostability is observed in the case of the Limulus polyphemus Hc. One of the reasons is the high degree of hemocyanin oligomerization.

  9. Exhibition of Stochastic Resonance in Vestibular Perception

    NASA Technical Reports Server (NTRS)

    Galvan-Garza, R. C.; Clark, T. K.; Merfeld, D. M.; Bloomberg, J. J.; Oman, C. M.; Mulavara, A. P.

    2016-01-01

    Astronauts experience sensorimotor changes during spaceflight, particularly during G-transitions. Post flight sensorimotor changes include spatial disorientation, along with postural and gait instability that may degrade operational capabilities of the astronauts and endanger the crew. A sensorimotor countermeasure that mitigates these effects would improve crewmember safety and decrease risk. The goal of this research is to investigate the potential use of stochastic vestibular stimulation (SVS) as a technology to improve sensorimotor function. We hypothesize that low levels of SVS will improve sensorimotor perception through the phenomenon of stochastic resonance (SR), when the response of a nonlinear system to a weak input signal is enhanced by the application of a particular nonzero level of noise. This study aims to advance the development of SVS as a potential countermeasure by 1) demonstrating the exhibition of stochastic resonance in vestibular perception, a vital component of sensorimotor function, 2) investigating the repeatability of SR exhibition, and 3) determining the relative contribution of the semicircular canals (SCC) and otolith (OTO) organs to vestibular perceptual SR. A constant current stimulator was used to deliver bilateral bipolar SVS via electrodes placed on each of the mastoid processes, as previously done. Vestibular perceptual motion recognition thresholds were measured using a 6-degree of freedom MOOG platform and a 150 trial 3-down/1-up staircase procedure. In the first test session, we measured vestibular perceptual thresholds in upright roll-tilt at 0.2 Hz (SCC+OTO) with SVS ranging from 0-700 µA. In a second test session a week later, we re-measured roll-tilt thresholds with 0, optimal (from test session 1), and 1500 µA SVS levels. A subset of these subjects, plus naive subjects, participated in two additional test sessions in which we measured thresholds in supine roll-rotation at 0.2 Hz (SCC) and upright y-translation at 1 Hz

  10. Virtual Exhibition and Fruition of Archaeological Finds

    NASA Astrophysics Data System (ADS)

    Manferdini, A. M.; Garagnani, S.

    2011-09-01

    During the last two decades, since digital technologies have become more sophisticated in acquiring real data and building faithful copies of them, their improvements have suggested interesting applications in the field of valorisation of Historical, Cultural and Artistic Heritage, with significant consequences in the share and widespread of knowledge. But although several technologies and methodologies for 3d digitization have recently been developed and improved, the lack of a standard procedure and the costs connected to their use still doesn't encourage the systematic digital acquisition of wide collections and heritage. The aim of this paper is to show the state of the art of a project whose aim is to provide a methodology and a procedure to create digital reproductions of artefacts for Institutions called to preserve, manage and enhance the fruition of archaeological finds inside museums or through digital exhibitions. Our project's aim is to find the most suitable procedure to digitally acquire archaeo logical artefacts that usually have small dimensions and have very complex and detailed surfaces. Within our methodology, particular attention has been paid to the use of widely shared and open-source visualization systems that enhance the involvement of the user by emphasizing three-dimensional characteristics of artefacts through virtual reality.

  11. Enzyme Amplified Detection of Microbial Cell Wall Components

    NASA Technical Reports Server (NTRS)

    Wainwright, Norman R.

    2004-01-01

    This proposal is MBL's portion of NASA's Johnson Space Center's Astrobiology Center led by Principal Investigator, Dr. David McKay, entitled: 'Institute for the Study of Biomarkers in Astromaterials.' Dr. Norman Wainwright is the principal investigator at MBL and is responsible for developing methods to detect trace quantities of microbial cell wall chemicals using the enzyme amplification system of Limulus polyphemus and other related methods.

  12. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  13. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C—Provisions Exhibit... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  14. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  15. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  16. 14 CFR Appendix to Subpart A of... - Listing of Exhibits

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Exhibit A—Budget Summary Exhibit B—Standard Grant and Cooperative Agreement Cover Page Exhibit C... Cooperative Agreements between NASA and the Commercial Space Centers Exhibit F—NASA 1674 Letter of Delegation... Reports Note: Exhibits are available at NASA Headquarters, Code HC, Washington, D.C. 20546....

  17. Marine bacteria exhibit a bipolar distribution.

    PubMed

    Sul, Woo Jun; Oliver, Thomas A; Ducklow, Hugh W; Amaral-Zettler, Linda A; Sogin, Mitchell L

    2013-02-01

    The microbial cosmopolitan dispersion hypothesis often invoked to explain distribution patterns driven by high connectivity of oceanographic water masses and widespread dispersal ability has never been rigorously tested. By using a global marine bacterial dataset and iterative matrix randomization simulation, we show that marine bacteria exhibit a significantly greater dispersal limitation than predicted by our null model using the "everything is everywhere" tenet with no dispersal limitation scenario. Specifically, marine bacteria displayed bipolar distributions (i.e., species occurring exclusively at both poles and nowhere else) significantly less often than in the null model. Furthermore, we observed fewer taxa present in both hemispheres but more taxa present only in a single hemisphere than expected under the null model. Each of these trends diverged further from the null expectation as the compared habitats became more geographically distant but more environmentally similar. Our meta-analysis supported a latitudinal gradient in bacterial diversity with higher richness at lower latitudes, but decreased richness toward the poles. Bacteria in the tropics also demonstrated narrower latitudinal ranges at lower latitudes and relatively larger ranges in higher latitudes, conforming to the controversial macroecological pattern of the "Rapoport rule." Collectively, our findings suggest that bacteria follow biogeographic patterns more typical of macroscopic organisms, and that dispersal limitation, not just environmental selection, likely plays an important role. Distributions of microbes that deliver critical ecosystem services, particularly those in polar regions, may be vulnerable to the same impacts that environmental stressors, climate warming, and degradation in habitat quality are having on biodiversity in animal and plant species. PMID:23324742

  18. Waves in geomaterials exhibiting negative stiffness behaviour

    NASA Astrophysics Data System (ADS)

    Esin, Maxim; Dyskin, Arcady; Pasternak, Elena

    2016-04-01

    Negative stiffness denotes the type of material behaviour when the force applied to the body decreases the body's deformation increases. Some geomaterials, for instance, rocks, demonstrate behaviour of this type at certain loads: during the compression tests the loading curves exhibit descending branch (post-peak softening). One of the possible mechanisms of the negative stiffness appearance in geomaterials is rotation of non-spherical grains. It is important to emphasize that in this case the descending branch may be reversible given that the testing machine is stiff enough (in general case it means an importance of boundary conditions). Existence of geomaterials with a negative modulus associated with rotations may have significant importance. In particular, important is understanding of the wave propagation in such materials. We study the stability of geomaterials with negative stiffness inclusions and wave propagation in it using two approaches: Cosserat continuum and discrete mass-spring models. In both cases we consider the rotational degrees of freedom in addition to the conventional translational ones. We show that despite non positiveness of the energy the materials with negative stiffness elements can be stable if certain conditions are met. In the case of Cosserat continuum the Cosserat shear modulus (the modulus relating the non-symmetrical part of shear stress and internal rotations) is allowed to assume negative values as long as its value does not exceed the value of the standard (positive) shear modulus. In the case of discrete mass-spring systems (with translational and rotational springs) the concentration of negative stiffness springs and the absolute values of negative spring stiffness are limited. The critical concentration when the system loses stability and the amplitude of the oscillations tends to infinity is equal to 1/2 and 3/5 for two- and three-dimensional cases respectively.

  19. Rats exhibit reference-dependent choice behavior.

    PubMed

    Bhatti, Mehwish; Jang, Hyeran; Kralik, Jerald D; Jeong, Jaeseung

    2014-07-01

    Human preferences depend on whether a chosen outcome appears to be a loss or a gain compared with what had been expected, i.e., in comparison to a reference point. Because reference dependence has such a strong influence on human decision-making, it is important to uncover its origins, which will in turn help delineate the underlying mechanisms. It remains unknown whether rats use reference points in decision-making, and yet, the study of rats could help address the question of whether reference dependence is evolutionarily conserved among mammals and could provide a nonhuman animal model to investigate the neural mechanisms underlying this important cognitive process. The aim of the current study was to determine whether rats show reference-dependent choice behavior. We developed a novel paradigm by modifying the "T" maze by installing "pockets" to the left and right of the "T" stem that held reward pellets so rats would potentially develop reference values for each option prior to choice. We found that the rats were indeed sensitive to the way alternatives were presented. That is, they exhibited reference-dependent choice behavior by avoiding the choice option framed as a loss (e.g., having four reward pellets in the pocket, but receiving only one), at least under conditions with certain outcomes and clear differences between the reference and outcome quantities. Despite the small number of rats in this study, this species-level capacity suggests that reference dependence in general and loss aversion in particular may be conserved traits that evolved at or before the emergence of mammals. PMID:24657593

  20. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  1. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  2. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  3. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  4. 37 CFR 1.95 - Copies of exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ..., Specimens § 1.95 Copies of exhibits. Copies of models or other physical exhibits will not ordinarily be furnished by the Office, and any model or exhibit in an application or patent shall not be taken from...

  5. Turbidimetric studies of Limulus coagulin gel formation.

    PubMed Central

    Moody, T P; Donovan, M A; Laue, T M

    1996-01-01

    The turbidity during trypsin-induced coagulin gel formation was studied over a range of wavelengths. The range of wavelengths used (686-326 nm) also made it possible to investigate the dependence of turbidity on wavelength (the wavelength exponent). Using the results from that work, and structural information on coagulin and the coagulin gel from other studies, a model gel-forming system was designed that consists of species for which the turbidity can be calculated relatively simply. These species include small particles (small in all dimensions relative to the wavelength of incident light); long rods and long random coils (particles that are large in just one dimension relative to the wavelength of incident light); and reflective regions (aggregated material that is large in more than one dimension relative to the wavelength of incident light). The turbidimetric characteristics of the real coagulin gel-forming system are compared with those of the model system. PMID:8889175

  6. Contrast adaptation in the Limulus lateral eye.

    PubMed

    Valtcheva, Tchoudomira M; Passaglia, Christopher L

    2015-12-01

    Luminance and contrast adaptation are neuronal mechanisms employed by the visual system to adjust our sensitivity to light. They are mediated by an assortment of cellular and network processes distributed across the retina and visual cortex. Both have been demonstrated in the eyes of many vertebrates, but only luminance adaptation has been shown in invertebrate eyes to date. Since the computational benefits of contrast adaptation should apply to all visual systems, we investigated whether this mechanism operates in horseshoe crab eyes, one of the best-understood neural networks in the animal kingdom. The spike trains of optic nerve fibers were recorded in response to light stimuli modulated randomly in time and delivered to single ommatidia or the whole eye. We found that the retina adapts to both the mean luminance and contrast of a white-noise stimulus, that luminance- and contrast-adaptive processes are largely independent, and that they originate within an ommatidium. Network interactions are not involved. A published computer model that simulates existing knowledge of the horseshoe crab eye did not show contrast adaptation, suggesting that a heretofore unknown mechanism may underlie the phenomenon. This mechanism does not appear to reside in photoreceptors because white-noise analysis of electroretinogram recordings did not show contrast adaptation. The likely site of origin is therefore the spike discharge mechanism of optic nerve fibers. The finding of contrast adaption in a retinal network as simple as the horseshoe crab eye underscores the broader importance of this image processing strategy to vision. PMID:26445869

  7. 29 CFR 2204.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 9 2011-07-01 2011-07-01 false Net worth exhibit. 2204.202 Section 2204.202 Labor... COMMISSION Information Required From Applicants § 2204.202 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant as of the date specified by § 2204.105(c). The exhibit...

  8. 29 CFR 2204.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 9 2010-07-01 2010-07-01 false Net worth exhibit. 2204.202 Section 2204.202 Labor... COMMISSION Information Required From Applicants § 2204.202 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant as of the date specified by § 2204.105(c). The exhibit...

  9. Temporary and Travelling Exhibitions. Museums and Monuments, X.

    ERIC Educational Resources Information Center

    Daifuku, Hiroshi; And Others

    The permanent exhibition, the most typical form of museum exhibition, has failed to attract repeated visitation, since visitors quickly become familiar with the objects shown. The temporary exhibition evolved as a result for the need of repeated visitation. The temporary exhibition, set up for a period of one to six months, introduces fresh…

  10. Development of Exhibit on Arctic Climate Change Called The Arctic: A Friend Acting Strangely Exhibition

    SciTech Connect

    Stauffer, Barbara W.

    2006-04-01

    The exhibition, The Arctic: A Friend Acting Strangely, was developed at the Smithsonian Institution’s National Museum of Natural History (NMNH) as a part of the museum’s Forces of Change exhibit series on global change. It opened to the public in Spring 2006, in conjunction with another Forces of Change exhibit on the Earth’s atmosphere called Change Is in the Air. The exhibit was a 2000 square-foot presentation that explored the forces and consequences of the changing Arctic as documented by scientists and native residents alike. Native peoples of the Arctic have always lived with year-to-year fluctuations in weather and ice conditions. In recent decades, they have witnessed that the climate has become unpredictable, the land and sea unfamiliar. An elder in Arctic Canada recently described the weather as uggianaqtuq —an Inuit word that can suggest strange, unexpected behavior, sometimes described as that of “a friend acting strangely.” Scientists too have been documenting dramatic changes in the Arctic. Air temperatures have warmed over most—though not all—of the Arctic since the 1950s; Arctic precipitation may have increased by as much as 8%; seasonal melting of the Greenland Ice Sheet has increased on average by 16% since 1979; polar-orbiting satellites have measured a 15¬–20% decline in sea ice extent since the 1970s; aircraft reconnaissance and ship observations show a steady decrease in sea ice since the 1950s. In response to this warming, plant distributions have begun to shift and animals are changing their migration routes. Some of these changes may have beneficial effects while others may bring hardship or have costly implications. And, many scientists consider arctic change to be a ‘bell-weather’ for large-scale changes in other regions of the world. The exhibition included text, photos artifacts, hands-on interactives and other exhibitry that illustrated the changes being documented by indigenous people and scientists alike.

  11. Joint assembly and genetic mapping of the Atlantic horseshoe crab genome reveals ancient whole genome duplication

    PubMed Central

    2014-01-01

    Background Horseshoe crabs are marine arthropods with a fossil record extending back approximately 450 million years. They exhibit remarkable morphological stability over their long evolutionary history, retaining a number of ancestral arthropod traits, and are often cited as examples of “living fossils.” As arthropods, they belong to the Ecdysozoa, an ancient super-phylum whose sequenced genomes (including insects and nematodes) have thus far shown more divergence from the ancestral pattern of eumetazoan genome organization than cnidarians, deuterostomes and lophotrochozoans. However, much of ecdysozoan diversity remains unrepresented in comparative genomic analyses. Results Here we apply a new strategy of combined de novo assembly and genetic mapping to examine the chromosome-scale genome organization of the Atlantic horseshoe crab, Limulus polyphemus. We constructed a genetic linkage map of this 2.7 Gbp genome by sequencing the nuclear DNA of 34 wild-collected, full-sibling embryos and their parents at a mean redundancy of 1.1x per sample. The map includes 84,307 sequence markers grouped into 1,876 distinct genetic intervals and 5,775 candidate conserved protein coding genes. Conclusions Comparison with other metazoan genomes shows that the L. polyphemus genome preserves ancestral bilaterian linkage groups, and that a common ancestor of modern horseshoe crabs underwent one or more ancient whole genome duplications 300 million years ago, followed by extensive chromosome fusion. These results provide a counter-example to the often noted correlation between whole genome duplication and evolutionary radiations. The new, low-cost genetic mapping method for obtaining a chromosome-scale view of non-model organism genomes that we demonstrate here does not require laboratory culture, and is potentially applicable to a broad range of other species. PMID:24987520

  12. African Past: Migrant Present. A Guide to the Exhibition.

    ERIC Educational Resources Information Center

    Twining, Mary Arnold; Roark-Calnek, Sue

    This exhibit guide describes an exhibition of African folk arts produced by seasonal migrant farmworkers in western New York State. Workers come from the American South, Haiti, Puerto Rico, and Jamaica. The exhibition pieces were collected through the BOCES Geneseo Migrant Center's Folk Arts Program and Creative Artists Migrant Program Services…

  13. Online Cultural Heritage Exhibitions: A Survey of Strategic Issues

    ERIC Educational Resources Information Center

    Liew, Chern Li

    2006-01-01

    Purpose: This paper seeks to report findings from a study that looked at a range of strategic issues faced in the development, management and maintenance of online cultural heritage exhibitions. The study examined exhibitions from different types of cultural agencies and asked questions about whether, for instance, the exhibitions are part of the…

  14. 49 CFR 826.22 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 7 2011-10-01 2011-10-01 false Net worth exhibit. 826.22 Section 826.22... Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the net worth of the applicant...

  15. 14 CFR 1262.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 5 2011-01-01 2010-01-01 true Net worth exhibit. 1262.202 Section 1262.202... PROCEEDINGS Information Required From Applicants § 1262.202 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant and any affiliates (as defiined in § 1262.104(f) when...

  16. 10 CFR 12.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Net worth exhibit. 12.202 Section 12.202 Energy NUCLEAR... Required From Applicants § 12.202 Net worth exhibit. (a) Each applicant, except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  17. 19 CFR 212.11 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 19 Customs Duties 3 2011-04-01 2011-04-01 false Net worth exhibit. 212.11 Section 212.11 Customs... IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 212.11 Net worth exhibit... with its application a detailed exhibit showing the net worth of the applicant and any affiliates...

  18. 17 CFR 201.42 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Net worth exhibit. 201.42... Regulations Pertaining to the Equal Access to Justice Act § 201.42 Net worth exhibit. (a) Each applicant... a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  19. 49 CFR 6.19 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 1 2011-10-01 2011-10-01 false Net worth exhibit. 6.19 Section 6.19... PROCEEDINGS Information Required from Applicants § 6.19 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant and any affiliates (as defined in this part) when...

  20. 39 CFR 960.10 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 39 Postal Service 1 2010-07-01 2010-07-01 false Net worth exhibit. 960.10 Section 960.10 Postal... JUSTICE ACT IN POSTAL SERVICE PROCEEDINGS Information Required From Applicants § 960.10 Net worth exhibit... with its application a detailed exhibit showing the net worth of the applicant and any affiliates...

  1. 31 CFR 6.9 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance: Treasury 1 2011-07-01 2011-07-01 false Net worth exhibit. 6.9 Section 6.9... EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 6.9 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  2. 7 CFR 1.191 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 1 2011-01-01 2011-01-01 false Net worth exhibit. 1.191 Section 1.191 Agriculture... § 1.191 Net worth exhibit. (a) An applicant, except a qualified tax-exempt organization or cooperative association, must provide with its application a detailed exhibit showing the net worth of the applicant...

  3. 10 CFR 12.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Net worth exhibit. 12.202 Section 12.202 Energy NUCLEAR... Required From Applicants § 12.202 Net worth exhibit. (a) Each applicant, except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  4. 49 CFR 826.22 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 7 2010-10-01 2010-10-01 false Net worth exhibit. 826.22 Section 826.22... Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the net worth of the applicant...

  5. 7 CFR 1.191 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 1 2010-01-01 2010-01-01 false Net worth exhibit. 1.191 Section 1.191 Agriculture... § 1.191 Net worth exhibit. (a) An applicant, except a qualified tax-exempt organization or cooperative association, must provide with its application a detailed exhibit showing the net worth of the applicant...

  6. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 1 2010-04-01 2010-04-01 false Net worth exhibit. 148.12... Required from Applicants § 148.12 Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  7. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 1 2011-04-01 2011-04-01 false Net worth exhibit. 148.12... Required from Applicants § 148.12 Net worth exhibit. (a) Each applicant except a qualified tax-exempt organization or cooperative association must provide with its application a detailed exhibit showing the...

  8. 14 CFR 1262.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 5 2010-01-01 2010-01-01 false Net worth exhibit. 1262.202 Section 1262... AGENCY PROCEEDINGS Information Required From Applicants § 1262.202 Net worth exhibit. (a) Each applicant... detailed exhibit showing the net worth of the applicant and any affiliates (as defiined in §...

  9. 10 CFR 1023.311 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Net worth exhibit. 1023.311 Section 1023.311 Energy... Access to Justice Act Information Required from Applicants § 1023.311 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  10. 17 CFR 201.42 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Net worth exhibit. 201.42... Regulations Pertaining to the Equal Access to Justice Act § 201.42 Net worth exhibit. (a) Each applicant... a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  11. 49 CFR 1016.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 49 Transportation 8 2011-10-01 2011-10-01 false Net worth exhibit. 1016.202 Section 1016.202... BY PARTIES TO BOARD ADJUDICATORY PROCEEDINGS Information Required From Applicants § 1016.202 Net worth exhibit. (a) Each applicant must provide with its application a detailed exhibit showing the...

  12. 5 CFR 2610.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Net worth exhibit. 2610.202 Section 2610... THE EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 2610.202 Net worth exhibit. (a... with its application a detailed exhibit showing the net worth of the applicant and any affiliates...

  13. 31 CFR 6.9 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 1 2010-07-01 2010-07-01 false Net worth exhibit. 6.9 Section 6.9... EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 6.9 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  14. 49 CFR 6.19 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 1 2010-10-01 2010-10-01 false Net worth exhibit. 6.19 Section 6.19... PROCEEDINGS Information Required from Applicants § 6.19 Net worth exhibit. (a) Each applicant except a... exhibit showing the net worth of the applicant and any affiliates (as defined in this part) when...

  15. 10 CFR 1023.311 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Net worth exhibit. 1023.311 Section 1023.311 Energy... Access to Justice Act Information Required from Applicants § 1023.311 Net worth exhibit. (a) Each... application a detailed exhibit showing the net worth of the applicant and any affiliates (as defined in §...

  16. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  17. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  18. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  19. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  20. 45 CFR 1160.4 - Eligibility for international exhibitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Eligibility for international exhibitions. 1160.4... AND ARTIFACTS INDEMNITY ACT § 1160.4 Eligibility for international exhibitions. An indemnity agreement for an international exhibition made under these regulations shall cover: (a) Eligible items...

  1. A Major Children's Educational Art Exhibit: An Evaluative Case Study.

    ERIC Educational Resources Information Center

    Schlenk, George W.; Shrock, Sharon A.

    Results of a case study of an exhibit of art and artifacts designed for children are presented. The focus of the study was to apply the principles of instructional-message design to the evaluation of the exhibit. The exhibit, "Art Inside Out: Exploring Art and Culture through Time," was displayed at the Art Institute of Chicago. Textual elements,…

  2. Weight lifting can facilitate appreciative comprehension for museum exhibits

    PubMed Central

    Yamada, Yuki; Harada, Shinya; Choi, Wonje; Fujino, Rika; Tokunaga, Akinobu; Gao, YueYun; Miura, Kayo

    2014-01-01

    Appreciation of exhibits in a museum can be equated to a virtual experience of lives in the contexts originally surrounding the exhibits. Here we focus on the importance of weight information, and hence tested whether experiencing a weight during museum exhibit appreciation affects the beholders' satisfaction and recognition memory for the exhibits. An experiment was performed at a museum exhibiting skeletal preparations of animals. We used nine preparations and prepared four weight stimuli as weight cues in accordance with the actual weight of four of the preparations: Remaining five preparations was displayed without weight stimuli. In the cued condition, participants were asked to lift up the weight stimuli during their observation of the four exhibits. In the uncued condition, participants observed the exhibits without touching the weight stimuli. After observation of the exhibits, the participants responded to a questionnaire that measured their impressions of the exhibits and the museum, and performed a recognition test on the exhibits. Results showed that memory performance was better and viewing duration was longer with weight lifting instruction than without instruction. A factor analysis on the questionnaires revealed four factors (likeability, contentment, value, and quality). A path analysis showed indirect effects of viewing duration on memory performance and willingness-to-pay (WTP) for the museum appreciation through the impression factors. Our findings provide insight into a new interactive exhibition that enables long appreciation producing positive effects on visitors' impression, memory, and value estimation for exhibits. PMID:24782807

  3. 18 CFR 157.16 - Exhibits relating to acquisitions.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ..., Sales, Service, Construction, Extension, Acquisition or Abandonment § 157.16 Exhibits relating to acquisitions. In addition to the exhibits required by § 157.14, every application involving acquisition of... follow the procedures set out in § 157.10(d). (a) Exhibit Q—Effect of acquisition on existing...

  4. Weight lifting can facilitate appreciative comprehension for museum exhibits.

    PubMed

    Yamada, Yuki; Harada, Shinya; Choi, Wonje; Fujino, Rika; Tokunaga, Akinobu; Gao, Yueyun; Miura, Kayo

    2014-01-01

    Appreciation of exhibits in a museum can be equated to a virtual experience of lives in the contexts originally surrounding the exhibits. Here we focus on the importance of weight information, and hence tested whether experiencing a weight during museum exhibit appreciation affects the beholders' satisfaction and recognition memory for the exhibits. An experiment was performed at a museum exhibiting skeletal preparations of animals. We used nine preparations and prepared four weight stimuli as weight cues in accordance with the actual weight of four of the preparations: Remaining five preparations was displayed without weight stimuli. In the cued condition, participants were asked to lift up the weight stimuli during their observation of the four exhibits. In the uncued condition, participants observed the exhibits without touching the weight stimuli. After observation of the exhibits, the participants responded to a questionnaire that measured their impressions of the exhibits and the museum, and performed a recognition test on the exhibits. Results showed that memory performance was better and viewing duration was longer with weight lifting instruction than without instruction. A factor analysis on the questionnaires revealed four factors (likeability, contentment, value, and quality). A path analysis showed indirect effects of viewing duration on memory performance and willingness-to-pay (WTP) for the museum appreciation through the impression factors. Our findings provide insight into a new interactive exhibition that enables long appreciation producing positive effects on visitors' impression, memory, and value estimation for exhibits. PMID:24782807

  5. How to create an effective scientific exhibit: analysis of award-winning exhibits from the 1998 RSNA meeting.

    PubMed

    Choi, J R; Kruskal, J B; Rosen, M P; Davis, R B

    2000-01-01

    Although the most important component of an effective scientific exhibit is content, the way in which an exhibit is constructed can greatly influence its overall effectiveness. Choice of format should be determined by carefully analyzing the purpose of one's exhibit, expected audience, and data at hand, as well as type of meeting and funding. Depending on the type of data to be presented and available equipment and budget, the most appropriate style for a scientific exhibit may be a traditional mat board, computer-generated tiles or large-print backboard panel, traditional mat board with viewbox exhibit, matted transparency tiles with viewbox exhibit, or computer-generated large-film display. The authors analyzed 993 of 1, 041 (95.4%) scientific exhibits on display at the 84th RSNA Scientific Assembly and Annual Meeting and categorized each exhibit according to the following characteristics: display type and size, color scheme, display font size, and graphic styles. These characteristics were then correlated with scientific exhibit and design awards as well as invitations for submission to RadioGraphics. Chance of winning an award or being asked to publish the presentation in RadioGraphics was significantly increased for viewbox exhibits (compared with backboard panel exhibits) and for larger exhibits (compared with smaller exhibits). PMID:10903695

  6. [Energy education exhibits for Insights El Paso Science Museum

    SciTech Connect

    Shubinski, R.

    1998-05-27

    The grant in question, DE-FG03-94ER75954, was awarded to Insights El Paso Science Museum to build key exhibits. These exhibits helped the Museum fulfill its mission to ``promote curiosity and stimulate interest by exploratory, entertaining, exciting, and participatory learning in a broad range of scientific disciplines to persons of all ages regionally and internationally.`` There are several current Board of Directors members who also were Board members during the grant period and who helped construct some of the exhibits. Through speaking with them and reviewing minutes of Board meetings during 1994, it has been determined that seven of the ten proposed exhibits were constructed, with an eighth exhibit constructed as an alternative. Photos of seven of the exhibits and preliminary sketches of some are attached. Following is a list of the constructed exhibits: Hot or Cold, Give and Take, Conduction, Convection, Sources of Energy, Wind Generator, Solar Tracker, and Perpetual Motion.

  7. Evolutionary Dynamics of Influenza A Viruses in US Exhibition Swine.

    PubMed

    Nelson, Martha I; Wentworth, David E; Das, Suman R; Sreevatsan, Srinand; Killian, Mary L; Nolting, Jacqueline M; Slemons, Richard D; Bowman, Andrew S

    2016-01-15

    The role of exhibition swine in influenza A virus transmission was recently demonstrated by >300 infections with influenza A(H3N2) variant viruses among individuals who attended agricultural fairs. Through active influenza A virus surveillance in US exhibition swine and whole-genome sequencing of 380 isolates, we demonstrate that exhibition swine are actively involved in the evolution of influenza A viruses, including zoonotic strains. First, frequent introduction of influenza A viruses from commercial swine populations provides new genetic diversity in exhibition pigs each year locally. Second, genomic reassortment between viruses cocirculating in exhibition swine increases viral diversity. Third, viral migration between exhibition swine in neighboring states demonstrates that movements of exhibition pigs contributes to the spread of genetic diversity. The unexpected frequency of viral exchange between commercial and exhibition swine raises questions about the understudied interface between these populations. Overall, the complexity of viral evolution in exhibition swine indicates that novel viruses are likely to continually reemerge, presenting threats to humans. PMID:26243317

  8. 18. INTERIOR OF CIVIL RIGHTS INSTITUTE, MILESTONE GALLERY EXHIBITION OF ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    18. INTERIOR OF CIVIL RIGHTS INSTITUTE, MILESTONE GALLERY EXHIBITION OF THE SIXTEENTH STREET CHURCH, LOOKING NORTHWEST - Sixteenth Street Baptist Church, 1530 Sixth Avenue North, Birmingham, Jefferson County, AL

  9. Outreach to Science Faculty and Students through Research Exhibitions

    ERIC Educational Resources Information Center

    Chan, Tina; Hebblethwaite, Chris

    2014-01-01

    Penfield Library at the State University of New York at Oswego (SUNY Oswego) has a gallery exhibit space near the front entrance that is used to showcase student-faculty research and art class projects. This article features the library's outreach efforts to science faculty and students through research exhibitions. The library held an…

  10. Modelling the Future: Exhibitions and the Materiality of Education

    ERIC Educational Resources Information Center

    Lawn, Martin, Ed.

    2009-01-01

    The role of World Exhibitions in the 19th and early 20th centuries was to confirm a relation between the nation state and modernity. As a display about industries, inventions and identities, the Exhibition, in a sense, put entire nations into an elevated, viewable space. It is a significant element in modernity as comparisons can be made, progress…

  11. A Critical Appraisal of State Level Science Exhibition

    ERIC Educational Resources Information Center

    Nath, Baiju K.

    2007-01-01

    Science exhibitions are really great opportunities to students as well as teachers to disseminate knowledge that they have, and to experience a variety of new inventions and innovations that also need wide dissemination. The great significance of exhibition is that it fosters acquisition of different process skills leading to the development of…

  12. 22 CFR Exhibit B to Part 204 - Assignment

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Assignment B Exhibit B to Part 204 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT HOUSING GUARANTY STANDARD TERMS AND CONDITIONS Pt. 204, Exh. B Exhibit B to Part 204—Assignment The undersigned, being the registered owner of a Note in...

  13. 17 CFR 229.1016 - (Item 1016) Exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 1016) Exhibits. File as an exhibit to the schedule: (a) Any disclosure materials furnished to security...-9 Disclosure Material X X X Loan Agreement X X Report, Opinion or Appraisal X Contracts, Arrangements or Understandings X X X Statement re: Appraisal Rights X Oral Solicitation Materials X X......

  14. 17 CFR 229.1016 - (Item 1016) Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 1016) Exhibits. File as an exhibit to the schedule: (a) Any disclosure materials furnished to security...-9 Disclosure Material X X X Loan Agreement X X Report, Opinion or Appraisal X Contracts, Arrangements or Understandings X X X Statement re: Appraisal Rights X Oral Solicitation Materials X X......

  15. 17 CFR 229.1016 - (Item 1016) Exhibits.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 1016) Exhibits. File as an exhibit to the schedule: (a) Any disclosure materials furnished to security...-9 Disclosure Material X X X Loan Agreement X X Report, Opinion or Appraisal X Contracts, Arrangements or Understandings X X X Statement re: Appraisal Rights X Oral Solicitation Materials X X......

  16. Online Cultural Heritage Exhibitions: A Survey of Information Retrieval Features

    ERIC Educational Resources Information Center

    Liew, Chern Li

    2005-01-01

    Purpose: What kinds of online cultural heritage exhibitions are now available on the internet? How far have these cultural heritage institutions voyaged in terms of harnessing the power of information and communication technology and the interactivity of multimedia systems to exhibit cultural heritage resources? This study aims to highlight the…

  17. The Development of Validated Museum Exhibits. Final Report.

    ERIC Educational Resources Information Center

    Nicol, Elizabeth H.

    Exhibit development, as conceived in this report, is an evolutionary process, drawing the museum visitor into the collaborative venture of testing and improving the exhibits. The findings of contemporary learning research were put to work in the arrangement of activities and specimens that engaged children through self-instructional sequences. The…

  18. 7 CFR Exhibit G to Subpart A of... - Performance Bond

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Performance Bond G Exhibit G to Subpart A of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL.... 1924, Subpt. A, Exh. G Exhibit G to Subpart A of Part 1924—Performance Bond KNOW ALL PERSONS BY...

  19. 7 CFR Exhibit G to Subpart G of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true G Exhibit G to Subpart G of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) GENERAL Environmental Program Exhibit G to Subpart G of Part 1940...

  20. 7 CFR Exhibit F to Subpart A of... - Payment Bond

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Payment Bond F Exhibit F to Subpart A of Part 1924.... A, Exh. F Exhibit F to Subpart A of Part 1924—Payment Bond KNOW ALL PERSONS BY THESE PRESENTS: that... persons, firms, and corporations having a direct contract with the PRINCIPAL or its...

  1. 7 CFR Exhibit F to Subpart A of... - Payment Bond

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Payment Bond F Exhibit F to Subpart A of Part 1924.... A, Exh. F Exhibit F to Subpart A of Part 1924—Payment Bond KNOW ALL PERSONS BY THESE PRESENTS: that... persons, firms, and corporations having a direct contract with the PRINCIPAL or its...

  2. 7 CFR Exhibit F to Subpart A of... - Payment Bond

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Payment Bond F Exhibit F to Subpart A of Part 1924.... A, Exh. F Exhibit F to Subpart A of Part 1924—Payment Bond KNOW ALL PERSONS BY THESE PRESENTS: that... persons, firms, and corporations having a direct contract with the PRINCIPAL or its...

  3. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 14 2013-01-01 2013-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  4. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 14 2012-01-01 2012-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  5. 7 CFR Exhibit A to Subpart A of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false A Exhibit A to Subpart A of Part 1902 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... SUPERVISED BANK ACCOUNTS Supervised Bank Accounts of Loan, Grant, and Other Funds Exhibit A to Subpart A...

  6. 7 CFR Exhibit A to Subpart A of... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false A Exhibit A to Subpart A of Part 1902 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... SUPERVISED BANK ACCOUNTS Supervised Bank Accounts of Loan, Grant, and Other Funds Exhibit A to Subpart A...

  7. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  8. 7 CFR Exhibit A to Subpart A of... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true A Exhibit A to Subpart A of Part 1902 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... SUPERVISED BANK ACCOUNTS Supervised Bank Accounts of Loan, Grant, and Other Funds Exhibit A to Subpart A...

  9. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  10. 7 CFR Exhibits A-F to Subpart A... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 14 2014-01-01 2014-01-01 false A Exhibits A-F to Subpart A of Part 1955 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Real and Chattel Property Exhibits A-F to Subpart A of Part 1955...

  11. 7 CFR Exhibit A to Subpart A of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false A Exhibit A to Subpart A of Part 1902 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... SUPERVISED BANK ACCOUNTS Supervised Bank Accounts of Loan, Grant, and Other Funds Exhibit A to Subpart A...

  12. 7 CFR Exhibit A to Subpart A of... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false A Exhibit A to Subpart A of Part 1902 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... SUPERVISED BANK ACCOUNTS Supervised Bank Accounts of Loan, Grant, and Other Funds Exhibit A to Subpart A...

  13. Students-Exhibits Interaction at a Science Center

    ERIC Educational Resources Information Center

    Botelho, Agostinho; Morais, Ana M.

    2006-01-01

    In this study we investigate students' learning during their interaction with two exhibits at a science center. Specifically, we analyze both students' procedures when interacting with exhibits and their understanding of the scientific concepts presented therein. Bernstein's theory of pedagogic discourse (1990, 2000) provided the sociological…

  14. 47 CFR 1.1512 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 1 2011-10-01 2011-10-01 false Net worth exhibit. 1.1512 Section 1.1512... Access to Justice Act (EAJA) in Agency Proceedings Information Required from Applicants § 1.1512 Net... must provide with its application a detailed exhibit showing the net worth of the applicant and...

  15. 12 CFR 1203.11 - Confidentiality of net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 7 2011-01-01 2011-01-01 false Confidentiality of net worth exhibit. 1203.11... INFORMATION ACT Information Required From Applicants § 1203.11 Confidentiality of net worth exhibit. Unless otherwise ordered by the Director, or required by law, the statement of net worth will be for...

  16. 22 CFR 134.12 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Net worth exhibit. 134.12 Section 134.12... Information Required From Applicants § 134.12 Net worth exhibit. (a) Each applicant except a qualifed tax... showing the net worth of the applicant and any affiliates (as defined in § 960.4(f)) when the...

  17. 28 CFR 24.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Net worth exhibit. 24.202 Section 24.202... DEPARTMENT OF JUSTICE ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 24.202 Net worth... submit with its application a detailed exhibit showing its net worth at the time the proceeding...

  18. 22 CFR 134.12 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Net worth exhibit. 134.12 Section 134.12... Information Required From Applicants § 134.12 Net worth exhibit. (a) Each applicant except a qualifed tax... showing the net worth of the applicant and any affiliates (as defined in § 960.4(f)) when the...

  19. 24 CFR 14.205 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 24 Housing and Urban Development 1 2010-04-01 2010-04-01 false Net worth exhibit. 14.205 Section... Required From Applicants § 14.205 Net worth exhibit. (a) Each applicant except a qualified tax-exempt... the net worth of the applicant and any affiliates (as defined in § 14.120(f) of this part) when...

  20. 28 CFR 24.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Net worth exhibit. 24.202 Section 24.202... DEPARTMENT OF JUSTICE ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 24.202 Net worth... submit with its application a detailed exhibit showing its net worth at the time the proceeding...

  1. 24 CFR 14.205 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 24 Housing and Urban Development 1 2011-04-01 2011-04-01 false Net worth exhibit. 14.205 Section... Required From Applicants § 14.205 Net worth exhibit. (a) Each applicant except a qualified tax-exempt... the net worth of the applicant and any affiliates (as defined in § 14.120(f) of this part) when...

  2. 29 CFR 16.202 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 29 Labor 1 2011-07-01 2011-07-01 false Net worth exhibit. 16.202 Section 16.202 Labor Office of the Secretary of Labor EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 16.202 Net... must provide with its application a detailed exhibit showing the net worth of the applicant and...

  3. 47 CFR 1.1512 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 1 2010-10-01 2010-10-01 false Net worth exhibit. 1.1512 Section 1.1512... Access to Justice Act (EAJA) in Agency Proceedings Information Required from Applicants § 1.1512 Net... must provide with its application a detailed exhibit showing the net worth of the applicant and...

  4. 29 CFR 16.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 29 Labor 1 2010-07-01 2010-07-01 true Net worth exhibit. 16.202 Section 16.202 Labor Office of the Secretary of Labor EQUAL ACCESS TO JUSTICE ACT Information Required From Applicants § 16.202 Net worth... provide with its application a detailed exhibit showing the net worth of the applicant and any...

  5. 14 CFR 14.11 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 1 2011-01-01 2011-01-01 false Net worth exhibit. 14.11 Section 14.11... IMPLEMENTING THE EQUAL ACCESS TO JUSTICE ACT OF 1980 Information Required From Applicants § 14.11 Net worth... provide with its application a detailed exhibit showing the net worth of the applicant and any...

  6. 32 CFR 705.25 - Navy Exhibit Center.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 5 2014-07-01 2014-07-01 false Navy Exhibit Center. 705.25 Section 705.25 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS PUBLIC AFFAIRS REGULATIONS § 705.25 Navy Exhibit Center. (a) The center is...

  7. 32 CFR 705.25 - Navy Exhibit Center.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 32 National Defense 5 2010-07-01 2010-07-01 false Navy Exhibit Center. 705.25 Section 705.25 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS PUBLIC AFFAIRS REGULATIONS § 705.25 Navy Exhibit Center. (a) The center is...

  8. 32 CFR 705.25 - Navy Exhibit Center.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 5 2012-07-01 2012-07-01 false Navy Exhibit Center. 705.25 Section 705.25 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS PUBLIC AFFAIRS REGULATIONS § 705.25 Navy Exhibit Center. (a) The center is...

  9. 32 CFR 705.25 - Navy Exhibit Center.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 32 National Defense 5 2011-07-01 2011-07-01 false Navy Exhibit Center. 705.25 Section 705.25 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS PUBLIC AFFAIRS REGULATIONS § 705.25 Navy Exhibit Center. (a) The center is...

  10. 32 CFR 705.25 - Navy Exhibit Center.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 32 National Defense 5 2013-07-01 2013-07-01 false Navy Exhibit Center. 705.25 Section 705.25 National Defense Department of Defense (Continued) DEPARTMENT OF THE NAVY UNITED STATES NAVY REGULATIONS AND OFFICIAL RECORDS PUBLIC AFFAIRS REGULATIONS § 705.25 Navy Exhibit Center. (a) The center is...

  11. 75 FR 3862 - Photography in Public Exhibit Space

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-01-25

    ..., 2009, NARA published a proposed rule in the Federal Register (74 FR 38153) for a 60-day public comment... RECORDS ADMINISTRATION 36 CFR Part 1280 RIN 3095-AB60 Photography in Public Exhibit Space AGENCY: National... 2003, NARA completed a two year renovation of the Rotunda and constructed additional exhibit space...

  12. 17 CFR 229.601 - (Item 601) Exhibits.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... INSTRUCTIONS FOR FILING FORMS UNDER SECURITIES ACT OF 1933, SECURITIES EXCHANGE ACT OF 1934 AND ENERGY POLICY... sequential numbering system where such exhibit can be found. Where exhibits are incorporated by reference.... (iii)(A) Any management contract or any compensatory plan, contract or arrangement, including but...

  13. 17 CFR 229.601 - (Item 601) Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... INSTRUCTIONS FOR FILING FORMS UNDER SECURITIES ACT OF 1933, SECURITIES EXCHANGE ACT OF 1934 AND ENERGY POLICY... sequential numbering system where such exhibit can be found. Where exhibits are incorporated by reference.... (iii)(A) Any management contract or any compensatory plan, contract or arrangement, including but...

  14. 7 CFR Exhibit C to Subpart N of... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 13 2014-01-01 2013-01-01 true C Exhibit C to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants Exhibit C to Subpart N of Part 1944...

  15. 7 CFR Exhibit C to Subpart N of... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 13 2013-01-01 2013-01-01 false C Exhibit C to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants Exhibit C to Subpart N of Part 1944...

  16. 7 CFR Exhibit C to Subpart N of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true C Exhibit C to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants Exhibit C to Subpart N of Part 1944...

  17. Champions of American Sport--A Major Exhibition.

    ERIC Educational Resources Information Center

    Sorani, Bob

    1981-01-01

    An exhibit of 100 photographs, portraits, and sculptures, entitled "Champions of American Sport", is the first major art exhibit ever devoted to outstanding American sports personalities and to the aesthetic qualities of sport and human movement. The Smithsonian Institution is sponsoring the traveling collection, which includes works from the…

  18. Using Museum Exhibits: An Innovation in Experiential Learning

    ERIC Educational Resources Information Center

    Das, Satarupa

    2015-01-01

    Museum exhibits can be a tool in experiential learning. While instructors have documented various methods of experiential learning, they have not sufficiently explored such learning from museum exhibits. Museum researchers, however, have long found a satisfying cognitive component to museum visits. This paper narrates the author's design to…

  19. 7 CFR Exhibit A to Subpart L of... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 13 2012-01-01 2012-01-01 false A Exhibit A to Subpart L of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Exhibit A to Subpart L of Part 1940...

  20. 7 CFR Exhibit A to Subpart L of... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 13 2014-01-01 2013-01-01 true A Exhibit A to Subpart L of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Exhibit A to Subpart L of Part 1940...

  1. 7 CFR Exhibit A to Subpart L of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true A Exhibit A to Subpart L of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Exhibit A to Subpart L of Part 1940...

  2. 7 CFR Exhibit A to Subpart L of... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 13 2013-01-01 2013-01-01 false A Exhibit A to Subpart L of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Exhibit A to Subpart L of Part 1940...

  3. 7 CFR Exhibit A to Subpart L of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 13 2010-01-01 2009-01-01 true A Exhibit A to Subpart L of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... Exhibit A to Subpart L of Part 1940...

  4. Making Your Trade Fair Exhibit More Productive and More Interesting.

    ERIC Educational Resources Information Center

    Newcomb, Jack

    1982-01-01

    Suggestions for producing a successful exhibit booth include the following: the effectiveness of an exhibit depends on the effectiveness of the people staffing it; avoid games and unrelated giveaway items; demonstrate product in the booth; give special attention to existing customers; and make literature available only from the booth personnel.…

  5. 7 CFR Exhibit G to Subpart G of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true G Exhibit G to Subpart G of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) GENERAL Environmental Program Exhibit G to Subpart G of Part 1940...

  6. 7 CFR Exhibit G to Subpart A of... - Performance Bond

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Performance Bond G Exhibit G to Subpart A of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL.... 1924, Subpt. A, Exh. G Exhibit G to Subpart A of Part 1924—Performance Bond KNOW ALL PERSONS BY...

  7. 7 CFR Exhibit G to Subpart G of... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 13 2012-01-01 2012-01-01 false G Exhibit G to Subpart G of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) GENERAL Environmental Program Exhibit G to Subpart G of Part 1940...

  8. 7 CFR Exhibits A-B to Subpart G... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false A Exhibits A-B to Subpart G to Part 1822 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE..., Procedures, and Authorizations Exhibits A-B to Subpart G to Part 1822...

  9. 7 CFR Exhibit G to Subpart A of... - Performance Bond

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Performance Bond G Exhibit G to Subpart A of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL.... 1924, Subpt. A, Exh. G Exhibit G to Subpart A of Part 1924—Performance Bond KNOW ALL PERSONS BY...

  10. 7 CFR Exhibit G to Subpart G of... - [Reserved

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 13 2014-01-01 2013-01-01 true G Exhibit G to Subpart G of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) GENERAL Environmental Program Exhibit G to Subpart G of Part 1940...

  11. 7 CFR Exhibit G to Subpart G of... - [Reserved

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 13 2013-01-01 2013-01-01 false G Exhibit G to Subpart G of Part 1940 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) GENERAL Environmental Program Exhibit G to Subpart G of Part 1940...

  12. 7 CFR Exhibit G to Subpart A of... - Performance Bond

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 12 2014-01-01 2013-01-01 true Performance Bond G Exhibit G to Subpart A of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS.... A, Exh. G Exhibit G to Subpart A of Part 1924—Performance Bond KNOW ALL PERSONS BY THESE...

  13. 7 CFR Exhibit F to Subpart A of... - Payment Bond

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Payment Bond F Exhibit F to Subpart A of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS.... A, Exh. F Exhibit F to Subpart A of Part 1924—Payment Bond KNOW ALL PERSONS BY THESE PRESENTS:...

  14. 7 CFR Exhibit F to Subpart A of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true F Exhibit F to Subpart A of Part 1962 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) PERSONAL PROPERTY Servicing and Liquidation of Chattel Security Exhibit F to Subpart...

  15. 7 CFR Exhibit F to Subpart A of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false F Exhibit F to Subpart A of Part 1962 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) PERSONAL PROPERTY Servicing and Liquidation of Chattel Security Exhibit F to Subpart...

  16. 7 CFR Exhibit C to Subpart N of... - [Reserved

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 13 2012-01-01 2012-01-01 false C Exhibit C to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants Exhibit C to Subpart N of Part 1944...

  17. Exhibitions: Connecting Classroom Assessment with Culminating Demonstrations of Mastery

    ERIC Educational Resources Information Center

    Davidson, Jill

    2009-01-01

    Exhibitions are public demonstrations of mastery that occur at culminating moments, such as at the conclusion of a unit of study, the transition from one level of schooling to the next, and graduation. Exhibitions require students to speak publicly, use evidence, present engaging visual displays, and otherwise demonstrate mastery to educators,…

  18. 7 CFR Exhibit C to Subpart N of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 13 2011-01-01 2009-01-01 true C Exhibit C to Subpart N of Part 1944 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE... REGULATIONS (CONTINUED) HOUSING Housing Preservation Grants Exhibit C to Subpart N of Part 1944...

  19. An Exhibition on Everyday Chemistry. Communicating Chemistry to the Public.

    ERIC Educational Resources Information Center

    Ucko, David A.; And Others

    1986-01-01

    Discusses a recent addition to the Museum of Science and Industry (Chicago) known as "Everyday Chemistry." This permanent exhibit on modern chemistry incorporates demonstrations of chemical reactions in ways intended to enhance public understanding. Describes the six cases in the exhibit and the automated aspects of their demonstrations. (TW)

  20. 48 CFR 6101.17 - Exhibits [Rule 17].

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 6101.17 Federal Acquisition Regulations System CIVILIAN BOARD OF CONTRACT APPEALS, GENERAL SERVICES ADMINISTRATION CONTRACT DISPUTE CASES 6101.17 Exhibits . (a) Marking of exhibits. (1) Documents and other... electronically stored information or printed versions of electronically stored information to be included in...

  1. 46 CFR 169.805 - Exhibition of merchant mariner credentials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 7 2014-10-01 2014-10-01 false Exhibition of merchant mariner credentials. 169.805 Section 169.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.805 Exhibition of merchant mariner credentials. Officers on any...

  2. 46 CFR 169.805 - Exhibition of merchant mariner credentials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 7 2010-10-01 2010-10-01 false Exhibition of merchant mariner credentials. 169.805 Section 169.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.805 Exhibition of merchant mariner credentials. Officers on any...

  3. 46 CFR 169.805 - Exhibition of merchant mariner credentials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 7 2011-10-01 2011-10-01 false Exhibition of merchant mariner credentials. 169.805 Section 169.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.805 Exhibition of merchant mariner credentials. Officers on any...

  4. 46 CFR 169.805 - Exhibition of merchant mariner credentials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 7 2012-10-01 2012-10-01 false Exhibition of merchant mariner credentials. 169.805 Section 169.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.805 Exhibition of merchant mariner credentials. Officers on any...

  5. 46 CFR 169.805 - Exhibition of merchant mariner credentials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 7 2013-10-01 2013-10-01 false Exhibition of merchant mariner credentials. 169.805 Section 169.805 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) NAUTICAL SCHOOLS SAILING SCHOOL VESSELS Operations § 169.805 Exhibition of merchant mariner credentials. Officers on any...

  6. 46 CFR Exhibit No. 1 to Subpart F... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false No. Exhibit No. 1 to Subpart F of Part 502 Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS RULES OF PRACTICE AND PROCEDURE Settlement; Prehearing Procedure Exhibit No. 1 to Subpart F of Part 502...

  7. 46 CFR Exhibit No. 1 to Subpart F... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 9 2011-10-01 2011-10-01 false No. Exhibit No. 1 to Subpart F of Part 502 Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS RULES OF PRACTICE AND PROCEDURE Settlement; Prehearing Procedure Exhibit No. 1 to Subpart F of Part 502...

  8. 14 CFR 77.59 - Subpoenas of witnesses and exhibits.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 2 2010-01-01 2010-01-01 false Subpoenas of witnesses and exhibits. 77.59 Section 77.59 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE OBJECTS AFFECTING NAVIGABLE AIRSPACE Rules of Practice for Hearings Under Subpart D § 77.59 Subpoenas of witnesses and exhibits....

  9. Three Pictures of an Exhibition: Warm, Cool, and Hard.

    ERIC Educational Resources Information Center

    McDonald, Joseph P.

    1993-01-01

    Describes several ways to view senior exhibits at an urban high school employing the Coalition of Essential Schools'"graduation by exhibition" assessment method. The coalition advocates a pedagogy combining a personalized, caring environment with a focus on student production. Judges must balance warm regard with cool, critical appraisal and…

  10. Crystal structures of arginine kinase in complex with ADP, nitrate, and various phosphagen analogs.

    PubMed

    Clark, Shawn A; Davulcu, Omar; Chapman, Michael S

    2012-10-12

    Arginine kinase catalyzes the reversible transfer of a phosphoryl group between ATP and l-arginine and is a monomeric homolog of the human enzyme creatine kinase. Arginine and creatine kinases belongs to the phosphagen kinase family of enzymes, which consists of eight known members, each of which is specific for its own phosphagen. Here, the source of phosphagen specificity in arginine kinase is investigated through the use of phosphagen analogs. Crystal structures have been determined for Limulus polyphemus arginine kinase with one of four arginine analogs bound in a transition state analog complex: l-ornithine, l-citrulline, imino-l-ornithine, and d-arginine. In all complexes, the enzyme achieves a closed conformation very similar to that of the cognate transition state analog complex, but differences are observed in the configurations of bound ligands. Arginine kinase exhibits no detectable activity towards ornithine, citrulline, or imino-l-ornithine, and only trace activity towards d-arginine. The crystal structures presented here demonstrate that phosphagen specificity is derived neither from a lock-and-key mechanism nor a modulation of induced-fit conformational changes, but potentially from subtle distortions in bound substrate configurations. PMID:22995310

  11. Multispecies modeling for adaptive management of horseshoe crabs and red knots in the delaware bay

    USGS Publications Warehouse

    McGowan, C.P.; Smith, D.R.; Sweka, J.A.; Martin, J.; Nichols, J.D.; Wong, R.; Lyons, J.E.; Niles, L.J.; Kalasz, K.; Brust, J.; Klopfer, M.; Spear, B.

    2011-01-01

    Adaptive management requires that predictive models be explicit and transparent to improve decisions by comparing management actions, directing further research and monitoring, and facilitating learning. The rufa subspecies of red knots (Calidris canutus rufa), which has recently exhibited steep population declines, relies on horseshoe crab (Limulus polyphemus) eggs as their primary food source during stopover in Delaware Bay during spring migration. We present a model with two different parameterizations for use in the adaptive management of horseshoe crab harvests in the Delaware Bay that links red knot mass gain, annual survival, and fecundity to horseshoe crab dynamics. The models reflect prevailing hypotheses regarding ecological links between these two species. When reported crab harvest from 1998 to 2008 was applied, projections corresponded to the observed red knot population abundances depending on strengths of the demographic relationship between these species. We compared different simulated horseshoe crab harvest strategies to evaluate whether, given this model, horseshoe crab harvest management can affect red knot conservation and found that restricting harvest can benefit red knot populations. Our model is the first to explicitly and quantitatively link these two species and will be used within an adaptive management framework to manage the Delaware Bay system and learn more about the specific nature of the linkage between the two species. ?? 2011 Wiley Periodicals, Inc.

  12. Multispecies modeling for adaptive management of horseshoe crabs and red knots in the Delaware Bay

    USGS Publications Warehouse

    McGowan, Conor P.; Smith, David; Sweka, John A.; Martin, Julien; Nichols, James D.; Wong, Richard; Lyons, J.E.; Niles, Lawrence J.; Kalasz, Kevin S.; Brust, Jeffrey; Klopfer, Michelle; Spear, Braddock

    2011-01-01

    Adaptive management requires that predictive models be explicit and transparent to improve decisions by comparing management actions, directing further research and monitoring, and facilitating learning. The rufa subspecies of red knots (Calidris canutus rufa), which has recently exhibited steep population declines, relies on horseshoe crab (Limulus polyphemus) eggs as their primary food source during stopover in Delaware Bay during spring migration. We present a model with two different parameterizations for use in the adaptive management of horseshoe crab harvests in the Delaware Bay that links red knot mass gain, annual survival, and fecundity to horseshoe crab dynamics. The models reflect prevailing hypotheses regarding ecological links between these two species. When reported crab harvest from 1998 to 2008 was applied, projections corresponded to the observed red knot population abundances depending on strengths of the demographic relationship between these species. We compared different simulated horseshoe crab harvest strategies to evaluate whether, given this model, horseshoe crab harvest management can affect red knot conservation and found that restricting harvest can benefit red knot populations. Our model is the first to explicitly and quantitatively link these two species and will be used within an adaptive management framework to manage the Delaware Bay system and learn more about the specific nature of the linkage between the two species.

  13. First major museum exhibit on the science of AIDS.

    PubMed

    Nary, G

    1995-05-01

    The Chicago Museum of Science and Industry recently opened its 4,000-square-foot permanent exhibit on the science of AIDS. The exhibit is designed to educate visitors about immunology and virology by presenting AIDS as an example of an immune system breakdown and showing advances made in research and prevention of diseases caused by viruses. The exhibit also seeks to engage preteens with compelling graphics and interactive displays in the hope of motivating them to pursue careers in science. One exhibit, called Frontline, allows visitors to question several physicians and researchers specializing in HIV/AIDS through a touch-screen video program. The exhibit allows these professionals to reveal their commitment and explain their views on the future of the pandemic. PMID:11362508

  14. Cosmic Origins: A Traveling Science Exhibit and Education Program

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.; Morrow, C. A.; Harold, J.

    2003-12-01

    The Space Science Institute of Boulder, Colorado, is developing a 3,000 square-foot traveling exhibition, called Cosmic Origins, which will bring origins-related research and discoveries to students and the American public. Cosmic Origins will have three interrelated exhibit areas: Star Formation, Planet Quest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in "habitable zones" around other stars; and finally they will be able to learn about the wide range of conditions for life on Earth and how scientists are looking for signs of life beyond Earth. Visitors will also learn about the tools scientists' use, such as space-based and ground-based telescopes, to improve our understanding of the cosmos. Exhibit content will address age-old questions that form the basis of NASA's Origins and Astrobiology programs: Where did we come from? Are we alone? In addition to the exhibit, our project will include workshops for educators and docents at host sites, as well as a public Web site that will use a virtual rendering of exhibit content. The exhibit's size will permit it to visit medium sized museums in underserved regions of the country. It will begin its 3-year tour to 9 host museums and science centers in early 2005. A second 3-year tour is also planned for 2008. The Association of Science-Technology Centers (ASTC) will manage the exhibit's national tour. Current partners in the Cosmic Origins project include ASTC, the Denver Museum of Nature and Science, Lawrence Hall of Science, NASA Astrobiology Institute, NASA missions (e.g. PlanetQuest, SIRTF, and Kepler), New York Hall of Science, the SETI Institute, and the Space Telescope Science Institute. The exhibition is supported by grants from NSF and NASA. This report will focus on the Planet Quest part of the exhibition.

  15. 7 CFR Exhibit C to Subpart C of... - Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals C Exhibit C to Subpart C of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE...

  16. 7 CFR Exhibit C to Subpart C of... - Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals C Exhibit C to Subpart C of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE...

  17. 7 CFR Exhibit C to Subpart C of... - Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 12 2013-01-01 2013-01-01 false Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals C Exhibit C to Subpart C of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE...

  18. 7 CFR Exhibit C to Subpart C of... - Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 12 2012-01-01 2012-01-01 false Checklist of Visual Exhibits and Documentation for RRH, RCH, and LH Proposals C Exhibit C to Subpart C of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE...

  19. An exploratory study of zoo visitors' exhibit experiences and reactions.

    PubMed

    Luebke, Jerry F; Matiasek, Jennifer

    2013-01-01

    Visiting a zoo or aquarium is not only fun, but can also have a positive impact on visitors' knowledge and attitudes regarding animals and the environment. The biggest challenge, however, is for these institutions to strategically provide opportunities for cognitive and affective learning while simultaneously facilitating enjoyment and fun. Recent studies in zoos and aquaria have examined various factors that can influence learning such as engaging visitors' emotions or connecting with visitors' prior knowledge and interests. The intent of the current study was to further this line of investigation and explore the relationship between visitors' predispositions and their cognitive and affective experiences and reactions as they walked through an animal exhibit. We selected three indoor immersion exhibits and one outdoor naturalistic exhibit for the study to obtain a wide range of different animals and exhibit settings. Research assistants randomly intercepted visitors leaving the exhibits and asked, among other things, the extent they experienced certain thoughts and feelings while they were walking through the exhibits. Results revealed that visitors' emotional responses to viewing animals were key experiences along with opportunities for introspection and reflection during their time in the exhibits. Implications of the study are discussed in reference to providing both fun and meaningful learning experiences for visitors. PMID:23740472

  20. 4. PENSTOCKS. EXHIBIT L, SANTA ANA RIVER NO. 1 PROJECT, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. PENSTOCKS. EXHIBIT L, SANTA ANA RIVER NO. 1 PROJECT, APR. 30, 1945. SCE drawing no. 523197 (sheet no. 7; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-1 Forebay & Penstock, Redlands, San Bernardino County, CA

  1. 54. ALDER CREEK DIVERSION, PROJECT 1933, EXHIBIT F, SANTA ANA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. ALDER CREEK DIVERSION, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 2 SCE drawing no. 5206858, no date (FERC no. 1933-48). - Santa Ana River Hydroelectric System, Redlands, San Bernardino County, CA

  2. 3. TAILRACE AND FOREBAY, SANTA ANA NO. 3, EXHIBIT L, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    3. TAILRACE AND FOREBAY, SANTA ANA NO. 3, EXHIBIT L, JAN. 25, 1956. SCE drawing no. 541475 (sheet 6; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-3 Forebay & Penstock, Redlands, San Bernardino County, CA

  3. 56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    56. CROSS SECTION OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 1. SCE drawing no. 5206856 (no date; FERC no. 1933-46). - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

  4. 54. PLAN OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ANA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    54. PLAN OF POWERHOUSE, PROJECT 1933, EXHIBIT F, SANTA ANA POWERHOUSE NO. 1. SCE drawing no. 5206855 (no date; FERC no. 1933-45). - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

  5. "Wenn die Erde bebt", an educational public exhibition in Vienna

    NASA Astrophysics Data System (ADS)

    Parithusta, Rizkita; Brueckl, Ewald; Heuer, Rudolf; Mitterbauer, Ulrike

    2010-05-01

    Natural disasters can cause the loss of human lives, an economic crisis and also the loss of irreplaceable cultural heritage. Earthquakes can mean instantaneous destruction without warning, causing extensive and often irreparable damage to our heritage. An exhibition with the title "Wenn die Erde bebt" (i.e. "When the Earth shakes") which was held at the Natural History Museum, Vienna; in an effort to introduce understanding, awareness, and preparedness to the public, facing earthquake phenomenon. The exhibition compiled and classified examples of large earthquakes and introduces into the basic principles of seismology. It further addresses earthquake impact and how to live with earthquakes, giving access to the most suitable procedure of safety education. The idea of the exhibition is communicated by the means of posters, videos, and physical models which support the understanding of seismometry, elastic rebound theory and earthquake resistant construction. The exhibition is an Austrian contribution to IYPE - International Year of Planet Earth and is now on tour through Austria.

  6. Science, providence, and progress at the Great Exhibition.

    PubMed

    Cantor, Geoffrey

    2012-09-01

    The Great Exhibition of 1851 is generally interpreted as a thoroughly secular event that celebrated progress in science, technology, and industry. In contrast to this perception, however, the exhibition was viewed by many contemporaries as a religious event of considerable importance. Although some religious commentators were highly critical of the exhibition and condemned the display of artifacts in the Crystal Palace as giving succor to materialism, others incorporated science and technology into their religious frameworks. Drawing on sermons, tracts, and the religious periodical press, this essay pays close attention to the ways in which science and technology were endowed with providentialist significance and particularly examines the notion of human progress used by a number of Christian writers, especially Congregationalists, who set scientific and technological progress within a teleological religious perspective. This discussion sheds fresh light not only on the Great Exhibition itself but also on the deployment of natural theology in mid-nineteenth-century Britain. PMID:23286186

  7. 17. INTERIOR VIEW OF BASEMENT EXHIBITION OF EVENTS OF CIVIL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    17. INTERIOR VIEW OF BASEMENT EXHIBITION OF EVENTS OF CIVIL RIGHTS MOVEMENT AND THE 1963 BOMBING OF THE CHURCH, LOOKING SOUTH - Sixteenth Street Baptist Church, 1530 Sixth Avenue North, Birmingham, Jefferson County, AL

  8. The role of exhibits in teacher workshops at science museums

    NASA Astrophysics Data System (ADS)

    Stein, Fred D.

    Between 1986 and 1998, the Exploratorium Institute for Inquiry offered multi-week science institutes for elementary educators involving museum exhibit use during a three-day independent investigation on light and color. Many museums tend to underutilize exhibit use in their teacher education programs. This study addresses the question, "What are the contributions of exhibit use to teachers' learning of science content during a workshop at a science museum?" Data from workshops over three successive years was collected in the form of 13 case studies of participants' investigations. Pre- and post-testing of six participants showed a large (ES = 3.0 SD) and significant gain in their understanding of light and color concepts. The case studies were analyzed by coding each incident of exhibit use according to how the exhibit interaction might have helped the participant in his or her learning. Clusters of recurring themes emerged inductively from the coding process suggesting that the exhibits conferred both logistical and conceptual benefits. Logistically, the exhibits acted as "labor-saving" devices, saving participants time because they were always set up and ready to use, and saving the workshop facilitators time because facilitators could recommend that a participant visit an exhibit rather than spend time giving them individual attention or helping them construct their own investigation apparatus. Conceptually, the exhibits supported each aspect of the Piagetian conceptual change process---accommodation, assimilation, and disequilibrium. They supported accommodation of idea structures and the development of new ones by encouraging participants to ask and answer "What would happen if...?" questions which often generated ideas to explain the new experiences. They supported assimilation of experiences into recently developed idea structures or schemes (supporting and consolidating them) by providing opportunities for participants to ask and answer "Will it happen if

  9. 15 CFR 18.12 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 15 Commerce and Foreign Trade 1 2011-01-01 2011-01-01 false Net worth exhibit. 18.12 Section 18.12... Information Required from Applicants § 18.12 Net worth exhibit. (a) Each applicant except a qualified tax... showing the net worth of the applicant and any affiliates (as defined in § 18.5(f) of this part) when...

  10. 15 CFR 18.12 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 15 Commerce and Foreign Trade 1 2010-01-01 2010-01-01 false Net worth exhibit. 18.12 Section 18.12... Information Required from Applicants § 18.12 Net worth exhibit. (a) Each applicant except a qualified tax... showing the net worth of the applicant and any affiliates (as defined in § 18.5(f) of this part) when...

  11. Bringing Planetary Science to the Public through Traveling Exhibitions

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.

    2001-11-01

    The Space Science Institute (SSI) of Boulder, Colorado has recently developed two museum exhibits called the Space Weather Center and MarsQuest. It is currently planning to develop another exhibit called Gas Giants. These exhibitions provide research scientists the opportunity to engage in a number of activities that are vital to the success of these major outreach programs. The Space Weather Center was developed in partnership with various research missions at NASA's Goddard Space Flight Center. The focus of the presentation will be on MarsQuest and Gas Giants. MarsQuest is a 5000 square-foot, 3M, traveling exhibition that is now touring the country. The exhibit's 3-year tour will enable millions of Americans to share in the excitement of the scientific exploration of Mars and learn more about their own planet in the process. The associated planetarium show and education program will also be described, with particular emphasis on workshops to orient museum staff (e.g. museum educators and docents) and workshops for master educators near host museums and science centers. The workshops make innovative connections between the exhibitions interactive experiences and lesson plans aligned with the National Science Education Standards. These exhibit programs are good models for actively involving scientists and their discoveries to help improve informal science education in the museum community and for forging a stronger connection between formal and informal education. The presentation will also discuss how Gas Giants, a proposed 4000 square-foot traveling exhibition on the mysteries and discoveries of the outer planets, will be able to take advantage of the connections and resources that have been developed by the MarsQuest project.

  12. University / Science Center Exhibit Development Collaboration: Strategies and Lessons Learned

    NASA Astrophysics Data System (ADS)

    Raddick, M. J.; Carliles, S.; Bartelme, L.; Patterson, J.

    2008-06-01

    Through funding from the NSF's Internship in Public Science Education (IPSE) program, Johns Hopkins University (JHU) and the Maryland Science Center (MSC) have worked together to create an exhibit based on JHU's research with the Sloan Digital Sky Survey, a project to map the universe. The exhibit is a kiosk-based interactive presentation that connects to online data about the sky. It is currently displayed in SpaceLink, an area at the MSC that focuses on current events and research in astronomy. The person primarily responsible for the exhibit was a graduate student in computer science in the JHU Physics and Astronomy department. He worked with an EPO professional in the department and two members of the MSC's planetarium and exhibit staff to plan the exhibit. The team also worked with a coordinator in the JHU chemistry department, and an external evaluator. Along with increased public understanding of science, our goal was to create and evaluate a sustainable partnership between a research university and a local science center. We are producing an evaluation report discussing our collaboration and detailing lessons learned. We hope that our experience can be a model for other university / science center collaborations in the future. Some lessons that we have learned in our development effort are: start all design decisions with learning goals and objectives, write goals with evaluation in mind, focus on the process of science, and do not underestimate the challenges of working with the web as part of the exhibit technology.

  13. Evaluating Education and Science in the KSC Visitor Complex Exhibits

    NASA Technical Reports Server (NTRS)

    Erickson, Lance K.

    2000-01-01

    The continuing development of exhibits at the Kennedy Space Center's Visitor Complex is an excellent opportunity for NASA personnel to promote science and provide insight into NASA programs and projects for the approximately 3 million visitors that come to KSC annually. Stated goals for the Visitor Complex, in fact, emphasize science awareness and recommend broadening the appeal of the displays and exhibits for all age groups. To this end, this summer project seeks to evaluate the science content of planned exhibits/displays in relation to these developing opportunities and identify specific areas for enhancement of existing or planned exhibits and displays. To help expand the educational and science content within the developing exhibits at the Visitor Complex, this project was structured to implement the goals of the Visitor Center Director. To accomplish this, the exhibits and displays planned for completion within the year underwent review and evaluation for science content and educational direction. Planning emphasis for the individual displays was directed at combining the elements of effective education with fundamental scientific integrity, within an appealing format.

  14. A phenomenological investigation of science center exhibition developers' expertise development

    NASA Astrophysics Data System (ADS)

    Young, Denise L.

    The purpose of this study was to examine the exhibition developer role in the context of United States (U.S.) science centers, and more specifically, to investigate the way science center exhibition developers build their professional expertise. This research investigated how successfully practicing exhibition developers described their current practices, how they learned to be exhibition developers, and what factors were the most important to the developers in building their professional expertise. Qualitative data was gathered from 10 currently practicing exhibition developers from three science centers: the Exploratorium, San Francisco, California; the Field Museum, Chicago, Illinois; and the Science Museum of Minnesota, St. Paul, Minnesota. In-depth, semistructured interviews were used to collect the data. The study embraced aspects of the phenomenological tradition and sought to derive a holistic understanding of the position and how expertise was built for it. The data were methodically coded and organized into themes prior to analysis. The data analysis found that the position consisted of numerous and varied activities, but the developers' primary roles were advocating for the visitor, storytelling, and mediating information and ideas. They conducted these activities in the context of a team and relied on an established exhibition planning process to guide their work. Developers described a process of learning exhibition development that was experiential in nature. Learning through daily practice was key, though they also consulted with mentors and relied on visitor studies to gauge the effectiveness of their work. They were adept at integrating prior knowledge gained from many aspects of their lives into their practice. The developers described several internal factors that contributed to their expertise development including the desire to help others, a natural curiosity about the world, a commitment to learning, and the ability to accept critique. They

  15. Black Holes Traveling Exhibition: This Time, It's Personal.

    NASA Astrophysics Data System (ADS)

    Dussault, Mary E.; Braswell, E. L.; Sunbury, S.; Wasser, M.; Gould, R. R.

    2012-01-01

    How can you make a topic as abstract as black holes seem relevant to the life of the average museum visitor? In 2009, the Harvard-Smithsonian Center for Astrophysics developed a 2500 square foot interactive museum exhibition, "Black Holes: Space Warps & Time Twists,” with funding from the National Science Foundation and NASA. The exhibition has been visited by more than a quarter million museum-goers, and is about to open in its sixth venue at the Reuben H. Fleet Science Center in San Diego, California. We have found that encouraging visitors to adopt a custom black hole explorer's identity can help to make the science of black holes more accessible and meaningful. The Black Holes exhibition uses networked exhibit technology that serves to personalize the visitor experience, to support learning over time including beyond the gallery, and to provide a rich quantitative source of embedded evaluation data. Visitors entering the exhibition create their own bar-coded "Black Holes Explorer's Card” which they use throughout the exhibition to collect and record images, movies, their own predictions and conclusions, and other black hole artifacts. This digital database of personal discoveries grows as visitors navigate through the gallery, and an automated web-content authoring system creates a personalized online journal of their experience that they can access once they get home. We report here on new intriguing results gathered from data generated by 112,000 visitors across five different venues. For example, an initial review of the data reveals correlations between visitors’ black hole explorer identity choices and their engagement with the exhibition. We will also discuss correlations between learning gains and personalization.

  16. The Powerful Educational Potential of Traveling Space Science Exhibits

    NASA Astrophysics Data System (ADS)

    Morrow, C. A.; Dusenbery, P. B.; Harold, J. H.

    2003-04-01

    Five traveling exhibits (both large and small) related to space science are currently touring the U. S., and two more have recently been funded by the National Science Foundation and NASA. These extraordinary educational resources address topics like space weather, Mars exploration, cosmology, the results of Hubble Space Telescope, and the origins of stars, planets, and life. The Space Science Institute (SSI) of Boulder, Colorado, plays leadership roles in four of the seven exhibits. This paper will summarize the nature and itineraries of these exhibits, and how they serve as rallying points for education and public outreach activities across the entire spectrum of science communication. The talk will give special attention to workshops SSI has conducted at MarsQuest host sites for museum educators, docents, and local educators to bolster the host site's ability to do programming around the exhibit content. These workshops have shown promise of leaving a host site with a legacy of new educational capabilities and enhanced connectivity with space scientists and educators in the region. The talk will also address progress on the MarsQuest On-Line project which uses the 5000 sq ft (500 sq m) exhibit as a conceptual framework for an interactive website.

  17. Space Research Institute (IKI) Exhibition as an Educational Project

    NASA Astrophysics Data System (ADS)

    Sadovski, Andrei; Antonenko, Elena

    2016-07-01

    The Exhibition "Space Science: Part and Future" in Space Research Institute (IKI) was opened in 2007 in commemoration of the 50th anniversary of the first man-made satellite launch. It covers the latest and the most important findings in space research, shows instruments which are used in space exploration, and presents past, current, and future Russian science missions. Prototypes of space instruments developed by Russian specialists and mockups of spacecraft and spaceships flown to space are displayed, together with information posters, describing space missions, their purposes and results. The Exhibition takes a great part in school space education. Its stuff actively works with schoolchildren, undergraduate students and also makes a great contribution in popularization of space researches. Moreover the possibility to learn about scientific space researches first-hand is priceless. We describe the main parts of the Exhibition and forms of it work and also describe the collaboration with other museums and educational organizations.

  18. Liberty Bell 7 Space Capsule Exhibit previews at Visitor Complex

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Children on a tour at the KSC Visitor Complex get an early look at the Discovery Channel's Liberty Bell 7 Space Capsule Exhibit, which opens to the public on Saturday, June 17. They are on a re- creation of the deck of Ocean Project, the ship that located and recovered the space capsule from the floor of the Atlantic Ocean. Liberty Bell 7 launched U.S. Air Force Captain Virgil '''Gus''' Grissom July 21, 1961, on a mission that lasted 15 minutes and 37 seconds before sinking. It lay undetected for nearly four decades before a Discovery Channel expedition located it and recovered it. The space capsule, now restored and preserved, is part of an interactive exhibit touring science centers and museums in 12 cities throughout the United States until 2003. The exhibit also includes hands-on elements such as a capsule simulator, a centrifuge, and ROV pilot.

  19. Mouse embryonic fibroblasts exhibit extensive developmental and phenotypic diversity

    PubMed Central

    Singhal, Prabhat K.; Sassi, Slim; Lan, Lan; Au, Patrick; Halvorsen, Stefan C.; Fukumura, Dai; Jain, Rakesh K.; Seed, Brian

    2016-01-01

    Analysis of embryonic fibroblasts from GFP reporter mice indicates that the fibroblast cell type harbors a large collection of developmentally and phenotypically heterogeneous subtypes. Some of these cells exhibit multipotency, whereas others do not. Multiparameter flow cytometry analysis shows that a large number of distinct populations of fibroblast-like cells can be found in cultures initiated from different embryonic organs, and cells sorted according to their surface phenotype typically retain their characteristics on continued propagation in culture. Similarly, surface phenotypes of individual cloned fibroblast-like cells exhibit significant variation. The fibroblast cell class appears to contain a very large number of denumerable subtypes. PMID:26699463

  20. One exhibition, many goals. Combining scientific research and risk communication

    NASA Astrophysics Data System (ADS)

    Charrière, Marie; Bogaard, Thom; Junier, Sandra; Malet, Jean-Philippe; Mostert, Erik

    2015-04-01

    How effective is visual communication to increase awareness of natural hazards and risks? To answer this research question, we developed a research design that was at the same time an experimental setting and an actual communication effort. Throughout the full length of the 2-years project held in the Ubaye valley (southeastern France), we collaborated with local and regional stakeholders (politicians and technicians). During a consultation phase, the communication context was determined, the audience of the project was defined and finally the testing activity-communication effort was determined. We were offered the opportunity to design an exhibition for the local public library. In a consultation phase that corresponded to the design of the exhibition, the stakeholders contributed to its content as well as helping with the funding of the exhibition. Finally, during the experimentation phase, the stakeholders participated in advertising the activity, gathering of participants and designing the scientific survey. In order to assess the effects of the exhibition on risk awareness, several groups of children, teenagers and adults were submitted to a research design, consisting of 1) a pre-test, 2) the visit of the exhibition and 3) a post-test similar to the pre-test. In addition, the children answered a second post-test 3 months after the visit. Close ended questions addressed the awareness indicators mentioned in the literature, i.e. worry level, previous experiences with natural hazards events, exposure to awareness raising, ability to mitigate/respond/prepare, attitude to risk, and demographics. In addition, the post-test included several satisfaction questions concerning the visual tools displayed in the exhibition. A statistical analysis of the changes between the pre- and post- tests (paired t-test, Wilcoxon signed-rank test and bootstrapping) allowed to verify whether the exhibition had an impact on risk awareness or not. In order to deduce which variable

  1. Mouse embryonic fibroblasts exhibit extensive developmental and phenotypic diversity.

    PubMed

    Singhal, Prabhat K; Sassi, Slim; Lan, Lan; Au, Patrick; Halvorsen, Stefan C; Fukumura, Dai; Jain, Rakesh K; Seed, Brian

    2016-01-01

    Analysis of embryonic fibroblasts from GFP reporter mice indicates that the fibroblast cell type harbors a large collection of developmentally and phenotypically heterogeneous subtypes. Some of these cells exhibit multipotency, whereas others do not. Multiparameter flow cytometry analysis shows that a large number of distinct populations of fibroblast-like cells can be found in cultures initiated from different embryonic organs, and cells sorted according to their surface phenotype typically retain their characteristics on continued propagation in culture. Similarly, surface phenotypes of individual cloned fibroblast-like cells exhibit significant variation. The fibroblast cell class appears to contain a very large number of denumerable subtypes. PMID:26699463

  2. Meeting Report: Ordinary Meeting and Exhibition Meeting, 2006 June 24

    NASA Astrophysics Data System (ADS)

    McGee, H.; Mobberley, M.

    2007-06-01

    Prior to the Ordinary Meeting, the annual Exhibition was opened by Richard Miles, President, who said he was pleased to report that all but two of the Sections had display stands this year, and that most of the Directors had also been able to attend and were available for members who wished to discuss their work. Although we had almost a full day of talks to enjoy, members should not be shy of coming and going from the lecture theatre at will, and in particular must make sure they took sufficient time to do justice to the excellent Exhibition on offer.

  3. Explanatory Parent-Child Conversation Predominates at an Evolution Exhibit

    ERIC Educational Resources Information Center

    Tare, Medha; French, Jason; Frazier, Brandy N.; Diamond, Judy; Evans, E. Margaret

    2011-01-01

    To investigate how parents support children's learning at an exhibit on evolution, the conversations of 12 families were recorded, transcribed, and coded (6,263 utterances). Children (mean age 9.6 years) and parents visited Explore Evolution, which conveyed current research about the evolution of seven organisms. Families were engaged with the…

  4. 2. SPILLWAYS AND ROCKDROP, SANTA ANA NO. 3, EXHIBIT L, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    2. SPILLWAYS AND ROCK-DROP, SANTA ANA NO. 3, EXHIBIT L, JAN. 25, 1956. SCE drawing no. 541724 (sheet 5; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-3 Forebay & Penstock, Redlands, San Bernardino County, CA

  5. 43. FLOOR PLAN OF POWER HOUSE, EXHIBIT L, SANTA ANA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    43. FLOOR PLAN OF POWER HOUSE, EXHIBIT L, SANTA ANA RIVER NO. 2 PROJECT, APR. 30, 1945. SCE drawing no. 523643 (sheet no. 14; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-2 Powerhouse, Redlands, San Bernardino County, CA

  6. 10. DETAILS OF STEEL FLUME, TYPICAL BENTS AND TRUSSES. EXHIBIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    10. DETAILS OF STEEL FLUME, TYPICAL BENTS AND TRUSSES. EXHIBIT L, SANTA ANA RIVER NO. 1 PROJECT, APR. 30, 1945. SCE drawing no. 523196 (sheet no. 6; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, Flumes & Tunnels below Sandbox, Redlands, San Bernardino County, CA

  7. 4. FOREBAY AND PENSTOCK, EXHIBIT L, SANTA ANA RIVER NO. ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    4. FOREBAY AND PENSTOCK, EXHIBIT L, SANTA ANA RIVER NO. 2 PROJECT, APR. 30, 1945. SCE drawing no. 523642 (sheet no. 13; for filing with the Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-2 Forebay & Penstock, Redlands, San Bernardino County, CA

  8. 9. DETAILS OF STEEL FLUME, TYPICAL CURVES AND TRANSITIONS. EXHIBIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. DETAILS OF STEEL FLUME, TYPICAL CURVES AND TRANSITIONS. EXHIBIT L, SANTA ANA RIVER NO. 1 PROJECT, APR. 30, 1945. SCE drawing no. 523195 (sheet no. 5; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, Flumes & Tunnels below Sandbox, Redlands, San Bernardino County, CA

  9. 9. HIGH LENNON FLUME, SANTA ANA NO 3, EXHIBIT L, ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. HIGH LENNON FLUME, SANTA ANA NO 3, EXHIBIT L, JAN. 25, 1956. SCE drawing no. 541723 (sheet 3; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, Warm Springs Canyon-SAR-3 Flumes, Redlands, San Bernardino County, CA

  10. 5. SANDBOX BETWEEN TUNNELS 12. SANTA ANA NO. 3, EXHIBIT ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    5. SANDBOX BETWEEN TUNNELS 1-2. SANTA ANA NO. 3, EXHIBIT L, JAN. 25, 1956. SCE drawing no. 541727 (sheet 2; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, Sandbox, SAR-3 Flowline, Redlands, San Bernardino County, CA

  11. 55. CROSS SECTION OF POWER HOUSE, EXHIBIT L, SANTA ANA ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    55. CROSS SECTION OF POWER HOUSE, EXHIBIT L, SANTA ANA RIVER NO. 1 PROJECT, APR. 30, 1945. SCE drawing no. 523199 (sheet no. 9, for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-1 Powerhouse, Redlands, San Bernardino County, CA

  12. 44. SECTIONS OF POWER HOUSE, EXHIBIT L, SANTA ANA RIVER ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    44. SECTIONS OF POWER HOUSE, EXHIBIT L, SANTA ANA RIVER NO. 2 PROJECT, APR. 30, 1945. SCE drawing no. 523644 (sheet no. 15; for filing with Federal Power Commission). - Santa Ana River Hydroelectric System, SAR-2 Powerhouse, Redlands, San Bernardino County, CA

  13. 7 CFR Exhibit B to Subpart B of... - Servicing Company

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... of Agriculture, 7 CFR 2.23; delegation of authority by the Assistant Secretary for Rural Development, 7 CFR 2.70) ... 7 Agriculture 12 2011-01-01 2011-01-01 false Servicing Company B Exhibit B to Subpart B of...

  14. 7 CFR Exhibit B to Subpart B of... - Servicing Company

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of Agriculture, 7 CFR 2.23; delegation of authority by the Assistant Secretary for Rural Development, 7 CFR 2.70) ... 7 Agriculture 12 2010-01-01 2010-01-01 false Servicing Company B Exhibit B to Subpart B of...

  15. A Zn based coordination polymer exhibiting long-lasting phosphorescence.

    PubMed

    Cepeda, Javier; Sebastian, Eider San; Padro, Daniel; Rodríguez-Diéguez, Antonio; García, Jose A; Ugalde, Jesus M; Seco, Jose M

    2016-07-01

    A new Zn(ii) based coordination polymer (CP) built by the cohesive pilling of 2D Shubnikov type layers is reported. This material exhibits time dependent multicoloured emission, part of which shows a persistent green phosphorescence visible for up to two seconds to the naked eye, which originates from multiple charge transfer mechanisms. PMID:27297330

  16. 12 CFR 625.11 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... regarding release of information (12 CFR part 602). ... 12 Banks and Banking 6 2011-01-01 2011-01-01 false Net worth exhibit. 625.11 Section 625.11 Banks... EXPENSES UNDER THE EQUAL ACCESS TO JUSTICE ACT Applicant Information Required § 625.11 Net worth...

  17. 12 CFR 625.11 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... regarding release of information (12 CFR part 602). ... 12 Banks and Banking 6 2010-01-01 2010-01-01 false Net worth exhibit. 625.11 Section 625.11 Banks... EXPENSES UNDER THE EQUAL ACCESS TO JUSTICE ACT Applicant Information Required § 625.11 Net worth...

  18. 12 CFR 625.11 - Net worth exhibit.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... regarding release of information (12 CFR part 602). ... 12 Banks and Banking 7 2013-01-01 2013-01-01 false Net worth exhibit. 625.11 Section 625.11 Banks... EXPENSES UNDER THE EQUAL ACCESS TO JUSTICE ACT Applicant Information Required § 625.11 Net worth...

  19. 12 CFR 625.11 - Net worth exhibit.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... regarding release of information (12 CFR part 602). ... 12 Banks and Banking 7 2012-01-01 2012-01-01 false Net worth exhibit. 625.11 Section 625.11 Banks... EXPENSES UNDER THE EQUAL ACCESS TO JUSTICE ACT Applicant Information Required § 625.11 Net worth...

  20. 12 CFR 625.11 - Net worth exhibit.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... regarding release of information (12 CFR part 602). ... 12 Banks and Banking 7 2014-01-01 2014-01-01 false Net worth exhibit. 625.11 Section 625.11 Banks... EXPENSES UNDER THE EQUAL ACCESS TO JUSTICE ACT Applicant Information Required § 625.11 Net worth...

  1. A Preliminary Evaluation of the "Birds in Canada" Exhibit.

    ERIC Educational Resources Information Center

    Clowes, Marya; Wolff, Lee

    This study of the Birds in Canada exhibit (National Museum of Natural Sciences) examines the effectiveness of traditional and modern displays and the visitors' use of identification labels, text, map, and film. Over 700 museum visitors comprised the random sample. Evaluation methods included observation, interview, and cognitive testing, using…

  2. 7 CFR Appendix - Exhibits to Subpart E of Part 1951

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 14 2012-01-01 2012-01-01 false Exhibits to Subpart E of Part 1951 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) SERVICING...

  3. 7 CFR Appendix - Exhibits to Subpart E of Part 1951

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 14 2014-01-01 2014-01-01 false Exhibits to Subpart E of Part 1951 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) SERVICING...

  4. 7 CFR Appendix - Exhibits to Subpart E of Part 1951

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 14 2013-01-01 2013-01-01 false Exhibits to Subpart E of Part 1951 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) SERVICING...

  5. 7 CFR Exhibit F to Subpart A of... - Payment Bond

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 12 2011-01-01 2011-01-01 false Payment Bond F Exhibit F to Subpart A of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE PROGRAM REGULATIONS CONSTRUCTION AND...

  6. 49 CFR 1016.202 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 8 2010-10-01 2010-10-01 false Net worth exhibit. 1016.202 Section 1016.202... BY PARTIES TO BOARD ADJUDICATORY PROCEEDINGS Information Required From Applicants § 1016.202 Net... worth of the applicant and any affiliates (as defined in § 1016.105(f) of this part) when the...

  7. 14 CFR 77.59 - Subpoenas of witnesses and exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 14 Aeronautics and Space 2 2011-01-01 2011-01-01 false Subpoenas of witnesses and exhibits. 77.59 Section 77.59 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION (CONTINUED) AIRSPACE OBJECTS AFFECTING NAVIGABLE AIRSPACE (Eff. until 1-18-11) Rules of Practice for...

  8. 17 CFR 229.1016 - (Item 1016) Exhibits.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false (Item 1016) Exhibits. 229.1016... AND CONSERVATION ACT OF 1975-REGULATION S-K Mergers and Acquisitions (Regulation M-A) § 229.1016 (Item... letter); (2) Solicitation or recommendation (including those referred to in Item 1012 of Regulation...

  9. 17 CFR 229.1016 - (Item 1016) Exhibits.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false (Item 1016) Exhibits. 229.1016... AND CONSERVATION ACT OF 1975-REGULATION S-K Mergers and Acquisitions (Regulation M-A) § 229.1016 (Item... letter); (2) Solicitation or recommendation (including those referred to in Item 1012 of Regulation...

  10. Exhibition of Humanities Portfolio with a Latino Urban Population.

    ERIC Educational Resources Information Center

    Estrada, Christelle L. Martinez

    1995-01-01

    Pasadena (California) High School's Puente Pilot Project encourages Hispanic students to pursue college and return home as leaders and mentors. A bilingual counselor, community liaison, and English teacher engage students in an integrated curriculum relevant to their life experiences. Portfolio exhibitions involving oral presentation and…

  11. Grandma Moses in the 21st Century. Learning from Exhibitions.

    ERIC Educational Resources Information Center

    Johnson, Mark M.

    2001-01-01

    Provides background information on the life and career of Grandma Moses who was born as Anna Mary Robertson and painted in the style of folk or naive art. Addresses the art exhibition entitled "Grandma Moses in the 21st Century" that explores the recurring themes in her artwork. (CMK)

  12. "Creation's Journey": Excerpts from the Inaugural Exhibition and Book.

    ERIC Educational Resources Information Center

    Hill, Tom, Hill, Richard W., Sr., Ed.

    1994-01-01

    Contains excerpts from the companion book to the inaugural exhibition "Creation's Journey: Masterworks of Native American Identity and Belief" at the George Gustav Heye Center of the National Museum of the American Indian in New York City. Describes the cultural traditions behind some of the 165 objects chosen for their artistic achievement,…

  13. 27 CFR 4.51 - Exhibiting certificates to Government officials.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Exhibiting certificates to Government officials. 4.51 Section 4.51 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT OF THE TREASURY LIQUORS LABELING AND ADVERTISING OF WINE Requirements...

  14. The Cheapbook: A Compendium of Inexpensive Exhibit Ideas, 1995 Edition.

    ERIC Educational Resources Information Center

    Orselli, Paul, Ed.

    This guide includes complete installation descriptions of 30 exhibits. They include: the adjustable birthday cake, ball-in-tube, Bernoulli Box, chain wave, collapsible truss bridge, double wave device, eddy currents raceway, full-length mirror, geodesic domes, giant magnetic tangrams, harmonic cantilever, hyperboloid of revolution, lifting lever,…

  15. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... to the Presiding Officer in a sealed envelope labeled “Confidential Financial Information... 17 Commodity and Securities Exchanges 1 2013-04-01 2013-04-01 false Net worth exhibit. 148.12 Section 148.12 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION IMPLEMENTATION...

  16. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... directly to the Presiding Officer in a sealed envelope labeled “Confidential Financial Information... 17 Commodity and Securities Exchanges 2 2014-04-01 2014-04-01 false Net worth exhibit. 148.12 Section 148.12 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION...

  17. 17 CFR 148.12 - Net worth exhibit.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... to the Presiding Officer in a sealed envelope labeled “Confidential Financial Information... 17 Commodity and Securities Exchanges 1 2012-04-01 2012-04-01 false Net worth exhibit. 148.12 Section 148.12 Commodity and Securities Exchanges COMMODITY FUTURES TRADING COMMISSION IMPLEMENTATION...

  18. Take To the Streets: Guide To Planning Outdoor, Public Exhibits.

    ERIC Educational Resources Information Center

    Cutting, Jennifer McGregor; And Others

    Placing exhibits in public places provides a unique opportunity to reach a broad non-museum-going audience. It offers marketing and publicity opportunities as well as the potential to develop relationships with agencies and individuals who are stakeholders in the public site. The purpose of this guidebook is to describe the steps in creating an…

  19. 40 CFR 17.12 - Net worth exhibit.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 1 2013-07-01 2013-07-01 false Net worth exhibit. 17.12 Section 17.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 17.12 Net...

  20. 40 CFR 17.12 - Net worth exhibit.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 1 2014-07-01 2014-07-01 false Net worth exhibit. 17.12 Section 17.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 17.12 Net...

  1. 40 CFR 17.12 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Net worth exhibit. 17.12 Section 17.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 17.12 Net...

  2. 40 CFR 17.12 - Net worth exhibit.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 1 2012-07-01 2012-07-01 false Net worth exhibit. 17.12 Section 17.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 17.12 Net...

  3. 40 CFR 17.12 - Net worth exhibit.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 1 2011-07-01 2011-07-01 false Net worth exhibit. 17.12 Section 17.12 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL IMPLEMENTATION OF THE EQUAL ACCESS TO JUSTICE ACT IN EPA ADMINISTRATIVE PROCEEDINGS Information Required From Applicants § 17.12 Net...

  4. Computerizing Museum Exhibits: The Beginnings of the Essential Conversation

    ERIC Educational Resources Information Center

    Burdick, Bruce

    1978-01-01

    Examples are given of some types of interaction between viewed and museum provided by an experimental computer based nutrition exhibit at the Chicago Museum of Science and Industry. Plans are being developed for a museum in which most of the information conveyed will appear through the use of video systems tied to a computer. (CMV)

  5. Peasants on display: the Czechoslavic Ethnographic Exhibition of 1895.

    PubMed

    Filipová, Marta

    2011-01-01

    In the increasingly modernized Central Europe of the late nineteenth century, folk culture, with its alleged ancient character, was still understood by some scholars as the bearer of national identity. The Czechoslavic [sic] Ethnographic Exhibition, which took place in Prague in 1895, aimed to promote the idea of the ethnically unified, but at the same time regionally diverse, identity of the Czech-speaking people living in Bohemia, Moravia and Slovakia. Having to negotiate their identity with the ethnic Germans of Bohemia, the Czechs consciously excluded them from the event both as organizers and as exhibitors. The exhibition could therefore be seen as a symptom of its time—in the late nineteenth century Central Europe, locating national heritage was crucial and folk culture played an important role in the national politics, and not only for the Czechs. This article focuses mainly on the ethnographic exhibit entitled ‘the Exhibition Village’, which consisted of an eclectic selection of village houses and their imitations from Bohemia, Moravia and Slovakia. On this basis, it explores the political intentions behind the display of folk culture to both urban and rural audiences and brings attention to the question of integration of the diverse regional objects in a utopian national whole. The article thus also aims to demonstrate issues related to the use of folk artefacts for the purposes of cultural nationalism in Austria-Hungary in the late nineteenth century. PMID:21574287

  6. The "Gravity-Powered Calculator," a Galilean Exhibit

    ERIC Educational Resources Information Center

    Cerreta, Pietro

    2014-01-01

    The Gravity-Powered Calculator is an exhibit of the Exploratorium in San Francisco. It is presented by its American creators as an amazing device that extracts the square roots of numbers, using only the force of gravity. But if you analyze his concept construction one can not help but recall the research of Galileo on falling bodies, the inclined…

  7. 45 CFR 1160.5 - Eligibility for domestic exhibitions.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Eligibility for domestic exhibitions. 1160.5 Section 1160.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES FEDERAL COUNCIL ON THE ARTS AND THE HUMANITIES INDEMNITIES UNDER THE...

  8. 45 CFR 1160.5 - Eligibility for domestic exhibitions.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 45 Public Welfare 3 2012-10-01 2012-10-01 false Eligibility for domestic exhibitions. 1160.5 Section 1160.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES FEDERAL COUNCIL ON THE ARTS AND THE HUMANITIES INDEMNITIES UNDER THE...

  9. 45 CFR 1160.5 - Eligibility for domestic exhibitions.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 45 Public Welfare 3 2011-10-01 2011-10-01 false Eligibility for domestic exhibitions. 1160.5 Section 1160.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES FEDERAL COUNCIL ON THE ARTS AND THE HUMANITIES INDEMNITIES UNDER THE...

  10. 45 CFR 1160.5 - Eligibility for domestic exhibitions.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 45 Public Welfare 3 2010-10-01 2010-10-01 false Eligibility for domestic exhibitions. 1160.5 Section 1160.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES FEDERAL COUNCIL ON THE ARTS AND THE HUMANITIES INDEMNITIES UNDER THE...

  11. 45 CFR 1160.5 - Eligibility for domestic exhibitions.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 45 Public Welfare 3 2014-10-01 2014-10-01 false Eligibility for domestic exhibitions. 1160.5 Section 1160.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL FOUNDATION ON THE ARTS AND THE HUMANITIES FEDERAL COUNCIL ON THE ARTS AND THE HUMANITIES INDEMNITIES UNDER THE...

  12. 13. VIEW OF RAILROAD EXHIBIT AT EL PORTAL. SHAY LOCOMOTIVE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    13. VIEW OF RAILROAD EXHIBIT AT EL PORTAL. SHAY LOCOMOTIVE IS FROM THE HETCH HETCHY RAILROAD. CABOOSE IS FROM THE YOSEMITE VALLEY RAILROAD. FOREST ROAD IN FOREGROUND IS THE ALIGNMENT OF THE YOSEMITE VALLEY RAILROAD. LOOKING W. GIS: N-37 40 27.0 / W-119 47 10.5 - Yosemite National Park Roads & Bridges, Yosemite Village, Mariposa County, CA

  13. 9. COPY OF PHOTOGRAPHIC EXHIBIT BOARD CREATED 19481949 SHOWING CONSTRUCTION ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    9. COPY OF PHOTOGRAPHIC EXHIBIT BOARD CREATED 1948-1949 SHOWING CONSTRUCTION OF ARCH HANGAR. BOARD LOCATED AT AIR FORCE BASE CONVERSION AGENCY, LORING AIR FORCE BASE, MAINE. - Loring Air Force Base, Arch Hangar, East of Arizona Road near southern end of runway, Limestone, Aroostook County, ME

  14. AERIAL OF VISITORS INFORMATION CENTER [VIC] & ROCKET GARDEN EXHIBIT

    NASA Technical Reports Server (NTRS)

    1975-01-01

    AERIAL OF VISITORS INFORMATION CENTER [VIC] & ROCKET GARDEN EXHIBIT KSC-375C-0604.12 116-KSC-375C-604.12, P-20220, ARCHIVE-04465 Aerial view of Kennedy Space Center Visitors Information Center looking east-northeastward. New food services building under construction is visible at upper left.

  15. 63. View of Klystron tube cutaway exhibit located at mezzanine ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    63. View of Klystron tube cut-away exhibit located at mezzanine level transmitter building no. 102, directly above RF power generation systems located on first floor. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

  16. 7 CFR Appendix - Exhibits to Subpart E of Part 1951

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 14 2011-01-01 2011-01-01 false Exhibits to Subpart E of Part 1951 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) SERVICING...

  17. 7 CFR Appendix - Exhibits to Subpart E of Part 1951

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 14 2010-01-01 2009-01-01 true Exhibits to Subpart E of Part 1951 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE (CONTINUED) PROGRAM REGULATIONS (CONTINUED) SERVICING...

  18. (Un)Disturbing Exhibitions: Indigenous Historical Memory at the NMAI

    ERIC Educational Resources Information Center

    Carpio, Myla Vicenti

    2006-01-01

    Museums in particular are educational tools used to create and perpetuate specific ideologies and historical memories. They have played a prominent role in defining the visibility of Indigenous peoples and cultures in America historical memory by creating exhibits of Indigenous peoples based on perceptions and views that benefit and justify…

  19. New Viruses Identified in Fig Trees Exhibiting Fig Mosaic Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fig mosaic disease has been known for decades, but the causal agent has been elusive. Here we present data on the incidence of at least four new viruses isolated from fig trees exhibiting mosaic symptoms. One of the viruses is closely related to the recently identified European mountain ash ringspo...

  20. 14 CFR 14.11 - Net worth exhibit.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Net worth exhibit. 14.11 Section 14.11 Aeronautics and Space FEDERAL AVIATION ADMINISTRATION, DEPARTMENT OF TRANSPORTATION PROCEDURAL RULES RULES IMPLEMENTING THE EQUAL ACCESS TO JUSTICE ACT OF 1980 Information Required From Applicants § 14.11 Net...

  1. Do Online Learning Patterns Exhibit Regional and Demographic Differences?

    ERIC Educational Resources Information Center

    Hsieh, Tsui-Chuan; Yang, Chyan

    2012-01-01

    This paper used a multi-level latent class model to evaluate whether online learning patterns exhibit regional differences and demographics. This study discovered that the Internet learning pattern consists of five segments, and the region of Taiwan is divided into two segments and further found that both the user and the regional segments are…

  2. 7 CFR Exhibit A to Subpart C of... - [Reserved

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE PROGRAM REGULATIONS CONSTRUCTION AND REPAIR Planning and Performing Site Development Work Exhibit A to Subpart C of Part 1924...

  3. 7 CFR Exhibit A to Subpart C of... - [Reserved

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 12 2010-01-01 2010-01-01 false A Exhibit A to Subpart C of Part 1924 Agriculture Regulations of the Department of Agriculture (Continued) RURAL HOUSING SERVICE, RURAL BUSINESS-COOPERATIVE SERVICE, RURAL UTILITIES SERVICE, AND FARM SERVICE AGENCY, DEPARTMENT OF AGRICULTURE PROGRAM REGULATIONS CONSTRUCTION AND REPAIR Planning...

  4. Alien Earths: A Traveling Science Exhibit and Education Program

    NASA Astrophysics Data System (ADS)

    Dusenbery, P. B.; Morrow, C. A.; Harold, J.

    2004-05-01

    Where did we come from? Are we alone? These age-old questions form the basis of NASA's Origins Program, a series of missions spanning the next twenty years that will use a host of space- and ground-based observatories to understand the origin and development of galaxies, stars, planets, and the conditions necessary to support life. The Space Science Institute in Boulder, CO, is developing a 3,000 square-foot traveling exhibition, called Alien Earths, which will bring origins-related research and discoveries to students and the American public. Alien Earths will have four interrelated exhibit areas: Our Place in Space, Star Birth, PlanetQuest, and Search for Life. Exhibit visitors will explore the awesome events surrounding the birth of stars and planets; they will join scientists in the hunt for planets outside our solar system including those that may be in "habitable zones" around other stars; and finally they will be able to learn about the wide range of conditions for life on Earth and how scientists are looking for signs of life beyond Earth. Visitors will also learn about the tools scientists use, such as space-based and ground-based telescopes, to improve our understanding of the cosmos. The exhibit's size will permit it to visit medium sized museums in all regions of the country. It will begin its 3-year tour to 9 host museums and science centers in early 2005 at the Lawrence Hall of Science in Berkeley, California. The Association of Science-Technology Centers (ASTC) will manage the exhibit's national tour. In addition to the exhibit, the project includes workshops for educators and docents at host sites, as well as a public website that will use exhibit content to delve deeper into origins research. Current partners in the Alien Earths project include ASTC, Denver Museum of Nature and Science, Lawrence Hall of Science, NASA Astrobiology Institute, NASA missions (Navigator, SIRTF, and Kepler), the SETI Institute, and the Space Telescope Science Institute

  5. Inside active volcanoes; an exhibit on the move!

    USGS Publications Warehouse

    Fiske, R.S.

    1990-01-01

    All of us are aware of the emphasis currently being placed in the United States on science education and public understanding of science. Most of this emphasis is directed toward mass audiences through book publications, school curricula, and television programs; sadly, most of it deals with non-earth science topics. In an effort to take advantage of this awakened consciousness and to highlight the earth sciences, the Smithsonian Institution and the U.S Geological Survey joined forces to prepare a traveling exhibit on volcanoes that is currently touring the country. This note will serve to bring you up to date on the progress of this exhibit as it reaches the mid-point of its tour. 

  6. Inuit Perspectives on Arctic Environmental Change': A Traveling Exhibition

    NASA Astrophysics Data System (ADS)

    Sheffield, E. M.; Hakala, J. S.; Gearheard, S.

    2006-12-01

    The Inuit of Nunavut, Canada, have an intimate relationship with their surroundings. As a culture that relies on knowledge of sea ice, snow, and weather conditions for success in hunting, fishing, and healthy wellbeing, Inuit have observed and studied environmental patterns for generations. An ongoing study into their traditional knowledge and their observations of environmental change is being conducted by researcher Dr. Shari Gearheard, who has worked with Inuit communities in Nunavut for over a decade. The results of the research have been published in scientific journals, and to communicate the results to a broader audience, Dr. Gearheard designed an interactive CD-ROM displaying photographs, maps, and interview videos of Inuit Elders' perspectives on the changes they have witnessed. Receiving immediate popularity since its release in 2004, copies of `When the Weather is Uggianaqtuq: Inuit Observations of Environmental Change' have been distributed worldwide, to indigenous peoples, social science and climate change researchers, teachers, students, and the general public. To further disseminate the information contained on the CD-ROM, the National Snow and Ice Data Center and the Museum of Natural History, both of the University of Colorado, are partnering to create an exhibition which will open at the Museum during the International Polar Year in April 2008. The exhibit, tentatively titled `Inuit Perspectives on Arctic Environmental Change,' will feature photographs, graphics, and text in both English and Inuktitut describing environmental change in the North. The goals are to make the information and interpretation contained on the CD-ROM available and more accessible to a broad audience and to raise awareness about Arctic climate change and the important contribution of Inuit knowledge. Following exhibition at the Museum, the exhibit will travel throughout the United States, Alaska, and Nunavut, through a network of museums, schools, libraries, tribal

  7. Environmental enrichment for a mixed-species nocturnal mammal exhibit.

    PubMed

    Clark, Fay E; Melfi, Vicky A

    2012-01-01

    Environmental enrichment (EE) is an integral aspect of modern zoo animal management but, empirical evaluation of it is biased toward species housed in single-species groups. Nocturnal houses, where several nocturnal species are housed together, are particularly overlooked. This study investigated whether three species (nine-banded armadillos, Dasypus novemcinctus; Senegal bush babies, Galago senegalensis; two-toed sloths, Choloepus didactylus) in the nocturnal house at Paignton Zoo Environmental Park, UK could be enriched using food-based and sensory EE. Subjects were an adult male and female of each species. EE was deemed effective if it promoted target species-typical behaviors, behavioral diversity, and increased use of enriched exhibit zones. Results from generalized linear mixed models demonstrated that food-based EE elicited the most positive behavioral effects across species. One set of food-based EEs (Kong®, termite mound and hanging food) presented together was associated with a significant increase in species-typical behaviors, increased behavioral diversity, and increased use of enriched exhibit zones in armadillos and bush babies. Although one type of sensory EE (scented pine cones) increased overall exhibit use in all species, the other (rainforest sounds) was linked to a significant decrease in species-typical behavior in bush babies and sloths. There were no intra or interspecies conflicts over EE, and commensalism occurred between armadillos and bush babies. Our data demonstrate that simple food-based and sensory EE can promote positive behavioral changes in a mixed-species nocturnal mammal exhibit. We suggest that both food and sensory EE presented concurrently will maximize opportunities for naturalistic activity in all species. PMID:21387395

  8. New neptunium(V) borates that exhibit the alexandrite effect.

    PubMed

    Wang, Shuao; Alekseev, Evgeny V; Depmeier, Wulf; Albrecht-Schmitt, Thomas E

    2012-01-01

    A new neptunium(V) borate, K[(NpO(2))B(10)O(14)(OH)(4)], was synthesized using boric acid as a reactive flux. The compound possesses a layered structure in which Np(V) resides in triangular holes, creating a hexagonal-bipyramidal environment around neptunium. This compound is unusual in that it exhibits the Alexandrite effect, a property that is typically restricted to neptunium(IV) compounds. PMID:22145669

  9. Uranium mining wastes, garden exhibition and health risks

    SciTech Connect

    Schmidt, Gerhard; Schmidt, Peter; Hinz, Wilko

    2007-07-01

    Available in abstract form only. Full text of publication follows: For more than 40 years the Soviet-German stockholding company SDAG WISMUT mined and milled Uranium in the East of Germany and became up to 1990 the world's third largest Uranium producer. After reunification of Germany, the new found state own company Wismut GmbH was faced with the task of decommissioning and rehabilitation of the mining and milling sites. One of the largest mining areas in the world, that had to be cleaned up, was located close to the municipality of Ronneburg near the City of Gera in Thuringia. After closing the operations of the Ronneburg underground mine and at the 160 m deep open pit mine with a free volume of 84 Mio.m{sup 3}, the open pit and 7 large piles of mine waste, together 112 Mio.m{sup 3} of material, had to be cleaned up. As a result of an optimisation procedure it was chosen to relocate the waste rock piles back into the open pit. After taking this decision and approval of the plan the disposal operation was started. Even though the transport task was done by large trucks, this took 16 years. The work will be finished in 2007, a cover consisting of 40 cm of uncontaminated material will be placed on top of the material, and the re-vegetation of the former open pit area will be established. When in 2002 the City of Gera applied to host the largest garden exhibition in Germany, Bundesgartenschau (BUGA), in 2007, Wismut GmbH supported this plan by offering parts of the territory of the former mining site as an exhibition ground. Finally, it was decided by the BUGA organizers to arrange its 2007 exhibition on grounds in Gera and in the valley adjacent to the former open pit mine, with parts of the remediated area within the fence of the exhibition. (authors)

  10. New Constitutively Active Phytochromes Exhibit Light-Independent Signaling Activity.

    PubMed

    Jeong, A-Reum; Lee, Si-Seok; Han, Yun-Jeong; Shin, Ah-Young; Baek, Ayoung; Ahn, Taeho; Kim, Min-Gon; Kim, Young Soon; Lee, Keun Woo; Nagatani, Akira; Kim, Jeong-Il

    2016-08-01

    Plant phytochromes are photoreceptors that mediate a variety of photomorphogenic responses. There are two spectral photoisomers, the red light-absorbing Pr and far-red light-absorbing Pfr forms, and the photoreversible transformation between the two forms is important for the functioning of phytochromes. In this study, we isolated a Tyr-268-to-Val mutant of Avena sativa phytochrome A (AsYVA) that displayed little photoconversion. Interestingly, transgenic plants of AsYVA showed light-independent phytochrome signaling with a constitutive photomorphogenic (cop) phenotype that is characterized by shortened hypocotyls and open cotyledons in the dark. In addition, the corresponding Tyr-303-to-Val mutant of Arabidopsis (Arabidopsis thaliana) phytochrome B (AtYVB) exhibited nuclear localization and interaction with phytochrome-interacting factor 3 (PIF3) independently of light, conferring a constitutive photomorphogenic development to its transgenic plants, which is comparable to the first constitutively active version of phytochrome B (YHB; Tyr-276-to-His mutant). We also found that chromophore ligation was required for the light-independent interaction of AtYVB with PIF3. Moreover, we demonstrated that AtYVB did not exhibit phytochrome B activity when it was localized in the cytosol by fusion with the nuclear export signal and that AsYVA exhibited the full activity of phytochrome A when localized in the nucleus by fusion with the nuclear localization signal. Furthermore, the corresponding Tyr-269-to-Val mutant of Arabidopsis phytochrome A (AtYVA) exhibited similar cop phenotypes in transgenic plants to AsYVA. Collectively, these results suggest that the conserved Tyr residues in the chromophore-binding pocket play an important role during the Pr-to-Pfr photoconversion of phytochromes, providing new constitutively active alleles of phytochromes by the Tyr-to-Val mutation. PMID:27325667

  11. Exhibition QIM-based watermarking for digital cinema

    NASA Astrophysics Data System (ADS)

    Callau, Pilar; Darazi, Rony; Macq, Benoît

    2009-02-01

    The copyright protection of Digital Cinema requires the insertion of forensic watermarks during exhibition playback. This paper presents a low-complexity exhibition watermarking method based on quantization index modulation (QIM) and embedded in the DCI compliant decoder. Watermark embedding is proposed to fit in the JPEG2000 decoding process, prior to the inverse wavelet transform and such as it has a minimal impact on the image quality, guarantying a strong link between decompression and watermarking. The watermark is embedded by using an adaptive-Spread Transform Dither Modulation (STDM) method, based on a new multi-resolution perceptual masking to adapt watermark strength. Watermark detection is thereafter performed over the wavelet transformation of the recovered images. The proposed approach offers a wide range of channel capacities according to robustness to several kinds of distortions while maintaining a low computational complexity. Watermarking detection performance on Digital Cinema pictures captured with a video camera from a viewing room has been preliminary assessed, showing very promising results. The proposed approach provides high levels of imperceptibility, yet good robustness to degradations resulting from camcorder exhibition capture, to common signal processing operations such as filtering or re-sampling, and to very high compression.

  12. Didactical Holographic Exhibit Including Holo TV (holographic Television)

    NASA Astrophysics Data System (ADS)

    Lunazzi, José J.; Magalhães, Daniel S. F.; Rivera, Noemí I. R.

    2008-04-01

    Our Institute of Physics exposes since 1980 didactical exhibitions of holography in Brazil where nice holograms are shown altogether with basic experiments of geometric and wave optics. This experiments lead to the understanding of the phenomenon of images of an ample way. Thousands of people have been present at them, in their majority of the Universidade Estadual de Campinas, where since 2002 they have taken the format of a course without formal evaluation. This way the exhibition has been divided in four modules, in each one of them are shown different holograms, experiments of optics and applications of diffractive images with white light developed in the Institute of Physics. The sequence of the learning through the modules begins with the geometric optics, later we explain the wave optics and finally holography. The phenomenon of the diffraction in daily elements is shown experimentally from the beginning. As well as the application of the holographic screens in white light: the television images that appear in front of the screen and the spectator can try to experience the reality illusion. Put something so exclusive (that only exists in the laboratory) to the public is a way to approximate the persons to an investigation in course. The vision of images that seem to be of holograms, but in movement, and size of until a square meter completes this exhibition of an exclusive way in the world.

  13. Liberty Bell 7 Space Capsule Exhibit previews at Visitor Complex

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Media gather at the KSC Visitor Complex for the kickoff of the Discovery Channel's Liberty Bell 7 Space Capsule Exhibit, which will open to the public on Saturday, June 17. At the podium is Mike Quattrone, executive vice president and general manager, Discovery Channel. Standing to the left of the podium is Rick Abramson, president and chief operating officer of Delaware North Parks Services of Spaceport, Inc., and far left, Jim Jennings, deputy director of Kennedy Space Center. Liberty Bell 7 launched U.S. Air Force Captain Virgil '''Gus''' Grissom July 21, 1961 on a mission that lasted 15 minutes and 37 seconds before sinking to the floor of the Atlantic Ocean, three miles deep. It lay undetected for nearly four decades before a Discovery Channel expedition located it and recovered it. The space capsule is now restored and preserved, and part of an interactive exhibit touring science centers and museums in 12 cities throughout the United States until 2003. The exhibit includes hands-on elements such as a capsule simulator, a centrifuge, and ROV pilot.

  14. Liberty Bell 7 Space Capsule Exhibit previews at Visitor Complex

    NASA Technical Reports Server (NTRS)

    2000-01-01

    The Discovery Channel's Liberty Bell 7 Space Capsule Exhibit, which opens to the public at the KSC Visitor Complex on Saturday, June 17, had a preview for the press today. Liberty Bell 7 launched U.S. Air Force Captain Virgil 'Gus' Grissom July 21, 1961, on a mission that lasted 15 minutes and 37 seconds before sinking. The capsule lay undetected for nearly four decades before a Discovery Channel expedition located it and recovered it. Standing in front of the restored Liberty Bell 7 capsule are (left to right) KSC's Deputy Director Jim Jennings; Gunther Wendt, who worked on the Liberty Bell 7 before its launch; Jim Lewis, who piloted the Hunt Club 1 helicopter that rescued Gus Grissom; and Larry Grissom, brother of Gus Grissom. The space capsule, now restored and preserved, is part of an interactive exhibit touring science centers and museums in 12 cities throughout the United States until 2003. The exhibit also includes hands-on elements such as a capsule simulator, a centrifuge, and ROV pilot.

  15. BOLD Subjective Value Signals Exhibit Robust Range Adaptation

    PubMed Central

    Cox, Karin M.

    2014-01-01

    Many theories of decision making assume that choice options are assessed along a common subjective value (SV) scale. The neural correlates of SV are widespread and reliable, despite the wide variation in the range of values over which decisions are made (e.g., between goods worth a few dollars, in some cases, or hundreds of dollars, in others). According to adaptive coding theories (Barlow, 1961), an efficient value signal should exhibit range adaptation, such that neural activity maintains a fixed dynamic range, and the slope of the value response varies inversely with the range of values within the local context. Although monkey data have demonstrated range adaptation in single-unit correlates of value (Padoa-Schioppa, 2009; Kobayashi et al., 2010), whether BOLD value signals exhibit similar range adaptation is unknown. To test for this possibility, we presented human participants with choices between a fixed immediate and variable delayed payment options. Across two conditions, the delayed options' SVs spanned either a narrow or wide range. SV-tracking activity emerged in the posterior cingulate, ventral striatum, anterior cingulate, and ventromedial prefrontal cortex. Throughout this network, we observed evidence consistent with the predictions of range adaptation: the SV response slope increased in the narrow versus wide range, with statistically significant slope changes confirmed for the posterior cingulate and ventral striatum. No regions exhibited a reliably increased BOLD activity range in the wide versus narrow condition. Our observations of range adaptation present implications for the interpretation of BOLD SV responses that are measured across different contexts or individuals. PMID:25471589

  16. Human Myocardial Pericytes: Multipotent Mesodermal Precursors Exhibiting Cardiac Specificity

    PubMed Central

    Chen, William C.W.; Baily, James E.; Corselli, Mirko; Diaz, Mary; Sun, Bin; Xiang, Guosheng; Gray, Gillian A.; Huard, Johnny; Péault, Bruno

    2015-01-01

    Perivascular mesenchymal precursor cells (i.e. pericytes) reside in skeletal muscle where they contribute to myofiber regeneration; however, the existence of similar microvessel-associated regenerative precursor cells in cardiac muscle has not yet been documented. We tested whether microvascular pericytes within human myocardium exhibit phenotypes and multipotency similar to their anatomically and developmentally distinct counterparts. Fetal and adult human heart pericytes (hHPs) express canonical pericyte markers in situ, including CD146, NG2, PDGFRβ, PDGFRα, αSMA, and SM-MHC, but not CD117, CD133 and desmin, nor endothelial cell (EC) markers. hHPs were prospectively purified to homogeneity from ventricular myocardium by flow cytometry, based on a combination of positive- (CD146) and negative-selection (CD34, CD45, CD56, and CD117) cell lineage markers. Purified hHPs expanded in vitro were phenotypically similar to human skeletal muscle-derived pericytes (hSkMPs). hHPs express MSC markers in situ and exhibited osteo- chondro-, and adipogenic potentials but, importantly, no ability for skeletal myogenesis, diverging from pericytes of all other origins. hHPs supported network formation with/without ECs in Matrigel cultures; hHPs further stimulated angiogenic responses under hypoxia, markedly different from hSkMPs. The cardiomyogenic potential of hHPs was examined following 5-azacytidine treatment and neonatal cardiomyocyte co-culture in vitro, and intramyocardial transplantation in vivo. Results indicated cardiomyocytic differentiation in a small fraction of hHPs. In conclusion, human myocardial pericytes share certain phenotypic and developmental similarities with their skeletal muscle homologs, yet exhibit different antigenic, myogenic, and angiogenic properties. This is the first example of an anatomical restriction in the developmental potential of pericytes as native mesenchymal stem cells. PMID:25336400

  17. Characterization of a new Arabidopsis mutant exhibiting enhanced disease resistance.

    PubMed

    Silva, H; Yoshioka, K; Dooner, H K; Klessig, D F

    1999-12-01

    In many plant-pathogen interactions, resistance is associated with the synthesis and accumulation of salicylic acid (SA) and pathogenesis-related (PR) proteins. At least two general classes of mutants with altered resistance to pathogen attack have been identified in Arabidopsis. One class exhibits increased susceptibility to pathogen infection; the other class exhibits enhanced resistance to pathogens. In an attempt to identify mutations in resistance-associated loci, we screened a population of T-DNA tagged Arabidopsis thaliana ecotype Wassilewskija (Ws) for mutants showing constitutive expression of the PR-1 gene (cep). A mutant was isolated and shown to constitutively express PR-1, PR-2, and PR-5 genes. This constitutive phenotype segregated as a single recessive trait in the Ws genetic background. The mutant also had elevated levels of SA, which are responsible for the cep phenotype. The cep mutant spontaneously formed hypersensitive response (HR)-like lesions on the leaves and cotyledons and also exhibited enhanced resistance to virulent bacterial and fungal pathogens. Genetic analyses of segregating progeny from outcrosses to other ecotypes unexpectedly revealed that alterations in more than one gene condition the constitutive expression of PR genes in the original mutant. One of the mutations, designated cpr20, maps to the lower arm of chromosome 4 and is required for the cep phenotype. Another mutation, which has been termed cpr21, maps to chromosome 1 and is often, but not always, associated with this phenotype. The recessive nature of the cep trait suggests that the CPR20 and CPR21 proteins may act as negative regulators in the disease resistance signal transduction pathway. PMID:10624014

  18. Homogeneous illusion device exhibiting transformed and shifted scattering effect

    NASA Astrophysics Data System (ADS)

    Mei, Jin-Shuo; Wu, Qun; Zhang, Kuang; He, Xun-Jun; Wang, Yue

    2016-06-01

    Based on the theory of transformation optics, a type of homogeneous illusion device exhibiting transformed and shifted scattering effect is proposed in this paper. The constitutive parameters of the proposed device are derived, and full-wave simulations are performed to validate the electromagnetic properties of transformed and shifted scattering effect. The simulation results show that the proposed device not only can visually shift the image of target in two dimensions, but also can visually transform the shape of target. It is expected that such homogeneous illusion device could possess potential applications in military camouflage and other field of electromagnetic engineering.

  19. 78 FR 55134 - Culturally Significant Object Imported for Exhibition Determinations: “Iran Modern”

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-09-09

    ... Culturally Significant Object Imported for Exhibition Determinations: ``Iran Modern'' ACTION: Notice..., number 153) of determinations made by the Department of State pertaining to the exhibit ``Iran Modern... in the exhibition ``Iran Modern,'' imported from abroad for temporary exhibition within the...

  20. DNA damage in cells exhibiting radiation-induced genomic instability

    DOE PAGESBeta

    Keszenman, Deborah J.; Kolodiuk, Lucia; Baulch, Janet E.

    2015-02-22

    Cells exhibiting radiation induced genomic instability exhibit varied spectra of genetic and chromosomal aberrations. Even so, oxidative stress remains a common theme in the initiation and/or perpetuation of this phenomenon. Isolated oxidatively modified bases, abasic sites, DNA single strand breaks and clustered DNA damage are induced in normal mammalian cultured cells and tissues due to endogenous reactive oxygen species generated during normal cellular metabolism in an aerobic environment. While sparse DNA damage may be easily repaired, clustered DNA damage may lead to persistent cytotoxic or mutagenic events that can lead to genomic instability. In this study, we tested the hypothesismore » that DNA damage signatures characterised by altered levels of endogenous, potentially mutagenic, types of DNA damage and chromosomal breakage are related to radiation-induced genomic instability and persistent oxidative stress phenotypes observed in the chromosomally unstable progeny of irradiated cells. The measurement of oxypurine, oxypyrimidine and abasic site endogenous DNA damage showed differences in non-double-strand breaks (DSB) clusters among the three of the four unstable clones evaluated as compared to genomically stable clones and the parental cell line. These three unstable clones also had increased levels of DSB clusters. The results of this study demonstrate that each unstable cell line has a unique spectrum of persistent damage and lead us to speculate that alterations in DNA damage signaling and repair may be related to the perpetuation of genomic instability.« less