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Sample records for leucocephalus columnar cactus

  1. Nurse Plants vs. Nurse Objects: Effects of Woody Plants and Rocky Cavities on the Recruitment of the Pilosocereus leucocephalus Columnar Cactus

    PubMed Central

    Munguía-Rosas, Miguel Angel; Sosa, Vinicio J.

    2008-01-01

    Background and Aims Most studies on cactus recruitment have focused on the role of woody plants as seedling facilitators. Although the spatial association of cacti with objects had been described, the mechanisms underlying this association remain unknown. The aims of this study were to identify which mechanisms facilitate the establishment of a columnar cactus under the shade and protection of objects and to compare these mechanisms with those involved in plant–plant facilitation. Methods Three split-split-plot field experiments were conducted to compare the effects of two microhabitats (inside rocky cavities and beneath plant canopies) on seed removal, germination, seedling survivorship and dry weight. Flat, open spaces were used as the control. For each microhabitat, the effect of seed or seedling protection and substrate limitation were explored; aboveground microclimate and some soil properties were also characterized. Key Results The permanence of superficial seeds was greater inside rocky cavities than beneath woody plant canopies or on flat, open areas. Germination was similar in cavities and beneath plant canopies, but significantly higher than on flat, open areas. Seedling survivorship was greater beneath plant canopies than inside cavities or on flat, open spaces. Conclusions The mechanisms of plant facilitation are different from those of object facilitation. There are seed–seedling conflicts involved in the recruitment of P. leucocephalus: nurse plants favour mainly seedling survivorship by providing a suitable microenvironment, while nurse objects mainly favour seed permanence, by protecting them from predators. PMID:18056054

  2. Sun/shade conditions affect recruitment and local adaptation of a columnar cactus in dry forests

    PubMed Central

    Miranda-Jácome, Antonio; Montaña, Carlos; Fornoni, Juan

    2013-01-01

    Background and Aims Facilitation among plants in water-limited environments (i.e. where evapotranspiration overcomes the availability of water during the growing season) has been considered a local adaptation to water and light conditions. Among cacti, early life-history stages can benefit from the facilitative effects of nurse plants that reduce solar radiation and water stress. However, whether light condition itself acts as an agent of selection through facilitation remains untested. The aim of this study was to determine (1) whether light conditions affect seedling recruitment, (2) whether the positive effect of shade on seedling recruitment is more intense under more stressful conditions and (3) whether shade condition (facilitation) reduces the magnitude of local adaptation on seedling recruitment relative to full sunlight conditions. Methods A reciprocal transplant experiment, coupled with the artificial manipulation of sun/shade conditions, was performed to test for the effects of local adaptation on germination, seedling survival and growth, using two demes of the columnar cactus Pilosocereus leucocephalus, representing different intensities of stressful conditions. Key Results Full sunlight conditions reduced recruitment success and supported the expectation of lower recruitment in more stressful environments. Significant local adaptation was mainly detected under full sunlight conditions, indicating that this environmental factor acts as an agent of selection at both sites. Conclusions The results supported the expectation that the magnitude of local adaptation, driven by the effects of facilitative nurse plants, is less intense under reduced stressful conditions. This study is the first to demonstrate that sun/shade conditions act as a selective agent accounting for local adaptation in water-limited environments, and that facilitation provided by nurse plants in these environments can attenuate the patterns of local adaptation among plants benefiting

  3. Population Genetic Structure of a Widespread Bat-Pollinated Columnar Cactus.

    PubMed

    Bustamante, Enriquena; Búrquez, Alberto; Scheinvar, Enrique; Eguiarte, Luis Enrique

    2016-01-01

    Bats are the main pollinators and seed dispersers of Stenocereus thurberi, a xenogamous columnar cactus of northwestern Mexico and a good model to illustrate spatial dynamics of gene flow in long-lived species. Previous studies in this cactus showed differences among populations in the type and abundance of pollinators, and in the timing of flowering and fruiting. In this study we analyzed genetic variability and population differentiation among populations. We used three primers of ISSR to analyze within and among populations genetic variation from eight widely separated populations of S. thurberi in Sonora, Mexico. Sixty-six out of 99 of the ISSR bands (P = 66.7%) were polymorphic. Total heterozygosity for all populations sampled revealed high genetic diversity (Hsp = 0.207, HBT = 0.224). The AMOVA showed that most of the genetic variation was within populations (80.5%). At the species level, estimates of population differentiation, θ = 0.175 and θB = 0.194, indicated moderate gene flow among populations. The absence of a significant correlation between genetic and geographic distances indicated little isolation by geographic distance. The large genetic variation and diversity found in S. thurberi is consistent with its open reproductive system and the high mobility of bats, a major pollinator. However, small changes in number or kind of pollinators and seed dispersal agents, in the directionality of migratory routes, and/or in the timing of flowering and fruiting among populations, can critically affect gene flow dynamics. PMID:27015281

  4. Population Genetic Structure of a Widespread Bat-Pollinated Columnar Cactus

    PubMed Central

    Bustamante, Enriquena; Búrquez, Alberto; Scheinvar, Enrique; Eguiarte, Luis Enrique

    2016-01-01

    Bats are the main pollinators and seed dispersers of Stenocereus thurberi, a xenogamous columnar cactus of northwestern Mexico and a good model to illustrate spatial dynamics of gene flow in long-lived species. Previous studies in this cactus showed differences among populations in the type and abundance of pollinators, and in the timing of flowering and fruiting. In this study we analyzed genetic variability and population differentiation among populations. We used three primers of ISSR to analyze within and among populations genetic variation from eight widely separated populations of S. thurberi in Sonora, Mexico. Sixty-six out of 99 of the ISSR bands (P = 66.7%) were polymorphic. Total heterozygosity for all populations sampled revealed high genetic diversity (Hsp = 0.207, HBT = 0.224). The AMOVA showed that most of the genetic variation was within populations (80.5%). At the species level, estimates of population differentiation, θ = 0.175 and θB = 0.194, indicated moderate gene flow among populations. The absence of a significant correlation between genetic and geographic distances indicated little isolation by geographic distance. The large genetic variation and diversity found in S. thurberi is consistent with its open reproductive system and the high mobility of bats, a major pollinator. However, small changes in number or kind of pollinators and seed dispersal agents, in the directionality of migratory routes, and/or in the timing of flowering and fruiting among populations, can critically affect gene flow dynamics. PMID:27015281

  5. Daily to decadal patterns of precipitation, humidity, and photosynthetic physiology recorded in the spines of the columnar cactus, Carnegiea gigantea

    NASA Astrophysics Data System (ADS)

    English, Nathan B.; Dettman, David L.; Sandquist, Darren R.; Williams, David G.

    2010-06-01

    Isotopic analyses of cactus spines grown serially from the apex of long-lived columnar cactuses may be useful for climatological and ecological studies if time series can be reliably determined from spines. To characterize the timescales over which spines may record this information, we measured spine growth in saguaro cactus over days, months, and years with time-lapse photography, periodic marking, and postbomb radiocarbon dating and then analyzed isotopic variability over these same timescales and compared these measurements to local climate. We used daily increments of growth, visible as transverse bands of light and dark tissue in spines, as chronometers to develop diurnally resolved δ13C and δ18O records from three spines grown in series over a 70 day period. We also constructed a 22 year record of δ13C variations from spine tips arranged in chronological sequence along the side of a 4 m tall, single-stemmed saguaro. We evaluated two mechanisms potentially responsible for daily, weekly, and annual variability in δ13C values of spines; both related to vapor pressure deficit (VPD). Our data suggest that stomatal conductance is unlikely to be the determinant of δ13C variation in spines. We suggest that either VPD-induced changes in the balance of nighttime- and daytime-assimilated CO2 or mesophyll-limited diffusion of CO2 at night are the most likely determinant of δ13C variation in spines. Intra-annual and interannual variability of δ18O in spine tissue appears to be controlled by the mass balance of 18O-depleted water taken up after rain events and evaporative enrichment of 18O in tissue water between rains. We were able to estimate the annual growth and areole generation rate of a saguaro cactus from its 22 yearlong isotopic record because VPD, rainfall, and evaporation exhibit strong annual cycles in the Sonoran Desert and these variations are recorded in the oxygen and carbon isotope ratios of spines.

  6. Cactus

    SciTech Connect

    Sexton, R.L.

    1983-03-01

    The CACTUS project (computer-aided control, tracking, and updating system) was initiated by the Bendix Kansas City Division to address specific work-in-process problems encountered in a cable department. Since then, the project has been expanded to additional electrical manufacturing departments because of potential productivity gains from the system. The philosophy of CACTUS is to add an element of distributed data proessing to the centralized data processing system currently in use for control of work in process. Under this system, the existing chain of communications between the host computer and the CRT terminals in a department is severed. A mini-computer established in the department communicates directly with the central system, and departmental communication is then established with the mini-computer. The advantages, disadvantages, operation performance, and economics of the system are discussed.

  7. Dating Cactus: Annual and Sub-annual Variations of Oxygen-18, Carbon-13 and Radiocarbon in Spines of a Columnar Cactus, Carnegiea gigantea.

    NASA Astrophysics Data System (ADS)

    Dettman, D. L.; English, N. B.; Sandquist, D. R.; Williams, D. G.

    2006-12-01

    We measured δ18O, δ13C and F14C of spines from a long-lived columnar cactus, Carnegiea gigantea (saguaro), to resolve a record of plant physiological responses to annual and sub-annual climate variation in the eastern Sonoran Desert. Spines grow from the apex of the cactus and are arranged serially along the side of the cactus oldest at the base, youngest at the apex. To establish the age of the spine series, we measured F14C of spines collected at 8 different heights from the apex (3.77 m) to the base of a naturally occurring saguaro. These spines yielded fractions of modern carbon (F14C) from 0.9679 and 1.5537, indicating the presence of carbon in spine tissue derived from atmospheric nuclear testing. We used the F14C of spine tissue to calculate the year of spine emergence for each of the 11 spines, assuming minimal re-allocation of stored carbon to growing spines. At the same 8 heights, we interpolated the date of spine emergence from observed height measurements made between 1964 and 2002. A very strong positive correlation (linear regression, r2 = 0.99, P < 0.0001) between the F14C age of spines and ages determined from direct height measurements was observed, with a two year offset suggesting incorporation of carbon from fossil fuel combustion sources in the Tucson basin. Additionally, spine tips from 97 spines collected serially from the top half of the same saguaro (between 1.77 and 3.50 m) and representing ~15 years of growth, yielded δ18O variations in spine bulk organic material from 38° to 50° (VSMOW) and in δ13C from ° to 11.5° (VPDB). The δ18O and δ13C values were positively correlated over the entire record (linear regression, r2 = 0.22, P < 0.0001). These variations occurred at or near an annual frequency. The most negative δ18O and δ13C values in bulk spine organic material from the naturally occurring cactus were observed in spines grown shortly following the 1983 and 1993 strong El Niño winter precipitation events in Tucson

  8. Cactus: a medicinal food.

    PubMed

    Shetty, Anoop A; Rana, M K; Preetham, S P

    2012-10-01

    With excellent quality and flavour of fresh fruits, young leaves of cactus serve as nutritious vegetable and salad dish and the immature fruits for making mock-gherkins. Cactus, with high water use efficiency produce forage for animals, vegetables, and fruits with 14% glucose. Traditionally cactus used as a valuable health supporting nutrient and it also has applications in pharmaceutical industries. Cactus with number of uses has immense potential to be the food of future. PMID:24082263

  9. Sarcocystis-associated meningoencephalitis in a bald eagle (Haliaeetus leucocephalus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protozoal meningoencephalitis is rare in raptors. An adult female bald eagle (Haliaeetus leucocephalus) with progressive neurological signs was euthanized after several months of treatment. The predominant histological lesion was lymphoplasmacytic and histiocytic meningoencephalitis involving the ...

  10. Identification and ecology of bacterial communities associated with necroses of three cactus species.

    PubMed

    Foster, J L; Fogleman, J C

    1993-01-01

    To compare the bacterial communities residing in necrotic tissues of columnar cacti of the Sonoran Desert, isolates from 39 organ pipe, 19 saguaro, and 16 senita cacti were obtained. The isolates were clustered into 28 conspecific groups on the basis of their fatty acid profiles. The distributions of the individual bacterial isolates varied among cactus species. Seven of the 28 species groups were unique to a particular cactus species, whereas 8 species groups were found in all three cacti. The effective number of bacterial species for each cactus species was positively correlated with both the chemical complexity and glucose concentration of the plant tissues. The effective number of bacterial species and bacterial distribution patterns were compared with those known for communities of cactophilic yeasts. The observed bacterial distribution patterns are most likely due to differences in the chemical compositions of the three cactus species. PMID:8439142

  11. Cactus spine injuries.

    PubMed

    Lindsey, D; Lindsey, W E

    1988-07-01

    Cactus spines produce injuries whose clinical significance is loosely in inverse proportion to the dimensions of the spine. Long and medium spines of saguaro and barrel cacti seldom result in embedded fragments, but when they do they are difficult to locate and remove. Other medium spines, those of prickly pear and cholla, are a nuisance but they can be removed readily by traction, as can the smaller spines (glochids) of the prickly pear. The very small spines (also glochids) of the polka dot or bunny's ear cactus (Opuntia microdasys) and the beavertail cactus (Opuntia basilaris) offer the most frustrating problem of all, but can be peeled off with a dried film of a professional facial gel. PMID:3390256

  12. Fatal toxoplasmosis in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Szabo, K A; Mense, M G; Lipscomb, T P; Felix, K J; Dubey, J P

    2004-08-01

    Toxoplasma gondii tachyzoites were identified in the myocardium of a bald eagle (Haliaeetus leucocephalus) that died of necrotizing myocarditis. The diagnosis was confirmed by immunohistochemical staining with T. gondii-specific polyclonal antibodies. This is a new host record for T. gondii. PMID:15357102

  13. Erysipelothrix rhusiopathiae infection in a captive bald eagle (Haliaeetus leucocephalus)

    USGS Publications Warehouse

    Franson, J. Christian; Galbreath, Elizabeth J.; Wiemeyer, Stanley N.; Abell, John M.

    1994-01-01

    An adult bald eagle (Haliaeetus leucocephalus) kept in captivity for nearly 7 yr at the Patuxent Wildlife Research Center, Laurel, Maryland, died suddenly with gross and microscopic lesions characteristic of septicemia. Erysipelothrix rhusiopathiae was isolated from the liver. Fish comprised part of the bird's diet and may have been the source of the organism.

  14. Flash electroretinography in the bald eagle (Haliaeetus leucocephalus).

    PubMed

    Kuhn, Sonia E; Hendrix, Diane V H; Sims, Michael H; Ward, Daniel A; Jones, Michael P; Baine, Katherine H

    2014-09-01

    Photopic and scotopic flash electroretinograms (fERGs) were done on 12 adult captive anesthetized bald eagles (Haliaeetus leucocephalus) following a complete ophthalmic exam. The b-wave amplitude in the bald eagle exceeds that seen in other species when using a similar protocol. This data may be used clinically as a reference for bald eagles undergoing fERG evaluation for retinal disease or as a preoperative screening tool before phacoemulsification. PMID:25314846

  15. Helminth parasites of the bald eagle, Haliaeetus leucocephalus, in Florida

    USGS Publications Warehouse

    Kinsella, J.M.; Foster, Garry W.; Cole, Rebecca A.; Forrester, Donald J.

    1998-01-01

    Twenty species of helminths (9 trematodes, 9 nematodes, and 2 acanthocephalans), including 9 new host records, were collected from 40 bald eagles (Haliaeetus leucocephalus) from Florida. Intensities of infection were low and no lesions were attributed to the parasites. No species were considered specialists in bald eagles; 5 species were considered raptor generalists and the remainder, generalists in other orders of fish-eating birds. An undescribed species of Hamatospiculum was found in 3 birds. Most of the common helminths were acquired from eating fish intermediate hosts.

  16. Mycobacteriosis in an American bald eagle (Haliaeetus leucocephalus).

    PubMed

    Hoenerhoff, Mark; Kiupel, Matti; Sikarskie, James; Bolin, Carole; Simmons, Heather; Fitzgerald, Scott

    2004-01-01

    Avian mycobacteriosis is an important disease in companion, captive, exotic, and wild birds worldwide. Mycobacterium avium is the most widely distributed and pathogenic organism causing tuberculous lesions in birds. Multiple factors including age, stress, immune status, and preexisting disease determine the pathogenicity of M. avium, and the disease can manifest itself in a variety of forms. Mycobacteriosis can cause severe losses in zoo aviaries, including the loss of rare and endangered bird species. We report a case of systemic avian mycobacteriosis in an adult, free-living male American bald eagle (Haliaeetus leucocephalus) that presented to the Diagnostic Center for Population and Animal Health in November 2003. PMID:15283434

  17. Cactus Graphs for Genome Comparisons

    NASA Astrophysics Data System (ADS)

    Paten, Benedict; Diekhans, Mark; Earl, Dent; St. John, John; Ma, Jian; Suh, Bernard; Haussler, David

    We introduce a data structure, analysis and visualization scheme called a cactus graph for comparing sets of related genomes. Cactus graphs capture some of the advantages of de Bruijn and breakpoint graphs in one unified framework. They naturally decompose the common substructures in a set of related genomes into a hierarchy of chains that can be visualized as multiple alignments and nets that can be visualized in circular genome plots.

  18. Cactus: HPC infrastructure and programming tools

    NASA Astrophysics Data System (ADS)

    Collaborative Effort

    2011-02-01

    Cactus provides computational scientists and engineers with a collaborative, modular and portable programming environment for parallel high performance computing. Cactus can make use of many other technologies for HPC, such as Samrai, HDF5, PETSc and PAPI, and several application domains such as numerical relativity, computational fluid dynamics and quantum gravity are developing open community toolkits for Cactus.

  19. Disseminated mycobacteriosis in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Heatley, J Jill; Mitchell, Mark M; Roy, Alma; Cho, Doo Youn; Williams, Diana L; Tully, Thomas N

    2007-09-01

    A mature bald eagle (Haliaeetus leucocephalus) was diagnosed with mycobacterial infection after being presented for an inability to fly, emaciation, and a swelling of the left tibiotarsal-tarso metatarsal joint. Results of a complete blood cell count revealed a persistent, marked leukocytosis, with heterophilia, monocytosis, and anemia. Radiographs revealed lysis of the left distal tibiotarsus and soft-tissue swelling around the left tibiotarsal-tarsometatarsal joint, multiple pulmonary opacities, and an enlarged liver. Endoscopic evaluation and biopsy of caseated material within the left caudal coelom revealed acid-fast organisms. The eagle was euthanatized, and results of necropsy and histologic evaluation revealed caseated granulomas of the intestine, lungs, air sacs, and subcutaneous regions of the hock. Results of culture, a polymerase chain reaction testing, and direct deoxyribonucleic acid (DNA) sequencing for mycobacterial 16S ribosomal ribonucleic acid DNA determined this organism most likely to be Mycobacterium avium. PMID:18087937

  20. Absolute polycythemia in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Fernandes, Andreia F; Fenton, Heather; Martinson, Shannon; Desmarchelier, Marion; Ferrell, Shannon T

    2014-12-01

    An approximately 6-mo-old female bald eagle (Haliaeetus leucocephalus) was presented for an inability to fly and bilateral drooped wings. Pectoral muscle atrophy with a moderate polycythemia was present. Over the course of 3 wk, there were no improvements in flight capacity, although the bird gained substantial weight. Further investigation revealed a prominent cyanosis that was responsive to oxygen therapy, a chronic respiratory acidosis with hypoxia, a cardiac murmur, and a persistent polycythemia. No obvious antemortem etiology for the clinical findings was discovered on computerized tomography, angiography, or echocardiography. The bird was euthanatized as a result of the poor prognosis. Necropsy and histopathology revealed no significant cardiovascular or pulmonary pathology. No myopathy was evident on electron microscopy of formalin-fixed tissues. Based on these diagnostics, a neuromuscular disorder is suspected as the cause for the blood gas abnormalities, with a resulting polycythemia from the hypoxia. PMID:25632692

  1. Mercury contamination in Idaho bald eagles, Haliaeetus leucocephalus.

    PubMed

    Bechard, Marc J; Perkins, Dusty N; Kaltenecker, Gregory S; Alsup, Steve

    2009-11-01

    Because mercury contamination is potentially threatening to bald eagle (Haliaeetus leucocephalus) populations, we collected molted feathers at nests to determine the level of contamination in bald eagles in the state of Idaho, USA. Eagle feathers contained measurable amounts of cadmium (Cd), chromium (Cr), selenium (Se), lead (Pb), as well as mercury (Hg). Cadmium, Cr, Se, and Pb levels averaged 0.17, 4.68, 2.02, and 1.29 mg/kg dry weight, respectively, and were at or below concentrations indicated as causing reproductive failure in bald eagles. Mercury contamination was found to be the highest averaging 18.74 mg/kg dry weight. Although a concentration of only 7.5 mg/kg dry weight Hg in bird feathers can cause reduced productivity and even sterility, all of the eagles we sampled bred successfully and the population of bald eagles continues to grow annually throughout the state. PMID:19690789

  2. Acanthocephala of the bald eagle (Haliaeetus leucocephalus) in North America

    USGS Publications Warehouse

    Richardson, D.J.; Cole, R.A.

    1997-01-01

    Examination of bald eagles (Haliaeetus leucocephalus) collected from several locations in North America contributed new information concerning the acanthocephalan fauna of this host. Representatives of Arythmorhynchus brevis, representing a new host record, were collected from eagles in Florida, New Hampshire, and Wisconsin. Plagiorhynchus sp. was collected from an eagle in Florida. Corynosoma strumosum was collected from an eagle in Alaska. Andracantha phalacrocoracis, representing a new host record, was collected from an eagle in Alaska. Southwellina hispida, representing a new host record, was collected from eagles in Maine and Virginia. The occurrence of gravid or mature females of A. brevis, Plagiorhynchus sp., and S. hispida suggests that the bald eagle may serve as a competent definitive host for these species.

  3. Dielectrophoretic columnar focusing device

    DOEpatents

    James, Conrad D.; Galambos, Paul C.; Derzon, Mark S.

    2010-05-11

    A dielectrophoretic columnar focusing device uses interdigitated microelectrodes to provide a spatially non-uniform electric field in a fluid that generates a dipole within particles in the fluid. The electric field causes the particles to either be attracted to or repelled from regions where the electric field gradient is large, depending on whether the particles are more or less polarizable than the fluid. The particles can thereby be forced into well defined stable paths along the interdigitated microelectrodes. The device can be used for flow cytometry, particle control, and other process applications, including cell counting or other types of particle counting, and for separations in material control.

  4. Are cactus growth forms related to germination responses to light? A test using Echinopsis species

    NASA Astrophysics Data System (ADS)

    Ortega-Baes, Pablo; Aparicio-González, Mónica; Galíndez, Guadalupe; del Fueyo, Patricia; Sühring, Silvia; Rojas-Aréchiga, Mariana

    2010-05-01

    In this study, we investigated the effect of light regimen (white light vs. darkness) on the germination of 12 species of the Echinopsis genus (tribe Trichocereeae, Cactaceae). This genus presents a variety of growth forms and relatively small and uniform seed size. These traits allowed us to test, within the same linage and removing seed mass effect, the hypothesis that the germination response to light (indifferent to light or positive photoblastic) is related to growth form. Our results reject this hypothesis since no seeds germinated in darkness, so all of the species can be classified as being positively photoblastic. The proportion of seed germination with white light was significantly different among cactus growth forms. Columnar cacti (arborescent, creeping and short) showed a greater proportion of seed germination than barrel and globose cacti. The germination rate differed among growth forms and species. At constant temperatures, creeping columnar cacti presented a significantly higher germination rate than the other growth forms. With alternating temperatures, columnar cacti showed higher germination rates than the other growth forms. The low proportion of seeds that germinated for some species indicates that they show seed dormancy. Our results suggest that germination responses to light in the cactus family could be related to seed mass and phylogenetic constraints.

  5. The cactus moth, Cactoblastis cactorum: Lessons in Biological Control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cactus moth was one of the success stories in classical biological control. In the 1920s, the prickly pear cactus was a serious pest in Australia. The cactus moth was imported from its native habitat in South America and proved so successful in controlling cactus that it was mass reared and exp...

  6. Disseminated mite infection with ocular involvement in a juvenile bald eagle (Haliaeetus leucocephalus).

    PubMed

    Bueno-Padilla, Irene; Klauss, Gia; Gardiner, Chris H; Wuenschmann, Arno

    2012-07-01

    A bald eagle (Haliaeetus leucocephalus) was found unable to fly and was admitted to The Raptor Center (TRC). Major clinical signs were thin body condition and a cardiac arrhythmia. Ten days after admission to TRC, ophthalmic examination revealed multiple, distinct serpiginous lesions of chorioretinal atrophy in the ocular fundus of the right eye (OD). The bird was euthanized because of clinical deterioration and poor prognosis. Mites of an undetermined species were found histologically in the retina, episcleral tissues, lungs, and liver at the postmortem examination. Disseminated mite infection should be considered in the differential diagnosis of serpiginous chorioretinal lesions in bald eagles (H. leucocephalus). PMID:22151197

  7. CACTUS SPRING ROADLESS AREA, CALIFORNIA.

    USGS Publications Warehouse

    Matti, Jonathan C.; Kuizon, Lucia

    1984-01-01

    Geologic, geochemical, and geophysical studies together with a review of historic mining and prospecting activities indicate that the Cactus Spring Roadless Area in California has little promise for the occurrence of mineral or energy resources. Marble bodies occur in the northern part of the roadless area and are possible resources for building stone, crushed and quarried aggregate, and lime and magnesium for Portland cement and industrial applications. It is recommended that the terrane of marble be mapped and sampled carefully in order to evaluate the quantity and quality of the carbonate resources.

  8. Bacteria Associated with Copestylum (Diptera, Syrphidae) Larvae and Their Cactus Host Isolatocereus dumortieri

    PubMed Central

    Martínez-Falcón, Ana Paola; Durbán, Ana; Latorre, Amparo; Antón, Josefa; Marcos-García, María de los Ángeles

    2011-01-01

    We describe the gut bacterial diversity inhabiting two saprophagous syrphids and their breeding substrate (decayed tissues of the columnar cactus Isolatocereus dumortieri). We analyzed the gut microbiota of Copestylum latum (scooping larvae that feed on decayed cactus tissues) and Copestylum limbipenne (whose larvae can also feed on semiliquid tissues) using molecular techniques. DNA was extracted from larval guts and cactus tissues. The V1-V3 region of the 16S rRNA genes was amplified and sequenced. A total of 31079 sequences were obtained. The main findings are: C. limbipenne is dominated by several Enterobacteriaceae, including putative nitrogen-fixing genera and pectinolitic species and some denitrifying species, whereas in C. latum unclassified Gammaproteobacteria predominate. Decayed tissues have a dominant lactic acid bacterial community. The bacterial communities were more similar between larval species than between each larva and its breeding substrate. The results suggest that the gut bacterial community in these insects is not strongly affected by diet and must be dependent on other factors, such as vertical transmission, evolutionary history and host innate immunity. PMID:22132101

  9. Transcriptional variation associated with cactus host plant adaptation in Drosophila mettleri populations.

    PubMed

    Hoang, Kim; Matzkin, Luciano M; Bono, Jeremy M

    2015-10-01

    Although the importance of host plant chemistry in plant-insect interactions is widely accepted, the genetic basis of adaptation to host plants is not well understood. Here, we investigate transcriptional changes associated with a host plant shift in Drosophila mettleri. While D. mettleri is distributed mainly throughout the Sonoran Desert where it specializes on columnar cacti (Carnegiea gigantea and Pachycereus pringleii), a population on Santa Catalina Island has shifted to chemically divergent coastal prickly pear cactus (Opuntia littoralis). We compared gene expression of larvae from the Sonoran Desert and Santa Catalina Island when reared on saguaro (C. gigantea), coastal prickly pear and laboratory food. Consistent with expectations based on the complexity and toxicity of cactus relative to laboratory food, within-population comparisons between larvae reared on these food sources revealed transcriptional differences in detoxification and other metabolic pathways. The majority of transcriptional differences between populations on the cactus hosts were independent of the rearing environment and included a disproportionate number of genes involved in processes relevant to host plant adaptation (e.g. detoxification, central metabolism and chemosensory pathways). Comparisons of transcriptional reaction norms between the two populations revealed extensive shared plasticity that likely allowed colonization of coastal prickly pear on Santa Catalina Island. We also found that while plasticity may have facilitated subsequent adaptive divergence in gene expression between populations, the majority of genes that differed in expression on the novel host were not transcriptionally plastic in the presumed ancestral state. PMID:26384860

  10. Use of cactus in mortars and concrete

    SciTech Connect

    Chandra, S.; Eklund, L.; Villarreal, R.R.

    1998-01-01

    Natural polymers have been used in ancient times to improve the durability of lime-based mortars and concretes. The natural polymers used were locally available. In this work, cactus extract from Mexico has been tested in a Portland cement mortar. It is seen that cactus extract increases the plasticity of the mortar and improves water absorption and freeze-salt resistance. Calcium hydroxide produced by Portland cement hydration interacts with the components of cactus extract, polysaccharides or proteins, and forms complexes. It affects the crystallization process. Painting of the concrete with this extract has also shown improved water resistance.

  11. Mineral resources of Cactus Plain and East Cactus Plain Wilderness Study Areas, La Paz County, Arizona

    SciTech Connect

    Tosdal, R.M.; Eppinger, R.G.; Erdman, J.A.; Hanna, W.F.; Pitkin, J.A.; Blank, H.R. Jr.; O'Leary, R.M.; Watterson, J.R. ); Kreidler, T.J. )

    1990-01-01

    This paper reports on geologic, geochemical, and geophysical studies in the Cactus Plain and East Cactus Plain Wilderness Study Areas outlined in areas with moderate to high potential for gold, silver, copper, lead, zinc, barite, fluorite, manganese, and sand suitable for foundry, fracturing, and abrasive uses and low resource potential for beryllium, uranium and bentonitic clays.

  12. MODIFIED LIVE FLAVOBACTERIUM COLUMNARE VACCINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is an aquatic bacterium that is highly infectious in both warm and cold water species of fish. In the channel catfish (Ictalurus punctatus) industry it causes columnaris disease and has a significant impact on production (~$30 million annually). Development of a successful...

  13. Genetic and Virulence Diversity of Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aim: To develop a method for conducting pulsed-field gel electrophoresis (PFGE) on Flavobacterium columnare, to use PFGE to characterize F. columnare channel catfish isolates, and to determine whether variation in pathogenic potential exists in F. columnare isolates from channel catfish. Methods and...

  14. 75 FR 41073 - South American Cactus Moth Regulations; Quarantined Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ... attacks primarily prickly pear cacti in arid and coastal areas. In the continental United States, the... United States belong to the genus Opuntia, also known as the prickly pear cactus. Opuntia cactus...

  15. CACTUS.

    ERIC Educational Resources Information Center

    Hyde, Hartley

    1992-01-01

    Utilizes LOGO to teach the concept of inequalities by programing the turtle to take random walks in the coordinate plane restricted to predetermined regions defined by inequalities. The students task is to discover the inequalities that define the illegal areas into which the turtle must not move. Provides examples and corresponding computer…

  16. Cactus

    ERIC Educational Resources Information Center

    Hyde, Hartley

    2007-01-01

    The transfer of data from one part of a computer to another has always been a complex task in which speed is traded against accuracy and the time required for error correction. Much more complex therefore is the transfer of information from one machine to another of a different type. Difficulties arise when machines are updated, when file formats…

  17. Mesoscopic modelling of columnar solidification

    NASA Astrophysics Data System (ADS)

    Založnik, M.; Viardin, A.; Souhar, Y.; Combeau, H.; Apel, M.

    2016-03-01

    We used two complementary modeling approaches for the simulation of columnar growth in directional solidification of organic alloys: a phase-field model and a mesoscopic envelope model of dendritic growth. While the phase-field method captures the details of the dendritic structure and of the growth dynamics, the mesoscopic model approximates the complex dendritic morphology by its envelope. The envelope growth is deduced from the velocities of the dendrite tips, calculated by an analytical LGK-type tip model that is matched to the heat and concentration fields in the stagnant film around the envelope. The computational cost of the mesoscopic model is several orders of magnitude lower and can bridge the gap between phase-field and macroscopic models. We demonstrate the applicability of the mesoscopic model to columnar growth and discuss its possibilities and limitations by comparisons with phase-field simulations for the same conditions.

  18. Laboratory experiments on columnar jointing

    NASA Astrophysics Data System (ADS)

    Goehring, L.; Morris, S. W.

    2003-12-01

    The mechanism causing columnar jointing has remained an enticing mystery since the basalt columns of the Giant's Causeway in N. Ireland were first reported to science in the 17th century. This phenomenon, in which shrinkage cracks form a quasi-hexagonal arrangement, has been shown to produce columns in starch, glass, coal, sandstone, and ice, as well as in a variety of lava flows. This suggests that this pattern-forming process is very general in nature. However, most studies of columnar jointing have been confined to field studies of basalt flows. Following Muller, we have experimented with desiccating corn starch in an effort to understand this pattern from a more general point of view. The diffusion and evaporation of water in starch is thought to be analogous to the diffusion and extraction of heat from a basalt flow. By combining direct sampling and x-ray tomography, fully 3D descriptions of columnar jointing were obtained with starch samples. We have characterized the pattern with several statistical indices, which describe its structure and relative disorder. These methods can resolve the ordering of the colonnade near the free surface. We identified two distinct mechanisms by which the mean column area increases during pattern evolution. We found both a slow, almost power-law increase in column area, as well as episodes of sudden catastrophic jumps in scale. The latter suggests that the column scale is not a simple single-valued function of drying rate, but rather a metastable state subject to hysteresis. Such metastable behaviour might explain a fundamental question about columnar jointing -- why the columns are so regular in the direction of their growth. Moreover, these experiments may help discriminate between the various theoretical models of this pattern forming process. Finally, our results lead to predictions that could be tested by field measurements on basaltic colonnades.

  19. The discovery of columnar jointing on Mars

    USGS Publications Warehouse

    Milazzo, M.P.; Keszthelyi, L.P.; Jaeger, W.L.; Rosiek, M.; Mattson, S.; Verba, C.; Beyer, R.A.; Geissler, P.E.; McEwen, A.S.; the HiRISE TEam

    2009-01-01

    We report on the discovery of columnar jointing in Marte Valles, Mars. These columnar lavas were discovered in the wall of a pristine, 16-km-diameter impact crater and exhibit the features of terrestrial columnar basalts. There are discontinuous outcrops along the entire crater wall, suggesting that the columnar rocks covered a surface area of at least 200 km2, assuming that the rocks obliterated by the impact event were similarly jointed. We also see columns in the walls of other fresh craters in the nearby volcanic plains of Elysium Planitia–Amazonis Planitia, which include Marte Vallis, and in a well-preserved crater in northeast Hellas.

  20. Differences in Tolerance to Host Cactus Alkaloids in Drosophila koepferae and D. buzzatii

    PubMed Central

    Soto, Ignacio M.; Carreira, Valeria P.; Corio, Cristian; Padró, Julián; Soto, Eduardo M.; Hasson, Esteban

    2014-01-01

    The evolution of cactophily in the genus Drosophila was a major ecological transition involving over a hundred species in the Americas that acquired the capacity to cope with a variety of toxic metabolites evolved as feeding deterrents in Cactaceae. D. buzzatii and D. koepferae are sibling cactophilic species in the D. repleta group. The former is mainly associated with the relatively toxic-free habitat offered by prickly pears (Opuntia sulphurea) and the latter has evolved the ability to use columnar cacti of the genera Trichocereus and Cereus that contain an array of alkaloid secondary compounds. We assessed the effects of cactus alkaloids on fitness-related traits and evaluated the ability of D. buzzatii and D. koepferae to exploit an artificial novel toxic host. Larvae of both species were raised in laboratory culture media to which we added increasing doses of an alkaloid fraction extracted from the columnar cactus T. terschekii. In addition, we evaluated performance on an artificial novel host by rearing larvae in a seminatural medium that combined the nutritional quality of O. sulphurea plus amounts of alkaloids found in fresh T. terschekii. Performance scores in each rearing treatment were calculated using an index that took into account viability, developmental time, and adult body size. Only D. buzzatii suffered the effects of increasing doses of alkaloids and the artificial host impaired viability in D. koepferae, but did not affect performance in D. buzzatii. These results provide the first direct evidence that alkaloids are key determinants of host plant use in these species. However, the results regarding the artificial novel host suggest that the effects of alkaloids on performance are not straightforward as D. koepferae was heavily affected. We discuss these results in the light of patterns of host plan evolution in the Drosophila repleta group. PMID:24520377

  1. Buoyancy-Induced, Columnar Vortices

    NASA Astrophysics Data System (ADS)

    Simpson, Mark; Glezer, Ari

    2015-11-01

    Free buoyancy-induced, columnar vortices (dust devils) that are driven by thermal instabilities of ground-heated, stratified air in areas with sufficient insolation convert the potential energy of low-grade heat in the surface air layer into a vortex flow with significant kinetic energy. A variant of the naturally-occurring vortex is deliberately triggered and anchored within an azimuthal array of vertical, stator-like flow vanes that form an open-top enclosure and impart tangential momentum to the radially entrained air. This flow may be exploited for power generation by coupling the vortex to a vertical-axis turbine. The fundamental mechanisms associated with the formation, evolution, and dynamics of an anchored, buoyancy-driven columnar vortex within such a facility are investigated experimentally using a heated ground plane. Specific emphasis is placed on the manipulation of the vortex formation and structure and the dependence of the vorticity production and sustainment mechanisms on the thermal resources and characteristic scales of the anchoring flow vanes using stereo-PIV. It is shown that manipulation of the formation and advection of vorticity concentrations within the enclosure can be exploited for increasing the available kinetic energy. Supported by ARPA-E.

  2. Low DDT residues in plasma of bald eagles (Haliaeetus leucocephalus) wintering in Colorado and Missouri

    USGS Publications Warehouse

    Henny, C.J.; Griffin, C.R.; Stahlecker, D.W.; Harmata, A.R.; Cromartie, E.

    1981-01-01

    Residues of DDT and its metabolites (Z:DDT) in blood plasma from Bald Eagles (Haliaeetus leucocephalus) wintering in Colorado and Missouri were low (0.06-0.14 ?g/g) in 1977 and 1978. Most of the adult wintering birds probably nest in Canada, although a few in Missouri may be from Minnesota or the Great Lakes region. DDE residues in eggs, estimated from those in plasma, were lower than those reported from Saskatchewan in 1969-1972 (4.5 ?g/g vs. 0.67 ?g//g); this suggests reduced environmental contamination.

  3. Flavobacterium columnare chemotaxis to channel catfish mucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is a Gram-negative pathogen of many species of wild and cultured fish, especially channel catfish (Ictalurus punctatus). This motile microbe is responsible for severe economic losses to the catfish industry. Flavobacterium columnare isolates from diseased channel catfish b...

  4. Minimum inhibitory concentration testing of flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple, accurate and reliable microdilution method has been developed to test the susceptibility of Flavobacterium columnare to antibiotics. The method has been used to determine the minimum inhibitory concentration (MIC) of 23 F. columnare isolates. The developed method conducted at 28 °C for 4...

  5. Habitat Suitability Index Models: Cactus Wren

    USGS Publications Warehouse

    Short, Henry L.

    1985-01-01

    A review and synthesis of existing information were used to develop a Habitat Suitability Index (HSI) model for the cactus wren (Campylorhynchus brunneicapillus). The model consolidates habitat use information into a framework appropriate for field application, and is scaled to produce an index between 0.0 (unsuitable habitat) to 1.0 (optimum habitat). HSI models are designed to be used with Habitat Evaluation Procedures previously developed by the U.S. Fish and Wildlife Service.

  6. Past climate changes and ecophysiological responses recorded in the isotope ratios of saguaro cactus spines.

    PubMed

    English, Nathan B; Dettman, David L; Sandquist, Darren R; Williams, David G

    2007-11-01

    The stable isotope composition of spines produced serially from the apex of columnar cacti has the potential to be used as a record of changes in climate and physiology. To investigate this potential, we measured the delta(18)O, delta(13)C and F(14)C values of spines from a long-lived columnar cactus, saguaro (Carnegiea gigantea). To determine plant age, we collected spines at 11 different heights along one rib from the stem apex (3.77 m height) to the base of a naturally occurring saguaro. Fractions of modern carbon (F(14)C) ranged from 0.9679 to 1.5537, which is consistent with ages between 1950 and 2004. We observed a very strong positive correlation (r = 0.997) between the F(14)C age of spines and the age of spines determined from direct and repeated height measurements taken on this individual over the past 37 years. A series of 96 spines collected from this individual had delta(18)O values ranging from 38 per thousand to 50 per thousand [Vienna standard mean ocean water (VSMOW)] and delta(13)C values from -11.5 per thousand to -8.5 per thousand [Vienna Peedee belemnite (VPDB)]. The delta(18)O and delta(13)C values of spines were positively correlated (r = 0.45, P < 0.0001) and showed near-annual oscillations over the approximately 15-year record. This pattern suggests that seasonal periods of reduced evaporative demand or greater precipitation input may correspond to increased daytime CO(2) uptake. The lowest delta(18)O and delta(13)C values of spines observed occurred during the 1983 and 1993 El Niño years, suggesting that the stable isotope composition recorded in spine tissue may serve as a proxy for these climate events. We compared empirical models and data from potted experimental cacti to validate these observations and test our hypotheses. The isotopic records presented here are the first ever reported from a chronosequence of cactus spines and demonstrate that tissues of columnar cacti, and potentially other long-lived succulents, may contain a

  7. Phenology of blue cactus moth Melitara prodenialis (Lepidoptera: Pyralidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Native cactus plants (Opuntia stricta Haw. [Cactaceae]) were sampled weekly at St. Marks National Wildlife Refuge, St. Marks, Florida (30.16 - 30° 1' N, -84.21 - 84° 1' W) from September 2006 to September 2007 for the native blue cactus moth, Melitara prodenialis Walker (Lepidoptera: Pyralidae) Meli...

  8. Biology and population dynamics of the cactus moth, Cactoblastis cactorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cactus moth, Cactoblastis cactorum, was a successful biological control agent against prickly pear cacti in Australia in the 1920’s. Since then, it was introduced to other countries including the Carribean islands. In 1989, the cactus moth was reported in Florida and has continued to spread nort...

  9. POPULATION DYNAMICS OF THE CACTUS MOTH, CACTOBLASTIS CACTORUM IN FLORIDA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Field populations of the cactus moth, Cactoblastis cactorum were surveyed weekly beginning in July 2006. We sampled the native cactus, Opuntia stricta visually to determine the densities and development of immature stages. Adult males were collected using a synthetic pheromone and a sticky wing trap...

  10. Discovery of columnar jointing on Mars

    USGS Publications Warehouse

    Milazzo, M.P.; Keszthelyi, L.P.; Jaeger, W.L.; Rosiek, M.; Mattson, S.; Verba, C.; Beyer, R.A.; Geissler, P.E.; McEwen, A.S.

    2009-01-01

    We report on the discovery of columnar jointing in Marte Valles, Mars. These columnar lavas were discovered in the wall of a pristine, 16-km-diameter impact crater and exhibit the features of terrestrial columnar basalts. There are discontinuous outcrops along the entire crater wall, suggesting that the columnar rocks covered a surface area of at least 200 km2, assuming that the rocks obliterated by the impact event were similarly jointed. We also see columns in the walls of other fresh craters in the nearby volcanic plains of Elysium Planitia-Amazonis Planitia, which include Marte Vallis, and in a well-preserved crater in northeast Hellas. ?? 2009 The Geological Society of America.

  11. Columnar liquid-crystalline dinaphthoperylenetetracarboxdiimides.

    PubMed

    Ferreira, Marli; Girotto, Edivandro; Bentaleb, Ahmed; Hillard, Elizabeth A; Gallardo, Hugo; Durola, Fabien; Bock, Harald

    2015-03-01

    Although the double Friedel-Crafts acylation of arenes with ethyl chloroglyoxylate is hindered by the strongly deactivating effect of the first-entering glyoxylic substituent, the double reaction is successful with the reactive arene perylene under long reaction times and with concomitant ester hydrolysis. The reaction is regiospecific, giving the 3,9-regioisomer exclusively. This perylenylenediglyoxylic acid is condensed first with o-bromophenylacetic acid and then with α-branched alkylamines to yield the title compounds. Whilst the corresponding tetraalkyl esters only show monotropic mesophases, these diimides show enantiotropic columnar mesophases that can be maintained at room temperature if racemically branched alkyl chains of moderate size are used. A palladium-induced C-C bond migration during the build-up of the arene system leads to an isomeric side product of reduced symmetry that can be isolated by aggregation-controlled chromatographic separation. The HOMO and LUMO energies of the title compounds are considerably higher than those of established perylenetetracarboxdiimides. PMID:25656752

  12. Ecology and control of an invasive pest, the cactus moth, Cactoblastis cactorum (Lepidoptera)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cactus moth, Cactoblastis cactorum, was one of the success stories in classical biological control. In the 1920s, the prickly pear cactus was a serious pest in Australia. The cactus moth was imported from its native habitat in South America and proved so successful in controlling cactus that it ...

  13. Nucleosome repeat lengths and columnar chromatin structure.

    PubMed

    Trifonov, Edward N

    2016-06-01

    Thorough quantitative study of nucleosome repeat length (NRL) distributions, conducted in 1992 by J. Widom, resulted in a striking observation that the linker lengths between the nucleosomes are quantized. Comparison of the NRL average values with the MNase cut distances predicted from the hypothetical columnar structure of chromatin (this work) shows a close correspondence between the two. This strongly suggests that the NRL distribution, actually, reflects the dominant role of columnar chromatin structure common for all eukaryotes. PMID:26208520

  14. Detection and characterization of a Trichomonas isolate from a rehabilitated bald eagle (Haliaeetus leucocephalus).

    PubMed

    Kelly-Clark, Whitney K; McBurney, Scott; Forzán, María J; Desmarchelier, Marion; Greenwood, Spencer J

    2013-12-01

    A hatching-year bald eagle (Haliaeetus leucocephalus) was presented for clinical examination after being found unable to fly. Upon admission, routine wet-mount microscopy detected no trichomonads. Five months later, oral cavity inspection found no abnormalities, but the eagle was swabbed for research on trichomonosis in maritime birds. The swab was used to inoculate an InPouch TF culture and trichomonads were visible within 24 hr. Genotyping (ITS) revealed a Trichomonas isolate that was 100% identical to an isolate from a bearded vulture (Gypaetus barbatus) from the Czech Republic. The eagle was treated with metronidazole (50 mg/kg q 12h PO for 5 consecutive days). Following treatment, the eagle was swabbed and the inoculated InPouch TF culture was monitored daily for 1 wk. No trichomonads were observed. Rehabilitation centers interested in surveillance should consider combining the InPouch TF technique with clinical inspection of live birds to confirm trichomonosis and for future research. PMID:24450084

  15. Sarcocystis sp.-associated meningoencephalitis in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Olson, Erik J; Wünschmann, Arno; Dubey, J P

    2007-09-01

    Protozoal meningoencephalitis is uncommon in raptors. An adult female bald eagle (Haliaeetus leucocephalus) was euthanized after several months of treatment for progressive neurologic signs. The predominant histologic lesion was lymphoplasmacytic and histiocytic meningoencephalitis involving the cerebrum and cerebellum. There was a marked segmental loss of granular cells and Purkinje cells, as well as segmental atrophy of the molecular layer in the cerebellum. Protozoal merozoites and schizonts were observed in the gray matter of the cerebellum. Ultrastructurally, the merozoites were classified as a species of Sarcocystis due to the lack of rhoptries. Immunohistochemistry of the agent revealed a positive reaction for Sarcocystis neurona, while sections were negative for Toxoplasma gondii and Neospora caninum. Sarcocystis sp. infection should be considered as a differential diagnosis in bald eagles with chronic neurologic disease. PMID:17823405

  16. Tibiotarsal fracture repair in a bald eagle (Haliaeetus leucocephalus) using an interlocking nail.

    PubMed

    Hollamby, Simon; Dejardin, Loic M; Sikarskie, James G; Haeger, Jennifer

    2004-03-01

    A 14-yr-old, 5.13-kg bald eagle (Haliaeetus leucocephalus) was hit by a car and presented to the Michigan State University Small Animal Clinic with an open, grade II, transverse, midshaft, Winquist-Hansen type-II-comminuted left tibiotarsal fracture. The fracture was reduced and fixation established with a 4.7-mm-diameter, 112-mm-long, four-hole veterinary intramedullary interlocking nail maintained in position by single 2-mm transcortical screws placed in the main proximal and distal fragments. The bird was weight bearing on the bandaged limb 48 hr postoperatively. Radiographs obtained 4 wk postoperatively revealed bridging callus over three of four cortices. The bird was released after 5 mo of rehabilitation. PMID:15193078

  17. A 26-year Composite Stable Isotope Record of Precipitation, Humidity and El Niño in the Spines of Saguaro Cactus, Carnegiea gigantea.

    NASA Astrophysics Data System (ADS)

    English, N. B.; Dettman, D. L.; Williams, D. G.

    2008-12-01

    Seasonal cycles of rainfall and humidity are recorded by stable isotopes in the spines of columnar cactuses. Multi-decadal δ18O and δ13C records of spine series from five saguaro cactuses, dated using bomb radiocarbon and semi-annual variations in δ13C, demonstrate the reproducibility of a climate signal. For δ18O and δ13C, the expressed population signal between 1980 and 2006 is 0.68 and 0.66, respectively, but 0.76 and 0.59 between 1980 and 1997, suggesting that age/height related effects are present in isotopic spine series. Composite δ18O and δ13C records constructed from five spine series show significant relationships to external climate forcing. Once dating errors are corrected, mean annual spine δ18O is negatively correlated with total annual precipitation (TAP) from November through October (P < 0.001) and positively correlated with mean annual nighttime vapor pressure deficit (VPD) (P < 0.01). Year to year decreases (> 2‰) in the maximum annual spine δ18O are positively correlated with the Southern Oscillation Index (P < 0.01). We hypothesize these decreases are caused by El Niño enhanced winter rainfall. While less significant, minimum annual δ13C is negatively correlated with TAP (P < 0.05) and mean nighttime VPD (P < 0.05). These results bolster proposed mechanistic models of isotopic variation in the spines of columnar cactuses and demonstrate the use of isotopic spine series as climate proxies.

  18. Columnar Liquid-Crystalline Dibenzopentacenodithiophenes by Photocyclization.

    PubMed

    Cabral, Marilia G Belarmino; Pereira de Oliveira Santos, Deise M; Bentaleb, Ahmed; Hillard, Elizabeth A; Cristiano, Rodrigo; Gallardo, Hugo; Durola, Fabien; Bock, Harald

    2016-06-01

    The twofold glyoxylic Perkin reaction of perylene-3,9-diglyoxylic acid with thiophene-diacetic acid followed by oxidative photocylization and reaction with α-branched primary alkylamines yields columnar liquid-crystalline diimides with two sulfur atoms in the condensed arene system. A broad temperature range of the hexagonal columnar mesophase is induced by racemic doubly branched alkyl chains. The HOMO and LUMO energy levels of these thiophene-derived diimides qualify them as electron donors with respect to perylene diimides. PMID:27141916

  19. Basal cactus phylogeny: implications of Pereskia (Cactaceae) paraphyly for the transition to the cactus life form.

    PubMed

    Edwards, Erika J; Nyffeler, Reto; Donoghue, Michael J

    2005-07-01

    The cacti are well-known desert plants, widely recognized by their specialized growth form and essentially leafless condition. Pereskia, a group of 17 species with regular leaf development and function, is generally viewed as representing the "ancestral cactus," although its placement within Cactaceae has remained uncertain. Here we present a new hypothesis of phylogenetic relationships at the base of the Cactaceae, inferred from DNA sequence data from five gene regions representing all three plant genomes. Our data support a basal split in Cactaceae between a clade of eight Pereskia species, centered around the Caribbean basin, and all other cacti. Two other Pereskia clades, distributed mostly in the southern half of South America, are part of a major clade comprising Maihuenia plus Cactoideae, and Opuntioideae. This result highlights several events in the early evolution of the cacti. First, during the transition to stem-based photosynthesis, the evolution of stem stomata and delayed bark formation preceded the evolution of the stem cortex into a specialized photosynthetic tissue system. Second, the basal split in cacti separates a northern from an initially southern cactus clade, and the major cactus lineages probably originated in southern or west-central South America. PMID:21646140

  20. DISPERSAL OF SEEDS AS NEST MATERIAL BY THE CACTUS WREN

    EPA Science Inventory

    Cactus wren (Campylorhynchus brunneicapillus) nests from the southern Chihuahuan Desert contained viable seeds of grasses, forbs, and shrubs. The most common plants used as construction material in these nests were Muhlenbergia porteri, Boerhavia spicata, and the alien grass Era...

  1. Genome sequence of the fish pathogen Flavobacterium columnare ATCC 49512

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is a Gram-negative, rod shaped, motile, and highly prevalent fish pathogen causing columnaris disease in freshwater fish worldwide. Here, we present the complete genome sequence of F. columnare strain ATCC 49512. ...

  2. Pharmacokinetics of intravenous and oral tramadol in the bald eagle (Haliaeetus leucocephalus).

    PubMed

    Souza, Marcy J; Martin-Jimenez, Tomas; Jones, Michael P; Cox, Sherry K

    2009-12-01

    Analgesia is becoming increasingly important in veterinary medicine, and little research has been performed that examined pain control in avian species. Tramadol is a relatively new drug that provides analgesia by opioid (mu), serotonin, and norepinephrine pathways, with minimal adverse effects. To determine the pharmacokinetics of tramadol and its major metabolite O-desmethyltramadol (M1) in eagles, 6 bald eagles (Haliaeetus leucocephalus) were each dosed with tramadol administered intravenously (4 mg/kg) and orally (11 mg/kg) in a crossover study. Blood was collected at various time points between 0 and 600 minutes and then analyzed with high-performance liquid chromatography to determine levels of tramadol and M1, the predominate active metabolite. The terminal half-life of tramadol after intravenous dosing was 2.46 hours. The maximum plasma concentration, time of maximum plasma concentration, and terminal half life for tramadol after oral dosing were 2156.7 ng/ml, 3.75 hours, and 3.14 hours, respec vely. In addition, the oral bioavailability was 97.9%. Although plasma concentrations of ramadol and M1 associated with analgesia in any avian species is unknown, based on the obtained data and known therapeutic levels in humans, a dosage of 5 mg/kg PO q12h is recommended for bald eagles. Pharmacodynamic studies are needed to better determine plasma levels of tramadol and M1 associated with analgesia in birds. PMID:20235455

  3. Behavioral ecology of bald eagles along the northwest coast: a landscape perspective. [Haliaeetus leucocephalus

    SciTech Connect

    Hansen, A.J.; Dyer, M.I.; Shugart, H.H.; Boeker, E.L.

    1986-02-01

    Much of the range of the bald eagle (Haliaeetus leucocephalus) has been subjected to anthropogenic disturbance of greater magnitude than the natural regimes of pre-European settlement times. Consequently, many eagle populations are depauperate. Eagle populations are large and stable, however, along the relatively pristine Pacific Northwest Coast of North America. This study examines: (1) the behavior and ecology of bald eagles along the northwest coast; and (2) the effects of environmental disturbance and resource dynamics on the ecology and evolution of eagles. The ephemeral nature of food supplies along the northwest coast apparently results in eagles being limited primarily by food stress. The foraging behavior of eagles was analyzed using evolutionary game theory as a theoretical construct. Productivity was found to be variable and generally declining in southeast Alaska. Eagles maximized energy input for survival by feeding opportunistically, making broad-scale movements to find food patches, locating food within a patch by searching for prey or for conspecifics with prey, assessing prey profitability, acquiring food by hunting and stealing, and by defending food through threat displays or fighting. Eagles obtain food for reproduction by defending feeding territories and by storing food in their nests. These strategies and adaptations translate up scale and influence characteristics of the regional population. 34 figs., 21 tabs.

  4. Relationship of diets and environmental contaminants in wintering bald eagles. [Haliaeetus leucocephalus

    SciTech Connect

    Frenzel, R.W.; Anthony, R.G. )

    1989-07-01

    We investigated the relationship between diets and potential hazards in contaminants of wintering bald eagles (Haliaeetus leucocephalus) in the Klamath Basin of northern California and southern Oregon. We studied diets by identifying remains of 913 prey items found at perches, examining 341 castings collected from communal night roots, and observing foraging eagles. We determined residues of organochlorine compounds, lead (Pb), and mercury (Hg) in bald eagles and their prey by analyzing eagle blood samples and carcasses and 8 major prey species. Bald eagles fed largely on waterfowl by scavenging cholera-killed ducks and geese and on microtine rodents during mid- to late winter. Residues of organochlorine pesticides and Hg in prey were low, and polychlorinated biphenyls (PCB's) were detected in low concentrations in 9% of prey samples. Means Pb concentrations in prey ranged from 0.15 to 4.79 ppm. Mercury was detected in all eagle blood samples, and Pb was detected in 41% of the bald eagle blood samples. Mean Pb concentration in livers of dead eagles was 2.09 ppm and ranged as high as 27 ppm in an eagle that died of Pb poisoning. Prey of the eagles were relatively free of contaminants with the possible exception of embedded Pb shot in waterfowl, which may present a potential for Pb poisoning of eagles.

  5. Fighting behavior in Bald Eagles: a test of game theory. [Haliaeetus leucocephalus

    SciTech Connect

    Hansen, A.J.

    1986-06-01

    Seven predictions of evolutionary game theory were examined in field studies of foraging behavior of Bald Eagles (Haliaeetus leucocephalus) wintering in the Chilkat Valley, Alaska. A cost/benefit analysis revealed that the frequencies of two foraging strategies (hunting and stealing from conspecifics) were balanced such that the payoffs of the two were nearly equal. Asymmetries in probable correlates of fighting ability (size and, possibly, spatial position (being in the air vs. on the ground), but not age) and expected gain in victory (hunger level) influenced the outcome of contests over food. Individuals used conditions strategies: small or young birds appeared to hung (rather than steal) relatively more often than others. Pirating eagles often assessed the size and hunger level of food defenders and attacked those most likely to retreat. Contrary to prediction, ritualized displays served to advertise expected gain in victory and were good indicators of subsequent behavior. The level of escalated fighting was inversely related to resource availability. Finally, a graphical model shows that pirating frequency may or may not be influenced by changes in food abundance. The results generally support the predictions of game theory and explain several aspects of Bald Eagle foraging behavior.

  6. Repair of a coracoid luxation and a tibiotarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Guzman, David Sanchez-Migallon; Bubenik, Loretta J; Lauer, Susanne K; Vasanjee, Sunil; Mitchell, Mark A

    2007-09-01

    A 4.5-kg, adult bald eagle (Haliaeetus leucocephalus) was presented after being found unable to fly. Crepitus was palpated in the left shoulder; however, the wing position was normal. Radiographs revealed caudoventral luxation of the left coracoid, affecting its distal articulation with the clavicle and its proximal articulation with the sternum. The luxation affecting the coracoid-sternum articulation was repaired by using a 4-hole, 1.5-mm T-plate and a 6-hole, 2.0-mm dynamic compression plate (DCP) placed side by side. The luxation affecting the coracoid and the clavicle was repaired by 2 cerclage wires in a simple interrupted pattern. Before a scheduled release, the bird sustained a closed, complete mid diaphyseal transverse fracture of the right tibiotarsus, which most likely occurred during recapture from the flight cage. The fracture was surgically repaired with 2 circumferential cerclage wires, an intramedullary Kirschner wire and one 10-hole, 2.7-mm DCP. The bird was successfully released, 105 days after the first surgery, near the location where it was found. PMID:18087935

  7. Multiple metals exposure and neurotoxic risk in bald eagles (Haliaeetus leucocephalus) from two Great Lakes states.

    PubMed

    Nam, Dong-Ha; Rutkiewicz, Jennifer; Basu, Niladri

    2012-03-01

    In the present study, the authors determined concentrations of several elements (As, Cd, Co, Cu, Cr, Mn, Pb, Sb, Zn) in the brains and livers of 46 bald eagles (Haliaeetus leucocephalus) from two Great Lakes states, Michigan and Minnesota. To explore whether exposures are of neurological concern, the authors assessed their associations with neurochemical receptors (N-methyl-D-aspartate [NMDA] and γ-aminobutyric acid A [GABA(A)]) and enzymes (glutamine synthetase [GS] and glutamic acid decarboxylase [GAD]) that play critical roles in vertebrate neurobehavior and reproduction. For most elements, levels in the livers and brains did not differ between region and gender. Hepatic Pb levels averaged 33.1 ppm (dry wt), 30.4% of all carcasses exceeded proposed avian Pb thresholds (>26.4 ppm), and in 30.8% of the birds examined evidence of Pb pellets or fragments was found. Significant changes in the activities of GS and GAD were related to brain concentrations of several metals (Pb, Cd, Co, Cu, Zn). No relationships were found among any of the nine elements and NMDA or GABA(A) receptor levels. When combined with the authors' previous study on these same eagles that showed Hg-associated alterations in GS, GAD, and NMDA receptor levels, the present research suggests that bald eagles are exposed to various elements, especially Pb and Hg, that are capable of causing changes in GABAergic and glutamatergic neurotransmission. The functional significance of these neurochemical changes warrants attention. PMID:22170515

  8. Parasitism enhances tilapia susceptibility to Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare, a Gram-negative bacterium, is the causative agent of columnaris disease. Many commercially important freshwater fish worldwide are susceptible to columnaris disease that can result in high fish mortality. Ichthyophthirius multifiliis (Ich) is a protozoan parasite in many ...

  9. Stem biomechanics of three columnar cacti from the Sonoran Desert.

    PubMed

    Molina-Freaner, F; Tinoco-Ojanguren, C; Niklas, K

    1998-08-01

    The allometric relationship of stem length L with respect to mean stem diameter D was determined for 80 shoots of each of three columnar cactus species (Stenocereus thurberi, Lophocereus schottii, and S. gummosus) to determine whether this relationship accords with that predicted by each of three contending models purporting to describe the mechanical architecture of vertical shoots (i.e., geometric, stress, and elastic similitude, which predict L proportional to D(alpha), with alpha = 1/1, 1/2, and 2/3, respectively). In addition, anatomical, physical, and biomechanical stem properties were measured to determine how the stems of these three species maintain their elastic stability as they increase in size. Reduced major axis regression of L with respect to D showed that alpha = 2.82 ± 0.14 for S. thurberi, 2.32 ± 0.19 for L. schottii, and 4.21 ± 0.31 for S. gummosus. Thus, the scaling exponents for the allometry of L differed significantly from that predicted by each of the three biomechanical models. In contrast, these exponents were similar to that for the allometry previously reported for saguaro. Analyses of biomechanical data derived from bending tests performed on 30 stems selected from each of the three species indicated that the bulk stem tissue stiffness was roughly proportional to L2, while stem flexural rigidity (i.e., the ability to resist a bending force) scaled roughly as L3. Stem length was significantly and positively correlated with the volume fraction of wood, while regression analysis of the pooled data from the three species (i.e., 90 stems) indicated that bulk tissue stiffness scaled roughly as the 5/3-power of the volume fraction of wood in stems. These data were interpreted to indicate that wood served as the major stiffening agent in stems and that this tissue accumulates at a sufficient rate to afford unusually high scaling exponents tot stem length with respect to stem diameter (i.e., disproportionately large increments of stem length

  10. Comparative cactus architecture and par interception

    SciTech Connect

    Geller, G.N.; Nobel, P.S. )

    1987-07-01

    Because CO{sup 2} uptake by cacti can be limited by low levels of photosynthetically active radiation (PAR) and because plant form affects PAR interception, various cactus forms were studied using a computer model, field measurements, and laboratory phototropic studies. Model predictions indicated that CO{sub 2} uptake by individual stems at an equinox was greatest when the stem were vertical, but at the summer and the winter solstice CO{sub 2} uptake was greatest for stems titled 30{degree} away from the equator. Stem tilting depended on form and taxonomic group. Not only can the shape of cacti be affected by PAR, but also shape influences PAR interception and hence CO{sub 2} uptake.

  11. Annealing a magnetic cactus into phyllotaxis

    NASA Astrophysics Data System (ADS)

    Nisoli, Cristiano; Gabor, Nathaniel M.; Lammert, Paul E.; Maynard, J. D.; Crespi, Vincent H.

    2010-04-01

    The appearance of mathematical regularities in the disposition of leaves on a stem, scales on a pine-cone, and spines on a cactus has puzzled scholars for millennia; similar so-called phyllotactic patterns are seen in self-organized growth, polypeptides, convection, magnetic flux lattices and ion beams. Levitov showed that a cylindrical lattice of repulsive particles can reproduce phyllotaxis under the (unproved) assumption that minimum of energy would be achieved by two-dimensional Bravais lattices. Here we provide experimental and numerical evidence that the Phyllotactic lattice is actually a ground state. When mechanically annealed, our experimental “magnetic cactus” precisely reproduces botanical phyllotaxis, along with domain boundaries (called transitions in Botany) between different phyllotactic patterns. We employ a structural genetic algorithm to explore the more general axially unconstrained case, which reveals multijugate (multiple spirals) as well as monojugate (single-spiral) phyllotaxis.

  12. Reproduction, longevity and survival of the cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae).

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Screened potted cactus plants (Opuntia ficus-indica (L.) Mill.) containing pairs of adult male and female cactus moths, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), were placed in a cactus field in St. Marks, Florida to measure oviposition patterns under field-realistic conditions. Results...

  13. COMPARATIVE PHENOLOGY OF CACTOBLASTIS CACTORUM AND MELITARA PRODENIALIS (LEPIDOPTERA): PESTS OF CACTUS IN FLORIDA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We surveyed native cactus plants (Opuntia stricta) at St. Marks National Wildlife Refuge, St. Marks, FL from September 2006 – September 2007 for the invasive cactus moth, Cactoblastis cactorum and the native blue cactus moth, Melitara prodenialis. Every week, we visually counted the numbers and reco...

  14. Nonequilibrium scale selection mechanism for columnar jointing

    PubMed Central

    Goehring, Lucas; Mahadevan, L.; Morris, Stephen W.

    2009-01-01

    Crack patterns in laboratory experiments on thick samples of drying cornstarch are geometrically similar to columnar joints in cooling lava found at geological sites such as the Giant's Causeway. We present measurements of the crack spacing from both laboratory and geological investigations of columnar jointing, and show how these data can be collapsed onto a single master scaling curve. This is due to the underlying mathematical similarity between theories for the cracking of solids induced by differential drying or by cooling. We use this theory to give a simple quantitative explanation of how these geometrically similar crack patterns arise from a single dynamical law rooted in the nonequilibrium nature of the phenomena. We also give scaling relations for the characteristic crack spacing in other limits consistent with our experiments and observations, and discuss the implications of our results for the control of crack patterns in thin and thick solid films. PMID:19129495

  15. Atmospheric Columnar Vortices (Paper 7R0104)

    NASA Astrophysics Data System (ADS)

    Snow, John T.

    1987-04-01

    The family of atmospheric columnar vortices includes tornadoes, waterspouts, firewhirls, dust devils and a variety of other whirlwinds. Each member of the family is characterized by the presence of a relatively tall, concentrated vortical core. Descriptions of such swirling flows are inherently complex, reflecting the presence of a multiplicity of length and velocity scales. In many cases, the flow is both three-dimensional and unsteady.

  16. Pulse seedling recruitment on the population dynamics of a columnar cactus: Effect of an extreme rainfall event

    NASA Astrophysics Data System (ADS)

    Arroyo-Cosultchi, Gabriel; Golubov, Jordan; Mandujano, María C.

    2016-02-01

    Demographic studies on the Cactaceae have highlighted several threats which are clearly human induced (e.g., disturbance) or intrinsic to their biology (e.g., infrequent recruitment). Most demographic studies suggest that early life stages of germination and seedling recruitment are crucial and often a limitation for population growth. The population dynamics of Neobuxbaumia polylopha (DC) Backeb. was modeled for a three-year period to assess the contribution of the early life cycle stages on population growth rate (λ). Two annual size-classified matrix population models were constructed for standard analysis, applied a life table response experiment (LTRE) analysis to explore the contributions of demographic processes, plant size, and temporal variability (years) to λ, and changes in the matrix elements were simulated including a seed bank, and seed-to-seedling transition using observed and experimental data. The population growth rates for 2012-2013 and 2013-2014 were 0.9916 (0.9906-0.9929) and 1.0216 (1.011-1.0280) respectively, suggesting two opposite growth rates for the studied period. The increase in λ in 2013-2014 was driven primarily by the increased growth and seedling recruitment and survival of small individuals. The rate of recruitment was higher in 2013-2014 with a left-skewed stable size distribution. Elasticity values were high for matrix entries corresponding to individuals remaining in the same category (stasis), followed by growth, retrogression and fecundity. The simulations show that the seed bank has a minor effect in comparison with the seed-seedling transition which became the population bottleneck under the assumption that seeds are not limited, so programs designed to preserve N. polylopha populations must focus on seedling establishment.

  17. Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

    SciTech Connect

    1997-02-01

    This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the CAU No. 426, which includes the Cactus Spring Waste Trenches, CAS No. RG-08-001-RG-CS. The Cactus Spring Waste Trenches are located at the Tonopah Test Range (TTR) which is part of the Nellis Air Force Range, approximately 255 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada, by air. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below the Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or without remediation), or no further action.

  18. Measurement of the flow past a cactus-inspired cylinder

    NASA Astrophysics Data System (ADS)

    Oweis, Ghanem F.; El-Makdah, Adnan M.

    2012-11-01

    Desert cacti are tall cylindrical plants characterized by longitudinal u- or v-shaped grooves that run parallel to the plant axis, covering its surface area. We study the wake flow modifications resulting from the introduction of cactus-inspired surface grooves to a circular cylinder. Particle image velocimetry PIV is implemented in a wind tunnel to visualize and quantify the wake flow from a cactus cylinder in cross wind and an equivalent circular cylinder at Re O(1E5). The cactus wake exhibits superior behavior over its circular counterpart as seen from the mean and turbulent velocity profiles. The surface flow within the grooves is also probed to elucidate the origins of the wake alterations. Lastly, we use simple statistical analysis based only on the wake velocity fields, under the assumption of periodicity of the shedding, to recover the time varying flow from the randomly acquired PIV snapshots.

  19. Theoretical Exploration of Barrel-Shaped Drops on Cactus Spines.

    PubMed

    Luo, Cheng

    2015-11-01

    To survive an arid environment, desert cacti are capable of harvesting water from fog by transporting condensed water drops using their spines. Cactus spines have a conical shape. In this work, on the basis of the difference of liquid pressure, a new theoretical model has been developed for a barrel-shaped liquid drop on a conical wire. This model is further simplified to interpret the effects of contact angles, conical angle, surface microgrooves, and gravity on the drop movement along a cactus spine. PMID:26473466

  20. Identification, Characterization, and Function Analysis of the Cactus Gene from Litopenaeus vannamei

    PubMed Central

    Zhang, Shuang; Lü, Ling; Chen, Yi-Hong; Chai, Jiaoting; Weng, Shaoping; Chen, Yong-Gui; He, Jianguo; Xu, Xiaopeng

    2012-01-01

    The nuclear factor-kappa B (NF-κB) pathways play important roles in innate immune responses. IκB is the main cytoplasmic inhibitor of NF-κB. In this study, we identified the LvCactus gene from Litopenaeus vannamei, which is the first cloned IκB homologue in subphylum Crustacea. LvCactus contains six predicted ankyrin repeats, which show similarities to those of Cactus proteins from insects. LvCactus localizes in cytoplasm and interacts with LvDorsal, an L. vannamei homologue to Drosophila melanogaster Dorsal belonging to class II NF-κB family, to prevent its nuclear translocation. Contrary to that of LvDorsal, over-expression of LvCactus down-regulates the activities of shrimp antimicrobial peptides promoters, suggesting LvCactus is an inhibitor of LvDorsal. The promoter of LvCactus was predicted to contain five putative NF-κB binding motifs, among which four were proved to be bound by LvDorsal by chromatin immunoprecipitation assays. Dual-luciferase reporter assays also showed that transcription of LvCactus was promoted by LvDorsal but inhibited by LvCactus itself, indicating a feedback regulatory pathway between LvCactus and LvDorsal. Expression of LvCactus was up-regulated after Lipopolysaccharides, poly (I:C), Vibrio parahaemolyticus, and Staphylococcus aureus injections, suggesting an activation response of LvCactus to bacterial and immune stimulant challenges. Differently, the LvCactus expression levels obviously decreased during white spot syndrome virus (WSSV) infection, indicating the feedback regulatory pathway of LvCactus/LvDorsal could be modified by WSSV. PMID:23185415

  1. Anomalous columnar order of charged colloidal platelets.

    PubMed

    Morales-Anda, L; Wensink, H H; Galindo, A; Gil-Villegas, A

    2012-01-21

    Monte Carlo computer simulations are carried out for a model system of like-charged colloidal platelets in the isothermal-isobaric ensemble (NpT). The aim is to elucidate the role of electrostatic interactions on the structure of synthetic clay systems at high particle densities. Short-range repulsions between particles are described by a suitable hard-core model representing a discotic particle. This potential is supplemented with an electrostatic potential based on a Yukawa model for the screened Coulombic potential between infinitely thin disklike macro-ions. The particle aspect-ratio and electrostatic parameters were chosen to mimic an aqueous dispersion of thin, like-charged, rigid colloidal platelets at finite salt concentration. An examination of the fluid phase diagram reveals a marked shift in the isotropic-nematic transition compared to the hard cut-sphere reference system. Several statistical functions, such as the pair correlation function for the center-of-mass coordinates and structure factor, are obtained to characterize the structural organization of the platelets phases. At low salinity and high osmotic pressure we observe anomalous hexagonal columnar structures characterized by interpenetrating columns with a typical intercolumnar distance corresponding to about half of that of a regular columnar phase. Increasing the ionic strength leads to the formation of glassy, disordered structures consisting of compact clusters of platelets stacked into finite-sized columns. These so-called "nematic columnar" structures have been recently observed in systems of charge-stabilized gibbsite platelets. Our findings are corroborated by an analysis of the static structure factor from a simple density functional theory. PMID:22280777

  2. Cactus pear fruit: a new source for a natural sweetner.

    PubMed

    Sáenz, C; Estévez, A M; Sepúlveda, E; Mecklenburg, P

    1998-01-01

    The use of cactus pear (Opuntia ficus indica L.) to obtain a new natural liquid sweetener was studied. The juice of the fruit (16.5 degrees Brix) was clarified with enzymes, treated with active carbon to take out the color and vacuum concentrated to obtain a 60 degrees Brix syrup or liquid sweetener. Physical and chemical characteristics determined included: a(w); reducing sugars (as inverted sugar); glucose (%); ash content (%); sugar composition by TLC; OD (420 nm) and Y, x, y chromaticity coordinates; viscosity (cps) and density (g/ml). Sensory analyses to determine the relative sweetness were also conducted. Cactus pear syrup contained 52.38% reducing sugar. The syrup had a pH of 4.31, a viscosity of 27.05 cps, an Aw of 0.83, a density of 1.2900 g/ml, an acidity (as citric acid) of 0.74% and an ash content of 1.4%. Compared with traditional sweeteners such as fructose and glucose syrup, the acidity was greater than that of HFCS (high fructose corn syrup) of 0.035%, and the ash values were considered a little high compared to glucose syrup which is 1.0%; these disparities can be attributed to the different processing conditions employed. Sensory evaluation revealed the same relative sweetness for cactus pear syrup and glucose, but lower than fructose; cactus pear syrup had a relative sweetness value of 67 with respect to sucrose (100). PMID:9839813

  3. CACTUS: Command and Control Training Using Knowledge-Based Simulations.

    ERIC Educational Resources Information Center

    Hartley, J. R.; And Others

    1992-01-01

    Describes a computer simulation, CACTUS, that was developed in the United Kingdom to help police with command and control training for large crowd control incidents. Use of the simulation for pre-event planning and decision making is discussed, debriefing is described, and the role of the trainer is considered. (LRW)

  4. CACTUS: Command and Control Training Using Knowledge-Based Simulations

    ERIC Educational Resources Information Center

    Hartley, Roger; Ravenscroft, Andrew; Williams, R. J.

    2008-01-01

    The CACTUS project was concerned with command and control training of large incidents where public order may be at risk, such as large demonstrations and marches. The training requirements and objectives of the project are first summarized justifying the use of knowledge-based computer methods to support and extend conventional training…

  5. Pereskia and the origin of the cactus life-form.

    PubMed

    Edwards, Erika J; Donoghue, Michael J

    2006-06-01

    The cactus life-form is cited as an example of a tight relationship between organism form and function: a succulent, long-lived, photosynthetic stem allows cacti to survive long periods of drought while maintaining a positive tissue water status. Pereskia (Cactaceae) comprises 17 species of leafy shrubs and trees that are thought to represent the original cactus condition. Recent phylogenetic work has shown that there are two separate clades of Pereskia species, which are basal and paraphyletic with respect to the rest of the cacti. We selected seven Pereskia species, representing both clades, and characterized their water relations by measuring a suite of physiological traits in wild populations. Additionally, we estimated basic climate parameters from collection localities for all 17 Pereskia species. Extant Pereskia species exhibit ecological water use patterns that are very similar to those of the leafless, stem-succulent cacti. Ancestral trait reconstruction for the physiological and environmental data provides a preliminary assessment of the ecology and water relations of the earliest cacti and suggests that several key elements of the cactus ecological niche were established before the evolution of the cactus life-form. We interpret these ecological traits as potentially important drivers of evolutionary innovation in the cacti. PMID:16649155

  6. Chemotaxis of Flavobacterium columnare: To Channel Catfish Mucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is the etiological agent of columnaris disease in fresh water fish. The disease is characterized by chronic skin lesions and severe mortality. The skin mucus constitutes a large portion of body and many infectious organisms including F. columnare, is believed to invade throu...

  7. Efficacy of a modified live Flavobacterium columnare vaccine in fish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is an aquatic bacterium that is responsible for columnaris disease. This aquatic pathogen has a worldwide distribution and is highly infectious to both warm and cold water fish. A modified live F. columnare vaccine was developed through repeated passage of a virulent strai...

  8. Improved method for minimum inhibitory concentration testing of flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple and reliable microdilution method has been developed to test the susceptibility of Flavobacterium columnare to antibiotics in vitro. The method has been used to determine the minimum inhibitory concentration (MIC) of 23 F. columnare isolates. The tests were conducted at 28 °C using a stan...

  9. Flavobacterium Columnare Genomovar virulence toward rainbow trout (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is the causative agent for columnaris disease and responsible for significant economic loss in the aquaculture industry. F. columnare is a gram negative bacteria with several genomovar classifications, based on the restriction fragment length polymorphism of the 16S rDNA gen...

  10. VIRULENCE OF Flavobacterium columnare GENOMOVARS IN RAINBOW TROUT (Oncorhynchus mykiss)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. F. columnare is a Gram-negative bacterium, and five genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rR...

  11. Complete genome sequence of Flavobacterium columnare strain 94-081

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish is one of the most important commodities in Mississippi and the largest aquaculture industry in the United States. Columnaris disease, caused by Flavobacterium columnare, affects many commercially important freshwater fish species. F. columnare strain 94-081 was isolated from disease...

  12. Magnetic resonance imaging is superior to radiography in evaluating spinal cord trauma in three bald eagles (Haliaeetus leucocephalus).

    PubMed

    Stauber, Erik; Holmes, Shannon; DeGhetto, Darlene L; Finch, Nickol

    2007-09-01

    Three bald eagles (Haliaeetus leucocephalus) found along highways and unable to fly were presented for evaluation. All eagles exhibited sternal recumbency, as well as flaccid hind limb and tail paralysis. Vertebral column and spinal cord trauma were suspected as the cause. One bird died, whereas the remaining 2 birds were stabilized for diagnostic imaging studies. All 3 birds were evaluated by radiography and magnetic resonance imaging (MRI) for diagnosis and for prognosis in the live birds. Radiographic findings in all 3 birds were inconclusive, whereas MRI results showed extensive damage of the spinal cord and vertebral column, precluding functional recovery. The 2 surviving birds were euthanatized. In all birds, MRI assessments correlated well with necropsy and histopathologic findings. PMID:18087936

  13. A new species of Caryospora (Apicomplexa: Eimeriidae) from the bald eagle, Haliaeetus leucocephalus (Accipitriformes: Accipitridae), from Kansas.

    PubMed

    McAllister, Chris T; Duszynski, Donald W; McKown, Richard D

    2013-04-01

    Between March 1989 and February 1994, 4 bald eagles ( Haliaeetus leucocephalus ) from various localities in Kansas were examined for coccidia. One (25%) of the bald eagles was found to be passing an undescribed species of Caryospora in its feces. Oocysts of Caryospora hanebrinki n. sp. are ellipsoidal to ovoidal with a bilayered wall and measure 48.1 × 42.1 μm with a shape index of 1.2. A micropyle, oocyst residuum, and polar granule were absent. Sporocysts are spheroidal, 24.8 μm wide. Stieda, substieda, and parastieda bodies were absent; a spheroidal sporocyst residuum is present; it measures 17.5 μm and is composed of many intact homogenous globules with a few dispersed in a loose spiral around the sporocysts. This is the first caryosporan documented from the bald eagle and is the largest known Caryospora from raptors. PMID:22992168

  14. Hematology and serum chemistries of nestling bald eagles (Haliaeetus leucocephalus) in the lower peninsula of MI, USA.

    PubMed

    Bowerman, W W; Stickle, J E; Giesy, J P

    2000-11-01

    Hematology constituents and serum biochemistries were determined in blood collected from 55 nestling bald eagles (Haliaeetus leucocephalus) from nest sites within the lower peninsula of Michigan in 1992. Hematological values were comparable to published ranges for birds for all but eosinophils, which were greater than normal. Serum chemistry values were similar to those of other birds for all but six parameters, uric acid, cholesterol, alkaline phosphatase, total protein, globulin, and urea nitrogen, which were greater and glucose which was less. Samples of blood collected from wild bald eagles can be used for hematologic parameters and serum chemistry. It is important for other studies of endangered species to obtain baseline data from healthy, wild animals in their natural environment, and for comparison of animals living in environments of greater exposure to those living in areas of lesser exposure to xenobiotics. We caution that arrangements for rapid analysis be done in advance of sample collection. PMID:11057684

  15. Columnar liquid crystals in cylindrical nanoconfinement.

    PubMed

    Zhang, Ruibin; Zeng, Xiangbing; Kim, Bongseock; Bushby, Richard J; Shin, Kyusoon; Baker, Patrick J; Percec, Virgil; Leowanawat, Pawaret; Ungar, Goran

    2015-02-24

    Axial orientation of discotic columnar liquid crystals in nanopores of inorganic templates, with the columns parallel to the axis of the nanochannels, is considered desirable for applications such as production of molecular wires. Here, we evaluate experimentally the role of the rigidity of the LC columns in achieving such orientation in nanopores where the planar anchoring (i.e., columns parallel to wall surface) is enforced. We studied the columnar phase of several discotic compounds with increasing column rigidity in the following order: dendronized carbazole, hexakis(hexyloxy)triphenylene (HAT6), a 1:1 HAT6-trinitrofluorenone (TNF) complex, and a helicene derivative. Using 2-D X-ray diffraction, AFM, grazing incidence diffraction, and polarized microscopy, we observed that the orientation of the columns changes from circular concentric to axial with increasing column rigidity. Additionally, when the rigidity is borderline, increasing pore diameter can change the configuration from axial back to circular. We derive expressions for distortion free energy that suggest that the orientation is determined by the competition between, on the one hand, the distortion energy of the 2-d lattice and the mismatch of its crystallographic facets with the curved pore wall in the axial orientation and, on the other hand, the bend energy of the columns in the circular configuration. Furthermore, the highly detailed AFM images of the core of the disclinations of strength +1 and +1/2 in the center of the pore reveal that the columns spiral down to the very center of the disclination and that there is no amorphous or misaligned region at the core, as suggested previously. PMID:25626118

  16. Modelling of Columnar-to-Equiaxed and Equiaxed-to- Columnar Transitions in Ingots Using a Multiphase Model

    NASA Astrophysics Data System (ADS)

    Leriche, N.; Combeau, H.; Gandin, Ch-A.; Založnik, M.

    2015-06-01

    We present a new method to handle a representative elementary volume (REV) with a mixture of columnar and equiaxed grains in ingot castings in the framework of an Eulerian volume averaged model. The multiscale model is based on a previously established fully equiaxed model. It consists of a three-phase (extra-granular liquid, intra-granular liquid and solid) grain-growth stage coupled with a two-phase (solid and liquid) macroscopic transport stage accounting for grain and nuclei movement. In this context, we take into account the formation of a columnar structure and its development using a simplified front-tracking method. Columnar solidification is coupled with the growth of equiaxed grains ahead of the columnar front. The particularity of the model is the treatment of concurrent growth of mixed columnar and equiaxed structures only in the volumes that contain the columnar front. Everywhere else, the structure is considered either fully columnar or fully equiaxed. This feature allows for reasonable computational times even in industrial size castings, while describing the solutal and mechanical blocking phenomena responsible for the Columnar-to-Equiaxed Transition. After a validation of the model, we discuss the numerical results for a 6.2-ton industrial steel ingot by comparison with experimental measurements. Final maps for macrosegregation and grain structures size and morphology are analysed. Furthermore, we quantify the impact of nuclei formation through fragmentation along the columnar front on the result. An attempt at predicting the occurrence of the Equiaxed-to-Columnar Transition in the later phases of the process is also made.

  17. Activities of wogonin analogs and other flavones against Flavobacterium columnare.

    PubMed

    Tan, Cheng-Xia; Schrader, Kevin K; Khan, Ikhlas A; Rimando, Agnes M

    2015-02-01

    In our on-going pursuit to discover natural products and natural product-based compounds to control the bacterial species Flavobacterium columnare, which causes columnaris disease in channel catfish (Ictalurus punctatus), we synthesized flavone and chalcone analogs, and evaluated these compounds, along with flavonoids from natural sources, for their antibacterial activities against two isolates of F. columnare (ALM-00-173 and BioMed) using a rapid bioassay. The flavonoids chrysin (1a), 5,7-dihydroxy-4'-methoxyflavone (11), isorhamnetin (26), luteolin (27), and biochanin A (29), and chalcone derivative 8b showed strong antibacterial activities against F. columnare ALM-00-173 based on minimum inhibition concentration (MIC) results. Flavonoids 1a, 8, 11, 13 (5,4'-dihydroxy-7-methoxyflavone), 26, and 29 exhibited strong antibacterial activities against F. columnare BioMed based upon MIC results. The 24-h 50% inhibition concentration (IC50 ) results revealed that 27 and 29 were the most active compounds against F. columnare ALM-00-173 (IC50 of 7.5 and 8.5 mg/l, resp.), while 26 and 29 were the most toxic compound against F. columnare BioMed (IC50 of 9.2 and 3.5 mg/l, resp.). These IC50 results were lower than those obtained for wogonin against F. columnare ALM-00-173 and F. columnare BioMed (28.4 and 5.4 mg/l, resp.). However, based on MIC results, none of the compounds evaluated in this study were as active as wogonin (MIC 0.3 mg/l for each F. columnare isolate). Further modification of the wogonin structure to enhance antibacterial is of interest. PMID:25676507

  18. Direct numerical simulation of flow past cactus--shaped cylinders

    NASA Astrophysics Data System (ADS)

    Babu, Pradeep; Mahesh, Krishnan

    2006-11-01

    The Saguaro cacti are tall, have short root systems and can withstand high wind velocities (Bulk 1984, Talley et al. 2002). Their trunks are essentially cylindrical with V--shaped longitudinal cavities. The size and number of cavities on the Saguaro cacti vary so that they have a near--constant fraction cavity depth (l/D ratio of about 0.07, Geller & Nobel 1984). Direct numerical simulations is used to assess the aerodynamic effect of the grooves on the cactus. DNS is performed for cactus shaped cylinders with l/d ratio's of 0.07 and 0.105, and smooth cylinders (l/d=0) at the same Reynolds number. Presence of the V--shaped cavities is found to decrease the drag on the cylindrical trunk as well as affect the fluctuating lift forces. The talk will quantify these differences, and discuss the physical mechanisms by which V--shaped cavities on the surface influence the flow.

  19. Search for Dark Matter Annihilations in Draco with CACTUS

    SciTech Connect

    Chertok, M.; Afonso, P.; Lizarazo, J.; Marleau, P.; Maruyama, S.; Stilley, J.; Tripathi, S. M.

    2006-07-11

    CACTUS is a ground-based Air Cherenkov Telescope (ACT) at the Solar 2 facility located near Barstow, California, and operated by UC Davis. It uses an array of 160 large solar tracking mirrors (heliostats) and a camera with 80 photomultiplier tubes, which, in a multiplexed fashion provides an effective camera with about 300 channels. By incorporating novel techniques of time projection imaging and triggering, CACTUS improves upon the first generation sampling arrays of its kind. We have recently completed observations of Draco, a dwarf spheroidal galaxy that is known to be rich in dark matter content. Supersymmetry-inspired models for dark matter predict observable annihilation rates producing gamma rays. We present the first results from our Draco campaign.

  20. The cuticle of the cactus Cereus peruvianus as a source of a homo-{alpha}-D-galacturonan

    SciTech Connect

    Alvarez, M.; Costa, S.C.; Huber, A.

    1995-12-31

    The waxy pecto-cellulosic cuticle of cladodes of the columnar cactus Cereus peruvianus (19% of the whole phytobiomass; dry wt) is a source of an {alpha}-D-polygalacturonic or pectic acid (35-40% yield, on a dry wt based on the wax-free pectocellulose layer). Warm EDTA/oxalate or room temperature strong acid/alkali cycles are efficient for pectic acid extraction, since divalent cation (mainly Ca{sup 2+}) is a barrier to be removed within the native and compact architecture of the cuticle. Despite some molecular dispersion arising from the application of strong mineral acid in the first extraction step, the pectic material appears to be quite homogeneous and, on acid or enzymatic analyses, was shown to contain only D-galacturonic acid as its monomer. Cereus cuticle pectate (sodium salt) tends to gel above a concentration of 1%, a useful property that can be more easily obtained by the inclusion of sucrose, light addition of calcium salt, and/or mild acidification.

  1. Differences between tangential geostrophy and columnar flow

    NASA Astrophysics Data System (ADS)

    Amit, Hagay; Pais, Maria Alexandra

    2013-07-01

    Core flows inverted from time-dependent geomagnetic field models image the geodynamo at the top of its generation region, the Earth's outer core. Physical assumptions incorporated in these inversions affect the resulting flows. Based on rapid rotation dominance, two assumptions similar in form yet different in essence have been proposed: tangential geostrophy (TG, LeMouël 1984) and columnar flow (CF, Amit & Olson 2004). We recall that CF is theoretically consistent with the quasi-geostrophy (QG) theory for an incompressible fluid with spherical solid boundaries whereas TG is not. As such, we highlight the importance of applying the CF assumption when inverting geomagnetic data for interior core (columnar) flows that can be used in kinematic dynamo and thermal convection models in the Boussinesq approximation. Next we evaluate the non-uniqueness associated with CF flows. The areas of ambiguous patches at the core surface where invisible TG or CF flows reside are roughly comparable. The spatial distribution of ambiguous patches for both TG and CF is quite asymmetric about the equator, so assuming equatorial symmetry is expected to reduce the non-uniqueness significantly. In fact, for assumed equatorial symmetry, the only possible non-unique flows will be those along hypothetical ζ-contours in the opposite hemispheres that their equatorial plane projections are parallel. TG flows exhibit a strong Atlantic/Pacific hemispheric dichotomy and a well-defined eccentric gyre whereas in CF flows the dichotomy between these two hemispheres is weaker and the gyre is less clear suggesting that the eccentric gyre might not conserve mass. Both TG and CF upwelling/downwelling patterns are strongly localized in the equatorial region. In addition, in both cases upwelling/downwelling is correlated with equatorward/poleward flow respectively, as expected for QG convection. CF upwelling is more intense than TG upwelling but the magnitude ratio is smaller than the factor 2

  2. The flow past a cactus-inspired grooved cylinder

    NASA Astrophysics Data System (ADS)

    El-Makdah, Adnan M.; Oweis, Ghanem F.

    2013-02-01

    The star-shaped cross section of giant cylindrical cactus plants is thought to be aerodynamically favorable for protection against toppling by strong winds. Particle image velocimetry is used to investigate the flow details within the surface grooves and in the immediate wake of a cactus-inspired model cylinder with eight longitudinal grooves, at biologically relevant Reynolds numbers between 50 × 103 and 170 × 103. The wake flow is analyzed and compared to a similarly sized circular cylinder. At the lowest Re tested, the wakes from the two geometries are similar. At higher Re, the cactus wake exhibits superior behavior as seen from the mean and turbulent velocities, suggesting that the flow mechanisms are Re dependent. The flow within the surface grooves reveals counter rotating rollers, while the geometrical ridges act as vortex generators known to help with the surface flow attachment. Lastly, a simplistic analysis is described to recover, qualitatively, certain time-dependent flow features from the randomly acquired PIV realizations.

  3. Corrective action investigation plan: Cactus Spring Waste Trenches. Revision 2

    SciTech Connect

    1997-02-01

    This Correction Action Investigation Plan (CAIP) contains environmental sample collection objectives and logic for the Corrective Action Unit No. 426, which includes the Cactus Spring Waste Trenches, located at the Tonopah Test Range. The purpose of this investigation is to generate sufficient data to establish the types of waste buried in the trenches, identify the presence and nature of contamination, determine the vertical extent of contaminant migration below the Cactus Spring Waste Trenches, and determine the appropriate course of action for the site. The potential courses of action for the site are clean closure, closure in place (with or without remediation), or no further action. The scope of this investigation will include drilling and collecting subsurface samples from within and below the trenches. Sampling locations will be biased toward the areas most likely to be contaminated. The Cactus Spring Waste Trenches Site is identified as one of three potential locations for buried, radioactively contaminated materials from the Double Tracks Test. This test was the first of four storage-transportation tests conducted in 1963 as part of Operation Roller Coaster. The experiment involved the use of live animals to assess the inhalation intake of a plutonium aerosol.

  4. miRNA expression during prickly pear cactus fruit development.

    PubMed

    Rosas-Cárdenas, Flor de Fátima; Caballero-Pérez, Juan; Gutiérrez-Ramos, Ximena; Marsch-Martínez, Nayelli; Cruz-Hernández, Andrés; de Folter, Stefan

    2015-02-01

    miRNAs are a class of small non-coding RNAs that regulate gene expression. They are involved in the control of many developmental processes, including fruit development. The increasing amount of information on miRNAs, on their expression, abundance, and conservation between various species, provides a new opportunity to study the role of miRNAs in non-model plant species. In this work, we used a combination of Northern blot and tissue print hybridization analysis to identify conserved miRNAs expressed during prickly pear cactus (Opuntia ficus indica) fruit development. Comparative profiling detected the expression of 34 miRNAs, which were clustered in three different groups that were associated with the different phases of fruit development. Variation in the level of miRNA expression was observed. Gradual expression increase of several miRNAs was observed during fruit development, including miR164. miR164 was selected for stem-loop RT-PCR and for a detailed spatial-temporal expression analysis. At early floral stages, miR164 was mainly localized in meristematic tissues, boundaries and fusion zones, while it was more homogenously expressed in fruit tissues. Our results provide the first evidence of miRNA expression in the prickly pear cactus and provide the basis for future research on miRNAs in Opuntia. Moreover, our analyses suggest that miR164 plays different roles during prickly pear cactus fruit development. PMID:25366556

  5. 75 FR 70897 - Notice of Request for Extension of Approval of an Information Collection; South American Cactus...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-11-19

    ... Collection; South American Cactus Moth; Quarantine and Regulations AGENCY: Animal and Plant Health Inspection... regulations for the interstate movement of regulated articles to prevent the spread of South American cactus... American cactus moth, contact Dr. Robyn Rose, Program Manager, Emergency and Domestic Programs, PPQ,...

  6. Vaccination of fish against Flavobacterium columnare and F. psychrophilum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are two primary Flavobacterium spp. involved in disease of aquaculture raised fish worldwide including, F. columnare, and F. psychrophilum; the etiologic agents of columnaris disease and bacterial coldwater disease (CWD) or rainbow trout fry syndrome (RTFS), respectively. Traditional vaccines...

  7. Water hardness influences Flavobacterium columnare pathogenesis in channel catfish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Studies were conducted to determine aspects of water chemistry responsible for large differences in pathogenesis and mortality rates in challenges of channel catfish Ictalurus punctatus with Flavobacterium columnare; challenges were conducted in water supplying the Stuttgart National Aquaculture Res...

  8. Differences between tangential geostrophy and columnar flow

    NASA Astrophysics Data System (ADS)

    Amit, H.; Pais, M. A.

    2012-12-01

    Core flows inverted from time-varying geomagnetic field models image the geodynamo at the top of its generation region, the Earth's outer core. Physical assumptions incorporated in these inversions may affect the resulting flows. Based on rapid rotation dominance, two assumptions similar in form yet different in essence were proposed: Tangential geostrophy (TG; LeMouël, 1984) and columnar flow (CF; Amit and Olson, 2004). We show that CF is theoretically consistent with the quasi-geostrophy theory for an incompressible fluid with spherical solid boundaries, whereas TG is not. The low-latitude ageostrophic belt associated with CF is broader than that associated with TG, but the global non-uniqueness reduction of TG and CF is roughly comparable. The spatial distribution of ambiguous patches for both TG and CF is quite asymmetric about the equator, so assuming equatorial symmetry may reduce the non-uniqueness significantly. TG flows exhibit a strong Atlantic/Pacific hemispheric dichotomy and a well-defined eccentric gyre, whereas in CF flows the dichotomy between these two hemispheres is weaker and the gyre is less clear, suggesting that the eccentric gyre might not conserve mass. Both TG and CF upwelling patterns are strongly localized in the equatorial region. In addition, in both TG and CF upwelling/downwelling is correlated with poleward/equatorward flow respectively. CF upwelling is more intense than TG upwelling, but the magnitude ratio is smaller than the expected value based on purely analytical arguments, perhaps indicating that the poloidal flow is constrained by the geomagnetic secular variation.

  9. Differences between tangential geostrophy and columnar flow

    NASA Astrophysics Data System (ADS)

    Amit, Hagay; Pais, M. Alexandra

    2013-04-01

    Core flows inverted from time-dependent geomagnetic field models image the geodynamo at the top of its generation region, the Earth's outer core. Physical assumptions incorporated in these inversions may affect the resulting flows. Based on rapid rotation dominance, two assumptions similar in form yet different in essence were proposed: Tangential geostrophy (TG, LeMouël, 1984) and columnar flow (CF, Amit and Olson, 2004). We show that CF is theoretically consistent with the quasi-geostrophy (QG) theory for an incompressible fluid with spherical solid boundaries, whereas TG is not. The areas of ambiguous patches at the core surface where invisible TG or CF flows reside are roughly comparable. The spatial distribution of ambiguous patches for both TG and CF is quite asymmetric about the equator, so assuming equatorial symmetry may hypothetically reduce the non-uniqueness significantly. TG flows exhibit a strong Atlantic/Pacific hemispheric dichotomy and a well-defined eccentric gyre, whereas in CF flows the dichotomy between these two hemispheres is weaker and the gyre is less clear, suggesting that the eccentric gyre might not conserve mass. Both TG and CF upwelling/downwelling patterns are strongly localized in the equatorial region. In addition, in both cases upwelling/downwelling is correlated with equatorward/poleward flow respectively, as expected for QG convection. CF upwelling is more intense than TG upwelling but the magnitude ratio is smaller than the factor 2 distinguishing the analytical expressions of the two assumptions due to the dominance of magnetic field advection by toroidal core flow in the geomagnetic secular variation.

  10. A rapid postmortem screening test for lead toxicosis in common loons (Gavia immer) and bald eagles (Haliaeetus leucocephalus).

    PubMed

    Kornetsky, Rachel; Rock, Meagan; Pokras, Mark

    2013-07-01

    In live animals, lead poisoning can be diagnosed by analyzing blood samples. For postmortem testing, blood samples are not available and analysis of liver or kidney is often used for diagnosis. Liver and kidney analysis is relatively expensive and results might not be quickly available. We examined an inexpensive, rapid method to screen animals for lead toxicosis postmortem by testing the mixture of body fluids (termed "tissue fluids") that pool in the body cavity at necropsy for lead. At necropsy we collected body fluid and liver samples from Common Loon (Gavia immer) and Bald Eagle (Haliaeetus leucocephalus) carcasses and determined concentrations of lead in tissue fluid using a desk-top blood lead analyzer. Concentrations of lead in liver were determined by inductively coupled plasma mass spectroscopy. There was strong correlation between tissue fluid and liver tissue lead concentrations, and receiver-operating characteristic analysis gave an area under the curve of 0.91, indicating that postmortem measurements of lead in tissue fluids can be utilized as a screening method for lead toxicosis. PMID:23778630

  11. Reference intervals, longitudinal analyses, and index of individuality of commonly measured laboratory variables in captive bald eagles (Haliaeetus leucocephalus).

    PubMed

    Jones, Michael P; Arheart, Kristopher L; Cray, Carolyn

    2014-06-01

    The objectives of this study were to determine reference intervals, perform longitudinal analyses, and determine the index of individuality (IoI) of 8 hematologic, and 13 biochemical and electrophoretic variables for a group of captive bald eagles (Haliaeetus leucocephalus). Reference intervals were determined from blood samples collected during annual wellness examinations for 41 eagles (23 male and 18 female) with ages ranging between 6 and 43 years (18.7 +/- 7.4, mean +/- SD) at the time of sample collection. Longitudinal analyses and IoI were determined for measured hematologic, biochemical, and protein electrophoretic variables, both individually and as a group, for a subset of 16 eagles (10 male and 6 female) during a 12-year period. This smaller group of eagles ranged in age between 2 and 20 years at the start of the study period, and between 14 and 32 years (21.9 +/- 5.0, mean +/- SD) at the end of the study period. Significant increases with age within the group of 16 eagles were observed only for red blood cells, percent heterophils, total protein, and beta-globulin protein fraction, while albumin:globulin decreased significantly with age. A low IoI (> or = 1.4) was determined for all hematologic and biochemical variables except gamma globulins, which had high IoI (< or = 0.6) for 3 individuals within the subset of 16. PMID:25115040

  12. Normal ocular parameters and characterization of ophthalmic lesions in a group of captive bald eagles (Haliaeetus leucocephalus).

    PubMed

    Kuhn, Sonia E; Jones, Michael P; Hendrix, Diane V H; Ward, Daniel A; Baine, Katherine H

    2013-06-01

    Sixteen adult captive bald eagles (Haliaeetus leucocephalus) underwent a complete bilateral ocular examination to assess normal ocular parameters and describe ophthalmic lesions. Tear production was measured with the Schirmer tear test 1 and intraocular pressure was measured with applanation tonometry. The menace response was normal bilaterally in 13 of 16 eagles. Two birds had normal menace responses despite having fundic lesions, and 2 birds with an inconsistent or absent menace response did not have appreciable ophthalmic lesions. Mean (SD) tear production was 14 +/- 2 mm/min (range, 8-19 mm/min). Mean intraocular pressure was 21.5 +/- 1.7 mm Hg (range, 15-26 mm Hg). At least 1 ocular lesion was present in 50% of examined eyes. Cataracts, the most common lesion observed, were present in 8 eyes of 5 birds. Three of 4 known geriatric birds were or had been affected with bilateral cataracts. Overall, ocular lesions are common in captive bald eagles, and cataracts appear to be more prevalent in geriatric bald eagles. An obvious positive menace response is present in most visual birds but may be absent in some eagles that are either normal or that do not have appreciable ophthalmic lesions. Applanation tonometry and the Schirmer tear test 1 can be performed easily on adult bald eagles and provide reproducible results. PMID:23971217

  13. Mercury residues in livers of bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada (1987-1994).

    PubMed

    Weech, S A; Wilson, L K; Langelier, K M; Elliott, J E

    2003-11-01

    Postmortem examinations were conducted on 82 bald eagles (Haliaeetus leucocephalus) found dead or dying in British Columbia, Canada, from 1987 to 1994. As part of the examination, livers were analyzed for total mercury (Hg) content, as well as methylmercury (meHg) and selenium (Se) in selected individuals. In total, 67 eagles were classed as having low Hg exposure [total Hg liver residues ranging from 0.5 to 17.2 mg/kg dry weight (dw)]. Fourteen eagles were moderately exposed (liver residues ranging from 19.2 to 36.8 mg/kg Hg dw). One eagle was judged to have died of Hg poisoning, with a total liver Hg content of 130.3 mg/kg dw, of which approximately 77% was meHg. The poisoned eagle and most of the exposed eagles were found in locations where effluent from pulp and paper processing plants is discharged along the British Columbia coast. In total, 6% of eagles examined died as a result of acute metal toxicosis (one from Hg poisoning, four from lead poisoning), in comparison to 72% dying from trauma (electrocution, vehicle/power line collision, eagle attack, trap, gunshot, drowning, and asphyxiation) and 11% from disease. The cause of death was undetermined in the remaining 11% of eagles. PMID:14708672

  14. Isolation of microsatellite loci and reliable genotyping using noninvasive samples of a critically endangered primate, Trachypithecus leucocephalus.

    PubMed

    Wang, Weiran; Qiao, Yu; Zheng, Yitao; Yao, Meng

    2016-07-01

    Genetic information can be critical in identifying conservation priorities and developing conservation strategies. There is an urgent need for noninvasive genetic tools to study the wild populations of Asian colobine monkeys. The majority of these species are threatened with habitat destruction, population reduction and even extinction, but generally lack information on their genetic diversity and population structure. Genetic sampling and tissue collection have been scarce in these species owing to strict regulations on manipulation of endangered species, and the difficulties and risks associated with capturing these arboreal and fast-moving monkeys in the challenging environments that they inhabit. These difficulties have hindered the development of molecular genetic markers, which are usually derived from tissues or blood. In this study, we present a method for de novo microsatellite isolation and genotyping using DNA from noninvasive origins of a critically endangered Asian colobine, the white-headed langur (Trachypithecus leucocephalus). Genomic DNA isolated from hair was shown to be sufficient for microsatellite enrichment and isolation, with similar isolation efficiencies as from tissue DNA. We identified and characterized 20 polymorphic microsatellite loci, and evaluated their amplification success and genotyping reliability with 86 field-collected fecal samples. These results show that this panel of loci can produce reliable genotypes from fecal samples, and represent a useful tool for noninvasive investigation of genetic structure, individual identification and kinship assessment in this highly endangered species. Our approach can be applied to conservation genetic studies of other wild species that lack sequence information and tissue samples. PMID:26889667

  15. IMMUNIZATION OF EYED CHANNEL CATFISH, ICTALURUS PUNCTATUS, EGGS WITH MONOVALENT FLAVOBACTERIUM COLUMNARE VACCINE AND BIVALENT F. COLUMNARE AND EDWARDSIELLA ICTALURI VACCINE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The efficacy of a modified live monovalent Flavobacterium columnare vaccine and bivalent F. columnare and Edwardsiella ictaluri vaccines were evaluated following immersion vaccination of eyed channel catfish (Ictalurus punctatus) eggs. The modified live F. columnare vaccine was grown in modified Sh...

  16. Introduced and invasive cactus species: a global review.

    PubMed

    Novoa, Ana; Le Roux, Johannes J; Robertson, Mark P; Wilson, John R U; Richardson, David M

    2014-01-01

    Understanding which species are introduced and become invasive, and why, are central questions in invasion science. Comparative studies on model taxa have provided important insights, but much more needs to be done to unravel the context dependencies of these findings. The cactus family (Cactaceae), one of the most popular horticultural plant groups, is an interesting case study. Hundreds of cactus species have been introduced outside their native ranges; a few of them are among the most damaging invasive plant species in the world. We reviewed the drivers of introductions and invasions in the family and seek insights that can be used to minimize future risks. We compiled a list of species in the family and determined which have been recorded as invasive. We also mapped current global distributions and modelled the potential global distributions based on distribution data of known invasive taxa. Finally, we identified whether invasiveness is phylogenetically clustered for cacti and whether particular traits are correlated with invasiveness. Only 57 of the 1922 cactus species recognized in this treatment have been recorded as invasive. There are three invasion hotspots: South Africa (35 invasive species recorded), Australia (26 species) and Spain (24 species). However, there are large areas of the world with climates suitable for cacti that are at risk of future invasion-in particular, parts of China, eastern Asia and central Africa. The invasive taxa represent an interesting subset of the total species pool. There is a significant phylogenetic signal: invasive species occur in 2 of the 3 major phylogenetic clades and in 13 of the 130 genera. This phylogenetic signal is not driven by human preference, i.e. horticultural trade, but all invasive species are from 5 of the 12 cactus growth forms. Finally, invasive species tend to have significantly larger native ranges than non-invasive species, and none of the invasive species are of conservation concern in their

  17. Introduced and invasive cactus species: a global review

    PubMed Central

    Novoa, Ana; Le Roux, Johannes J.; Robertson, Mark P.; Wilson, John R.U.; Richardson, David M.

    2015-01-01

    Understanding which species are introduced and become invasive, and why, are central questions in invasion science. Comparative studies on model taxa have provided important insights, but much more needs to be done to unravel the context dependencies of these findings. The cactus family (Cactaceae), one of the most popular horticultural plant groups, is an interesting case study. Hundreds of cactus species have been introduced outside their native ranges; a few of them are among the most damaging invasive plant species in the world. We reviewed the drivers of introductions and invasions in the family and seek insights that can be used to minimize future risks. We compiled a list of species in the family and determined which have been recorded as invasive. We also mapped current global distributions and modelled the potential global distributions based on distribution data of known invasive taxa. Finally, we identified whether invasiveness is phylogenetically clustered for cacti and whether particular traits are correlated with invasiveness. Only 57 of the 1922 cactus species recognized in this treatment have been recorded as invasive. There are three invasion hotspots: South Africa (35 invasive species recorded), Australia (26 species) and Spain (24 species). However, there are large areas of the world with climates suitable for cacti that are at risk of future invasion—in particular, parts of China, eastern Asia and central Africa. The invasive taxa represent an interesting subset of the total species pool. There is a significant phylogenetic signal: invasive species occur in 2 of the 3 major phylogenetic clades and in 13 of the 130 genera. This phylogenetic signal is not driven by human preference, i.e. horticultural trade, but all invasive species are from 5 of the 12 cactus growth forms. Finally, invasive species tend to have significantly larger native ranges than non-invasive species, and none of the invasive species are of conservation concern in their

  18. Field Survey of Cactus Crater Storage Facility (Runit Dome)

    SciTech Connect

    Douglas Miller, Terence Holland

    2008-10-31

    The US Department of Energy, Office of Health and Safety (DOE/HS-10), requested that National Security Technologies, LLC, Environmental Management directorate (NSTec/EM) perform a field survey of the Cactus Crater Storage Facility (Runit Dome), similar to past surveys conducted at their request. This field survey was conducted in conjunction with a Lawrence Livermore National Laboratory (LLNL) mission on Runit Island in the Enewetak Atoll in the Republic of the Marshall Islands (RMI). The survey was strictly a visual survey, backed up by digital photos and a written description of the current condition.

  19. Error-correcting code on a cactus: A solvable model

    NASA Astrophysics Data System (ADS)

    Vicente, R.; Saad, D.; Kabashima, Y.

    2000-09-01

    An exact solution to a family of parity check error-correcting codes is provided by mapping the problem onto a Husimi cactus. The solution obtained in the thermodynamic limit recovers the replica-symmetric theory results and provides a very good approximation to finite systems of moderate size. The probability propagation decoding algorithm emerges naturally from the analysis. A phase transition between decoding success and failure phases is found to coincide with an information-theoretic upper bound. The method is employed to compare Gallager and MN codes.

  20. Experimental investigation of the scaling of columnar joints.

    PubMed

    Goehring, Lucas; Morris, Stephen W; Lin, Zhenquan

    2006-09-01

    Columnar jointing is a fracture pattern common in igneous rocks in which cracks self-organize into a roughly hexagonal arrangement, leaving behind an ordered colonnade. We report observations of columnar jointing in a laboratory analog system, desiccated corn starch slurries. Using measurements of moisture density, evaporation rates, and fracture advance rates as evidence, we suggest that an advective-diffusive system is responsible for the rough scaling behavior of columnar joints. This theory explains the order of magnitude difference in scales between jointing in lavas and in starches. We investigated the scaling of average columnar cross-sectional areas due to the evaporation rate, the analog of the cooling rate of igneous columnar joints. We measured column areas in experiments where the evaporation rate depended on lamp height and time, in experiments where the evaporation rate was fixed using feedback methods, and in experiments where gelatin was added to vary the rheology of the starch. Our results suggest that the column area at a particular depth is related to both the current conditions, and hysteretically to the geometry of the pattern at previous depths. We argue that there exists a range of stable column scales allowed for any particular evaporation rate. PMID:17025716

  1. Radiating columnar joints in Gyeongju, Korea as a educational site

    NASA Astrophysics Data System (ADS)

    Woo, H.; Kim, J. H.; Jang, Y. D.

    2015-12-01

    Gyeongju is located in the central eastern part of South Korea. There are various directional columnar joint sets in Tertiary trachytic basalt formation along the shore. In particular, rare radiating columnar joints occur in this area. Columnar joints are parallel, prismatic columns that are formed as a result of contraction during the rapid cooling of lava flow, forming a three dimensional fracture network. In general, the radius and direction of the rock column represent the cooling rate and surface respectively. Radiating direction of columns here indicates that dome- or lobe-shaped lava was cooled from its surface to the core during the viscous lava flow. The fact that the trachytic textures of plagioclase laths are indistinct suggests that the radiating columnar joints are equivalent to the frontal end of the lava lobes. This area is currently has a shore trail course, which is being developed into a picturesque educational park. There are corresponding information boards on the trail near each type of columnar joints to explain not only the forming process and geological mechanisms but the importance of nature conservation to visitors, especially students. A variety of educational materials and educational programs linked to regular school curriculum are also being developed.

  2. Betalain, Acid Ascorbic, Phenolic Contents and Antioxidant Properties of Purple, Red, Yellow and White Cactus Pears

    PubMed Central

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R2 = 0.90) and ascorbic acid (R2 = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

  3. Betalain, Acid ascorbic, phenolic contents and antioxidant properties of purple, red, yellow and white cactus pears.

    PubMed

    Sumaya-Martínez, María Teresa; Cruz-Jaime, Sandra; Madrigal-Santillán, Eduardo; García-Paredes, Juan Diego; Cariño-Cortés, Raquel; Cruz-Cansino, Nelly; Valadez-Vega, Carmen; Martinez-Cardenas, Leonardo; Alanís-García, Ernesto

    2011-01-01

    Commercialization of cactus pears based on their antioxidant properties can generate competitive advantages, and these can turn into business opportunities and the development of new products and a high-value ingredient for the food industry. This work evaluated the antioxidant activities (1,1-diphenyl-2-picrylhydrazyl radical-scavenging, protection against oxidation of a β-carotene-linoleic acid emulsion, and iron (II) chelation), the content of total phenolic compounds, ascorbic acid, betacyanin, betaxanthin and the stability of betacyanin pigments in presence of Cu (II)-dependent hydroxyl radicals (OH•), in 18 cultivars of purple, red, yellow and white cactus pear from six Mexican states. Our results indicated that the antiradical activities from yellow and white cactus pear cultivars were not significantly different (p < 0.05) and were lower than the average antiradical activities in red and purple cultivars. The red cactus pear from the state of Zacatecas showed the highest antioxidant activity. The free radical scavenging activity for red cactus pears was significantly correlated (p < 0.05) to the concentration of total phenolic compounds (R(2) = 0.90) and ascorbic acid (R(2) = 0.86). All 18 cultivars of cactus pears studied showed significant chelating activity of ferrous ions. The red and purple cactus pears showed a great stability when exposed to OH•. PMID:22072899

  4. Calpain A modulates Toll responses by limited Cactus/IκB proteolysis

    PubMed Central

    Fontenele, Marcio; Lim, Bomyi; Oliveira, Danielle; Buffolo, Márcio; Perlman, David H.; Schupbach, Trudi; Araujo, Helena

    2013-01-01

    Calcium-dependent cysteine proteases of the calpain family are modulatory proteases that cleave their substrates in a limited manner. Among their substrates, calpains target vertebrate and invertebrate IκB proteins. Because proteolysis by calpains potentially generates novel protein functions, it is important to understand how this affects NFκB activity. We investigate the action of Calpain A (CalpA) on the Drosophila melanogaster IκB homologue Cactus in vivo. CalpA alters the absolute amounts of Cactus protein. Our data indicate, however, that CalpA uses additional mechanisms to regulate NFκB function. We provide evidence that CalpA interacts physically with Cactus, recognizing a Cactus pool that is not bound to Dorsal, a fly NFκB/Rel homologue. We show that proteolytic cleavage by CalpA generates Cactus fragments lacking an N-terminal region required for Toll responsiveness. These fragments are generated in vivo and display properties distinct from those of full-length Cactus. We propose that CalpA targets free Cactus, which is incorporated into and modulates Toll-responsive complexes in the embryo and immune system. PMID:23864715

  5. Columnar versus smectic order in systems of charged colloidal rods

    NASA Astrophysics Data System (ADS)

    Wensink, H. H.

    2007-05-01

    We study the stability of inhomogeneous liquid crystalline states in systems of monodisperse, stiff, charged rods. By means of a bifurcation analysis applied to the Onsager free energy for charged rods in strongly nematic states, we investigate nematic-smectic and nematic-columnar instabilities as a function of the Debye screening length κ-1. While the nematic-smectic transition clearly preempts the nematic-columnar one in the regime of strong screening (i.e., small κ-1) a marked stability of hexagonal columnar order is observed at larger screening lengths. The theoretical results are substantiated by Brownian dynamics computer simulation results based on the Yukawa site model. Our connect to experiments on tobacco mosaic virus rods, in particular, but might be relevant for soft rodlike mesogens in strong external directional fields in general.

  6. Anchoring transition in confined discotic columnar liquid crystal films

    NASA Astrophysics Data System (ADS)

    Brunet, Thomas; Thiebaut, Olivier; Charlet, Émilie; Bock, Harald; Kelber, Julien; Grelet, Éric

    2011-01-01

    We report the achievement of ultrathin films (down to 25 nm thick) of thermotropic columnar liquid crystals in homeotropic alignment (columns normal to the interface) confined between a glass slide and a thin metallic electrode (about 150 nm thick). The face-on orientation of the discotic compound is obtained by anchoring transition of a columnar liquid crystalline phase from a degenerate planar orientation to the homeotropic alignment without any phase transition to the isotropic liquid phase. The kinetic dependence on temperature of such anchoring transition is investigated revealing various diffusive growth regimes of the homeotropic domains. Finally, confining effects are also considered by varying the thickness of the columnar liquid crystal film to reach the typical value required in organic solar cells thus demonstrating the reliability of such alignment process in a photovoltaic context.

  7. COLUMNAR ORGANIZATION OF SPATIAL PHASE IN VISUAL CORTEX

    PubMed Central

    Wang, Yushi; Jin, Jianzhong; Kremkow, Jens; Lashgari, Reza; Komban, Stanley J.; Alonso, Jose M.

    2014-01-01

    Images are processed in the primary visual cortex by neurons that encode different stimulus orientations and spatial phases. In primates and carnivores, neighboring cortical neurons share similar orientation preferences but spatial phases were thought to be randomly distributed. Here we reveal a columnar organization for spatial phase in cats that shares resemblances with the columnar organization for orientation. For both orientation and phase, the mean difference across vertically aligned neurons was less than 1/4 of a cycle. Cortical neurons showed three times more diversity in phase than orientation preference, however, the average phase of local neuronal populations was similar through the depth of layer 4. We conclude that columnar organization for visual space is not only defined by the spatial location of the stimulus but also by absolute phase. Taken together with previous studies, our results suggest that this phase-visuotopy is responsible for the emergence of orientation maps. PMID:25420070

  8. Biological effects of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls in bald eagle (Haliaeetus leucocephalus) chicks

    SciTech Connect

    Elliott, J.E. |; Norstrom, R.J.; Lorenzen, A.; Kennedy, S.W.; Hart, L.E.; Bellward, G.D.; Cheng, K.M.; Philibert, H.; Stegeman, J.J.

    1996-05-01

    During the 1992 breeding season, eggs of bald eagles (Haliaeetus leucocephalus) were collected within a gradient of exposure to chlorinated hydrocarbon pollutants on the southern coast of British Columbia. Twenty-five eggs were placed in a laboratory incubator, of which 18 hatched; chicks were sacrificed within 24 h. Hatching success was not significantly different between eggs taken from pulp mill sites and reference sites. A hepatic cytochrome P4501A (CYP1A) cross-reactive protein was induced nearly sixfold in chicks from near a pulp mill at Powell River compared to those from a reference site. Hepatic ethoxyresorufin-O-deethylase (EROD) and benzyloxyresorufin O-dealkylase (BROD) activities were also significantly elevated in chicks from nests located near pulp mills compared to reference sites. A hepatic CYP2B cross-reactive protein was threefold higher in chicks from pulp mill versus reference sites, but the difference was not significant. Residual yolk sacs of eggs collected near pulp mill sites contained greater concentrations of 2,3,7,8-substituted polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) compared to reference areas. No significant differences in concentrations of polychlorinated biphenyls (PCBs), non-ortho congeners, and organochlorine pesticides occurred among sites. Regressions showed that the hepatic CYP1A cross-reactive protein and EROD and BROD activities were positively correlated with 2,3,7,8-TCDD, 2,3,7,8-TCDF, and toxic equivalents (TEQs{sub WHO}--World Health Organization toxic equivalence factors) in yolk sacs. No significant concentration-related effects were found for morphological, physiological, or histological parameters, such as chick growth, edema, or density of thymic lymphocytes. Using hepatic CYP1A induction as a biomarker, a no-observed-effect-level of 100 ng/kg and a lowest-observed-effect-level of 210 ng/kg TEQs{sub WHO} on a whole egg (wet weight basis) are suggested for bald eagle chicks.

  9. Relationships among mercury, selenium, and neurochemical parameters in common loons (Gavia immer) and bald eagles (Haliaeetus leucocephalus).

    PubMed

    Scheuhammer, A M; Basu, N; Burgess, N M; Elliott, J E; Campbell, G D; Wayland, M; Champoux, L; Rodrigue, J

    2008-02-01

    Fish-eating birds can be exposed to levels of dietary methylmercury (MeHg) known or suspected to adversely affect normal behavior and reproduction, but little is known regarding Hg's subtle effects on the avian brain. In the current study, we explored relationships among Hg, Se, and neurochemical receptors and enzymes in two fish-eating birds--common loons (Gavia immer) and bald eagles (Haliaeetus leucocephalus). In liver, both species demonstrated a wide range of total Hg (THg) concentrations, substantial demethylation of MeHg, and a co-accumulation of Hg and Se. In liver, there were molar excesses of Se over Hg up to about 50-60 microg/g THg, above which there was an approximate 1:1 molar ratio of Hg:Se in both species. However, in brain, bald eagles displayed a greater apparent ability to demethylate MeHg than common loons. There were molar excesses of Se over Hg in brains of bald eagles across the full range of THg concentrations, whereas common loons often had extreme molar excesses of Hg in their brains, with a higher proportion of THg remaining as MeHg compared with eagles. There were significant positive correlations between brain THg and muscarinic cholinergic receptor concentrations in both species studied; whereas significant negative correlations were observed between N-methyl-D-aspartic acid (NMDA) receptor levels and brain Hg concentration. There were no significant correlations between brain Se and neurochemical receptors or enzymes (cholinesterase and monoamine oxidase) in either species. Our findings suggest that there are significant differences between common loons and bald eagles with respect to cerebral metabolism and toxicodynamics of MeHg and Se. These interspecies differences may influence relative susceptibility to MeHg toxicity; however, neurochemical responses to Hg in both species were similar. PMID:17899374

  10. Brominated flame retardants and halogenated phenolic compounds in North American west coast bald eaglet (Haliaeetus leucocephalus) plasma.

    PubMed

    McKinney, Melissa A; Cesh, Lillian S; Elliott, John E; Williams, Tony D; Garcelon, David K; Letcher, Robert J

    2006-10-15

    We report on the identity, characterization, and spatial trends of several brominated flame retardants and hydroxylated (OH-) and methoxylated (MeO-) organohalogen contaminants in bald eagle (Haliaeetus leucocephalus) nestling plasma collected from sites along the west coast of North America. Samples were from four southwestern British Columbia (BC) locations, a reference site in northern BC (Fort St. James; FSJ), and from Santa Catalina Island, CA (SCI), an area of high DDT and PCB contamination. Mean concentrations of sigma polybrominated diphenyl ether (sigma PBDE (8 congeners monitored); 1.78-8.49 ng/g), sigma OH-polychlorinated biphenyl (sigma OH-PCB (30 congeners monitored); 0.44-0.87 ng/g), and sigma OH-PBDE (14 congeners monitored; 0.31-0.92 ng/g) were similar in eaglets from southwestern BC yet lower than for SCl and significantly higher than for FSJ. Dominant PBDE congeners were BDE47, BDE99, and BDE100, but SCl eaglets also contained low levels of higher brominated congeners. 4-OH-CB187 and 4'-OH-CB202 accounted for 65-100% of sigma OH-PCB in all BC eaglets, with 4'-OH-CB202 as well as 3'-OH-CB138 and 4-OH-CB146 dominating in SCl eaglets. Ostensibly of biogenic origin, 6'-OH-BDE49 and 6-OH-BDE47 were found in BC nestlings. Only 4'-OH-BDE49 (2.10 ng/g) was found in SCl eaglets. MeO-PBDEs and total hexabromocyclododecane (HBCD) were not found in any birds, but the polybrominated biphenyl BB101 was detected in southwestern BC samples. This study demonstrates that west coast North American bald eagles contain previously unreported organohalogens, which have the potential to impact the health and survival of these raptors. PMID:17120553

  11. Hepatic polybrominated diphenyl ether (PBDE) levels in Wisconsin river otters (Lontra canadensis) and Michigan bald eagles (Haliaeetus leucocephalus)

    PubMed Central

    Dornbos, Peter; Chernyak, Sergei; Rutkiewicz, Jennifer; Cooley, Thomas; Strom, Sean; Batterman, Stuart; Basu, Niladri

    2015-01-01

    Polybrominated diphenyl ethers (PBDEs) are persistent and toxic flame-retardant chemicals widespread in the Great Lakes ecosystem. These chemicals are now being regulated and phased-out of the region; therefore it remains important to understand the extent of contamination in order to track the efficacy of recent actions. Here, Σ4PBDE congeners (PBDE-47, 99, 100, 153;wetweight basis unless indicated)were determined in liver tissues from Wisconsin river otters (Lontra canadensis; n = 35; 2009–2010) and Michigan bald eagles (Haliaeetus leucocephalus; n = 33; 2009–2011). In otters, Σ4PBDE ranged from0.5 to 72.9 ng/g, with a mean (±SD) and median (25th–75th percentile inter-quartile range) of 16.3 ± 16.4 ng/g and 11.3 (5.6–18.9) ng/g, respectively. The mean lipid-adjusted Σ4PBDE was 1377 ± 1485 ng/g. In eagles, Σ4PBDE ranged from 0 to 1,538.8 ng/g, with a mean and median of 74.3 ± 266.7 ng/g and 21.2 (5.7–28.9) ng/g, respectively. The mean lipid-adjusted Σ4PBDE was 5274.5 ± 19,896.1 ng/g. In both species, PBDE-47 accounted for >50% of the Σ4PBDE, followed by PBDE-99 and PBDE-100 (each ~17–19% of the total). The PBDE levels reported here in otters are similar to mammalian wildlife elsewhere, though the levels in eagles are among the highest worldwide across studied birds. The findings indicate that apex Great Lakes wildlife remain exposed to appreciable levels of PBDEs and more work is needed to understand whether such exposures are associated with adverse health outcomes. PMID:25745277

  12. The population dynamics of an endemic collectible cactus

    NASA Astrophysics Data System (ADS)

    Mandujano, María C.; Bravo, Yolotzin; Verhulst, Johannes; Carrillo-Angeles, Israel; Golubov, Jordan

    2015-02-01

    Astrophytum is one of most collected genera in the cactus family. Around the world several species are maintained in collections and yearly, several plants are taken from their natural habitats. Populations of Astorphytum capricorne are found in the northern Chihuahuan desert, Mexico, and as many endemic cactus species, it has a highly restricted habitat. We conducted a demographic study from 2008 to 2010 of the northern populations found at Cuatro Ciénegas, Mexico. We applied matrix population models, included simulations, life table response experiments and descriptions of the population dynamics to evaluate the current status of the species, and detect key life table stages and demographic processes. Population growth rate decreased in both years and only 4% individual mortality can be attributed to looting, and a massive effort is needed to increase seedling recruitment and reduce adult mortality. The fate of individuals differed between years even having the same annual rainfall mainly in accentuated stasis, retrogression and high mortality in all size classes, which coupled with low seed production, no recruitment and collection of plants are the causes contributing to population decline, and hence, increase the risk in which A. capricorne populations are found. Reintroduction of seedlings and lowering adult mortality are urgently needed to revert the alarming demographic condition of A. capricorne populations.

  13. Trail Marking by Larvae of the Cactus Moth, Cactoblastis cactorum

    PubMed Central

    Fitzgerald, Terrence D.; Wolfin, Michael; Rossi, Frank; Carpenter, James E.; Pescador-Rubio, Alfonso

    2014-01-01

    The cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae), spends most of its larval life feeding within the cladodes of Opuntia cactuses, but the gregarious caterpillars begin their life outside the plant, and in the later instars make intermittent excursions over plant surfaces to access new cladodes and to thermoregulate. The study reported here showed that when the caterpillars move en masse, they mark and follow trails that serve to keep the cohort together. Artificial trails prepared from hexane extracts of the caterpillar's paired mandibular glands were readily followed by the caterpillars. The glands are remarkably large, and their fluid contents, which constitute approximately 1% of the total wet mass of a caterpillar, are secreted onto the substrate as they move. Although the caterpillars also lay down copious quantities of silk, the material in itself neither elicits trail following nor is it a requisite component of pathways that elicit trail following. Previous analyses of the mandibular glands of other species of pyralid caterpillars showed that they contain a series of structurally distinct 2-acyl-1,3 cyclohexane diones. Chemical analysis indicates that the glands of C. cactorum contain structurally similar compounds, and bioassays indicate that trail following occurs in response to these chemicals. While the mandibular glands' fluids have been shown to act as semiochemicals, effecting both interspecific and intraspecific behavior in other species of pyralids, the present study is the first to report their use as a trail pheromone. PMID:25373211

  14. Columnar jointing pattern: characterization and interpretation

    NASA Astrophysics Data System (ADS)

    Hetényi, György; Garel, Fanny; Médard, Etienne; Taisne, Benoît.; Mattsson, Hannes B.; Bosshard, Sonja

    2010-05-01

    Columnar Jointing (CJ) is commonly observed in slowly cooling lava bodies. The characteristic diameter of the columns is thought to depend on the cooling rate, faster (respectively slower) cooling resulting in larger (smaller) thermo-elastic strain yielding more slender (stout) columns. One of the goals of our CJ project is to analyse whether the characteristic diameter of the columns is also dependent on other factors, such as the chemical composition of the lava and the setting of the cooling lava body. While the laboratory measurements are finished and the bibliography compiled, we present our field measurements including photos, methods and first results. In order to compare different CJ sites, we develop a procedure to quantitatively characterize the columns. On the field, we collect photos with a well visible scale, either perpendicular or parallel to the columns. Then we use a self-developed, interactive software that processes the photos and performs statistical analyses on the average length of a side (L), on the average cross-sectional area (A), and on the number of sides of columns (N). Using these values, the parabolic relation between A and L2 is determined as a function of N, and compared to ideal polygons. Data from 25 sites across Europe show that the observed areas are smaller than those of the ideal polygons by about 7%. To be able to use photos taken from the side, we calculate the ratios of the distance to the 2nd and 3rd vertices to L, again as a function of N. The averages of these ratios are as those of ideal polygons, but their standard deviations suggest that the geometry of individual column cross-sections is anisotropic in a random direction. This explanation also underlines the previous result of smaller areas compared to ideal, and suggests that for a given area, the total length of joints is not fully minimized. This is in line with earlier and also present observations that the average number of sides at any CJ site is less than 6

  15. Use of a locking compression plate as an external fixator for repair of a tarsometatarsal fracture in a bald eagle (Haliaeetus leucocephalus).

    PubMed

    Montgomery, Ronald D; Crandall, Elizabeth; Bellah, Jamie R

    2011-06-01

    We describe the successful treatment of a tarsometatarsal fracture in a mature bald eagle (Haliaeetus leucocephalus) using a locking compression plate as an external fixator. The anatomy of the area (inelastic dermis and minimal subcutaneous space) and the high forces placed on a fracture at that site necessitated a unique approach to fixation. The unconventional use of a locking compression plate as an external fixator was minimally invasive, well tolerated by the eagle, and provided adequate stability in opposing fracture forces. This technique may serve as a method of fixation for tarsometatarsal fractures in other large avian species. PMID:21877449

  16. Plant population and habitat characteristics of the endemic Sonoran Desert cactus Peniocereus striatus in Organ Pipe Cactus National Monument, Arizona

    USGS Publications Warehouse

    Anderson, Greta; Rutman, Sue; Munson, Seth M.

    2010-01-01

    Peniocereus striatus (Brandegee) Buxb. (Cactaceae) is an endemic Sonoran Desert cactus that reaches its northern range limit in southwestern Arizona. One U.S. population occupies a small area of Organ Pipe Cactus National Monument near the U.S./Mexico international boundary, which has been monitored since 1939. An extensive survey conducted in 2002, covering 177 ha, resulted in the discovery of 88 new plants, in addition to the relocation of 57 plants found in previous surveys. Despite potential increases in population size and spatial distribution, mean plant height and number of basal stems has not significantly changed in recent years. Bud scars revealed that a majority of the population was sexually mature. Peniocereus striatus occurrence increased with decreasing slope, spanned every slope aspect, and was highest on rocky soils, but was noticeably low on west and northwest slopes and areas where severe land degradation had previously occurred. Over half of P. striatus plants were nursed by shrubs and subshrubs, while 40% occurred under leguminous trees. A severe frost in January 2002 top-killed 19% of the population, with the greatest damage in drainage bottoms. However, long-term (1944–2002) climate records show that there has been an overall increase in the number of frost free days in the region, which, coupled with land use change, has implications for the future health of this population.

  17. Genome Sequence of the Fish Pathogen Flavobacterium columnare Genomovar II Strain 94-081

    PubMed Central

    Kumru, Salih; Tekedar, Hasan C.; Waldbieser, Geoffrey C.

    2016-01-01

    Flavobacterium columnare causes columnaris disease in fresh and brackish water worldwide. F. columnare strain 94-081 was isolated from a diseased channel catfish in 1994; its genome sequence is the first completed genomovar II sequence. PMID:27231366

  18. Genome Sequence of the Fish Pathogen Flavobacterium columnare Genomovar II Strain 94-081.

    PubMed

    Kumru, Salih; Tekedar, Hasan C; Waldbieser, Geoffrey C; Karsi, Attila; Lawrence, Mark L

    2016-01-01

    Flavobacterium columnare causes columnaris disease in fresh and brackish water worldwide. F. columnare strain 94-081 was isolated from a diseased channel catfish in 1994; its genome sequence is the first completed genomovar II sequence. PMID:27231366

  19. Effect of ultrasound on survival and growth of Escherichia coli in cactus pear juice during storage.

    PubMed

    Cruz-Cansino, Nelly Del Socorro; Reyes-Hernández, Isidro; Delgado-Olivares, Luis; Jaramillo-Bustos, Diana Pamela; Ariza-Ortega, José Alberto; Ramírez-Moreno, Esther

    2016-01-01

    The aim of this study was to investigate the effectiveness of ultrasound as a conservation method for the inactivation of Escherichia coli inoculated into cactus pear juices (green and purple). Total soluble solids, pH, titratable acidity, and the kinetics of E. coli in cactus pear juices treated by ultrasound (60%, 70%, 80% and 90% amplitude levels for 1, 3 and 5min) were evaluated over 5 days. Total inactivation was observed in both fruit juices after 5min of ultrasound treatment at most amplitude levels (with the exception of 60% and 80%). After one and two days of storage, the recovery of bacteria counts was observed in all cactus pear juices. Ultrasound treatment at 90% amplitude for 5min resulted in non-detectable levels of E. coli in cactus pear juice for 2 days. The parameters of pH, titratable acidity and soluble solids were unaffected. PMID:26991288

  20. Physicochemical characterization of cactus pads from Opuntia dillenii and Opuntia ficus indica.

    PubMed

    Méndez, Lorena Pérez; Flores, Fidel Tejera; Martín, Jacinto Darias; Rodríguez Rodríguez, Elena M; Díaz Romero, Carlos

    2015-12-01

    Physicochemical characteristics (weight, length, width, thickness, moisture, Brix degree, total fiber, protein, ash, pH, acidity, ascorbic acid, total phenolic compounds, P, Na, K, Ca, Mg, Fe, Cu, Zn, Mn and Cr) were determined in cactus pads from Opuntia dillenii and Opuntia ficus indica. The physicochemical characteristics of both species were clearly different. There were important differences between the orange and green fruit pulp of O. ficus indica; the cactus pads of O. dillenii could be differentiated according to the region (North and South). Consumption of cactus pads contributes to the intake of dietary fiber, total phenolic compounds, K, Mg, Mn and Cr. Applying factor and/or discriminant analysis, the cactus pad samples were clearly differentiated according to the species, the fruit pulp color and production region. PMID:26041209

  1. Seasonal photosynthetic gas exchange and water-use efficiency in a constitutive CAM plant, the giant saguaro cactus (Carnegiea gigantea).

    PubMed

    Bronson, Dustin R; English, Nathan B; Dettman, David L; Williams, David G

    2011-11-01

    Crassulacean acid metabolism (CAM) and the capacity to store large quantities of water are thought to confer high water use efficiency (WUE) and survival of succulent plants in warm desert environments. Yet the highly variable precipitation, temperature and humidity conditions in these environments likely have unique impacts on underlying processes regulating photosynthetic gas exchange and WUE, limiting our ability to predict growth and survival responses of desert CAM plants to climate change. We monitored net CO(2) assimilation (A(net)), stomatal conductance (g(s)), and transpiration (E) rates periodically over 2 years in a natural population of the giant columnar cactus Carnegiea gigantea (saguaro) near Tucson, Arizona USA to investigate environmental and physiological controls over carbon gain and water loss in this ecologically important plant. We hypothesized that seasonal changes in daily integrated water use efficiency (WUE(day)) in this constitutive CAM species would be driven largely by stomatal regulation of nighttime transpiration and CO(2) uptake responding to shifts in nighttime air temperature and humidity. The lowest WUE(day) occurred during time periods with extreme high and low air vapor pressure deficit (D(a)). The diurnal with the highest D(a) had low WUE(day) due to minimal net carbon gain across the 24 h period. Low WUE(day) was also observed under conditions of low D(a); however, it was due to significant transpiration losses. Gas exchange measurements on potted saguaro plants exposed to experimental changes in D(a) confirmed the relationship between D(a) and g(s). Our results suggest that climatic changes involving shifts in air temperature and humidity will have large impacts on the water and carbon economy of the giant saguaro and potentially other succulent CAM plants of warm desert environments. PMID:21822726

  2. Investigations of electromagnetic scattering by columnar ice crystals

    NASA Technical Reports Server (NTRS)

    Weil, H.; Senior, T. B. A.

    1976-01-01

    An integral equation approach was developed to determine the scattering and absorption of electromagnetic radiation by thin walled cylinders of arbitrary cross-section and refractive index. Based on this method, extensive numerical data was presented at infrared wavelengths for hollow hexagonal cross section cylinders which simulate columnar sheath ice crystals.

  3. Columnar organization of orientation domains in V1

    NASA Astrophysics Data System (ADS)

    Liedtke, Joscha; Wolf, Fred

    In the primary visual cortex (V1) of primates and carnivores, the functional architecture of basic stimulus selectivities appears similar across cortical layers (Hubel & Wiesel, 1962) justifying the use of two-dimensional cortical models and disregarding organization in the third dimension. Here we show theoretically that already small deviations from an exact columnar organization lead to non-trivial three-dimensional functional structures. We extend two-dimensional random field models (Schnabel et al., 2007) to a three-dimensional cortex by keeping a typical scale in each layer and introducing a correlation length in the third, columnar dimension. We examine in detail the three-dimensional functional architecture for different cortical geometries with different columnar correlation lengths. We find that (i) topological defect lines are generally curved and (ii) for large cortical curvatures closed loops and reconnecting topological defect lines appear. This theory extends the class of random field models by introducing a columnar dimension and provides a systematic statistical assessment of the three-dimensional functional architecture of V1 (see also (Tanaka et al., 2011)).

  4. DIFFERENTIAL GENE EXPRESSION OF PUTATIVE VIRULENCE GENES IN Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A shot-gun genomic library of the Flavobacterium columnare ALG-530 virulent strain has been constructed and more than 3,000 clones have been sequenced to date (800 contigs). Based on sequence identity with putative known virulence genes from related species, seven genes were selected for differentia...

  5. Chemotactic response of Flavobacterium columnare to channel catfish mucus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research has demonstrated that genomovar II Flavobacterium columnare isolates are more pathogenic for channel catfish (Ictalurus punctatus) and have a higher capacity for adhesion than genomovar I isolates. To begin to define the basis for this, the objectives of the present study were to determine...

  6. Antibacterial activity of acylglucinol derivatives against Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Columnaris disease is one of the most common bacterial diseases of pond-raised channel catfish (Ictalurus punctatus) in the southeastern United States of America. The Gram-negative, rod-shaped bacterium Flavobacterium columnare is the cause of columnaris disease. Direct economic losses to catfish pr...

  7. Activities of wogonin analogs and other flavones against Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In our continuing pursuit to discover natural products and natural product-based compounds for the control of the bacterial species Flavobacterium columnare which causes columnaris disease in channel catfish (Ictalurus punctatus), we synthesized eighteen flavone and three chalcone analogues and thes...

  8. Ungeremine and its hemisynthetic analogues as bactericides against Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Gram-negative bacterium Flavobacterium columunare is the cause of colmunaris disease in channel catfish (Ictalurus punctatus). In a previous study, the betaine-type alkaloid ungeremine, 1 obtained from Pancratium maritimum L. was found to have strong antibacterial activity against F. columnare. ...

  9. Parasitism by Ich enhanced susceptibility of tilapia to Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In aquaculture systems, fish are commonly infected by two or more pathogens. Bacterium Flavobacterium columnare and parasite Ichthyophthirius multifiliis (Ich) are two common pathogens of cultured fish and result in heavy economic losses for aquaculture. There is no published information available ...

  10. Research on non-direct reflection columnar microstructure

    NASA Astrophysics Data System (ADS)

    Wu, B. Q.; Wang, X. Z.; Dong, L. H.

    2015-10-01

    To minimize the risk of laser accidents, especially those involving eye and skin injuries, it is crucial to pay more attention to laser safety. To control the risk of injury, depending on the laser power and wavelength, a number of required safety measures have been put forward, such as specific protection walls, and wearing safety goggles when operating lasers. The direct reflection columnar microstructure can also be used for laser safety. Based on mathematical foundations , a columnar microstructure is designed by the optical design software LightTools. Simulation showed that there is a tilt angle between the emergent and incident light, the incident light being perpendicular to the microstructure, as well as the phenomenon of no direct reflection happened. A novel testing platform was built for the columnar microstructure after it was machined. The applied testing method can measure the angle between the emergent and incident light. The method lays the condition for the further research. It is shown that the columnar microstructure with no direct reflection can be utilized in laser protection systems.

  11. Alcohol dehydrogenase polymorphism in barrel cactus populations of Drosophila mojavensis.

    PubMed

    Cleland, S; Hocutt, G D; Breitmeyer, C M; Markow, T A; Pfeiler, E

    1996-07-01

    Starch gel electrophoresis revealed that the alcohol dehydrogenase (ADH-2) locus was polymorphic in two populations (from Agua Caliente, California and the Grand Canyon, Arizona) of cactophilic Drosophila mojavensis that utilize barrel cactus (Ferocactus acanthodes) as a host plant. Electromorphs representing products of a slow (S) and a fast (F) allele were found in adult flies. The frequency of the slow allele was 0.448 in flies from Agua Caliente and 0.659 in flies from the Grand Canyon. These frequencies were intermediate to those of the low (Baja California peninsula, Mexico) and high (Sonora, Mexico and southern Arizona) frequency Adh-2S populations of D. mojavensis that utilize different species of host cacti. PMID:8765684

  12. Shock-induced effects in calcite from Cactus Crater

    NASA Technical Reports Server (NTRS)

    Vizgirda, J.; Ahrens, T. J.; Tsay, F.-D.

    1980-01-01

    The paper discusses shock metamorphism of calcite from coralline limestone samples retrieved from a borehole drilled into rocks beneath Cactus Crater, a nuclear explosion crater at Eniwetok Atoll. The metamorphism was detected and quantified using electron spin resonance (ESR); the ESR spectra of Mn(+) present as a trace constituent in the coral samples, show a consistent decrease in hyperfine peak splitting with decreasing depth of sample. It is suggested that the decrease in hyperfine peak splitting reflects a decrease in crystal field splitting, and therefore, small increases on cation-anion distances produced by mechanical energy input during the shock process. Two alternative crater models suggested by the ESR results are a depiction of a steady decay of the shock wave, and a delineation of a breccia lens with a breccia-bedrock interface at 20 plus or minus 5 m.

  13. Epizootic vacuolar myelinopathy of the central nervous system of bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana)

    USGS Publications Warehouse

    Thomas, N.J.; Meteyer, C.U.; Sileo, L.

    1998-01-01

    Unprecedented mortality occurred in bald eagles (Haliaeetus leucocephalus) at DeGray Lake, Arkansas, during the winters of 1994-1995 and 1996-1997. The first eagles were found dead during November, soon after arrival from fall migration, and deaths continued into January during both episodes. In total, 29 eagles died at or near DeGray Lake in the winter of 1994-1995 and 26 died in the winter of 1996-1997; no eagle mortality was noted during the same months of the intervening winter or in the earlier history of the lake. During the mortality events, sick eagles were observed overflying perches or colliding with rock walls. Signs of incoordination and limb paresis were also observed in American coots (Fulica americana) during the episodes of eagle mortality, but mortality in coots was minimal. No consistent abnormalities were seen on gross necropsy of either species. No microscopic findings in organs other than the central nervous system (CNS) could explain the cause of death. By light microscopy, all 26 eagles examined and 62/77 (81%) coots had striking, diffuse, spongy degeneration of the white matter of the CNS. Vacuolation occurred in all myelinated CNS tissue, including the cerebellar folia and medulla oblongata, but was most prominent in the optic tectum. In the spinal cord, vacuoles were concentrated near the gray matter, and occasional swollen axons were seen. Vacuoles were uniformly present in optic nerves but were not evident in the retina or peripheral or autonomic nerves. Cellular inflammatory response to the lesion was distinctly lacking. Vacuoles were 8-50 microns in diameter and occurred individually, in clusters, or in rows. In sections stained by luxol fast blue/periodic acid-Schiff stain, the vacuoles were delimited and transected by myelin strands. Transmission electron microscopy revealed intramyelinic vacuoles formed in the myelin sheaths by splitting of one or more myelin lamellae at the intraperiodic line. This lesion is characteristic of

  14. Epizootic vacuolar myelinopathy of the central nervous system of bald eagles (Haliaeetus leucocephalus) and American coots (Fulica americana).

    PubMed

    Thomas, N J; Meteyer, C U; Sileo, L

    1998-11-01

    Unprecedented mortality occurred in bald eagles (Haliaeetus leucocephalus) at DeGray Lake, Arkansas, during the winters of 1994-1995 and 1996-1997. The first eagles were found dead during November, soon after arrival from fall migration, and deaths continued into January during both episodes. In total, 29 eagles died at or near DeGray Lake in the winter of 1994-1995 and 26 died in the winter of 1996-1997; no eagle mortality was noted during the same months of the intervening winter or in the earlier history of the lake. During the mortality events, sick eagles were observed overflying perches or colliding with rock walls. Signs of incoordination and limb paresis were also observed in American coots (Fulica americana) during the episodes of eagle mortality, but mortality in coots was minimal. No consistent abnormalities were seen on gross necropsy of either species. No microscopic findings in organs other than the central nervous system (CNS) could explain the cause of death. By light microscopy, all 26 eagles examined and 62/77 (81%) coots had striking, diffuse, spongy degeneration of the white matter of the CNS. Vacuolation occurred in all myelinated CNS tissue, including the cerebellar folia and medulla oblongata, but was most prominent in the optic tectum. In the spinal cord, vacuoles were concentrated near the gray matter, and occasional swollen axons were seen. Vacuoles were uniformly present in optic nerves but were not evident in the retina or peripheral or autonomic nerves. Cellular inflammatory response to the lesion was distinctly lacking. Vacuoles were 8-50 microns in diameter and occurred individually, in clusters, or in rows. In sections stained by luxol fast blue/periodic acid-Schiff stain, the vacuoles were delimited and transected by myelin strands. Transmission electron microscopy revealed intramyelinic vacuoles formed in the myelin sheaths by splitting of one or more myelin lamellae at the intraperiodic line. This lesion is characteristic of

  15. Columnar mesophases of hexabenzocoronene derivatives. II. Charge carrier mobility.

    PubMed

    Kirkpatrick, James; Marcon, Valentina; Kremer, Kurt; Nelson, Jenny; Andrienko, Denis

    2008-09-01

    Combining atomistic molecular dynamic simulations, Marcus-Hush theory description of charge transport rates, and master equation description of charge dynamics, we correlate the temperature-driven change of the mesophase structure with the change of charge carrier mobilities in columnar phases of hexabenzocoronene derivatives. The time dependence of fluctuations in transfer integrals shows that static disorder is predominant in determining charge transport characteristics. Both site energies and transfer integrals are distributed because of disorder in the molecular arrangement. It is shown that the contributions to the site energies from polarization and electrostatic effects are of opposite sign for positive charges. We look at three mesophases of hexabenzocoronene: herringbone, discotic, and columnar disordered. All results are compared to time resolved microwave conductivity data and show excellent agreement with no fitting parameters. PMID:19044876

  16. Columnar grown copper films on polyimides strained beyond 100.

    PubMed

    Sun, Jeong-Yun; Lee, Hae-Ryung; Oh, Kyu Hwan

    2015-01-01

    Many flexible electronic devices contain metal films on polymer substrates to satisfy requirements for both electrical conductivity and mechanical durability. Despite numerous trials to date, the stretchability of metal interconnects remains an issue. In this paper, we have demonstrated a stretchable metal interconnect through control of the texture of a copper film with columnar grown grains on a polyimide (PI) substrate. The columnar grown copper films (CGC films) were deposited by regulating radio frequency (RF) sputtering powers. CGC films were able to sustain their electrical conductivity at strains above 100%. Instead of ultimate electrical discontinuity by channel crack propagation, CGC films maintained their conductivity by forming ligament structures, or a 'conductive net,' through trapped micro-cracks. XRD, AFM and in situ SEM analysis were used to investigate these stretchable conductors. PMID:26337668

  17. Columnar grown copper films on polyimides strained beyond 100%

    PubMed Central

    Sun, Jeong-Yun; Lee, Hae-Ryung; Hwan Oh, Kyu

    2015-01-01

    Many flexible electronic devices contain metal films on polymer substrates to satisfy requirements for both electrical conductivity and mechanical durability. Despite numerous trials to date, the stretchability of metal interconnects remains an issue. In this paper, we have demonstrated a stretchable metal interconnect through control of the texture of a copper film with columnar grown grains on a polyimide (PI) substrate. The columnar grown copper films (CGC films) were deposited by regulating radio frequency (RF) sputtering powers. CGC films were able to sustain their electrical conductivity at strains above 100%. Instead of ultimate electrical discontinuity by channel crack propagation, CGC films maintained their conductivity by forming ligament structures, or a ‘conductive net,’ through trapped micro-cracks. XRD, AFM and in situ SEM analysis were used to investigate these stretchable conductors. PMID:26337668

  18. Columnar grown copper films on polyimides strained beyond 100%

    NASA Astrophysics Data System (ADS)

    Sun, Jeong-Yun; Lee, Hae-Ryung; Hwan Oh, Kyu

    2015-09-01

    Many flexible electronic devices contain metal films on polymer substrates to satisfy requirements for both electrical conductivity and mechanical durability. Despite numerous trials to date, the stretchability of metal interconnects remains an issue. In this paper, we have demonstrated a stretchable metal interconnect through control of the texture of a copper film with columnar grown grains on a polyimide (PI) substrate. The columnar grown copper films (CGC films) were deposited by regulating radio frequency (RF) sputtering powers. CGC films were able to sustain their electrical conductivity at strains above 100%. Instead of ultimate electrical discontinuity by channel crack propagation, CGC films maintained their conductivity by forming ligament structures, or a ‘conductive net,’ through trapped micro-cracks. XRD, AFM and in situ SEM analysis were used to investigate these stretchable conductors.

  19. Quantum depinning of flux lines from columnar defects

    SciTech Connect

    Chudnovsky, E.M. ); Ferrera, A.; Vilenkin, A. )

    1995-01-01

    The depinning of a flux line from a columnar defect is studied within the path-integral approach. Instantons of the quantum field theory in 1+1 dimensions are computed for the flux line whose dynamics is dominated by the Magnus force. The universal temperature dependence of the decay rate in the proximity of the critical current is obtained. This problem provides an example of macroscopic quantum tunneling, which is accessible to the direct comparison between theory and experiment.

  20. Form Birefringence in Thin Films with Oblique Columnar Structures

    NASA Astrophysics Data System (ADS)

    Wang, Jian-Guo; Shao, Jian-Da; Wang, Su-Mei; He, Hong-Bo; Fan, Zheng-Xiu

    2005-08-01

    Effective medium theory is useful for designing optical elements with form birefringent subwavelength structures. Thin films fabricated by oblique deposition are similar to the two-dimensional surface relief subwavelength gratings. We use the effective medium theory to calculate the anisotropic optical properties of the thin films with oblique columnar structures. The effective refractive indices and the directions are calculated from effective medium theory. It is shown that optical thin films with predetermined refractive indices and birefringence may be engineered.

  1. An international cooperative effort to protect Opuntia cactus resources in the American Southwest and Mexico from the South American cactus moth, Cactoblastis cactorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The South American Cactus moth, Cactoblastis cactorum, was intentionally introduced to an island in the Caribbean in the 1950’s and eventually made its way to the Florida peninsula by 1989. In 2004, the United States Department of Agriculture’s (USDA) Animal and Plant Health Inspection Service (APH...

  2. Virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss.

    PubMed

    Evenhuis, Jason P; LaFrentz, Benjamin R

    2016-08-01

    Flavobacterium columnare is the causative agent of columnaris disease and is responsible for significant economic losses in aquaculture. F. columnare is a Gram-negative bacterium, and 5 genetic types or genomovars have been described based on restriction fragment length polymorphism of the 16S rRNA gene. Previous research has suggested that genomovar II isolates are more virulent than genomovar I isolates to multiple species of fish, including rainbow trout Oncorhynchus mykiss. In addition, improved genotyping methods have shown that some isolates previously classified as genomovar I, and used in challenge experiments, were in fact genomovar III. Our objective was to confirm previous results with respect to genomovar II virulence, and to determine the susceptibility of rainbow trout to other genomovars. The virulence of 8 genomovar I, 4 genomovar II, 3 genomovar II-B, and 5 genomovar III isolates originating from various sources was determined through 3 independent challenges in rainbow trout using an immersion challenge model. Mean cumulative percent mortality (CPM) of ~49% for genomovar I isolates, ~1% for genomovar II, ~5% for the II-B isolates, and ~7% for the III isolates was observed. The inability of genomovar II isolates to produce mortalities in rainbow trout was unanticipated based on previous studies, but may be due to a number of factors including rainbow trout source and water chemistry. The source of fish and/or the presence of sub-optimal environment may influence the susceptibility of rainbow trout to different F. columnare genomovars. PMID:27503917

  3. The cactus webworm, Loxomorpha flavidissimalis (Grote, 1878) (Pyraloidea, Crambidae): its distribution and a potential pest in Mexico

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We report Loxomorpha flavidissimalis, the cactus webworm, for the first time from Tamaulipas, Mexico, as an herbivore of the cultivated cactus, Opuntia ficus-indica. We observed larvae over a four year period (2010-2014) during the months of March to November and found young cladode losses attributa...

  4. Revealing the elusive sex pheromone of the renowned cactus moth, Cactoblastis cactorum (Lepidoptera:Pyralidae): A tribute to Robert Heath

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The South American cactus moth, Cactoblastis cactorum (Berg.) (Lepidoptera: Pyralidae), became famous as a biocontrol agent during campaigns in Australia and South Africa to control exotic weedy Opuntia spp. During these campaigns, monitoring the impact and success of the cactus moth did not requir...

  5. 77 FR 26000 - Cactus Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF ENERGY Federal Energy Regulatory Commission Cactus Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing...-referenced proceeding of Cactus Energy LLC's application for market-based rate authority, with...

  6. Effects of ultrasound treatment in purple cactus pear (Opuntia ficus-indica) juice.

    PubMed

    Zafra-Rojas, Quinatzin Yadira; Cruz-Cansino, Nelly; Ramírez-Moreno, Esther; Delgado-Olivares, Luis; Villanueva-Sánchez, Javier; Alanís-García, Ernesto

    2013-09-01

    Cactus pear (Opuntia ficus-indica) fruit is a berry with a tasty pulp full of seeds that constitutes about 10-15% of the edible pulp. In Mexico, cactus pear is mainly consumed fresh, but also has the potential to be processed in other products such as juice. The objective of this study was to evaluate the effect of different ultrasound conditions at amplitude levels ranging (40% and 60% for 10, 15, 25 min; 80% for 3, 5, 8, 10, 15 and 25 min) on the characteristics of purple cactus pear juice. The evaluated parameters were related with the quality (stability, °Brix, pH), microbial growth, total phenolic compounds, ascorbic acid and antioxidant activity (ABTS, DPPH and % chelating activity) of purple cactus pear juices. The ultrasound treatment for time period of 15 and 25 min significantly reduced the microbial count in 15 and 25 min, without affecting the juice quality and its antioxidant properties. Juice treated at 80% of amplitude level showed an increased of antioxidant compounds. Our results demonstrated that sonication is a suitable technique for cactus pear processing. This technology allows the achievement of juice safety and quality standards without compromising the retention of antioxidant compounds. PMID:23545106

  7. Integrating the Forensic Sciences in Wildlife Case Investigations: A Case Report of Pentobarbital and Phenytoin Toxicosis in a Bald Eagle (Haliaeetus leucocephalus).

    PubMed

    Viner, T C; Hamlin, B C; McClure, P J; Yates, B C

    2016-09-01

    The application of medical knowledge to the purpose of law is the foundation of forensic pathology. A forensic postmortem examination often involves the expertise of multiple scientific disciplines to reconstruct the full story surrounding the death of an animal. Wildlife poses additional challenges in forensic investigations due to little or no associated history, and the disruptive effects of decomposition. To illustrate the multidisciplinary nature of wildlife forensic medicine, the authors outline a case of secondary pentobarbital/phenytoin toxicosis in a bald eagle (Haliaeetus leucocephalus). The eagle was the single fatality in a group of 8 birds that fed on euthanized domestic cat remains that had been improperly disposed of in a landfill. Cooperation between responding law enforcement officers, pathologists, and other forensic scientists led to the successful diagnosis and resolution of the case. PMID:27030371

  8. Phytochemicals, nutritionals and antioxidant properties of two prickly pear cactus cultivars (Opuntia ficus indica Mill.) growing in Taif, KSA.

    PubMed

    Abdel-Hameed, El-Sayed S; Nagaty, Mohamed A; Salman, Mahmood S; Bazaid, Salih A

    2014-10-01

    The antioxidant properties, some phytochemicals and nutritionals were characterized in two prickly pear cactus (Opuntia ficus indica Mill.) cultivars; red and yellow; growing in Taif, Kingdom of Saudi Arabia (KSA). The antioxidant properties of red cactus cultivar were higher than the yellow cactus cultivar. Linear correlation appeared between the antioxidant properties and total phenolics. All samples nearly have the same quantity of iron, copper, sodium and potassium. Some phenolic compounds were detected by HPLC-UV analysis. HPLC-RI analysis of all samples revealed the absence of sucrose and the presence of glucose and fructose. According to the above results, this study gave a good indication about the nutritional and pharmaceutical potential of the two cactus cultivars that must be widespread cultivated in arid and semiarid regions as KSA accompanying with establishment of industries beside the cactus farms that used all parts of plants. PMID:24799205

  9. Agglomerative percolation on the Bethe lattice and the triangular cactus

    NASA Astrophysics Data System (ADS)

    Chae, Huiseung; Yook, Soon-Hyung; Kim, Yup

    2013-08-01

    Agglomerative percolation (AP) on the Bethe lattice and the triangular cactus is studied to establish the exact mean-field theory for AP. Using the self-consistent simulation method based on the exact self-consistent equations, the order parameter P∞ and the average cluster size S are measured. From the measured P∞ and S, the critical exponents βk and γk for k = 2 and 3 are evaluated. Here, βk and γk are the critical exponents for P∞ and S when the growth of clusters spontaneously breaks the Zk symmetry of the k-partite graph. The obtained values are β2 = 1.79(3), γ2 = 0.88(1), β3 = 1.35(5) and γ3 = 0.94(2). By comparing these exponents with those for ordinary percolation (β∞ = 1 and γ∞ = 1), we also find β∞ < β3 < β2 and γ∞ > γ3 > γ2. These results quantitatively verify the conjecture that the AP model belongs to a new universality class if the Zk symmetry is broken spontaneously, and the new universality class depends on k.

  10. Acoustic emissions correlated with hydration of Saguaro Cactus

    NASA Astrophysics Data System (ADS)

    Wardell, L. J.; Rowe, C. A.

    2013-12-01

    For some years it has been demonstrated that hardwood trees produce acoustic emissions during periods of drought, which arise from cavitation in the xylem as water is withdrawn. These emissions not only provide insights into the fluid transport behavior within these trees, but also the degree to which cavitation can proceed before inevitable tree mortality. Such studies can have significant impact on our understanding of forest die-off in the face of climate change. Plant mortality is not limited to woody trees, however, and it is not only the coniferous and deciduous forests whose response to climate and rainfall changes are important. In the desert Southwest we observe changes to survival rates of numerous species of flora. One of the most conspicuous of these plants is the iconic Saguaro Cactus (Carnegiea gigantean). These behemoths of the Sonoran Desert are very sensitive to small perturbations in their environment. Specifically, during the summer monsoon season when the cacti become well-hydrated, they can absorb hundreds of gallons of water within a very short time frame. We have obtained a juvenile saguaro on which we are conducting experiments to monitor acoustic emissions during hydration and dessication cycles. We will report on our observations obtained using piezoelectric ceramic accelerometers whose signals are digitized up to 44 Khz and recorded during hydration.

  11. Acoustic emissions correlated with hydration of Saguaro Cactus

    NASA Astrophysics Data System (ADS)

    Wardell, L. J.; Rowe, C. A.

    2012-12-01

    For some years it has been demonstrated that hardwood trees produce acoustic emissions during periods of drought, which arise from cavitation in the xylem as water is withdrawn. These emissions not only provide insights into the fluid transport behavior within these trees, but also the degree to which cavitation can proceed before inevitable tree mortality. Such studies can have significant impact on our understanding of forest die-off in the face of climate change. Plant mortality is not limited to woody trees, however, and it is not only the coniferous and deciduous forests whose response to climate and rainfall changes are important. In the desert Southwest we observe changes to survival rates of numerous species of flora. One of the most conspicuous of these plants is the iconic Saguaro Cactus (Carnegiea gigantean). These behemoths of the Sonoran Desert are very sensitive to small perturbations in their environment. Specifically, during the summer monsoon season when the cacti become well-hydrated, they can absorb hundreds of gallons of water within a very short time frame. We have obtained a juvenile saguaro on which we are conducting experiments to monitor acoustic emissions during hydration and dessication cycles. We will report on our observations obtained using piezoelectric ceramic accelerometers whose signals are digitized up to 44 Khz and recorded during hydration.

  12. Soil compaction vulnerability at Organ Pipe Cactus National Monument, Arizona

    USGS Publications Warehouse

    Webb, Robert H.; Nussear, Kenneth E.; Carmichael, Shinji; Esque, Todd C.

    2014-01-01

    Compaction vulnerability of different types of soils by hikers and vehicles is poorly known, particularly for soils of arid and semiarid regions. Engineering analyses have long shown that poorly sorted soils (for example, sandy loams) compact to high densities, whereas well-sorted soils (for example, eolian sand) do not compact, and high gravel content may reduce compaction. Organ Pipe Cactus National Monument (ORPI) in southwestern Arizona, is affected greatly by illicit activities associated with the United States–Mexico border, and has many soils that resource managers consider to be highly vulnerable to compaction. Using geospatial soils data for ORPI, compaction vulnerability was estimated qualitatively based on the amount of gravel and the degree of sorting of sand and finer particles. To test this qualitative assessment, soil samples were collected from 48 sites across all soil map units, and undisturbed bulk densities were measured. A scoring system was used to create a vulnerability index for soils on the basis of particle-size sorting, soil properties derived from Proctor compaction analyses, and the field undisturbed bulk densities. The results of the laboratory analyses indicated that the qualitative assessments of soil compaction vulnerability underestimated the area of high vulnerability soils by 73 percent. The results showed that compaction vulnerability of desert soils, such as those at ORPI, can be quantified using laboratory tests and evaluated using geographic information system analyses, providing a management tool that managers potentially could use to inform decisions about activities that reduce this type of soil disruption in protected areas.

  13. A multi-structural and multi-functional integrated fog collection system in cactus

    PubMed Central

    Ju, Jie; Bai, Hao; Zheng, Yongmei; Zhao, Tianyi; Fang, Ruochen; Jiang, Lei

    2012-01-01

    Multiple biological structures have demonstrated fog collection abilities, such as beetle backs with bumps and spider silks with periodic spindle-knots and joints. Many Cactaceae species live in arid environments and are extremely drought-tolerant. Here we report that one of the survival systems of the cactus Opuntia microdasys lies in its efficient fog collection system. This unique system is composed of well-distributed clusters of conical spines and trichomes on the cactus stem; each spine contains three integrated parts that have different roles in the fog collection process according to their surface structural features. The gradient of the Laplace pressure, the gradient of the surface-free energy and multi-function integration endow the cactus with an efficient fog collection system. Investigations of the structure–function relationship in this system may help us to design novel materials and devices to collect water from fog with high efficiencies. PMID:23212376

  14. Construction of two selectable markers for integrative/conjugative plasmids in Flavobacterium columnare

    NASA Astrophysics Data System (ADS)

    Zhang, Jin; Zou, Hong; Wang, Liangfa; Huang, Bei; Li, Nan; Wang, Guitang; Nie, Pin

    2012-03-01

    Flavobacterium columnare, the etiological agent of columnaris disease, is one of the most important and widespread bacterial pathogens of freshwater fish. In this study, we constructed two artificial selectable markers (chloramphenicol and spectinomycin resistance) for gene transfer in F. columnare. These two new artificial selectable markers, which were created by placing the chloramphenicol or spectinomycin resistance gene under the control of the native acs regulatory region of F. columnare, were functional in both F. columnare and Escherichia coli. The integrative/conjugative plasmids constructed by using these markers were introduced into F. columnare G4 via electroporation or conjugation. The integrated plasmid DNA was confirmed by Southern blotting and PCR analysis. These two markers can be employed in future investigations into gene deletion and the pathogenicity of virulence factors in F. columnare.

  15. Unravelling columnar joints temperatures: a thermo-mechanical experimental approach

    NASA Astrophysics Data System (ADS)

    Lavallée, Yan; Lamur, Anthony; Iddon, Fiona E.; Kendrick, Jackie E.; Hornby, Adrian J.; Eggertson, Gudjon H.; Von Aulock, Felix W.; Wadsworth, Fabian B.

    2016-04-01

    Columnar joints are a widespread, spectacular volcanic phenomenon representing a complex cracking pattern induced by contraction of the lava upon cooling. The hexagonal geometry results from the complex interaction between heat dissipation, contraction and tensile fracturing of the material. While the formation mechanism is nowadays fairly well constrained, very little is known on the temperature at which these features form. Here, we present the results of a novel type of thermo-mechanical experiment, in which the ends of 16 mm rods of basalt were locked into position during cooling at different rates. We monitored the stress build-up and temperature within the samples in order to constrain the temperature of columnar jointing. Our experiments were applied to basaltic rocks sampled on a lava flow at the base of Eyjafjallajoküll volcano in Iceland. Results demonstrate that thermal contraction upon cooling triggers microscopic fracturing (at ~820 °C) that quickly evolves into localised macroscopic fracturing at 750-780 °C. Striaes observed along fracture planes can hence be interpreted as the reflection of this two-stage fracture propagation dynamics. We emphasize that columnar jointing occurs well within the solid state of volcanic rocks, not in a molten regime. These results are supported by complementary analysis of the expansion coefficient of these lavas as well as strain-to-failure acquired during Brazilian tensile tests. The nonlinearity of the coefficient of expansion has important implications for the development of a permeable network. At higher temperatures, micro-fracturing is caused by a quasi-linear coefficient of expansion, leading to a small increase in permeability. As cooling occurs, the coefficient of expansion drops increasingly rapidly, leading to an increasingly faster developing permeable network, which is controlled in-part by the scale of the columns that influences crack aperture opening. Our findings hence have implications in volcanic

  16. Cortisol directly impacts Flavobacterium columnare in vitro growth characteristics.

    PubMed

    Declercq, Annelies Maria; Aerts, Johan; Ampe, Bart; Haesebrouck, Freddy; De Saeger, Sarah; Decostere, Annemie

    2016-01-01

    Teleost fish faced with stressful stimuli launch an endocrine stress response through activation of the hypothalamic-pituitary-interrenal axis to release glucocorticoids, in particular cortisol, into the blood. For the majority of bacterial fish pathogens, stress is considered a key factor in disease outbreaks. Based upon studies in mammals, there is considerable evidence to suggest that, besides impairing the immune system, cortisol can have a direct effect on bacterial cells. Hitherto, this intriguing field of microbial endocrinology has remained largely unexplored in aquatic diseases. The present study investigated in vitro the impact of cortisol on phenotypic traits of the fresh water fish pathogen Flavobacterium columnare. Colonies obtained from the highly virulent (HV) isolates resulted in significantly larger and more spreading colonies compared to those from the low virulent (LV) isolates. High cortisol doses added displayed a direct effect on the bacterial cells and induced a significant decrease in colony size. An additional intriguing finding was the inverse relationship between cortisol concentrations added to the broth and the spreading character of colonies retrieved, with higher cortisol doses resulting in less rhizoid to rough and even smooth colony formation (the latter only in the LV trout isolate), suggesting a dose-response effect. The loss of the rhizoid appearance of the F. columnare colonies upon administration of cortisol, and hence the loss of motility, might indicate a phenotypic change to the biofilm state. These findings form the basis for further research on the impact of glucocorticoids on other virulence factors and biofilm formation of F. columnare. PMID:27530746

  17. Architecture of Columnar Nacre, and Implications for Its Formation Mechanism

    SciTech Connect

    Metzler, Rebecca A.; Olabisi, Ronke M.; Coppersmith, Susan N.; Gilbert, P. U. P. A.; Abrecht, Mike; Frazer, Bradley H.; Ariosa, Daniel; Johnson, Christopher J.

    2007-06-29

    We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation's polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers.

  18. Architecture of Columnar Nacre, and Implications for Its Formation Mechanism

    NASA Astrophysics Data System (ADS)

    Metzler, Rebecca A.; Abrecht, Mike; Olabisi, Ronke M.; Ariosa, Daniel; Johnson, Christopher J.; Frazer, Bradley H.; Coppersmith, Susan N.; Gilbert, P. U. P. A.

    2007-06-01

    We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation’s polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers.

  19. Waves on a columnar vortex in a strongly stratified fluid

    NASA Astrophysics Data System (ADS)

    Billant, Paul; Le Dizès, Stéphane

    2009-10-01

    This paper investigates the discrete bounded waves sustained by a vertical columnar Rankine vortex in a strongly stratified fluid. We show that these waves are very different from their well-known counterpart in homogeneous fluid (Kelvin vortex waves); they exist only for nonzero azimuthal wavenumber m, their frequency lies in the interval [0,mΩ] (Ω is the angular velocity in the vortex core) and they are unstable because of an outward radiation from the vortex. The instability mechanism is explained in terms of an over-reflection phenomenon by means of a Wentzel-Kramers-Brillouin-Jeffreys analysis for large axial wavenumber.

  20. Architecture of columnar nacre, and implications for its formation mechanism.

    PubMed

    Metzler, Rebecca A; Abrecht, Mike; Olabisi, Ronke M; Ariosa, Daniel; Johnson, Christopher J; Frazer, Bradley H; Coppersmith, Susan N; Gilbert, P U P A

    2007-06-29

    We analyze the structure of Haliotis rufescens nacre, or mother-of-pearl, using synchrotron spectromicroscopy and x-ray absorption near-edge structure spectroscopy. We observe imaging contrast between adjacent individual nacre tablets, arising because different tablets have different crystal orientations with respect to the radiation's polarization vector. Comparing previous data and our new data with models for columnar nacre growth, we find the data are most consistent with a model in which nacre tablets are nucleated by randomly distributed sites in the organic matrix layers. PMID:17678131

  1. Genome organization and gene expression of saguaro cactus carmovirus.

    PubMed

    Weng, Z; Xiong, Z

    1997-03-01

    The complete sequence of the single-stranded, (+)-sense RNA genome of saguaro cactus carmovirus (SCV) has been determined. The 3879 nucleotide genome contains five open reading frames (ORFs). The 5'-proximal ORF encodes a 26 kDa protein (p26) and terminates with an amber codon which is readthrough into an in-frame p57 ORF to generate an 86 kDa fusion protein (p86). Two small, centrally located ORFs encode a 6 kDa protein (p6) and a 9 kDa protein (p9), respectively. The 3'-proximal ORF encodes a 37 kDa (p37) capsid protein (CP). Analysis of the nucleotide and predicted amino acid sequences supports the classification of SCV in the genus Carmovirus in the family Tombusviridae. All predicted SCV proteins are expressed in an in vitro translation system. SCV p26 and the readthrough fusion protein p86 are synthesized from the genomic RNA while p6, p9 and p37 CP ORFs at the 3' half of the genome are expressed from two subgenomic (sg) RNAs. The 5' termini of both sg RNAs have been mapped. The large 1614 nucleotide sg RNA contains the p6 and p9 ORFs as the first and the second ORFs respectively from its 5' end. It directs the synthesis of abundant p6 but a small amount of p9. While a synthetic transcript with the p9 ORF at the 5' end is a more efficient messenger for p9, no corresponding sg RNA has been identified in vivo. The smaller 1396 nucleotide sg RNA contains only the p37 ORF and directs the synthesis of SCV CP. PMID:9049400

  2. Columnar molecular aggregation in the aqueous solutions of disodium cromoglycate.

    PubMed

    Agra-Kooijman, Dena M; Singh, Gautam; Lorenz, Alexander; Collings, Peter J; Kitzerow, Heinz-S; Kumar, Satyendra

    2014-06-01

    Stack, chimneylike, and threadlike assemblies have previously been proposed for the structure of disodium cromoglycate (DSCG) aggregates in aqueous solutions. The results of the synchrotron x-ray scattering investigations reported here reveal the formation of simple columnar assemblies with π-π stacking at a separation of 3.4 Å between the DSCG molecules. Lateral separation between the assemblies is concentration and temperature dependent, varying from ∼35 to 42 Å in the orientationally ordered nematic (N) phase and from 27 to 32 Å in the columnar or middle (M) phase having long range lateral positional order. The assemblies' length depends on concentration and consists of ∼23 molecules in the N phase, becoming three to ten times larger in the M phase. The scission energy is concentration dependent in the N phase with values ∼7.19 ± 0.14 k_{B}T (15 wt %), 2.73 ± 0.4 k_{B}T (20 wt %), and 3.05 ± 0.2 k_{B}T (25 wt %). Solutions of all concentrations undergo a spinodal decomposition at temperatures above ∼40 °C, resulting in DSCG-rich regions with the M phase and water-rich regions in the N and isotropic phases. PMID:25019802

  3. Nano-scale twinning associated with columnar defects in YBCO

    NASA Astrophysics Data System (ADS)

    Yan, Yong; Kirk, M. A.

    1998-03-01

    Transmission electron microscopy study reveals that high energy ( GeV) heavy ion (U+, Xe+, and Au+) irradiation in high-Tc superconductors leads to the formation of aligned columnar defects which are usually amorphous. The associated volume expansion causes strain in surrounding matrix. Our study shows that the stress field induced by ion irradiation along the c axis direction of YBa2Cu3O7-d can be relaxed by local oxygen re-ordering in the ab planes which gives a 90o reorientation of the orthorhombic unit cell in the affected area. As the ion dose increases (>1011/cm2), a characteristic microstructure, the joining of oxygen re-ordering regions, has been observed. Thus a number of local ``twin'' boundaries are formed between two or more amorphous cores. The local a/b interfaces between the matrix and the oxygen re-ordering regions tend to either 110 plane of YBa2Cu3O7-d. These interfaces are similar to the pre-existing twin boundaries formed during the tetragonal to orthorhombic transformation, but they are more diffuse. Cross-sectional TEM study shows that the diameter of aligned amorphous columns is far from uniform along the ion path. Three typical morphologies: discontinuous, modulated, and uniform columns were observed in our study, which certainly must affect the degree of local twinning associated with the columnar defect.

  4. Columnar to equiaxed transition in high Cr white iron castings

    SciTech Connect

    Dogan, O.N.

    1996-07-15

    White cast irons are frequently used in applications requiring high wear resistance. High Cr white cast irons have a composite microstructure composed of hard (Fe,Cr){sub 7}C{sub 3} carbides in a steel matrix. In thick section castings, long rod-shaped carbides may grow perpendicular to the mold wall to form the columnar zone of the casting, or their long axes may grow in random directions to form equiaxed grains. Previous research has indicated that the equiaxed region of these high Cr white iron castings is much more wear resistant under high stress abrasive conditions than the columnar region, when the carbides are oriented perpendicular to the wear surface. Therefore, in order to maximize their abrasion resistance, it is essential that wear resistant cast parts with thick sections be produced with completely equiaxed macrostructures to maximize their abrasion resistance. In the present study, the effect of both the chemical composition, particularly carbon content, and the pouring superheat of the melt on the macrostructure of high Cr white iron castings is investigated.

  5. Columnar molecular aggregation in the aqueous solutions of disodium cromoglycate

    NASA Astrophysics Data System (ADS)

    Agra-Kooijman, Dena M.; Singh, Gautam; Lorenz, Alexander; Collings, Peter J.; Kitzerow, Heinz-S.; Kumar, Satyendra

    2014-06-01

    Stack, chimneylike, and threadlike assemblies have previously been proposed for the structure of disodium cromoglycate (DSCG) aggregates in aqueous solutions. The results of the synchrotron x-ray scattering investigations reported here reveal the formation of simple columnar assemblies with π-π stacking at a separation of 3.4 Å between the DSCG molecules. Lateral separation between the assemblies is concentration and temperature dependent, varying from ˜35 to 42 Å in the orientationally ordered nematic (N) phase and from 27 to 32 Å in the columnar or middle (M) phase having long range lateral positional order. The assemblies' length depends on concentration and consists of ˜23 molecules in the N phase, becoming three to ten times larger in the M phase. The scission energy is concentration dependent in the N phase with values ˜7.19 ± 0.14 kBT (15 wt %), 2.73 ± 0.4 kBT (20 wt %), and 3.05 ± 0.2 kBT (25 wt %). Solutions of all concentrations undergo a spinodal decomposition at temperatures above ˜40 °C, resulting in DSCG-rich regions with the M phase and water-rich regions in the N and isotropic phases.

  6. Columnar phases of discotics with orientation-dependent interactions

    NASA Astrophysics Data System (ADS)

    Martínez-Haya, Bruno; Cuetos, Alejandro

    2009-08-01

    The liquid crystal phase diagram of fluids of rigid discotics with soft interactions has been investigated by means of Monte Carlo simulations. The particles are modeled by spherocylinders or Gay-Berne ellipsoids with thickness/diameter aspect ratios of L /D=0.2. The study includes a variety of pair interaction potentials, featuring different energetic dependencies on the orientation of the particles. Three distinct types of models are considered: (i) models with a homogeneous interaction around the molecular core, (ii) models favoring stacked pair configurations, and (iii) models favoring edge-to-edge configurations. The stability and internal structure of the isotropic, nematic, and the different hexatic columnar phases exhibited by these fluids are discussed. The results indicate that the spherocylinder and ellipsoidal models differ in fundamental trends of their phase behavior. The spherocylinder fluids display more extended ranges of stability and longer pair correlation lengths in the columnar phases than the ellipsoidal models. As a consequence, as opposed to ellipsoids, the nematic phase for spherocylinders with the title aspect ratio tends to be entropically suppressed, even under favorable energetics.

  7. Columnar phases of discotics with orientation-dependent interactions.

    PubMed

    Martínez-Haya, Bruno; Cuetos, Alejandro

    2009-08-21

    The liquid crystal phase diagram of fluids of rigid discotics with soft interactions has been investigated by means of Monte Carlo simulations. The particles are modeled by spherocylinders or Gay-Berne ellipsoids with thickness/diameter aspect ratios of L/D=0.2. The study includes a variety of pair interaction potentials, featuring different energetic dependencies on the orientation of the particles. Three distinct types of models are considered: (i) models with a homogeneous interaction around the molecular core, (ii) models favoring stacked pair configurations, and (iii) models favoring edge-to-edge configurations. The stability and internal structure of the isotropic, nematic, and the different hexatic columnar phases exhibited by these fluids are discussed. The results indicate that the spherocylinder and ellipsoidal models differ in fundamental trends of their phase behavior. The spherocylinder fluids display more extended ranges of stability and longer pair correlation lengths in the columnar phases than the ellipsoidal models. As a consequence, as opposed to ellipsoids, the nematic phase for spherocylinders with the title aspect ratio tends to be entropically suppressed, even under favorable energetics. PMID:19708757

  8. Spatial relationships among three columnar systems in cat area 17.

    PubMed

    Hübener, M; Shoham, D; Grinvald, A; Bonhoeffer, T

    1997-12-01

    In the primary visual cortex, neurons with similar response properties are arranged in columns. As more and more columnar systems are discovered it becomes increasingly important to establish the rules that govern the geometric relationships between different columns. As a first step to examine this issue we investigated the spatial relationships between the orientation, ocular dominance, and spatial frequency domains in cat area 17. Using optical imaging of intrinsic signals we obtained high resolution maps for each of these stimulus features from the same cortical regions. We found clear relationships between orientation and ocular dominance columns: many iso-orientation lines intersected the borders between ocular dominance borders at right angles, and orientation singularities were concentrated in the center regions of the ocular dominance columns. Similar, albeit weaker geometric relationships were observed between the orientation and spatial frequency domains. The ocular dominance and spatial frequency maps were also found to be spatially related: there was a tendency for the low spatial frequency domains to avoid the border regions of the ocular dominance columns. This specific arrangement of the different columnar systems might ensure that all possible combinations of stimulus features are represented at least once in any given region of the visual cortex, thus avoiding the occurrence of functional blind spots for a particular stimulus attribute in the visual field. PMID:9364073

  9. Diversity of unavailable polysaccharides and dietary fiber in domesticated nopalito and cactus pear fruit (Opuntia spp.).

    PubMed

    Peña-Valdivia, Cecilia Beatriz; Trejo, Carlos; Arroyo-Peña, V Baruch; Sánchez Urdaneta, Adriana Beatriz; Balois Morales, Rosendo

    2012-08-01

    The aim of this study was to quantify mucilages, pectins, hemicelluloses, and cellulose of nopalitos (edible, as vegetable, young cladodes of flat-stemmed spiny cacti) of most consumed Mexican cultivars, and sweet and acid cactus pear fruits of Opuntia spp. The hypothesis is that, regardless of their unavailable polysaccharides diversity, nopalitos and cactus pear fruits are rich sources of soluble and insoluble dietary fiber. Twelve cultivars of Opuntia spp. were used. Nopalitos had a significant variation in structural polysaccharides among the cultivars: mucilages (from 3.8 to 8.6% dry matter (DM)) averaged near a half of pectins content (from 6.1 to 14.2% DM) and tightly bound hemicelluloses (from 2.2 to 4.7% DM), which were the less abundant polysaccharides, amounted 50% of the loosely bound hemicelluloses (from 4.3 to 10.7% DM). Acid fruits (or 'xoconostle') had significantly higher unavailable polysaccharides content than sweet fruit, and contain similar proportions than nopalitos. Unavailable polysaccharides represent a high proportion of dry tissues of nopalitos and cactus pear fruits, composition of both of these soluble and insoluble polysaccharides (total dietary fiber) widely vary among cultivars without an evident pattern. Nopalitos and cactus pear fruit can be considered an excellent source of dietary fiber. PMID:22899620

  10. Phylogeographic analysis of Harrisia cactus mealybug, Hypogeococcus pungens (Hemiptera: Pseudoccidae) populations: work in progress

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Harrisia cactus mealybug (HCM), Hypogeococcus pungens (Hemiptera: Pseudoccidae) Granara de Willink (1981) is infesting and killing cacti in the southern coast of Puerto Rico, covering an area of about 1,400 km2. The 13 species of cacti occurring in Puerto Rico are threatened by this new pest; three...

  11. Trail marking by the larvae of the cactus moth, Cactoblastis cactorum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cactoblastis cactorum (Lepidoptera: Pyralidae) spends most of its larval life feeding within the cladodes of Opuntia cactuses, but the gregarious caterpillars begin their life outside the plant, and in the later instars make intermittent excursions over plant surfaces to access new cladodes and to t...

  12. Biology, Distribution And Control Of The Cactus Moth, Cactoblastis Cactorum (Berg) (Lepidoptera: Pyralide)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) became a textbook example of successful classical biological control after it was imported from Argentina into Australia in 1926 to control invasive Opuntia cacti. To date, the moth continues to play an active role in controlling...

  13. Mating frequency of the male cactus moth Cactoblastis cactorum (Lepidoptera:Pyralidae), under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the number of times that males of the invasive cactus moth Cactoblastis cactorum (Berg) mate under laboratory conditions. Virgin females were provided to each male at 24 h intervals until male death. Females removed from the containers were dissected to ascertain their mating ...

  14. DEVELOPMENT OF CONTROL TACTICS AGAINST THE INVASIVE CACTUS MOTH, CACTOBLASTIS CACTORUM, IN NORTH AMERICA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most successful classical biocontrol of weeds program has been the control of invasive prickly-pears (Opuntia spp.) by the Argentine cactus moth Cactoblastis cactorum. However, the moth has invaded North America and its ability to control its host plant raises concerns for the safety and surviva...

  15. Mating frequency of the male cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae), under laboratory conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This study evaluated the effects of three constant temperatures (20°, 25° and 30°C) on the rate of development and life history of the invasive cactus moth Cactoblastis cactorum (Berg). Results from these laboratory experiments were used to predict C. cactorum rate of development in the field during...

  16. Enhanced susceptibility of hybrid tilapia to Flavobacterium columnare after parasitism by Ichthyophthirius multifiliis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and protozoan Ichthyophthirius multifiliis are two common pathogens of cultured fish. The objective of this study was to evaluate the susceptibility of hybrid tilapia (Oreochromis spp.) to the bacterium F. columnare, including fish mortality and bacterial loads in ...

  17. Chemotactic factors of Flavobacterium columnare to skin mucus of healthy channel catfish (Ictalurus punctatus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain insight into chemotactic factors involved in chemotaxis, we exposed a virulent strain of Flavobacterium columnare to various treatments followed by analysis of its chemotactic activity. Chemotactic activity of F. columnare was significantly (p < 0.05) inhibited when cells were pretreated by ...

  18. Isolation and characterization of Flavobacterium columnare strains infecting fishes inhabiting the Laurentian Great Lakes basin

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare, the etiological agent of columnaris disease, causes significant losses in fish worldwide. In this study, F. columnare infection prevalence was assessed in representative Great Lakes fish species. Over 2,000 wild, feral, and hatchery-propagated salmonids, percids, centrarc...

  19. Complete genome sequence of the fish pathogen Flavobacterium columnare strain C#2

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is a Gram-negative bacterial pathogen that causes columnaris disease of freshwater fish. Flavobacterium columnare strain C#2 was isolated from a diseased warm water fish and is typed as genomovar II. The genome consists of a single 3.33 Mb circular chromosome with 2,689 pred...

  20. Chemotactic factors of Flavobacterium columnare to skin mucus of healthy channel catfish (Ictalurus punctatus)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    To gain insight into chemotactic factors involved in chemotaxis, we exposed a virulent strain of Flavobacterium columnare to various treatments followed by analysis of its chemotactic activity. The chemotactic activity of F. columnare was significantly (p < 0.05) inhibited when cells were pretreated...

  1. Complete Genome Sequence of the Fish Pathogen Flavobacterium columnare Pf1

    PubMed Central

    Zhang, Yulei

    2016-01-01

    Flavobacterium columnare is the etiologic agent of columnaris disease, a devastating fish disease prevailing in worldwide aquaculture industry. Here, we describe the complete genome of F. columnare strain Pf1, a highly virulent strain isolated from yellow catfish (Pelteobagrus fulvidraco) in China. PMID:27587818

  2. Development and use of a modified live Flavobacterium columnare vaccine in fish

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is an aquatic bacterium that is highly infectious in warm and cold water fish. In the channel catfish (Ictalurus punctatus) industry it causes columnaris disease and has a negative impact on production (~$30 million/year). We developed a modified F. columnare isolate by pa...

  3. Title of Manuscript: Examining the universal genetic diversity of Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Genetic variability among strains of Flavobacterium columnare, isolated in the United States, was characterized by restriction fragment length polymorphism (RFLP) and phylogenetic analysis based on the sequence of the 16S rRNA gene. Twenty-seven isolates of F. columnare were differentiated into thr...

  4. Complete Genome Sequence of the Fish Pathogen Flavobacterium columnare Strain C#2

    PubMed Central

    Newton, Ryan J.; Zhu, Yongtao; Li, Nan; LaFrentz, Benjamin R.

    2016-01-01

    Flavobacterium columnare is a Gram-negative bacterial pathogen that causes columnaris disease of freshwater fish. Flavobacterium columnare strain C#2 was isolated from a diseased warm-water fish and is typed as genomovar II. The genome consists of a single 3.33-Mb circular chromosome with 2,689 predicted coding genes. PMID:27340080

  5. Complete Genome Sequence of the Fish Pathogen Flavobacterium columnare Strain C#2.

    PubMed

    Bartelme, Ryan P; Newton, Ryan J; Zhu, Yongtao; Li, Nan; LaFrentz, Benjamin R; McBride, Mark J

    2016-01-01

    Flavobacterium columnare is a Gram-negative bacterial pathogen that causes columnaris disease of freshwater fish. Flavobacterium columnare strain C#2 was isolated from a diseased warm-water fish and is typed as genomovar II. The genome consists of a single 3.33-Mb circular chromosome with 2,689 predicted coding genes. PMID:27340080

  6. Basal polarization of the mucosal compartment in Flavobacterium columnare susceptible and resistant channel catfish Ictalurus punctatus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The freshwater bacterial pathogen, Flavobacterium columnare, infects a variety of ornamental and farmed fish species worldwide through mucosal attachment points on the gill and skin. While previous studies have demonstrated a chemotactic response of F. columnare to fish mucus, little is known about ...

  7. Genome sequence of the fish pathogen Flavobacterium columnare genomovar II strain 94-081

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Channel catfish is one of the most important commodities in Mississippi and the largest aquaculture industry in the United States. Columnaris disease, caused by Flavobacterium columnare, affects many commercially important freshwater fish species. F. columnare strain 94-081 was isolated from disease...

  8. Complete Genome Sequence of the Fish Pathogen Flavobacterium columnare Pf1.

    PubMed

    Zhang, Yulei; Nie, Pin; Lin, Li

    2016-01-01

    Flavobacterium columnare is the etiologic agent of columnaris disease, a devastating fish disease prevailing in worldwide aquaculture industry. Here, we describe the complete genome of F. columnare strain Pf1, a highly virulent strain isolated from yellow catfish (Pelteobagrus fulvidraco) in China. PMID:27587818

  9. Passive immunization of channel catfish Ictalurus punctatus with anti-Flavobacterium columnare sera

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Passive immunization of channel catfish, Ictalurus punctatus (Rafinesque), was conducted to determine if anti-Flavobacterium columnare serum was protective when injected intraperitoneally (i.p.) into channel catfish. The anti-F. columnare serum was produced by actively immunizing (i.p. injection) ch...

  10. Reproducible challenge model to investigate the virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare is a Gram-negative bacterium that causes columnaris disease and has significant economic impacts on aquaculture production worldwide. Molecular analyses have demonstrated that there is genetic diversity among F. columnare isolates. A review of the published literature that u...

  11. Composition of Extracellular Polymeric Substances (EPS) produced by Flavobacterium columnare isolated from tropical fish in Brazil

    PubMed Central

    de Alexandre Sebastião, Fernanda; Pilarski, Fabiana; Lemos, Manoel Victor Franco

    2013-01-01

    Thirty nine isolates of Flavobacterium columnare from Brazilian fish farms had their carbohydrate composition of EPS evaluated by high efficiency liquid chromatography, using the phenol-sulfuric acid method of EPS. The occurrence of capsules on F. columnare cells was not directly related to biofilm formation, and the predominant monosaccharide is glucose. PMID:24516426

  12. Azimuthal Frustration and Bundling in Columnar DNA Aggregates

    PubMed Central

    Harreis, H. M.; Likos, C. N.; Löwen, H.

    2003-01-01

    The interaction between two stiff parallel DNA molecules is discussed using linear Debye-Hückel screening theory with and without inclusion of the dielectric discontinuity at the DNA surface, taking into account the helical symmetry of DNA. The pair potential furthermore includes the amount and distribution of counterions adsorbed on the DNA surface. The interaction does not only depend on the interaxial separation of two DNA molecules, but also on their azimuthal orientation. The optimal mutual azimuthal angle is a function of the DNA-DNA interaxial separation, which leads to azimuthal frustrations in an aggregate. On the basis of the pair potential, the positional and orientational order in columnar B-DNA assemblies in solution is investigated. Phase diagrams are calculated using lattice sums supplemented with the entropic contributions of the counterions in solution. A variety of positionally and azimuthally ordered phases and bundling transitions is predicted, which strongly depend on the counterion adsorption patterns. PMID:12770870

  13. A novel serrated columnar phased array ultrasonic transducer

    NASA Astrophysics Data System (ADS)

    Zou, Cheng; Sun, Zhenguo; Cai, Dong; Song, Hongwei; Chen, Qiang

    2016-02-01

    Traditionally, wedges are required to generate transverse waves in a solid specimen and mechanical rotation device is needed for interrogation of a specimen with a hollow bore, such as high speed railway locomotive axles, turbine rotors, etc. In order to eliminate the mechanical rotation process, a novel array pattern of phased array ultrasonic transducers named as serrated columnar phased array ultrasonic transducer (SCPAUT) is designed. The elementary transducers are planar rectangular, located on the outside surface of a cylinder. This layout is aimed to generate electrically rotating transverse waveforms so as to inspect the longitudinal cracks on the outside surface of a specimen which has a hollow bore at the center, such as the high speed railway locomotive axles. The general geometry of the SCPAUT and the inspection system are illustrated. A FEM model and mockup experiment has been carried out. The experiment results are in good agreement with the FEM simulation results.

  14. Hexagonal columnar liquid crystal in the cells secreting spider silk.

    PubMed

    Knight, D; Vollrath, F

    1999-12-01

    The liquid crystallinity of spider dragline silk dope is thought to be important for both the spinning process and the extreme mechanical properties of the final thread. Although the formation of the liquid crystalline units is poorly understood, it has been suggested that spider silk proteins are secreted in a random coil and then aggregate end-to-end into rod-shaped units to form supramolecular liquid crystals. However, evidence presented here from transmission electron microscopy indicates that coat protein of the dragline silk of a Nephila spider is stored as hexagonal columnar liquid crystals within the intracellular secretory vesicles. This implies that this component is already folded into short rods within the gland cells and forms molecular rather than supramolecular liquid crystals. PMID:18627876

  15. Electric field controlled columnar and planar patterning of cholesteric colloids.

    PubMed

    D'Adamo, G; Marenduzzo, D; Micheletti, C; Orlandini, E

    2015-05-01

    We study how dispersions of colloidal particles in a cholesteric liquid crystal behave under a time-dependent electric field. By controlling the amplitude and shape of the applied field wave, we show that the system can be reproducibly driven out of equilibrium through different kinetic pathways and navigated through a glassylike free energy landscape encompassing many competing metastable equilibria. Such states range from simple Saturn rings to complex structures featuring amorphous defect networks, or stacks of disclination loops. A nonequilibrium electric field can also trigger the alignment of particles into columnar arrays, through defect-mediated force impulses, or their repositioning within a plane. Our results are promising in terms of providing new avenues towards controlled patterning and self-assembly of soft colloid-liquid crystal composite materials. PMID:25978263

  16. Columnar epitaxy of hexagonal and orthorhombic silicides on Si(111)

    NASA Technical Reports Server (NTRS)

    Fathauer, R. W.; Nieh, C. W.; Xiao, Q. F.; Hashimoto, Shin

    1990-01-01

    Columnar grains of PtSi and CrSi2 surrounded by high-quality epitaxial silicon are obtained by ultrahigh vacuum codeposition of Si and metal in an approximately 10:1 ratio on Si(111) substrates heated to 610-840 C. This result is similar to that found previously for CoSi2 (a nearly-lattice-matched cubic-fluorite crystal) on Si(111), in spite of the respective orthorhombic and hexagonal structures of PtSi and CrSi2. The PtSi grains are epitaxial and have one of three variants of the relation defined by PtSi(010)/Si(111), with PtSi 001 line/Si 110 line type.

  17. Experimental study of columnar recombination in fission chambers

    NASA Astrophysics Data System (ADS)

    Filliatre, P.; Lamirand, V.; Geslot, B.; Jammes, C.

    2016-05-01

    In this paper, we present experimental saturation curves of a small gap miniature fission chamber obtained in the MINERVE reactor. The chamber is filled with argon at various pressures, and the fissile material can be coated on the anode, cathode, or both. For analyzing the recombination regime, we consider a model of columnar recombination and discuss its applicability to our chamber. By applying this model to the data, it is possible to estimate the ratio between the recombination coefficient k and an effective column radius b, appearing in the model, to be k / b =(2.5 ± 0.9) ×10-6m2 / s for argon. From these results, a routine measurement of the recombination regime is proposed in order to detect gas leakage. This online diagnosis would be beneficial in terms of lifetime and reliability of the neutron instrumentation of nuclear reactors.

  18. Mechanical Stiffening of Porphyrin Nanorings through Supramolecular Columnar Stacking

    PubMed Central

    2013-01-01

    Solvent-induced aggregates of nanoring cyclic polymers may be transferred by electrospray deposition to a surface where they adsorb as three-dimensional columnar stacks. The observed stack height varies from single rings to four stacked rings with a layer spacing of 0.32 ± 0.04 nm as measured using scanning tunneling microscopy. The flexibility of the nanorings results in distortions from a circular shape, and we show, through a comparison with Monte Carlo simulations, that the bending stiffness increases linearly with the stack height. Our results show that noncovalent interactions may be used to control the shape and mechanical properties of artificial macromolecular aggregates offering a new route to solvent-induced control of two-dimensional supramolecular organization. PMID:23789845

  19. Nopal cactus (Opuntia ficus-indica) as a source of bioactive compounds for nutrition, health and disease.

    PubMed

    El-Mostafa, Karym; El Kharrassi, Youssef; Badreddine, Asmaa; Andreoletti, Pierre; Vamecq, Joseph; El Kebbaj, M'Hammed Saïd; Latruffe, Norbert; Lizard, Gérard; Nasser, Boubker; Cherkaoui-Malki, Mustapha

    2014-01-01

    Opuntia ficus-indica, commonly referred to as prickly pear or nopal cactus, is a dicotyledonous angiosperm plant. It belongs to the Cactaceae family and is characterized by its remarkable adaptation to arid and semi-arid climates in tropical and subtropical regions of the globe. In the last decade, compelling evidence for the nutritional and health benefit potential of this cactus has been provided by academic scientists and private companies. Notably, its rich composition in polyphenols, vitamins, polyunsaturated fatty acids and amino acids has been highlighted through the use of a large panel of extraction methods. The identified natural cactus compounds and derivatives were shown to be endowed with biologically relevant activities including anti-inflammatory, antioxidant, hypoglycemic, antimicrobial and neuroprotective properties. The present review is aimed at stressing the major classes of cactus components and their medical interest through emphasis on some of their biological effects, particularly those having the most promising expected health benefit and therapeutic impacts. PMID:25232708

  20. Morbidity and mortality of bald eagles (Haliaeetus leucocephalus) and peregrine falcons (Falco peregrinus) admitted to the Wildlife Center of Virginia, 1993-2003.

    PubMed

    Harris, M Camille; Sleeman, Jonathan M

    2007-03-01

    Medical records from 111 threatened bald eagles (86%, Haliaeetus leucocephalus) and peregrine falcons (14%, Falco peregrinus) admitted to the Wildlife Center of Virginia from 1993 to 2003 were reviewed to identify submitters, causes of morbidity and mortality, and final disposition. Half of all patients admitted were submitted by the Virginia Department of Game and Inland Fisheries personnel. Trauma was the most common reason for presentation in bald eagles (70%) and peregrine falcons (81%). Additional causes of morbidity and mortality in bald eagles included toxicoses (10%), infectious diseases (8%), and orphaned young (1%). Neoplasia was confirmed in two trauma cases, suggesting underlying disease might have increased susceptibility to acute traumatic injuries. Peregrine falcons were also admitted for infectious disease (19%). The most frequent infectious disease for both species was West Nile virus. Thirty-nine percent of patients were released back into the wild, 28% were euthanized, 20% died, and 13% were placed in captivity. Postrelease monitoring that would determine whether rehabilitated animals survived to contribute to threatened populations was not performed in this study. PMID:17469277

  1. Sensitivity of bald eagle (Haliaeetus leucocephalus) hepatocyte cultures to induction of cytochrome P4501A by 2,3,7,8-tetrachlorodibenzo-p-dioxin.

    PubMed

    Kennedy, Sean W; Jones, Stephanie P; Elliott, John E

    2003-01-01

    Graded doses of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) were added to primary hepatocyte cultures of bald eagle (Haliaeetus leucocephalus) embryos to determine their sensitivity to induction of cytochrome P4501A (CYP1A) and porphyrin accumulation. No porphyrin accumulation was observed, but both CYP1A catalytic activity (using the ethoxyresorufin-O-deethylase (EROD) assay) and immunodetectable CYP1A were induced by relatively high concentrations of TCDD. Bald eagle hepatocytes were less sensitive to CYP1A induction than hepatocytes from any other avian species that we have studied to date. These in vitro results are in general agreement with recent assessments of field data, which indicate that bald eagles are relatively insensitive to some of the effects of TCDD and related compounds. Preparation of bald eagle hepatocytes was challenging because existing methods did not yield monolayers of cells. Here we describe details of a new method that was successful for bald eagle hepatocytes. This new method is used routinely in our laboratory to prepare hepatocyte cultures from birds for examination of various biochemical responses to environmental contaminants. PMID:12739865

  2. Columnar cell lesions of the canine mammary gland: pathological features and immunophenotypic analysis

    PubMed Central

    2010-01-01

    Background It has been suggested that columnar cell lesions indicate an alteration of the human mammary gland involved in the development of breast cancer. They have not previously been described in canine mammary gland. The aim of this paper is describe the morphologic spectrum of columnar cell lesions in canine mammary gland specimens and their association with other breast lesions. Methods A total of 126 lesions were subjected to a comprehensive morphological review based upon the human breast classification system for columnar cell lesions. The presence of preinvasive (epithelial hyperplasia and in situ carcinoma) and invasive lesions was determined and immunophenotypic analysis (estrogen receptor (ER), progesterone receptor (PgR), high molecular weight cytokeratin (34βE-12), E-cadherin, Ki-67, HER-2 and P53) was perfomed. Results Columnar cell lesions were identified in 67 (53.1%) of the 126 canine mammary glands with intraepithelial alterations. They were observed in the terminal duct lobular units and characterized at dilated acini may be lined by several layers of columnar epithelial cells with elongated nuclei. Of the columnar cell lesions identified, 41 (61.2%) were without and 26 (38.8%) with atypia. Association with ductal hyperplasia was observed in 45/67 (67.1%). Sixty (89.5%) of the columnar cell lesions coexisted with neoplastic lesions (20 in situ carcinomas, 19 invasive carcinomas and 21 benign tumors). The columnar cells were ER, PgR and E-cadherin positive but negative for cytokeratin 34βE-12, HER-2 and P53. The proliferation rate as measured by Ki-67 appeared higher in the lesions analyzed than in normal TDLUs. Conclusions Columnar cell lesions in canine mammary gland are pathologically and immunophenotypically similar to those in human breast. This may suggest that dogs are a suitable model for the comparative study of noninvasive breast lesions. PMID:20178635

  3. Derivation of Aerosol Columnar Mass from MODIS Optical Depth

    NASA Technical Reports Server (NTRS)

    Gasso, Santiago; Hegg, Dean A.

    2003-01-01

    In order to verify performance, aerosol transport models (ATM) compare aerosol columnar mass (ACM) with those derived from satellite measurements. The comparison is inherently indirect since satellites derive optical depths and they use a proportionality constant to derive the ACM. Analogously, ATMs output a four dimensional ACM distribution and the optical depth is linearly derived. In both cases, the proportionality constant requires a direct intervention of the user by prescribing the aerosol composition and size distribution. This study introduces a method that minimizes the direct user intervention by making use of the new aerosol products of MODIS. A parameterization is introduced for the derivation of columnar aerosol mass (AMC) and CCN concentration (CCNC) and comparisons between sunphotometer, MODIS Airborne Simulator (MAS) and in-measurements are shown. The method still relies on the scaling between AMC and optical depth but the proportionality constant is dependent on the MODIS derived r$_{eff}$,\\eta (contribution of the accumulation mode radiance to the total radiance), ambient RH and an assumed constant aerosol composition. The CCNC is derived fkom a recent parameterization of CCNC as a function of the retrieved aerosol volume. By comparing with in-situ data (ACE-2 and TARFOX campaigns), it is shown that retrievals in dry ambient conditions (dust) are improved when using a proportionality constant dependent on r$ {eff}$ and \\eta derived in the same pixel. In high humidity environments, the improvement inthe new method is inconclusive because of the difficulty in accounting for the uneven vertical distribution of relative humidity. Additionally, two detailed comparisons of AMC and CCNC retrieved by the MAS algorithm and the new method are shown. The new method and MAS retrievals of AMC are within the same order of magnitude with respect to the in-situ measurements of aerosol mass. However, the proposed method is closer to the in-situ measurements than

  4. Divergence in Olfactory Host Plant Preference in D. mojavensis in Response to Cactus Host Use

    PubMed Central

    Stensmyr, Marcus C.; Shann, Jodi; Hansson, Bill S.; Rollmann, Stephanie M.

    2013-01-01

    Divergence in host adaptive traits has been well studied from an ecological and evolutionary perspective, but identification of the proximate mechanisms underlying such divergence is less well understood. Behavioral preferences for host plants are often mediated by olfaction and shifts in preference may be accompanied by changes in the olfactory system. In this study, we examine the evolution of host plant preferences in cactophilic Drosophila mojavensis that feeds and breeds on different cacti throughout its range. We show divergence in electrophysiological responses and olfactory behavior among populations with host plant shifts. Specifically, significant divergence was observed in the Mojave Desert population that specializes on barrel cactus. Differences were observed in electrophysiological responses of the olfactory organs and in behavioral responses to barrel cactus volatiles. Together our results suggest that the peripheral nervous system has changed in response to different ecological environments and that these changes likely contribute to divergence among D. mojavensis populations. PMID:23936137

  5. Fish and wildlife to determine endangered status of San Rafael Cactus

    SciTech Connect

    Not Available

    1986-09-01

    The US Fish and Wildlife Service has proposed to determine the endangered status of the San Rafael Cactus. Although the only known occurrences of the species do not appear to fall within the boundaries of the San Rafael Swell Special Tar Sands Area, nearby combined hydrocarbon leasing could be impacted. There are two known populations of Pediocactus despainii, about 25 miles apart and each containing 2000 to 3000 individuals. Both occur in central Utah (Emery County), mainly in areas administered by the Bureau of Land Management. This rare species is being sought be cactus collectors, one population is heavily impacted by recreational off-road vehicles, and approximately one-half of each population is in areas covered by oil and gas leases and/or mining claims for gypsum. If the species is determined to be endangered, then the Fish and Wildlife Service could define a critical habitat for its preservation.

  6. Divergence in olfactory host plant preference in D. mojavensis in response to cactus host use.

    PubMed

    Date, Priya; Dweck, Hany K M; Stensmyr, Marcus C; Shann, Jodi; Hansson, Bill S; Rollmann, Stephanie M

    2013-01-01

    Divergence in host adaptive traits has been well studied from an ecological and evolutionary perspective, but identification of the proximate mechanisms underlying such divergence is less well understood. Behavioral preferences for host plants are often mediated by olfaction and shifts in preference may be accompanied by changes in the olfactory system. In this study, we examine the evolution of host plant preferences in cactophilic Drosophila mojavensis that feeds and breeds on different cacti throughout its range. We show divergence in electrophysiological responses and olfactory behavior among populations with host plant shifts. Specifically, significant divergence was observed in the Mojave Desert population that specializes on barrel cactus. Differences were observed in electrophysiological responses of the olfactory organs and in behavioral responses to barrel cactus volatiles. Together our results suggest that the peripheral nervous system has changed in response to different ecological environments and that these changes likely contribute to divergence among D. mojavensis populations. PMID:23936137

  7. Analysis of core soil and water samples from the Cactus Crater Disposal Site at Enewetak atoll

    SciTech Connect

    Robison, W.L.; Noshkin, V.E.

    1981-02-18

    Core soil samples and water samples were collected from the Cactus Crater Disposal Site at Enewetak for analysis of /sup 137/Cs, /sup 90/Sr, /sup 239 +240/Pu and /sup 241/Am by both gamma spectroscopy and, through a contractor laboratory, by wet chemistry procedures. The samples processing methods, the analytical methods and the analytical quality control are all procedures developed for the continuing Marshall Island radioecology and dose assessment work.

  8. Color, betalain pattern, and antioxidant properties of cactus pear (Opuntia spp.) clones.

    PubMed

    Stintzing, Florian C; Herbach, Kirsten M; Mosshammer, Markus R; Carle, Reinhold; Yi, Weiguang; Sellappan, Subramani; Akoh, Casimir C; Bunch, Ron; Felker, Peter

    2005-01-26

    Total phenolics, ascorbic acid, and betalain contents of differently colored cactus pear clones (nine Opuntia ficus-indica [L.] Mill. clones and one O. robusta Wendl. clone) were investigated and related to their respective antioxidant potential assessed by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays. TEAC and ORAC values were very highly correlated with each other and also with values for total phenolics, betalain contents, and ascorbic acid concentrations. Total phenolics had the greatest contribution to ORAC and TEAC values. High-performance liquid chromatography (HPLC)-diode array detector (DAD)-tandem mass spectrometry (MS/MS) measurements of cactus pear juices permitted the differentiation of the clones based on variations in pigment patterns and betalain concentrations. The red and yellow betalains were absent in lime green colored cactus fruits. The ratio and concentration of these pigments were responsible for the yellow, orange, red, and purple colors in the other clones. Progeny of purple and lime green colored parents were characterized by 12% and 88% of plants bearing lime green and purple fruit, respectively. This implies that the genes for betalain production were lacking in the lime green fruits but could be provided by a parent with a complete set of genes, that is, purple fruits. Besides known pigments typical of Cactaceae, two unexpected betalains were identified. Whereas gomphrenin I was found for the first time in tissues of cactus plants, methionine-betaxanthin has never been described before as a genuine betalain. In addition to their alleged health-promoting properties, various combinations of yellow betaxanthins and red-purple betacyanins may allow the development of new food products without using artificial colorants. PMID:15656686

  9. Dark matter and gamma-rays from Draco: MAGIC, GLAST and CACTUS

    SciTech Connect

    Bergstrom, Lars; Hooper, Dan; /Fermilab

    2005-12-01

    The dwarf spheroidal galaxy Draco has long been considered likely to be one of the brightest point sources of gamma-rays generated through dark matter annihilations. Recent studies of this object have found that it remains largely intact from tidal striping, and may be more massive than previously thought. In this article, we revisit Draco as a source of dark matter annihilation radiation, with these new observational constraints in mind. We discuss the prospects for the experiments MAGIC and GLAST to detect dark matter in Draco, as well as constraints from the observations of EGRET. We also discuss the possibility that the CACTUS experiment has already detected gamma-rays from Draco. We find that it is difficult to generate the flux reported by CACTUS without resorting to non-thermally produced WIMPs and/or a density spike in Draco's dark matter distribution due to the presence of an intermediate mass black hole. We also find that for most annihilation modes, a positive detection of Draco by CACTUS would be inconsistent with the lack of events seen by EGRET.

  10. Habitat fragmentation in coastal southern California disrupts genetic connectivity in the cactus wren (Campylorhynchus brunneicapillus)

    USGS Publications Warehouse

    Barr, Kelly R.; Kus, Barbara E.; Preston, Kristine; Howell, Scarlett; Perkins, Emily; Vandergast, Amy

    2015-01-01

    Achieving long-term persistence of species in urbanized landscapes requires characterizing population genetic structure to understand and manage the effects of anthropogenic disturbance on connectivity. Urbanization over the past century in coastal southern California has caused both precipitous loss of coastal sage scrub habitat and declines in populations of the cactus wren (Campylorhynchus brunneicapillus). Using 22 microsatellite loci, we found that remnant cactus wren aggregations in coastal southern California comprised 20 populations based on strict exact tests for population differentiation, and 12 genetic clusters with hierarchical Bayesian clustering analyses. Genetic structure patterns largely mirrored underlying habitat availability, with cluster and population boundaries coinciding with fragmentation caused primarily by urbanization. Using a habitat model we developed, we detected stronger associations between habitat-based distances and genetic distances than Euclidean geographic distance. Within populations, we detected a positive association between available local habitat and allelic richness and a negative association with relatedness. Isolation-by-distance patterns varied over the study area, which we attribute to temporal differences in anthropogenic landscape development. We also found that genetic bottleneck signals were associated with wildfire frequency. These results indicate that habitat fragmentation and alterations have reduced genetic connectivity and diversity of cactus wren populations in coastal southern California. Management efforts focused on improving connectivity among remaining populations may help to ensure population persistence.

  11. Dark matter and gamma rays from Draco: MAGIC, GLAST and CACTUS

    SciTech Connect

    Bergstroem, Lars; Hooper, Dan

    2006-03-15

    The dwarf spheroidal galaxy Draco has long been considered likely to be one of the brightest point sources of gamma rays generated through dark matter annihilations. Recent studies of this object have found that it remains largely intact from tidal striping, and may be more massive than previously thought. In this article, we revisit Draco as a source of dark matter annihilation radiation, with these new observational constraints in mind. We discuss the prospects for the experiments MAGIC and GLAST to detect dark matter in Draco, as well as constraints from the observations of EGRET. We also discuss the possibility that the CACTUS experiment has already detected gamma rays from Draco. We find that it is difficult to generate the flux reported by CACTUS without resorting to nonthermally produced WIMPs and/or a density spike in Draco's dark matter distribution due to the presence of an intermediate mass black hole. We also find that for most annihilation modes, a positive detection of Draco by CACTUS would be inconsistent with the lack of events seen by EGRET.

  12. Room temperature supramolecular columnar liquid crystals formed by hydrogen bonding of isoquinoline derivatives

    NASA Astrophysics Data System (ADS)

    Hyup Lee, Jun; Lee, Seung Jun; Jho, Jae Young

    2014-07-01

    We report new self-assembled discotic liquid crystals exhibiting columnar mesophases at room temperature, which are constructed by intermolecular hydrogen bonding between the core of 1,3,5-trihydroxybenzene or 1,3,5-cyclohexanetricarboxylic acid and the peripheral molecules of isoquinoline derivatives. The mesomorphic properties of supramolecular liquid crystals were investigated by differential scanning calorimetry, polarized optical microscopy, and X-ray diffraction studies. The self-assembled liquid crystals exhibited rectangular columnar phases (Colro) with an ordered stacking structure of the mesogens in a column at room temperature, regardless of the type of the core molecule, due probably to the close-packed aromatic rings around a core molecule and the angular structure in three arms of the discotic mesogen. These room temperature columnar phases are rare examples for the discotic liquid crystals, and our findings in the present study provide a new way to prepare low melting columnar liquid crystalline materials for molecular electronics.

  13. Formalin treatment of Trichondina sp. reduced Flavobacterium columnare infection in tilapia

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Bacterium Flavobacterium columnare and protozoan Trichodina spp. are common pathogens of cultured fish. Recent studies on parasite-bacterium interaction show evidence that concurrent infections increase severity of some infectious diseases, especially bacterial diseases. The effect of parasite treat...

  14. Effect of far-field flow on a columnar crystal in the convective undercooled melt

    NASA Astrophysics Data System (ADS)

    Ji, Xiao-Jian; Chen, Ming-Wen; Xu, Xiao-Hua; Wang, Zi-Dong

    2015-01-01

    The growth behavior of a columnar crystal in the convective undercooled melt affected by the far-field uniform flow is studied and the asymptotic solution for the interface evolution of the columnar crystal is derived by means of the asymptotic expansion method. The results obtained reveal that the far-field flow induces a significant change of the temperature around the columnar crystal and the convective flow caused by the far-field flow accelerates the growth velocity of the interface of the growing columnar crystal in the upstream direction and inhibits its growth velocity in the downstream direction. Our results are similar to the experimental data and numerical simulations. Project supported by the Overseas Distinguished Scholar Program by the Ministry of Education of China (Grant No. MS2010BJKJ005), the National Natural Science Foundation of China (Grant No. 10972030), and the Science and Technology Support Project of Jiangxi, China (Grant No. 20112BBE50006).

  15. Analysis of the Flavobacterium columnare transcriptome reveals gene expression signatures mediating virulence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater cultured fish species. Despite its importance, a broader understanding of the genes and their protein products that mediate virulence is urgently needed. Therefore, in t...

  16. Scale selection in columnar jointing: Insights from experiments on cooling stearic acid and numerical simulations

    NASA Astrophysics Data System (ADS)

    Christensen, Amalie; Raufaste, Christophe; Misztal, Marek; Celestini, Franck; Guidi, Maria; Ellegaard, Clive; Mathiesen, Joachim

    2016-03-01

    Many natural fracture systems are characterized by a single length scale, which is the distance between neighboring fractures. Examples are mud cracks and columnar jointing. In columnar jointing the origin of this scale has been a long-standing issue. Here we present a comprehensive study of columnar jointing based on experiments on cooling stearic acids, numerical simulations using both discrete and finite element methods and basic analytical calculations. We show that the diameter of columnar joints is a nontrivial function of the material properties and the cooling conditions of the system. We determine the shape of this function analytically and show that it is in agreement with the experiments and the numerical simulations.

  17. Compounds with Inhibitory Activity Against the Channel Catfish Pathogens Edwardsiella ictaluri and Flavobacterium columnare

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Enteric septicemia of catfish (ESC) and columnaris, the most common channel catfish Ictalurus punctatus diseases in the southeastern United States, are caused by the bacteria Edwardsiella ictaluri and Flavobacterium columnare, respectively. Although producers may rely on antibiotics and certain the...

  18. Formation of columnar (In,Ga)As quantum dots on GaAs(100)

    SciTech Connect

    He, J.; Noetzel, R.; Offermans, P.; Koenraad, P.M.; Gong, Q.; Hamhuis, G.J.; Eijkemans, T.J.; Wolter, J.H.

    2004-10-04

    Columnar (In,Ga)As quantum dots (QDs) with homogeneous composition and shape in the growth direction are realized by molecular-beam epitaxy on GaAs(100) substrates. The columnar (In,Ga)As QDs are formed on InAs seed QDs by alternating deposition of thin GaAs intermediate layers and monolayers of InAs with extended growth interruptions after each layer. The height of the columnar (In,Ga)As QDs is controlled by varying the number of stacked GaAs/InAs layers. The structural and optical properties are studied by cross-sectional scanning tunneling microscopy, atomic force microscopy, and photoluminescence spectroscopy. With increase of the aspect ratio of the columnar QDs, the emission wavelength is redshifted and the linewidth is reduced.

  19. Columnar-thin-film acquisition of fingermark topology

    NASA Astrophysics Data System (ADS)

    Shaler, Robert C.; Lakhtakia, Akhlesh; Rogers, Jessica W.; Pulsifer, Drew P.; Martín-Palma, Raúl J.

    2010-08-01

    Fingerprint visualization obtained from physical evidence taken from crime scenes for subsequent comparison typically requires the use of physical and chemical techniques. One physical technique to visualize or develop sebaceous fingerprints on various surfaces employs the deposition of metals such as gold and zinc thereon. We have developed a different vacuum technology: the conformal-evaporated-film-by-rotation technique to deposit dense columnar thin films (CTFs) on latent fingerprints on different types of surfaces. Sample fingerprints, acting as nonplanar substrates, deposited on different surfaces were placed in a vacuum chamber with the fingerprint side facing a boat containing an evaporant material such as chalcogenide glass. Thermal evaporation of the solid material led to the formation of a dense CTF on the fingerprint, thereby capturing the topographical texture with high resolution. Our results show that it is possible to acquire the topology of latent fingerprints on non-porous surfaces. Additionally, deposition of CTFs on overlapping fingerprints suggested ours may be a technique for elucidating the sequence of deposition of the fingerprints at the scene.

  20. Columnar-thin-film acquisition of fingerprint topology

    NASA Astrophysics Data System (ADS)

    Shaler, Robert C.; Lakhtakia, Akhlesh; Rogers, Jessica W.; Pulsifer, Drew P.; Martín-Palma, Raúl J.

    2011-01-01

    Fingerprint visualization obtained from physical evidence taken from crime scenes for subsequent comparison typically requires the use of physical and chemical techniques. One physical technique to visualize or develop sebaceous fingerprints on various surfaces employs the deposition of metals such as gold and zinc thereon. We have developed a different vacuum technology: the conformal-evaporated-film-by-rotation technique to deposit dense columnar thin films (CTFs) on latent fingerprints on different types of surfaces. Sample fingerprints, acting as nonplanar substrates, deposited on different surfaces were placed in a vacuum chamber with the fingerprint side facing a boat containing an evaporant material such as chalcogenide glass. Thermal evaporation of the solid material led to the formation of a dense CTF on the fingerprint, thereby capturing the topographical texture with high resolution. Our results show that it is possible to acquire the topology of latent fingerprints on nonporous surfaces. Additionally, deposition of CTFs on overlapping fingerprints suggested ours may be a technique for elucidating the sequence of deposition of the fingerprints at the scene.

  1. Anisotropic Bruggeman effective medium approaches for slanted columnar thin films

    NASA Astrophysics Data System (ADS)

    Schmidt, Daniel; Schubert, Mathias

    2013-08-01

    Two different formalisms for the homogenization of composite materials containing ellipsoidal inclusions based on Bruggeman's original formula for spherical inclusions can be found in the literature. Both approximations determine the effective macroscopic permittivity of such an idealized composite assuming randomly distributed dielectric particles of equal shape and differ only in the definition of the depolarization factors. The two approaches are applied to analyze ellipsometric Mueller matrix spectra acquired in the visible and near-infrared spectral region from metal and semiconductor slanted columnar thin films. Furthermore, the effective dielectric function tensor generated by the two Bruggeman formalisms is compared to effective major axes dielectric functions individually determined with a homogeneous biaxial layer approach. Best-match model parameters of all three model approaches are discussed and compared to estimates from scanning electron microscope images. The structural parameters obtained from all three optical modeling approaches agree well with the electron microscopy technique. A comparative discussion is given for the validity and applicability of the three model approaches for analysis of future devices structures that may require optical readout using generalized ellipsometry methods.

  2. Numerical Investigation of Synthetic Buoyancy-Induced Columnar Vortices

    NASA Astrophysics Data System (ADS)

    Malaya, Nicholas; Stogner, Roy; Moser, Robert

    2015-11-01

    Much of the solar energy incident on the Earth's surface is absorbed into the ground, which in turn heats the air layer above the surface. This buoyant air layer contains considerable gravitational potential energy. The energy can drive the formation of columnar vortices (``Dust-Devils'') which arise naturally in the atmosphere. These ``Dust-Devils'' occur over a wide range of scales in many different locations across the Earth, as well as on Mars. A new energy harvesting approach makes use of this ubiquitous process by creating and anchoring the vortices artificially and extracting energy from them. In this talk we explore the characteristics of these vorticies through numerical simulation. Computational models of the turning vane system used to generate the vortex have been developed. We will discuss the formulation of these models and their validation against available experimental measurements. We will also describe the use of these simulations to optimize the turning vane configuration to maximize the power extraction, as well as serving as a vehicle to probe the dynamics of the underlying physical processes. Finally, this talk will conclude with comparisons between the synthetic vorticies and the naturally occurring phenomena. This work supported by the Department of Energy [ARPA-E] under Award Number [DE-FOA-0000670].

  3. Clinical, pathological, and immunohistochemical findings in bald eagles (Haliaeetus leucocephalus) and golden eagles (Aquila chrysaetos) naturally infected with West Nile virus.

    PubMed

    Wünschmann, Arno; Timurkaan, Necati; Armien, Aníbal G; Bueno Padilla, Irene; Glaser, Amy; Redig, Patrick T

    2014-09-01

    Fifteen bald eagles (Haliaeetus leucocephalus) and 3 golden eagles (Aquila chrysaetos) were diagnosed with West Nile disease based on 1) presence of lesions in brain, eyes, and heart, 2) viral antigen detection in brain, eyes, heart, kidney, and/or liver by immunohistochemical staining, 3) detection of viral RNA in tissue samples and/or cerebrospinal fluid (CSF) by polymerase chain reaction, and/or 4) detection of West Nile virus (WNV)-specific antibodies in CSF by serum neutralization assay. West Nile virus-associated gross lesions included cerebral pan-necrosis with hydrocephalus ex vacuo (7/15 bald eagles), fibrin exudation into the fundus in 1 golden eagle, retinal scarring in 1 bald eagle, and myocardial pallor and rounded heart apex in 4 bald eagles. Histologic lesions included lymphoplasmacytic encephalitis, most prominently in the cerebrum (17 eagles), lymphoplasmacytic pectenitis and choroiditis (15 and 8 eagles, respectively), and myocarditis (12 eagles). West Nile virus antigen was detected in the majority of the eagles in neurons of the brain (cerebrum and cerebellum), and less commonly present in neurons of the retina, tubular epithelial cells of the kidney, and cardiomyocytes. West Nile disease was diagnosed in 2 bald eagles based on the presence of cerebral pan-necrosis and WNV-specific antibodies in the CSF despite lacking viral antigen and RNA. In conclusion, WNV infection causes a fatal disease in bald and golden eagles. A variety of gross and histologic lesions are highly suggestive of WN disease in most eagles. A combination of detection of viral antigen and/or RNA or virus-specific antibodies proved useful in confirming the diagnosis. PMID:25085868

  4. Low Genetic Diversity and Strong Geographical Structure of the Critically Endangered White-Headed Langur (Trachypithecus leucocephalus) Inferred from Mitochondrial DNA Control Region Sequences

    PubMed Central

    Wang, Weiran; Qiao, Yu; Pan, Wenshi; Yao, Meng

    2015-01-01

    Many Asian colobine monkey species are suffering from habitat destruction and population size decline. There is a great need to understand their genetic diversity, population structure and demographic history for effective species conservation. The white-headed langur (Trachypithecus leucocephalus) is a Critically Endangered colobine species endemic to the limestone karst forests in southwestern China. We analyzed the mitochondrial DNA (mtDNA) control region sequences of 390 fecal samples from 40 social groups across the main distribution areas, which represented one-third of the total extant population. Only nine haplotypes and 10 polymorphic sites were identified, indicating remarkably low genetic diversity in the species. Using a subset of 77 samples from different individuals, we evaluated genetic variation, population structure, and population demographic history. We found very low values of haplotype diversity (h = 0.570 ± 0.056) and nucleotide diversity (π = 0.00323 ± 0.00044) in the hypervariable region I (HVRI) of the mtDNA control region. Distribution of haplotypes displayed marked geographical pattern, with one population (Chongzuo, CZ) showing a complete lack of genetic diversity (having only one haplotype), whereas the other population (Fusui, FS) having all nine haplotypes. We detected strong population genetic structure among habit patches (ΦST = 0.375, P < 0.001). In addition, the Mantel test showed a significant correlation between the pairwise genetic distances and geographical distances among social groups in FS (correlation coefficient = 0.267, P = 0.003), indicting isolation-by-distance pattern of genetic divergence in the mtDNA sequences. Analyses of demographic history suggested an overall stable historical population size and modest population expansion in the last 2,000 years. Our results indicate different genetic diversity and possibly distinct population history for different local populations, and suggest that CZ and FS should be

  5. Experimental study on the mechanical properties of simulated columnar jointed rock masses

    NASA Astrophysics Data System (ADS)

    Xiao, Wei-min; Deng, Rong-gui; Zhong, Zhi-bin; Fu, Xiao-min; Wang, Cong-yan

    2015-02-01

    Columnar jointed rock mass is a kind of structural rock mass commonly encountered in igneous rocks. Due to the effects of columnar joint networks, anisotropy is the typical mechanical property of columnar jointed rock mass, i.e. deformation and strength varying with loading direction. Correct understanding of the mechanical anisotropy of columnar jointed rock mass is a key problem that should be solved for demonstration and design of large scale rock mass projects such as dams and underground cavern excavations constructed in it. Plaster simulated columnar jointed rock mass specimens at dip angles varying from 0° to 90° with respect to the axial stress were tested under uniaxial compression conditions to investigate the mechanical anisotropy and failure modes. Based on analyses of experimental results, it was found that the strength and deformation of columnar jointed rock masses had pronounced ‘U-shaped’ anisotropy. In the anisotropic curves, the maximum and minimum values occurred at β = 90° and β = 45°, respectively. It was also shown that the lateral strain ratio was relatively high, especially when the dip angle was close to (45° - φj/2), where φj was the joint friction angle. An empirical expression was adopted to predict the ‘U-shaped’ anisotropy of deformation and strength and the predicted anisotropic curves agreed reasonably well with experimental data. Furthermore, four types of failure modes were summarized based on experimental results and corresponding mechanisms were also discussed.

  6. Statistic study on developing condition of horizontal columnar joints in Jeongja and Eupchon beach areas, SE Korea

    NASA Astrophysics Data System (ADS)

    Jin, K.; Kim, Y.; Geologic Structure; Geohazard Research Group

    2010-12-01

    Unusual patterns of columnar joints are developed in Tertiary volcanic rocks along the Jeongja and Eupchon beach areas, SE Korea. The columnar joints represent various features in shape and orientation, including horizontal and inclined column distribution. The shape and orientation of columnar joints were statistically analyzed to understand the causes of the unusual column patterns. For this purpose, the shape of the column face perpendicular to the column direction and the trend and plunge of the column are analyzed. Most columnar joints in the study areas have five or six column faces, and the column diameter perpendicular to the column direction is in a range of between 30 to 50 cm. Columnar joints generally develop vertically due to cooling from both top and bottom surfaces. However, unusual horizontal and inclined columnar joints are observed in the study areas. Therefore, the horizontal and inclined columnar joints developed in the study areas may suggest abnormal cooling condition. The volcanic rocks in the study areas intruded or extruded in late Miocene (22-16 Ma), which coincides with a period of high sea level in the Miocene. The sea level is almost the same as the present sea level. This may suggest that the unusual columnar joint patterns that have developed in the study areas may have been affected by sea water. Therefore, if the characteristics of these columnar joints are more intensively studied on a morphological, petrological, geochemical, and chronological level, we can better understand the developing mechanism of horizontal columnar joints.

  7. DEVELOPMENT OF THE STERILE INSECT TECHNIQUE TO MANAGE AN INVASIVE INSECT PEST, CACTOBLASTIS CACTORUM, ATTACKING PRICKLY PEAR CACTUS IN QUINTANA ROO, MEXICO, AND SOUTHEASTERN USA

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The most successful classical biological control of weeds program has been the control of invasive prickly-pear cactus (Opuntia spp.) by the Argentine cactus moth Cactoblastis cactorum. However, the moth has now become an invasive pest in the southeastern USA and its ability to dramatically control ...

  8. Phenology and egg production of the cactus moth, Cactoblastis cactorum(Lepidoptera: Pyralidae): comparison of field census data and life stage development in the field

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Natural phenology and development of the cactus moth, Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) was studied under field conditions in St. Marks National Wildlife Refuge, St. Marks, FL. from July 2006 to September 2007. Cactus pads (Opuntia stricta Haw. [Cactaceae]) were visually surveyed...

  9. Synthesis of "cactus" top-decorated aligned carbon nanotubes and their third-order nonlinear optical properties.

    PubMed

    Li, P H; Qu, Y L; Xu, X J; Zhu, Y W; Yu, T; Chin, K C; Mi, J; Gao, X Y; Lim, C T; Shen, Z X; Wee, A T S; Ji, W; Sow, C H

    2006-04-01

    We report a new morphology of "cactus" top-decorated aligned carbon nanotubes grown by the PECVD method using pure C2H2 gas. Unlike most previous reports, no additional carrier gas is used for pretreatment. Carbon nanotubes can still grow and maintain the tubular structure underneath the "cactus" tops. It is proposed that the H atoms produced by the dissociation of C2H2 activate the catalyst nanoparticles. Scanning electron microscopy (SEM) shows that the top "cactus" morphology is composed of a large quantity of small nanosheets. Transmission electron microscopy (TEM) reveals the amorphous carbon nature of these "cactus" structures. The formation of these "cactus" structures is possibly due to covalent absorption and reconstruction of carbon atoms on the broken graphite layers of nanotubes produced by the strong ion bombardment under plasma. The third-order optical nonlinearities and nonlinear dynamics are also investigated. The third-order nonlinear susceptibility magnitude /chi(3)/ is found to be 2.2 x 10(-11) esu, and the relaxation process takes place in about 1.8 ps. PMID:16736755

  10. Review of samples of sediment, tailings, and waters adjacent to the Cactus Queen gold mine, Kern County, California

    USGS Publications Warehouse

    Rytuba, James J.; Kim, Christopher S.; Goldstein, Daniel N.

    2011-01-01

    The Cactus Queen Mine is located in the western Mojave Desert in Kern County, California. The Cactus Queen gold-silver (Au-Ag) deposit is similar to other Au-Ag deposits hosted in Miocene volcanic rocks that consist of silicic domes and associated flows, pyroclastic rocks, and subvolcanic intrusions. The volcanic rocks were emplaced onto a basement of Mesozoic silicic intrusive rocks. A part of the Cactus Queen Mine is located on Federal land managed by the U.S. Bureau of Land Management (BLM). Staff from the BLM initially sampled the mine area and documented elevated concentrations of arsenic (As) in tailings and sediment. BLM then requested that the U.S. Geological Survey (USGS), in collaboration with Chapman University, measure and characterize As and other geochemical constituents in sediment, tailings, and waters on the part of the mine on Federal lands. This report is made in response to the request by the BLM, the lead agency mandated to conduct a Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) - Removal Site Investigation (RSI). The RSI applies to the potential removal of As-contaminated mine waste from the Cactus Queen Mine as a means of reducing As release and exposure to humans and biota. This report summarizes data obtained from field sampling of sediments, mine tailings, and surface waters at the Cactus Queen Mine on January 27, 2008. Our results provide a preliminary assessment of the sources of As and associated chemical constituents that could potentially impact humans and biota.