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Sample records for leucocephalus columnar cactus

  1. Pollination system of the Pilosocereus leucocephalus columnar cactus (tribe Cereeae) in eastern Mexico.

    PubMed

    Munguía-Rosas, M A; Sosa, V J; Jácome-Flores, M E

    2010-07-01

    It has been suggested that there is a geographic dichotomy in the pollination systems of chiropterophilous columnar cacti: in intra-tropical areas they are pollinated almost exclusively by bats, whereas in extratropical areas they are pollinated by bats, birds and bees. However, currently the studies are clumped both taxonomically (mainly Pachycereeae species) and geographically (mainly in the Tehuacan Valley and the Sonoran Desert). This clumping limits the possibility of generalising the pattern to other regions or cactus tribes. Only four of the 36 chiropterophilous cacti in Pilosocereus have been studied. Despite the tropical distribution of two Pilosocereus species, bees account for 40-100% of their fruit set. We examined how specialised is the pollination system of P. leucocephalus in eastern Mexico. As we studied tropical populations, we expected a bat-specialised pollination system. However, previous studies of Pilosocereus suggest that a generalised pollination system is also possible. We found that this cactus is mainly bat-pollinated (bats account for 33-65% of fruit set); although to a lesser degree, diurnal visitors also caused some fruit set (7-15%). Diurnal visitors were more effective in populations containing honeybee hives. P. leucocephalus is partially self-compatible (14-18% of fructification) but unable to set fruit without visitors. Despite the variation in pollination system, P. leucocephalus shows more affinity with other columnar cacti from tropical regions than with those from extratropical regions. Although we report here that a new species of tropical Pilosocereus is relatively bat-specialised, this Cereeae genus is more flexible in its pollination system than the Pachycereeae genera.

  2. 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

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

    PubMed

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

    2013-02-01

    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. 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. 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. 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 from the nurse effect.

  4. 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

  5. Extensive ribosomal DNA genic variation in the columnar cactus Lophocereus.

    PubMed

    Hartmann, S; Nason, J D; Bhattacharya, D

    2001-08-01

    Sequence analysis of the hypervariable internal transcribed spacer (ITS) regions of ribosomal DNA (rDNA) is commonly used to gain insights into plant and animal population structure and phylogeny. We characterized ITS1, ITS2, and the 5.8S coding region of 18 senita (Lophocereus) individuals from 12 different populations in Baja as well as from closely related cactus species. Analyses of multiple clones demonstrated extensive paralogy in the senita rDNA gene family. We identified at least two putatively non-recombining rDNA operons in senita as well as multiple paralogous sequences within each operon. Usage of PCR, reverse transcriptase (RT)-PCR, Southern blot, primary sequence analyses of the 18S rDNA gene, and secondary structure analyses of the 5.8S rRNA showed that one of the operons encodes rDNA pseudogenes in a low copy-number (Truncated), whereas the second operon encodes an expressed rRNA (Functional). Surprisingly, we found extensive paralogy not only in the ITS regions but also in the 5.8S coding regions in senita both within and between operons. Phylogenetic analyses suggest that the second rDNA operon originated prior to the divergence of Lophocereus. A significant (p < 0.05) divergence-rate acceleration was found in the Lophocereus 5.8S rDNA coding region in the Functional operon in comparison to Pereskiopsis porteri (Cactaceae) and Portulaca molokiniensis (Portulacaceae) with Silene dioica and Spinacia oleracea as the outgroups.

  6. 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.

  7. 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

  8. Pollination ecology of Stenocereus queretaroensis (Cactaceae), a chiropterophilous columnar cactus, in a tropical dry forest of Mexico.

    PubMed

    Ibarra-Cerdeña, Carlos N; Iñiguez-Dávalos, Luis I; Sánchez-Cordero, Víctor

    2005-03-01

    Flowers of columnar cacti are animal-pollinated, often displaying a chiropterophylic syndrome. This study examined if the columnar cactus Stenocereus queretaroensis, a tropical species endemic to western Mexico, is bat-pollinated, by studying its pollination biology and the foraging behavior of potential pollinators. Flowers were produced in winter through spring, peaking in April. Anthesis was nocturnal, and stigma and anther turgidity began around 2200 hours. Production of nectar secretion and highest sugar concentration and energy supply were nocturnal, peaking between 2200 and 2400 hours. Manual auto-pollination and exclusion experiments showed that self-pollination yielded no fruits, while nocturnal pollinators resulted in high fruit set and seed set compared to diurnal pollination treatments. The nectar-feeding bat Leptonycteris curasoae (Phyllostomidae) was the main nocturnal pollinator with the highest effective pollination. Peak bat visitation coincided with peaks in nectar production. The high abundance of L. curasoae throughout the 4-yr study, suggests that it is a seasonally reliable pollinator for this columnar cactus. While pollination syndromes have been increasingly called into question in recent years, this study suggests that at least for this system, there is a fairly close fit between pollinator and pollination syndrome.

  9. 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.

  10. 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.

  11. 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

  12. Development of microsatellite markers using next-generation sequencing for the columnar cactus Echinopsis chiloensis (Cactaceae).

    PubMed

    Ossa, Carmen G; Larridon, Isabel; Peralta, Gioconda; Asselman, Pieter; Pérez, Fernanda

    2016-12-01

    The aim of this study was to develop microsatellite markers as a tool to study population structure, genetic diversity and effective population size of Echinopsis chiloensis, an endemic cactus from arid and semiarid regions of Central Chile. We developed 12 polymorphic microsatellite markers for E. chiloensis using next-generation sequencing and tested them in 60 individuals from six sites, covering all the latitudinal range of this species. The number of alleles per locus ranged from 3 to 8, while the observed (Ho) and expected (He) heterozygosity ranged from 0.0 to 0.80 and from 0.10 to 0.76, respectively. We also detected significant differences between sites, with FST values ranging from 0.05 to 0.29. Microsatellite markers will enable us to estimate genetic diversity and population structure of E. chiloensis in future ecological and phylogeographic studies.

  13. The genetic structure of a columnar cactus with a disjunct distribution: Stenocereus gummosus in the Sonoran desert.

    PubMed

    Clark-Tapia, R; Molina-Freaner, F

    2003-06-01

    Stenocereus gummosus is a columnar cactus endemic to the Sonoran desert that exhibits a disjunct distribution: it is widely distributed in Baja California and restricted to a small coastal area in mainland Sonora. In this paper, we examine the genetic structure and the mating system of this species in order to explore the origin of the disjunction and describe aspects of the pollination biology. Flowers are nocturnal, pollinated mainly by sphingids and self-incompatible. Polymorphism for allozymes (11 loci) was relatively high (P=75%) but moderate levels of heterozygosity were detected (H(o)=0.103 and H(e)=0.261). Sonoran populations exhibited higher levels of genetic variation than peninsular populations. H(e) declined with latitude when just peninsular and two island populations are included. Substantial levels of inbreeding within populations (f=0.60), moderate differentiation among populations (theta=0.10), and no evidence of isolation by distance were detected. The neighbor-joining phenogram showed Sonoran and island populations nested within peninsular populations. Mainland populations showed greater genetic similarity to island populations, supporting a dispersal hypothesis for the origin of the disjunction. Future studies using DNA markers are suggested in order to better understand the forces that have shaped the genetic structure of this species.

  14. Insectivorous bat pollinates columnar cactus more effectively per visit than specialized nectar bat.

    PubMed

    Frick, Winifred F; Price, Ryan D; Heady, Paul A; Kay, Kathleen M

    2013-01-01

    Plant-pollinator interactions are great model systems to investigate mutualistic relationships. We compared pollinator effectiveness between facultative and obligate nectar-feeding bats to determine how foraging specialization influences mutualistic interactions in a bat-adapted cactus. We predicted that a specialized nectarivorous bat would deliver more pollen than an opportunistic nectar-feeding bat because of specialized adaptations to nectar feeding that indicate close association with their food plants. Counter to our predictions, the opportunistic Antrozous pallidus delivered significantly more pollen grains per visit than the specialized Leptonycteris yerbabuenae. Higher pollinator effectiveness, based on visitation rates and pollen deposition levels, varied between species by site, and although A. pallidus visits flowers much less frequently than L. yerbabuenae over all sites, it is likely an effective and reliable pollinator of Pachycereus pringlei in Baja, Mexico. Our results suggest that morphological adaptations and dietary specialization on nectar do not necessarily confer advantages for pollination over less specialized plant visitors and highlight the reciprocally exploitative nature of mutualisms.

  15. Effect of habitat disturbance on pollination biology of the columnar cactus Stenocereus quevedonis at landscape-level in central Mexico.

    PubMed

    Rodríguez-Oseguera, A G; Casas, A; Herrerías-Diego, Y; Pérez-Negrón, E

    2013-05-01

    Stenocereus quevedonis ('pitire') is a columnar cactus endemic to central Mexico, grown for its edible fruit. Phenology, pollination biology and behaviour of flower visitors of this species were compared in six conserved and disturbed sites, hypothesising that: (i) pitire pollination is self-incompatible, requiring animal vectors; (ii) higher incidence of radiation on plants in cleared forest may lead to a higher number of flowers per pitire plant and longer blooming season, and disturbing and differential spatial availability of flower resources may determine differential attraction of pollinators to conserved and disturbed areas; (iii) if pitire pollination system is specialised, reproductive success would decrease with pollinator scarcity, or other species may substitute for main pollinators. In all sites, pitire reproduction started in January, flowering peak occurring in April, anthesis duration was 15 h and predominantly nocturnal (9 h), pollen was released at 23:00 h, nectar was produced throughout anthesis, and breeding system was self-incompatible. Flower production per plant was similar in disturbed and conserved sites, but flower availability was higher (because of higher tree density) and longer in disturbed sites. Pollination is nocturnal, the most frequent legitimate pollinator being the bat Leptonycteris yerbabuenae; diurnal pollination is rare but possible, carried out by bee species. Fruit and seed set in control and nocturnal pollination treatments at disturbed sites were higher than in conserved sites. Frequency of L. yerbabuenae visits was similar among site types, but more visits of complementary nocturnal and diurnal pollinators were recorded in disturbed sites, which could explain differences in reproductive success.

  16. Historical vicariance and postglacial colonization effects on the evolution of genetic structure in Lophocereus, a Sonoran Desert columnar cactus.

    PubMed

    Nason, John D; Hamrick, J L; Fleming, Theodore H

    2002-11-01

    Distinguishing the historical effects of gene migration and vicariance on contemporary genetic structure is problematic without testable biogeographic hypotheses based on preexisting geological and environmental evidence. The availability of such hypotheses for North America's Sonoran Desert has contributed to our understanding of the effect of historical vicariance and dispersal events on the diversification of this region's vertebrate biota but have not yet been applied to its flora. In this paper we describe a detailed allozyme analysis of the population genetic structure and phylogeography of the Sonoran Desert columnar cactus, Lophocereus schottii (senita). Inferred phylogroup distributions reflect two historical vicariance events: (1) a middle Pliocene northward transgression of the Sea of Cortéz that is reflected in well-supported Baja California peninsular and continental phylogroups but not in current taxonomic treatments of the species; and (2) a late Pliocene transpeninsular seaway across southern Baja that is reflected in tentative support for peninsular and southern Cape Region phylogroups corresponding to taxonomic varieties L. schottii var. schottii and L. schottii var. australis, respectively. A middle Pleistocene midpeninsular seaway hypothesized to explain congruent phylogroup distributions in several vertebrate taxa is not reflected in L. s. var. schottii, nor is the distinction of a third variety, L. s. var. tenuis, from continental populations of L. s. var. schottii. Linear regression of pairwise estimates of interpopulation differentiation (M and F(ST)/[1 - F(ST)]) on interpopulation geographic distance revealed significant evidence of isolation by distance within peninsular and continental phylogroups but not between them, consistent with historical vicariance between but not within these regions. We also found significant evidence of isolation by distance between putative L. s. var. schottii and L. s. var. australis phylogroups, suggesting

  17. Growth and reproductive characteristics of the columnar cactus Stenocereus queretaroensis and their relationships with environmental factors and colonization by arbuscular mycorrhizae.

    PubMed

    Pimienta-Barrios, Eulogio; Pimienta-Barrios, Enrique; Salas-Galván, Mariá Eugenia; Zañudo-Hernandez, Julia; Nobel, Park S

    2002-06-01

    Three natural populations of pitayo (Stenocereus queretaroensis (Weber) Buxbaum), a columnar arborescent cactus, were studied in their subtropical environments in western Mexico. All of the sites were characterized by shallow, nutrient-poor soils. Percentage of colonization by arbuscular mycorrhizae (AM) fungi, stem growth, fruit mass, and percentage germination were greater in S. queretaroensis at Autlan, Jalisco (AJ) than at Zacoalco de Torres, Jalisco (ZTJ) or Santa Rosa, Zacatecas (SRZ). The onset of root colonization by arbuscular mycorrhizae during the middle of the summer wet period preceded increases in stem extension rate and stem phosphorus concentration. Based on previous studies of effects of environmental factors on photosynthesis, climatic conditions were more favorable for photosynthesis at AJ than at SRZ and ZTJ, as indicated by the amount of summer rainfall, the amount of light, and the moderate air temperatures that prevailed during the fall and winter seasons. There was a significant positive correlation between stem growth and percentage of total root length colonized by arbuscules of AM fungi for S. queretaroensis at SRZ and AJ, but not at ZTJ. A negative significant correlation was observed between stem growth and maximal and minimal air temperatures at the three study sites. Stem growth was positively related to rainfall only at SRZ, and light was statistically related to stem growth only at ZTJ. Among sites, S. queretaroensis at AJ had the highest carbon gain and greatest AM colonization, creating physiological conditions that led to the highest stem growth, fruit mass and percentage of seed germination.

  18. Direct and indirect estimates of gene flow among wild and managed populations of Polaskia chichipe, an endemic columnar cactus in Central Mexico.

    PubMed

    Otero-Arnaiz, Adriana; Casas, Alejandro; Hamrick, James L

    2005-12-01

    Microsatellite markers were used to obtain direct and indirect estimates of gene flow in populations of Polaskia chichipe under different management regimes, in order to understand the genetic consequences of gene flow in the evolutionary process of domestication. P. chichipe is a columnar cactus endemic to the Tehuacan Valley, Central Mexico, and has come under domestication for its edible fruit. Morphological, phenological, physiological, and reproductive differences, apparently attributable to artificial selection, exist between wild and managed populations, which grow sympatrically. However, strong gene flow may counteract the effects of this selection. In this study, we used paternity analysis to demonstrate that although most of the pollinations occur among individuals within the same population at distances < 40 m, pollen flow from other populations is considerable (27 +/- 5%). Heterogeneity in pollen clouds sampled by mother plants (FST = 0.12) indicated nonrandom mating, which is probably due to temporal heterogeneity in pollen movement. Spatial structure on local and regional scales is consistent with an isolation-by-distance model. The similarity of indirect, direct and demographic estimates of neighbourhood size (74-250 individuals) suggests that this genetic structure is representative of an equilibrium state. These results suggest that traditional management practices have conserved the genetic resources of this species in situ, but also that gene flow is counteracting the effect of domestication to some degree. We discuss our results in the general context of genetic exchange between cultivated and wild populations during the domestication process.

  19. Columnar homoconjugation

    SciTech Connect

    Angus, R.O. Jr.; Johnson, R.P.

    1988-01-22

    Homoconjunctive orbital interactions in columnar cyclic arrays of ..pi.. bonds are analyzed through a simple perturbation approach and through ab initio calculations. These interactions lead to Hueckel arrays of bonding and antibonding orbitals and should have a net destabilizing effect. Specific compounds (1-3) which engender columnar homoconjugation consist of n(n greater than or equal to 3) 1,4-cyclohexadiene units which are connected in a cyclic structure of D/sub nh/ symmetry. These have been previously referred to as beltenes. Optimized geometries (STO-2G, RHF) are reported for compounds with n = 3-5. Single point 3-21G calculations have been performed at optimized geometries. The double bonds in these columnar structures are predicted to be significantly pyramidalized. Orbital interactions and estimates for the potential stability of columnar structures are discussed. 18 references, 4 figures, 3 tables.

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  1. 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.

  2. 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.

  3. Scaling in Columnar Joints

    NASA Astrophysics Data System (ADS)

    Morris, Stephen

    2007-03-01

    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, we suggest 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 in experiments where the evaporation rate was fixed using feedback methods. 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.

  4. 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.

  5. 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.

  6. 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.

  7. Columnar lined Barrett's oesophagus.

    PubMed

    Sharma, Neel; Ho, Khek Yu

    2015-12-01

    Over the past few years, the definition of Barrett's oesophagus has altered with no real agreement on histological understanding. This article highlights the increasing confusion regarding Barrett's oesophagus with a focus on the all-too-frequently ignored aspect of the columnar lined oesophagus.

  8. 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.

  9. 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.

  10. 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.

  11. 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.

  12. 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.

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

    PubMed

    Richardson, D J; Cole, R A

    1997-06-01

    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.

  14. Columnar-lined esophagus. Definitions.

    PubMed

    Spechler, Stuart Jon

    2002-02-01

    Recognition of a columnar-lined esophagus requires precise criteria by which to delimit the esophagus and the stomach. Endoscopically recognizable landmarks such as the squamocolumnar junction (SCJ or Z-line) can be used to identify structures at the gastroesophageal junction. Once the SCJ is located proximal to the gastroesophageal junction, a columnar-lined segment of esophagus is visible. If biopsy specimens from the columnar-lined segment show specialized intestinal metaplasia, then the patient has Barrett's esophagus (BE), and the extent of the columnar lining determines if it is short- or long-segment BE.

  15. 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.

  16. How Nectar-Feeding Bats Localize their Food: Echolocation Behavior of Leptonycteris yerbabuenae Approaching Cactus Flowers

    PubMed Central

    Koblitz, Jens C.; Fleming, Theodore H.; Medellín, Rodrigo A.; Kalko, Elisabeth K. V.; Schnitzler, Hans-Ulrich; Tschapka, Marco

    2016-01-01

    Nectar-feeding bats show morphological, physiological, and behavioral adaptations for feeding on nectar. How they find and localize flowers is still poorly understood. While scent cues alone allow no precise localization of a floral target, the spatial properties of flower echoes are very precise and could play a major role, particularly at close range. The aim of this study is to understand the role of echolocation for classification and localization of flowers. We compared the approach behavior of Leptonycteris yerbabuenae to flowers of a columnar cactus, Pachycereus pringlei, to that to an acrylic hollow hemisphere that is acoustically conspicuous to bats, but has different acoustic properties and, contrary to the cactus flower, present no scent. For recording the flight and echolocation behaviour we used two infrared video cameras under stroboscopic illumination synchronized with ultrasound recordings. During search flights all individuals identified both targets as a possible food source and initiated an approach flight; however, they visited only the cactus flower. In experiments with the acrylic hemisphere bats aborted the approach at ca. 40–50 cm. In the last instant before the flower visit the bats emitted a long terminal group of 10–20 calls. This is the first report of this behaviour for a nectar-feeding bat. Our findings suggest that L. yerbabuenae use echolocation for classification and localization of cactus flowers and that the echo-acoustic characteristics of the flower guide the bats directly to the flower opening. PMID:27684373

  17. 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.

  18. Development and characterization of 10 microsatellite loci in the giant cardon cactus, Pachycereus pringlei (Cactaceae).

    PubMed

    Gutiérrez Flores, Carina; Lozano Garza, O Adrian; León de la Luz, José L; García de León, Francisco J

    2014-02-01

    Microsatellite primers were developed for the cardon, a giant columnar cactus (Pachycereus pringlei) of the Sonoran Desert, to investigate intraspecific genetic patterns of diversity and population structure. • Using 454 GS-FLX technology and bioinformatics tools, microsatellite primers were successfully identified on 282 reads, including di-, tri-, tetra-, penta-, and hexanucleotides. A set of 10 primers were characterized on 80 individuals collected in two areas of the Baja California peninsula, Mexico. All 10 loci were polymorphic, with a mean of 6.3 alleles per locus and overall levels of observed and expected heterozygosities ranging from 0.41 to 0.59 and from 0.40 to 0.57, respectively. Alleles per individual plant ranged from one to four, suggesting a polyploidal genome. • These loci should be useful for future investigations of population structure, genetic diversity, and gene flow in the cardon cactus.

  19. Development and characterization of 10 microsatellite loci in the giant cardon cactus, Pachycereus pringlei (Cactaceae)1

    PubMed Central

    Gutiérrez Flores, Carina; Lozano Garza, O. Adrian; León de la Luz, José L.; García de León, Francisco J.

    2014-01-01

    • Premise of the study: Microsatellite primers were developed for the cardon, a giant columnar cactus (Pachycereus pringlei) of the Sonoran Desert, to investigate intraspecific genetic patterns of diversity and population structure. • Methods and Results: Using 454 GS-FLX technology and bioinformatics tools, microsatellite primers were successfully identified on 282 reads, including di-, tri-, tetra-, penta-, and hexanucleotides. A set of 10 primers were characterized on 80 individuals collected in two areas of the Baja California peninsula, Mexico. All 10 loci were polymorphic, with a mean of 6.3 alleles per locus and overall levels of observed and expected heterozygosities ranging from 0.41 to 0.59 and from 0.40 to 0.57, respectively. Alleles per individual plant ranged from one to four, suggesting a polyploidal genome. • Conclusions: These loci should be useful for future investigations of population structure, genetic diversity, and gene flow in the cardon cactus. PMID:25202601

  20. Cactus granuloma of the skin.

    PubMed

    Suzuki, H; Baba, S

    1993-07-01

    A case of cactus granuloma due to the thorns of Opuntia bieglovii Engelman is reported. A 24-year-old Japanese man contacted the thorns of this cactus in Palm Springs, California, U.S.A., and, three months later, numerous, slightly elevated papules 2 to 4 mm in diameter appeared on the dorsum of his right hand and fingers. Histopathological examination revealed many small granulomas surrounding the bristle fragments throughout the dermis. The granulomas consisted of epithelioid cells, Langhans type and foreign body type giant cells. The fragments of the barbed bristles gave strongly positive reactions with PAS. Two hypothetical mechanisms, one allergic and the other non-allergic, are offered to explain this granuloma formation and are discussed with reference to the literature.

  1. Functional trade-offs in succulent stems predict responses to climate change in columnar cacti.

    PubMed

    Williams, David G; Hultine, Kevin R; Dettman, David L

    2014-07-01

    Columnar cacti occur naturally in many habitats and environments in the Americas but are conspicuously dominant in very dry desert regions. These majestic plants are widely regarded for their cultural, economic, and ecological value and, in many ecosystems, support highly diverse communities of pollinators, seed dispersers, and frugivores. Massive amounts of water and other resources stored in the succulent photosynthetic stems of these species confer a remarkable ability to grow and reproduce during intensely hot and dry periods. Yet many columnar cacti are potentially under severe threat from environmental global changes, including climate change and loss of habitat. Stems in columnar cacti and other cylindrical-stemmed cacti are morphologically diverse; stem volume-to-surface area ratio (V:S) across these taxa varies by almost two orders of magnitude. Intrinsic functional trade-offs are examined here across a broad range of V:S in species of columnar cacti. It is proposed that variation in photosynthetic gas exchange, growth, and response to stress is highly constrained by stem V:S, establishing a mechanistic framework for understanding the sensitivity of columnar cacti to climate change and drought. Specifically, species that develop stems with low V:S, and thus have little storage capacity, are expected to express high mass specific photosynthesis and growth rates under favourable conditions compared with species with high V:S. But the trade-off of having little storage capacity is that low V:S species are likely to be less tolerant of intense or long-duration drought compared with high V:S species. The application of stable isotope measurements of cactus spines as recorders of growth, water relations, and metabolic responses to the environment across species of columnar cacti that vary in V:S is also reviewed. Taken together, our approach provides a coherent theory and required set of observations needed for predicting the responses of columnar cacti to

  2. 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). © 2011 American College of Veterinary Ophthalmologists.

  3. Demographic monitoring of Wright fishhook cactus

    Treesearch

    Ronald J. Kass

    2001-01-01

    Wright fishhook cactus (Sclerocactus wrightiae Benson) is a small barrel cactus endemic to the San Rafael Swell in south-central Utah. It was listed as an endangered species in 1979 due to its small population size, threats of over-collecting, and development associated with oil and gas. Demographic monitoring was initiated in 1993 with the following objectives: to...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  5. Night roosts of bald eagles (Haliaeetus leucocephalus) wintering in northern Arizona

    Treesearch

    Prabin K. Joshi

    2009-01-01

    Bald eagles (Haliaeetus leucocephalus) were delisted from threatened or endangered status in 2007 in the conterminous states because of their encouraging comeback throughout most of North America. However the recent court decision on 1 May 2008 forced USFWS to issue a rule to amend the regulations for the Federal List of Endangered and Threatened Wildlife by...

  6. Mercury Exposure in Bald Eagles (Haliaeetus leucocephalus) Admitted for Rehabilitation in Iowa, USA.

    PubMed

    Blanchong, Julie A; Reiter-Marolf, William J; Dinsmore, Stephen J

    2017-04-01

    To gain insight into mercury exposure in Bald Eagles ( Haliaeetus leucocephalus ) in Iowa, US we collected blood from 22 rehabilitation eagles in 2012-13. The geometric mean blood mercury level was 0.144 μg/g (95% confidence interval: 0.066-0.314) and was at the lower end of the range of levels reported elsewhere.

  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. © 2015 John Wiley & Sons Ltd.

  10. Bacteria associated with Copestylum (Diptera, Syrphidae) larvae and their cactus host Isolatocereus dumortieri.

    PubMed

    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 31,079 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.

  11. 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.

  12. Specialization clines in the pollination systems of agaves (Agavaceae) and columnar cacti (Cactaceae): A phylogenetically controlled meta-analysis.

    PubMed

    Munguía-Rosas, Miguel A; Sosa, Vinicio J; Ojeda, Mario M; De-Nova, J Arturo

    2009-10-01

    The biogeography of plant-animal interactions is a novel topic on which many disciplines converge (e.g., reproductive biology, biogeography, and evolutionary biology). Narrative reviews have indicated that tropical columnar cacti and agaves have highly specialized pollination systems, while extratropical species have generalized systems. However, this dichotomy has never been quantitatively tested. We tested this hypothesis using traditional and phylogenetically informed meta-analysis. Three effect sizes were estimated from the literature: diurnal, nocturnal, and hand cross-pollination (an indicator of pollen limitation). Columnar cactus pollination systems ranged from purely bat-pollinated in the tropics to generalized pollination, with diurnal visitors as effective as nocturnal visitors in extratropical regions; even when phylogenetic relatedness among species is taken into account. Metaregressions identified a latitudinal increase in pollen limitation in columnar cacti, but this increase was not significant after correcting for phylogeny. The currently available data for agaves do not support any latitudinal trend. Nectar production of columnar cacti varied with latitude. Although this variation is positively correlated with pollination by diurnal visitors, it is influenced by phylogeny. The degree of specificity in the pollination systems of columnar cacti is heavily influenced by ecological factors and has a predictable geographic pattern.

  13. 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.

  14. 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.

  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. 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…

  18. Pillar of strength: Columnar cactus as a key factor in Yoreme heritage and wildland preservation.

    PubMed

    Semotiuk, Andrew J; Colunga-GarcíaMarín, Patricia; Valenzuela Maldonado, David; Ezcurra, Exequiel

    2017-09-05

    The persistence of traditional cultures and modes of land use within rapidly changing, globalized societies is a central issue in understanding ecological and cultural change in the Anthropocene. Located in the heart of the Green Revolution, the Yoreme (Mayo) people of the Mayo Valley in Mexico still obtain a significant proportion of their sustenance from wild ecosystems in the midst of this intensive technological and agricultural development. They live in and around the thornscrub dominated by pitaya (Stenocereus thurberi (Engelm.) Buxb.). In this study, we hypothesize that pitaya supports Yoreme heritage and sustenance amidst anthropogenic changes to the landscape, and we asked three specific questions: What is the land-use status of the S. thurberi habitat? What are its potential uses? Does S. thurberi provide economic value? To address these questions, we conducted interviews, vegetation surveys, and land-use analysis based on geographic information systems. We found that (a) land conversion of the pitaya-rich thornscrub is occurring at a precipitous rate, (b) local producers preserve and adapt their traditions, and (c) S. thurberi supports Yoreme heritage while providing economic benefit. The resulting land-use projections along with the cultural value of pitaya products shows the importance of conserving land and promoting sustainable projects instead of clearing land for other uses. If habitat shrinking continues at the current rate, it is likely that both Yoreme livelihoods and continued cultural practices will suffer.

  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.; ,

    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. Columnar Jointing Thermo-Mechanics

    NASA Astrophysics Data System (ADS)

    Iddon, Fiona; Hornby, Adrian; Kendrick, Jackie; Wadsworth, Fabian; von Aulock, Felix; Lavallée, Yan

    2014-05-01

    Thermo-mechanical effects, common to a wide range of geological phenomena, are integral to the formation of columnar joints during cooling and crystallisation of lava flows. The process, and resultant geometry, relies on a complex inter-play between heat distribution, contraction and tensile strength, yet the kinetics of their formation remains elusive. Results are presented from a combination of field survey, thermo-analytical characterisation and mechanical investigation to constrain conditions favourable for columnar jointing. Columnar joints from Seljavallir, Iceland, produce quadratic to heptagonal cross sectional patterns with column widths ranging from 20 to 70 cm in size. The fracture surfaces are characterised by striae of which spacing (between 1 to 6 cm) appear to share a positive linear relationship to the joint spacing. The striae exhibit both a smooth and rough portion, interpreted to express a change in deformation regime from fully brittle, mode-I fracture propagation to an increasingly ductile response of the lava with tensile fracture dissipation as the fracture event wanes. The contraction of the basalts has been investigated via the expansion coefficient determined in a dilatometer (at 3mN of normal stress and a rate of 2 °C/min). The expansion coefficient has been constrained to 10-5/°C and the onset of melting (and completion of natural crystallisation) at 1150°C. Experiments are currently being conducted to assess the effect of cooling rate and normal stress on the properties of the Seljavallir basalts. The mechanical properties of the rock in tension have been tested at room temperature in a uniaxial press (high-temperature tests are also scheduled). During true-tension pull test at a strain rate of 10-4 s-1, elastic deformation agrees to a Young's modulus of 6.3 GPa. Tensile failure initiated after 0.35% strain with the generation of a large crack at a peak stress of 2.2 MPa. The fracture induced a stress drop and upon stress build-up to

  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. Flavobacterium columnare chemotaxis to channel catfish mucus

    USDA-ARS?s Scientific Manuscript database

    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...

  3. 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

  4. Differences in tolerance to host cactus alkaloids in Drosophila koepferae and D. buzzatii.

    PubMed

    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.

  5. The evolution of obligate pollination mutualisms: senita cactus and senita moth.

    PubMed

    Fleming, Theodore H; Holland, J Nathaniel

    1998-04-01

    We report a new obligate pollination mutualism involving the senita cactus, Lophocereus schottii (Cactaceae, Pachyceereae), and the senita moth, Upiga virescens (Pyralidae, Glaphyriinae) in the Sonoran Desert and discuss the evolution of specialized pollination mutualisms. L. schottii is a night-blooming, self-incompatible columnar cactus. Beginning at sunset, its flowers are visited by U. virescens females, which collect pollen on specialized abdominal scales, actively deposit pollen on flower stigmas, and oviposit a single egg on a flower petal. Larvae spend 6 days eating ovules before exiting the fruit and pupating in a cactus branch. Hand-pollination and pollinator exclusion experiments at our study site near Bahia Kino, Sonora, Mexico, revealed that fruit set in L. schottii is likely to be resource limited. About 50% of hand-outcrossed and open-pollinated senita flowers abort by day 6 after flower opening. Results of exclusion experiments indicated that senita moths accounted for 75% of open-pollinated fruit set in 1995 with two species of halictid bees accounting for the remaining fruit set. In 1996, flowers usually closed before sunrise, and senita moths accounted for at least 90% of open-pollinated fruit set. The net outcome of the senita/senita moth interaction is mutualistic, with senita larvae destroying about 30% of the seeds resulting from pollination by senita moths. Comparison of the senita system with the yucca/yucca moth mutualism reveals many similarities, including reduced nectar production, active pollination, and limited seed destruction. The independent evolution of many of the same features in the two systems suggests that a common pathway exists for the evolution of these highly specialized pollination mutualisms. Nocturnal flower opening, self-incompatible breeding systems, and resource-limited fruit production appear to be important during this evolution.

  6. Candida orba sp. nov., a new cactus-specific yeast species from Queensland, Australia.

    PubMed

    Starmer, W T; Phaff, H J; Ganter, P F; Lachance, M A

    2001-03-01

    A new species of yeast from decaying cladodes of Opuntia cactus, Candida orba, is described. This species is a member of a four-species clade of cactophilic yeasts. The new species has only been found in one region of Queensland, Australia, where it was presumably introduced during attempts to eradicate prickly pear cactus. DNA-DNA relatedness, phylogenetic analysis, physiological differences, killer-sensitivity profiles and mating reactions establish the distinctness of the taxon as a new species. C. orba is most closely related to Phaffomyces thermotolerans, a species found associated with columnar cacti in the North American Sonoran Desert. The type strain of C. orba, isolated from rotting cladodes of Opuntia stricta in the State of Queensland, Australia, is strain UCD-FST 84-833.1T (= CBS 8782T = NRRL Y-27336T = ATCC MYA-341). Only the h- mating type of the species has been recovered. The lack of the opposite mating type could be the result of a bottleneck during its introduction to Australia. The original geographic/host distribution of this species in the Americas is unknown.

  7. Comparative pollination biology of Venezuelan columnar cacti and the role of nectar-feeding bats in their sexual reproduction.

    PubMed

    Nassar, J; Ramirez, N; Linares, O

    1997-07-01

    The floral biology, reproductive system, and visitation behavior of pollinators of four species of columnar cacti, Stenocereus griseus, Pilosocereus moritzianus, Subpilocereus repandus, and Subpilocereus horrispinus, were studied in two arid zones in the north of Venezuela. Our results support the hypothesis that Venezuelan species of columnar cacti have evolved toward specialization on bat pollination. Additional information on the floral biology of a fifth species, Pilosocereus lanuginosus, was also included. All species showed the typical traits that characterize the pollination syndrome of chiropterophily. All species but Pilosocereus moritzianus were obligate outcrossers. Nectar and pollen were restricted to nocturnal floral visitors. Two species of nectar-feeding bats, Leptonycteris curasoae Miller and Glossophaga longirostris Miller, were responsible for practically all the fruit set in these cacti. Frequency of bat visitation per flower per night was highly variable within and between species of cactus, with average frequencies varying between 27 and 78 visits/flower/night. In general terms, the pattern of floral visitation through the night was significantly correlated with the pattern of nectar production and nectar sugar concentration for all species of cactus. Under natural pollination, fruit:flower ratios varied from 0.46 in Subpilocereus repandus to 0.76 in Stenocereus griseus. The efficiency of bat pollination in terms of seed:ovule ratio was high in all species, varying between 0.70 and 0.94.

  8. Kranc: Cactus modules from Mathematica equations

    NASA Astrophysics Data System (ADS)

    Husa, Sascha; Hinder, Ian; Lechner, Christiane; Schnetter, Erik; Wardell, Barry

    2016-09-01

    Kranc turns a tensorial description of a time dependent partial differential equation into a module for the Cactus Computational Toolkit (ascl:1102.013). This Mathematica application takes a simple continuum description of a problem and generates highly efficient and portable code, and can be used both for rapid prototyping of evolution systems and for high performance supercomputing.

  9. Experimental columnar metaplasia in the canine oesophagus.

    PubMed

    Gillen, P; Keeling, P; Byrne, P J; West, A B; Hennessy, T P

    1988-02-01

    Regeneration of canine oesophageal mucosa was studied under basal conditions and in the presence of gastro-oesophageal reflux. In normal circumstances mucosal defects in the oesophagus regenerate by squamous epithelium. In the presence of gastro-oesophageal reflux of either acid or a combination of acid and bile, regeneration was frequently by columnar epithelium (Barrett's oesophagus). This columnar regeneration was not seen with bile reflux alone. By the use of squamous barriers to proximal migration of columnar epithelium in the stomach, it was demonstrated that columnar re-epithelialization may occur from cells intrinsic to the oesophagus and is not dependent on proximal migration of cardiac columnar epithelium. The cell of origin of this epithelium may be located in oesophageal gland ducts and is likely to be a multipotential stem cell since the regenerated columnar epithelium may contain goblet and parietal cells not normally found in the oesophagus. This epithelium is morphologically distinct on mucin histochemistry from cardiac columnar epithelium. These findings support the concept that Barrett's epithelium is metaplastic.

  10. Phylogenetic origins of Lophocereus (Cactaceae) and the senita cactus-senita moth pollination mutualism.

    PubMed

    Hartmann, Stefanie; Nason, John D; Bhattacharya, Debashish

    2002-07-01

    Recent ecological research has revealed that the Sonoran Desert columnar cactus Lophocereus and the pyralid moth Upiga virescens form an obligate pollination mutualism, a rare but important case of coevolution. To investigate the phylogenetic origins of this unusual pollination system, we used molecular sequence data to reconstruct the phylogeny of the four taxa within the genus Lophocereus and to determine the phylogenetic position of Lophocereus within the North American columnar cacti (tribe Pachycereeae). Our analysis included Lophocereus, six Pachycereus species, Carnegiea gigantea, and Neobuxbaumia tetetzo within the subtribe Pachycereinae, and Stenocereus thurberi as an outgroup within the Stenocereinae. Extensive screening of chloroplast and mitochondrial genomes failed to reveal sequence variation within Lophocereus. At a deeper phylogenetic level, however, we found strong support for the placement of Lophocereus within Pachycereus as sister group to the hummingbird-pollinated P. marginatus. We discuss possible hypotheses that may explain the transition from bat pollination (ancestral) to moth and hummingbird pollination in Lophocereus and P. marginatus, respectively. Additional phylogenetic analyses suggest that the genus Pachycereus should be expanded to include Lophocereus, Carnegiea, Neobuxbaumia, and perhaps other species, whereas P. hollianus may need to be excluded from this clade. Future study will be needed to test taxonomic distinctions within Lophocereus, to test for parallel cladogenesis between phylogroups within Lophocereus and Upiga, and to fully delineate the genus Pachycereus and relationships among genera in the Pachycereinae.

  11. Differentiation of columnar epithelia: the hensin pathway.

    PubMed

    Vijayakumar, Soundarapandian; Takito, Jiro; Gao, XiaoBo; Schwartz, George J; Al-Awqati, Qais

    2006-12-01

    Epithelia, the most common variety of cells in complex organisms exist in many shapes. They are sheets of polarized cells that separate two compartments and selectively transport materials from one to the other. After acquiring these general characteristics, they differentiate to become specialized types such as squamous columnar or transitional epithelia. High density seeding converts a kidney-derived cell line from flat ;generic' epithelial cells to columnar cells. The cells acquire all the characteristics of differentiated columnar cells, including microvilli, and the capacity for apical endocytosis. The high seeding density induces the deposition of a new protein termed hensin and polymerization of hensin is the crucial event that dictates changes in epithelial phenotype. Hensin is widely expressed in most epithelia. Its deletion in mice leads to embryonic lethality at the time of generation of the first columnar epithelium, the visceral endoderm. Moreover many human cancers have deletions in the hensin gene, which indicates that it is a tumor suppressor.

  12. 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.

  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.

  14. 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

  15. Annealing a magnetic cactus into phyllotaxis.

    PubMed

    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.

  16. 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.

  17. Betacyanins from vine cactus Hylocereus polyrhizus.

    PubMed

    Wybraniec, S; Platzner, I; Geresh, S; Gottlieb, H E; Haimberg, M; Mogilnitzki, M; Mizrahi, Y

    2001-12-01

    The presence of betacyanin pigments and their isoforms has been detected in the fruit of Hylocereus polyrhizus, a vine cactus native to South America. Along with the known betanin and phyllocactin (6'-O-malonylbetanin), a new betacyanin was structurally elucidated as betanidin 5-O-[6'-O-(3"-hydroxy-3"-methyl-glutaryl)-beta-D-glucopyranoside] (proposed trivial name hylocerenin) by means of electrospray MS/MS, HPLC, and NMR techniques.

  18. Catecholamine metabolism in a psychoactive cactus.

    PubMed

    Keller, W J; Yeary, R A

    1980-04-01

    The Dona Ana cactus, Coryphantha macromeris (Engelm.) Br. and R. and its runyonii (Br. and R.) L. Benson variety are being promoted as natural and legal psychedelic agents with about one-fifth potency of peyote [Lophophora williamsii (Lem.) Coult.]. Like peyote, Dona Ana produces and accumulates various methylated catecholamine derivatives. Of these phenethylamines, normacromerine (N-methyl-3,4-dimethoxy-beta-hydroxyphenethylamine) is by far the most abundant and has been shown to affect animal behavior in such a way as to suggest psychoactivity. It has been demonstrated that the catecholamines epinephrine and norepinephrine occur naturally in C. macromeris var. runyonii and serve as biosynthetic intermediates in normacromerine biosynthesis. Catecholamine precursors and derivatives have also been shown to be part of the metabolic pathway leading to the formation of normacromerine in Dona Ana. Normacromerine appears to be the end product of catecholamine metabolism since recent studies have revealed that very little of this compound is metabolized once it has been formed by the cactus. Completed research of this type has allowed the comparison of catecholamine metabolism leading to the formation of a mind-altering drug in a cactus plant and the metabolism of catecholamines in humans. These data together with evidence from future research will allow biochemical analogies which may suggest etiologies for certain types of mental illness.

  19. 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.

  20. 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.

  1. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  4. Carpet: Adaptive Mesh Refinement for the Cactus Framework

    NASA Astrophysics Data System (ADS)

    Schnetter, Erik; Hawley, Scott; Hawke, Ian

    2016-11-01

    Carpet is an adaptive mesh refinement and multi-patch driver for the Cactus Framework (ascl:1102.013). Cactus is a software framework for solving time-dependent partial differential equations on block-structured grids, and Carpet acts as driver layer providing adaptive mesh refinement, multi-patch capability, as well as parallelization and efficient I/O.

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  6. Cactus mild mottle virus is a new cactus-infecting tobamovirus.

    PubMed

    Min, B E; Chung, B N; Kim, M J; Ha, J H; Lee, B Y; Ryu, K H

    2006-01-01

    A new cactus-infecting tobamovirus, Cactus mild mottle virus (CMMoV), was isolated from diseased grafted cactus, Gymnocalycium mihanovichii and its molecular properties were characterized. CMMoV is distantly related to known species of the genus Tobamovirus on the basis of serological and sequence analyses. Western blot analysis showed that CMMoV is serologically unrelated to Sammon's Opuntia virus, which is the only known species of the genus Tobamovirus found in cactus plants. The 3'-terminal 2,910 nucleotides of CMMoV have been sequenced. The coat protein (CP) and movement protein (MP) genes encode 161 and 306 amino acids residues, respectively, and the 3' untranslated region (UTR) consists of 229 nucleotides long. The nucleotide and amino acid sequences of the CP of CMMoV were 39.6% to 49.2% and 25.8% to 40.3% identical to other seventeen tobamoviruses, respectively. The MP shared 34.9% to 40.6% and 16.3% to 27.0% and 44.6% to 63.4% identities, respectively, at the amino acid and nucleotide levels with other members of the genus. Percentage identities of nucleotides of the 3' UTR ranged from 42.5% to 63.4%. Phylogenetic tree analyses of the CP and MP suggest the existence of the fifth cactus-infecting subgroup in the genus Tobamovirus. Sequence analyses of these two viral proteins revealed that the highest amino acid sequence identity between the virus and seventeen other tobamoviruses was 40.6%, supporting the view that CMMoV is a new definite species of the genus Tobamovirus.

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

    USDA-ARS?s Scientific Manuscript database

    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. ...

  8. Genome Sequence of the Fish Pathogen Flavobacterium columnare ATCC 49512

    PubMed Central

    Tekedar, Hasan C.; Karsi, Attila; Gillaspy, Allison F.; Dyer, David W.; Benton, Nicole R.; Zaitshik, Jeremy; Vamenta, Stefanie; Banes, Michelle M.; Gülsoy, Nagihan; Aboko-Cole, Mary; Waldbieser, Geoffrey C.

    2012-01-01

    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. PMID:22535941

  9. Low genetic diversity and strong population structure shaped by anthropogenic habitat fragmentation in a critically endangered primate, Trachypithecus leucocephalus.

    PubMed

    Wang, W; Qiao, Y; Li, S; Pan, W; Yao, M

    2017-02-15

    Habitat fragmentation may strongly impact population genetic structure and reduce the genetic diversity and viability of small and isolated populations. The white-headed langur (Trachypithecus leucocephalus) is a critically endangered primate species living in a highly fragmented and human-modified habitat in southern China. We examined the population genetic structure and genetic diversity of the species and investigated the environmental and anthropogenic factors that may have shaped its population structure. We used 214 unique multi-locus genotypes from 41 social groups across the main distribution area of T. leucocephalus, and found strong genetic structure and significant genetic differentiation among local populations. Our landscape genetic analyses using a causal modelling framework suggest that a large habitat gap and geographical distance represent the primary landscape elements shaping genetic structure, yet high levels of genetic differentiation also exist between patches separated by a small habitat gap or road. This is the first comprehensive study that has evaluated the population genetic structure and diversity of T. leucocephalus using nuclear markers. Our results indicate strong negative impacts of anthropogenic land modifications and habitat fragmentation on primate genetic connectivity between forest patches. Our analyses suggest that two management units of the species could be defined, and indicate that habitat continuity should be enforced and restored to reduce genetic isolation and enhance population viability.Heredity advance online publication, 15 February 2017; doi:10.1038/hdy.2017.2.

  10. Parasitism enhances tilapia susceptibility to Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    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 ...

  11. Reduced gravity favors columnar crystal growth

    NASA Technical Reports Server (NTRS)

    Kattamis, T. Z.; Papazian, J. M.

    1981-01-01

    In zero gravity, alined columnar microstructures form at expense of equiaxed growth. Preferential crystal growth occurs in solidification chamber consisting of semicylindrical copper chill block brazed to stainless steel top plate. Method is best utilized in castings where directional dependence of physical properties is beneficial, as in turbine blades.

  12. 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.

  13. Effects of a natural fire on a Kuenzler's hedgehog cactus (Echinocereus fendleri var. kuenzleri) and nylon hedgehog cactus (Echinocereus viridiflorus) population in Southeastern New Mexico

    Treesearch

    Robert C. Sivinski

    2007-01-01

    During the summer of 1992, a natural wildfire burned 250 acres of juniper savanna on Rawhide Ridge in the Guadalupe Mountains of southeastern New Mexico. This fire burned through the center of a Kuenzler's hedgehog cactus population. This threatened cactus is locally sympatric with the more abundant nylon hedgehog cactus, which has similar growth form and stature...

  14. 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

  15. 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.

  16. 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...

  17. 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...

  18. A video-aided study of the diet of wild white-headed Langurs (Trachypithecus leucocephalus).

    PubMed

    Yin, Lijie; Liu, Wei; Zhao, Qing; Qin, Dagong; Li, Xingdong; Wang, Dezhi; Jin, Tong; Chen, Mei; Pan, Wenshi

    2011-01-01

    Asian leaf-eating monkeys have flexible, environmentally adaptable feeding strategies. The diet and food choices of white-headed langurs (Trachypithecus leucocephalus) have, however, not yet been studied in the Nongguan Karst Hills in China, where one of the two main surviving populations of this endangered species lives. From 2000 to 2002 inclusive, we adopted an innovative video playback analysis method to identify the food species used by the langurs and to calculate the corresponding feeding frequency for each species. The video-aided methodology was shown to be efficient. It provided high-quality images, and the plant species could be identified in 98.3% of the feeding records. Based on this analysis, we found that the langurs in Nongguan fed on 70 species of plants, among which 24 were identified as their staple food species. The cumulative curve for the staple food species reached a plateau at 255 (43.7%) feeding records. This result indicated that most of the langurs' staple food species had been identified by the analysis.

  19. 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. Copyright © 2011 SETAC.

  20. 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.

  1. 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.

  2. 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.

  3. To migrate, stay put, or wander? Varied movement strategies in bald eagles (Haliaeetus leucocephalus).

    PubMed

    Wheat, Rachel E; Lewis, Stephen B; Wang, Yiwei; Levi, Taal; Wilmers, Christopher C

    2017-01-01

    Quantifying individual variability in movement behavior is critical to understanding population-level patterns in animals. Here, we explore intraspecific variation in movement strategies of bald eagles (Haliaeetus leucocephalus) in the north Pacific, where there is high spatiotemporal resource variability. We tracked 28 bald eagles (five immature, 23 adult) using GPS transmitters between May 2010 and January 2016. We found evidence of four movement strategies among bald eagles in southeastern Alaska and western Canada: breeding individuals that were largely sedentary and remained near nest sites year-round, non-breeding migratory individuals that made regular seasonal travel between northern summer and southern winter ranges, non-breeding localized individuals that displayed fidelity to foraging sites, and non-breeding nomadic individuals with irregular movement. On average, males traveled farther per day than females. Most nomadic individuals were immature, and all residential individuals (i.e. breeders and localized birds) were adults. Alternative movement strategies among north Pacific eagles are likely associated with the age and sex class, as well as breeding status, of an individual. Intraspecific variation in movement strategies within the population results in different space use patterns among contingents, which has important implications for conservation and management.

  4. Choroidal Vasculopathy and Retinal Detachment in a Bald Eagle ( Haliaeetus leucocephalus ) With Lead Toxicosis.

    PubMed

    Eid, Ramzi; Guzman, David Sanchez-Migallon; Keller, Krista A; Wiggans, K Tomo; Murphy, Christopher J; LaDouceur, Elise E B; Keel, M Kevin; Reilly, Christopher M

    2016-12-01

    A subadult male bald eagle ( Haliaeetus leucocephalus ) was presented for severe depression and weakness. Physical examination findings included depressed mentation, dehydration, sternal recumbency, poor body condition, and bilateral, whole-head, horizontal nystagmus. A heavy-metal panel was performed, and blood lead levels were 6.1 ppm. Treatment for lead poisoning was initiated, including subcutaneous fluids and parenteral calcium-disodium ethylenediaminetetraacetic acid, ceftiofur, and meloxicam. Ophthalmic examination findings included absent menace response, absent dazzle reflex, slow and incomplete direct pupillary light reflex, mild anterior uveitis, incipient cataracts, multifocal retinal tears, and retinal separation in both eyes. Because of poor prognosis for vision and release to the wild, the eagle was euthanatized. No lesions were observed on gross postmortem examination. Histologically, extensive myocardial necrosis and multisystemic arteriolar vasculopathy were identified. The eyes were examined after tissue processing, and the vasculopathy extended into the choriocapillaris and was associated with a secondary, bilateral, exudative, retinal detachment. This is the first report in avian species characterizing the histopathologic ocular lesions of lead poisoning.

  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. 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.

  7. Population transcriptomics of cactus host shifts in Drosophila mojavensis.

    PubMed

    Matzkin, Luciano M

    2012-05-01

    In the presence of environmental change, natural selection can shape the transcriptome. Under a scenario of environmental change, genotypes that are better able to modulate gene expression to maximize fitness will tend to be favoured. Therefore, it is important to examine gene expression at the population level to distinguish random or neutral gene expression variation from the pattern produced by natural selection. This study investigates the natural variation in transcriptional response to a cactus host shift utilizing the mainland Sonora population of Drosophila mojavensis. Drosophila mojavensis is a cactophilic species composed of four cactus host populations endemic to the deserts of North America. Overall, the change in cactus host was associated with a significant reduction in larval viability as well as the differential expression of 21% of the genome (3109 genes). Among the genes identified were a set of genes previously known to be involved in xenobiotic metabolism, as well as genes involved in cellular energy production, oxidoreductase/carbohydrate metabolism, structural components and mRNA binding. Interestingly, of the 3109 genes whose expression was affected by host use, there was a significant overrepresentation of genes that lacked an orthologous call to the D. melanogaster genome, suggesting the possibility of an accelerated rate of evolution in these genes. Of the genes with a significant cactus effect, the majority, 2264 genes, did not exhibit a significant cactus-by-line interaction. This population-level approach facilitated the identification of genes involved in past cactus host shifts. © 2012 Blackwell Publishing Ltd.

  8. 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.

  9. 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

  10. Visualization of columnar defects in superconductors

    NASA Astrophysics Data System (ADS)

    Bauer, P.; Rossel, C.; Williams, E. J.; Berger, R.; Daniel, J.; Irmer, B.; Kraus, M.; Kreiselmeyer, G.; Saemann-Ischenko, G.; Karpinski, J.

    1996-02-01

    Columnar defects in single crystals of superconductors were investigated using scanning probe microscopy. We show that the observable topography strongly depends on the crystal structure as well as on the type of the interaction with the probe. In scanning tunneling microscopy studies, the low conductance of the amorphous tracks leads to tip-surface contact. Owing to this contact, the defects are imaged as hollows having a depth that primarily reflects the tunneling distance. For the high transition temperature materials, atomic force microscopy images the real defect structure as hillocks growing out of the surface. This outgrowth of amorphous material is time dependent and produced by the relaxation of irradiation-induced stress. The dynamic outgrowth of the columnar defects is discussed in terms of a so-called “tooth paste” model.

  11. Columnar self-assembly of colloidal nanodisks.

    PubMed

    Saunders, Aaron E; Ghezelbash, Ali; Smilgies, Detlef-M; Sigman, Michael B; Korgel, Brian A

    2006-12-01

    The self-assembly of sterically stabilized colloidal copper sulfide nanodisks, 14-20 nm in diameter and 5-7 nm thick, was studied. The nanodisks were observed by electron microscopy and small-angle X-ray scattering to form columnar arrays when evaporated as thin films from concentrated dispersions. These superstructured nanomaterials might give rise to technologically useful properties, such as anisotropic electrical transport and electrorheological and optical properties.

  12. Population genetics and phylogenetic relationships of beetles (Coleoptera: Histeridae and Staphylinidae) from the Sonoran Desert associated with rotting columnar cacti.

    PubMed

    Pfeiler, Edward; Johnson, Sarah; Richmond, Maxi Polihronakis; Markow, Therese A

    2013-12-01

    Dozens of arthropod species are known to feed and breed in the necrotic tissues (rots) of columnar cacti in the Sonoran Desert. Because the necrotic patches are ephemeral, the associated arthropods must continually disperse to new cacti and therefore the populations of any given species are expected to show very little local genetic differentiation. While this has been found to be true for the cactophilic Drosophila, the evolutionary histories and characteristics of other arthropods inhabiting the same necrotic patches, especially the beetles, have yet to be examined. Here we used nucleotide sequence data from segments of the mitochondrial 16S rRNA and cytochrome c oxidase subunit I (COI) genes to examine population structure and demographic history of three sympatric beetle species (Coleoptera: Histeridae and Staphylinidae) collected on senita cactus (Lophocereus schottii) from six widely-separated localities on the Baja California peninsula of northwestern Mexico. Two histerids, Iliotona beyeri and Carcinops gilensis, and an unidentified staphylinid, Belonuchus sp., showed little or no population structure over a broad geographic area on the peninsula, consistent with the prediction that these beetles should show high dispersal ability. Demographic tests revealed varying levels of historical population expansion among the beetle species analyzed, which are discussed in light of their ecologies and concurrent biogeographic events. Additionally, phylogenetic analyses of COI sequences in Carcinops collected on a variety of columnar cacti from both peninsular and mainland Mexico localities revealed several species-level partitions, including a putative undescribed peninsular species that occurred sympatrically with C. gilensis on senita.

  13. Reproductive parameters of wild Trachypithecus leucocephalus: seasonality, infant mortality and interbirth interval.

    PubMed

    Jin, Tong; Wang, De-Zhi; Zhao, Qing; Yin, Li-Jie; Qin, Da-Gong; Ran, Wen-Zhong; Pan, Wen-Shi

    2009-07-01

    Understanding the reproductive parameters of endangered primate species is vital for evaluating the status of populations and developing adequate conservation measures. This study provides the first detailed analysis of the reproductive parameters of wild white-headed langurs (Trachypithecus leucocephalus), based on demographic data collected over an 8-year period in the Nongguan Karst Hills in Chongzuo County, Guangxi, China. From 1998 to 2002, a total of 133 live births were recorded in the population based on systematic censuses. Births occurred throughout the year, but the temporal pattern was highly correlated with seasonal variation in temperature and rainfall, with the birth peak coinciding with the dry and cold months of November-March. The average birthrate was 0.47+/-0.13 births per female per year and mortality for infants younger than 20 months was 15.8%. From 1998 to 2006, 14 females gave birth to 41 infants in four focal groups. The average age at first birth for female langurs was 5-6 years (n = 5) and the interbirth interval (IBI) was 23.2+/-5.2 months (median = 24.5 months, n = 27). Infants are weaned at 19-21 months of age. The IBI for females with infant loss before weaning was significantly shorter than those for females whose infants survived. It appears that birth seasonality in the white-headed langurs is influenced by seasonal changes in food availability. The timing of conceptions was found to coincide with peak food availability. The reproductive parameters for white-headed langurs reported here are quite similar to those reported for other colobine species. One major difference is our observation of lower infant mortality in Trachypithecus.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  16. 75 FR 81087 - South American Cactus Moth Quarantine; Addition of the State of Louisiana

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-27

    ... Health Inspection Service 7 CFR Part 301 South American Cactus Moth Quarantine; Addition of the State of... South American cactus moth regulations by adding the entire State of Louisiana to the list of... American cactus moth to noninfested areas of the United States. DATES: Effective on December 27, 2010,...

  17. 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.

  18. 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. © 2012 American Institute of Physics

  19. Tuning properties of columnar nanocomposite oxides

    NASA Astrophysics Data System (ADS)

    Liao, Zhaoliang; Gao, Peng; Stadler, Shane; Jin, Rongying; Pan, Xiaoqing; Plummer, E. W.; Zhang, Jiandi

    2013-07-01

    One major challenge for engineering functional nanocomposites is how to tune the geometry structure and control the chemical composition. We demonstrate here that columnar nanocomposite films can be grown by using alternate deposition of La2/3Sr1/3MnO3 and V2O3 on LaAlO3 (111). A solid state reaction, rather than simple spinodal decomposition, dictates the nanocomposite structure, chemical composition, and functionality. By controlling the deposition time ratio of the two compounds, the physical properties of the composite films can be tuned, thus providing a flexible way to tailor nanocomposites for advanced functionality.

  20. 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.

  1. 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.

  2. The incomplete ordering of columnar fracture

    NASA Astrophysics Data System (ADS)

    Goehring, Lucas; Morris, Stephen

    2004-03-01

    Columnar fracture has been studied for centuries, and occurs in a wide range of media, from lava, to glass and starch. The best known examples of such fracture patterns include the basalts of the Giant's Causeway in N. Ireland, and the Devil's Postpile in California. Recently, we have performed experiments on columnar fracture in corn starch, which have lead to a fully three dimensional characterization of this pattern. It has been traditionally believed that a colonnade, in cross-section, tends toward a perfectly ordered hexagonal lattice (Budkewitsch & Robin, 1993), or some nearby local minima in energy (Jagla and Rojo, 2002). However, we show that the disorder in this pattern does not vanish, but tends toward a large, limiting value. Statistical quantification of this residual disorder, in two very different systems, desiccated starch and convectively cooled lava, tend toward identical, constant values. We can demonstrate that there is a strong ordering process for patterns that are more disordered than this limiting case. This suggests that residual disorder is inherent to this natural pattern.

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

    PubMed

    Luo, Cheng

    2015-11-03

    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.

  4. Cactus pear: a natural product in cancer chemoprevention

    PubMed Central

    Zou, Da-ming; Brewer, Molly; Garcia, Francisco; Feugang, Jean M; Wang, Jian; Zang, Roungyu; Liu, Huaguang; Zou, Changping

    2005-01-01

    Background Cancer chemoprevention is a new approach in cancer prevention, in which chemical agents are used to prevent cancer in normal and/or high-risk populations. Although chemoprevention has shown promise in some epithelial cancers, currently available preventive agents are limited and the agents are costly, generally with side effects. Natural products, such as grape seed, green tea, and certain herbs have demonstrated anti-cancer effects. To find a natural product that can be used in chemoprevention of cancer, we tested Arizona cactus fruit solution, the aqueous extracts of cactus pear, for its anti-cancer effects in cultured cells and in an animal model. Method Aqueous extracts of cactus pear were used to treat immortalized ovarian and cervical epithelial cells, as well as ovarian, cervical, and bladder cancer cells. Aqueous extracts of cactus pear were used at six concentrations (0, 0.5, 1, 5, 10 or 25%) to treat cells for 1, 3, or 5 days. Growth inhibition, apoptosis induction, and cell cycle changes were analyzed in the cultured cells; the suppression of tumor growth in nude mice was evaluated and compared with the effect of a synthetic retinoid N-(4-hydroxyphernyl) retinamide (4-HPR), which is currently used as a chemoprevention agent. Immunohistochemistry staining of tissue samples from animal tumors was performed to examine the gene expression. Results Cells exposed to cactus pear extracts had a significant increase in apoptosis and growth inhibition in both immortalized epithelial cells and cancer cells in a dose- and time-dependent manner. It also affected cell cycle of cancer cells by increasing G1 and decreasing G2 and S phases. Both 4-HPR and cactus pear extracts significantly suppressed tumor growth in nude mice, increased annexin IV expression, and decreased VEGF expression. Conclusion Arizona cactus pear extracts effectively inhibited cell growth in several different immortalized and cancer cell cultures, suppressed tumor growth in nude mice

  5. Cactus pear: a natural product in cancer chemoprevention.

    PubMed

    Zou, Da-ming; Brewer, Molly; Garcia, Francisco; Feugang, Jean M; Wang, Jian; Zang, Roungyu; Liu, Huaguang; Zou, Changping

    2005-09-08

    Cancer chemoprevention is a new approach in cancer prevention, in which chemical agents are used to prevent cancer in normal and/or high-risk populations. Although chemoprevention has shown promise in some epithelial cancers, currently available preventive agents are limited and the agents are costly, generally with side effects. Natural products, such as grape seed, green tea, and certain herbs have demonstrated anti-cancer effects. To find a natural product that can be used in chemoprevention of cancer, we tested Arizona cactus fruit solution, the aqueous extracts of cactus pear, for its anti-cancer effects in cultured cells and in an animal model. Aqueous extracts of cactus pear were used to treat immortalized ovarian and cervical epithelial cells, as well as ovarian, cervical, and bladder cancer cells. Aqueous extracts of cactus pear were used at six concentrations (0, 0.5, 1, 5, 10 or 25%) to treat cells for 1, 3, or 5 days. Growth inhibition, apoptosis induction, and cell cycle changes were analyzed in the cultured cells; the suppression of tumor growth in nude mice was evaluated and compared with the effect of a synthetic retinoid N-(4-hydroxyphernyl) retinamide (4-HPR), which is currently used as a chemoprevention agent. Immunohistochemistry staining of tissue samples from animal tumors was performed to examine the gene expression. Cells exposed to cactus pear extracts had a significant increase in apoptosis and growth inhibition in both immortalized epithelial cells and cancer cells in a dose- and time-dependent manner. It also affected cell cycle of cancer cells by increasing G1 and decreasing G2 and S phases. Both 4-HPR and cactus pear extracts significantly suppressed tumor growth in nude mice, increased annexin IV expression, and decreased VEGF expression. Arizona cactus pear extracts effectively inhibited cell growth in several different immortalized and cancer cell cultures, suppressed tumor growth in nude mice, and modulated expression of tumor

  6. Identification, characterization, and function analysis of the Cactus gene from Litopenaeus vannamei.

    PubMed

    Li, Chaozheng; Chen, Yi-Xiao; 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  9. Chemotaxis of Flavobacterium columnare: To Channel Catfish Mucus

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Parasite treatment reduced Flavobacterium columnare infection in tilapia

    USDA-ARS?s Scientific Manuscript database

    Bacterium Flavobacterium columnare and parasite Trichodina are common pathogens of cultured fish. The authors conducted a study to evaluate whether treatment of Trichodina parasitized tilapia with formalin would improve fish survival and reduce F. columnare infection in fish. Tilapia parasitized by...

  11. Multiplex PCR for rapid genotyping of Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease, caused by the Gram-negative bacterium Flavobacterium columnare, is one of the leading causes of disease losses to the catfish industry in the Southeast USA. Recent research in our laboratory has deciphered the genetic diversity among F. columnare isolates through whole genome seq...

  12. Genomovars and genomes: Deciphering the genetic diversity of Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease, caused by the Gram-negative bacterium Flavobacterium columnare, is one of the leading causes of disease losses to the catfish industry in the Southeast USA. An exceptionally high level of genetic diversity among isolates of F. columnare has long been recognized, yet very little h...

  13. The Flavobacterium columnare challenge: host, genomovar and virulence

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is pathogenic to most if not all species of freshwater fish throughout the world. The ubiquitous nature of F. columnare makes understanding the disease and disease agent troublesome. The host-pathogen-environment relationship theory described by Snieszko can be applied to o...

  14. High-frequency micromechanical columnar resonators

    PubMed Central

    Kehrbusch, Jenny; Ilin, Elena A; Bozek, Peter; Radzio, Bernhard; Oesterschulze, Egbert

    2009-01-01

    High-frequency silicon columnar microresonators are fabricated using a simple but effective technological scheme. An optimized fabrication scheme was invented to obtain mechanically protected microcolumns with lateral dimensions controlled on a scale of at least 1 μm. In this paper, we investigate the influence of the environmental conditions on the mechanical resonator properties. At ambient conditions, we observed a frequency stability δf/f of less than 10−6 during 5 h of operation at almost constant temperature. However, varying the temperature shifts the frequency by approximately −173 Hz °C− 1. In accordance with a viscous damping model of the ambient gas, we perceived that the quality factor of the first flexural mode decreased with the inverse of the square root of pressure. However, in the low-pressure regime, a linear dependence was observed. We also investigated the influence of the type of the immersing gas on the resonant frequency. PMID:27877296

  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.

  16. 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.

  17. 75 FR 41073 - South American Cactus Moth Regulations; Quarantined Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-07-15

    ...;having general applicability and legal effect, most of which are keyed #0;to and codified in the Code of... potential economic effects of this action on small entities. South American cactus moth is a pest that... emergency forage for cattle during periods of drought and as wildlife feed for game animals. This...

  18. 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…

  19. 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)

  20. 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)

  1. Functional genomics of cactus host shifts in Drosophila mojavensis.

    PubMed

    Matzkin, Luciano M; Watts, Thomas D; Bitler, Benjamin G; Machado, Carlos A; Markow, Therese A

    2006-12-01

    Understanding the genetic basis of adaptation to novel environments remains one of the major challenges confronting evolutionary biologists. While newly developed genomic approaches hold considerable promise for addressing this overall question, the relevant tools have not often been available in the most ecologically interesting organisms. Our study organism, Drosophila mojavensis, is a cactophilic Sonoran Desert endemic utilizing four different cactus hosts across its geographical range. Its well-known ecology makes it an attractive system in which to study the evolution of gene expression during adaptation. As a cactophile, D. mojavensis oviposits in the necrotic tissues of cacti, therefore exposing larvae and even adults to the varied and toxic compounds of rotting cacti. We have developed a cDNA microarray of D. mojavensis to examine gene expression associated with cactus host use. Using a population from the Baja California population we examined gene expression differences of third instar larvae when reared in two chemically distinct cactus hosts, agria (Stenocereus gummosus, native host) vs. organpipe (Stenocereus thurberi, alternative host). We have observed differential gene expression associated with cactus host use in genes involved in metabolism and detoxification.

  2. 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…

  3. EVALUATION OF LEAD AND MERCURY PREVALENCE IN BALD EAGLES (HALIAEETUS LEUCOCEPHALUS) FROM THE MID-ATLANTIC UNITED STATES.

    PubMed

    Eleftheriou, Andreas; Murphy, Lisa; Welte, Sallie

    2017-09-01

    Heavy metal contamination of the environment remains a critical issue. Lead and mercury exposure, particularly, can affect avian health. Bald eagles (Haliaeetus leucocephalus) ingest these metals through their diets. Lead and mercury prevalence were examined in bald eagles from three mid-Atlantic US states between 2004 and 2013. Blood samples were analyzed using atomic absorption spectrometry. Wilcoxon score tests were used to detect differences in lead and mercury over time. Counties of origin for birds with clinically significant metal levels were identified. There were no temporal trends found in lead and mercury prevalence. Eagles with clinically significant lead levels (>0.6 ppm) originated from near Chesapeake and Delaware bays, but most birds with clinically significant mercury levels (>1 ppm) originated from near Delaware and Barnegat bays. These findings indicate that lead and mercury contamination persists in this region and that routine sampling of bald eagles is a useful monitoring tool.

  4. 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.

  5. 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.

  6. 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.

  7. 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.

  8. 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

  9. Water hardness influences Flavobacterium columnare pathogenesis in channel catfish

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Protonospheric columnar electron content determination. I - Analysis.

    NASA Technical Reports Server (NTRS)

    Almeida, O. G.

    1973-01-01

    A combination of phase-path length difference and Faraday rotation angle data obtained from geostationary satellite transmissions is used to determine the integration constant necessary to convert phase-path length difference information into absolute values of total slant columnar electron content. The total content thus determined, which is the sum of the ionospheric and protonospheric contents, is measured with uncertainties about one order of magnitude smaller than the value of the protonospheric content. It is thus, in principle, possible to determine the latter by subtracting from the measurement the so-called 'Faraday content.' This idea, proposed by several authors in the past, is critically examined in the present paper. It is impossible to totally eliminate the ionospheric contribution to the measurements; however, it is shown that the degree of elimination depends on the type of distribution of the longitudinal component of the geomagnetic field along the path of observation. Satisfactory minimization of the ionospheric contribution can be accomplished only under certain geometries of observation.

  11. Protonospheric columnar electron content determination. I - Analysis.

    NASA Technical Reports Server (NTRS)

    Almeida, O. G.

    1973-01-01

    A combination of phase-path length difference and Faraday rotation angle data obtained from geostationary satellite transmissions is used to determine the integration constant necessary to convert phase-path length difference information into absolute values of total slant columnar electron content. The total content thus determined, which is the sum of the ionospheric and protonospheric contents, is measured with uncertainties about one order of magnitude smaller than the value of the protonospheric content. It is thus, in principle, possible to determine the latter by subtracting from the measurement the so-called 'Faraday content.' This idea, proposed by several authors in the past, is critically examined in the present paper. It is impossible to totally eliminate the ionospheric contribution to the measurements; however, it is shown that the degree of elimination depends on the type of distribution of the longitudinal component of the geomagnetic field along the path of observation. Satisfactory minimization of the ionospheric contribution can be accomplished only under certain geometries of observation.

  12. 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.

  13. 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.

  14. Kinks and Rotons in a Magnetic Cactus: Dynamical Phyllotaxis.

    NASA Astrophysics Data System (ADS)

    Nisoli, Cristiano; Monroe Gabor, Nathaniel; Crespi, Vincent Henry; Decatur Maynard, Julian

    2004-03-01

    The disposition of the leaves on a stem, spines on a cactus, seeds in a sunflower and other self-organized arrangements of repeated units in plant morphology, are denoted as phyllotaxis. Phyllotactic patterns are also found in polypeptide chains, cells of Bernard convection, and flux lattices in layered superconductors. Here we describe a "magnetic cactus," a model of interacting magnetic dipoles disposed along a cylindrical stem, based on the mechanical theory of phyllotaxis proposed by S. L. Levitov (1991). While the appearance of phyllotactic patterns in the static properties is well predicted by current theory, the dynamics bring new physics beyond that possible in biological systems: we demonstrate the formation and propagation of domain walls between stable structures, the number-theoretical properties that regulate their vibrational spectra, and show the appearence of what to our knowledge is the first example of classical rotons.

  15. Nopal Cactus (Opuntia Ficus-Indica) as a Holographic Material

    PubMed Central

    Olivares-Pérez, Arturo; Toxqui-López, Santa; Padilla-Velasco, Ana L.

    2012-01-01

    The nopal cactus (Opuntia ficus-indica) releases a substance through its mucilage, which comes from the degradation of pectic substances and chlorophyll. Combined in a polyvinyl alcohol matrix, this substance can be used as a recording medium. The resulting extract material has excellent photosensitizer properties, is easy to handle, has a low cost, and low toxicity. This material has the property of self-developing, and it can be used in holographic applications. The polyvinyl alcohol and extract from the nopal cactus was deposited by a gravity technique on a glass substrate, which dried to form a photosensitive emulsion. We show experimental results on a holographic grating using this material, written by a He-Cd laser (442 nm). We obtained diffraction gratings by transmission with a diffraction efficiency of approximately 32.3% to first order.

  16. Cactus (Opuntia dillenii Grahm) stem: a new source of energy

    NASA Astrophysics Data System (ADS)

    Deshpande, V. K.; Joshi, A. M.

    An electrochemical cell has been fabricated using cactus stem as an electrlolyte. A study of the discharge characteristics reveals that, at a current drain of 100 φA, the cell gives an optimum energy density of 175 mWh kg-1. The power generated by these cells is sufficient to run piezoelectric buzzer and a LCD calculator for a few hours. This work opens up a new interdisciplinary area for physicists, botanists and electro-chemists.

  17. Determination of antioxidant constituents in cactus pear fruits.

    PubMed

    Fernández-López, José A; Almela, Luís; Obón, José M; Castellar, Rosario

    2010-09-01

    An analytical study was carried out on the presence of antioxidant constituents and the in vitro antioxidant capacity in the extracts of three species of Spanish red-skinned cactus pear fruits (Opuntia ficus-indica, Opuntia undulata and Opuntia stricta). The cactus pear fruit extracts were analyzed for determined constituents: ascorbic acid, flavonoids (quercetin, isorhamnetin, myricetin, kaempferol and luteolin), betalains, taurine, total carotenoids and total phenolics. The antioxidant capacity was assessed by means of two different methods: the 2,2'-azinobis(3-ethylbenzothiazoline-6-sulfonic acid) (Trolox equivalent antioxidant capacity) method and the 2,2-diphenyl-1-picrylhydrazyl radical method. Opuntia ficus-indica fruit extract had the strongest antioxidant capacity and taurine content. O. stricta fruits were the richest in ascorbic acid and total phenolics, whereas O. undulata fruits showed the highest carotenoid content. Quercetin and isorhamnetin were the main flavonoids detected. This study provides basic information on the presence of bioactive compounds and antioxidant capacity in extracts of cactus pear fruits, in order to consider these extracts as ingredient for the production of health-promoting food.

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Columnar aerosol characterization over Scandinavia and Svalbard

    NASA Astrophysics Data System (ADS)

    Toledano, C.; Cachorro, V. E.; Ortiz de Galisteo, J. P.; Bennouna, Y.; Berjón, A.; Torres, B.; Fuertes, D.; González, R.; de Frutos, A. M.

    2013-05-01

    An overview of sun photometer measurements of aerosol properties in Scandinavia and Svalbard was provided by Toledano et al. (2012) thanks to the collaborative effort of various research groups from different countries that maintain a number of observation sites in the European Arctic and sub-Arctic regions. The spatial coverage of this kind of data has remarkably improved in the last years, thanks, among other things, to projects carried out within the framework of the International Polar Year 2007-08. The data from a set of operational sun photometer sites belonging either to national or international measurement networks (AERONET, GAW-PFR) were evaluated. The direct sun observations provided spectral aerosol optical depth (AOD) and Ångström exponent (AE), that are parameters with sufficient long-term records for a first characterization at all sites. At the AERONET sites, microphysical properties derived from inversion of sun-sky radiance data were also examined. AOD (500nm) ranged from 0.08 to 0.10 in Arctic and sub-Arctic sites whereas the aerosol load was higher in more populated areas in Southern Scandinavia (average AOD about 0.10-0.12 at 500 nm). On the Norwegian coast, aerosols showed larger mean size than in continental areas. Columnar particle size distributions and related parameters were used to evaluate aerosol volume efficiencies. The aerosol optical depth characterization revealed that the seasonal patterns in the high Arctic (with the typical hazy spring), in the sub-Arctic region and Southern Scandinavia are all different. The clean continental, polluted continental and maritime aerosols constitute the three main aerosol types, although persistent (Asian) dust was also detected in Svalbard.

  4. A tale of two cacti-the complex relationship between peyote (Lophophora williamsii) and endangered star cactus (Astrophytum asterias)

    Treesearch

    M. Terry; D. Price; J. Poole

    2007-01-01

    Astrophytum asterias, commonly called star cactus, is a federally listed endangered cactus endemic to the Tamaulipan thornscrub ecoregion of extreme southern Texas, USA, and Tamaulipas and Nuevo Leon, Mexico. Only three metapopulations totaling less than 4000 plants are presently known in Texas. Star cactus, known locally as “star peyote”, is highly...

  5. RAPD analysis of the last population of a likely Florida Keys endemic cactus

    Treesearch

    D.R. Gordon; Thomas L. Kubisiak

    1998-01-01

    The semaphore cactus in the Florida Keys has until recently been considered a disjunct location of the Jamaican Opuntia spinosissima. Loss of all but one population in the Keys coupled with recent suggestions that the species should be taxonomically separated from the Jamaican cactus and is, therefore, a Florida Keys endemic, makes this population of conservation...

  6. Anti-tumor effect of cactus polysaccharides on lung squamous carcinoma cells (SK-MES-1).

    PubMed

    Li, W; Wu, D; Wei, B; Wang, S; Sun, Hx; Li, Xl; Zhang, F; Zhang, Cl; Xin, Y

    2014-01-01

    Cactus polysaccharides are the active components of Opuntia dillenii which have been used extensively in folk medicine. In this study, we investigate the anti-tumor effect of cactus polysaccharides on lung squamous carcinoma cells SK-MES-1. The inhibitory effect of Cactus polysaccharides on lung squamous carcinoma cells were detected by MTT assay. Cell cycle was determined by flow cytometry and cell apoptosis was determined by AnnexinV assay. Western-blotting was applied to detect P53 and PTEN protein expression in the cells treated with cactus polysaccharides. Results showed that different concentrations of wild cactus polysaccharides prevent SK-MES-1 cells growth and induces S phase arrest. The data also revealed that cactus polysaccharides cause apoptosis in SK-MES-1 cells determined by Annexin-V assay. Furthermore, cactus polysaccharides induced growth arrest and apoptosis may be due to the increase of P53 and phosphatase and tension homolog deleted on chromosome ten (PTEN) protein. Cactus polysaccharides have anti-tumor activity on lung squamous carcinoma cells.

  7. Endophytic bacteria in cacti seeds can improve the development of cactus seedlings.

    Treesearch

    M. Esther Puente; Ching Y. Li; Yoav Bashan

    2009-01-01

    A plant-bacterium association between the giant cardon cactus Pachycereus pringlei and endophytic bacteria help seedlings establish and grow on barren rock, This cactus, together with other desert plants, is responsible for weathering ancient lava flows in the Baja California Peninsula of Mexico.When cardon seeds are inoculated with endophytic...

  8. Experimental investigation of the scaling of columnar joints

    NASA Astrophysics Data System (ADS)

    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.

  9. 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.

  10. Himalayan black bulbuls (Hypsipetes leucocephalus niggerimus) exhibit sexual dichromatism under ultraviolet light that is invisible to the human eye

    PubMed Central

    Hung, Hsin-Yi; Yeung, Carol K. L.; Omland, Kevin E.; Yao, Cheng-Te; Yao, Chiou-Ju; Li, Shou-Hsien

    2017-01-01

    Sexual dichromatism is a key proxy for the intensity of sexual selection. Studies of dichromatism in birds may, however, have underestimated the intensity and complexity of sexual selection because they used museum specimens alone without taking colour-fading into account or only measured conspicuous visual traits in live animals. We investigated whether the Himalayan black bulbul (Hypsipetes leucocephalus nigerrimus), which is sexually monomorphic to the human eye, exhibits sexual dichromatism distinguishable by a spectrometer. We measured the reflectance (within both the human visual perceptive and the ultraviolet ranges) of two carotenoid-based parts and eight dull and melanin-based parts for each individual live bird or museum skin sampled. According to an avian model of colour discrimination thresholds, we found that males exhibited perceptibly redder beaks, brighter tarsi and darker plumage than did females. This suggests the existence of multiple cryptic sexually dichromatic traits within this species. Moreover, we also observed detectable colour fading in the museum skin specimens compared with the live birds, indicating that sexual dichromatism could be underestimated if analysed using skin specimens alone. PMID:28382942

  11. 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.

  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.

  13. 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.

  14. 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.

  15. 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.

  16. 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

  17. Carnegiea gigantea (Engelm.) Britton & Rose saguaro or giant cactus

    Treesearch

    Susan E. Meyer

    2008-01-01

    Saguaro - Carnegiea gigantea (Engelm.) Britton & Rose - has the northernmost distribution of any of the large, columnar cacti of the tropical and subtropical Americas. Formerly regarded as a member of the genus Cereus, it is now considered the single species of its own genus, Carnegiea. It is a principal indicator species of the Sonoran Desert and is found at...

  18. High frequency columnar silicon microresonators for mass detection

    SciTech Connect

    Kehrbusch, J.; Ilin, E. A.; Hullin, M.; Oesterschulze, E.

    2008-07-14

    A simple but effective technological scheme for the fabrication of high frequency silicon columnar microresonators is presented. With the proposed technique the dimensions of the microresonators are controlled on a scale of at least 1 {mu}m. Characterization of the mechanical properties of silicon columns gave resonant frequencies of the lowest flexural mode of 3-7 MHz with quality factors of up to 2500 in air and {approx}8800 under vacuum condition. Columnar microresonators were operated as mass balance with a sensitivity of 1 Hz/fg. A mass detection limit of 25 fg was deduced from experiments.

  19. Turbulence and columnar vortex formation through inertial-wave focusing.

    PubMed

    Duran-Matute, Matias; Flór, Jan-Bert; Godeferd, Fabien S; Jause-Labert, Clément

    2013-04-01

    In this experimental and numerical study, we consider the role of inertial waves in the inverse energy cascade and the transfer of momentum in a rotating fluid. An oscillating torus generates two inertial-wave cones with their energy focusing at their apex. For high wave amplitudes, turbulence is generated locally around the focal point, resulting in angular momentum mixing and the generation of a columnar cyclonic vortex. The results suggest that nonlinear dynamics is essential for the wave induced momentum transport towards columnar vortices in rotating turbulence.

  20. Mid-Esophagus Columnar Metaplasia: What Is the Biopathogenic Pathway?

    PubMed

    Rolim, Inês; Rodrigues, Rita Vale; Bettencourt, António; Barros, Rita; Camilo, Vânia; Dias Pereira, António; Almeida, Raquel; Chaves, Paula

    2016-10-05

    We report a case of metaplastic columnar epithelium in the mid-esophagus in a patient with history of caustic ingestion. A cardiac-type gastric phenotype, with early signs of intestinalization, was confirmed by immunohistochemistry studies (MUC5AC, MUC6, SOX2, and CDX2). Nonmetaplastic mucosa had histologic evidence of gastroesophageal reflux. In this case, esophageal reepithelization seems to have been modulated by acidic gastroesophageal reflux, which might activate transcription factors leading to phenotypic reprogramming of the regenerative epithelium. Most interestingly, it is a clinical example showcasing the origin of columnar metaplasia from stem cells located within the esophageal epithelium.

  1. On the scaling and ordering of columnar joints

    NASA Astrophysics Data System (ADS)

    Goehring, Lucas Allan Ziola

    Columnar jointing is a fracture pattern, best known from locations such as the Giant's Causeway, or Fingal's Cave, in which cracks self-organize into a nearly hexagonal arrangement, leaving behind an ordered colonnade. In this thesis observations of columnar jointing are reported from both a controlled laboratory setting, and in cooled lava flows. Experiments were performed in slurries of corn starch and water, which form columnar joints when dried. This drying process is examined in detail, and it is shown how desiccation leads to the propagation of a sharp shrinkage front. In general, but with some significant exceptions, the size of columnar joints is inversely dependent on the speed of this shrinkage front during their formation. The exceptions, which include sudden jumps in column scale, show that hysteresis is also important in choosing the column scale. Novel observations of the 3D structure of joints in starch show that columnar joints do not settle down to a perfect hexagonal pattern, but rather mature into a continuously evolving dynamic pattern. This pattern is scale invariant, and the same statistical distribution of column shapes applies equally to joints in both starch and lava. Field work was performed to study columnar jointing in the basalts of the Columbia River Basalt Group and the island of Staffa, and the more heterogeneous lava flows of Southwestern British Columbia. The widths of columns and the heights of striae (chisel-like markings that record details of cooling) were examined in detail, and these length scales are shown to be inversely proportional to each other. An additional length scale, that of wavy columns, is also first reported here. Based on these measurements, empirical advective-diffusive models are developed to describe the transport of water in a drying starch-cake, and the transport of heat in a cooling lava flow. These models have only a single scaling parameter, the Peclet number, which relates the fracture front velocity

  2. 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.

  3. 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

    2014-12-03

    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

  4. 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

  5. Phenotypic characterization and genetic diversity of Flavobacterium columnare isolated from red tilapia, Oreochromis sp. in Thailand

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is the etiologic agent of columnaris disease and severely affects various freshwater aquaculture fish species worldwide. The objectives of this study were to determine the phenotypic characteristics and genetic variability among F. columnare isolates isolated from red tilapi...

  6. Possible role of the Flavobacterium columnare chemotactic response to skin mucus in virulence

    USDA-ARS?s Scientific Manuscript database

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

  7. 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

  8. 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

  9. 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•.

  10. 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

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

    USDA-ARS?s Scientific Manuscript database

    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. ...

  12. Antibacterial activity of acylglucinol derivatives against Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  14. Chemotactic response of Flavobacterium columnare to channel catfish mucus

    USDA-ARS?s Scientific Manuscript database

    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...

  15. Chemotactic response of Flavobacterium columnare to channel catfish mucus

    USDA-ARS?s Scientific Manuscript database

    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...

  16. 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)).

  17. Numerical simulation and rational design of optically anisotropic columnar films

    NASA Astrophysics Data System (ADS)

    Leontyev, Viktor A.; Hawkeye, Matthew M.; Wakefield, Nicholas G.; Tabunshchyk, Kyrylo; Sit, Jeremy C.; Kovalenko, Andriy; Brett, Michael J.

    2011-03-01

    Optical anisotropy is an inherent property of columnar dielectric films, such as those fabricated by the glancing angle deposition (GLAD) technique. This process utilizes physical vapor deposition combined with computer-controlled substrate motion to finely tune the direction of column growth and vital morphological parameters such as column cross-section and inter-columnar spacing. Control over the anisotropic properties of the porous film provides an opportunity to design polarization-selective photonic devices and films with improved band gap properties. Anisotropic defects in multilayer films also result in a polarization-sensitive position of resonant transmission modes. We employed the finite-difference time-domain and frequency-domain methods to theoretically analyze and design columnar films with unique band-gap properties. The following morphologies were considered: (i) S-shaped columnar films with polarization-dependent band-gap position and width. Using numerical simulations we have shown that the competitive effect of different sources of anisotropy can be used to engineer photonic band gaps with strong selectivity to linearly-polarized light; (ii) Rugate thin films with an anisotropic defect, which exhibit resonant mode splitting. Optical devices were fabricated using titanium dioxide because it has good transparency in the visible range of the optical spectrum and a large bulk refractive index. Experimental results were compared to simulations to verify the designs and understand the limitations of the fabrication process.

  18. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  20. 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

  1. 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.

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

    PubMed

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

    2015-03-01

    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.

  3. 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.

  4. 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.

  5. Distribution of 2-deoxy-2-fluoro-d-glucose in the coelom of healthy bald eagles (Haliaeetus leucocephalus).

    PubMed

    Jones, Michael P; Morandi, Federica; Wall, Jonathan S; Long, Misty J; Stuckey, Alan C; LeBlanc, Amy K

    2013-03-01

    To determine 2-deoxy-2-fluoro (fluorine 18)-d-glucose ((18)FDG) biodistribution in the coelom of bald eagles (Haliaeetus leucocephalus). 8 healthy adult bald eagles. For each eagle, whole-body transmission noncontrast CT, 60-minute dynamic positron emission tomography (PET) of the celomic cavity (immediately after (18)FDG injection), whole-body static PET 60 minutes after (18)FDG injection, and whole-body contrast CT with iohexol were performed. After reconstruction, images were analyzed. Regions of interest were drawn over the ventricular myocardium, liver, spleen, proventriculus, cloaca, kidneys, and lungs on dynamic and static PET images. Standardized uptake values were calculated. Kidneys had the most intense (18)FDG uptake, followed by cloaca and intestinal tract; liver activity was mild and slightly more intense than that of the spleen; proventricular activity was always present, whereas little to no activity was identified in the wall of the ventriculus. Activity in the myocardium was present in all birds but varied in intensity among birds. The lungs had no visibly discernible activity. Mean ± SD standardized uptake values calculated with representative regions of interest at 60 minutes were as follows: myocardium, 1. 6 ± 0.2 (transverse plane) and 1.3 ± 0.3 (sagittal plane); liver, 1.1 ± 0.1; spleen, 0.9 ± 0.1; proventriculus, 1.0 ± 0.1; cloaca, 4.4 ± 2.7; right kidney, 17.3 ± 1.0; left kidney, 17.6 ± 0.3; and right and left lungs (each), 0.3 ± 0.02. The study established the biodistribution of (18)FDG in adult eagles, providing a baseline for clinical investigation and future research.

  6. Comparative analysis of the Flavobacterium columnare genomovar I and II genomes

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease caused by Gram-negative rod Flavobacterium columnare is one of the most common diseases of catfish. F. columnare is also a common problem in other cultured fish species worldwide. F. columnare has three major genomovars; we have sequenced a representative strain from genomovar I (...

  7. 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.

  8. 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

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

    PubMed

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

    2014-05-13

    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 bio- assays 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 intra- specific behavior in other species of pyralids, the present study is the first to report their use as a trail pheromone.

  10. Fenton Discoloration of Ultrasonicated Purple Cactus Pear Juice.

    PubMed

    Reyes-Hernández, Isidro; Cruz-Cansino, Nelly Del S; Santander-Martínez, Ingrid Renata; Alanís-García, Ernesto; Delgado-Olivares, Luis; Ramírez-Moreno, Esther; Ariza-Ortega, José A; Omaña-Covarrubias, Ariana; Torres-Valencia, Jesús Martín; Manríquez-Torres, José de Jesús

    2017-08-15

    The aim of this study was to evaluate the stability of color, betaxanthin, and betacyanin pigments in the presence of Cu(II)-dependent hydroxyl radicals (HO•) from ultrasonicated purple cactus pear juice at amplitudes of 40%, 60%, and 80%, in comparison to untreated sample. L* parameter of juice treated at 40% and 80% amplitude for 25 and 15 min, respectively (11.3 and 9.3, respectively), were significantly higher compared to the control; b* and hue parameters of juice treated at 80%, 25 min showed values of 1.7 and 0.1, respectively. Color differences (ΔE) were lower (<3) for juices treated at high amplitude (80%) and short times (3-5 min). Juice treated at 40% 15 min, 60% 25 min, 80% 15 and 25 min presented high values of betacyanins (281.7 mg·L(-1), 255.9 mg·L(-1), 294.4 mg·L(-1), and 276.7 mg·L(-1), respectively). Betaxanthin values were higher in the juices treated at 40% 5 min and 80% 15 and 25 min (154.2 mg·L(-1), 135.2 mg·L(-1), and 128.5 mg·L(-1), respectively). Purple cactus pear juice exhibited significant chelating activity of copper ions and great stability when exposed to HO•.

  11. 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.

  12. 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.

  13. Room-Temperature Columnar Nematic and Soft Crystalline Columnar Assemblies of a New Series of Perylene-Centred Disc Tetramers.

    PubMed

    Bala, Indu; Gupta, Santosh Prasad; De, Joydip; Pal, Santanu Kumar

    2017-06-28

    Three new oligomeric perylene (PE) tetraester derivatives, consisting of a PE-based core with four pentaalkynylbenzene units attached through flexible alkyl spacers, are reported. These derivatives were investigated for their mesomorphic properties and thermal, photophysical, and electrochemical behaviour. Small- (SAXS) and wide-angle X-ray scattering (WAXS) studies were performed to deduce the exact nature of the phases. To resolve overlapping reflections and facilitate their indexing, grazing-incidence SAXS/WAXS experiments were carried out on oriented thin films on indium tin oxide (ITO)-coated glass substrate. The corresponding electron density maps were derived from the intensities observed in the diffraction pattern. Whereas compounds with shorter alkyl spacers (n=6 and 8) were found to self-organise into soft crystalline columnar assemblies, those with longer spacers (n=10) exhibited a liquid-crystalline columnar nematic mesophase. This is in contrast to previous reports that describe highly symmetric 2D hexagonal and rectangular columnar structures of PE-based mesogens. The morphology of self-assembly was found to transform from soft crystal columnar to nematic columnar phase through simple variation in the number of alkyl spacers. All compounds exhibited excellent fluorescence emission properties with a very good quantum yield and large band gap. Apart from high solubility and good quantum yield, these compounds can serve as standards to measure quantum yields of unknown samples. These compounds also display green luminescence and may find applications for various optoelectronic devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Effects of Plant Size and Weather on the Flowering Phenology of the Organ Pipe Cactus (Stenocereus thurberi)

    PubMed Central

    Bustamante, Enriquena; Búrquez, Alberto

    2008-01-01

    Background and Aims Flowering phenology is a critical life-history trait that influences reproductive success. It has been shown that genetic, climatic and other factors such as plant size affect the timing of flowering and its duration. The spatial and temporal variation in the reproductive phenology of the columnar cactus Stenocereus thurberi and its association with plant size and environmental cues was studied. Methods Flowering was monitored during 3 years in three populations of S. thurberi along a latitudinal gradient. Plant size was related to phenological parameters. The actual and past weather were used for each site and year to investigate the environmental correlates of flowering. Key Results There was significant variation in the timing of flowering within and among populations. Flowering lasted 4 months in the southern population and only 2 months in the northern population. A single flowering peak was evident in each population, but ocurred at different times. Large plants produced more flowers, and bloomed earlier and for a longer period than small plants. Population synchrony increased as the mean duration of flowering per individual decreased. The onset of flowering is primarily related to the variance in winter minimum temperatures and the duration to the autumn–winter mean maximum temperature, whereas spring mean maximum temperature is best correlated with synchrony. Conclusions Plant size affects individual plant fecundity as well as flowering time. Thus the population structure strongly affects flowering phenology. Indications of clinal variation in the timing of flowering and reproductive effort suggest selection pressures related to the arrival of migrating pollinators, climate and resource economy in a desert environment. These pressures are likely to be relaxed in populations where individual plants can attain large sizes. PMID:18854374

  15. 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.

  16. Population Genetic Structure of the Giant Cactus Echinopsis terscheckii in Northwestern Argentina Is Shaped by Patterns of Vegetation Cover.

    PubMed

    Quipildor, Vilma B; Mathiasen, Paula; Premoli, Andrea C

    2017-07-01

    Species inhabiting drylands commonly depend on the surrounding vegetation for recruitment under stress, while competition may affect populations in moister environments. Our objective was to analyze how different climates and vegetation affect the fine-scale spatial genetic structure (SGS) of the columnar cactus Echinopsis terscheckii. At 4 sites, we estimated vegetation cover by digitized patches and the normalized difference vegetation index (NDVI). We mapped 30 individuals per population and collected tissue for isozyme electrophoresis using 15 putative loci. Spatial autocorrelation between all possible genotype pairs and the number of genetically homogeneous groups and families were calculated for each population. Greater cover (66%) and average NDVI values were detected in the most humid habitat that consisted of fewer, larger, and more dispersed vegetation patches. All populations were genetically diverse and showed significant SGS. Positive correlations were found between the distance at which maximum autocorrelation and kinship values were reached and vegetation area and patch size. Also higher NDVI values were associated with lower number of patches. Populations exposed to higher precipitation and vegetation cover consisted of sparse individuals that clustered at larger distances whereas vegetation patches in arid climates produced groups of closely related genotypes at small distances. These results support the stress-gradient genetic hypothesis. Under water stress, facilitation promotes establishment underneath patchy vegetation resulting in fine-scale family structure. In moister xerophilous forests, competition for resources, that is, light, results in sparse individuals and thus coarse-scale neighborhoods. This information can guide conservation and/or restoration efforts, such as the spatial scale to be considered in germplasm collection. © The American Genetic Association 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  17. 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. Copyright © 2015 Elsevier Ltd. All rights reserved.

  18. Effects of massage treatment combined with topical cactus and aloe on puerperal milk stasis.

    PubMed

    Meng, Shan; Deng, Qingchun; Feng, Chunyu; Pan, Yinglian; Chang, Qing

    2015-01-01

    Puerperal milk stasis is one of the most common puerperal complication that directly affects breastfeeding. Massage treatment with topical cactus and aloe for puerperal milk stasis might be a superior treatment, and it does not affect breastfeeding. The intervention group was treated with massages with cactus and aloe cold compresses, and the control group was treated with massage treatment or cactus and aloe cold compresses alone. We evaluated the efficacies of the treatments through comparisons of the feeding patterns, hardness, and pain after treatment between the three groups. We found that breastfeeding rates were significantly increased in the massage combine with combined with cactus and aloe cold compress group (P < 0.05 for both). Breast hardness and pain were reduced to greater extents in massage combine with combined with cactus and aloe cold compress group than in the massage or cold compress group (P < 0.05). Massage treatment with topical cactus and aloe topical effectively improved the pain status, hard lump of puerperal milk stasis and increase breastfeeding rate.

  19. 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

  20. 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

  1. 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

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

    NASA Astrophysics Data System (ADS)

    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.

  3. Solvent effect on columnar formation in solar-cell geometry

    NASA Astrophysics Data System (ADS)

    Park, J. H.; Sosa-Vargas, L.; Takanishi, Y.; Kim, K. H.; Kim, Y. S.; Park, Y. W.; Yamamoto, J.; Labardi, M.; Lagerwall, J. P. F.; Shimizu, Y.; Scalia, G.

    2016-03-01

    The efficiency of the conduction of photocurrent in discotic liquid crystals is known to depend on the quality of the columnar organization. Solvents have shown to be able to influence the formation of wire structures on substrates promoting very long and ordered wired formations or bulkier structures depending on the affinity of the solvent with parts of the molecular structure of discotics. Here we present a study on the effect of solvents when the liquid crystal is confined between two substrates with the columns running perpendicular to them, geometry used in solar cells. We focused on toluene and dodecane, solvents that have shown to promote on substrates the formation of aligned and long nanowires and bulk large and isolated fibers, respectively. The phase transition behavior indicates that toluene does not interfere with the columnar formation while dodecane strongly influence increasing the disorder in the structure.

  4. Numerical Investigation of Buoyancy-Induced Columnar Vortices

    NASA Astrophysics Data System (ADS)

    Malaya, Nicholas; Stogner, Roy; Moser, Robert

    2014-11-01

    Buoyancy driven columnar vortices arise naturally in the atmosphere. A new energy harvesting approach makes use of this phenomenon by creating and anchoring the vortices artificially and extracting energy from them. In this talk, we explore the characteristics of these ``solar vortices'' through numerical simulation. Computational models of the turning vane system used to generate the solar vortex and the turbine used to extract energy have been developed. The formulation of these models and their validation against available experimental measurements will be discussed, as will the details of the columnar vortex structure and its interaction with the turbine. In addition, the computational models are being used to optimize the turning vane configuration and the turbine characteristics to maximize the power extraction, and to characterize the effects of environmental conditions such as cross winds and topography. Preliminary results from these studies will also be presented. This work supported by the Department of Energy [ARPA-E] under Award Number [DE-FOA-0000670].

  5. Columnar grain growth in non-oriented electrical steels

    NASA Astrophysics Data System (ADS)

    Kovác̆, F.; Dz̆ubinský, M.; Sidor, Y.

    2004-03-01

    Decarburising annealing in the two-phase region is a known method to provide columnar grain growth in silicon non-oriented electrical steel that can improve magnetic properties. This method includes long-term preliminary annealing in vacuum and subsequent decarburising annealing in a wet hydrogen atmosphere (J. Mater. Eng. Perform. 5 (1996) 316). In the present paper an alternative method to produce the columnar microstructure in low and medium silicon non-oriented electrical steel without preliminary vacuum annealing is described. The influence of applied annealing temperature regimes and atmospheres on the development of the material microstructure are studied under the conditions of industrial continuous annealing. The dependence of the final material texture on the aforementioned conditions is presented.

  6. 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.

  7. 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.

  8. 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.

  9. Ballistic performance of oriented columnar-grained tungsten polycrystals

    SciTech Connect

    Leonard, W.; Magness, L.S.; Dowding, R.J.; Trogolo, J.; Chung, M.; Kapoor, D.

    1996-06-01

    Prior ballistic tests have demonstrated that the crystallographic orientation of a single crystal tungsten penetrator with respect to the penetrator axis influences penetration performance. The difference in penetration performance is attributed to anisotropy of the flow and failure of the monocrystalline tungsten penetrators during the penetration of the armor target. In preliminary ballistic experiments, the performance and deformation behaviors of polycrystalline tungsten penetrators having columnar grains oriented in the [100], [110], or [111] crystallographic directions were explored.

  10. Growth performance of lambs in Phangrang, Vietnam: effects of a dietary supplement containing prickly-pear cactus.

    PubMed

    Tien, D V; Beynen, A C

    2005-04-01

    In Phanrang, Vietnam, sheep production is limited by the sparse availability of green roughage. Although prickly-pear cactus (Opuntia elator) is abundant in the area, it is not used. It was considered relevant therefore to test whether prickly-pear cactus could be used a component of feed supplements. With the use of the cactus and other local products--namely groundnut cake, fish sauce by-product, molasses, rice bran and cassava flour--two supplements were prepared. The level of cactus in the two supplements was 670 g/kg product (320 g/kg dry matter). The cactus was burned to remove the spines, chopped and sun-dried before use. The cactus preparation contained only 12 g crude protein/kg (68 g/ kg dry matter). The protein content of the two supplements was raised with either groundnut cake or fish sauce by-product. Sheep that were grazing during the day were offered either no supplement or one of the supplements when confined during the night. During a period of 3 months, non-supplemented control sheep gained 98 +/- 10.5 g/day (mean +/- SD, n=10). Sheep supplemented with cactus and groundnut gained 145 +/- 12.3 g/day, and those given cactus and fish sauce gained 130 +/- 11.7 g/day. It is concluded that prickly-pear cactus has potential as component of feed supplements for sheep.

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

    PubMed

    Evenhuis, Jason P; LaFrentz, Benjamin R

    2016-08-09

    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.

  12. Large-scale columnar vortices in rotating turbulence

    NASA Astrophysics Data System (ADS)

    Yokoyama, Naoto; Takaoka, Masanori

    2016-11-01

    In the rotating turbulence, flow structures are affected by the angular velocity of the system's rotation. When the angular velocity is small, three-dimensional statistically-isotropic flow, which has the Kolmogorov spectrum all over the inertial subrange, is formed. When the angular velocity increases, the flow becomes two-dimensional anisotropic, and the energy spectrum has a power law k-2 in the small wavenumbers in addition to the Kolmogorov spectrum in the large wavenumbers. When the angular velocity decreases, the flow returns to the isotropic one. It is numerically found that the transition between the isotropic and anisotropic flows is hysteretic; the critical angular velocity at which the flow transitions from the anisotropic one to the isotropic one, and that of the reverse transition are different. It is also observed that the large-scale columnar structures in the anisotropic flow depends on the external force which maintains a statistically-steady state. In some cases, small-scale anticyclonic structures are aligned in a columnar structure apart from the cyclonic Taylor column. The formation mechanism of the large-scale columnar structures will be discussed. This work was partially supported by JSPS KAKENHI.

  13. Study of columnar-equiaxed transition and anaxial columnar dendrites growth of hypoeutectic alloy with synchrotron radiation

    NASA Astrophysics Data System (ADS)

    Li, F. G.; Zhang, J.; Dong, Q.; Dai, Y. B.; Sun, B. D.; Xie, H. L.

    2013-10-01

    Among solidification processes, the columnar to equiaxed transition (CET) is critical component for formation either of microstructure or macrostructure. Directional solidification of Al-Cu alloy was performed at the BL13W beamline of Shanghai Synchrotron Radiation Facility (SSRF). The imaging results reveal that CET was provoked by external thermal disturbance. The fragment of dendrite tips were come from solute-rich-zone. And they floated to the mushy zone to form the equiaxed dendrites. As the conditions are suitable, a new dendrite morphology sprout and grow up, in which dendrites grow along <110> directions in a binary Al-Cu alloy. These dendrites have no obvious primary arms and were named anaxial columnar dendrites.

  14. The immunophenotypic relationship between the submucosal gland unit, columnar metaplasia and squamous islands in the columnar-lined oesophagus.

    PubMed

    Lörinc, Ester; Mellblom, Lennart; Öberg, Stefan

    2015-12-01

    To characterize the immunophenotypic relationship between the squamous and the glandular compartments in the oesophagus of patients with columnar-lined oesophagus (CLO). Eight tissue blocks from three oesophageal resection specimens from patients who underwent oesophagectomy for adenocarcinoma of the oesophagus were selected for immunohistochemical analysis. The markers of intestinal differentiation [CK20, CDX2 and MUC2] were all expressed in the expected pattern, solely in the glandular compartment of the resection specimens. CK4, CK17 and lysozyme were expressed in both the glandular and the squamous compartments. In addition, CK17 expression was found on both the squamous and glandular margins of the squamocolumnar transformation zones and in the submucosal gland (SMG) intraglandular and excretory ducts. There is an immunophenotypic relationship between the squamous and the glandular compartments of the CLO, with expression of lysozyme, CK4 and CK17 in both squamous and columnar cells. These overlapping immunophenotypes indicate similar differentiation paths, and link the SMG unit with the columnar metaplasia and the neosquamous islands in CLO. Our findings support the theory of a cellular origin of CLO and neosquamous islands from the SMG unit. © 2015 John Wiley & Sons Ltd.

  15. Dif and cactus are colocalized in the larval nervous system of Drosophila melanogaster.

    PubMed

    Cantera, R; Roos, E; Engström, Y

    1999-01-01

    The Rel protein Dif is a transcription factor suggested to control part of the immune response in the fruit fly Drosophila melanogaster. In uninfected animals, Dif is normally located in the cytoplasm, most likely in a complex with an IkappaB molecule such as Cactus. Upon infection, Dif is enriched in the nucleus of immunoresponsive tissues such as fat body and blood cells. Rel proteins in mammals not only participate in the control of the immune response, but are also thought to play important roles in the function of the nervous system. Here, we demonstrate that both Dif and Cactus are expressed in the central nervous system (CNS) of Drosophila. Interestingly, Dif and Cactus colocalize in their distribution, suggesting a functional link between these proteins in the CNS. In the larval CNS, both Dif and Cactus are expressed at relatively low levels in most cells and at high levels in the mushroom bodies and in small subsets of neurosecretory cells. The cytoplasmic localization of Dif and Cactus in the CNS cells is not affected by bacterial challenge. Instead, we observed changes in nuclear versus cytoplasmic localization of Cactus (but not Dif) along the dark-light cycle, with a strong nuclear localization in perineurial glia toward the end of the dark period. In the CNS of the prepupa, the intensity of the immunostaining for both Dif and Cactus is higher than in the larva. Interestingly, in fat body of uninfected prepupae, the Dif localization was mainly nuclear, suggesting a function for Dif during the process of pupariation.

  16. 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.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  18. Characterization of an Avipoxvirus From a Bald Eagle ( Haliaeetus leucocephalus ) Using Novel Consensus PCR Protocols for the rpo147 and DNA-Dependent DNA Polymerase Genes.

    PubMed

    Stephen, Alexa A; Leone, Angelique M; Toplon, David E; Archer, Linda L; Wellehan, James F X

    2016-12-01

    A juvenile female bald eagle ( Haliaeetus leucocephalus ) was presented with emaciation and proliferative periocular lesions. The eagle did not respond to supportive therapy and was euthanatized. Histopathologic examination of the skin lesions revealed plaques of marked epidermal hyperplasia parakeratosis, marked acanthosis and spongiosis, and eosinophilic intracytoplasmic inclusion bodies. Novel polymerase chain reaction (PCR) assays were done to amplify and sequence DNA polymerase and rpo147 genes. The 4b gene was also analyzed by a previously developed assay. Bayesian and maximum likelihood phylogenetic analyses of the obtained sequences found it to be poxvirus of the genus Avipoxvirus and clustered with other raptor isolates. Better phylogenetic resolution was found in rpo147 rather than the commonly used DNA polymerase. The novel consensus rpo147 PCR assay will create more accurate phylogenic trees and allow better insight into poxvirus history.

  19. 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. © The Author(s) 2016.

  20. Ungeremine and Its hemisynthesized analogues as bactericides against Flavobacterium columnare.

    PubMed

    Schrader, Kevin K; Avolio, Fabiana; Andolfi, Anna; Cimmino, Alessio; Evidente, Antonio

    2013-02-13

    The Gram-negative bacterium Flavobacterium columnare is the cause of columnaris disease, which can occur 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. In this study, analogues of 1 were evaluated using a rapid bioassay for activity against F. columnare to determine if the analogues might provide greater antibacterial activity and to determine structure-activity relationships of the test compounds. Several ungeremine analogues were prepared by hydrochlorination of the alkaloid and by selenium dioxide oxidation of both lycorine, 7, and pseudolycorine, 8, which yielded the isomer of ungeremine, 3, and zefbetaine, 4, respectively. The treatment of lycorine with phosphorus oxychloride allowed the synthesis of an anhydrolycorine lactam, 5, showing, with respect to 1, the deoxygenation and oxygenation of C-2 and C-7 of the C and B rings, respectively. The results of the structure-activity relationship studies showed that the aromatization of the C ring and the oxidation to an azomethine group of C-7 of the B ring are structural features important for antibacterial activity. In addition, the position of the oxygenation of the C ring as well as the presence of the 1,3-dioxole ring joined to the A ring of the pyrrolo[de]phenanthridine skeleton also plays a significant role in imparting antibacterial activity. On the basis of 24-h 50% inhibition concentration (IC(50)) results, ungeremine hydrochloride, 2, was similar in toxicity to 1, whereas 5 had the lowest activity. Analogue 2 is soluble in water, which may provide the benefit for use as an effective feed additive or therapeutant compared to ungeremine.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  3. 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... moth. DATES: We will consider all comments that we receive on or before January 18, 2011. ADDRESSES... American cactus moth, contact Dr. Robyn Rose, Program Manager, Emergency and Domestic Programs, PPQ,...

  4. The transcriptomes of columnar and standard type apple trees (Malus x domestica) - a comparative study.

    PubMed

    Krost, Clemens; Petersen, Romina; Schmidt, Erwin R

    2012-05-01

    Columnar apple trees (Malus x domestica) provide several economic advantages due to their specific growth habit. The columnar phenotype is the result of the dominant allele of the gene Co and is characterized by thick stems with short internodes and reduced lateral branching. Co is located on chromosome 10 and often appears in a heterozygous state (Co/co). The molecular explanation of columnar growth is not well established. Therefore, we studied the transcriptomes of columnar and standard type apple trees using 454 and Illumina next generation sequencing (NGS) technologies. We analyzed the transcriptomes of shoot apical meristems (SAMs) because we expect that these organs are involved in forming the columnar growth phenotype. The results of the comparative transcriptome analysis show significant differences in expression levels of hundreds of genes. Many of the differentially expressed genes are associated with membrane and cell wall growth or modification and can be brought in line with the columnar phenotype. Additionally, earlier findings on the hormonal state of shoots of columnar apples could be affirmed. Our study resulted in a large number of genes differentially expressed in columnar vs. standard type apple tree SAMs. Although we have not unraveled the nature of the Co gene, we could show that the modified expression of these genes, most likely due to the presence of Co, can determine the columnar phenotype. Furthermore, the usefulness of NGS for the analysis of the molecular basis of complex phenotypes is discussed. Copyright © 2012 Elsevier B.V. All rights reserved.

  5. 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. Copyright © 2013 Elsevier B.V. All rights reserved.

  6. Ultraviolet spectrophotometer for measuring columnar atmospheric ozone from aircraft

    NASA Technical Reports Server (NTRS)

    Hanser, F. A.; Sellers, B.; Briehl, D. C.

    1978-01-01

    An ultraviolet spectrophotometer (UVS) to measure downward solar fluxes from an aircraft or other high altitude platform is described. The UVS uses an ultraviolet diffuser to obtain large angular response with no aiming requirement, a twelve-position filter wheel with narrow (2-nm) and broad (20-nm) bandpass filters, and an ultraviolet photodiode. The columnar atmospheric ozone above the UVS (aircraft) is calculated from the ratios of the measured ultraviolet fluxes. Comparison with some Dobson station measurements gives agreement to 2%. Some UVS measured ozone profiles over the Pacific Ocean for November 1976 are shown to illustrate the instrument's performance.

  7. Chiral discotic columnar germs of nucleosome core particles.

    PubMed Central

    Livolant, F; Leforestier, A

    2000-01-01

    In concentrated solution and in the presence of high concentrations of monovalent cations, nucleosome core particles order into a discotic columnar mesophase. This phase is limited to finite-sized hexagonal germs that further divide into six coiled branches, following an iterative process. We show how the structure of the germs comes from the competition between hexagonal packing and chirality with a combination of dendritic facetting and double-twist configurations. Geometrical considerations lead us to suspect that the chirality of the eukaryotic chromosomes may originate from the same competition. PMID:10777768

  8. 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.

  9. 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. Copyright © 2014 Elsevier Ltd. All rights reserved.

  10. 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.

  11. 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.

  12. 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.

  13. 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.

  14. Spaceborne observation of columnar water vapor - SSMI observations and algorithm

    NASA Technical Reports Server (NTRS)

    Tjemkes, Stephen A.; Stephens, Graeme L.; Jackson, Darren L.

    1991-01-01

    An analysis of the transfer of radiation with a frequency between 10 and 40 GHz through a cloud-free atmosphere is given, and the limitations of employing observations at 22.235 GHz for sensing the columnar water vapor (CWV) in the moist atmosphere (CWV above 40 kg/sq m) are shown. It is because of this limitation that a new method for the retrieval of columnar water vapor is described. This method uses both the horizontally and vertically polarized brightness temperatures measured at 19.35 GHz by the special sensor microwave imager (SSMI) which was launched as part of the Defense Military Satellite Program. The water vapor derived from the SSMI observations is validated against radiosonde observations that are near coincident in time and space with an rms error of 6 kg/sq m. This large rms is in part due to sensitivity of the retrieval method to the surface emission. Distributions of CWV over the oceans were obtained for a 3-month period starting September, 1987. These results are compared to other water vapor retrievals for the same period using the same microwave radiance data; they show close agreement except over the warmest water in the equatorial tropics.

  15. 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.

  16. 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.

  17. Columnar domains and anisotropic growth laws in dipolar systems

    NASA Astrophysics Data System (ADS)

    Bupathy, Arunkumar; Banerjee, Varsha; Puri, Sanjay

    2017-06-01

    Magnetic and dielectric solids are well-represented by the Ising model with dipolar interactions (IM+DI). The latter are long-ranged, fluctuating in sign, and anisotropic. Equilibrium studies have revealed novel consequences of these complicated interactions, but their effect on nonequilibrium behavior is not explored. We perform a deep temperature quench to study the kinetics of domain growth in the d =3 IM+DI. Our main observations are (i) the emergence of columnar domains along the z axis (Ising axis) with a transient periodicity in the x y plane; (ii) anisotropic growth laws: ℓρ(t ) ˜tϕ ; ℓz(t ) ˜tψ , where ρ ⃗=(x ,y ) and ℓ is the characteristic length scale; (iii) generalized dynamical scaling for the correlation function: C (ρ ,z ;t ) =g (ρ /ℓρ,z /ℓz) ; and (iv) an asymptotic Porod tail in the corresponding structure factor: S (kρ,0 ;t ) ˜kρ-3 ; S (0 ,kz;t ) ˜kz-2 . Our results explain the experimentally observed columnar morphologies in a wide range of dipolar systems, and they have important technological implications.

  18. Columnar Jointing and Quasihexagonal Crack Patterns in Corn Starch

    NASA Astrophysics Data System (ADS)

    Goehring, Lucas; Morris, Stephen W.

    2003-03-01

    The well-known geophysical phenomenon of basaltic columnar jointing, occurring most spectacularly in the Giant's Causeway in N. Ireland, has inspired several theories describing the origin and evolution of quasihexagonal crack patterns (P. Budkewitsch and P-Y. Robin, J. Volcanol. Geotherm. Res., 59, 219 (1994); E. A. Jagla and A. G. Rojo, Phys. Rev. E, 65, 026203 (2002) for example). Field studies have not been able to distinguish between these theories. However, the desiccation of water-starch mixtures also produces quasihexagonal crack patterns (G. Müller, J. Geophys. Res. 103, 15239 (1998)). The diffusion and evaporation of water is thought to be analogous to the diffusion and extraction of heat from a basalt flow. To better understand hexagonal columnar jointing, we have desiccated corn starch under controlled conditions. We have studied the dynamics of the crack pattern, and measured several maturation indices. Such indices attempt to quantify how disordered cracks evolve into ordered hexagonal patterns. Our objective is to determine whether laboratory tests can discriminate between the theoretical models of this interesting geological pattern.

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

    PubMed

    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.

  20. 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

  1. Enzyme-assisted extraction of cactus bioactive molecules under high hydrostatic pressure.

    PubMed

    Kim, Jae Hwan; Park, Yooheon; Yu, Kwang Won; Imm, Jee-Young; Suh, Hyung Joo

    2014-03-30

    To improve the extraction and recovery of bioactive materials from cactus, the present study investigated the effect of polysaccharide-degrading enzymes [Rapidase-Viscozyme mixture, 1/3 (v/v)] treatment under high hydrostatic pressure (HHP). The dry weight of the extract increased with the use of increasing pressure regardless of enzyme treatment. However, the polyphenol content showed a tendency to decrease with the increase in pressure in the cactus extract with or without enzyme treatment. The enzyme-assisted extraction resulted in an increase of dry weight and polyphenol content in the cactus extract. The total sugar and reducing sugar contents of the cactus extract increased with increasing pressure in enzyme-assisted extraction. The uronic acid content of the cactus extract showed a pattern similar to that of the reducing sugars. The enzyme-assisted extraction also increased the contents of taxifolin, quercetin and isorhametin. The cactus extract obtained through enzyme-assisted extraction showed intense scavenging activity of both DPPH and ABTS radicals. The crude polysaccharides isolated from the extract (51.2% at 1000 µg mL⁻¹ for HHP extraction at 300 MPa) had higher anti-complementary activity than the others except for lipopolysaccharide (60.00% at 1000 µg mL⁻¹). HHP extraction and enzyme-assisted extraction using HHP showed an increase of anti-complementary activity compared with the heat and enzyme controls, respectively. Overall, the use of HHP in enzyme-assisted extraction resulted in more efficient extraction than the use of enzyme treatment alone. © 2013 Society of Chemical Industry.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  3. Optimized reverse primer for 16S-RFLP analysis and genomovar assignment of Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is the causative agent of columnaris disease which severely impacts channel catfish production in the USA and has emerged as an important pathogen in the US rainbow trout industry. Our laboratory previously standardized a genetic typing system for F. columnare in which a por...

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  6. The role of the Flavobacterium columnare chemotactic response to skin mucus in virulence

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is a Gram-negative pathogen of many species of wild and cultured fish, especially channel catfish (Ictalurus punctatus). This bacterium is responsible for severe economic losses in the aquaculture industry. Flavobacterium columnare isolated from diseased channel catfish be...

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

    USDA-ARS?s Scientific Manuscript database

    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. 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

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  12. Comparative Genomics and Transcriptional Analysis of Flavobacterium columnare Strain ATCC 49512

    PubMed Central

    Tekedar, Hasan C.; Karsi, Attila; Reddy, Joseph S.; Nho, Seong W.; Kalindamar, Safak; Lawrence, Mark L.

    2017-01-01

    Flavobacterium columnare is a Gram-negative fish pathogen causing columnaris disease in wild and cultured fish species. Although the pathogen is widespread in aquatic environments and fish worldwide, little is known about biology of F. columnare and mechanisms of columnaris disease pathogenesis. Previously we presented the complete genome sequence of F. columnare strain ATCC 49512. Here we present a comparison of the strain ATCC 49512 genome to four other Flavobacterium genomes. In this analysis, we identified predicted proteins whose functions indicate F. columnare is capable of denitrification, which would enable anaerobic growth in aquatic pond sediments. Anaerobic growth of F. columnare ATCC 49512 with nitrate supplementation was detected experimentally. F. columnare ATCC 49512 had a relatively high number of insertion sequences and genomic islands compared to the other Flavobacterium species, suggesting a larger degree of horizontal gene exchange and genome plasticity. A type VI subtype III secretion system was encoded in F. columnare along with F. johnsoniae and F. branchiophilum. RNA sequencing proved to be a valuable technique to improve annotation quality; 41 novel protein coding regions were identified, 16 of which had a non-traditional start site (TTG, GTG, and CTT). Candidate small noncoding RNAs were also identified. Our results improve our understanding of F. columnare ATCC 49512 biology, and our results support the use of RNA sequencing to improve annotation of bacterial genomes, particularly for type strains. PMID:28469601

  13. Star Photometry for the Characterization of Columnar Aerosol Properties

    NASA Astrophysics Data System (ADS)

    Perez-Ramirez, D.; Lyamani, H.; Olmo Reyes, F. J.; Alados-Arboledas, L.; Whiteman, D. N.; Aceituno, J.

    2015-12-01

    Knowledge of columnar aerosol particles at nighttime is essential to completely understand aerosol dynamics and so will largely improve aerosol models. However, the current knowledge columnar nighttime aerosol is poor due to the lack of continuous measurements partly associated with previous technological limitations. Here we present the development, set up, calibration and data quality algorithms for the star photometer at the station of Granada (37.16 N, 3.60 W, 680 m a.s.l.) in Spain. The main advantage of this instrument is that make uses of a CCD camera as detector allowing direct star flux measurements. Filters center at 380, 440, 500, 670, 880 and 1020 nm allows spectral aerosol optical depth (AOD) measurements. Among all the stars, only those that are isolated and possess constant extratarrestial flux are considered. Two methods for the calibration of the system at high mountain places are presented. The first one consists of doing a Langley calibration of a selected star together with measurements of other stars. From the Langley calibration, we transferred AOD and get the calibration constants for other stars. The second method is the Astronomical Langley Method that consists of dividing the measurements by the optical air mass and so more stable calibration constant are obtained. On the other hand, the atmospheric turbulence is important for very short exposure times (< 1 s) and so uncertainties in AOD are of ±0.02 for λ < 800nm and ±0.01 for λ > 800nm. The instrument operated continuously for more than four consecutive years and so a large database was created. Cloud screening and data quality algorithms following AERONET inheritance were developed. Basically, moving averages are applied with different temporal-windows combined with a procedure to detect outliers. On the other hand, with quality data guaranteed the analysis of day-to-night columnar aerosol properties is presented. Mean AOD(440 nm) (0.18 ± 0.10 and 0.19 ± 0.11 for daytime and

  14. Nocardioides opuntiae sp. nov., isolated from soil of a cactus.

    PubMed

    Lee, Soon Dong; Seong, Chi Nam

    2014-06-01

    A novel high G+C actinobacterium, designated strain OS1-21(T), was isolated from the rhizosphere soil of a cactus (Opuntia fiscus-indica var. sanboten) and the taxonomic status was investigated using a polyphasic approach. Cells of strain OS1-21(T) were aerobic, Gram-stain-positive, non-endospore-forming, non-motile rods; colonies of the cells were circular, translucent, smooth and moderate yellow in colour. LL-Diaminopimelic acid was the diagnostic diamino acid in cell-wall peptidoglycan. The predominant menaquinone was MK-8(H4). The major fatty acids were iso-C(16 : 0), iso-C(16 : 0) 2-OH, 10-methyl C(17 : 0), 10-methyl C(18 : 0) and C(17 : 1)cis9. The polar lipids contained diphosphatidylglycerol, phosphatidylglycerol, phosphatidylinositol and two unknown phospholipids. The DNA G+C content was 73.7 mol%. Based on 16S rRNA gene sequence analysis, the closest phylogenetic neighbours were Nocardioides panacihumi Gsoil 616(T) (98.7% sequence similarity) and Nocardioides terrae VA15(T) (97.8%), followed by Nocardioides marinus CL-DD14(T) (97.1%). DNA-DNA relatedness values of strain OS1-21(T) with the type strains of the closest phylogenetic neighbours were low (<16.0%). Combined data of polyphasic taxonomic analyses revealed that the organism could be assigned to a novel species of the genus Nocardioides, for which the name Nocardioides opuntiae sp. nov. is proposed. The type strain is OS1-21(T) ( = KCTC 19804(T) = NBRC 107915(T)). © 2014 IUMS.

  15. Electronic structure of vortices pinned by columnar defects

    NASA Astrophysics Data System (ADS)

    Mel'Nikov, A. S.; Samokhvalov, A. V.; Zubarev, M. N.

    2009-04-01

    The electronic structure of a vortex line trapped by an insulating columnar defect in a type-II superconductor is analyzed within the Bogolubov-de Gennes theory. For quasiparticle trajectories with small impact parameters defined with respect to the vortex axis, the normal reflection of electrons and holes at the defect surface results in the formation of an additional subgap spectral branch. The increase in the impact parameter at this branch is accompanied by the decrease in the excitation energy. When the impact parameter exceeds the radius of the defect this branch transforms into the Caroli-de Gennes-Matricon one. As a result, the minigap in the quasiparticle spectrum increases with the increase in the defect radius. The scenario of the spectrum transformation is generalized for the case of arbitrary vorticity.

  16. 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.

  17. 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.

  18. D2-D1 phase transition of columnar liquid crystals

    NASA Astrophysics Data System (ADS)

    Sun, Y. F.; Swift, J.

    1986-04-01

    The D2-D1 phase transition in columnar liquid crystals of the HAT series [e.g., HAT11 (triphenelene hexa-n-dodecanoate)] is discussed within the framework of Landau theory. The order parameters which describe the transition are abstracted from a tensor density function, and are associated with two irreducible representations of the symmetry group of the high-temperature D2 phase. A mechanism for a first-order transition is then suggested in accordance with both theoretical considerations and the experimental result for the D2-D1 transition. Two possible arrangements of the herringbone structure of the D1 phase are obtained, each of which gives six orientational states in the low-temperature D1 phase.

  19. 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.

  20. 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.

  1. Population genetic structure of Venezuelan chiropterophilous columnar cacti (Cactaceae).

    PubMed

    Nassar, Jafet M; Hamrick, J L; Fleming, Theodore H

    2003-11-01

    We conducted allozyme surveys of three Venezuelan self-incompatible chiropterophilous columnar cacti: two diploid species, Stenocereus griseus and Cereus repandus, and one tetraploid, Pilosocereus lanuginosus. The three cacti are pollinated by bats, and both bats and birds disperse seeds. Population sampling comprised two spatial scales: all Venezuelan arid zones (macrogeographic) and two arid regions in northwestern Venezuela (regional). Ten to 15 populations and 17-23 loci were analyzed per species. Estimates of genetic diversity were compared with those of other allozyme surveys in the Cactaceae to examine how bat-mediated gene dispersal affects the population genetic attributes of the three cacti. Genetic diversity was high for both diploid (P(s) = 94.1-100, P(p) = 56.7-72.3, H(s) = 0.182-0.242, H(p) = 0.161-0.205) and tetraploid (P(s) = 93.1, P(p) = 76.1, H(s) = 0.274, H(p) = 0.253) species. Within-population heterozygote deficit was detected in the three cacti at macrogeographic (F(IS) = 0.145-0.182) and regional (F(IS) = 0.057-0.174) levels. Low genetic differentiation was detected at both macrogeographic (G(ST) = 0.043-0.126) and regional (G(ST) = 0.009-0.061) levels for the three species, suggesting substantial gene flow among populations. Gene exchange among populations seems to be regulated by distance among populations. Our results support the hypothesis that bat-mediated gene dispersal confers high levels of genetic exchange among populations of the three columnar cacti, a process that enhances levels of genetic diversity within their populations.

  2. Evolving fracture patterns: columnar joints, mud cracks, and polygonal terrain

    NASA Astrophysics Data System (ADS)

    Goehring, L.

    2012-12-01

    Contraction cracks can form captivating patterns, such as the artistic craquelure sometimes found in pottery glazes, to the cracks in dried mud, or the polygonal networks covering the polar regions of Earth and Mars. Two types are frequently encountered: those with irregular rectilinear patterns, such as that formed by an homogeneous slurry when dried (or cooled) uniformly, and more regular hexagonal patterns, such as those typified by columnar joints. Once cracks start to form in a thin contracting layer, they will sequentially break the layer into smaller and smaller pieces. A rectilinear crack pattern encodes information about the order of cracks, as later cracks tend to intersect with earlier cracks at right angles. In this manner they relieve the stresses perpendicular to the pre-existing crack. In a hexagonal pattern, in contrast, the angles between all cracks at a vertex are near 120°. In this presentation it will be shown how both types of pattern can arise from identical forces, and that a rectilinear, T-junction dominated pattern will develop into to a hexagonal pattern, with Y-junctions, if allowed to. Such an evolution can be explained as the result of three conditions: (1) if cracks advance through space, or heal and recur, that the previous positions of a crack tip acts as a line of weakness, guiding the next iteration of cracking; (2) that the order of opening of cracks can change in each iteration; and (3) that crack tips curve to maximise the local strain energy release rate. The ordering of crack patterns are seen in a number of systems: columnar joints in starch and lava; desiccation cracks in clays that are repeatedly wetted and dried; cracks in eroding gypsum-cemented sand layers; and the cracks in permafrost known as polygonal terrain. These patterns will each be briefly explored, in turn, and shown to obey the above principles of crack pattern evolution.

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    USDA-ARS?s Scientific Manuscript database

    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...

  5. 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.

  6. Response of vegetable pads of two cactus cultivars to the presence of Salmonella strains

    USDA-ARS?s Scientific Manuscript database

    Tender cactus pads (cladodes) or nopalitos (Opuntia ficus-indica L) are an important vegetable in Mexico. They are often pre-trimmed, cut and packaged, and while usually consumed cooked, they may also be eaten raw in salads. Salmonella is an enteropathogenic bacterium that can adapt to adverse envir...

  7. Phytobezoar from the stem ("quiote") of the cactus Agave americana: report of case.

    PubMed

    Villarreal, R; Martinez, O; Berumen, U

    1985-11-01

    Agave americana is a cactus growing abundantly in Mexico. Its cooked stem ("quiote") yields by mastication a sweet juice which is swallowed, while the fibers ("bagazo") are spit out. That is the way Mexicans are taught to chew quiote since their early childhood, and it accounts for the rarity of bezoars from this origin. One of such cases is reported herein.

  8. Preliminary report on the reproductive biology of the threatened Chisos Mountain hedgehog cactus

    Treesearch

    Bonnie B. Amos; Christos Vassiliou

    2001-01-01

    The Chisos Mountain hedgehog cactus (Echinocereus chisoensis, Cactaceae) is a narrow endemic restricted to an approximately 100 square mile area in Big Bend National Park, Texas. It was listed as threatened in 1987 as Echinocereus chisoensis var. chisoensis. An investigation of the reproductive biology and pollination ecology conducted in 1999 and 2000 revealed the...

  9. Characterization of a male reproductive transcriptome for Peromyscus eremicus (Cactus mouse)

    PubMed Central

    2016-01-01

    Rodents of the genus Peromyscus have become increasingly utilized models for investigations into adaptive biology. This genus is particularly powerful for research linking genetics with adaptive physiology or behaviors, and recent research has capitalized on the unique opportunities afforded by the ecological diversity of these rodents. Well characterized genomic and transcriptomic data is intrinsic to explorations of the genetic architecture responsible for ecological adaptations. Therefore, this study characterizes the transcriptome of three male reproductive tissues (testes, epididymis and vas deferens) of Peromyscus eremicus (Cactus mouse), a desert specialist. The transcriptome assembly process was optimized in order to produce a high quality and substantially complete annotated transcriptome. This composite transcriptome was generated to characterize the expressed transcripts in the male reproductive tract of P. eremicus, which will serve as a crucial resource for future research investigating our hypothesis that the male Cactus mouse possesses an adaptive reproductive phenotype to mitigate water-loss from ejaculate. This study reports genes under positive selection in the male Cactus mouse reproductive transcriptome relative to transcriptomes from Peromyscus maniculatus (deer mouse) and Mus musculus. Thus, this study expands upon existing genetic research in this species, and we provide a high quality transcriptome to enable further explorations of our proposed hypothesis for male Cactus mouse reproductive adaptations to minimize seminal fluid loss. PMID:27812417

  10. 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. Copyright © 2016 Sociedade Brasileira de Microbiologia. Published by Elsevier Editora Ltda. All rights reserved.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  12. Ecology and conservation of the cactus ferruginous pygmy-owl in Arizona

    Treesearch

    Jean-Luc E. Cartron; Deborah M. Finch

    2000-01-01

    This report is the result of a cooperative effort by the Rocky Mountain Research Station and the USDA Forest Service Region 3, with participation by the Arizona Game and Fish Department and the Bureau of Land Management. It assesses the state of knowledge related to the conservation status of the cactus ferruginous pygmy-owl in Arizona. The population decline of this...

  13. Knowlton's cactus (Pediocactus knowltonii): Eighteen years of monitoring and recovery actions

    Treesearch

    Robert C. Sivinski; Charlie McDonald

    2007-01-01

    Pediocactus knowltonii is a rare, endemic cactus that is presently known to occur on a single 10-hectare hill in northwestern New Mexico near the Colorado border. It was listed as federally endangered in 1979. Population monitoring and recovery actions were initiated when the Recovery Plan was adopted in 1985. The land at the type locality has been...

  14. Historical biogeography of longhorn cactus beetles: the influence of Pleistocene climate changes on American desert communities

    Treesearch

    Christopher Irwin Smith; Brian Dorsey Farrell

    2005-01-01

    Mitochondrial sequence data from three species of flightless cactus beetles, Moneilema gigas, M. armatum, and M. appressum, were analyzed. The coalescent models implemented in the program FLUCTUATE were used to test the hypothesis that these species experienced range changes following the end of the last glacial...

  15. Chapter 6: Research needs for the conservation of the cactus ferruginous pygmy-owl in Arizona

    Treesearch

    Jean-Luc E. Cartron; W. Scott Richardson; Deborah M. Finch; David J. Krueper

    2000-01-01

    In this chapter, we describe research needs for the conservation of the cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) in Arizona. Estimates of population size, structure, and dynamics, as well as demographic data, are needed for the recovery team to formulate sound population objectives. Habitat loss due to residential development...

  16. Five-Year Monitoring Study of Siler's Pincushion Cactus (Pediocactus sileri) in Kane County, Utah

    Treesearch

    Alyce M. Hreha; Therese B. Meyer

    2001-01-01

    Siler's pincushion cactus (Pediocuctus sileri) occurs primarily on Bureau of Land Management (BLM) lands in Washington and Kane Counties in southwestern Utah and across the border in northwestern Arizona. This 5 year (1993-1997) monitoring study was set up as a challenge cost-share project between Red Butte Garden and the Utah State BLM Office in Salt Lake City. A...

  17. Chapter 1: The cactus ferruginous pygmy-owl: Taxonomy, distribution, and natural history

    Treesearch

    Jean-Luc E. Cartron; W. Scott Richardson; Glenn A. Proudfoot

    2000-01-01

    The cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) is a small, cryptic owl that is often difficult to observe. Its natural history and conservation needs are poorly understood. Despite ongoing research in Texas and Arizona, the available information remains limited. In addition, factors influencing demographics (e.g., habitat...

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

    USDA-ARS?s Scientific Manuscript database

    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...

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

    PubMed

    Faisal, M; Diamanka, A; Loch, T P; LaFrentz, B R; Winters, A D; García, J C; Toguebaye, B S

    2017-05-01

    Flavobacterium columnare, the aetiological agent of columnaris disease, causes significant losses in fish worldwide. In this study, the prevalence of F. columnare infection was assessed in representative Great Lakes fish species. Over 2000 wild, feral and hatchery-propagated salmonids, percids, centrarchids, esocids and cyprinids were examined for systemic F. columnare infections. Logistic regression analyses showed that the prevalence of F. columnare infection varied temporally and by the sex of the fish, whereby females had significantly higher prevalence of infection. A total of 305 isolates of F. columnare were recovered. Amplification of the near complete 16S rRNA gene from 34 representative isolates and subsequent restriction fragment length polymorphism analyses demonstrated that all belonged to F. columnare genomovar I. Phylogenetic analysis of near complete 16S rRNA gene sequences also placed the isolates in genomovar I, but revealed some intragenomovar heterogeneity. Together, these results suggest that F. columnare genomovar I is widespread in the Great Lakes Basin, where its presence may lead to mortality. © 2016 John Wiley & Sons Ltd.

  20. The influence of herbivory and weather on the vital rates of two closely related cactus species.

    PubMed

    Sauby, Kristen E; Kilmer, John; Christman, Mary C; Holt, Robert D; Marsico, Travis D

    2017-09-01

    Herbivory has long been recognized as a significant driver of plant population dynamics, yet its effects along environmental gradients are unclear. Understanding how weather modulates plant-insect interactions can be particularly important for predicting the consequences of exotic insect invasions, and an explicit consideration of weather may help explain why the impact can vary greatly across space and time. We surveyed two native prickly pear cactus species (genus Opuntia) in the Florida panhandle, USA, and their specialist insect herbivores (the invasive South American cactus moth, Cactoblastis cactorum, and three native insect species) for five years across six sites. We used generalized linear mixed models to assess the impact of herbivory and weather on plant relative growth rate (RGR) and sexual reproduction, and we used Fisher's exact test to estimate the impact of herbivory on survival. Weather variables (precipitation and temperature) were consistently significant predictors of vital rate variation for both cactus species, in contrast to the limited and varied impacts of insect herbivory. Weather only significantly influenced the impact of herbivory on Opuntia humifusa fruit production. The relationships of RGR and fruit production with precipitation suggest that precipitation serves as a cue in determining the trade-off in the allocation of resources to growth or fruit production. The presence of the native bug explained vital rate variation for both cactus species, whereas the invasive moth explained variation only for O. stricta. Despite the inconsistent effect of herbivory across vital rates and cactus species, almost half of O. stricta plants declined in size, and the invasive insect negatively affected RGR and fruit production. Given that fruit production was strongly size-dependent, this suggests that O. stricta populations at the locations surveyed are transitioning to a size distribution of predominantly smaller sizes and with reduced sexual

  1. Columnar joint morphology and cooling rate: A starch-water mixture experiment

    NASA Astrophysics Data System (ADS)

    Toramaru, A.; Matsumoto, T.

    2004-02-01

    An analogue experiment using a starch-water mixture has been carried out in order to understand the effect of cooling rate on the morphological characteristics of a basalt columnar joint. If the contraction of material is essential for the formation of columnar joint structure, the water loss rate by desiccation (hereafter referred to as desiccation rate) in the experiment is analogous to the cooling rate in solidifying basalt. In the experiment the desiccation rate is controlled by varying the distance between the starch-water mixture and a lamp used as the heat source. We find that there are three regimes in the relation between joint formation and desiccation rate: (1) At desiccation rates higher than ˜1.4 × 10-2 (g cm-2 h-1) (normal columnar joint regime), the average cross-sectional area S of a column is inversely proportional to the average desiccation rate, (i.e., S ∝ -δ, with δ = 1). (2) Between that desiccation rate and a critical desiccation rate, 0.8 × 10-2 (g/cm2h), S approaches infinity as decreases close to a critical desiccation rate (i.e., exponent δ monotonically increases from unity to infinity) (critical regime). (3) Below the critical desiccation rate, no columnar structure forms (no columnar joint regime forms). Applying the present experimental result to the formation of basalt column, the basalt columnar cross-sectional area is inversely proportional to the cooling rate with factors including elasticity, crack growth coefficient, thermal expansion, glass transition temperature, and crack density ratio at stress maximum. Also, it can be predicted that there exists a critical cooling rate below which the columnar joint does not form; the presence of a critical regime between the normal columnar jointing and no columnar jointing during a certain cooling rate range can also be predicted. We find that at higher cooling rate the preferred column shape is a pentagon, whereas at lower cooling rate it is a hexagon.

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

    PubMed

    Ferreira, Enio; Gobbi, Helenice; Saraiva, Bruna S; Cassali, Geovanni D

    2010-02-23

    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. 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 (34betaE-12), E-cadherin, Ki-67, HER-2 and P53) was perfomed. 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 34betaE-12, HER-2 and P53. The proliferation rate as measured by Ki-67 appeared higher in the lesions analyzed than in normal TDLUs. 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.

  3. Columnar cell variant of papillary thyroid carcinoma: A diagnostic dilemma in fine-needle aspiration cytology.

    PubMed

    Verma, Ritu; Paul, Paramita

    2016-10-01

    Columnar cell variant of papillary thyroid carcinoma (PTC) is an uncommon variant with an aggressive course as compared to classic papillary carcinoma. Cytologic diagnosis of these tumors is difficult due to absence of characteristic nuclear features of classic pattern of papillary carcinoma. We present a case of columnar cell variant in a young female misdiagnosed on aspiration cytology. A 21-year-old female presented with solitary nodule in the left aspect of thyroid. A diagnosis of medullary thyroid carcinoma was rendered. The resected thyoroidectomy specimen revealed a columnar cell variant of PTC which was further supported by immunohistochemical staining. Diagn. Cytopathol. 2016;44:816-819. © 2016 Wiley Periodicals, Inc.

  4. INFLUENCE OF SNOWFALL ON BLOOD LEAD LEVELS OF FREE-FLYING BALD EAGLES (HALIAEETUS LEUCOCEPHALUS) IN THE UPPER MISSISSIPPI RIVER VALLEY.

    PubMed

    Lindblom, Ronald A; Reichart, Letitia M; Mandernack, Brett A; Solensky, Matthew; Schoenebeck, Casey W; Redig, Patrick T

    2017-10-01

    Lead poisoning of scavenging raptors occurs primarily via consumption of game animal carcasses containing lead, which peaks during fall firearm hunting seasons. We hypothesized that snowfall would mitigate exposure by concealing carcasses. We categorized blood lead level (BLL) for a subsample of Bald Eagles (Haliaeetus leucocephalus) from the Upper Mississippi River Valley and described BLL with respect to age, sex, and snowfall. We captured Bald Eagles overwintering in the Upper Mississippi River Valley (n=55) between December 1999 and January 2002. Individual BLL ranged from nondetectable to 335 μg/dL, with 73% of the samples testing positive for acute exposure to lead. Eagle BLL did not significantly differ between age or sex, but levels were higher immediately following the hunting season, and they were lower when the previous month's snowfall was greater than 11 cm. This study suggests a window of time between the white-tailed deer (Odocoileus virginianus) hunting season and the onset of snow when the population experienced peak exposure to lead. Combining these findings with existing research, we offer a narrative of the annual lead exposure cycle of Upper Mississippi River Valley Bald Eagles. These temporal associations are necessary considerations for accurate collection and interpretation of BLL.

  5. 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.

  6. 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.

  7. 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

    2014-09-17

    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.

  8. 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

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

    USDA-ARS?s Scientific Manuscript database

    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...

  10. Assessment of Flavobacterium columnare from golden shiners Notemingonus crysoleucas subject to crowding stress

    USDA-ARS?s Scientific Manuscript database

    Intensive aquaculture practices and exposure to environmental stressors can trigger outbreaks of Flavobacterium columnare, a bacterial pathogen that causes columnaris disease in commercially important fish including Golden Shiners. A rapid assessment of the bacterial load is essential to prevent out...

  11. Growth of columnar hydrogel colloidal crystals in water-organic solvent mixture.

    PubMed

    Zhou, Jun; Cai, Tong; Tang, Shijun; Marquez, Manuel; Hu, Zhibing

    2006-01-31

    A novel emulsion method has been demonstrated to grow columnar hydrogel colloidal crystals by mixing an aqueous suspension of poly-N-isopropylacrylamide-co-allylamine microgels with organic solvent, driven by the coalescence of micelles consisting of organic oil droplets coated by many microgels. This method leads to microgel colloidal crystals of several centimeters growing from the top to the bottom along the gravity direction. Both temperature and polymer concentration play critical roles for the formation of columnar crystals. A phase diagram has been determined, and it can be used as a guide to selectively grow different crystals, including columnar crystals and randomly oriented crystals, and enable the coexistence of columnar crystals and randomly oriented crystals.

  12. Polypeptide synthesis in columnar and squamous explants of human uterine cervix.

    PubMed

    Cowan, M E; Ward, K; Woodman, C B; Skinner, G R

    1982-10-01

    There were quantitative and qualitative differences in the in-vitro synthesis of 3 polypeptides between squamous and columnar epithelial explants of human cervix. One cross-linked keratin-like polypeptide of mol. wt 50,000 was synthesized and phosphorylated by squamous but not by columnar explants; a second cross-linked keratin-like polypeptide of mol. wt 52,000, which was present in larger amounts in squamous than columnar explants, was both glycosylated and phosphorylated during in-vitro explantation of squamous tissue; a third polypeptide of mol. wt 25,200 which was keratin-like but not cross-linked, was synthesized in squamous-tissue explants but in only 4% of columnar-tissue explants.

  13. Polypeptide synthesis in columnar and squamous explants of human uterine cervix.

    PubMed Central

    Cowan, M. E.; Ward, K.; Woodman, C. B.; Skinner, G. R.

    1982-01-01

    There were quantitative and qualitative differences in the in-vitro synthesis of 3 polypeptides between squamous and columnar epithelial explants of human cervix. One cross-linked keratin-like polypeptide of mol. wt 50,000 was synthesized and phosphorylated by squamous but not by columnar explants; a second cross-linked keratin-like polypeptide of mol. wt 52,000, which was present in larger amounts in squamous than columnar explants, was both glycosylated and phosphorylated during in-vitro explantation of squamous tissue; a third polypeptide of mol. wt 25,200 which was keratin-like but not cross-linked, was synthesized in squamous-tissue explants but in only 4% of columnar-tissue explants. Images Fig. 1 Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 PMID:6184064

  14. The carbohydrate L-rhamnose promotes biofilm formation which enhances Flavobacterium columnare virulence

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry, continual efforts to better understand basic mechanisms that contribute to disease...

  15. Sickeningly sweet: L-rhamnose stimulates Flavobacterium columnare biofilm formation and virulence

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare, the causative agent of columnaris disease causes substantial mortality worldwide in numerous freshwater finfish species. Due to its global significance and impact on the aquaculture industry continual efforts to better understand basic mechanisms that contribute to disease ...

  16. 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.

  17. 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.

  18. 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].

  19. Comparative Analysis of the Flavobacterium columnare Genomovar I and II Genomes

    PubMed Central

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

    2017-01-01

    Columnaris disease caused by Gram-negative rod Flavobacterium columnare is one of the most common diseases of catfish. F. columnare is also a common problem in other cultured fish species worldwide. F. columnare has three major genomovars; we have sequenced a representative strain from genomovar I (ATCC 49512, which is avirulent in catfish) and genomovar II (94-081, which is highly pathogenic in catfish). Here, we present a comparative analysis of the two genomes. Interestingly, F. columnare ATCC 49512 and 94-081 meet criteria to be considered different species based on the Average Nucleotide Identity (90.71% similar) and DNA–DNA Hybridization (42.6% similar). Genome alignment indicated the two genomes have a large number of rearrangements. However, function-based comparative genomics analysis indicated that the two strains have similar functional capabilities with 2,263 conserved orthologous clusters; strain ATCC 49512 has 290 unique orthologous clusters while strain 94-081 has 391. Both strains carry type I secretion system, type VI secretion system, and type IX secretion system. The two genomes also have similar CRISPR capacities. The F. columnare strain ATCC 49512 genome contains a higher number of insertion sequence families and phage regions, while the F. columnare strain 94-081 genome has more genomic islands and more regulatory gene capacity. Transposon mutagenesis using Tn4351 in pathogenic strain 94-081 yielded six mutants, and experimental infections of fish showed hemolysin and glycine cleavage protein mutants had 15 and 10% mortalities, respectively, while the wild-type strain caused 100% mortalities. Our comparative and mutational analysis yielded important information on classification of genomovars I and II F. columnare as well as potential virulence genes in F. columnare strain 94-081. PMID:28790987

  20. Multiple regression analysis in modeling of columnar ozone in Peninsular Malaysia.

    PubMed

    Tan, K C; Lim, H S; Mat Jafri, M Z

    2014-06-01

    This study aimed to predict monthly columnar ozone (O3) in Peninsular Malaysia by using data on the concentration of environmental pollutants. Data (2003-2008) on five atmospheric pollutant gases (CO2, O3, CH4, NO2, and H2O vapor) retrieved from the satellite Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) were employed to develop a model that predicts columnar ozone through multiple linear regression. In the entire period, the pollutants were highly correlated (R = 0.811 for the southwest monsoon, R = 0.803 for the northeast monsoon) with predicted columnar ozone. The results of the validation of columnar ozone with column ozone from SCIAMACHY showed a high correlation coefficient (R = 0.752-0.802), indicating the model's accuracy and efficiency. Statistical analysis was utilized to determine the effects of each atmospheric pollutant on columnar ozone. A model that can retrieve columnar ozone in Peninsular Malaysia was developed to provide air quality information. These results are encouraging and accurate and can be used in early warning of the population to comply with air quality standards.

  1. 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.

  2. The effect of variety and location on cactus pear (Opuntia ficus-indica) fruit quality.

    PubMed

    de Wit, Maryna; Nel, Philip; Osthoff, Gernot; Labuschagne, Maryke T

    2010-06-01

    Little is known about the performance of South African cactus pear varieties in different agro-ecological regions. Effects of locality on internal quality parameters of available cactus pear varieties were examined. With only one exception, no significant differences among the mean replication values for the different parameters between the different locations were observed. The differences between mean values for most individual parameters at the three localities were highly significant. Highly significant differences between the mean values for the measured characteristics were observed, not only among the locations (except for the pulp glucose values), but also for the influences of genotype and interaction between locality and genotype. Significant variations existed between mean values of the different characteristics between localities. Genotype x environmental interactions were noted. It was concluded that Meyers is the most appropriate cultivar for economical purposes in South Africa.

  3. 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

  4. 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.

  5. 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.

  6. 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.

  7. Feral livestock threatens landscapes dominated by columnar cacti

    NASA Astrophysics Data System (ADS)

    Malo, J. E.; Acebes, P.; Giannoni, S. M.; Traba, J.

    2011-05-01

    The introduction and naturalization of alien species represents a serious threat to many natural protected areas. One such case of worldwide concern is the impact of feral livestock on arid ecosystems. Damage suffered by Echinopsis (= Trichocereus) terscheckii dominating the landscape of rocky slopes was surveyed in seven locations within the Ischigualasto-Talampaya World Heritage Site (Argentina) by measuring the frequency, position on the plant and extent of damage. At the same time we employed transects to estimate the abundance of autochtonous and feral large herbivores ( Lama guanicoe, Bos taurus, Equus asinus) from their dung. Our results show relatively high damage levels (40-77% of individuals damaged, more than 5 dm 3 removed by plant in some sites), particularly within 0.50-1.75 m above the ground, showing herbivores to be the main responsible for them. We also found significant differences between sites in variables measuring damage level and in the intensity of use by the two feral livestock species but not by guanacos. The frequency of damaged cacti below 1.75 m (but not above) was significantly positively correlated among locations with the frequencies of cattle and donkey dung, and the damage suffered by individual cacti was also correlated with donkey and cattle dung in their surroundings after correcting for spatial effects. However, all correlations were non-significant in the case of guanacos. We conclude that the continued presence of feral livestock, particularly donkeys, leads to damages to columnar cacti with potential effects on their populations and the physiognomy of this protected landscape.

  8. Length Scales in Columnar Jointing of the Columbia Basalt Group

    NASA Astrophysics Data System (ADS)

    Goehring, L.; Morris, S. W.

    2004-12-01

    We report a set of observations and interpretations of the pattern of columnar jointing as displayed in the Columbia Basalt Group of Washington and Oregon. This pattern of nearly hexagonal prismatic columns of rock originates when lava pools, and slowly cools from its surfaces. Fractures initiate at the cooling surfaces, and advance periodically into the flow. The length scale of each fracture advance is believed to be related to the height of the elastic layer between the already fractured rock, and the still compliant interior of the flow. This sequential advance leaves behind alternating bands of rough and smooth rock, called striae, on the sides of the columns. Field observations were made along the Grand Coulee, and in the Snake and Columbia River valleys, investigating the relationship between striae height and the face widths of individual columns. We confirm that, on average, there is a significant correlation between the striae height and the column width. However, this correlation can be misleading, as striae heights can vary by over a factor of three on some columns -- without corresponding changes in column widths. Observations made near the edges of flow units show a tendency of the striae width to increase away from the flow margins. We suggest that, although both striae and face length scales may be linked to the cooling rate of the flow, the striae length scale can more readily adapt to changing cooling conditions than can the column width. This hypothesis is supported by recent experiments in laboratory analog systems. We also report tentative observations of a zig-zag modulation visible on some column faces. The height of each zig (or zag) presents a length scale 3 to 5 times larger than that of corresponding striae heights, and is about half the size of the column widths.

  9. Growth of modern branched columnar stromatolites in Lake Joyce, Antarctica.

    PubMed

    Mackey, T J; Sumner, D Y; Hawes, I; Jungblut, A D; Andersen, D T

    2015-07-01

    Modern decimeter-scale columnar stromatolites from Lake Joyce, Antarctica, show a change in branching pattern during a period of lake level rise. Branching patterns correspond to a change in cyanobacterial community composition as preserved in authigenic calcite crystals. The transition in stromatolite morphology is preserved by mineralized layers that contain microfossils and cylindrical molds of cyanobacterial filaments. The molds are composed of two populations with different diameters. Large diameter molds (>2.8 μm) are abundant in calcite forming the oldest stromatolite layers, but are absent from younger layers. In contrast, <2.3 μm diameter molds are common in all stromatolites layers. Loss of large diameter molds corresponds to the transition from smooth-sided stromatolitic columns to branched and irregular columns. Mold diameters are similar to trichome diameters of the four most abundant living cyanobacteria morphotypes in Lake Joyce: Phormidium autumnale morphotypes have trichome diameters >3.5 μm, whereas Leptolyngbya antarctica, L. fragilis, and Pseudanabaena frigida morphotypes have diameters <2.3 μm. P. autumnale morphotypes were only common in mats at <12 m depth. Mats containing abundant P. autumnale morphotypes were smooth, whereas mats with few P. autumnale morphotypes contained small peaks and protruding bundles of filaments, suggesting that the absence of P. autumnale morphotypes allowed small-scale topography to develop on mats. Comparisons of living filaments and mold diameters suggest that P. autumnale morphotypes were present early in stromatolite growth, but disappeared from the community through time. We hypothesize that the mat-smoothing behavior of P. autumnale morphotypes inhibited nucleation of stromatolite branches. When P. autumnale morphotypes were excluded from the community, potentially reflecting a rise in lake level, short-wavelength roughness provided nuclei for stromatolite branches. This growth history provides a

  10. 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. © 2014 The Author(s).

  11. 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.

  12. 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.

  13. 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.

  14. Impact of cooking process on nutritional composition and antioxidants of cactus cladodes (Opuntia ficus-indica).

    PubMed

    De Santiago, Elsy; Domínguez-Fernández, Maite; Cid, Concepción; De Peña, María-Paz

    2018-02-01

    The impact of cooking methods (boiling, microwaving, griddling and frying in olive and soybean oils) on nutritional composition (protein, minerals, fat, carbohydrates, fibre, fatty acid profile and energy), antioxidant capacity and (poly)phenolic compounds of cactus cladodes (Opuntia ficus-indica) was evaluated. Culinary processes, except boiling, increased soluble and insoluble fibre up to 5.0g/100g becoming a good fibre source. Cactus cladodes fried in olive oil showed a healthier fatty acid profile and lower ω-6/ω-3 ratio than in soybean oil. Flavonoids accounted for 80% of total (poly)phenolic compounds, being isorhamnetin the most abundant. Heat treatment, particularly griddling and microwaving, increased every flavonoid and phenolic acid up to 3.2-fold higher than in raw samples, and consequently their antioxidant capacity. Even boiling induced losses in total (poly)phenols and antioxidant capacity by leaching into water, the main compounds were maintained. Principal Component Analysis distributed heat treated cactus cladodes according to their distinctive polyphenols and antioxidant capacity. Copyright © 2017 Elsevier Ltd. All rights reserved.

  15. Genetic variation and population structure of the mixed-mating cactus, Melocactus curvispinus (Cactaceae).

    PubMed

    Nassar, J M; Hamrick, J L; Fleming, T H

    2001-07-01

    Genetic diversity was measured in the mixed-mating cactus, Melocactus curvispinus, in Venezuela. Allozyme diversity was surveyed in 19 putative loci over 18 populations. Compared to other plant taxa, this cactus is rich in polymorphic loci (Ps=89.5%), with high numbers of alleles per polymorphic locus (APs=3.82), but moderate levels of heterozygosity (Hes=0.145). Substantial levels of inbreeding were detected across loci and populations at macrogeographic (FIS=0.348) and regional levels (FIS=0.194-0.402). Moderate levels of genetic differentiation among populations were detected at macrogeographical (FST=0.193) and regional (FST=0.084-0.187) scales, suggesting that gene flow is relatively restricted, but increases within regions without topographic barriers. The population genetic structure observed for this cactus was attributed to, at least, three factors: short-distance pollination and seed dispersal, the mixed-mating condition of the species, and genetic drift. High genetic identities between populations (I=0.942) supported the conspecific nature of all populations surveyed. The levels and patterns of genetic structure observed for M. curvispinus were consistent with its mating system and gene dispersal mechanisms.

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

    NASA Astrophysics Data System (ADS)

    Bergström, Lars; Hooper, Dan

    2006-03-01

    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 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.

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

    PubMed

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

    2015-05-01

    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. Published 2015. This article is a U.S. Government work and is in the public domain in the USA.

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

    USDA-ARS?s Scientific Manuscript database

    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...

  19. A novel function for the IκB inhibitor Cactus in promoting Dorsal nuclear localization and activity in the Drosophila embryo.

    PubMed

    Cardoso, Maira Arruda; Fontenele, Marcio; Lim, Bomyi; Bisch, Paulo Mascarello; Shvartsman, Stanislav Y; Araujo, Helena Marcolla

    2017-08-15

    The evolutionarily conserved Toll signaling pathway controls innate immunity across phyla and embryonic patterning in insects. In the Drosophila embryo, Toll is required to establish gene expression domains along the dorsal-ventral axis. Pathway activation induces degradation of the IκB inhibitor Cactus, resulting in a ventral-to-dorsal nuclear gradient of the NFκB effector Dorsal. Here, we investigate how cactus modulates Toll signals through its effects on the Dorsal gradient and on Dorsal target genes. Quantitative analysis using a series of loss- and gain-of-function conditions shows that the ventral and lateral aspects of the Dorsal gradient can behave differently with respect to Cactus fluctuations. In lateral and dorsal embryo domains, loss of Cactus allows more Dorsal to translocate to the nucleus. Unexpectedly, cactus loss-of-function alleles decrease Dorsal nuclear localization ventrally, where Toll signals are high. Overexpression analysis suggests that this ability of Cactus to enhance Toll stems from the mobilization of a free Cactus pool induced by the Calpain A protease. These results indicate that Cactus acts to bolster Dorsal activation, in addition to its role as a NFκB inhibitor, ensuring a correct response to Toll signals. © 2017. Published by The Company of Biologists Ltd.

  20. 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

    USDA-ARS?s Scientific Manuscript database

    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 ...

  1. Carcinogenic HPV infection in the cervical squamo-columnar junction.

    PubMed

    Mirkovic, Jelena; Howitt, Brooke E; Roncarati, Patrick; Demoulin, Stephanie; Suarez-Carmona, Meggy; Hubert, Pascale; McKeon, Frank D; Xian, Wa; Li, Anita; Delvenne, Philippe; Crum, Christopher P; Herfs, Michael

    2015-07-01

    Recent studies have suggested the involvement of a unique population of cells at the cervical squamo-columnar junction (SCJ) in the pathogenesis of early (squamous intraepithelial lesion or SIL) and advanced (squamous cell and adeno-carcinomas) cervical neoplasia. However, there is little evidence to date showing that SCJ cells harbour carcinogenic HPV or are instrumental in the initial phases of neoplasia. This study was designed to (1) determine if normal-appearing SCJ cells contained evidence of carcinogenic HPV infection and (2) trace their transition to early SIL. Sections of cervix from high-risk reproductive age women were selected and SCJ cells were analysed by using several techniques which increasingly implicated HPV infection: HPV DNA (genotyping and in situ hybridization)/RNA (PCR), immunostaining for HPV16 E2 (an early marker of HPV infection), p16(ink4), Ki67, and HPV L1 protein. In 22 cases with a history of SIL and no evidence of preneoplastic lesion in the excision specimen, HPV DNA was isolated from eight of ten with visible SCJ cells, six of which were HPV16/18 DNA-positive. In five of these latter cases, the SCJ cells were positive for p16(ink4) and/or HPV E2. Transcriptionally active HPV infection (E6/E7 mRNAs) was also detected in microdissected SCJ cells. Early squamous atypia associated with the SCJ cells demonstrated in addition diffuse p16(ink4) immunoreactivity, elevated proliferative index, and rare L1 antigen positivity. We present for the first time direct evidence that normal-appearing SCJ cells can be infected by carcinogenic HPV. They initially express HPV E2 and their progression to SIL is heralded by an expanding metaplastic progeny with increased proliferation and p16(ink4) expression. Whether certain SCJs are more vulnerable than others to carcinogenic HPV genotypes and what variables determine transition to high-grade SIL remain unresolved, but the common event appears to be a vulnerable cell at the SCJ.

  2. Mechanical behavior and elastic properties of prestrained columnar ice

    NASA Astrophysics Data System (ADS)

    Snyder, Scott Aaron

    Experiments on columnar-grained ice at --10 °C reveal changes to its mechanical behavior and elastic properties due to compressive prestrain. Laboratory-grown (152-mm cube) specimens of freshwater and saline ice were prestrained under uniaxial across-column compression (to levels from epsilon p = 0.003 to epsilonp = 0.20, at constant strain rates in the ductile regime) and then reloaded, again under uniaxial across-column compression (at rates from 1x10--6 s--1 to 3 x 10--2s--1). Prestrain caused solid-state recrystallization as well as damage in the form of non-propagating microcracks. These microstructural changes were quantified by analysis of thin sections. Elastic properties in across-column directions, both parallel (x1) and perpendicular ( x2) to the initial loading direction, were obtained from P-wave and S-wave ultrasonic velocities. As a result (and depending on the level) of the prestrain imparted in both materials, Young's modulus E was reduced by as much as 30%; the ductile-to-brittle (D--B) transition strain rate epsilon D/B was increased up to a factor of 3 to 10; and the ductile behavior with respect to loading along a direction within the horizontal ( x1-x2) plane of the parent ice sheet changed from isotropic to anisotropic. As the prestrain rate approached the nominal D--B transition rate of initially undamaged material, the magnitudes of prestrain effects on elastic compliance increased. The shift in the D--B transition, on the other hand, was less sensitive to the prestrain rate. The results are interpreted within the framework of a recent model that predicts the transition strain rate based on the micromechanical boundary between creep and fracture processes. Prestrain primarily affected certain parameters in the model, specifically the power-law creep coefficient B (more so than the creep exponent n), Young's modulus E and, by extension, the fracture toughness KIc. The physical implications of these effects are discussed.

  3. 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.

  4. 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.

  5. Evolution of oesophageal adenocarcinoma from metaplastic columnar epithelium without goblet cells in Barrett's oesophagus

    PubMed Central

    Lavery, Danielle L; Martinez, Pierre; Gay, Laura J; Cereser, Biancastella; Novelli, Marco R; Rodriguez-Justo, Manuel; Meijer, Sybren L; Graham, Trevor A; McDonald, Stuart A C; Wright, Nicholas A; Jansen, Marnix

    2016-01-01

    Objective Barrett's oesophagus commonly presents as a patchwork of columnar metaplasia with and without goblet cells in the distal oesophagus. The presence of metaplastic columnar epithelium with goblet cells on oesophageal biopsy is a marker of cancer progression risk, but it is unclear whether clonal expansion and progression in Barrett's oesophagus is exclusive to columnar epithelium with goblet cells. Design We developed a novel method to trace the clonal ancestry of an oesophageal adenocarcinoma across an entire Barrett's segment. Clonal expansions in Barrett's mucosa were identified using cytochrome c oxidase enzyme histochemistry. Somatic mutations were identified through mitochondrial DNA sequencing and single gland whole exome sequencing. Results By tracing the clonal origin of an oesophageal adenocarcinoma across an entire Barrett's segment through a combination of histopathological spatial mapping and clonal ordering, we find that this cancer developed from a premalignant clonal expansion in non-dysplastic (‘cardia-type’) columnar metaplasia without goblet cells. Conclusion Our data demonstrate the premalignant potential of metaplastic columnar epithelium without goblet cells in the context of Barrett's oesophagus. PMID:26701877

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

    PubMed

    Lafrentz, B R; Lapatra, S E; Shoemaker, C A; Klesius, P H

    2012-11-08

    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 used restriction fragment length polymorphism analysis of the 16S rRNA gene revealed that all isolates typed from salmonids were Genomovar I. Our objective was to develop a laboratory challenge model for F. columnare in rainbow trout Oncorhynchus mykiss (Walbaum) and use the model to determine the virulence of Genomovar I and II isolates. Six F. columnare isolates were obtained from rainbow trout experiencing losses due to columnaris disease and were determined to be Genomovar I. Three of these were chosen for a preliminary assessment of virulence, and isolate 051-10-S5 was chosen for additional experiments to determine the reproducibility of the waterborne challenge model. In 2 independent experiments, cumulative percent mortalities (CPM) were 49 ± 10% and 50 ± 19%. Challenge of rainbow trout with Genomovar I and II isolates demonstrated a difference in the CPM, with the Genomovar II isolates inducing significantly higher CPM. This reproducible waterborne challenge model for columnaris disease in rainbow trout will be useful to investigate host-pathogen interactions, vaccine development, and other potential control strategies. This research also provides a basis for further defining the molecular diversity and virulence associated with F. columnare genomovars in rainbow trout and other salmonid species.

  7. Biofilm Formation by the Fish Pathogen Flavobacterium columnare: Development and Parameters Affecting Surface Attachment

    PubMed Central

    Cai, Wenlong; De La Fuente, Leonardo

    2013-01-01

    Flavobacterium columnare is a bacterial fish pathogen that affects many freshwater species worldwide. The natural reservoir of this pathogen is unknown, but its resilience in closed aquaculture systems posits biofilm as the source of contagion for farmed fish. The objectives of this study were (i) to characterize the dynamics of biofilm formation and morphology under static and flow conditions and (ii) to evaluate the effects of temperature, pH, salinity, hardness, and carbohydrates on biofilm formation. Nineteen F. columnare strains, including representatives of all of the defined genetic groups (genomovars), were compared in this study. The structure of biofilm was characterized by light microscopy, confocal laser scanning microscopy, and scanning electron microscopy. F. columnare was able to attach to and colonize inert surfaces by producing biofilm. Surface colonization started within 6 h postinoculation, and microcolonies were observed within 24 h. Extracellular polysaccharide substances and water channels were observed in mature biofilms (24 to 48 h). A similar time course was observed when F. columnare formed biofilm in microfluidic chambers under flow conditions. The virulence potential of biofilm was confirmed by cutaneous inoculation of channel catfish fingerlings with mature biofilm. Several physicochemical parameters modulate attachment to surfaces, with the largest influence being exerted by hardness, salinity, and the presence of mannose. Maintenance of hardness and salinity values within certain ranges could prevent biofilm formation by F. columnare in aquaculture systems. PMID:23851087

  8. Thermal Cycling Behavior of Quasi-Columnar YSZ Coatings Deposited by PS-PVD

    NASA Astrophysics Data System (ADS)

    Yang, Jiasheng; Zhao, Huayu; Zhong, Xinghua; Shao, Fang; Liu, Chenguang; Zhuang, Yin; Ni, Jinxing; Tao, Shunyan

    2017-01-01

    Columnar-structured thermal barrier coatings, owing to their high strain tolerance, are expected for their potential possibilities to substantially extend turbine lives and improve engine efficiencies. In this paper, plasma spray-physical vapor deposition (PS-PVD) process was used to deposit yttria partially stabilized zirconia (YSZ) coatings with quasi-columnar structures. Thermal cyclic tests on burner rigs and thermal shock tests by heating and water-quenching method were involved to evaluate the thermal cycling and thermal shock behaviors of such kind of structured thermal barrier coatings (TBCs). Evolution of the microstructures, phase composition, residual stresses and failure behaviors of quasi-columnar YSZ coatings before and after the thermal tests was investigated. The quasi-columnar coating obtained had an average life of around 623 cycles when the spallation area reached about 10% of the total coating surface during burner rig tests with the coating surface temperature of 1250 °C. Failure of the coating is mainly due to the break and pull-out of center columnar segments.

  9. Biofilm formation by the fish pathogen Flavobacterium columnare: development and parameters affecting surface attachment.

    PubMed

    Cai, Wenlong; De La Fuente, Leonardo; Arias, Covadonga R

    2013-09-01

    Flavobacterium columnare is a bacterial fish pathogen that affects many freshwater species worldwide. The natural reservoir of this pathogen is unknown, but its resilience in closed aquaculture systems posits biofilm as the source of contagion for farmed fish. The objectives of this study were (i) to characterize the dynamics of biofilm formation and morphology under static and flow conditions and (ii) to evaluate the effects of temperature, pH, salinity, hardness, and carbohydrates on biofilm formation. Nineteen F. columnare strains, including representatives of all of the defined genetic groups (genomovars), were compared in this study. The structure of biofilm was characterized by light microscopy, confocal laser scanning microscopy, and scanning electron microscopy. F. columnare was able to attach to and colonize inert surfaces by producing biofilm. Surface colonization started within 6 h postinoculation, and microcolonies were observed within 24 h. Extracellular polysaccharide substances and water channels were observed in mature biofilms (24 to 48 h). A similar time course was observed when F. columnare formed biofilm in microfluidic chambers under flow conditions. The virulence potential of biofilm was confirmed by cutaneous inoculation of channel catfish fingerlings with mature biofilm. Several physicochemical parameters modulate attachment to surfaces, with the largest influence being exerted by hardness, salinity, and the presence of mannose. Maintenance of hardness and salinity values within certain ranges could prevent biofilm formation by F. columnare in aquaculture systems.

  10. ISS-Experiments of Columnar-to-Equiaxed Transition in Solidification Processing

    NASA Technical Reports Server (NTRS)

    Sturz, Laszlo; Zimmermann, Gerhard; Gandin, Charles, Andre; Billia, Bernard; Magelinck, Nathalie; Nguyen-Thi, Henry; Browne, David John; Mirihanage, Wajira U.; Voss, Daniela; Beckermann, Christoph; Karma, Alain

    2012-01-01

    The main topic of the research project CETSOL in the framework of the Microgravity Application Promotion (MAP) programme of the European Space Agency (ESA) is the investigation of the transition from columnar to equiaxed grain growth during solidification. Microgravity environment allows for suppression of buoyancy-driven melt flow and for growth of equiaxed grains free of sedimentation and buoyancy effects. This contribution will present first experimental results obtained in microgravity using hypo-eutectic AlSi alloys in the Materials Science Laboratory (MSL) on-board the International Space Station (ISS). The analysis of the experiments confirms the existence of a columnar to equiaxed transition, especially in the refined alloy. Temperature evolution and grain structure analysis provide critical values for the position, the temperature gradient and the solidification velocity at the columnar to equiaxed transition. These data will be used to improve modeling of solidification microstructures and grain structure on different lengths scales.

  11. Columnar transmitter based wireless power delivery system for implantable device in freely moving animals.

    PubMed

    Eom, Kyungsik; Jeong, Joonsoo; Lee, Tae Hyung; Lee, Sung Eun; Jun, Sang Bum; Kim, Sung June

    2013-01-01

    A wireless power delivery system is developed to deliver electrical power to the neuroprosthetic devices that are implanted into animals freely moving inside the cage. The wireless powering cage is designed for long-term animal experiments without cumbersome wires for power supply or the replacement of batteries. In the present study, we propose a novel wireless power transmission system using resonator-based inductive links to increase power efficiency and to minimize the efficiency variations. A columnar transmitter coil is proposed to provide lateral uniformity of power efficiency. Using this columnar transmitter coil, only 7.2% efficiency fluctuation occurs from the maximum transmission efficiency of 25.9%. A flexible polymer-based planar type receiver coil is fabricated and assembled with a neural stimulator and an electrode. Using the designed columnar transmitter coil, the implantable device successfully operates while it moves freely inside the cage.

  12. A theoretical study of CsI:Tl columnar scintillator image quality parameters by analytical modeling

    NASA Astrophysics Data System (ADS)

    Kalyvas, N.; Valais, I.; Michail, C.; Fountos, G.; Kandarakis, I.; Cavouras, D.

    2015-04-01

    Medical X-ray digital imaging systems such as mammography, radiography and computed tomography (CT), are composed from efficient radiation detectors, which can transform the X-rays to electron signal. Scintillators are materials that emit light when excited by X-rays and incorporated in X-ray medical imaging detectors. Columnar scintillator, like CsI:T1 is very often used for X-ray detection due to its higher performance. The columnar form limits the lateral spread of the optical photons to the scintillator output, thus it demonstrates superior spatial resolution compared to granular scintillators. The aim of this work is to provide an analytical model for calculating the MTF, the DQE and the emission efficiency of a columnar scintillator. The model parameters were validated against published Monte Carlo data. The model was able to predict the overall performance of CsI:Tl scintillators and suggested an optimum thickness of 300 μm for radiography applications.

  13. Columnar order in jammed LiFePO4 cathodes: ion transport catastrophe and its mitigation.

    PubMed

    Smith, Kyle C; Mukherjee, Partha P; Fisher, Timothy S

    2012-05-21

    The high-rate, high-capacity potential of LiFePO4-based lithium-ion battery cathodes has motivated numerous experimental and theoretical studies aiming to realize such performance through nano-sizing, tailoring of particle shape through synthesis conditions, and doping. Here, a granular mechanics study of microstructures formed by dense jammed packings of experimentally and theoretically inspired LiFePO4 particle shapes is presented. A strong dependence of the resultant packing structures on particle shapes is observed, in which columnar structures aligned with the [010] direction inhibit diffusion along [010] in anisotropic LiFePO4. Transport limitations are induced by [010] columnar order and lead to catastrophic performance degradation in anisotropic LiFePO4 electrodes. Further, judicious mixing of nanoplatelets with additive nanoparticles can frustrate columnar ordering and thereby enhance the rate capability of LiFePO4 electrodes by nearly an order of magnitude.

  14. First identification of Flavobacterium columnare infection in farmed freshwater striped catfish Pangasianodon hypophthalmus.

    PubMed

    Tien, Nguyen Thi; Dung, Tu Thanh; Tuan, Nguyen Anh; Crumlish, Mags

    2012-08-13

    The bacterium Flavobacterium columnare was recovered and identified as the aetiological agent causing freshwater columnaris infection in farmed striped catfish Pangasianodon hypophthalmus (Sauvage) fingerlings that had suffered high mortality rates within commercial hatchery ponds in Vietnam. The gross clinical signs were typical of columnaris-infected fish. Histological examination found numerous Gram-negative, filamentous bacteria present on the skin, muscle and gill tissues of affected fish. The yellow-pigmented bacteria were isolated and identified as F. columnare using primary, biochemical and PCR methods. An experimental immersion-challenge study with 2 strains was also performed. It fulfilled Koch's postulates and showed a median lethal concentration (LC50) of 4.27 × 105 and 1.66 × 106 cfu ml-1 for the F. columnare strains FC-HN and FC-CT, respectively. To the best of our knowledge this is the first report of freshwater columnaris infection in P. hypophthalmus.

  15. Moisture proof columnar Cesium Iodide (CsI) layers for gas avalanche microdetectors

    SciTech Connect

    Park, I.J.; Cho, H.S.; Hong, W.S.; Perez-Mendez, V.; Kadyk, J.

    1999-05-05

    Cesium iodide columnar layers having a diameter of 3 {micro}m, and wall spacing of {approx} 1 {micro}m act as secondary electron emitters and can be used for detection of radiation: charged particles, X-rays and gamma rays. With a large enough electric field across the columnar layers, {approx} 400 {micro}m in thickness, gas avalanche gain is evident when placed in a suitable gas, such as P10 or argon-ethane mixtures. The cesium iodide columns are damaged by ambient moisture. This damage can be prevented by evaporating protective layers of insoluble, low boiling point inorganic materials, such as mercuric iodide. Columnar layers with 20 nm coatings of mercuric iodide yield more than 30,000 electrons on average when traversed by electrons from a {sup 90}Sr beta source.

  16. Seasonal resource value and male size influence male aggressive interactions in the leaf footed cactus bug, Narnia femorata.

    PubMed

    Nolen, Zachary J; Allen, Pablo E; Miller, Christine W

    2017-02-06

    In animal contests, resource value (the quality of a given resource) and resource holding potential (a male's absolute fighting ability) are two important factors determining the level of engagement and outcome of contests. Few studies have tested these factors simultaneously. Here, we investigated whether natural, seasonal differences in cactus phenology (fruit quality) influence interactions between males in the leaf-footed cactus bug, Narnia femorata (Hemiptera: Coreidae). We also considered whether males were more likely to interact when they were similar in size, as predicted by theory. Finally, we examined if male size relative to the size of an opponent predicted competitive success. We found that males have more interactions on cactus with high value ripe fruit, as we predicted. Further, we found that males that were closer in size were more likely to interact, and larger males were more likely to become dominant.

  17. Validation of CME Detection Software (CACTus) by Means of Simulated Data, and Analysis of Projection Effects on CME Velocity Measurements

    NASA Astrophysics Data System (ADS)

    Bonte, K.; Jacobs, C.; Robbrecht, E.; de Groof, A.; Berghmans, D.; Poedts, S.

    2011-05-01

    In the context of space weather forecasting, an automated detection of coronal mass ejections (CMEs) becomes more and more important for efficiently handling a large data flow which is expected from recently-launched and future solar missions. In this paper we validate the detection software package "CACTus" by applying the program to synthetic data from our 3D time-dependent CME simulations instead of observational data. The main strength of this study is that we know in advance what should be detected. We describe the sensitivities and strengths of automated detection, more specific for the CACTus program, resulting in a better understanding of CME detection on one hand and the calibration of the CACTus software on the other hand, suggesting possible improvements of the package. In addition, the simulation is an ideal tool to investigate projection effects on CME velocity measurements.

  18. Microbial populations and activities in the rhizoplane of rock-weathering desert plants. II. Growth promotion of cactus seedlings.

    PubMed

    Puente, M E; Li, C Y; Bashan, Y

    2004-09-01

    Four bacterial species isolated from the rhizoplane of cacti growing in bare lava rocks were assessed for growth promotion of giant cardon cactus seedlings (Pachycereus pringlei). These bacteria fixed N(2), dissolved P, weathered extrusive igneous rock, marble, and limestone, and significantly mobilized useful minerals, such as P, K, Mg, Mn, Fe, Cu, and Zn in rock minerals. Cardon cactus seeds inoculated with these bacteria were able to sprout and grow normally without added nutrients for at least 12 months in pulverized extrusive igneous rock (ancient lava flows) mixed with perlite. Cacti that were not inoculated grew less vigorously and some died. The amount of useful minerals (P, K, Fe, Mg) for plant growth extracted from the pulverized lava, measured after cultivation of inoculated plants, was significant. This study shows that rhizoplane bacteria isolated from rock-growing cacti promote growth of a cactus species, and can help supply essential minerals for a prolonged period of time.

  19. A Combined Study of Mesomorphism, Optical and Electronic Properties of Novel Columnar Liquid Crystals

    NASA Astrophysics Data System (ADS)

    Chen, Shuai

    Columnar mesophases of discotic liquid crystals (DLCs) are a separate class of organic semiconductors. Anisotropic charge transport, high charge carrier mobility, and self-organizing properties have been regarded as superior properties of DLCs but their performance in devices, such as organic light-emitting diodes, has been inferior to the best performing conventional organic semiconductors. Our group recently demonstrated that a DLC of donor-acceptor structure can bias electron over hole conduction if the occupied and unoccupied frontier orbitals are localized on different parts of the molecule and only the unoccupied frontier orbitals electronically interact in columnar stacks. This thesis describes the first systematic approach to different types of donor-acceptor DLCs and the investigation of their mesomorphism and optoelectronic properties. In spite of their large aspect ratios, four board-shaped donor-acceptor-donor quinoxalinophenanthrophenazine (QPP) dyes (Chapters 2 and 3) induce complex columnar mesomorphism over wide temperature ranges. These QPP derivatives also show strong fluorescence in solution and as thin films. This strong fluorescence in columnar mesophases is explained with a nonparallel orientation of the elongated donor-acceptor cores in the columnar stacks that minimizes interactions between transition dipole moments of co-facially stacked molecules. Opto-electronic properties suggest that the QPP derivatives are organic semiconductors. Inspired by the donor-acceptor concept, we generated novel ionic DLCs based on imidazole and imidazolium structures (Chapter 5). Unexpectedly, only the ionic triphenylenoimidazolium derivatives display columnar mesomorphism. Strong ionic interactions between the cores are apparently required for the formation of columnar mesophases. Overall, these compounds are rather unusual because few ionic DLCs have the charge localized on the aromatic core. Most often the charged group is attached via spacer chains. A

  20. Columnar discharge mode between parallel dielectric barrier electrodes in atmospheric pressure helium

    SciTech Connect

    Hao, Yanpeng; Zheng, Bin; Liu, Yaoge

    2014-01-15

    Using a fast-gated intensified charge-coupled device, end- and side-view photographs were taken of columnar discharge between parallel dielectric barrier electrodes in atmospheric pressure helium. Based on three-dimensional images generated from end-view photographs, the number of discharge columns increased, whereas the diameter of each column decreased as the applied voltage was increased. Side-view photographs indicate that columnar discharges exhibited a mode transition ranging from Townsend to glow discharges generated by the same discharge physics as atmospheric pressure glow discharge.

  1. Ionic Switch Induced by a Rectangular-Hexagonal Phase Transition in Benzenammonium Columnar Liquid Crystals.

    PubMed

    Soberats, Bartolome; Yoshio, Masafumi; Ichikawa, Takahiro; Zeng, Xiangbing; Ohno, Hiroyuki; Ungar, Goran; Kato, Takashi

    2015-10-21

    We demonstrate switching of ionic conductivities in wedge-shaped liquid-crystalline (LC) ammonium salts. A thermoreversible phase transition between the rectangular columnar (Colr) and hexagonal columnar (Colh) phases is used for the switch. The ionic conductivities in the Colh phase are about four orders of magnitude higher than those in the Colr phase. The switching behavior of conductivity can be ascribed to the structural change of assembled ionic channels. X-ray experiments reveal a highly ordered packing of the ions in the Colr phase, which prevents the ion transport.

  2. Columnar/herringbone dual crystal packing of pyrenylsumanene and its photophysical properties

    PubMed Central

    Shrestha, Binod Babu

    2014-01-01

    Summary A single crystal of pyrenylsumanene was found to exhibit both columnar and herringbone crystal packing. The sumanene moieties form unidirectional columnar structures based on π–π stacking while the pyrene moieties generate herringbone structures due to CH–π interactions. The absorption and emission maxima of pyrenylsumanene were both red-shifted relative to those of sumanene and pyrene, owing to the extension of π-conjugation. Monomer emission with high quantum yield (0.82) was observed for pyrenylsumanene in solution, while excimer-type red-shifted emission was evident in the crystalline phase. PMID:24778739

  3. Does flat epithelial atypia have rounder nuclei than columnar cell change/hyperplasia? A morphometric approach to columnar cell lesions of the breast.

    PubMed

    Yamashita, Yoshiko; Ichihara, Shu; Moritani, Suzuko; Yoon, Han-Seung; Yamaguchi, Masahiro

    2016-06-01

    Columnar cell lesions of the breast encompass columnar cell change/hyperplasia (CCC/CCH) and flat epithelial atypia (FEA). These have attracted researchers because emerging data suggest that FEA may represent the earliest histologically detectable non-obligate precursor of breast cancer. However, it is occasionally difficult to distinguish FEA from CCC/CCH because of similar histology. Although the nuclei of FEA are frequently described as relatively round compared with those of CCC/CCH, there are few morphometric studies to support this statement. The aim of this study was to provide objective data as to the nuclear shape in columnar cell lesions. As a shape descriptor, we adopted ellipticity that is defined by the formula 2b/2a, where a is the length of the long axis of the ellipse and b is the length of the short axis. Contrary to circularity, ellipticity reflects the overall configuration of an ellipse irrespective of surface irregularity. Our image analysis included generating whole slide images, extracting glandular cell nuclei, measuring nuclear ellipticity, and superimposing graded colors based on execution of results on the captured images. A total of 7917 nuclei extracted from 22 FEA images and 5010 nuclei extracted from 13 CCC/CCH images were analyzed. There was a significant difference in nuclear roundness between FEA and CCC/CCH with mean ellipticity values of 0.723 and 0.679, respectively (p < 0.001, Welch's t test). Furthermore, FEA with malignancy had significantly rounder nuclei than FEA without malignancy (p < 0.001). Our preliminary results suggest that nuclear ellipticity is a key parameter in reproducibly classifying columnar cell lesions of the breast.

  4. Development of a reproducible challenge model to investigate the virulence of Flavobacterium columnare genomovars in rainbow trout Oncorhynchus mykiss (Walbaum)

    USDA-ARS?s Scientific Manuscript database

    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...

  5. Flavobacterium columnare: Chemotaxis and adhesion to channel catfish mucus is mediated by lectin-like capsular substances

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is an important Gram-negative pathogen of fresh water fish that may cause chronic skin lesions and severe mortality. Isolates of F. columnare belong to either the virulent genomovar II or the less virulent genomovar I. Chemotaxis and adhesion assays were conducted in vitro...

  6. Growth and survival of the fish pathogenic bacterium, Flavobacterium columnare, in tilapia mucus and porcine gastric mucin

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is an economically important gram negative bacterium that infects most freshwater farmed fish worldwide. Flavobacterium columnare colonizes the skin and gills of fish in the initial steps of pathogenesis. The fish’s surface is coated with mucus made up of high molecular we...

  7. Impact of oral and waterborne administration of rhamnolipids on the susceptibility of channel catfish (Ictalurus punctatus) to Flavobacterium columnare infection

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is the causative agent of columnaris disease and causes tremendous morbidity and mortality of farmed fish globally. Previously, we identified a potential lectin-mediator (a rhamnose-binding lectin; RBL1a) of F. columnare adhesion and showed higher RBL1a expression in suscept...

  8. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora.

    PubMed

    Bae, Sooil; Kim, Sang Gyu; Kim, Young Ho

    2013-03-01

    One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus.

  9. Cactus cladodes (Opuntia humifusa) extract minimizes the effects of UV irradiation on keratinocytes and hairless mice.

    PubMed

    Park, Kyungmi; Choi, Hyeon-Son; Hong, Yang Hee; Jung, Eun Young; Suh, Hyung Joo

    2017-12-01

    Cactus cladodes [Opuntia humifusa (Raf.) Raf. (Cactaceae)] is one of the cactus genera, which has long been used as a folk medicine for skin disorders. This study investigated the skincare potential of cactus cladodes extract (OHE), including its ability to regulate ultraviolet B (UVB)-induced hyaluronic acid (HA) production. Gene expression levels of hyaluronic acid synthases (HASs) and hyaluronidase (HYAL) were measured in UVB-irradiated HaCaT cells with OHE treatment (10, 25, 50, 100 μg/mL) by real-time polymerase chain reaction (PCR). The HA content was analyzed in hairless mice (SKH-1, male, 6 weeks old) treated with OHE for 10 weeks by using enzyme-linked immunosorbent assay (ELISA). Haematoxylin and eosin (H&E) and immunohistological staining were performed to examine epidermal thickness and levels of CD44 and hyaluronic acid-binding protein (HABP). HA synthases (HAS,1 HAS2, HAS3) mRNA levels were increased by 1.9-, 2.2- and 1.6-fold, respectively, with OHE treatment (100 μg/mL), while UVB-induced increase of hyaluronidase mRNA significantly decreased by 35%. HA content in animal was decreased from 42.9 to 27.1 ng/mL by OHE treatment. HAS mRNA levels were decreased by 39%, but HYAL mRNA was increased by 50% in OHE group. CD44 and HABP levels, which were greatly increased by UVB-irradiation, were reduced by 64 and 60%, respectively. Epidermal thickness, transepidermal water loss (TEWL), and erythema formation was also decreased by 45 (45.7 to 24.2 μm), 48 (48.8 to 25 g/h/m(2)) and 33%, respectively. OHE protects skin from UVB-induced skin degeneration in HaCaT cells and hairless mice.

  10. Biocontrol Characteristics of Bacillus Species in Suppressing Stem Rot of Grafted Cactus Caused by Bipolaris cactivora

    PubMed Central

    Bae, Sooil; Kim, Sang Gyu; Kim, Young Ho

    2013-01-01

    One of the most important limiting factors for the production of the grafted cactus in Korea is the qualitative and quantitative yield loss derived from stem rots especially caused by Bipolaris cactivora. This study is aimed to develop microbial control agents useful for the control of the bipolaris stem rot. Two bacteria (GA1-23 and GA4-4) selected out of 943 microbial isolates because of their strong antibiotic activity against B. cactivora were identified as Bacillus subtilis and B. amyloliquefaciens, respectively, by the cultural characteristics, Biolog program and 16S rRNA sequencing analyses. Both bacterial isolates significantly inhibited the conidial germination and mycelial growth of the pathogen with no significant difference between the two, of which the inhibitory efficacies varied depending on the cultural conditions such as temperature, nutritional compositions and concentrations. Light and electron microscopy of the pathogen treated with the bacterial isolates showed the inhibition of spore germination with initial malformation of germ tubes and later formation of circle-like vesicles with no hyphal growth and hyphal disruption sometimes accompanied by hyphal swellings and shrinkages adjacent to the bacteria, suggesting their antibiotic mode of antagonistic activity. Control efficacy of B. subtilis GA1-23 and B. amyloliquefaciens GA4-4 on the cactus stem rot were not as high as but comparable to that of fungicide difenoconazole when they were treated simultaneously at the time of pathogen inoculation. All of these results suggest the two bacterial isolates have a good potential to be developed as biocontrol agents for the bipolaris stem rot of the grafted cactus. PMID:25288927

  11. Carcass characteristics of lambs fed spineless cactus as a replacement for sugarcane.

    PubMed

    Oliveira, Juliana Paula Felipe de; Ferreira, Marcelo de Andrade; Alves, Adryanne Marjorie Souza Vitor; Melo, Ana Caroline Cerqueira de; Andrade, Ida Barbosa de; Urbano, Stela Antas; Suassuna, Juraci Marcos Alves; Barros, Leonardo José Assis de; Melo, Tobias Tobit de Barros

    2017-08-16

    The fresh sugarcane has been a new roughage source for ruminant's in semiarid region, in function of the decadence of sugar and alcohol industry in the last years. However, the date published for lambs fed sugarcane associated with spineless cactus is scared. This study evaluated the effect of sugarcane replacement with spineless cactus (0, 33, 66, and 100%) in the diet of Santa Inês lambs on carcass characteristics. Thirty-six non-castrated Santa Ines lambs at four months of age and an initial body weight of 22 ± 2.3 kg were assigned in a randomized block design and slaughtered after 70 days of confinement. The effects of spineless cactus as a replacement for sugarcane in the diet of the lambs on the carcass characteristics, commercial cut weight and yield, leg tissue composition, and carcass measurements were studied. The study revealed quadratic behavior in slaughter body weight, and hot and cold carcass weight, with maximum values of 38.60, 18.60, and 18.11 kg and replacement levels of 40.18, 44.42, and 43.14%, respectively. The Cold carcass yield presented an increasing linear behavior presented quadratic behavior. The compactness index of carcass and leg presented a quadratic effect, with estimated maximal values of 0.28 and 0.57 kg/cm and replacement levels of 43.37 and 45.5%, respectively. The weights of commercial cuts of leg, loin, shoulder, and breast showed quadratic behavior, with maximum values of 2.79, 0.852, 1.46, and 1.30 kg and replacement levels of 49.5, 45.32, 39.0, and 40.7, respectively. For tissue composition, quadratic behavior was verified for leg weight, subcutaneous fat, and total fat. The replacement of sugarcane by spineless cactus at level 44% is recommended for finishing lambs considering that this level improved most of the carcass characteristics, weights, and yields of commercial cuts and leg tissue composition.

  12. Increased acidification in the rhizosphere of cactus seedlings induced by Azospirillum brasilense

    NASA Astrophysics Data System (ADS)

    Carrillo, Angel; Li, Ching; Bashan, Yoav

    2002-08-01

    Acidification of the rhizosphere of cactus seedlings (giant cardon, Pachycereus pringlei) after inoculation with the plant growth-promoting bacterium Azospirillum brasilense Cd, in the presence or absence of ammonium and nitrate, was studied to understand how to increase growth of cardon seedlings in poor desert soils. While ammonium enhanced rhizosphere and liquid culture acidification, inoculation with the bacteria enhanced it further. On the other hand, nitrate increased pH of the rhizosphere, but combined with the bacterial inoculation, increase in pH was significantly smaller. Bacterial inoculation with ammonium enhanced plant growth.

  13. The development of CACTUS : a wind and marine turbine performance simulation code.

    SciTech Connect

    Barone, Matthew Franklin; Murray, Jonathan

    2010-12-01

    CACTUS (Code for Axial and Cross-flow TUrbine Simulation) is a turbine performance simulation code, based on a free wake vortex method, under development at Sandia National Laboratories (SNL) as part of a Department of Energy program to study marine hydrokinetic (MHK) devices. The current effort builds upon work previously done at SNL in the area of vertical axis wind turbine simulation, and aims to add models to handle generic device geometry and physical models specific to the marine environment. An overview of the current state of the project and validation effort is provided.

  14. Compounds from Terminalli brownii extracts with toxicity against the fish pathogenic bacterium Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    The pond-raised channel catfish (Ictalurus punctatus) industry in the United States of America can incur losses of over a $100 million annually due to bacterial diseases including columnaris disease caused by Flavobacterium columnare. One management approach available to catfish producers is the use...

  15. Study of the photoinduced supramolecular chirality in columnar liquid crystals by infrared and VCD spectroscopies.

    PubMed

    Avilés Moreno, Juan Ramón; López González, Juan Jesús; Partal Ureña, Francisco; Vera, Francisco; Ros, M Blanca; Sierra, Teresa

    2012-04-26

    IR and VCD spectroscopies are employed to clarify the molecular origins of supramolecular chirality in azobenzene-containing columnar liquid crystals. The different columnar mesomorphic assemblies, Colr and Colh, of an achiral and a chiral propeller-like hydrogen-bonded complex, respectively, are used for this study. The mesomorphic behavior of the achiral complex is studied here for the first time, and the structural parameters of its Colr mesophase are determined by X-ray diffraction. Both complexes bear azobenzene units and this makes it possible to implement photoresponsive columnar architectures, the chirality of which can be induced and modulated by irradiation with 488 nm circularly polarized light (CPL). Thin films of the respective rectangular and hexagonal columnar phases of these complexes have been processed in order to study the IR absorption spectra and the vibrational circular dichroism responses upon irradiation with CPL. These studies allow confirming that the outer part of the columns, consisting on azobenzene groups, is mainly involved in the photoinduced supramolecular chirality, rather than the inner part of the columns where a melamine core is located. This supports a structural model based on the helical disposition of the azobenzene groups along the stacked propeller-like complexes.

  16. Characterization of atypical Flavobacterium columnare and identification of a new genomovar

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare is the etiological agent of columnaris disease and is the second most prevalent disease in farm-raised channel catfish. This is a Gram-negative bacterium characterized by adherent yellow pigmented rhizoid colonies. It can be further described by gliding motility, growth in t...

  17. Kaolinitic clay protects against Flavobacterium columnare infection in channel catfish Ictalurus punctatus (Rafinesque)

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide in aquaculture settings. Despite the far-reaching negative impacts of columnaris disease, safe and efficacious preventatives and curatives for this disease remain limited. In th...

  18. Rhamnose binding lectins influence Flavobacterium columnare pathogenesis in channel catfish Ictalurus punctatus

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide and commonly leads to tremendous losses of both wild and cultured freshwater fish, particularly in intensively farmed aquaculture species such as channel catfish. Despite its ecol...

  19. Draft genome sequence of the fish pathogen Flavobacterium columnare strain CSF-298-10

    USDA-ARS?s Scientific Manuscript database

    We announce the genome assembly of Flavobacterium columnare strain CSF-298-10, a strain isolated from an outbreak of Columnaris disease at a commercial trout farm in Snake River Valley Idaho, USA. The complete genome consists of 13 contigs totaling 3,284,579 bp, average G+C content of 31.5% and 2933...

  20. Columnaris (Flavobacterium columnare) challenge using fathead minnows (Pimephales promelas) in an ultra-low flow system

    USDA-ARS?s Scientific Manuscript database

    Arkansas baitfish farms routinely struggle with columnaris disease, which is caused by Flavobacterium columnare. Columnaris is ubiquitous in fathead minnows (Pimephales promelas) especially after harvest while they are being held in vats and during the transport prior to being sold. Columnaris disea...

  1. Host-specific association between Flavobacterium columnare genomovars and fish species

    USDA-ARS?s Scientific Manuscript database

    A total of 90 Flavobacterium columnare isolates were recovered from predominant wild fish species in the Mobile River, Alabama, USA. Isolates were identified and confirmed by fatty acid methyl ester analysis and specific PCR amplification. Genomovar ascription was performed using 16S-restriction fra...

  2. New hosts and genetic diversity of Flavobacterium columnare isolated from Brazilian native species and Nile tilapia.

    PubMed

    Barony, G M; Tavares, G C; Assis, G B N; Luz, R K; Figueiredo, H C P; Leal, C A G

    2015-11-17

    Flavobacterium columnare is responsible for disease outbreaks in freshwater fish farms. Several Brazilian native fish have been commercially exploited or studied for aquaculture purposes, including Amazon catfish Leiarius marmoratus × Pseudoplatystoma fasciatum and pacamã Lophiosilurus alexandri. This study aimed to identify the aetiology of disease outbreaks in Amazon catfish and pacamã hatcheries and to address the genetic diversity of F. columnare isolates obtained from diseased fish. Two outbreaks in Amazon catfish and pacamã hatcheries took place in 2010 and 2011. Four F. columnare strains were isolated from these fish and identified by PCR. The disease was successfully reproduced under experimental conditions for both fish species, fulfilling Koch's postulates. The genomovar of these 4 isolates and of an additional 11 isolates from Nile tilapia Oreochromis niloticus was determined by 16S rRNA restriction fragment length polymorphism PCR. The genetic diversity was evaluated by phylogenetic analysis of the 16S rRNA gene and repetitive extragenic palindromic PCR (REP-PCR). Most isolates (n = 13) belonged to genomovar II; the remaining 2 isolates (both from Nile tilapia) were assigned to genomovar I. Phylogenetic analysis and REP-PCR were able to demonstrate intragenomovar diversity. This is the first report of columnaris in Brazilian native Amazon catfish and pacamã. The Brazilian F. columnare isolates showed moderate diversity, and REP-PCR was demonstrated to be a feasible method to evaluate genetic variability in this bacterium.

  3. White bass Morone chrysops is less susceptible than its hybrid to experimental infection with Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Hybrid striped bass (HSB) and white bass (WB) were evaluated for their susceptibility to Flavobacterium columnare, the causative agent of columnaris disease, in three fundamental studies. In the first experiment, we determined whether columnaris disease could be developed by experimental challenge ...

  4. Effectiveness of copper sulfate and potassium permanganate on channel catfish infected with Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Copper sulfate (CuSO4) and potassium permanganate (KMnO4) were evaluated for their effectiveness to curtail mortality and decrease bacterial load in fish tissues and water in channel catfish Ictalurus punctatus naturally infected with Flavobacterium columnare, the causative agent of columnaris. Fis...

  5. Two-dimensional simulation of spatiotemporal generation of dielectric barrier columnar discharges in atmospheric helium

    SciTech Connect

    Huang, Zhiming; Hao, Yanpeng; Yang, Lin; Han, Yongxia; Li, Licheng

    2015-12-15

    A two-dimensional (2D) fluid model is presented to investigate the spatiotemporal generation and dynamic mechanics of dielectric barrier columnar discharges in atmospheric helium. The model was examined with discharge currents measured in experiments and images taken by an intensified charge couple device camera. Based on the model, a columnar discharge was simulated for several cycles after being ignited. The discharge could be regarded as an initial unstable stage for the first three and a half cycles, then a steady state for the following cycles. In the initial stage, the discharge evolves from a uniform pattern into a columnar one. The calculated equipotential lines, 2D radial electric field, and electron density distributions at the edge of uniform discharges show the radial electric field accounts for the shrinking discharge area and the formation of discharge columns in the end. The columnar glow discharges and the Townsend discharges beyond the columns could coexist in the initial stage, and a Townsend discharge might develop into a new glow column in the next half-cycle. The radial electric field surrounding a glow discharge column has an inhibiting effect on the ionization in the peripheral area.

  6. A liquid-crystalline hexagonal columnar phase in highly-dilute suspensions of imogolite nanotubes

    NASA Astrophysics Data System (ADS)

    Paineau, Erwan; Krapf, Marie-Eve M.; Amara, Mohamed-Salah; Matskova, Natalia V.; Dozov, Ivan; Rouzière, Stéphan; Thill, Antoine; Launois, Pascale; Davidson, Patrick

    2016-01-01

    Liquid crystals have found wide applications in many fields ranging from detergents to information displays and they are also increasingly being used in the `bottom-up' self-assembly approach of material nano-structuration. Moreover, liquid-crystalline organizations are frequently observed by biologists. Here we show that one of the four major lyotropic liquid-crystal phases, the columnar one, is much more stable on dilution than reported so far in literature. Indeed, aqueous suspensions of imogolite nanotubes, at low ionic strength, display the columnar liquid-crystal phase at volume fractions as low as ~0.2%. Consequently, due to its low visco-elasticity, this columnar phase is easily aligned in an alternating current electric field, in contrast with usual columnar liquid-crystal phases. These findings should have important implications for the statistical physics of the suspensions of charged rods and could also be exploited in materials science to prepare ordered nanocomposites and in biophysics to better understand solutions of rod-like biopolymers.

  7. Flavobacterium columnare type IX secretion system mutations result in defects in gliding motility and virulence

    USDA-ARS?s Scientific Manuscript database

    Background: The gliding bacterium Flavobacterium columnare causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. The related bacterium Flavobacterium johnsoniae uses a type IX secretion system (T9SS) to secrete enzy...

  8. More than just antibodies: protective mechanisms of a mucosal vaccine against fish pathogen Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    A recently developed attenuated vaccine (17-23) for Flavobacterium columnare has been demonstrated to provide superior protection for channel catfish, Ictalurus punctatus, against genetically diverse columnaris isolates. First, we were interested in elucidating the host responses generated by a viru...

  9. A liquid-crystalline hexagonal columnar phase in highly-dilute suspensions of imogolite nanotubes

    PubMed Central

    Paineau, Erwan; Krapf, Marie-Eve M.; Amara, Mohamed-Salah; Matskova, Natalia V.; Dozov, Ivan; Rouzière, Stéphan; Thill, Antoine; Launois, Pascale; Davidson, Patrick

    2016-01-01

    Liquid crystals have found wide applications in many fields ranging from detergents to information displays and they are also increasingly being used in the ‘bottom-up' self-assembly approach of material nano-structuration. Moreover, liquid-crystalline organizations are frequently observed by biologists. Here we show that one of the four major lyotropic liquid-crystal phases, the columnar one, is much more stable on dilution than reported so far in literature. Indeed, aqueous suspensions of imogolite nanotubes, at low ionic strength, display the columnar liquid-crystal phase at volume fractions as low as ∼0.2%. Consequently, due to its low visco-elasticity, this columnar phase is easily aligned in an alternating current electric field, in contrast with usual columnar liquid-crystal phases. These findings should have important implications for the statistical physics of the suspensions of charged rods and could also be exploited in materials science to prepare ordered nanocomposites and in biophysics to better understand solutions of rod-like biopolymers. PMID:26728415

  10. Evaluation of the antibody response to the LV-359-01 strain of flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare, the causative agent of columnaris disease produces substantial mortality worldwide among numerous freshwater farmed finfish species. As aquaculture production continues to increase the frequency of columnaris disease will only continue to rise. Add to this an increase in re...

  11. Growth and survival of Flavobacterium columnare in fish mucus and porcine gastric mucin

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare, an economically important gram negative bacterium of freshwater farmed fish, colonizes the skin and gills in the initial steps of pathogenesis. The surface of fish is coated with mucus made up of high molecular weight glycoproteins. Limited studies have described the abili...

  12. There must be something in the water (for F. columnare pathogenesis)

    USDA-ARS?s Scientific Manuscript database

    Why can we routinely produce columnaris infections in our lab, while the lab on the other side of the ditch can't? Anecdotal reports suggest that tannins may inhibit F. columnare. Do tannins in their water prevent this, or are other water chemistry parameters involved? In the first experiment, tw...

  13. A solutal interaction mechanism for the columnar-to-equiaxed transition in alloy solidification

    NASA Astrophysics Data System (ADS)

    Martorano, M. A.; Beckermann, C.; Gandin, C.-A.

    2003-08-01

    A multiphase/multiscale model is used to predict the columnar-to-equiaxed transition (CET) during solidification of binary alloys. The model consists of averaged energy and species conservation equations, coupled with nucleation and growth laws for dendritic structures. A new mechanism for the CET is proposed based on solutal interactions between the equiaxed grains and the advancing columnar front—as opposed to the commonly used mechanical blocking criterion. The resulting differences in the CET prediction are demonstrated for cases where a steady state can be assumed, and a revised isotherm velocity (V T ) vs temperature gradient (G) map for the CET is presented. The model is validated by predicting the CET in previously performed unsteady, unidirectional solidification experiments involving Al-Si alloys of three different compositions. Good agreement is obtained between measured and predicted cooling curves. A parametric study is performed to investigate the dependence of the CET position on the nucleation undercooling and the density of nuclei in the equiaxed zone. Nucleation undercoolings are determined that provide the best agreement between measured and calculated CET positions. It is found that for all three alloy compositions, the nucleation undercoolings are very close to the maximum columnar dendrite tip undercoolings, indicating that the origin of the equiaxed grains may not be heterogeneous nucleation, but rather a breakdown or fragmentation of the columnar dendrites.

  14. The type IX secretion system is required for virulence of the fish pathogen Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare, a member of the phylum Bacteroidetes, causes columnaris disease in wild and aquaculture-reared freshwater fish. The mechanisms responsible for columnaris disease are not known. Many members of the phylum Bacteroidetes use type IX secretion systems (T9SSs) to secrete enzymes...

  15. Evaluation of Diquat against an acute experimental infection of Flavobacterium columnare in channel catfish, Ictalurus punctatus

    USDA-ARS?s Scientific Manuscript database

    A trial was performed to evaluate the efficacy of diquat (6,7-Dihydrodipyrido[1,2-a:2',1'-c]pyrazinediium dibromide) against an acute experimental infection of Flavobacterium columnare in channel catfish, Ictalurus punctatus. Diquat is an Environmental Protection Agency-approved herbicide and has t...

  16. A bundled-stack discotic columnar liquid crystalline phase with inter-stack electronic coupling

    DOE PAGES

    Wang, Bin; Sun, Runkun; Günbaş, Duygu D.; ...

    2015-06-15

    The first compound proving to be capable of forming a bundled-stack discotic columnar liquid crystalline (BSDCLC) phase was designed and synthesized. Finally, the unique perylene anhydride inter-stack interaction was found to be the key to the formation of the BSDCLC structure and inter-stack electronic coupling (ISEC).

  17. Evaluating innate resistance to Flavobacterium Columnare in rainbow trout (Oncorhynchus mykiss)

    USDA-ARS?s Scientific Manuscript database

    Flavobacterium columnare (Fc) is the causative agent for columnaris disease and a problem for several fish species. Recently, columnaris has been recognized as an emerging problem in farmed trout cultured within the Hagerman valley of Idaho. A long term breeding program at the NCCCWA has produced ...

  18. Induced stabilization of columnar phases in binary mixtures of discotic liquid crystals.

    PubMed

    Cienega-Cacerez, Octavio; García-Alcántara, Consuelo; Moreno-Razo, José Antonio; Díaz-Herrera, Enrique; Sambriski, Edward John

    2016-01-28

    Three discotic liquid-crystalline binary mixtures, characterized by their extent of bidispersity in molecular thickness, were investigated with molecular dynamics simulations. Each equimolar mixture contained A-type (thin) and B-type (thick) discogens. The temperature-dependence of the orientational order parameter reveals that A-type liquid samples produce ordered phases more readily, with the (hexagonal) columnar phase being the most structured variant. Moderately and strongly bidisperse mixtures produce globally-segregated samples for temperatures corresponding to ordered phases; the weakly bidisperse mixture displays microheterogeneities. Ordered phases in the B-type liquid are induced partially by the presence of the A-type fluid. In the moderately bidisperse mixture, order is induced through orientational frustration: a mixed prenematic-like phase precedes global segregation to yield nematic and columnar mesophases upon further cooling. In the strongly bidisperse mixture, order is induced less efficiently through a paranematic-like mechanism: a highly-ordered A-type fluid imparts order to B-type discogens found at the interface of a fully-segregated sample. This ordering effect permeates into the disordered B-type domain until nematic and columnar phases emerge upon further cooling. At sufficiently low temperatures, all samples investigated exhibit the (hexagonal) columnar mesophase.

  19. Measurements of head-scatter factors with cylindrical build-up caps and columnar miniphantoms.

    PubMed

    Jursinic, P A; Thomadsen, B R

    1999-04-01

    Head-scatter factors, Sh, also referred to as output factors, are measured in-air with an ion chamber and a semiconductor diode fitted with cylindrical build-up caps and columnar miniphantoms fabricated from materials of different atomic number. Sh increases with field size less rapidly when cylindrical build-up caps are constructed from high atomic number materials. This is a consequence of a net scatter of contamination electrons away from the detector. Ion chambers and diodes give identical results when the same type of build-up caps are used. Contamination electrons can be avoided by the use of columnar miniphantoms that have sufficient wall thickness in the radial direction. This radial wall thickness is characterized in this work for 6, 10, and 18 MV x-ray beams. Sh increases with field size less rapidly when columnar miniphantoms are constructed from high atomic number materials. This is due to the decrease in the average energy of photons at large field sizes. It is concluded that to obtain Sh for dosimetry in water, cylindrical build-up caps and columnar miniphantoms should be constructed from material with an atomic number close to that of water.

  20. The stress hormone cortisol: a (co)regulator of biofilm formation in Flavobacterum columnare?

    USDA-ARS?s Scientific Manuscript database

    Previously, we demonstrated a direct effect of cortisol on Flavobacterium columnare, a notorious fish pathogenic bacterium, engendering a new perspective to bacteria-host communication in aquaculture. As stressed fish harbour increased cortisol levels in the skin and gill mucus, highly virulent F. c...

  1. A bundled-stack discotic columnar liquid crystalline phase with inter-stack electronic coupling

    SciTech Connect

    Wang, Bin; Sun, Runkun; Günbaş, Duygu D.; Zhang, Hao; Grozema, Ferdinand C.; Xiao, Kai; Jin, Shi

    2015-06-15

    The first compound proving to be capable of forming a bundled-stack discotic columnar liquid crystalline (BSDCLC) phase was designed and synthesized. Finally, the unique perylene anhydride inter-stack interaction was found to be the key to the formation of the BSDCLC structure and inter-stack electronic coupling (ISEC).

  2. Gene Deletion Strategy To Examine the Involvement of the Two Chondroitin Lyases in Flavobacterium columnare Virulence

    PubMed Central

    Li, Nan; Qin, Ting; Zhang, Xiao Lin; Huang, Bei; Liu, Zhi Xin; Xie, Hai Xia; Zhang, Jin; McBride, Mark J.

    2015-01-01

    Flavobacterium columnare is an important bacterial pathogen of freshwater fish that causes high mortality of infected fish and heavy economic losses in aquaculture. The pathogenesis of this bacterium is poorly understood, in part due to the lack of efficient methods for genetic manipulation. In this study, a gene deletion strategy was developed and used to determine the relationship between the production of chondroitin lyases and virulence. The F. johnsoniae ompA promoter (PompA) was fused to sacB to construct a counterselectable marker for F. columnare. F. columnare carrying PompA-sacB failed to grow on media containing 10% sucrose. A suicide vector carrying PompA-sacB was constructed, and a gene deletion strategy was developed. Using this approach, the chondroitin lyase-encoding genes, cslA and cslB, were deleted. The ΔcslA and ΔcslB mutants were both partially deficient in digestion of chondroitin sulfate A, whereas a double mutant (ΔcslA ΔcslB) was completely deficient in chondroitin lyase activity. Cells of F. columnare wild-type strain G4 and of the chondroitin lyase-deficient ΔcslA ΔcslB mutant exhibited similar levels of virulence toward grass carp in single-strain infections. Coinfections, however, revealed a competitive advantage for the wild type over the chondroitin lyase mutant. The results indicate that chondroitin lyases are not essential virulence factors of F. columnare but may contribute to the ability of the pathogen to compete and cause disease in natural infections. The gene deletion method developed in this study may be employed to investigate the virulence factors of this bacterium and may have wide application in many other members of the phylum Bacteroidetes. PMID:26253667

  3. Analysis of EDZ Development of Columnar Jointed Rock Mass in the Baihetan Diversion Tunnel

    NASA Astrophysics Data System (ADS)

    Hao, Xian-Jie; Feng, Xia-Ting; Yang, Cheng-Xiang; Jiang, Quan; Li, Shao-Jun

    2016-04-01

    Due to the time dependency of the crack propagation, columnar jointed rock masses exhibit marked time-dependent behaviour. In this study, in situ measurements, scanning electron microscope (SEM), back-analysis method and numerical simulations are presented to study the time-dependent development of the excavation damaged zone (EDZ) around underground diversion tunnels in a columnar jointed rock mass. Through in situ measurements of crack propagation and EDZ development, their extent is seen to have increased over time, despite the fact that the advancing face has passed. Similar to creep behaviour, the time-dependent EDZ development curve also consists of three stages: a deceleration stage, a stabilization stage, and an acceleration stage. A corresponding constitutive model of columnar jointed rock mass considering time-dependent behaviour is proposed. The time-dependent degradation coefficient of the roughness coefficient and residual friction angle in the Barton-Bandis strength criterion are taken into account. An intelligent back-analysis method is adopted to obtain the unknown time-dependent degradation coefficients for the proposed constitutive model. The numerical modelling results are in good agreement with the measured EDZ. Not only that, the failure pattern simulated by this time-dependent constitutive model is consistent with that observed in the scanning electron microscope (SEM) and in situ observation, indicating that this model could accurately simulate the failure pattern and time-dependent EDZ development of columnar joints. Moreover, the effects of the support system provided and the in situ stress on the time-dependent coefficients are studied. Finally, the long-term stability analysis of diversion tunnels excavated in columnar jointed rock masses is performed.

  4. Gene deletion strategy to examine the involvement of the two chondroitin lyases in Flavobacterium columnare virulence.

    PubMed

    Li, Nan; Qin, Ting; Zhang, Xiao Lin; Huang, Bei; Liu, Zhi Xin; Xie, Hai Xia; Zhang, Jin; McBride, Mark J; Nie, Pin

    2015-11-01

    Flavobacterium columnare is an important bacterial pathogen of freshwater fish that causes high mortality of infected fish and heavy economic losses in aquaculture. The pathogenesis of this bacterium is poorly understood, in part due to the lack of efficient methods for genetic manipulation. In this study, a gene deletion strategy was developed and used to determine the relationship between the production of chondroitin lyases and virulence. The F. johnsoniae ompA promoter (PompA) was fused to sacB to construct a counterselectable marker for F. columnare. F. columnare carrying PompA-sacB failed to grow on media containing 10% sucrose. A suicide vector carrying PompA-sacB was constructed, and a gene deletion strategy was developed. Using this approach, the chondroitin lyase-encoding genes, cslA and cslB, were deleted. The ΔcslA and ΔcslB mutants were both partially deficient in digestion of chondroitin sulfate A, whereas a double mutant (ΔcslA ΔcslB) was completely deficient in chondroitin lyase activity. Cells of F. columnare wild-type strain G4 and of the chondroitin lyase-deficient ΔcslA ΔcslB mutant exhibited similar levels of virulence toward grass carp in single-strain infections. Coinfections, however, revealed a competitive advantage for the wild type over the chondroitin lyase mutant. The results indicate that chondroitin lyases are not essential virulence factors of F. columnare but may contribute to the ability of the pathogen to compete and cause disease in natural infections. The gene deletion method developed in this study may be employed to investigate the virulence factors of this bacterium and may have wide application in many other members of the phylum Bacteroidetes.

  5. Phylogeography of the Cactophilic Drosophila and Other Arthropods Associated with Cactus Necroses in the Sonoran Desert

    PubMed Central

    Pfeiler, Edward; Markow, Therese A.

    2011-01-01

    Studies on the population genetics, phylogenetic relationships, systematics and evolution of arthropods that inhabit necrotic tissue of cacti in the Sonoran Desert of North America are reviewed. These studies have focused upon several species of insects (orders Diptera and Coleoptera) and arachnids (order Pseudoscorpiones). For most taxa studied, little genetic structure and high dispersal ability are found in populations inhabiting the mainland and Baja California peninsula regions of the Sonoran Desert, consistent with the availability of the rotting cactus microhabitat which is patchily distributed and ephemeral. There is evidence, however, that the Gulf of California, which bisects the Sonoran Desert, has played a role in limiting gene flow and promoting speciation in several taxa, including histerid beetles, whereas other taxa, especially Drosophila nigrospiracula and D. mettleri, apparently are able to freely cross the Gulf, probably by taking advantage of the Midriff Islands in the northern Gulf as dispersal “stepping stones”. Genetic evidence has also been found for historical population expansions dating to the Pleistocene and late Pliocene in several taxa. Overall, these studies have provided important insights into how arthropods with different life history traits, but generally restricted to a necrotic cactus microhabitat, have evolved in an environmentally harsh and tectonically active region. In addition, they suggest some taxa for further, and more detailed, hypothesis driven studies of speciation. PMID:26467624

  6. Developmental changes in composition and quality of prickly pear cactus cladodes (nopalitos).

    PubMed

    Rodriguez-Felix, A; Cantwell, M

    1988-01-01

    The composition and quality of edible tender stems or cladodes of 3 Prickly Pear Cactus species (Opuntia amyclaea, O. ficus-indica, and O. inermis) were studied at different stages of development. This traditional Mexican vegetable is called "nopalitos" in Spanish and "cactus leaves" in English. Cladodes harvested when 20 cm in length have the following average composition per 100 g: 91.7 g of water, 1.1 g of protein, 0.2 g of lipid, 1.3 g of ash, 1.1 g of crude fiber, 4.6 g of complex carbohydrates and 0.82 g of simple sugars, 12.7 mg of ascorbic acid and 28.9 micrograms of carotenes. The cladode's juice has an average pH of 4.6, 0.45% titratable acidity and 6.9% soluble solids. The components which varied most during development of the cladodes were: carotenes, acidity and total carbohydrates which increased, and protein and crude fiber (acid-detergent) which decreased. The nutritive value of the tender cladodes in the stages of growth at which they are commonly harvested and consumed (15 to 25 cm long weighing 50 to 80 g per stem), was similar for the 3 species.

  7. Marketability of ready-to-eat cactus pear as affected by temperature and modified atmosphere.

    PubMed

    Cefola, Maria; Renna, Massimiliano; Pace, Bernardo

    2014-01-01

    In order to increase the diffusion of cactus pear fruits, in this study, the proper maturity index for peeling and processing them as ready-to-eat product was evaluated and characterized. Thereafter, the effects of different storage temperatures and modified atmosphere conditions on the marketability of ready-to-eat cactus pear were studied. The storage of ready-to-eat fruits at 4 °C in both passive (air) and semi-active (10 kPa O2 and 10 kPa CO2) modified atmosphere improved the marketability by 30%, whereas the storage at 8 °C caused a dangerous reduction in O2 partial pressure inside modified atmosphere packages, due to fruits' increased metabolic activity. A very low level of initial microbial growth was detected, while a severe increase in mesophilic and psychrophilic bacteria was shown in control samples at both temperatures during storage; an inhibitory effect of modified atmosphere on microbial growth was also observed. In conclusion, modified atmosphere improved only the marketability of fruits stored at 4 °C; whereas the storage at 8 °C resulted in deleterious effects on the ready-to-eat fruits, whether stored in air or in modified atmosphere.

  8. Antibacterial and antioxidant activities in extracts of fully grown cladodes of 8 cultivars of cactus pear.

    PubMed

    Sánchez, E; Dávila-Aviña, J; Castillo, S L; Heredia, N; Vázquez-Alvarado, R; García, S

    2014-04-01

    The antimicrobial and antioxidant activities of some cultivars of the nopal cactus have not been determined. In this study, 8 cultivars of nopal cacti from Mexico were assayed for phenolic content, antioxidant activities, and antimicrobial activities against Campylobacter Jejuni, Vibrio cholera, and Clostridium Perfringens. Plant material was washed, dried, and macerated in methanol. Minimum bactericidal concentrations (MBCs) were determined using the broth microdilution method. Antioxidant activities were quantitatively determined using spectrophotometric methods. The MCBs of the nopal cacti ranged from 1.1 to 12.5 mg/mL for c. jejuni, 4.4 to 30 mg/mL for V. cholera, and 0.8 to 16 mg/mL for C. perfringens in the cultivars Cardon Blanco, Real de Catorce, and Jalpa, respectively. High quantities of total phenols and total flavonoids were found in the Jalpa cacti (3.80 mg of gallic acid equivalent GAE/g dry weight [DW] and 36.64 mg of quercetin equivalents [QE]/g DW, respectively). 2,2-Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging activities (RSA) were correlated to bioactive compound contents. The Villanueva cacti had the highest %RSA at 42.31%, and the lowest activity was recorded in Copena V1 at 19.98%. In conclusion, we found that some of the 8 cactus pear cultivars studied may be used for their antioxidant compounds or antimicrobials to control or prevent the contamination of foods. © 2014 Institute of Food Technologists®

  9. A purified extract from prickly pear cactus (Opuntia fuliginosa) controls experimentally induced diabetes in rats.

    PubMed

    Trejo-González, A; Gabriel-Ortiz, G; Puebla-Pérez, A M; Huízar-Contreras, M D; Munguía-Mazariegos, M R; Mejía-Arreguín, S; Calva, E

    1996-12-01

    The hypoglycemic activity of a purified extract from prickly pear cactus (Opuntia fuliginosa) was evaluated on STZ-induced diabetic rats. Blood glucose and glycated hemoglobin levels were reduced to normal values by a combined treatment of insulin and Opuntia extract. When insulin was withdrawn from the combined treatment, the prickly pear extract alone maintained normoglycemic state in the diabetic rats. The blood glucose response to administered glucose also showed that the rats receiving the combination treatment of insulin and Opuntia extract for 7 weeks followed by Opuntia extract alone were capable of rapidly returning blood glucose to the levels of the nondiabetic rats. Although the mechanism of action is unknown, the magnitude of the glucose control by the small amount of Opuntia extract required (1 mg/kg body weight per day) preclude a predominant role for dietary fiber. These very encouraging results for diabetes control by the purified extract of this Opuntia cactus make the need for clinical studies in humans evident.

  10. Cactus pear cladodes powders as a source of dietary fibre: purification and properties.

    PubMed

    Saenz, Carmen; Yoong, Maylin; Figuerola, Fernando; Chiffelle, Italo; María Estevez, Ana

    2012-05-01

    Cactus pear cladodes of 2-3 years were used to obtain a natural purified dietary fibre and their physical, chemical and technological properties were determined. The effect of particle size and washing temperature on the technological properties was studied. Purification produces a decrease in green colour (a*) and an increase in total dietary fibre but reduces the total phenolic compounds, mainly when cladodes are washed at higher temperatures. Technological properties did not present changes in the water retention capacity (WRC), water adsorption capacity and cationic exchange capacity, but it did in swelling capacity (SC), oil absorption capacity, apparent density and setting density, which were influenced by the particle size of the cactus powders. The purified fibre shows a high WRC between 5.20 and 5.86 g g(- 1) and a high SC (7.02-8.27 mL g(- 1)). Purified fibre with a particle size between 600 and 1200 μm, independent of the washing temperature had better insoluble to soluble dietary fibre ratio, total phenolic content and technological properties.

  11. Intake, performance, and carcass characteristics of lambs fed spineless cactus replacing wheat bran.

    PubMed

    Felix, Sabrina Carla Rodrigues; Pessoa, Ricardo Alexandre Silva; Ferreira, Marcelo de Andrade; Soares, Luciana Felizardo Pereira; Silva, Janaina de Lima; de Abreu, Karen Santos Felix; de Melo, Ana Caroline Cerqueira

    2016-02-01

    To assess the intake, digestibility of nutrients, ingestive behavior, performance, and carcass characteristics of feedlot lambs, 36 F1 Santa Ines × Dorper male lambs with an initial average weight of 19.5 ± 0.27 kg were fed with different levels of spineless cactus (0, 33, 66, and 100 %) as a replacement of the wheat bran. The replacement diets had no effect on the intake of dry matter (DM) or crude protein (CP), whose average values were 962 and 140 g/day, respectively. There was a quadratic effect on the intake of digestible organic matter (OM) and the digestibility of DM, CP, neutral detergent fiber (NDF), and non-fiber carbohydrates (NFC). The highest average daily gain (ADG) of 168 g/day was achieved at 58.7 % replacement level. The highest hot and cold carcass weights of 15.4 and 14.5 kg were achieved at 62.4 and 56.9 % replacement levels. For lambs in the feedlot, we recommend replacing wheat bran with up to 58.7 % spineless cactus.

  12. Effective directional self-gathering of drops on spine of cactus with splayed capillary arrays.

    PubMed

    Liu, Chengcheng; Xue, Yan; Chen, Yuan; Zheng, Yongmei

    2015-12-07

    We report that the fast droplet transport without additional energy expenditure can be achieved on the spine of cactus (Gymnocalycium baldianum) with the assistance of its special surface structure: the cactus spine exhibits a cone-like structure covered with tilted scales. A single scale and the spine surface under it cooperatively construct a splayed capillary tube. The arrays of capillary tube formed by the overlapping scales build up the out layer of the spine. The serial drops would be driven by the asymmetric structure resulted from tilt-up scales-by-scales on the cone-shaped spine, and move directionally toward the bottom from top of spine, by means of the Laplace pressure in differences. In addition, after the past of the first droplet, thin liquid film of drop is trapped in the splayed capillary micro-tube on the surface of spine, which greatly reduces the friction of subsequential droplet transport in efficiency. This finding provides a new biological model which could be used to transport droplet spontaneously and directionally. Also this work offers a way to reduce the surface adhesion by constructing liquid film on the surface, which has great significance in prompting droplet transport efficiency.

  13. Factors affecting establishment success of the endangered Caribbean cactus Harrisia portoricensis (Cactaceae).

    PubMed

    Rojas-Sandoval, Julissa; Meléndez-Ackerman, Elvia

    2012-06-01

    Early plant stages may be the most vulnerable within the life cycle of plants especially in arid ecosystems. Interference from exotic species may exacerbate this condition. We evaluated germination, seedling survival and growth in the endangered Caribbean cactus Harrisia portoricensis, as a function of sunlight exposure (i.e., growing under open and shaded areas), different shade providers (i.e., growing under two native shrubs and one exotic grass species), two levels of predation (i.e., exclusion and non-exclusion) and variable microenvironmental conditions (i.e., temperature, PAR, humidity). Field experiments demonstrated that suitable conditions for germination and establishment of H. portoricensis seedling are optimal in shaded areas beneath the canopy of established species, but experiments also demonstrated that the identity of the shade provider can have a significant influence on the outcome of these processes. Harrisia portoricensis seedlings had higher probabilities of survival and grew better (i.e., larger diameters) when they were transplanted beneath the canopy of native shrubs, than beneath the exotic grass species, where temperature and solar radiation values were on average much higher than those obtained under the canopies of native shrubs. We also detected that exclusion from potential predators did not increase seedling survival. Our combined results for H. portoricensis suggested that the modification of microenvironmental conditions by the exotic grass may lower the probability of recruitment and establishment of this endangered cactus species.

  14. Influence of abscisic acid and sucrose on somatic embryogenesis in Cactus Copiapoa tenuissima Ritt. forma mostruosa.

    PubMed

    Lema-Rumińska, J; Goncerzewicz, K; Gabriel, M

    2013-01-01

    Having produced the embryos of cactus Copiapoa tenuissima Ritt. forma monstruosa at the globular stage and callus, we investigated the effect of abscisic acid (ABA) in the following concentrations: 0, 0.1, 1, 10, and 100  μ M on successive stages of direct (DSE) and indirect somatic embryogenesis (ISE). In the indirect somatic embryogenesis process we also investigated a combined effect of ABA (0, 0.1, 1  μ M) and sucrose (1, 3, 5%). The results showed that a low concentration of ABA (0-1  μ M) stimulates the elongation of embryos at the globular stage and the number of correct embryos in direct somatic embryogenesis, while a high ABA concentration (10-100  μ M) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somatic embryogenesis study in this cactus suggests that lower ABA concentrations enhance the increase in calli fresh weight, while a high concentration of 10  μ M ABA or more changes calli color and decreases its proliferation rate. However, in the case of indirect somatic embryogenesis, ABA had no effect on the number of somatic embryos and their maturation. Nevertheless, we found a positive effect of sucrose concentration for both the number of somatic embryos and the increase in calli fresh weight.

  15. Not all the infected develop the disease - A "Lotus and Cactus" model.

    PubMed

    Pitchappan, Ramasamy M

    2016-06-01

    The immunogenetic dictum "not all the infected develop the disease" can best be explained by a "Lotus and Cactus" model. Lotuses grow in ponds and cacti in deserts: analogously, we can say that tubercle patient's lung (genetic makeup) functions as an ideal 'broth' for Mycobacterium tuberculosis (M.tb) germs to grow, but not the lungs of an endemic control. HLA association studies from Europe to Asia since 1983 till date, have shown a persistent HLA DR2 (15) association. Further, HLA DR2 and non-DR2 endemic controls showed disparate patterns of immune responses and gene expressions. The host and pathogen MHC diversities, Th1-Th2 paradigm and cytokine circuits all may play a crucial role in TB susceptibility. It is possible to decipher the protective immunity by controlling the known confounders - epidemiological, demographic, socio-biological and also host and pathogen diversities. This has become significant with our understanding on the 'out of Africa' migration and neolithic co-dispersal of M.tb with modern human. Divergence and expansion of various MHCs (eg HLA-DRB1*15, HLA-B*57) and non-MHC alleles in various continents might be responsible for the skewed transmission and distribution of the infectious diseases around the globe. The 'Lotus and Cactus' model proposed here exemplifies this. A holistic genetic epidemiology approach employing modern tools is the need of the hour to better understand infectious disease susceptibility. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Influence of Abscisic Acid and Sucrose on Somatic Embryogenesis in Cactus Copiapoa tenuissima Ritt. forma mostruosa

    PubMed Central

    Lema-Rumińska, J.; Goncerzewicz, K.; Gabriel, M.

    2013-01-01

    Having produced the embryos of cactus Copiapoa tenuissima Ritt. forma monstruosa at the globular stage and callus, we investigated the effect of abscisic acid (ABA) in the following concentrations: 0, 0.1, 1, 10, and 100 μM on successive stages of direct (DSE) and indirect somatic embryogenesis (ISE). In the indirect somatic embryogenesis process we also investigated a combined effect of ABA (0, 0.1, 1 μM) and sucrose (1, 3, 5%). The results showed that a low concentration of ABA (0-1 μM) stimulates the elongation of embryos at the globular stage and the number of correct embryos in direct somatic embryogenesis, while a high ABA concentration (10–100 μM) results in growth inhibition and turgor pressure loss of somatic embryos. The indirect somatic embryogenesis study in this cactus suggests that lower ABA concentrations enhance the increase in calli fresh weight, while a high concentration of 10 μM ABA or more changes calli color and decreases its proliferation rate. However, in the case of indirect somatic embryogenesis, ABA had no effect on the number of somatic embryos and their maturation. Nevertheless, we found a positive effect of sucrose concentration for both the number of somatic embryos and the increase in calli fresh weight. PMID:23843737

  17. The cactus worm : experiments with dynamic resource discovery and allocation in a grid environment.

    SciTech Connect

    Allen, G.; Angulo, D.; Foster, I.; Lanfermann, G.; Liu, C.; Radke, T.; Seidel, E.; Shalf, J.; Mathematics and Computer Science; Albert-Einstein-Inst.; Univ. of Chicago; LBNL

    2001-01-01

    The ability to harness heterogeneous, dynamically available grid resources is attractive to typically resource-starved computational scientists and engineers, as in principle it can increase, by significant factors, the number of cycles that can be delivered to applications. However, new adaptive application structures and dynamic runtime system mechanisms are required if we are to operate effectively in grid environments. To explore some of these issues in a practical setting, the authors are developing an experimental framework, called Cactus, that incorporates both adaptive application structures for dealing with changing resource characteristics and adaptive resource selection mechanisms that allow applications to change their resource allocations (e.g., via migration) when performance falls outside specified limits. The authors describe the adaptive resource selection mechanisms and describe how they are used to achieve automatic application migration to 'better' resources following performance degradation. The results provide insights into the architectural structures required to support adaptive resource selection. In addition, the authors suggest that the Cactus Worm affords many opportunities for grid computing.

  18. Effect of extrusion cooking on bioactive compounds in encapsulated red cactus pear powder.

    PubMed

    Ruiz-Gutiérrez, Martha G; Amaya-Guerra, Carlos A; Quintero-Ramos, Armando; Pérez-Carrillo, Esther; Ruiz-Anchondo, Teresita de J; Báez-González, Juan G; Meléndez-Pizarro, Carmen O

    2015-05-18

    Red cactus pear has significant antioxidant activity and potential as a colorant in food, due to the presence of betalains. However, the betalains are highly thermolabile, and their application in thermal process, as extrusion cooking, should be evaluated. The aim of this study was to evaluate the effect of extrusion conditions on the chemical components of red cactus pear encapsulated powder. Cornstarch and encapsulated powder (2.5% w/w) were mixed and processed by extrusion at different barrel temperatures (80, 100, 120, 140 °C) and screw speeds (225, 275, 325 rpm) using a twin-screw extruder. Mean residence time (trm), color (L*, a*, b*), antioxidant activity, total polyphenol, betacyanin, and betaxanthin contents were determined on extrudates, and pigment degradation reaction rate constants (k) and activation energies (Ea) were calculated. Increases in barrel temperature and screw speed decreased the trm, and this was associated with better retentions of antioxidant activity, total polyphenol, betalain contents. The betacyanins k values ranged the -0.0188 to -0.0206/s and for betaxanthins ranged of -0.0122 to -0.0167/s, while Ea values were 1.5888 to 6.1815 kJ/mol, respectively. The bioactive compounds retention suggests that encapsulated powder can be used as pigments and to provide antioxidant properties to extruded products.

  19. Effective directional self-gathering of drops on spine of cactus with splayed capillary arrays

    NASA Astrophysics Data System (ADS)

    Liu, Chengcheng; Xue, Yan; Chen, Yuan; Zheng, Yongmei

    2015-12-01

    We report that the fast droplet transport without additional energy expenditure can be achieved on the spine of cactus (Gymnocalycium baldianum) with the assistance of its special surface structure: the cactus spine exhibits a cone-like structure covered with tilted scales. A single scale and the spine surface under it cooperatively construct a splayed capillary tube. The arrays of capillary tube formed by the overlapping scales build up the out layer of the spine. The serial drops would be driven by the asymmetric structure resulted from tilt-up scales-by-scales on the cone-shaped spine, and move directionally toward the bottom from top of spine, by means of the Laplace pressure in differences. In addition, after the past of the first droplet, thin liquid film of drop is trapped in the splayed capillary micro-tube on the surface of spine, which greatly reduces the friction of subsequential droplet transport in efficiency. This finding provides a new biological model which could be used to transport droplet spontaneously and directionally. Also this work offers a way to reduce the surface adhesion by constructing liquid film on the surface, which has great significance in prompting droplet transport efficiency.

  20. Chapter 2: A historical perspective on the population decline of the cactus ferruginous pygmy-owl in Arizona

    Treesearch

    R. Roy Johnson; Jean-Luc E. Cartron; Lois T. Haight; Russell B. Duncan; Kenneth J. Kingsley

    2000-01-01

    The cactus ferruginous pygmy-owl (Glaucidium brasilianum cactorum) was discovered in the U.S. by Bendire in 1872 in the Tucson area (Coues 1872). During the next five decades, naturalists collected many specimens of this owl and typically described the subspecies as common or fairly common along some streams and rivers of central and southern Arizona...

  1. Pollination of pima pineapple cactus (Coryphantha sheeri var. robustispina): does pollen flow limit abundance of this endangered species?

    Treesearch

    Christopher J. McDonald; Guy R. McPherson

    2005-01-01

    Pima pineapple cactus (PPC) (Coryphantha sheeri var. robustispina), a federally listed endangered species, occurs throughout southeastern Arizona and has relatively low population densities. To determine whether pollination limits reproduction of PPC we used florescent dye to quantify pollen flow between individuals in a PPC...

  2. Betalains, Phenols and Antioxidant Capacity in Cactus Pear [Opuntia ficus-indica (L.) Mill.] Fruits from Apulia (South Italy) Genotypes

    PubMed Central

    Albano, Clara; Negro, Carmine; Tommasi, Noemi; Gerardi, Carmela; Mita, Giovanni; Miceli, Antonio; De Bellis, Luigi; Blando, Federica

    2015-01-01

    Betacyanin (betanin), total phenolics, vitamin C and antioxidant capacity (by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays) were investigated in two differently colored cactus pear (Opuntia ficus-indica (L.) Mill.) genotypes, one with purple fruit and the other with orange fruit, from the Salento area, in Apulia (South Italy). In order to quantitate betanin in cactus pear fruit extracts (which is difficult by HPLC because of the presence of two isomers, betanin and isobetanin, and the lack of commercial standard with high purity), betanin was purified from Amaranthus retroflexus inflorescence, characterized by the presence of a single isomer. The purple cactus pear variety showed very high betanin content, with higher levels of phenolics, vitamin C, and antioxidant capacity (TEAC) than the orange variety. These findings confirm the potential for exploiting the autochthonous biodiversity of cactus pear fruits. In particular, the purple variety could be an interesting source of colored bioactive compounds which not only have coloring potential, but are also an excellent source of dietary antioxidant components which may have beneficial effects on consumers’ health. PMID:26783704

  3. Rearing a native cactus moth, Melitara prodenialis (Lepidoptera: Pyralidae), on artificial diet and Opuntia cladodes: Preliminary comparisons

    USDA-ARS?s Scientific Manuscript database

    This study compared several biological parameters of native cactus moth, Melitara prodenialis, reared on an artificial versus the natural diet of Opuntia spp. cladodes. Results suggest that the current artificial diet developed for mass rearing C. cactorum can provide nutritional value for the rear...

  4. External morphology of the egg of the native (Melitara prodenialis) and exotic (Cactoblastis cactorum) cactus moths (Lepidoptera: Pyralidae)

    USDA-ARS?s Scientific Manuscript database

    Scanning electron microscopy was used to study the morphology of the chorionic surface of two pyralids that feed on Opuntia cactus. The chorionic surface of Cactoblastis cactorum has a reticulate pattern due to the ridges on the surface and aeropyles. The surface has a granular appearance at low m...

  5. Analysis of factors that affect the potential of star fruit (Averhoa Bilimbi) and cactus (Gymnocalycium Hossei) extracts as alternative battery

    NASA Astrophysics Data System (ADS)

    Rahmawati, Sitti; Agnesstacia

    2014-03-01

    This research analyzes the factors that affect the work of the battery from the star fruit extract and the cactus extract. The value voltage and current generated are measure the work of the battery. Voltage measurement based on the electrode distance function, and electrode surface area. Voltage as a surface area electrode function and electrode distance function determined the current density and the voltage generated. From the experimental results obtained that the battery voltage is large enough, it is about 1.8 V for the extract of star fruit, and 1.7 V for the extract of cactus, which means that the juice extract from star fruit and the juice extract of cactus can become an alternative as battery replacement. The measurements with different electrode surface area on the star fruit and cactus extract which has the depth of the electrode 0.5 cm to 4 cm causes a decrease in the electric current generated from 12.5 mA to 1.0 mA, but obtained the same voltage.

  6. Chapter 3: The status of the cactus ferruginous pygmy-owl in Arizona: Population surveys and habitat assessment

    Treesearch

    W. Scott Richardson; Jean-Luc E. Cartron; David J. Krueper; Lauren Turner; Thomas H. Skinner

    2000-01-01

    In 1993, the Arizona Game and Fish Department (AGFD) began formal population surveys in an attempt to document the numbers and distribution of cactus ferruginous pygmy-owls (Glaucidium brasilianum cactorum) in Arizona. Surveys were initiated to gather information on this little-known subspecies which was considered for listing at the time. Prior to...

  7. Growing Opuntia (cactus) and Brassica species for the long-term remediation of selenium-contaminated soil under field conditions

    USDA-ARS?s Scientific Manuscript database

    Identifying alternative crops for planting in Se-containing agricultural soils of western central California will depend upon the plants’ ability to tolerate high salt and boron (B) conditions. Multi-year field studies were conducted on Se-laden soils with different cactus clones (Opuntia-ficus indi...

  8. Current management efforts against Cactoblastis cactorum as a pest of North American prickly pear cactus, Opuntia spp.

    USDA-ARS?s Scientific Manuscript database

    The unintentional arrival of Cactoblastis cactorum (Lepidoptera: Pyralidae) to Florida changed the scope of this celebrated weed biological control agent from savior to pest. Based on this insects’ substantial control of non-native Opuntia spp. (prickly pear cactus) in Australia and other parts of ...

  9. 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

    ... [Federal Register Volume 77, Number 85 (Wednesday, May 2, 2012)] [Notices] [Page 26000] [FR Doc No: 2012-10555] DEPARTMENT OF ENERGY Federal Energy Regulatory Commission [Docket No. ER12-1604-000] Cactus Energy LLC; Supplemental Notice That Initial Market-Based Rate Filing Includes Request for...

  10. Distribution of Paradine plains cactus in pinyon-juniper woodland on the North Kaibab Ranger District, Kaibab National Forest

    Treesearch

    Arthur M. Phillips; Debra J. Kennedy; Barbara G. Phillips; Diedre Weage

    2001-01-01

    Surveys for Paradine plains cactus (Pediocactus paradinei B. W. Benson) conducted for the Kaibab National Forest, North Kaibab Ranger District in 1992-94 qualitatively showed a fairly substantial population of scattered individuals in the pinyon-juniper woodland, and indicated that there might be a correlation between plant distribution and dripline of trees. This...

  11. Betalains, Phenols and Antioxidant Capacity in Cactus Pear [Opuntia ficus-indica (L.) Mill.] Fruits from Apulia (South Italy) Genotypes.

    PubMed

    Albano, Clara; Negro, Carmine; Tommasi, Noemi; Gerardi, Carmela; Mita, Giovanni; Miceli, Antonio; De Bellis, Luigi; Blando, Federica

    2015-04-01

    Betacyanin (betanin), total phenolics, vitamin C and antioxidant capacity (by Trolox-equivalent antioxidant capacity (TEAC) and oxygen radical absorbance capacity (ORAC) assays) were investigated in two differently colored cactus pear (Opuntia ficus-indica (L.) Mill.) genotypes, one with purple fruit and the other with orange fruit, from the Salento area, in Apulia (South Italy). In order to quantitate betanin in cactus pear fruit extracts (which is difficult by HPLC because of the presence of two isomers, betanin and isobetanin, and the lack of commercial standard with high purity), betanin was purified from Amaranthus retroflexus inflorescence, characterized by the presence of a single isomer. The purple cactus pear variety showed very high betanin content, with higher levels of phenolics, vitamin C, and antioxidant capacity (TEAC) than the orange variety. These findings confirm the potential for exploiting the autochthonous biodiversity of cactus pear fruits. In particular, the purple variety could be an interesting source of colored bioactive compounds which not only have coloring potential, but are also an excellent source of dietary antioxidant components which may have beneficial effects on consumers' health.

  12. Microbial populations and activities in the rhizoplane of rock-weathering desert plants. II. growth promotion of cactus seedlings.

    Treesearch

    M.E. Puente; C.Y. Li; Y. Bashan

    2004-01-01

    Four bacterial species isolated from the rhizoplane of cacti growing in bare lava rocks were assessed for growth promotion of giant cardon cactus seedlings (Pachycereus pringlei). These bacteria fixed N2, dissolved P, weathered extrusive igneous rock, marble, and limestone, and significantly mobilized useful minerals, such as...

  13. Evaluation of the hormonal state of columnar apple trees (Malus x domestica) based on high throughput gene expression studies.

    PubMed

    Krost, Clemens; Petersen, Romina; Lokan, Stefanie; Brauksiepe, Bastienne; Braun, Peter; Schmidt, Erwin R

    2013-02-01

    The columnar phenotype of apple trees (Malus x domestica) is characterized by a compact growth habit with fruit spurs instead of lateral branches. These properties provide significant economic advantages by enabling high density plantings. The columnar growth results from the presence of a dominant allele of the gene Columnar (Co) located on chromosome 10 which can appear in a heterozygous (Co/co) or homozygous (Co/Co) state. Although two deep sequencing approaches could shed some light on the transcriptome of columnar shoot apical meristems (SAMs), the molecular mechanisms of columnar growth are not yet elaborated. Since the influence of phytohormones is believed to have a pivotal role in the establishment of the phenotype, we performed RNA-Seq experiments to study genes associated with hormone homeostasis and clearly affected by the presence of Co. Our results provide a molecular explanation for earlier findings on the hormonal state of columnar apple trees. Additionally, they allow hypotheses on how the columnar phenotype might develop. Furthermore, we show a statistically approved enrichment of differentially regulated genes on chromosome 10 in the course of validating RNA-Seq results using additional gene expression studies.

  14. Use of a monoclonal antibody to sucrase-isomaltase for evaluation of the columnar cuff after stapled restorative proctocolectomy.

    PubMed

    Thompson-Fawcett, Mark W; McC Mortensen, Neil J; Jewel, Derek P; Warren, Bryan F

    2007-09-01

    Restorative proctocolectomy with a double-stapled pouch-anal anastomosis retains a cuff of diseased columnar mucosa (columnar cuff) in the upper anal canal that may require biopsy. Biopsying this can be difficult and colonic phenotypic change in the pouch can lead to errors interpreting the histology. This study was designed to investigate the use of a monoclonal antibody to sucrase-isomaltase for differentiating ileal pouch from columnar cuff mucosa. Then, by using this antibody, the ability to accurately take and report biopsies from the anal canal was examined. The technique of staining for sucrase-isomaltase was developed. From 113 patients who had a double-stapled pouch-anal anastomosis, 467 formalin-fixed biopsies and 177 fresh-frozen biopsies were taken from the ileal pouch, columnar cuff, or anal transitional zone. Biopsies were stained with a monoclonal antibody to sucrase-isomaltase, and fixed biopsies were routinely reported after staining with hematoxylin and eosin. A monoclonal antibody to sucrase-isomaltase reliably discriminated between ileal from rectal mucosa. A biopsy of columnar cuff mucosa as reported by routine histology was obtained during 72 percent of attempted outpatient examinations. Sucrase-isomaltase staining of reported columnar cuff biopsies showed that biopsies were of pouch rather than columnar cuff in 4.4 percent (95 percent confidence interval, 2-8) of outpatient examinations. The monoclonal antibody to sucrase-isomaltase used in this study may have a clinical role when interpreting columnar cuff biopsies from patients being investigated for pouch dysfunction, or in patients having surveillance biopsies to exclude neoplasia in the columnar cuff.

  15. Field-driven transition in Ba1-x K x Fe2As2 with splayed columnar defects

    NASA Astrophysics Data System (ADS)

    Ito, N.; Park, A.; Pyon, S.; Kambara, T.; Tamegai, T.

    2017-07-01

    Columnar defects in type-II superconductors serve as artificial pinning centers, which lead to enhancement of critical current density. However, little is known about the details of vortex motion in iron-based superconductors with columnar defects. In this study, we performed magnetization measurements in Ba0.6K0.4Fe2As2 single crystals with splayed columnar defects for several directions of magnetic field in order to investigate an anomalous peak effect in the system. We report results of detailed magnetization measurements, and discuss possible origins of the field-driven transition.

  16. Genesis of the columnar joints from welded tuff in Mount Mudeung National Geopark, Republic of Korea

    NASA Astrophysics Data System (ADS)

    Lim, Chungwan; Huh, Min; Yi, Keewook; Lee, Changyeol

    2015-09-01

    Mount Mudeung National Geopark (MMNG), Gwangju, Republic of Korea (1187 masl), is known for its huge, broad occurrences of columnar jointed colonnades in the Cretaceous Mudeungsan Tuff. To understand the genesis of columnar joints infilling a volcanic vent, integrated geochemical and geophysical studies were conducted. Most colonnades in the Geopark are located in regions higher than 700 masl and show elevation-dependent variations in the mean face width of the columns. These mean widths are approximately 1.7, 1.3, 2.9, and 1.2 m for the summit (>1100 masl), upper (950-1100 masl), lower (850-950 masl), and lowest (700-850 masl) colonnades, respectively. This variation implies that columnar jointing resulted from discontinuous tuff depositions on relatively planar ground, which is associated with caldera structures and landslides from the emptied caldera rim. Geochemical analyses of major, minor, and trace elements show that the andesitic-dacitic Mudeungsan Tuff resulted from the arc magmatism associated with subduction of the Izanagi Plate and involved crustal components. Few geochemical variations of the Mudeungsan Tuff indicate that tuff originated from a single magma chamber. U-Pb age dating indicates that the Mudeungsan Tuff was deposited at ~85 Ma except for the Chotdae-bong colonnades, which were dated to ~87 Ma. However, a scaling analysis of the elevation-dependent variations of face widths and simplified numerical model calculations indicate that the variation in face widths with elevation indicates the sequential emplacement, cooling, and compaction of separate welded tuffs. Thus, the welded tuffs of MMNG can be thought to be formed by three discontinuous large explosive eruptions with periods of repose after each eruption. These tuffs include 1) the highest-elevation columnar joints of colonnades in the summit area (>1100 m), corresponding to the lower colonnades of the third tuff; 2) the intermediate-elevation columnar joints of colonnades

  17. The cactus effect: an alternative to the lupin effect for increasing ovulation rate in sheep reared in semi-arid regions?

    PubMed

    Rekik, M; Gonzalez-Bulnes, A; Lassoued, N; Ben Salem, H; Tounsi, A; Ben Salem, I

    2012-04-01

    The present study evaluated the effects of supplementation with cactus cladodes on follicular dynamics and ovulatory response of sheep reared in semi-arid areas. A total of 76 ewes were distributed into two equal groups supplemented with either concentrated feed or cactus cladodes. After 30 days of supplementation, no differences were found between feeding regimens on the final live weight (LW; 41.5 ± 0.6 and 42.1 ± 0.7 kg in the Concentrate and Cactus groups respectively) and body condition score (BCS; 1.8 ± 0.3 and 1.8 ± 0.4 for Concentrate and Cactus group respectively). Moreover, no differences were found between the initial and the final values of both LW and BCS; thus, there were no effects of supplementation on any of both parameters. Analysis of follicular population showed that, during the follicular phase induced by ram effect, the number of follicles reaching ovulatory size increased in both groups. However, the number was always higher in Cactus ewes and, at oestrus, Cactus ewes had 1.6 ± 0.2 and Concentrate sheep had 1.2 ± 0.2 large follicles (p < 0.05). Thereafter, ovulation rate was affected by duration of supplementation; being higher in sheep fed with cactus for 6-10 days (1.7 ± 0.1) than in ewes supplied with cactus for more than 11 days (1.3 ± 0.1; p < 0.05), in sheep fed with concentrate for 6-10 days (1.2 ± 0.1; p < 0.01) and even than in individuals subjected to classical flushing with concentrate (1.3 ± 0.1; p < 0.05). © 2011 Blackwell Verlag GmbH.

  18. Microencapsulation of betalains obtained from cactus fruit (Opuntia ficus-indica) by spray drying using cactus cladode mucilage and maltodextrin as encapsulating agents.

    PubMed

    Otálora, María Carolina; Carriazo, José Gregorio; Iturriaga, Laura; Nazareno, Mónica Azucena; Osorio, Coralia

    2015-11-15

    The microencapsulation of betalains from cactus fruit by spray drying was evaluated as a stabilization strategy for these pigments. The betalains used as active agent were extracted from purple fruits of Opuntia ficus-indica (BE) and encapsulated with maltodextrin and cladode mucilage MD-CM and only with MD. The microcapsulates were characterized by scanning electron microscopy (SEM), thermal analysis (TGA-DSC), tristimulus colorimetry, as well as, their humidity, water activity and dietary fiber content were also determined. The active agent content was measured by UV-Vis spectrophotometry and its composition confirmed by HPLC-ESIMS. A pigment storage stability test was performed at 18 °C and different relative humidities. The addition of CM in the formulation increased the encapsulation efficiency, diminished the moisture content, and allowed to obtain more uniform size and spherical particles, with high dietary fiber content. These microencapsulates are promising functional additive to be used as natural colorant in the food industry. Copyright © 2015 Elsevier Ltd. All rights reserved.

  19. Modelling the viscoplastic behavior and the heterogeneous intracrystalline deformation of columnar ice polycrystals

    SciTech Connect

    Lebensohn, Ricardo A; Montagnat, Maurine; Mansuy, Philippe; Duval, Paul; Philip, A

    2008-01-01

    A full-field formulation based on Fast Fourier Transforms (FFT) has been adapted and used to predict the micromechanical fields that develop in columnar Ih ice polycrystals deforming in compression by dislocation creep. The predicted intragranular mechanical fields are in qualitative good agreement with experimental observations, in particular those involving the formation of shear and kink bands. These localization bands are associated with the large internal stresses that develop during creep in such anisotropic material, and their location, intensity, morphology and extension are found to depend strongly on the crystallographic orientation of the grains and on their interaction with neighbor crystals. The predictions of the model are also discussed in relation with the deformation of columnar sea and lake ice, and with the mechanical behavior of granular ice of glaciers and polar ice sheets, as well.

  20. Thermally activated Hall creep of flux lines from a columnar defect

    NASA Astrophysics Data System (ADS)

    Gorokhov, D. A.; Blatter, G.

    1998-02-01

    We analyze the thermally activated depinning of an elastic string (line tension ɛ) governed by Hall dynamics from a columnar defect modeled as a cylindrical potential well of depth V0 for the case of a small external force F. An effective one-dimensional-field Hamiltonian is derived in order to describe the two-dimensional string motion. At high temperatures the decay rate is proportional to F5/2T-1/2exp[F0/F-U(F)/T], with F0 a constant of order of the critical force and U(F)~(ɛV0)1/2V0/F the activation energy. The results are applied to vortices pinned by columnar defects in superclean superconductors.

  1. Discotic columnar liquid crystal studied in the bulk and nanoconfined states by molecular dynamics simulation

    NASA Astrophysics Data System (ADS)

    Busselez, Rémi; Cerclier, Carole V.; Ndao, Makha; Ghoufi, Aziz; Lefort, Ronan; Morineau, Denis

    2014-10-01

    A prototypical Gay Berne discotic liquid crystal was studied by means of molecular dynamics simulations both in the bulk state and under confinement in a nanoporous channel. The phase behavior of the confined system strongly differs from its bulk counterpart: the bulk isotropic-to-columnar transition is replaced by a continuous ordering from a paranematic to a columnar phase. Moreover, a new transition is observed at a lower temperature in the confined state, which corresponds to a reorganization of the intercolumnar order. It reflects the competing effects of pore surface interaction and genuine hexagonal packing of the columns. The translational molecular dynamics in the different phases has been thoroughly studied and discussed in terms of collective relaxation modes, non-Gaussian behavior, and hopping processes.

  2. The tumor suppressor PTEN and the PDK1 kinase regulate formation of the columnar neural epithelium.

    PubMed

    Grego-Bessa, Joaquim; Bloomekatz, Joshua; Castel, Pau; Omelchenko, Tatiana; Baselga, José; Anderson, Kathryn V

    2016-01-26

    Epithelial morphogenesis and stability are essential for normal development and organ homeostasis. The mouse neural plate is a cuboidal epithelium that remodels into a columnar pseudostratified epithelium over the course of 24 hr. Here we show that the transition to a columnar epithelium fails in mutant embryos that lack the tumor suppressor PTEN, although proliferation, patterning and apical-basal polarity markers are normal in the mutants. The Pten phenotype is mimicked by constitutive activation of PI3 kinase and is rescued by the removal of PDK1 (PDPK1), but does not depend on the downstream kinases AKT and mTORC1. High resolution imaging shows that PTEN is required for stabilization of planar cell packing in the neural plate and for the formation of stable apical-basal microtubule arrays. The data suggest that appropriate levels of membrane-associated PDPK1 are required for stabilization of apical junctions, which promotes cell elongation, during epithelial morphogenesis.

  3. Evidence for columnar order in the fully frustrated transverse field Ising model on the square lattice.

    PubMed

    Wenzel, Sandro; Coletta, Tommaso; Korshunov, Sergey E; Mila, Frédéric

    2012-11-02

    Using extensive classical and quantum Monte Carlo simulations, we investigate the ground-state phase diagram of the fully frustrated transverse field Ising model on the square lattice. We show that pure columnar order develops in the low-field phase above a surprisingly large length scale, below which an effective U(1) symmetry is present. The same conclusion applies to the quantum dimer model with purely kinetic energy, to which the model reduces in the zero-field limit, as well as to the stacked classical version of the model. By contrast, the 2D classical version of the model is shown to develop plaquette order. Semiclassical arguments show that the transition from plaquette to columnar order is a consequence of quantum fluctuations.

  4. Topological Control of Columnar Stacking Made of Liquid‐Crystalline Thiophene‐Fused Metallonaphthalocyanines

    PubMed Central

    Suzuki, Hiroyuki; Kawano, Koki; Ohta, Kazuchika; Shimizu, Yo; Kobayashi, Nagao

    2015-01-01

    Abstract The spontaneous organization of two‐dimensional polyaromatic molecules into well‐defined nanostructures through noncovalent interactions is important in the development of organic‐based electronic and optoelectronic devices. Two regioisomers of thiophene‐fused zinc naphthalocyanines ZnTNcendo and ZnTNcexo have been designed and synthesized to obtain photo‐ and electroactive liquid crystalline materials. Both compounds exhibited liquid crystalline behavior over a wide temperature range through intermolecular π–π interactions and local phase segregation between the aromatic cores and peripheral side chains. The structural differences between ZnTNcendo and ZnTNcexo affected the stacking mode in self‐assembled columns, as well as symmetry of the two‐dimensional rectangular columnar lattice. The columnar structure in liquid crystalline phase exhibited an ambipolar charge‐transport behavior. PMID:27308226

  5. In vitro comparisons of the inhibitory activity of florfenicol copper sulfate and potassium permanganate towards Aeromonas hydrophila and Flavobacterium columnare

    USDA-ARS?s Scientific Manuscript database

    Aeromonas hydrophila and Flavobacterium columnare, the etiological agents of motile aeromonas septicemia (MAS) and columnaris disease, respectively, have been recently causing crippling moralities to the sunshine bass, Morone chrysops female X Morone saxatilis male (Percichthyidae), industry in the ...

  6. Quality control ranges for testing broth microdilution susceptibility of Flavobacterium columnare and F. psychrophilium to nine antimicrobials

    USDA-ARS?s Scientific Manuscript database

    A multi-laboratory broth microdilution method trial was performed to standardize the specialized test conditions required for fish pathogens Flavobacterium columnare and F. pyschrophilum. Nine laboratories tested the quality control (QC) strains Escherichia coli ATCC 25922 and Aeromonas salmonicid...

  7. Isolation and identification of flavobacterium columnare and Steptococcus iniae antibacterial compounds from the terrestrial plant Atraphaxis laetevirens

    USDA-ARS?s Scientific Manuscript database

    Columnaris disease, enteric septicemia of catfish, and streptococcosis are common bacterial diseases of certain freshwater fish and are caused by Flavobacterium columnare, Edwardsiella ictaluri, and Streptococcus iniae, respectively. Various plants were selected to evaluate, isolate, and identify co...

  8. Columnar architecture sculpted by GABA circuits in developing cat visual cortex.

    PubMed

    Hensch, Takao K; Stryker, Michael P

    2004-03-12

    The mammalian visual cortex is organized into columns. Here, we examine cortical influences upon developing visual afferents in the cat by altering intrinsic gamma-aminobutyric acid (GABA)-mediated inhibition with benzodiazepines. Local enhancement by agonist (diazepam) infusion did not perturb visual responsiveness, but did widen column spacing. An inverse agonist (DMCM) produced the opposite effect. Thus, intracortical inhibitory circuits shape the geometry of incoming thalamic arbors, suggesting that cortical columnar architecture depends on neuronal activity.

  9. Thermoplastic High Strain Multishape Memory Polymer: Side-Chain Polynorbornene with Columnar Liquid Crystalline Phase.

    PubMed

    Zhao, Ruiying; Zhao, Tipeng; Jiang, Xuqiang; Liu, Xin; Shi, Dong; Liu, Chenyang; Yang, Shuang; Chen, Er-Qiang

    2017-03-01

    A thermoplastic high strain multishape memory polymer can be fabricated using a hemiphasmid side-chain polynorbornene (P1) with hexagonal columnar liquid crystalline (ΦH ) phase. Without any chemical crosslinks, P1 can memorize multiple temporary shapes with high strain and exhibit excellent shape fixity and shape recovery. As the building blocks of ΦH , the multichain columns in P1 act as robust physical crosslinks. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Organization of columnar inputs in the third optic ganglion of a highly visual crab.

    PubMed

    Bengochea, Mercedes; Berón de Astrada, Martín

    2014-01-01

    Motion information provides essential cues for a wide variety of animal behaviors such as mate, prey, or predator detection. In decapod crustaceans and pterygote insects, visual codification of object motion is associated with visual processing in the third optic neuropile, the lobula. In this neuropile, tangential neurons collect motion information from small field columnar neurons and relay it to the midbrain where behavioral responses would be finally shaped. In highly ordered structures, detailed knowledge of the neuroanatomy can give insight into their function. In spite of the relevance of the lobula in processing motion information, studies on the neuroarchitecture of this neuropile are scant. Here, by applying dextran-conjugated dyes in the second optic neuropile (the medulla) of the crab Neohelice, we mass stained the columnar neurons that convey visual information into the lobula. We found that the arborizations of these afferent columnar neurons lie at four main lobula depths. A detailed examination of serial optical sections of the lobula revealed that these input strata are composed of different number of substrata and that the strata are thicker in the centre of the neuropile. Finally, by staining the different lobula layers composed of tangential processes we combined the present characterization of lobula input strata with the previous characterization of the neuroarchitecture of the crab's lobula based on reduced-silver preparations. We found that the third lobula input stratum overlaps with the dendrites of lobula giant tangential neurons. This suggests that columnar neurons projecting from the medulla can directly provide visual input to the crab's lobula giant neurons.

  11. Surface roughening, columnar growth and intrinsic stress formation in amorphous CuTi films

    SciTech Connect

    Huelsen, U.V.; Geyer, U.; Thiyagarajan, P.

    1997-11-01

    The growth of amorphous CuTi films, prepared by electron beam evaporation, is investigated by Scanning Tunneling Microscopy (STM), Small Angle Neutron Scattering (SANS) and in situ measurements of intrinsic mechanical stresses (ISM). In early growth stages the films develop compressive stresses and, with increasing film thickness, a crossover to tensile stresses. In the same thickness range the STM investigations show a change in the growth mode. The experiments suggest a transition from planar growth with statistical surface roughening to columnar growth.

  12. Rock Cracking Indices for Improved Tunnel Support Design: A Case Study for Columnar Jointed Rock Masses

    NASA Astrophysics Data System (ADS)

    Feng, Xia-Ting; Hao, Xian-Jie; Jiang, Quan; Li, Shao-jun; Hudson, John A.

    2016-06-01

    Measurements indicate that the development of cracking is a key feature relating to the strength and collapse of a columnar jointed rock mass. In this context, a new support design method utilising rock cracking indices for columnar jointed rock mass under high stress is proposed to restrain the development of cracking in the surrounding rock mass. The method involves limiting the cracking evolution of the surrounding rock mass by designing the appropriate parameters and time of installation of the support system. Two indices are suggested: the allowable depth of the excavation damaged zone (EDZ); and the allowable damage extent of the rock mass in the EDZ. The method involves limiting the evolution of cracking in the surrounding rock mass by designing the parameters and time of installation of the support system. The support system should have a suitable stiffness and installation time so as to restrain the evolution of the depth and damage extent of the EDZ within the surrounding rock. Therefore, the depth and damage extent of the EDZ, as well as the axial stress in the anchor bolts, are calculated at different distances between the support location and the tunnel working face to find the appropriate stiffness and installation time of the support system. The method has been successfully adopted to determine the thickness of shotcrete, the arrangement and installation time of rockbolts, and other parameters, for five large diversion tunnels at the Baihetan hydropower station, China, which were excavated in columnar jointed rock masses.

  13. Use of nanoporous columnar thin film in the wafer-level packaging of MEMS devices

    NASA Astrophysics Data System (ADS)

    Lee, Byung-Kee; Choi, Dong-Hoon; Yoon, Jun-Bo

    2010-04-01

    This paper presents a new packaging technology that uses a nanoporous columnar thin film to seal microelectromechanical system (MEMS) devices at the wafer level. In the proposed packaging process, the processing temperature is 350 °C. The process is relatively inexpensive compared to wafer level packaging processes, because the wafer-bonding step is eliminated and the die size is shrunk. In the suggested approach, a sputtered columnar thin film at room temperature forms vertical nanopores as etch holes, and an air cavity is formed by the removal of a sacrificial layer through the nanopores in the columnar membrane. Subsequent hermetic vacuum packaging of the cavity is achieved by depositing thin films over the membrane under low pressure. The hermeticity of the packaging was verified by using an optical surface morphology microscope to measure the deflection change of the sealing membrane before and after breaking of the vacuum through an interconnected membrane. The long-term hermeticity was monitored by measuring the maximum central deflection of the PECVD sealing layer over a period of 170 days. The precise pressure (0.7 Torr) and short-term (30 days) pressure change inside the cavity were measured by encapsulated Ni Pirani gauges, representing packaged freestanding MEMS devices.

  14. MH-DAB gene polymorphism and disease resistance to Flavobacterium columnare in grass carp (Ctenopharyngodon idellus).

    PubMed

    Yu, Hui; Tan, Shuwen; Zhao, Hongjuan; Li, Hua

    2013-09-10

    In this study, the association between MH-DAB gene polymorphism and disease resistance was evaluated by challenging grass carp (Ctenopharyngodon idellus) with Flavobacterium columnare. Eight genotypes and six alleles were found, and named by common nomenclature. The genotypes AA, BB, EE, and DE, and the alleles Ctid-DAB1*0101, Ctid-DAB1*0201 and Ctid-DAB1*0401 were more preponderant in fish. The genotype BB was associated with higher resistance to F. columnare, as well as two alleles Ctid-DAB*0101 and Ctid-DAB*0201. Allele Ctid-DAB*0102 has decreased resistance to F. columnare. The expression of MH-DAB gene was decreased in the liver, kidney, and intestine but not in the spleen, gill, and skin at 2 days post infection (dpi), versus to that in the control group. MH-DAB gene expression was up-regulated in most tissues but remained at normal levels in the intestine at 15 days post infection. Our data suggested that MH-DAB polymorphism can be used as a potential genetic marker for disease resistance breeding of grass carp in the future.

  15. Immunohistochemical/histochemical double staining method in the study of the columnar metaplasia of the oesophagus.

    PubMed

    Cabibi, D; Giannone, A G; Mascarella, C; Guarnotta, C; Castiglia, M; Pantuso, G; Fiorentino, E

    2014-03-05

    Intestinal metaplasia in Barrett's oesophagus (BO) represents an important risk factor for oesophageal adenocarcinoma. Instead, few and controversial data are reported about the progression risk of columnar-lined oesophagus without intestinal metaplasia (CLO), posing an issue about its clinical management. The aim was to evaluate if some immunophenotypic changes were present in CLO independently of the presence of the goblet cells. We studied a series of oesophageal biopsies from patients with endoscopic finding of columnar metaplasia, by performing some immunohistochemical stainings (CK7, p53, AuroraA) combined with histochemistry (Alcian-blue and Alcian/PAS), with the aim of simultaneously assess the histochemical features in cells that shows an aberrant expression of such antigens. We evidenced a cytoplasmic expression of CK7 and a nuclear expression of Aurora A and p53,  both in goblet cells of BO and in non-goblet cells of CLO, some of which showing mild dysplasia. These findings suggest that some immunophenotypic changes are present in CLO and they can precede the appearance of the goblet cells or can be present independently of them, confirming the conception of BO as the condition characterized by any extention of columnar epithelium. This is the first study in which a combined immunohistochemical/histochemical method has been applied to Barrett pathology.

  16. Preparation and characterization of vertically columnar boron doped diamond array electrode

    NASA Astrophysics Data System (ADS)

    Zhao, Yang; Yu, Hongtao; Quan, Xie; Chen, Shuo; Zhao, Huimin; Zhang, Yaobin

    2014-06-01

    A vertically columnar boron doped diamond (BDD) array electrode was fabricated by microwave plasma chemical vapor deposition. Observed by scanning electron microscopy, the fabricated samples were structured with aligned columns whose diameter and height was 8 μm and 12 μm, respectively, and the minimum interval of neighboring columns was 2 μm. The results of electrochemistry measurement showed that the columnar BDD array electrode possessed high oxygen evolution potential and low background current. Besides that, comparing with flat BDD electrode, the columnar BDD array electrode showed higher electrochemical activity (due to its inner active surface being up to 4.25 cm2), lower impedance of electric double layer, and especially enhanced electrical response signal (2.12 μA/μM, 4 times of flat BDD in glucose detection as a sample). These excellent performances may open the door for the BDD materials to be applied in wide areas including electrochemical detection, electrochemistry degradation, electrochemical synthesis, and so on.

  17. Antimicrobial susceptibility pattern of Flavobacterium columnare isolates collected worldwide from 17 fish species.

    PubMed

    Declercq, A M; Boyen, F; Van den Broeck, W; Bossier, P; Karsi, A; Haesebrouck, F; Decostere, A

    2013-01-01

    Flavobacterium columnare is the causative agent of columnaris disease in diverse fish species worldwide. Although columnaris is an important disease, the antimicrobial susceptibility pattern of F. columnare is not well studied. Thus, the purpose of this study was to test the in vitro antimicrobial susceptibility of 97 F. columnare isolates collected worldwide between 1987 and 2011 from 17 fish species. The broth microdilution technique was utilized for reliable testing of these fastidious organisms. None of the isolates displayed acquired resistance to florfenicol, gentamicin, ormetoprim-sulfadimethoxine and trimethoprim-sulfamethoxazole. Acquired resistance to chloramphenicol was detected in 1%, to nitrofuran in 5%, to oxytetracycline in 11% and to enrofloxacin, flumequine and oxolinic acid in 10%, 16% and 16% of the isolates, respectively, as reflected by a bimodal or trimodal distribution of their minimum inhibitory concentrations (MICs). One isolate showed acquired resistance towards several antimicrobial agents including erythromycin. Another isolate revealed acquired resistance towards - amongst others - ampicillin. The isolates displaying acquired resistance originated from ornamental fish species or Vietnamese catfish, except for two isolates coming from wild channel catfish in which acquired resistance was encountered towards oxytetracycline only. Fifty per cent of the resistant isolates from ornamental fish were shown to have acquired resistance against three classes of antimicrobial agents, assigning these isolates as multiple resistant. These data might indicate less prudent use of antimicrobials especially in ornamental fish species. © 2012 Blackwell Publishing Ltd.

  18. Estimation of columnar concentrations of absorbing and scattering fine mode aerosol components using AERONET data

    NASA Astrophysics Data System (ADS)

    Choi, Yongjoo; Ghim, Young Sung

    2016-11-01

    Columnar concentrations of absorbing and scattering components of fine mode aerosols were estimated using Aerosol Robotic Network (AERONET) data for a site downwind of Seoul. The study period was between March 2012 and April 2013 including the period of the Distributed Regional Aerosol Gridded Observation Networks (DRAGON)-Asia campaign in March to May 2012. The Maxwell Garnett mixing rule was assumed for insoluble components embedded in a host solution, while the volume average mixing rule was assumed for the aqueous solution of soluble components. During the DRAGON-Asia campaign the surface concentrations of major components of fine particles were measured. The columnar mass fractions of black carbon (BC), organic carbon (OC), mineral dust (MD), and ammonium sulfate (AS) were 1.5, 5.9, 6.6, and 52%, respectively, which were comparable to the mass fractions measured at the surface for BC, OC, and secondary inorganic aerosols at 2.3, 18, and 55%. The vertical distributions of BC and AS were investigated by employing the concept of a column height. While the column height for BC was similar to the planetary boundary layer (PBL) height, that for AS was 4.4 times higher than the PBL height and increased with air temperature from March to May. The monthly variations of the columnar mass concentrations during the study period were generally well explained in term of meteorology and emission characteristics. However, certain variations of MD were different from those typically observed primarily because only fine mode aerosols were considered.

  19. Cactus and Visapult: A case study of ultra-high performance distributed visualization using connectionless protocols

    SciTech Connect

    Shalf, John; Bethel, E. Wes

    2002-05-07

    This past decade has seen rapid growth in the size, resolution, and complexity of Grand Challenge simulation codes. Many such problems still require interactive visualization tools to make sense of multi-terabyte data stores. Visapult is a parallel volume rendering tool that employs distributed components, latency tolerant algorithms, and high performance network I/O for effective remote visualization of massive datasets. In this paper we discuss using connectionless protocols to accelerate Visapult network I/O and interfacing Visapult to the Cactus General Relativity code to enable scalable remote monitoring and steering capabilities. With these modifications, network utilization has moved from 25 percent of line-rate using tuned multi-streamed TCP to sustaining 88 percent of line rate using the new UDP-based transport protocol.

  20. The origins of an important cactus crop, Opuntia ficus-indica (Cactaceae): new molecular evidence.

    PubMed

    Griffith, M Patrick

    2004-11-01

    Opuntia ficus-indica is a long-domesticated cactus crop that is important in agricultural economies throughout arid and semiarid parts of the world. The biogeographic and evolutionary origins of this species have been obscured through ancient and widespread cultivation and naturalization. The origin of O. ficus-indica is investigated through the use of Bayesian phylogenetic analyses of nrITS DNA sequences. These analyses support the following hypotheses: that O. ficus-indica is a close relative of a group of arborescent, fleshy-fruited prickly pears from central and southern Mexico; that the center of domestication for this species is in central Mexico; and that the taxonomic concept of O. ficus-indica may include clones derived from multiple lineages and therefore be polyphyletic.

  1. Dye-sensitized solar cells using Aloe Vera and Cladode of Cactus extracts as natural sensitizers

    NASA Astrophysics Data System (ADS)

    Ganta, D.; Jara, J.; Villanueva, R.

    2017-07-01

    The purpose of this study is to develop dye-sensitized solar cells (DSSCs) from natural plant-based dyes, extracted from the Cladode (nopal) of the Thornless Prickly Pear Cactus (Opuntia ficus-indica), the gel of Aloe Vera (Aloe barbadensis miller), and the combination of Cladode and Aloe Vera extracts on side-by-side configuration. Optical properties were analyzed using UV-Vis Absorption and Fourier Transform Infrared Spectroscopy. Open circuit voltages (Voc) varied from 0.440 to 0.676 V, fill factors (FF) were greater than 40%, short-circuit photocurrent densities (Jsc) ranged from 0.112 to 0.290 mA/cm2 and highest conversion efficiency of 0.740% was reported for the Cladode DSSC.

  2. Genetic variability of Dactylopius opuntiae (Hemiptera, Dactylopiidae) on forage cactus in northeast Brazil.

    PubMed

    Silva, D M P; do E S Mergulhão, A C; de Medeiros, L V; Figueiredo, M V B; Burity, H A

    2013-10-30

    The carmine cochineal Dactylopius opuntiae is a key pest in productive fields of forage cactus in Pernambuco, Brazil. Species identification by means of molecular markers assists in understanding the genetic profile, underpins morphological characterization, and supports the monitoring of populations in integrated management programs designed to control this pest. We evaluated the genetic variability of natural populations of D. opuntiae. Genetic variability was analyzed with ISSR and RAPD primers in 24 populations from 12 municipalities of Pernambuco State in Brazil. Morphological characterization confirmed that D. opuntiae was the only cochineal species present in all samples. Nine ISSR primers and six RAPD produced a total of 62 and 58 polymorphic fragments, respectively. Both types of markers showed an average genetic similarity of 80% regardless of the geographic origin of samples. The low genetic variability demonstrates a high degree of relatedness among these D. opuntiae populations.

  3. A cactus-derived toxin-like cystine knot Peptide with selective antimicrobial activity.

    PubMed

    Aboye, Teshome L; Strömstedt, Adam A; Gunasekera, Sunithi; Bruhn, Jan G; El-Seedi, Hesham; Rosengren, K Johan; Göransson, Ulf

    2015-05-04

    Naturally occurring cystine knot peptides show a wide range of biological activity, and as they have inherent stability they represent potential scaffolds for peptide-based drug design and biomolecular engineering. Here we report the discovery, sequencing, chemical synthesis, three-dimensional solution structure determination and bioactivity of the first cystine knot peptide from Cactaceae (cactus) family: Ep-AMP1 from Echinopsis pachanoi. The structure of Ep-AMP1 (35 amino acids) conforms to that of the inhibitor cystine knot (or knottin) family but represents a novel diverse sequence; its activity was more than 500 times higher against bacterial than against eukaryotic cells. Rapid bactericidal action and liposome leakage implicate membrane permeabilisation as the mechanism of action. Sequence homology places Ec-AMP1 in the plant C6-type of antimicrobial peptides, but the three dimensional structure is highly similar to that of a spider neurotoxin. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  4. Corrective action plan for CAU 426: Cactus Spring Waste Trenches, Tonopah Test Range

    SciTech Connect

    1997-09-01

    This Corrective Action Plan (CAP) provides the selected corrective action alternative and proposes the closure implementation methodology for the Cactus Spring Waste Trenches Corrective Action Unit (CAU) No. 426. The site is located on the Tonopah Test Range (TTR), approximately 225 kilometers (km) (140 miles) northwest of Las Vegas, Nevada. The US Department of Energy/Nevada Operations Office (DOE/NV) verbally requested approval for the schedule to be accelerated from the Nevada Division of Environmental Protection (NDEP) in July 1997. Currently, field closure activities are anticipated to be completed by September 30, 1997. CAU 426 consists of one Corrective Action Site (CAS) comprised of four waste trenches. The trenches were excavated to receive solid waste generated in support of Operation Roller Coaster, primarily the Double Tracks Test in 1963.

  5. The effects of cactus inspired spines on the aerodynamics of a cylinder

    NASA Astrophysics Data System (ADS)

    Levy, Benjamin; Liu, Yingzheng

    2013-05-01

    The effect of cactus-like spines on the topology and the dynamics of the flow past a stationary or pivoted cylinder are experimentally studied. The experiments are performed either in a water channel or a wind tunnel at low to moderate Reynolds number (390-12 500). The instantaneous velocity field is recorded using TR-PIV and investigated for three different configurations: no spines, short spines (0.1D) and long spines (0.2D). The results show how the spines are able to slow the flow past the cylinder and then increase the recirculation area by up to 128% while the maximum fluctuating kinetic energy intensity is decreased by up to 35%. Moreover, the spines have a significant effect on the vortex shedding and the dynamic pressure at the surface of the cylinder, thus significantly reducing both the amplitude and the frequency at which a pivoted cylinder oscillates.

  6. Forensic identification of CITES protected slimming cactus (Hoodia) using DNA barcoding.

    PubMed

    Gathier, Gerard; van der Niet, Timotheus; Peelen, Tamara; van Vugt, Rogier R; Eurlings, Marcel C M; Gravendeel, Barbara

    2013-11-01

    Slimming cactus (Hoodia), found only in southwestern Africa, is a well-known herbal product for losing weight. Consequently, Hoodia extracts are sought-after worldwide despite a CITES Appendix II status. The failure to eradicate illegal trade is due to problems with detecting and identifying Hoodia using morphological and chemical characters. Our aim was to evaluate the potential of molecular identification of Hoodia based on DNA barcoding. Screening of nrITS1 and psbA-trnH DNA sequences from 26 accessions of Ceropegieae resulted in successful identification, while conventional chemical profiling using DLI-MS led to inaccurate detection and identification of Hoodia. The presence of Hoodia in herbal products was also successfully established using DNA sequences. A validation procedure of our DNA barcoding protocol demonstrated its robustness to changes in PCR conditions. We conclude that DNA barcoding is an effective tool for Hoodia detection and identification which can contribute to preventing illegal trade.

  7. Chemical composition and antibacterial activity of Opuntia ficus-indica f. inermis (cactus pear) flowers.

    PubMed

    Ennouri, Monia; Ammar, Imene; Khemakhem, Bassem; Attia, Hamadi

    2014-08-01

    Opuntia ficus-indica f. inermis (cactus pear) flowers have wide application in folk medicine. However, there are few reports focusing on their biological activity and were no reports on their chemical composition. The nutrient composition and hexane extracts of Opuntia flowers at 4 flowering stages and their antibacterial and antifungal activities were investigated. The chemical composition showed considerable amounts of fiber, protein, and minerals. Potassium (K) was the predominant mineral followed by calcium (Ca), magnesium (Mg), sodium (Na), iron (Fe), and zinc (Zn). The main compounds in the various hexane extracts were 9.12-octadecadienoic acid (29-44%) and hexadecanoic acid (8.6-32%). The antibacterial activity tests showed that O. inermis hexane extracts have high effectiveness against Escherichia coli and Staphylococcus aureus, making this botanical source a potential contender as a food preservative or food control additive.

  8. Identification of differentially expressed genes in female Drosophila antonietae and Drosophila meridionalis in response to host cactus odor.

    PubMed

    Borgonove, Camila M; Cavallari, Carla B; Santos, Mateus H; Rossetti, Rafaela; Hartfelder, Klaus; Manfrin, Maura H

    2014-09-02

    Studies of insect-plant interactions have provided critical insights into the ecology and evolution of adaptive processes within and among species. Cactophilic Drosophila species have received much attention because larval development occurs in the necrotic tissues of cacti, and both larvae and adults feed on these tissues. Such Drosophila-cactus interactions include effects of the host plant on the physiology and behavior of the flies, especially so their nutritional status, mating condition and reproduction. The aim of this work was to compare the transcriptional responses of two species, Drosophila antonietae and Drosophila meridionalis, and identify genes potentially related to responses to odors released by their host cactus, Cereus hildmannianus. The two fly species are sympatric in most of their populations and use this same host cactus in nature. We obtained 47 unique sequences (USs) for D. antonietae in a suppression subtractive hybridization screen, 30 of these USs had matches with genes predicted for other Drosophila species. For D. meridionalis we obtained 81 USs, 46 of which were orthologous with genes from other Drosophila species. Functional information (Gene Ontology) revealed that these differentially expressed genes are related to metabolic processes, detoxification mechanisms, signaling, response to stimuli, and reproduction. The expression of 13 genes from D. meridionalis and 12 from D. antonietae were further analyzed by quantitative real time-PCR, showing that four genes were significantly overexpressed in D. antonietae and six in D. meridionalis. Our results revealed the differential expression of genes related to responses to odor stimuli by a cactus, in two associated fly species. Although the majority of activated genes were similar between the two species, we also observed that certain metabolic pathways were specifically activated, especially those related to signaling pathways and detoxification mechanisms. The activation of these genes

  9. Viruses in laboratory-reared cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae)

    SciTech Connect

    Marti, O.G.; Myers, R.E.; Carpenter, J.E.; Styer, E.L.

    2007-03-15

    The cactus moth, Cactoblastis cactorum (Lepidoptera: Pyralidae: Phycitinae), is a non-native species threatening a variety of native cacti, particularly endangered species of Opuntia (Zimmerman et al. 2001), on the coast of the Gulf of Mexico. Cactoblastis cactorum populations have expanded from Florida northward along the Atlantic coast as far as Charleston, SC, and westward along the Gulf of Mexico to Dauphin Island, south of Mobile, AL. It is feared that further movement to the west will allow C. cactorum to enter the US desert Southwest and Mexico, particularly the latter. Numerous cactus species, especially those of the genera Opuntia and Nopalea, are native to the U.S. and Mexico. Local economies based on agricultural and horticultural uses of cacti could be devastated by C. cactorum (Vigueras and Portillo 2001). A bi-national control program between the US and Mexico is being developed, utilizing the sterile insect technique (SIT). In the SIT program, newly emerged moths are irradiated with a {sup 60}Co source and released to mate with wild individuals. The radiation dose completely sterilizes the females and partially sterilizes the males. When irradiated males mate with wild females, the F1 progeny of these matings are sterile. In order for the SIT program to succeed, large numbers of moths must be reared from egg to adult on artificial diet in a quarantined rearing facility (Carpenter et al. 2001). Irradiated insects must then be released in large numbers at the leading edge of the invasive population and at times which coincide with the presence of wild individuals available for mating. Mortality from disease in the rearing colony disrupts the SIT program by reducing the numbers of insects available for release.

  10. Vivipary and offspring survival in the epiphytic cactus Epiphyllum phyllanthus (Cactaceae).

    PubMed

    Cota-Sánchez, J Hugo; Abreu, Deusa D

    2007-01-01

    Vivipary, the germination of seeds before they are shed from the parent plant, is a rare event in angiosperms involving complex ecophysiological processes. Pseudovivipary and cryptovivipary occur in approximately 30 (2%) species of the cactus family. A remarkable case of vivipary in Epiphyllum phyllanthus is described here. Information is provided regarding the biology of viviparous fruits, morphology, mortality, survival rates of viviparous offspring, and some eco-evolutionary implications of this reproductive strategy in the Cactaceae. This epiphytic cactus has no host-specific relationship. A low proportion (33.3%) of individuals produced viviparous fruits. Seed number/fruit varied from 197 to 230 with percentage of viviparous germination from 97.5% to 99%. The viviparous seedlings exhibited normal development and were no different from non-viviparous offspring. Transplanting experiments showed that the first week is critical for seedling establishment, and high mortality occurred in the three treatments used: 69% on the phorophyte surface, 58.6% on the ground, and 44.8% under controlled conditions. The number of survivors gradually stabilized, and the contribution to establishment was comparable in each of the treatments after the acclimation phase. It is suggested that vivipary is associated with thermoregulation, parental care, conspecific nursing, and rapid seedling establishment. Germination is not a limiting factor in the perpetuation of this viviparous species, but seedling establishment is. In viviparous individuals of E. phyllanthus, seedling mortality during establishment rather than failure to germinate within the fruit is a limiting factor affecting local population density. Overall, viviparity is an intrinsic, genetic event involving high metabolic costs favouring germination and dispersal of the fittest offspring regardless of substrate and environmental conditions.

  11. Spineless cactus as a replacement for sugarcane in the diets of finishing lambs.

    PubMed

    de Oliveira, Juliana Paula Felipe; de Andrade Ferreira, Marcelo; Alves, Adryanne Marjorie Souza Vitor; de Melo, Ana Caroline Cerqueira; de Andrade, Ida Barbosa; Suassuna, Juraci Marcos Alves; de Barros, Leonardo José Assis; de Barros Melo, Tobias Tobit; de Lima Silva, Janaina

    2017-01-01

    The effects of replacement of sugarcane by spineless cactus (0, 33, 66, and 100 % on dry matter (DM) basis) were evaluated on intake, digestibility of nutrients, ingestive behavior, and performance of finishing lambs. Thirty-six non-castrated Santa Ines lambs at 4 months of age and an initial body weight of 22 ± 2.3 kg were assigned in a randomized block design. A quadratic effect was found for intake of DM, organic matter (OM), crude protein (CP), neutral detergent fiber (NDF), and digestible organic matter (DOM), with maximum values of 1.31, 1.19, 0.219, 0.358, and 0.845 g/day estimated with 42.5, 38.5, 38.8, 21.3, and 44.9 % replacement level, respectively. The digestibility of DM, OM, CP, and EE increased linearly; however, there was a quadratic effect on NDF digestibility with maximum value estimated of 500 g/kg with 64.2 % replacement level. Rumination time, total chewing, and rumination efficiency decreased linearly with the replacement levels; however, idle time increased linearly. A quadratic effect was found for final weight, body weight gain, and total weight gain with maximum values estimated of 38.6 kg, 0.232 kg/day, and 16.2 kg with 39.1, 38.2, and 40.4 % replacing levels. The replacement of 49.5 % sugarcane by spineless cactus can be recommended as optimal level, and problems related to intake, digestibility, and performance are concentrated outside that level.

  12. Tifton hay, soybean hulls, and whole cottonseed as fiber source in spineless cactus diets for sheep.

    PubMed

    de Miranda Costa, Suellen Brandão; de Andrade Ferreira, Marcelo; Pessoa, Ricardo A Silva; Batista, Angela Maria Vieira; Ramos, Alenice Ozino; da Conceição, Maria Gabriela; dos Santos Gomes, Luiz Henrique

    2012-12-01

    The objective of this paper was to evaluate the effect of three different sources of fiber (tifton hay, soybean hulls, and whole cottonseed) in spineless cactus diets for sheep in the semiarid region of northeastern Brazil. Twenty-one sheep in finishing phase with indeterminate breed, non-castrated, and with initial weight of 18.90 ± 1.07 kg were randomly distributed to individual stalls where they were confined for the duration of the experiment. The intakes of dry and organic matter, total carbohydrates, and total digestive nutrients were not influenced (P > 0.10) by the different fiber sources (1.10, 0.97, 0.73, and 0.80 kg/day, respectively). However, sheep which received the whole cottonseed diet were characterized by a lower (P < 0.10) intake of crude protein and neutral detergent fiber and greater (P < 0.10) intake of ether extract (0.11, 0.29, and 0.048 kg/day, respectively). The different sources of fiber resulted in similar times spent feeding (P > 0.10), although the rumination time was greater for tifton hay (P < 0.10) (429.05 min/day). The digestibility coefficient of dry and organic matter differed between the treatments (P < 0.10), with the soybean hull diet showing a higher level of digestion (83.23 and 86.72 %, respectively). The whole cottonseed diet gave the smallest digestibility coefficient of crude protein (68.95 %) and greatest for ether extract (85.94 %). The daily weight gain of animals fed on whole cottonseed was significantly lower (P < 0.10). On the basis of these findings, we recommend the use of tifton hay or soybean hulls as important additional source of fiber in forage spineless cactus diets for sheep in finishing phase.

  13. Lack of association between Flavobacterium columnare genomovar and virulence in hybrid tilapia Oreochromis niloticus (L.)×Oreochromis aureus (Steindachner).

    PubMed

    Shoemaker, C A; LaFrentz, B R

    2015-05-01

    Columnaris disease can be problematic in tilapia (Oreochromis spp.) production. An understanding of the pathogenesis and virulence of Flavobacterium columnare is needed to develop prevention strategies. The objective of this study was to determine the virulence of genetically defined isolates of F. columnare in sex-reversed hybrid tilapia, Oreochromis niloticus (L.)×O. aureus (Steindachner). A series of immersion challenge trials were performed using isolates of the five established genomovars of F. columnare: I, II, II-B, III and I/II. The mean per cent mortality of fish challenged with genomovar I, II and III isolates ranged from 0 to 100, 3.3-78 and 3.3-75%, respectively. The mean per cent mortality of fish challenged with genomovar II-B ranged from 35 to 96.7%, and the only genomovar I/II isolate tested caused no mortality. Contrary to previous work in other fish species, there did not appear to be an association between F. columnare genomovar and virulence in tilapia. The challenge model used resulted in acute mortality. An alternative challenge model was tested by cohabitating healthy fish with dead fish infected with F. columnare. This method resulted in rapid appearance of clinical signs and mortality, suggesting the potential for F. columnare to increase in virulence upon growth on/in a fish host.

  14. Growth and survival of the fish pathogenic bacterium, Flavobacterium columnare, in tilapia mucus and porcine gastric mucin.

    PubMed

    Shoemaker, Craig A; LaFrentz, Benjamin R

    2015-02-01

    Flavobacterium columnare, an economically important Gram-negative bacterium of freshwater farmed fish, colonizes the skin and gills in the initial steps of pathogenesis. The surface of fish is coated with mucus made up of high molecular weight glycoproteins. Limited studies have described the ability of bacterial pathogens to grow in fish mucus. Our objective was to determine if F. columnare isolates could grow and survive in formulated water (FW) containing autoclaved tilapia mucus or porcine gastric mucin. We demonstrated the ability of F. columnare genomovars I, II, II-B and III to replicate (2-3 logs) and survive (21 to >100 days) in FW containing tilapia mucus. In a second experiment, genomovar I and II isolates were found to replicate in FW containing tilapia mucus or porcine mucin but not in FW only. From a practical standpoint, fish handling and/or hauling results in stress that leads to mucus sloughing often with subsequent F. columnare infection. Flavobacterium columnare utilizes fish mucus as a nutrient source, and studies are underway to determine if growth in mucus or mucin results in differential protein expression and/or increased virulence of F. columnare towards fish. © FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

  15. Submucosal glands in the columnar-lined oesophagus: evidence of an association with metaplasia and neosquamous epithelium.

    PubMed

    Lörinc, Ester; Öberg, Stefan

    2012-07-01

    A multipotential stem cell, possibly located in the submucosal gland ducts, has been suggested as the origin of metaplastic mucosa in the oesophagus. The topographic distribution of these glands and their excretory ducts (SMG) within the columnar lined oesophagus (CLO) is largely unknown. The aim of this study was to examine the distribution of SMG in relation to the type of overlying epithelium in patients with CLO. Seven oesophageal resection specimens were examined histologically in toto. The median frequency of SMG was similar in the metaplastic segments (0.12 SMG/mm) and the normal squamous segments (0.10 SMG/mm). Within the metaplastic segments, the median frequency of SMG beneath the squamous islands was significantly higher than that observed under the columnar lined parts (0.22 versus 0.08 SMG/mm, P = 0.046), There was a strong accumulation of SMG at the squamo-columnar transition zones (0.53 SMG/mm), which was significantly greater than that found in the columnar and squamous parts (P = 0.001 and 0.002, respectively). The relative accumulation of SMG beneath squamous islands and the squamo-columnar junctions within the metaplastic segment supports the hypothesis that both metaplastic columnar mucosa and neosquamous epithelium originate from a progenitor in the SMG. © 2012 Blackwell Publishing Ltd.

  16. Fast magnetic response in gigahertz-band for columnar-structured Fe nanoparticle assembly

    SciTech Connect

    Ogawa, T. Tate, R.; Kura, H.; Oikawa, T.; Hata, K.

    2014-05-07

    High density Fe-based ferromagnetic nanoparticle (NP) assembly is expected to have unique magnetic properties, such as superferromagnetism and super-spin-glass, different from magnetically isolated NP systems due to strong dipole interactions among the NPs. A high dipole interaction field, H{sub dip}, of ∼3.5 kOe can result in a high effective internal field to the magnetic moment of the NP, expecting for ultra-fast magnetic response, that is, a high magnetic resonance frequency, f{sub r}, of ∼10 GHz. However, for a simply molded Fe NP assembly, a low f{sub r} was observed due to inhomogeneous distribution of the internal field, implying the necessity of a unidirectional state of H{sub dip} for higher f{sub r}. In this study, we fabricated a columnar Fe NP assembly for realizing the unidirectional state of H{sub dip} by applying our uniquely developed external field-induced agglomeration method for monodispersed Fe NPs (13 nm in average size) as a function of the field (0–30 kOe) and volume fraction of the Fe NPs (0.5%–51%) in a polymer matrix with dimensions of 4 mm × 4 mm × 0.7 mm{sup t}. A columnar-structured Fe NP assembly was successfully achieved along an in-plane direction (defined as the x-axis) under optimized conditions. From static magnetization curves, induced uniaxial magnetic anisotropy was observed according to the shape of the columnar structure of the Fe NP assembly, where easy and hard axes of magnetization were realized along the parallel (x-axis) and normal directions (in-plane y-axis and z-axis in the thickness direction) to the external field during the process, respectively. Interestingly, this fabricated columnar-structured Fe NP assembly exhibited very high f{sub r} in the range from 3 to 11 GHz judging from the complex susceptibility spectra obtained. The f{sub r} values were well-scaled by a modified Snoek's-limit-law using demagnetization factors quantitatively estimated from the static magnetization curves. Thus, shape

  17. Putative roles for a rhamnose binding lectin in Flavobacterium columnare pathogenesis in channel catfish Ictalurus punctatus.

    PubMed

    Beck, Benjamin H; Farmer, Bradley D; Straus, David L; Li, Chao; Peatman, Eric

    2012-10-01

    Columnaris disease, caused by the bacterial pathogen Flavobacterium columnare, continues to be a major problem worldwide and commonly leads to tremendous losses of both wild and cultured freshwater fish, particularly in intensively farmed aquaculture species such as channel catfish. Despite its ecologic and economic impacts, the fundamental molecular mechanisms of the host immune response to this pathogen remain unclear. While F. columnare can induce marked pathologic changes in numerous ectopic tissues, the adhesion of F. columnare to the gill in particular is strongly associated with pathogen virulence and host susceptibility. Recently, in this regard, using RNA-seq expression profiling we found that a rhamnose-binding lectin (RBL) was dramatically upregulated in the gill of fish infected with F. columnare (as compared to naïve fish). Thus, in the present study we sought to further characterize and understand the RBL response in channel catfish (Ictalurus punctatus). We first identified two distinct catfish families with differential susceptibilities to columnaris disease; one family was found to be completely resistant while the other was susceptible (0% mortality versus 18.3% respectively, P < 0.001). Exclusively, in the susceptible family, we observed an acute and robust upregulation in catfish RBL that persisted for at least 24 h (P < 0.05). To elucidate whether RBL play a more direct role in columnaris pathogenesis, we exposed channel catfish to different doses of the putative RBL ligands l-rhamnose and d-galactose, and found that these sugars, protected channel catfish against columnaris disease, likely through competition with F. columnare binding of host RBL. Finally, we examined the role of nutritional status on RBL regulation and found that RBL expression was upregulated (>120-fold; P < 0.05) in fish fasted for 7 d (as compared to fish fed to satiation daily), yet expression levels returned to those of satiated fish within 4 h after re

  18. Characterization and comparison of serratia marcescens isolated from edible cactus and from silkworm for virulence potential and chitosan susceptibility.

    PubMed

    Li, Bin; Yu, Rongrong; Liu, Baoping; Tang, Qiaomei; Zhang, Guoqing; Wang, Yanli; Xie, Guanlin; Sun, Guochang

    2011-01-01

    Representative strains of Serratia marcescens from an edible cactus plant and silkworms were characterized and a comparison based on their cellular fatty acid composition, 16S rRNA and groE gene sequence analysis as well as silkworm virulence and chitosan susceptibility was carried out. Results from this study indicate that there are no significant differences between the phenotypic and molecular characterization, virulence and chitosan susceptibility of the S. marcescens strains from the cactus plant and silkworms. Silkworms inoculated with S. marcescens from either plant or silkworm resulted in nearly 100% mortality. Chitosan solution exhibited strong antibacterial activity against S. marcescens. This activity increased with the increase of chitosan concentration and incubation time regardless of the strain source. Also, the results indicate that the plant associated S. marcescens maybe plays a possible role in the contamination of humans and animals, in particular silkworms, while chitosan showed a potential to control the contamination caused by S. marcescens.

  19. Characterization and Comparison of Serratia Marcescens Isolated from Edible Cactus and from Silkworm for Virulence Potential and Chitosan Susceptibility

    PubMed Central

    Li, Bin; Yu, Rongrong; Liu, Baoping; Tang, Qiaomei; Zhang, Guoqing; Wang, Yanli; Xie, Guanlin; Sun, Guochang

    2011-01-01

    Representative strains of Serratia marcescens from an edible cactus plant and silkworms were characterized and a comparison based on their cellular fatty acid composition, 16S rRNA and groE gene sequence analysis as well as silkworm virulence and chitosan susceptibility was carried out. Results from this study indicate that there are no significant differences between the phenotypic and molecular characterization, virulence and chitosan susceptibility of the S. marcescens strains from the cactus plant and silkworms. Silkworms inoculated with S. marcescens from either plant or silkworm resulted in nearly 100% mortality. Chitosan solution exhibited strong antibacterial activity against S. marcescens. This activity increased with the increase of chitosan concentration and incubation time regardless of the strain source. Also, the results indicate that the plant associated S. marcescens maybe plays a possible role in the contamination of humans and animals, in particular silkworms, while chitosan showed a potential to control the contamination caused by S. marcescens. PMID:24031610

  20. Cactus stem (Opuntia ficus-indica Mill): anatomy, physiology and chemical composition with emphasis on its biofunctional properties.

    PubMed

    Ventura-Aguilar, Rosa Isela; Bosquez-Molina, Elsa; Bautista-Baños, Silvia; Rivera-Cabrera, Fernando

    2017-06-20

    Cactus stem (Opuntia ficus-indica Mill) is native to Mesoamerica and marketed in different forms such as fresh, frozen or pre-cooked. Worldwide, this vegetable is recognized for its pharmaceutical actions, including its antioxidant, diuretic, anticarcinogenic, anti-inflammatory, anti-diabetic, and anti-hypercholesterolemic properties, as well as their antiviral and antispermatogenic effects. However, not all of these properties have been associated with its chemical composition; therefore, this review aims to present and integrate information available on the physiology and anatomy of cactus stem and its chemical composition, focusing on some of the many factors that determine its biofunctionality. © 2017 Society of Chemical Industry. © 2017 Society of Chemical Industry.

  1. Effects of Bermudagrass hay and soybean hulls inclusion on performance of sheep fed cactus-based diets.

    PubMed

    Santos, A O A; Batista, Angela M V; Mustafa, Arif; Amorim, G L; Guim, A; Moraes, A C; de Lucena, R B; de Andrade, R

    2010-03-01

    The objective of this experiment was to determine the effects of replacing corn with soybean hulls (SH) or Bermudagrass tifton hay (TH) on performance of sheep fed cactus-based diets. Three ruminally fistulated sheep were used in a 3 x 3 Latin square experiment with 21-day periods. All diets contained 75% spineless cactus (dry matter basis, DM) and formulated to be isonitrogenous. Fiber source had no influence on nutrient intakes except for the intake of neutral detergent fiber (NDF) which was lower (p<0.05) for animals fed corn relative to those fed SH or TH. Time expended in rumination and total chewing time were higher (p<0.05) for animals fed TH than those fed SH or corn. In vivo nutrient digestibilities were similar for all dietary treatments and averaged 69.6%, 74.8%, 69.9%, and 61.8% for DM, organic matter, crude protein, and NDF, respectively. Feeding SH relative to TH and corn decreased ruminal pH (p<0.05) and increased concentration of total volatile fatty acids (p<0.05). However, ruminal NH3-N concentration was higher (p<0.05) for animal fed TH than for those fed SH or corn. Abdominal distension and ruminal biofilm production were greater (p<0.05) in animals fed corn or SH than in those fed TH. It was concluded that replacing corn with SH or TH up to 15% of the diet DM in a cactus-based diet had no effect on nutrient intakes or total tract nutrient utilization. Changes in ruminal fermentation parameters reflected differences in ruminal degradability between the two fiber sources. Bermudagrass tifton hay was more effective than SH in reducing the risk of bloat associated with feeding high levels of spineless cactus to ruminants.

  2. Corrrective action decision document for the Cactus Spring Waste Trenches (Corrective Action Unit No. 426). Revision No. 1

    SciTech Connect

    1997-06-01

    The Corrective Action Decision Document (CADD) for the Cactus Spring Waste Trenches (Corrective Action Unit [CAU] No. 426) has been prepared for the US Department of Energy`s (DOE) Nevada Environmental Restoration Project. This CADD has been developed to meet the requirements of the Federal Facility Agreement and Consent Order (FFACO) of 1996, stated in Appendix VI, {open_quotes}Corrective Action Strategy{close_quotes} (FFACO, 1996). The Cactus Spring Waste Trenches Corrective Action Site (CAS) No. RG-08-001-RG-CS is included in CAU No. 426 (also referred to as the {open_quotes}trenches{close_quotes}); it has been identified as one of three potential locations for buried, radioactively contaminated materials from the Double Tracks Test. The trenches are located on the east flank of the Cactus Range in the eastern portion of the Cactus Spring Ranch at the Tonopah Test Range (TTR) in Nye County, Nevada, on the northern portion of Nellis Air Force Range. The TTR is approximately 225 kilometers (km) (140 miles [mi]) northwest of Las Vegas, Nevada, by air and approximately 56 km (35 mi) southeast of Tonopah, Nevada, by road. The trenches were dug for the purpose of receiving waste generated during Operation Roller Coaster, primarily the Double Tracks Test. This test, conducted in 1963, involved the use of live animals to assess the biological hazards associated with non-nuclear detonation of plutonium-bearing devices (i.e., inhalation uptake of plutonium aerosol). The CAS consists of four trenches that received solid waste and had an overall impacted area of approximately 36 meters (m) (120 feet [ft]) long x 24 m (80 ft) wide x 3 to 4.5 m (10 to 15 ft) deep. The average depressions at the trenches are approximately 0.3 m (1 ft) below land surface.

  3. Protective role of cactus cladodes extract on sodium dichromate-induced testicular injury and oxidative stress in rats.

    PubMed

    Hfaiedh, Mbarka; Brahmi, Dalel; Zourgui, Lazhar

    2014-06-01

    Cactus (Opuntia ficus-indica) is a xerophyte plant that belongs to the Cactaceae family. The present study was designed to investigate the possible protective effects of cactus cladodes extract (CCE) on sodium dichromate-induced testis damage in adult male Wistar rats. For this purpose, CCE at a dose of 100 mg/kg was orally administrated, followed by 10 mg/kg sodium dichromate (intraperitoneal injection). After 40 days of treatment, the rats were sacrificed, and the testes were excised for histological, lipid peroxidation (LPO), and antioxidant enzyme analyses. Sodium dichromate treatment significantly (P<0.01) decreased the body, testis, and accessory sex organ weights, sperm count and motility, and serum testosterone level. In addition, histological analysis revealed pronounced morphological alterations with tubular necrosis and reduction in the number of gametes in the lumen of the seminiferous tubules of sodium dichromate-intoxicated rats. Furthermore, exposure to sodium dichromate significantly (P<0.01) increased LPO level and decreased superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) activities in testis. Interestingly, pretreatment with CCE significantly (P<0.01) restored the serum testosterone level, sperm count, and motility to the levels of the control group. Moreover, CCE administration was capable of reducing the elevated level of LPO and significantly (P<0.01) increased SOD, CAT, and GPx activities in testis. Cactus cladodes supplementation minimized oxidative damage and reversed the impairment of spermatogenesis and testosterone production induced by sodium dichromate in the rat testis.

  4. Use of Spineless Cactus (Opuntia ficus indica f. inermis) for Dairy Goats and Growing Kids: Impacts on Milk Production, Kid's Growth, and Meat Quality

    PubMed Central

    Mahouachi, M.; Atti, N.; Hajji, H.

    2012-01-01

    The objective of this study was to determine the effect of spineless cactus incorporation in food of dairy goats and growing kids on milk production and composition and on kid's growth and meat characteristics. Two experiments were conducted on Tunisian local goats. In the first, 30 females were divided into two groups; goats of Control group were reared on grazing pasture receiving indoor 0.5 kg of hay and 0.4 kg of concentrate. Goats for the second group (Cac-FL) were kept in feedlot and fed cactus ad libitum more 0.5 kg of hay and 0.4 kg of concentrate. In the second experiment, 14 kids were divided into 2 groups receiving 600 g of hay. The Control group received ad libitum a concentrate containing 130 g crude protein (CP) per kg of dry matter. The second group received cactus ad-libitum plus the half concentrate quantity of control one with 260 g CP/kg DM (Cactus). The daily milk production averaged 485 ml for Control group and 407 ml for Cac-FL one. The milk fat content was significantly higher for Control than Cac-FL group. In the second experiment, animals in Control and Cactus groups had similar growth rate. Carcass fat was significantly lower in Cactus than in the Control group. Cactus in the diet was associated with more C18:2 and conjugated linoleic acid as well as a higher proportion of PUFA than Control ones. PMID:22536135

  5. Effects of Cactus Fiber on the Excretion of Dietary Fat in Healthy Subjects: A Double Blind, Randomized, Placebo-Controlled, Crossover Clinical Investigation

    PubMed Central

    Uebelhack, Ralf; Busch, Regina; Alt, Felix; Beah, Zhi-Ming; Chong, Pee-Win

    2014-01-01

    Background Cactus (Opuntia ficus-indica) fiber was shown to promote weight loss in a 3-month clinical investigation. As demonstrated by in vitro studies, cactus fiber binds to dietary fat and its use results in reduced absorption, which in turn leads to reduced energy absorption and ultimately the reduction of body weight. Objective The objective of our study was to elucidate the dietary fat binding capacity of cactus fiber through determination of fecal fat excretion in healthy volunteers. Subjects and Methods This clinical investigation was performed as a double-blind, randomized, placebo-controlled, crossover study in healthy subjects for a period of approximately 45 days. Twenty healthy volunteer subjects were randomized to receive cactus fiber or placebo, 2 tablets thrice daily with main meals. All subjects were provided with meals during the study period (except washout) according to a standardized meal plan, with 35% of daily energy need coming from fat. Two 24-hour feces samples were collected during both the baseline and treatment periods for analysis of the fat content. Results Cactus fiber showed an increased fecal fat excretion compared with placebo (mean [SD] = 15.79% [5.79%] vs 4.56% [3.09%]; P < 0.001). No adverse events were reported throughout the study period. Conclusions Cactus fiber has been shown to significantly promote fecal fat excretion in healthy adults. The results of our study support the hypothesis that cactus fiber helps in reducing body weight by binding to dietary fat and increasing its excretion, thus reducing dietary fat available for absorption. ClinicalTrials.gov identifier: NCT01590667. PMID:25067985

  6. Performance of goats fed on low quality veld hay supplemented with fresh spiny cactus (Opuntia megacantha) mixed with browse legumes hay in Zimbabwe.

    PubMed

    Gusha, Jacob; Halimani, Tinyiko Edward; Katsande, Simbarashe; Zvinorova, Plaxedis Ivy

    2014-10-01

    Nutrition is a major constraint in smallholder livestock production; hence, the use of alternative sources which are adaptive to long dry seasons is imperative. The study was conducted to establish options of improving nutrition and palatability and also to determine the performance of goats fed on cactus-browse hay as dry season supplements. Palatability and adequacy of nutrition was investigated using 32 castrated male goat kids. The kids were housed in individual metabolism cages for 84 days in a complete randomised design (CRD) with eight replicates for the four treatment diets. Daily experimental diet, basal diet and water intake were measured, and live mass was measured at weekly intervals. Daily diet intake was significantly different (P < 0.05) among treatments. Kids that were supplemented with cactus-Leucaena leucocephala meal (CLLM) consumed more than those on cactus-Acacia angustissima meal (CAAM), cactus-Gliricidia sepium meal (CGSM) and cactus-Pennisetum purpureum meal (CPPM) in that order. CGSM was not readily palatable as goat kids refused to take it when mixed with fresh cactus. Animals that were not supplemented with a source of nitrogen together with those that were supplemented with less palatable diet of CGSM lost weight significantly (P < 0.05) initially but gained weight slightly towards the end of the study. Significantly higher weight gains (P < 0.05) were observed in animals in CLLM and CAAM treatment. It was concluded that fresh cactus could be used to improve poor quality roughage intakes in goats, and therefore, there is need to promote its use in periods of feed deficit especially in smallholder sector.

  7. Columnar- Equiaxed Transition in Solidification processing: The ESA-MAP CETSOL project

    NASA Astrophysics Data System (ADS)

    Billia, Bernard; Gandin, Charles-André; Zimmermann, Gerhard; Browne, David; Dupouy, Marie-Danielle

    2005-03-01

    Many castings are the result of a competition between the growth of columnar and equiaxed grains. Indeed, microstructures are at the center of materials science and engineering, and solidification is the most important processing route for structural materials, especially metals and alloys. Presently, microstructure models remain mostly based on diffusive transport mechanisms so that there is a need of critical benchmark data to test fundamental theories of microstructure formation, which often necessitates to have recourse to solidification experiments in the reduced-gravity environment of space. Accordingly, the CETSOL (Columnar-Equiaxed Transition in SOLidification processing)-MAP project of ESA is gathering together European groups with complementary skills to carry out experiments and model the processes, in particular in view of the utilization of reduced-gravity environment that will be afforded by the International Space Station (ISS) to get benchmark data. The ultimate objective of the CETSOL research program is to significantly contribute to the improvement of integrated modeling of grain structure in industrially important castings. To reach this goal, the approach is devised to deepen the quantitative understanding of the basic physical principles that, from the microscopic to the macroscopic scales, govern microstructure formation in solidification processing under diffusive conditions and with fluid flow in the melt. Pending questions are attacked by well-defined model experiments on technical alloys and/or on model transparent systems, physical modeling at microstructure and mesoscopic scales (e.g. large columnar front or equiaxed crystals) and numerical simulation at all scales, up to the macroscopic scales of casting with integrated numerical models.

  8. Experimental Study of Disruption of Columnar Grains During Rapid Solidification in Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Manogharan, Guha; Yelamanchi, Bharat; Aman, Ronald; Mahbooba, Zaynab

    2016-03-01

    Over the years, many studies have been conducted to study and analyze the grain structures of metal alloys during additive manufacturing to improve mechanical properties. In particular, columnar grains are observed predominantly during rapid solidification of molten metal. This leads to lower mechanical properties and requires expensive secondary heat-treatment processes. This study is aimed at disrupting the formation of columnar grain growth during rapid solidification using ultrasonic vibration and analyzes the effects on grain structure and mechanical properties. A gas-metal arc welder mounted on a Rep-Rap-based low-cost metal 3 Dimension printer was used to deposit ER70S-6 mild steel layers on a plate. A contact-type ultrasonic transducer with a control system to vary the frequency and power of the vibration was used. The effects of ultrasonic vibration were determined from the statistical analysis of microstructure and micro-indentation techniques on the deposited layer and heat-affected zone. It was found that both frequency and interaction between frequency and power had significant impact on the refinement of average grain size up to 10.64% and increased the number of grains by approximately 41.78%. Analysis of micro-indentation tests showed that there was an increase of approximately 14.30% in micro-hardness due to the applied frequency during rapid solidification. A pole diagram shows that application of vibration causes randomization of grain orientation. Along with the results from this study, further efforts in modeling and experimentation of multi-directional vibrations would lead to a better understanding of disrupting columnar grains in applications that use mechanical vibrations, such as welding, directed energy deposition, brazing, etc.

  9. Optical response of columnar TiO2:Co on Si substrate

    NASA Astrophysics Data System (ADS)

    Anggraeni, G. P.; Saripudin, A.; Rusydi, A.; Darma, Y.

    2015-09-01

    Vertically arranged columnar TiO2:Co structure has been deposited on Si (100) substrate using the metal organic chemical vapor deposition (MOCVD) technique. SEM images confirm the columnar structure of the TiO2:Co layer on Si (100). Concentration of the Co dopant has been defined by means of the energy dispersive x-ray (EDX) spectra. Co concentrations are varied at 0.18, 0.33, and 0.68 at. % using pure TiO2 as the reference. X-ray diffraction (XRD) spectra show that the TiO2:Co layer have a rutile phase. Further analysis of this structure has been performed by using room temperature spectroscopic ellipsometry (SE) measurements in the energy range of 0.5 - 6.5 eV. This optical response shows the unique feature of significantly high density fringe especially below the band gap energy region (lower than 3.3 eV) in contrast to the conventional TiO2 thin film structure. This unique feature is interpreted as a dominant contribution of the vertical interfaces at columnar boundaries towards reflected light from the sample. The evolution of Ψ and Δ will be discussed as the function of Co concentration and some optical properties will be extracted after reasonably well data fitting by multilayer modelling. Furthermore, by comparing the SE data from different measurement orientations, it has been shown that TiO2:Co tends to be anisotropic. This study enables us to further evaluate structural properties through optical responses given by SE measurement.

  10. Optical response of columnar TiO{sub 2}:Co on Si substrate

    SciTech Connect

    Anggraeni, G. P.; Saripudin, A.; Rusydi, A.; Darma, Y.

    2015-09-30

    Vertically arranged columnar TiO{sub 2}:Co structure has been deposited on Si (100) substrate using the metal organic chemical vapor deposition (MOCVD) technique. SEM images confirm the columnar structure of the TiO{sub 2}:Co layer on Si (100). Concentration of the Co dopant has been defined by means of the energy dispersive x-ray (EDX) spectra. Co concentrations are varied at 0.18, 0.33, and 0.68 at. % using pure TiO{sub 2} as the reference. X-ray diffraction (XRD) spectra show that the TiO{sub 2}:Co layer have a rutile phase. Further analysis of this structure has been performed by using room temperature spectroscopic ellipsometry (SE) measurements in the energy range of 0.5 - 6.5 eV. This optical response shows the unique feature of significantly high density fringe especially below the band gap energy region (lower than 3.3 eV) in contrast to the conventional TiO{sub 2} thin film structure. This unique feature is interpreted as a dominant contribution of the vertical interfaces at columnar boundaries towards reflected light from the sample. The evolution of Ψ and Δ will be discussed as the function of Co concentration and some optical properties will be extracted after reasonably well data fitting by multilayer modelling. Furthermore, by comparing the SE data from different measurement orientations, it has been shown that TiO{sub 2}:Co tends to be anisotropic. This study enables us to further evaluate structural properties through optical responses given by SE measurement.

  11. Scales of columnar jointing in igneous rocks: field measurements and controlling factors

    NASA Astrophysics Data System (ADS)

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

    2012-03-01

    Columnar jointing is a common feature of solidified lavas, sills and dikes, but the factors controlling the characteristic stoutness of columns remain debated, and quantitative field observations are few in number. In this paper, we provide quantitative measurements on sizing of columnar joint sets and our assessment of the principal factors controlling it. We focus on (1) chemistry, as it is the major determinant of the physical (mechanical and thermal) properties of the lava, and (2) geology, as it influences the style of emplacement and lava geometry, setting boundary conditions for the cooling process and the rate of heat loss. In our analysis, we cover lavas with a broad range of chemical compositions (from basanite to phonolite, for six of which we provide new geochemical analyses) and of geological settings. Our field measurements cover 50 columnar jointing sites in three countries. We provide reliable, manually digitized data on the size of individual columns and focus the mathematical analysis on their geometry (23,889 data on side length, of which 17,312 are from full column sections and 3,033 data on cross-sectional area and order of polygonality). The geometrical observations show that the variation in characteristic size of columns between different sites exceeds one order of magnitude (side length ranging from 8 to 338 cm) and that the column-bounding polygons' average order is less than 6. The network of fractures is found to be longer than required by a minimum-energy hexagonal configuration, indicating a non-equilibrium, geologically quick process. In terms of the development and characteristic sizing of columnar joint sets, our observations suggest that columns are the result of an interplay between the geological setting of emplacement and magma chemistry. When the geological setting constrains the geometry of the emplaced body, it exerts a stronger control on characteristic column stoutness. At unconstrained geometries (e.g. unconfined lava

  12. Columnar deformation of human red blood cell by highly localized fiber optic Bessel beam stretcher

    PubMed Central

    Lee, Sungrae; Joo, Boram; Jeon, Pyo Jin; Im, Seongil; Oh, Kyunghwan

    2015-01-01

    A single human red blood cell was optically stretched along two counter-propagating fiber-optic Bessel-like beams in an integrated lab-on-a-chip structure. The beam enabled highly localized stretching of RBC, and it induced a nonlinear mechanical deformation to finally reach an irreversible columnar shape that has not been reported. We characterized and systematically quantified this optically induced mechanical deformation by the geometrical aspect ratio of stretched RBC and the irreversible stretching time. The proposed RBC mechanism can realize a versatile and compact opto-mechanical platform for optical diagnosis of biological substances in the single cell level. PMID:26601005

  13. Stable Isotopic Variations in Columnar Cacti: are Responses to Climate Recorded in Spines?

    NASA Astrophysics Data System (ADS)

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

    2004-12-01

    The behavior of the North American monsoon (NAM), particularly with respect to times of continental drought and its relationship to the Pacific-North American (PNA) teleconnection pattern and the El Nino/Southern Oscillation (ENSO) is of great interest to paleoclimatologists and water managers. Long-term instrumental precipitation and tree ring records in the southwestern United States and northwestern Mexico at low elevations are sparse and this has hindered research on NAM variability at interannual timescales. Saguaro cacti (Carnegiea gigantea) and other columnar cacti in North and South America are long-lived and have the potential to record climate variability on land with high temporal and spatial resolution. The vertical sequence of spines on the saguaro's exterior represents a high resolution (4 to 6 per year), and long (over 150 years) record of environmental change. We present results from an experiment where we tracked the oxygen isotopic values in the source waters, stem tissue waters and spine tissue for three treatments over the course of three months. These data are then compared to a previously developed mechanistic model of isotopic variation that reflects the physiological responses of Saguaro to climate variation over seasonal to century long time-scales. We also present the rationale for a new method to determine the growth rate of columnar cacti using the radiocarbon bomb spike. Our measurements reveal that oxygen and hydrogen isotopic variation among the sequentially produced and persistent spines covering the saguaro body record fluctuations in saguaro water balance. The model successfully predicts isotopic variation in spines and constrains controlling variables, yielding a powerful and high-resolution stable isotope index of water stress in the low desert. The development and refinement of an isotopic model for saguaro will serve as the basis for models applied to other species of columnar cacti in North and South America. The role of the

  14. Fine genetic mapping of the Co locus controlling columnar growth habit in apple.

    PubMed

    Bai, Tuanhui; Zhu, Yuandi; Fernández-Fernández, Felicidad; Keulemans, Johan; Brown, Susan; Xu, Kenong

    2012-05-01

    Tree architecture is an important, complex and dynamic trait affected by diverse genetic, ontogenetic and environmental factors. 'Wijcik McIntosh', a columnar (reduced branching) sport of 'McIntosh' and a valuable genetic resource, has been used intensively in apple-breeding programs for genetic improvement of tree architecture. The columnar growth habit is primarily controlled by the dominant allele of gene Co (columnar) on linkage group-10. But the Co locus is not well mapped and the Co gene remains unknown. To precisely map the Co locus and to identify candidate genes of Co, a sequence-based approach using both peach and apple genomes was used to develop new markers linked more tightly to Co. Five new simple sequence repeats markers were developed (C1753-3520, C18470-25831, C6536-31519, C7223-38004 and C7629-22009). The first four markers were obtained from apple genomic sequences on chromosome-10, whereas the last (C7629-22009) was from an unanchored apple contig that contains an apple expressed sequence tag CV082943, which was identified through synteny analysis between the peach and apple genomes. Genetic mapping of these five markers in four F(1) populations of 528 genotypes and 290 diverse columnar selections/cultivars (818 genotypes in total) delimited the Co locus in a genetic interval with 0.37 % recombination between markers C1753-3520 and C7629-22009. Marker C18470-25831 co-segregates with Co in the 818 genotypes studied. The Co region is estimated to be 193 kb and contains 26 predicted gene in the 'Golden Delicious' genome. Among the 26 genes, three are putative LATERAL ORGAN BOUNDARIES (LOB) DOMAIN (LBD) containing transcription factor genes known of essential roles in plant lateral organ development, and are therefore considered as strong candidates of Co, designated MdLBD1, MdLBD2, and MdLBD3. Although more comprehensive studies are required to confirm the function of MdLBD1-3, the present work represents an important step forward to better

  15. Surface roughening and columnar growth of thin amorphous CuTi films

    NASA Astrophysics Data System (ADS)

    Geyer, U.; von Hülsen, U.; Thiyagarajan, P.

    1997-03-01

    Different growth stages and the microstructure of amorphous CuTi films are investigated by scanning tunneling microscopy and small angle neutron scattering. During film growth at room temperature, the initially smooth films show increasing surface roughening and finally a change to a columnar growth mode with column diameters of about 20 nm. The interfacial energies associated with the column boundaries are higher than those of grain boundaries in crystalline systems. The column boundaries might be the origin of high intrinsic tensile stresses measured before in the amorphous CuTi films.

  16. Fröhlich modes in GaN columnar nanostructures

    NASA Astrophysics Data System (ADS)

    Tiginyanu, I. M.; Sarua, A.; Irmer, G.; Monecke, J.; Hubbard, S. M.; Pavlidis, D.; Valiaev, V.

    2001-12-01

    GaN columnar nanostructures fabricated by electrochemical dissolution of bulk material have been studied by micro-Raman spectroscopy. The anodization induces an increase in the intensity of Raman scattering accompanied by a breakdown of the polarization selection rules and by the appearance of a new mode at 716 cm-1, i.e., in the frequency gap between the transverse optical and longitudinal optical bulk phonons. We present a Raman line-shape analysis based on the effective dielectric function of a composite that brings to light the Fröhlich character of this mode.

  17. Computer-aided vaccine designing approach against fish pathogens Edwardsiella tarda and Flavobacterium columnare using bioinformatics softwares

    PubMed Central

    Mahendran, Radha; Jeyabaskar, Suganya; Sitharaman, Gayathri; Michael, Rajamani Dinakaran; Paul, Agnal Vincent

    2016-01-01

    Edwardsiella tarda and Flavobacterium columnare are two important intracellular pathogenic bacteria that cause the infectious diseases edwardsiellosis and columnaris in wild and cultured fish. Prediction of major histocompatibility complex (MHC) binding is an important issue in T-cell epitope prediction. In a healthy immune system, the T-cells must recognize epitopes and induce the immune response. In this study, T-cell epitopes were predicted by using in silico immunoinformatics approach with the help of bioinformatics tools that are less expensive and are not time consuming. Such identification of binding interaction between peptides and MHC alleles aids in the discovery of new peptide vaccines. We have reported the potential peptides chosen from the outer membrane proteins (OMPs) of E. tarda and F. columnare, which interact well with MHC class I alleles. OMPs from E. tarda and F. columnare were selected and analyzed based on their antigenic and immunogenic properties. The OMPs of the genes TolC and FCOL_04620, respectively, from E. tarda and F. columnare were taken for study. Finally, two epitopes from the OMP of E. tarda exhibited excellent protein–peptide interaction when docked with MHC class I alleles. Five epitopes from the OMP of F. columnare had good protein–peptide interaction when docked with MHC class I alleles. Further in vitro studies can aid in the development of potential peptide vaccines using the predicted peptides. PMID:27284239

  18. Preparation of High Silicon Electrical Steel Sheets with Strong {100} Recrystallization Texture by the Texture Inheritance of Initial Columnar Grains

    NASA Astrophysics Data System (ADS)

    Pan, Hongjiang; Zhang, Zhihao; Xie, Jianxin

    2016-05-01

    Texture evolutions and recrystallization texture features in warm- and cold-rolled sheets of high silicon electrical steel with two different initial microstructures (columnar-grained and equiaxed-grained microstructures) were investigated. The relationships between the recrystallization textures and the initial textures (the textures before rolling) of the samples were analyzed. The results showed that after annealing at 1073 K (800 °C) for 1 hour, strong {100} recrystallization textures with volume fractions of more than 47 pct were obtained in the columnar-grained samples fabricated by warm and cold rolling along the growing direction of the columnar grains. While after rolling and annealing in the same processes, only 12.8 pct volume fractions of {100} recrystallization texture were revealed in the equiaxed-grained samples. The formation of strong {100} recrystallization texture in the annealed sheets of high silicon electrical steel with initial columnar grains was attributed to the favorable texture inheritance of the initial texture during rolling and annealing. The columnar grains of strong near {100}<001> ({100}<001> {310}<001>) orientation in the samples before rolling were transferred into deformed grains with orientations such as {100}<011> and {100}<012>. after rolling. Afterwards, these deformed grains were further transferred into {100} oriented recrystallized grains, which formed strong {100} recrystallization texture in the annealed sheets and exhibited preferable soft magnetic properties.

  19. Complete genome sequence analysis of the fish pathogen Flavobacterium columnare provides insights into antibiotic resistance and pathogenicity related genes.

    PubMed

    Zhang, Yulei; Zhao, Lijuan; Chen, Wenjie; Huang, Yunmao; Yang, Ling; Sarathbabu, V; Wu, Zaohe; Li, Jun; Nie, Pin; Lin, Li

    2017-10-01

    We analyzed here the complete genome sequences of a highly virulent Flavobacterium columnare Pf1 strain isolated in our laboratory. The complete genome consists of a 3,171,081 bp circular DNA with 2784 predicted protein-coding genes. Among these, 286 genes were predicted as antibiotic resistance genes, including 32 RND-type efflux pump related genes which were associated with the export of aminoglycosides, indicating inducible aminoglycosides resistances in F. columnare. On the other hand, 328 genes were predicted as pathogenicity related genes which could be classified as virulence factors, gliding motility proteins, adhesins, and many putative secreted proteases. These genes were probably involved in the colonization, invasion and destruction of fish tissues during the infection of F. columnare. Apparently, our obtained complete genome sequences provide the basis for the explanation of the interactions between the F. columnare and the infected fish. The predicted antibiotic resistance and pathogenicity related genes will shed a new light on the development of more efficient preventional strategies against the infection of F. columnare, which is a major worldwide fish pathogen. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Application of the Prague C and M criteria for endoscopic description of columnar-lined esophagus in South Korea

    PubMed Central

    Choe, Jung Wan; Kim, Young Choon; Joo, Moon Kyung; Kim, Hyo Jung; Lee, Beom Jae; Kim, Ji Hoon; Yeon, Jong Eun; Park, Jong-Jae; Kim, Jae Seon; Byun, Kwan Soo; Bak, Young-Tae

    2016-01-01

    AIM: To ascertain whether the Prague circumferential (C) length and maximal (M) length criteria for grading the extent of Barrett’s esophagus can be applied prior to its widespread application in South Korea. METHODS: Two hundred and thirteen consecutive cases with endoscopic columnar-lined esophagus (CLE) were included and classified according to the Prague C and M criteria. RESULTS: Of 213 cases with CLE, the distribution of maximum CLE lengths was: 0.5-0.9 cm in 99 cases (46.5%); 1.0-1.4 cm in 63 cases (29.6%); 1.5-1.9 cm in 15 cases (7.0%); 2.0-2.4 cm in 14 cases (6.6%); 2.5-2.9 cm in 1 case (0.5%); and 7.0 cm in 1 case (0.5%). Twenty cases (9.4%) had columnar islands alone. Two hundred and eight cases (97.7%) lacked the circumferential CLE component (C0Mx). Columnar islands were found in 70 cases (32.9%), of which 20 cases (9.4%) had columnar islands alone. CONCLUSION: In regions where most CLE patients display short or ultrashort tongue-like appearance, more detailed descriptions of CLE’s in < 1.0 cm lengths and columnar islands, as well as avoidance of repeating the prefix “C0” need to be considered in parallel with the widespread application of the Prague system in South Korea. PMID:27114749