Science.gov

Sample records for lance nematode hoplolaimus

  1. First report of Lance Nematode (Hoplolaimus magnistylus) on corn, soybean and cotton in Tennessee

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lance nematode, Hoplolaimus galeatus, has been reported in Tennessee on field crops, forage pastures, home gardens, woody ornamentals, turf, and commercial vegetables across the state. In May 2011, another lance nematodes, H. magnistylus, was recovered from corn, cotton and soybean fields in west Te...

  2. High genetic diversity and geographic subdivision of three lance nematode species (Hoplolaimus spp.) in the United States.

    PubMed

    Holguin, Claudia M; Baeza, Juan A; Mueller, John D; Agudelo, Paula

    2015-07-01

    Lance nematodes (Hoplolaimus spp.) feed on the roots of a wide range of plants, some of which are agronomic crops. Morphometric values of amphimictic lance nematode species overlap considerably, and useful morphological characters for their discrimination require high magnification and significant diagnostic time. Given their morphological similarity, these Hoplolaimus species provide an interesting model to investigate hidden diversity in crop agroecosystems. In this scenario, H. galeatus may have been over-reported and the related species that are morphologically similar could be more widespread in the United States that has been recognized thus far. The main objectives of this study were to delimit Hoplolaimus galeatus and morphologically similar species using morphology, phylogeny, and a barcoding approach, and to estimate the genetic diversity and population structure of the species found. Molecular analyses were performed using sequences of the cytochrome c oxidase subunit 1 (Cox1) and the internal transcribed spacer (ITS1) on 23 populations. Four morphospecies were identified: H. galeatus, H. magnistylus, H. concaudajuvencus, and H. stephanus, along with a currently undescribed species. Pronounced genetic structure correlated with geographic origin was found for all species, except for H. galeatus. Hoplolaimus galeatus also exhibited low genetic diversity and the shortest genetic distances among populations. In contrast, H. stephanus, the species with the fewest reports from agricultural soils, was the most common and diverse species found. Results of this project may lead to better delimitation of lance nematode species in the United States by contributing to the understanding the diversity within this group.

  3. High genetic diversity and geographic subdivision of three lance nematode species (Hoplolaimus spp.) in the United States

    PubMed Central

    Holguin, Claudia M; Baeza, Juan A; Mueller, John D; Agudelo, Paula

    2015-01-01

    Lance nematodes (Hoplolaimus spp.) feed on the roots of a wide range of plants, some of which are agronomic crops. Morphometric values of amphimictic lance nematode species overlap considerably, and useful morphological characters for their discrimination require high magnification and significant diagnostic time. Given their morphological similarity, these Hoplolaimus species provide an interesting model to investigate hidden diversity in crop agroecosystems. In this scenario, H. galeatus may have been over-reported and the related species that are morphologically similar could be more widespread in the United States that has been recognized thus far. The main objectives of this study were to delimit Hoplolaimus galeatus and morphologically similar species using morphology, phylogeny, and a barcoding approach, and to estimate the genetic diversity and population structure of the species found. Molecular analyses were performed using sequences of the cytochrome c oxidase subunit 1 (Cox1) and the internal transcribed spacer (ITS1) on 23 populations. Four morphospecies were identified: H. galeatus, H. magnistylus, H. concaudajuvencus, and H. stephanus, along with a currently undescribed species. Pronounced genetic structure correlated with geographic origin was found for all species, except for H. galeatus. Hoplolaimus galeatus also exhibited low genetic diversity and the shortest genetic distances among populations. In contrast, H. stephanus, the species with the fewest reports from agricultural soils, was the most common and diverse species found. Results of this project may lead to better delimitation of lance nematode species in the United States by contributing to the understanding the diversity within this group. PMID:26306177

  4. Molecular Analysis of the Lance Nematode, Hoplolaimus spp., Using the First Internal Transcribed Spacer and the D1-D3 Expansion Segments of 28S Ribosomal DNA1

    PubMed Central

    Bae, CH; Szalanski, AL; Robbins, RT

    2008-01-01

    DNA sequence analyses of the nuclear ribosomal ITS1 region of the ribosomal DNA and D1-D3 expansion segments of the 28S gene were conducted to characterize the genetic variation of six amphimictic Hoplolaimus species, including H. magnistylus, H. concaudajuvencus, H. galeatus, Hoplolaimus sp. 1, Hoplolaimus sp. 2 and Hoplolaimus sp. 3, and two closely related parthenogenetic species, H. columbus and H. seinhorsti. PCR amplifications of the combined D1-D3 expansion segments and the ITS1 region each yielded one distinct amplicon. In the D1-D3 region, there was no nucleotide sequence variation between populations of H. columbus, H. magnistylus, Hoplolaimus sp. 2 and Hoplolaimus sp. 3, whereas the ITS1 sequences had nucleotide variation among species. We detected conserved ITS1 regions located at the 3’ and 5’ end of ITS1 and also in the middle of the ITS1 among Hoplolaimus species. These regions were compared with sequences of distantly related Heterodera and Globedera. PCR-RFLP and sequence analysis of ITS1 and 28S PCR products revealed that several haplotypes existed in the same genome of H. columbus, H. magnistylus, H. seinhorsti, H. concaudajuvencus and Hoplolaimus sp. 1. Maximum likelihood and maximum parsimony analysis using the combined ITS1 and D1-D3 expansion segment sequences always produced trees with similar topology; H. columbus and H. seinhorsti grouped in one clade and the other six species (H. galeatus, H. concaudajuvencus, H. magnistylus, Hoplolaimus sp. 1, Hoplolaimus sp. 2, Hoplolaimus sp. 3) grouped in another. Molecular analysis supports morphological schemes for this genus to be divided into two groups based on several phenotypic traits derived from morphological evolution. PMID:19440260

  5. A Description of Males of Hoplolaimus columbus

    PubMed Central

    Fassuliotis, G.

    1974-01-01

    The male of the Columbia lance nematode, Hoplolaimus columbus, is described and illustrated from a harvested soybean field in Holly Hill, South Carolina. It is morphologically similar to the female, except for reproductive structures. PMID:19308111

  6. Impact of Cotton Production Systems on Management of Hoplolaimus columbus

    PubMed Central

    Koenning, S. R.; Edmisten, K. L.; Barker, K. R.; Morrison, D. E.

    2003-01-01

    The effectiveness of selected cultural practices in managing the Columbia lance nematode, Hoplolaimus columbus, on cotton was evaluated in experiments in growers' infested fields. The effects of planting date, cotton cultivar, treatment with the growth regulator mepiquat chloride, and destruction of cotton-root systems after harvest on cotton-lint yield and population densities of H. columbus were studied. The yield of cotton cultivar Deltapine 50 was negatively related (P = 0.054) to initial population density of H. columbus whereas the yield of Deltapine 90 was not affected by preplant density of this nematode, indicating tolerance in Deltapine 90. Reproduction of this nematode did not differ on the two cultivars. Planting date and treatment with the growth regulator mepiquat chloride did not influence cotton yield in a consistent manner. Application of mepiquat chloride suppressed (P ≤ 0.05) numbers of Columbia lance nematode, although there was an interaction (P ≤ 0.05) with cultivar and year. Early vs. late destruction of cotton-root systems did not impact population densities of this nematode either year, and had no impact on the subsequent cotton crop. The nematicide fenamiphos increased (P ≤ 0.03) cotton yield when H. columbus numbers exceeded the damage threshold. PMID:19265977

  7. Parasitism of Hoplolaimus galeatus on Diploid and Polyploid St. Augustine grasses

    PubMed Central

    Giblin-Davis, R. M.; Busey, P.; Center, B. J.

    1995-01-01

    'Floratam' and 'FX-313' St. Augusfinegrasses (Stenotaphrum secundatum) were compared in a time-course experiment for host suitability and susceptibility to the lance nematode, Hoplolaimus galeatus. Nematode densities were determined in the soil and acid-fuchsin stained roots 42, 84, 126, 168, and 210 days after pots containing 230 cm³ of autoclaved native Margate fine sand/pot were infested with 104 ± 9 nematodes and maintained at 25 ± 2 C in the laboratory. 'FX-313' was a more suitable host for H. galeatus. Numbers of H. galeatus reached a maximum at 210 days after inoculation, with 5,550 and 4,120 nematodes (adults plus juveniles)/pot for 'FX-313' and 'Floratam,' respectively. Root and shoot dry weights of both grasses were not affected by H. galeatus throughout the experiment. Three polyploid, 2n = 30 to 32 ('Floratam,' 'FX-10,' and 'Bitterblue') and three diploid, 2n = 18 ('FX-313,' 'Florida Common,' and 'Seville') S. secundatum genotypes were inoculated with H. galeatus (99 ± 9/pot) and compared with uninoculated controls 210 days after inoculation. St. Augustinegrass genotypes differed as hosts of H. galeatus. 'FX-313' and 'Florida Common' represented the high and low extremes, respectively, for nematode reproduction (9,750 and 5,490 nematodes/pot or 4,239 and 2,387 nematodes/100 cm³ of soil). However, differences in root and shoot growth were not detected 210 days after inoculation with H. galeatus. PMID:19277314

  8. Parasitism of Hoplolaimus galeatus on Diploid and Polyploid St. Augustine grasses.

    PubMed

    Giblin-Davis, R M; Busey, P; Center, B J

    1995-12-01

    'Floratam' and 'FX-313' St. Augusfinegrasses (Stenotaphrum secundatum) were compared in a time-course experiment for host suitability and susceptibility to the lance nematode, Hoplolaimus galeatus. Nematode densities were determined in the soil and acid-fuchsin stained roots 42, 84, 126, 168, and 210 days after pots containing 230 cm(3) of autoclaved native Margate fine sand/pot were infested with 104 +/- 9 nematodes and maintained at 25 +/- 2 C in the laboratory. 'FX-313' was a more suitable host for H. galeatus. Numbers of H. galeatus reached a maximum at 210 days after inoculation, with 5,550 and 4,120 nematodes (adults plus juveniles)/pot for 'FX-313' and 'Floratam,' respectively. Root and shoot dry weights of both grasses were not affected by H. galeatus throughout the experiment. Three polyploid, 2n = 30 to 32 ('Floratam,' 'FX-10,' and 'Bitterblue') and three diploid, 2n = 18 ('FX-313,' 'Florida Common,' and 'Seville') S. secundatum genotypes were inoculated with H. galeatus (99 +/- 9/pot) and compared with uninoculated controls 210 days after inoculation. St. Augustinegrass genotypes differed as hosts of H. galeatus. 'FX-313' and 'Florida Common' represented the high and low extremes, respectively, for nematode reproduction (9,750 and 5,490 nematodes/pot or 4,239 and 2,387 nematodes/100 cm(3) of soil). However, differences in root and shoot growth were not detected 210 days after inoculation with H. galeatus.

  9. Management of Hoplolaimus columbus with Tolerant Soybean and Nematicides.

    PubMed

    Schmitt, D P; Imbriani, J L

    1987-10-01

    Two experiments, one site per year, were conducted in Scotland County, North Carolina, to determine the usefulness of selected cultivars and nematicides for limiting soybean losses due to Hoplolaimus columbus. Coker 317 was relatively tolerant to this nematode, and Coker 156, Centennial, Dehapine 105, and Gordon were generally intolerant. Most nematicides significantly increased soybean yields, and many gave an economic return.

  10. Efficacy of Fumigant Nematicides to Control Hoplolaimus columbus on Cotton.

    PubMed

    Noe, J P

    1990-10-01

    Four rates of methyl bromide (Mbr) (16.8, 33.6, 67,2, and 134.4 kg a.i./ha) and one rate of 1,3-dichloropropene (1,3-D) (28.1 liters a.i./ha) were evaluated over 2 years for control of Hoplolaimus columbus on cotton. All nematicide treatments were applied through a tarpless subsoiler-bedder prior to planting cotton, Gossypium hirsutum cv. Dehapine 90. Nematode population densities were monitored before and after treatment, at midseason, and at harvest, and yields were measured at maturity. Soil fertility variables (pH, P, K, Ca, Mg) were measured for each plot. Cotton yields were significantly increased by treatment with 1,3-D in 1988 and by all nematicidal treatments in 1989. Levels of nematode control varied from year to year among treatments. The responses of H. columbus numbers to rate of Mbr were best described by quadratic regression models. Levels of soil calcium and magnesium were significant factors in a multiple regression model relating a measure of control efficacy to rates of Mbr.

  11. Lancing: Quo Vadis?

    PubMed Central

    Heinemann, Lutz; Boecker, Dirk

    2011-01-01

    Today, lancing fingertips or alternative sites for obtaining a blood sample for self-monitoring of blood glucose (SMBG) is a standard procedure for most patients with diabetes. The need for frequent lancing and associated discomfort and pain can be seen as a key hurdle for patients to comply with SMBG regimens. This article provides an overview of the status quo and future of lancing, focusing on key areas for future developments driven by customer and market needs. We also review technical issues and provide a background for possible improvements. The act of puncturing the skin with a lancet to obtain a blood sample seems to remain the standard procedure for the foreseeable future, because alternate ways of providing a blood sample have not demonstrated overall superiority (e.g., with laser technology). Other methods, which avoid lancing entirely, have also not gained broad market acceptance (e.g., minimally invasive continuous glucose monitoring) or not shown technical viability (e.g., noninvasive glucose monitoring). In relation to blood glucose (BG) meters and test strips, lancing has been a “stepchild” with regards to commercial attention and development efforts. Nevertheless, significant technological improvements have been made in this field to address key customer needs, including better performance (regarding pain, wound healing, and long-term sensitivity), reduced cost, and higher integration with other components of BG monitoring (e.g., integration of the lancing device with the glucose monitor). From a technical perspective, it is apparent that highly comfortable lancing can be accomplished; however, this still requires fairly advanced and complex devices. New developments are necessary to achieve this level of sophistication and performance with less intricate and costly system designs. Manufacturers' motivation to pursue these developments is compromised by the fact that they might not recoup their development cost on commercial advanced lancing

  12. A Key and Diagnostic Compendium to the Species of the Genus Hoplolaimus Daday, 1905 (Nematoda: Hoplolaimidae)

    PubMed Central

    Handoo, Zafar A.; Golden, A. Morgan

    1992-01-01

    An identification key to 29 valid species of Hoplolaimus is given. A compendium of the most important diagnostic characters for use in identification of species is included as a practical alternative and supplement to the key. Diagnosis of Hoplolaimus is emended and lists of species of the genus, their synonymies, species inquirendae, nomina nuda, and species transferred to other genera are given. Hoplolaimus sheri, H. chambus, H. casparus, and H. capensis are recognized as valid species. PMID:19283201

  13. Description of Hoplolaimus bachlongviensis sp. n. (Nematoda: Hoplolaimidae) from banana soil in Vietnam

    PubMed Central

    Nguyen, Tien Huu; Bui, Quang Duc

    2015-01-01

    Abstract Background The genus Hoplolaimus Daday, 1905 belongs to the subfamily Hoplolaimine Filipiev, 1934 of family Hoplolaimidae Filipiev, 1934 (Krall 1990). Daday established this genus on a single female of H. tylenchiformis recovered from a mud hole on Banco Island, Paraguay in 1905 (Sher 1963​, Krall 1990). Hoplolaimus species are distributed worldwide and cause damage on numerous agricultural crops (Luc et al. 1990 Robbins et al. 1998​). In 1992, Handoo and Golden reviewed 29 valid species of genus Hoplolaimus Dayday, 1905 (Handoo and Golden 1992). Siddiqi (2000) recognised three subgenera in Hoplolaimus: Hoplolaimus (Hoplolaimus) with ten species, is characterized by lateral field distinct, with four incisures, excretory pore behind hemizonid; Hoplolaimus (Basirolaimus) with 18 species, is characterized by lateral field with one to three incisures, obliterated, excretory pore anterior to hemizonid, dorsal oesophageal gland quadrinucleate; and Hoplolaimus (Ethiolaimus) with four species is characterized by lateral field with one to three incisures, obliterated; excretory pore anterior to hemizonid, dorsal oesophageal gland uninucleate (Siddiqi 2000). Since then, Hoplolaimus puriensis Ali, Shaheen & Pervez, 2009 has been described (​Ali et al. 2009). Up to now, there have been two species of genus Hoplolaimus reported in Vietnam, viz H. seinhorsti and H. chambus (Nguyen and Nguyen 2000). New information Hoplolaimus bachlongviensis sp. n. was isolated from banana soil in Bach Long Vi Island, Vietnam. The female of this species is described and illustrated below. Some diagnostic characters of this species include body slightly curved ventrally, offset lip region exhibiting three to four annules, lateral field reduced, pharyngeal glands with six nuclei, excretory pore anterior to hemizonid, epiptygma absent, intestine not overlapping rectum and male was not found. PMID:26696764

  14. Host Status of 'SeaIsle 1' Seashore Paspalum (Paspalum vaginatum) to Belonolaimus longicaudatus and Hoplolaimus galeatus

    PubMed Central

    Hixson, A. C.; Crow, W. T.; McSorley, R.; Trenholm, L. E.

    2004-01-01

    Belonolaimus longicaudatus and Hoplolaimus galeatus are considered among the most damaging pathogens of turfgrasses in Florida. However, the host status of seashore paspalum (Paspalum vaginatum) is unknown. Glasshouse experiments were performed in 2002 and 2003 to determine the tolerance of 'SeaIsle 1' seashore paspalum to a population of B. longicaudatus and a population of H. galeatus, and to compare to 'Tifdwarf' bermudagrass for differences. Both nematode species reproduced well on either grass, but only B. longicaudatus consistently reduced root growth as measured by root length. Belonolaimus longicaudatus reduced root growth (P ≤ 0.05) by 35% to 45% at 120 days after inoculation on both grasses. In 2003, higher inoculum levels of H. galeatus reduced root growth (P ≤ 0.05) by 19.4% in seashore paspalum and by 14% in bermudagrass after 60 and 120 days of exposure, respectively. Percentage reductions in root length caused by H. galeatus and B. longicaudatus indicated no differences between grass species, although Tifdwarf bermudagrass supported higher soil population densities of both nematodes than SeaIsle 1 seashore paspalum. PMID:19262830

  15. Description of Hoplolaimus magnistylus n. sp. (Nematoda: Hoplolaimidae)

    PubMed Central

    Robbins, R. T.

    1982-01-01

    Hoplolaimus magnistylus n. sp. is described and illustrated. It was found in soil around roots of soybean in Arkansas and Mississippi. It is similar to H. galeatus and H. concaudajuvencus. It differs from H. galeatus in all stages primarily by possession of a longer stylet. It differs from H. concaudajuvencus by the possession of rounded tails in second-stage juveniles vs. conically pointed tails with acute termini, having fewer subdivisions in female basal lip annules, and the greater distance from female anterior end to posterior end of esophageal lobes. Morphometrics and descriptions of second-, third-, and fourth-stage juveniles are given. A paratype female of H. sheri was examined and found to have six esophageal gland nuclei. PMID:19295743

  16. Comment on Lance Wallace's perspective

    SciTech Connect

    Alm, A.L. )

    1993-04-01

    The author uses Lance Wallace's Perspective ( A Decade of Studies of Human Exposure: What Have We Learned', Risk Analysis, Vol 13, No. 2, 1993, pp. 135-142) as a good case for much greater national attention to indoor air pollution. This article describes the reasons why so little attention has been devoted to indoor air pollution despite convincing evidence of the threats posed to the public by this aspect of pollution.

  17. Social Security for Composers and Free Lances.

    ERIC Educational Resources Information Center

    Rossel-Majdan, Karl

    1982-01-01

    Internationally, cultural policies are tending toward increased socioeconomic and legal support for creative artists. Austrian cultural policies which encourage art and cultural professional organizations, increased copyright protection, and greater social security for free-lance artists are discussed. (AM)

  18. Description and Larval Heteromorphism of Hoplolaimus concaudajuvencus, n. sp. (Nematoda: Hoplolain-lidae)

    PubMed Central

    Golden, A. M.; Minton, N. A.

    1970-01-01

    Hoplolaimus concaudajuvencus n. sp., of the genus Hoplolaimus Daday, 1905, characterized by larval heteromorphism, is described and illustrated as recovered from ryegrass/bermudagrass golf green turf in Florida. Females and males are closely related to H. galeatus (Cobb, 1913) Thorne, 1935, but have longer stylets with more definitely tulip-shaped stylet knobs which anteriorly tend to close upon the stylet shaft more than in H. galeatus. First and second-stage larvae have a conically-pointed tail unlike any known species of the genus. Subsequent stages, including females, have rounded tails essentially similar to other species of the genus and males possess the typical hopolaimid tail and bursa. The first molt was found to occur within the egg. PMID:19322290

  19. Description and Larval Heteromorphism of Hoplolaimus concaudajuvencus, n. sp. (Nematoda: Hoplolain-lidae).

    PubMed

    Golden, A M; Minton, N A

    1970-04-01

    Hoplolaimus concaudajuvencus n. sp., of the genus Hoplolaimus Daday, 1905, characterized by larval heteromorphism, is described and illustrated as recovered from ryegrass/bermudagrass golf green turf in Florida. Females and males are closely related to H. galeatus (Cobb, 1913) Thorne, 1935, but have longer stylets with more definitely tulip-shaped stylet knobs which anteriorly tend to close upon the stylet shaft more than in H. galeatus. First and second-stage larvae have a conically-pointed tail unlike any known species of the genus. Subsequent stages, including females, have rounded tails essentially similar to other species of the genus and males possess the typical hopolaimid tail and bursa. The first molt was found to occur within the egg.

  20. Distribution, Frequency, and Population Density of Nematodes in West Virginia Peach Orchards

    PubMed Central

    Kotcon, James B.

    1990-01-01

    Nematode population densities were determined in soil and root samples collected from 205 peach (Prunus persica L.) orchard blocks between 25 March and 5 May 1986. Representative specimens from 75 blocks were identified to species; 28 species of plant-parasitic nematodes were identified. Predaceous nematodes (Mononchidae) were observed in 71% of the samples. The most common plant-parasitic genera were Paratylenchus, Helicotylenchus, Pratylenchus, and Xiphinema, occurring in 85, 84, 77, and 74% of the samples, respectively. Population densities of Xiphinema, Pratylenchus, Meloidogyne, Hoplolaimus, and Criconemella were at potentially damaging levels in 74, 19, 13, 10, and 2% of the samples, respectively. Potentially damaging nematode densities were observed in 78% of orchard blocks surveyed, with 35% having two or more nematodes with densities high enough to warrant concern. Nematode densities differed among soil types and tree rootstocks and were correlated with tree mortality rates. PMID:19287785

  1. Influence of plant-parasitic nematodes on longleaf pine seedlings.

    PubMed

    Ruehle, J L

    1973-01-01

    Seedlings of longleaf pine (Pinus palustris) were grown in 20-cm pots for 5 to 7 months in the greenhouse following inoculation with a high or low level of one of seven species of plant-parasitic nematodes. Belonolaimus longicaudatus and Helicotylenchus dihystera had no effect on seedling growth. High inoculum densities of Hoplolaimus galeatus and Tylenchorhynchus claytoni caused a significant reduction of fresh weight of seedling roots. Root and top weights of seedlings grown in soil infested with Meloidodera floridensis or Pratylenchus brachyurus were significantly less than those of seedlings in noninfested soil. Root growth of seedlings was stimulated by the higher inoculum density of Scutellonema brachyurum.

  2. Nematodes associated with blackberry in arkansas.

    PubMed

    Wehunt, E J; Golden, A M; Clark, J R; Kirkpatrick, T L; Baker, E C; Brown, M A

    1991-10-01

    A survey of the nematodes in blackberry (Rubus sp.) rhizospheres was conducted in Arkansas from 1986 to 1989. The state was divided arbitrarily into four quadrants. A total of 134 soil samples was collected, and 150-cm 3 subsamples were assayed for nematodes. Twenty-one species of plant-parasitic nematodes in 11 genera were extracted from the samples. There were differences (P = 0.05) among quadrants of the state in percentage occurrence of the nematodes and in population densities in samples. Xiphinema americanum, Helicotylenchus spp. (H. paraplatyurus, H. platyurus, and H. pseudorobustus), and Pratylenchus spp. (P. vulnus and P. zeae) were found in all quadrants. Xiphinema americanum population density was near 1,000 per 150 cm(3) soil in soil samples from two locations. Other nematodes found in one or more quadrants were Criconemella spp. (C. axeste, C. curvata, C. denoudeni, C. ornata, C. sphaerocephala, and C. xenoplax), Paratrichodorus minor, Tylenchorhynchus claytoni, Hirschmanniella oryzae, Hoplolaimus magnistylus, Scutellonema bradys, and undescribed species of Criconema, Tylenchulus, Xiphinema, and Meloidogyne. Criconemella sphaerocephala and Helicotylenchus platyurus are reported from Arkansas for the first time. Helicotylenchus paraplatyurus is reported from the United States for the first time.

  3. Permanent synchronization of camcorders via LANC protocol

    NASA Astrophysics Data System (ADS)

    Vrancic, Damir; Smith, Steven L.

    2006-02-01

    A device, which keeps two camcorders permanently in synchronization, has been developed. The mentioned device uses LANC (CONTROL-L) camcorder's inputs for synchronization. It enables controlling of two camcorders simultaneously via built-in buttons, by using external LANC remote controller and/or by the PC via serial (RS232) communication. Since device requires LANC inputs on camcorders or ACC inputs on still cameras, it can be used on some camcorders produced by manufacturers Sony and Canon or some still cameras produced by Sony. The device initially synchronizes camcorders or still cameras by applying arbitrarily delayed power-up pulses on LANC (ACC) inputs. Then, on user demand, the camcorders can be permanently synchronized (valid only for some camcorders produced by Sony). The effectiveness of the proposed device is demonstrated by several experiments on three types of camcorders (DCR-TRV900E, HDR-HC1, HVR-Z1U) and one type of still camera (DSC-V1). The electronic schemes, PCB layouts, firmware and communication programs are freely available (under GPL licence).

  4. A Chance to Be Like Lance

    ERIC Educational Resources Information Center

    Prouty, Anne

    2004-01-01

    The authors' seventh-grade science curriculum includes a study of nutrition, anatomy, and physiology. Over several years, the authors' teaching partner and herself reworked the nine-week unit to include the Tour de France and the exploits of Lance Armstrong. What makes this unit so engaging for middle school students is that it provides an…

  5. The effect of lance geometry and carbon coating of silicon lances on propidium iodide uptake in lance array nanoinjection of HeLa 229 cells

    NASA Astrophysics Data System (ADS)

    Sessions, John W.; Lindstrom, Dallin L.; Hanks, Brad W.; Hope, Sandra; Jensen, Brian D.

    2016-04-01

    Connecting technology to biologic discovery is a core focus of non-viral gene therapy biotechnologies. One approach that leverages both the physical and electrical function of microelectromechanical systems (MEMS) in cellular engineering is a technology previously described as lance array nanoinjection (LAN). In brief, LAN consists of a silicon chip measuring 2 cm by 2 cm that has been etched to contain an array of 10 μm tall, solid lances that are spaced every 10 μm in a grid pattern. This array of lances is used to physically penetrate hundreds of thousands of cells simultaneously and to then electrically deliver molecular loads into cells. In this present work, two variables related to the microfabrication of the silicon lances, namely lance geometry and coating, are investigated. The purpose of both experimental variables is to assess these parameters’ effect on propidium iodide (PI), a cell membrane impermeable dye, uptake to injected HeLa 229 cells. For the lance geometry experimentation, three different microfabricated lance geometries were used which include a flat/narrow (FN, 1 μm diameter), flat/wide (FW, 2-2.5 μm diameter), and pointed (P, 1 μm diameter) lance geometries. From these tests, it was shown that the FN lances had a slightly better cell viability rate of 91.73% and that the P lances had the best PI uptake rate of 75.08%. For the lance coating experimentation, two different lances were fabricated, both silicon etched lances with some being carbon coated (CC) in a  <100 nm layer of carbon and the other lances being non-coated (Si). Results from this experiment showed no significant difference between lance types at three different nanoinjection protocols (0V, +1.5V DC, and  +5V Pulsed) for both cell viability and PI uptake rates. One exception to this is the comparison of CC/5V Pul and Si/5V Pul samples, where the CC/5V Pul samples had a cell viability rate 5% higher. Both outcomes were unexpected and reveal how to better

  6. Effect of Certain Nematodes on the Growth of Pinus edulis and Juniperus monosperma seedlings

    PubMed Central

    Riffle, J. W.

    1972-01-01

    Pinus edulis and Juniperus monosperma seedlings were inoculated separately with each of seven nematode species, and grown for 9 months at 20 C soil temperature. Hoplolaimus galeatus, Rotylenchus pumilis, Tylenchus exiguus, and Xiphinema americanum parasitized P. edulis seedlings, but did not significantly reduce seedling growth. Pinus edulis was not a host for Tylenchorhynchus cylindricus, Aphelenchoides cibolensis, or Criconemoides humilis. Xiphinema americanum and R. pumilis parasitized J. monosperma seedlings, and reduced their root weights and root collar diameters. Juniperus monosperma was not a host for A. cibolensis and T. exiguus, and parasitism of this tree species by T. cylindricus and C. humilis remains uncertain. PMID:19319253

  7. Heat transfer and lance clogging during submerged powder injection

    NASA Astrophysics Data System (ADS)

    Irons, G. A.

    1987-03-01

    Nitrogen and silica particles of 30, 130, and 450 μm average diameters were injected at solid-to-gas loadings up to 280 kg/m3 into liquid lead at 400°C through a steel lance equipped with four thermo-couples. The lance was positioned adjacent to a transparent wall in the lead retort so that the flow patterns could be photographed. It was found that 130 and 450 μm particle injection produced bubling in the lead and clogging at high loadings, while the 30 μm particles produced jetting with no clogging. Analysis of the thermocouple responses permitted the determination of the heat transfer coefficients at the inner and outer lance surfaces. The inner surface heat transfer coefficient increased with loading, whereas the one at the outer surface was independent of loading. A two-phase, unsteady-state, one-dimensional model was developed for momentum and heat transfer in the lance permitting the calculation of gas and particle velocities, volume fractions, and temperatures as well as the lance temperatures. Using the experimentally determined heat transfer coefficients, it is shown that the gas and particles are heated only 20 to 40 K in the lance. Nevertheless, this is a large heat demand which chills the lance so that clogging will occur in the bubbling regime.

  8. 3. EASTERN VIEW OF HOISTING RIG FOR OXYGEN LANCES ON ...

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

    3. EASTERN VIEW OF HOISTING RIG FOR OXYGEN LANCES ON THE FLUX STORAGE FLOOR OF THE FURNACE AISLE IN THE BOP SHOP. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  9. Effects of nematicides on nematode densities in turf in Connecticut.

    PubMed

    Miller, P M

    1978-04-01

    The plant-parasitic nematodes Criconemoides lobatum, Hoplolaimus tylenchiformis, and Tylenchorhynchus dubius were present in the top 7.5 cm of sod consisting of numerous stolons and fibrous roots. Phenamiphos and 1,2-dibromo-3-chloropropane (DBCP) controlled all three species, whereas ethoprop and oxamyl controlled H. tylenchiformis and T. dubius but not C. lobatum. Benomyl and carbofuran controlled H. tylenchiformis but had poor control of C. lobatum and T. dubius. The effectiveness of carbofuran varied with the type of formulation, being most effective as a quick-release formulation. C. lobatum was the most difficult to control with chemicals. No chemical treatment improved the growth of 'Astoria colonial' bentgrass (A. tenuis Sibth.) or Kentucky bluegrass (Poa pratensis L.) under the moist condtions prevalent in these tests.

  10. Saline Irrigation Affects Belonolaimus longicaudatus and Hoplolaimus galeatus on Seashore Paspalum

    PubMed Central

    Hixson, A. C.; Crow, W. T.; McSorley, R.; Trenholm, L.E.

    2005-01-01

    Seashore paspalum (Paspalum vaginatum) has great potential for use in salt-affected turfgrass sites. Use of this grass on golf courses, athletic fields, and lawns in subtropical coastal areas may aid in conservation of freshwater resources. Belonolaimus longicaudatus and Hoplolaimus galeatus are considered among the most damaging root pathogens of turfgrasses in Florida. Glasshouse experiments were performed in 2002 and 2003 to examine the effects of increasing levels of irrigation salinity on B. longicaudatus and H. galeatus. Irrigation treatments were formulated by concentrating deionized water to six salinity levels (0, 5, 10, 15, 20, and 25 dS/m). Final population densities of H. galeatus followed a negative linear regression (r² = 0.92 and 0.83; P <= 0.01) with increasing salinity levels. Final population densities of B. longicaudatus were quadratically (r² = 0.72 and 0.78; P <= 0.01) related to increasing salinity levels from 0 to 25 dS/m. An increase in population densities of B. longicaudatus was observed at moderate salinity levels (10 and 15 dS/m) compared to 0 dS/m. Root-length comparisons revealed that B. longicaudatus caused root stunting at low salinity levels, 0 to 10 dS/m, but roots were not affected at 15 to 25 dS/m. These results indicate that the ability of B. longicaudatus to feed and stunt root growth was negatively affected at salinity levels of 15 dS/m and above. PMID:19262841

  11. Phytoparasitic Nematode Populations in Festuca arundinacea Field Plots in Southwestern Missouri

    PubMed Central

    O'Day, M. H.; Niblack, T. L.; Bailey, W. C.

    1993-01-01

    Field plots of tall rescue (Festuca arundinacea) at two locations on the same experimental farm in southwestern Missouri were sampled (one in 1987-88, the other in 1988-89) to inventory root-parasitic nematodes and to determine whether cultivars or endophyte (Acremonium coenophialum) infection frequencies (EIF) affected nematode population densities within single growing seasons. Plots were planted with seven tall rescue cultivars: Kentucky-31, Kenhy, Johnstone, Martin, Mozark, Missouri-96, and Forager. Kentucky-31 seed with high and low EIF were planted in separate plots. Plant-parasitic nematodes were extracted from soil samples, identified to genus, and enumerated four and three times per year for the 1987-1988 and 1988-1989 studies, respectively. Several plant-parasitic genera were identified from both fields, including Helicotylenchus, Heterodera, Hoplolaimus, Paratylenchus, Pratylenchus, Tylenchorhynchus, and members of genera grouped in the family Tylenchidae. Densities of five of these seven groups of nematodes differed among tall fescue cultivars in the 1987-88 study, but only two out of eight groups did so in the 1988-89 study. Irrespective of tall rescue cultivar, EIF had no consistent impact on nematode densities. The putative suppressive effect of endophyte infection on infection by plant-parasitic nematodes is not detectable within single growing seasons and deserves long-term study in field situations. PMID:19279861

  12. Analysis of the comparison of lancing devices for self-monitoring of blood glucose regarding lancing pain.

    PubMed

    Lekarcyk, Joyce; Ghiloni, Suzanne

    2009-09-01

    Reducing barriers to self-monitoring of blood glucose (SMBG) remains an ongoing goal. One major reported barrier is lancing pain. This analysis was written in response to the article by Kocher and associates in this issue of Journal of Diabetes Science and Technology in which 157 patients with diabetes experienced in the use of SMBG compared high market share blood glucose monitoring systems and lancing devices. Upon review of their findings, we found that their conclusions-Accu-check systems and lancing devices were preferred-were valid within the limitations of the study. However, we noted some factors that would warrant further study and possibly change the outcome. Information from this and other studies on the topic will be useful as a reference for patients and providers in working towards removing barriers to SMBG.

  13. Information Brokers/Free-Lance Librarians: An Alternative Reference Service.

    ERIC Educational Resources Information Center

    Hogan, Matthew

    This paper examines the profession of information brokerage through a look at types of services provided, and through a discussion of major issues, including that of fee for service. The types of information broker and free-lance librarian services are identified: (1) non-profit reference and research services administered by public libraries and…

  14. An Integrated Approach for Accessing Multiple Datasets through LANCE

    NASA Astrophysics Data System (ADS)

    Murphy, K. J.; Teague, M.; Conover, H.; Regner, K.; Beaumont, B.; Masuoka, E.; Vollmer, B.; Theobald, M.; Durbin, P.; Michael, K.; Boller, R. A.; Schmaltz, J. E.; Davies, D.; Horricks, K.; Ilavajhala, S.; Thompson, C. K.; Bingham, A.

    2011-12-01

    The NASA/GSFC Land Atmospheres Near-real time Capability for EOS (LANCE) provides imagery for approximately 40 data products from MODIS, AIRS, AMSR-E and OMI to support the applications community in the study of a variety of phenomena. Thirty-six of these products are available within 2.5 hours of observation at the spacecraft. The data set includes the population density data provided by the EOSDIS Socio-Economic Data and Applications Center (SEDAC). The purpose of this paper is to describe the variety of tools that have been developed by LANCE to support user access to the imagery. The long-standing Rapid Response system has been integrated into LANCE and is a major vehicle for the distribution of the imagery to end users. There are presently approximately 10,000 anonymous users per month accessing these imagery. The products are grouped into 14 applications categories such as Smoke Plumes, Pollution, Fires, Agriculture and the selection of any category will make relevant subsets of the 40 products available as possible overlays in an interactive Web Client utilizing Web Mapping Service (WMS) to support user investigations (http://lance2.modaps.eosdis.nasa.gov/wms/). For example, selecting Severe Storms will include 6 products for MODIS, OMI, AIRS, and AMSR-E plus the SEDAC population density data. The client and WMS were developed using open-source technologies such as OpenLayers and MapServer and provides a uniform, browser-based access to data products. All overlays are downloadable in PNG, JPEG, or GeoTiff form up to 200MB per request. The WMS was beta-tested with the user community and substantial performance improvements were made through the use of such techniques as tile-caching. LANCE established a partnership with Physical Oceanography Distributed Active Archive Center (PO DAAC) to develop an alternative presentation for the 40 data products known as the State of the Earth (SOTE). This provides a Google Earth-based interface to the products grouped in

  15. LANCE Q-flex accelerometer qualification test program

    NASA Astrophysics Data System (ADS)

    Hunter, J. S.; Mitchell, J. N.; Hester, T.; Searcy, D.

    1982-03-01

    This report covers the performance obtained on six Sundstrand Q-Flex accelerometers during the qualification test program for the LANCE missile. The Qualification Test Program was divided into three parts: (1) Flight Assurance Tests (FAT), (2) Storage and Transportation Tests (SATT), and (3) Reliability Overstress Tests (ROT). All testing was performed in accordance with Vought accelerometer procurement specification 704-166C dated 8 June 1978.

  16. "Sea Lance" Littoral Warfare Small Combatant System

    DTIC Science & Technology

    2001-01-01

    system that uses biotreatment in conjunction with microfiltration to treat the liquid waste. The effluent will meet the following standards: iv...detailed description of the treatment system. SEA LANCE will process oily waste with a Combined Oily Waste Membrane System. The Navy Integrate... Membrane System (NIMS) will produce an effluent less than 15-PPM oil. All bilge water will be processed through the oily waste system. Appendix I

  17. Music modulates behaviour of premature infants following heel lance.

    PubMed

    Butt, M L; Kisilevsky, B S

    2000-03-01

    The physiological and behavioural effects of music during recovery from heel lance were examined in 14 preterm infants at 29 to 36 weeks post-conceptual age (PCA). Infants were tested on 2 occasions: during a music condition and during a no-music control condition. Each condition was videotaped during 3 periods: baseline, heel lance, and recovery. Infants were divided into 2 age groups for data analyses: less than and greater than 31 weeks PCA. Mixed model ANOVAs showed that heel lance elicited a stress response (i.e., increased heart rate, decreased oxygen saturation, increased state-of-arousal, and increased facial actions indicative of pain) in both age groups. The stress response was greater in the older group. During recovery, the older group had a more rapid return of heart rate, behavioural state, and facial expressions of pain to baseline levels in the presence of compared to the absence of music. It was concluded that music is an effective NICU intervention following a stress-provoking stimulus in infants older than 31 weeks PCA.

  18. Survey of crop losses in response to phytoparasitic nematodes in the United States for 1994.

    PubMed

    Koenning, S R; Overstreet, C; Noling, J W; Donald, P A; Becker, J O; Fortnum, B A

    1999-12-01

    Previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. Reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the University of Georgia, the Beltwide Cotton Conference, and selected groups concerned with soybean. The Society of Nematologists Extension Committee contacted extension personnel in 49 U.S. states for information on estimated crop losses caused by plant-parasitic nematodes in major crops for the year 1994. Included in this paper are survey results from 35 states on various crops including corn, cotton, soybean, peanut, wheat, rice, sugarcane, sorghum, tobacco, numerous vegetable crops, fruit and nut crops, and golf greens. The data are reported systematically by state and include the estimated loss, hectarage of production, source of information, nematode species or taxon when available, and crop value. The major genera of phytoparasitic nematodes reported to cause crop losses were Heterodera, Hoplolaimus, Meloidogyne, Pratylenchus, Rotylenchulus, and Xiphinema.

  19. Survey of Crop Losses in Response to Phytoparasitic Nematodes in the United States for 1994

    PubMed Central

    Koenning, S. R.; Overstreet, C.; Noling, J. W.; Donald, P. A.; Becker, J. O.; Fortnum, B. A.

    1999-01-01

    Previous reports of crop losses to plant-parasitic nematodes have relied on published results of survey data based on certain commodities, including tobacco, peanuts, cotton, and soybean. Reports on crop-loss assessment by land-grant universities and many commodity groups generally are no longer available, with the exception of the University of Georgia, the Beltwide Cotton Conference, and selected groups concerned with soybean. The Society of Nematologists Extension Committee contacted extension personnel in 49 U.S. states for information on estimated crop losses caused by plant-parasitic nematodes in major crops for the year 1994. Included in this paper are survey results from 35 states on various crops including corn, cotton, soybean, peanut, wheat, rice, sugarcane, sorghum, tobacco, numerous vegetable crops, fruit and nut crops, and golf greens. The data are reported systematically by state and include the estimated loss, hectarage of production, source of information, nematode species or taxon when available, and crop value. The major genera of phytoparasitic nematodes reported to cause crop losses were Heterodera, Hoplolaimus, Meloidogyne, Pratylenchus, Rotylenchulus, and Xiphinema. PMID:19270925

  20. Effects of Perennial Peanut (Arachis glabrata) Ground Cover on Nematode Communities in Citrus

    PubMed Central

    Macchia, E. T.; McSorley, R.; Duncan, L. W.; Syvertsen, J. S.

    2003-01-01

    The effects of perennial peanut (Arachis glabrata) ground cover on the nematode community in a citrus orchard were examined. Samples were taken from two different ground cover treatments (perennial peanut or bare ground) at each of three distances from the tree trunk. Richness, measured as total numbers of nematode genera per sample, and total numbers of nematodes were greatest in the perennial peanut treatment (P < 0.05). Abundance of many genera of bacterivores, fungivores, and omnivores were increased by the perennial peanut ground cover. Total numbers of plant parasites were greater in perennial peanut treatments on three of the five sampling dates (P < 0.05), mainly due to trends in numbers of Mesocriconema. Distance from a tree trunk and the interaction of ground cover treatments and proximity to a tree trunk were most influential for Belonolaimus and Hoplolaimus. Although differences among treatments were observed for nematode genera and trophic groups, ecological indices were not consistently sensitive to treatments. Among several ecological indices evaluated, richness was most often affected by ground cover treatment. PMID:19262779

  1. Effects of Perennial Peanut (Arachis glabrata) Ground Cover on Nematode Communities in Citrus.

    PubMed

    Macchia, E T; McSorley, R; Duncan, L W; Syvertsen, J S

    2003-12-01

    The effects of perennial peanut (Arachis glabrata) ground cover on the nematode community in a citrus orchard were examined. Samples were taken from two different ground cover treatments (perennial peanut or bare ground) at each of three distances from the tree trunk. Richness, measured as total numbers of nematode genera per sample, and total numbers of nematodes were greatest in the perennial peanut treatment (P < 0.05). Abundance of many genera of bacterivores, fungivores, and omnivores were increased by the perennial peanut ground cover. Total numbers of plant parasites were greater in perennial peanut treatments on three of the five sampling dates (P < 0.05), mainly due to trends in numbers of Mesocriconema. Distance from a tree trunk and the interaction of ground cover treatments and proximity to a tree trunk were most influential for Belonolaimus and Hoplolaimus. Although differences among treatments were observed for nematode genera and trophic groups, ecological indices were not consistently sensitive to treatments. Among several ecological indices evaluated, richness was most often affected by ground cover treatment.

  2. A feature study of innovative high-speed lancing device and safety lancet.

    PubMed

    Chang, Ho; Yeh, Yao-Jen; Lee, Rahnfong; Shyu, Jenq-Huey

    2016-12-01

    The study developed two models of an innovative high-speed lancing device and safety lancet, where the specially designed structure causes high-speed motion of the lancet, resulting in only one puncture of the skin. The two experimental models and other lancing devices sold on market were compared in order to: (1) measure the forces of lancets piercing animal skin by a load cell; (2) observe the wound areas caused by lancing devices under a microscope. The experimental results showed that, after using this innovative high-speed lancing device, the maximum force of a lancet piercing skin is only 1/3 of the force of conventional lancing devices, and the duration of the former under the skin is 1/6 of the latter. In addition, the wound area caused by the innovative lancing device is 20 % smaller than those of the conventional lancing devices. Usage of this innovative high-speed safety lancet shows that its maximum skin-piercing force is only 2/3 of conventional safety lancets, its duration under the skin is 1/4 of conventional safety lancets, and the wound area is 12 % smaller. In conclusion, both the innovative high-speed lancing device and safety lancet are proved effective in alleviating pain for diabetics and shortening the recovering time for wounds, thus, providing a more comfortable process for the self-monitoring of blood glucose.

  3. Enhancements to NASA's Land Atmosphere Near Real-Time Capability for EOS (LANCE)

    NASA Technical Reports Server (NTRS)

    Davies, Diane; Michael, Karen; Schmaltz, Jeffrey; Boller, Ryan A.; Masuoka, Ed; Ye, Gang; Roman, Miguel; Vermote, Eric; Harrison, Sherry; Rinsland, Pamela; Protack, Steve; Durbin, Phil; Ding, Feng; Justice, Chris

    2016-01-01

    NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE) supports application users interested in monitoring a wide variety of natural and man-made phenomena. Near Real- Time (NRT) data and imagery from the AIRS, AMSR2, MISR, MLS, MODIS, OMPS, OMI and VIIRS instruments are available much quicker than routine processing allows. Most data products are available within 3 hours from satellite observation. NRT imagery are generally available 3-5 hours after observation. This article describes the LANCE and the enhancements made to the LANCE over the last year. These enhancements include the addition of NRT products from AMSR2, MISR, OMPS and VIIRS. In addition, the selection of LANCE NRT imagery that can be interactively viewed through Worldview and the Global Imagery Browse Services (GIBS) has been expanded. Next year, data from the MOPITT will be added to the LANCE.

  4. Influence of Poultry Litter Applications on Nematode Communities in Cotton Agroecosystems

    PubMed Central

    Koenning, S. R.; Barker, K. R.

    2004-01-01

    The effects of the application of poultry litter at 0.0, 6.7, 13.4, and 20.1 tons/ha on population changes during the growing season on nematode communities were evaluated in two cotton production fields in North Carolina. Numbers of bactivorous nematodes increased at midseason in response to the rate at which litter was applied but decreased with increasing litter application rates at cotton harvest. Numbers of fungivores at cotton harvest were related positively to the rate of litter applied, and this affected a positive increase in the fungivore-to-bacterivore ratio at this sampling date. The rate at which poultry litter was applied resulted in an increase in the bacterivore to plant-parasite ratio, and this corresponded with increased cotton lint yield. Trophic diversity was increased by litter application rate at cotton harvest at one location but not at another. The plant-parasite maturity index was greater consistently at one site than at a second site where the Hoplolaimus columbus population density was above the damage threshold for cotton. The population density of H. columbus was suppressed with increasing rates of poultry litter application, but other plant-parasitic nematodes were affected marginally. PMID:19262834

  5. The dawn of the e-lance economy.

    PubMed

    Malone, T W; Laubacher, R J

    1998-01-01

    Will the large industrial corporation dominate the twenty-first century as it did the twentieth? Maybe not. Drawing on their research at MIT's Initiative on Inventing the Organizations of the 21st Century, Thomas Malone and Robert Laubacher postulate a world in which business is not controlled through a stable chain of management in a large, permanent company. Rather, it is carried out autonomously by independent contractors connected through personal computers and electronic networks. These electronically connected free-lancers-e-lancers-would join together into fluid and temporary networks to produce and sell goods and services. When the job is done--after a day, a month, a year--the network would dissolve and its members would again become independent agents. Far from being a wild hypothesis, the e-lance economy is, in many ways, already upon us. We see it in the rise of outsourcing and telecommuting, in the increasing importance within corporations of ad-hoc project teams, and in the evolution of the Internet. Most of the necessary building blocks of this type of business organization--efficient networks, data interchange standards, groupware, electronic currency, venture capital micromarkets--are either in place or under development. What is lagging behind is our imagination. But, the authors contend, it is important to consider sooner rather than later the profound implications of how such an e-lance economy might work. They examine the opportunities, and the problems, that may arise and anticipate how the role of managers may change fundamentally--or possibly even disappear altogether.

  6. Enhancements to NASA's Land Atmosphere Near Real-Time Capability for Eos (LANCE)

    NASA Astrophysics Data System (ADS)

    Davies, D.; Murphy, K. J.; Schmaltz, J. E.; Boller, R. A.; Cechini, M. F.; Mauoka, E.; Ye, G.; Conover, H.; Regner, K. J.; Harrison, S.

    2014-12-01

    NASA's Land Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) provides data and imagery from Terra, Aqua and Aura satellites in less than 3 hours from satellite observation, to meet the needs of the near real-time (NRT) applications community. This article describes LANCE and enhancements made to LANCE over the last year. These enhancements include: 3 new NRT products, additional search and download data capability through Worldview, and a greater selection of NRT imagery that can be interactively viewed through Worldview and the Global Imagery Browse Services (GIBS). LANCE is also working to ingest and process AMSR2 data in NRT. This presentation describes the enhancements, and the potential uses for the new products, which include daily NRT 8-day rolling Vegetation Indices (VI) and Land Surface Reflectance (LSR) products and a 16-day rolling Bidirectional Reflectance Distribution Function (BRDF) product.

  7. Simulation of three-phase flow and lance height effect on the cavity shape

    NASA Astrophysics Data System (ADS)

    Dong, Kai; Zhu, Rong; Gao, Wei; Liu, Fu-hai

    2014-06-01

    A three-dimensional computational fluid dynamics (CFD) model was developed to simulate a 150-t top-blown converter. The effect of different lance heights on the cavity shape was investigated using the volume of fluid (VOF) method. Numerical simulation results can reflect the actual molten bath surface waves impinged by the supersonic oxygen jets. With increasing lance height, the cavity depth decreases, and the cavity area, varying like a parabola, increases and then decreases. The cavity area maximizes at the lance height of 1.3 m. Under the three different lance heights simulated in this study, all of the largest impact velocities at the molten bath surface are between 50 m/s and 100 m/s.

  8. LANCE in ECHO - Merging Science and Near Real-Time Data Search and Order

    NASA Astrophysics Data System (ADS)

    Kreisler, S.; Murphy, K. J.; Vollmer, B.; Lighty, L.; Mitchell, A. E.; Devine, N.

    2012-12-01

    NASA's Earth Observing System (EOS) Data and Information System (EOSDIS) Land Atmosphere Near real-time Capability for EOS (LANCE) project provides expedited data products from the Terra, Aqua, and Aura satellites within three hours of observation. In order to satisfy latency requirements, LANCE data are produced with relaxed ancillary data resulting in a product that may have minor differences from its science quality counterpart. LANCE products are used by a number of different groups to support research and applications that require near real-time earth observations, such as disaster relief, hazard and air quality monitoring, and weather forecasting. LANCE elements process raw rate-buffered and/or session-based production datasets into higher-level products, which are freely available to registered users via LANCE FTP sites. The LANCE project also generates near real-time full resolution browse imagery from these products, which can be accessed through the Global Imagery Browse Services (GIBS). In an effort to support applications and services that require timely access to these near real-time products, the project is currently implementing the publication of LANCE product metadata to the EOS ClearingHouse (ECHO), a centralized EOSDIS registry of EOS data. Metadata within ECHO is made available through an Application Program Interface (API), and applications can utilize the API to allow users to efficiently search and order LANCE data. Publishing near real-time data to ECHO will permit applications to access near real-time product metadata prior to the release of its science quality counterpart and to associate imagery from GIBS with its underlying data product.

  9. Flowrate testing of the bag filter LANCS-BOP 6CPVC-1.5-2SPVC (LANCS Industries) at 1 psig

    SciTech Connect

    Moore, Murray E.; Currie, Karissa Lyn; Berg, Charlotte Katherine

    2016-09-13

    The air flowrate through a flexible HEPA grade filter (Part LANCS-BOP 6CPVC-1.5-2SPVC www.lancsindustries.com) was measured at 48 ALPM for a differential pressure drop of 1.0 psig (28 inWC, 7.0 kPa). These filters are rated by the manufacturer to have a flowrate of 3 ALPM at a differential pressure drop of 1 inWC (0.25 kPa). The Los Alamos National Laboratory Aerosol Engineering Facility used one of their test rigs (originally developed to measure the pressure drop in capsule HEPA filters) to measure the airflow through the LANCS bag filter.

  10. Nematodes (Rhabditida: Steinernematidae and Heterorhabditidae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes are roundworms in the phylum Nematoda. Although most are free-living, some nematodes are parasites of plants, humans, or livestock. Entomopathogenic nematodes in the families Steinernematidae & Heterorhabditidae only parasitize insects. These nematodes are used as environmentally friend...

  11. Global Agricultural Monitoring (GLAM) using MODAPS and LANCE Data Products

    NASA Astrophysics Data System (ADS)

    Anyamba, A.; Pak, E. E.; Majedi, A. H.; Small, J. L.; Tucker, C. J.; Reynolds, C. A.; Pinzon, J. E.; Smith, M. M.

    2012-12-01

    The Global Inventory Modeling and Mapping Studies / Global Agricultural Monitoring (GIMMS GLAM) system is a web-based geographic application that offers Moderate Resolution Imaging Spectroradiometer (MODIS) imagery and user interface tools to data query and plot MODIS NDVI time series. The system processes near real-time and science quality Terra and Aqua MODIS 8-day composited datasets. These datasets are derived from the MOD09 and MYD09 surface reflectance products which are generated and provided by NASA/GSFC Land and Atmosphere Near Real-time Capability for EOS (LANCE) and NASA/GSFC MODIS Adaptive Processing System (MODAPS). The GIMMS GLAM system is developed and provided by the NASA/GSFC GIMMS group for the U.S. Department of Agriculture / Foreign Agricultural Service / International Production Assessment Division (USDA/FAS/IPAD) Global Agricultural Monitoring project (GLAM). The USDA/FAS/IPAD mission is to provide objective, timely, and regular assessment of the global agricultural production outlook and conditions affecting global food security. This system was developed to improve USDA/FAS/IPAD capabilities for making operational quantitative estimates for crop production and yield estimates based on satellite-derived data. The GIMMS GLAM system offers 1) web map imagery including Terra & Aqua MODIS 8-day composited NDVI, NDVI percent anomaly, and SWIR-NIR-Red band combinations, 2) web map overlays including administrative and 0.25 degree Land Information System (LIS) shape boundaries, and crop land cover masks, and 3) user interface tools to select features, data query, plot, and download MODIS NDVI time series.

  12. Maturation, fecundity, and intertidal spawning of Pacific sand lance in the northern Gulf of Alaska

    USGS Publications Warehouse

    Robards, Martin D.; Piatt, John F.; Rose, G.A.

    1999-01-01

    Pacific sand lance Ammodytes hexapterus in Kachemak Bay, Alaska, showed no sexual dimorphism in length-to-weight (gonad-free) ratio or length-at-age relationship. Most matured in their second year, males earlier in the season than females, but females (31%) attained a higher gonadosomatic index than males (21%). Sand lance spawned intertidally once each year in late September and October on fine gravel or sandy beaches soon after the seasonal peak in water temperatures. Sand lance in Cook Inlet and Prince William Sound displayed similar maturation schedules. Schools were dominated 2: 1 by males as they approached the intertidal zone at a site where spawning has taken place for decades. Sand lance spawned vigorously in dense formations, leaving scoured pits in beach sediments. Fecundity of females (93–199 mm) was proportional to length, ranging from 1468 to 16 081 ova per female. About half of the overall spawning school fecundity was derived from age group 1 females (55% of the school by number). Spawned eggs were 1·02 mm in diameter, demersal, slightly adhesive, and deposited in the intertidal just below the waterline. Sand lance embryos developed over 67 days through periods of intertidal exposure and sub-freezing air temperatures.

  13. Repeated Sampling to Determine the Precision of Estimating Nematode Population Densities

    PubMed Central

    Schmitt, D. P.; Barker, K. R.; Noe, J. P.; Koenning, S. R.

    1990-01-01

    The first phase of this study involved repeated samplings of five fields using composite samples of 10, 20, 40, and 80 soil cores, to determine the precision of nematode assays. The second phase focused on randomly selecting two and four 2-ha subunits (data on Meloidogyne spp.) of 24 fields ranging from 6 to 40 ha and computing the precision of estimated means for these numbers ofsubunits versus the general field mean (based on all 2-ha subunits). Average numbers of nematodes from most samples containing Meloidogyne spp., Heterodera glycines, Helicotylenchus dihystera, Scutellonema brachyurum, and (or) Hoplolaimus galeatus were within 50% of the overall means. Coefficient of variation (CV) values were generally lower for 40 cores than for 10, 20, and 80 cores per sample. When data for all nematodes and fields were combined, this value was lowest for 40 and 80 cores. The CV values were higher for Meloidogyne spp. than for H. glycines. Means of two samplings increased the probability of obtaining numbers nearer the mean for that field than numbers from a single composite sample. For the second phase, population estimates of Meloidogyne spp. based on four 2-ha subunits generally were closer to field means than were those for two subunits. Sampling precision with these subunits diminished greatly in large fields with variable soils and (or) mixed cropping histories. Either two or four subunits gave population estimates within 3-20% of the field mean in most instances. The mean man hours required for sampling ca. 2-ha parcels of 4-20-ha fields was 0.54 hours. PMID:19287757

  14. Entomopathogenic nematodes and insect management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes (genera Heterorhabditis, Steinernema, and Neosteinernema) are used as bioinsecticides. The nematodes are ubiquitous and have been isolated in soil of every continent except Antarctica. The nematodes kill insects through a mutualism with a bacterium (Photorhabdus spp. or ...

  15. Diversity and Occurrence of Plant-parasitic Nematodes Associated with Golf Course Turfgrasses in North and South Carolina, USA

    PubMed Central

    Zeng, Yongsan; Ye, Weimin; Bruce Martin, S.; Martin, Matt; Tredway, Lane

    2012-01-01

    One hundred and eleven golf courses from 39 counties in the Carolinas were surveyed for plant-parasitic nematodes. Species diversity within habitats was analyzed with five diversity indices including Diversity index (H’), Evenness (J’), Richness (SR), Dominance (λ) and Diversity (H2). The results revealed a remarkably high diversity of 24 nematode species belonging to 19 genera and 11 families. Of those, 23 species were found in SC, 19 species in NC, and 18 species were detected in both states. Helicotylenchus dihystera, Mesocriconema xenoplax, Hoplolaimus galeatus, Tylenchorhynchus claytoni, Belonolaimus longicaudatus, Meloidogyne graminis and Paratrichodorus minor were the most prevalent and abundant species in golf course turfgrasses in both states. Twelve species were new records of plant parasitic nematodes in turfgrasses in both NC and SC. The results also revealed effects of different habitats on diversity of nematode species in turfgrass ecosystem. H’ and SR values were higher in SC than in NC. H’, J’ and H2 values were significantly higher in sandy than in clay soil in NC, but no significant differences between sand and clay soil were detected in SC or in pooled data from both states. There were no significant differences for all indices among the management zones (putting green, fairway and tee) in NC. However, in SC and pooled data, H’, SR and H2 were significantly higher in putting greens than in fairways and tees. Significant differences from different grass species (bermudagrass, creeping bentgrass and zoysiagrass) were detected only in H’, which was significantly higher in zoysiagrass than in bentgrass or bermudagrass in NC. In pooled data, H’ was significantly higher in zoysiagrass samples than in creeping bentgrass samples but was not significantly different from bermudagrass samples. PMID:23482422

  16. On-Site Oxy-Lance Size Reduction of South Texas Project Reactor Vessel Heads - 12324

    SciTech Connect

    Posivak, Edward; Keeney, Gilbert; Wheeler, Dean

    2012-07-01

    On-Site Oxy-Lance size reduction of mildly radioactive large components has been accomplished at other operating plants. On-Site Oxy-Lance size reduction of more radioactive components like Reactor Vessel Heads had previously been limited to decommissioning projects. Building on past decommissioning and site experience, subcontractors for South Texas Project Nuclear Operating Company (STPNOC) developed an innovative integrated system to control smoke, radioactive contamination, worker dose, and worker safety. STP's innovative, easy to use CEDM containment that provided oxy lance access, smoke control, and spatter/contamination control was the key to successful segmentation for cost-effective and ALARA packaging and transport for disposal. Relative to CEDM milling, STP oxy-lance segmentation saved approximately 40 person- REM accrued during 9,000 hours logged into the radiological controlled area (RCA) during more than 3,800 separate entries. Furthermore there were no personnel contamination events or respiratory uptakes of radioactive material during the course of the entire project. (authors)

  17. Learning from LANCE: Developing a Web Portal Infrastructure for NASA Earth Science Data (Invited)

    NASA Astrophysics Data System (ADS)

    Murphy, K. J.

    2013-12-01

    NASA developed the Land Atmosphere Near real-time Capability for EOS (LANCE) in response to a growing need for timely satellite observations by applications users, operational agencies and researchers. EOS capabilities originally intended for long-term Earth science research were modified to deliver satellite data products with sufficient latencies to meet the needs of the NRT user communities. LANCE products are primarily distributed as HDF data files for analysis, however novel capabilities for distribution of NRT imagery for visualization have been added which have expanded the user base. Additionally systems to convert data to information such as the MODIS hotspot/active fire data are also provided through the Fire Information for Resource Management System (FIRMS). LANCE services include: FTP/HTTP file distribution, Rapid Response (RR), Worldview, Global Imagery Browse Services (GIBS) and FIRMS. This paper discusses how NASA has developed services specifically for LANCE and is taking the lessons learned through these activities to develop an Earthdata Web Infrastructure. This infrastructure is being used as a platform to support development of data portals that address specific science issues for much of EOSDIS data.

  18. 5. MOTOR/WINCH DRUM ASSEMBLY FOR OXYGEN LANCE HOISTING RIG ON ...

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

    5. MOTOR/WINCH DRUM ASSEMBLY FOR OXYGEN LANCE HOISTING RIG ON THE WEIGHING FLOOR OF THE FURNACE AISLE IN THE BOP SHOP LOOKING SOUTHEAST. - U.S. Steel Duquesne Works, Basic Oxygen Steelmaking Plant, Along Monongahela River, Duquesne, Allegheny County, PA

  19. The Use of LANCE Imagery Products to Investigate Hazards and Disasters

    NASA Astrophysics Data System (ADS)

    Schmaltz, J. E.; Teague, M.; Conover, H.; Regner, K.; Masuoka, E.; Vollmer, B. E.; Durbin, P.; Murphy, K. J.; Boller, R. A.; Davies, D.; Ilavajhala, S.; Thompson, C. K.; Bingham, A.; Rao, S.

    2011-12-01

    The NASA/GSFC Land Atmospheres Near-real time Capability for EOS (LANCE) has endeavored to integrate a variety of products from the Terra, Aqua, and Aura missions to assist in meeting the needs of the applications user community. This community has a need for imagery products to support the investigation of a wide variety of phenomena including hazards and disasters. The Evjafjallajokull eruption, the tsunamis/flood in Japan, and the Gulf of Mexico oil spill are recent examples of applications benefiting from the timely and synoptic view afforded by LANCE data. Working with the instrument science teams and the applications community, LANCE has identified 14 applications categories and the LANCE products that will support their investigation. The categories are: Smoke Plumes, Ash Plumes, Dust Storms, Pollution, Severe Storms, Shipping hazards, Fishery hazards, Land Transportation, Fires, Floods, Drought, Vegetation, Agriculture, and Oil Spills. Forty products from AMSR-E, MODIS, AIRS, and OMI have been identified to support analyses and investigations of these phenomena. In each case multiple products from two or more instruments are available which gives a more complete picture of the evolving hazard or disaster. All Level 2 (L2) products are available within 2.5 hours of observation at the spacecraft and the daily L3 products are updated incrementally as new data become available. LANCE provides user access to imagery using two systems: a Web Mapping Service (WMS) and a Google Earth-based interface known as the State of the Earth (SOTE). The latter has resulted from a partnership between LANCE and the Physical Oceanography Distributed Active Archive Center (PO DAAC). When the user selects one of the 14 categories, the relevant products are established within the WMS (http://lance2.modaps.eosdis.nasa.gov/wms/). For each application, population density data are available for densities in excess of 100 people/sqkm with user-defined opacity. These data are provided by

  20. Growth and abundance of Pacific Sand Lance, Ammodytes hexapterus, under differing oceanographic regimes

    USGS Publications Warehouse

    Robards, Martin D.; Gray, Floyd; Piatt, John F.

    2002-01-01

    Dramatic changes in seabird and marine mammal stocks in the Gulf of Alaska have been linked to shifts in abundance and composition of forage fish stocks over the past 20 years. The relative value (e.g., size and condition of individual fish, abundance) of specific forage fish stocks to predators under temporally changing oceanographic regimes is also expected to vary. We inferred potential temporal responses in abundance, growth, and age structure of a key forage fish, sand lance, by studying across spatially different oceanographic regimes. Marked meso-scale differences in abundance, growth, and mortality existed in conjunction with these differing regimes. Growth rate within stocks (between years) was positively correlated with temperature. However, this relationship did not exist among stocks (locations) and differing growth rates were better correlated to marine productivity. Sand lance were least abundant and grew slowest at the warmest site (Chisik Island), an area of limited habitat and low food abundance. Abundance and growth of juvenile sand lance was highest at the coolest site (Barren Islands), an area of highly productive upwelled waters. Sand lance at two sites located oceanographically between the Barren Islands and Chisik Island (inner- and outer-Kachemak Bay) displayed correspondingly intermediate abundance and growth. Resident predators at these sites are presented with markedly different numbers and quality of this key prey species. Our results suggest that at the decadal scale, Gulf of Alaska forage fish such as sand lance are probably more profoundly affected by changes in abundance and quality of their planktonic food, than by temperature alone.

  1. Nematode nervous systems.

    PubMed

    Schafer, William

    2016-10-24

    Nematodes comprise one of the largest phyla in the animal kingdom, both in terms of individual numbers and species diversity. Although only 20,000-30,000 species have been described, it is estimated that the true number ranges between 100,000 and 10 million. Marine, freshwater, and terrestrial species are all widespread, and some nematodes have even been isolated from such inhospitable environments as deserts, hot springs, and polar seas. Some nematode species are parasitic, with either plant or animal hosts; other species are free-living microbivores, scavengers, or predators of insects or other nematodes. Nematodes vary widely in size, from small microbivores that grow no larger than 100 μm to large animal parasites growing to several meters in length. They adopt a variety of reproductive strategies: most species are gonochoristic (i.e., have male and female sexes), but self-fertile hermaphroditic species are not uncommon, and parthenogenetic species are also known. Nematodes belong to the superphylum Ecdysozoa, a clade of moulting animals that also includes arthropods, tardigrades and priapulids. Although nematode fossils are rare, the origin of the nematode phylum is believed to be very ancient, with the divergence from arthropods estimated based on molecular data to have been between 900 and 1,300 Ma.

  2. The Nematode Caenorhabditis Elegans.

    ERIC Educational Resources Information Center

    Kenyon, Cynthia

    1988-01-01

    Discusses advantages of nematode use for studying patterns of cell division, differentiation, and morphogenesis. Describes nematode development. Cites experimental approaches available for genetic studies. Reviews the topics of control of cell division and differentiation, the nervous system, and muscle assembly and function of the organism. (RT)

  3. Evaluating the OneTouch® Delica™: a low-pain lancing system for self-monitoring of blood glucose.

    PubMed

    Ginsberg, Barry H; Shemain, Ashley; Pines, Mary Kate; Wallace, Derek A; Pineau, Mitchel

    2011-07-01

    The pain associated with lancing can be a significant barrier to self-monitoring of blood glucose (SMBG). The OneTouch® Delica™ lancing device contains features to reduce lancing pain, including improved lancet control and stability, reduced vibration, and a thinner, 33-gauge lancet. This 2-visit, randomized controlled trial assessed perceived pain of lancing with the OneTouch® Delica™ compared with 4 other common lancing devices: OneTouch® Comfort™, ACCU-CHEK® Softclix, ACCU-CHEK® Multiclix, and Ascensia® Microlet™2. Two hundred patients with type 1 or type 2 diabetes mellitus were assigned to the OneTouch® Delica™ and also randomized to 1 of the 4 comparator devices (n=50 per device pair). At visit 1, we determined the minimum depth settings required to produce≥1 μL of fingertip blood for each patient with each device. At visit 2, patients lanced their fingertips with the devices at the predetermined depths and used a 150-mm visual analog scale (VAS) to rate lancing pain relative to their "usual pain" associated with SMBG. The VAS ranged from "much less painful" (0 mm) to "much more painful" (150 mm), with the midpoint (75 mm) labeled as "usual pain." Fingertip pain scores from patients using OneTouch® Delica™ were significantly lower than those obtained using OneTouch® Comfort™, ACCU-CHEK® Multiclix, and Ascensia® Microlet™2. Pain scores for OneTouch® Delica™ and ACCU-CHEK® Softclix were not significantly different. In conclusion, OneTouch® Delica™ was either less painful or no different than the comparator devices when used for fingertip lancing. Innovative lancing devices that cause less pain may improve compliance and persistence with prescribed SMBG.

  4. LANCE Usage and User Analysis: Creating a Better System that Meets User Needs

    NASA Astrophysics Data System (ADS)

    Davies, D.; Boller, R. A.; Schmaltz, J. E.; Murphy, K. J.; Ilavajhala, S.; Ullah, A.; Joshi, T.

    2012-12-01

    This paper describes known uses of NASA's Land Atmosphere Near-real time Capability for EOS (LANCE) data and imagery and summarizes findings from informal interviews with LANCE users, undertaken to better understand their needs. LANCE, the NRT component of EOSDIS, provides products from MODIS, AIRS, OMI and MLS within 3 hours of satellite observation. LANCE has in excess of 50,000 unique anonymous users per month using data and imagery for wildfire management, air quality measurements, shipping, agricultural forecasting as well as monitoring volcanic plumes, dust storms, smoke plumes and floods etc. Users can be categorized as end users or as brokers who may repackage the imagery and pass it on to their own end users. Interactions with a sample of end users found the following: users like MODIS Rapid Response imagery but do not want to be confined to pre-defined subsets; they want a broader selection of imagery and those with higher bandwidth want the capability to pull in imagery in to their own web-mapping or GIS applications. Users with lower bandwidth want the capability to define their own areas-of-interest for simple download of an image file. Users also expressed a desire to see historic as well as near-real time data, so they can compare the current situation to the recent past. Users want download capabilities to enable information to be shared quickly and easily. These and other findings are being fed back to EOSDIS developers who are creating tools and services to better meet user needs. The findings from users have been valuable in ensuring that developers are on track. The most recent offerings, available http://earthdata.nasa.gov/lance, are Worldview - a web-based client which provides capability to interactively browse full-resolution, global, near real-time satellite imagery from 50+ data products from LANCE, and the Global Imagery Browse Services (GIBS) which enables both users and brokers to pull the latest imagery in to their own web mapping

  5. Evaluation of the TORE(R)Lance for Radioactive Waste Mobilization and Retrieval from Underground Storage Tanks

    SciTech Connect

    Bamberger, Judith A.; Bates, Cameron J.; Bates, James M.; White, M.

    2002-09-25

    The TORE? Lance is a hand-held hydro transportation device with the ability to convey solids at pre-determined slurry concentrations over great distances. The TORE? Lance head generates a precessing vortex core to mobilize solids. Solids retrieval is accomplished using an eductor. The device contains no parts and requires pressurized fluid to operate the eductor and produce mobilization. Three configurations of TORE? Lance operation were evaluated for mobilization and eduction during these tests: compressed air, water, and an air and water mixture. These tests have shown that the TORE? Lance is a tool that can be used at Hanford for mobilization and retrieval of wastes. The system is versatile and can be configured for many types of applications. These studies showed that the diverse applications require unique solutions so care is recommended for TORE? Lance equipment selection for each application. The two components of the TORE? Lance are the precessing vortex for mobilizing and the eductor for retrieval. The precessing vortex is sensitive to fluid flow rate and pressure. In the hand-held unit these parameters are controlled both internally, by changing shim spacing, and externally by controlling the flow split between the eductor and the head. For in-tank applications out-of-tank control of both these parameters are recommended.

  6. Integrated reservoir description and analysis of the Lance formation at Jonah Field, Sublette County, Wyoming

    SciTech Connect

    Robinson, J.W.; Delozier, D.L.; Flinch, R.

    1996-06-01

    Log, core, and production data from the 16 wells in Jonah field have been used to characterize sandstone reservoirs in the Lance Formation (Cretaceous) in the northern Green River basin. The Lance Fm. is composed of 2500 feet of heterolithic fluvial strata that were deposited on a broad alluvial plain. Sandstones were deposited in east- flowing channels 10-20 feet deep and 150-4000 feet wide; some amalgamated sandstone intervals are >100 feet thick and over a mile wide. Fluvial architecture varies from isolated meandering river deposits to amalgamated braided river deposits. Sandstones are dominantly composed of detrital chert and quartz grains. The Lance Fm. has been divided into several informal pay intervals that have different reservoir character and performance. Wardell interval sandstones produce gas in eight wells and are poor reservoirs due to fine grain size, high clay and cement content, and greater depth. Yellow Point interval sandstones have shown average performance in five wells. The Jonah interval produces in 10 wells and is the most prolific pay zone with up to 150 net feet of sandstone having core porosity of 8-12% and permeability of .01-0.9 mD. Upper and middle Lance sandstones have better than average performance from five wells. All pay intervals require greater than 8% porosity and less than 35% water saturation. Pre-frac pressure build-up analysis indicates in situ permeabilities of 3-20 microdarcys and suggests that fractures are a significant contributor to deliverability. Estimated reserves of 0.4-4.0 BCFG/well are based on decline curve analysis. Liquid yields vary from 6-86 BO/MMCFG and increase with depth. Pressure gradients range from .55 to .59 psi/ft. Reservoir overpressure is a result of continuous migration of hydrocarbons into available pore space via microfracture seepage.

  7. Locomotory transition from water to sand and its effects on undulatory kinematics in sand lances (Ammodytidae).

    PubMed

    Gidmark, Nicholas J; Strother, James A; Horton, Jaquan M; Summers, Adam P; Brainerd, Elizabeth L

    2011-02-15

    Sand lances, fishes in the genus Ammodytes, exhibit a peculiar burrowing behavior in which they appear to swim rapidly into the substrate. They use posteriorly propagated undulations of the body to move in both water, a Newtonian fluid, and in sand, a non-Newtonian, granular substrate. In typical aquatic limbless locomotion, undulations of the body push against water, which flows because it is incapable of supporting the static stresses exerted by the animal, thus the undulations move in world space (slipping wave locomotion). In typical terrestrial limbless locomotion, these undulations push against substrate irregularities and move relatively little in world space (non-slipping wave locomotion). We used standard and X-ray video to determine the roles of slipping wave and non-slipping wave locomotion during burrowing in sand lances. We find that sand lances in water use slipping wave locomotion, similar to most aquatic undulators, but switch to non-slipping waves once they burrow. We identify a progression of three stages in the burrowing process: first, aquatic undulations similar to typical anguilliform locomotion (but without head yaw) push the head into the sand; second, more pronounced undulations of the aquatic portion of the body push most of the animal below ground; third, the remaining above-ground portion of the body ceases undulation and the subterranean portion takes over, transitioning to non-slipping wave locomotion. We find no evidence that sand lances use their body motions to fluidize the sand. Instead, as soon as enough of the body is underground, they undergo a kinematic shift and locomote like terrestrial limbless vertebrates.

  8. Entomopathogenic nematode application technology

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biocontrol success when using entomopathogenic nematodes (EPNs) in the genera Heterorhabditis and Steinernema relies on a variety of factors including components of the application event itself. Successful application encompasses both abiotic and biotic influences. For example, adverse array of equi...

  9. Computational Investigation of Swirling Supersonic Jets Generated Through a Nozzle-Twisted Lance

    NASA Astrophysics Data System (ADS)

    Li, Mingming; Li, Qiang; Zou, Zongshu; An, Xizhong

    2017-02-01

    The dynamic characteristics of supersonic swirling jets generated through a nozzle-twisted lance are numerically studied. The essential features of the swirling jets are identified by defining a deviation angle. The effects of nozzle twist angle (NTA) on swirling flow intensity, coalescence characteristics, and dynamic parameter distributions of the jets are discussed. The rotational flow characteristics are revealed. The results show that the jets from the nozzle-twisted lance are imparted to a circumferential rotating movement around the lance axis, and such swirling flow is enhanced by increasing NTA. The enhanced swirling flow causes weaker coalescence of the jets, faster attenuations of the axial velocity, and higher heat transfer rate between the jets and surroundings. The supersonic core length, however, is found to be less sensitive to the swirling flow intensity. The radial spreading of the jets, changing non-monotonically with NTA, arrives at its maximum at 5 deg of NTA. Furthermore, the swirling flow induces a considerable tangential velocity component, and as a result, a holistic and effective horizontal swirling flow field develops. The y-vorticity distribution range and the corresponding magnitude turn larger with increasing NTA, which promote the vortex motion of the local fluid element and thus intensify the local mixing.

  10. Kangaroo mother care diminishes pain from heel lance in very preterm neonates: A crossover trial

    PubMed Central

    Johnston, C Celeste; Filion, Francoise; Campbell-Yeo, Marsha; Goulet, Celine; Bell, Linda; McNaughton, Kathryn; Byron, Jasmine; Aita, Marilyn; Finley, G Allen; Walker, Claire-Dominique

    2008-01-01

    Background Skin-to-skin contact, or kangaroo mother care (KMC) has been shown to be efficacious in diminishing pain response to heel lance in full term and moderately preterm neonates. The purpose of this study was to determine if KMC would also be efficacious in very preterm neonates. Methods Preterm neonates (n = 61) between 28 0/7 and 31 6/7 weeks gestational age in three Level III NICU's in Canada comprised the sample. A single-blind randomized crossover design was employed. In the experimental condition, the infant was held in KMC for 15 minutes prior to and throughout heel lance procedure. In the control condition, the infant was in prone position swaddled in a blanket in the incubator. The primary outcome was the Premature Infant Pain Profile (PIPP), which is comprised of three facial actions, maximum heart rate, minimum oxygen saturation levels from baseline in 30-second blocks from heel lance. The secondary outcome was time to recover, defined as heart rate return to baseline. Continuous video, heart rate and oxygen saturation monitoring were recorded with event markers during the procedure and were subsequently analyzed. Repeated measures analysis-of-variance was employed to generate results. Results PIPP scores at 90 seconds post lance were significantly lower in the KMC condition (8.871 (95%CI 7.852–9.889) versus 10.677 (95%CI 9.563–11.792) p < .001) and non-significant mean differences ranging from 1.2 to1.8. favoring KMC condition at 30, 60 and 120 seconds. Time to recovery was significantly shorter, by a minute(123 seconds (95%CI 103–142) versus 193 seconds (95%CI 158–227). Facial actions were highly significantly lower across all points in time reaching a two-fold difference by 120 seconds post-lance and heart rate was significantly lower across the first 90 seconds in the KMC condition. Conclusion Very preterm neonates appear to have endogenous mechanisms elicited through skin-to-skin maternal contact that decrease pain response, but not as

  11. Roles of Steroids in Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The inability of nematodes to biosynthesize steroids de novo and the resulting dependence of parasitic nematodes upon their hosts have enhanced the importance of elucidating the metabolism of sterols and the hormonal and other functions of steroids in nematodes. Biochemical research has revealed th...

  12. Nematode cholinergic pharmacology

    SciTech Connect

    Segerberg, M.A.

    1989-01-01

    Nematode acetylcholine (ACh) receptors were characterized using both biochemical and electrophysiological techniques, including: (1) receptor binding studies in crude homogenates of the free-living nematode Caenorhabditis elegans and the parasitic nematode Ascaris lumbricoides with the high-affinity probe ({sup 3}H)N-methylscopolamine (({sup 3}H)NMS) which binds to muscarinic receptors in many vertebrate and invertebrate tissues (2) measurement of depolarization and contraction induced by a variety of cholinergic agents, including N-methylscopolamine (NMS), in an innervated dorsal muscle strip preparation of Ascaris; (3) examination of the antagonistic actions of d-tubocurarine (dTC) and NMS at dorsal neuromuscular junction; (4) measurement of input resistance changes in Ascaris commissural motorneurons induced by ACh, dTC, NMS, pilocarpine and other cholinergic drugs.

  13. Comparative genomics of nematodes.

    PubMed

    Mitreva, Makedonka; Blaxter, Mark L; Bird, David M; McCarter, James P

    2005-10-01

    Recent transcriptome and genome projects have dramatically expanded the biological data available across the phylum Nematoda. Here we summarize analyses of these sequences, which have revealed multiple unexpected results. Despite a uniform body plan, nematodes are more diverse at the molecular level than was previously recognized, with many species- and group-specific novel genes. In the genus Caenorhabditis, changes in chromosome arrangement, particularly local inversions, are also rapid, with breakpoints occurring at 50-fold the rate in vertebrates. Tylenchid plant parasitic nematode genomes contain several genes closely related to genes in bacteria, implicating horizontal gene transfer events in the origins of plant parasitism. Functional genomics techniques are also moving from Caenorhabditis elegans to application throughout the phylum. Soon, eight more draft nematode genome sequences will be available. This unique resource will underpin both molecular understanding of these most abundant metazoan organisms and aid in the examination of the dynamics of genome evolution in animals.

  14. NASA's Land, Atmosphere Near real-time Capability for EOS (LANCE): Changing patterns in the use of NRT satellite imagery

    NASA Astrophysics Data System (ADS)

    Davies, D.; Michael, K.; Schmaltz, J. E.; Harrison, S.; Ding, F.; Durbin, P. B.; Boller, R. A.; Cechini, M. F.; Rinsland, P. L.; Ye, G.; Mauoka, E.

    2015-12-01

    NASA's Land, Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) provides data and imagery approximately 3 hours from satellite observation, to monitor natural events globally and to meet the needs of the near real-time (NRT) applications community. This article describes LANCE, and how the use of NRT data and imagery has evolved. Since 2010 there has been a four-fold increase in both the volume of data and the number of files downloaded. Over the last year there has been a marked shift in the way in which users are accessing NRT imagery; users are gravitating towards Worldview and the Global Imagery Browse Services (GIBS) and away from MODIS Rapid Response, in part due to the increased exposure through social media. In turn this is leading to a broader range of users viewing NASA NRT imagery. This article also describes new, and planned, product enhancements to LANCE. Over the last year, LANCE has expanded to support NRT products from the Advanced Microwave Scanning Radiometer 2 (AMSR2), and the Multi-angle Imaging SpectroRadiometer (MISR). LANCE elements are also planning to ingest and process NRT data from the Visible Infrared Imager Radiometer Suite (VIIRS), and the advanced Ozone Mapping and Profiler Suite (OMPS) instruments onboard the Suomi National Polar-orbiting Partnership (S-NPP) satellite in the near future.

  15. Identifying subtidal burying habitat of Pacific sand lance (Ammodytes hexapterus) in the Strait of Georgia, British Columbia, Canada

    NASA Astrophysics Data System (ADS)

    Robinson, Clifford L. K.; Hrynyk, Doug; Barrie, J. Vaughn; Schweigert, Jake

    2013-08-01

    Pacific sand lance (Ammodytes hexapterus), an important prey species for many vertebrate predators in the northeast Pacific, lacks a swim bladder and relies on coarse sand substrates to bury in overnight and during the winter. Surprisingly little information is available describing the spatial distribution and extent of its burying habitat along the British Columbia coast. Thus, a habitat suitability model was developed for Pacific sand lance in the Strait of Georgia that considered information on shallow depths (<80 m), high bottom current speeds (25-63 cm s-1) and coarse sand (0.25-2.0 mm grain diameter). Overall, the model identified 6% of the study domain as suitable burying habitat, with the southern Strait containing the largest burying areas. By-catch data from mid-water trawl and purse seine sets was also used to map the location of pelagic schools of foraging sand lance. The persistent location of large Pacific sand lance by-catches over many years identified key foraging areas adjacent to several burying habitats. The median distance of 88 sand lance schools to coarse sand patches was 2 km; 75% of the schools were found within 4.9 km of coarse sand. The mapping of suitable burying and foraging areas in the Strait of Georgia will assist managers in guarding against anthropogenic activities that might impact the relatively uncommon and patchy habitats of a key coastal food-web species.

  16. In Situ Chemical Oxidation Through Lance Permeation at the Portsmouth Gaseous Diffusion Plant (PORTS)

    SciTech Connect

    Martin, M.Z.

    2003-05-01

    In situ chemical oxidation through lance permeation (ISCO-LP) is an emerging remediation technology in which chemical oxidants (such as potassium or sodium permanganate) are delivered to the subsurface using vertical lance-like injectors. It is applicable to sites with oxidizable contaminants such as chlorinated solvents and fuel hydrocarbons. Because vertical lance injections can be deployed at relatively close spacing, ISCO-LP potentially can be used to clean-up contamination in low-permeability media. This document provides information that can help potential users determine whether ISCO-LP would apply to a particular environmental management problem. It contains a general description of the technology (Section 2), performance data from a field demonstration (Section 3), an assessment of technology applicability (Section 4), a summary of cost elements (Section 5), and a list of regulatory, environmental safety and health issues (Section 6). It is patterned after the Innovative Technology Summary Reports (ITSR) published by the Department of Energy's (DOE) Office of Science and Technology under the Subsurface Contaminants Focus Area (SCFA). As in the previously published ITSRs, the technology described in this report was developed through funding from SCFA. Most of the information contained in this report was obtained from a field demonstration of ISCO-LP conducted in July-August 2000 at DOE's Portsmouth Gaseous Diffusion Plant (PORTS). The field test was not completed due to an accident that caused a field worker serious injuries. Although performance assessment data are very limited, the field test highlighted important health and safety issues that must be considered by site managers and technology vendors interested in implementing ISCO-LP.

  17. Phase I Field Test Results of an Innovative DNAPL Remediation Technology: The Hydrophobic Lance

    SciTech Connect

    Tuck, D.M.

    1999-01-28

    An innovative technology for recovery of pure phase DNAPL was deployed in the subsurface near the M-Area Settling Basin, continuing the support of the A/M Area Ground Water Corrective Action Program (per Part B requirements). This technology, the Hydrophobic Lance, operates by placing a neutral/hydrophobic surface (Teflon) in contact with the DNAPL. This changes the in situ conditions experienced by the DNAPL, allowing it to selectively drain into a sump from which it can be pumped. Collection of even small amounts of DNAPL can save years of pump-and-treat operation because of the generally low solubility of DNAPL components.

  18. Nematode management in pecans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2002, the pecan root-knot nematode (Meloidogyne partityla = PRKN) was found on pecan in the southeastern U.S. and was associated with stressed trees exhibiting dead branches in the upper canopy and (or) typical mouse ear (ME) associated foliar symptoms. This research evaluates the host susceptib...

  19. How nematode sperm crawl.

    PubMed

    Bottino, Dean; Mogilner, Alexander; Roberts, Tom; Stewart, Murray; Oster, George

    2002-01-15

    Sperm of the nematode, Ascaris suum, crawl using lamellipodial protrusion, adhesion and retraction, a process analogous to the amoeboid motility of other eukaryotic cells. However, rather than employing an actin cytoskeleton to generate locomotion, nematode sperm use the major sperm protein (MSP). Moreover, nematode sperm lack detectable molecular motors or the battery of actin-binding proteins that characterize actin-based motility. The Ascaris system provides a simple 'stripped down' version of a crawling cell in which to examine the basic mechanism of cell locomotion independently of other cellular functions that involve the cytoskeleton. Here we present a mechanochemical analysis of crawling in Ascaris sperm. We construct a finite element model wherein (a) localized filament polymerization and bundling generate the force for lamellipodial extension and (b) energy stored in the gel formed from the filament bundles at the leading edge is subsequently used to produce the contraction that pulls the rear of the cell forward. The model reproduces the major features of crawling sperm and provides a framework in which amoeboid cell motility can be analyzed. Although the model refers primarily to the locomotion of nematode sperm, it has important implications for the mechanics of actin-based cell motility.

  20. Using Open and Interoperable Ways to Publish and Access LANCE AIRS Near-Real Time Data

    NASA Astrophysics Data System (ADS)

    Zhao, P.; Lynnes, C.; Vollmer, B.; Savtchenko, A. K.; Yang, W.

    2011-12-01

    Atmospheric Infrared Sounder (AIRS) Near-Real Time (NRT) data from the Land Atmosphere Near real time Capability for EOS (LANCE) provide the information on the global and regional atmospheric state with very low latency. An open and interoperable platform is useful to facilitate access to and integration of LANCE AIRS NRT data. This paper discusses the use of open-source software components to build Web services for publishing and accessing AIRS NRT data in the context of Service Oriented Architecture (SOA). The AIRS NRT data have also been made available through an OPeNDAP server. OPeNDAP allows several open-source netCDF-based tools such as Integrated Data Viewer, Ferret and Panoply to directly display the Level 2 data over the network. To enable users to locate swath data files in the OPeNDAP server that lie within a certain geographical area, graphical "granule maps" are being added to show the outline of each file on a map of the Earth. The metadata of AIRS NRT data and services is then explored to implement information advertisement and discovery in catalogue systems. Datacasting, an RSS-based technology for accessing Earth Science data and information to facilitate the subscriptions to AIRS NRT data availability, filtering, downloading and viewing data, is also discussed. To provide an easy entry point to AIRS NRT data and services, a Web portal designed for customized data downloading and visualization is introduced.

  1. Using Open and Interoperable Ways to Publish and Access LANCE AIRS Near-Real Time Data

    NASA Technical Reports Server (NTRS)

    Zhao, Peisheng; Lynnes, Christopher; Vollmer, Bruce; Savtchenko, Andrey; Theobald, Michael; Yang, Wenli

    2011-01-01

    The Atmospheric Infrared Sounder (AIRS) Near-Real Time (NRT) data from the Land Atmosphere Near real-time Capability for EOS (LANCE) element at the Goddard Earth Sciences Data and Information Services Center (GES DISC) provides information on the global and regional atmospheric state, with very low temporal latency, to support climate research and improve weather forecasting. An open and interoperable platform is useful to facilitate access to, and integration of, LANCE AIRS NRT data. As Web services technology has matured in recent years, a new scalable Service-Oriented Architecture (SOA) is emerging as the basic platform for distributed computing and large networks of interoperable applications. Following the provide-register-discover-consume SOA paradigm, this presentation discusses how to use open-source geospatial software components to build Web services for publishing and accessing AIRS NRT data, explore the metadata relevant to registering and discovering data and services in the catalogue systems, and implement a Web portal to facilitate users' consumption of the data and services.

  2. Management of pain from heel lance with lidocaine-prilocaine (EMLA) cream: is it safe and efficacious in preterm infants?

    PubMed

    Stevens, B; Johnston, C; Taddio, A; Jack, A; Narciso, J; Stremler, R; Koren, G; Aranda, J

    1999-08-01

    Hospitalized preterm infants undergo multiple painful heel lances. A two-phase, randomized, controlled trial was undertaken to determine the safety and efficacy of lidocaine-prilocaine 5% cream (EMLA, Astra Pharmaceuticals, L.P, Westborough, MA) for relieving pain from heel lance. One hundred twenty infants were randomly assigned to receive 0.5 g of EMLA or placebo cream for 30 minutes (Phase 1) or 60 minutes (Phase 2) before a routine heel lance. Efficacy was assessed using the Premature Infant Pain Profile (PIPP). Safety was determined by methemoglobin concentration 8 hours after EMLA application and by clinical signs of methemoglobinemia. No significant differences existed on PIPP scores between EMLA and placebo groups in Phase 1 (p < .480) or Phase 2 (p < .831). No infant had any clinical signs of methemoglobinemia. The mean methemoglobin concentration was 1.19% (.47). Approximately 10% of infants had minor skin reactions, and approximately 20% of EMLA-treated infants had blanching at the application site. The authors conclude that EMLA is safe but not efficacious for relieving pain from heel lance in preterm infants.

  3. Use of the Published Lance Armstrong Cancer Story to Teach Health Science Content to High School Students

    ERIC Educational Resources Information Center

    Burns, E. Robert

    2008-01-01

    Lance Armstrong (2000) authored a book titled "It's Not About the Bike -- My Journey Back to Life," regarding his battle with testicular cancer. It became a "New York Times" Bestseller and was selected by the "School Library Journal" as one of the "Best Adult Books for High School Students for 2001." The goal of the project described in this…

  4. "Tras de un Amoroso Lance" como Estructura Expresiva (The Poem, "Behind the Amorous Cast" as an Expressive Structure).

    ERIC Educational Resources Information Center

    Bratosevich, Nicolas

    1967-01-01

    An analysis of a poem by San Juan de la Cruz (St. John of the Cross), the sixteenth century Spanish mystic, identifies symbols and images, explains themes, and offers a synthesis of his structural patterns. The poem, "Tras de amoroso lance", deals with the theme of the search of the beloved (i.e., the soul) for the lover, and…

  5. Neuroparasitic Infections: Nematodes

    PubMed Central

    Walker, M.D.; Zunt, J.R.

    2009-01-01

    Globalization has produced an increase in the number of people at risk for contracting parasitic infection. Central nervous system infection by nematodal parasites can be devastating. Early recognition and treatment of infection can significantly decrease morbidity of the parasitic infection, as well as the risk of secondary superinfection. The clinical presentation, diagnosis, and treatment for five of the more common nematodal infections of the nervous system—Angiostrongylus spp., Baylisacaris procyonis, Gnathostoma spinigerum, Strongyloides stercoralis, and Toxocara spp.—is reviewed. Objectives On completion of this article, the reader should be able to summarize the clinical presentation, diagnosis, and treatment of the common nematodal infections of the nervous system. Accreditation The Indiana University School of Medicine is accredited by the Accreditation Council for Continuing Medical Education to provide continuing medical education for physicians. Credit The Indiana University School of Medicine designates this educational activity for a maximum of 1 Category 1 credit toward the AMA Physicians Recognition Award. Each physician should claim only those credits that he/she actually spent in the educational activity. Disclosure Statements of disclosure have been obtained regarding the authors’ relevant financial relationships. The authors have nothing to disclose. PMID:16170738

  6. New Frontiers in Nematode Ecology

    PubMed Central

    Ferris, Howard

    1993-01-01

    Future areas of emphasis for research and scholarship in nematode ecology are indicated by pressing agricultural and environmental issues, by new directions in applied nematology, and by current technological advances. Studies in nematode ecology must extend beyond observation, counting, and simple statistical analysis. Experimentation and the testing of hypotheses are needed for understanding the biological mechanisms of ecological systems. Opportunities for fruitful experimentation in nematode ecology are emerging at the ecosystem, community, population, and individual levels. Nematode ecologists will best promote their field of study by closely monitoring and participating in the advances, initiatives, developments, and directions in the larger field of ecology. PMID:19279783

  7. Informing future NRT satellite distribution capabilities: Lessons learned from NASA's Land Atmosphere NRT capability for EOS (LANCE)

    NASA Astrophysics Data System (ADS)

    Davies, D.; Murphy, K. J.; Michael, K.

    2013-12-01

    NASA's Land Atmosphere Near real-time Capability for EOS (Earth Observing System) (LANCE) provides data and imagery from Terra, Aqua and Aura satellites in less than 3 hours from satellite observation, to meet the needs of the near real-time (NRT) applications community. This article describes the architecture of the LANCE and outlines the modifications made to achieve the 3-hour latency requirement with a view to informing future NRT satellite distribution capabilities. It also describes how latency is determined. LANCE is a distributed system that builds on the existing EOS Data and Information System (EOSDIS) capabilities. To achieve the NRT latency requirement, many components of the EOS satellite operations, ground and science processing systems have been made more efficient without compromising the quality of science data processing. The EOS Data and Operations System (EDOS) processes the NRT stream with higher priority than the science data stream in order to minimize latency. In addition to expediting transfer times, the key difference between the NRT Level 0 products and those for standard science processing is the data used to determine the precise location and tilt of the satellite. Standard products use definitive geo-location (attitude and ephemeris) data provided daily, whereas NRT products use predicted geo-location provided by the instrument Global Positioning System (GPS) or approximation of navigational data (depending on platform). Level 0 data are processed in to higher-level products at designated Science Investigator-led Processing Systems (SIPS). The processes used by LANCE have been streamlined and adapted to work with datasets as soon as they are downlinked from satellites or transmitted from ground stations. Level 2 products that require ancillary data have modified production rules to relax the requirements for ancillary data so reducing processing times. Looking to the future, experience gained from LANCE can provide valuable lessons on

  8. Lance for fuel and oxygen injection into smelting or refining furnace

    DOEpatents

    Schlichting, Mark R.

    1994-01-01

    A furnace 10 for smelting iron ore and/or refining molten iron 20 is equipped with an overhead pneumatic lance 40, through which a center stream of particulate coal 53 is ejected at high velocity into a slag layer 30. An annular stream of nitrogen or argon 51 enshrouds the coal stream. Oxygen 52 is simultaneously ejected in an annular stream encircling the inert gas stream 51. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus 84 to react with carbon monoxide gas rising from slag layer 30, thereby adding still more heat to the furnace.

  9. Lance for fuel and oxygen injection into smelting or refining furnace

    DOEpatents

    Schlichting, M.R.

    1994-12-20

    A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figures.

  10. Bacteria can mobilize nematode-trapping fungi to kill nematodes.

    PubMed

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-12-16

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode-predatory form; this predacious form is characterized by formation of specialized cellular structures or 'traps'. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator-prey interactions in prey defense mechanisms.

  11. Computational Fluid Dynamic Modeling of Zinc Slag Fuming Process in Top-Submerged Lance Smelting Furnace

    NASA Astrophysics Data System (ADS)

    Huda, Nazmul; Naser, Jamal; Brooks, Geoffrey; Reuter, Markus A.; Matusewicz, Robert W.

    2012-02-01

    Slag fuming is a reductive treatment process for molten zinciferous slags for extracting zinc in the form of metal vapor by injecting or adding a reductant source such as pulverized coal or lump coal and natural gas. A computational fluid dynamic (CFD) model was developed to study the zinc slag fuming process from imperial smelting furnace (ISF) slag in a top-submerged lance furnace and to investigate the details of fluid flow, reaction kinetics, and heat transfer in the furnace. The model integrates combustion phenomena and chemical reactions with the heat, mass, and momentum interfacial interaction between the phases present in the system. A commercial CFD package AVL Fire 2009.2 (AVL, Graz, Austria) coupled with a number of user-defined subroutines in FORTRAN programming language were used to develop the model. The model is based on three-dimensional (3-D) Eulerian multiphase flow approach, and it predicts the velocity and temperature field of the molten slag bath, generated turbulence, and vortex and plume shape at the lance tip. The model also predicts the mass fractions of slag and gaseous components inside the furnace. The model predicted that the percent of ZnO in the slag bath decreases linearly with time and is consistent broadly with the experimental data. The zinc fuming rate from the slag bath predicted by the model was validated through macrostep validation process against the experimental study of Waladan et al. The model results predicted that the rate of ZnO reduction is controlled by the mass transfer of ZnO from the bulk slag to slag-gas interface and rate of gas-carbon reaction for the specified simulation time studied. Although the model is based on zinc slag fuming, the basic approach could be expanded or applied for the CFD analysis of analogous systems.

  12. Hormonal correlates of social status and courtship display in the cooperatively lekking lance-tailed manakin.

    PubMed

    DuVal, Emily H; Goymann, Wolfgang

    2011-01-01

    Though cooperative behavior has long been a focus of evolutionary biology, the proximate hormonal mechanisms underlying cooperative interactions remain poorly understood. Lance-tailed manakins (Chiroxiphia lanceolata) are tropical passerines that form long-term male-male partnerships and cooperate in paired male courtship displays. To elucidate patterns of natural hormonal variation in relation to cooperation and reproductive behavior, we examined circulating androgen levels of male lance-tailed manakins in relation to social status, display behavior, and time of year. We found significantly higher circulating androgen levels in alpha-ranked (breeding) males compared to non-alpha adult males in the population. Beta males, which participated in courtship displays but did not copulate, had androgen levels indistinguishable from those of unpaired adult males that never displayed for females, suggesting that an elevated concentration of plasma testosterone in tropical lekking birds may be associated primarily with copulatory behavior or other status-specific traits, and not the performance of courtship display. Androgens decreased throughout the breeding season for males of all status categories. Interestingly, alphas that displayed for females in the observation session prior to sampling had lower androgen levels than alphas that did not display for females. This pattern may result from female discrimination against alpha males at display areas with high levels of social conflict among males, as social disruption is linked to elevated testosterone in many species. However, recent change of a display partner was not related to alpha androgen levels. We discuss alternative explanations and the possible implications of these results, and generate several testable predictions for future investigations.

  13. Social networks of educated nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound...

  14. Managing Nematodes without Methyl Bromide

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Methyl bromide is an effective pre-plant soil fumigant used to control nematodes in many high-input, high-value production systems including vegetables, nurseries, ornamentals, tree fruits, strawberries, and grapes. Because methyl bromide has provided a reliable return on investment for nematode c...

  15. Site Specific Nematode Management—Development and Success in Cotton Production in the United States

    PubMed Central

    Overstreet, C.; McGawley, E. C.; Khalilian, A.; Kirkpatrick, T. L.; Monfort, W. S.; Henderson, W.; Mueller, J. D.

    2014-01-01

    Variability in edaphic factors such as clay content, organic matter, and nutrient availability within individual fields is a major obstacle confronting cotton producers. Adaptation of geospatial technologies such global positioning systems (GPS), yield monitors, autosteering, and the automated on-and-off technology required for site-specific nematicide application has provided growers with additional tools for managing nematodes. Multiple trials in several states were conducted to evaluate this technology in cotton. In a field infested with Meloidogyne spp., both shallow (0 to 0.3 m) and deep (0 to 0.91 m) apparent electrical conductivity (ECa) readings were highly correlated with sand content. Populations of Meloidogyne spp. were present when shallow and deep EC values were less than 30 and 90 mS/m, respectively. Across three years of trials in production fields in which verification strips (adjacent nematicide treated and untreated rows across all soil zones) were established to evaluate crop response to nematicide application, deep EC values from 27.4-m wide transects of verification strips were more predictive of yield response to application of 1,3-dichloropropene than were shallow EC values in one location and both ECa values equally effective at predicting responses at the second location. In 2006, yields from entire verification strips across three soil zones in four production fields showed that nematicide response was greatest in areas with the lowest EC values indicating highest content of sand. In 2008 in Ashley and Mississippi Counties, AR, nematicide treatment by soil zone resulted in 36% and 42% reductions in the amount of nematicide applied relative to whole-field application. In 2007 in Bamberg County, SC, there was a strong positive correlation between increasing population densities of Meloidogyne incognita and increasing sand content. Trials conducted during 2007 and 2009 in South Carolina against Hoplolaimus columbus showed a stepwise response

  16. Interactions of microfungi and plant parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant parasitic nematodes and microfungi inhabit many of the same ecological habitats and interact in almost every conceivable way. Nematodes can feed on fungi, and conversely fungi can use nematodes as a food source. Fungi have been widely studied as biological controls of plant parasitic nematod...

  17. Bacteria can mobilize nematode-trapping fungi to kill nematodes

    PubMed Central

    Wang, Xin; Li, Guo-Hong; Zou, Cheng-Gang; Ji, Xing-Lai; Liu, Tong; Zhao, Pei-Ji; Liang, Lian-Ming; Xu, Jian-Ping; An, Zhi-Qiang; Zheng, Xi; Qin, Yue-Ke; Tian, Meng-Qing; Xu, You-Yao; Ma, Yi-Cheng; Yu, Ze-Fen; Huang, Xiao-Wei; Liu, Shu-Qun; Niu, Xue-Mei; Yang, Jin-Kui; Huang, Ying; Zhang, Ke-Qin

    2014-01-01

    In their natural habitat, bacteria are consumed by bacterivorous nematodes; however, they are not simply passive preys. Here we report a defensive mechanism used by certain bacteria to mobilize nematode-trapping fungi to kill nematodes. These bacteria release urea, which triggers a lifestyle switch in the fungus Arthrobotrys oligospora from saprophytic to nematode–predatory form; this predacious form is characterized by formation of specialized cellular structures or ‘traps’. The bacteria significantly promote the elimination of nematodes by A. oligospora. Disruption of genes involved in urea transport and metabolism in A. oligospora abolishes the urea-induced trap formation. Furthermore, the urea metabolite ammonia functions as a signal molecule in the fungus to initiate the lifestyle switch to form trap structures. Our findings highlight the importance of multiple predator–prey interactions in prey defense mechanisms. PMID:25514608

  18. The Politics of NATO Short-Range Nuclear Modernization 1983-1990: The Follow-On-to-Lance Missile Decisions

    DTIC Science & Technology

    1991-06-01

    and their associated launchers suffer from the same mechanical and corrosive effects of aging and weather as do conventional weapons, with the...pp. 184-212; and Waltz, Theory of International Relations, pp. 165-66. 58Paul Buteux, Strategy. Doctrine. and the Politics of Alliance: Theatre ...in the 1987-1990 SNF debate concerned the replacement for the aging Lance missile. That program was terminated in May 1990, so the years ahead will

  19. Review of Matters Related to the Sexual Assault of Lance Corporal Maria Lauterbach, U.S. Marine Corps

    DTIC Science & Technology

    2011-10-18

    Davis Highway, Suite 1204, Arlington VA 22202-4302. Respondents should be aware that notwithstanding any other provision of law , no person shall be...The PDUSD (P&R) requested we review command and other responses to the rape complaint of Lance Corporal (LCpl) Maria Lauterbach, assigned to...facts and circumstances involved in responses to the rape complaint and the Naval Criminal Investigative Service (NCIS) rape investigation, and

  20. Nematode-trapping fungi eavesdrop on nematode pheromones

    PubMed Central

    Hsueh, Yen-Ping; Mahanti, Parag; Schroeder, Frank C.; Sternberg, Paul W.

    2013-01-01

    Summary The recognition of molecular patterns associated with specific pathogens or food sources is fundamental to ecology and plays a major role in the evolution of predator-prey relationships [1]. Recent studies showed that nematodes produce an evolutionarily highly conserved family of small molecules, the ascarosides, which serve essential functions in regulating nematode development and behavior [2-4]. Here we show that nematophagous fungi, natural predators of soil-dwelling nematodes [5], can detect and respond to ascarosides. Nematophagous fungi use specialized trapping devices to catch and consume nematodes, and previous studies demonstrated that most fungal species do not produce traps constitutively but rather initiate trap-formation in response to their prey [6]. We found that ascarosides, which are constitutively secreted by many species of soil-dwelling nematodes, represent a conserved molecular pattern used by nematophagous fungi to detect prey and trigger trap formation. Ascaroside-induced morphogenesis is conserved in several closely related species of nematophagous fungi and occurs only under nutrient-deprived condition. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey co-evolution. We anticipate that these findings will have broader implications for understanding other inter-kingdom interactions involving nematodes, which are found in almost any ecological niche on Earth. PMID:23246407

  1. Nematode-trapping fungi eavesdrop on nematode pheromones.

    PubMed

    Hsueh, Yen-Ping; Mahanti, Parag; Schroeder, Frank C; Sternberg, Paul W

    2013-01-07

    The recognition of molecular patterns associated with specific pathogens or food sources is fundamental to ecology and plays a major role in the evolution of predator-prey relationships. Recent studies showed that nematodes produce an evolutionarily highly conserved family of small molecules, the ascarosides, which serve essential functions in regulating nematode development and behavior. Here, we show that nematophagous fungi, natural predators of soil-dwelling nematodes, can detect and respond to ascarosides. Nematophagous fungi use specialized trapping devices to catch and consume nematodes, and previous studies demonstrated that most fungal species do not produce traps constitutively but rather initiate trap formation in response to their prey. We found that ascarosides, which are constitutively secreted by many species of soil-dwelling nematodes, represent a conserved molecular pattern used by nematophagous fungi to detect prey and trigger trap formation. Ascaroside-induced morphogenesis is conserved in several closely related species of nematophagous fungi and occurs only under nutrient-deprived conditions. Our results demonstrate that microbial predators eavesdrop on chemical communication among their metazoan prey to regulate morphogenesis, providing a striking example of predator-prey coevolution. We anticipate that these findings will have broader implications for understanding other interkingdom interactions involving nematodes, which are found in almost any ecological niche on Earth.

  2. Social Networks of Educated Nematodes

    PubMed Central

    Willett, Denis S.; Alborn, Hans T.; Duncan, Larry W.; Stelinski, Lukasz L.

    2015-01-01

    Entomopathogenic nematodes are obligate lethal parasitoids of insect larvae that navigate a chemically complex belowground environment while interacting with their insect hosts, plants, and each other. In this environment, prior exposure to volatile compounds appears to prime nematodes in a compound specific manner, increasing preference for volatiles they previously were exposed to and decreasing attraction to other volatiles. In addition, persistence of volatile exposure influences this response. Longer exposure not only increases preference, but also results in longer retention of that preference. These entomopathogenic nematodes display interspecific social behavioral plasticity; experienced nematodes influence the behavior of different species. This interspecific social behavioral plasticity suggests a mechanism for rapid adaptation of belowground communities to dynamic environments. PMID:26404058

  3. Nematode Chemosensilla: Form and Function

    PubMed Central

    Wright, K. A.

    1983-01-01

    As an introduction to a symposium of nematode chemoreception, the anatomy of nematode chemosensilla, their distribution on plant parasitic nematodes, and their possible functional roles is briefly reviewed. Comparison of nematode chemosensilla with those of other animals shows their greater resemblance to olfactory primary sense cells of vertebrates. Although the sensory process is obviously derived from a cilium, the absence of many ciliary features is noted. Retention of the ciliary necklace may be important functionally. A simple model is proposed, wherein binding of stimulant molecules to receptors in the membrane of the cilium-derived process results in entry of Na⁺ and Ca⁺⁺ (the latter via the ciliary necklace) to produce a receptor potential that spreads along the dendrite to the cell body where action potentials continue along the short axon to synapses. PMID:19295785

  4. [Effects of piracetam therapy in a case of Lance-Adams syndrome].

    PubMed

    Hoshino, Ai; Kumada, Satoko; Yokochi, Fusako; Hachiya, Yasuo; Hanafusa, Yukiko; Tomita, Sunao; Okiyama, Ryoich; Kurihara, Eiji

    2009-09-01

    We report a 17-year-old female patient with Lance-Adams syndrome caused by anoxic encephalopathy during a severe attack of bronchial asthma. She had difficulty in writing because of action myoclonus in her arms. She also exhibited freezing gait and was unable to walk without cane. Although her gait disturbance resembled those seen in patients with parkinsonism secondary to anoxic encephalopathy, surface electromyography revealed that it was caused by action myoclonus in her legs. The presence of giant somatosensory evoked potentials and enhanced cortical reflexes in response to the electrical stimulation to her posterior tibial nerves supported our diagnosis. A combined therapy with valproate sodium, clonazepam and piracetam (15 g/day) was not effective. However, her freezing gait remarkably improved and she was able to walk without help, after the treatment with sufficient dose of piracetam (21 g/day). Cortical hyperexcitability as revealed by electrophysiological examination also improved. We concluded that the combined therapy with antiepileptic drugs and piracetam was effective in the treatment for action myoclonus. However, because the effects seemed dose-related, the dosage of piracetam needed to be increased until the optimum effects were obtained.

  5. Skin Conductance at Baseline and Post-Heel Lance Reflects Sympathetic Activation in Neonatal Opiate Withdrawal

    PubMed Central

    Oji-Mmuo, Christiana N.; Michael, Eric J.; McLatchy, Jacqueline; Lewis, Mary M.; Becker, Julie E.; Doheny, Kim Kopenhaver

    2015-01-01

    Aim Skin conductance (SC) provides an objective measure of autonomic system regulation through sympathetic-mediated filling of sweat glands. This study aimed to test the utility of SC to detect sympathetic activation in neonatal abstinence syndrome (NAS). Methods 14 term (mean, SE: 38.8 ± 0.35 weeks gestational age) neonates with chronic prenatal opiate exposure were enrolled. SC (peaks/sec and mean of peaks) were measured at baseline, during heel lance/squeeze (HLS) and recovery from HLS at 24-48 (mean 38) hours of life prior to treatment for NAS. Blinded coders with established reliability assessed neonates using the Modified Finnegan Neonatal Scoring System (MFNSS). Non-parametric tests were used to determine group differences, phase differences from baseline to HLS and HLS to recovery, and associations between MFNSS and SC measures. Results Neonates that would later require morphine treatment for NAS (n = 6) had higher baseline SC mean of peaks than those that did not require treatment (n = 8) (P<0.05). Moreover, there were unique phase differences between groups and SC positively correlated with MFNSS (P< 0.05). Conclusion SC provides early identification of NAS severity. However, a larger sample is needed to determine sensitivity and specificity of SC for early identification of NAS and treatment effectiveness. PMID:26613197

  6. Implementing Land and Atmosphere Near Real-Time Capability for EOS (LANCE)

    NASA Astrophysics Data System (ADS)

    Thanvi, V.; Michael, K.; Murphy, K. J.; Masuoka, E.; Vollmer, B.; Tilmes, C.; Conover, H.; Teague, M.; Durbin, P.; Regner, K.

    2010-12-01

    The past decade has seen a rapid increase in availability and usage of near real-time data from sensors on board the earth observing satellites. NASA’s Earth Observing System Data and Information System (EOSDIS) provides a wealth of data and products supporting scientific research of the atmosphere, oceans, and land. The Earth Observing System (EOS) instruments onboard Terra, Aqua and Aura satellites make global measurements daily which are processed into higher-level “standard” products within 8 to 40 hours of observation and then made available to users, primarily earth science researchers. However applications users, operational agencies, and even researchers desire EOS products in near real-time to support research and applications, including numerical weather and climate prediction and forecasting, monitoring of natural hazards, ecological/invasive species, agriculture, air quality, disaster relief and homeland security. These users usually need data within 3 hours, and are willing to trade science product quality for timely access. In response to this need, NASA developed the Land, Atmosphere Near Real-time Capability for EOS (LANCE) that provides land and atmosphere data acquired by AIRS, AMSR-E, MLS, MODIS, and OMI instruments.

  7. Basic and applied research: Entomopathogenic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema kill arthropods with the aid of their bacterial symbionts. These nematodes are potent microbial control agents that have been widely commercialized for control of economically important insect pests. Biocontrol efficacy relies...

  8. Venepuncture is preferable to heel lance for blood sampling in term neonates

    PubMed Central

    Ogawa, S; Ogihara, T; Fujiwara, E; Ito, K; Nakano, M; Nakayama, S; Hachiya, T; Fujimoto, N; Abe, H; Ban, S; Ikeda, E; Tamai, H

    2005-01-01

    Background: The analgesic effect of oral sucrose in newborn infants undergoing painful procedures is generally accepted. For blood sampling, some studies have shown that venepuncture (VP) is less painful than heel lance (HL). Objective: To determine the least painful and most effective method among blood sampling by VP or HL with or without sucrose. Design: Randomised, double blind, placebo controlled trial. Subjects: A total of 100 healthy, full term newborn infants being screened for inborn errors of metabolism were randomly allocated to one of four experimental groups (25 infants in each). Intervention and outcome measure: Seven specially trained nurses took turns to carry out blood sampling two minutes after administration of oral sucrose or water. Neonatal pain was assessed by the neonatal facial coding system (NFCS), as well as by crying. Results: Without sucrose, the NFCS score was higher in the HL group than the VP group during blood sampling (median 58 v 23, p<0.001). Oral sucrose significantly reduced the score of the HL group (58 v 47, p<0.01) and also tended to reduce the score of the VP group (23 v 2, p<0.1). However, the HL with sucrose group still had a higher score than the VP without sucrose group (47 v 23, p<0.01). Crying and the total procedure time showed the same trends as the NFCS score. Conclusions: VP is less painful and more effective than HL for blood sampling in newborn infants. Although oral sucrose may have an additive analgesic effect, it is not necessarily required if VP is used for blood sampling. PMID:15871991

  9. Complete genome sequence of Fer-de-Lance Virus reveals a novel gene in reptilian Paramyxoviruses

    USGS Publications Warehouse

    Kurath, G.; Batts, W.N.; Ahne, W.; Winton, J.R.

    2004-01-01

    The complete RNA genome sequence of the archetype reptilian paramyxovirus, Fer-de-Lance virus (FDLV), has been determined. The genome is 15,378 nucleotides in length and consists of seven nonoverlapping genes in the order 3??? N-U-P-M-F-HN-L 5???, coding for the nucleocapsid, unknown, phospho-, matrix, fusion, hemagglutinin-neuraminidase, and large polymerase proteins, respectively. The gene junctions contain highly conserved transcription start and stop signal sequences and tri-nucleotide intergenic regions similar to those of other Paramyxoviridae. The FDLV P gene expression strategy is like that of rubulaviruses, which express the accessory V protein from the primary transcript and edit a portion of the mRNA to encode P and I proteins. There is also an overlapping open reading frame potentially encoding a small basic protein in the P gene. The gene designated U (unknown), encodes a deduced protein of 19.4 kDa that has no counterpart in other paramyxoviruses and has no similarity with sequences in the National Center for Biotechnology Information database. Active transcription of the U gene in infected cells was demonstrated by Northern blot analysis, and bicistronic N-U mRNA was also evident. The genomes of two other snake paramyxovirus genotypes were also found to have U genes, with 11 to 16% nucleotide divergence from the FDLV U gene. Pairwise comparisons of amino acid identities and phylogenetic analyses of all deduced FDLV protein sequences with homologous sequences from other Paramyxoviridae indicate that FDLV represents a new genus within the subfamily Paramyxovirinae. We suggest the name Ferlavirus for the new genus, with FDLV as the type species.

  10. Application and commercialization of nematodes.

    PubMed

    Peters, Arne

    2013-07-01

    While nematodes are most commonly known for their negative impact on plants, animals, and humans, there are a number of species which are commercially explored. This review highlights some of the most important success stories for the application of nematodes. They are used as bioindicators in ecological and toxicity studies, as model organisms for elucidating fundamental biological questions and for high throughput screening of drugs. Besides these indirect uses, direct applications include the use of Beddingia siricidicola against a major forest pest and the commercialization of Steinernema, Heterorhabditis, and Phasmarhabditis as biological pest control products. New directions for the commercialization of nematodes are the use as living food, specifically loaded with essential nutrients for various fish and shrimp larvae. Even human parasites or closely related species have been successfully used for curing autoimmune disorders and are currently in the process of being developed as drugs. With the striving development of life sciences, we are likely to see more applications for nematodes in the future. A prerequisite is that we continue to explore the vast number of yet undiscovered nematode species.

  11. Nematode neuropeptides as transgenic nematicides.

    PubMed

    Warnock, Neil D; Wilson, Leonie; Patten, Cheryl; Fleming, Colin C; Maule, Aaron G; Dalzell, Johnathan J

    2017-02-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars.

  12. Nematode neuropeptides as transgenic nematicides

    PubMed Central

    Patten, Cheryl; Fleming, Colin C.; Maule, Aaron G.

    2017-01-01

    Plant parasitic nematodes (PPNs) seriously threaten global food security. Conventionally an integrated approach to PPN management has relied heavily on carbamate, organophosphate and fumigant nematicides which are now being withdrawn over environmental health and safety concerns. This progressive withdrawal has left a significant shortcoming in our ability to manage these economically important parasites, and highlights the need for novel and robust control methods. Nematodes can assimilate exogenous peptides through retrograde transport along the chemosensory amphid neurons. Peptides can accumulate within cells of the central nerve ring and can elicit physiological effects when released to interact with receptors on adjoining cells. We have profiled bioactive neuropeptides from the neuropeptide-like protein (NLP) family of PPNs as novel nematicides, and have identified numerous discrete NLPs that negatively impact chemosensation, host invasion and stylet thrusting of the root knot nematode Meloidogyne incognita and the potato cyst nematode Globodera pallida. Transgenic secretion of these peptides from the rhizobacterium, Bacillus subtilis, and the terrestrial microalgae Chlamydomonas reinhardtii reduce tomato infection levels by up to 90% when compared with controls. These data pave the way for the exploitation of nematode neuropeptides as a novel class of plant protective nematicide, using novel non-food transgenic delivery systems which could be deployed on farmer-preferred cultivars. PMID:28241060

  13. Using entomopathogenic nematodes for crop insect control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The objective of this paper is to provide an overview on using entomopathogenic nematodes for insect pest control. Entomopathogenic nematodes (genera Steinernema and Heterorhabditis), are be used as natural biopesticides. Unlike plant parasitic nematodes, which can be serious crop pests, entomopat...

  14. In vivo production of entomopathogenic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In nature, entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are obligate parasites of insects. The nematodes are used widely as biocontrol agents for insect pests. More than a dozen entomopathogenic nematode species have been commercialized for use as biopesticides. One of ...

  15. Comparison of 2D and 3D Computational Multiphase Fluid Flow Models of Oxygen Lancing of Pyrometallurgical Furnace Tap-Holes

    NASA Astrophysics Data System (ADS)

    Erwee, M. W.; Reynolds, Q. G.; Zietsman, J. H.

    2016-06-01

    Furnace tap-holes vary in design depending on the type of furnace and process involved, but they share one common trait: The tap-hole must be opened and closed periodically. In general, tap-holes are plugged with refractory clay after tapping, thereby stopping the flow of molten material. Once a furnace is ready to be tapped, drilling and/or lancing with oxygen are typically used to remove tap-hole clay from the tap-hole. Lancing with oxygen is an energy-intensive, mostly manual process, which affects the performance and longevity of the tap-hole refractory material as well as the processes inside the furnace. Computational modeling offers an opportunity to gain insight into the possible effects of oxygen lancing on various aspects of furnace operation.

  16. Nonhost Root Penetration by Soybean Cyst Nematode

    PubMed Central

    Riggs, R. D.

    1987-01-01

    A total of 66 plants in 50 species were inoculated with eggs and juveniles of soybean cyst nematode, Heterodera glycines. Roots were stained and observed for penetration and development of the nematode. Twenty-six plants were not penetrated; twenty-three were penetrated, but there was no development of the nematode; eight were penetrated with some nematode development; two were penetrated and had considerable nematode development, but few nematodes, if any, matured; and seven were penetrated with many nematodes maturing. The penetration of nonhosts may imply some susceptibility and that populations eventually would build up on the penetrated plants. Plants not penetrated may be useful as rotation plants because no reproduction would occur. PMID:19290137

  17. Free-living nematode peptides

    Technology Transfer Automated Retrieval System (TEKTRAN)

    All nematodes employ a wide array of peptide messengers to control nearly all aspects of the life cycle, including hatching, locomotion, feeding, defense, mating, reproduction, and other behavioral and metabolic events. There are molecular and biological similarities, as well as significant differen...

  18. Jonah field, sublette county, Wyoming: Gas production from overpressured Upper Cretaceous Lance sandstones of the Green River basin

    USGS Publications Warehouse

    Montgomery, S.L.; Robinson, J.W.

    1997-01-01

    Jonah field, located in the northwestern Green River basin, Wyoming, produces gas from overpressured fluvial channel sandstones of the Upper Cretaceous Lance Formation. Reservoirs exist in isolated and amalgamated channel facies 10-100 ft (3-30 m) thick and 150-4000 ft (45-1210 m) wide, deposited by meandering and braided streams. Compositional and paleocurrent studies indicate these streams flowed eastward and had their source area in highlands associated with the Wyoming-Idaho thrust belt to the west. Productive sandstones at Jonah have been divided into five pay intervals, only one of which (Jonah interval) displays continuity across most of the field. Porosities in clean, productive sandstones range from 8 to 12%, with core permeabilities of .01-0.9 md (millidarcys) and in-situ permeabilities as low as 3-20 ??d (microdarcys), as determined by pressure buildup analyses. Structurally, the field is bounded by faults that have partly controlled the level of overpressuring. This level is 2500 ft (758 m) higher at Jonah field than in surrounding parts of the basin, extending to the top part of the Lance Formation. The field was discovered in 1975, but only in the 1990s did the area become fully commercial, due to improvements in fracture stimulation techniques. Recent advances in this area have further increased recoverable reserves and serve as a potential example for future development of tight gas sands elsewhere in the Rocky Mountain region.

  19. Detection of plant-parasitic nematode DNA in the gut of predatory and omnivorous nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A protocol for molecular gut analysis of nematodes was developed to determine if predatory and omnivorous nematodes from five different guilds prey on Rotylenchulus reniformis, Meloidogyne incognita, and Radopholus similis. Mononchoides, Mononchus, Neoactinolaimus, Mesodorylaimus, and Aporcelaimell...

  20. Changes in proximate composition and somatic energy content for Pacific sand lance (Ammodytes hexapterus) from Kachemak Bay, Alaska relative to maturity and season

    USGS Publications Warehouse

    Robards, Martin D.; Anthony, Jill A.; Rose, George A.; Piatt, John F.

    1999-01-01

    Mean dry-weight energy values of adult Pacific sand lance (Ammodytes hexapterus) peaked in spring and early summer (20.91 kJg−1 for males, 21.08 kJg−1 for females), then declined by about 25% during late summer and fall (15.91 kJg−1 for males, 15.74 kJg−1 for females). Late summer declines in energy density paralleled gonadal development. Gender differences in energy density (maleslance spawn in October, entering the winter with close to their minimum whole body energy content. Juvenile sand lance exhibited a relatively constant protein to lipid ratio until they reached 80 mm fork length. Thereafter, relative proportions of protein remained constant while lipid proportions increased significantly. Dry weight energy densities of juveniles increased from a minimum 16.67 kJg−1 to a maximum of 19.68 kJg−1, and (per g) are higher than adults in late summer. The seasonal food value of adult sand lance to predators varies markedly, but maximum energetic value coincides with important feeding periods for marine mammals, fish, and seabirds.

  1. Survey of Nematodes on Coffee in Hawaii

    PubMed Central

    Schenck, S.; Schmitt, D. P.

    1992-01-01

    Surveys of coffee fields in Hawaii during 1989-1991 indicated the presence of 10 nematode species in 8 genera. After coffee was planted in fields previously in sugarcane, populations of Criconemella sp. and Pratylenchus zeae gradually decreased, while Rotylenchulus reniformis and, in one field, Meloidogyne incognita, increased in numbers. Coffee is a poor host of R. reniformis, but weeds in coffee plantations may support this nematode. At present, nematodes pose no serious threat to Hawaii's expanding coffee industry. PMID:19283060

  2. Management of the Citrus Nematode, Tylenchulus semipenetrans

    PubMed Central

    Verdejo-Lucas, S.; McKenry, M. V.

    2004-01-01

    Of the many nematode species that parasitize citrus, Tylenchulus semipenetrans is the most important on a worldwide basis. Management of the citrus nematode remains problematic as no one tactic gives adequate control of the nematode. An overall management strategy must include such components as site selection, use of non-infected nursery stock, use of at lease one post-plant nematode control tactic, and careful management of other elements of the environment that may stress the trees. Nematicides continue to play a key role in management of this pest. Optimum results require careful attention to application techniques. PMID:19262822

  3. Determining the Habitat Preference of Sand Lance (Ammodytes hexapterus) Using Multibeam Bathymetry in the San Juan Islands, Washington

    NASA Astrophysics Data System (ADS)

    Davidson, E.; Greene, H.; Harmsen, F. J.

    2010-12-01

    Ammodytes hexapterus (Pacific Sand Lance or PSL) is an important forage fish supporting many marine populations, ranging from salmon, harbor seals, and whales. Previous studies have shown PSL to be highly substrate specific (Robards et al., 1999). Sand lance spend time buried in the substrate and come out into the water column to feed. This is due to the lack of swim bladders. If the sand particles are too fine their gills can be clogged (Wright et al., 2000). Little is known about the species sub-tidal habitat and new information regarding habitat preferences in deep water would be beneficial in determining their distribution and abundance. Preliminary examination undertaken in this investigation was limited to three sand wave fields: one, the central San Juan Channel (a known PSL sub-tidal habitat), and two previously un-sampled fields west of Sucia Island and southwest of Lopez Island in the waters surrounding the San Juan Islands, Washington. Multibeam bathymetric data, subsea video, and sediment analysis show that PSL have occupied the San Juan Channel, which is composed of well-sorted medium grained (~500 μm size) siliciclastic sand. Several sediment samples from in and around the fields were collected and analyzed to determine a grain size distribution of the sediments. The two un-sampled fields examined have an average grain size higher and lower respectively than the San Juan Channel field. The expected results of this study are to determine whether or not the two newly sampled sediment wave fields are potential sub-tidal habitats of PSL.

  4. Endemic Oscheius Nematodes of Hawai'i

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes (EPNs) parasitize insects utilizing mutualistic bacteria to kill the host, allowing the nematode to feed and reproduce within the insect cadaver. Consequently EPNs are highly sought after for their biological control potential. A survey for EPNs was conducted on O’ahu and...

  5. Blends of ascarosides regulate dispersal in nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Blends of ascarosides regulate dispersal in nematodes Presenter: Dr. Fatma Kaplan Dispersal is an important behavior for many organisms. It can easily be observed when infectious juveniles of entomopathogenic nematodes (Steinernema and Heterorhabditis) leave a consumed insect host. Dauer larvae of ...

  6. Interspecific nematode signals regulate dispersal behavior

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective ...

  7. Biological Control of Nematodes with Bacteria

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Biological control of nematodes is receiving increased attention as environmental considerations with the use of nematicides have increased in importance and their high cost prohibits use on many crops. In addition, nematode resistant cultivars are not available for many crops and resistance that i...

  8. How do humans affect wildlife nematodes?

    USGS Publications Warehouse

    Weinstein, Sara B.; Lafferty, Kevin D.

    2015-01-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host–parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  9. How do humans affect wildlife nematodes?

    PubMed

    Weinstein, Sara B; Lafferty, Kevin D

    2015-05-01

    Human actions can affect wildlife and their nematode parasites. Species introductions and human-facilitated range expansions can create new host-parasite interactions. Novel hosts can introduce parasites and have the potential to both amplify and dilute nematode transmission. Furthermore, humans can alter existing nematode dynamics by changing host densities and the abiotic conditions that affect larval parasite survival. Human impacts on wildlife might impair parasites by reducing the abundance of their hosts; however, domestic animal production and complex life cycles can maintain transmission even when wildlife becomes rare. Although wildlife nematodes have many possible responses to human actions, understanding host and parasite natural history, and the mechanisms behind the changing disease dynamics might improve disease control in the few cases where nematode parasitism impacts wildlife.

  10. Improved nematode extraction from carrot disk culture.

    PubMed

    Kaplan, D T; Davis, E L

    1990-07-01

    Radopholus spp. were reared in carrot tissue culture via established procedures, with slight modification. Several plant tissue maceration enzymes and flotation media (salts and sucrose) were evaluated with regard to nematode toxicity and extraction efficiency. Best extraction of viable nematodes and eggs was attained when carrot tissue infested with Radopholus citrophilus or R. similis was macerated with a mixture of 0.50% driselase and 0.50% cellulysin, w/v each, with 2.5 ml of enzyme solution based for each gram of carrot tissue. Maceration slurries containing carrot tissue and nematodes were maintained in open flasks on a rotary shaker (175 rpm) at 26 C for 24 hours. Nematodes and eggs were extracted from resultant culture slurries by flotation with MgSO-7H0 (sp gr 1.1). A protocol is presented to extract large quantities of viable burrowing nematodes and their eggs from carrot disk cultures.

  11. Current research on the major nematode problems in Japan.

    PubMed

    Ichinohe, M

    1988-04-01

    AMONG IMPORTANT NEMATODE SPECIES OCCURRING IN JAPAN, CURRENT RESEARCH ACHIEVEMENTS WITH THE FOLLOWING FOUR NEMATODES ARE REVIEWED: 1) Soybean cyst nematode (SCN), Heterodera glycines - breeding for resistance, race determination, association with Cephalosporium gregatum in azuki bean disease, and isolation of hatching stimulant. 2) Potato-cyst nematode (PCN), Globodera rostochiensis - pathotype determination (Ro 1), breeding for resistance, and control recommendations. 3) Pinewood nematode (PWN), Bursaphelenchus xylophilus - primary pathogen in pine wilt disease, life cycle exhibiting a typical symbiosis with Japanese pine sawyer, Monochamus alternatus, and project for control. 4) Rice root nematodes (RRN), Hirschmanniella imamuri and H. oryzae - distribution of species, population levels in roots, and role of these nematodes in rice culture.

  12. Ascaroside Signaling is Widely Conserved Among Nematodes

    PubMed Central

    Choe, Andrea; von Reuss, Stephan H.; Kogan, Dima; Gasser, Robin B.; Platzer, Edward G.; Schroeder, Frank C.; Sternberg, Paul W.

    2012-01-01

    Summary Background Nematodes are among the most successful animals on earth and include important human pathogens, yet little is known about nematode pheromone systems. A group of small molecules called ascarosides has been found to mediate mate finding, aggregation, and developmental diapause in Caenorhabditis elegans, but it is unknown whether ascaroside signaling exists outside of the genus Caenorhabditis. Results To determine whether ascarosides are used as signaling molecules by other nematode species, we performed a mass spectrometry-based screen for ascarosides in secretions from a variety of both free-living and parasitic (plant, insect, and animal) nematodes. We found that most of the species analyzed, including nematodes from several different clades, produce species-specific ascaroside mixtures. In some cases, ascaroside biosynthesis patterns appear to correlate with phylogeny, whereas in other cases, biosynthesis seems to correlate with lifestyle and ecological niche. We further show that ascarosides mediate distinct nematode behaviors, such as retention, avoidance, and long-range attraction, and that different nematode species respond to distinct, but overlapping, sets of ascarosides. Conclusions Our findings indicate that nematodes utilize a conserved family of signaling molecules despite having evolved to occupy diverse ecologies. Their structural features and level of conservation are evocative of bacterial quorum sensing, where acyl homoserine lactones (AHLs) are both produced and sensed by many species of Gram-negative bacteria. The identification of species-specific ascaroside profiles may enable pheromone-based approaches to interfere with reproduction and survival of parasitic nematodes, which are responsible for significant agricultural losses and many human diseases worldwide. PMID:22503501

  13. Groundwater well inventory and assessment in the area of the proposed Normally Pressured Lance natural gas development project, Green River Basin, Wyoming, 2012

    USGS Publications Warehouse

    Sweat, Michael J.

    2013-01-01

    During May through September 2012, the U.S. Geological Survey, in cooperation with the Bureau of Land Management, inventoried and assessed existing water wells in southwestern Wyoming for inclusion in a possible groundwater-monitor network. Records were located for 3,282 wells in the upper Green River Basin, which includes the U.S. Geological Survey study area and the proposed Normally Pressured Lance natural gas development project area. Records for 2,713 upper Green River Basin wells were determined to be unique (not duplicated) and to have a Wyoming State Engineers Office permit. Further, 376 of these wells were within the U.S. Geological Survey Normally Pressured Lance study area. Of the 376 wells in the U.S. Geological Survey Normally Pressured Lance study area, 141 well records had sufficient documentation, such as well depth, open interval, geologic log, and depth to water, to meet many, but not always all, established monitor well criteria. Efforts were made to locate each of the 141 wells and to document their current condition. Field crews were able to locate 121 of the wells, and the remaining 20 wells either were not located as described, or had been abandoned and the site reclaimed. Of the 121 wells located, 92 were found to meet established monitor well criteria. Results of the field efforts during May through September 2012, and specific physical characteristics of the 92 wells, are presented in this report.

  14. The influence of particle size of dietary prey on food consumption and ecological conversion efficiency of young-of-the-year sand lance, Ammodytes personatus

    NASA Astrophysics Data System (ADS)

    Sun, Yao; Liu, Yong; Liu, Xinfu; Tang, Oisheng

    2010-06-01

    The Eggers model was used to study the influence of two particle sizes of dietary prey on food consumption and ecological conversion efficiency of young-of-the-year sand lance, Ammodytes personatus, in continuous flow-through seawater in 2.5-m 3 tanks in the laboratory. The sand lances (average body weight 0.85 ± 0.21 g) were fed larval (average body length 0.56 ± 0.08 mm) or adult (average body length 10.12 ± 1.61 mm) Artemia salina. The gastric evacuation rate of the fish feeding on larval Artemia was 0.214, higher than that of those feeding on adult Artemia (0.189). The daily food consumption of the fish feeding on larval Artemia was 60.14 kJ/100 g in terms of energy content, higher than that of the fish feeding on adult Artemia (51.69 kJ/100 g), but the daily growth rate of fish feeding on larval Artemia was 14.86 kJ/100 g, significantly lower than that of the fish feeding on adult Artemia (19.50 kJ/100 g), indicating that less energy was used for growth when the food particles were smaller. Slow growth of sand lances preying on larval Artemia was probably due to the high energy consumption during predation, consistent with the basic suppositions of optimal foraging theory.

  15. [Nematodes of humans in the Primorye Territory].

    PubMed

    Ermolenko, A V; Rumiantseva, E E; Bartkova, A D; Voronok, V M; Poliakova, L F

    2013-01-01

    Nematodes occupy the top in the general pattern of human parasitic diseases in the Primorye Territory. In the south of the Far East, there are a total of 28 nematode species that can parasitize man. However, the authors have identified only 8 nematode-induced diseases, such as ascariasis, enterobiasis, toxocariasis, trichocephaliasis, anisakiasis, trichinosis, dirofilariasis, dioctophymosis. The latter has been found only once in the 1920s. According to official statistical data, the proportion of ascariasis and enterobiasis accounted for 43.8 and 53.5% of the total number of helminthiases, respectively.

  16. The politics of NATO short-range nuclear modernization, 1983-1990: The follow-on to Lance missile decisions

    SciTech Connect

    Larsen, J.A.

    1991-01-01

    The follow-on to Lance (FOTL) missile was born in 1983 with a consensual decision by NATO, in the face of a worsening strategic situation, to pursue short-range nuclear force (SNF) modernization. The program continued despite increasing popular and political opposition in Europe. It ended with a May 1990 cancellation decision by the American bureaucracy that reflected converging pressures from the international system, from America's allies, and from the domestic arena. The study asks three questions concerning the FOTL case. Why did NATO decide to upgrade its SNF forces, particularly FOTL Why did NATO continue to support FOTL's development in the face of increasing public opposition as the decade wore on Why did the United States cancel FOTL when it did The thesis attempts to answer each question through the use of one of three analytical perspective: systemic theory, alliance politics, or domestic politics. It concludes that during this time of diminishing threat at the systemic level, domestic-level factors within the German and American milieu became more important.

  17. Occupational injuries with captive lance-headed vipers (Bothrops moojeni): experience from a snake farm in Brazil.

    PubMed

    Nishioka, S A; Silveira, P V; Peixoto-Filho, F M; Jorge, M T; Sandoz, A

    2000-07-01

    We studied occupational injuries with captive lance-headed vipers (Bothrops moojeni) that occurred in a snake farm in south-eastern Brazil from February 1981 to May 1999. The risk of injury, taking into account 13 cases of snake-associated injuries (12 of them snake bites) was 2.73 per 10,000 person-days of work, and 3.51 per 100,000 venom extractions. Thirteen cases of injury occurred in seven workers, whereas 18 workers were never injured, suggesting that some individuals have a higher risk of injury than others perhaps due to lack of concentration or overconfidence. Eight episodes of occupational injuries occurring in four technicians, including a case of eye injury due to splashed venom during extraction, are reported. Assessment of whether envenoming occurred was facilitated by knowledge of the snake species and size, history of recent venom extraction and snake feeding, and examination of snake venom glands. Hypersensitivity reactions (anaphylaxis and serum sickness) to antivenom are a risk particularly to those workers who were bitten more than once and medicated previously. Antivenom therefore should not be administered to these individuals unless there is clear evidence that envenoming occurred or is likely to have occurred. Hypersensitivity to the venom is also a health concern for workers from snake farms.

  18. Nematode endogenous small RNA pathways

    PubMed Central

    Hoogstrate, Suzanne W; Volkers, Rita JM; Sterken, Mark G; Kammenga, Jan E; Snoek, L Basten

    2014-01-01

    The discovery of small RNA silencing pathways has greatly extended our knowledge of gene regulation. Small RNAs have been presumed to play a role in every field of biology because they affect many biological processes via regulation of gene expression and chromatin remodeling. Most well-known examples of affected processes are development, fertility, and maintenance of genome stability. Here we review the role of the three main endogenous small RNA silencing pathways in Caenorhabditis elegans: microRNAs, endogenous small interfering RNAs, and PIWI-interacting RNAs. After providing an entry-level overview on how these pathways function, we discuss research on other nematode species providing insight into the evolution of these small RNA pathways. In understanding the differences between the endogenous small RNA pathways and their evolution, a more comprehensive picture is formed of the functions and effects of small RNAs. PMID:25340013

  19. Nematode molecular diagnostics: from bands to barcodes.

    PubMed

    Powers, Tom

    2004-01-01

    Nematodes are considered among the most difficult animals to identify. DNA-based diagnostic methods have already gained acceptance in applications ranging from quarantine determinations to assessments of biodiversity. Researchers are currently in an information-gathering mode, with intensive efforts applied to accumulating nucleotide sequence of 18S and 28S ribosomal genes, internally transcribed spacer regions, and mitochondrial genes. Important linkages with collateral data such as digitized images, video clips and specimen voucher web pages are being established on GenBank and NemATOL, the nematode-specific Tree of Life database. The growing DNA taxonomy of nematodes has lead to their use in testing specific short sequences of DNA as a "barcode" for the identification of all nematode species.

  20. Interactions between Nematodes and Earthworms: Enhanced Dispersal of Steinernema carpocapsae

    PubMed Central

    Shapiro, D. I.; Berry, E. C.; Lewis, L. C.

    1993-01-01

    Dispersal of the nematode Steinernema carpocapsae (All strain), applied on the top or the bottom of soil columns, was tested in the presence or absence of two earthworm species, Lumbricus terrestris or Aporrectodea trapezoides. Nematode dispersal was estimated after a 2-week period with a bioassay against the greater wax moth, Galleria mellonella. Vertical dispersal of nematodes was increased in the presence of earthworms. When nematodes were placed on the surface of soil columns, significantly more nematodes dispersed to the lower half of the columns when either earthworm species was present than when earthworms were not present. When nematodes were placed on the bottom of soil columns, significantly more nematodes dispersed to the upper half of the columns when L. terrestris was present than when A. trapezoides was present or in the absence of earthworms. Because nematodes were found on the exterior and in the interior of earthworms, nematode dispersal may be enhanced by direct contact with the earthworms. PMID:19279757

  1. Conserving and enhancing biological control of nematodes.

    PubMed

    Timper, Patricia

    2014-06-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  2. Conserving and Enhancing Biological Control of Nematodes

    PubMed Central

    Timper, Patricia

    2014-01-01

    Conservation biological control is the modification of the environment or existing practices to protect and enhance antagonistic organisms to reduce damage from pests. This approach to biological control has received insufficient attention compared with inundative applications of microbial antagonists to control nematodes. This review provides examples of how production practices can enhance or diminish biological control of plant-parasitic nematodes and other soilborne pests. Antagonists of nematodes can be enhanced by providing supplementary food sources such as occurs when organic amendments are applied to soil. However, some organic amendments (e.g., manures and plants containing allelopathic compounds) can also be detrimental to nematode antagonists. Plant species and genotype can strongly influence the outcome of biological control. For instance, the susceptibility of the plant to the nematode can determine the effectiveness of control; good hosts will require greater levels of suppression than poor hosts. Plant genotype can also influence the degree of rhizosphere colonization and antibiotic production by antagonists, as well the expression of induced resistance by plants. Production practices such as crop rotation, fallow periods, tillage, and pesticide applications can directly disrupt populations of antagonistic organisms. These practices can also indirectly affect antagonists by reducing their primary nematode host. One of the challenges of conservation biological control is that practices intended to protect or enhance suppression of nematodes may not be effective in all field sites because they are dependent on indigenous antagonists. Ultimately, indicators will need to be identified, such as the presence of particular antagonists, which can guide decisions on where it is practical to use conservation biological control. Antagonists can also be applied to field sites in conjunction with conservation practices to improve the consistency, efficacy, and

  3. Influence of metalaxyl on three nematodes of citrus.

    PubMed

    Kaplan, D T

    1983-07-01

    Metalaxyl significantly reduced population of Pratylenchus coffeae, Radopholus similis, and Tylenchulus semipenetrans in roots of Citrus limon (rough lemon) under greenhouse conditions. Postinoculation treatment of rough lemon seedlings was not as effective i n reducing nematode populations as was treatment before inoculation. Fewer nematodes infected metalaxyl-treated roots than nontreated roots. However, incubation of nematodes in metalaxyl did not inhibit nematode motility or their ability to locate and infect roots. Cellular responses to nematode injection differed between treated and nontreated tissues. Metalaxyl appeared to confer nematode contraol by modifying citrus roots such that a normally susceptible rootstock became tolerant.

  4. Induced resistance to nematodes in cotton: a novel contribution to nematode management.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Induced resistance against plant-parasitic nematodes has not previously been shown in cotton. We tested whether co-infection of cotton by Meloidogyne incognita and Rotylenchulus reniformis affected population levels of either nematode compared to single-species infection. In split-root experiments, ...

  5. Interspecific Nematode Signals Regulate Dispersal Behavior

    PubMed Central

    Kaplan, Fatma; Alborn, Hans T.; von Reuss, Stephan H.; Ajredini, Ramadan; Ali, Jared G.; Akyazi, Faruk; Stelinski, Lukasz L.; Edison, Arthur S.; Schroeder, Frank C.; Teal, Peter E.

    2012-01-01

    Background Dispersal is an important nematode behavior. Upon crowding or food depletion, the free living bacteriovorus nematode Caenorhabditis elegans produces stress resistant dispersal larvae, called dauer, which are analogous to second stage juveniles (J2) of plant parasitic Meloidogyne spp. and infective juveniles (IJ)s of entomopathogenic nematodes (EPN), e.g., Steinernema feltiae. Regulation of dispersal behavior has not been thoroughly investigated for C. elegans or any other nematode species. Based on the fact that ascarosides regulate entry in dauer stage as well as multiple behaviors in C. elegans adults including mating, avoidance and aggregation, we hypothesized that ascarosides might also be involved in regulation of dispersal behavior in C. elegans and for other nematodes such as IJ of phylogenetically related EPNs. Methodology/Principal Findings Liquid chromatography-mass spectrometry analysis of C. elegans dauer conditioned media, which shows strong dispersing activity, revealed four known ascarosides (ascr#2, ascr#3, ascr#8, icas#9). A synthetic blend of these ascarosides at physiologically relevant concentrations dispersed C. elegans dauer in the presence of food and also caused dispersion of IJs of S. feltiae and J2s of plant parasitic Meloidogyne spp. Assay guided fractionation revealed structural analogs as major active components of the S. feltiae (ascr#9) and C. elegans (ascr#2) dispersal blends. Further analysis revealed ascr#9 in all Steinernema spp. and Heterorhabditis spp. infected insect host cadavers. Conclusions/Significance Ascaroside blends represent evolutionarily conserved, fundamentally important communication systems for nematodes from diverse habitats, and thus may provide sustainable means for control of parasitic nematodes. PMID:22701701

  6. Two new species of soil nematodes from Manipur, India.

    PubMed

    Chanu, Loukrakpam Bina; Meitei, N Mohilal; Shah, M Manjur

    2016-09-01

    Survey for soil nematodes associated with mulberry plants in valley districts of Manipur revealed the presence of two new species of soil nematodes of the genus Tylenchus sp. and Telotylenchus sp. The two new species are described and illustrated here.

  7. Molecular Transfer of Nematode Resistance Genes

    PubMed Central

    Williamson, V. M.; Ho, J.-Y.; Ma, H. M.

    1992-01-01

    Recombinant DNA techniques have been used to introduce agronomically valuable traits, including resistance to viruses, herbicides, and insects, into crop plants. Introduction of these genes into plants frequently involves Agrobacterium-mediated gene transfer. The potential exists for applying this technology to nematode control by introducing genes conferring resistance to nematodes. Transferred genes could include those encoding products detrimental to nematode development or reproduction as well as cloned host resistance genes. Host genes that confer resistance to cyst or root-knot nematode species have been identified in many plants. The best characterized is Mi, a gene that confers resistance to root-knot nematodes in tomato. A map-based cloning approach is being used to isolate the gene. For development of a detailed map of the region of the genome surrounding Mi, DNA markers genetically linked to Mi have been identified and analyzed in tomato lines that have undergone a recombination event near Mi. The molecular map will be used to identify DNA corresponding to Mi. We estimate that a clone of Mi will be obtained in 2-5 years. An exciting prospect is that introduction of this gene will confer resistance in plant species without currently available sources of resistance. PMID:19282989

  8. Does cooperation increase helpers' later success as breeders? A test of the skills hypothesis in the cooperatively displaying lance-tailed manakin.

    PubMed

    DuVal, Emily H

    2013-07-01

    Experience improves individual performance in many tasks. Pre-breeding cooperation may provide important experience that improves later success as a breeder, offering one compelling explanation for why some individuals delay reproduction to help others breed (the 'skills hypothesis'). However, confounding effects of age, quality and alternative selective benefits have complicated rigorous tests of this hypothesis. Male lance-tailed manakins perform cooperative courtship displays involving partnerships between unrelated alpha and beta males, and alphas monopolize resulting copulations. Beta males therefore do not receive immediate direct or indirect fitness benefits, but may gain skills during cooperation that increase their later success as an alpha. To date, however, the effect of cooperative experience on later success as a breeder has never been tested in any cooperatively displaying taxon. The effects of prior cooperative experience on reproductive success of alpha lance-tailed manakins were analysed in a mixed model framework using 12 years of information on cooperative experience and annual and lifetime genetic reproductive success for 57 alpha males. Models included previously identified effects of age and alpha tenure. Individual-level random effects controlled for quality differences to test for an independent influence of beta experience on success. Males accumulated up to 5 years of beta experience before becoming alphas, but 42·1% of alphas had no prior beta experience. Betas became alphas later in life, and experienced significantly lower reproductive success in their final year as alpha than males that were never beta, but did not have higher lifetime success or longer alpha tenures. Differences in patterns of annual siring success were best explained by age-dependent patterns of reproductive improvement and senescence among alphas, not beta experience. Cooperative experience does not increase relative breeding success for male lance-tailed manakins

  9. Nature and Inheritance of Nematode Resistance in Cereals

    PubMed Central

    Cook, R.

    1974-01-01

    Resistance to a number of nematodes is present in varieties of temperate and tropical cereals. The occurrence, nature, and inheritance of varietal resistance in cereals is reviewed. Evaluation of the practical significance of nematode resistance in a particular host-nematode combination is discussed in relation to host efficiency, host sensitivity, genetic control of resistance, and presence of virulence in the nematode population. PMID:19308117

  10. Nematode feeding sites: unique organs in plant roots.

    PubMed

    Kyndt, Tina; Vieira, Paulo; Gheysen, Godelieve; de Almeida-Engler, Janice

    2013-11-01

    Although generally unnoticed, nearly all crop plants have one or more species of nematodes that feed on their roots, frequently causing tremendous yield losses. The group of sedentary nematodes, which are among the most damaging plant-parasitic nematodes, cause the formation of special organs called nematode feeding sites (NFS) in the root tissue. In this review we discuss key metabolic and cellular changes correlated with NFS development, and similarities and discrepancies between different types of NFS are highlighted.

  11. Biocontrol: The Potential of Entomophilic Nematodes in Insect Management

    PubMed Central

    Webster, John M.

    1980-01-01

    A review of the development of entomophilic nematology and a commentary on the potential of entomophilic nematodes in controlling insect pests. The paper considers some of the major contributions to our knowledge of entomophilic nematology; factors involved in insect pest management and how they are applicable to the use of nematodes; nematodes which are most promising as biological control agents; and problems to be solved to facilitate the use of entomophilic nematodes in insect management. PMID:19300702

  12. Towards a genome sequence for reniform nematode (Rotylenchulus reniformis)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reniform nematode (Rotylenchulus reniformis) currently accounts for $130M in annual losses to the U.S. cotton industry and has supplanted root-knot nematode as the major nematode pest of cotton in Mississippi, Louisiana, and Alabama. Moreover, in other cotton-producing states the range and influenc...

  13. A novel flavivirus in the soybean cyst nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Heterodera glycines, the soybean cyst nematode (SCN) is a subterranean root pathogen that causes the most damaging disease of soybean in the United States. A novel nematode virus genome, soybean cyst nematode virus 5 (SbCNV5), was identified in RNASeq data from SCN eggs and second-stage juveniles. T...

  14. Nematode CLE signaling in Arabidopsis requires CLAVATA2 and CORYNE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic cyst nematodes secrete CLAVATA3 (CLV3)/ESR(CLE)-like effector proteins. These proteins have been shown to act as ligand mimics of plant CLE peptides and are required for successful nematode infection; however, the receptors for nematode CLE-like peptides have not been identified. Her...

  15. Site-Specific Detection and Management of Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematode distribution varies significantly throughout a field and is highly correlated to soil texture and other edaphic factors. Field-wide application results in nematicides being applied to areas without nematodes and the application of sub-effective levels in areas with high nematode densities. ...

  16. Opportunity to use native nematodes for pest control

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We have surveyed wild cranberry bogs in WI and found three isolates of native nematodes. We have been testing these nematodes as potential biological control agents in for cranberry insect pests including sparganothis fruitworm and flea beetle. The nematodes seem to be effective at finding and killi...

  17. Nematode problems affecting agriculture in the Philippines.

    PubMed

    Davide, R G

    1988-04-01

    Nematodes are considered major pests on most economic crops in the Philippines, particularly on banana, pineapple, citrus, tomato, ramie, and sugarcane. Radopholus similis is the most destructive nematode on banana, while Meloidogyne spp. are more serious on various vegetable crops such as tomato, okra, and celery and on fiber crops such as ramie. Tylenchulus semipenetrans is a problem on citrus and Rotylenchulus reniformis on pineapple and some legume crops. Hirschmanniella oryzae and Aphelenchoides besseyi are becoming serious on rice, and Pratylenchus zeae is affecting corn in some areas. Lately, Globodera rostochiensis has been causing serious damage on potato in the highlands. Control measures such as crop rotation, planting resistant varieties, chemical nematicide application, and biological control have been recommended to control these nematodes.

  18. Nematode taxonomy: from morphology to metabarcoding

    NASA Astrophysics Data System (ADS)

    Ahmed, M.; Sapp, M.; Prior, T.; Karssen, G.; Back, M.

    2015-11-01

    Nematodes represent a species rich and morphologically diverse group of metazoans inhabiting both aquatic and terrestrial environments. Their role as biological indicators and as key players in nutrient cycling has been well documented. Some groups of nematodes are also known to cause significant losses to crop production. In spite of this, knowledge of their diversity is still limited due to the difficulty in achieving species identification using morphological characters. Molecular methodology has provided very useful means of circumventing the numerous limitations associated with classical morphology based identification. We discuss herein the history and the progress made within the field of nematode systematics, the limitations of classical taxonomy and how the advent of high throughput sequencing is facilitating advanced ecological and molecular studies.

  19. Remote Sensing of Parasitic Nematodes in Plants

    NASA Technical Reports Server (NTRS)

    Lawrence, Gary W.; King, Roger; Kelley, Amber T.; Vickery, John

    2007-01-01

    A method and apparatus for remote sensing of parasitic nematodes in plants, now undergoing development, is based on measurement of visible and infrared spectral reflectances of fields where the plants are growing. Initial development efforts have been concentrated on detecting reniform nematodes (Rotylenchulus reniformis) in cotton plants, because of the economic importance of cotton crops. The apparatus includes a hand-held spectroradiometer. The readings taken by the radiometer are processed to extract spectral reflectances at sixteen wavelengths between 451 and 949 nm that, taken together, have been found to be indicative of the presence of Rotylenchulus reniformis. The intensities of the spectral reflectances are used to estimate the population density of the nematodes in an area from which readings were taken.

  20. Immunological control of gastrointestinal nematode infections.

    PubMed

    Klei, T R

    1997-11-01

    Control of nematode parasitism by an active manipulation of the host immune response has been a goal of veterinary and medical parasitologists for decades. The reality of achieving this goal has been questioned vigorously and demonstrations of the feasibility of using immunological control under field conditions are minimal. Nevertheless, with the rapid growth of modern biotechnology and the identification of novel parasite molecules as vaccine targets, the potential for success in this area has recently generated considerable excitement. The induction and regulation of the ruminant immune response against nematode parasites can be controlled either by management programs which include anthelmintic treatment or by vaccination. Both approaches will be discussed in this session.

  1. Detecting Nematode Features from Digital Images

    PubMed Central

    de la Blanca, N. Pérez; Fdez-Valdivia, J.; Castillo, P.; Gómez-Barcina, A.

    1992-01-01

    Procedures for estimating and calibrating nematode features from digitial images are described and evaluated by illustration and mathematical formulae. Technical problems, such as capturing and cleaning raw images, standardizing the grey level range of images, and the detection of characteristics of the body habitus, presence or absence of stylet knobs, and tail and lip region shape are discussed. This study is the first of a series aimed at developing a set of automated methods to permit more rapid, objective characterizations of nematode features than is achievable by cumbersome conventional methods. PMID:19282998

  2. Mining nematode genome data for novel drug targets.

    PubMed

    Foster, Jeremy M; Zhang, Yinhua; Kumar, Sanjay; Carlow, Clotilde K S

    2005-03-01

    Expressed sequence tag projects have currently produced over 400 000 partial gene sequences from more than 30 nematode species and the full genomic sequences of selected nematodes are being determined. In addition, functional analyses in the model nematode Caenorhabditis elegans have addressed the role of almost all genes predicted by the genome sequence. This recent explosion in the amount of available nematode DNA sequences, coupled with new gene function data, provides an unprecedented opportunity to identify pre-validated drug targets through efficient mining of nematode genomic databases. This article describes the various information sources available and strategies that can expedite this process.

  3. The Lance Insertion Retardation meter (LIRmeter): an instrument for in situ determination of sea floor properties—technical description and performance evaluation

    NASA Astrophysics Data System (ADS)

    Stephan, Sebastian; Kaul, Norbert; Villinger, Heinrich

    2012-09-01

    Within this paper we present the Lance Insertion Retardation meter (LIRmeter) as an instrument to determine the strength of marine sediments by a measurement of the deceleration of a probe during penetration into the seafloor. The instrument has been designed for the penetration of the upper 4 m of marine sediments and is therefore suitable for site investigation applications such as cable route surveys. The LIRmeter can be easily deployed from a floating platform in water depths of up to 4,500 m. The system is suitable for long lasting missions (more than 12 h) with pogo-style measurements due to a rugged design and a special selection of sensors and electronics. The LIRmeter provides a custom data acquisition software and a web interface for acquisition setup, data download and system administration. An adaptation of the instrument to specific problems (i.e. extremely soft sediments) is possible due to interchangeable tips and adjustable weights of the lance. The specifically developed user interface and the rugged design make the instrument very easy to handle and to maintain. The sensors and the data acquisition were tested in the laboratory as well as in the field. Field measurements took place in the North Sea, where numerous measurements were performed. This paper gives an extensive description of the design of the LIRmeter (mechanics, electronics and data acquisition) supplemented by a description of data analysis and results of field- and laboratory-tests.

  4. A Trojan horse mechanism of bacterial pathogenesis against nematodes

    PubMed Central

    Niu, Qiuhong; Huang, Xiaowei; Zhang, Lin; Xu, Jianping; Yang, Dongmei; Wei, Kangbi; Niu, Xuemei; An, Zhiqiang; Bennett, Joan Wennstrom; Zou, Chenggang; Yang, Jinkui; Zhang, Ke-Qin

    2010-01-01

    Understanding the mechanisms of host–pathogen interaction can provide crucial information for successfully manipulating their relationships. Because of its genetic background and practical advantages over vertebrate model systems, the nematode Caenorhabditis elegans model has become an attractive host for studying microbial pathogenesis. Here we report a “Trojan horse” mechanism of bacterial pathogenesis against nematodes. We show that the bacterium Bacillus nematocida B16 lures nematodes by emitting potent volatile organic compounds that are much more attractive to worms than those from ordinary dietary bacteria. Seventeen B. nematocida-attractant volatile organic compounds are identified, and seven are individually confirmed to lure nematodes. Once the bacteria enter the intestine of nematodes, they secrete two proteases with broad substrate ranges but preferentially target essential intestinal proteins, leading to nematode death. This Trojan horse pattern of bacterium–nematode interaction enriches our understanding of microbial pathogenesis. PMID:20733068

  5. Cuticle surface coat of plant-parasitic nematodes.

    PubMed

    Davies, Keith G; Curtis, Rosane H C

    2011-01-01

    The surface coat (SC) of the plant-parasitic nematode cuticle is an understudied area of current research, even though it likely plays key roles in both nematode-plant and nematode-microbe interactions. Although in several ways Caenorhabditis elegans is a poor model for plant-parasitic nematodes, it is a useful starting point for investigations of the cuticle and its SC, especially in the light of recent work using this species as a model for innate immunity and the generic biology underpinning much host-parasite biology. We review the research focused on the involvement of the SC of plant-parasitic nematodes. Using the insights gained from animal-parasitic nematodes and other sequenced nematodes, we discuss the key roles that the SC may play.

  6. Meloidogyne incognita nematode resistance QTL in carrot

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root-knot nematodes (Meloidogyne spp.) are major pests attacking carrots (Daucus carota) worldwide, causing galling and forking of the storage roots, rendering them unacceptable for market. Genetic resistance could significantly reduce the need for broad-spectrum soil fumigants in carrot production....

  7. Potato cyst nematodes: pests of national importance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Potato cyst nematodes (PCN; G. rostochiensis and G. pallida) are internationally-recognized quarantine pests and considered the most devastating pests of potatoes due to annual worldwide yield losses estimated at 12.2%. PCNs continue to spread throughout North America and were recently detected in I...

  8. The Future of Nematode Management in Cotton

    PubMed Central

    Starr, J. L.; Koenning, S. R.; Kirkpatrick, T. L.; Robinson, A. F.; Roberts, P. A.; Nichols, R. L.

    2007-01-01

    The importance of plant-parasitic nematodes as yield-limiting pathogens of cotton has received increased recognition and attention in the United States in the recent past. This paper summarizes the remarks made during a symposium of the same title that was held in July 2007 at the joint meeting of the Society of Nematologists and the American Phytopathological Society in San Diego, California. Although several cultural practices, including crop rotation, can be effective in suppressing the populations of the important nematode pathogens of cotton, the economic realities of cotton production limit their use. The use of nematicides is also limited by issues of efficacy and economics. There is a need for development of chemistries that will address these limitations. Also needed are systems that would enable precise nematicide application in terms of rate and placement only in areas where nematode population densities warrant application. Substantial progress is being made in the identification, characterization and mapping of loci for resistance to Meloidogyne incognita and Rotylenchulus reniformis. These data will lead to efficient marker-assisted selection systems that will likely result in development and release of nematode-resistant cotton cultivars with superior yield potential and high fiber quality. PMID:19259500

  9. Dolichodorus aestuarius n. sp. (Nematode: Dolichodoridae)

    PubMed Central

    Chow, F. H.; Taylor, A. L.

    1978-01-01

    Dolichodorus aestuarius n. sp. from an estuarine habitat near Cedar Key, Florida is described. This nematode has a stylet range of 62-76 μm in females and 60-72 μm in males. The stylet is shorter than those of all described species except D. brevistilus. The probable host plant is Juncus roemerianus. PMID:19305840

  10. Molecular analysis of plant-parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In addition to traditional morphology-based taxonomic approaches, molecular methods are often required to confirm diagnoses or to establish phylogenetic relationships among plant-parasitic nematodes. Current challenges, including limitations of existing methods, and new research directions will be d...

  11. Considering field physical characteristics in assessing risk and delineating nematode management zones

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Site-specific management (SSM) of nematodes requires identifying factors affecting nematode distribution, nematode population density, and nematode-induced yield losses, and then using that information to predict where nematode management will cost-effectively reduce yield loss. Using cotton (Gossy...

  12. Top 10 plant-parasitic nematodes in molecular plant pathology.

    PubMed

    Jones, John T; Haegeman, Annelies; Danchin, Etienne G J; Gaur, Hari S; Helder, Johannes; Jones, Michael G K; Kikuchi, Taisei; Manzanilla-López, Rosa; Palomares-Rius, Juan E; Wesemael, Wim M L; Perry, Roland N

    2013-12-01

    The aim of this review was to undertake a survey of researchers working with plant-parasitic nematodes in order to determine a 'top 10' list of these pathogens based on scientific and economic importance. Any such list will not be definitive as economic importance will vary depending on the region of the world in which a researcher is based. However, care was taken to include researchers from as many parts of the world as possible when carrying out the survey. The top 10 list emerging from the survey is composed of: (1) root-knot nematodes (Meloidogyne spp.); (2) cyst nematodes (Heterodera and Globodera spp.); (3) root lesion nematodes (Pratylenchus spp.); (4) the burrowing nematode Radopholus similis; (5) Ditylenchus dipsaci; (6) the pine wilt nematode Bursaphelenchus xylophilus; (7) the reniform nematode Rotylenchulus reniformis; (8) Xiphinema index (the only virus vector nematode to make the list); (9) Nacobbus aberrans; and (10) Aphelenchoides besseyi. The biology of each nematode (or nematode group) is reviewed briefly.

  13. Microbiota from Rhabditis regina may alter nematode entomopathogenicity.

    PubMed

    Jiménez-Cortés, Jesús Guillermo; Canales-Lazcano, Jorge; Lara-Reyes, Nancy; Rosenblueth, Mónica; Martínez-Romero, Esperanza; Contreras-Garduño, Jorge

    2016-11-01

    Here we report the presence of the entomopathogenic nematode Rhabditis (Rhabditoides) regina affecting white grubs (Phyllophaga sp. and Anomala sp.) in Mexico and R. regina-associated bacteria. Bioassays were performed to test the entomopathogenic capacity of dauer and L2 and L3 (combined) larval stages. Furthermore, we determined the diversity of bacteria from laboratory nematodes cultivated for 2 years (dauer and L2-L3 larvae) and from field nematodes (dauer and L2-L3 larvae) in addition to the virulence in Galleria mellonella larvae of some bacterial species from both laboratory and field nematodes. Dauer and non-dauer larvae of R. regina killed G. mellonella. Bacteria such as Serratia sp. (isolated from field nematodes) and Klebsiella sp. (isolated from larvae of laboratory and field nematodes) may explain R. regina entomopathogenic capabilities. Different bacteria were found in nematodes after subculturing in the laboratory suggesting that R. regina may acquire bacteria in different environments. However, there were some consistently found bacteria from laboratory and field nematodes such as Pseudochrobactrum sp., Comamonas sp., Alcaligenes sp., Klebsiella sp., Acinetobacter sp., and Leucobacter sp. that may constitute the nematode microbiome. Results showed that some bacteria contributing to entomopathogenicity may be lost in the laboratory representing a disadvantage when nematodes are cultivated to be used for biological control.

  14. How reliably can northeast Atlantic sand lances of the genera Ammodytes and Hyperoplus be distinguished? A comparative application of morphological and molecular methods

    PubMed Central

    Thiel, Ralf; Knebelsberger, Thomas

    2016-01-01

    Abstract Accurate stock assessments for each of the dominant species of sand lances in the northeast Atlantic Ocean and adjacent areas are not available due to the lack of a reliable identification procedure; therefore, appropriate measures of fisheries management or conservation of sand lances cannot be implemented. In this study, detailed morphological and molecular features are assessed to discriminate between four species of sand lances belonging to the genera Ammodytes and Hyperoplus. Morphological characters described by earlier authors as useful for identification of the genera are confirmed, and two additional distinguishing characters are added. A combination of the following morphological characters is recommended to distinguish between the genera Hyperoplus and Ammodytes: the protrusibility of the premaxillae, the presence of hooked ends of the prevomer, the number of dermal plicae, and the pectoral-fin length as a percentage of the standard length. The discriminant function analysis revealed that morphometric data are not very useful to distinguish the species of each of the two genera. The following meristic characters improve the separation of Hyperoplus lanceolatus from Hyperoplus immaculatus: the number of lower arch gill rakers, total number of gill rakers, numbers of caudal vertebrae and total vertebrae, and numbers of dorsal-fin and anal-fin rays. It is confirmed that Ammodytes tobianus differs from Ammodytes marinus by its belly scales that are organised in tight chevrons, scales which are present over the musculature at the base of the caudal fin, as well as by the lower numbers of dermal plicae, dorsal-fin rays, and total vertebrae. In contrast to the morphological data, mitochondrial COI sequences (DNA barcodes) failed to separate unambiguously the four investigated species. Ammodytes tobianus and Hyperoplus lanceolatus showed an overlap between intraspecific and interspecific K2P genetic distances and cannot be reliably distinguished using

  15. How reliably can northeast Atlantic sand lances of the genera Ammodytes and Hyperoplus be distinguished? A comparative application of morphological and molecular methods.

    PubMed

    Thiel, Ralf; Knebelsberger, Thomas

    2016-01-01

    Accurate stock assessments for each of the dominant species of sand lances in the northeast Atlantic Ocean and adjacent areas are not available due to the lack of a reliable identification procedure; therefore, appropriate measures of fisheries management or conservation of sand lances cannot be implemented. In this study, detailed morphological and molecular features are assessed to discriminate between four species of sand lances belonging to the genera Ammodytes and Hyperoplus. Morphological characters described by earlier authors as useful for identification of the genera are confirmed, and two additional distinguishing characters are added. A combination of the following morphological characters is recommended to distinguish between the genera Hyperoplus and Ammodytes: the protrusibility of the premaxillae, the presence of hooked ends of the prevomer, the number of dermal plicae, and the pectoral-fin length as a percentage of the standard length. The discriminant function analysis revealed that morphometric data are not very useful to distinguish the species of each of the two genera. The following meristic characters improve the separation of Hyperoplus lanceolatus from Hyperoplus immaculatus: the number of lower arch gill rakers, total number of gill rakers, numbers of caudal vertebrae and total vertebrae, and numbers of dorsal-fin and anal-fin rays. It is confirmed that Ammodytes tobianus differs from Ammodytes marinus by its belly scales that are organised in tight chevrons, scales which are present over the musculature at the base of the caudal fin, as well as by the lower numbers of dermal plicae, dorsal-fin rays, and total vertebrae. In contrast to the morphological data, mitochondrial COI sequences (DNA barcodes) failed to separate unambiguously the four investigated species. Ammodytes tobianus and Hyperoplus lanceolatus showed an overlap between intraspecific and interspecific K2P genetic distances and cannot be reliably distinguished using the common

  16. Rolling Circle Amplification of Complete Nematode Mitochondrial Genomes

    PubMed Central

    Tang, Sha; Hyman, Bradley C.

    2005-01-01

    To enable investigation of nematode mitochondrial DNA evolution, methodology has been developed to amplify intact nematode mitochondrial genomes in preparative yields using a rolling circle replication strategy. Successful reactions were generated from whole cell template DNA prepared by alkaline lysis of the rhabditid nematode Caenorhabditis elegans and a mermithid nematode, Thaumamermis cosgrovei. These taxa, representing the two major nematode classes Chromodorea and Enoplea, maintain mitochondrial genomes of 13.8 kb and 20.0 kb, respectively. Efficient amplifications were conducted on template DNA isolated from individual or pooled nematodes that were alive or stored at -80°C. Unexpectedly, these experiments revealed that multiple T. cosgrovei mitochondrial DNA haplotypes are maintained in our local population. Rolling circle amplification products can be used as templates for standard PCR reactions with specific primers that target mitochondrial genes or for direct DNA sequencing. PMID:19262866

  17. Immunity to gastrointestinal nematodes: mechanisms and myths.

    PubMed

    Grencis, Richard K; Humphreys, Neil E; Bancroft, Allison J

    2014-07-01

    Immune responses to gastrointestinal nematodes have been studied extensively for over 80 years and intensively investigated over the last 30-40 years. The use of laboratory models has led to the discovery of new mechanisms of protective immunity and made major contributions to our fundamental understanding of both innate and adaptive responses. In addition to host protection, it is clear that immunoregulatory processes are common in infected individuals and resistance often operates alongside modulation of immunity. This review aims to discuss the recent discoveries in both host protection and immunoregulation against gastrointestinal nematodes, placing the data in context of the specific life cycles imposed by the different parasites studied and the future challenges of considering the mucosal/immune axis to encompass host, parasite, and microbiome in its widest sense.

  18. Mucocutaneous manifestations of helminth infections: Nematodes.

    PubMed

    Lupi, Omar; Downing, Christopher; Lee, Michael; Pino, Livia; Bravo, Francisco; Giglio, Patricia; Sethi, Aisha; Klaus, Sidney; Sangueza, Omar P; Fuller, Claire; Mendoza, Natalia; Ladizinski, Barry; Woc-Colburn, Laila; Tyring, Stephen K

    2015-12-01

    In the 21st century, despite increased globalization through international travel for business, medical volunteerism, pleasure, and immigration/refugees into the United States, there is little published in the dermatology literature regarding the cutaneous manifestations of helminth infections. Approximately 17% of travelers seek medical care because of cutaneous disorders, many related to infectious etiologies. This review will focus on the cutaneous manifestations of helminth infections and is divided into 2 parts: part I focuses on nematode infections, and part II focuses on trematode and cestode infections. This review highlights the clinical manifestations, transmission, diagnosis, and treatment of helminth infections. Nematodes are roundworms that cause diseases with cutaneous manifestations, such as cutaneous larval migrans, onchocerciasis, filariasis, gnathostomiasis, loiasis, dracunculiasis, strongyloidiasis, ascariasis, streptocerciasis, dirofilariasis, and trichinosis. Tremadotes, also known as flukes, cause schistosomiasis, paragonimiasis, and fascioliasis. Cestodes (tapeworms) are flat, hermaphroditic parasites that cause diseases such as sparganosis, cysticercosis, and echinococcus.

  19. All the microbiology nematodes can teach us

    PubMed Central

    Bulgheresi, Silvia

    2016-01-01

    Be it their pervasiveness, experimental tractability or their impact on human health and agriculture, nematode–bacterium associations are far-reaching research subjects. Although the omics hype did not spare them and helped reveal mechanisms of communication and exchange between the associated partners, a huge amount of knowledge still awaits to be harvested from their study. Here, I summarize and compare the kind of research that has been already performed on the model nematode Caenorhabditis elegans and on symbiotic nematodes, both marine and entomopathogenic ones. The emerging picture highlights how complementing genetic studies with ecological ones (in the case of well-established genetic model systems such as C. elegans) and vice versa (in the case of the yet uncultured Stilbonematinae) will deepen our understanding of how microbial symbioses evolved and how they impact our environment. PMID:26839382

  20. Immunity to gastrointestinal nematodes: mechanisms and myths

    PubMed Central

    Grencis, Richard K; Humphreys, Neil E; Bancroft, Allison J

    2014-01-01

    Immune responses to gastrointestinal nematodes have been studied extensively for over 80 years and intensively investigated over the last 30–40 years. The use of laboratory models has led to the discovery of new mechanisms of protective immunity and made major contributions to our fundamental understanding of both innate and adaptive responses. In addition to host protection, it is clear that immunoregulatory processes are common in infected individuals and resistance often operates alongside modulation of immunity. This review aims to discuss the recent discoveries in both host protection and immunoregulation against gastrointestinal nematodes, placing the data in context of the specific life cycles imposed by the different parasites studied and the future challenges of considering the mucosal/immune axis to encompass host, parasite, and microbiome in its widest sense. PMID:24942690

  1. The control of Corynebacterium pseudotuberculosis infection in sheep flocks: a mathematical model of the impact of vaccination, serological testing, clinical examination and lancing of abscesses.

    PubMed

    O'Reilly, K M; Medley, G F; Green, L E

    2010-06-01

    A mathematical model of Corynebacterium pseudotuberculosis infection in sheep flocks was used to evaluate strategies for control and elimination of caseous lymphadenitis (CLA). Control strategies tested were vaccination, serological testing and removal of seropositives, clinical examination and removal of sheep with abscesses, lancing abscesses, and appropriate combinations. Three different infection rates with and without replacement of culled ewes were used to evaluate the control options. Controls were either implemented immediately after infection was detected in a flock or once CLA was at endemic equilibrium, and with different frequencies of examination or testing. Elimination of infection was defined as 99% confidence that no sheep were infected with C. pseudotuberculosis. The control strategies were evaluated by estimating the reduction in infection or probability of elimination and the number of ewes culled from the flock. Lancing abscesses reduced the prevalence of infection when the initial prevalence was <0.60, but elimination was unlikely. A vaccine efficacy of 0.79 or more led to elimination of infection from the flock, provided that the endemic prevalence of infection was <0.60. A combination of vaccination and clinical examination reduced the prevalence of infection at a faster rate than using clinical examination or vaccination alone where five rounds of clinical examination were done. Serological testing led to elimination of infection after five tests, but was highly dependent upon the diagnostic test sensitivity and specificity and management options used: a test sensitivity of 0.90 always resulted in elimination. A test specificity greater than 0.90 prevented removal of many false positive ewes and consequently prevented a large reduction in lamb production. Elimination was most likely using a serological test with sensitivity and specificity >0.90, but vaccination combined with clinical examination reduced infection rapidly with little impact

  2. Anatomy and Taxonomic Status of the Chasmosaurine Ceratopsid Nedoceratops hatcheri from the Upper Cretaceous Lance Formation of Wyoming, U.S.A

    PubMed Central

    Farke, Andrew A.

    2011-01-01

    Background The validity of Nedoceratops hatcheri, a chasmosaurine ceratopsid dinosaur known from a single skull recovered in the Lance Formation of eastern Wyoming, U.S.A., has been debated for over a century. Some have argued that the taxon is an aberrant Triceratops, and most recently it was proposed that N. hatcheri represents an intermediate ontogenetic stage between “young adult” and “old adult” forms of a single taxon previously split into Triceratops and Torosaurus. Methodology/Principal Findings The holotype skull of Nedoceratops hatcheri was reexamined in order to map reconstructed areas and compare the specimen with other ceratopsids. Although squamosal fenestrae are almost certainly not of taxonomic significance, some other features are unique to N. hatcheri. These include a nasal lacking a recognizable horn, nearly vertical postorbital horncores, and relatively small parietal fenestrae. Thus, N. hatcheri is tentatively considered valid, and closely related to Triceratops spp. The holotype of N. hatcheri probably represents an “old adult,” based upon bone surface texture and the shape of the horns and epiossifications on the frill. In this study, Torosaurus is maintained as a genus distinct from Triceratops and Nedoceratops. Synonymy of the three genera as ontogenetic stages of a single taxon would require cranial changes otherwise unknown in ceratopsids, including additions of ossifications to the frill and repeated alternation of bone surface texture between juvenile and adult morphotypes. Conclusions/Significance Triceratops, Torosaurus, and likely Nedoceratops, are all distinct taxa, indicating that species richness for chasmosaurine ceratopsids in the Lance Formation just prior to the Cretaceous-Paleocene extinction was roughly equivalent to that earlier in the Cretaceous. PMID:21283763

  3. On the Methodology of Nematode Extraction from Field Samples: Density Flotation Techniques

    PubMed Central

    Viglierchio, David R.; Yamashita, Tom T.

    1983-01-01

    Density flotation has been frequently used for the extraction of nematodes from field samples. Density flotation curves for four nematode species and five solutes have been prepared. The curves confirm that flotation was governed by several factors: solute density, solute osmotic activity, and physiological properties of the nematode species. Nematode viability and function can be adversely affected by improper selection of solute for density extraction of nematodes; nevertheless, some nematode species can be enriched from mixtures by density and solute selection. PMID:19295831

  4. Assaying environmental nickel toxicity using model nematodes

    USGS Publications Warehouse

    Rudel, David; Douglas, Chandler; Huffnagle, Ian; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegansand P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  5. A White Paper on Nematode Comparative Genomics

    PubMed Central

    Bird, David McK.; Blaxter, Mark L.; McCarter, James P.; Mitreva, Makedonka; Sternberg, Paul W.; Thomas, W. Kelley

    2005-01-01

    In response to the new opportunities for genome sequencing and comparative genomics, the Society of Nematology (SON) formed a committee to develop a white paper in support of the broad scientific needs associated with this phylum and interests of SON members. Although genome sequencing is expensive, the data generated are unique in biological systems in that genomes have the potential to be complete (every base of the genome can be accounted for), accurate (the data are digital and not subject to stochastic variation), and permanent (once obtained, the genome of a species does not need to be experimentally re-sampled). The availability of complete, accurate, and permanent genome sequences from diverse nematode species will underpin future studies into the biology and evolution of this phylum and the ecological associations (particularly parasitic) nematodes have with other organisms. We anticipate that upwards of 100 nematode genomes will be solved to varying levels of completion in the coming decade and suggest biological and practical considerations to guide the selection of the most informative taxa for sequencing. PMID:19262884

  6. Evolution of plant parasitism among nematodes.

    PubMed

    Baldwin, J G; Nadler, S A; Adams, B J

    2004-01-01

    Despite extraordinary diversity of free-living species, a comparatively small fraction of nematodes are parasites of plants. These parasites represent at least three disparate clades in the nematode tree of life, as inferred from rRNA sequences. Plant parasites share functional similarities regarding feeding, but many similarities in feeding structures result from convergent evolution and have fundamentally different developmental origins. Although Tylenchida rRNA phylogenies are not fully resolved, they strongly support convergent evolution of sedentary endoparasitism and plant nurse cells in cyst and root-knot nematodes. This result has critical implications for using model systems and genomics to identify and characterize parasitism genes for representatives of this clade. Phylogenetic studies reveal that plant parasites have rich and complex evolutionary histories that involve multiple transitions to plant parasitism and the possible use of genes obtained by horizontal transfer from prokaryotes. Developing a fuller understanding of plant parasitism will require integrating more comprehensive and resolved phylogenies with appropriate choices of model organisms and comparative evolutionary methods.

  7. Assaying environmental nickel toxicity using model nematodes.

    PubMed

    Rudel, David; Douglas, Chandler D; Huffnagle, Ian M; Besser, John M; Ingersoll, Christopher G

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species.

  8. Entomopathogenic Nematode Production and Application Technology

    PubMed Central

    Shapiro-Ilan, David I.; Han, Richou; Dolinksi, Claudia

    2012-01-01

    Production and application technology is critical for the success of entomopathogenic nematodes (EPNs) in biological control. Production approaches include in vivo, and in vitro methods (solid or liquid fermentation). For laboratory use and small scale field experiments, in vivo production of EPNs appears to be the appropriate method. In vivo production is also appropriate for niche markets and small growers where a lack of capital, scientific expertise or infrastructure cannot justify large investments into in vitro culture technology. In vitro technology is used when large scale production is needed at reasonable quality and cost. Infective juveniles of entomopathogenic nematodes are usually applied using various spray equipment and standard irrigation systems. Enhanced efficacy in EPN applications can be facilitated through improved delivery mechanisms (e.g., cadaver application) or optimization of spray equipment. Substantial progress has been made in recent years in developing EPN formulations, particularly for above ground applications, e.g., mixing EPNs with surfactants or polymers or with sprayable gels. Bait formulations and insect host cadavers can enhance EPN persistence and reduce the quantity of nematodes required per unit area. This review provides a summary and analysis of factors that affect production and application of EPNs and offers insights for their future in biological insect suppression. PMID:23482883

  9. Reniform Nematode Resistance in Selected Soybean Cultivars

    PubMed Central

    Robbins, R. T.; Rakes, L.; Jackson, L. E.; Dombek, D. G.

    1999-01-01

    Two hundred eighty-two soybean cultivars from the variety testing programs of Arkansas and Mississippi were tested in greenhouse pot experiments during summer 1998 to identify soybean cultivars with resistance to the reniform nematode, Rotylenchulus reniformis. Also included in the tests were the resistant cultivars Forrest and Hartwig, the susceptible control Braxton, and fallow infested soil, which were used as controls. Numbers of reniform nematode extracted from the soil and roots and the ratio of the numbers reproducing on each cultivar compared to the number reproducing on Forrest are reported. Cultivars with reproduction not significantly different from Forrest were classified resistant, whereas those with greater reproductive indices were considered susceptible. One of the 18 cultivars of relative maturity group (RMG) ≤4.4 was classified as resistant. For the 86 cultivars of RMG 4.5-4.9, 18 were found to be resistant. Of the 43 cultivars of RMG 5.0-5.4, 16 were resistant, while 43 of the 91 cultivars of RMG 5.5-5.9 were resistant. Fifteen of the cultivars with an RMG of ≥6.0 were classed as resistant. These data will be useful in the selection of soybean cultivars to use in rotation with cotton to help control the reniform nematode. PMID:19270934

  10. Assaying Environmental Nickel Toxicity Using Model Nematodes

    PubMed Central

    Rudel, David; Douglas, Chandler D.; Huffnagle, Ian M.; Besser, John M.; Ingersoll, Christopher G.

    2013-01-01

    Although nickel exposure results in allergic reactions, respiratory conditions, and cancer in humans and rodents, the ramifications of excess nickel in the environment for animal and human health remain largely undescribed. Nickel and other cationic metals travel through waterways and bind to soils and sediments. To evaluate the potential toxic effects of nickel at environmental contaminant levels (8.9-7,600 µg Ni/g dry weight of sediment and 50-800 µg NiCl2/L of water), we conducted assays using two cosmopolitan nematodes, Caenorhabditis elegans and Pristionchus pacificus. We assayed the effects of both sediment-bound and aqueous nickel upon animal growth, developmental survival, lifespan, and fecundity. Uncontaminated sediments were collected from sites in the Midwestern United States and spiked with a range of nickel concentrations. We found that nickel-spiked sediment substantially impairs both survival from larval to adult stages and adult longevity in a concentration-dependent manner. Further, while aqueous nickel showed no adverse effects on either survivorship or longevity, we observed a significant decrease in fecundity, indicating that aqueous nickel could have a negative impact on nematode physiology. Intriguingly, C. elegans and P. pacificus exhibit similar, but not identical, responses to nickel exposure. Moreover, P. pacificus could be tested successfully in sediments inhospitable to C. elegans. Our results add to a growing body of literature documenting the impact of nickel on animal physiology, and suggest that environmental toxicological studies could gain an advantage by widening their repertoire of nematode species. PMID:24116204

  11. Nematode locomotion in unconfined and confined fluids

    NASA Astrophysics Data System (ADS)

    Bilbao, Alejandro; Wajnryb, Eligiusz; Vanapalli, Siva A.; Blawzdziewicz, Jerzy

    2013-08-01

    The millimeter-long soil-dwelling nematode Caenorhabditis elegans propels itself by producing undulations that propagate along its body and turns by assuming highly curved shapes. According to our recent study [V. Padmanabhan et al., PLoS ONE 7, e40121 (2012), 10.1371/journal.pone.0040121] all these postures can be accurately described by a piecewise-harmonic-curvature model. We combine this curvature-based description with highly accurate hydrodynamic bead models to evaluate the normalized velocity and turning angles for a worm swimming in an unconfined fluid and in a parallel-wall cell. We find that the worm moves twice as fast and navigates more effectively under a strong confinement, due to the large transverse-to-longitudinal resistance-coefficient ratio resulting from the wall-mediated far-field hydrodynamic coupling between body segments. We also note that the optimal swimming gait is similar to the gait observed for nematodes swimming in high-viscosity fluids. Our bead models allow us to determine the effects of confinement and finite thickness of the body of the nematode on its locomotion. These effects are not accounted for by the classical resistive-force and slender-body theories.

  12. Entomopathogenic and plant pathogenic nematodes as opposing forces in agriculture.

    PubMed

    Kenney, Eric; Eleftherianos, Ioannis

    2016-01-01

    Plant-parasitic nematodes are responsible for substantial damages within the agriculture industry every year, which is a challenge that has thus far gone largely unimpeded. Chemical nematicides have been employed with varying degrees of success, but their implementation can be cumbersome, and furthermore they could potentially be neutralising an otherwise positive effect from the entomopathogenic nematodes that coexist with plant-parasitic nematodes in soil environments and provide protection for plants against insect pests. Recent research has explored the potential of employing entomopathogenic nematodes to protect plants from plant-parasitic nematodes, while providing their standard degree of protection against insects. The interactions involved are highly complex, due to both the three-organism system and the assortment of variables present in a soil environment, but a strong collection of evidence has accumulated regarding the suppressive capacity of certain entomopathogenic nematodes and their mutualistic bacteria, in the context of limiting the infectivity of plant-parasitic nematodes. Specific factors produced by certain entomopathogenic nematode complexes during the process of insect infection appear to have a selectively nematicidal, or at least repellant, effect on plant-parasitic nematodes. Using this information, an opportunity has formed to adapt this relationship to large-scale, field conditions and potentially relieve the agricultural industry of one of its most substantial burdens.

  13. Distribution patterns of entomopathogenic nematodes applied through drip irrigation systems.

    PubMed

    Wennemann, L; Cone, W W; Wright, L C; Perez, J; Conant, M M

    2003-04-01

    The distribution of entomopathogenic nematodes applied by drip irrigation was evaluated by injecting small volumes of Steinernema carpocapsae (Weiser) All strain, Steinernema feltiae (Filipjev) SN strain, Steinernema glaseri Steiner, and Heterorhabditis bacteriophora HP 88 strain Poinar suspensions into drip irrigation lines. Additionally, Steinernema riobrave Cabanillas, Poinar, & Raulston, and S. carpocapsae were injected in a 10-liter volume of water with an injection pump. Overall, the nematodes were evenly distributed along the drip lines. The total number of nematodes recovered from drip emitters was variable ranging from 42 to 92%. However, drip irrigation lines have potential to deliver entomopathogenic nematodes efficiently into pest habitats.

  14. Nematodes Associated with Plants from Naturally Acidic Wetlands Soil

    PubMed Central

    Cox, Robert John; Smart, Grover C.

    1994-01-01

    Four plants, Cyperus ochraceus, Eriocaulon compressum, Lythrum alatum, and Xyris jupicai, growing along the shoreline of an oligotrophic lake in north central Florida were sampled for nematodes. The nematodes recovered were placed in four trophic groups: bacterivores, herbivores, omnivores, and predators. When the nematodes on all plants were considered, 27% were bacterivores, 23% were herbivores, 7% were omnivores, and 43% were predators. Tripyla was the dominant predator and the dominant genus of all nematodes, and Malenchus was the dominant herbivore. Dominance was not clearly pronounced in the other trophic groups. PMID:19279927

  15. Detection and Description of Soils with Specific Nematode Suppressiveness

    PubMed Central

    Westphal, Andreas

    2005-01-01

    Soils with specific suppressiveness to plant-parasitic nematodes are of interest to define the mechanisms that regulate population density. Suppressive soils prevent nematodes from establishing and from causing disease, and they diminish disease severity after initial nematode damage in continuous culturing of a host. A range of non-specific and specific soil treatments, followed by infestation with a target nematode, have been employed to identify nematode-suppressive soils. Biocidal treatments, soil transfer tests, and baiting approaches together with observations of the plant-parasitic nematode in the root zone of susceptible host plants have improved the understanding of nematode-suppressive soils. Techniques to demonstrate specific soil suppressiveness against plant-parasitic nematodes are compared in this review. The overlap of studies on soil suppressiveness with recent advances in soil health and quality is briefly discussed. The emphasis is on methods (or criteria) used to detect and identify soils that maintain specific soil suppressiveness to plant-parasitic nematodes. While biocidal treatments can detect general and specific soil suppressiveness, soil transfer studies, by definition, apply only to specific soil suppressiveness. Finally, potential strategies to exploit suppressive soils are presented. PMID:19262851

  16. [Resistance to anthelmintics in nematodes in sheep and goats].

    PubMed

    Praslicka, J; Corba, J

    1995-08-01

    The article offers a brief view on the most important theoretical knowledge of resistance of gastrointestinal nematodes to anthelmintic drugs in sheep and goats. Besides the definition and basic terms, factors of development and occurrence of resistance on farm are analyzed. Furthermore, methods for detection of resistant nematodes as well as complex of recommended preventive measures are given.

  17. Viability and virulence of entomopathogenic nematodes exposed to ultraviolet radiation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure environmental stress such as from ultraviolet radiation. Our objective was to compare UV tolerance among a broad array of nematode species. We compared 9 different EPN species and ...

  18. 76 FR 60357 - Golden Nematode; Removal of Regulated Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-09-29

    ... nematode (Globodera rostochiensis) is a destructive pest of potatoes and other solanaceous plants. Potatoes... no longer required. From 1977 until 2010, potato production fields in the townships of Elba and Byron... nematode quarantine. In 2007, there were 13 farms in Genesee County that harvested potatoes. These...

  19. Control of the peachtree borer using beneficial nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The peachtree borer, Synanthedon exitiosa, is a major pest of peaches and other stone fruits. Our research indicates that entomopathogenic nematodes, also known as beneficial nematodes, can be used effectively to control the insect. We conducted replicated experiments in randomized block designs ov...

  20. Development of Reniform Nematode Resistance in Upland Cotton

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The purpose of this review is to assess development of resistance to the reniform nematode (Rotylenchulus reniformis) in Upland Cotton (Gossypium hirsutum). Cotton cultivars with reniform nematode resistance are needed. The development of resistant cultivars appears possible but presents a signifi...

  1. Book review: Systematics of Cyst Nematodes (Nematoda: Heteroderinae)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cyst nematodes are an important group of plant-parasitic nematodes that cause billions of dollars in economic damage to crops every year. This article reviews a recently published, two-volume monograph that describes the morphological and molecular characteristics of these agriculturally signif...

  2. A SURVEY OF CYST NEMATODES (HETERODERA SPP.) IN NORTHERN EGYPT

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information concerning the occurrence and distribution of cyst nematodes (Heterodera spp.) in Egypt is important to assess their potential to cause economic damage to crop plants. A nematode survey was conducted in Alexandria and El-Behera Governorates in northern Egypt to identify the species of cy...

  3. Conserved nematode signaling molecules elicit plant defenses and pathogen resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes, which are ubiquitous in soil and are estimated to cause $100 B of agricultural damage annually, produce novel, highly conserved small sugar-based molecules call ascarosides. Ascarosides play critical roles in nematode development and behavior. We report here that plants recognize these un...

  4. Granite rock outcrops: an extreme environment for soil nematodes?

    PubMed

    Austin, Erin; Semmens, Katharine; Parsons, Charles; Treonis, Amy

    2009-03-01

    We studied soil nematode communities from the surface of granite flatrock outcrops in the eastern Piedmont region of the United States. The thin soils that develop here experience high light intensity and extreme fluctuations in temperature and moisture and host unique plant communities. We collected soils from outcrop microsites in Virginia (VA) and North Carolina (NC) in various stages of succession (Primitive, Minimal, and Mature) and compared soil properties and nematode communities to those of adjacent forest soils. Nematodes were present in most outcrop soils, with densities comparable to forest soils (P > 0.05). Nematode communities in Mature and Minimal soils had lower species richness than forest soils (P < 0.05) and contained more bacterial-feeders and fewer fungal-feeders (P < 0.05). Primitive soils contained either no nematodes (NC) or only a single species (Mesodorylaimus sp., VA). Nematode communities were similar between Mature and Minimal soils, according to trophic group representation, MI, PPI, EI, SI, and CI (P > 0.05). Forest soils had a higher PPI value (P < 0.05), but otherwise community indices were similar to outcrop soils (P > 0.05). Outcrop nematode communities failed to group together in a Bray-Curtis cluster analysis, indicating higher variability in community structure than the Forest soils, which did cluster together. A high proportion of the nematodes were extracted from outcrop soils in coiled form (33-89%), indicating that they used anhydrobiosis to persist in this unique environment.

  5. High Sensitivity NMR and Mixture Analysis for Nematode Behavioral Metabolomics

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes are the most abundant animal on earth, and they parasitize virtually all plants and animals. Caenorhabditis elegans is a free-living nematode that lives in soil and composting material. We have shown that C. elegans releases at least 40 small molecules into its environment including many...

  6. Sex-specific mating pheromones in the nematode Panagrellus redivivus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Despite advances in medicine and crop genetics, nematodes remain significant human pathogens and agricultural pests. This warrants investigation of alternative strategies for pest control, such as interference with pheromone-mediated reproduction. Because only two nematode species have had their phe...

  7. Soybean lines evaluated for resistance to reniform nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Seventy-four wild and domestic soybean (Glycine max and G. soja) lines were evaluated for resistance to reniform nematode (Rotylenchulus reniformis) in growth chamber tests with a day length of 16 hours and temperature held constant at 28 C. Several entries for which reactions to reniform nematode w...

  8. Soybean Cyst Nematode in North America - 55 Years Later

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean cyst nematode, Heterodera glycines, was first discovered in North America in 1954 in Hanover County, North Carolina, USA, when it was found on soybean in a field that had been planted to Easter lilies obtained from Japan prior to World War II. The nematode is now distributed throughout soybe...

  9. Pineapple Nematode Research in Hawaii: Past, Present, and Future

    PubMed Central

    Caswell, E. P.; Apt, W. J.

    1989-01-01

    The first written record of pineapple in Hawaii is from 1813. In 1901 commercial pineapple production started, and in 1924 the Experiment Station for pineapple research was established. Nematode-related problems were recognized in the early 1900s by N. A. Cobb. From 1920 to approximately 1945 nematode management in Hawaiian pineapple was based on fallowing and crop rotation. During the 1920s and 1930s G. H. Godfrey conducted research on pineapple nematode management. In the 1930s and 1940s M. B. Linford researched biological control and described several new species of nematodes including Rotylenchulus reniformis. In 1941 nematology and nematode management were advanced by Walter Carter's discovery of the first economical soil fumigant for nematodes, D-D mixture. Subsequently, DBCP was discovered and developed at the Pineapple Research Institute (PRI). Since 1945 soil fumigation has been the main nematode management strategy in Hawaiian pineapple production. Recent research has focused on the development of the nonvolatile nematicides, their potential as systemic nematicides, and their application via drip irrigation. Current and future research addresses biological and cultural alternatives to nematicide-based nematode management. PMID:19287592

  10. Correlations of Nematodes and Soil Properties in Soybean Fields

    PubMed Central

    Norton, D. C.; Frederick, L. R.; Ponchillia, P. E.; Nyhan, J. W.

    1971-01-01

    Soil samples from 40 soybean fields were collected in 1967 and 1968 and analyzed for nematodes and soil properties. Correlations o f total nematodes, non-stylet nematodes, Dorylaimoidea (excluding Xiphinema americanum), X. americanum, Helicotylenchus pseudorobustus, Tylenchus spp., Aphelenchus avenae, and other groupings of nematodes were made with pH; percentage sand, silt, and clay; percentage organic matter; cation exchange capacity; saturation percentage, and percentage saturation. Organic matter, pH, and cation exchange capacity were most consistently highly correlated with the nematodes. H. pseudorobustus had the most consistently significant correlations with the soil factors. Correlations of nematodes were with more soil factors and were stronger in a wet than in a dry year. The highest numbers of nematodes were usually found in the lighter soils, except in the loamy sand where moisture probably was limiting. In general, soil moisture levels below 20% saturation were probably limiting for most nematodes studied, except for the dorylaims which survived in large numbers in soils with less than 20% saturation. PMID:19322361

  11. Aggregative group behavior in insect parasitic nematode disperal

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Movement behavior is critical to determination of spatial ecology and success of foraging in predators and parasites. In this study movement behavior of entomopathogenic nematodes was explored. Movement patterns in sand were investigated when nematodes were applied to a specific locus or when the ne...

  12. Nematodes from terrestrial and freshwater habitats in the Arctic.

    PubMed

    Holovachov, Oleksandr

    2014-01-01

    WE PRESENT AN UPDATED LIST OF TERRESTRIAL AND FRESHWATER NEMATODES FROM ALL REGIONS OF THE ARCTIC, FOR WHICH RECORDS OF PROPERLY IDENTIFIED NEMATODE SPECIES ARE AVAILABLE: Svalbard, Jan Mayen, Iceland, Greenland, Nunavut, Northwest territories, Alaska, Lena River estuary, Taymyr and Severnaya Zemlya and Novaya Zemlya. The list includes 391 species belonging to 146 genera, 54 families and 10 orders of the phylum Nematoda.

  13. Antagonists of Plant-parasitic Nematodes in Florida Citrus

    PubMed Central

    Walter, David Evans; Kaplan, David T.

    1990-01-01

    In a survey of antagonists of nematodes in 27 citrus groves, each with a history of Tylenchulus semipenetrans infestation, and 17 noncitrus habitats in Florida, approximately 24 species of microbial antagonists capable of attacking vermiform stages of Radopholus citrophilus were recovered. Eleven of these microbes and a species of Pasteuria also were observed attacking vermiform stages of T. semipenetrans. Verticillium chlamydosporium, Paecilomyces lilacinus, P. marquandii, Streptomyces sp., Arthrobotrys oligospora, and Dactylella ellipsospora were found infecting T. semipenetrans egg masses. Two species of nematophagous amoebae, five species of predatory nematodes, and 29 species of nematophagous arthropods also were detected. Nematode-trapping fungi and nematophagous arthropods were common inhabitants of citrus groves with a history of citrus nematode infestation; however, obligate parasites of nematodes were rare. PMID:19287759

  14. Survey of nematodes associated with terrestrial slugs in Norway.

    PubMed

    Ross, J L; Ivanova, E S; Hatteland, B A; Brurberg, M B; Haukeland, S

    2016-09-01

    A survey of nematodes associated with terrestrial slugs was conducted for the first time in Norway. A total of 611 terrestrial slugs were collected from 32 sample sites. Slugs were identified by means of morphological examination, dissection of genitalia and molecular analysis using mitochondrial DNA. Twelve slug species were identified, representing four different slug families. Internal nematodes were identified by means of morphological analysis and the sequencing of the 18S rRNA gene. Of the sample sites studied, 62.5% were found to be positive for nematode parasites, with 18.7% of all slugs discovered being infected. Five nematode species were identified in this study: Alloionema appendiculatum, Agfa flexilis, Angiostoma limacis, Angiostoma sp. and Phasmarhabditis hermaphrodita. Of these species, only one nematode was previously undescribed (Angiostoma sp.). This is the first record of the presence of A. appendiculatum, A. flexilis and A. limacis in Norway.

  15. Antagonists of Plant-parasitic Nematodes in Florida Citrus.

    PubMed

    Walter, D E; Kaplan, D T

    1990-10-01

    In a survey of antagonists of nematodes in 27 citrus groves, each with a history of Tylenchulus semipenetrans infestation, and 17 noncitrus habitats in Florida, approximately 24 species of microbial antagonists capable of attacking vermiform stages of Radopholus citrophilus were recovered. Eleven of these microbes and a species of Pasteuria also were observed attacking vermiform stages of T. semipenetrans. Verticillium chlamydosporium, Paecilomyces lilacinus, P. marquandii, Streptomyces sp., Arthrobotrys oligospora, and Dactylella ellipsospora were found infecting T. semipenetrans egg masses. Two species of nematophagous amoebae, five species of predatory nematodes, and 29 species of nematophagous arthropods also were detected. Nematode-trapping fungi and nematophagous arthropods were common inhabitants of citrus groves with a history of citrus nematode infestation; however, obligate parasites of nematodes were rare.

  16. Multifaceted effects of host plants on entomopathogenic nematodes.

    PubMed

    Hazir, Selcuk; Shapiro-Ilan, David I; Hazir, Canan; Leite, Luis G; Cakmak, Ibrahim; Olson, Dawn

    2016-03-01

    The success of parasites can be impacted by multi-trophic interactions. Tritrophic interactions have been observed in parasite-herbivore-host plant systems. Here we investigate aspects of multi-trophic interactions in a system involving an entomopathogenic nematode (EPN), its insect host, and host plant. Novel issues investigated include the impact of tritrophic interactions on nematode foraging behavior, the ability of EPNs to overcome negative tritrophic effects through genetic selection, and interactions with a fourth trophic level (nematode predators). We tested infectivity of the nematode, Steinernema riobrave, to corn earworm larvae (Helicoverpa zea) in three host plants, tobacco, eggplant and tomato. Tobacco reduced nematode virulence and reproduction relative to tomato and eggplant. However, successive selection (5 passages) overcame the deficiency; selected nematodes no longer exhibited reductions in phenotypic traits. Despite the loss in virulence and reproduction nematodes, first passage S. riobrave was more attracted to frass from insects fed tobacco than insects fed on other host plants. Therefore, we hypothesized the reduced virulence and reproduction in S. riobrave infecting tobacco fed insects would be based on a self-medicating tradeoff, such as deterring predation. We tested this hypothesis by assessing predatory success of the mite Sancassania polyphyllae and the springtail Sinella curviseta on nematodes reared on tobacco-fed larvae versus those fed on greater wax moth, Galleria mellonella, tomato fed larvae, or eggplant fed larvae. No advantage was observed in nematodes derived from tobacco fed larvae. In conclusion, our results indicated that insect-host plant diet has an important effect on nematode foraging, infectivity and reproduction. However, negative host plant effects, might be overcome through directed selection. We propose that host plant species should be considered when designing biocontrol programs using EPNs.

  17. First report of the root-lesion nematode, Pratylenchus scribneri, infecting potato in North Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root-lesion nematodes (Pratylenchus spp.) are the most common nematode pests of potato. Five soil samples were collected from a harvested potato field near Cogswell (Sargent County), ND in October 2014 to investigate the occurrence of root-lesion nematodes. Plant-parasitic nematodes were extracted, ...

  18. Vertebrate herbivores influence soil nematodes by modifying plant communities.

    PubMed

    Veen, G F; Olff, Han; Duyts, Henk; van der Putten, Wim H

    2010-03-01

    Abiotic soil properties, plant community composition, and herbivory all have been reported as important factors influencing the composition of soil communities. However, most studies thus far have considered these factors in isolation, whereas they strongly interact in the field. Here, we study how grazing by vertebrate herbivores influences the soil nematode community composition of a floodplain grassland while we account for effects of grazing on plant community composition and abiotic soil properties. Nematodes are the most ubiquitous invertebrates in the soil. They include a variety of feeding types, ranging from microbial feeders to herbivores and carnivores, and they perform key functions in soil food webs. Our hypothesis was that grazing affects nematode community structure and composition through altering plant community structure and composition. Alternatively, we tested whether the effects of grazing may, directly or indirectly, run via changes in soil abiotic properties. We used a long-term field experiment containing plots with and without vertebrate grazers (cattle and rabbits). We compared plant and nematode community structure and composition, as well as a number of key soil abiotic properties, and we applied structural equation modeling to investigate four possible pathways by which grazing may change nematode community composition. Aboveground grazing increased plant species richness and reduced both plant and nematode community heterogeneity. There was a positive relationship between plant and nematode diversity indices. Grazing decreased the number of bacterial-feeding nematodes, indicating that in these grasslands, top-down control of plant production by grazing leads to bottom-up control in the basal part of the bacterial channel of the soil food web. According to the structural equation model, grazing had a strong effect on soil abiotic properties and plant community composition, whereas plant community composition was the main determinant of

  19. Entomopathogenic nematodes in agricultural areas in Brazil.

    PubMed

    de Brida, Andressa Lima; Rosa, Juliana Magrinelli Osório; Oliveira, Cláudio Marcelo Gonçalves de; Castro, Bárbara Monteiro de Castro E; Serrão, José Eduardo; Zanuncio, José Cola; Leite, Luis Garrigós; Wilcken, Silvia Renata Siciliano

    2017-04-06

    Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) can control pests due to the mutualistic association with bacteria that kill the host by septicemia and make the environment favorable for EPNs development and reproduction. The diversity of EPNs in Brazilian soils requires further study. The identification of EPNs, adapted to environmental and climatic conditions of cultivated areas is important for sustainable pest suppression in integrated management programs in agricultural areas of Brazil. The objective was to identify EPNs isolated from agricultural soils with annual, fruit and forest crops in Brazil. Soil samples were collected and stored in 250 ml glass vials. The nematodes were isolated from these samples with live bait traps ([Galleria mellonella L. (Lepidoptera: Pyralidae) larvae]. Infective juveniles were collected with White traps and identified by DNA barcoding procedures by sequencing the D2/D3 expansion of the 28S rDNA region by PCR. EPNs identified in agricultural areas in Brazil were Heterorhabditis amazonensis, Metarhabditis rainai, Oscheios tipulae and Steinernema rarum. These species should be considered pest biocontrol agents in Brazilian agricultural areas.

  20. Osmoregulation in the parasitic nematode Pseudoterranova decipiens.

    PubMed

    Fusé, M; Davey, K G; Sommerville, R I

    1993-02-01

    When subjected to hyper- or hypo-osmotic stress at 5 degrees C for 24 h, third-stage larvae of the parasitic nematode Pseudoterranova decipiens do not exhibit changes in mass or in the osmotic pressure of the pseudocoelomic fluid. Immersion in solutions containing 3H2O demonstrates that exchange with the water in the pseudocoelomic fluid is substantially complete within 24 h. Sacs composed of cylinders of body wall without the intestine and pseudocoelomic fluid do not gain weight when immersed for 24 h in hypotonic medium. Metabolic poisons abolish the ability of whole worms and sacs to maintain their weight when immersed in hypotonic media. These observations support the conclusion that the nematode is capable of at least short-term osmoregulation and that the site of osmoregulation is the body wall. The observations that more fluid is passed from the anus in some hypo-osmotically stressed worms and that worms ligatured at the tail exhibit a small increase in mass when exposed to hypo-osmotic conditions may indicate that the intestine plays a minor and subsidiary role in osmoregulation.

  1. Entomopathogenic nematodes in agricultural areas in Brazil

    PubMed Central

    de Brida, Andressa Lima; Rosa, Juliana Magrinelli Osório; Oliveira, Cláudio Marcelo Gonçalves de; Castro, Bárbara Monteiro de Castro e; Serrão, José Eduardo; Zanuncio, José Cola; Leite, Luis Garrigós; Wilcken, Silvia Renata Siciliano

    2017-01-01

    Entomopathogenic nematodes (EPNs) (Steinernematidae and Heterorhabditidae) can control pests due to the mutualistic association with bacteria that kill the host by septicemia and make the environment favorable for EPNs development and reproduction. The diversity of EPNs in Brazilian soils requires further study. The identification of EPNs, adapted to environmental and climatic conditions of cultivated areas is important for sustainable pest suppression in integrated management programs in agricultural areas of Brazil. The objective was to identify EPNs isolated from agricultural soils with annual, fruit and forest crops in Brazil. Soil samples were collected and stored in 250 ml glass vials. The nematodes were isolated from these samples with live bait traps ([Galleria mellonella L. (Lepidoptera: Pyralidae) larvae]. Infective juveniles were collected with White traps and identified by DNA barcoding procedures by sequencing the D2/D3 expansion of the 28S rDNA region by PCR. EPNs identified in agricultural areas in Brazil were Heterorhabditis amazonensis, Metarhabditis rainai, Oscheios tipulae and Steinernema rarum. These species should be considered pest biocontrol agents in Brazilian agricultural areas. PMID:28382937

  2. Evolution of Parasitism in Insect-transmitted Plant Nematodes

    PubMed Central

    Giblin-Davis, R. M.; Davies, K. A.; Morris, K.; Thomas, W. K.

    2003-01-01

    Nematode-insect associations have evolved many times in the phylum Nematoda, but these lineages involve plant parasitism only in the Secernentean orders Aphelenchida and Tylenchida. In the Aphelenchida (Aphelenchoidoidea), Bursaphelenchus xylophilus (Pine wood nematode), B. cocophilus (Red ring or Coconut palm nematode) (Parasitaphelenchidae), and the many potential host-specific species of Schistonchus (fig nematodes) (Aphelenchoididae) nematode-insect interactions probably evolved independently from dauer-forming, mycophagous ancestors that were phoretically transmitted to breeding sites of their insect hosts in plants. Mycophagy probably gave rise to facultative or obligate plant-parasitism because of opportunities due to insect host switches or peculiarities in host behavior. In the Tylenchida, there is one significant radiation of insect-associated plant parasites involving Fergusobia nematodes (Fergusobiinae: Neotylenchidae) and Fergusonina (Fergusoninidae) flies as mutualists that gall myrtaceous plant buds or leaves. These dicyclic nematodes have different phases that are parasitic in either the insect or the plant hosts. The evolutionary origin of this association is unclear. PMID:19265987

  3. Susceptibility of the Plum Curculio, Conotrachelus nenuphar, to Entomopathogenic Nematodes

    PubMed Central

    Shapiro-Ilan, David I.; Mizell, Russell F.; Campbell, James F.

    2002-01-01

    The plum curculio, Conotrachelus nenuphar, is a major pest of pome and stone fruit. Our objective was to determine virulence and reproductive potential of six commercially available nematode species in C. nenuphar larvae and adults. Nematodes tested were Heterorhabditis bacteriophora (Hb strain), H. marelatus (Point Reyes strains), H. megidis (UK211 strain), Steinernema riobrave (355 strain), S. carpocapsae (All strain), and S. feltiae (SN strain). Survival of C. nenuphar larvae treated with S. feltiae and S. riobrave, and survival of adults treated with S. carpocapsae and S. riobrave, was reduced relative to non-treated insects. Other nematode treatments were not different from the control. Conotrachelus nenuphar larvae were more susceptible to S. feltiae infection than were adults, but for other nematode species there was no significant insect-stage effect. Reproduction in C. nenuphar was greatest for H. marelatus, which produced approximately 10,000 nematodes in larvae and 5,500 in adults. Other nematodes produced approximately 1,000 to 3,700 infective juveniles per C. nenuphar with no significant differences among nematode species or insect stages. We conclude that S. carpocapsae or S. riobrave appears to have the most potential for controlling adults, whereas S. feltiae or S. riobrave appears to have the most potential for larval control. PMID:19265940

  4. Pack hunting by a common soil amoeba on nematodes.

    PubMed

    Geisen, Stefan; Rosengarten, Jamila; Koller, Robert; Mulder, Christian; Urich, Tim; Bonkowski, Michael

    2015-11-01

    Soils host the most complex communities on Earth, including the most diverse and abundant eukaryotes, i.e. heterotrophic protists. Protists are generally considered as bacterivores, but evidence for negative interactions with nematodes both from laboratory and field studies exist. However, direct impacts of protists on nematodes remain unknown. We isolated the soil-borne testate amoeba Cryptodifflugia operculata and found a highly specialized and effective pack-hunting strategy to prey on bacterivorous nematodes. Enhanced reproduction in presence of prey nematodes suggests a beneficial predatory life history of these omnivorous soil amoebae. Cryptodifflugia operculata appears to selectively impact the nematode community composition as reductions of nematode numbers were species specific. Furthermore, we investigated 12 soil metatranscriptomes from five distinct locations throughout Europe for 18S ribosomal RNA transcripts of C. operculata. The presence of C. operculata transcripts in all samples, representing up to 4% of the active protist community, indicates a potential ecological importance of nematophagy performed by C. operculata in soil food webs. The unique pack-hunting strategy on nematodes that was previously unknown from protists, together with molecular evidence that these pack hunters are likely to be abundant and widespread in soils, imply a considerable importance of the hitherto neglected trophic link 'nematophagous protists' in soil food webs.

  5. Assaying Predatory Feeding Behaviors in Pristionchus and Other Nematodes

    PubMed Central

    Okumura, Misako; Sommer, Ralf J.

    2016-01-01

    This protocol provides multiple methods for the analysis and quantification of predatory feeding behaviors in nematodes. Many nematode species including Pristionchus pacificus display complex behaviors, the most striking of which is the predation of other nematode larvae. However, as these behaviors are absent in the model organism Caenorhabditis elegans, they have thus far only recently been described in detail along with the development of reliable behavioral assays 1. These predatory behaviors are dependent upon phenotypically plastic but fixed mouth morphs making the correct identification and categorization of these animals essential. In P. pacificus there are two mouth types, the stenostomatous and eurystomatous morphs 2, with only the wide mouthed eurystomatous containing an extra tooth and being capable of killing other nematode larvae. Through the isolation of an abundance of size matched prey larvae and subsequent exposure to predatory nematodes, assays including both "corpse assays" and "bite assays" on correctly identified mouth morph nematodes are possible. These assays provide a means to rapidly quantify predation success rates and provide a detailed behavioral analysis of individual nematodes engaged in predatory feeding activities. In addition, with the use of a high-speed camera, visualization of changes in pharyngeal activity including tooth and pumping dynamics are also possible. PMID:27684744

  6. Nematode Assemblages in Native Plant Communities of Molokai, Hawaii

    PubMed Central

    Bernard, E. C.; Schmitt, D. P.

    2005-01-01

    Four native plant community types (in decreasing elevation: montane bog, rain forest, wet mesic forest, drier forest) on Molokai were sampled for nematodes. Six samples of 10 cores each were gathered from each community. Nematodes were extracted from 200 cm³ soil by elutriation. All extracted nematodes were counted and identified to species-level taxa. Sixty-seven species were identified among the four plant communities; only eight species occurred in all four communities. Species diversity and evenness were greater in the rain forest and mesic forest than in the bog and the drier forest, but the drier forest and mesic forest had similar species communities. The bog nematode community was not similar to the other three sites. In a presence/absence cluster analysis, all six bog sample assemblages clustered together. The rain forest samples also clustered together but were associated with the mesic forest sample closest to the rain forest edge. Of 11 nematode orders collected, Tylenchida accounted for 40% to 73% of all individuals, followed by Dorylaimida (5% to 17%). Diplogasterida were absent. No plant-parasitic nematodes of known Hawaiian agricultural importance or occurrence were collected in these native plant communities. Calculated nematode densities (76,000 to 321,300/m²) were comparable to those reported for some other Pacific tropical forests. PMID:19262867

  7. Politics of NATO short-range nuclear modernization 1983-1990: The follow-on-to-Lance missile decisions. Doctoral thesis

    SciTech Connect

    Larsen, J.A.

    1991-06-01

    The follow-on to Lance (FOTL) missile was born in 1983 with a consensual decision by NATO, in the face of a worsening strategic situation, to pursue short-range nuclear force (SNF) modernization. The program continued despite increasing popular and political opposition in Europe. It ended with a May 1990 cancellation decision by the American bureaucracy that reflected converging pressures from the international system, from America's allies, and from the domestic arena. The thesis attempts to answer each question through the use of one of three analytical perspectives: systemic theory, alliance politics, or domestic politics. It concludes that during this time of diminishing threat at the systemic level, domestic-level factors within the German and American milieu became more important. While certain perspectives are better at explaining particular aspects or temporal periods of modernization cases, analysts should not focus on one perspective to the exclusion of others. Unexplained residual variables fall through the filter of each perspective, calling for further study by other approaches.

  8. Leaching of the fine fraction of the argon oxygen decarburization with lance (AOD-L) sludge for the preferential removal of iron.

    PubMed

    Majuste, Daniel; Mansur, Marcelo Borges

    2009-02-15

    The fine fraction of the argon oxygen decarburization with lance (AOD-L) sludge is a hazardous waste generated by the stainless steel industry which is normally disposed in landfills. Due to the relative high content of Fe, Cr and Ni as well as its low granulometry, a hydrometallurgical route based on sequential leaching steps is being investigated to treat it. In this paper, an attempt made to remove Fe from the sludge and concentrate Cr and Ni in the solid is highlighted. Leaching was carried out at atmospheric pressure using H(2)SO(4) and HCl at varying temperature (25, 40, 55 and 70 degrees C) and acid concentration (3, 6 and 12%, v/v). For both acids, leaching rate increased with temperature and acid concentration, and higher dissolutions of Fe and Ni were obtained in comparison with that of Cr. HCl was found more selective for Fe over Ni and Cr. The content of Fe was reduced nearly 50% (w/w) at 70 degrees C and HCl 12% (v/v), while Cr remained mostly in the solid; however, around 40% (w/w) of Ni was dissolved and it may hinder such leaching step in the studied route. The study points out that total metal leaching of sludge under high temperature and pressure conditions must be considered.

  9. Characterization of the fine fraction of the argon oxygen decarburization with lance (AOD-L) sludge generated by the stainless steelmaking industry.

    PubMed

    Majuste, Daniel; Mansur, Marcelo Borges

    2008-05-01

    The argon oxygen decarburization with lance (AOD-L) sludge generated by the stainless steelmaking industry is a hazardous waste due to the presence of chromium. While its coarse fraction is usually recycled into the own industrial process, the fine fraction is normally disposed in landfills. Techniques such as briquetting or magnetic separation were found to be inadequate to treat it for reuse purposes. So, in this work, the fine fraction of the AOD-L sludge was characterized aiming to find alternative methods to treat it. This sludge consists of a fine powder (mean diameter of 1 microm) containing 34 +/- 2% (w/w) of iron, 10.2 +/- 0.9% (w/w) of chromium and 1.4 +/- 0.1% (w/w) of nickel. The main crystalline phases identified in this study were chromite (FeCr(2)O(4)), magnetite (Fe(3)O(4)), hematite (Fe(2)O(3)) and calcite (CaCO(3)). In the digestion tests, the addition of HClO(4) has favored the dissolution of chromite which is a very stable oxide in aqueous media. Nickel was found in very fine particles, probably in the metallic form or associated with iron and oxygen. The sludge was classified as hazardous waste, so its disposal in landfills should be avoided.

  10. Intestinal Enterobacteriaceae that Protect Nematodes from the Effects of Benzimidazoles

    PubMed Central

    Whittaker, John H; Robertson, Alan P; Kimber, Michael J; Day, Tim A; Carlson, Steve A

    2016-01-01

    The objective of this study was to investigate an interaction between nematodes and gut Enterobacteriaceae that use benzimidazoles as a carbon source. By addressing this objective, we identified an anthelmintic resistance-like mechanism for gastrointestinal nematodes. We isolated 30 gut bacteria (family Enterobacteriaceae) that subsist on and putatively catabolize benzimidazole-class anthelmintics. C. elegans was protected from the effects of benzimidazoles when co-incubated with these Enterobacteriaceae that also protect adult ascarids from the effects of albendazole. This bacterial phenotype represents a novel mechanism by which gastrointestinal nematodes are potentially spared from the effects of benzimidazoles, without any apparent fitness cost to the parasite. PMID:28066686

  11. Biocontrol: Bacillus penetrans and Related Parasites of Nematodes

    PubMed Central

    Sayre, R. M.

    1980-01-01

    Bacillus penetrans Mankau, 1975, previously described as Duboscqia penetrans Thorne 1940, is a candidate agent for biocontrol of nematodes. This review considers the life stages of this bacterium: vegetative growth phase, colony fragmentation, sporogenesis, soil phase, spore attachment, and penetration into larvae of root-knot nematodes. The morphology of the microthallus colonies and the unusual external features of the spore are discussed. Taxonomic affinities with the actinomycetes, particularly with the genus Pasteuria, are considered. Also discussed are other soil bacterial species that are potential biocontrol agents. Products of their bacterial fermentation in soil are toxic to nematodes, making them effective biocontrol agents. PMID:19300701

  12. Suppression of plant parasitic nematodes in the chinampa agricultural soils.

    PubMed

    Zuckerman, B M; Dicklow, M B; Coles, G C; Garcia-E, R; Marban-Mendoza, N

    1989-06-01

    Soil from the chinampa agricultural system in the Valley of Mexico suppressed damage by plant-parasitic nematodes to tomatoes and beans in greenhouse and growth chamber trials. Sterilization of the chinampa soil resulted in a loss of the suppressive effect, thereby indicating that one or more biotic factors were responsible for the low incidence of nematode damage. Nine organisms were isolated from chinampa soil, which showed antinematodal properties in culture. Naturally occurring populations of plant-parasitic nematodes were of lower incidence in chinampa soil than in Chapingo soil.

  13. The effects of root-knot nematode infection and mi-mediated nematode resistance in tomato on plant fitness.

    PubMed

    Corbett, Brandon P; Jia, Lingling; Sayler, Ronald J; Arevalo-Soliz, Lirio Milenka; Goggin, Fiona

    2011-06-01

    The Mi-1.2 resistance gene in tomato (Solanum lycopersicum) confers resistance against several species of root-knot nematodes (Meloidogyne spp.). This study examined the impact of M. javanica on the reproductive fitness of near-isogenic tomato cultivars with and without Mi-1.2 under field and greenhouse conditions. Surprisingly, neither nematode inoculation or host plant resistance impacted the yield of mature fruits in field microplots (inoculum=8,000 eggs/plant), or fruit or seed production in a follow-up greenhouse bioassay conducted with a higher inoculum level (20,000 eggs/plant). However, under heavy nematode pressure (200,000 eggs/plant), greenhouse-grown plants carrying Mi-1.2 had more than ten-fold greater fruit production than susceptible plants and nearly forty-fold greater estimated lifetime seed production, confirming prior reports of the benefits of Mi-1.2. In all cases Mi-mediated resistance significantly reduced nematode reproduction. These results indicated that tomato can utilize tolerance mechanisms to compensate for moderate levels of nematode infection, but that the Mi-1.2 resistance gene confers a dramatic fitness benefit under heavy nematode pressure. No significant cost of resistance was detected in the absence of nematode infection.

  14. Effects of catechin polyphenols and preparations from the plant-parasitic nematode Heterodera glycines on protease activity and behavior in three nematode species

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Protease activities in preparations from the plant-parasitic nematodes Heterodera glycines and Meloidogyne incognita and the free-living nematode Panagrellus redivivus were inhibited by exposure to a series of 8 catechin polyphenol analogs, (+)-catechin, (-)- epicatechin (EC), (-)-gallocatechin (GC)...

  15. A Nematode Growth Factor from Baker's Yeast

    PubMed Central

    Buecher, E. J.; Hansen, E. L.; Gottfried, T.

    1970-01-01

    An extract prepared from commercially available yeast supported maturation of the free-living nematode Caenorhabditis briggsae. The extract can be used to supplement a chemically defined medium or, after a limited dialysis, as a complete medium. Several biologically active fractions were prepared; those containing larger amounts of ribonucleic acid (RNA) had greater biological activity, the most active being a pellet resuspended after centrifugation at 30,000 × g for 30 min. This fraction could be substituted for serum in a medium which supports the maturation of the animal parasites Trichinella spiralis and Hymenolepis nana. Addition of protamine sulfate decreased the RNA content, leaving inactive protein fractions which could be reactivated by specific treatments that caused protein precipitation. It is postulated that biological activity is associated with protein sedimented with ribosomes. PMID:19322277

  16. MSP Dynamics and Retraction in Nematode Sperm

    NASA Astrophysics Data System (ADS)

    Wolgemuth, Charles W.

    2005-03-01

    Most eukaryotic cells can crawl over surfaces. In general, this motility requires three distinct actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the Major Sperm Protein (MSP) cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly I propose a model for disassembly-induced retraction that fit the in vitro experimental data. This model explains the mechanism by which deconstruction of the cytoskeleton produces the force necessary to pull the cell body forward and suggest further experiments that can test the validity of the model.

  17. MSP dynamics and retraction in nematode sperm

    NASA Astrophysics Data System (ADS)

    Wolgemuth, Charles; Miao, Long; Vanderlinde, Orion; Roberts, Tom; Oster, George

    2005-03-01

    Most eukaryotic cells can crawl over surfaces. In general, this motility requires three distinct actions: polymerization at the leading edge, adhesion to the substrate, and retraction at the rear. Recent in vitro experiments with extracts from spermatozoa from the nematode Ascaris suum suggest that retraction forces are generated by depolymerization of the Major Sperm Protein (MSP) cytoskeleton. Combining polymer entropy with a simple kinetic model for disassembly I propose a model for disassembly-induced retraction that fit the in vitro experimental data. This model explains the mechanism by which deconstruction of the cytoskeleton produces the force necessary to pull the cell body forward and suggest further experiments that can test the validity of the model.

  18. Ecological Biogeography of the Terrestrial Nematodes of Victoria Land, Antarctica

    PubMed Central

    Adams, Byron J.; Wall, Diana H.; Virginia, Ross A.; Broos, Emma; Knox, Matthew A.

    2014-01-01

    Abstract The terrestrial ecosystems of Victoria Land, Antarctica are characteristically simple in terms of biological diversity and ecological functioning. Nematodes are the most commonly encountered and abundant metazoans of Victoria Land soils, yet little is known of their diversity and distribution. Herein we present a summary of the geographic distribution, habitats and ecology of the terrestrial nematodes of Victoria Land from published and unpublished sources. All Victoria Land nematodes are endemic to Antarctica, and many are common and widely distributed at landscape scales. However, at smaller spatial scales, populations can have patchy distributions, with the presence or absence of each species strongly influenced by specific habitat requirements. As the frequency of nematode introductions to Antarctica increases, and soil habitats are altered in response to climate change, our current understanding of the environmental parameters associated with the biogeography of Antarctic nematofauna will be crucial to monitoring and possibly mitigating changes to these unique soil ecosystems. PMID:25061360

  19. SCREENING OF TRANSGENIC ANTHURIUMS FOR BACTERIAL BLIGHT AND NEMATODE RESISTANCE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Anthuriums exhibit limited resistance to bacterial blight caused by Xanthomonas axonopodis pv. dieffenbachiae and to the nematodes Radopholus simile and Meloidogyne javanica. Agrobacterium tumefaciens transformation of embryogenic calli with strains LBA4404, EHA105, and AGLO resulted in transgenic p...

  20. Breeding a super nematode for enhanced insect pest suppression

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes in the genera Heterorhabditis and Steinernema are important regulators of natural insect populations, and are used commercially as biological control agents for pest suppression. Successful biocontrol applications depend on the introduced organism having an array of benef...

  1. Nematodes Attacking Cultivars of Peach in North Carolina

    PubMed Central

    Barker, K. R.; Clayton, C. N.

    1973-01-01

    Criconemoides xenoplax and Meloidogyne incognita were the nematode species most frequently associated with peach in North Carolina. Other nematodes often found in high numbers on that crop were Pratylenehus vulnus, Helicotylenchus spp., Trichodorus christiei, Xiphinema amerieanum and Tylenchorhynchus claytoni. P. vulnus and P. penetrans reproduced well on rootstocks of 21 peach cultivars tested in the greenhouse. P. zeae, P. brachyurus, P. coffeae and P. scribneri decreased or increased only slightly in most instances. C. xenoplax increased as much as 330-fold and reproduced on all cultivars tested. In a field experiment with six peach cultivars and moderate numbers of P. brachyurus, P. vulnus, C. xenoplax, and M. incognita, only M. incognita caused significant stunting in 30 months. This nematode increased only on root-knot susceptible cultivars, whereas the other nematodes followed the same patterns observed in the greenhouse. In a second field experiment, seedlings were stunted significantly by high numbers of C. xenoplax during an 18-month period. PMID:19319348

  2. Human gastrointestinal nematode infections: are new control methods required?

    PubMed Central

    Stepek, Gillian; Buttle, David J; Duce, Ian R; Behnke, Jerzy M

    2006-01-01

    Gastrointestinal (GI) nematode infections affect 50% of the human population worldwide, and cause great morbidity as well as hundreds of thousands of deaths. Despite modern medical practices, the proportion of the population infected with GI nematodes is not falling. This is due to a number of factors, the most important being the lack of good healthcare, sanitation and health education in many developing countries. A relatively new problem is the development of resistance to the small number of drugs available to treat GI nematode infections. Here we review the most important parasitic GI nematodes and the methods available to control them. In addition, we discuss the current status of new anthelmintic treatments, particularly the plant cysteine proteinases from various sources of latex-bearing plants and fruits. PMID:16965561

  3. Survey of fresh vegetables for nematodes, amoebae, and Salmonella.

    PubMed

    Rude, R A; Jackson, G J; Bier, J W; Sawyer, T K; Risty, N G

    1984-01-01

    Contamination by nematodes, amoebae, and bacteria of the genus Salmonella was estimated in a 2-year survey of salad vegetables obtained from wholesale and retail sources. The vegetables examined were cucumbers, cabbage, lettuce, celery, carrots, radishes, tomatoes, mushrooms, cauliflower, and spinach. Nematode eggs and larvae were recovered by the Nacconol-ether centrifugation method. Some nematode eggs were identified as parasitic Ascaris sp.; the majority of larval nematodes were thought to be soil-dwelling species. Amoebae were recovered by rinsing the vegetables with distilled water, centrifuging the rinse water, and transferring the sediment to agar plates on which a bacterial lawn had previously been grown; trophozoites identified as the potentially pathogenic species--Acanthamoeba polyphaga, A. rhysodes, and A. castellanii--were the most common amoebae recovered on the plates. Salmonella spp. were grown from 4 of 50 samples.

  4. Soil Organic Matter and Management of Plant-Parasitic Nematodes

    PubMed Central

    Widmer, T. L.; Mitkowski, N. A.; Abawi, G. S.

    2002-01-01

    Organic matter and its replenishment has become a major component of soil health management programs. Many of the soil's physical, chemical, and biological properties are a function of organic matter content and quality. Adding organic matter to soil influences diverse and important biological activities. The diversity and number of free-living and plant-parasitic nematodes are altered by rotational crops, cover crops, green manures, and other sources of organic matter. Soil management programs should include the use of the proper organic materials to improve soil chemical, physical, and biological parameters and to suppress plant-parasitic nematodes and soilborne pathogens. It is critical to monitor the effects of organic matter additions on activities of major and minor plant-parasitic nematodes in the production system. This paper presents a general review of information in the literature on the effects of crop rotation, cover crops, and green manures on nematodes and their damage to economic crops. PMID:19265946

  5. Exploring the transcriptome of the burrowing nematode Radopholus similis.

    PubMed

    Jacob, Joachim; Mitreva, Makedonka; Vanholme, Bartel; Gheysen, Godelieve

    2008-07-01

    Radopholus similis is an important nematode pest on fruit crops in the tropics. Unraveling the transcriptome of this migratory plant-parasitic nematode can provide insight in the parasitism process and lead to more efficient control measures. For the first high throughput molecular characterization of this devastating nematode, 5,853 expressed sequence tags from a mixed stage population were generated. Adding 1,154 tags from the EST division of GenBank for subsequent analysis, resulted in a total of 7,007 ESTs, which represent approximately 3,200 genes. The mean G + C content of the nucleotides at the third codon position (GC3%) was calculated to be as high as 64.8%, the highest for nematodes reported to date. BLAST-searches resulted in about 70% of the clustered ESTs having homology to (DNA and protein) sequences from the GenBank database, whereas one-third of them did not match to any known sequence. Roughly 40% of these latter sequences are predicted to be coding, representing putative novel protein coding genes. Functional annotation of the sequences by GO annotation revealed the abundance of genes involved in reproduction and development, which reflects the nematode population biology. Genes with a role in the parasitism process are identified, as well as genes essential for nematode survival, providing information useful for parasite control. No evidence was found for the presence of trans-spliced leader sequences commonly occurring in nematodes, despite the use of various approaches. In conclusion, we found three different sources for the EST sequences: the majority has a nuclear origin, approximately 1% of the EST sequences are derived from the mitochondrial transcriptome, and interestingly, 1% of the tags are with high probability derived from Wolbachia, providing the first molecular indication for the presence of this endosymbiont in a plant-parasitic nematode.

  6. Evaluation of Three Nematicides for the Control of Phytoparasitic Nematodes in 'Tifgreen II' Bermudagrass.

    PubMed

    Giblin-Davis, R M; Cisar, J L; Bilz, F G

    1988-10-01

    Three nematicides were evaluated for control of Belonolaimus longicaudatus, Hoplolaimus galeatus, Criconemella spp., and Meloidogyne spp. in 'Tifgreen II' bermudagrass mowed at golf course fairway height (1.3 cm) in Fort Lauderdale, Florida. Bermudagrass plots were treated with fenamiphos (13.5 kg a.i./ha), oxamyl (13.5 kg a.i./ha), or 30% formaldehyde (6.4 liter a.i./ha). The plots treated with fenamiphos or formaldehyde were split 14 days later and one-half of each plot received two biweekly applications of formaldehyde. Forty-two days after the treatments were applied, the turfgrass vigor ratings and dry root weights in plots treated with fenamiphos were higher (P < 0.05) than the control, oxamyl, or formaldehyde treatments. The population levels of B. longicaudatus were suppressed (P < 0.05) in the fenamiphos, fenamiphos plus formaldehyde, and oxamyl treatments.

  7. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance.

    PubMed

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W; Williamson, Valerie M; Schroeder, Frank C; Klessig, Daniel F

    2015-07-23

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture.

  8. Conserved nematode signalling molecules elicit plant defenses and pathogen resistance

    PubMed Central

    Manosalva, Patricia; Manohar, Murli; von Reuss, Stephan H.; Chen, Shiyan; Koch, Aline; Kaplan, Fatma; Choe, Andrea; Micikas, Robert J.; Wang, Xiaohong; Kogel, Karl-Heinz; Sternberg, Paul W.; Williamson, Valerie M.; Schroeder, Frank C.; Klessig, Daniel F.

    2015-01-01

    Plant-defense responses are triggered by perception of conserved microbe-associated molecular patterns (MAMPs), for example, flagellin or peptidoglycan. However, it remained unknown whether plants can detect conserved molecular patterns derived from plant-parasitic animals, including nematodes. Here we show that several genera of plant-parasitic nematodes produce small molecules called ascarosides, an evolutionarily conserved family of nematode pheromones. Picomolar to micromolar concentrations of ascr#18, the major ascaroside in plant-parasitic nematodes, induce hallmark defense responses including the expression of genes associated with MAMP-triggered immunity, activation of mitogen-activated protein kinases, as well as salicylic acid- and jasmonic acid-mediated defense signalling pathways. Ascr#18 perception increases resistance in Arabidopsis, tomato, potato and barley to viral, bacterial, oomycete, fungal and nematode infections. These results indicate that plants recognize ascarosides as a conserved molecular signature of nematodes. Using small-molecule signals such as ascarosides to activate plant immune responses has potential utility to improve economic and environmental sustainability of agriculture. PMID:26203561

  9. Cryopreservation of Radopholus similis, a tropical plant-parasitic nematode.

    PubMed

    Elsen, Annemie; Vallterra, Salvador Ferrandis; Van Wauwe, Tom; Thuy, Trinh Thi Thu; Swennen, Rony; De Waele, Dirk; Panis, Bart

    2007-10-01

    For obligate plant-parasitic nematodes, cryopreservation has advantages over the usual preservation methods on whole plants or axenic culture systems, because the latter two are labourious and time and space consuming. In addition, cross contamination among different isolates can occur easily. Moreover, specific genetic studies require maintenance of the original population. The nematode under investigation, Radopholus similis, is a plant-parasitic nematode from the humid tropics. Therefore, any treatment at low temperatures is likely to add extra stress to the nematode, making the development of a cryopreservation protocol extremely difficult. In this paper, we describe experiments to achieve a successful cryopreservation protocol for the tropical nematode R. similis using vitrification solution-based methods based on a well defined mixture of cryoprotectants in combination with ultra-rapid cooling and thawing rates. A two-step treatment was used consisting of an incubation in glycerol followed by the application of a vitrifying mixture of methanol, glycerol and glucose. After cryopreservation, the pathogenicity of the nematodes was not altered, since they could infect and reproduce on carrot discs after recovery in the Ringer solution. The cryopreservation method described can be used for routine cryopreservation of R. similis lines from different origins.

  10. Nematode Communities in Organically and Conventionally Managed Agricultural Soils

    PubMed Central

    Neher, Deborah A.

    1999-01-01

    Interpretation of nematode community indices requires a reference to a relatively undisturbed community. Maturity and trophic diversity index values were compared for five pairs of certified organically and conventionally managed soils in the Piedmont region of North Carolina. Available nitrogen (nitrate, ammonium) was estimated at various lag periods relative to times of sampling for nematode communities to determine the strength of correlative relationship between nematode communities and nitrogen availability. Soils were sampled six times yearly in 1993 and 1994 to determine the best time of year to sample. Maturity values for plant parasites were greater in organically than conventionally managed soils, and differences between management systems were greater in fall than spring months. However, other maturity and diversity indices did not differ between the two management practices. Differences in crop species grown in the two systems accounted for most differences observed in the community of plant-parasitic nematodes. Indices of free-living nematodes were correlated negatively with concentrations of ammonium, whereas indices of plant-parasitic nematodes were correlated positively with concentrations of nitrate. Due to the similarity of index values between the two systems, organically managed soils are not suitable reference sites for monitoring and assessing the biological aspects of soil quality for annually harvested crops. PMID:19270884

  11. Allelopathy in the Management of Plant-Parasitic Nematodes

    PubMed Central

    Halbrendt, J. M.

    1996-01-01

    There are numerous reports of nematicidal chemicals in crude plant homogenates, leachates, and decomposing residues. These compounds are usually assumed to be secondary metabolites, which serve as chemical defenses against disease and parasites. When such compounds are released into the rhizosphere, they are known as allelochemicals. The possibility exists to exploit allelochemicals for nematode control, and there have been many attempts to use this approach either by rotation, intercropping, or green manure treatments. Results have met with mixed success. Proof of allelochemical activity in field situations is difficult to obtain, but it is evident that some rotation crops are significantly better at reducing nematode populations than others. Rotations with non-host plants may simply deny the nematode population an adequate food source for reproduction (passive suppression), whereas allelopathic crops kill nematodes by the production of toxic compounds (active suppression). Progress toward sustainable agriculture should benefit from studies on allelopathic nematode control. However, grower acceptance of new plant-rotation strategies are based on economic and logistical considerations as well as efficacy. A potential practical application of allelopathic nematode control that involves using rapeseed as a green manure crop to reduce populations of Xiphinema americanum sensu lato in temperate orchards is presented. PMID:19277340

  12. Soil sampling and isolation of entomopathogenic nematodes (Steinernematidae, Heterorhabditidae).

    PubMed

    Orozco, Rousel A; Lee, Ming-Min; Stock, S Patricia

    2014-07-11

    Entomopathogenic nematodes (a.k.a. EPN) represent a group of soil-inhabiting nematodes that parasitize a wide range of insects. These nematodes belong to two families: Steinernematidae and Heterorhabditidae. Until now, more than 70 species have been described in the Steinernematidae and there are about 20 species in the Heterorhabditidae. The nematodes have a mutualistic partnership with Enterobacteriaceae bacteria and together they act as a potent insecticidal complex that kills a wide range of insect species. Herein, we focus on the most common techniques considered for collecting EPN from soil. The second part of this presentation focuses on the insect-baiting technique, a widely used approach for the isolation of EPN from soil samples, and the modified White trap technique which is used for the recovery of these nematodes from infected insects. These methods and techniques are key steps for the successful establishment of EPN cultures in the laboratory and also form the basis for other bioassays that consider these nematodes as model organisms for research in other biological disciplines. The techniques shown in this presentation correspond to those performed and/or designed by members of S. P. Stock laboratory as well as those described by various authors.

  13. Temperature-based bioclimatic parameters can predict nematode metabolic footprints.

    PubMed

    Bhusal, Daya Ram; Tsiafouli, Maria A; Sgardelis, Stefanos P

    2015-09-01

    Nematode metabolic footprints (MFs) refer to the lifetime amount of metabolized carbon per individual, indicating a connection to soil food web functions and eventually to processes supporting ecosystem services. Estimating and managing these at a convenient scale requires information upscaling from the soil sample to the landscape level. We explore the feasibility of predicting nematode MFs from temperature-based bioclimatic parameters across a landscape. We assume that temperature effects are reflected in MFs, since temperature variations determine life processes ranging from enzyme activities to community structure. We use microclimate data recorded for 1 year from sites differing by orientation, altitude and vegetation cover. At the same sites we estimate MFs for each nematode trophic group. Our models show that bioclimatic parameters, specifically those accounting for temporal variations in temperature and extremities, predict most of the variation in nematode MFs. Higher fungivorous and lower bacterivorous nematode MFs are predicted for sites with high seasonality and low isothermality (sites of low vegetation, mostly at low altitudes), indicating differences in the relative contribution of the corresponding food web channels to the metabolism of carbon across the landscape. Higher plant-parasitic MFs were predicted for sites with high seasonality. The fitted models provide realistic predictions of unknown cases within the range of the predictor's values, allowing for the interpolation of MFs within the sampled region. We conclude that upscaling of the bioindication potential of nematode communities is feasible and can provide new perspectives not only in the field of soil ecology but other research areas as well.

  14. Alternatives to anthelmintics for the control of nematodes in livestock.

    PubMed

    Stear, M J; Doligalska, M; Donskow-Schmelter, K

    2007-02-01

    Efficient and welfare-friendly livestock production demands the control of nematode infection. Current control measures rely upon anthelmintic treatment but are threatened by the widespread evolution of drug-resistance in parasite populations. Several methods have been advocated to control nematodes without relying on effective anthelmintics. These include grazing management, biological control, nutritional supplementation, vaccination, and genetic approaches. Each method has its advantages and disadvantages. There are several grazing management schemes that can reduce the severity of infection but they are insufficient on their own to control infection. Biological control includes the use of predatory fungi to control nematode populations and the use of pasture species that can reduce the intensity of infection. Fungi can control nematodes but the current requirement for daily feeding means that this approach will be most useful for animals that are handled daily. Feeding supplementary protein can control nematode infection. The method is simple but can be expensive and may not be cost-effective for some marginal enterprises. Genetic approaches include the use of resistant breeds and selective breeding. Some breeds will thrive in conditions that kill animals from other breeds but substitution of resistant breeds is not always feasible. Selective breeding is effective and inexpensive but requires a high level of expertise. The most appropriate method or set of methods to minimize the adverse consequences of nematode infection may vary among farms.

  15. Diverse Host-Seeking Behaviors of Skin-Penetrating Nematodes

    PubMed Central

    Castelletto, Michelle L.; Gang, Spencer S.; Okubo, Ryo P.; Tselikova, Anastassia A.; Nolan, Thomas J.; Platzer, Edward G.; Lok, James B.; Hallem, Elissa A.

    2014-01-01

    Skin-penetrating parasitic nematodes infect approximately one billion people worldwide and are responsible for some of the most common neglected tropical diseases. The infective larvae of skin-penetrating nematodes are thought to search for hosts using sensory cues, yet their host-seeking behavior is poorly understood. We conducted an in-depth analysis of host seeking in the skin-penetrating human parasite Strongyloides stercoralis, and compared its behavior to that of other parasitic nematodes. We found that Str. stercoralis is highly mobile relative to other parasitic nematodes and uses a cruising strategy for finding hosts. Str. stercoralis shows robust attraction to a diverse array of human skin and sweat odorants, most of which are known mosquito attractants. Olfactory preferences of Str. stercoralis vary across life stages, suggesting a mechanism by which host seeking is limited to infective larvae. A comparison of odor-driven behavior in Str. stercoralis and six other nematode species revealed that parasite olfactory preferences reflect host specificity rather than phylogeny, suggesting an important role for olfaction in host selection. Our results may enable the development of new strategies for combating harmful nematode infections. PMID:25121736

  16. Communities of terrestrial nematodes after different approaches to heathland restoration

    NASA Astrophysics Data System (ADS)

    Radochova, Petra; Frouz, Jan

    2016-04-01

    Since the 20th century, the distribution of European heathlands rapidly decreased due to agricultural intensification, heavy use of artificial fertilizers or acidification (Aerts & Heil, 1993). Therefore, various attempts of heathland restoration are under way in these days. Analysis of nematode community composition can be one of the tools suitable for succession evaluation (Ferris et al., 2001). In 2011, 2013 and 2014, soil samples were collected from heathland restoration experiment (launched in 2011) where different restoration methods were applied in a 3 × 3 factorial experiment; existing heathlands were also sampled to identify the target community both in dry and wet heathland. A total of 60 samples of extracted nematodes were analysed for absolute abundance, trophic groups, and genera dominance. Various indices were calculated to describe the nematode community. We were able to prove faster development of wet heathlands towards the target community. However, because of large data variability, there was no significant difference between treatments. Development of wet and dry heathlands differed also in increased proportion of omniphagous nematodes in 2013 and predators in 2014 in dry heathlands. After three years of heathland restoration, nematode community has not yet reached parameters of the target community. References Aerts, R., Heil, G. W., 1993. Heathlands: patterns and processes in a changing environment, 1st ed, Geobotany: 20. Springer Netherlands, Dordrecht, p. 229. Ferris, H., Bongers, T., De Goede, R. G. M., 2001. A framework for soil food web diagnostics: Extension of the nematode faunal analysis oncept. Appl. Soil Ecol. 18, 13-29.

  17. Directional movement of entomopathogenic nematodes in response to electrical fields: Effects of species, magnitude of voltage, and infective juvenile age

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes respond to a variety of stimuli when foraging. Previously, we reported a directional response to electrical fields for two entomopathogenic nematode species; specifically, when electrical fields were generated on agar plates Steinernema glaseri (a nematode that utilizes a...

  18. Plant-parasitic Nematode Acetylcholinesterase Inhibition by Carbamate and Organophosphate Nematicides.

    PubMed

    Opperman, C H; Chang, S

    1990-10-01

    The sensitivity of acetylcholinesterases (ACHE) isolated from the plant-parasitic nematodes Meloidogyne arenaria, M. incognita, and Heterodera glycines and the free-living nematode Caenorhabditis elegans to carbamate and organophosphate nematicides was examined. The AChE from plant-parasitic nematode species were more sensitive to carbamate inhibitors than was AChE from C. elegans, but response to the organophosphates was approximately equivalent. The sulfur-containing phosphate nematicides were poor inhibitors of nematode acetylcholinesterase, but treatment with an oxidizing agent greatly improved inhibition. Behavioral bioassays with living nematodes revealed a poor relationship between enzyme inhibition and expression of symptoms in live nematodes.

  19. Tomato transgenic plants expressing hairpin construct of a nematode protease gene conferred enhanced resistance to root-knot nematodes

    PubMed Central

    Dutta, Tushar K.; Papolu, Pradeep K.; Banakar, Prakash; Choudhary, Divya; Sirohi, Anil; Rao, Uma

    2015-01-01

    Root-knot nematodes (Meloidogyne incognita) cause substantial yield losses in vegetables worldwide, and are difficult to manage. Continuous withdrawal of environmentally-harmful nematicides from the global market warrants the need for novel nematode management strategies. Utility of host-delivered RNAi has been demonstrated in several plants (Arabidopsis, tobacco, and soybean) that exhibited resistance against root-knot and cyst nematodes. Herein, a M. incognita-specific protease gene, cathepsin L cysteine proteinase (Mi-cpl-1), was targeted to generate tomato transgenic lines to evaluate the genetically modified nematode resistance. In vitro knockdown of Mi-cpl-1 gene led to the reduced attraction and penetration of M. incognita in tomato, suggesting the involvement of Mi-cpl-1 in nematode parasitism. Transgenic expression of the RNAi construct of Mi-cpl-1 gene resulted in 60–80% reduction in infection and multiplication of M. incognita in tomato. Evidence for in vitro and in vivo silencing of Mi-cpl-1 was confirmed by expression analysis using quantitative PCR. Our study demonstrates that Mi-cpl-1 plays crucial role during plant-nematode interaction and plant-mediated downregulation of this gene elicits detrimental effect on M. incognita development, reinforcing the potential of RNAi technology for management of phytonematodes in crop plants. PMID:25883594

  20. Pan-phylum Comparison of Nematode Metabolic Potential.

    PubMed

    Tyagi, Rahul; Rosa, Bruce A; Lewis, Warren G; Mitreva, Makedonka

    2015-05-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  1. Pan-phylum Comparison of Nematode Metabolic Potential

    PubMed Central

    Tyagi, Rahul; Rosa, Bruce A.; Lewis, Warren G.; Mitreva, Makedonka

    2015-01-01

    Nematodes are among the most important causative pathogens of neglected tropical diseases. The increased availability of genomic and transcriptomic data for many understudied nematode species provides a great opportunity to investigate different aspects of their biology. Increasingly, metabolic potential of pathogens is recognized as a critical determinant governing their development, growth and pathogenicity. Comparing metabolic potential among species with distinct trophic ecologies can provide insights on overall biology or molecular adaptations. Furthermore, ascertaining gene expression at pathway level can help in understanding metabolic dynamics over development. Comparison of biochemical pathways (or subpathways, i.e. pathway modules) among related species can also retrospectively indicate potential mistakes in gene-calling and functional annotation. We show with numerous illustrative case studies that comparisons at the level of pathway modules have the potential to uncover biological insights while remaining computationally tractable. Here, we reconstruct and compare metabolic modules found in the deduced proteomes of 13 nematodes and 10 non-nematode species (including hosts of the parasitic nematode species). We observed that the metabolic potential is, in general, concomitant with phylogenetic and/or ecological similarity. Varied metabolic strategies are required among the nematodes, with only 8 out of 51 pathway modules being completely conserved. Enzyme comparison based on topology of metabolic modules uncovered diversification between parasite and host that can potentially guide therapeutic intervention. Gene expression data from 4 nematode species were used to study metabolic dynamics over their life cycles. We report unexpected differential metabolism between immature and mature microfilariae of the human filarial parasite Brugia malayi. A set of genes potentially important for parasitism is also reported, based on an analysis of gene expression in

  2. The nematode Caenorhabditis elegans and its genome.

    PubMed

    Hodgkin, J; Plasterk, R H; Waterston, R H

    1995-10-20

    Over the past two decades, the small soil nematode Caenorhabditis elegans has become established as a major model system for the study of a great variety of problems in biology and medicine. One of its most significant advantages is its simplicity, both in anatomy and in genomic organization. The entire haploid genetic content amounts to 100 million base pairs of DNA, about 1/30 the size of the human value. As a result, C. elegans has also provided a pilot system for the construction of physical maps of larger animal and plant genomes, and subsequently for the complete sequencing of those genomes. By mid-1995, approximately one-fifth of the complete DNA sequence of this animal had been determined. Caenorhabditis elegans provides a test bed not only for the development and application of mapping and sequencing technologies, but also for the interpretation and use of complete sequence information. This article reviews the progress so far toward a realizable goal--the total description of the genome of a simple animal.

  3. GABA localization in the nematode Ascaris

    SciTech Connect

    Guastella, J.

    1988-01-01

    A histochemical approach was used to examine the distribution of GABA-associated neurons in the nematode Ascaris, an organism whose small number of morphologically simple neurons make it an excellent preparation for analyzing neuronal phenotypes. Two GABAergic markers were examined: GABA-like immunoreactivity (GLIR), a marker for endogenous stores of GABA; and ({sup 3}H)-GABA uptake, a marker for GABA uptake sites. Strong GLIR was present in the cell bodies, neurites and commissures of dorsal and ventral inhibitory motorneurons present in this region. Strong GLIR was also present in the cell bodies and processes of the four RME neurons in the nerve ring and in several other ganglionic neurons. Staining was absent in excitatory motorneurons, in ventral cord interneurons and in muscle cells and hypodermis. GABA uptake sites were found in single neural processes in both the ventral and dorsal nerve cords. ({sup 3}H)-GABA labeling was also observed in the other two RME cells and several other cephalic neurons. Four putative cholinergic excitatory motorneurons in the retrovesicular ganglion (RVG) were heavily labeled. Ventral and dorsal nerve cord inhibitory motorneurons did not take up ({sup 3}H)-GABA. Labeling of the ventral cord excitatory motorneuron somata and cell bodies was at or slightly above background. Heavy labeling of muscle cells was also observed.

  4. Geologic map of the Peach Orchard Flat quadrangle, Carbon County, Wyoming, and descriptions of new stratigraphic units in the Upper Cretaceous Lance Formation and Paleocene Fort Union Formation, eastern Greater Green River Basin, Wyoming-Colorado

    USGS Publications Warehouse

    Honey, J.D.; Hettinger, R.D.

    2004-01-01

    This report provides a geologic map of the Peach Orchard Flat 7.5-minute quadrangle, located along the eastern flank of the Washakie Basin, Wyo. Geologic formations and individual coal beds were mapped at a scale of 1:24,000; surface stratigraphic sections were measured and described; and well logs were examined to determine coal correlations and thicknesses in the subsurface. In addition, four lithostratigraphic units were named: the Red Rim Member of the Upper Cretaceous Lance Formation, and the China Butte, Blue Gap, and Overland Members of the Paleocene Fort Union Formation.

  5. Precision and Selection of Extraction Methods of Aphelenchid Nematodes from Maritime Pine Wood, Pinus pinaster L.

    PubMed Central

    Penas, Ana C.; DIias, Luis S.; Mota, Manuel M.

    2002-01-01

    Four extraction methods for Bursaphelenchus xylophilus and other aphelenchid nematodes were compared on the number of nematodes per gram recovered, and on the precision of the mean number of nematodes per gram of pine wood. The number of nematodes per gram recovered by each method, in addition to its inherent shortcomings when the actual number of nematodes is unknown, failed to provide clear rankings among the extraction methods. The precision of the mean number of nematodes per gram did provide clear guidelines for selection. Selection of the method may be based on prior knowledge about the range of nematodes to be expected or the independence of precision from the mean number of nematodes. PMID:19265909

  6. Phenotypic and molecular evaluation of cotton hairy roots as a model system for studying nematode resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The cellular mechanisms that mediate resistance of allotetraploid cotton (Gossypium spp.) to root-knot nematode (Meloidogyne incognita) and reniform nematode (Rotylenchulus reniformis) are poorly understood. Here, Agrobacterium rhizogenes-induced hairy roots were investigated as a possible research...

  7. Taxonomy, morphology and phylogenetics of coffee-associated root-lesion nematodes, Pratylenchus spp

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract: Although lesion nematodes (Pratylenchus species) can reduce coffee yield worldwide, methods for their identification are often difficult to implement. This review summarizes the diagnostic morphological features for distinguishing the eight previously described lesion nematode sp...

  8. BACTERIAL PREFERENCES OF THE BACTERIVOROUS SOIL NEMATODE CEPHALOBUS BREVICAUDA (CEPHALOBIDAE): EFFECT OF BACTERIAL TYPE AND SIZE

    EPA Science Inventory

    Cell size and type may affect availability of bacteria for consumption by bacterivorous nematodes in the soil and in culture. This study explored the bacterial preferences of the bacterivorous soil nematode Cephalobus brevicauda (Cephalobidae) by comparing bactgeria isolated dir...

  9. In vitro proteolysis of nematode FLPs by preparations from the free-living nematode Panagrellus redivivus and two plant-parasitic nematodes (Heterodera glycines and Meloidogyne incognita)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Proteolytic activities in extracts from three nematodes, the plant parasites Heterodera glycines and Meloidogyne incognita, and the free-living Panagrellus redivivus, were surveyed for substrate preferences using a battery of seven FRET-modified peptide substrates, all derived from members of the la...

  10. The dual effects of root-cap exudates on nematodes: from quiescence in plant-parasitic nematodes to frenzy in entomopathogenic nematodes

    PubMed Central

    Hiltpold, Ivan; Jaffuel, Geoffrey; Turlings, Ted C. J.

    2015-01-01

    To defend themselves against herbivores and pathogens, plants produce numerous secondary metabolites, either constitutively or de novo in response to attacks. An intriguing constitutive example is the exudate produced by certain root-cap cells that can induce a state of reversible quiescence in plant-parasitic nematodes, thereby providing protection against these antagonists. The effect of such root exudates on beneficial entomopathogenic nematodes (EPNs) remains unclear, but could potentially impair their use in pest management programmes. We therefore tested how the exudates secreted by green pea (Pisum sativum) root caps affect four commercial EPN species. The exudates induced reversible quiescence in all EPN species tested. Quiescence levels varied with the green pea cultivars tested. Notably, after storage in root exudate, EPN performance traits were maintained over time, whereas performances of EPNs stored in water rapidly declined. In sharp contrast to high concentrations, lower concentrations of the exudate resulted in a significant increase in EPN activity and infectiousness, but still reduced the activity of two plant-parasitic nematode species. Our study suggests a finely tuned dual bioactivity of the exudate from green pea root caps. Appropriately formulated, it can favour long-term storage of EPNs and boost their infectiousness, while it may also be used to protect plants from plant-parasitic nematodes. PMID:25165149

  11. The FMRFamide-Like Peptide Family in Nematodes

    PubMed Central

    Peymen, Katleen; Watteyne, Jan; Frooninckx, Lotte; Schoofs, Liliane; Beets, Isabel

    2014-01-01

    In the three decades since the FMRFamide peptide was isolated from the mollusk Macrocallista nimbosa, structurally similar peptides sharing a C-terminal RFamide motif have been identified across the animal kingdom. FMRFamide-like peptides (FLPs) represent the largest known family of neuropeptides in invertebrates. In the phylum Nematoda, at least 32 flp-genes are classified, making the FLP system of nematodes unusually complex. The diversity of the nematode FLP complement is most extensively mapped in Caenorhabditis elegans, where over 70 FLPs have been predicted. FLPs have shown to be expressed in the majority of the 302 C. elegans neurons including interneurons, sensory neurons, and motor neurons. The vast expression of FLPs is reflected in the broad functional repertoire of nematode FLP signaling, including neuroendocrine and neuromodulatory effects on locomotory activity, reproduction, feeding, and behavior. In contrast to the many identified nematode FLPs, only few peptides have been assigned a receptor and there is the need to clarify the pathway components and working mechanisms of the FLP signaling network. Here, we review the diversity, distribution, and functions of FLPs in nematodes. PMID:24982652

  12. Plant genes involved in harbouring symbiotic rhizobia or pathogenic nematodes.

    PubMed

    Damiani, Isabelle; Baldacci-Cresp, Fabien; Hopkins, Julie; Andrio, Emilie; Balzergue, Sandrine; Lecomte, Philippe; Puppo, Alain; Abad, Pierre; Favery, Bruno; Hérouart, Didier

    2012-04-01

    The establishment and development of plant-microorganism interactions involve impressive transcriptomic reprogramming of target plant genes. The symbiont (Sinorhizobium meliloti) and the root knot-nematode pathogen (Meloidogyne incognita) induce the formation of new root organs, the nodule and the gall, respectively. Using laser-assisted microdissection, we specifically monitored, at the cell level, Medicago gene expression in nodule zone II cells, which are preparing to receive rhizobia, and in gall giant and surrounding cells, which play an essential role in nematode feeding and constitute the typical root swollen structure, respectively. We revealed an important reprogramming of hormone pathways and C1 metabolism in both interactions, which may play key roles in nodule and gall neoformation, rhizobia endocytosis and nematode feeding. Common functions targeted by rhizobia and nematodes were mainly down-regulated, whereas the specificity of the interaction appeared to involve up-regulated genes. Our transcriptomic results provide powerful datasets to unravel the mechanisms involved in the accommodation of rhizobia and root-knot nematodes. Moreover, they raise the question of host specificity and the evolution of plant infection mechanisms by a symbiont and a pathogen.

  13. Heme acquisition in the parasitic filarial nematode Brugia malayi

    PubMed Central

    Luck, Ashley N.; Yuan, Xiaojing; Voronin, Denis; Slatko, Barton E.; Hamza, Iqbal; Foster, Jeremy M.

    2016-01-01

    Nematodes lack a heme biosynthetic pathway and must acquire heme from exogenous sources. Given the indispensable role of heme, this auxotrophy may be exploited to develop drugs that interfere with heme uptake in parasites. Although multiple heme-responsive genes (HRGs) have been characterized within the free-living nematode Caenorhabditis elegans, we have undertaken the first study of heme transport in Brugia malayi, a causative agent of lymphatic filariasis. Through functional assays in yeast, as well as heme analog, RNAi, and transcriptomic experiments, we have shown that the heme transporter B. malayi HRG-1 (BmHRG-1) is indeed functional in B. malayi. In addition, BmHRG-1 localizes both to the endocytic compartments and cell membrane when expressed in yeast cells. Transcriptomic sequencing revealed that BmHRG-1, BmHRG-2, and BmMRP-5 (all orthologs of HRGs in C. elegans) are down-regulated in heme-treated B. malayi, as compared to non–heme-treated control worms. Likely because of short gene lengths, multiple exons, other HRGs in B. malayi (BmHRG-3–6) remain unidentified. Although the precise mechanisms of heme homeostasis in a nematode with the ability to acquire heme remains unknown, this study clearly demonstrates that the filarial nematode B. malayi is capable of transporting exogenous heme.—Luck, A. N., Yuan, X., Voronin, D., Slatko, B. E., Hamza, I., Foster, J. M. Heme acquisition in the parasitic filarial nematode Brugia malayi. PMID:27363426

  14. A bioassay to estimate root penetration by nematodes.

    PubMed

    Kaplan, D T; Davis, E L

    1991-10-01

    An in vitro bioassay with a 96-well microtiter plate was used to study the effect of lectins on burrowing nematode penetration of citrus roots. In each well, one 4-mm root segment, excised from the zone of elongation of rough lemon roots, was buried in 0.88 g dry sand. Addition of a Radopholus citrophilus suspension containing ca. 300 nematodes in 50 mu1 test solution completely moistened the sand in each well. The technique assured uniform treatment concentration throughout the medium. Within 16-24 hours, burrowing nematodes penetrated citrus root pieces, primarily through the cut ends. The lectins (100 mug/ml) Concanavalin A (Con A), soybean agglutinin (SBA), wheat germ agglutinin (WGA), and Lotus tetragonolobus agglutinin (LOT) stimulated an increase in penetration of citrus root segments by Radopholus citrophilus. Concentrations as low as 12.5 mug/ml Con A, LOT, and WGA stimulated burrowing nematode penetration of citrus roots. Heat denaturation of the lectins reversed their effect on penetration; however, incubation of nematodes in lectin (25 mug/ml) with 25 mM competitive sugars did not. The reason for enhanced penetration associated with lectins is unclear.

  15. Experimental Studies with Nematodes in Ecotoxicology: An Overview

    PubMed Central

    Hägerbäumer, Arne; Höss, Sebastian; Heininger, Peter; Traunspurger, Walter

    2015-01-01

    With respect to their high abundances, their role as intermediaries between microorganisms and higher trophic levels, and their ubiquitous occurrence in all habitats, nematodes are of strong potential interest as environmental indicators. Ecotoxicological methods to evaluate the risk of anthropogenic pollutants on ecosystems require both in vitro and in vivo toxicity tests to investigate either mechanisms or pathways of toxicity and to set accurate toxicity thresholds. For this, the interest in nematodes as model organisms in ecotoxicology increased over the past few decades and existing appropriate experimental methods are reviewed in this manuscript. An overview of the various existing ecotoxicological tools for nematodes, ranging from molecular laboratory methods to experimental model ecosystem approaches, and their role as indicator organisms is given. The reviewed studies, approaches that range from species-based to community-based methods, reveal exciting possibilities for the future use of nematodes in ecotoxicological studies. Suitable ecotoxicological tools and ecological indices for nematodes should be integrated in weight-of-evidence approaches for assessing the ecological risk of contamination. PMID:25861113

  16. Organic and Inorganic Nitrogen Amendments to Soil as Nematode Suppressants

    PubMed Central

    Rodríguez-Kábana, R.

    1986-01-01

    Inorganic fertilizers containing ammoniacal nitrogen or formulations releasing this form of N in the soil are most effective for suppressing nematode populations. Anhydrous ammonia has been shown to reduce soil populations of Tylenchorhynchus claytoni, Helicotylenchus dihystera, and Heterodera glycines. The rates required to obtain significant suppression of nematode populations are generally in excess of 150 kg N/ha. Urea also suppresses several nematode species, including Meloidogyne spp., when applied at rates above 300 kg N/ha. Additional available carbon must be provided with urea to permit soil microorganisms to metabolize excess N and avoid phytotoxic effects. There is a direct relation between the amount of "protein" N in organic amendments and their effectiveness as nematode population suppressants. Most nematicidal amendments are oil cakes, or animal excrements containing 2-7% (w:w) N; these materials are effective at rates of 4-10 t/ha. Organic soil amendments containing mucopolysaccharides (e.g., mycelial wastes, chitinous matter) are also effective nematode suppressants. PMID:19294153

  17. 78 FR 1713 - Golden Nematode; Removal of Regulated Areas in Livingston and Steuben Counties, NY

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-01-09

    ... The golden nematode (Globodera rostochiensis) is a destructive pest of potatoes and other solanaceous plants. Potatoes cannot be economically grown on land that contains large numbers of the nematode. The... total of 262,847 acres. Golden nematode is a major pest of potato plants and also attacks...

  18. Root knot nematode effects on metabolic profiles of susceptible and resistant grapevine rootstocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root knot nematodes (Meloidogyne spp.) can negatively impact newly planted and stressed vineyards. Nematode infestations also may increase grapevine susceptibility to other stresses such as water deficit or various diseases. However, little is known about direct or indirect effects of nematode feedi...

  19. First report of the root-lesion nematode Pratylenchus neglectus on wheat in North Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root-lesion nematodes (Pratylenchus spp.) are important nematode pests that invade roots of plants and restrict productivity of wheat. In August 2015, a soil sample was collected from a harvested wheat field in Walsh County, ND and was found to contain 1,044 root-lesion nematodes per kg of soil usin...

  20. Mechanisms of molecular mimicry of plant CLE peptide ligands by the parasitic nematode Globodera rostochiensis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes that parasitize plant roots cause huge economic losses and have few mechanisms for control. Many parasitic nematodes infect plants by reprogramming root development to drive the formation of feeding structures. How nematodes take control of plant development is largely unknown. The CLE ...

  1. Discovery and virulence-screening of native nematodes in Wisconsin cranberries

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Three newly discovered entomopathogenic nematodes have been recovered from wild Wisconsin cranberry marshes. All three nematode strains have been shown to attack Sparganothis Fruitworm (SFW), and all seem similar in their virulence (ability to kill the host). Only one nematode line, however, has bee...

  2. Occurence of phytoparasitic nematodes associated with some crop plants in Northern Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information concerning the occurrence and distribution of phytoparasitic nematodes in Egypt is very important for agricultural production. A nematode survey was conducted in northern Egypt to identify the genera and species of phytoparasitic nematodes associated with some crop plants. A total of 240...

  3. Molecular and morphological characterization of the corn cyst nematode, Heterodera zeae, from Greece

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The corn cyst nematode Heterodera zeae was first detected in India, where it has wide distribution. This nematode has also been reported from Pakistan, Egypt, Thailand, Nepal, the United States, and Portugal. There is limited information regarding nematodes attacking cereals in Greece, and thus far ...

  4. Chemical ecology and isolation of biologically active compounds from parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root knot nematodes (Meloidogyne spp) are possibly the economically most important and best-studied species of plant parasitic nematodes. However, for Meloidogyne spp and the intensely studied nematode, Caenorhabditis elegans, very little is known about signaling within and in-between species. It h...

  5. A SNARE-like protein and biotin are implicated in soybean cyst nematode virulence

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Some phytoparasitic nematodes have the ability to infect and reproduce on plants that are normally considered resistant to nematode infection. Such nematodes are referred to as virulent and the mechanisms they use to evade or suppress host plant defenses are not well understood. Here, we report the ...

  6. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 7 Agriculture 5 2012-01-01 2012-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  7. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 7 Agriculture 5 2010-01-01 2010-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  8. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 7 Agriculture 5 2014-01-01 2014-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  9. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 7 Agriculture 5 2011-01-01 2011-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  10. 7 CFR 301.85-9 - Movement of live golden nematodes.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 7 Agriculture 5 2013-01-01 2013-01-01 false Movement of live golden nematodes. 301.85-9 Section... INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE DOMESTIC QUARANTINE NOTICES Golden Nematode Quarantine and Regulations § 301.85-9 Movement of live golden nematodes. Regulations requiring a permit for and...

  11. New germplasm lines with high yield and fiber quality combined with nematode resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The lines BAR-8, -11, -13, -25, -33, -41, and -48 were developed to have both resistance to nematodes and superior yield and quality. All have resistance to reniform nematodes derived from G. barbadense GB 713 and several carry the DNA marker for Mi1, the gene for resistance to root-knot nematodes....

  12. The development of RNA interference (RNAi) in gastrointestinal nematodes.

    PubMed

    Selkirk, Murray E; Huang, Stanley C; Knox, David P; Britton, Collette

    2012-04-01

    Despite the utility of RNAi for defining gene function in Caenorhabditis elegans and early successes reported in parasitic nematodes, RNAi has proven to be stubbornly inconsistent or ineffective in the animal parasitic nematodes examined to date. Here, we summarise some of our experiences with RNAi in parasitic nematodes affecting animals and discuss the available data in the context of our own unpublished work, taking account of mode of delivery, larval activation, site of gene transcription and the presence/absence of essential RNAi pathway genes as defined by comparisons to C. elegans. We discuss future directions briefly including the evaluation of nanoparticles as a means to enhance delivery of interfering RNA to the target worm tissue.

  13. Efficacy of extracts of immature mango on ovine gastrointestinal nematodes.

    PubMed

    Nery, Patrícia S; Nogueira, Flávia A; Oliveira, Neide J F; Martins, Ernane R; Duarte, Eduardo R

    2012-12-01

    The principal health problem in small ruminants is helminthiasis and the rapid development of nematode resistance to anthelminthics has limited the success of control in several countries, stimulating the search for alternatives. In this study, extracts of immature fruits of the mango Mangifera indica L. var Ubá were evaluated for inhibition of larval development and fecal egg count reduction in sheep naturally infected with gastrointestinal nematodes. In the phytochemical analyses, tannins and flavonoids were the metabolites identified. Aqueous extracts of immature fruits at 100 mg ml(-1) showed 100 % inhibition of larval development. The LC(90) of the extract was 35.9 mg ml(-1) and the in vivo anthelminthic efficacy at 0.740 g kg(-1) (BW, orally) was 53 %. The identification of larvae showed that 99.8 % were Haemonchus spp. In vitro and in vivo results indicate that this fruit could assist ovine nematode control.

  14. New Insights into the Mechanism of Fertilization in Nematodes

    PubMed Central

    Singaravelu, Gunasekaran; Singson, Andrew

    2012-01-01

    Fertilization results from the fusion of male and female gametes in all sexually reproducing organisms. Much of nematode fertility work was focused on Caenorhabditis elegans and Ascaris suum. The C. elegans hermaphrodite produces a limited number of sperm initially, and then commits to the exclusive production of oocytes. The post-meiotic differentiation called spermiogenesis converts sessile spermatids into motile spermatozoa. The motility of spermatozoa depends on dynamic assembly and disassembly of a MSP (Major Sperm Protein)-based cytoskeleton uniquely found in nematodes. Both self-derived and male-derived spermatozoa are stored in spermatheca, the site of fertilization in hermaphrodites. The oocytes are arrested in meiotic prophase I until a sperm derived signal relieves the inhibition allowing the meiotic maturation to occur. Oocyte undergoes meiotic maturation, enters into spermatheca, gets fertilized, completes meiosis and exits into uterus as a zygote. This review focuses on our current understanding of the events around fertilization in nematodes. PMID:21749902

  15. Natural Occurrence of Entomogenous Nematodes in Tennessee Nursery Soils

    PubMed Central

    Rueda, L. M.; Osawaru, S. O.; Georgi, L. L.; Harrison, R. E.

    1993-01-01

    To isolate potential insect biocontrol agents, entomogenous nematodes were surveyed in Tennessee plant nurseries in 1991. Soil samples from 113 nursery sites were baited with greater wax moth (Galleria mellonella) larvae, house cricket (Acheta domesticus) adults, lesser mealworm (Alphitobius diaperings) adults, and house fly (Musca domestica) larvae. Heterorhabditis bacteriophora and Steinernema carpocapsae were each recovered from 17 soil samples. Heterorhabditis bacteriophora was more common in habitats with crape myrtle (Lagerstroemia indica) and Chinese juniper (Juniperus chinensis) than other nursery plants, and S. carpocapsae was more frequently recovered from habitats with juniper and Southern magnolia (Magnolia grandiflora). Bulk density, electrical conductivity, organic matter, pH, temperature, and moisture content of the entomogenous-nematode positive soil samples were compared. Other nematode genera recovered with insect baits included Rhabditis sp., Pelodera sp., Cryptaphelenchoides sp., and Mesodiplogaster sp., which was recovered from a greater percentage of soil samples than the other five genera. PMID:19279756

  16. Meningomyelitis due to nematode infection in four cats.

    PubMed

    Gómez, M; Mieres, M; Moroni, M; Mora, A; Barrios, N; Simeone, C; Lindsay, D S

    2010-06-24

    Spinal cord parasitic migrations in cats are uncommon. This report describes four cases of chronic hindlimb paraparesis in cats associated with nematode infection. Complete neurologic, hematologic, serum chemistry and radiographic examination was performed on all animals. Computed tomographic (CT)-myelographic examination at the lumbar area in one cat showed a slight swelling of the spinal cord. Necropsy examination of the spinal cord revealed generalized edema and marked submeningeal hemorrhage at the thoracic region in three cats. On histopathologic examination, numerous sections of adult nematodes and eggs were present in histological sections of the affected spinal cord segments in all cats. The morphologic features of the nematode, location and appearance of the lesions suggest that the parasite responsible for the paralysis in these cats is Gurltia paralysans.

  17. Plant-Parasitic Nematodes in Maine Agricultural Soils

    PubMed Central

    Huettel, W N.; Francl, L. J.; Henn, A.; Bourgoin, T.

    1990-01-01

    In a survey of plant-parasitic nematodes associated with agricultural crops in nine Maine counties, 744 soil samples from 26 potential host plants were analyzed between November 1987 and January 1989. The most commonly encountered nematode genus was Pratylenchus, occurring in 85% of the samples from most crops, except blueberries and onions. Pratylenchus penetrans and P. crenatus were found commonly as species mixtures, with P. penetrans composing 40-80% of the mixture. Meloidogyne hapla was encountered in 16% of the samples in four counties, generally in potato rotations. Other nematodes encountered were Aphelenchoides spp., Criconemella curvature, Ditylenchus spp., Helicotylenchus pseudorobustus, H. digonicus, Heterodera trifolii, Paratylenchus projectus, Trichodorus spp., Tylenchorhynchus maximus, and Xiphinema americanum. Potato fields were the most heavily sampled and thus weighted the statewide results. PMID:19287791

  18. Infection with parasitic nematodes confounds vaccination efficacy.

    PubMed

    Urban, Joseph F; Steenhard, Nina R; Solano-Aguilar, Gloria I; Dawson, Harry D; Iweala, Onyinye I; Nagler, Cathryn R; Noland, Gregory S; Kumar, Nirbhay; Anthony, Robert M; Shea-Donohue, Terez; Weinstock, Joel; Gause, William C

    2007-08-19

    T helper (Th) cells produce signature cytokine patterns, induced largely by intracellular versus extracellular pathogens that provide the cellular and molecular basis for counter regulatory expression of protective immunity during concurrent infections. The production of IL-12 and IFN-gamma, for example, resulting from exposure to many bacterial, viral, and protozoan pathogens is responsible for Th1-derived protective responses that also can inhibit development of Th2-cells expressing IL-4-dependent immunity to extracellular helminth parasites and vice versa. In a similar manner, concurrent helminth infection alters optimal vaccine-induced responses in humans and livestock; however, the consequences of this condition have not been adequately studied especially in the context of a challenge infection following vaccination. Demands for new and effective vaccines to control chronic and emerging diseases, and the need for rapid deployment of vaccines for bio security concerns requires a systematic evaluation of confounding factors that limit vaccine efficacy. One common albeit overlooked confounder is the presence of gastrointestinal nematode parasites in populations of humans and livestock targeted for vaccination. This is particularly important in areas of the world were helminth infections are prevalent, but the interplay between parasites and emerging diseases that can be transmitted worldwide make this a global issue. In addition, it is not clear if the epidemic in allergic disease in industrialized countries substitutes for geohelminth infection to interfere with effective vaccination regimens. This presentation will focus on recent vaccination studies in mice experimentally infected with Heligmosomoides polygyrus to model the condition of gastrointestinal parasite infestation in mammalian populations targeted for vaccination. In addition, a large animal vaccination and challenge model against Mycoplasma hyopneumonia in swine exposed to Ascaris suum will provide

  19. Respiratory nematodes in cat populations of Italy.

    PubMed

    Di Cesare, Angela; Veronesi, Fabrizia; Grillotti, Eleonora; Manzocchi, Simone; Perrucci, Stefania; Beraldo, Paola; Cazzin, Stefania; De Liberato, Claudio; Barros, Luciano A; Simonato, Giulia; Traversa, Donato

    2015-12-01

    The occurrence of common respiratory parasites of domestic cats (the metastrongyloid "cat lungworm" Aelurostrongylus abstrusus and the trichuroid Capillaria aerophila) and of neglected respiratory nematodes of felids (Troglostrongylus brevior, Angiostrongylus chabaudi and Oslerus rostratus) was here evaluated in two and three geographical sites of Northern and Central Italy, respectively. In 2014-2015, individual fecal samples of 868 domestic cats were examined microscopically and genetically, and epidemiological data related to parasitic infections were evaluated as possible risk factors by binary logistic regression models. The most common parasite was A. abstrusus in both mono- and poli-specific infections, followed by T. brevior and C. aerophila, while cats scored negative for other parasites. Cats positive for A. abstrusus (1.9-17 % infection rate) and C. aerophila (0.9-4.8 % infection rate) were found in all examined sites, while cats scored positive for T. brevior (1-14.3 % infection rate) in four sites. Also, T. brevior was here found for the first time in a domestic cat from a mountainous area of Northern Italy. The occurrence of lungworms was statistically related to the presence of respiratory signs and more significant in cats with mixed infection by other lungworms and/or intestinal parasites. Cats living in site C of Central Italy resulted statistically more at risk of infection for lungworms than cats living in the other study sites, while animals ageing less than 1 year were at more risk for troglostrongylosis. Finally, the presence of lungworms was more significant in cats with mixed infection by other lungworms and/or intestinal parasites. These results are discussed under epidemiological and clinical points of views.

  20. Nematode Spatial and Ecological Patterns from Tropical and Temperate Rainforests

    PubMed Central

    Porazinska, Dorota L.; Giblin-Davis, Robin M.; Powers, Thomas O.; Thomas, W. Kelley

    2012-01-01

    Large scale diversity patterns are well established for terrestrial macrobiota (e.g. plants and vertebrates), but not for microscopic organisms (e.g. nematodes). Due to small size, high abundance, and extensive dispersal, microbiota are assumed to exhibit cosmopolitan distributions with no biogeographical patterns. This assumption has been extrapolated from local spatial scale studies of a few taxonomic groups utilizing morphological approaches. Recent molecularly-based studies, however, suggest something quite opposite. Nematodes are the most abundant metazoans on earth, but their diversity patterns are largely unknown. We conducted a survey of nematode diversity within three vertical strata (soil, litter, and canopy) of rainforests at two contrasting latitudes in the North American meridian (temperate: the Olympic National Forest, WA, U.S.A and tropical: La Selva Biological Station, Costa Rica) using standardized sampling designs and sample processing protocols. To describe nematode diversity, we applied an ecometagenetic approach using 454 pyrosequencing. We observed that: 1) nematode communities were unique without even a single common species between the two rainforests, 2) nematode communities were unique among habitats in both rainforests, 3) total species richness was 300% more in the tropical than in the temperate rainforest, 4) 80% of the species in the temperate rainforest resided in the soil, whereas only 20% in the tropics, 5) more than 90% of identified species were novel. Overall, our data provided no support for cosmopolitanism at both local (habitats) and large (rainforests) spatial scales. In addition, our data indicated that biogeographical patterns typical of macrobiota also exist for microbiota. PMID:22984536

  1. Viability and Virulence of Entomopathogenic Nematodes Exposed to Ultraviolet Radiation

    PubMed Central

    Shapiro-Ilan, David I.; Hazir, Selcuk; Lete, Luis

    2015-01-01

    Entomopathogenic nematodes (EPNs) can be highly effective biocontrol agents, but their efficacy can be reduced due to exposure to environmental stress such as from ultraviolet (UV) radiation. Our objectives were to 1) compare UV tolerance among a broad array of EPN species, and 2) investigate the relationship between reduced nematode viability (after exposure to UV) and virulence. Nematodes exposed to a UV radiation (254 nm) for 10 or 20 min were assessed separately for viability (survival) and virulence to Galleria mellonella. We compared 9 different EPN species and 15 strains: Heterorhabditis bacteriophora (Baine, fl11, Oswego, and Vs strains), H. floridensis (332), H. georgiana (Kesha), H. indica (HOM1), H. megidis (UK211), Steinernema carpocapsae (All, Cxrd, DD136, and Sal strains), S. feltiae (SN), S. rarum (17C&E), and S. riobrave (355). In viability assessments, steinernematids, particularly strains of S. carpocapsae, generally exhibited superior UV tolerance compared with the heterorhabditids. However, some heterorhabditids tended to be more tolerant than others, e.g., H. megidis and H. bacteriophora (Baine) were most susceptible and H. bacteriophora (Vs) was the only heterorhabditid that did not exhibit a significant effect after 10 min of exposure. All heterorhabditids experienced reduced viability after 20 min exposure though several S. carpocapsae strains did not. In total, after 10 or 20 min exposure, the viability of seven nematode strains did not differ from their non-UV exposed controls. In virulence assays, steinernematids (particularly S. carpocapsae strains) also tended to exhibit higher UV tolerance. However, in contrast to the viability measurements, all nematodes experienced a reduction in virulence relative to their controls. Correlation analysis revealed that viability among nematode strains is not necessarily related to virulence. In conclusion, our results indicate that the impact of UV varies substantially among EPNs, and viability alone

  2. Nematicidal Bacteria Associated to Pinewood Nematode Produce Extracellular Proteases

    PubMed Central

    Francisco, Romeu; Verissimo, Paula; Santos, Susana S.; Fonseca, Luís; Abrantes, Isabel M. O.; Morais, Paula V.

    2013-01-01

    Bacteria associated with the nematode Bursaphelenchus xylophilus, a pathogen of trees and the causal agent of pine wilt disease (PWD) may play a role in the disease. In order to evaluate their role (positive or negative to the tree), strains isolated from the track of nematodes from infected Pinus pinaster trees were screened, in vitro, for their nematicidal potential. The bacterial products, from strains more active in killing nematodes, were screened in order to identify and characterize the nematicidal agent. Forty-seven strains were tested and, of these, 21 strains showed capacity to produce extracellular products with nematicidal activity. All Burkholderia strains were non-toxic. In contrast, all Serratia strains except one exhibited high toxicity. Nematodes incubated with Serratia strains showed, by SEM observation, deposits of bacteria on the nematode cuticle. The most nematicidal strain, Serratia sp. A88copa13, produced proteases in the supernatant. The use of selective inhibitors revealed that a serine protease with 70 kDa was majorly responsible for the toxicity of the supernatant. This extracellular serine protease is different phylogenetically, in size and biochemically from previously described proteases. Nematicidal assays revealed differences in nematicidal activity of the proteases to different species of Bursaphelenchus, suggesting its usefulness in a primary screen of the nematodes. This study offers the basis for further investigation of PWD and brings new insights on the role bacteria play in the defense of pine trees against B. xylophilus. Understanding all the factors involved is important in order to develop strategies to control B. xylophilus dispersion. PMID:24244546

  3. An evolutionary perspective on gastrointestinal nematodes of sheep.

    PubMed

    Stear, M J; Singleton, D; Matthews, L

    2011-06-01

    The purpose of this paper was to discuss from an evolutionary perspective the interaction between domestic sheep (Ovis aries) and their gastrointestinal nematodes. Although evolution is the central theme of biology, there has been little attempt to consider how evolutionary forces have shaped and continue to shape the relationships between domestic animals and their parasite community. Mathematical modelling of the host-parasite relationship indicated that the system is remarkably robust to perturbations in its parameters. This robustness may be a consequence of the long coevolution of host and parasites. Although nematodes can potentially evolve faster than the host, coevolution is not dominated by the parasite and there are several examples where breeds of cattle or sheep have evolved high levels of resistance to disease. Coevolution is a more equal partnership between host and nematode than is commonly assumed. Coevolution between parasites and the host immune system is often described as an arms race where both host immune response genes and parasite proteins evolve rapidly in response to each other. However, initial results indicate that nematode antigens are not evolving rapidly; the arms race between the immune system and nematodes, if it exists, is happening very slowly. Fisher's fundamental theorem of natural selection states that genes with positive effects on fitness will be fixed by natural selection. Consequently, heritable variation in fitness traits is expected to be low. Contrary to this argument, there is considerable genetic variation in resistance to nematode infection. In particular, the heritabilities of nematode-specific IgA and IgE activity are moderate to high. The reasons for this apparent violation of the fundamental theorem of natural selection are not clear but several possible explanations are explored. Faecal nematode egg counts increase at the beginning of the grazing season - a phenomenon known as the periparturient rise. This

  4. Statistical and Economic Techniques for Site-specific Nematode Management.

    PubMed

    Liu, Zheng; Griffin, Terry; Kirkpatrick, Terrence L

    2014-03-01

    Recent advances in precision agriculture technologies and spatial statistics allow realistic, site-specific estimation of nematode damage to field crops and provide a platform for the site-specific delivery of nematicides within individual fields. This paper reviews the spatial statistical techniques that model correlations among neighboring observations and develop a spatial economic analysis to determine the potential of site-specific nematicide application. The spatial econometric methodology applied in the context of site-specific crop yield response contributes to closing the gap between data analysis and realistic site-specific nematicide recommendations and helps to provide a practical method of site-specifically controlling nematodes.

  5. Stacking resistance to crown gall and nematodes in walnut rootstocks

    PubMed Central

    2013-01-01

    Background Crown gall (CG) (Agrobacterium tumefaciens) and the root lesion nematodes (RLNs) (Pratylenchus vulnus) are major challenges faced by the California walnut industry, reducing productivity and increasing the cost of establishing and maintaining orchards. Current nematode control strategies include nematicides, crop rotation, and tolerant cultivars, but these methods have limits. Developing genetic resistance through novel approaches like RNA interference (RNAi) can address these problems. RNAi-mediated silencing of CG disease in walnut (Juglans regia L.) has been achieved previously. We sought to place both CG and nematode resistance into a single walnut rootstock genotype using co-transformation to stack the resistance genes. A. tumefaciens, carrying self-complimentary iaaM and ipt transgenes, and Agrobacterium rhizogenes, carrying a self-complimentary Pv010 gene from P. vulnus, were used as co-transformation vectors. RolABC genes were introduced by the resident T-DNA in the A. rhizogenes Ri-plasmid used as a vector for plant transformation. Pv010 and Pv194 (transgenic control) genes were also transferred separately using A. tumefaciens. To test for resistance, transformed walnut roots were challenged with P. vulnus and microshoots were challenged with a virulent strain of A. tumefaciens. Results Combining the two bacterial strains at a 1:1 rather than 1:3 ratio increased the co-transformation efficiency. Although complete immunity to nematode infection was not observed, transgenic lines yielded up to 79% fewer nematodes per root following in vitro co-culture than untransformed controls. Transgenic line 33-3-1 exhibited complete crown gall control and 32% fewer nematodes. The transgenic plants had thicker, longer roots than untransformed controls possibly due to insertion of rolABC genes. When the Pv010 gene was present in roots with or without rolABC genes there was partial or complete control of RLNs. Transformation using only one vector showed 100

  6. ORGANIC VS CONVENTIONAL: SOIL NEMATODE COMMUNITY STRUCTURE AND FUNCTION.

    PubMed

    Kapp, C; Storey, S G; Malan, A P

    2014-01-01

    Global increases in human population are creating an ever-greater need for food production. Poor soil management practices have degraded soil to such an extent that rapidly improved management practices is the only way to ensure future food demands. In South Africa, deciduous fruit producers are realising the need for soil health, and for an increased understanding of the benefits of soil ecology, to ensure sustainable fruit production. This depends heavily on improved orchard management. Conventional farming relies on the addition of artificial fertilizers, and the application of chemicals, to prevent or minimise, the effects of the soil stages of pest insects, and of plant-parasitic nematodes. Currently, there is resistance toward conventional farming practices, which, it is believed, diminishes biodiversity within the soil. The study aimed to establish the soil nematode community structure and function in organically, and conventionally, managed deciduous fruit orchards. This was done by determining the abundance, the diversity, and the functionality of the naturally occurring free-living, and plant-parasitic, nematodes in deciduous fruit orchards in the Western Cape province of South Africa. The objective of the study was to form the basis for the use of nematodes as future indicators of soil health in deciduous fruit orchards. Orchards from neighbouring organic, and conventional, apricot farms, and from an organic apple orchard, were studied. All the nematodes were quantified, and identified, to family level. The five nematode-classified trophic groups were found at each site, while 14 families were identified in each orchard, respectively. Herbivores were dominant in all the orchards surveyed. Organic apples had the fewest herbivores and fungivores, with the highest number of carnivores. When comparing organic with conventional apricot orchards, higher numbers of plant-parasitic nematodes were found in the organic apricot orchards. The Maturity Index (MI

  7. Commercial Development and Future Prospects for Entomogenous Nematodes

    PubMed Central

    Petersen, J. J.; Cupello, J. M.

    1981-01-01

    Although entomogenous nenmtodes generally have many of the attributes of the ideal biocontrol agent, many of these attributes make the nematodes less than desirable for commercial production. Environmental limitations, lack of patent protection, "shelf life," shipping problems, and the need for users to receive specialized training are factors that have discouraged the involvement of larger companies. The future of these nematodes as commercially available biocontrol products appears to lie with the smaller "cottage industries" or with government-subsidized production. Problems encountered with attempts to produce commercially the mosquito parasite Romanomermis culicivorax are discussed. PMID:19300763

  8. Comparative SDS-page protein patterns of four ascaridid nematodes.

    PubMed

    Ashour, A A; Taha, H A; Mohammad A el-H

    1995-12-01

    In order to investigate the degree of homogeneity and heterogeneity of the ascaridid nematodes. Toxascaris leonina, Parascaris equorum, Toxocara canis and T. vitulorum, protein extracts from adult worms of the four nematodes were resolved into a number of bands. Comparative analysis of dominant bands showed that 13 bands were common among the four species, but certain unique bands were also found in each species including 4 in T. vitulorum, one in T. leonina, two in T. canis, while P. equorum shares both T. canis and T. leonina in most of their bands. Among the four ascaridid studied, T. vitulorum appears to be the most divergent species.

  9. Studies onPaecilomyces marquandii from nematode suppressive chinampa soils.

    PubMed

    Marban-Mendoza, N; Garcia-E, R; Dicklow, M B; Zuckerman, B M

    1992-05-01

    Two applications of isolates ofPaecilomyces marquandii from suppressive chinampa soils or P. lilacinus from Peru, fungi that parasitize nematode eggs, generally gave better control of tomato root-knot due toMeloidogyne incognita than did a single application. The effects on root galling by each of thePaecilomyces isolates varied between experiments; however, the ovicidal potential of the three isolates did not differ significantly. Proteins specific for each of the isolates were demonstrated by SDS gel electrophoresis. The results indicate thatP. marquandii is one of the natural soil organisms that contribute to nematode suppression in the chinampa agricultural soils.

  10. A Simple Method to Measure Nematodes' Propulsive Thrust and the Nematode Ratchet.

    NASA Astrophysics Data System (ADS)

    Bau, Haim; Yuan, Jinzhou; Raizen, David

    2015-11-01

    Since the propulsive thrust of micro organisms provides a more sensitive indicator of the animal's health and response to drugs than motility, a simple, high throughput, direct measurement of the thrust is desired. Taking advantage of the nematode C. elegans being heavier than water, we devised a simple method to determine the propulsive thrust of the animals by monitoring their velocity when swimming along an inclined plane. We find that the swimming velocity is a linear function of the sin of the inclination angle. This method allows us to determine, among other things, the animas' propulsive thrust as a function of genotype, drugs, and age. Furthermore, taking advantage of the animals' inability to swim over a stiff incline, we constructed a sawteeth ratchet-like track that restricts the animals to swim in a predetermined direction. This research was supported, in part, by NIH NIA Grant 5R03AG042690-02.

  11. Nematodes from terrestrial, freshwater and brackish water habitats in Belgium: an updated list with special emphasis on compost nematodes.

    PubMed

    Steel, Hanne; Coomans, August; Decraemer, Wilfrida; Moens, Tom; Bert, Wim

    2014-02-17

    A study of nematodes from a semi-artificial and controlled composting process in Eastern Flanders revealed 35 taxa, 21 of which were new records for Belgium. An updated checklist of free-living, plant-parasitic and entomopathogenic nematodes from terrestrial, freshwater and brackish water habitats in Belgium is presented. The Belgian non-marine nematofauna comprises 418 taxa, representing 4 subclasses, 14 orders, and 76 families. In total 127 new records were added: i.e. 21 from the newly explored compost habitat, 7 from freshwater samples and 99 from published data in literature.

  12. Nematode community structure and diversity pattern in sandy beaches of Qingdao, China

    NASA Astrophysics Data System (ADS)

    Hua, Er; Mu, Fanghong; Zhang, Zhinan; Yang, Shichao; Zhang, Ting; Li, Jia

    2016-02-01

    We investigated the diversity and structure of free-living marine nematode communities at three sandy beaches representing typical intertidal environments of a temperate zone in Qingdao, Shandong Province, China. Average nematode abundance ranged from 1006 to 2170 ind. 10 cm-2, and a total of 34 nematode genera were recorded, of which only 8 were common in all the studied beaches. Pielou's evenness and Shannon-Wiener diversity index were the lowest at the second beach where nematode abundance was the highest. The highest species diversity index coincided with the lowest nematode abundance at Shilaoren beach. Sediment median grain size, sorting coefficient, and chlorophyll-a content were essential for differentiation in nematode abundance and species diversity, whereas taxonomic diversity of nematode was homogeneous across the three beaches. In 0-20 cm sediment profile, nematode abundance declined abruptly with depth, whereas nematode diversity changed gently with obvious difference in 16-20 cm layer. Sediment granulometry and chlorophyll- a content were the two foremost factors which influenced the vertical distribution pattern of nematode generic diversity. Non-selective deposit feeders constituted the most dominant trophic group, followed by epistratum feeders. Bathylaimus (family: Tripyloididae) dominated at the second and Yangkou beach, while Theristus (family: Xyalidae) prevailed at Shilaoren beach. Omnivores and predators became important at Shilaoren beach because of the high proportion of Enoplolaimus. Even though, nematode community of the studied beaches did not differ significantly from each other.

  13. Stem nematode counteracts plant resistance of aphids in alfalfa, Medicago sativa.

    PubMed

    Ramirez, Ricardo A; Spears, Lori R

    2014-10-01

    Plants are exploited by a diverse community of insect herbivores and phytopathogens that interact indirectly through plant-mediated interactions. Generally, plants are thought to respond to insects and pathogens through different defensive signaling pathways. As plants are selected for resistance to one phytophagous organism type (insect vs. pathogen) in managed systems, it is not clear how this selection may affect community interactions. This study examined the effect of nematode-resistant varieties on aphid (Acyrthosiphon pisum) suppression, and then determined how infection by the stem nematode, Ditylenchus dipsaci, mediated ecological effects on aphids and on plant defense proteins. Four alfalfa (Medicago sativa) varieties were selected with resistance to nematodes only (+,-), aphids only (-,+), nematodes and aphids (+,+), and susceptibility to nematodes and aphids (-,-). Field and greenhouse experiments were conducted to isolate the effect of nematode infection and aphid abundance on each variety. We found that varieties resistant to nematode, regardless of aphid resistance, had the lowest aphid counts, suggesting possible cross-resistance. Aphid abundance, however, increased when plants were exposed to nematodes. Resistant varieties were associated with elevated saponins but these compounds were not affected by insect or pathogen feeding. Concentrations of peroxidases and trypsin inhibitors, however, were increased in nematode resistant varieties when exposed to nematodes and aphids, respectively. The patterns of plant defense were variable, and a combination of resistance traits and changes in nutrient availability may drive positive interactions between nematodes and aphids aboveground.

  14. Genome Similarity Implies that Citrus-Parasitic Burrowing Nematodes do not Represent a Unique Species.

    PubMed

    Kaplan, D T; Opperman, C H

    1997-12-01

    Burrowing nematodes from Central America, Dominican Republic, Florida, Guadeloupe, Hawaii, and Puerto Rico were characterized for their ability to parasitize citrus, but citrus parasites were found only in Florida. Sequence tag sites originally amplified from a citrus-parasitic burrowing nematode were polymorphic among 37 burrowing nematode isolates and were not correlated with citrus parasitism, nematode isolate collection site, or amplification of a 2.4-kb sequence tag site (DK#1). Results of a RAPD analysis and characterization of the isozymes phosphoglucose isomerase, lactate dehydrogenase, and malate dehydrogenase indicated that the burrowing nematode isolates were highly similar. Citrus parasitism in Florida appears to be associated with limited changes in the burrowing nematode genome. Findings did not substantiate a previous report that R. citrophilus was present in Hawaii. Overall, these data do not support assignment of sibling species status to burrowing nematodes that differ with respect to citrus parasitism.

  15. The Pumping Mechanism of the Nematode Esophagus

    PubMed Central

    Saunders, J. Richard; Burr, A. H.

    1978-01-01

    The radial orientation of the myofilaments in the nematode esophagus raises interesting questions as to how such a structure can function as a pump. A physical model of the esophagus of Ascaris lumbricoides was developed and the membrane theory of shells applied in order to relate the observed dimensional changes to myofilament force, pressure stresses, and membrane elastic constants. By stressing the excised esophagus passively with osmotic pressure, the esophagus was shown to be elastically anisotropic with the ratio of circumferential to longitudinal elastic constants, Eψ/El ≃ 2.74. When this value was incorporated, the model predicted the ratio of the respective strains, εψ/εl, to be 0.52 during an equilibrium contraction of the esophagus. This agreed with the experimental value, 0.46 ± 0.10, measured during occasional, prolonged muscle contractions. When measured during normal pumping, on the other hand, the value of εψ/εl was 0 ± 0.10. This indicated that a nonequilibrium condition normally occurs in which a greater myofilament force per unit area of lumen membrane is not balanced by internal pressure and therefore acceleration of the lumen contents and negative intraluminal pressure occurs. The pumping action of esophagi dissected from Ascaris was observed to be normally peristaltic and periodic. Contraction was initiated by a spontaneous depolarization that propagated at 4.0 ± 0.20 cm/s along the esophageal membrane. A wave of localized increases in the internal pressure of the muscle and localized changes in external dimensions was observed. A subsequent spontaneous repolarization, which propagated at 5.8 ± 0.23 cm/s, triggered relaxation of the muscle during which the localized pressure and dimensional changes returned to resting values. A mechanism was deduced in which fluid is drawn into and moved along the lumen by the wave of contraction. During the wave of relaxation, the lumen contents are pressurized and injected into the intestine by

  16. Doramectin efficacy against gastrointestinal nematodes in pigs.

    PubMed

    Stewart, T B; Fox, M C; Wiles, S E

    1996-11-01

    Four controlled trials with growing pigs were performed to determine efficacy of doramectin against natural and induced populations of nematodes. In Trial 1 (T1), 20 pigs with natural infections were assigned to one of two like groups on the basis of weight, sex and worm egg counts. In Trial 2 (T2), 20 pigs with negative worm egg counts were assigned to one of two groups on the basis of weight and sex. Each pig was subsequently given (per os) 3000 Trichuris suis embryonated eggs; 2000 Ascaris suum embryonated eggs; 10000 Oesophagostomum spp. infective larvae and 10,000 Strongyloides ransomi infective larvae (SC injection). In Trial 3 (T3), 20 pigs with negative worm egg counts were assigned as in T2, and each pig was subsequently given (per os) 2000 A. suum embryonated eggs, 15000 Oesophagostomum quadrispinulatum infective larvae, and 2891 Hyostrongylus rubidus infective larvae. In Trial 4 (T4), 16 pigs with negative worm egg counts were each assigned to one of two groups as in T2 and were given (per os) 2670 T. suis embryonated eggs. On Day 0 of each trial, each pig of the control group was injected IM in the neck with sterile saline at the rate of 1.5 ml 50 kg-1. Each pig in the treated group of each trial was similarly injected with doramectin at the rate of 300 micrograms kg-1. All pigs were necropsied 14 or 15 days post-treatment and parasites recovered by standard parasitological procedures. Efficacies against natural infections were: A. suum, 100%; Oesophagostomum spp. 100%; H. rubidus, 99.4%; and Strongyloides ransomi, 99.9%. Efficacies against induced infections were: 4th stage A. suum, 100%; 4th stage O.dentatum, 99.9%; 4th stage O.quadrispinulatum, 97.1 and 99.6%; 4th stage H. rubidus, 100%; adult S. ransomi, 100%; adult Trichuris suis in mixed infection, 54.1%; and in pure infection, 95.3%.

  17. Herbal dewormer fails to control gastrointestinal nematodes in goats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal nematode (GIN) parasitism is the most important disease of small ruminants. Control is usually based on the use of chemical anthelmintics (dewormers); but these are prohibited from use in organic livestock, and the effectiveness of chemical anthelmintics in conventional operations ...

  18. Garlic exhibits lack of control over gastrointestinal nematodes in goats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Gastrointestinal nematodes (GIN) continue to hinder small ruminant production because of anthelmintic resistance and lack of effective products for GIN control in organic production. The objective of this study was to examine the effectiveness of a commercially available certified organic garlic pr...

  19. Grazing sericea lespedeza for control of gastrointestinal nematodes in lambs

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Alternatives to chemical dewormers are needed to counter anthelmintic resistance and improve organic management systems. The objective was to examine the effectiveness of grazing sericea lespedeza (SL) compared with grass pastures for control of gastrointestinal nematodes (GIN) in lambs. In Experi...

  20. Detecting Microbial Nucleic Acids within Nematode Bodies: A Photo Essay

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We developed a taxa-specific, fluorescence in situ hybridization (FISH) technique to localize microbial nucleic acids within nematode bodies. This technique involves hybridization of a nucleic acid probe to target microbial sequences. Hybridization is detected microscopically, as the probes have f...

  1. 75 FR 54592 - Pale Cyst Nematode; Update of Quarantined Areas

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-08

    ... INFORMATION: Background The pale cyst nematode (PCN, Globodera pallida) is a major pest of potato crops in... some weeds. The PCN is thought to have originated in Peru and is now widely distributed in many potato-growing regions of the world. PCN infestations may be expressed as patches of poor growth. Affected...

  2. Rooting out Defense Mechanisms in Wheat against Plant Parasitic Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Root-lesion nematodes (Pratylenchus spp.) are soil borne pathogens of many important agricultural crops including wheat. Pratylenchus invade root cells and feed using a stylet, resulting in cell death. Common signs of Pratylenchus damage are root lesions, girdling, and lack of lateral branching. ...

  3. Response of Pinus ponderosa Seedlings to Stylet-Bearing Nematodes

    PubMed Central

    Viglierchio, D. R.

    1979-01-01

    Of 12 stylet-bearing nematodes used for inoculations, Pratylenchus penetrans, P. brachyurus, P. vulnus, Ditylenchus destructor, Meloidogyne incognita, M. javanica, and M. hapla reproduced on Pinus ponderosa, while Xiphinema index, Aphelenchus avenae, Paratylenehus neoamblycephalus, Tylenchulus semipenetrans, and Macroposthonia xenoplax did not. P. vulnus, P. brachyurus, P. penetrans, A. avenae, D. destructor, T. semipenetrans, and P. neoamblycephalus significantly suppressed both the shoot and root wet weights of ponderosa pine seedlings obtained from stands in five different locations. X. index significantly suppressed root wet weights, M. xenoplax siguificantly suppressed shoot wet weight, and M. incognita, M. javanica, and M. hapla suppressed neither at the inoculation levels used. Injurious nematodes tended to suppress root growth more than shoot growth. Seedlings from two locations produced greater shoot growth wet weight than did seedlings from the other three locations. The more injurious nematodes tended to cause an increase in the water content of shoots. Frequency analyses of seedling population shoot-root ratios indicated that ponderosa pine seedlings could be selected for better shoot-root ratios as well as for resistance to several pathogenic nematodes. PMID:19300659

  4. Evolutionary history of nematodes associated with sweat bees.

    PubMed

    McFrederick, Quinn S; Taylor, Douglas R

    2013-03-01

    Organisms that live in close association with other organisms make up a large part of the world's diversity. One driver of this diversity is the evolution of host-species specificity, which can occur via reproductive isolation following a host-switch or, given the correct circumstances, via cospeciation. In this study, we explored the diversity and evolutionary history of Acrostichus nematodes that are associated with halictid bees in North America. First, we conducted surveys of bees in Virginia, and found six halictid species that host Acrostichus. To test the hypothesis of cospeciation, we constructed phylogenetic hypotheses of Acrostichus based on three genes. We found Acrostichus puri and Acrostichus halicti to be species complexes comprising cryptic, host-specific species. Although several nodes in the host and symbiont phylogenies were congruent and tests for cospeciation were significant, the host's biogeography, the apparent patchiness of the association across the host's phylogeny, and the amount of evolution in the nematode sequence suggested a mixture of cospeciation, host switching, and extinction events instead of strict cospeciation. Cospeciation can explain the relationships between Ac. puri and its augochlorine hosts, but colonization of Halictus hosts is more likely than cospeciation. The nematodes are vertically transmitted, but sexual transmission is also likely. Both of these transmission modes may explain host-species specificity and congruent bee and nematode phylogenies. Additionally, all halictid hosts come from eusocial or socially polymorphic lineages, suggesting that sociality may be a factor in the suitability of hosts for Acrostichus.

  5. Genome-scale evidence of the nematode-arthropod clade

    PubMed Central

    Dopazo, Hernán; Dopazo, Joaquín

    2005-01-01

    Background The issue of whether coelomates form a single clade, the Coelomata, or whether all animals that moult an exoskeleton (such as the coelomate arthropods and the pseudocoelomate nematodes) form a distinct clade, the Ecdysozoa, is the most puzzling issue in animal systematics and a major open-ended subject in evolutionary biology. Previous single-gene and genome-scale analyses designed to resolve the issue have produced contradictory results. Here we present the first genome-scale phylogenetic evidence that strongly supports the Ecdysozoa hypothesis. Results Through the most extensive phylogenetic analysis carried out to date, the complete genomes of 11 eukaryotic species have been analyzed in order to find homologous sequences derived from 18 human chromosomes. Phylogenetic analysis of datasets showing an increased adjustment to equal evolutionary rates between nematode and arthropod sequences produced a gradual change from support for Coelomata to support for Ecdysozoa. Transition between topologies occurred when fast-evolving sequences of Caenorhabditis elegans were removed. When chordate, nematode and arthropod sequences were constrained to fit equal evolutionary rates, the Ecdysozoa topology was statistically accepted whereas Coelomata was rejected. Conclusions The reliability of a monophyletic group clustering arthropods and nematodes was unequivocally accepted in datasets where traces of the long-branch attraction effect were removed. This is the first phylogenomic evidence to strongly support the 'moulting clade' hypothesis. PMID:15892869

  6. Induction of Tolerance to Root-Knot Nematode by Oxycom

    PubMed Central

    Anwar, Safdar A.; McKenry, M. V.; Yang, Kwang-Yeol; Anderson, A. J.

    2003-01-01

    Oxycom applications increased plant growth and population levels of Meloidogyne incognita on susceptible tomato. A single Oxycom drench at 2,500 ppm applied 7 days prior to inoculation with M. incognita provided remediation of plant growth measured 63 days later. This occurred without reducing nematode population levels. Follow-up drenches at 2,500 ppm at 10-day intervals stunted shoots and roots (P = 0.05). The same application rates at 20-day intervals did not reduce plant growth. Plants receiving multiple drenches had more galls (P = 0.05), females, and second-stage juveniles (J2) per root system compared to plants receiving only the single treatment. Foliar mass and height of plants treated with a single pre-inoculation Oxycom drench were indistinguishable from plants without nematodes. Oxycom treatments activated signaling pathways for plant defense as confirmed by detection of elevated defense gene transcripts in root tissues. The finding of increased reproduction of root-knot nematode without loss of plant growth is consistent with the definition of induced tolerance. Frequency, rate, and timing of applications need further study with other nematodes and various field settings. PMID:19262766

  7. Root-Knot Nematode Parasitism Suppresses Host RNA Silencing.

    PubMed

    Walsh, E; Elmore, J M; Taylor, C G

    2017-04-12

    Root-knot nematodes damage crops around the world by developing complex feeding sites from normal root cells of their hosts. The ability to initiate and maintain this feeding site (composed of individual "giant cells") is essential to their parasitism process. RNA silencing pathways in plants serve a diverse set of functions, from directing growth and development to defending against invading pathogens. Influencing a host's RNA silencing pathways as a pathogenicity strategy has been well-documented for viral plant pathogens, but recently, it has become clear that silencing pathways also play an important role in other plant pathosystems. To determine if RNA silencing pathways play a role in nematode parasitism, we tested the susceptibility of plants that express a viral suppressor of RNA silencing. We observed an increase in susceptibility to nematode parasitism in plants expressing viral suppressors of RNA silencing. Results from studies utilizing a silenced reporter gene suggest that active suppression of RNA silencing pathways may be occurring during nematode parasitism. With these studies, we provide further evidence to the growing body of plant-biotic interaction research that suppression of RNA silencing is important in the successful interaction between a plant-parasitic animal and its host.

  8. Dietary copper sulfate for control of gastrointestinal nematodes in goats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Prevalence of anthelmintic resistance in goats has necessitated studies for alternative means of gastrointestinal nematode (GIN) control. The objective was to determine the effectiveness of dietary copper sulfate for control of GIN in meat goats. Naturally infected buck kids received 0 (LC), 78 (M...

  9. Radiation Effects on Nematodes: Results from IML-1 Esperiments

    NASA Technical Reports Server (NTRS)

    Nelson, G. A.; Schubert, W. W.; Kazarians, G. A.; Righards, G. F.; Benton, E. V; Benton, E. R.; Henke, R.

    1993-01-01

    The nematode Caenorhabditis elegans was exposed to natural space radiation using the ESA Biorack facility aboard Spacelab on International Microgravity Laboratory 1, STS-42. For the major experimental objective dormant animals were suspended in buffer or on agar or immobilized next to CR-39 plactic nuclear track detectors to correlate fluence of HZE particles with genetic events.

  10. Mermithid Nematodes: Physiological Relationships with their Insect Hosts

    PubMed Central

    Gordon, Roger

    1981-01-01

    This paper assesses our state of knowledge of physiological processes involved in the relationships between insects and their mermithid nematode parasites. Three major components of the host-parasite relationship(s) are reviewed: effects of mermithids on host physiology, effects of host physiology on mermithids, and the physiology of the nematodes themselves. Mermithids induce an array of changes in host physiology, and the effects on host metabolism and endocrinology are discussed at some length. Few studies have been done to ascertain the effects of the host on the parasites from a physiological standpoint. Whereas host immunity mechanisms against mermithids have been described at the ultrastructural level, the physiological basis of such responses is not known. Mermithids are atypical nematodes, both structurally and physiologically. In the absence of a functional gut, nutrients are absorbed across the outer cuticle and stored in a trophosome. The transcuticular mode of feeding, storage within the trophosome, and metabolism of storage products are discussed. The usefulness of physiological information toward expediting in vitro culture of these nematodes is discussed, and problems that need to be addressed are defined. PMID:19300761

  11. Efficient nematode swimming in a shear thinning colloidal suspension.

    PubMed

    Park, Jin-Sung; Kim, Daeyeon; Shin, Jennifer H; Weitz, David A

    2016-02-14

    The swimming behavior of a nematode Caenorhabditis elegans (C. elegans) is investigated in a non-Newtonian shear thinning colloidal suspension. At the onset value (ϕ∼ 8%), the suspension begins to exhibit shear thinning behavior, and the average swimming speed of worms jumps by approximately 12% more than that measured in a Newtonian solution exhibiting no shear dependent viscosity. In the shear thinning regime, we observe a gradual yet significant improvement in swimming efficiency with an increase in ϕ while the swimming speed remains nearly constant. We postulate that this enhanced swimming can be explained by the temporal change in the stroke form of the nematode that is uniquely observed in a shear thinning colloidal suspension: the nematode features a fast and large stroke in its head to overcome the temporally high drag imposed by the viscous medium, whose effective viscosity (ηs) is shown to drop drastically, inversely proportional to the strength of its stroke. Our results suggest new insights into how nematodes efficiently maneuver through the complex fluid environment in their natural habitat.

  12. Putatively novel sources of resistance to soybean cyst nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Soybean cyst nematode (SCN) remains to be the most economically devastating endo-root parasite of soybean [Glycine max L. (Merrill)], in the USA and worldwide. Currently, two resistance loci, rhg1 and Rhg4 have been the main sources of resistance to SCN. Over 95% of soybean cultivars with SCN resist...

  13. Multifaceted effects of host plants on entomopathogenic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The success of parasites can be impacted by multi-trophic interactions. Here we investigate aspects of multi-trophic interactions in a system involving an entomopathogenic nematode (EPN), its insect host, and host plant. Novel issues investigated include the impact of tritrophic interactions on nema...

  14. DNA barcoding of parasitic nematodes: is it kosher?

    PubMed

    Siddall, Mark E; Kvist, Sebastion; Phillips, Anna; Oceguera-Figuero, Alejandro

    2012-06-01

    Nematode parasites were encountered in kosher-certified fish meat and roe, and the question was raised as to whether or not these food products were kosher as concerns food preparation standards-a matter that pertains to the identity and, by extension, the life cycle of the parasites. To ascertain the identities of parasitic nematodes, given the distorted or damaged nature of the specimens, molecular techniques were applied in the form of DNA barcoding. To our knowledge, this is the first application of this technique to an obviously cultural concern as opposed to one of health or economic significance. Results, based both on cytochrome c oxidase subunits I and II, suggested that the parasite species found in the fish products are anisakine species that do not inhabit the intestinal lumen of the fish hosts examined. Thus, there was no evidence of failure to adhere to food preparation practices consistent with the proscriptions of Orthodox Judaism. Notwithstanding the success of DNA barcoding in determining at least the higher taxonomic identities of the parasites, some shortcomings of the DNA barcoding pipeline as it pertains to nematode parasites were encountered; specifically, the paucity of data available for the DNA barcoding locus, even for very common nematode taxa.

  15. Mitochondrial genome diversity in dagger and needle nematodes (Nematoda: Longidoridae).

    PubMed

    Palomares-Rius, J E; Cantalapiedra-Navarrete, C; Archidona-Yuste, A; Blok, V C; Castillo, P

    2017-02-02

    Dagger and needle nematodes included in the family Longidoridae (viz. Longidorus, Paralongidorus, and Xiphinema) are highly polyphagous plant-parasitic nematodes in wild and cultivated plants and some of them are plant-virus vectors (nepovirus). The mitochondrial (mt) genomes of the dagger and needle nematodes, Xiphinema rivesi, Xiphinema pachtaicum, Longidorus vineacola and Paralongidorus litoralis were sequenced in this study. The four circular mt genomes have an estimated size of 12.6, 12.5, 13.5 and 12.7 kb, respectively. Up to date, the mt genome of X. pachtaicum is the smallest genome found in Nematoda. The four mt genomes contain 12 protein-coding genes (viz. cox1-3, nad1-6, nad4L, atp6 and cob) and two ribosomal RNA genes (rrnL and rrnS), but the atp8 gene was not detected. These mt genomes showed a gene arrangement very different within the Longidoridae species sequenced, with the exception of very closely related species (X. americanum and X. rivesi). The sizes of non-coding regions in the Longidoridae nematodes were very small and were present in a few places in the mt genome. Phylogenetic analysis of all coding genes showed a closer relationship between Longidorus and Paralongidorus and different phylogenetic possibilities for the three Xiphinema species.

  16. The Wolbachia endosymbiont as an anti-filarial nematode target

    PubMed Central

    Taylor, Mark J.; Foster, Jeremy M.

    2010-01-01

    Human disease caused by parasitic filarial nematodes is a major cause of global morbidity. The parasites are transmitted by arthropod intermediate hosts and are responsible for lymphatic filariasis (elephantiasis) or onchocerciasis (river blindness). Within these filarial parasites are intracellular alpha-proteobacteria, Wolbachia, that were first observed almost 30 years ago. The obligate endosymbiont has been recognized as a target for anti-filarial nematode chemotherapy as evidenced by the loss of worm fertility and viability upon antibiotic treatment in an extensive series of human trials. While current treatments with doxycycline and rifampicin are not practical for widespread use due to the length of required treatments and contraindications, anti-Wolbachia targeting nevertheless appears a promising alternative for filariasis control in situations where current programmatic strategies fail or are unable to be delivered and it provides a superior efficacy for individual therapy. The mechanisms that underlie the symbiotic relationship between Wolbachia and its nematode hosts remain elusive. Comparative genomics, bioinfomatic and experimental analyses have identified a number of potential interactions, which may be drug targets. One candidate is de novo heme biosynthesis, due to its absence in the genome sequence of the host nematode, Brugia malayi, but presence in Wolbachia and its potential roles in worm biology. We describe this and several additional candidate targets, as well as our approaches for understanding the nature of the host-symbiont relationship. PMID:20730111

  17. Developing Nematode Management Zones Using Soil EC Data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Much research work is ongoing that is investigating methods and tools for delineating cotton root knot nematode [M. incognita] management zones via soil texture. Apparent soil electrical conductivity (ECa) can be a surrogate measurement for determining soil texture as clay content is a dominant phy...

  18. Evaluation of coffee genotypes for root-knot nematode resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Meloidogyne konaensis causes severe damage to the root systems of Coffea arabica cv. Typica ‘Guatemala’ grown in Kona, Hawaii. Farmers currently employ grafting of the nematode tolerant C. liberica var. dewevrei ‘Fukunaga’ to C. arabica cv. Typica scions. Greenhouse experiments confirmed C. liberi...

  19. Influence of Lysobacter enzymogenes Strain C3 on Nematodes

    PubMed Central

    Chen, J.; Moore, W. H.; Yuen, G. Y.; Kobayashi, D.; Caswell-Chen, E. P.

    2006-01-01

    Chitinolytic microflora may contribute to biological control of plant-parasitic nematodes by causing decreased egg viability through degradation of egg shells. Here, the influence of Lysobacter enzymogenes strain C3 on Caenorhabditis elegans, Heterodera schachtii, Meloidogyne javanica, Pratylenchus penetrans, and Aphelenchoides fragariae is described. Exposure of C. elegans to L. enzymogenes strain C3 on agar resulted in almost complete elimination of egg production and death of 94% of hatched juveniles after 2 d. Hatch of H. schachtii eggs was about 50% on a lawn of L. enzymogenes strain C3 on agar as compared to 80% on a lawn of E. coli. Juveniles that hatched on a lawn of L. enzymogenes strain C3 on agar died due to disintegration of the cuticle and body contents. Meloidogyne javanica juveniles died after 4 d exposure to a 7-d-old chitin broth culture of L. enzymogenes strain C3. Immersion of A. fragariae, M. javanica, and P. penetrans juveniles and adults in a nutrient broth culture of L. enzymogenes strain C3 led to rapid death and disintegration of the nematodes. Upon exposure to L. enzymogenes strain C3 cultures in nutrient broth, H. schachtii juveniles were rapidly immobilized and then lysed after three days. The death and disintegration of the tested nematodes suggests that toxins and enzymes produced by this strain are active against a range of nematode species. PMID:19259452

  20. IN VITRO CULTURING OF THE PREDATORY SOIL NEMATODE CLARKUS PAPILLATUS

    EPA Science Inventory

    Clarkus papillatus is a widely distributed predatory soil nematode and is of interest in the study of soil ecology, yet very little information exists on its in vitro culturing. In this investigation, an artificial environment was created to maintain C. papillatus for multi-gener...

  1. Mitochondrial genome diversity in dagger and needle nematodes (Nematoda: Longidoridae)

    PubMed Central

    Palomares-Rius, J. E.; Cantalapiedra-Navarrete, C.; Archidona-Yuste, A.; Blok, V. C.; Castillo, P.

    2017-01-01

    Dagger and needle nematodes included in the family Longidoridae (viz. Longidorus, Paralongidorus, and Xiphinema) are highly polyphagous plant-parasitic nematodes in wild and cultivated plants and some of them are plant-virus vectors (nepovirus). The mitochondrial (mt) genomes of the dagger and needle nematodes, Xiphinema rivesi, Xiphinema pachtaicum, Longidorus vineacola and Paralongidorus litoralis were sequenced in this study. The four circular mt genomes have an estimated size of 12.6, 12.5, 13.5 and 12.7 kb, respectively. Up to date, the mt genome of X. pachtaicum is the smallest genome found in Nematoda. The four mt genomes contain 12 protein-coding genes (viz. cox1-3, nad1-6, nad4L, atp6 and cob) and two ribosomal RNA genes (rrnL and rrnS), but the atp8 gene was not detected. These mt genomes showed a gene arrangement very different within the Longidoridae species sequenced, with the exception of very closely related species (X. americanum and X. rivesi). The sizes of non-coding regions in the Longidoridae nematodes were very small and were present in a few places in the mt genome. Phylogenetic analysis of all coding genes showed a closer relationship between Longidorus and Paralongidorus and different phylogenetic possibilities for the three Xiphinema species. PMID:28150734

  2. Immunological aspects of nematode parasite control in sheep.

    PubMed

    Miller, J E; Horohov, D W

    2006-04-01

    Gastrointestinal nematode parasitism is arguably the most serious constraint affecting sheep production worldwide. Economic losses are caused by decreased production, the costs of prophylaxis and treatment, and the death of the infected animals. The nematode of particular concern is Haemonchus contortus, which can cause severe blood loss resulting in anemia, anorexia, depression, loss of condition, and eventual death. The control of nematode parasites traditionally relies on anthelmintic treatment. The evolution of anthelmintic resistance in nematode populations threatens the success of drug treatment programs. Alternative strategies for control of nematode infections are being developed, and one approach is to take advantage of the host's natural or acquired immune responses, which can be used in selection programs to increase the level of resistance in the population. Vaccination can also be used to stimulate or boost the host's acquired immunity. The induction of protective resistance is dependent on the pattern of cytokine gene expression induced during infection by two defined CD4+ T-helper cell subsets, which have been designated as Th1 or Th2. Intracellular parasites most often invoke a Th1-type response, and helminth parasites a Th2-type response. Breeds of sheep resistant to infection have developed resistance over a much longer term of host-parasite relationship than genetically selected resistant lines. The immune components involved in these different responses and types of host-parasite relationships will be reviewed. The potential for using vaccines has been investigated, with variable results, for several decades. The few successes and potential new antigen candidates will also be reviewed.

  3. Mermithid nematodes found in adult Anopheles from southeastern Senegal

    PubMed Central

    2012-01-01

    Background Over two dozen mermithid nematodes have been described parasitizing mosquitoes worldwide, however, only two species were found in Africa. Mermithid nematodes kill their mosquito host upon emergence, which suggests that they could be developed as biological control agents of mosquitoes. Both Romanomermis culicivorax and Romanomermis iyengari have been reared for mass release to control numerous Anopheles species vector populations, and in one instance this may have led to reduced malaria prevalence in a human population. Methods Anopheles mosquitoes were collected during a malaria study in southeastern Senegal. Two different adult blood fed mosquitoes had a single mermithid nematode emerge from their anus while they were being held post-capture. Primers from the 18 S rDNA were developed to sequence nematode DNA and screen mosquitoes for mermithid DNA. 18 S rDNA from the Senegalese mermithid and other mermithid entries in GenBank were used to create a Maximum Parsimony tree of the Mermithidae family. Results The mermithid was present in 1.8% (10/551) of the sampled adult Anopheles species in our study area. The mermithid was found in An. gambiae s.s., An. funestus, and An. rufipes from the villages of Ndebou, Boundoucondi, and Damboucoye. Maximum parsimony analysis confirmed that the nematode parasites found in Anopheles were indeed mermithid parasites, and of the mermithid sequences available in GenBank, they are most closely related to Strelkovimermis spiculatus. Conclusions To our knowledge, this is the first report of mermithids from adult Anopheles mosquitoes in Senegal. The mermithid appears to infect Anopheles mosquitoes that develop in diverse larval habitats. Although maximum parsimony analysis determined the mermithid was closely related to Strelkovimermis spiculatus, several characteristics of the mermithid were more similar to the Empidomermis genus. Future mermithid isolations will hopefully allow: formal taxonomic identification

  4. Detrended-Fluctuation Analysis of Nematode Movement in Heterogeneous Environment

    NASA Astrophysics Data System (ADS)

    Hapca, S. M.; Gonzalez-Nieto, P.; Tarquis, A. M.

    2009-04-01

    We consider multifractal analysis in time scale to analyse the effect of structural heterogeneity on the movement of the slug-parasitic nematode, Phasmarhabditis hermaphrodita. The study involves image recording and analysis of nematode movement on a homogeneous layer of technical agar compared to movement of nematodes in a structurally heterogeneous environment that was created by adding sand particles to the plates of agar. The temporal scaling properties of the recorded trails were studied using a detrended fluctuation based method to capture the complex dynamic of movement data by comparing the multiscaling characteristics of nematode step lengths as affected by the different environments. A systematic analysis of the exponent of the structure function and the generalized Hurst exponent revealed that, while in homogeneous environment the movement was characterized by a long-range correlation with a Hurst exponent H(q) close to 1, varying little with respect to the order q of the fluctuation function, the impact of sand particle was to reduce the degree of persistence in the movement, the step lenghts being characterized by a smaller Hurst exponent, yet more variable. The results suggest that the presence of structural heterogeneity introduces a new bias into the movement, which plays an important role in complex environments where the nematode movement may be obstructed by soil particles. References Tarquis, A.M., Morato, M. C., Castellanos M.T., Perdigones A. 2009. Comparison of Structure Function and Detrended Fluctuation Analysis of Wind Time Series, Riv. Nuevo Cimento, in press. Gao, J., Cao, Y., Tung, W.-W., Hu J., 2007. Multiscale Analysis of Complex Times Series. Eds. John Wiley & Sons.

  5. A sensory code for host seeking in parasitic nematodes

    PubMed Central

    Hallem, Elissa A.; Dillman, Adler R.; Hong, Annie V.; Zhang, Yuanjun; Yano, Jessica M.; DeMarco, Stephanie F.

    2011-01-01

    Summary Nematodes comprise a large phylum of both free-living and parasitic species that show remarkably diverse lifestyles, ecological niches, and behavioral repertoires. Parasitic species in particular often display highly specialized host-seeking behaviors that reflect their specific host preferences. Many host-seeking behaviors can be triggered by the presence of host odors, yet little is known about either the specific olfactory cues that trigger these behaviors or the neural circuits that underlie them. Heterorhabditis bacteriophora and Steinernema carpocapsae are phylogenetically distant insect-parasitic nematodes whose host-seeking and host-invasion behavior resembles that of some of the most devastating human- and plant-parasitic nematodes. Here we compare the olfactory responses of H. bacteriophora and S. carpocapsae infective juveniles (IJs) to those of Caenorhabditis elegans dauers, which are analogous life stages [1]. We show that the broad host range of these parasites results from their ability to respond to the universally-produced signal carbon dioxide (CO2) as well as a wide array of odors, including host-specific odors that we identified using TD-GC-MS. We show that CO2 is attractive for the parasitic IJs and C. elegans dauers despite being repulsive for C. elegans adults [2–4], and we identify an ancient and conserved sensory neuron that mediates CO2 response in both parasitic and free-living species regardless of whether CO2 is an attractive or a repulsive cue. Finally, we show that the parasites’ odor response profiles are more similar to each other than to that of C. elegans despite their greater phylogenetic distance, likely reflecting evolutionary convergence to insect parasitism. Our results suggest that the olfactory responses of parasitic versus free-living nematodes are highly diverse and that this diversity is critical to the evolution of nematode behavior. PMID:21353558

  6. Potential of an Alkaline-stabilized Biosolid to Manage Nematodes: Case Studies on Soybean Cyst and Root-knot Nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In 2001 a collaborative research effort was initiated to evaluate an alkaline stabilized biosolid amendment for plant-parasitic nematode management. This biosolid amendment, N-Viro Soil (NVS), is produced from a unique process that destroys pathogens through a combination of the following stresses:...

  7. A Large Collection of Novel Nematode-Infecting Microsporidia and Their Diverse Interactions with Caenorhabditis elegans and Other Related Nematodes

    PubMed Central

    Zhang, Gaotian; Sachse, Martin; Prevost, Marie-Christine; Troemel, Emily R.; Félix, Marie-Anne

    2016-01-01

    Microsporidia are fungi-related intracellular pathogens that may infect virtually all animals, but are poorly understood. The nematode Caenorhabditis elegans has recently become a model host for studying microsporidia through the identification of its natural microsporidian pathogen Nematocida parisii. However, it was unclear how widespread and diverse microsporidia infections are in C. elegans or other related nematodes in the wild. Here we describe the isolation and culture of 47 nematodes with microsporidian infections. N. parisii is found to be the most common microsporidia infecting C. elegans in the wild. In addition, we further describe and name six new species in the Nematocida genus. Our sampling and phylogenetic analysis further identify two subclades that are genetically distinct from Nematocida, and we name them Enteropsectra and Pancytospora. Interestingly, unlike Nematocida, these two genera belong to the main clade of microsporidia that includes human pathogens. All of these microsporidia are horizontally transmitted and most specifically infect intestinal cells, except Pancytospora epiphaga that replicates mostly in the epidermis of its Caenorhabditis host. At the subcellular level in the infected host cell, spores of the novel genus Enteropsectra show a characteristic apical distribution and exit via budding off of the plasma membrane, instead of exiting via exocytosis as spores of Nematocida. Host specificity is broad for some microsporidia, narrow for others: indeed, some microsporidia can infect Oscheius tipulae but not its sister species Oscheius sp. 3, and conversely some microsporidia found infecting Oscheius sp. 3 do not infect O. tipulae. We also show that N. ausubeli fails to strongly induce in C. elegans the transcription of genes that are induced by other Nematocida species, suggesting it has evolved mechanisms to prevent induction of this host response. Altogether, these newly isolated species illustrate the diversity and ubiquity of

  8. Overview of organic amendments for management of plant-parasitic nematodes, with case studies from Florida.

    PubMed

    McSorley, Robert

    2011-06-01

    Organic amendments have been widely used for management of plant-parasitic nematodes. Relatively rapid declines in nematode population levels may occur when decomposing materials release toxic compounds, while longer-term effects might include increases in nematode antagonists. Improved crop nutrition and plant growth following amendment use may lead to tolerance of plant-parasitic nematodes. Results depend on a great variety of factors such as material used, processing/composting of material, application rate, test arena, crop rotation and agronomic practices, soil type, climate, and other environmental factors. Reasons for variable performance and interpretation of results from amendment studies are discussed. Case studies of amendments for nematode management are reviewed from Florida, where composts and crop residues are the most frequently used amendments. Plant growth was often improved by amendment application, free-living nematodes (especially bacterivores) were often stimulated, but suppression of plant-parasitic nematodes was inconsistent. Amendments were generally not as effective as soil fumigation with methyl bromide for managing root-knot nematodes (Meloidogyne spp.), and often population levels or galling of root-knot nematodes in amended plots did not differ from those in non-amended control plots. While amendments may improve plant growth and stimulate soil food webs, additional study and testing are needed before they could be used reliably for management of plant-parasitic nematodes under Florida conditions.

  9. Overview of Organic Amendments for Management of Plant-Parasitic Nematodes, with Case Studies from Florida

    PubMed Central

    2011-01-01

    Organic amendments have been widely used for management of plant-parasitic nematodes. Relatively rapid declines in nematode population levels may occur when decomposing materials release toxic compounds, while longer-term effects might include increases in nematode antagonists. Improved crop nutrition and plant growth following amendment use may lead to tolerance of plant-parasitic nematodes. Results depend on a great variety of factors such as material used, processing/composting of material, application rate, test arena, crop rotation and agronomic practices, soil type, climate, and other environmental factors. Reasons for variable performance and interpretation of results from amendment studies are discussed. Case studies of amendments for nematode management are reviewed from Florida, where composts and crop residues are the most frequently used amendments. Plant growth was often improved by amendment application, free-living nematodes (especially bacterivores) were often stimulated, but suppression of plant-parasitic nematodes was inconsistent. Amendments were generally not as effective as soil fumigation with methyl bromide for managing root-knot nematodes (Meloidogyne spp.), and often population levels or galling of root-knot nematodes in amended plots did not differ from those in non-amended control plots. While amendments may improve plant growth and stimulate soil food webs, additional study and testing are needed before they could be used reliably for management of plant-parasitic nematodes under Florida conditions. PMID:22791915

  10. Distribution and evolution of glycoside hydrolase family 45 cellulases in nematodes and fungi

    PubMed Central

    2014-01-01

    Background Horizontal gene transfer (HGT) has been suggested as the mechanism by which various plant parasitic nematode species have obtained genes important in parasitism. In particular, cellulase genes have been acquired by plant parasitic nematodes that allow them to digest plant cell walls. Unlike the typical glycoside hydrolase (GH) family 5 cellulase genes which are found in several nematode species from the order Tylenchida, members of the GH45 cellulase have only been identified in a cluster including the families Parasitaphelenchidae (with the pinewood nematode Bursaphelenchus xylophilus) and Aphelenchoididae, and their origins remain unknown. Results In order to investigate the distribution and evolution of GH45 cellulase genes in nematodes and fungi we performed a wide ranging screen for novel putative GH45 sequences. This revealed that the sequences are widespread mainly in Ascomycetous fungi and have so far been found in a single major nematode lineage. Close relationships between the sequences from nematodes and fungi were found through our phylogenetic analyses. An intron position is shared by sequences from Bursaphelenchus nematodes and several Ascomycetous fungal species. Conclusions The close phylogenetic relationships and conserved gene structure between the sequences from nematodes and fungi strongly supports the hypothesis that nematode GH45 cellulase genes were acquired via HGT from fungi. The rapid duplication and turnover of these genes within Bursaphelenchus genomes demonstrate that useful sequences acquired via HGT can become established in the genomes of recipient organisms and may open novel niches for these organisms to exploit. PMID:24690293

  11. Sequence mining and transcript profiling to explore cyst nematode parasitism

    PubMed Central

    Elling, Axel A; Mitreva, Makedonka; Gai, Xiaowu; Martin, John; Recknor, Justin; Davis, Eric L; Hussey, Richard S; Nettleton, Dan; McCarter, James P; Baum, Thomas J

    2009-01-01

    Background Cyst nematodes are devastating plant parasites that become sedentary within plant roots and induce the transformation of normal plant cells into elaborate feeding cells with the help of secreted effectors, the parasitism proteins. These proteins are the translation products of parasitism genes and are secreted molecular tools that allow cyst nematodes to infect plants. Results We present here the expression patterns of all previously described parasitism genes of the soybean cyst nematode, Heterodera glycines, in all major life stages except the adult male. These insights were gained by analyzing our gene expression dataset from experiments using the Affymetrix Soybean Genome Array GeneChip, which contains probeset sequences for 6,860 genes derived from preparasitic and parasitic H. glycines life stages. Targeting the identification of additional H. glycines parasitism-associated genes, we isolated 633 genes encoding secretory proteins using algorithms to predict secretory signal peptides. Furthermore, because some of the known H. glycines parasitism proteins have strongest similarity to proteins of plants and microbes, we searched for predicted protein sequences that showed their highest similarities to plant or microbial proteins and identified 156 H. glycines genes, some of which also contained a signal peptide. Analyses of the expression profiles of these genes allowed the formulation of hypotheses about potential roles in parasitism. This is the first study combining sequence analyses of a substantial EST dataset with microarray expression data of all major life stages (except adult males) for the identification and characterization of putative parasitism-associated proteins in any parasitic nematode. Conclusion We have established an expression atlas for all known H. glycines parasitism genes. Furthermore, in an effort to identify additional H. glycines genes with putative functions in parasitism, we have reduced the currently known 6,860 H

  12. A novel ascaroside controls the parasitic life cycle of the entomopathogenic nematode Heterorhabditis bacteriophora.

    PubMed

    Noguez, Jaime H; Conner, Elizabeth S; Zhou, Yue; Ciche, Todd A; Ragains, Justin R; Butcher, Rebecca A

    2012-06-15

    Entomopathogenic nematodes survive in the soil as stress-resistant infective juveniles that seek out and infect insect hosts. Upon sensing internal host cues, the infective juveniles regurgitate bacterial pathogens from their gut that ultimately kill the host. Inside the host, the nematode develops into a reproductive adult and multiplies until unknown cues trigger the accumulation of infective juveniles. Here, we show that the entomopathogenic nematode Heterorhabditis bacteriophora uses a small-molecule pheromone to control infective juvenile development. The pheromone is structurally related to the dauer pheromone ascarosides that the free-living nematode Caenorhabditis elegans uses to control its development. However, none of the C. elegans ascarosides are effective in H. bacteriophora, suggesting that there is a high degree of species specificity. Our report is the first to show that ascarosides are important regulators of development in a parasitic nematode species. An understanding of chemical signaling in parasitic nematodes may enable the development of chemical tools to control these species.

  13. Reflections on Plant and Soil Nematode Ecology: Past, Present and Future

    PubMed Central

    Ferris, Howard; Griffiths, Bryan S.; Porazinska, Dorota L.; Powers, Thomas O.; Wang, Koon-Hui; Tenuta, Mario

    2012-01-01

    The purpose of this review is to highlight key developments in nematode ecology from its beginnings to where it stands today as a discipline within nematology. Emerging areas of research appear to be driven by crop production constraints, environmental health concerns, and advances in technology. In contrast to past ecological studies which mainly focused on management of plant-parasitic nematodes, current studies reflect differential sensitivity of nematode faunae. These differences, identified in both aquatic and terrestrial environments include response to stressors, environmental conditions, and management practices. Methodological advances will continue to influence the role nematodes have in addressing the nature of interactions between organisms, and of organisms with their environments. In particular, the C. elegans genetic model, nematode faunal analysis and nematode metagenetic analysis can be used by ecologists generally and not restricted to nematologists. PMID:23482864

  14. The neural basis of the locomotion of nematodes

    NASA Astrophysics Data System (ADS)

    Erdös, Paul; Niebur, Ernst

    A model of electrotonic neurons is presented which allows computer simulation of a physiologically realistic neural network, such as that found in nematodes. The undulatory locomotion of Caenorhabditis elegans is investigated by solving the equations of motion of a segmented model of the discretized body taking into account all internal and external forces. The spatio-temporal muscle excitation patterns which produce locomotion are determined, and it is concluded that these are most probably generated by stretch receptor cells and signals which globally turn on or off the neural circuitry governing forward or backward motion. The results are illustrated in the form of a computer generated videotape and compared with the observed motion of a nematode.

  15. Formation and Regulation of Adaptive Response in Nematode Caenorhabditis elegans

    PubMed Central

    Zhao, Y.-L.; Wang, D.-Y.

    2012-01-01

    All organisms respond to environmental stresses (e.g., heavy metal, heat, UV irradiation, hyperoxia, food limitation, etc.) with coordinated adjustments in order to deal with the consequences and/or injuries caused by the severe stress. The nematode Caenorhabditis elegans often exerts adaptive responses if preconditioned with low concentrations of agents or stressor. In C. elegans, three types of adaptive responses can be formed: hormesis, cross-adaptation, and dietary restriction. Several factors influence the formation of adaptive responses in nematodes, and some mechanisms can explain their response formation. In particular, antioxidation system, heat-shock proteins, metallothioneins, glutathione, signaling transduction, and metabolic signals may play important roles in regulating the formation of adaptive responses. In this paper, we summarize the published evidence demonstrating that several types of adaptive responses have converged in C. elegans and discussed some possible alternative theories explaining the adaptive response control. PMID:22997543

  16. Underground leaves of Philcoxia trap and digest nematodes

    PubMed Central

    Pereira, Caio G.; Almenara, Daniela P.; Winter, Carlos E.; Fritsch, Peter W.; Lambers, Hans; Oliveira, Rafael S.

    2012-01-01

    The recently described genus Philcoxia comprises three species restricted to well lit and low-nutrient soils in the Brazilian Cerrado. The morphological and habitat similarities of Philcoxia to those of some carnivorous plants, along with recent observations of nematodes over its subterranean leaves, prompted the suggestion that the genus is carnivorous. Here we report compelling evidence of carnivory in Philcoxia of the Plantaginaceae, a family in which no carnivorous members are otherwise known. We also document both a unique capturing strategy for carnivorous plants and a case of a plant that traps and digests nematodes with underground adhesive leaves. Our findings illustrate how much can still be discovered about the origin, distribution, and frequency of the carnivorous syndrome in angiosperms and, more generally, about the diversity of nutrient-acquisition mechanisms that have evolved in plants growing in severely nutrient-impoverished environments such as the Brazilian Cerrado, one of the world's 34 biodiversity hotspots. PMID:22232687

  17. Plant-parasitic Nematode Problems in the Pacific Islands.

    PubMed

    Bridge, J

    1988-04-01

    The Pacific islands have a diverse range of food and cash crops with indigenous and introduced nematode problems. The staple food crops have serious nematode pests, such as Meloidogyne spp. on sweet potato, Hirschmanniella miticausa causing corm rot of taro, and Pratylenchus coffeae and Radopholus sp. producing tuber dry rot of yams. Bananas are infested with P. coffeae or R. similis, citrus with Tylenchulus semipenetrans, rice with Aphelenchoides besseyi, and ginger with Meloidogyne spp. and R. similis. Rotylenchulus reniformis, P. zeae, P. brachyurus, and Helicotylenchus spp. are important on all of these and other crops, such as sugarcane, passion fruit, pawpaw, and cassava. Meloidogyne spp. cause serious damage to local and introduced leaf and fruit vegetables and other crops, such as tobacco, sugarcane, pawpaw, black pepper, and pyrethrum. Many other plant-parasitic genera and species, some undescribed, occur in the Pacific, and there are many islands still to be investigated.

  18. Structure and Function of Nematode RNA-Binding Proteins

    PubMed Central

    Kaymak, Ebru; Wee, L.M.; Ryder, Sean P.

    2010-01-01

    RNA-binding proteins are critical effectors of gene expression. They guide mRNA localization, translation, and stability, and potentially play a role in regulating mRNA synthesis. The structural basis for RNA recognition by RNA-binding proteins is the key to understanding how they target specific transcripts for regulation. Compared to other metazoans, nematode genomes contain a significant expansion in several RNA-binding protein families, including Pumilio-FBF (PUF), TTP-like zinc finger (TZF), and argonaute-like (AGO) proteins. Genetic data suggest that individual members of each family have distinct functions, presumably due to sequence variations that alter RNA binding specificity or protein interaction partners. In this review, we highlight example structures and identify the variable regions that likely contribute to functional divergence in nematodes. PMID:20418095

  19. Nematode Parasites of Teiid Lizards from the Brazilian Amazon Rainforest.

    PubMed

    Macedo, Lilian Cristina; Gardner, Scott L; Melo, Francisco Tiago Vasconcelos; Giese, Elane Guerreiro; Dos Santos, Jeannie Nascimento

    2016-11-30

    This study presents the helminth composition and parameters of infection by several species of nematodes in teiid lizards, Ameiva a. ameiva (Linnaeus, 1758), Cnemidophorus cryptus Cole & Dessauer, 1993, and Kentropyx calcarata Spix, 1825 from the Brazilian Amazonian Rainforest. The lizard populations we studied were parasitized by six species of Nemata, including: Spinicauda spinicauda (Olfers, 1919), Parapharyngodon alvarengai Freitas, 1957, Physaloptera sp. (adults), Physaloptera sp. (larvae), Piratuba digiticauda Lent and Freitas, 1941, and Anisakidae (larvae). The overall prevalence was 66.17% and the mean intensity of infection was 19.40 ± 25.48. The association between the body-length of lizards and abundance and richness of parasitic nematodes was statistically significant only in Ameiva a. ameiva. A new host record is reported here with one specimen of the family Anasakidae in Ameiva a. ameiva. Both S. spinicauda and Physaloptera sp. represent new records from C. cryptus.

  20. Draft genome of the filarial nematode parasite Brugia malayi.

    PubMed

    Ghedin, Elodie; Wang, Shiliang; Spiro, David; Caler, Elisabet; Zhao, Qi; Crabtree, Jonathan; Allen, Jonathan E; Delcher, Arthur L; Guiliano, David B; Miranda-Saavedra, Diego; Angiuoli, Samuel V; Creasy, Todd; Amedeo, Paolo; Haas, Brian; El-Sayed, Najib M; Wortman, Jennifer R; Feldblyum, Tamara; Tallon, Luke; Schatz, Michael; Shumway, Martin; Koo, Hean; Salzberg, Steven L; Schobel, Seth; Pertea, Mihaela; Pop, Mihai; White, Owen; Barton, Geoffrey J; Carlow, Clotilde K S; Crawford, Michael J; Daub, Jennifer; Dimmic, Matthew W; Estes, Chris F; Foster, Jeremy M; Ganatra, Mehul; Gregory, William F; Johnson, Nicholas M; Jin, Jinming; Komuniecki, Richard; Korf, Ian; Kumar, Sanjay; Laney, Sandra; Li, Ben-Wen; Li, Wen; Lindblom, Tim H; Lustigman, Sara; Ma, Dong; Maina, Claude V; Martin, David M A; McCarter, James P; McReynolds, Larry; Mitreva, Makedonka; Nutman, Thomas B; Parkinson, John; Peregrín-Alvarez, José M; Poole, Catherine; Ren, Qinghu; Saunders, Lori; Sluder, Ann E; Smith, Katherine; Stanke, Mario; Unnasch, Thomas R; Ware, Jenna; Wei, Aguan D; Weil, Gary; Williams, Deryck J; Zhang, Yinhua; Williams, Steven A; Fraser-Liggett, Claire; Slatko, Barton; Blaxter, Mark L; Scott, Alan L

    2007-09-21

    Parasitic nematodes that cause elephantiasis and river blindness threaten hundreds of millions of people in the developing world. We have sequenced the approximately 90 megabase (Mb) genome of the human filarial parasite Brugia malayi and predict approximately 11,500 protein coding genes in 71 Mb of robustly assembled sequence. Comparative analysis with the free-living, model nematode Caenorhabditis elegans revealed that, despite these genes having maintained little conservation of local synteny during approximately 350 million years of evolution, they largely remain in linkage on chromosomal units. More than 100 conserved operons were identified. Analysis of the predicted proteome provides evidence for adaptations of B. malayi to niches in its human and vector hosts and insights into the molecular basis of a mutualistic relationship with its Wolbachia endosymbiont. These findings offer a foundation for rational drug design.

  1. Influence of Salinity on Survival and Infectivity of Entomopathogenic: Nematodes

    PubMed Central

    Thurston, Graham S.; Ni, Yansong; Kaya, Harry K.

    1994-01-01

    Exposure to NaC1, KCI, and CaCl₂ affected the entomopathogenic nematodes Heterorhabditis bacteriophora and Steinernema glaseri differently. Survival, virulence, and penetration efficiency of S. glaseri were not affected by these salts. At high concentrations, however, all three salts inhibited its ability to move through a soil column and locate and infect a susceptible host. Calcium chloride and KCl had no effect on H. bacteriophora survival, penetration efficiency, or movement through a soil column, but moderate concentrations of these salts enhanced H. bacteriophora virulence. NaCl, however, adversely affected each of these parameters at high salinities (>16 dS/m). Salt effects on S. glaseri are attributed solely to interference with nematode host-finding ability, whereas the NaCl effects on H. bacteriophora are attributed to its toxicity and possibly to interference with host-finding behavior. PMID:19279902

  2. [Prevalence of intestinal nematodes in dogs from Warsaw region].

    PubMed

    Turkowicz, Monika; Cielecka, Danuta

    2002-01-01

    Prevalence of intestinal nematodes in dogs from Warsaw region. Investigation of prevalence of intestinal parasites in dogs have been conducted in order to protect human and animal health. The aim of the study was to establish species composition of intestinal parasites and to evaluate their prevalence in dogs from the shelter in Józefów situated on north from Warsaw. Additionally, urban dogs from Warsaw and village dogs from areas near the shelter, were examined. The prevalence of nematodes was: 62.3% in dogs from shelter, 37.5% in village dogs and 18.8% in urban dogs. In homeless dogs, the most common parasite was Uncinaria stenocephala, then Trichuris vulpis and Toxascaris leonina. In village dogs only eggs of U. stenocephala were detected; in urban dogs Toxocara canis and U. stenocephala were found.

  3. Integrated management of root-knot nematode, Meloidogyne incognita infestation in tomato and grapevine.

    PubMed

    Kumari, N Swarna; Sivakumar, C V

    2005-01-01

    An integrated approach with the obligate bacterial parasite, Pasteuria penetrans and nematicides was assessed for the management of the root-knot nematode, Meloidogyne incognita infestation in tomato and grapevine. Seedlings of tomato cv. Co3 were transplanted into pots filled with sterilized soil and inoculated with nematodes (5000 juveniles/pot). The root powder of P. penetrans at 10 mg/pot was applied alone and in combination with carbofuran at 6 mg/pot. Application of P. penetrans along with carbofuran recorded lowest nematode infestation (107 nematodes/200 g soil) compared to control (325 nematodes/200 g soil). The rate of parasitization was 83.1% in the carbofuran and P. penetrans combination treatment as against 61.0% in the P. penetrans treatment only. The plant growth was also higher in the combination treatment compared to all other treatments. A field trial was carried out to assess the efficacy of P. penetrans and nematicides viz., carbofuran and phorate in the management of root-knot nematode, M. incognita infestation of grapevine cv. Muscat Hamburg. A nematode and P. penetrans infested grapevine field was selected and treatments either with carbofuran or phorate at 1 g a.i/vine was given. The observations were recorded at monthly interval. The results showed that the soil nematode population was reduced in nematicide treated plots. Suppression of nematodes was higher under phorate (117 nematodes/200 g soil) than under carbofuran (126.7 nematodes/200 g soil) treatment. The number of juveniles parasitized was also influenced by nematicides and spore load carried/juvenile with phorate being superior and the increase being 17.0 and 29.0% respectively over the control. The results of these experiment confirmed the compatibility of P. penetrans with nematicides and its biological control potential against the root-knot nematode.

  4. Curative Control of the Peachtree Borer Using Entomopathogenic Nematodes

    PubMed Central

    Shapiro-Ilan, David I.; Cottrell, Ted E.; Mizell, Russell F.; Horton, Dan L.

    2016-01-01

    The peachtree borer, Synanthedon exitiosa (Say 1823), is a major pest of stone fruit trees in North America. Current management relies upon preventative control using broad-spectrum chemical insecticides, primarily chlorpyrifos, applied in the late summer or early fall. However, due to missed applications, poor application timing, or other factors, high levels of S. exitiosa infestation may still occur and persist through the following spring. Curative treatments applied in the spring to established infestations would limit damage to the tree and prevent the next generation of S. exitiosa from emerging within the orchard. However, such curative measures for control of S. exitiosa do not exist. Our objective was to measure the efficacy of the entomopathogenic nematode, Steinernema carpocapsae, as a curative control for existing infestations of S. exitiosa. In peach orchards, spring applications of S. carpocapsae (obtained from a commercial source) were made to infested trees and compared with chlorpyrifos and a water-only control in 2014 and 2015. Additionally, types of spray equipment were compared: nematodes were applied via boom sprayer, handgun, or trunk sprayer. To control for effects of application method or nematode source, in vivo laboratory-grown S. carpocapsae, applied using a watering can, was also included. Treatment effects were assessed 39 d (2014) or 19 d (2015) later by measuring percentage of trees still infested, and also number of surviving S. exitiosa larvae per tree. Results indicated that S. carpocapsae provided significant curative control (e.g., >80% corrected control for the handgun application). In contrast, chlorpyrifos failed to reduce S. exitiosa infestations or number of surviving larvae. In most comparisons, no effect of nematode application method was detected; in one assessment, only the handgun and watering can methods reduced infestation. In conclusion, our study indicates that S. carpocapsae may be used as an effective curative

  5. Caenorhabditis elegans: A Genetic Guide to Parasitic Nematode Biology

    PubMed Central

    Bird, D. McK.; Opperman, C. H.

    1998-01-01

    The advent of parasite genome sequencing projects, as well as an increase in biology-directed gene discovery, promises to reveal genes encoding many of the key molecules required for nematode-host interactions. However, distinguishing parasitism genes from those merely required for nematode viability remains a substantial challenge. Although this will ultimately require a functional test in the host or parasite, the free-living nematode Caenorhabditis elegans can be exploited as a heterologous system to determine function of candidate parasitism genes. Studies of C. elegans also have revealed genetic networks, such as the dauer pathway, that may also be important adaptations for parasitism. As a more directed means of identifying parasitism traits, we developed classical genetics for Heterodera glycines and have used this approach to map genes conferring host resistance-breaking phenotypes. It is likely that the C. elegans and H. glycines genomes will be at least partially syntenic, thus permitting predictive physical mapping of H. glycines genes of interest. PMID:19274223

  6. Genome Editing in C. elegans and Other Nematode Species

    PubMed Central

    Sugi, Takuma

    2016-01-01

    Caenorhabditis elegans, a 1 mm long free-living nematode, is a popular model animal that has been widely utilized for genetic investigations of various biological processes. Characteristic features that make C. elegans a powerful model of choice for eukaryotic genetic studies include its rapid life cycle (development from egg to adult in 3.5 days at 20 °C), well-annotated genome, simple morphology (comprising only 959 somatic cells in the hermaphrodite), and transparency (which facilitates non-invasive fluorescence observations). However, early approaches to introducing mutations in the C. elegans genome, such as chemical mutagenesis and imprecise excision of transposons, have required large-scale mutagenesis screens. To avoid this laborious and time-consuming procedure, genome editing technologies have been increasingly used in nematodes including C. briggsae and Pristionchus pacificus, thereby facilitating their genetic analyses. Here, I review the recent progress in genome editing technologies using zinc-finger nucleases (ZFNs), transcriptional activator-like nucleases (TALENs), and clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9 in nematodes and offer perspectives on their use in the future. PMID:26927083

  7. Functional diversification of Argonautes in nematodes: an expanding universe

    PubMed Central

    Buck, Amy H.; Blaxter, Mark

    2013-01-01

    In the last decade, many diverse RNAi (RNA interference) pathways have been discovered that mediate gene silencing at epigenetic, transcriptional and post-transcriptional levels. The diversity of RNAi pathways is inherently linked to the evolution of Ago (Argonaute) proteins, the central protein component of RISCs (RNA-induced silencing complexes). An increasing number of diverse Agos have been identified in different species. The functions of most of these proteins are not yet known, but they are generally assumed to play roles in development, genome stability and/or protection against viruses. Recent research in the nematode Caenorhabditis elegans has expanded the breadth of RNAi functions to include transgenerational epigenetic memory and, possibly, environmental sensing. These functions are inherently linked to the production of secondary siRNAs (small interfering RNAs) that bind to members of a clade of WAGOs (worm-specific Agos). In the present article, we review briefly what is known about the evolution and function of Ago proteins in eukaryotes, including the expansion of WAGOs in nematodes. We postulate that the rapid evolution of WAGOs enables the exceptional functional plasticity of nematodes, including their capacity for parasitism. PMID:23863149

  8. Scavenging hagfish as a transport host of Anisakid nematodes.

    PubMed

    Luo, Hao-Yuan; Chen, Hui-Yu; Chen, Hui-Guan; Shih, Hsiu-Hui

    2016-03-15

    Hagfish are the most primitive craniates and scavengers, feeding on dead organisms as well as fish and invertebrates. Hagfish play an important ecological role in recycling nutrients, helping to recycle biomass from the upper water column. We investigated 265 specimens of four hagfish species, including Eptatretus burgeri, Eptatretus yangi, Eptatretus sheni and Eptatretus taiwanae from northeastern Taiwanese waters of the northwestern Pacific from November 2013 to June 2014. Eight species of Anisakid nematodes were identified: Anisakis pegreffii, Anisakis simplex s.s., a recombinant genotype of A. pegreffii and A. simplex s.s., Anisakis typica, Anisakis sp., Anisakis brevispiculata, Anisakis physeteris and Hysterothylacium amoyense. Anisakis sp. and H. amoyense represented new locality records. The prevalence, mean intensity and mean abundance of anisakid nematodes for all specimens were 21.51%, 5.39 larvae per fish and 1.16 larvae per fish, respectively. A. pegreffii was the most frequent species in E. burgeri, E. yangi and E. taiwanae, whereas in E. sheni, the dominant species was Anisakis sp. The number of nematodes was significantly related to the host length for E. burgeri and E. sheni, but was not related to the sex of the four hagfish species. This report of scavenging hagfish infected with Anisakid larvae suggests hagfish as a transport/paratenic host between cetaceans and piscivores. Anisakiasis may be caused by the consumption of infectious third-stage larvae in raw or undercooked hagfish.

  9. Sex-specific mating pheromones in the nematode Panagrellus redivivus.

    PubMed

    Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H; Dossey, Aaron T; Yim, Joshua J; Ajredini, Ramadan; Kolawa, Adam A; Kaplan, Fatma; Alborn, Hans T; Teal, Peter E A; Schroeder, Frank C; Sternberg, Paul W; Edison, Arthur S

    2012-12-18

    Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes.

  10. Sex-specific mating pheromones in the nematode Panagrellus redivivus

    PubMed Central

    Choe, Andrea; Chuman, Tatsuji; von Reuss, Stephan H.; Dossey, Aaron T.; Yim, Joshua J.; Ajredini, Ramadan; Kolawa, Adam A.; Kaplan, Fatma; Alborn, Hans T.; Teal, Peter E. A.; Schroeder, Frank C.; Sternberg, Paul W.; Edison, Arthur S.

    2012-01-01

    Nematodes use an extensive chemical language based on glycosides of the dideoxysugar ascarylose for developmental regulation (dauer formation), male sex attraction, aggregation, and dispersal. However, no examples of a female- or hermaphrodite-specific sex attractant have been identified to date. In this study, we investigated the pheromone system of the gonochoristic sour paste nematode Panagrellus redivivus, which produces sex-specific attractants of the opposite sex. Activity-guided fractionation of the P. redivivus exometabolome revealed that males are strongly attracted to ascr#1 (also known as daumone), an ascaroside previously identified from Caenorhabditis elegans hermaphrodites. Female P. redivivus are repelled by high concentrations of ascr#1 but are specifically attracted to a previously unknown ascaroside that we named dhas#18, a dihydroxy derivative of the known ascr#18 and an ascaroside that features extensive functionalization of the lipid-derived side chain. Targeted profiling of the P. redivivus exometabolome revealed several additional ascarosides that did not induce strong chemotaxis. We show that P. redivivus females, but not males, produce the male-attracting ascr#1, whereas males, but not females, produce the female-attracting dhas#18. These results show that ascaroside biosynthesis in P. redivivus is highly sex-specific. Furthermore, the extensive side chain functionalization in dhas#18, which is reminiscent of polyketide-derived natural products, indicates unanticipated biosynthetic capabilities in nematodes. PMID:23213209

  11. Microfluidic bioassay to characterize parasitic nematode phenotype and anthelmintic resistance.

    PubMed

    Chen, Baozhen; Deutmeyer, Alex; Carr, John; Robertson, Alan P; Martin, Richard J; Pandey, Santosh

    2011-01-01

    With increasing resistance to anti-parasitic drugs, it has become more important to detect and recognize phenotypes of resistant isolates. Molecular methods of detecting resistant isolates are limited at present. Here, we introduce a microfluidic bioassay to measure phenotype using parameters of nematode locomotion. We illustrate the technique on larvae of an animal parasite Oesophagostomum dentatum. Parameters of sinusoidal motion such as propagation velocity, wavelength, wave amplitude, and oscillation frequency depended on the levamisole-sensitivity of the isolate of parasitic nematode. The levamisole-sensitive isolate (SENS) had a mean wave amplitude of 135 μm, which was larger than 123 μm of the levamisole-resistant isolate (LEVR). SENS had a mean wavelength of 373 μm, which was less than 393 μm of LEVR. The mean propagation velocity of SENS, 149 μm s-1, was similar to LEVR, 143 μm s-1. The propagation velocity of the isolates was inhibited by levamisole in a concentration-dependent manner above 0.5 μm. The EC50 for SENS was 3 μm and the EC50 for LEVR was 10 μm. This microfluidic technology advances present-day nematode migration assays and provides a better quantification and increased drug sensitivity. It is anticipated that the bioassay will facilitate study of resistance to other anthelmintic drugs that affect locomotion.

  12. Recruitment of entomopathogenic nematodes by insect-damaged maize roots.

    PubMed

    Rasmann, Sergio; Köllner, Tobias G; Degenhardt, Jörg; Hiltpold, Ivan; Toepfer, Stefan; Kuhlmann, Ulrich; Gershenzon, Jonathan; Turlings, Ted C J

    2005-04-07

    Plants under attack by arthropod herbivores often emit volatile compounds from their leaves that attract natural enemies of the herbivores. Here we report the first identification of an insect-induced belowground plant signal, (E)-beta-caryophyllene, which strongly attracts an entomopathogenic nematode. Maize roots release this sesquiterpene in response to feeding by larvae of the beetle Diabrotica virgifera virgifera, a maize pest that is currently invading Europe. Most North American maize lines do not release (E)-beta-caryophyllene, whereas European lines and the wild maize ancestor, teosinte, readily do so in response to D. v. virgifera attack. This difference was consistent with striking differences in the attractiveness of representative lines in the laboratory. Field experiments showed a fivefold higher nematode infection rate of D. v. virgifera larvae on a maize variety that produces the signal than on a variety that does not, whereas spiking the soil near the latter variety with authentic (E)-beta-caryophyllene decreased the emergence of adult D. v. virgifera to less than half. North American maize lines must have lost the signal during the breeding process. Development of new varieties that release the attractant in adequate amounts should help enhance the efficacy of nematodes as biological control agents against root pests like D. v. virgifera.

  13. Recent advances in our knowledge of Australian anisakid nematodes

    PubMed Central

    Shamsi, Shokoofeh

    2014-01-01

    Anisakidosis is an emerging infection associated with a wide range of clinical syndromes in humans caused by members of the family Anisakidae. Anisakid nematodes have a cosmopolitan distribution and infect a wide range of invertebrates and vertebrates during their life cycles. Since the first report of these parasites in humans during the early 60s, anisakid nematodes have attracted considerable attention as emerging zoonotic parasites. Along with rapid development of various molecular techniques during last several decades, this has caused a significant change in the taxonomy and systematics of these parasites. However, there are still huge gaps in our knowledge on various aspects of the biology and ecology of anisakid nematodes in Australia. Although the use of advanced morphological and molecular techniques to study anisakids had a late start in Australia, great biodiversity was found and unique species were discovered. Here an updated list of members within the family and the current state of knowledge on Australian anisakids will be provided. Given that the employment of advanced techniques to study these important emerging zoonotic parasites in Australia is recent, further research is needed to understand the ecology and biology of these socio economically important parasites. After a recent human case of anisakidosis in Australia, such understanding is crucial if control and preventive strategies are to be established in this country. PMID:25180162

  14. Attraction of undulatory swimmers, such as nematodes, to surfaces

    NASA Astrophysics Data System (ADS)

    Yuan, Jinzhou; Raizen, David; Bau, Haim

    2014-11-01

    Nematodes play a significant role in the ecosystem; agriculture; human, animal, and plant disease; and medical research. The interactions between nematodes and surfaces may play an important role in nematodes' life cycle and ability to invade a host. We studied the effect of a surface on the dynamics of low-Reynolds number, undulating swimmers such as Caenorhabditis (C.) elegans -both wild type and touch-insensitive. The experiments demonstrated that swimmers located far from a surface selected randomly their direction of motion. In contrast, surface-proximate swimmers rotated towards, collided with, and swam along the surface for considerable time intervals, periodically contacting the surface with their anterior. Likewise, swimmers in a swarm were present at higher concentrations close to the surface. Both resistive force theory-based calculations and symmetry arguments predict that short range hydrodynamic torque, resulting from the interaction between the swimmer-induced flow field and the surface, rotate the swimmer towards the surface. We conclude that the surface attraction and following results from the interplay between short-range hydrodynamic and steric forces and is genotype-independent. The work was supported, in part, by NIH NIA 5R03AG042690-02 and NBIC NSF NSEC DMR08-32802.

  15. Functional diversification of Argonautes in nematodes: an expanding universe.

    PubMed

    Buck, Amy H; Blaxter, Mark

    2013-08-01

    In the last decade, many diverse RNAi (RNA interference) pathways have been discovered that mediate gene silencing at epigenetic, transcriptional and post-transcriptional levels. The diversity of RNAi pathways is inherently linked to the evolution of Ago (Argonaute) proteins, the central protein component of RISCs (RNA-induced silencing complexes). An increasing number of diverse Agos have been identified in different species. The functions of most of these proteins are not yet known, but they are generally assumed to play roles in development, genome stability and/or protection against viruses. Recent research in the nematode Caenorhabditis elegans has expanded the breadth of RNAi functions to include transgenerational epigenetic memory and, possibly, environmental sensing. These functions are inherently linked to the production of secondary siRNAs (small interfering RNAs) that bind to members of a clade of WAGOs (worm-specific Agos). In the present article, we review briefly what is known about the evolution and function of Ago proteins in eukaryotes, including the expansion of WAGOs in nematodes. We postulate that the rapid evolution of WAGOs enables the exceptional functional plasticity of nematodes, including their capacity for parasitism.

  16. Differential vascularization of nematode-induced feeding sites

    PubMed Central

    Hoth, Stefan; Stadler, Ruth; Sauer, Norbert; Hammes, Ulrich Z.

    2008-01-01

    Sedentary nematodes are destructive plant pathogens that cause significant yield losses. In the roots of their host plants, cyst nematodes (CNs) and root-knot nematodes (RKNs) induce different, highly specialized feeding sites—syncytia or giant cells (GCs), respectively—to optimize nutrient uptake. We compared the mechanisms by which nutrients are delivered from the model host plant, Arabidopsis, to GCs induced by the RKN Meloidogyne incognita or to syncytia induced by the CN Heterodera schachtii. From previous work, syncytia were known to be symplastically connected to newly formed host phloem composed of sieve elements (SEs) and companion cells. Here we studied the formation of plasmodesmata (PD) during GC and syncytia development by monitoring a viral movement protein that targets branched PD and the development of host phloem during GC formation by applying confocal laser scanning microscopy and immunocytochemistry. Analyses of plants expressing soluble or membrane-anchored green fluorescent protein in their phloem demonstrated symplastic isolation of GCs. GCs were found to be embedded in a tissue that consists exclusively of SEs. These de novo-formed SEs, contained nuclei and were interconnected by secondary PD. A similar interconnection of SEs was observed around syncytia. However, these secondary PD were also present at the SE–syncytium interface, demonstrating the postulated symplastic connection. Our results show that CNs and RKNs, despite their close phylogenetic relatedness, employ fundamentally different strategies to withdraw nutrients from host plants. PMID:18711135

  17. A New Methodology for Evaluation of Nematode Viability

    PubMed Central

    Ferreira, Sebastião Rodrigo; Mendes, Tiago Antônio Oliveira; Bueno, Lilian Lacerda; de Araújo, Jackson Victor; Bartholomeu, Daniella Castanheira; Fujiwara, Ricardo Toshio

    2015-01-01

    Nematodes infections are responsible for debilitating conditions and economic losses in domestic animals as well as livestock and are considered an important public health problem due to the high prevalence in humans. The nematode resistance for drugs has been reported for livestock, highlighting the importance for development of new anthelmintic compounds. The aim of the current study was to apply and compare fluorimetric techniques using Sytox and propidium iodide for evaluating the viability of C. elegans larvae after treatment with anthelmintic drugs. These fluorescent markers were efficient to stain larvae treated with ivermectin and albendazole sulfoxide. We observed that densitometric values were proportional to the concentration of dead larvae stained with both markers. Furthermore, data on motility test presented an inverse correlation with fluorimetric data when ivermectin was used. Our results showed that lower concentrations of drugs were effective to interfere in the processes of cellular transport while higher drugs concentrations were necessary in order to result in any damage to cell integrity. The methodology described in this work might be useful for studies that aim to evaluate the viability of nematodes, particularly for testing of new anthelminthic compounds using an easy, economic, reproducible, and no time-consuming technique. PMID:25866820

  18. Discovery of filarial nematode DNA in Amblyomma americanum in Northern Virginia.

    PubMed

    Henning, Tyler C; Orr, John M; Smith, Joshua D; Arias, Jorge R; Rasgon, Jason L; Norris, Douglas E

    2016-03-01

    Ticks collected in 2011 were screened for the presence of filarial nematode genetic material, and positive samples were sequenced for analysis. Monanema-like filarial nematode DNA was recently discovered in Amblyomma americanum in northern Virginia, marking the first time genetic material from this parasite has been discovered in ticks in the state. Phylogenetic analysis revealed that this material was directly related to a previously discovered filarial nematode in A. americanum populations in Maryland as well as recently identified parasites in Ixodes scapularis from southern Connecticut. Further study is warranted to visually confirm the presence of these nematodes, characterize their distribution, and determine if these ticks are intermediate hosts.

  19. Sensitivity of Nematode Life-History Groups to Ions and Osmotic Tensions of Nitrogenous Solutions

    PubMed Central

    Tenuta, Mario; Ferris, Howard

    2004-01-01

    Guild designation of nematodes of similar trophic function and life-history strategy provides a basis for using nematode faunal analyses in an integrative assessment of soil food web condition. Omnivorous and predaceous nematodes, categorized at the upper end of a colonizer-persister (c-p) continuum of nematode functional guilds are generally not abundant in cropped soil. These nematodes are more sensitive to heavy metal concentrations than those in other c-p groups, but whether sensitivity to agrochemicals contributes to the observed low abundance of high c-p groups in cropped soils is less well understood. An exposure assay in solution was used to compare the sensitivity of nematodes representing various guilds obtained from field soils and from laboratory culture to several nitrogen sources. Nematodes in c-p groups 4 and 5 were more sensitive to nitrogen solutions than nematodes representing lower c-p groups. There were both osmotic and specific ion effects—the latter most evident in exposure of nematodes to NaNO₂ and (NH₄)₂SO₄. The RC₅₀ (concentration resulting in nematode recovery of one half of that of distilled water) for (NH₄)₂SO₄ was < 0.052 M-N for c-p groups 4 and 5 compared to much greater values (0.34 to 0.81 M-N) for c-p groups 1 to 3. In non-ionic polyethylene glycol (PEG) solutions, osmotic tensions of 0.40 to 0.43 MPa reduced the recovery of exposed nematodes by half (RT₅₀; water potential of solution resulting in nematode recovery of one half of that of distilled water) for c-p groups 4 and 5 compared to > 1.93 MPa for c-p groups 1 to 3. RT₅₀ values for urea solutions, also non-ionic, were greater than for PEG. Caenorhabditis elegans N2 (c-p 1) and Meloidogyne javanica (c-p 3) reared on solid medium and in hydroponic culture, respectively, were slightly more sensitive to specific ion and osmotic effects than nematodes of similar c-p groups obtained from soil. The greater sensitivity of c-p 4 and 5 nematodes to nitrogen

  20. Nematodes Infect, But Do Not Manipulate Digging By, Sand Crabs, Lepidopa benedicti

    PubMed Central

    Joseph, Meera; Faulkes, Zen

    2014-01-01

    We examined sand crabs (Lepidopa benedicti) for endoparasites, and found the only parasite consistently infecting the studied population were small nematodes. Because many nematodes have complex life cycles involving multiple hosts, often strongly manipulating their hosts, we hypothesized that nematodes alter the behavior of their sand crab hosts. We predicted that more heavily infected crabs would spend more time above sand than less heavily infected crabs. Our data indicate infection by nematodes was not correlated with duration of time crabs spent above sand. We also suggest that organisms living in sandy beaches may benefit from relatively low parasite loads due to the low diversity of species in the habitat. PMID:24916475

  1. Identification and analysis of insulin like peptides in nematode secretomes provide targets for parasite control

    PubMed Central

    Gahoi, Shachi; Gautam, Budhayash

    2016-01-01

    Insulin-like (ins) peptides play an important role in development and metabolism across the metazoa. In nematodes, these are also required for dauer formation and longevity and are expressed in different types of neurons across various life stages which demonstrate their role in parasites and could become possible targets for parasite control. To date, many nematode genomes are publically available. However, a systematic screening of ins peptides across different nematode group has not been reported. In the present study, we systematically identified ins peptides in the secretomes of 73 nematodes with fully sequenced genomes covering five different groups viz. plant parasitic, animal parasitic, human parasitic, entomopathogenic and free living nematodes. From the total of 93,949 secretory proteins, 176 proteins were uniquely mapped to 40 identified C. elegans ins families. The obtained result showed that 74.15% of the identified ins proteins were represented in free living nematodes only and remaining 25.84% were combinedly identified in all other nematode groups. The ins-1, ins-17 and ins-18 were the only ins families which were detected in all the studied nematode groups. Out of 176 proteins, 96 of ins proteins were predicted as hydrophilic in nature and 39 proteins were found stable using ProtParam analysis. Our study provides insight into the distribution of ins peptides across different group of nematodes and this information could be useful for further experimental study. PMID:28356679

  2. Nematode-Bacterium Symbioses - Cooperation and Conflict Revealed in the 'Omics' Age

    PubMed Central

    Murfin, Kristen E.; Dillman, Adler R.; Foster, Jeremy M.; Bulgheresi, Silvia; Slatko, Barton E.; Sternberg, Paul W.; Goodrich-Blair, Heidi

    2012-01-01

    Nematodes are ubiquitous organisms that have a significant global impact on ecosystems, economies, agriculture, and human health. The applied importance of nematodes and the experimental tractability of many species have promoted their use as models in various research areas, including developmental biology, evolutionary biology, ecology, and animal-bacterium interactions. Nematodes are particularly well suited for investigating host associations with bacteria because all nematodes have interacted with bacteria during their evolutionary history and engage in a diversity of association types. Interactions between nematodes and bacteria can be positive (mutualistic) or negative (pathogenic/parasitic) and may be transient or stably maintained (symbiotic). Furthermore, since many mechanistic aspects of nematode-bacterium interactions are conserved their study can provide broader insights into other types of associations, including those relevant to human diseases. Recently, genome-scale studies have been applied to diverse nematode-bacterial interactions, and have helped reveal mechanisms of communication and exchange between the associated partners. In addition to providing specific information about the system under investigation, these studies also have helped inform our understanding of genome evolution, mutualism, and innate immunity. In this review we will discuss the importance and diversity of nematodes, 'omics' studies in nematode-bacterial systems, and the wider implications of the findings. PMID:22983035

  3. Soil nematode responses to increases in nitrogen deposition and precipitation in a temperate forest.

    PubMed

    Sun, Xiaoming; Zhang, Xiaoke; Zhang, Shixiu; Dai, Guanhua; Han, Shijie; Liang, Wenju

    2013-01-01

    The environmental changes arising from nitrogen (N) deposition and precipitation influence soil ecological processes in forest ecosystems. However, the corresponding effects of environmental changes on soil biota are poorly known. Soil nematodes are the important bioindicator of soil environmental change, and their responses play a key role in the feedbacks of terrestrial ecosystems to climate change. Therefore, to explore the responsive mechanisms of soil biota to N deposition and precipitation, soil nematode communities were studied after 3 years of environmental changes by water and/or N addition in a temperate forest of Changbai Mountain, Northeast China. The results showed that water combined with N addition treatment decreased the total nematode abundance in the organic horizon (O), while the opposite trend was found in the mineral horizon (A). Significant reductions in the abundances of fungivores, plant-parasites and omnivores-predators were also found in the water combined with N addition treatment. The significant effect of water interacted with N on the total nematode abundance and trophic groups indicated that the impacts of N on soil nematode communities were mediated by water availability. The synergistic effect of precipitation and N deposition on soil nematode communities was stronger than each effect alone. Structural equation modeling suggested water and N additions had direct effects on soil nematode communities. The feedback of soil nematodes to water and nitrogen addition was highly sensitive and our results indicate that minimal variations in soil properties such as those caused by climate changes can lead to severe changes in soil nematode communities.

  4. Free-Living Nematodes in the Freshwater Food Web: A Review

    PubMed Central

    Majdi, Nabil; Traunspurger, Walter

    2015-01-01

    Free-living nematodes are well-recognized as an abundant and ubiquitous component of benthic communities in inland waters. Compelling evidence from soil and marine ecosystems has highlighted the importance of nematodes as trophic intermediaries between microbial production and higher trophic levels. However, the paucity of empirical evidence of their role in freshwater ecosystems has hampered their inclusion in our understanding of freshwater food web functioning. This literature survey provides an overview of research efforts in the field of freshwater nematode ecology and of the complex trophic interactions between free-living nematodes and microbes, other meiofauna, macro-invertebrates, and fishes. Based on an analysis of the relevant literature and an appreciation of the potential of emerging approaches for the evaluation of nematode trophic ecology, we point out research gaps and recommend relevant directions for further research. The latter include (i) interactions of nematodes with protozoans and fungi; (ii) nonconsumptive effects of nematodes on microbial activity and the effects of nematodes on associated key ecosystem processes (decomposition, primary production); and (iii) the feeding selectivity and intraspecific feeding variability of nematodes and their potential impacts on the structure of benthic communities. PMID:25861114

  5. Control of root-knot nematodes on tomato in stone wool substrate with biological nematicides.

    PubMed

    López-Pérez, Jose Antonio; Edwards, Scott; Ploeg, Antoon

    2011-06-01

    The efficacy of four biological nematicides on root-galling, root-knot nematode (Meloidogyne incognita) reproduction, and shoot weight of tomato (Solanum lycopersicum) grown in stone wool substrate or in pots with sandy soil was compared to an oxamyl treatment and a non-treated control. In stone wool grown tomato, Avid® (a.i. abamectin) was highly effective when applied as a drench at time of nematode inoculation. It strongly reduced root-galling and nematode reproduction, and prevented a reduction in tomato shoot weight. However, applying the product one week before, or two weeks after nematode inoculation was largely ineffective. This shows that Avid® has short-lived, non-systemic activity. The effects of Avid® on nematode symptoms and reproduction on soil-grown tomato were only very minor, probably due to the known strong adsorption of the active ingredient abamectin to soil particles. The neem derived product Ornazin® strongly reduced tomato root-galling and nematode reproduction only in stone wool and only when applied as a drench one week prior to nematode inoculation, suggesting a local systemic activity or modification of the root system, rendering them less suitable host for the nematodes. This application however also had some phytotoxic effect, reducing tomato shoot weights. The other two products, Nema-Q™ and DiTera®, did not result in strong or consistent effects on nematode symptoms or reproduction.

  6. Effect of Crotalaria juncea Amendment on Nematode Communities in Soil with Different Agricultural Histories

    PubMed Central

    Wang, K.-H.; McSorley, R.; Gallaher, R. N.

    2003-01-01

    Effect of sunn hemp (Crotalaria juncea) hay amendment on nematode community structure in the soil surrounding roots of yellow squash (Cucurbita pepo) infected with root-knot nematodes was examined in two greenhouse experiments. Soils were from field plots treated long-term (LT) with yard-waste compost or no yard-waste compost in LT experiment, and from a short-term (ST) agricultural site in ST experiment. Soils collected were either amended or not amended with C. juncea hay. Nematode communities were examined 2 months after squash was inoculated with Meloidogyne incognita. Amendment increased (P < 0.05) omnivorous nematodes in both experiments but increased only bacterivorous nematodes in ST experiment (P < 0.05), where the soil had relatively low organic matter (<2%). This effect of C. juncea amendment did not occur in LT experiment, in which bacterivores were already abundant. Fungivorous nematodes were not increased by C. juncea amendment in either experiment, but predatory nematodes were increased when present. Although most nematode faunal indices, including enrichment index, structure index, and channel index, were not affected by C. juncea amendment, structure index values were affected by previous soil organic matter content. Results illustrate the importance of considering soil history (organic matter, nutrient level, free-living nematode number) in anticipating changes following amendment with C. juncea hay. PMID:19262764

  7. Control of Larval Northern Corn Rootworm. (Diabrotica barberi) with Two Steinernematid Nematode Species

    PubMed Central

    Thurston, G. S.; Yule, W. N.

    1990-01-01

    The entomogenous nematodes Steinerema feltiae and S. bibionis did not penetrate the roots of corn, Zea mays, to infect larval northern corn rootworm (NCR), Diabrotica barberi, feeding within. Laboratory bioassays against first instar NCR indicated that S. feltiae, Mexican strain (LD₅₀ = 49 nematodes/insect) is more virulent than S. bibionis (LD₅₀ = 100). Numbers of NCR larvae in a grain corn crop were reduced by both nematode species applied at corn seeding time at the rate of 10,000 infective-stage juveniles per linear meter of corn row. The chemical insecticide fonofos provided significantly better control than either nematode species. PMID:19287699

  8. RNA-Seq reveals the molecular mechanism of trapping and killing of root-knot nematodes by nematode-trapping fungi.

    PubMed

    Pandit, Ramesh; Patel, Reena; Patel, Namrata; Bhatt, Vaibhav; Joshi, Chaitanya; Singh, Pawan Kumar; Kunjadia, Anju

    2017-04-01

    Nematode-trapping fungi are well known for their inherent potential to trap and kill nematodes using specialized trapping devices. However, the molecular mechanisms underlying the trapping and subsequent processes are still unclear. Therefore, in this study, we examined differential genes expression in two nematode-trapping fungi after baiting with nematode extracts. In Arthrobotrys conoides, 809 transcripts associated with diverse functions such as signal transduction, morphogenesis, stress response and peroxisomal proteins, proteases, chitinases and genes involved in the host-pathogen interaction showed differential expression with fold change (>±1.5 fold) in the presence of nematode extract with FDR (p-value < 0.001). G-proteins and mitogen activated protein kinases are considered crucial for signal transduction mechanism. Results of qRT-PCR of 20 genes further validated the sequencing data. Further, variations in gene expression among Duddingtonia flagrans and A. conoides showed septicity of nematode-trapping fungi for its host. The findings illustrate the molecular mechanism of fungal parasitism in A. conoides which may be helpful in developing a potential biocontrol agent against parasitic nematodes.

  9. Bioinformatic prediction of arthropod/nematode-like peptides in non-arthropod, non-nematode members of the Ecdysozoa.

    PubMed

    Christie, Andrew E; Nolan, Daniel H; Garcia, Zachery A; McCoole, Matthew D; Harmon, Sarah M; Congdon-Jones, Benjamin; Ohno, Paul; Hartline, Niko; Congdon, Clare Bates; Baer, Kevin N; Lenz, Petra H

    2011-02-01

    The Onychophora, Priapulida and Tardigrada, along with the Arthropoda, Nematoda and several other small phyla, form the superphylum Ecdysozoa. Numerous peptidomic studies have been undertaken for both the arthropods and nematodes, resulting in the identification of many peptides from each group. In contrast, little is known about the peptides used as paracrines/hormones by species from the other ecdysozoan taxa. Here, transcriptome mining and bioinformatic peptide prediction were used to identify peptides in members of the Onychophora, Priapulida and Tardigrada, the only non-arthropod, non-nematode members of the Ecdysozoa for which there are publicly accessible expressed sequence tags (ESTs). The extant ESTs for each phylum were queried using 106 arthropod/nematode peptide precursors. Transcripts encoding calcitonin-like diuretic hormone and pigment-dispersing hormone (PDH) were identified for the onychophoran Peripatopsis sedgwicki, with transcripts encoding C-type allatostatin (C-AST) and FMRFamide-like peptide identified for the priapulid Priapulus caudatus. For the Tardigrada, transcripts encoding members of the A-type allatostatin, C-AST, insect kinin, orcokinin, PDH and tachykinin-related peptide families were identified, all but one from Hypsibius dujardini (the exception being a Milnesium tardigradum orcokinin-encoding transcript). The proteins deduced from these ESTs resulted in the prediction of 48 novel peptides, six onychophoran, eight priapulid and 34 tardigrade, which are the first described from these phyla.

  10. Paralysis of nematodes: shifts in the transcriptome of the nematode-trapping fungus Monacrosporium haptotylum during infection of Caenorhabditis elegans.

    PubMed

    Fekete, Csaba; Tholander, Margareta; Rajashekar, Balaji; Ahrén, Dag; Friman, Eva; Johansson, Tomas; Tunlid, Anders

    2008-02-01

    The transcriptional response in the parasitic fungus Monacrosporium haptotylum and its nematode host Caenorhabditis elegans were analysed during infection using cDNA microarrays. The array contained 2684 fungal and 372 worm gene reporters. Dramatic shifts occurred in the transcriptome of M. haptotylum during the different stages of the infection. An initial transcriptional response was recorded after 1 h of infection when the traps adhered to the cuticle, but before immobilization of the captured nematodes. Among the differentially expressed genes were two serine protease genes (spr1 and spr2), and several homologues to genes known to be regulated in other pathogenic fungi. After 4 h, when approximately 40% of the nematodes were paralysed, we identified an upregulated cluster of 372 fungal genes which were not regulated during the other phases of the infection. This cohort contained a large proportion (79%) of genes that appear to be specific for M. haptotylum and closely related species. These genes were of two different classes: those translating into presumably functional peptides and those with no apparent protein coding potential (non-coding RNAs). Among the infection-induced C. elegans genes were those encoding antimicrobial peptides, protease inhibitors and lectins.

  11. Carbofuran effects in soil nematode communities: using trait and taxonomic based approaches.

    PubMed

    Chelinho, Sónia; Dieter Sautter, Klaus; Cachada, Anabela; Abrantes, Isabel; Brown, George; Costa Duarte, Armando; Sousa, José Paulo

    2011-10-01

    This work intends to implement the use of native soil nematode communities in ecotoxicological tests using a model pesticide and two geographically nematode communities (Mediterranean and sub-tropical) in order to obtain new perspectives on the evaluation of the toxic potential of chemical substances. The environmental condition of the nematode communities was described using a trait-based approach (grouping the organisms according to their feeding traits) and a traditional taxonomic method (identification to family level). Effects on total nematode abundance, number of families and abundance of nematode feeding groups as well as potential shifts in both trophic and family structure were assessed. Agricultural soils from Curitiba (Brazil) and Coimbra (Portugal) were sampled and the corresponding nematode communities were extracted. Part of the collected soil was defaunated and spiked with four doses of a carbofuran commercial formulation. Afterwards each of the replicates was inoculated with a nematode suspension containing ≈200 or 300 nematodes. After 14 and 28 d of exposure the nematodes were extracted, counted and identified at family level and separately classified according to their feeding traits. The patterns of nematode responses revealed a decrease in the total abundance and a reduction in the number of families. Despite the similar effects observed for both communities, statistically significant toxic effects were only found within the Portuguese community. The total nematode abundance was significantly reduced at the highest carbofuran concentrations and significant shifts in the family structure were detected. However, the trophic structure, i.e., the contribution of each feeding group for the overall community structure, did not significantly change along the contamination gradient. Results showed that using such a trait-based approach may increase the ecological relevance of toxicity data, by establishing communalities in the response to a chemical

  12. Sensory interaction between attractant diacetyl and repellent 2-nonanone in the nematode Caenorhabditis elegans.

    PubMed

    Matsuura, Tetsuya; Izumi, Junichi; Hioki, Mamoru; Nagaya, Hiroki; Kobayashi, Yasuaki

    2013-06-01

    In the nematode Caenorhabditis elegans, the odorant diacetyl is sensed by AWA sensory neurons in the amphid sensory organ and elicits an attractive response, whereas 2-nonanone is sensed by AWB amphid sensory neurons and elicits an avoidance response. In the present study, we report that nematodes exhibit a sensory interaction between the attractant diacetyl and repellent 2-nonanone. In the presence of food, the chemotactic response to 0.01% diacetyl in nematodes preexposed to 0.1% diacetyl was greater than that in nonexposed naive nematodes (P < 0.05). The response to diacetyl was also greater in nematodes preexposed to 3% 2-nonanone in the presence of food than that in naive nematodes (P < 0.01). In the absence of food, the response to diacetyl in nematodes preexposed to diacetyl or 2-nonanone was significantly lower than that in nonexposed control nematodes (P < 0.01). The avoidance response to 10% 2-nonanone in nematodes preexposed to each odorant in the presence or absence of food was lower than that in nonexposed nematodes (P < 0.05). To confirm the validity of our results, the chemotactic responses to diacetyl and 2-nonanone were observed using che-3, odr-4, and odr-10 mutants, which exhibited defective sensitivity to diacetyl or 2-nonanone. From the results of our experiments, we conclude that nematodes exhibit a sensory interaction between diacetyl and 2-nonanone and speculate that this interaction is driven by higher-level neuronal circuits that underlie sensory integration.

  13. Soil nematode assemblages as bioindicators of radiation impact in the Chernobyl Exclusion Zone.

    PubMed

    Lecomte-Pradines, C; Bonzom, J-M; Della-Vedova, C; Beaugelin-Seiller, K; Villenave, C; Gaschak, S; Coppin, F; Dubourg, N; Maksimenko, A; Adam-Guillermin, C; Garnier-Laplace, J

    2014-08-15

    In radioecology, the need to understand the long-term ecological effects of radioactive contamination has been emphasised. This requires that the health of field populations is evaluated and linked to an accurate estimate of received radiological dose. The aim of the present study was to assess the effects of current radioactive contamination on nematode assemblages at sites affected by the fallout from the Chernobyl accident. First, we estimated the total dose rates (TDRs) absorbed by nematodes, from measured current soil activity concentrations, Dose Conversion Coefficients (DCCs, calculated using EDEN software) and soil-to-biota concentration ratios (from the ERICA tool database). The impact of current TDRs on nematode assemblages was then evaluated. Nematodes were collected in spring 2011 from 18 forest sites in the Chernobyl Exclusion Zone (CEZ) with external gamma dose rates, measured using radiophotoluminescent dosimeters, varying from 0.2 to 22 μGy h(-1). These values were one order of magnitude below the TDRs. A majority of bacterial-, plant-, and fungal-feeding nematodes and very few of the disturbance sensitive families were identified. No statistically significant association was observed between TDR values and nematode total abundance or the Shannon diversity index (H'). The Nematode Channel Ratio (which defines the relative abundance of bacterial- versus fungal-feeding nematodes) decreased significantly with increasing TDR, suggesting that radioactive contamination may influence nematode assemblages either directly or indirectly by modifying their food resources. A greater Maturity Index (MI), usually characterising better soil quality, was associated with higher pH and TDR values. These results suggest that in the CEZ, nematode assemblages from the forest sites were slightly impacted by chronic exposure at a predicted TDR of 200 μGy h(-1). This may be imputable to a dominant proportion of pollutant resistant nematodes in all sites. This might

  14. Insights into adaptations to a near-obligate nematode endoparasitic lifestyle from the finished genome of Drechmeria coniospora

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematophagous fungi employ three distinct predatory strategies: nematode trapping, parasitism of females and eggs, and endoparasitism. While endoparasites play key roles in controlling nematode populations in nature, their application for integrated pest management is hindered by the limited underst...

  15. New Discoveries in Resistances to Columbia Root-knot Nematode and Corky Ringspot Disease

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The Columbia root-knot nematode CRKN (Meloidogyne chitwoodi) is a serious pest of potato in the Pacific Northwest. In the warmer zones, with longer growing seasons, this nematode builds up to high populations and damages the potato tubers by invading and causing discoloration and galling. It is pr...

  16. Screening Locally Adapted Spring Wheat Lines for Resistance to Cereal Cyst Nematode

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cereal cyst nematode (Heterodera avenae) has become an increasing problem in the high precipitation areas of eastern Washington and the Palouse. Since 2010, surveys have discovered serious infestations of this nematode, which infects wheat, barley and grassy weeds. It causes severe yield loss, restr...

  17. Nematode and Grape Rootstock Interactions Including an Improved Understanding of Tolerance

    PubMed Central

    McKenry, M.V.; Anwar, Safdar A.

    2006-01-01

    Sixteen cultivars of grape were screened over a two-year period in the presence or absence of 10 different nematode populations. Populations of Meloidogyne spp., Xiphinema index, and Mesocriconema xenoplax developed more rapidly and caused greater damage than populations of X. americanum and Tylenchulus semipenetrans. Populations of mixed Meloidogyne spp. having a history of feeding on grape were among the fastest developing populations. Tolerance to nematode parasitism appeared to be based on different mechanisms. Slow developing, less pathogenic nematode populations often stimulated vine growth, thus vines appeared to possess tolerance. Likewise, cultivars selected for nematode resistance often stimulated vine growth when fed upon by the nematode. However, tolerance sources that resulted from nematode resistance are vulnerable due to the occurrence of populations that break resistance mechanisms. Growth of cultivars with phylloxera (Daktalospharia vitifoliae) resistance was unchanged by the presence of nematodes, indicating that phylloxera resistance may provide a useful source of nematode relief. These and several additional sources of specific tolerance are discussed. PMID:19259534

  18. Resiliency of a nematode community and suppressive service to tillage and nematicide application.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We hypothesized that populations of predatory and omnivorous nematodes would be slower to recover from conventional tillage and nematicide application than the other nematode trophic groups, and that lower populations of predators and omnivores would lead to greater survival and reproduction of plan...

  19. Observations on the foliar nematode, Aphelenchoides besseyi, infecting tuberose and rice in India

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The foliar nematode Aphelenchoides besseyi causes white tip disease in rice (Oryza sativa L.) and floral malady in tuberose (Polianthes tuberosa L.). This nematode is widely distributed in the rice fields of many states of India, including West Bengal (WB), Andhra Pradesh (AP), Madhya Pradesh (MP) a...

  20. Toxicity of 2,4-diacetylphloroglucinol (DAPG) to Plant-parasitic and Bacterial-feeding Nematodes

    PubMed Central

    Halbrendt, John M.; Carta, Lynn K.; Skantar, Andrea M.; Liu, Ting; Abdelnabby, Hazem M. E.; Vinyard, Bryan T.

    2009-01-01

    The antibiotic 2,4-diacetylphloroglucinol (DAPG) is produced by some isolates of the beneficial bacterium Pseudomonas fluorescens. DAPG is toxic to many organisms, and crop yield increases have been reported after application of DAPG-producing P. fluorescens. This study was conducted to determine whether DAPG is toxic to selected nematodes. The plant-parasitic nematodes Heterodera glycines, Meloidogyne incognita, Pratylenchus scribneri and Xiphinema americanum, and the bacterial-feeding nematodes Caenorhabditis elegans, Pristionchus pacificus, and Rhabditis rainai, were immersed in concentrations ranging from 0 to 100 μg/ml DAPG. Egg hatch and viability of juveniles and adults were determined. DAPG was toxic to X. americanum adults, with an LD50 of 8.3 μg/ml DAPG. DAPG decreased M. incognita egg hatch, but stimulated C. elegans hatch during the first hours of incubation. Viability of M. incognita J2 and of C. elegans J1 and adults was not affected. There were no observed effects on the other nematodes. The study indicated that DAPG is not toxic to all nematodes, and did not affect the tested species of beneficial bacterial-feeding nematodes. Augmentation of DAPG-producing P. fluorescens populations for nematode biocontrol could be targeted to specific nematode species known to be affected by this compound and by other antibiotics produced by the bacteria, or these bacteria could be used for other possible effects, such as induced plant resistance. PMID:22736826

  1. Onchocerca lupi Nematodes in Dogs Exported from the United States into Canada

    PubMed Central

    Conboy, Gary; Lejeune, Manigandan; Marron, Fany; Hanna, Paul; MacDonald, Erin; Skorobohach, Brian; Wilcock, Brian; Kutz, Susan J.; Gilleard, John S.

    2016-01-01

    The Onchocerca lupi nematode is an emerging helminth capable of infecting pets and humans. We detected this parasite in 2 dogs that were imported into Canada from the southwestern United States, a region to which this nematode is endemic. We discuss risk for establishment of O. lupi in Canada. PMID:27434170

  2. A novel approach to biocontrol: release of live insect hosts pre-infected with entomopathogenic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    As a new application approach, we tested the efficacy of releasing live insect hosts that were pre-infected with entomopathogenic nematodes against insect pests living in cryptic habitats. We hypothesized that the pre-infected hosts could carry the next generation of emerging nematode infective juv...

  3. Assessment of the effects of Hirsutella minnesotensis on Soybean Cyst Nematode and growth of soybean

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hirsutella minnesotensis is a fungal endoparasite of nematodes juvenile and parasitizes soybean cyst nematodes (SCN) with high frequency. In this study, the effects of two H. minnesotensis isolates on population and distribution of SCN and growth of soybean were evaluated. Experiments were conducted...

  4. Registration of JTN-5203 soybean germplasm with resistance to multiple cyst nematode populations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    JTN-5203 soybean [Glycine max (L.) Merr.] (Reg. No. XX-XXX, PI 664903) was developed and released by USDA-ARS in collaboration with the University of Tennessee in 2012 for its broad resistance to soybean cyst nematode (SCN; Heterodera glycines Ichinohe), as well as reniform nematode (Rotylenchulus ...

  5. Enhanced biological control potential of the entomopathogenic nematode, Steinernema carpocapsae, applied with a protective gel formulation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes combined with the anti-desiccation gel, Barricade®, have potential as an effective pest management tool. We (1) ascertained whether Barricade® could provide protection to entomopathogenic nematode s at low concentrations when applied in direct sun, (2) determined if other ...

  6. Is there any seasonal variation in marine nematodes within the sediments of the intertidal zone?

    PubMed

    Yodnarasri, Supaporn; Montani, Shigeru; Tada, Kuninao; Shibanuma, Seiichiro; Yamada, Toshiro

    2008-01-01

    The sediment parameters and nematode assemblages in the intertidal zone of the Hichirippu shallow lagoon, Hokkaido, Japan, were investigated. The objectives of this study were to observe the seasonal variation in the nematodes in the sediment, and to investigate the relationships between the nematodes and environmental factors. Samples were collected bi-monthly from five stations on the tidal flat from April 2003 to February 2004. It was found that the sediment parameters (Chl a concentration, AVS, TOC and TN contents) varied throughout the 10-month study. Fifty-four species of nematodes were found in the study area. The density and biomass of the nematodes varied in accordance with the sediment temperature during the sampling period. In this study, there was a seasonal variation in the nematode assemblage found in the intertidal zone of this shallow lagoon. The important factors affecting this variation were sediment temperature, and food competition among the nematodes themselves. The seasonal variation of the nematode also showed a relationship with the Chl a concentration in the sediment during the sampling period.

  7. [Structural characteristics of soil nematodes community under different land uses in Changchun City].

    PubMed

    Wu, Donghui; Zhang, Bai; Chen, Peng

    2006-03-01

    In this paper, an investigation on the species richness and abundance of soil nematodes in farmland, natural secondary forest, shelter forest and green space was made in Changchun City in July and September, 2003. Soil nematodes were extracted with Baermann extractor, and identified to the genus level with the aid of microscope. A total of 7273 soil nematode individuals were captured, and fell into 2 classes, 7 orders, 20 families, and 27 genera. Aphelenchus, Tylenchus and Pratylenchus were the dominant genera, which accounted for 61.58% of total individuals. Land use type had a significant effect on the community structure of soil nematodes, and aboveground litter removal and cultivation activity were the main factors affecting soil nematodes community structure. Above-ground litter removal considerably decreased soil nematodes individual density and community diversity, while cultivation activity changed the vertical distribution of soil nematodes individual density in the soil profile. Above-ground vegetation structure and landscape pattern appeared to have little effect on the ecological structure of soil nematodes community.

  8. Transcriptome analysis of resistant and susceptible alfalfa cultivars infected with root-knot nematode Meloidogyne incognita

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nematodes are one of the major limiting factors in alfalfa production. Root knot nematodes (RKN, Meloidogyne spp.) are widely distributed and economically important sedentary endoparasites of agricultural crops (Castagnone-Sereno et al. 2013) and they may inflict significant damage to alfalfa fields...

  9. Transcript Analysis of Parasitic Females of the Sedentary Semi-Endoparasitic Nematode Rotylenchulus reniformis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reniform nematode, Rotylenchulus reniformis Linford & Oliveira, is a sedentary semi-endoparasitic roundworm that infects the roots of many economically important plant species. Engineered resistance to plant-parasitic nematodes (PPNs) via RNA-interference (RNAi) has shown promise in providing h...

  10. Post-transcriptional gene silencing of root knot-nematode in transformed soybean roots

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic nematodes cause about $100 billion in crop losses annually. Root-knot nematodes (RKN; Meloidogyne spp.) are sedentary endoparasites, and the genus has been found on more than 3000 host plant species. In this study four different gene constructs were designed to produce RNA interferen...

  11. A novel nematode effector suppresses plant immunity by activating host reactuve oxygen species-scavenging system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Oxidative burst is a hallmark event of the pathogen-associated molecular pattern (PAMP) triggered immunity (PTI), which is the first line of plant defense mechanisms, but it remains unclear how nematodes can overcome this defense mechanism. In this study, we show that plant-parasitic nematode Meloid...

  12. Effects of Midas® on Nematodes in Commercial Floriculture Production in Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cut flower producers currently have limited options for nematode control. Four field trials were conducted in 2006 and 2007 to evaluate Midas® (iodomethane:chloropicrin 50:50) for control of root-knot nematodes (Meloidogyne arenaria) on Celosia argentea var. cristata in a commercial floriculture pr...

  13. Identification of a SNP marker associated with WB242 nematode resistance in sugar beet

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The beet-cyst nematode (Heterodera schachtii Schmidt) is one of the major diseases of sugar beet. The identification of molecular markers associated to the nematode resistance would be helpful for developing resistant varieties. The aim of this study was the identification of SNP (Single Nucleotide ...

  14. Molecular markers and mapping of root-knot nematode resistance in cotton.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host-plant resistance is economic and highly effective for root-knot nematode (RKN) Meloidogyne incognita control in cotton Gossypium hirsutum. Recently, nematode R gene mapping in cotton has revealed relationships between resistance sources and linked molecular markers. Markers are important for th...

  15. HOW FUNGI INTERACT WITH NEMATODE TO ACTIVATE THE PLANT DEFENCE RESPONSE TO TOMATO PLANTS.

    PubMed

    Leonetti, P; Costanza, A; Zonno, M C; Molinari, S; Altomare, C

    2014-01-01

    Management of plant parasitic nematodes with nematode predators, parasites or antagonists is an eco-friendly approach that may avoid the problems arisen by the use of toxic chemicals. Fungi belonging to Trichoderma spp. are well known in literature for their role in control of plant parasitic nematodes. Root-knot nematodes (RKNs), Meloidogyne spp., are obligate parasites that cause the formation of familiar galls on the roots of many cultivated plants. The interaction between the M. incognita motile second stage juveniles (J2s) and the isolate ITEM 908 of Trichoderma harzianum was examined in its effect on the nematode infestation level of susceptible tomato plants. To gain insight into the mechanisms by which ITEM 908 interacts with nematode-infected tomato plants, the expression patterns of the genes PR1 (marker of Salycilic Acid-depending resistance signalling pathway) and JERF3 (marker of the Jasmonic Acid/Ethylene-depending resistance signalling pathway) were detected over time in: i) untreated roots; ii) roots pre-treated with the fungus; iii) roots inoculated with the nematode; iv) pre-treated and inoculated roots. Infestation parameters were checked in untreated plants and plants treated with the fungus to test the effect of the fungus on nematode infestation level and to compare this effect with the expression of the genes PR1 and JERF3, involved in induced resistance.

  16. Low cost production of nematodes for biological control of insect pests

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Entomopathogenic nematodes are produced in two ways: in artificial media using liquid or solid fermentation methods (in vitro) or by mass producing insect hosts to be artificially exposed to mass infection by nematodes (in vivo). The yellow mealworm (Tenebrio molitor) is a good host for in vivo nema...

  17. First report of the stubby root nematode Paratrichodorus allius on potato in North Dakota

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Stubby root nematodes (Paratrichodorus and Trichodorus) are migratory ectoparasites that feed on roots and vector tobraviruses. These nematodes are important to the potato industry as they transmit Tobacco rattle virus (TRV) causing corky ringspot (CRS) disease that has a direct economic impact on g...

  18. Evaluating the predatory potential of carnivorous nematodes against Rotylenchulus reniformis and Meloidogyne incognita

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Predatory behavior of a nematode is usually determined through gut content observation or prey delimitation counts. In this experiment, Mononchus and Neoactinolaimus predation of Rotylenchulus reniformis or Meloidogyne incognita was determined using a PCR-based nematode gut content analysis. Soil sa...

  19. DYNAMICS OF NEMATODE POPULATIONS IN CACAO GROWN UNDER TRADIONALLY SYSTEM OF MANAGEMENT IN PERUVIAN AMAZON

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Nature of crops and management systems greatly influences population dynamics of parasitic and nonparasitic nematodes in soil. An experiment was undertaken at Tropical Crop Research institute (ICT), Tarapoto, Peru to assess the population dynamics of nematodes in a Cocoa (Theobroma cacao L.)-Banana ...

  20. Evaluation of University of Georgia turfgrass for response to sting nematode feeding

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Turfgrasses grown in the sandy, well-drained soils of the Atlantic coastal plain in the United States will likely encounter sting nematode (Belonolaimus longicaudatus) pressure. The identification of resistance or tolerance genes which would allow new cultivars to thrive in plant-parasitic nematode...

  1. Poly(T) variation in heteroderid nematode mitochondrial genomes is predominantly an artifact of amplification

    Technology Transfer Automated Retrieval System (TEKTRAN)

    We assessed the rate of in vitro polymerase errors at polythymidine tracts in the mitochondrial DNA (mtDNA) of a heteroderid nematode (Heterodera cajani). The mtDNA of these nematodes contains unusually high numbers of poly(T) tracts, and has previously been suggested to contain biological poly(T) l...

  2. Helminths and helminthoses in Central Europe: diseases caused by nematodes (roundworms).

    PubMed

    Auer, Herbert; Aspöck, Horst

    2014-10-01

    The third part of the overview "Helminths and helminthoses in Central Europe" deals with the medically relevant nematodes (roundworms) and nematode-caused diseases occurring in Central Europe. The paper comprises data on the biology of the parasites and their ways of transmission, describes the symptomatology of the diseases, summarizes the possibilities of diagnosis and refers to the prophylactic means.

  3. Extensive mitochondrial gene rearrangement in a genus of plant parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The nematodes Globodera pallida and G. rostochiensis are two of the only animals known to have multipartite mitochondrial genomes. In such genomes, mitochondrial genes are distributed on multiple circles. The entire sequence of a nematode (Radopholus similis) that belongs to the same superfamily (...

  4. Role of nematode peptides and other small molecules in plant parasitism

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Molecular, genetic, and biochemical studies are demonstrating an increasingly important role of peptide signaling in nematode parasitism of plants. To date, the majority of nematode-secreted peptides identified share similarity with plant CLAVATA3/ESR (CLE) peptides, but bioinformatics analyses of n...

  5. Activation of geminivirus V-sense promoters in roots is restricted to nematode feeding sites.

    PubMed

    Escobar, Carolina; García, Alejandra; Aristizábal, Fabio; Portillo, Mary; Herreros, Esther; Munoz-Martín, M Angeles; Grundler, Florian; Mullineaux, Phillip M; Fenoll, Carmen

    2010-05-01

    Obligate sedentary endoparasitic nematodes, such as the root-knot and cyst nematodes, elicit the differentiation of specialized nematode nurse or feeding cells [nematode feeding sites (NFS), giant cells and syncytia, respectively]. During NFS differentiation, marked changes in cell cycle progression occur, partly similar to those induced by some geminiviruses. In this work, we describe the activation of V-sense promoters from the Maize streak virus (MSV) and Wheat dwarf virus (WDV) in NFS formed by root-knot and cyst nematodes. Both promoters were transiently active in microinjection experiments. In tobacco and Arabidopsis transgenic lines carrying promoter-beta-glucuronidase fusions, the MSV V-sense promoter was activated in the vascular tissues of aerial plant parts, primarily leaf and cotyledon phloem tissue and some floral structures. Interestingly, in roots, promoter activation was restricted to syncytia and giant cells tested with four different nematode populations, but undetectable in the rest of the root system. As the activity of the promoter in transgenic rootstocks should be restricted to NFS only, the MSV promoter may have utility in engineering grafted crops for nematode control. Therefore, this study represents a step in the provision of some of the much needed additional data on promoters with restricted activation in NFS useful in biotechnological nematode control strategies.

  6. Canine Infections with Onchocerca lupi Nematodes, United States, 2011–2014

    PubMed Central

    Giannelli, Alessio; Latrofa, Maria S.; Dantas-Torres, Filipe; Trumble, Nicole Scotty; Chavkin, Matt; Kennard, Gavin; Eberhard, Mark L.; Bowman, Dwight D.

    2015-01-01

    Infections with Onchocerca lupi nematodes are diagnosed sporadically in the United States. We report 8 cases of canine onchocercosis in Minnesota, New Mexico, Colorado, and Florida. Identification of 1 cytochrome c oxidase subunit 1 gene haplotype identical to 1 of 5 from Europe suggests recent introduction of this nematode into the United States. PMID:25897859

  7. Current status of phytoparasitic nematodes and their host plants in Egypt

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In Egypt many phytoparasitic nematodes constitute a major constraint to agricultural production, especially in sandy soil and reclaimed desert lands. Nematological surveys were conducted to determine the genera and species of phytoparasitic nematodes on associated host plants in Egypt. The results i...

  8. The use of entomopathogenic nematodes in the US and issues related to genetic degradation

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Research and commercial application of entomopathogenic nematodes in North America has a long history. In the pursuit of commercial viability, there have been a number of success stories, but also quite a number of dead ends. We provide insight into new opportunities for entomopathogenic nematodes...

  9. The plant-parasitic nematode collections of RRIP: The realization of an ISTC project

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic nematodes are important pests of agricultural and wild plants throughout Russia and the world. The best strategy for management of nematode damage is an integrated approach to the problem: i.e., the use of agrotechnological approaches (crop rotation, soil amendments, etc.), reasonabl...

  10. Some taxonomic and phylogenetic trends for free-living and plant-parasitic nematodes

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The information, techniques and strategies used by nematode taxonomists have improved in major ways over the last 15 years. New methods of specimen preparation, new microscopic procedures, and new morphological and molecular characters have improved the quality of nematode descriptions. Testing taxo...

  11. A survey of plant-parasitic nematodes associated with forage crops in Bingol, Turkey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    During June 2011, a survey was conducted in four districts of Bingol Province, Turkey, to investigate the occurrence, population abundance and spatial distribution of plant-parasitic nematodes associated with pastures. A total of 24 soil samples were collected. Nematodes were extracted from soil by ...

  12. Evaluation of Rubus spp. and Hybrids for Root Lesion Nematode, Pratylenchus penetrans, Resistance

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The root lesion nematode, Pratylenchus penetrans, is a production-limiting pest in red raspberry, Rubus ideaus, in the United States. Having resistance as a tool to manage P. penetrans in raspberries would reduce the impact of this nematode on raspberry productivity as well as reduce the need for p...

  13. Host status of Rubus species and hybrids for the root lesion nematode, Pratylenchus penetrans

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The root lesion nematode, Pratylenchus penetrans, is a production-limiting pest in red raspberry, Rubus idaeus, in the United States. Having resistance as a tool to manage P. penetrans in raspberries would reduce the impact of this nematode on raspberry productivity as well as reduce the need for pr...

  14. Product evaluation for reniform nematode suppression in Mississippi Delta sweetpotato production, 2011

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The reniform nematode, Rotylenchulus reniformis, can cause significant losses in sweetpotato, Ipomoea batatas, production in the Mississippi Delta. Reniform nematode is a microscopic plant parasite that feeds on sweetpotato roots causing severe stunting of root growth. Reduction in yield due to the ...

  15. The discovery of fluazaindolizine: A new product for the control of plant parasitic nematodes.

    PubMed

    Lahm, George P; Desaeger, Johan; Smith, Ben K; Pahutski, Thomas F; Rivera, Michel A; Meloro, Tony; Kucharczyk, Roman; Lett, Renee M; Daly, Anne; Smith, Brenton T; Cordova, Daniel; Thoden, Tim; Wiles, John A

    2017-04-01

    Fluazaindolizine is a new highly effective and selective product for the control of plant parasitic nematodes. Specificity for nematodes coupled with absence of activity against the target sites of commercial nematicides suggests that fluazaindolizine has a novel mode of action. The discovery, structure-activity development and biological properties for this new class of nematicides are presented.

  16. Post-Plant nematicides for the control of root lesion nematode in red raspberry

    Technology Transfer Automated Retrieval System (TEKTRAN)

    There are currently few registered post-plant nematicides available to control root lesion nematode (Pratylenchus penetrans, RLN) in red raspberry (Rubus ideaus). The rate of raspberry decline due to RLN depends upon the nematode population density but usually occurs over a 3- to 4-year period. To ...

  17. Distribution and infestation rate of cyst nematodes (Tylenchida: Heteroderidae) in cabbage growing areas in Samsun

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Information concerning the occurrence and distribution of cyst nematodes (Heterodera spp.) in Samsun, Turkey is needed to assess their potential to cause economic damage on many crop plants. Surveys on the distribution and infestation rates of cyst nematodes in cabbage fields in Samsun were conducte...

  18. Cotton Cultivar Response to Root-Knot Nematodes in Two Tillage Regimes, 2008

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Six cotton cultivars were evaluated for yield response to the root-knot nematode in a naturally infested field at E. V. Smith Research and Extension Center, near Shorter, Alabama. The field had a long history of root-knot nematode infestation, and the soil type was classified as a sandy loam. Plots ...

  19. Canine Infections with Onchocerca lupi Nematodes, United States, 2011-2014.

    PubMed

    Otranto, Domenico; Giannelli, Alessio; Latrofa, Maria S; Dantas-Torres, Filipe; Trumble, Nicole Scotty; Chavkin, Matt; Kennard, Gavin; Eberhard, Mark L; Bowman, Dwight D

    2015-05-01

    Infections with Onchocerca lupi nematodes are diagnosed sporadically in the United States. We report 8 cases of canine onchocercosis in Minnesota, New Mexico, Colorado, and Florida. Identification of 1 cytochrome c oxidase subunit 1 gene haplotype identical to 1 of 5 from Europe suggests recent introduction of this nematode into the United States.

  20. Biological Control of the Nematode Infective larvae of Trichostrongylidae Family With Filamentous Fungi

    PubMed Central

    Zarrin, Majid; Rahdar, Mahmoud; Gholamian, Abbas

    2015-01-01

    Background: Biological control of parasitic nematodes by microorganisms is a promising approach to control such parasites. Microorganisms such as fungi, viruses and bacteria are recognized as biocontrol agents of nematodes. Objectives: The current study mainly aimed to evaluate the in vitro Potential of various saprophyte soil-fungi in reducing the infective larvae stage of parasitic nematode Trichostrongylidae family. Materials and Methods: Sheep feces were employed to provide the required third stage larvae source for the experiments. The nematode infective larvae of Trichostrongylidae family including three species of Ostertagia circumcincta, Marshalgia marshali and Heamonchos contortus were collected by Berman apparatus. Fifteen isolates of filamentous fungi were tested in the current study. One milliliter suspension containing 200 third stage larvae of Trichostrongylidae family was separately added to the fungal cultures in 2% water-agar medium Petri-dishes. Every day the live larvae were counted with light microscope (10X) and the number of captured larvae was recorded on different days. Results: Significant differences were observed in the results of co-culture of nematodes larva and fungi after seven days. The most effective fungi against the nematodes larvae were Cladosporium sp., Trichoderma sp., Fusarium equisetti, after seven days of incubation. Conclusions: The studies on fungi could be applied as suitable tools in biocontrol of nematode infections. However, additional surveys are required to select efficient with the ability to reduce the nematode larvae in the environment. PMID:25893084

  1. Two simple methods for the collection of individual life stages of reniform nematode, Rotylenchulus reniformis

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The sedentary semi-endoparasitic nematode Rotylenchulus reniformis, the reniform nematode, is a serious pest of cotton and soybean in the United States. In recent years, interest in the molecular biology of the interaction between R. reniformis and its plant hosts has increased; however, the unusual...

  2. Sunn Hemp cover cropping and organic fertilizer effects on the nematode community under temperate growing conditions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plantings of sunn hemp as a cover crop have been experimentally shown to improve soil health, reduce plant-parasitic nematodes, and increase nematode-antagonistic microorganisms. However, these studies have been largely conducted in tropical and subtropical regions. To investigate the impacts of sun...

  3. Effects of mixed cropping on a soil nematode community in honduras.

    PubMed

    Powers, L E; McSorley, R; Dunn, R A

    1993-12-01

    Nematode-resistant tropical legumes are effective in reducing populations of plant-parasitic nematodes when used in rotation systems. Mixed cropping is a common practice of many small farmers in Central America, but little is known about the effects of tropical legumes on nematode communities under these systems. To examine the effects of intercropping on the nematode fauna associated with squash (Cucurbita pepo) and cucumber (Cucumis sativa) in Honduras, two field experiments were conducted to compare nematode density and diversity in soil under cucurbits grown as a monocrop with that in soil under cucurbits intercropped with alfalfa (Medicago sativa) or hairy indigo (Indigofera hirsuta). A parallel series of field tests compared soil nematode communities associated with a cucurbit monocrop and a cucurbit intercropped with marigold (Tagetes patula), which may decrease nematode populations through the production of toxic root exudates. Among all four tests, over a period of 90 days, there were no consistent differences in densities of various nematode genera or trophic groups in intercropped versus monocropped plants, nor were there consistent differences in community diversities among treatments.

  4. Ecology of Nematodes Under Influence of Cucurbita spp. and Different Fertilizer Types

    PubMed Central

    Porazinska, D. L.; Coleman, D. C.

    1995-01-01

    In a field study conducted in Georgia, cucurbit plants with high (Cucurbita andreana) and low (Cucurbita maxima) concentrations of cucurbitacins were used in combination with two types of fertilizers to investigate their effects on the community of soil nematodes. Ecological measures of soil nematode community structure such as total nematode abundance, number of genera, trophic diversity, trophic group proportions, fungivore/bacterivore ratio, and modified maturity index were assessed and compared among treatments. In general, poultry manure (an organic source of nitrogen) and synthetic fertilizer (a nonorganic source of nitrogen) did not differ in their effects on the nematode communities throughout one growing season. Few differences between the two plant species were found for any of the nematode community measurements. Bacterial- and fungal-feeding nematodes were the most abundant trophic groups, averaging 60% and 20% of the nematode community, respectively. Trophic diversity, nematode maturity index, and fungivore/ bacterivore values were lowest at the beginning and highest at the end of the experiment. PMID:19277330

  5. Plant-parasitic nematodes associated with grapevines, Vitis vinifera, in Washington and Idaho

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Surveys were conducted in eastern Washington and Idaho to determine the plant-parasitic nematodes associated with wine grape (Vitis vinifera) vineyards. The most commonly encountered plant-parasitic nematodes in eastern Washington and Idaho wine grape vineyards were Meloidogyne hapla, Paratylenchus ...

  6. Effects of grafted heirloom tomatoes on parasitic nematode populations in an organic production system

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Grafting vegetable crops has shown potential to contribute to root-knot nematode management alone and in combination with chemical treatments. In organic production, there are extremely limited options currently available to growers for control of phytoparasitic nematodes. Grafting desirable tomat...

  7. Impact of grapevine (Vitis vinifera) varieties on reproduction of the northern root-knot nematode (Meloidogyne hapla)

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Plant-parasitic nematodes are microscopic soil worms that attack the roots of grape plants and cause yield loss. One of the most commonly encountered plant-parasitic nematodes in eastern Washington Vitis vinifera vineyards is Meloidogyne hapla, the northern root-knot nematode. The selection of plant...

  8. In-vitro Assays of Meloidogyne incognita and Heterodera glycines for Detection of Nematode-antagonistic Fungal Compounds

    PubMed Central

    Nitao, James K.; Meyer, Susan L. F.; Chitwood, David J.

    1999-01-01

    In-vitro methods were developed to test fungi for production of metabolites affecting nematode egg hatch and mobility of second-stage juveniles. Separate assays were developed for two nematodes: root-knot nematode (Meloidogyne incognita) and soybean cyst nematode (Heterodera glycines). For egg hatch to be successfully assayed, eggs must first be surface-disinfested to avoid the confounding effects of incidental microbial growth facilitated by the fungal culture medium. Sodium hypochlorite was more effective than chlorhexidine diacetate or formaldehyde solutions at surface-disinfesting soybean cyst nematode eggs from greenhouse cultures. Subsequent rinsing with sodium thiosulfate to remove residual chlorine from disinfested eggs did not improve either soybean cyst nematode hatch or juvenile mobility. Soybean cyst nematode hatch in all culture media was lower than in water. Sodium hypochlorite was also used to surface-disinfest root-knot nematode eggs. In contrast to soybean cyst nematode hatch, root-knot nematode hatch was higher in potato dextrose broth medium than in water. Broth of the fungus Fusarium equiseti inhibited root-knot nematode egg hatch and was investigated in more detail. Broth extract and its chemical fractions not only inhibited egg hatch but also immobilized second-stage juveniles that did hatch, confirming that the fungus secretes nematode-antagonistic metabolites. PMID:19270887

  9. The Effect of Endophytic Fungi on Nematode Populations in Summer-dormant and Summer-active Tall Fescue

    PubMed Central

    Rogers, James K.; Walker, Nathan R.; Young, Carolyn A.

    2016-01-01

    Summer-active (continental) and summer-dormant (Mediterranean) tall fescue morphotypes are each adapted to different environmental conditions. Endophyte presence provides plant parasitic nematode resistance, but not with all endophyte strains and cultivar combinations. This study sought to compare effects of four nematode genera on continental and Mediterranean cultivars infected with common toxic or novel endophyte strains. A 6-mon greenhouse study was conducted with continental cultivars, Kentucky 31 (common toxic) and Texoma MaxQ II (novel endophyte) and the Mediterranean cultivar Flecha MaxQ (novel endophyte). Endophyte-free plants of each cultivar were controls. Each cultivar × endophyte combination was randomly assigned to a control, low or high inoculation rate of a mixed nematode culture containing stunt nematodes (Tylenchorhynchus spp.), ring nematodes (Criconemella spp.), spiral nematodes (Helicotylenchus spp.), and lesion nematodes (Pratylenchus spp.). Endophyte infection had no effect on nematode population densities. The cultivar × endophyte interaction was significant. Population densities of stunt nematode, spiral nematode, and ring nematodes were higher for Flecha MaxQ than other cultivar × endophyte combinations. Novel endophyte infection enhances suitability of Flecha MaxQ as a nematode host. PMID:27418701

  10. Mercury in parasitic nematodes and trematodes and their double-crested cormorant hosts: bioaccumulation in the face of sequestration by nematodes.

    PubMed

    Robinson, Stacey A; Forbes, Mark R; Hebert, Craig E

    2010-10-15

    Endoparasites can alter their host's heavy metal concentrations by sequestering metals in their own tissues. Contracaecum spp. (a nematode), but not Drepanocephalus spathans (a trematode), were bioaccumulating mercury to concentrations 1.5 times above cormorant hosts. Nematodes did not have significantly greater stable nitrogen isotope values (δ(15)N) than their hosts, which is contradictory to prey-predator trophic enrichment studies, but is in agreement with other endoparasite-host relationships. However, Contracaecum spp. δ(13)C values were significantly greater than their hosts, which suggest that nematodes were consuming host tissues. Nematodes were accumulating and thus sequestering some of their cormorant hosts' body burden of methyl mercury; however, they were not dramatically reducing their hosts' accumulation of methyl mercury.

  11. Effects of gastrointestinal nematode infection on the ruminant immune system.

    PubMed

    Gasbarre, L C

    1997-11-01

    Gastrointestinal (GI) nematodes of ruminants evoke a wide variety of immune responses in their hosts. In terms of specific immune responses directed against parasite antigens, the resulting immune responses may vary from those that give strong protection from reinfection after a relatively light exposure (e.g. Oesophagostomum radiatum) to responses that are very weak and delayed in their onset (e.g. Ostertagia ostertagi). The nature of these protective immune responses has been covered in another section of the workshop and the purpose of this section will be to explore the nature of changes that occur in the immune system of infected animals and to discuss the effect of GI nematode infections upon the overall immunoresponsiveness of the host. The discussion will focus primarily on Ostertagia ostertagi because this parasite has received the most attention in published studies. The interaction of Ostertagia and the host immune system presents what appears to be an interesting contradiction. Protective immunity directed against the parasite is slow to arise and when compared to some of the other GI nematodes, is relatively weak. Although responses that reduce egg output in the feces or increase the number of larvae undergoing inhibition may occur after a relatively brief exposure (3-4 months), immune responses which reduce the number of parasites that can establish in the host are not evident until the animal's second year. Additionally, even older animals that have spent several seasons on infected pastures will have low numbers of Ostertagia in their abomasa, indicating that sterilizing immune responses against the parasite are uncommon. In spite of this apparent lack of specific protective immune responses, infections with Ostertagia induce profound changes in the host immune system. These changes include a tremendous expansion of both the number of lymphocytes in the local lymph nodes and the number of lymphoid cells in the mucosa of the abomasum. This expansion

  12. Plant-parasitic nematode infections in rice: molecular and cellular insights.

    PubMed

    Kyndt, Tina; Fernandez, Diana; Gheysen, Godelieve

    2014-01-01

    Being one of the major staple foods in the world, and an interesting model monocot plant, rice (Oryza sativa L.) has recently received attention from molecular nematologists studying the cellular and molecular aspects of the interaction between this crop and plant-parasitic nematodes. In this review, we highlight recent advances in this field, with a focus on the best-studied root-knot nematodes. Histological studies have revealed the cellular changes inside root-knot nematode-induced feeding sites, both in the compatible interaction with Oryza sativa and the incompatible interaction with the related species Oryza glaberrima. After comparing the published data from transcriptome analyses, mutant studies, and exogenous hormone applications, we provide a comprehensive model showing the role and interaction of plant hormone pathways in defense of this monocot crop against root nematodes, where jasmonate seems to play a key role. Finally, recent evidence indicates that effectors secreted from rice-infecting nematodes can suppress plant defense.

  13. Field Responses of Bermudagrass and Seashore paspalum Cultivars to Sting and Spiral Nematodes

    PubMed Central

    Pang, Wenjing; Luc, John E.; Crow, William T.; Kenworthy, Kevin E.; Giblin-Davis, Robin M.; McSorley, Robert; Kruse, Jason K.

    2011-01-01

    Belonolaimus longicaudatus and Helicotylenchus spp. are damaging nematode species on bermudagrass (Cynodon spp.) and seashore paspalum (Paspalum vaginatum) in sandy soils of the southeastern United States. Eight bermudagrass and three seashore paspalum cultivars were tested for responses to both nematode species in field plots for two years in Florida. Soil samples were taken every three months and nematode population densities in soil were quantified. Turfgrass aboveground health was evaluated throughout the growing season. Results showed that all bermudagrass cultivars, except TifSport, were good hosts for B. longicaudatus, and all seashore paspalum cultivars were good hosts for H. pseudorobustus. Overall, bermudagrass was a better host for B. longicaudatus while seashore paspalum was a better host for H. pseudorobustus. TifSport bermudagrass and SeaDwarf seashore paspalum cultivars supported the lowest population densities of B. longicaudatus. Seashore paspalum had a higher percent green cover than bermudagrass in the nematode-infested field. Nematode intolerant cultivars were identified. PMID:23430148

  14. Community Analyses of Plant-Parasitic Nematodes in the Kalsow Prairie, Iowa

    PubMed Central

    Norton, Don C.; Schmitt, Donald P.

    1978-01-01

    Twenty-one species of plant-parasitic nematodes were recovered from 15 sites in the Kalsow Prairie, Iowa. Nematode communities were analyzed by prominence and importance values of the nematode species and also by diversity and concentration of dominance. The use of numbers and biomass were compared in indices of diversity and concentration of dominance. Tylenchorhynchus maximns ranked first in mean density/site, prominence value, and importance value, although it was not found as frequently as many other nematodes. Xiphinema americanum and T. maximus were among the dominant nematodes in 11 of 15 sites when biomass was used in the concentration-of-dominance index, but they were dominant in only five sites when numbers were used. PMID:19305833

  15. Field Application of Entomopathogenic Nematodes for Control of Delia radicum in Collards

    PubMed Central

    Simser, Dave

    1992-01-01

    Control of Delia radicum (cabbage maggot) in field collards (Brassica oleracea) was compared after one or two applications of entomopathogenic nematodes, Steinernema carpocapsae (All strain) and Heterorhabditis bacterophora (HP88 strain), a single application of granular chlorpyrifos, and a water-only treatment. Nematodes were applied with a sprayer during the egg stage of first-generation D. radicum, and chlorpyrifos was hand placed around collard stems during the same period. A second nematode application was made 10 days later. Chlorpyrifos treatment resulted in fewer puparia per plant, less root damage and higher yield than all other treatments, including the control. Collard yield from nematode-treated beds did not differ from controls. These data indicate that, under these field conditions, the species or strains of entomopathogenic nematodes tested did not reduce the number of active cabbage maggots, nor did they prevent collard root damage. PMID:19283012

  16. Suppression of Root-knot Nematode Populations with Selected Rapeseed Cultivars as Green Manure

    PubMed Central

    Mojtahedi, H.; Santo, G. S.; Hang, A. N.; Wilson, J. H.

    1991-01-01

    Meloidogyne chitwoodi races 1 and 2 and M. hapla reproduced on 12 cultivars of Brassica napus and two cultivars of B. campestris. The mean reproductive factors (Rf), Rf = Pf at 55 days ÷ 5,000, for the three nematodes were 8.3, 2.2, and 14.3, respectively. All three nematodes reproduced more efficiently (P < 0.05) on B. campestris than on B. napus. Amending M. chitwoodi-infested soil in plastic bags with chopped shoots of Jupiter rapeseed reduced the nematode population more (P < 0.05) than amendment with wheat shoots. Incorporating Jupiter shoots to soil heavily infested with M. chitwoodi in microplots reduced the nematode population more (P < 0.05) than fallow or corn shoot treatments. The greatest reduction in nematode population density was attained by cropping rapeseed for 2 months and incorporating it into the soil as a green manure. PMID:19283108

  17. Ancient horizontal transfers of retrotransposons between birds and ancestors of human pathogenic nematodes

    PubMed Central

    Suh, Alexander; Witt, Christopher C.; Menger, Juliana; Sadanandan, Keren R.; Podsiadlowski, Lars; Gerth, Michael; Weigert, Anne; McGuire, Jimmy A.; Mudge, Joann; Edwards, Scott V.; Rheindt, Frank E.

    2016-01-01

    Parasite host switches may trigger disease emergence, but prehistoric host ranges are often unknowable. Lymphatic filariasis and loiasis are major human diseases caused by the insect-borne filarial nematodes Brugia, Wuchereria and Loa. Here we show that the genomes of these nematodes and seven tropical bird lineages exclusively share a novel retrotransposon, AviRTE, resulting from horizontal transfer (HT). AviRTE subfamilies exhibit 83–99% nucleotide identity between genomes, and their phylogenetic distribution, paleobiogeography and invasion times suggest that HTs involved filarial nematodes. The HTs between bird and nematode genomes took place in two pantropical waves, >25–22 million years ago (Myr ago) involving the Brugia/Wuchereria lineage and >20–17 Myr ago involving the Loa lineage. Contrary to the expectation from the mammal-dominated host range of filarial nematodes, we hypothesize that these major human pathogens may have independently evolved from bird endoparasites that formerly infected the global breadth of avian biodiversity. PMID:27097561

  18. Meiobenthos and nematode community in Yenisei Bay and adjacent parts of the Kara Sea shelf

    NASA Astrophysics Data System (ADS)

    Portnova, D. A.; Garlitska, L. A.; Udalov, A. A.; Kondar, D. V.

    2017-01-01

    Material is collected on a meridional profile from Yenisei Bay to adjacent parts of the Kara Sea shelf. The length of the profile is 550 km; 13 to 62 m depths. A multiple corer and Niemistö corer are used as sampling tools. The meiobenthos is represented by 13 taxa. Nematodes are the most abundant taxon, and harpacticoid copepods (Harpacticoida) are subdominant. The abundance and taxonomic diversity of meiobenthos and nematodes increases from the freshwater part of Yenisei Bay towards the Kara Sea shelf. Three types of taxocene are distinguished: freshwater, brackish-water, and marine. The taxocene of the estuary is not distinguished by any specific set of species and consists of species characteristic of the nematode community both in the freshwater and marine zones. The trophic structure of the taxocene of nematodes in Yenisei Bay is dominated by nematodes with well-defined stoma and are differently armed. The estuary and shelf are dominated by selective and nonselective deposit feeders.

  19. Orsay, Santeuil and Le Blanc viruses primarily infect intestinal cells in Caenorhabditis nematodes.

    PubMed

    Franz, Carl J; Renshaw, Hilary; Frezal, Lise; Jiang, Yanfang; Félix, Marie-Anne; Wang, David

    2014-01-05

    The discoveries of Orsay, Santeuil and Le Blanc viruses, three viruses infecting either Caenorhabditis elegans or its relative Caenorhabditis briggsae, enable the study of virus-host interactions using natural pathogens of these two well-established model organisms. We characterized the tissue tropism of infection in Caenorhabditis nematodes by these viruses. Using immunofluorescence assays targeting proteins from each of the viruses, and in situ hybridization, we demonstrate viral proteins and RNAs localize to intestinal cells in larval stage Caenorhabditis nematodes. Viral proteins were detected in one to six of the 20 intestinal cells present in Caenorhabditis nematodes. In Orsay virus-infected C. elegans, viral proteins were detected as early as 6h post-infection. The RNA-dependent RNA polymerase and capsid proteins of Orsay virus exhibited different subcellular localization patterns. Collectively, these observations provide the first experimental insights into viral protein expression in any nematode host, and broaden our understanding of viral infection in Caenorhabditis nematodes.

  20. Distribution of plant-parasitic nematodes on sugarcane in louisiana and efficacy of nematicides.

    PubMed

    Bond, J P; McGawley, E C; Hoy, J W

    2000-12-01

    A survey conducted from May 1995 through August 1998 revealed diverse nematode communities in Louisiana sugarcane fields. High populations of Mesocriconema, Paratrichodorus, Pratylenchus, and Tylenchorhynchus were widespread in nine sugarcane production parishes. Comparisons of plant cane and ratoon sugarcane crops indicated that nematode community levels increase significantly in successive ratoon crops. Nematicide trials evaluated the efficacy of aldicarb, ethoprop, and phorate against indigenous nematode populations. Aldicarb consistently increased the number of millable stalks, cane tonnage, and yield of sucrose in soils with a high sand content. Yield increases were concomitant with reductions in the density of the nematode community shortly after planting and at harvest. In soils with a higher clay content, the chemicals were less effective in controlling nematode populations and, as a result, yield increases were minimal.

  1. Granular Nematicides as Adjuncts to Fumigants for Control of Cotton Root-knot Nematodes.

    PubMed

    Jorgenson, E C

    1979-04-01

    Growth and yield of cotton were best with combinations of fumigants and organophosphate and carbamate nematicides. Organophosphates or carbamates used alone did not give season-long control of root-knot nematodes. Long-term control was poor because the temporary sublethal effects of these materials diminished soon enough lhat the nematodes could reproduce. The nematodes survived the treatments and a year of nonhost culture, and damaged a susceptible host crop 2 years after treatment. No such damage occurred in plots treated with fumigant, fumigant plus organophosphate, or fumigant plus carbamate. Treatment of seed and treatment of cotton, either in furrow at planting or sidedressing at midseason, with organophosphate and carbamate nematicides resulted in little or no yield increase, because nematode control was only minimal and temporary; or in a yield decrease, because the toxicity of the materials was manifested when nematode populations were low.

  2. Treatment of Nematodes with Ozone Gas: A Sustainable Alternative to Nematicides

    NASA Astrophysics Data System (ADS)

    Msayleb, Nahed; Ibrahim, Saiid

    This study tests Ozone as a Nematicides' alternative. Nematode-infected soil samples were treated with ascending doses of O3 by submerging the outlet of an "MB1000 Ozone Generator" in the 40 ml samples; then to test the O3 nematicidal effect by gas fumigation, Ozone gas was released into a sealed bag containing 80 g of each of the 6 nematode-infected soil samples with ascending doses and a repetition of each. With water-ozonation, 900 mg O3 were needed to kill 100% of nematodes, and the O3-Nematodes LD50 was identified by 420 mg. With the second experiment, O3 soil fumigation for 50 minutes at a dose of 1,125 mg in an air volume of 5 litres, were needed to control 95% of living nematodes.

  3. nGASP – the nematode genome annotation assessment project

    PubMed Central

    Coghlan, Avril; Fiedler, Tristan J; McKay, Sheldon J; Flicek, Paul; Harris, Todd W; Blasiar, Darin; Stein, Lincoln D

    2008-01-01

    Background While the C. elegans genome is extensively annotated, relatively little information is available for other Caenorhabditis species. The nematode genome annotation assessment project (nGASP) was launched to objectively assess the accuracy of protein-coding gene prediction software in C. elegans, and to apply this knowledge to the annotation of the genomes of four additional Caenorhabditis species and other nematodes. Seventeen groups worldwide participated in nGASP, and submitted 47 prediction sets across 10 Mb of the C. elegans genome. Predictions were compared to reference gene sets consisting of confirmed or manually curated gene models from WormBase. Results The most accurate gene-finders were 'combiner' algorithms, which made use of transcript- and protein-alignments and multi-genome alignments, as well as gene predictions from other gene-finders. Gene-finders that used alignments of ESTs, mRNAs and proteins came in second. There was a tie for third place between gene-finders that used multi-genome alignments and ab initio gene-finders. The median gene level sensitivity of combiners was 78% and their specificity was 42%, which is nearly the same accuracy reported for combiners in the human genome. C. elegans genes with exons of unusual hexamer content, as well as those with unusually many exons, short exons, long introns, a weak translation start signal, weak splice sites, or poorly conserved orthologs posed the greatest difficulty for gene-finders. Conclusion This experiment establishes a baseline of gene prediction accuracy in Caenorhabditis genomes, and has guided the choice of gene-finders for the annotation of newly sequenced genomes of Caenorhabditis and other nematode species. We have created new gene sets for C. briggsae, C. remanei, C. brenneri, C. japonica, and Brugia malayi using some of the best-performing gene-finders. PMID:19099578

  4. Specific microbial attachment to root knot nematodes in suppressive soil.

    PubMed

    Adam, Mohamed; Westphal, Andreas; Hallmann, Johannes; Heuer, Holger

    2014-05-01

    Understanding the interactions of plant-parasitic nematodes with antagonistic soil microbes could provide opportunities for novel crop protection strategies. Three arable soils were investigated for their suppressiveness against the root knot nematode Meloidogyne hapla. For all three soils, M. hapla developed significantly fewer galls, egg masses, and eggs on tomato plants in unsterilized than in sterilized infested soil. Egg numbers were reduced by up to 93%. This suggested suppression by soil microbial communities. The soils significantly differed in the composition of microbial communities and in the suppressiveness to M. hapla. To identify microorganisms interacting with M. hapla in soil, second-stage juveniles (J2) baited in the test soil were cultivation independently analyzed for attached microbes. PCR-denaturing gradient gel electrophoresis of fungal ITS or 16S rRNA genes of bacteria and bacterial groups from nematode and soil samples was performed, and DNA sequences from J2-associated bands were determined. The fingerprints showed many species that were abundant on J2 but not in the surrounding soil, especially in fungal profiles. Fungi associated with J2 from all three soils were related to the genera Davidiella and Rhizophydium, while the genera Eurotium, Ganoderma, and Cylindrocarpon were specific for the most suppressive soil. Among the 20 highly abundant operational taxonomic units of bacteria specific for J2 in suppressive soil, six were closely related to infectious species such as Shigella spp., whereas the most abundant were Malikia spinosa and Rothia amarae, as determined by 16S rRNA amplicon pyrosequencing. In conclusion, a diverse microflora specifically adhered to J2 of M. hapla in soil and presumably affected female fecundity.

  5. Distribution of the entomopathogenic nematodes from La Rioja (Northern Spain).

    PubMed

    Campos-Herrera, Raquel; Escuer, Miguel; Labrador, Sonia; Robertson, Lee; Barrios, Laura; Gutiérrez, Carmen

    2007-06-01

    Entomopathogenic nematodes (EPNs) distribution in natural areas and crop field edges in La Rioja (Northern Spain) has been studied taking into account environmental and physical-chemical soil factors. Five hundred soil samples from 100 sites of the most representative habitats were assayed for the presence of EPNs. The occurrence of EPNs statistically fitted to a negative binomial distribution, which pointed out that the natural distribution of these nematodes in La Rioja was in aggregates. There were no statistical differences (p < or = 0.05) in the abundance of EPNs to environmental and physical-chemical variables, although, there were statistical differences in the altitude, annual mean air temperature and rainfall, potential vegetation series and moisture percentage recovery frequency. Twenty-seven samples from 14 sites were positive for EPNs. From these samples, twenty isolates were identified to a species level and fifteen strains were selected: 11 Steinernema feltiae, two S. carpocapsae and two S. kraussei strains. S. kraussei was isolated from humid soils of cool and high altitude habitats and S. carpocapsae was found to occur in heavy soils of dry and temperate habitats. S. feltiae was the most common species with a wide range of altitude, temperature, rainfall, pH and soil moisture, although this species preferred sandy soils. The virulence of nematode strains were assessed using G. mellonella as insect host, recording the larval mortality percentage and the time to insect die, as well as the number of infective juveniles produced to evaluate the reproductive potential and the time tooks to leave the insect cadaver to determinate the infection cycle length. The ecological trends and biological results are discussed in relationship with their future use as biological control.

  6. Microsporidia Are Natural Intracellular Parasites of the Nematode Caenorhabditis elegans

    PubMed Central

    Troemel, Emily R; Félix, Marie-Anne; Whiteman, Noah K; Barrière, Antoine; Ausubel, Frederick M

    2008-01-01

    For decades the soil nematode Caenorhabditis elegans has been an important model system for biology, but little is known about its natural ecology. Recently, C. elegans has become the focus of studies of innate immunity and several pathogens have been shown to cause lethal intestinal infections in C. elegans. However none of these pathogens has been shown to invade nematode intestinal cells, and no pathogen has been isolated from wild-caught C. elegans. Here we describe an intracellular pathogen isolated from wild-caught C. elegans that we show is a new species of microsporidia. Microsporidia comprise a large class of eukaryotic intracellular parasites that are medically and agriculturally important, but poorly understood. We show that microsporidian infection of the C. elegans intestine proceeds through distinct stages and is transmitted horizontally. Disruption of a conserved cytoskeletal structure in the intestine called the terminal web correlates with the release of microsporidian spores from infected cells, and appears to be part of a novel mechanism by which intracellular pathogens exit from infected cells. Unlike in bacterial intestinal infections, the p38 MAPK and insulin/insulin-like growth factor (IGF) signaling pathways do not appear to play substantial roles in resistance to microsporidian infection in C. elegans. We found microsporidia in multiple wild-caught isolates of Caenorhabditis nematodes from diverse geographic locations. These results indicate that microsporidia are common parasites of C. elegans in the wild. In addition, the interaction between C. elegans and its natural microsporidian parasites provides a system in which to dissect intracellular intestinal infection in vivo and insight into the diversity of pathogenic mechanisms used by intracellular microbes. PMID:19071962

  7. Anthelmintic resistance in cattle nematodes in the US.

    PubMed

    Gasbarre, Louis C

    2014-07-30

    The first documented case of macrocyclic lactone resistance in gastrointestinal (GI) nematodes of cattle was seen in the US approximately 10 years ago. Since that time the increase incidence of anthelmintic resistance has continued at an alarming rate. Currently parasites of the genera Cooperia and/or Haemonchus resistant to generic or brand-name macrocyclic lactones have be demonstrated in more than half of all operations examined. Both of these parasite genera are capable of causing economic losses by decreasing food intake and subsequently animal productivity. Currently, there are no easy and quick means to detect anthelmintic resistant GI nematodes. Definitive identification requires killing of cattle. The most commonly used field detection method is the fecal egg count reduction test (FECRT). This method can be adapted for use as a screening agent for Veterinarians and producers to identify less than desired clearance of the parasites after anthelmintic treatment. Further studies can then define the reasons for persistence of the egg counts. The appearance of anthelmintic resistance is largely due to the development of very effective nematode control programs that have significantly improved the productivity of the US cattle industry, but at the same time has placed a high level of selective pressure on the parasite genome. The challenges ahead include the development of programs that control the anthelmintic resistant nematodes but at the same time result in more sustainable parasite control. The goal is to maintain high levels of productivity but to exert less selective pressures on the parasites. One of the most effective means to slow the development of drug resistance is through the simultaneous use of multiple classes of anthelmintics, each of which has a different mode of action. Reduction of the selective pressure on the parasites can be attained through a more targeted approach to drug treatments where the producer's needs are met by selective

  8. A Pathogenic Nematode Targets Recognition Proteins to Avoid Insect Defenses

    PubMed Central

    Toubarro, Duarte; Avila, Mónica Martinez; Montiel, Rafael; Simões, Nelson

    2013-01-01

    Steinernemacarpocapsae is a nematode pathogenic in a wide variety of insect species. The great pathogenicity of this nematode has been ascribed to its ability to overcome the host immune response; however, little is known about the mechanisms involved in this process. The analysis of an expressed sequence tags (EST) library in the nematode during the infective phase was performed and a highly abundant contig homologous to serine protease inhibitors was identified. In this work, we show that this contig is part of a 641-bp cDNA that encodes a BPTI-Kunitz family inhibitor (Sc-KU-4), which is up-regulated in the parasite during invasion and installation. Recombinant Sc-KU-4 protein was produced in Escherichia coli and shown to inhibit chymotrypsin and elastase activities in a dose-dependent manner by a competitive mechanism with Ki values of 1.8 nM and 2.6 nM, respectively. Sc-KU-4 also inhibited trypsin and thrombin activities to a lesser extent. Studies of the mode of action of Sc-KU-4 and its effects on insect defenses suggest that although Sc-KU-4 did not inhibit the activation of hemocytes or the formation of clotting fibers, it did inhibit hemocyte aggregation and the entrapment of foreign particles by fibers. Moreover, Sc-KU-4 avoided encapsulation and the deposition of clotting materials, which usually occurs in response to foreign particles. We show by protein-protein interaction that Sc-KU-4 targets recognition proteins of insect immune system such as masquerade-like and serine protease-like homologs. The interaction of Sc-KU-4 with these proteins explains the ability of the nematode to overcome host reactions and its large pathogenic spectrum, once these immune proteins are well conserved in insects. The discovery of this inhibitor targeting insect recognition proteins opens new avenues for the development of S. carpocapsae as a biological control agent and provides a new tool to study host-pathogen interactions. PMID:24098715

  9. Cambium Destruction in Conifers Caused by Pinewood Nematodes

    PubMed Central

    Myers, Ronald F.

    1986-01-01

    Percentage and rate of mortality in 2-4-year-old conifers depended upon the numbers of pinewood nematodes Bursaphelenchus xylophilus inoculated into their stems. In addition, percentage of conifer mortality was greater for spring inoculations when cambial activity was greater than for late summer and fall inoculations. Gross and histological examination of stems revealed destruction of the cambial layer, including fusiform and ray intitials and their derivatives. These data suggest that cambial and ray destruction causes tree death through blockage of tracheids by gas, oleoresin, or metabolites from dying ray tissues. PMID:19294198

  10. Line Detection and Texture Analysis for Automatic Nematode Identification

    PubMed Central

    Fdez-Valdivia, J.; Pérez de la Blanca, N.; Castillo, P.; Gómez-Barcina, A.

    1992-01-01

    This paper is the second in a series studying procedures for estimating and calibrating features of nematodes from digital images. Two kinds of features were analyzed for recognition: those with a directional component and those with a textural component. Features that have a directional component (lateral field and annules) were preprocessed with classic algorithms and modified by directional filters. Features having texture (esophagus and intestine) were analyzed with vectors of measures to define them and the statistical technique CART (classification and regression trees) to explain the role that each measure plays in the identification and discrimination process. PMID:19283037

  11. Generalists at the interface: Nematode transmission between wild and domestic ungulates

    PubMed Central

    Walker, Josephine G.; Morgan, Eric R.

    2014-01-01

    Many parasitic nematode species are generalists capable of infecting multiple host species. The complex life cycle of nematodes, involving partial development outside of the host, facilitates transmission of these parasites between host species even when there is no direct contact between hosts. Infective nematode larvae persist in the environment, and where grazing or water sources are shared ingestion of parasite larvae deposited by different host species is likely. In this paper we examine the extent to which nematode parasite species have been observed in sympatric wild and domestic ungulates. First, using existing host–parasite databases, we describe expected overlap of 412 nematode species between 76 wild and 8 domestic ungulate host species. Our results indicate that host-specific parasites make up less than half of the nematode parasites infecting any particular ungulate host species. For wild host species, between 14% (for common warthog) and 76% (for mouflon) of parasitic nematode species are shared with domestic species. For domestic host species, between 42% (for horse) and 77% (for llamas/alpacas) of parasitic nematode species are shared with wild species. We also present an index of liability to describe the risk of cross-boundary parasites to each host species. We then examine specific examples from the literature in which transmission of nematode parasites between domestic and wild ungulates is described. However, there are many limitations in the existing data due to geographical bias and certain host species being studied more frequently than others. Although we demonstrate that many species of parasitic nematode are found in both wild and domestic hosts, little work has been done to demonstrate whether transmission is occurring between species or whether similar strains circulate separately. Additional research on cross-species transmission, including the use of models and of genetic methods to define strains, will provide evidence to answer

  12. Nematicide impacts on nematodes and feedbacks on plant productivity in a plant diversity gradient

    NASA Astrophysics Data System (ADS)

    Eisenhauer, Nico; Ackermann, Michael; Gass, Svenja; Klier, Matthias; Migunova, Varvara; Nitschke, Norma; Ruess, Liliane; Sabais, Alexander C. W.; Weisser, Wolfgang W.; Scheu, Stefan

    2010-09-01

    A major issue in current ecological research is the effect of biodiversity on ecosystem functioning. Although several studies reported a positive diversity - productivity relationship, the role of soil animals has been largely neglected. Nematodes are among the most widespread and important herbivores causing substantial yield losses in agriculture; however, impacts of nematodes on the diversity - productivity relationship in semi-natural plant communities have not been investigated until today. In the framework of the Jena Experiment (Thuringia, Germany) we established control and nematicide treated subplots to manipulate nematode densities on plots varying in plant species (1-16) and functional group richness (1-4). We explored the interacting effects of nematicide application and plant diversity on the main trophic groups of nematodes and on aboveground plant productivity. Nematicide application reduced the number of nematodes significantly, particularly that of plant feeders and predators. The negative impact of nematicide application on plant and bacterial feeders depended however on the diversity of the plant community. Total plant shoot biomass tended to decrease in the presence of ambient nematode densities. In detail, nematode effects varied however with plant functional group identity by reducing only the shoot biomass of herbs significantly but not that of legumes. Furthermore, the shoot biomass of grasses tended to decrease in the presence of ambient nematode densities. In contrast to total shoot biomass, nematodes decreased grass shoot biomass only in high diverse but not in low diverse plant communities. Thus, the present study for the first time highlights that nematodes likely modify the community structure und functions of semi-natural plant communities by altering the competition between plant functional groups and by attenuating the diversity - productivity relationship.

  13. [Characteristics of soil nematode communities in coastal wetlands with different vegetation types].

    PubMed

    Liu, Bei-Bei; Ye, Cheng-Long; Yu, Li; Jiao, Jia-Guo; Liu, Man-Qiang; Hu, Feng; Li, Hui-Xin

    2012-11-01

    An investigation was conducted on the characteristics of soil nematode communities in different vegetation belts (Spartina alterniflora belt, Sa; Suaeda glauca belt, Sg; bare land, B1; Phragmites australis belt, Pa; and wheat land, Wl) of Yancheng Wetland Reserve, Jiangsu Province of East China. A total of 39 genera and 20 families of soil nematodes were identified, and the individuals of dominant genera and common genera occupied more than 90% of the total. The total number of the nematodes differed remarkably with vegetation belts, ranged from 79 to 449 individuals per 100 grams of dry soil. Wheat land had the highest number of soil nematodes, while bare land had the lowest one. The nematode ecological indices responded differently to the vegetation belts. The Shannon index (H) and evenness index (J) decreased in the order of Pa > Sg > Wl > Sa > Bl, and the dominance index (lambda) was in the order of Bl > Sa > Wl > Sg > Pa, suggesting that the diversity and stability of the nematode community in bare land were lower than those in the other vegetation belts, and the nematode community in the bare land tended to be simplified. The maturity index (MI) was higher in uncultivated vegetation belts than in wheat land, suggesting that the wheat land was disturbed obviously. The nematode community structure differed significantly with vegetation belts, and the main contributing species in different vegetation belts also differed. There existed significant correlations between the soil physical and chemical characteristics and the nematode numbers, trophic groups, and ecological indices. Our results demonstrated that the changes of soil nematode community structure could be used as an indicator well reflecting the diversity of vegetation belt habitat, and an important bio-indicator of coastal wetland ecosystem.

  14. Nematode community composition and feeding shaped by contrasting productivity regimes in the Southern Ocean

    NASA Astrophysics Data System (ADS)

    Lins, Lidia; da Silva, Maria Cristina; Hauquier, Freija; Esteves, André Morgado; Vanreusel, Ann

    2015-05-01

    In the Southern Ocean, during the ANT-XXVIII expedition (RV Polarstern), four stations contrasting in terms of surface primary productivity were studied along the Polar Front from 39°W to 10°E. We investigated to what extent differences in surface primary productivity, together with benthic environmental parameters (concentration of Chlorophyll a and its derivatives, and sediment fatty acid composition) mirrored in nematode standing stocks (i.e. density and biomass) and differences in community composition. Moreover, nematode fatty acid (FA) analyses were performed to unravel feeding selectivity patterns on "bulk" nematodes and particular nematode taxa (Desmodora and Desmoscolecidae). South Georgia station, located NW of South Georgia island, possessed not only highest surface primary productivity, but also highest Chlorophyll a (and its derivatives) and total sediment FA concentrations, also reflected in up to 10-fold higher nematode standing stocks. FA composition from "bulk" nematodes, Desmodora and desmoscolecids revealed a planktonic-based diet, as revealed by diatom biomarkers (16:1 ω 7/16:0 > 1) for "bulk" nematodes and Desmodora from South Georgia. Nematodes at the other stations situated more to the east showed non-selectivity for fresh diatom material based on the FA composition, associated with low surface primary productivity and low labile carbon concentrations (low Chlorophyll a values) in these areas. Uncommonly found in typical deep-sea environments, the nematode genus Desmodora exhibited high numbers at South Georgia station, probably as a response to the high primary productivity at the surface, confirming the strong benthic-pelagic coupling even at great depths. This study suggests that alterations in nematode standing stocks and community composition, together with selective feeding reflected by distinct FA composition, can be positively associated and shaped by surface productivity regimes.

  15. Acidic chitinase primes the protective immune response to gastrointestinal nematodes.

    PubMed

    Vannella, Kevin M; Ramalingam, Thirumalai R; Hart, Kevin M; de Queiroz Prado, Rafael; Sciurba, Joshua; Barron, Luke; Borthwick, Lee A; Smith, Allen D; Mentink-Kane, Margaret; White, Sandra; Thompson, Robert W; Cheever, Allen W; Bock, Kevin; Moore, Ian; Fitz, Lori J; Urban, Joseph F; Wynn, Thomas A

    2016-05-01

    Acidic mammalian chitinase (AMCase) is known to be induced by allergens and helminths, yet its role in immunity is unclear. Using AMCase-deficient mice, we show that AMCase deficiency reduced the number of group 2 innate lymphoid cells during allergen challenge but was not required for establishment of type 2 inflammation in the lung in response to allergens or helminths. In contrast, AMCase-deficient mice showed a profound defect in type 2 immunity following infection with the chitin-containing gastrointestinal nematodes Nippostrongylus brasiliensis and Heligmosomoides polygyrus bakeri. The impaired immunity was associated with reduced mucus production and decreased intestinal expression of the signature type 2 response genes Il13, Chil3, Retnlb, and Clca1. CD103(+) dendritic cells, which regulate T cell homing, were also reduced in mesenteric lymph nodes of infected AMCase-deficient mice. Thus, AMCase functions as a critical initiator of protective type 2 responses to intestinal nematodes but is largely dispensable for allergic responses in the lung.

  16. Evaluation of Eucalyptus citriodora essential oil on goat gastrointestinal nematodes.

    PubMed

    Macedo, Iara Tersia Freitas; Bevilaqua, Claudia Maria Leal; de Oliveira, Lorena Mayana Beserra; Camurça-Vasconcelos, Ana Lourdes Fernandes; Vieira, Luiz da Silva; Amóra, Sthenia Dos Santos Albano

    2011-01-01

    Phytotherapy may be an alternative strategy for controlling gastrointestinal parasites. This study evaluated the anthelmintic efficacy of Eucalyptus citriodora essential oil (EcEO). The in vitro effects of EcEO were determined through testing the inhibition of egg hatching and larval development of Haemonchus contortus. EcEO was subjected to acute toxicity testing on mice, orally and intraperitoneally. The in vivo effects of EcEO were determined by the fecal egg count reduction test (FECRT) in goats infected with gastrointestinal nematodes. The results showed that 5.3 mg.mL(-1) EcEO inhibited egg hatching by 98.8% and 10.6 mg.mL(-1) EcEO inhibited H. contortus larval development by 99.71%. The lethal doses for 50% of the mice were 4153 and 622.8 mg.kg(-1), for acute toxicity orally and intraperitoneally. In the FECRT, the efficacy of EcEO and ivermectin was 66.25 and 79.16% respectively, on goat gastrointestinal nematodes eight days after treatment. EcEO showed in vitro and in vivo anthelmintic activity.

  17. Mitochondrial Phylogenomics yields Strongly Supported Hypotheses for Ascaridomorph Nematodes

    PubMed Central

    Liu, Guo-Hua; Nadler, Steven A.; Liu, Shan-Shan; Podolska, Magdalena; D’Amelio, Stefano; Shao, Renfu; Gasser, Robin B.; Zhu, Xing-Quan

    2016-01-01

    Ascaridomorph nematodes threaten the health of humans and other animals worldwide. Despite their medical, veterinary and economic importance, the identification of species lineages and establishing their phylogenetic relationships have proved difficult in some cases. Many working hypotheses regarding the phylogeny of ascaridomorphs have been based on single-locus data, most typically nuclear ribosomal RNA. Such single-locus hypotheses lack independent corroboration, and for nuclear rRNA typically lack resolution for deep relationships. As an alternative approach, we analyzed the mitochondrial (mt) genomes of anisakids (~14 kb) from different fish hosts in multiple countries, in combination with those of other ascaridomorphs available in the GenBank database. The circular mt genomes range from 13,948-14,019 bp in size and encode 12 protein-coding genes, 2 ribosomal RNAs and 22 transfer RNA genes. Our analysis showed that the Pseudoterranova decipiens complex consists of at least six cryptic species. In contrast, the hypothesis that Contracaecum ogmorhini represents a complex of cryptic species is not supported by mt genome data. Our analysis recovered several fundamental and uncontroversial ascaridomorph clades, including the monophyly of superfamilies and families, except for Ascaridiidae, which was consistent with the results based on nuclear rRNA analysis. In conclusion, mt genome analysis provided new insights into the phylogeny and taxonomy of ascaridomorph nematodes. PMID:27982084

  18. Family of FLP Peptides in Caenorhabditis elegans and Related Nematodes

    PubMed Central

    Li, Chris; Kim, Kyuhyung

    2014-01-01

    Neuropeptides regulate all aspects of behavior in multicellular organisms. Because of their ability to act at long distances, neuropeptides can exert their effects beyond the conventional synaptic connections, thereby adding an intricate layer of complexity to the activity of neural networks. In the nematode Caenorhabditis elegans, a large number of neuropeptide genes that are expressed throughout the nervous system have been identified. The actions of these peptides supplement the synaptic connections of the 302 neurons, allowing for fine tuning of neural networks and increasing the ways in which behaviors can be regulated. In this review, we focus on a large family of genes encoding FMRFamide-related peptides (FaRPs). These genes, the flp genes, have been used as a starting point to identifying flp genes throughout Nematoda. Nematodes have the largest family of FaRPs described thus far. The challenges in the future are the elucidation of their functions and the identification of the receptors and signaling pathways through which they function. PMID:25352828

  19. Neuronal uptake of pesticides disrupts chemosensory cells of nematodes.

    PubMed

    Winter, M D; McPherson, M J; Atkinson, H J

    2002-12-01

    Low doses of the acetylcholinesterase-inhibiting carbamate nematicides disrupt chemoreception in plant-parasitic nematodes. Fluorescein isothiocyanate (FITC)/dextran conjugates up to 12 kDa are taken up from the external medium by certain chemosensory neurons in Caenorhabditis elegans. Similar chemoreceptive neurons of the non-feeding infective stage of Heterodera glycines (soybean cyst nematode) fill with FITC and the nuclei of their cell bodies selectively stain with bisbenzimide. The widely used nematicide aldicarb disrupts the chemoreceptive response of H. glycines with 50% inhibition at very low concentrations (ca 1 pM), some 10(-6)-fold lower than required to affect locomotion. Similarly, the anthelmintic levamisole had this effect at 1 nM. Peptides selected as mimetics of aldicarb and levamisole also disrupt chemoreception in H. glycines and Globodera pallida at 10(-3)-fold or lower concentration than required to inhibit locomotion. We propose an uptake pathway for aldicarb, levamisole, peptide mimetics and other soluble molecules by retrograde transport along dendrites of chemoreceptive neurons to the cell bodies and synapses where they act. This may prove to be a general mechanism for the low-dose effects of some nematicides and anthelmintics.

  20. Differential Toxicities of Nickel Salts to the Nematode Caenorhabditis elegans.

    PubMed

    Meyer, Dean; Birdsey, Jennifer M; Wendolowski, Mark A; Dobbin, Kevin K; Williams, Phillip L

    2016-08-01

    This study focused on assessing whether nickel (Ni) toxicity to the nematode Caenorhabditis elegans was affected by the molecular structure of the Ni salt used. Nematodes were exposed to seven Ni salts [Ni sulfate hexahydrate (NiSO4·6H2O), Ni chloride hexahydrate (NiCl2·6H2O), Ni acetate tetrahydrate (Ni(OCOCH3)2·4H2O), Ni nitrate hexahydrate (N2NiO6·6H2O), anhydrous Ni iodide (NiI2), Ni sulfamate hydrate (Ni(SO3NH2)2·H2O), and Ni fluoride tetrahydrate (NiF2·4H2O)] in an aquatic medium for 24 h, and lethality curves were generated and analyzed. Ni fluoride, Ni iodide, and Ni chloride were most toxic to C. elegans, followed by Ni nitrate, Ni sulfamate, Ni acetate, and Ni sulfate. The LC50 values of the halogen-containing salts were statistically different from the corresponding value of the least toxic salt, Ni sulfate. This finding is consistent with the expected high bioavailability of free Ni ions in halide solutions. We recommend that the halide salts be used in future Ni testing involving aquatic invertebrates.

  1. Pathogenesis in Pine Wilt Caused by Pinewood Nematode, Bursaphelenchus xylophilus

    PubMed Central

    Myers, Ronald F.

    1988-01-01

    The progression of events in the development of pine wilt disease following the invasion by Bursaphelenchus xylophilus is reviewed from early migration through pine tissues until symptom development on foliage. Disease resistance in pines, especially the hypersensitive reaction that is successful in controlling many potential pests and pathogens, is explored. Pathologies resulting from the activities of pinewood nematode include cortical trails and cavities; formation of cambial gaps and traumatic resin cysts; browning and death of cortex, phloem, cambium, and ray tissues; granulation and shrinkage of cell cytoplasm in rays; and destruction of resin canal epithelial and ray parenchyma cells. Death of parenchyma, production of toxins, and leakage of oleoresins and other material into tracheids are typical of the hypersensitive reaction occurring in pines following migration of small numbers of pinewood nematodes. The hypothesis presented is that a spreading hypersensitive reaction results in some of the observed pathologies and symptoms and eventually causes pine death. The growth-differentiation balance hypothesis is used to help explain predisposition, oleoresin production and toxicity, susceptibility and resistance, and the effects of variation in climate on host pines as related to pinewilt disease. PMID:19290207

  2. Effects of climatic changes on anisakid nematodes in polar regions

    NASA Astrophysics Data System (ADS)

    Rokicki, Jerzy

    2009-11-01

    Anisakid nematodes are common in Antarctic, sub-Antarctic, and Arctic areas. Current distributional knowledge of anisakids in the polar regions is reviewed. Climatic variables influence the occurrence and abundance of anisakids, directly influencing their free-living larval stages and also indirectly influencing their predominantly invertebrate (but also vertebrate) hosts. As these parasites can also be pathogenic for humans, the paucity of information available is a source of additional hazard. As fish are a major human dietary component in Arctic and Antarctic areas, and are often eaten without heat processing, a high risk of infection by anisakid larvae might be expected. The present level of knowledge, particularly relating to anisakid larval stages present in fishes, is far from satisfactory. Preliminary molecular studies have revealed the presence of species complexes. Contemporary climate warming is modifying the marine environment and may result in an extension of time during which anisakid eggs can persist and hatch, and of the time period during which newly hatched larvae remain viable. As a result there may be an increase in the extent of anisakid distribution. Continued warming will modify the composition of the parasitic nematode fauna of marine animals, due to changes in feeding habits, as the warming of the sea and any localised reduction in salinity (from freshwater runoff) can be expected to bring about changes in the species composition of pelagic and benthic invertebrates.

  3. Reproduction of the Reniform Nematode on Thirty Soybean Cultivars

    PubMed Central

    Robbins, R. T.; Rakes, L.; Elkins, C. R.

    1994-01-01

    In greenhouse experiments conducted in 1991 and 1992, the 30 soybean (Glycine max) cultivars most commonly grown in Arkansas in 1990 were tested for resistance to the reniform nematode, Rotylenchulus reniformis. 'Forrest' was the most resistant cultivar, whereas 'Braxton' was the most susceptible to R. reniformis. Cultivars Coker 485, Centennial, Stonewall, and Sharkey did not differ from Forrest (P = 0.01). Cultivars Lee 74, Coker 6955, Waiters, Davis, Pioneer 9442, and Narow did not differ from Braxton (P = 0.01). Cultivar Lloyd had the second highest reproductive index (Pf/Pi) in 1992 and for the combined test, but was significantly different from Braxton in 1991. The remaining cultivars were inconsistent in their reproductive indices. Two cultivars, Leflore and Lloyd, exhibited large variation in Pf/Pi. This may be due to multiple resistance genes and (or) segregation for resistance among individual seedlings. Segregation is possible because these varieties were not selected or tested for reniform nematode resistance during the cultivar development process. PMID:19279944

  4. The mitochondrial genome of the soybean cyst nematode, Heterodera glycines.

    PubMed

    Gibson, Tracey; Farrugia, Daniel; Barrett, Jeff; Chitwood, David J; Rowe, Janet; Subbotin, Sergei; Dowton, Mark

    2011-07-01

    We sequenced the entire coding region of the mitochondrial genome of Heterodera glycines. The sequence obtained comprised 14.9 kb, with PCR evidence indicating that the entire genome comprised a single, circular molecule of approximately 21-22 kb. The genome is the most T-rich nematode mitochondrial genome reported to date, with T representing over half of all nucleotides on the coding strand. The genome also contains the highest number of poly(T) tracts so far reported (to our knowledge), with 60 poly(T) tracts ≥ 12 Ts. All genes are transcribed from the same mitochondrial strand. The organization of the mitochondrial genome of H. glycines shows a number of similarities compared with Radopholus similis, but fewer similarities when compared with Meloidogyne javanica. Very few gene boundaries are shared with Globodera pallida or Globodera rostochiensis. Partial mitochondrial genome sequences were also obtained for Heterodera cardiolata (5.3 kb) and Punctodera chalcoensis (6.8 kb), and these had identical organizations compared with H. glycines. We found PCR evidence of a minicircular mitochondrial genome in P. chalcoensis, but at low levels and lacking a noncoding region. Such circularised genome fragments may be present at low levels in a range of nematodes, with multipartite mitochondrial genomes representing a shift to a condition in which these subgenomic circles predominate.

  5. The regulation of spermatogenesis and sperm function in nematodes

    PubMed Central

    Ellis, Ronald E.; Stanfield, Gillian M.

    2014-01-01

    In the nematode C. elegans, both males and self-fertile hermaphrodites produce sperm. As a result, researchers have been able to use a broad range of genetic and genomic techniques to dissect all aspects of sperm development and function. Their results show that the early stages of spermatogenesis are controlled by transcriptional and translational processes, but later stages are dominated by protein kinases and phosphatases. Once spermatids are produced, they participate in many interactions with other cells — signals from the somatic gonad determine when sperm activate and begin to crawl, signals from the female reproductive tissues guide the sperm, and signals from sperm stimulate oocytes to mature and be ovulated. The sperm also show strong competitive interactions with other sperm and oocytes. Some of the molecules that mediate these processes have conserved functions in animal sperm, others are conserved proteins that have been adapted for new roles in nematode sperm, and some are novel proteins that provide insights into evolutionary change. The advent of new techniques should keep this system on the cutting edge of research in cellular and reproductive biology. PMID:24718317

  6. Mitochondrial Phylogenomics yields Strongly Supported Hypotheses for Ascaridomorph Nematodes.

    PubMed

    Liu, Guo-Hua; Nadler, Steven A; Liu, Shan-Shan; Podolska, Magdalena; D'Amelio, Stefano; Shao, Renfu; Gasser, Robin B; Zhu, Xing-Quan

    2016-12-16

    Ascaridomorph nematodes threaten the health of humans and other animals worldwide. Despite their medical, veterinary and economic importance, the identification of species lineages and establishing their phylogenetic relationships have proved difficult in some cases. Many working hypotheses regarding the phylogeny of ascaridomorphs have been based on single-locus data, most typically nuclear ribosomal RNA. Such single-locus hypotheses lack independent corroboration, and for nuclear rRNA typically lack resolution for deep relationships. As an alternative approach, we analyzed the mitochondrial (mt) genomes of anisakids (~14 kb) from different fish hosts in multiple countries, in combination with those of other ascaridomorphs available in the GenBank database. The circular mt genomes range from 13,948-14,019 bp in size and encode 12 protein-coding genes, 2 ribosomal RNAs and 22 transfer RNA genes. Our analysis showed that the Pseudoterranova decipiens complex consists of at least six cryptic species. In contrast, the hypothesis that Contracaecum ogmorhini represents a complex of cryptic species is not supported by mt genome data. Our analysis recovered several fundamental and uncontroversial ascaridomorph clades, including the monophyly of superfamilies and families, except for Ascaridiidae, which was consistent with the results based on nuclear rRNA analysis. In conclusion, mt genome analysis provided new insights into the phylogeny and taxonomy of ascaridomorph nematodes.

  7. Technological advancements and their importance for nematode identification

    NASA Astrophysics Data System (ADS)

    Ahmed, Mohammed; Sapp, Melanie; Prior, Thomas; Karssen, Gerrit; Back, Matthew Alan

    2016-06-01

    Nematodes represent a species-rich and morphologically diverse group of metazoans known to inhabit both aquatic and terrestrial environments. Their role as biological indicators and as key players in nutrient cycling has been well documented. Some plant-parasitic species are also known to cause significant losses to crop production. In spite of this, there still exists a huge gap in our knowledge of their diversity due to the enormity of time and expertise often involved in characterising species using phenotypic features. Molecular methodology provides useful means of complementing the limited number of reliable diagnostic characters available for morphology-based identification. We discuss herein some of the limitations of traditional taxonomy and how molecular methodologies, especially the use of high-throughput sequencing, have assisted in carrying out large-scale nematode community studies and characterisation of phytonematodes through rapid identification of multiple taxa. We also provide brief descriptions of some the current and almost-outdated high-throughput sequencing platforms and their applications in both plant nematology and soil ecology.

  8. Postplant Fumigation with DBCP for Citrus Nematode Control in Florida

    PubMed Central

    Tarjan, A. C.; O'Bannon, J. H.

    1974-01-01

    Eleven citrus groves of diverse varieties and ages infected with Tylenchulus semipenetrans growing in differing soils in Florida were treated with three rates of 1,2-dibromo-3-chloropropane (DBCP) applied by various means. Yield, fruit size, and T. semipenetrans populations in the roots were compared between DBCP-treated and untreated trees over a period of I-3 yr. Maximum fruit size and yield were obtained by applying DBCP at 38-58 kg/hectare (ha) (34-52 lb/acre); whereas best nematode control was with a rate of 77 kg/ha (69 lb/acre). Application of chemical emulsion with a special, drilled, low-profile sprinkler irrigation ground pipe was the most suitable method. Effect of DBCP treatment generally lasted for 3 yr. A mean annual I. 1% increase in fruit diameter, 15.2% increase in fruit yield and a 55.7% decrease incitrus nematode populations was found for D BC P-treated trees in contrast to untreated trees. PMID:19319363

  9. Plant-parasitic Nematodes Associated with Cherry Rootstocks in Michigan.

    PubMed

    Melakeberhan, H; Bird, G W; Perry, R

    1994-12-01

    In two field trials, 10-year-old sweet and tart cherry rooted on 'Mazzard', 'Mahaleb', 'MXM 2', 'MXM 14', 'MXM 39', 'MXM 60', 'MXM 97', and 'Colt' showed 10-203 Pratylenchus penetrans per g fresh root from all tart rootstocks, and up to 46 Pratylenchus, Criconemella, and Xiphinema spp. per 100 cm(3) soil. Infestation of soil containing 1-year-old Mazzard, Mahaleb, MXM 60, 'GI148-1', and 'G1148-8' with 625/100 cm(3) soil of either P. penetrans or C. xenoplax resulting in final nematode population densities of 123-486 and 451-2,496/g fresh root plus 100 cm(3) soil, respectively, and had little effect on plant height or dry weight after 157 days in a greenhouse. Population densities of neither nematode differed among the five rootstocks. In a second greenhouse experiment, soil containing the same rootstocks was infested with P. penetrans (1,250/100 cm(3) soil), maintained for 8 months in a greenhouse, 4 months in a cold room (2-4 C), and 3 additional months in a greenhouse. The number of P. penetrans recovered at the end of 475 days was approximately 10% of those recovered in the first experiment, probably due to the cold treatment. The ability of P. penetrans and C. xenoplax to infect the cherry rootstocks may be of concern in cherry management programs.

  10. The nucleotide sequence of a nematode vitellogenin gene.

    PubMed Central

    Spieth, J; Denison, K; Zucker, E; Blumenthal, T

    1985-01-01

    The nematode, Caenorhabditis elegans, contains a family of six genes that code for vitellogenins. Here we report the complete nucleotide sequence of one of these genes, vit-5. The gene specifies a mRNA of 4869 nucleotides, including untranslated regions of 9 bases at the 5' end and 51 bases at the 3' end. Vit-5 contains four short introns totalling 218 bp. The predicted vitellogenin, yp170A, has a molecular weight of 186,430. At its N terminus it is clearly related to the vitellogenins of vertebrates. However, the vit-5-encoded protein does not contain a serine-rich sequence related to the vertebrate vitellin, phosvitin. In fact, the amino acid composition of the nematode protein is very similar to that of the vertebrate protein without phosvitin. Vit-5 has a highly asymmetric codon choice dictionary. The favored codons are different from those favored in other organisms, but are characteristic of highly expressed C. elegans genes. The strong selection against rare codons is not as great near the 5' end of the gene; rare codons are 15 times more frequent within the first 54 bp than in the next 4.8 kb. PMID:3855245

  11. Hormone signaling and phenotypic plasticity in nematode development and evolution.

    PubMed

    Sommer, Ralf J; Ogawa, Akira

    2011-09-27

    Phenotypic plasticity refers to the ability of an organism to adopt different phenotypes depending on environmental conditions. In animals and plants, the progression of juvenile development and the formation of dormant stages are often associated with phenotypic plasticity, indicating the importance of phenotypic plasticity for life-history theory. Phenotypic plasticity has long been emphasized as a crucial principle in ecology and as facilitator of phenotypic evolution. In nematodes, several examples of phenotypic plasticity have been studied at the genetic and developmental level. In addition, the influence of different environmental factors has been investigated under laboratory conditions. These studies have provided detailed insight into the molecular basis of phenotypic plasticity and its ecological and evolutionary implications. Here, we review recent studies on the formation of dauer larvae in Caenorhabditis elegans, the evolution of nematode parasitism and the generation of a novel feeding trait in Pristionchus pacificus. These examples reveal a conserved and co-opted role of an endocrine signaling module involving the steroid hormone dafachronic acid. We will discuss how hormone signaling might facilitate life-history and morphological evolution.

  12. Trophic interactions in soils as they affect energy and nutrient dynamics. III. Biotic interactions of bacteria, amoebae, and nematodes.

    PubMed

    Anderson, R V; Elliott, E T; McClellan, J F; Coleman, D C; Cole, C V; Hunt, H W

    1977-12-01

    Bacteria (Pseudomonas), amoebae (Acanthamoeba), and nematodes (Mesodiplogaster) were raised in soil microcosms with and without glucose additions. Nematode and amoebal grazing on bacteria significantly reduced bacterial populations by the end of a 24-day incubation period. Amoebal numbers decreased in the presence of nematodes with a corresponding increase in nematode numbers which reached a maximum of 230 nematodes/g of soil in the treatment with amoebae and glucose additions. After 24 days the nematode populations in the treatments without carbon additions were dominated by resistant dauer larvae indicating the unavailability of food. Although larval numbers were high in the treatments with glucose additions, the adult component of the population was still increasing at the end of the 24-day experiment. The effect of the presence of amoebae on nematode abundance was of the same magnitude as addition of 600Μg glucose-C.

  13. Ascarosides coordinate the dispersal of a plant-parasitic nematode with the metamorphosis of its vector beetle

    PubMed Central

    Zhao, Lilin; Zhang, Xinxing; Wei, Yanan; Zhou, Jiao; Zhang, Wei; Qin, Peijun; Chinta, Satya; Kong, Xiangbo; Liu, Yunpeng; Yu, Haiying; Hu, Songnian; Zou, Zhen; Butcher, Rebecca A.; Sun, Jianghua

    2016-01-01

    Insect vectors are required for the transmission of many species of parasitic nematodes, but the mechanisms by which the vectors and nematodes coordinate their life cycles are poorly understood. Here, we report that ascarosides, an evolutionarily conserved family of nematode pheromones, are produced not only by a plant-parasitic nematode, but also by its vector beetle. The pinewood nematode and its vector beetle cause pine wilt disease, which threatens forest ecosystems world-wide. Ascarosides secreted by the dispersal third-stage nematode LIII larvae promote beetle pupation by inducing ecdysone production in the beetle and up-regulating ecdysone-dependent gene expression. Once the beetle develops into the adult stage, it secretes ascarosides that attract the dispersal fourth-stage nematode LIV larvae, potentially facilitating their movement into the beetle trachea for transport to the next pine tree. These results demonstrate that ascarosides play a key role in the survival and spread of pine wilt disease. PMID:27477780

  14. Gastrointestinal nematode community of spiny mice (Acomys dimidiatus) from St. Katherine, South Sinai, Egypt.

    PubMed

    Soliman, Maha F M; Ibrahim, Mohamed M; Zalat, Samy M

    2015-12-01

    The objective of this work was to study gastrointestinal nematode community infecting Acomys dimidiatus in different wadis of St. Katherine, South Sinai, Egypt. Fieldwork was conducted in three Wadis over a 4 weeks period during April-May, 2003 in St. Katherine, South Sinai, Egypt. Faecal samples from 47 spiny mice were analysed for gastrointestinal nematode community. The nematodes community consisted of four genera Dentostomella spp., Syphacia spp., Aspicularis spp. and Spirurids species. The overall prevalence of infection was 55.3 %. A significant difference in prevalence was found per wadis. Wadi Toffaha showed the highest diversity when compared to other Wadis. Mean species richness was higher in Wadi Tlah (0.87) when compared to other Wadis. Syphacia spp. was frequently found coexisting with other nematodes. A significant interaction was found between both site and co-infection for Aspicularis spp. The spatial stability of nematode community was discussed compared to other related studies. In terms of similarity, the nematode community from Wadi Toffaha was closest to Wadi Tlah. In conclusion, this study showed that there is spatial variation in the distribution of nematode community. Possible factors affecting the stability of parasite community were discussed and further studies are needed.

  15. Investigation of Low-Pressure Ultraviolet Radiation on Inactivation of Rhabitidae Nematode from Water

    PubMed Central

    DEHGHANI, Mohammad Hadi; JAHED, Gholam-Reza; ZAREI, Ahmad

    2013-01-01

    Background: Rhabditidae is a family of free-living nematodes. Free living nematodes due to their active movement and resistance to chlorination, do not remove in conventional water treatment processes thus can be entered to distribution systems and cause adverse health effects. Ultraviolet radiation (UV) can be used as a method of inactivating for these organisms. This cross sectional study was done to investigate the efficiency of ultraviolet lamp in the inactivation of free living nematode in water. Methods: The effects of radation time, turbidity, pH and temperature were invistigated in this study. Ultraviolet lamp used in this study was a 11 W lamp and intensity of this lamp was 24 μw / cm2. Results: Radiation time required to achieve 100% efficiency for larvae nematode and adults was 9 and 10 minutes respectively. There was a significant correlation between the increase in radiation time, temperature rise and turbidity reduction with inactivation efficiency of lamp (P<0.001). Increase of turbidity up 25 NTU decreased inactivation efficiency of larvae and adult nematodes from 100% to 66% and 100% to 64% respectively. Change in pH range from 6 to 9 did not affect the efficiency of inactivation. With increasing temperature inactivation rate increased. Also the effect of the lamp on inactivation of larvae nematod was mor than adults. Conclusions: It seems that with requiring the favorable conditions low-pressure ultraviolet radiation systems can be used for disinfection of water containing Rhabitidae nematode. PMID:23641409

  16. NemaCount: quantification of nematode chemotaxis behavior in a browser.

    PubMed

    O'Halloran, Damien M

    2016-06-01

    Nematodes such as Caenorhabditis elegans offer a very effective and tractable system to probe the underlying mechanisms of diverse sensory behaviors. Numerous platforms exist for quantifying nematode behavior and often require separate dependencies or software. Here I describe a novel and simple tool called NemaCount that provides a versatile solution for the quantification of nematode chemotaxis behavior. The ease of installation and user-friendly interface makes NemaCount a practical tool for measuring diverse behaviors and image features of nematodes such as C. elegans. The main advantage of NemaCount is that it operates from within a modern browser such as Google Chrome or Apple Safari. Any features that change in total number, size, shape, or angular distance between control and experimental preparations are suited to NemaCount for image analysis, while commonly used chemotaxis assays can be quantified, and statistically analyzed using a suite of functions from within NemaCount. NemaCount also offers image filtering options that allow the user to improve object detection and measurements. NemaCount was validated by examining nematode chemotaxis behavior; angular distances of locomotory tracks in C. elegans; and body lengths of Heterorhabditis bacteriophora nematodes. Apart from a modern browser, no additional software is required to operate NemaCount, making NemaCount a cheap, simple option for the analysis of nematode images and chemotaxis behavior.

  17. Manipulation of plant cells by cyst and root-knot nematode effectors.

    PubMed

    Hewezi, Tarek; Baum, Thomas J

    2013-01-01

    A key feature of sedentary plant-parasitic nematodes is the release of effector proteins from their esophageal gland cells through their stylets into host roots. These proteinaceous stylet secretions have been shown to be crucial for successful parasitism by mediating the transition of normal root cells into specialized feeding sites and by negating plant defenses. Recent technical advances of purifying mRNA from esophageal gland cells of plant-parasitic nematodes coupled with emerging sequencing technologies is steadily expanding our knowledge of nematode effector repertoires. Host targets and biological activities of a number of nematode effectors are continuously being reported and, by now, a first picture of the complexity of sedentary nematode parasitism at the molecular level is starting to take shape. In this review, we highlight effector mechanisms that recently have been uncovered by studying the host-pathogen interaction. These mechanisms range from mediating susceptibility of host plants to the actual triggering of defense responses. In particular, we portray and discuss the mechanisms by which nematode effectors modify plant cell walls, negate host defense responses, alter auxin and polyamine signaling, mimic plant molecules, regulate stress signaling, and activate hypersensitive responses. Continuous molecular characterization of newly discovered nematode effectors will be needed to determine how these effectors orchestrate host signaling pathways and biological processes leading to successful parasitism.

  18. Helminth.net: expansions to Nematode.net and an introduction to Trematode.net.

    PubMed

    Martin, John; Rosa, Bruce A; Ozersky, Philip; Hallsworth-Pepin, Kymberlie; Zhang, Xu; Bhonagiri-Palsikar, Veena; Tyagi, Rahul; Wang, Qi; Choi, Young-Jun; Gao, Xin; McNulty, Samantha N; Brindley, Paul J; Mitreva, Makedonka

    2015-01-01

    Helminth.net (http://www.helminth.net) is the new moniker for a collection of databases: Nematode.net and Trematode.net. Within this collection we provide services and resources for parasitic roundworms (nematodes) and flatworms (trematodes), collectively known as helminths. For over a decade we have provided resources for studying nematodes via our veteran site Nematode.net (http://nematode.net). In this article, (i) we provide an update on the expansions of Nematode.net that hosts omics data from 84 species and provides advanced search tools to the broad scientific community so that data can be mined in a useful and user-friendly manner and (ii) we introduce Trematode.net, a site dedicated to the dissemination of data from flukes, flatworm parasites of the class Trematoda, phylum Platyhelminthes. Trematode.net is an independent component of Helminth.net and currently hosts data from 16 species, with information ranging from genomic, functional genomic data, enzymatic pathway utilization to microbiome changes associated with helminth infections. The databases' interface, with a sophisticated query engine as a backbone, is intended to allow users to search for multi-factorial combinations of species' omics properties. This report describes updates to Nematode.net since its last description in NAR, 2012, and also introduces and presents its new sibling site, Trematode.net.

  19. Strategies for transgenic nematode control in developed and developing world crops.

    PubMed

    Atkinson, Howard J; Lilley, Catherine J; Urwin, Peter E

    2012-04-01

    Nematodes cause an estimated $118b annual losses to world crops and they are not readily controlled by pesticides or other control options. For many crops natural resistance genes are unavailable to plant breeders or progress by this approach is slow. Transgenic plants can provide nematode resistance for such crops. Two approaches have been field trialled that control a wide range of nematodes by either limiting use of their dietary protein uptake from the crop or by preventing root invasion without a direct lethality. In addition, RNA interference increasingly in tandem with genomic studies is providing a range of potential resistance traits that involve no novel protein production. Transgenic resistance can be delivered by tissue specific promoters to just root tissues where most economic nematodes invade and feed rather than the harvested yield. High efficacy and durability can be provided by stacking nematode resistance traits including any that natural resistance provides. The constraints to uptake centre on market acceptance and not the availability of appropriate biotechnology. The need to deploy nematode resistance is intensifying with loss of pesticides, an increased need to protect crop profit margins and in many developing world countries where nematodes severely damage both commodity and staple crops.

  20. Influence of mycorrhizal fungus, phosphorus, and burrowing nematode interactions on growth of rough lemon citrus seedlings.

    PubMed

    Smith, G S; Kaplan, D T

    1988-10-01

    Rough lemon seedlings were grown in mycorrhizal-infested or phosphorus-amended soil (25 and 300 mg P/kg) in greenhouse experiments. Plants Were inoculated with the citrus burrowing nematode, Radopholus citrophilus (0, 50, 100, or 200 nematodes per pot). Six months later, mycorrhizal plants and nonmycorrhizal, high-P plants had larger shoot and root weights than did non-mycorrhizal, low-P plants. Burrowing nematode population densities were lower in roots of mycorrhizal or nonmycorrhizal, high-P plants than in roots of nonmycorrhizal, low-P plants; however, differences in plant growth between mycorrhizal and nonmycorrhizal plants were not significant with respect to initial nematode inoculum densities. Phosphorus content in leaf tissue was significantly greater in mycorrhizal and nonmycorrhizal, high-P plants compared with nonmycorrhizal, low-P plants. Nutrient concentrations of K, Mg, and Zn were unaffected by nematode parasitism, whereas P, Ca, Fe, and Mn were less in nematode-infected plants. Enhanced growth associated with root colonization by the mycorrhizal fungus appeared to result from improved P nutrition and not antagonism between the fungus and the nematode.