Sample records for ig prey females

  1. Prey

    NSDL National Science Digital Library

    2011-01-01

    The Prey application is quite invaluable and it is a fine way to locate a missing phone or computer. After downloading Prey, users can gather information regarding the device's location, hardware, and network status. Also, users can grab a screenshot of what the device is doing at that moment and they can also even take a picture of the potential thief with the device's webcam. This particular version is compatible with those computers running Mac OS X 10.4 and newer, Windows 2000 and newer, and Linux.

  2. Differential Binding of IgG and IgA to Mucus of the Female Reproductive Tract

    PubMed Central

    Fahrbach, Kelly M.; Malykhina, Olga; Stieh, Daniel J.; Hope, Thomas J.

    2013-01-01

    Cells of the endocervix are responsible for the secretion of mucins, which provide an additional layer of protection to the female reproductive tract (FRT). This barrier is likely fortified with IgA as has previously been shown in the gastrointestinal tract and lungs of mice. Mucus associated IgA can facilitate clearance of bacteria. While a similar function for IgG has been proposed, an association with mucus has not yet been demonstrated. Here we find that IgA and IgG are differentially associated with the different types of mucus of the FRT. We observed that while both IgA and IgG are stably associated with cervical mucus, only IgG is associated with cervicovaginal mucus. These findings reveal that antibodies can bind tightly to mucus, where they can play a significant role in the fortification of the mucus barriers of the FRT. It may be possible to harness this interaction in the development of vaccines designed to protect the FRT mucosal barriers from sexually transmitted diseases such as HIV. PMID:24098437

  3. Transfer of IgG in the female genital tract by MHC class I-related neonatal Fc receptor (FcRn) confers protective immunity to vaginal infection

    Technology Transfer Automated Retrieval System (TEKTRAN)

    IgG is a major immunoglobulin subclass in mucosal secretions of human female genital tract, where it predominates over the IgA isotype. Despite the abundance of IgG, surprisingly little is known about whether and how IgG enters the lumen of the genital tract and the exact role of local IgG may play ...

  4. Prey-mediated avoidance of an intraguild predator by its intraguild prey

    Microsoft Academic Search

    Ryan R. Wilson; Terry L. Blankenship; Mevin B. Hooten; John A. Shivik

    2010-01-01

    Intraguild (IG) predation is an important factor influencing community structure, yet factors allowing coexistence of IG predator\\u000a and IG prey are not well understood. The existence of spatial refuges for IG prey has recently been noted for their importance\\u000a in allowing coexistence. However, reduction in basal prey availability might lead IG prey to leave spatial refuges for greater\\u000a access to

  5. Incontinentia pigmenti in combination with decreased IgG subclass concentrations in a female newborn.

    PubMed

    Pauly, Eva; Linderkamp, Otwin; Pöschl, Johannes

    2005-01-01

    Incontinentia pigmenti (IP) is a rare neurocutaneous disorder caused by mutations in the NEMO (NF-kappaB essential modulator) gene. Skin lesions are typically the first manifestation of IP though they may be accompanied by multiple malformations. This report presents the case of a female newborn with early onset of IP lesions within the 1st day of life. After the age of 1 month she developed frequent episodes of severe gastroenteritis. Examination of the immune system revealed low concentrations of IgG subclasses. This study suggests that, contrary to previous belief, IP is associated with immune deficiency. PMID:16103646

  6. Sex-stratified Linkage Analysis Identifies a Female-specific Locus for IgE to Cockroach in Costa Ricans

    PubMed Central

    Hunninghake, Gary M.; Lasky-Su, Jessica; Soto-Quirós, Manuel E.; Avila, Lydiana; Liang, Catherine; Lake, Stephen L.; Hudson, Thomas J.; Spesny, Mitzi; Fournier, Eduardo; Sylvia, Jody S.; Freimer, Nelson B.; Klanderman, Barbara J.; Raby, Benjamin A.; Celedón, Juan C.

    2008-01-01

    Rationale: The basis for gender influences on allergen-specific IgEs is unclear. Objectives: To perform regular and sex-stratified genomewide linkage analyses of IgE to each of three allergens (Ascaris lumbricoides, Blatella germanica [German cockroach]), and Dermatophagoides pteronyssinus [dust mite]) and to conduct an association study of a candidate gene in a linked genomic region. Methods: Genomewide linkage analyses of allergen-specific IgEs were conducted in 653 members of eight large families of Costa Rican children with asthma. An analysis of the association between single-nucleotide polymorphisms in thymic stromal lymphopoietin (TSLP) and IgE measurements was conducted in 417 parent–child trios in Costa Rica. Significant results were replicated in 470 families of white children in the Childhood Asthma Management Program (CAMP). Measurements and Main Results: Among all subjects, there was suggestive evidence of linkage (LOD ? 2.72) to IgE to Ascaris (on chromosome 7q) and IgE to dust mite (on chromosomes 7p and 12q). In a sex-stratified analysis, there was significant evidence of linkage to IgE to cockroach on chromosome 5q23 (peak LOD, 4.14 at 127 cM) in female subjects. TSLP is located within the 1.5 LOD-unit support interval for this linkage peak and has female-specific effects on lung disease in mice. In a sex-stratified analysis, the T allele of single-nucleotide polymorphism rs2289276 in TSLP was associated with reductions in IgE to cockroach (in Costa Rican girls) and total IgE (in girls in Costa Rica and in CAMP; P value for sex-by-genotype interaction, <0.01 in both studies). Conclusions: Consistent with findings in murine models, a variant in TSLP may have female-specific effects on allergic phenotypes. PMID:18244952

  7. Comparison patterns of 4 T1 antigens recognized by humoral immune response mediated by IgG and IgM antibodies in female and male mice with breast cancer using 2D-immnunoblots.

    PubMed

    Díaz-Zaragoza, Mariana; Hernández-Ávila, Ricardo; Govezensky, Tzipe; Mendoza, Luis; Meneses-Ruíz, Dulce María; Ostoa-Saloma, Pedro

    2015-09-01

    The early detection of cancer is one of the most promising approaches to reduce its growing burden and develop a curative treatment before the tumor is established. The early diagnosis of breast cancer is the most demanding of all tumors, because it is the most common cancer in women worldwide. We have described a new approach to analyze humoral immune reactions against 4 T1 cell antigens in female mice, reporting that the IgG and IgM responses differed and varied over time and between individuals. In this study, we compared and analyzed the detection of tumor antigens with IgG and IgM from the sera of male mice that were injected with 4 T1 cells into the mammary gland nipple in 2D immunoblot images. The variability in IgM and IgG responses in female and male mice with breast cancer at various stages of disease was characterized, and the properties with regard to antigen recognition were correlated statistically with variables that were associated with the individuals and tumors. The ensuing IgG and IgM responses differed. Only the IgG response decreased over time in female mice - not in male mice. The IgM response was maintained during tumor development in both sexes. Each mouse had a specific pattern of antigen recognition - ie, an immunological signature - represented by a unique set of antigen spots that were recognized by IgM or IgG. These data would support that rationale IgM is a better tool for early diagnosis, because it is not subject to immunosuppression like IgG in female mice with breast cancer. PMID:26026196

  8. New parasitoid-predator associations: female parasitoids do not avoid competition with generalist predators when sharing invasive prey.

    PubMed

    Chailleux, Anaïs; Wajnberg, Eric; Zhou, Yuxiang; Amiens-Desneux, Edwige; Desneux, Nicolas

    2014-12-01

    Optimal habitat selection is essential for species survival in ecosystems, and interspecific competition is a key ecological mechanism for many observed species association patterns. Specialized animal species are commonly affected by resource and interference competition with generalist and/or omnivorous competitors, so avoidance behavior could be expected. We hypothesize that specialist species may exploit broad range cues from such potential resource competitors (i.e., cues possibly common to various generalist and/or omnivorous predators) to avoid costly competition regarding food or reproduction, even in new species associations. We tested this hypothesis by studying short-term interactions between a native larval parasitoid and a native generalist omnivorous predator recently sharing the same invasive host/prey, the leaf miner Tuta absoluta. We observed a strong negative effect of kleptoparasitism (food resource stealing) instead of classical intraguild predation on immature parasitoids. There was no evidence that parasitoid females avoided the omnivorous predator when searching for oviposition sites, although we studied both long- and short-range known detection mechanisms. Therefore, we conclude that broad range cue avoidance may not exist in our biological system, probably because it would lead to too much oviposition site avoidance which would not be an efficient and, thus, beneficial strategy. If confirmed in other parasitoids or specialist predators, our findings may have implications for population dynamics, especially in the current context of increasing invasive species and the resulting creation of many new species associations. PMID:25331170

  9. New parasitoid-predator associations: female parasitoids do not avoid competition with generalist predators when sharing invasive prey

    NASA Astrophysics Data System (ADS)

    Chailleux, Anaïs; Wajnberg, Eric; Zhou, Yuxiang; Amiens-Desneux, Edwige; Desneux, Nicolas

    2014-12-01

    Optimal habitat selection is essential for species survival in ecosystems, and interspecific competition is a key ecological mechanism for many observed species association patterns. Specialized animal species are commonly affected by resource and interference competition with generalist and/or omnivorous competitors, so avoidance behavior could be expected. We hypothesize that specialist species may exploit broad range cues from such potential resource competitors (i.e., cues possibly common to various generalist and/or omnivorous predators) to avoid costly competition regarding food or reproduction, even in new species associations. We tested this hypothesis by studying short-term interactions between a native larval parasitoid and a native generalist omnivorous predator recently sharing the same invasive host/prey, the leaf miner Tuta absoluta. We observed a strong negative effect of kleptoparasitism (food resource stealing) instead of classical intraguild predation on immature parasitoids. There was no evidence that parasitoid females avoided the omnivorous predator when searching for oviposition sites, although we studied both long- and short-range known detection mechanisms. Therefore, we conclude that broad range cue avoidance may not exist in our biological system, probably because it would lead to too much oviposition site avoidance which would not be an efficient and, thus, beneficial strategy. If confirmed in other parasitoids or specialist predators, our findings may have implications for population dynamics, especially in the current context of increasing invasive species and the resulting creation of many new species associations.

  10. Cues of intraguild predators affect the distribution of intraguild prey

    PubMed Central

    Choh, Yasuyuki; van der Hammen, Tessa; Sabelis, Maurice W.

    2010-01-01

    Theory on intraguild (IG) predation predicts that coexistence of IG-predators and IG-prey is only possible for a limited set of parameter values, suggesting that IG-predation would not be common in nature. This is in conflict with the observation that IG-predation occurs in many natural systems. One possible explanation for this difference might be antipredator behaviour of the IG-prey, resulting in decreased strength of IG-predation. We studied the distribution of an IG-prey, the predatory mite Neoseiulus cucumeris (Acari: Phytoseiidae), in response to cues of its IG-predator, the predatory mite Iphiseius degenerans. Shortly after release, the majority of IG-prey was found on the patch without cues of IG-predators, suggesting that they can rapidly assess predation risk. IG-prey also avoided patches where conspecific juveniles had been killed by IG-predators. Because it is well known that antipredator behaviour in prey is affected by the diet of the predator, we also tested whether IG-prey change their distribution in response to the food of the IG-predators (pollen or conspecific juveniles), but found no evidence for this. The IG-prey laid fewer eggs on patches with cues of IG-predators than on patches without cues. Hence, IG-prey changed their distribution and oviposition in response to cues of IG-predators. This might weaken the strength of IG-predation, possibly providing more opportunities for IG-prey and IG-predators to co-exist. PMID:20354730

  11. IgG avidity antibodies against Toxoplasma gondii in high risk females of reproductive age group in India.

    PubMed

    Siddiqui, Naushaba; Shujatullah, Fatima; Khan, Haris M; Rabbani, Tamkin; Khan, Parvez A

    2014-10-01

    Toxoplasma gondii is an obligate intracellular protozoan that is distributed worldwide. Recently, several tests for avidity of Toxoplasma IgG antibodies have been introduced to help discriminate between recently acquired and distant infections. The study was conducted in Jawaharlal Nehru Medical College and Hospital, India from February 2011 to September 2012. Serum specimens were subjected to Toxoplasma IgM ELISA and IgG avidity ELISA test. Out of 48 patients with abortions, 17 (35.4%) were positive for IgM ELISA, and 8 (16.6%) had low IgG avidity antibodies. Out of 48 patients with other obstetric problems, 23 (47.9%) were positive for IgM ELISA, and 17 (35.4%) had low IgG avidity antibodies. Combining both groups on avidity test, only 25 of 40 (62.5%) IgM-positive women had low-avidity IgG antibodies suggesting a recent T. gondii infection in these women. More importantly, 15 (37.5%) of the IgM-positive women had high-avidity antibodies suggesting that the infection was acquired before gestation The relation of IgM seropositivity with the following risk factors was not found to be statistically significant; contact with cats (0.13), non-vegetarian food habits (0.05), and low socio-economic status (0.49). While, for IgG avidity ELISA, only contact with cats (0.01) was significantly associated with seropositivity. All other risk factors have P-values of >0.05 (not significant). IgG avidity test when used in combination with IgM test was a valuable assay for diagnosis of ongoing or recently acquired T. gondii infection in India. PMID:25352696

  12. Prey Preference, Intraguild Predation and Population Dynamics of an Arthropod Food Web on Plants

    Microsoft Academic Search

    Madelaine Venzon; Arne Janssen; Maurice W. Sabelis

    2001-01-01

    The theory of intraguild predation (IGP) largely studies effects on equilibrium densities of predators and prey, while experiments mostly concern transient dynamics. We studied the effects of an intraguild (IG) predator, the bug Orius laevigatus, on the population dynamics of IG-prey, the predatory mite Phytoseiulus persimilis, and a shared prey, the phytophagous two-spotted spider mite Tetranychus urticae, as well as

  13. AN IMMUNOLOGICAL TECHNIQUE FOR IDENTIFYING MULTIPLE PREDATOR—PREY INTERACTIONS IN A COMPLEX ARTHROPOD ASSEMBLAGE

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A laboratory feeding study was conducted to determine if predation events could be detected from predators that consumed prey marked with foreign protein. In laboratory feeding trials I determined that large and small rabbit immunoglobulin G (IgG) marked prey can be detected by a rabbit IgG-specifi...

  14. Mucosal immunization of lactating female rhesus monkeys with a transmitted/founder HIV-1 envelope induces strong Env-specific IgA antibody responses in breast milk.

    PubMed

    Fouda, Genevieve G A; Amos, Joshua D; Wilks, Andrew B; Pollara, Justin; Ray, Caroline A; Chand, Anjali; Kunz, Erika L; Liebl, Brooke E; Whitaker, Kaylan; Carville, Angela; Smith, Shannon; Colvin, Lisa; Pickup, David J; Staats, Herman F; Overman, Glenn; Eutsey-Lloyd, Krissey; Parks, Robert; Chen, Haiyan; Labranche, Celia; Barnett, Susan; Tomaras, Georgia D; Ferrari, Guido; Montefiori, David C; Liao, Hua-Xin; Letvin, Norman L; Haynes, Barton F; Permar, Sallie R

    2013-06-01

    We previously demonstrated that vaccination of lactating rhesus monkeys with a DNA prime/vector boost strategy induces strong T-cell responses but limited envelope (Env)-specific humoral responses in breast milk. To improve vaccine-elicited antibody responses in milk, hormone-induced lactating rhesus monkeys were vaccinated with a transmitted/founder (T/F) HIV Env immunogen in a prime-boost strategy modeled after the moderately protective RV144 HIV vaccine. Lactating rhesus monkeys were intramuscularly primed with either recombinant DNA (n = 4) or modified vaccinia virus Ankara (MVA) poxvirus vector (n = 4) expressing the T/F HIV Env C.1086 and then boosted twice intramuscularly with C.1086 gp120 and the adjuvant MF59. The vaccines induced Env-binding IgG and IgA as well as neutralizing and antibody-dependent cellular cytotoxicity (ADCC) responses in plasma and milk of most vaccinated animals. Importantly, plasma neutralization titers against clade C HIV variants MW965 (P = 0.03) and CAP45 (P = 0.04) were significantly higher in MVA-primed than in DNA-primed animals. The superior systemic prime-boost regimen was then compared to a mucosal-boost regimen, in which animals were boosted twice intranasally with C.1086 gp120 and the TLR 7/8 agonist R848 following the same systemic prime. While the systemic and mucosal vaccine regimens elicited comparable levels of Env-binding IgG antibodies, mucosal immunization induced significantly stronger Env-binding IgA responses in milk (P = 0.03). However, the mucosal regimen was not as potent at inducing functional IgG responses. This study shows that systemic MVA prime followed by either intranasal or systemic protein boosts can elicit strong humoral responses in breast milk and may be a useful strategy to interrupt postnatal HIV-1 transmission. PMID:23596289

  15. Aggressive mimicry, prey-specific predatory behaviour and predator-recognition in the predator-prey interactions of Portia fimbriata and Euryattus sp., jumping spiders from Queensland

    Microsoft Academic Search

    Robert R. Jackson; R. Stimson Wilcox

    1990-01-01

    Adults and large juveniles of Queensland Portia fimbriata, a salticid spider known to prey on other spiders (including other salticids), are shown to use prey-specific predatory behaviour against Euryattus sp., one of the salticids on which it feeds. Euryattus females are unusual because they nest inside suspended rolled-up leaves. P. fimbriata used vibratory displays to lure Euryattus females from their

  16. Unidirectional prey–predator facilitation: apparent prey enhance predators' foraging success on cryptic prey

    Microsoft Academic Search

    Yixin Zhang; John S. Richardson

    2007-01-01

    Food availability can strongly affect predator- prey dynamics. When change in habitat con- dition reduces the availability of one prey type, predators often search for other prey, perhaps in a different habitat. Interactions between beha- vioural and morphological traits of different prey may influence foraging success of visual predators through trait-mediated indirect interactions (TMIIs), such as prey activity and body

  17. Efficacy, prey stage preference and optimum predator–prey ratio of the predatory mite, Neoseiulus longispinosus Evans (Acari: Phytoseiidae) to control the red spider mite, Oligonychus coffeae Nietner (Acari: Tetranychidae) infesting tea

    Microsoft Academic Search

    Vattakandy Jasin Rahman; Azariah Babu; Amsalingam Roobakkumar; Kandasamy Perumalsamy; Duraikkannu Vasanthakumar; Mariappan Sankara Rama Subramaniam

    2011-01-01

    The predatory mite, N. longispinosus preys up on red spider mite, O. coffeae infesting tea in south India. An attempt has been made to determine the predatory potential, prey stage preference and optimum predator–prey ratio of N. longispinosus under laboratory and green house conditions. When 50 adult female O. coffeae were given, the number of adults reduced by eight days

  18. Efficacy, prey stage preference and optimum predator–prey ratio of the predatory mite, Neoseiulus longispinosus Evans (Acari: Phytoseiidae) to control the red spider mite, Oligonychus coffeae Nietner (Acari: Tetranychidae) infesting tea

    Microsoft Academic Search

    Vattakandy Jasin Rahman; Azariah Babu; Amsalingam Roobakkumar; Kandasamy Perumalsamy; Duraikkannu Vasanthakumar; Mariappan Sankara Rama Subramaniam

    2012-01-01

    The predatory mite, N. longispinosus preys up on red spider mite, O. coffeae infesting tea in south India. An attempt has been made to determine the predatory potential, prey stage preference and optimum predator–prey ratio of N. longispinosus under laboratory and green house conditions. When 50 adult female O. coffeae were given, the number of adults reduced by eight days

  19. Seasonal foraging ecology of non-migratory cougars in a system with migrating prey.

    PubMed

    Elbroch, L Mark; Lendrum, Patrick E; Newby, Jesse; Quigley, Howard; Craighead, Derek

    2013-01-01

    We tested for seasonal differences in cougar (Puma concolor) foraging behaviors in the Southern Yellowstone Ecosystem, a multi-prey system in which ungulate prey migrate, and cougars do not. We recorded 411 winter prey and 239 summer prey killed by 28 female and 10 male cougars, and an additional 37 prey items by unmarked cougars. Deer composed 42.4% of summer cougar diets but only 7.2% of winter diets. Males and females, however, selected different proportions of different prey; male cougars selected more elk (Cervus elaphus) and moose (Alces alces) than females, while females killed greater proportions of bighorn sheep (Ovis canadensis), pronghorn (Antilocapra americana), mule deer (Odocoileus hemionus) and small prey than males. Kill rates did not vary by season or between males and females. In winter, cougars were more likely to kill prey on the landscape as: 1) elevation decreased, 2) distance to edge habitat decreased, 3) distance to large bodies of water decreased, and 4) steepness increased, whereas in summer, cougars were more likely to kill in areas as: 1) elevation decreased, 2) distance to edge habitat decreased, and 3) distance from large bodies of water increased. Our work highlighted that seasonal prey selection exhibited by stationary carnivores in systems with migratory prey is not only driven by changing prey vulnerability, but also by changing prey abundances. Elk and deer migrations may also be sustaining stationary cougar populations and creating apparent competition scenarios that result in higher predation rates on migratory bighorn sheep in winter and pronghorn in summer. Nevertheless, cougar predation on rare ungulates also appeared to be influenced by individual prey selection. PMID:24349498

  20. Predators and Prey

    ERIC Educational Resources Information Center

    Kramm, Kenneth R.

    1975-01-01

    Reviews basic concepts of predator-prey interaction, encourages the presentation of the predator's role and describes a model of predator behavior to be used in secondary school or college classes. (LS)

  1. Effect of prior diet on consumption and digestion of prey and non-prey food by adults of the generalist predator Coleomegilla maculata (Coleoptera: Coccinellidae

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Coleomegilla maculata adults fed on prey (Colorado potato beetle eggs) or non-prey (corn pollen) food following 7 days of feeding on a mixed diet, showed differences in ingestion, with females consuming greater quantities of pollen, and males consuming greater quantities of eggs, under no-choice con...

  2. L-shaped prey isocline in the Gause predator-prey experiments with a prey refuge.

    PubMed

    K?ivan, Vlastimil; Priyadarshi, Anupam

    2015-04-01

    Predator and prey isoclines are estimated from data on yeast-protist population dynamics (Gause et al., 1936). Regression analysis shows that the prey isocline is best fitted by an L-shaped function that has a vertical and a horizontal part. The predator isocline is vertical. This shape of isoclines corresponds with the Lotka-Volterra and the Rosenzweig-MacArthur predator-prey models that assume a prey refuge. These results further support the idea that a prey refuge changes the prey isocline of predator-prey models from a horizontal to an L-shaped curve. Such a shape of the prey isocline effectively bounds amplitude of predator-prey oscillations, thus promotes species coexistence. PMID:25644756

  3. PredatorPrey Relationships 933 PredatorPrey

    E-print Network

    are predators, but some are also preyed upon by other species. Theoretically, the interaction between marine interactions. I. Evolutionary Time Scales Predator­prey relationships have been likened to an evolutionary arms of the interactions between the predators and their prey (Taylor, 1984). As predators, marine mammals feed primarily

  4. Effects of prey concentration, prey size, predator life stage, predator starvation, and season on predation rates of the carnivorous copepod Euchaeta elongata

    Microsoft Academic Search

    J. Yen

    1983-01-01

    Adult females of the large carnivorous copepod Euchaeta elongata Esterly were collected from 1977 to 1980 in Port Susan, Washington, USA. Predation rates of the adult females increased with increasing prey abundance when fed the following 4 sizes of copepods: adult females of Calanus pacificus (average prosome length [PL] of 2 650 µm), adults of Aetideus divergens (PL of 1

  5. Increased prey vulnerability as a result of prey-prey interactions

    Microsoft Academic Search

    Frank Johansson

    1995-01-01

    This study examines indirect effects in a trophic system with three levels, consisting of two prey species, a top predator,\\u000a and an intermediate predator. Qualitative data showed that the activity of both the top predator Aeshna juncea (Odonata) and the active prey Heterocope saliens, (Copepoda) caused bouts of swimming in the sedentary prey Sida crystallina (Cladocera). These swimming bouts caused

  6. A predator’s preference for egg-carrying prey: a novel cost of parental care

    Microsoft Academic Search

    Daiqin Li; Robert R. Jackson

    2003-01-01

    Using a subsocial spitting spider ( Scytodes pallida) as the prey and a spider-eating jumping spider ( Portia labiata) as the predator, the cost of parental care is investigated. Our findings suggest that being singled out as preferred prey by P. labiata is, for egg-carrying females of S. pallida, an important cost of parental care. In survival tests, during which

  7. The influence of initial age structure on predator–prey interaction

    Microsoft Academic Search

    Th. Hance; G. Van Impe

    1999-01-01

    Initial age structure influences the growth of a prey population and the outcome of the predator–prey interaction. In order to quantify that influence, we employed a simple numerical model using experimental data from the system Tetranychus urticae–Phytoseiulus persimilis. Four major points were drawn from the results: (1) A population created by young females grows much faster than a population created

  8. Indirect effects of primary prey population dynamics on alternative prey.

    PubMed

    Barraquand, Frédéric; New, Leslie F; Redpath, Stephen; Matthiopoulos, Jason

    2015-08-01

    We develop a theory of generalist predation showing how alternative prey species are affected by changes in both mean abundance and variability (coefficient of variation) of their predator's primary prey. The theory is motivated by the indirect effects of cyclic rodent populations on ground-breeding birds, and developed through progressive analytic simplifications of an empirically-based model. It applies nonetheless to many other systems where primary prey have fast life-histories and can become superabundant, thus facilitating impact on alternative prey species and generating highly asymmetric interactions. Our results suggest that predator effects on alternative prey should generally decrease with mean primary prey abundance, and increase with primary prey variability (low to high CV)-unless predators have strong aggregative responses, in which case these results can be reversed. Approximations of models including predator dynamics (general numerical response with possible delays) confirm these results but further suggest that negative temporal correlation between predator and primary prey is harmful to alternative prey. Finally, we find that measurements of predator numerical responses are crucial to predict-even qualitatively-the response of ecosystems to changes in the dynamics of outbreaking prey species. PMID:25930160

  9. Does a Polyphagous Predator Prefer Prey Species That Confer Reproductive Advantage?: Case Study of Podisus maculiventris

    Microsoft Academic Search

    Jesusa Crisostomo Legaspi; Benjamin C. Legaspi

    2004-01-01

    The purpose of this study was to determine whether preferred prey of Podisus macu- liventris (Say) (Heteroptera: Pentatomidae) adult females also conferred maximal fecundity. We also studied egg development and maturation as a function of predator age, i.e., \\

  10. Attraction of two lacewing species to volatiles produced by host plants and aphid prey

    NASA Astrophysics Data System (ADS)

    Zhu, J.; Obrycki, J. J.; Ochieng, Samuel A.; Baker, Thomas C.; Pickett, J. A.; Smiley, D.

    2005-06-01

    It is well documented that host-related odors enable many species of parasitoids and predatory insects to locate their prey and prey habitats. This study reports the first characterization of prey and prey host odor reception in two species of lacewings, Chrysoperla carnea (Say) and Chrysopa oculata L. 2-Phenylethanol, one of the volatiles emitted from their prey’s host plants (alfalfa and corn) evoked a significant EAG response from antennae of C. carnea. Traps baited with this compound attracted high numbers of adult C. carnea, which were predominantly females. One of the sex pheromone components (1R,4aS,7S,7aR)-nepetalactol of an aphid species, Acyrthosiphon pisum (Harris) attracted only C. oculata adults. Single sensillum recordings showed that the olfactory neurons of C. carnea responded to both 2-phenylethanol and aphid sex pheromone components, but those of C. oculata only responded to the latter.

  11. Unidirectional prey-predator facilitation: apparent prey enhance predators' foraging success on cryptic prey.

    PubMed

    Zhang, Yixin; Richardson, John S

    2007-06-22

    Food availability can strongly affect predator-prey dynamics. When change in habitat condition reduces the availability of one prey type, predators often search for other prey, perhaps in a different habitat. Interactions between behavioural and morphological traits of different prey may influence foraging success of visual predators through trait-mediated indirect interactions (TMIIs), such as prey activity and body coloration. We tested the hypothesis that foraging success of stream-dwelling cutthroat trout (Onchorhyncus clarki) on cryptically coloured, less-active benthic prey (larval mayfly; Paraleptophebia sp.) can be enhanced by the presence of distinctly coloured, active prey (larval stonefly shredder; Despaxia augusta). Cutthroat trout preyed on benthic insects when drifting invertebrates were unavailable. When stonefly larvae were present, the trout ate most of the stoneflies and also consumed a higher proportion of mayflies than under mayfly only treatment. The putative mechanism is that active stonefly larvae supplied visual cues to the predator that alerted trout to the mayfly larvae. Foraging success of visual predators on cryptic prey can be enhanced by distinctly coloured, active benthic taxa through unidirectional facilitation to the predators, which is a functional change of interspecific interaction caused by a third species. This study suggests that prey-predator facilitation through TMIIs can modify species interactions, affecting community dynamics. PMID:17426008

  12. Goshawk prey have more bacteria than non-prey.

    PubMed

    Møller, A P; Peralta-Sánchez, J M; Nielsen, J T; López-Hernández, E; Soler, J J

    2012-03-01

    1. Predators often prey on individuals that are sick or otherwise weakened. Although previous studies have shown higher abundance of parasites in prey, whether prey have elevated loads of micro-organisms remains to be determined. 2. We quantified the abundance of bacteria and fungi on feathers of woodpigeons Columba palumbus L., jays Garrulus glandarius L. and blackbirds Turdus merula L. that either fell prey to goshawks Accipiter gentilis L. or were not depredated. 3. We found an almost three-fold increase in bacterial load of prey compared with non-prey, while there was no significant difference between prey and non-prey in level of fungal infection of the plumage. 4. The results were not confounded by differences in size or mass of feathers, date of collection of feathers, or date of analysis of feathers for micro-organisms. 5. These findings suggest a previously unknown contribution of bacteria to risk of predation, with important implications for behaviour, population ecology and community ecology. PMID:22039986

  13. Predators and Prey

    NSDL National Science Digital Library

    The Concord Consortium

    2011-12-11

    This activity uses a model of the Virtual Ecosystem with three species in it: grass, rabbits, and hawks, enabling the students to explore the effect of predation on the prey population. At first students explore protective coloration as they ?become? a hawk and try to catch and eat brown and white rabbits on a snowy field. The latter blend into the background and are harder to see, so they have a selective advantage. Students then explore how the color of the rabbit population changes as the environment changes over time.

  14. Evaluation of the Abbott ARCHITECT Toxo IgM assay

    Microsoft Academic Search

    Eva Sickinger; Hans-Bertram Braun; Gerald Praast; Myriam Stieler; Cordelia Gundlach; Claudia Birkenbach; John Prostko; Mary Ann Palafox; Edwin Frias; Stephen Hsu; Matthew Matias; Dominick Pucci; Michael Hausmann; Ulrich Sagel; Darwin Smith

    2009-01-01

    Development of the ARCHITECT Toxo IgM assay has been done to assist the clinician in acute Toxoplasma gondii infection detection, especially in pregnant women. Its use, in conjunction with ARCHITECT Toxo IgG and Toxo Avidity assays, will provide an array of assays particularly useful in the monitoring of pregnant females to determine the risk of maternal transmission of the parasite.

  15. Both Predator and Prey

    PubMed Central

    Löw, Andreas; Lang, Peter J.; Smith, J. Carson; Bradley, Margaret M.

    2013-01-01

    This research examined the psychophysiology of emotional arousal anticipatory to potentially aversive and highly pleasant outcomes. Human brain reactions (event-related potentials) and body reactions (heart rate, skin conductance, the probe startle reflex) were assessed along motivational gradients determined by apparent distance from sites of potential punishment or reward. A predator-prey survival context was simulated using cues that signaled possible money rewards or possible losses; the cues appeared to loom progressively closer to the viewer, until a final step when a rapid key response could ensure reward or avoid a punishing loss. The observed anticipatory response patterns of heightened vigilance and physiological mobilization are consistent with the view that the physiology of emotion is founded on action dispositions that evolved in mammals to facilitate survival by dealing with threats or capturing life-sustaining rewards. PMID:18947351

  16. Survival and efficiency of three spider mite predators (Acarina: phytoseiidae) at low levels of prey availability

    E-print Network

    Friese, Daniel David

    1980-01-01

    of ovipositional period for A. californicus at standard laboratory conditions. 20 4. Influence of several levels of prey availability on the total and daily number of prey killed by females of A. californicus at standard laboratory conditions 21 5. Influence... for several instars of A. californicus to contact and capture daily food requirements 58 28, Estimated population densities of T. urticae necessary for several ins tars of A. californicus to contact and capture daily food requirements 59 29. Estimated...

  17. The influence of prey distribution on the foraging strategy of the lizard Oligosoma grande (Reptilia: Scincidae)

    Microsoft Academic Search

    Douglas A. Eifler; Maria A. Eifler

    1999-01-01

    The grand skink, Oligosoma grande, is a diurnal rock-dwelling lizard from the tussock grasslands of Central Otago, New Zealand, whose diet includes a variety\\u000a of arthropods and fruit. We conducted a field experiment to examine the influence of prey distribution on foraging behavior\\u000a and spacing patterns. On sites where prey distribution was unaltered (control sites), males and females differed in

  18. Relating wolf scat content to prey consumed

    USGS Publications Warehouse

    Floyd, T.J.; Mech, L.D.; Jordan, P.A.

    1978-01-01

    In 9 trials, captive wolves (Canis lupus) were fed prey varying in size from snowshoe hares (Lepus americanus) to adult deer (Odocoileus virginianus), and the resulting scats were counted. Field-collectible scats were distinguished from liquid, noncollectible stools. I n collectible scats, the remains of small prey occurred in greater proportion relative to the prey's weight, and in lesser proportion relative to the prey's numbers, than did the remains of larger prey. A regression equation with an excellent, fit to the data (r2 = 0.97) was derived to estimate the weight of prey eaten per collectible scat for any prey. With this information and average prey weights, the relative numbers of different prey eaten also can be calculated.

  19. Active foraging for toxic prey during gestation in a snake with maternal provisioning of sequestered chemical defences.

    PubMed

    Kojima, Yosuke; Mori, Akira

    2015-01-01

    Many animals sequester dietary defensive compounds and incorporate them into the offspring, which protects the young against predation. One possible but poorly investigated question is whether females of such species actively prey upon toxic diets. The snake Rhabdophis tigrinus sequesters defensive steroids from toads consumed as prey; it also feeds on other amphibians. Females produce chemically armed offspring in direct proportion to their own level of toad-derived toxins by provisioning the toxins to their eggs. Our field observations of movements and stomach contents of radio-tracked R. tigrinus showed that gravid snakes preyed upon toads by actively foraging in the habitat of toads, even though toads were a scarce resource and toad-searching may incur potential costs. Our Y-maze experiments demonstrated that gravid females were more likely to trail the chemical cues of toads than were males or non-gravid females. These results showed behavioural switching in females and active foraging for scarce, toxic prey during gestation. Because exploitation of toads by gravid females results in their offspring being more richly endowed with prey-derived toxins, active foraging for toxic prey is expected to be an adaptive antipredator trait, which may enhance chemical defence in offspring. PMID:25392472

  20. Complex interactions between components of individual prey specialization affect mechanisms of niche variation in a grasshopper-hunting wasp.

    PubMed

    Santoro, Davide; Polidori, Carlo; Asís, Josep D; Tormos, José

    2011-11-01

    1.?Individual foraging behaviour defines the use of resources by a given population and its variation in different ways such as, for example, unpredictable interactions between taxon-biased and size-biased selection. Here we investigated how the environmental availability of prey and individual specialization, for both prey taxa and prey size, shape niche variation across generations in the grasshopper-hunting digger wasp Stizus continuus. 2.?The population of S. continuus expressed selective predation, females mainly hunting species encountered on large bushes; diet changed across generations, due more to size increase in potential prey than to changes in the orthopteran community. 3.?Individual females of both generations weakly overlapped the size and taxa of prey, and the niche width of the second generation increased for both prey size and taxa. 4.?The greater variance in prey size in the environment accounted for the enlarged prey size niche of the second generation, but the load-lifting constraints of the wasps maintained individual prey size specialization constant. In contrast, the enlarged prey taxon niche paralleled a smaller overlap of diets between wasps in the second generation. 5.?Increased niche width in the S. continuus population was thus achieved in two ways. Regarding prey size, all individuals shifted towards the use of the full set of available resources (parallel release). For prey taxa, according to the classical niche variation hypothesis, individuals diverged to minimize resource use overlap and perhaps intraspecific competition. These two mechanisms were observed for the first time simultaneously in a single predator population. PMID:21644980

  1. Chemotactic predator-prey dynamics

    NASA Astrophysics Data System (ADS)

    Sengupta, Ankush; Kruppa, Tobias; Löwen, Hartmut

    2011-03-01

    A discrete chemotactic predator-prey model is proposed in which the prey secrets a diffusing chemical which is sensed by the predator and vice versa. Two dynamical states corresponding to catching and escaping are identified and it is shown that steady hunting is unstable. For the escape process, the predator-prey distance is diffusive for short times but exhibits a transient subdiffusive behavior which scales as a power law t1/3 with time t and ultimately crosses over to diffusion again. This allows us to classify the motility and dynamics of various predatory microbes and phagocytes. In particular, there is a distinct region in the parameter space where they prove to be infallible predators.

  2. Predator-Prey Simulation Exercises for the Classroom

    NSDL National Science Digital Library

    James Waddell (University of Maine at Orono; )

    2009-08-26

    Illustrations of predator-prey interactions looking at different prey distributions, structural complexity of the environment, prey's reproductive rate,and both predator-prey reproduction in a complex environment.

  3. Facilitation of intraguild prey by its intraguild predator in a three-species Lotka-Volterra model.

    PubMed

    Shchekinova, Elena Y; Löder, Martin G J; Boersma, Maarten; Wiltshire, Karen H

    2014-03-01

    Explaining the coexistence of multiple species in the competition and predation theatre has proven a great challenge. Traditional intraguild predation (IGP) models have only relatively small regions of stable coexistence of all species. Here, we investigate potential additional mechanisms that extend these regions of stable coexistence. We used a 3-species Lotka-Volterra system to which we added an interaction term to model a unidirectional facilitative relationship between the two predators in the IGP. In this modelling study the IG predator was able to precondition a part of the common resource by an instantaneous manipulation, which resulted in the immobilization of the resource species. This mechanism of immobilization facilitated the resource uptake by the IG prey and thus increased its growth rates even in the presence of the common predator. The facilitative relationship of the IG prey by the IG predator produced a stable coexistence of both predators even though the IG prey was an inferior competitor for a common resource, which cannot be attained with the traditional IGP models. Furthermore, our model predicted a 3-species stable coexistence even at high enrichment where no coexistence was found in the basic IGP model. Thus, we showed that diversity of resource traits could significantly alter emergent community patterns via shifts in exploitative competition of IGP-related predators. The described mechanism could potentially lead to a higher efficiency in exploitation of common resources and thus promote higher diversity in a real community. PMID:24325813

  4. RESEARCH ARTICLE Prey Capture Behavior of Native

    E-print Network

    Gibb, Alice C.

    predators, and Sonora sucker (Catostomus insignis) and common carp (Cyprinus carpio), benthic omnivores; in contrast, Sonora sucker remove attached prey via scraping. When presented with different prey types, common

  5. Innate prey preference overridden by familiarisation with detrimental prey in a specialised myrmecophagous predator.

    PubMed

    Pekár, Stano; Cárdenas, Manuel

    2015-02-01

    Prey-specialised spiders often do not have brood care and may not deposit eggs in the proximity of the preferred prey. Thus, naïve spiderlings are left to their own to find their focal prey. Our aim was to reveal whether the choice of a specific prey is innate and whether familiarisation with a certain prey will condition prey choice. We used the myrmecophagous spider Euryopis episinoides, which specialises on Messor ants. It finds ants using chemical cues deposited on the substrate. Naïve spiderlings were offered chemical cues from Messor and Myrmica ants and Drosophila flies. They chose significantly more chemical cues from Messor ants than those from Drosophila flies. Then spiderlings were assigned to three prey treatments: fed with Messor ants only (optimal prey), fed with Myrmica ants only (suboptimal prey) or fed with Drosophila flies only (detrimental prey) until adulthood. Every 2 weeks, all spiders from all treatments were offered chemical cues from the three prey types and the frequency of choice and latency to assuming a posture were recorded. Experienced spiderlings preferred chemical cues from the prey in which they were raised. They suffered high mortality on Drosophila flies and attained largest size on the optimal prey. We show here that majority of spiderlings are born with an innate preference to their focal prey, which can be altered by familiarisation with alternative prey, irrespective of whether such a prey is beneficial. PMID:25645732

  6. Innate prey preference overridden by familiarisation with detrimental prey in a specialised myrmecophagous predator

    NASA Astrophysics Data System (ADS)

    Pekár, Stano; Cárdenas, Manuel

    2015-02-01

    Prey-specialised spiders often do not have brood care and may not deposit eggs in the proximity of the preferred prey. Thus, naïve spiderlings are left to their own to find their focal prey. Our aim was to reveal whether the choice of a specific prey is innate and whether familiarisation with a certain prey will condition prey choice. We used the myrmecophagous spider Euryopis episinoides, which specialises on Messor ants. It finds ants using chemical cues deposited on the substrate. Naïve spiderlings were offered chemical cues from Messor and Myrmica ants and Drosophila flies. They chose significantly more chemical cues from Messor ants than those from Drosophila flies. Then spiderlings were assigned to three prey treatments: fed with Messor ants only (optimal prey), fed with Myrmica ants only (suboptimal prey) or fed with Drosophila flies only (detrimental prey) until adulthood. Every 2 weeks, all spiders from all treatments were offered chemical cues from the three prey types and the frequency of choice and latency to assuming a posture were recorded. Experienced spiderlings preferred chemical cues from the prey in which they were raised. They suffered high mortality on Drosophila flies and attained largest size on the optimal prey. We show here that majority of spiderlings are born with an innate preference to their focal prey, which can be altered by familiarisation with alternative prey, irrespective of whether such a prey is beneficial.

  7. Availability of prey resources drives evolution of predator–prey interaction

    Microsoft Academic Search

    Ville-Petri Friman; Teppo Hiltunen; Jouni Laakso; Veijo Kaitala

    2008-01-01

    Productivity is predicted to drive the ecological and evolutionary dynamics of predator-prey interaction through changes in resource allocation between different traits. Here we report results of an evolutionary experiment where prey bacteria Serratia marcescens was exposed to predatory protozoa Tetrahymena thermophila in low- and high-resource environments for approximately 2400 prey generations. Predation generally increased prey allocation to defence and caused

  8. Lotka-Volterra Predator-Prey Model Prey V(t), Predator P(t)

    E-print Network

    Caraco, Thomas

    (interactions) at one scale can induce pattern at extended spatio-temporal scales. #12;Example: Predator-PreyLotka-Volterra Predator-Prey Model Prey V(t), Predator P(t) Equilibrium Nodes: (0, 0) and (V* = D Temporal Behavior #12;Ricklefs and Miller, 2000 Ecology #12;Examine Neutral Stability, Predator-Prey

  9. Prey pursuit and interception in dragonflies

    Microsoft Academic Search

    R. M. Olberg; A. H. Worthington; K. R. Venator

    2000-01-01

    Perching dragonflies (Libellulidae; Odonata) are sit-and-wait predators, which take off and pursue small flying insects.\\u000a To investigate their prey pursuit strategy, we videotaped 36 prey-capture flights of male dragonflies, Erythemis simplicicollis and Leucorrhinia intacta, for frame-by-frame analysis. We found that dragonflies fly directly toward the point of prey interception by steering to\\u000a minimize the movement of the prey's image on

  10. Seabird foraging behaviour indicates prey type

    Microsoft Academic Search

    Kyle Hamish Elliott; Kerry Woo; Anthony J. Gaston; Silvano Benvenuti; Luigi Dall' Antonia; Gail K. Davoren

    2008-01-01

    To investigate how a generalist marine predator modifies its foraging behaviour by prey type, we attached time-depth-temperature recorders to chick-rearing thick-billed murres (n = 204) at Coats Island, Nunavut, Canada from 1999 to 2007. Predators varied their behavior along 3 major 'axes': foraging effort, prey depth and prey lifestyle (benthic\\/pelagic). Dive behaviours for different prey — fish doctor, squid, sandlance,

  11. Diet of intraguild predators affects antipredator behavior in intraguild prey

    Microsoft Academic Search

    Sara Magalhaes; Christian Tudorache; Marta Montserrat; Roos van Maanen; Maurice W. Sabelis

    2004-01-01

    In two-predator, one-prey systems with intraguild predation and patchily distributed prey, the intraguild prey may face a choice between prey patches with and without intraguild predators. To minimize falling victim to intraguild predation, intraguild prey are expected to perceive cues specifically associated with the presence of intraguild predators. We investigate whether intraguild prey avoided intraguild predators and which cues triggered

  12. Qualitative and Quantitative Prey Requirements of two Aphidophagous Coccinellids, Adalia tetraspilota and Hippodamia variegata

    PubMed Central

    Shah, Mohd Abas; Khan, Akhtar Ali

    2014-01-01

    The suitability of two prey species, Aphis pomi De Geer (Hemiptera: Aphididae) and Brevicoryne brassicae (L.), for two generalist aphidophagous coccinellids, Adalia tetraspilota (Hope) (Coleoptera: Coccinellidae) and Hippodamia variegata (Goeze), at various abundance levels was investigated under laboratory conditions. While both A. pomi and B. brassicae were found to be suitable, the predators performed better when feeding upon B. brassicae. The prey densities affected the developmental parameters of the two predators appreciably. Optimal growth and development was noted in the prey density range of 40–80 aphids per day per predator. Both species and abundance levels of prey significantly affected the larval period of the two predators. Appreciable variation in survivorship of larvae, prepupal and pupal period, and adult weight was noted by varying the prey species and prey abundance. Longer reproductive period (oviposition period) and shorter non-reproductive periods (pre-oviposition and post-oviposition periods) were noted for females that fed on B. brassicae as compared to those that fed on A. pomi. Reproductive output was appreciably higher for females that fed on B. brassicae, and the fecundity decreased drastically under food shortage. PMID:25373219

  13. Mountain lions prey selectively on prion-infected mule deer.

    PubMed

    Krumm, Caroline E; Conner, Mary M; Hobbs, N Thompson; Hunter, Don O; Miller, Michael W

    2010-04-23

    The possibility that predators choose prey selectively based on age or condition has been suggested but rarely tested. We examined whether mountain lions (Puma concolor) selectively prey upon mule deer (Odocoileus hemionus) infected with chronic wasting disease, a prion disease. We located kill sites of mountain lions in the northern Front Range of Colorado, USA, and compared disease prevalence among lion-killed adult (> or =2 years old) deer with prevalence among sympatric deer taken by hunters in the vicinity of kill sites. Hunter-killed female deer were less likely to be infected than males (odds ratios (OR) = 0.2, 95% confidence intervals (CI) = 0.1-0.6; p = 0.015). However, both female (OR = 8.5, 95% CI = 2.3-30.9) and male deer (OR = 3.2, 95% CI = 1-10) killed by a mountain lion were more likely to be infected than same-sex deer killed in the vicinity by a hunter (p < 0.001), suggesting that mountain lions in this area actively selected prion-infected individuals when targeting adult mule deer as prey items. PMID:19864271

  14. Prey life-history and bioenergetic responses across a predation gradient.

    PubMed

    Rennie, M D; Purchase, C F; Shuter, B J; Collins, N C; Abrams, P A; Morgan, G E

    2010-10-01

    To evaluate the importance of non-consumptive effects of predators on prey life histories under natural conditions, an index of predator abundance was developed for naturally occurring populations of a common prey fish, the yellow perch Perca flavescens, and compared to life-history variables and rates of prey energy acquisition and allocation as estimated from mass balance models. The predation index was positively related to maximum size and size at maturity in both male and female P. flavescens, but not with life span or reproductive investment. The predation index was positively related to size-adjusted specific growth rates and growth efficiencies but negatively related to model estimates of size-adjusted specific consumption and activity rates in both vulnerable (small) and invulnerable (large) size classes of P. flavescens. These observations suggest a trade-off between growth and activity rates, mediated by reduced activity in response to increasing predator densities. Lower growth rates and growth efficiencies in populations with fewer predators, despite increased consumption suggests either 1) a reduction in prey resources at lower predator densities or 2) an intrinsic cost of rapid prey growth that makes it unfavourable unless offset by a perceived threat of predation. This study provides evidence of trade-offs between growth and activity rates induced by predation risk in natural prey fish populations and illustrates how behavioural modification induced through predation can shape the life histories of prey fish species. PMID:21039502

  15. Predator-Prey Interactions in Communities with prey dispersal and Allee effects

    Microsoft Academic Search

    F. Berezovskaya; S. Wirkus; C. Castillo-Chavez

    2009-01-01

    The population dynamics of predator-prey systems in the presence of patch-specific predators are explored in a setting where the prey population has access to both habitats. The emphasis is in situations where patch-prey abundance drives prey-dispersal between patches, with the fragile prey populations, that is, populations subject to the Allee effect. The resulting four-dimensional model's mathematical analysis is carried out

  16. Effects of prey size and mobility on prey-capture kinematics in leopard sharks triakis semifasciata

    PubMed

    Ferry-Graham

    1998-08-01

    Recent work on teleosts suggests that attack behaviors or kinematics may be modified by a predator on the basis of the size of the prey or the ability of the prey to sense predators and escape capture (elusivity). Sharks are generally presumed to be highly visual predators; thus, it is reasonable to expect that they might also be capable of such behavioral modulation. In this study, I investigated the effect of prey item size and type on prey-capture behavior in leopard sharks (Triakis semifasciata) that had been acclimated to feeding in the laboratory. Using high-speed video, sharks were filmed feeding on two sizes of the same prey item (thawed shrimp pieces) and two potentially more elusive prey items (live earthworms and live mud shrimp). In leopard sharks, little effect of prey elusivity was found for kinematic variables during prey capture. However, the large proportion of successful captures of the live prey suggests that they did not prove to be truly elusive prey items for the leopard shark. There were significant size effects on prey-capture kinematics, with the larger non-elusive items inducing greater head expansion during prey capture. Ram-suction index values also indicated that strikes on large, non-elusive prey had a significantly larger suction component than strikes on similar small prey items. This finding is interesting given that the two sizes of non-elusive prey item offered no differential challenge in terms of a performance consequence (reduced capture success). PMID:9679105

  17. Prey pursuit and interception in dragonflies.

    PubMed

    Olberg, R M; Worthington, A H; Venator, K R

    2000-02-01

    Perching dragonflies (Libellulidae; Odonata) are sit-and-wait predators, which take off and pursue small flying insects. To investigate their prey pursuit strategy, we videotaped 36 prey-capture flights of male dragonflies, Erythemis simplicicollis and Leucorrhinia intacta, for frame-by-frame analysis. We found that dragonflies fly directly toward the point of prey interception by steering to minimize the movement of the prey's image on the retina. This behavior could be guided by target-selective descending interneurons which show directionally selective visual responses to small-object movement. We investigated how dragonflies discriminate distance of potential prey. We found a peak in angular velocity of the prey shortly before take-off which might cue the dragonfly to nearby flying targets. Parallax information from head movements was not required for successful prey pursuit. PMID:10707313

  18. Bacterial Predator-Prey Interaction atLowPreyDensity

    Microsoft Academic Search

    M. VARON; ANDB. P. ZEIGLER

    1978-01-01

    A bacterial predator-prey interaction wasstudied using Bdellovibrio andbio- luminescent preybacteria. Theattacking bdeliovibrio causes decayofbiolumi- nescence, whichiscorrelated withbdellovibrio penetration intotheprey. The behavior ofthepreyandpredator populations overtimewasfoundtobewell described byaLotka-Volterra model. Byusing this model, theprobability of bdellovibrio penetration after encountering apreycell wasfound tobeapproxi- mately 3.0%. Thepreydensity required togivethebdellovibrios a50%chance of survival wascalculated tobeatleast 3.0x 106cells perml,andthedensity required forpopulation equilibria wascalculated tobeabout 7x105preybacteria perml.Thesevalues, notgenerally

  19. A stochastic simulation model for Anelosimus studiosus during prey capture: a case study for determination of optimal spacing.

    PubMed

    Joyner, Michele L; Ross, Chelsea R; Watts, Colton; Jones, Thomas C

    2014-12-01

    In this paper, we develop a stochastic differential equation model to simulate the movement of a social/subsocial spider species, Anelosimus studiosus, during prey capture using experimental data collected in a structured environment. In a subsocial species, females and their maturing offspring share a web and cooperate in web maintenance and prey capture. Furthermore, observations indicate these colonies change their positioning throughout the day, clustered during certain times of the day while spaced out at other times. One key question was whether or not the spiders spaced out ``optimally'' to cooperate in prey capture. In this paper, we first show the derivation of the model where experimental data is used to determine key parameters within the model. We then use this model to test the success of prey capture under a variety of different spatial configurations for varying colony sizes to determine the best spatial configuration for prey capture. PMID:25365607

  20. Investigating Predator-Prey Interactions

    NSDL National Science Digital Library

    Ethel D. Stanley (Beloit College; Biology)

    2006-05-20

    In a mixed culture, how does the population of Didinium affect the population of Paramecium â?? and vice versa? Predator-prey cycles can be modeled using the Biota simulation. How do variables such as the presence of a refuge or the availability of food perturb the population cycles? * study the effects that the presence of a refuge from predators has on a model microbial population

  1. Biology Graphs - Predator and Prey

    NSDL National Science Digital Library

    The phenomenon is the numerical relationship between the population growth of predator (lynx) and prey (hare) over a 90 year period as shown in a graph. The graph shows that as the population of hares increases, the population of lynx increases. As the population of lynx continue to increase, the population of hares decreases. Questions probe student thinking on this relationship and other factors that may impact the population of the hare and the lynx.

  2. Optimal Forager against Ideal Free Distributed Prey.

    PubMed

    Garay, József; Cressman, Ross; Xu, Fei; Varga, Zoltan; Cabello, Tomás

    2015-07-01

    The introduced dispersal-foraging game is a combination of prey habitat selection between two patch types and optimal-foraging approaches. Prey's patch preference and forager behavior determine the prey's survival rate. The forager's energy gain depends on local prey density in both types of exhaustible patches and on leaving time. We introduce two game-solution concepts. The static solution combines the ideal free distribution of the prey with optimal-foraging theory. The dynamical solution is given by a game dynamics describing the behavioral changes of prey and forager. We show (1) that each stable equilibrium dynamical solution is always a static solution, but not conversely; (2) that at an equilibrium dynamical solution, the forager can stabilize prey mixed patch use strategy in cases where ideal free distribution theory predicts that prey will use only one patch type; and (3) that when the equilibrium dynamical solution is unstable at fixed prey density, stable behavior cycles occur where neither forager nor prey keep a fixed behavior. PMID:26098343

  3. When Optimal Strategy Matters to Prey Fish.

    PubMed

    Soto, Alberto; Stewart, William J; McHenry, Matthew J

    2015-07-01

    Predator-prey interactions are commonly studied with an interest in determining the optimal strategy for prey. However, the implications of deviating from optimal strategy are often unclear. The present study considered these consequences by studying how the direction of an escape response affects the strategy of prey fish. We simulated these interactions with numerical and analytical mathematics and compared our predictions with measurements in zebrafish larvae (Danio rerio), which are preyed upon by adults of the same species. Consistent with existing theory, we treated the minimum distance between predator and prey as the strategic payoff that prey aim to maximize. We found that these interactions may be characterized by three strategic domains that are defined by the speed of predator relative to the prey. The "fast predator" domain occurs when the predator is more than an order of magnitude faster than the prey. The escape direction of the prey had only a small effect on the minimum distance under these conditions. For the "slow predator" domain, when the prey is faster than the predator, we found that differences in direction had no effect on the minimum distance for a broad range of escape angles. This was the regime in which zebrafish were found to operate. In contrast, the optimal escape angle offers a large benefit to the minimum distance in the intermediate strategic domain. Therefore, optimal strategy is most meaningful to prey fish when predators are faster than prey by less than a factor of 10. This demonstrates that the strategy of a prey animal does not matter under certain conditions that are created by the behavior of the predator. PMID:25964496

  4. Prey selectivity and the influence of prey carbon:nitrogen ratio on microflagellate grazing.

    PubMed

    John, E H.; Davidson, K

    2001-05-31

    We investigated the influence of prey species and nutritional value, in terms of carbon:nitrogen (C:N) ratio, on prey selection by the predatory microflagellate Paraphysomonas vestita. Experiments were conducted with two phytoplankton prey species of similar diameter to remove size-specific grazing effects. Live cells of both low and high C:N ratio (ranging from 4.8 to 14; N-replete and N-deplete, respectively) were offered to the predator either individually or in combination. By utilising analytical flow cytometry, we were able to enumerate the two prey species and, hence, study selective predation in the mixed-prey assemblage. In single prey experiments, the maximum observed ingestion rates were found to be higher, at all prey C:N ratios, when Isochrysis galbana was the prey item when compared to Pavlova lutheri, whilst maximum specific predator division rates were similar for both prey. Ingestion rates were influenced by prey nutrient status, higher values being observed with N-replete than N-deplete prey. When the two prey species were presented to P. vestita as a mixture, I. galbana was ingested more rapidly than P. lutheri, although ingestion was found to be suppressed when compared to when this was the sole prey species. Conversely, the presence of I. galbana did not influence the rate of ingestion of P. lutheri. P. vestita was, therefore, able to modify its rate of ingestion on the basis of prey type and prey C:N ratio and to discriminate between alternative prey of similar size in mixed-prey assemblages. PMID:11358573

  5. Functional response of the predator Eriopis connexa (Coleoptera: Coccinellidae) to different prey types

    Microsoft Academic Search

    Renato Almeida Sarmento; Angelo Pallini; Madelaine Venzon; Og Francisco Fonseca de Souza; Adrián José Molina-Rugama; Claudinei Lima de Oliveira

    2007-01-01

    This work evaluated the functional response of adul t females of Eriopis connexa to different densities of Macrosiphum euphorbiae and Tetranychus evansi . When preying upon aphids, E. connexa presented a sigmoidal functional response (Type III). This behavior, howe ver, changed drastically to an exponential (Type II ) functional response, when mites ( T. evansi ), rather than aphids, were

  6. The effect of prey consumption on territorial defense by harriers: differential responses to neighbors versus floaters

    Microsoft Academic Search

    E. J. Temeles

    1989-01-01

    Food consumption may reduce fighting intensity of territory owners by decreasing resource value (additional food cannot be consumed) and\\/or increasing fighting costs (food in the digestive tract may raise injury risks). A territorial harrier's (Circus cyaneus, adult females) decision to reduce its level of aggression should depend upon whether or not the intruder was a competitor for individual prey items

  7. Specific color sensitivities of prey and predator explain camouflage in different visual systems

    Microsoft Academic Search

    Marc Théry; Martine Debut; Doris Gomez; Jérôme Casas

    2005-01-01

    In situations of aggressive mimicry, predators adapt their color to that of the substrate on which they sit for hunting, a behavior that is presumed to hide them from prey as well as from their own predators. Females of few crab-spider species encounter such situations when lying on flowers to ambush pollinators. To evaluate the efficiency of spider camouflage on

  8. Prey selection in a nocturnal web-building spider, Eriophora edax (Araneae Araneidae)

    Microsoft Academic Search

    L. C. Meraz; Y. Hénaut; L. Legal

    2012-01-01

    A field study was conducted to compare hourly captures by nocturnal adult female orb-web spiders (Eriophora edax) and the insect fauna collected at the same time, using a UV light trap. Predation of the spiders is related to the activity patterns of Lepidoptera, since this order of insects was the dominant prey type of E. edax. Also, E. edax showed

  9. Prey selection in a nocturnal web-building spider, Eriophora edax (Araneae Araneidae)

    Microsoft Academic Search

    L. C. Meraz; Y. Hénaut; L. Legal

    2011-01-01

    A field study was conducted to compare hourly captures by nocturnal adult female orb-web spiders (Eriophora edax) and the insect fauna collected at the same time, using a UV light trap. Predation of the spiders is related to the activity patterns of Lepidoptera, since this order of insects was the dominant prey type of E. edax. Also, E. edax showed

  10. Cannibalism and Intraguild Predation Among Phytoseiid Mites: Are Aggressiveness and Prey Preference Related to Diet Specialization?

    Microsoft Academic Search

    Peter Schausberger; Brian A. Croft

    2000-01-01

    We tested whether specialist and generalist phytoseiid mites differ in aggressiveness and prey choice in cannibalism and intraguild predation. Specialists tested were Galendromus occidentalis, Neoseiulus longispinosus, Phytoseiulus persimilis, and P. macropilis; tested were Amblyseius andersoni, Euseius finlandicus, E. hibisci, Kampimodromus aberrans, Neoseiulus barkeri, N. californicus, N. cucumeris, N. fallacis, and Typhlodromus pyri. Aggressiveness of cannibalistic females against larvae was not

  11. Whole-body inhalation exposure to 1-bromopropane suppresses the IgM response to sheep red blood cells in female B6C3F1 mice and Fisher 344/N rats.

    PubMed

    Anderson, Stacey E; Munson, Albert E; Butterworth, Leon F; Germolec, Dori; Morgan, Daniel L; Roycroft, Joseph A; Dill, Jeffrey; Meade, B J

    2010-02-01

    1-Bromopropane (1-BP) is categorized as a high-production-volume chemical and is currently used in the manufacture of pharmaceuticals, pesticides, and other chemicals. Its usage is estimated to be around 5 million pounds per year, resulting in the potential for widespread exposure in the workplace. Case reports and animal studies have suggested exposure to this compound may cause adverse reproductive and neurological effects. Using a battery of immunological assays, the immunotoxicity of 1-BP after whole body inhalation exposure in both mice and rats was evaluated. Significant decreases in the spleen immunoglobulin (Ig) M response to sheep red blood cells (SRBC) were observed in both mice (125-500 ppm) and rats (1000 ppm) after exposure to 1-BP for 10 wk. In addition, total spleen cells and T cells were significantly decreased after approximately 4 wk of 1-BP exposure in both mice (125-500 ppm) and rats (1000 ppm). No change in natural killer (NK) cell activity was observed. The observed alterations in spleen cellularity, phenotypic subsets, and impairment of humoral immune function across species raise further concern about human exposure to 1-BP and demonstrate the need for additional investigations into potential adverse health effects. PMID:20041805

  12. Prey perception of predation risk: volatile chemical cues mediate non-consumptive effects of a predator on a herbivorous insect.

    PubMed

    Hermann, Sara L; Thaler, Jennifer S

    2014-11-01

    Predators can affect prey in two ways-by reducing their density (consumptive effects) or by changing their behavior, physiology or other phenotypic traits (non-consumptive effects). Understanding the cues and sensory modalities prey use to detect predators is critical for predicting the strength of non-consumptive effects and the outcome of predator-prey encounters. While predator-associated cues have been well studied in aquatic systems, less is known about how terrestrial prey, particularly insect larvae, detect their predators. We evaluated how Colorado potato beetle, Leptinotarsa decemlineata, larvae perceive predation risk by isolating cues from its stink bug predator, the spined soldier bug, Podisus maculiventris. When exposed to male "risk" predators that were surgically manipulated so they could hunt but not kill, beetles reduced feeding 29% compared to controls. Exposure to risk females caused an intermediate response. Beetles ate 24% less on leaves pre-exposed to predators compared to leaves never exposed to predators, indicating that tactile and visual cues are not required for the prey's response. Volatile odor cues from predators reduced beetle feeding by 10% overall, although male predators caused a stronger reduction than females. Finally, visual cues from the predator had a weak effect on beetle feeding. Because multiple cues appear to be involved in prey perception of risk, and because male and female predators have differential effects, beetle larvae likely experience tremendous variation in the information about risk from their local environment. PMID:25234373

  13. Effects of Optimal Antipredator Behavior of Prey on Predator–Prey Dynamics: The Role of Refuges

    Microsoft Academic Search

    Vlastimil K?ivan

    1998-01-01

    The influence of optimal antipredator behavior of prey on predator–prey dynamics in a two-patch environment is studied. One patch represents an open habitat while the other is a refuge for prey. It is assumed that prey maximize their fitness measured by the instantaneous per capita growth rate. In each patch population dynamics is described by the Lotka–Volterra time continuous model.

  14. Predator-prey interactions in size-structured fish communities: implications of prey growth

    Microsoft Academic Search

    Mark H. Olson

    1996-01-01

    Predator-prey interactions among size-structured populations may be strongly influenced by factors which affect growth rates of prey. I examined the importance of prey growth in the interaction between large-mouth bass (Micropterus salmoides) and their prey, bluegill (Lepomis macrochirus), by analyzing diets and growth rates of bass in a set of seven lakes in south-central Wisconsin. Sizes of bluegill consumed by

  15. Coevolution can reverse predator–prey cycles

    PubMed Central

    Cortez, Michael H.; Weitz, Joshua S.

    2014-01-01

    A hallmark of Lotka–Volterra models, and other ecological models of predator–prey interactions, is that in predator–prey cycles, peaks in prey abundance precede peaks in predator abundance. Such models typically assume that species life history traits are fixed over ecologically relevant time scales. However, the coevolution of predator and prey traits has been shown to alter the community dynamics of natural systems, leading to novel dynamics including antiphase and cryptic cycles. Here, using an eco-coevolutionary model, we show that predator–prey coevolution can also drive population cycles where the opposite of canonical Lotka–Volterra oscillations occurs: predator peaks precede prey peaks. These reversed cycles arise when selection favors extreme phenotypes, predator offense is costly, and prey defense is effective against low-offense predators. We present multiple datasets from phage–cholera, mink–muskrat, and gyrfalcon–rock ptarmigan systems that exhibit reversed-peak ordering. Our results suggest that such cycles are a potential signature of predator–prey coevolution and reveal unique ways in which predator–prey coevolution can shape, and possibly reverse, community dynamics. PMID:24799689

  16. Effect of vitamin E on IgE antibody formation in mice.

    PubMed

    Inagaki, N; Nagai, H; Koda, A

    1984-01-01

    Effect of vitamin E (alpha-tocopheryl acetate and alpha-tocopheryl nicotinate) on IgE antibody formation in mice was investgiated . Female BALB/c mice were immunized with dinitrophenylated ascaris protein (DNP-As) and aluminium hydroxide gel (alum). Supplementation of vitamin E in diets or oral administration of vitamin E mixed with sesame oil resulted in a suppression of IgE antibody formation. On the contrary to IgE antibody formation, IgM or IgG (hemagglutinin; HA) formation was significantly enhanced. These results indicate that vitamin E is capable of suppressing IgE antibody formation and enhancing non-IgE antibody formation. PMID:6726616

  17. Controllability and Optimal Harvesting of a Prey-Predator Model Incorporating a Prey Refuge

    ERIC Educational Resources Information Center

    Kar, Tapan Kumar

    2006-01-01

    This paper deals with a prey-predator model incorporating a prey refuge and harvesting of the predator species. A mathematical analysis shows that prey refuge plays a crucial role for the survival of the species and that the harvesting effort on the predator may be used as a control to prevent the cyclic behaviour of the system. The optimal…

  18. Prey-handling behaviour of Octopus vulgaris (Mollusca, Cephalopoda) on Bivalve preys

    Microsoft Academic Search

    G Fiorito; F Gherardi

    1999-01-01

    This study examines the ability of Octopus vulgaris to prey on bivalve molluscs showing that octopuses exhibited the same behavioural pattern irrespective of the prey species. When the initial pulling method did not result efficient octopuses skipped to drilling accompanied by an increase in the handling time. A complete behavioural repertoire of O. vulgaris in handling bivalve preys is also

  19. The Packaging Problem: Bivalve Prey Selection and Prey Entry Techniques of the Octopus Enteroctopus dofleini

    Microsoft Academic Search

    Roland C. Anderson; Jennifer A. Mather

    2007-01-01

    Many predators face a complex step of prey preparation before consumption. Octopuses faced with bivalve prey use several techniques to penetrate the shells to gain access to the meat inside. When given prey of mussels Mytilus trossulus, Manila clams Venerupis philippinarum, and littleneck clams Protothaca staminea, Enteroctopus dofleini solved the problem differently. They pulled apart V. philippinarum and M. trossulus,

  20. Prey capture kinematics in batoids using different prey types: investigating the role of the cephalic lobes.

    PubMed

    Mulvany, Samantha; Motta, Philip J

    2014-11-01

    Cephalic lobes are novel structures found in some myliobatid stingrays. While undulatory batoids utilize the pectoral fins for prey capture and locomotion, lobed species partition locomotion to the pectoral fins, utilizing the lobes exclusively for prey capture. We investigated the use of the anterior pectoral fins and cephalic lobes in prey capture in five batoid species. The purpose of this study was to investigate the: (1) prey capture kinematics and use of the cephalic lobes in lobed and lobeless batoids; (2) role of the cephalic lobes in modulating capture behavior based on prey type. It was hypothesized that lobed species would display unique capture behaviors resulting in faster and more successful capture of prey, and display greater modulation in capture behavior. Findings showed that lobed species used only the head region for capture, were faster at pouncing and tenting, but slower at mouth opening. The cephalic lobes were more movable than the anterior pectoral fins of lobeless species. Modulation occurred in all species. Elusive prey increased tent duration for the lobeless species, increased mouth opening duration in the lobed Aetobatus narinari, and were farther away from the mouth than non-elusive prey during biting for all species. All species had few prey escapes. Overall, species with cephalic lobes captured prey faster but did not display increased modulatory ability or feeding success. The cephalic lobes help localize prey capture to the head region, speeding up the prey capture event and maintaining an efficient capture rate despite having less flexible pectoral fins. PMID:25074721

  1. "Prey Play": Learning about Predators and Prey through an Interactive, Role-Play Game

    ERIC Educational Resources Information Center

    Deaton, Cynthia C. M.; Dodd, Kristen; Drennon, Katherine; Nagle, Jack

    2012-01-01

    "Prey Play" is an interactive role-play activity that provides fifth-grade students with opportunities to examine predator-prey interactions. This four-part, role-play activity allows students to take on the role of a predator and prey as they reflect on the behaviors animals exhibit as they collect food and interact with one another, as well as…

  2. Deterministic and Stochastic Analysis of a Prey-Dependent Predator-Prey System

    ERIC Educational Resources Information Center

    Maiti, Alakes; Samanta, G. P.

    2005-01-01

    This paper reports on studies of the deterministic and stochastic behaviours of a predator-prey system with prey-dependent response function. The first part of the paper deals with the deterministic analysis of uniform boundedness, permanence, stability and bifurcation. In the second part the reproductive and mortality factors of the prey and…

  3. Male courtship vibrations delay predatory behaviour in female spiders

    PubMed Central

    Wignall, Anne E.; Herberstein, Marie E.

    2013-01-01

    During courtship, individuals transfer information about identity, mating status and quality. However, male web-building spiders face a significant problem: how to begin courting female spiders without being mistaken for prey? Male Argiope spiders generate distinctive courtship vibrations (shudders) when entering a female's web. We tested whether courtship shudders delay female predatory behaviour, even when live prey is present in the web. We presented a live cricket to females during playbacks of shudder vibrations, or white noise, and compared female responses to a control in which we presented a live cricket with no playback vibrations. Females were much slower to respond to crickets during playback of shudder vibrations. Shudder vibrations also delayed female predatory behaviour in a related spider species, showing that these vibrations do not simply function for species identity. These results suggest that male web-building spiders employ a phylogenetically conserved vibratory signal to ameliorate the risk of pre-copulatory cannibalism. PMID:24356181

  4. Male courtship vibrations delay predatory behaviour in female spiders.

    PubMed

    Wignall, Anne E; Herberstein, Marie E

    2013-01-01

    During courtship, individuals transfer information about identity, mating status and quality. However, male web-building spiders face a significant problem: how to begin courting female spiders without being mistaken for prey? Male Argiope spiders generate distinctive courtship vibrations (shudders) when entering a female's web. We tested whether courtship shudders delay female predatory behaviour, even when live prey is present in the web. We presented a live cricket to females during playbacks of shudder vibrations, or white noise, and compared female responses to a control in which we presented a live cricket with no playback vibrations. Females were much slower to respond to crickets during playback of shudder vibrations. Shudder vibrations also delayed female predatory behaviour in a related spider species, showing that these vibrations do not simply function for species identity. These results suggest that male web-building spiders employ a phylogenetically conserved vibratory signal to ameliorate the risk of pre-copulatory cannibalism. PMID:24356181

  5. Nutrition for optimal predatory performance of adult female Orius insidiosus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reproduction in a female predator, Orius insidiosus, is a nutritionally stringent process. Adult females acquire the nutrition needed for egg development from their prey, and rates of egg development are dependent on nutrients acquired in that life stage. When released as a biological control agen...

  6. Problems with studying wolf predation on small prey in summer via global positioning system collars

    USGS Publications Warehouse

    Palacios, Vicente; Mech, L. David

    2010-01-01

    We attempted to study predation on various-sized prey by a male and female wolf (Canis lupus) with global positioning system (GPS) collars programmed to acquire locations every 10 min in the Superior National Forest of Minnesota. During May to August 2007, we investigated 147 clusters of locations (31% of the total) and found evidence of predation on a white-tailed deer (Odocoileus virginianus) fawn and yearling, a beaver (Castor canadensis), ruffed grouse (Bonasa umbellus), and fisher (Martes pennanti) and scavenging on a road-killed deer and other carrion. However, we missed finding many prey items and discuss the problems associated with trying to conduct such a study.

  7. Reference Intervals for Serum Immunoglobulins IgG, IgA, IgM and Complements C3 and C4 in Iranian Healthy Children

    PubMed Central

    Kardar, GA; Oraei, M; Shahsavani, M; Namdar, Z; Kazemisefat, GE; Haghi Ashtiani, MT; Shams, S; Pourpak, Z; Moin, M

    2012-01-01

    Background: Determination of reference ranges of each serum protein in normal population of each country is required for studies and clinical interpretation. The aim of this study was defining reference range values of immunoglobulins and complement components in Iranian healthy children. Methods: This study was conducted from June 2003 to June 2006 in Immunology, Asthma and Allergy Research Institute, Tehran University of Medical Sciences. Serum levels of IgG, IgM, IgA, C3 and C4 in 800 Iranian healthy children from newborn to 18 years of age in four population were measured by nephelometry. Kolmogrov-Smirnov tests and Pearson correlation tests were used for analysis. Results: Our results mainly agree with previous reports, except for some discrepancy that might be due to the ethnic and geographic variety. There was a significant difference between two sexes only with IgA in the group of 1–3 months old, which was higher in male group and IgM in groups of 3–5, 6–8 and 9–11 years old that were higher in female groups. Mean of other serum immunoglobulins and complements was not significantly different between male and female groups. Conclusion: These results can be considered as a local reference for use in laboratories, clinical interpretations, and research for Iranian children. PMID:23113211

  8. Managing fisheries involving predator and prey species

    Microsoft Academic Search

    Villy Christensen; Lake Victoria; Lake Tanganyika

    1996-01-01

    Several management strategies for ecosystems with biological interaction are discussed, including predator removal, predator-prey coexistence, prey exploitation, overexploitation, and introduction of sanctuaries. Some case studies related to ecosystem management are briefly presented; these describe Lakes Victoria and Tanganyika, discarding from shrimp trawl fisheries and the development in the North Sea that led to introduction of multispecies analysis. The concept of

  9. Winter Prey Selection of Canada Lynx in

    Microsoft Academic Search

    The roles that diet and prey abundance play in habitat selection of Canada lynx (Lynx canadensis) in the contiguous United States is poorly understood. From 1998-2002, we back-tracked radiocollared lynx (6 F, 9 M) for a distance of 582 km and we located 86 kills in northwestern Montana, USA. Lynx preyed on 7 species that included blue grouse (Dendragapus obscurus),

  10. Neurobiology: imaging prey capture circuits in zebrafish.

    PubMed

    Nikolaou, Nikolas; Meyer, Martin P

    2015-03-30

    Two recent studies used a virtual hunting assay and functional imaging to identify prey-capture circuits in zebrafish. Together they show that the optic tectum and a pretectal region are two retinorecipient areas important for the recognition and capture of prey. PMID:25829009

  11. Predator prey interactions with time delays

    Microsoft Academic Search

    J. M. Cushing

    1976-01-01

    A general (Volterra-Lotka type) integrodifferential system which describes a predator-prey interaction subject to delay effects is considered. A rather complete picture is drawn of certain qualitative aspects of the solutions as they are functions of the parameters in the system. Namely, it is argued that such systems have, roughly speaking, the following features. If the carrying capacity of the prey

  12. Global stability of predator-prey interactions

    Microsoft Academic Search

    Gary W. Harrison

    1979-01-01

    A Lyapunov function is given that extends functions used by Volterra, Goh, and Hsu to a wide class of predator-prey models, including Leslie type models, and a biological interpretation of this function is given. It yields a simple stability criterion, which is used to examine the effect on stability of intraspecific competition among both prey and predators, of a refuge

  13. Unusual Multiorgan Immunoglobulin G4 (IgG4) Inflammation: Autoimmune Pancreatitis, Mikulicz Syndrome, and IgG4 Mastitis.

    PubMed

    Dít?, Petr; Trna, Jan; Kinkor, Zden?k; Novotný, Ivo; Lata, Jan; Kiani?ka, Bohuslav; Hermanová, Markéta

    2013-09-01

    Autoimmune pancreatitis (AIP) type 1 is commonly associated with simultaneous involvement of extrapancreatic organs. Sclerosing cholangitis, sialadenitis, retroperitoneal fibrosis, Sjögren syndrome, and other extrapancreatic lesions are often observed concurrently with AIP. High levels of immunoglobulin G4 (IgG4) in the blood serum and affected tissues are typical of this diagnostic entity. We describe a case report of a 58-year-old female with findings of AIP (according to Asian criteria), IgG4-positive mastitis, and histologically verified Mikulicz syndrome. The effect of corticoid therapy supported the diagnosis of AIP and simultaneously led to the eradication of recurrent mastitis. To the best of our knowledge, this is the first reported case of concurrent findings of AIP and IgG4 mastitis. Our case report supports the concept of systemic IgG4 syndrome with multisystem involvement. Timely diagnosis and appropriate therapy can be effective in a high percentage of patients. PMID:24073323

  14. Predator-Prey Interactions in Communities with prey dispersal and Allee effects

    E-print Network

    Berezovskaya, F; Castillo-Chavez, C

    2009-01-01

    The population dynamics of predator-prey systems in the presence of patch-specific predators are explored in a setting where the prey population has access to both habitats. The emphasis is in situations where patch-prey abundance drives prey-dispersal between patches, with the fragile prey populations, that is, populations subject to the Allee effect. The resulting four-dimensional model's mathematical analysis is carried out via sub-models that focus in lower dimensional settings. The outcomes depend on, and in fact they are quite sensitive to, the structure of the system, the range of parameter values, and initial conditions. We show that the system can support multi-stability and a diverse set of predator-prey life-history dynamics that includes rather complex dynamical system outcomes. It is argued that in general evolution should favor heterogeneous settings including Allee effects, prey-refuges, and patch-specific predators.

  15. Serum levels of tumour necrosis factor alpha (TNF-alpha) versus immunoglobulins (IgG., IgM., and IgE.) in Egyptian scabietic children.

    PubMed

    Morsy, T A; el Alfy, M S; Arafa, M A; Salama, M M; Habib, K S

    1995-12-01

    The tumour necrosis factor-alpha (TNF-alpha or Cachectin) is a protein produced mainly by macrophages, with a wide range of biological activities and in inflammatory process. On the other hand, scabies is a skin disease caused by Sarcoptes scabiei which is typified by severe itching (particularly at night), red papules and often secondary infection. The female mite tunnels in the skin to lay her eggs and the newly hatched mites pass easily from person to person by contact. Commonly the infested areas are the groin, penis, nipples and the skin between the fingers. In this paper, the serum levels of TNF-alpha versus IgG., IgM., and IgE. were estimated in parasitologically proven scabietic male children (8-13 years) with no secondary infection or other parasitic infection. The results showed high significant elevation of serum TNF-alpha in 94.1% (P = 7.763E-04) and IgE in 100% (P = 1.530E-07) in the scabietic patients than in the control group, and non significant increase in IgG in 47% (P = 0.0605) and in IgM in 5.9% (P = 0.9404). It was concluded that TNF-alpha plays a role in the pathogenesis of human scabies. Extensive study is ongoing to clarify the outcome of TNF-alpha in human scabies. PMID:8586872

  16. Egg Load Decreases Mobility and Increases Predation Risk in Female Black-Horned Tree Crickets (Oecanthus nigricornis)

    PubMed Central

    Ercit, Kyla; Martinez-Novoa, Andrew; Gwynne, Darryl T.

    2014-01-01

    Female-biased predation is an uncommon phenomenon in nature since males of many species take on riskier behaviours to gain more mates. Several species of sphecid wasps have been observed taking more female than male prey, and it is not fully understood why. The solitary sphecid Isodontia mexicana catches more adult female tree cricket (Oecanthus nigricornis) prey. Previous work has shown that, although female tree crickets are larger and thus likely to be more valuable as prey than males, body size alone cannot fully explain why wasps take more females. We tested the hypothesis that wasps catch adult female tree crickets more often because bearing eggs impedes a female’s ability to escape predation. We compared female survivors to prey of I. mexicana, and found that females carrying more eggs were significantly more likely to be caught by wasps, regardless of their body size and jumping leg mass. We also conducted laboratory experiments where females’ jumping responses to a simulated attack were measured and compared to her egg load and morphology. We found a significant negative relationship between egg load and jumping ability, and a positive relationship between body size and jumping ability. These findings support the hypothesis that ovarian eggs are a physical handicap that contributes to female-biased predation in this system. Predation on the most fecund females may have ecological-evolutionary consequences such as collapse of prey populations or selection for alternate life history strategies and behaviours. PMID:25330090

  17. Ig Nobel Prizes

    NSDL National Science Digital Library

    2000-01-01

    On October 5, the tenth annual Ig Nobel awards ceremony was held at Harvard University. The Ig Nobel awards honor individuals whose achievements "cannot or should not be reproduced." This year's illustrious winners include, in the Physics category, Andre Geim of the University of Nijmegen (the Netherlands) and Sir Michael Berry of Bristol University (UK) for using magnets to levitate a frog and a sumo wrestler, and the Peace award goes to the British Royal Navy, for ordering its sailors to stop using live cannon shells, and to instead just shout "Bang!" A complete list of winners with links to further information is provided at the site, along with previous winners and an archived webcast of this and past year's ceremonies (free registration required).

  18. Cross-modality effects of prey odour during the intraspecific interactions of a mosquito-specialist predator

    PubMed Central

    Cross, Fiona R.; Jackson, Robert R.

    2014-01-01

    One of the predictions from evolutionary game theory is that individuals will increase their willingness (i.e., become primed) to escalate aggression when they detect the presence of a limiting resource. Here we test this prediction in the context of prey odour priming escalation decisions during vision-based encounters by Evarcha culicivora. This East African jumping spider (Salticidae) feeds indirectly on vertebrate blood by actively choosing blood-carrying female mosquitoes as preferred prey. Unlike many salticid species, it also expresses pronounced mutual mate choice. As predicted, we show here that, in the presence of odour from their preferred prey, both sexes of E. culicivora escalate during vision-based same-sex encounters. This is further evidence that the odour of blood-carrying mosquitoes is salient to this salticid. For both sexes of E. culicivora, this particular prey may be a resource that matters in the context of intrasexual selection. PMID:24839338

  19. Individual variation in prey choice in a predator-prey community.

    PubMed

    Okuyama, Toshinori

    2011-05-01

    One predator-two prey community models are studied with an emphasis on individual variation in predator behavior. The predator behaves according to a well-known prey choice model. The behavioral model predicts that predators should always attack the primary prey (more profitable prey of the two), but only attack the alternative prey (less profitable prey of the two) when the density of the primary prey is below a threshold density. The predator that accepts the alternative prey does not discriminate between the primary and alternative prey (all-or-nothing preference for the alternative prey). However, empirical studies do not result in clear all-or-nothing responses. Previous models examined the relaxation of the all-or-nothing response by assuming partial preference (e.g., predators preferentially forage on the primary prey even when they also attack the alternative prey). In this study, I consider individual variation in two predator traits (prey density perception and handling time) as the sources of the variation in the threshold density, which can make empirical data appear deviated from the expectation. I examine how community models with partial preference and individual variation differ in their dynamics and show that the differences can be substantial. For example, the dynamics of a model based on individual variation can be more stable (e.g., stable in a wider parameter region) than that of a model based on partial preference. As the general statistical property (Jensen's inequality) is a main factor that causes the differences, the results of the study have general implications to the interpretation of models based on average per-capita rates. PMID:21354194

  20. Disentangling taste and toxicity in aposematic prey

    PubMed Central

    Holen, Øistein Haugsten

    2013-01-01

    Many predators quickly learn to avoid attacking aposematic prey. If the prey vary in toxicity, the predators may alternatively learn to capture and taste-sample prey carefully before ingesting or rejecting them (go-slow behaviour). An increase in prey toxicity is generally thought to decrease predation on prey populations. However, while prey with a higher toxin load are more harmful to ingest, they may also be easier to recognize and reject owing to greater distastefulness, which can facilitate a taste-sampling foraging strategy. Here, the classic diet model is used to study the separate effects of taste and toxicity on predator preferences. The taste-sampling process is modelled using signal detection theory. The model is applicable to automimicry and Batesian mimicry. It shows that when the defensive toxin is sufficiently distasteful, a mimicry complex may be less profitable to the predator and better protected against predation if the models are moderately toxic than if they are highly toxic. Moreover, taste mimicry can reduce the profitability of the mimicry complex and increase protection against predation. The results are discussed in relation to the selection pressures acting on prey defences and the evolution of mimicry. PMID:23256198

  1. Approach Strategy by which Male Mediterranean Tarantulas Adjust to the Cannibalistic Behaviour of Females

    E-print Network

    Illinois at Chicago, University of

    experiments, we offered a grasshopper (typical prey) or a male L. tarantula to females at night and during changes in the female's tendency to attack both the grasshopper and the male spider. These findings to mate when forced to approach females from the front, directly exposing them to her raptorial legs, than

  2. IgG4-Related Systemic Disease Can Be Easily Mistaken as a Uroepithelial Tumor

    PubMed Central

    Han, Song Yi; Lee, Seung Ik; Lee, Yeon Hee; Kim, Ae Jin; Lim, Hye Jin; Ro, Han; Chang, Jae Hyun; Lee, Hyun Hee; Chung, Wookyung

    2015-01-01

    Immunoglobulin G4-related disease (IgG4-RD) is a newly recognized systemic syndrome characterized by elevated serum IgG4 concentrations and tumefaction or tissue infiltration by IgG4-positive plasma cells. We experienced a case of IgG4-RD involving multiple organs in a 64-year-old female who was referred for a suspected uroepithelial tumor. A mass biopsy confirmed dense lymphoplasmacytic infiltration with an increased number of IgG4-positive plasma cells. We discuss this case and review the literature to bring IgG4-RD to the attention to clinicians because it responds dramatically well to steroid therapy and should be kept in mind as a differential diagnosis to avoid unnecessary surgery. PMID:25914879

  3. Allotypes of mouse IgM immunoglobulin

    Microsoft Academic Search

    Noel L. Warner; James W. Goding; George A. Gutman; Gregory W. Warr

    1977-01-01

    GENETIC polymorphism of the structural genes encoding the class-specific (heavy) polypeptide chains of the immunoglobulin (Ig) molecules provides a useful set of markers for elucidating the arrangement and expression of these genes. On the basis of various antigenic, physiochemical and biological properties, the immunoglobulins of the mouse have been divided into eight distinct classes, IgM, IgD, IgA, IgG1, IgG2a, IgG2b,

  4. Putting predators back into behavioral predator–prey interactions

    Microsoft Academic Search

    Steven L. Lima

    2002-01-01

    In the study of behavioral predator–prey interactions, predators have been treated as abstract sources of risk to which prey respond, rather than participants in a larger behavioral interaction. When predators are put back into the picture by allowing them to respond strategically to prey behavior, expectations about prey behavior can change. Something as simple as allowing predators to move in

  5. SPECIAL FEATURE When Predators Don't Eat Their Prey

    E-print Network

    Bolnick, Daniel I.

    of nonconsumptive interactions between predators and their prey and illustrate that NCE may extend a predator and colleagues that reviews the role of NCE in several ``textbook'' examples of predator­prey interactions rather than decreasing prey density). The classic predator­prey interaction between wolves and moose

  6. Gluttonous predators: how to estimate prey size when there are too many prey.

    PubMed

    Araújo, M S; Pinheiro, A; Reis, S F

    2008-05-01

    Prey size is an important factor in food consumption. In studies of feeding ecology, prey items are usually measured individually using calipers or ocular micrometers. Among amphibians and reptiles, there are species that feed on large numbers of small prey items (e.g. ants, termites). This high intake makes it difficult to estimate prey size consumed by these animals. We addressed this problem by developing and evaluating a procedure for subsampling the stomach contents of such predators in order to estimate prey size. Specifically, we developed a protocol based on a bootstrap procedure to obtain a subsample with a precision error of at the most 5%, with a confidence level of at least 95%. This guideline should reduce the sampling effort and facilitate future studies on the feeding habits of amphibians and reptiles, and also provide a means of obtaining precise estimates of prey size. PMID:18660959

  7. Response of female cuttlefish Sepia officinalis (Cephalopoda) to mirrors and conspecifics: evidence for signaling in female cuttlefish

    Microsoft Academic Search

    M. E. Palmer; M. Richard Calvé; Shelley A. Adamo

    2006-01-01

    Cuttlefish have a large repertoire of body patterns that are used for camouflage and interspecific signaling. Intraspecific\\u000a signaling by male cuttlefish has been well documented but studies on signaling by females are lacking. We found that females\\u000a displayed a newly described body pattern termed Splotch toward their mirror image and female conspecifics, but not to males,\\u000a prey or inanimate objects.

  8. Human Activity Helps Prey Win the Predator-Prey Space Race

    Microsoft Academic Search

    Tyler B. Muhly; Christina Semeniuk; Alessandro Massolo; Laura Hickman; Marco Musiani; Matjaz Perc

    2011-01-01

    Predator-prey interactions, including between large mammalian wildlife species, can be represented as a “space race”, where prey try to minimize and predators maximize spatial overlap. Human activity can also influence the distribution of wildlife species. In particular, high-human disturbance can displace large carnivore predators, a trait-mediated direct effect. Predator displacement by humans could then indirectly benefit prey species by reducing

  9. IGS 1996 Analysis Center Workshop

    NASA Technical Reports Server (NTRS)

    Neilan, R. E. (Editor); VanScoy, P. A. (Editor); Zumberge, J. F. (Editor)

    1996-01-01

    Components of the IGS[International GPS (Global Positioning System) Service for geodynamics], have operated a GPS tracking system for several years. The network now contains more than 100 stations and has produced a combined GPS ephemeris that has become the standard for geodesists and geophysicists worldwide. IGS data and products are freely available to all thanks to the cooperation and participation of all the IGS members. The IGS has initiated development of several new products, and technical issues permitting greater accuracy of IGS products have been identified. The IGS convened a workshop on March 1996 in Silver Spring, Maryland, USA, to coordinate these developments and to examine technical problems and solutions. The following topics were addressed: orbit/clock combination; Earth orientation; antenna calibration; SINEX and densification of the International Terrestrial Reference Frame (ITRF) using the GPS; receiver standards and performance; and atmospheric topics.

  10. Severe IgG4-Related Disease in a Young Child: A Diagnosis Challenge

    PubMed Central

    Ferraz, Catarina; Nunes, Teresa; Fonseca, Elsa; Vaz, Luísa Guedes

    2015-01-01

    Immunoglobulin G4-related disease (IgG4-RD) is an increasingly recognized syndrome that can appear with multiple organ involvement, typically with tumor-like swelling, lymphoplasmacytic infiltrate rich in IgG4-positive plasma cells, and elevated serum IgG4 concentrations. We report the case of a 22-month-old female child with failure to thrive and recurrent respiratory tract infections since 8 months of age. Physical examination was normal except for pulmonary auscultation with bilateral crackles and wheezes. Laboratory tests revealed elevated erythrocyte sedimentation rate, and elevated serum IgG and IgG4 with polyclonal hypergammaglobulinemia. Thoracic CT and MRI showed multiple mediastinal lymphadenopathies and a nodular posterior mediastinal mass in right paratracheal location with bronchial compression. Initial fine needle aspiration biopsy was compatible with reactive lymphadenopathy but after clinical worsening a thoracoscopic partial resection of the mass was performed and tissue biopsy revealed lymphoplasmacytic infiltrate and increased number of IgG4-positive plasma cells and a ratio of IgG4/IgG positive cells above 40%. Glucocorticoids therapy was started with symptomatic improvement, reduction in the size of the mass, and decrease of serum IgG4 levels after 6 weeks. There are very few reports of IgG4-RD in children. Long-term follow-up is necessary to monitor relapses and additional organ involvement. PMID:25705537

  11. Prey selection by linyphiid spiders: molecular tracking of the effects of alternative prey on rates of aphid consumption in the field.

    PubMed

    Harwood, James D; Sunderland, Keith D; Symondson, William O C

    2004-11-01

    A molecular approach, using aphid-specific monoclonal antibodies, was used to test the hypothesis that alternative prey can affect predation on aphids by linyphiid spiders. These spiders locate their webs in cereal crops within microsites where prey density is high. Previous work demonstrated that of two subfamilies of Linyphiidae, one, the Linyphiinae, is web-dependent and makes its webs at sites where they were more likely to intercept flying insects plus those (principally aphids) falling from the crop above. The other, the Erigoninae, is less web-dependent, making its webs at ground level at sites with higher densities of ground-living detritivores, especially Collembola. The guts of the spiders were analysed to detect aphid proteins using enzyme-linked immunosorbent assay (ELISA). Female spiders were consuming more aphid than males of both subfamilies and female Linyphiinae were, as predicted, eating more aphid than female Erigoninae. Rates of predation on aphids by Linyphiinae were related to aphid density and were not affected by the availability of alternative prey. However, predation by the Erigoninae on aphids was significantly affected by Collembola density. Itinerant Linyphiinae, caught away from their webs, contained the same concentration of aphid in their guts as web-owners. However, nonweb-owning Erigoninae, living away from Collembola aggregations at web-sites, contained significantly higher concentrations of aphid. For both subfamilies there was evidence of a disproportionate increase in predation on aphids once Collembola populations had declined. It was concluded that nonaphid prey, by helping to maintain spiders in the field, can significantly affect predation on aphids. PMID:15488011

  12. PREY OF NESTING BALD EAGLES IN TEXAS

    Microsoft Academic Search

    DAVID W. MABIE; M. TODD MERENDINO; DAVID H. REID

    Food habits of nesting bald eagles (Haliaeetus leucocephalus) in Texas were assessed by examining prey remains collected from within and beneath nests. We collected and identified 661 prey items from 27 nesting territories. Nesting bald eagles appeared to be opportunistic feeders and their diets contained nearly equal proportions of birds (33.7%), reptiles (30.7%), and fish (30.1%); American coots (Fulica americana),

  13. Are lemmings prey or predators?

    NASA Astrophysics Data System (ADS)

    Turchin, P.; Oksanen, L.; Ekerholm, P.; Oksanen, T.; Henttonen, H.

    2000-06-01

    Large oscillations in the populations of Norwegian lemmings have mystified both professional ecologists and lay public. Ecologists suspect that these oscillations are driven by a trophic mechanism: either an interaction between lemmings and their food supply, or an interaction between lemmings and their predators. If lemming cycles are indeed driven by a trophic interaction, can we tell whether lemmings act as the resource (`prey') or the consumer (`predator')? In trophic interaction models, peaks of resource density generally have a blunt, rounded shape, whereas peaks of consumer density are sharp and angular. Here we have applied several statistical tests to three lemming datasets and contrasted them with comparable data for cyclic voles. We find that vole peaks are blunt, consistent with their cycles being driven by the interaction with predators. In contrast, the shape of lemming peaks is consistent with the hypothesis that lemmings are functional predators, that is, their cycles are driven by their interaction with food plants. Our findings suggest that a single mechanism, such as interaction between rodents and predators, is unlikely to provide the `universal' explanation of all cyclic rodent dynamics.

  14. Patterns in prey use among fur seals and seabirds in the Pribilof Islands

    Microsoft Academic Search

    E. H. Sinclair; L. S. Vlietstra; D. S. Johnson; T. K. Zeppelin; G. V. Byrd; A. M. Springer; R. R. Ream; G HUNTJR

    2008-01-01

    We explored correlation in diet trends for five piscivorous predators that reproduce on the Pribilof Islands as illustrative of the shifting structure of the Bering Sea ecosystem. We evaluated the size and species of prey consumed by adult female and juvenile northern fur seals (Callorhinus ursinus) and adults and chicks of black-legged kittiwakes (Rissa tridactyla), red-legged kittiwakes (Rissa brevirostris), thick-billed

  15. Arctic skate Amblyraja hyperborea preys on remarkably large glacial eelpouts Lycodes frigidus.

    PubMed

    Byrkjedal, I; Christiansen, J S; Karamushko, O V; Langhelle, G; Lynghammar, A

    2015-01-01

    During scientific surveys on the continental slopes north-west of Spitsbergen and off north-east Greenland (c. 600 and 1000?m depths), two female Arctic skates Amblyraja hyperborea were caught while swallowing extraordinary large individuals of glacial eelpout Lycodes frigidus. The total length (LT) of the prey constituted 50 and 80% of the LT of the skates, which reveal that A. hyperborea are capable predators of fishes of surprisingly large relative size. PMID:25413102

  16. Positive effect of predators on prey growth rate through induced modications of prey behaviour

    E-print Network

    Peacor, Scott

    Abstract Many prey modify behaviour in response to predation risk and this modi®cation frequently leads: trait modi®cations that reduce predation risk are predicted to cause a reduction in foraging rate could be widespread. A predator-induced reduction in prey foraging rate can have two opposing effects

  17. Predator–prey interactions of Procambarus clarkii with aquatic macroinvertebrates in single and multiple prey systems

    Microsoft Academic Search

    Alexandra Marçal Correia; Nuno Bandeira; Pedro Manuel Anastácio

    2005-01-01

    Understanding the interspecific interactions of Procambarus clarkii with other aquatic macroinvertebrates will help to unveil the mechanisms and processes underlying biological invasiveness. The purpose of this study was to investigate predator–prey interactions of two ontogenic phases of P. clarkii with native and exotic species of aquatic macroinvertebrates at a single and multiple prey level. We performed laboratory experiments to determine

  18. EFFECT OF PROBIOTICS ADDED GOAT AND COW MILK YOGURT CONSUMPTION ON IMMUNOGLOBULIN A (IgA) INDUCTION IN HEALTHY ADOLESCENTS

    Microsoft Academic Search

    Jukkrit Wungrath; Aphirak Pianmongkhol; Tri Indrarini Wirjantoro

    2009-01-01

    This study investigated whether daily ingestion of probiotics (Bifidobacterium bifidum and Lactobacillus acidophilus) added mixture goat and cow milk yogurt over 8 weeks would enhance innate immune function in healthy adolescents. The parameter of the innate immunity assessed was immunoglobulin A (IgA). The trial was performed in 20 healthy adolescents (10 males and 10 females) with 20 controls. IgA was

  19. Learning predator promotes coexistence of prey species in host-parasitoid systems.

    PubMed

    Ishii, Yumiko; Shimada, Masakazu

    2012-03-27

    Ecological theory suggests that frequency-dependent predation, in which more common prey types are disproportionately favored, promotes the coexistence of competing prey species. However, many of the earlier empirical studies that investigated the effect of frequency-dependent predation were short-term and ignored predator-prey dynamics and system persistence. Therefore, we used long-term observation of population dynamics to test how frequency-dependent predation influences the dynamics and coexistence of competing prey species using insect laboratory populations. We established two-host-one-parasitoid populations with two bruchid beetles, Callosobruchus chinensis and C. maculatus, as the hosts and the pteromalid wasp Anisopteromalus calandrae as their common parasitoid. When the parasitoid was absent, C. chinensis was competitively excluded in ?20 wk. Introducing the parasitoid greatly enhanced the coexistence time to a maximum of 118 wk. In the replicates of long-lasting coexistence, the two host species C. maculatus and C. chinensis exhibited periodic antiphase oscillations. Behavioral experiments showed frequency-dependent predation of A. calandrae that was caused by learning. Females of A. calandrae learned host-related olfactory cues during oviposition and increased their preference for the common host species. Numerical simulations showed that parasitoid learning was the essential mechanism that promoted persistence in this host-parasitoid system. Our study is an empirical demonstration that frequency-dependent predation has an important role in greatly enhancing the coexistence of prey populations, suggesting that predator learning affects predator-prey population dynamics and shapes biological communities in nature. PMID:22411808

  20. Learning predator promotes coexistence of prey species in host–parasitoid systems

    PubMed Central

    Ishii, Yumiko; Shimada, Masakazu

    2012-01-01

    Ecological theory suggests that frequency-dependent predation, in which more common prey types are disproportionately favored, promotes the coexistence of competing prey species. However, many of the earlier empirical studies that investigated the effect of frequency-dependent predation were short-term and ignored predator–prey dynamics and system persistence. Therefore, we used long-term observation of population dynamics to test how frequency-dependent predation influences the dynamics and coexistence of competing prey species using insect laboratory populations. We established two-host–one-parasitoid populations with two bruchid beetles, Callosobruchus chinensis and C. maculatus, as the hosts and the pteromalid wasp Anisopteromalus calandrae as their common parasitoid. When the parasitoid was absent, C. chinensis was competitively excluded in ?20 wk. Introducing the parasitoid greatly enhanced the coexistence time to a maximum of 118 wk. In the replicates of long-lasting coexistence, the two host species C. maculatus and C. chinensis exhibited periodic antiphase oscillations. Behavioral experiments showed frequency-dependent predation of A. calandrae that was caused by learning. Females of A. calandrae learned host-related olfactory cues during oviposition and increased their preference for the common host species. Numerical simulations showed that parasitoid learning was the essential mechanism that promoted persistence in this host–parasitoid system. Our study is an empirical demonstration that frequency-dependent predation has an important role in greatly enhancing the coexistence of prey populations, suggesting that predator learning affects predator–prey population dynamics and shapes biological communities in nature. PMID:22411808

  1. Effects of prey quality and predator body size on prey DNA detection success in a centipede predator.

    PubMed

    Eitzinger, B; Unger, E M; Traugott, M; Scheu, S

    2014-08-01

    Predator body size and prey quality are important factors driving prey choice and consumption rates. Both factors might affect prey detection success in PCR-based gut content analysis, potentially resulting in over- or underestimation of feeding rates. Experimental evidence, however, is scarce. We examined how body size and prey quality affect prey DNA detection success in centipede predators. Due to metabolic rates increasing with body size, we hypothesized that prey DNA detection intervals will be shorter in large predators than in smaller ones. Moreover, we hypothesized that prey detection intervals of high-quality prey, defined by low carbon-to-nitrogen ratio will be shorter than in low-quality prey due to faster assimilation. Small, medium and large individuals of centipedes Lithobius spp. (Lithobiidae, Chilopoda) were fed Collembola and allowed to digest prey for up to 168 h post-feeding. To test our second hypothesis, medium-sized lithobiids were fed with either Diptera or Lumbricidae. No significant differences in 50% prey DNA detection success time intervals for a 272-bp prey DNA fragment were found between the predator size groups, indicating that body size does not affect prey DNA detection success. Post-feeding detection intervals were significantly shorter in Lumbricidae and Diptera compared to Collembola prey, apparently supporting the second hypothesis. However, sensitivity of diagnostic PCR differed between prey types, and quantitative PCR revealed that concentration of targeted DNA varied significantly between prey types. This suggests that both DNA concentration and assay sensitivity need to be considered when assessing prey quality effects on prey DNA detection success. PMID:24383982

  2. Predator functional response and prey survival: Direct and indirect interactions affecting a marked prey population

    USGS Publications Warehouse

    Miller, David A.; Grand, J.B.; Fondell, T.F.; Anthony, M.

    2006-01-01

    1. Predation plays an integral role in many community interactions, with the number of predators and the rate at which they consume prey (i.e. their functional response) determining interaction strengths. Owing to the difficulty of directly observing predation events, attempts to determine the functional response of predators in natural systems are limited. Determining the forms that predator functional responses take in complex systems is important in advancing understanding of community interactions. 2. Prey survival has a direct relationship to the functional response of their predators. We employed this relationship to estimate the functional response for bald eagle Haliaeetus leucocepalus predation of Canada goose Branta canadensis nests. We compared models that incorporated eagle abundance, nest abundance and alternative prey presence to determine the form of the functional response that best predicted intra-annual variation in survival of goose nests. 3. Eagle abundance, nest abundance and the availability of alternative prey were all related to predation rates of goose nests by eagles. There was a sigmoidal relationship between predation rate and prey abundance and prey switching occurred when alternative prey was present. In addition, predation by individual eagles increased as eagle abundance increased. 4. A complex set of interactions among the three species examined in this study determined survival rates of goose nests. Results show that eagle predation had both prey- and predator-dependent components with no support for ratio dependence. In addition, indirect interactions resulting from the availability of alternative prey had an important role in mediating the rate at which eagles depredated nests. As a result, much of the within-season variation in nest survival was due to changing availability of alternative prey consumed by eagles. 5. Empirical relationships drawn from ecological theory can be directly integrated into the estimation process to determine the mechanisms responsible for variation in observed survival rates. The relationship between predator functional response and prey survival offers a flexible and robust method to advance our understanding of predator-prey interactions in many complex natural systems where prey populations are marked and regularly visited. ?? 2006 British Ecological Society.

  3. PROLACTIN-ADRENAL INTERACTIONS IN THE IMMATURE FEMALE RAT

    E-print Network

    Paris-Sud XI, Université de

    PROLACTIN-ADRENAL INTERACTIONS IN THE IMMATURE FEMALE RAT Marie GELATO, J. DIBBET* S. MARSHALL J in the timing of the onset of puberty in female rats. GORSKI and I,AWTON (ig!2) reported that adrenalectomy up injections or median eminence implants of prolactin significantly enhanced vaginal opening. In the adult rat

  4. Prey aggregation is an effective olfactory predator avoidance strategy

    PubMed Central

    Dunn, Alison M.; Morrell, Lesley J.

    2014-01-01

    Predator–prey interactions have a major effect on species abundance and diversity, and aggregation is a well-known anti-predator behaviour. For immobile prey, the effectiveness of aggregation depends on two conditions: (a) the inability of the predator to consume all prey in a group and (b) detection of a single large group not being proportionally easier than that of several small groups. How prey aggregation influences predation rates when visual cues are restricted, such as in turbid water, has not been thoroughly investigated. We carried out foraging (predation) experiments using a fish predator and (dead) chironomid larvae as prey in both laboratory and field settings. In the laboratory, a reduction in visual cue availability (in turbid water) led to a delay in the location of aggregated prey compared to when visual cues were available. Aggregated prey suffered high mortality once discovered, leading to better survival of dispersed prey in the longer term. We attribute this to the inability of the dead prey to take evasive action. In the field (where prey were placed in feeding stations that allowed transmission of olfactory but not visual cues), aggregated (large groups) and semi-dispersed prey survived for longer than dispersed prey—including long term survival. Together, our results indicate that similar to systems where predators hunt using vision, aggregation is an effective anti-predator behaviour for prey avoiding olfactory predators. PMID:24918032

  5. Scarcity in the prey community yields anti-predator benefits

    NASA Astrophysics Data System (ADS)

    Hayward, Matt W.

    2011-07-01

    The majority of individuals in a community belong to a small number of abundant species. Understanding why some species are rare and others are common has been a long-held goal for ecologists. Africa's large carnivore guild preferentially preys on a small number of species within a limited weight range. Within this weight range however, some species that are expected to be significantly preferred as prey are not. I tested whether these species avoid preferential predation through their low densities. Records of over 40,000 kills from up to 48 different communities were used to test if non-preferred species within the expected prey weight ranges of each large predator avoid preferential predation and why. Species expected to be prey of Africa's large predators based on their body mass, that are preferred are preyed upon significantly more frequently at low densities than non-preferred prey. This results in a negative relationship between relative abundance and preference for preferred prey, but a positive relationship for non-preferred prey. The non-preferred prey species that are within the expected prey weight ranges of Africa's large predators are significantly less abundant within the prey community than significantly preferred prey. Rarity in African ungulates may convey an anti-predator benefit in that it was suboptimal for predators to evolve morphological or behavioral strategies to optimally forage on them or in that prey species can avoid predators by existing in habitats with low carrying capacity.

  6. IgG4-related disease of the ileocecal region mimicking malignancy: A case report

    PubMed Central

    Hiyoshi, Yukiharu; Oki, Eiji; Zaitsu, Yoko; Ando, Koji; Ito, Shuhei; Saeki, Hiroshi; Morita, Masaru; Yamamoto, Hidetaka; Baba, Hideo; Maehara, Yoshihiko

    2014-01-01

    INTRODUCTION Immunoglobulin G4-related disease (IgG4-RD) is a systemic disease characterized by chronic fibrosing inflammation with abundant IgG4-positive plasma cells, and responds well to steroids. Previous reports of IgG4-RD have focused on pancreatic and extrapancreatic including the gastrointestinal tract, however, the colonic IgG4-RD is rare. PRESENTATION OF CASE We herein report the case of a 74-year-old female with edematous wall thickening of the terminal ileum to the lower ascending colon confirmed by several preoperative imaging studies, who underwent right hemi-colectomy for suspected malignant lymphoma. The resected specimen showed an irregular wall thickness with subserosal sclerosis, and the lesion was 10 cm in length from the terminal ileum to the ascending colon. The patient was diagnosed with IgG4-RD by pathological examinations, which demonstrated an increased number of IgG4-positive plasma cells (150/HPF), and an elevated IgG4/IgG ratio (50%). DISCUSSION Gastrointestinal IgG4-RD appears to be difficult to diagnose prior to surgical resection because of its rarity, and the similarity of its features to malignancy. The measurement of the serum IgG4 levels, immunohistochemical examination of biopsy specimens and use of several imaging modalities might help us to diagnose the disease without surgical resection, and this disease can generally be treated with steroid therapy. However, surgical resection for IgG4-RD may still be also necessary for patients with concerns regarding malignancy or with intractable gastrointestinal obstruction caused by this disease. CONCLUSION Gastrointestinal IgG4-RD often mimics malignancy, and we should therefore consider this disease in the differential diagnosis of colonic lesions in order to optimize the treatment. PMID:25194601

  7. Observations on the nesting and prey of the solitary wasp, Tachysphex inconspicuus, with a review of nesting behavior in the T. obscuripennis species group.

    PubMed

    Kurczewski, Frank E; Coville, Rollin E; Schal, Coby

    2010-01-01

    The nesting behaviors of 10 females of Tachysphex inconspicuus (Kirby) (Hymenoptera: Crabronidae) were studied on a sandy, mowed lawn at the La Selva Biological Station in northeastern Costa Rica on 27-29 April 1980. Twenty-four completed nests were observed, excavated, and measured. The nests had oblique, short burrows leading to one or two shallow cells. Prey cockroaches belonging to 11 species of Chorisoneura and Riatia fulgida (Saussure) (Blattaria: Blattellidae), all tropical wet forest canopy indicator species, were removed from the cells, weighed, and identified. The cockroaches consisted mainly of adult females, selectively preyed upon over adult males and nymphs due to their larger sizes. The aggregate prey mass in cells was separable into prospective larger (heavier) female and smaller (lighter) male cells. Wasps usually oviposited on the heaviest cockroach in a cell, in most cases an adult female. Atypical genus behavior included (1) prey being carried to one side of the wasp and perhaps grasped by a hindleg during removal of the temporary entrance closure and nest entry and (2) wasp's egg being laid affixed to a forecoxal corium and extending backward in a longitudinally posteriad position across the prey's ventral thorax. A comparison with the nesting behavior of other species in the Tachysphex obscuripennis species group is made. PMID:21062142

  8. Observations on the Nesting and Prey of the Solitary Wasp, Tachysphex inconspicuus, with a Review of Nesting Behavior in the T. obscuripennis species group

    PubMed Central

    Kurczewski, Frank E.; Coville, Rollin E.; Schal, Coby

    2010-01-01

    The nesting behaviors of 10 females of Tachysphex inconspicuus (Kirby) (Hymenoptera: Crabronidae) were studied on a sandy, mowed lawn at the La Selva Biological Station in northeastern Costa Rica on 27–29 April 1980. Twenty-four completed nests were observed, excavated, and measured. The nests had oblique, short burrows leading to one or two shallow cells. Prey cockroaches belonging to 11 species of Chorisoneura and Riatia fulgida (Saussure) (Blattaria: Blattellidae), all tropical wet forest canopy indicator species, were removed from the cells, weighed, and identified. The cockroaches consisted mainly of adult females, selectively preyed upon over adult males and nymphs due to their larger sizes. The aggregate prey mass in cells was separable into prospective larger (heavier) female and smaller (lighter) male cells. Wasps usually oviposited on the heaviest cockroach in a cell, in most cases an adult female. Atypical genus behavior included (1) prey being carried to one side of the wasp and perhaps grasped by a hindleg during removal of the temporary entrance closure and nest entry and (2) wasp's egg being laid affixed to a forecoxal corium and extending backward in a longitudinally posteriad position across the prey's ventral thorax. A comparison with the nesting behavior of other species in the Tachysphex obscuripennis species group is made. PMID:21062142

  9. Functional response of wolves preying on barren-ground caribou in a multiple-prey ecosystem

    USGS Publications Warehouse

    Dale, B.W.; Adams, Layne G.; Bowyer, R.T.

    1994-01-01

    1. We investigated the functional response of wolves (Canis lupus) to varying abundance of ungulate prey to test the hypothesis that switching from alternate prey to preferred prey results in regulation of a caribou (Rangifer tarandus) population at low densities. 2. We determined prey selection, kill rates, and prey abundance for four wolf packs during three 30-day periods in March 1989, March 1990, November 1990, and created a simple discrete model to evaluate the potential for the expected numerical and observed functional responses of wolves to regulate caribou populations. 3. We observed a quickly decelerating type II functional response that, in the absence of numerical response, implicates an anti-regulatory effect of wolf predation on barren-ground caribou dynamics. 4. There was little potential for regulation caused by the multiplicative effect of increasing functional and numerical responses because of presence of alternative prey. This resulted in high wolf:caribou ratios at low prey densities which precluded the effects of an increasing functional response. 5. Inversely density-dependent predation by other predators, such as bears, reduces the potential for predators to regulate caribou populations at low densities, and small reductions in predation by one predator may have disproportionately large effects on the total predation rate.

  10. Effect of light, prey density, and prey type on the feeding rates of Hemimysis anomala

    USGS Publications Warehouse

    Halpin, Kathleen E.; Boscarino, Brent T.; Rudstam, Lars G.; Walsh, Mureen G.; Lantry, Brian F.

    2013-01-01

    Hemimysis anomala is a near-shore mysid native to the Ponto-Caspian region that was discovered to have invaded Great Lakes ecosystems in 2006. We investigated feeding rates and prey preferences of adult and juvenile Hemimysis in laboratory experiments to gain insight on the potential for Hemimysis to disrupt food webs. For both age groups (AGs), we measured feeding rates as a function of prey abundance (Bosmina longirostris as prey), prey type (B. longirostris, Daphnia pulex, and Mesocyclops sp.), and light levels (no light and dim light). Mean feeding rates on Bosmina increased with prey density and reached 23 ind. (2 h)?1 for adults and 17 ind. (2 h)?1 for juveniles. Dim light had little effect on prey selection or feeding rate compared to complete darkness. When feeding rates on alternate prey were compared, both AGs fed at higher rates on Bosmina than Daphnia, but only juveniles fed at significantly higher rates on Bosmina relative to Mesocyclops. No significant differences were observed between feeding rates on Mesocyclops and on Daphnia. Hemimysis feeding rates were on the order of 30–60% of their body weight per day, similar to predatory cladocerans that have been implicated in zooplankton declines in Lakes Huron and Ontario.

  11. Active Touch During Shrew Prey Capture

    PubMed Central

    Munz, Martin; Brecht, Michael; Wolfe, Jason

    2010-01-01

    Although somatosensation in multiple whisker systems has been studied in considerable detail, relatively little information is available regarding whisker usage and movement patterns during natural behaviors. The Etruscan shrew, one of the smallest mammals, relies heavily on its whisker system to detect and kill its highly mobile insect prey. Here, we tracked whisker and body motion during prey capture. We found that shrews made periodic whisker movements (whisking) with frequencies ranging from 12 to 17?Hz. We compared shrew and rat whisking and found that shrew whisking was smaller amplitude and higher frequency than rat whisking, but that the shrew and rat whisking cycle were similar in that the velocity was higher during retraction than protraction. We were able to identify four phases during the shrew hunting behavior: (i) an immobile phase often preceding hunting, (ii) a search phase upon the initiation of hunting, (iii) a contact phase defined by whisker-to-cricket contact, and (iv) an attack phase, characterized by a rapid head movement directed toward the cricket. During the searching phase, whisking was generally rhythmic and whiskers were protracted forward. After prey contact, whisking amplitude decreased and became more variable. The final strike was associated with an abrupt head movement toward the prey with high head acceleration. Prey capture proceeded extremely fast and we obtained evidence that shrews can initiate corrective maneuvers with a minimal latency <30?ms. While the shrew's rostrum is straight and elongated during most behaviors, we show for the first time that shrews bend their rostrum during the final strike and grip their prey with a parrot beak shaped snout. PMID:21283557

  12. Active touch during shrew prey capture.

    PubMed

    Munz, Martin; Brecht, Michael; Wolfe, Jason

    2010-01-01

    Although somatosensation in multiple whisker systems has been studied in considerable detail, relatively little information is available regarding whisker usage and movement patterns during natural behaviors. The Etruscan shrew, one of the smallest mammals, relies heavily on its whisker system to detect and kill its highly mobile insect prey. Here, we tracked whisker and body motion during prey capture. We found that shrews made periodic whisker movements (whisking) with frequencies ranging from 12 to 17?Hz. We compared shrew and rat whisking and found that shrew whisking was smaller amplitude and higher frequency than rat whisking, but that the shrew and rat whisking cycle were similar in that the velocity was higher during retraction than protraction. We were able to identify four phases during the shrew hunting behavior: (i) an immobile phase often preceding hunting, (ii) a search phase upon the initiation of hunting, (iii) a contact phase defined by whisker-to-cricket contact, and (iv) an attack phase, characterized by a rapid head movement directed toward the cricket. During the searching phase, whisking was generally rhythmic and whiskers were protracted forward. After prey contact, whisking amplitude decreased and became more variable. The final strike was associated with an abrupt head movement toward the prey with high head acceleration. Prey capture proceeded extremely fast and we obtained evidence that shrews can initiate corrective maneuvers with a minimal latency <30?ms. While the shrew's rostrum is straight and elongated during most behaviors, we show for the first time that shrews bend their rostrum during the final strike and grip their prey with a parrot beak shaped snout. PMID:21283557

  13. 2001 Ig Nobel Prize Winners

    NSDL National Science Digital Library

    2001-01-01

    In the United States, another set of awards were passed out this week: the Ig Nobels. Awarded by humor rag The Annals of Improbable Research, the Ig Nobels honor people whose achievements "cannot or should not be reproduced." This year's illustrious Ig Nobel laureates include, for Medicine, the publisher of "Injuries Due to Falling Coconuts," in the Journal of Trauma, the founder of the Apostrophe Protection Society (Literature), and the Peace Prize goes to the Lithuanian who built an amusement park known colloquially as "Stalin World."

  14. Nutrient acquisition by female Harlequin Ducks prior to spring migration and reproduction: evidence for body mass optimization

    Microsoft Academic Search

    Jeanine C. Bond; Daniel Esler

    2006-01-01

    We analysed variation in body mass of adult female Harlequin Ducks (Histrionicus histrionicus (L., 1758)) on coastal wintering sites in southern British Columbia, Canada, to investigate nutrient acquisition prior to migration and re- production. On average, female mass increased by 7% from late winter to premigration; however, the chronology of mass gain varied depending on prey type. Females feeding on

  15. Density-dependent effects of multiple predators sharing a common prey in an endophytic habitat.

    PubMed

    Aukema, Brian H; Clayton, Murray K; Raffa, Kenneth F

    2004-05-01

    Multiple predator species feeding on a common prey can lead to higher or lower predation than would be expected by simply combining their individual effects. Such emergent multiple predator effects may be especially prevalent if predators share feeding habitat. Despite the prevalence of endophagous insects, no studies have examined how multiple predators sharing an endophytic habitat affect prey or predator reproduction. We investigated density-dependent predation of Thanasimus dubius (Coleoptera: Cleridae) and Platysoma cylindrica (Coleoptera: Histeridae) on a bark beetle prey, Ips pini (Coleoptera: Scolytidae), in a laboratory assay. I. pini utilize aggregation pheromones to group-colonize and reproduce within the stems of conifers. T. dubius and P. cylindrica exploit these aggregation pheromones to arrive simultaneously with the herbivore. Adult T. dubius prey exophytically, while P. cylindrica adults enter and prey within the bark beetle galleries. Larvae of both predators prey endophytically. We used a multiple regression analysis, which avoids confounding predator composition with density, to examine the effects of varying predator densities alone and in combination on herbivore establishment, herbivore reproduction, and predator reproduction. Predators reduced colonization success by both sexes, and decreased I. pini reproduction on a per male and per female basis. The combined effects of these predators did not enhance or reduce prey establishment or reproduction in unexpected manners, and these predators were entirely substitutable. The herbivore's net replacement rate was never reduced significantly below one at prey and predator densities emulating field conditions. Similar numbers of each predator species emerged from the logs, but predator reproduction suffered from high intraspecific interference. The net replacement rate of P. cylindrica was not affected by conspecifics or T. dubius. In contrast, the net replacement rate of T. dubius decreased with the presence of conspecifics or P. cylindrica. Combinations of both predators led to an emergent effect, a slightly increased net replacement rate of T. dubius. This may have been due to predation by larval T. dubius on pupal P. cylindrica, as P. cylindrica develops more rapidly than T. dubius within this shared habitat. PMID:14968356

  16. Effect of colostrum administration practices on serum IgG in goat kids

    Microsoft Academic Search

    A. Argüello; N. Castro; J. Capote; J. W. Tyler; N. M. Holloway

    2004-01-01

    Sixty Canary Caprine kids (30 males and 30 females) were assigned to three colostrum feeding managements, natural suckling (NS), hand-fed ad libitum colostrum (HALC) and restricted hand-fed colostrum (RHC). IgG concentrations were recorded in colostrum and kids serum at 12, 24, 36, 48, 60, 70, and 84 h of life. No significant differences in serum IgG concentrations were observed between

  17. Diurnal and nocturnal prey detection by Dunlins Calidris alpina

    Microsoft Academic Search

    K. N. Mouritsen

    1993-01-01

    Field experiments suggest that Dunlins rely on visual prey detection by day and tactile prey detection by night to a larger extent than observations of their foraging technique would initially indicate.

  18. Competition between Serum IgG, IgM, and IgA Anti-Glycan Antibodies

    PubMed Central

    Muthana, Saddam M.; Xia, Li; Campbell, Christopher T.; Zhang, Yalong; Gildersleeve, Jeffrey C.

    2015-01-01

    Anti-glycan antibodies are an abundant subpopulation of serum antibodies with critical functions in many immune processes. Changes in the levels of these antibodies can occur with the onset of disease, exposure to pathogens, or vaccination. As a result, there has been significant interest in exploiting anti-glycan antibodies as biomarkers for many diseases. Serum contains a mixture of anti-glycan antibodies that can recognize the same antigen, and competition for binding can potentially influence the detection of antibody subpopulations that are more relevant to disease processes. The most abundant antibody isotypes in serum are IgG, IgM, and IgA, but little is known regarding how these different isotypes compete for the same glycan antigen. In this study, we developed a multiplexed glycan microarray assay and applied it to evaluate how different isotypes of anti-glycan antibodies (IgA, IgG, and IgM) compete for printed glycan antigens. While IgG and IgA antibodies typically outcompete IgM for peptide or protein antigens, we found that IgM outcompete IgG and IgA for many glycan antigens. To illustrate the importance of this effect, we provide evidence that IgM competition can account for the unexpected observation that IgG of certain antigen specificities appear to be preferentially transported from mothers to fetuses. We demonstrate that IgM in maternal sera compete with IgG resulting in lower than expected IgG signals. Since cord blood contains very low levels of IgM, competition only affects maternal IgG signals, making it appear as though certain IgG antibodies are higher in cord blood than matched maternal blood. Taken together, the results highlight the importance of competition for studies involving anti-glycan antibodies. PMID:25807519

  19. Dynamics of Prey Capture and Escape Wednesday, March 6th

    E-print Network

    Eddy, Sean

    during predation? 10:15 am Sheila Patek, University of Massachusetts Power and the evolution of prey capture 10:40 am Break 11:10 am Session 3: Closed loop visually driven prey capture I Chair: Cynthia Moss Maryland Latency and stochasticity in prey capture 3:05 pm Cynthia F. Moss, University of Maryland Adaptive

  20. WINTER PREY CACHING BY NORTHERN HAWK OWLS IN MINNESOTA

    Microsoft Academic Search

    Richard R. Schaefer; D. Craig Rudolph; Jesse F. Fagan

    2007-01-01

    Northern Hawk Owls (Surnia ulula) have been reported to cache prey during the breeding season for later consumption, but detailed reports of prey caching during the non-breeding season are com- paratively rare. We provided prey to four individual Northern Hawk Owls in wintering areas in northeast- ern Minnesota during 2001 and 2005 and observed their caching behavior. These owls cached

  1. Blue whale habitat and prey in the California Channel Islands

    Microsoft Academic Search

    Paul C. Fiedler; Stephen B. Reilly; Roger P. Hewitt; David Demer; Valerie A. Philbrick; Susan Smith; Wesley Armstrong; Donald A. Croll; Bernie R. Tershy; Bruce R. Mate

    1998-01-01

    Whale Habitat and Prey Studies were conducted off southern California during August 1995 (WHAPS95) and July 1996 (WHAPS96) to (1) study the distribution and activities of blue whales and other large whales, (2) survey the distribution of prey organisms (krill), and (3) measure physical and biological habitat variables that influence the distribution of whales and prey. A total of 1307

  2. Interaction of Bdellovibrio with Its prey in mixed microbial populations

    Microsoft Academic Search

    Mazal Varon

    1981-01-01

    The interaction ofBdellovibrio with its prey can be affected by the presence of other microorganisms regardless of whether they serve as a prey for the bdellovibrios. This was shown in a system in which the fate of one prey could be followed in mixed bacterial populations thanks to a specific trait, bioluminescence. The attacking bdellovibrio causes decay of bioluminescence, and

  3. Gastropods as Predators and Prey at Easter Island

    Microsoft Academic Search

    ALAN J. KOHN

    First observations are reported of predator-prey relationships among gastropod mollusks of the depauperate, Indo-West Pacific derivative, intertidal and shallow subtidal benthic fauna of Easter Island. Conus miliaris, which will be reported in detail in a separate paper, and Pisania decapitata englerli prey on polychaete annelids; Mitraflavocingulatapreys on sipunculans; and Neothais nesiotes preys on barnacles intertidally and gastropods subtidally. Gastropods of

  4. Molecular assessment of heterotrophy and prey digestion in zooxanthellate cnidarians.

    PubMed

    Leal, M C; Nejstgaard, J C; Calado, R; Thompson, M E; Frischer, M E

    2014-08-01

    Zooxanthellate cnidarians are trophically complex, relying on both autotrophy and heterotrophy. Although several aspects of heterotrophy have been studied in these organisms, information linking prey capture with digestion is still missing. We used prey-specific PCR-based tools to assess feeding and prey digestion of two zooxanthellate cnidarians - the tropical sea anemone Aiptasia sp. and the scleractinian coral Oculina arbuscula. Prey DNA disappeared rapidly for the initial 1-3 days, whereas complete digestion of prey DNA required up to 10 days in O. arbuscula and 5 or 6 days in Aiptasia sp. depending on prey species. These digestion times are considerably longer than previously reported from microscopy-based examination of zooxanthellate cnidarians and prey DNA breakdown in other marine invertebrates, but similar to prey DNA breakdown reported from terrestrial invertebrates such as heteroptera and spiders. Deprivation of external prey induced increased digestion rates during the first days after feeding in O. arbuscula, but after 6 days of digestion, there were no differences in the remaining prey levels in fed and unfed corals. This study indicates that prey digestion by symbiotic corals may be slower than previously reported and varies with the type of prey, the cnidarian species and its feeding history. These observations have important implications for bioenergetic and trophodynamic studies on zooxanthellate cnidarians. PMID:24118448

  5. The forces exerted by aquatic suction feeders on their prey

    E-print Network

    Wainwright, Peter C.

    magnitude under conditions that are common in aquatic predator­prey interactions. We focus on three forces), the nature of the interaction of this flow with the prey has received less attention (Lauder & Clark 1984; deThe forces exerted by aquatic suction feeders on their prey Peter C. Wainwright1,* and Steven W

  6. Predator-prey Interactions with Delays Due to Juvenile Maturation

    Microsoft Academic Search

    Kenneth L. Cooke; Richard H. Elderkin; Wenzhang Huang

    2006-01-01

    This paper focuses on predator-prey models with juvenile\\/mature class structure for each of the predator and prey populations in turn, further classified by whether juvenile or mature individuals are active with respect to the predation process. These models include quite general prey recruitment at every stage of analysis, with mass action predation, linear predator mortality as well as delays in

  7. Stochastic predator-prey models: Population oscillations, spatial correlations,

    E-print Network

    Wirosoetisno, Djoko

    NSF-DMR 0308548, IAESTE #12;Outline · Introductory remarks · Lotka-Volterra predator-prey interaction interaction · predators: A 0 death, rate · prey: B B+B birth, rate · predation: A+B A+A, rate (AStochastic predator-prey models: Population oscillations, spatial correlations, and the effect

  8. The Role of Space in Reducing PredatorPrey Cycles

    E-print Network

    .1 Introduction Throughout the history of ecology, the interaction between predators and their prey has received-based models. We then present a simple two-patch model for predator­prey interaction, followed by a gen of interacting predator and prey individ- uals, one needs to keep track of all individuals and their positions

  9. Molecular interactions between human IgG, IgM rheumatoid factor and streptococcal IgG Fc receptors.

    PubMed

    Schröder, A K; Gharavi, A E; Christensen, P

    1988-01-01

    Group A streptococci type M15 were previously shown to bind both human IgG via the Fc component and a purified monoclonal IgM kappa rheumatoid factor (IgM RF). Using 125I-labelled IgG and 125I-labelled IgM RF, the present study gave association constants of 2.2 x 10(7) and 2.9 x 10(8) M-1, respectively. The binding of 125I-IgG to the streptococci was inhibited by unlabelled IgG, IgG Fc and fragment D of staphylococcal protein A but not by the IgM RF or F(ab')2 of anti-idiotype antibodies to RF (anti-Id RF). Inversely, unlabelled IgM RF and anti-Id RF inhibited the binding of 125I-IgM RF markedly and unlabelled human IgG and IgG Fc only slightly or moderately, respectively. Thus, group A streptococci type M15 showed different binding sites for IgG Fc and the antibody combining sites of a human monoclonal RF. The findings were still more complex on a background of previous reports showing that streptococcal IgG Fc receptors and RFs bind to the same amino acids on the Fc molecule. This complex pattern may play a role in the pathogenesis of rheumatoid arthritis. PMID:3286523

  10. IgG autoantibody to IgE in atopic patients.

    PubMed

    Carini, C; Fratazzi, C; Barbato, M

    1988-01-01

    An IgG type of antibody directed against IgE has been studied in serum from healthy and allergic individuals. The technique used is based on a solid phase paper radioimmunoassay in which the discs were sensitized with purified IgE myeloma. After incubation with patients' serum, human IgG labeled with iodine 125 was added. The anti-IgE antibodies were partially blocked by endogenous IgE in the serum and heating the serum samples at 56 degrees C disrupted the immune complexes (ie, IgG-aIgE:IgE), thereby increasing the detectable levels of IgG anti-IgE. The specificity of anti-IgE autoantibody was confirmed by both competitive inhibition and absorption experiments, using IgG, IgM, IgA, IgE, and rabbit anti-human IgG. Significantly raised levels of anti-IgE autoantibody were found in patients suffering from atopic disorders in comparison to the controls. These observations may suggest that the anti-IgE autoantibody could play a certain role in the modulation of IgE-mediated immune system and the pathogenesis of atopic diseases. PMID:2447812

  11. Motor control: how dragonflies catch their prey.

    PubMed

    Dickinson, Michael H

    2015-03-16

    Detailed measurements of head and body motion have revealed previously unknown complexity in the predatory behavior of dragonflies. The new evidence suggests that the brains of these agile predators compute internal models of their own actions and those of their prey. PMID:25784042

  12. Mathematical Models Of Predator-Prey Systems

    E-print Network

    Linder, Tamás

    ) = BCNP - DP #12;Diffusion Driven Instability ? Without the diffusion terms the stable equilibrium are N conditions required for diffusion-driven instability. They are fNd + gP > 0 and f2 Nd2 + 2d(fNgP - fPgN) + g2Mathematical Models Of Predator-Prey Systems Bobby, Jostein, Shane, Jeff, Majid, Carly, Jay

  13. Hydrodynamics of prey capture in sharks: effects

    E-print Network

    Nauwelaerts, Sandra

    REPORT Hydrodynamics of prey capture in sharks: effects of substrate Sandra Nauwelaerts1,*, Cheryl predictions regarding the effects of substrate proximity on the feeding hydrodynamics of a benthic shark. An oblique circular cylinder and a shark head model were used. To test the models, we used digital particle

  14. Modelling Seasonal Predator-Prey Interactions

    Microsoft Academic Search

    Jeppe Sturis; Carsten Knudsen

    1996-01-01

    We analyse an existing two variable model of predator-prey interactions. The analysis reveals problems in the model formulation. The main problem is related to the fact that the model is a mixture of empirically and causally based dynamic equations. An attempt to repair the model is made, but a completely satisfactory solution is not reached. We argue that model constructions,

  15. Consequences of intraspecific variation in female body size in Stagmomantis limbata (Mantodea: Mantidae): feeding ecology, male attraction, and egg production.

    PubMed

    Maxwell, Michael R; Frinchaboy, Caylin

    2014-02-01

    Body size is an important feature of organisms, influencing many components of life history and fitness, such as feeding success and reproductive output. Body size is considered especially salient for solitary predators, whose food intake hinges on individual predation success, which in turn is often driven by the relative sizes of predator and prey. The current study examined intraspecific variation in adult female length and its fitness consequences in a solitary predator, the praying mantid Stagmomantis limbata Hahn. Through a 5-yr integration of observational and experimental work in the field and captivity, we investigated the relationship between female pronotum length and prey size, diet breadth, male attraction, and measures of egg production (fecundity and ootheca mass). We found that longer females ate longer prey in the field and showed greater breadth of prey size than shorter females. Longer females did not necessarily feed at higher rates in the field, as measured by the rate of abdominal expansion. Female length failed to show significant effects on male attraction or on the incidence of cannibalism. Longer females had higher fecundity (mature eggs in body at death) and laid heavier oothecae than shorter females. In nature, longer females consistently emerged as adults earlier in the season than shorter females. Shorter female adults emerged when feeding rates were higher in the field, suggesting an incidental ecological benefit of shorter adult size. PMID:24341955

  16. When Parasitoid Males Make Decisions: Information Used when Foraging for Females

    E-print Network

    Paris-Sud XI, Université de

    When Parasitoid Males Make Decisions: Information Used when Foraging for Females Claire M-S Dufour for prey, female parasitoids looking for hosts, or herbivorous searching for food. In this study, information use and patch time allocation were investigated using male parasitoids looking for mates

  17. Nest-Site Selection by Female Black-Capped Chickadees: Settlement Based on Conspecific Attraction?

    Microsoft Academic Search

    Scott M. Ramsay; Ken A. Otter; Laurene M. Ratcliffe

    1999-01-01

    Female Black-capped Chickadees (Poecile atricapillus) solicit extrapair copulations (EPCs) from neighboring high-ranking males, and these EPCs result in extrapair young. Females might choose to locate their nests near the territory boundaries of attractive males to facilitate access to EPCs. Other hypotheses might also explain choice of nest site, namely (1) habitat characteristics, (2) prey abundance, and (3) previous experience. We

  18. 3.11 Predator-Prey models Let )(tx be the population density of prey, )(ty be the population density of

    E-print Network

    Hsu, Sze-Bi

    density of predator at time t . The general model for predator-prey interaction is following ),( yxxf dt§3.11 Predator-Prey models Let )(tx be the population density of prey, )(ty be the population assume the prey grows exponentially in the absence of predation. The prey is consumed by predator

  19. Alterations in prey capture and induction of metallothioneins in grass shrimp fed cadmium-contaminated prey

    SciTech Connect

    Wallace, W.G.; Hoexum Brouwer, T.M.; Brouwer, M.; Lopez, G.R.

    2000-04-01

    The aquatic oligochaete Limnodrilus hoffmeisteri from a Cd-contaminated cove on the Hudson River, Foundry Cove, New York, USA, has evolved Cd resistance. Past studies have focused on how the mode of detoxification of Cd by these Cd-resistant worms influences Cd trophic transfer to the grass shrimp Palaemonetes pugio. In the present study, the authors investigate reductions in prey capture in grass shrimp fed Cd-contaminated prey. They also investigate the induction of metal-binding proteins, metallothioneins, in these Cd-exposed shrimp. Grass shrimp were fed field-exposed Cd-contaminated Foundry Cove oligochaetes or laboratory-exposed Cd-contaminated Artemia salina. Following these exposures, the ability of Cd- dosed and control shrimp to capture live A. salina was compared. Results show that shrimp fed laboratory-exposed Cd-contaminated A. salina for 2 weeks exhibit significant reductions in their ability to successfully capture prey (live A. salina). Reductions in prey capture were also apparent, though not as dramatic in shrimp fed for 1 week on field-exposed Cd-contained Foundry Cove oligochaetes. Shrimp were further investigated for their subcellular distribution of Cd to examine if alterations in prey capture could be linked to saturation of Cd-metallothionein. Cd-dosed shrimp produced a low molecular weight CD-binding metallothionein protein in a dose- and time-dependent manner. Most importantly, successful prey capture decreased with increased Cd body burdens and increased Cd concentration bound to high molecular weight proteins.

  20. IgG isotype and isotype specificity of murine monoclonal IgG rheumatoid factors.

    PubMed Central

    Taguchi, H; Kanoh, M; Takubo, N; Kadota, S; Kanazawa, K; Hitsumoto, Y; Shibata, T; Utsumi, S

    1990-01-01

    Immune complexes of lipopolysaccharide (LPS) with homologous IgG antibody induces rheumatoid factor (RF) predominantly of the IgG class in normal mice, while LPS alone induces mostly IgM RF directed to homologous IgG1. In this study, IgG monoclonal RFs (mRF) were prepared from hybridomas derived from spleen cells of BALB/c mice which were immunized with complexes of TNP-LPS with anti-TNP mouse IgG and their specificity to mouse IgG subclasses was assessed by analysing dissociation kinetics of the ligands due to RF-specific and non-specific interactions. Of the 19 IgG mRFs (11 IgG1, five IgG2a, one IgG2b and two IgG3 types) tested, 14 were directed to either IgG3 or IgG2b or both, while only one exhibited a significant binding capacity to IgG1. Other mRFs, although reactive to rabbit IgG, exhibited little homophilic activity. None of these mRFs reacted strongly with their own isotypes. The results suggest that the IgG RF producing cells are not direct progenies of the IgG1-directed IgM RF-producing cells but may have developed via a rigorous selection process to eliminate clones that produce self-reactive RF. PMID:2323099

  1. Problems with studying wolf predation on small prey in summer via global positioning system collars

    USGS Publications Warehouse

    Palacios, V.; Mech, L.D.

    2011-01-01

    We attempted to study predation on various-sized prey by a male and female wolf (Canis lupus) with global positioning system (GPS) collars programmed to acquire locations every 10 min in the Superior National Forest of Minnesota. During May to August 2007, we investigated 147 clusters of locations (31% of the total) and found evidence of predation on a white-tailed deer (Odocoileus virginianus) fawn and yearling, a beaver (Castor canadensis), ruffed grouse (Bonasa umbellus), and fisher (Martes pennanti) and scavenging on a road-killed deer and other carrion. However, we missed finding many prey items and discuss the problems associated with trying to conduct such a study. ?? 2010 US Government.

  2. Intense or spatially heterogeneous predation can select against prey dispersal.

    PubMed

    Barraquand, Frederic; Murrell, David J

    2012-01-01

    Dispersal theory generally predicts kin competition, inbreeding, and temporal variation in habitat quality should select for dispersal, whereas spatial variation in habitat quality should select against dispersal. The effect of predation on the evolution of dispersal is currently not well-known: because predation can be variable in both space and time, it is not clear whether or when predation will promote dispersal within prey. Moreover, the evolution of prey dispersal affects strongly the encounter rate of predator and prey individuals, which greatly determines the ecological dynamics, and in turn changes the selection pressures for prey dispersal, in an eco-evolutionary feedback loop. When taken all together the effect of predation on prey dispersal is rather difficult to predict. We analyze a spatially explicit, individual-based predator-prey model and its mathematical approximation to investigate the evolution of prey dispersal. Competition and predation depend on local, rather than landscape-scale densities, and the spatial pattern of predation corresponds well to that of predators using restricted home ranges (e.g. central-place foragers). Analyses show the balance between the level of competition and predation pressure an individual is expected to experience determines whether prey should disperse or stay close to their parents and siblings, and more predation selects for less prey dispersal. Predators with smaller home ranges also select for less prey dispersal; more prey dispersal is favoured if predators have large home ranges, are very mobile, and/or are evenly distributed across the landscape. PMID:22247764

  3. Effects of uniform rotational flow on predator-prey system

    NASA Astrophysics Data System (ADS)

    Lee, Sang-Hee

    2012-12-01

    Rotational flow is often observed in lotic ecosystems, such as streams and rivers. For example, when an obstacle interrupts water flowing in a stream, energy dissipation and momentum transfer can result in the formation of rotational flow, or a vortex. In this study, I examined how rotational flow affects a predator-prey system by constructing a spatially explicit lattice model consisting of predators, prey, and plants. A predation relationship existed between the species. The species densities in the model were given as S (for predator), P (for prey), and G (for plant). A predator (prey) had a probability of giving birth to an offspring when it ate prey (plant). When a predator or prey was first introduced, or born, its health state was assigned an initial value of 20 that subsequently decreased by one with every time step. The predator (prey) was removed from the system when the health state decreased to less than zero. The degree of flow rotation was characterized by the variable, R. A higher R indicates a higher tendency that predators and prey move along circular paths. Plants were not affected by the flow because they were assumed to be attached to the streambed. Results showed that R positively affected both predator and prey survival, while its effect on plants was negligible. Flow rotation facilitated disturbances in individuals’ movements, which consequently strengthens the predator and prey relationship and prevents death from starvation. An increase in S accelerated the extinction of predators and prey.

  4. Forest type affects prey foraging of saddleback tamarins, Saguinus nigrifrons.

    PubMed

    Kupsch, Denis; Waltert, Matthias; Heymann, Eckhard W

    2014-07-01

    Callitrichids can persist in secondary forests where they may benefit from elevated prey abundance. However, how tamarins forage for prey in secondary forest compared to primary forest has not been examined. Using scan and focal sampling, we compared prey foraging and capture success of two groups of Saguinus nigrifrons in north-eastern Peru: one ranging in primary forest, the other with access to a 10-year-old anthropogenic secondary forest. There was a trend for more prey search in the secondary forest, but prey feeding, capture success and size were lower compared to the primary forest. Tamarins avoided the forest floor, used vertical supports less often and searched on a lower variety of substrates in the secondary forest. In the secondary forest, tamarins did not capture flushed prey, which make up a substantial part of the total prey captures biomass in primary forests. Reduced prey capture success is unlikely to reflect reduced prey availability, since more Orthoptera were found in secondary forest through ultrasonic surveys. Therefore, the prey search activity of S. nigrifrons in young secondary forests seemed rather opportunistic, presumably influenced by altered predation patterns, vegetation structure, as well as prey diversity. PMID:24687729

  5. Developing an IGS time scale.

    PubMed

    Senior, Ken; Koppang, Paul; Ray, Jim

    2003-06-01

    Currently, the International GPS Service (IGS) provides a set of clock products for both satellites and tracking receivers, tabulated at 5-min intervals. These products allow users to determine consistent coordinates and clock values for an isolated GPS receiver with an internal accuracy at the few-cm level. However, because the underlying time scale for the IGS combined clocks is based on a linear alignment to broadcast GPS Time for each day separately, the day-to-day stability of this reference is poor. We show the results of a new filter package written to automate the production of an integrated IGS frequency scale based on a dynamically weighted ensemble of the included frequency standards. The new scale is loosely steered to GPS Time. PMID:12839170

  6. Optimal Foraging and Predator-Prey Dynamics

    PubMed

    Krivan

    1996-06-01

    A system consisting of a population of predators and two types of prey is considered. The dynamics of the system is described by differential equations with controls. The controls model how predators forage on each of the two types of prey. The choice of these controls is based on the standard assumption in the theory of optimal foraging which requires that each predator maximizes the net rate of energy intake during foraging. Since this choice depends on the densities of populations involved, this allows us to link the optimal behavior of an individual with the dynamics of the whole system. Simple qualitative analysis and some simulations show the qualitative behavior of such a system. The effect of the optimal diet choice on the stability of the system is discussed. PMID:8813025

  7. IgG4-related disease mimicking chalazion in the upper eyelid with skin manifestations on the trunk.

    PubMed

    Leivo, Tiina; Koskenmies, Sari; Uusitalo, Marita; Tynninen, Olli

    2015-08-01

    IgG4-related disease is a recently defined inflammatory process characterized by IgG4-bearing plasma cells in the involved tissues. The most common sites of involvement are the pancreas, hepatobiliary tract, salivary glands, lymph nodes, retroperitoneum and orbit, especially the lacrimal glands. Other ocular or ocular adnexal sites are rare. To our knowledge, there is one reported case of a conjunctival involvement. We describe a patient, who had an IgG4-RD mimicking chalazion in the upper eyelid, confined to the tarsus, with multiple skin lesions on the trunk. This is a case report of a 55-year-old female. A 55-year-old female presented with an upper eyelid lesion, which was clinically diagnosed as chalazion and drained three times. Histopathological diagnoses were chalazion and inflammation with mixed cells, respectively. Additionally, the patient had had skin nodules on the trunk for several years. Finally, after a third recurrence, the tarsal eyelid lesion was completely excised. The tarsal pathology specimen showed 85 IgG4 positive plasma cells per HPF and the IgG4/IgG ratio was 0.64, suggesting a probable IgG4-related disease. The re-examined skin lesions resembled histologically the eyelid lesion. It is essential to be aware of IgG4-related disease, including in recurrent chalazia. PMID:25834990

  8. Predator-Prey Interactions of Marine Invaders

    Microsoft Academic Search

    Gil Rilov

    Predator-prey interactions are among the most fundamental processes shaping the structure and function of ecological communities,\\u000a particularly in marine systems. In the past several decades, it has become clear that humans are interfering considerably\\u000a with these interactions in many marine systems, mainly by removing top predators via harvesting (Myers and Worm 2003), but\\u000a also through biological introductions. Most introduced species

  9. Blood plasma IgG Fc glycans are significantly altered in Alzheimer's disease and progressive mild cognitive impairment.

    PubMed

    Lundström, Susanna L; Yang, Hongqian; Lyutvinskiy, Yaroslav; Rutishauser, Dorothea; Herukka, Sanna-Kaisa; Soininen, Hilkka; Zubarev, Roman A

    2014-01-01

    Blood-based anti-amyloid-? (A?) immunoglobulins (IgGs) and peripheral inflammation are factors correlating with development of Alzheimer's disease (AD). IgG functionality can drastically change from anti- to pro-inflammatory via alterations in the IgG-Fc N-glycan structure. Herein, we tested if IgG-Fc glycosylation in plasma is indeed altered during the development of AD. Samples from age-matched subjects of 23 controls, 58 patients with stable mild cognitive impairment (SMCI), 34 patients with progressive (P)MCI, and 31 patients with AD were investigated. Label-free shotgun proteomics was applied without glycoprotein enrichment. Glycans on peptides EEQYNSTYR (IgG1) and EEQFNSTFR (IgG2) were quantified, and their abundances were normalized to total IgGn glycoform abundance. Univariate and multivariate statistics were employed to investigate the correlations between the patients groups and the abundances of the IgG glycoforms as well as those of inflammatory mediating proteins. Significant differences (p ? 0.05) were found, with a lower abundance of complex galactosylated and sialylated forms in AD. For females, a decline in glycoform complexity correlated with disease progress but an inverse change was found in males prior to the onset of AD. Principal component analysis (PCA; Males: R(2)X(cum) = 0.65, Q(2)(cum) = 0.34; Females: R(2)X(cum) = 0.62, Q(2)(cum) = 0.36), confirmed the gender similarities (for controls, SMCI and AD) as well as differences (for PMCI), and showed a close correlation between pro-inflammatory protein markers, AD, female PMCI, and truncated IgG-Fc glycans. The differences observed between genders prior to the onset of AD may indicate a lower ability in females to suppress peripheral inflammation, which may lead to exacerbated disease progression. PMID:24028868

  10. Prey DNA detection success following digestion by intraguild predators: influence of prey and predator species.

    PubMed

    Gagnon, A-È; Doyon, J; Heimpel, G E; Brodeur, J

    2011-11-01

    Intraguild predation (IGP) has been increasingly recognized as an important interaction in ecological systems over the past two decades, and remarkable insights have been gained into its nature and prevalence. We have developed a technique using molecular gut-content analysis to compare the rate of IGP between closely related species of coccinellid beetles (lady beetles or ladybirds), which had been previously known to prey upon one another. We first developed PCR primers for each of four lady beetle species: Harmonia axyridis, Coccinella septempunctata, Coleomegilla maculata and Propylea quatuordecimpunctata. We next determined the prey DNA detection success over time (DS(50) ) for each combination of interacting species following a meal. We found that DS(50) values varied greatly between predator-prey combinations, ranging from 5.2 to 19.3 h. As a result, general patterns of detection times based upon predator or prey species alone are not discernable. We used the DS(50) values to correct field data to demonstrate the importance of compensation for detection times that are specific to particular predator-prey combinations. PMID:21749673

  11. Prey selection by the Lake Superior fish community

    USGS Publications Warehouse

    Isaac, Edmund J.; Hrabik, Thomas R.; Stockwell, Jason D.; Gamble, Allison E.

    2012-01-01

    Mysis diluviana is an important prey item to the Lake Superior fish community as found through a recent diet study. We further evaluated this by relating the quantity of prey found in fish diets to the quantity of prey available to fish, providing insight into feeding behavior and prey preferences. We describe the seasonal prey selection of major fish species collected across 18 stations in Lake Superior in spring, summer, and fall of 2005. Of the major nearshore fish species, bloater (Coregonus hoyi), rainbow smelt (Osmerus mordax), and lake whitefish (Coregonus clupeaformis) consumed Mysis, and strongly selected Mysis over other prey items each season. However, lake whitefish also selected Bythotrephes in the fall when Bythotrephes were numerous. Cisco (Coregonus artedi), a major nearshore and offshore species, fed largely on calanoid copepods, and selected calanoid copepods (spring) and Bythotrephes (summer and fall). Cisco also targeted prey similarly across bathymetric depths. Other major offshore fish species such as kiyi (Coregonus kiyi) and deepwater sculpin (Myoxocephalus thompsoni) fed largely on Mysis, with kiyi targeting Mysis exclusively while deepwater sculpin did not prefer any single prey organism. The major offshore predator siscowet lake trout (Salvelinus namaycush siscowet) consumed deepwater sculpin and coregonines, but selected deepwater sculpin and Mysis each season, with juveniles having a higher selection for Mysis than adults. Our results suggest that Mysis is not only a commonly consumed prey item, but a highly preferred prey item for pelagic, benthic, and piscivorous fishes in nearshore and offshore waters of Lake Superior.

  12. Prey switching with a linear preference trade-off

    E-print Network

    S. H. Piltz; M. A. Porter; P. K. Maini

    2013-02-25

    In ecology, prey switching refers to a predator's adaptive change of habitat or diet in response to prey abundance. In this paper, we study piecewise-smooth models of predator-prey interactions with a linear trade-off in a predator's prey preference. We consider optimally foraging predators and derive a model for a 1 predator-2 prey interaction with a tilted switching manifold between the two sides of discontinuous vector fields. We show that the 1 predator-2 prey system undergoes a novel adding-sliding-like (center to two-part periodic orbit; "C2PO") bifurcation in which the prey ratio transitions from constant to time-dependent. Further away from the bifurcation point, the period of the oscillating prey ratio period doubles, suggesting a possible cascade to chaos. We compare our model predictions with data and demonstrate that we successfully capture the periodicity in the ratio between the predator's preferred and alternative prey types in data on freshwater plankton. Our study suggests that it is useful to investigate prey ratio as a possible indicator of how population dynamics can be influenced by ecosystem diversity.

  13. Protection of rhein on IgA nephropathy mediated by inhibition of fibronectin expression in rats

    PubMed Central

    Sheng-Nan, Peng; Hui-Hong, Zeng; Ai-Xiang, FU; Xiao-Wen, Chen; Qing-Xian, Zhu

    2013-01-01

    Objective: To investigate the protective effects of rhein on IgA nephropathy (IgAN) in the rat model. Materials and Methods: Twenty-eight female sprague dawley rats were divided randomly into four groups, namely control, IgAN, rhein-prevented and rhein-treated. The pathologic changes on renal tissue were observed by the H and E, staining and the amount of urinary red blood cells and 24-h urinary protein excretion were measured. The glomerular deposition of immune globulin A (IgA) was measured by immunofluorescence staining. Fibronectin (FN) and ?-smooth muscle actin (?-SMA) expression on renal tissue were measured via immunohistochemistry. Results: The model of IgAN was established according to Bovine serum albumin-Lipopolysaccharide-Carbon tetrachloride protocol, which was evidenced by histological structural lesions of glomeruli, IgA deposition and urinary measurement. Histological examination of kidney sections from both rhein-prevented group and rhein-treated group showed that glomerular hypertrophy, mesangial expansion, excessive extracellular matrix, and renal capsule dilation were markedly ameliorated compared with IgAN group. Moreover, rhein treatment significantly reduced IgA deposition in glomerulus, the volume of urinary red blood cells and 24-h urinary protein excretion. More importantly, increased FN expression in IgAN was back to normal level in rhein-prevented and rhein-treated group, which was along with the reduction of ?-SMA expression in renal tissues. Conclusions: These findings indicate that rhein prevents the development of glomerulosclerosis and halts the progression of IgAN via inhibition of FN and ?-SMA expression. PMID:23716895

  14. Infomechanical specializations for prey capture in knifefish

    NASA Astrophysics Data System (ADS)

    Maciver, Malcolm; Patankar, Neelesh; Curet, Oscar; Shirgaonkar, Anup

    2007-11-01

    How does an animal's mechanics and its information acquisition system work together to solve crucial behavioral tasks? We examine this question for the black ghost weakly electric knifefish (Apteronotus albifrons), which is a leading model system for the study of sensory processing in vertebrates. These animals hunt at night by detecting perturbations of a self-generated electric field caused by prey. While the fish searches for prey, it pitches at 30 . Fully resolved Navier-Stokes simulations of their swimming, which occurs through undulations of a long ribbon-like fin along the bottom edge of the body, indicates that this configuration enables maximal thrust while minimizing pitch moment. However, pitching the body also increases drag. Our analysis of the sensory volume for detection of prey shows this volume to be similar to a cylinder around the body. Thus, pitching the body enables a greater swept volume of scanned fluid. Examining the mechanical and information acquisition demands on the animal in this task gives insight into how these sometimes conflicting demands are resolved.

  15. The effect of background cuing on prey detection.

    PubMed

    Kono; Reid; Kamil

    1998-10-01

    Studies of prey detection have typically focused on how search image affects the capture of cryptic items. This study also considers how background vegetation influences cryptic prey detection. Blue jays, Cyanocitta cristata, searched digitized images for two Catocala moths: C. ilia, which is cryptic on oak, and C. relicta, which is cryptic on birch. Some images contained moths while others did not. The ability of blue jays to detect prey during repeated presentations of one prey type within a session was compared with their performance during randomly alternating presentations of both prey types within a session to examine search-image formation under two background conditions (informative and ambiguous). In the informative background condition, both trees in the image were of the same species and therefore, the background was a reliable indicator of which prey type might be present. In the ambiguous background condition, there was one tree of each species in the image and either prey type could be present. The results indicate that: (1) a search-image effect was observed only for the more cryptic prey type and only when the background was informative; (2) as accuracy on prey images (those with moths) increased, response latency remained unchanged; (3) performance on nonprey images (those without moths) was primarily determined by the difficulty of searching the background and not by the prey type in the accompanying prey images; and (4) search-image effects disappeared with extended practice. These results suggest that the ability to detect prey is influenced by background and that the presence of either multiple backgrounds or multiple prey types interferes with search-image formation. Copyright 1998 The Association for the Study of Animal Behaviour. PMID:9790707

  16. Evaluation of the new architect cytomegalovirus immunoglobulin M (IgM), IgG, and IgG avidity assays.

    PubMed

    Lagrou, K; Bodeus, M; Van Ranst, M; Goubau, P

    2009-06-01

    A panel of new cytomegalovirus (CMV) assays for use on the Architect instrument has been developed, including a CMV avidity assay based on a new technology. The purpose of this study was to compare the performance characteristics of the fully automated CMV immunoglobulin M (IgM), IgG, and IgG avidity tests on the Architect instrument with those of other available assays. A total of 503 consecutive fresh patient serum specimens (routine serum specimens) and 96 serum specimens from 33 pregnant women with a recent CMV primary infection (seroconversion serum specimens) were tested for CMV IgM and IgG by the Architect (Abbott), Vidas (BioMérieux), and Enzygnost (Siemens) assays. The seroconversion sera and 100 preselected serum specimens IgM negative and IgG positive by the AxSYM assay were also tested by the IgG avidity tests on the Architect and Vidas instruments. The relative agreements for CMV IgM determination with routine sera between the Architect assay and the Vidas, Enzygnost, and AxSYM assays were 97%, 94%, and 93%, respectively, for the CMV IgM tests and 99%, 98%, and 98%, respectively, for the CMV IgG tests. The specificities of the CMV IgG avidity test were 98% for the Architect assay and 76% for the Vidas assay. No high CMV IgG avidity test results were found within the first 3 months after seroconversion by either of those assays. The correlation between the results of the newly developed CMV IgM and IgG tests on the Architect instrument with the Vidas and Enzygnost assays was excellent (> or = 94%). The CMV IgG avidity test reliably excluded patients with recent infections and showed an excellent specificity (98%). PMID:19339470

  17. Autoimmune Dysfunction and Subsequent Renal Insufficiency in a Collegiate Female Athlete: A Case Report

    Microsoft Academic Search

    James E. Leone; Amie Kern; Joshua D. Williamson; Robert M. Colandreo

    2010-01-01

    Objective: To present the case of a female collegiate basketball player who was diagnosed with Wegener granulomatosis of the eyes and immunoglobulin A (IgA) nephropathy.\\u000aBackground: A 19-year-old female collegiate basketball player presented to a rheumatologist, urologist, and nephrologist with severe eye pain and was diagnosed with Wegener granulomatosis and IgA nephropathy. At age 20, during routine follow-up testing, urine

  18. IgG4-related sclerosing disease clinically mimicking oral squamous cell carcinoma.

    PubMed

    Khurram, Syed Ali; Fernando, Malee; Smith, Austen T; Hunter, Keith D

    2013-02-01

    IgG4-related sclerosing disease is a distinct clinicopathologic entity known to involve the maxillofacial region, particularly the salivary, lacrimal, and pituitary glands. We report a case with lesions involving the tongue and palatine tonsil with associated skin lesions. A 45-year-old female patient presented with a history of soreness, dysphagia, and an asymptomatic rash involving the upper trunk. The initial clinical diagnosis of her oral lesions was squamous cell carcinoma. The diagnosis of an IgG4-related lesion was confirmed by histologic examination of the oral and skin lesions as well as confirmation of raised serum IgG4 levels. Tapering systemic corticosteroid therapy resulted in complete resolution of the lesions. This is the first report of IgG4-related sclerosing disease presenting as concurrent oral and skin lesions, with the oral lesion clinically resembling oral squamous cell carcinoma. Such lesions present a diagnostic challenge, but the outcome is very favorable. PMID:22901649

  19. High-Affinity IgG Antibodies Develop Naturally in Ig-Knockout Rats Carrying Germline Human IgH/Ig?/Ig? Loci Bearing the Rat CH Region

    PubMed Central

    Osborn, Michael J.; Ma, Biao; Avis, Suzanne; Binnie, Ashleigh; Dilley, Jeanette; Yang, Xi; Lindquist, Kevin; Ménoret, Séverine; Iscache, Anne-Laure; Ouisse, Laure-Hélène; Rajpal, Arvind; Anegon, Ignacio; Neuberger, Michael S.

    2013-01-01

    Mice transgenic for human Ig loci are an invaluable resource for the production of human Abs. However, such mice often do not yield human mAbs as effectively as conventional mice yield mouse mAbs. Suboptimal efficacy in delivery of human Abs might reflect imperfect interaction between the human membrane IgH chains and the mouse cellular signaling machinery. To obviate this problem, in this study we generated a humanized rat strain (OmniRat) carrying a chimeric human/rat IgH locus (comprising 22 human VHs, all human D and JH segments in natural configuration linked to the rat CH locus) together with fully human IgL loci (12 V?s linked to J?-C? and 16 V?s linked to J?-C?). The endogenous Ig loci were silenced using designer zinc finger nucleases. Breeding to homozygosity resulted in a novel transgenic rat line exclusively producing chimeric Abs with human idiotypes. B cell recovery was indistinguishable from wild-type animals, and human V(D)J transcripts were highly diverse. Following immunization, the OmniRat strain performed as efficiently as did normal rats in yielding high-affinity serum IgG. mAbs, comprising fully human variable regions with subnanomolar Ag affinity and carrying extensive somatic mutations, are readily obtainable, similarly to conventional mAbs from normal rats. PMID:23303672

  20. National prevalence estimates for cytomegalovirus IgM and IgG avidity and association between high IgM antibody titer and low IgG avidity.

    PubMed

    Dollard, Sheila C; Staras, Stephanie A S; Amin, Minal M; Schmid, D Scott; Cannon, Michael J

    2011-11-01

    Primary cytomegalovirus (CMV) infection of the mother during pregnancy presents risk of CMV infection of the fetus with resulting permanent disability. CMV IgM antibody is generated following primary CMV infection but also can appear during nonprimary CMV infection and is thus of limited diagnostic use by itself. In contrast, the presence of low CMV IgG avidity has been shown to be a unique and reliable serologic indicator of primary CMV infection. We measured CMV IgG and IgM antibody levels and IgG avidity in sera from a population sample of 6,067 U.S. women aged 12 to 49 years from NHANES (National Health and Nutrition Examination Survey). The CMV IgG prevalence was 58% overall and increased strongly with age. The CMV IgM prevalence was 3.0% overall and remained relatively flat across age groups. The prevalence of low IgG avidity was 2.0% overall, decreased sharply with age, and was seen mainly among IgM-positive sera. Fourteen to 18% of the CMV IgM-positive sera were low IgG avidity, presumably representing primary CMV infection. High CMV IgM antibody titer was a strong predictor of low IgG avidity. The ability to reliably identify primary CMV infection during pregnancy is important for management of the pregnancy, including possible treatment options for the fetus. Both IgM and IgG avidity measurements provide useful clinical information for evaluating primary CMV infection, although commercial tests for CMV IgG avidity are not yet widely available in the United States. PMID:21918114

  1. Interleukin 10 induces B lymphocytes from IgA-deficient patients to secrete IgA.

    PubMed Central

    Brière, F; Bridon, J M; Chevet, D; Souillet, G; Bienvenu, F; Guret, C; Martinez-Valdez, H; Banchereau, J

    1994-01-01

    We have previously shown that human B lymphocytes cultured in the CD40 system, composed of an anti-CD40 mAb presented by a CD32-transfected fibroblastic cell line, proliferate but do not secrete antibodies. However, the addition of particles of Staphylococcus aureus Cowan (SAC) induces B cell differentiation even in the absence of exogenous cytokines (CD40/SAC system). Additionally, B lymphocytes cultured in the CD40 system in the presence of human IL-10, produce IgM, IgG, and IgA, and Ig levels are further increased by SAC. Here, we have studied the capacity of peripheral blood lymphocytes from patients with IgA deficiency (IgA-D) to secrete Igs, particularly IgA after CD40 triggering. Peripheral blood mononuclear cells (PBMNC) from IgA-D patients cultured in the CD40/SAC system produced IgM and IgG, but not IgA. The addition of IL-10 to the cultures, enhanced the production of IgM and IgG and most strikingly induced the production of high amounts of IgA. The addition of IL-10 to PBMNC from IgA-D patients activated through CD40 alone resulted in the production of IgA. Thus, SAC and anti-CD40 mAb stimulate B cells to differentiate into cells secreting IgG and IgM whereas IL-10 plays a central role in inducing B cells from IgA-D patients to differentiate into IgA secreting cells. PMID:7518836

  2. Pneumococcal IgA1 Protease Subverts Specific Protection By Human IgA1

    PubMed Central

    Janoff, Edward N.; Rubins, Jeffrey B.; Fasching, Claudine; Charboneau, Darlene; Rahkola, Jeremy T.; Plaut, Andrew G.; Weiser, Jeffrey N.

    2015-01-01

    Bacterial IgA1 proteases may sabotage the protective effects of IgA. In vitro, both exogenous and endogenously-produced IgA1 protease inhibited phagocytic killing of Streptococcus pneumoniae by capsule-specific IgA1 human monoclonal antibodies (hMAb's), but not IgA2. These IgA1 proteases cleaved and reduced binding of the the effector Fc?1 heavy chain but not the antigen-binding F(ab)/light chain to pneumococcal surfaces. In vivo, IgA1 protease-resistant IgA2, but not IgA1 protease-sensitive IgA1, supported 60% survival in mice infected with wild-type S. pneumoniae. IgA1 hMAb's protected mice against IgA1 protease-deficient, but not -producing pneumococci. Parallel mouse sera with human IgA2 showed more efficient complement-mediated reductions in pneumococci with neutrophils than did IgA1, particularly with protease-producing organisms. After natural human pneumococcal bacteremia, purified serum IgG inhibited IgA1 protease activity in 7 of 11 patients (64%). These observations provide the first evidence in vivo that IgA1 protease can circumvent killing of S. pneumoniae by human IgA. Acquisition of IgA1 protease-neutralizing IgG after infection directs attention to IgA1 protease both as a determinant of successful colonization and infection and as a potential vaccine candidate. PMID:23820749

  3. Tetrameric and Homodimeric Camelid IgGs Originate from the Same IgH Locus

    E-print Network

    Utrecht, Universiteit

    and homodimeric IgGs by constructing an alpaca (Lama pacos) genomic cosmid library. We showed that a single IgH locus in alpaca chromosome 4 contains all of the genetic elements required for the generation of the two types of Igs. The alpaca IgH locus is composed of a V region that contains both VHH and VH genes

  4. The biomechanics of fast prey capture in aquatic bladderworts

    PubMed Central

    Singh, Amit K.; Prabhakar, Sunil; Sane, Sanjay P.

    2011-01-01

    Carnivorous plants match their animal prey for speed of movements and hence offer fascinating insights into the evolution of fast movements in plants. Here, we describe the mechanics of prey capture in aquatic bladderworts Utricularia stellaris, which prey on swimming insect larvae or nematodes to supplement their nitrogen intake. The closed Utricularia bladder develops lower-than-ambient internal pressures by pumping out water from the bladder and thus setting up an elastic instability in bladder walls. When the external sensory trigger hairs on their trapdoor are mechanically stimulated by moving prey, the trapdoor opens within 300–700 ?s, causing strong inward flows that trap their prey. The opening time of the bladder trapdoor is faster than any recorded motion in carnivorous plants. Thus, Utricularia have evolved a unique biomechanical system to gain an advantage over their animal prey. PMID:21389013

  5. System behaviour in predator-prey interaction, with special reference to acarine predator-prey system

    Microsoft Academic Search

    Akio Takafuji; Yoshio Tsuda; Toshihiro Miki

    1983-01-01

    Summary  \\u000a \\u000a \\u000a \\u000a 1. \\u000a \\u000a Laboratory experiments on the interaction between phytophagous tetranychid mites and predacious phytoseiid mites in multi-patch\\u000a systems showed that it was difficult to obtain a continued interaction between them when prey heavily over-exploit their host\\u000a plants. The experiments suggested that the stability conditions concluded from theMaynard Smith model which assumed a stable relationship between prey and resource would be

  6. Signaling through CD40 rescues IgE but not IgG or IgA secretion in X-linked immunodeficiency with hyper-IgM.

    PubMed Central

    Saiki, O; Tanaka, T; Wada, Y; Uda, H; Inoue, A; Katada, Y; Izeki, M; Iwata, M; Nunoi, H; Matsuda, I

    1995-01-01

    The ligand for CD40 (CD40L) is a membrane protein on activated T cells that induces B cell proliferation and differentiation. Several mutations of the CD40L gene were reported responsible for defective class switching of B cells in an X-linked immunodeficiency with hyper IgM (X-HIM). We studied four affected males from three families and found three independent mutations including new mutations of CD40L gene. In every X-HIM patient tested, however, anti-CD40 plus IL-10 did not induce class switching from IgM to IgG or IgA, even in the presence of Staphylococcus aureus Cowan I strain (SAC). CD4+ T cell clones, expressing CD40L on their surface, also did not rescue IgG or IgA induction by X-HIM peripheral blood B cells in vitro. But signaling through CD40 induced both B cell proliferation and IgE secretion when IL-4 was added to the culture. Taken together, these results show that in vitro signaling through CD40 rescues IgE but not IgG or IgA secretion by peripheral blood X-HIM B cells and suggest that in vivo CD40 and CD40L interaction might be necessary for IgG and IgA differentiation in X-HIM. PMID:7532185

  7. IgA, igG1, IgG2, IgM, and BSA in serum and mammary secretion throughout lactation.

    PubMed

    Guidry, J; Butler, J E; Pearson, R E; Weinland, B T

    1980-12-01

    Bovine IgG1, IgG2, IgA, and IgM were measured in the serum and lacteal secretions of six cows from 10 days prepartum to 240 days of lactation. Immunoglobulins in lacteal secretions were expressed in units of concentration (mg/ml) as well as in total daily output. All isotypes were selectively accumulated during colostrum formation. The rate of IgG1 accumulation decreased rapidly after calving; this decrease corresponded to a return to normal serum levels of this immunoglobulin. Selective accumulation of IgA > IgM > IgG1 was maintained throughout lactation, but IgG2 showed no selective accumulation beyond 5 days postpartum. In serum, IgA and IgM levels were elevated at parturition and showed a significant decrease postpartum. Increases in serum IgA levels 60 days postpartum corresponded to a rise in lacteal concentration. The concentration of all immunoglobulins increased during late lactation, coincident with a major reduction in milk yield. Six strains of mastitis-causing organisms were cultured during the period of the experiment; however, none resulted in clinical mastitis or showed an effect on immunoglobulin secretion. PMID:15615051

  8. IgG Purification and Depletion Kits

    E-print Network

    Lebendiker, Mario

    EnchantTM IgG Purification and Depletion Kits · Simple, easy to use Protein A or Protein G affinity Enchant Protein A IgG 50 purifications Purification/Depletion Kit 5300-IGGPROG Enchant Protein G IgG 10, desalting columns and the required binding and Elution Buffers. Affinity purification via Protein A and G

  9. The maintenance of Bdellovibrio at low prey density

    Microsoft Academic Search

    Mazal Varon; Miriam Fine; Anat Stein

    1984-01-01

    A mathematical model for the interaction ofBdellovibrio and its prey predicted that a relatively high prey density (7×105 cells ml?1) would be required for the establishment of an equilibrium in a mixed population [8]. The present report shows thatBdellovibrio can be maintained in a continuous culture when the prey cell density is much lower (2–5×104 cells ml?1), and closer to

  10. Visual control of cursorial prey pursuit by tiger beetles (Cicindelidae)

    Microsoft Academic Search

    C. Gilbert

    1997-01-01

    Target detection poses problems for moving animals, such as tiger beetles, that track targets visually. The pursuer's movements\\u000a degrade target image contrast and induce reafferent image movement that confounds continuous detection of prey. In nature,\\u000a beetles pursue prey discontinuously with several iterations of stop-and-go running. The beetle's dynamics were analyzed by\\u000a filming pursuits of prey or experimenter-controlled dummies. Durations of

  11. Nash Equilibria in Noncooperative Predator-Prey Games

    SciTech Connect

    Ramos, Angel Manuel [Departamento de Matematica Aplicada, Universidad Complutense de Madrid, Plaza de Ciencias 3, 28040 (Spain)], E-mail: Angel_Ramos@mat.ucm.es; Roubicek, Tomas [Mathematical Institute, Charles University, Sokolovska 83, CZ-186 75 Praha 8 and Institute of Information Theory and Automation, Academy of Sciences, Pod vodarenskou vezi 4 (Czech Republic)], E-mail: roubicek@karlin.mff.cuni.cz

    2007-09-15

    A noncooperative game governed by a distributed-parameter predator-prey system is considered, assuming that two players control initial conditions for predator and prey, respectively. Existence of a Nash equilibrium is shown under the condition that the desired population profiles and the environmental carrying capacity for the prey are sufficiently small. A conceptual approximation algorithm is proposed and analyzed. Finally, numerical simulations are performed, too.

  12. Is Meat Flavor a Factor in Hunters’ Prey Choice Decisions?

    Microsoft Academic Search

    Jeremy M. Koster; Jennie J. Hodgen; Maria D. Venegas; Toni J. Copeland

    2010-01-01

    By focusing on the caloric composition of hunted prey species, optimal foraging research has shown that hunters usually make\\u000a economically rational prey choice decisions. However, research by meat scientists suggests that the gustatory appeal of wildlife\\u000a meats may vary dramatically. In this study, behavioral research indicates that Mayangna and Miskito hunters in Nicaragua inconsistently\\u000a pursue multiple prey types in the

  13. Prey selectivity affects reproductive success of a corallivorous reef fish.

    PubMed

    Brooker, Rohan M; Jones, Geoffrey P; Munday, Philip L

    2013-06-01

    Most animals consume a narrower range of food resources than is potentially available in the environment, but the underlying basis for these preferences is often poorly understood. Foraging theory predicts that prey selection should represent a trade-off between prey preferences based on nutritional value and prey availability. That is, species should consume preferred prey when available, but select less preferred prey when preferred prey is rare. We employed both field observation and laboratory experiments to examine the relationship between prey selection and preferences in the obligate coral-feeding filefish, Oxymonacanthus longirostris. To determine the drivers of prey selection, we experimentally established prey preferences in choice arenas and tested the consequences of prey preferences for key fitness-related parameters. Field studies showed that individuals fed almost exclusively on live corals from the genus Acropora. While diet was dominated by the most abundant species, Acropora nobilis, fish appeared to preferentially select rarer acroporids, such as A. millepora and A. hyacinthus. Prey choice experiments confirmed strong preferences for these corals, suggesting that field consumption is constrained by availability. In a longer-term feeding experiment, reproductive pairs fed on non-preferred corals exhibited dramatic reductions to body weight, and in hepatic and gonad condition, compared with those fed preferred corals. The majority of pairs fed preferred corals spawned frequently, while no spawning was observed for any pairs fed a non-preferred species of coral. These experiments suggest that fish distinguish between available corals based on their intrinsic value as prey, that reproductive success is dependent on the presence of particular coral species, and that differential loss of preferred corals could have serious consequences for the population success of these dietary specialists. PMID:23124333

  14. Sex differences in impaling behaviour of Great Grey Shrike Lanius excubitor: do males have better impaling skills than females?

    PubMed

    Antczak, Marcin; Hromada, Martin; Tryjanowski, Piotr

    2012-09-01

    Prey impaling in shrikes Laniidae is considered to be a feeding adaptation to dismember and consume large prey and is unique among food-storing animals. However, other exaptations of this behaviour were recorded, including signals in mate choice, where cache size is a sign of male quality. Thus, due to a strong sexual selection, male and female birds might differ in their behavioural patterns of impaling behaviour. We examined sex differences in impaling behaviour of the Great Grey Shrike Lanius excubitor - one of the species where caches are known to be sexual signals. Data were collected in western Poland during breeding seasons in the years 2006-2010. In the studied population, we recorded several sex-specific differences in impaling behaviour. Males impaled prey, invertebrates as well as vertebrates, faster and with fewer attempts per impaling event than females. Sexes differed in the location of impaled prey; males selected more visible places, especially during the mating and courtship phase, whereas females impaled prey in concealed locations. Males also had slightly better impaling success compared to females. We suggest that sex differences in impaling behaviour may be due to different uses of impaled prey, and the better impaling skills of males may be the result of better experience in impaling which is forced by sexual selection in this species. We also discuss other factors which might trigger sex-specific differences in food caching by shrikes. PMID:22659619

  15. Reward for Bdellovibrio bacteriovorus for preying on a polyhydroxyalkanoate producer.

    PubMed

    Martínez, Virginia; Jurkevitch, Edouard; García, José Luis; Prieto, María Auxiliadora

    2013-04-01

    Bdellovibrio bacteriovorus?HD100 is an obligate predator that invades and grows within the periplasm of Gram-negative bacteria, including mcl-polyhydroxyalkanoate (PHA) producers such as Pseudomonas putida. We investigated the impact of prey PHA content on the predator fitness and the potential advantages for preying on a PHA producer. Using a new procedure to control P.?putida?KT2442 cell size we demonstrated that the number of Bdellovibrio progeny depends on the prey biomass and not on the viable prey cell number or PHA content. The presence of mcl-PHA hydrolysed products in the culture supernatant after predation on P.?putida?KT42Z, a PHA producing strain lacking PhaZ depolymerase, confirmed the ability of Bdellovibrio to degrade the prey's PHA. Predator motility was higher when growing on PHA accumulating prey. External addition of PHA polymer (latex suspension) to Bdellovibrio preying on the PHA minus mutant P.?putida?KT42C1 restored predator movement, suggesting that PHA is a key prey component to sustain predator swimming speed. High velocities observed in Bdellovibrio preying on the PHA producing strain were correlated to high intracellular ATP levels of the predator. These effects brought Bdellovibrio fitness benefits as predation on PHA producers was more efficient than predation on non-producing bacteria. PMID:23227863

  16. Prey processing in the Siamese fighting fish (Betta splendens).

    PubMed

    Konow, Nicolai; Krijestorac, Belma; Sanford, Christopher P J; Boistel, Renauld; Herrel, Anthony

    2013-07-01

    We studied prey processing in the Siamese fighting fish (Betta splendens), involving slow, easily observed head-bobbing movements, which were compared with prey processing in other aquatic feeding vertebrates. We hypothesized that head-bobbing is a unique prey-processing behaviour, which alternatively could be structurally and functionally analogous with raking in basal teleosts, or with pharyngognathy in neoteleosts. Modulation of head-bobbing was elicited by prey with different motility and toughness. Head-bobbing involved sustained mouth occlusion and pronounced cranial elevation, similar to raking. However, the hyoid and pectoral girdle were protracted, and not retracted as in both raking and pharyngognathy. High-speed videofluoroscopy of hyoid movements confirmed that head-bobbing differs from other known aquatic prey-processing behaviours. Nevertheless, head-bobbing and other prey-processing behaviours converge on a recurrent functional theme in the trophic ecology of aquatic feeding vertebrates; the use of intraoral and oropharyngeal dentition surfaces to immobilize, reduce and process relatively large, tough or motile prey. Prey processing outside the pharyngeal region has not been described for neoteleosts previously, but morphological evidence suggests that relatives of Betta might use similar processing behaviours. Thus, our results suggest that pharyngognathy did not out-compete ancestral prey-processing mechanisms completely during the evolution of neoteleosts. PMID:23612845

  17. Differences in the ingestion mechanisms of IgG and C3b particles in phagocytosis by neutrophils

    PubMed Central

    Hed, J.; Stendahl, O.

    1982-01-01

    A prominent feature of the surface interaction between the phagocyte and particles coated with IgG and C3b is its remarkably discriminatory character. IgG primarily promotes ingestion whereas C3b primarily promotes attachment. However, in several systems the C3b molecule is reported to cause membrane pertubation as efficiently as the IgG molecule. In this study we have used yeast particles coated with specific IgG or C3b as preys in a newly developed phagocytic assay. The number of particles interacting with polymorphonuclear leucocytes (PMN) was correlated with effector responses monitored as percentage ingested particles, superoxide anion production, and sensitivity of the ingestion process to cytochalasin B. During phagocytosis only 60% of PMN-associated yeast-C3b particles were ingested compared with 95% of yeast IgG. In cytochalasin B treated PMN, where ingestion was virtually abolished, attached yeast IgG-induced superoxide anion production whereas the same number of attached yeast C3b did not. Attempts to induce superoxide anion production in the C3b system failed by increasing incubation time, number of added particles or by increasing the concentration of the opsonizing protein. A low concentration of cytochalasin B (1 ?g/ml) decreased the IgG-dependent ingestion to 65% without affecting the C3b-dependent ingestion. The results indicate the existence of different ingestion processes in PMN—one more `basal' ingestion process represented by the C3b-promoted ingestion independent of membrane activation and another `active' ingestion process represented by the IgG-promoted ingestion dependent on membrane activation and an active response of the PMN. ImagesFigure 6 PMID:6279489

  18. Risky prey behavior evolves in risky habitats

    PubMed Central

    Urban, Mark C.

    2007-01-01

    Longstanding theory in behavioral ecology predicts that prey should evolve decreased foraging rates under high predation threat. However, an alternative perspective suggests that growth into a size refuge from gape-limited predation and the future benefits of large size can outweigh the initial survival costs of intense foraging. Here, I evaluate the relative contributions of selection from a gape-limited predator (Ambystoma opacum) and spatial location to explanations of variation in foraging, growth, and survival in 10 populations of salamander larvae (Ambystoma maculatum). Salamander larvae from populations naturally exposed to intense A. opacum predation risk foraged more actively under common garden conditions. Higher foraging rates were associated with low survival in populations exposed to free-ranging A. opacum larvae. Results demonstrate that risky foraging activity can evolve in high predation-risk habitats when the dominant predators are gape-limited. This finding invites the further exploration of diverse patterns of prey foraging behavior that depends on natural variation in predator size-selectivity. In particular, prey should adopt riskier behaviors under predation threat than expected under existing risk allocation models if foraging effort directly reduces the duration of risk by growth into a size refuge. Moreover, evidence from this study suggests that foraging has evolved over microgeographic scales despite substantial modification by regional gene flow. This interaction between local selection and spatial location suggests a joint role for adaptation and maladaptation in shaping species interactions across natural landscapes, which is a finding with implications for dynamics at the population, community, and metacommunity levels. PMID:17724339

  19. Elaphoidella grandidieri (Harpacticoida: Copepoda): demographic characteristics and possible use as live prey in aquaculture.

    PubMed

    Nandini, S; Nunez Ortiz, Alma Rosa; Sarma, S S S

    2011-07-01

    In freshwater ecosystems, rotifers and cladocerans are ideal prey for fish larvae whereas copepods, due to their purported low growth rate and predatory tendency, are not. We recently isolated the parthenogenetic Elaphoidella grandidieri (Gueme et Richard, 1893) a benthic freshwater harpacticoid, from a fish farm in the State of Morelos, central Mexico and tested its potential as a live prey organism for larval vertebrates. Population growth and life table demography experiments were conducted, in 100 ml recipients with 50 ml of test medium on a diet of Scenedesmus acutus at a density of 1.0 X 10(6) cell ml(-1); the former on live algae alone while the latter on live algae as well as detritus. We also conducted experiments to document the prey preference for this copepod by the larval Ameca splendens (Pisces: Goodeidae) and Ambystoma mexicanum (Amphibia: Ambystomatidae), fed the rotifer Plationus patulus, the ostracod Heterocypris incongruens, and the cladocerans Moina macrocopa and Daphnia pulex. Elaphoidella grandidieri is relatively easy to maintain under laboratory conditions, reaching densities (copepodites and adults) of more than 10,000 l(-1). The generation time ranged between 30-45 days, depending on the diet. The net reproductive rate was as high as 60 nauplii female(-1) day (1). Population growth rates ranged between 0.03 and 0.11 d(-1), live algae being the superior diet compared to detritus. Both predators showed no preference for E. grandidieri, but in the absence of alternate prey they consumed 80% of the harpacticoids offered. The data have been discussed in relation to the potential of E. grandidierias live food for aquaculture. PMID:22315830

  20. Habitat structure and prey aggregation determine the functional response in a soil predator–prey interaction

    Microsoft Academic Search

    Olivera Vucic-Pestic; Klaus Birkhofer; Björn C. Rall; Stefan Scheu; Ulrich Brose

    2010-01-01

    Functional responses describe the per capita consumption rates of predators depending on prey density, which quantifies the energy transfer between trophic levels. We studied a typical interaction of the litter–soil systems between hunting spiders (Pardosa lugubris; Araneae: Lycosidae) and springtails (Heteromurus nitidus; Collembola: Entomobryidae) at varying habitat structure, i.e. with moss vs. without moss. We found a hyperbolic increase in

  1. Variation in prey selection of a piscivorous fish after the impoundment of a neotropical reservoir: prey size and type.

    PubMed

    Cantanhêde, G; Fugi, R; Hahn, N S

    2009-07-01

    The relative abundance and size of prey fish in the stomachs of the predator Acestrorhynchus pantaneiro were compared with those recorded in the field to estimate prey selection. Fish samples were taken monthly in the Manso Reservoir (State of Mato Grosso, Brazil) immediately after the impoundment, from March 2000 to February 2001 (period I) and from March 2003 to February 2004 (period II). In period I, the small relative dominance of the prey in the environment seemed to have lead to random foraging. In period II, however, when the forage fish Moenkhausia dichroura was dominant in the environment, the predator shifted its diet, foraging mainly on this prey. Species with short relative body depth were positively selected. The prey size classes between 30 and 49 mm, and 50 and 69 mm standard length (L(S)) were the most abundant in the environment. Small prey were predominantly selected by A. pantaneiro. Even when a given prey or prey size was predominant in the environment, A. pantaneiro was a selective predator and maintained its preferences associated to prey type and L(S), although it consumed the most abundant resource. PMID:20738483

  2. Specific IgE response to different grass pollen allergen components in children undergoing sublingual immunotherapy

    PubMed Central

    2012-01-01

    Background Grass pollen is a major cause of respiratory allergy worldwide and contain a number of allergens, some of theme (Phl p 1, Phl p 2, Phl p 5, and Phl 6 from Phleum pratense, and their homologous in other grasses) are known as major allergens. The administration of grass pollen extracts by immunotherapy generally induces an initial rise in specific immunoglobulin E (sIgE) production followed by a progressive decline during the treatment. Some studies reported that immunotherapy is able to induce a de novo sensitisation to allergen component previously unrecognized. Methods We investigated in 30 children (19 males and 11 females, mean age 11.3 years), 19 treated with sublingual immunotherapy (SLIT) by a 5-grass extract and 11 untreated, the sIgE and sIgG4 response to the different allergen components. Results Significant increases (p?IgE levels induced in response to Phl p 7 and Phl p 12 were low or absent at baseline and unchanged following SLIT treatment; no new sensitisation was detected. As to IgG4, significant increases were found for Phl p2 and Phl p 5, while the increase for Phl p 12 was not significant. In the control group, no significant increase in sIgE for any single allergen component was found. Conclusions These findings confirm that the initial phase of SLIT with a grass pollen extract enhances the sIgE synthesis and show that the sIgE response concerns the same allergen components which induce IgE reactivity during natural exposure. PMID:22694773

  3. Histologically confirmed isolated IgG4-related hypophysitis: two case reports in young women

    PubMed Central

    Sosa, Gabriela Alejandra; Bell, Soledad; Christiansen, Silvia Beatriz; Pietrani, Marcelo; Glerean, Mariela; Loto, Monica; Lovazzano, Soledad; Carrizo, Antonio; Ajler, Pablo

    2014-01-01

    Summary IgG4-related hypophysitis is a recently described entity belonging to the group of IgG4-related diseases. Many other organs can also be affected, and it is more common in older men. To date, 32 cases of IgG4-related hypophysitis have been reported in the literature, 11 of which included confirmatory tissue biopsy and the majority affecting multiple organs. The aim of this report is to present two cases of biopsy-proven IgG4-related hypophysitis occurring in two young female patients with no evidence of involvement of other organs at the time of diagnosis. Learning points IgG4-related hypophysitis belongs to the group of IgG4-related diseases, and is a fibro-inflammatory condition characterized by dense lymphoplasmacytic infiltrates rich in IgG4-positive plasma cells and storiform fibrosis.It is more common in older men, but young women may also present this type of hypophysitis.Although involvement of other organs is frequent, isolated pituitary disease is possible.Frequent clinical manifestations include anterior hypopituitarism and/or diabetes insipidus.The diagnosis may be confirmed with any of the following criteria: a pituitary biopsy with lymphoplasmacytic infiltrates, with more than ten IgG4-positive cells; a sellar mass and/or thickened pituitary stalk and a biopsy-proven involvement of another organ; a sellar mass and/or thickened pituitary stalk and IgG4 serum levels >140?mg/dl and sellar mass reduction and symptom improvement after corticosteroid treatment.Glucocorticoids are recommended as first-line therapy. PMID:25298883

  4. Detection of IgE, IgG, IgA and IgM antibodies against raw and processed food antigens

    PubMed Central

    Vojdani, Aristo

    2009-01-01

    Background Despite the first documented case of food allergy to cooked food in 1921 by Prausnitz and Kustner, all commercial food antigens are prepared from raw food. Furthermore, all IgE and IgG antibodies against dietary proteins offered by many clinical laboratories are measured against raw food antigens. Methods We developed an enzyme-linked immunosorbent assay for the measurement of IgE, IgG, IgA and IgM antibodies against raw and processed food antigens. Sera with low or high reactivity to modified food antigens were subjected to myelin basic protein, oxidized low density lipoprotein, and advanced glycation end products (AGE) such as AGE-human serum albumin and AGE-hemoglobin. Results Compared to raw food antigens, IgE antibodies showed a 3–8-fold increase against processed food antigens in 31% of the patients. Similarly, IgG, IgA and IgM antibodies against modified food antigens overall were found at much higher levels than antibody reactions against raw food antigens. Almost every tested serum with high levels of antibodies against modified food antigens showed very high levels of antibodies against myelin basic protein, oxidized low density lipoprotein, AGE-human serum albumin and AGE-hemoglobin. Conclusion We conclude that the determination of food allergy, intolerance and sensitivity would be improved by testing IgE, IgG, IgA and IgM antibodies against both raw and processed food antigens. Antibodies against modified food antigens, by reacting with AGEs and tissue proteins, may cause perturbation in degenerative and autoimmune diseases such as diabetes, atherosclerosis, inflammation, autoimmunity, neurodegeneration and neuroautoimmunity. PMID:19435515

  5. Toxicological Effects of Nickel Chloride on IgA+ B Cells and sIgA, IgA, IgG, IgM in the Intestinal Mucosal Immunity in Broilers

    PubMed Central

    Wu, Bangyuan; Cui, Hengmin; Peng, Xi; Fang, Jing; Zuo, Zhicai; Deng, Junliang; Huang, Jianying

    2014-01-01

    The objective of this study was to investigate the toxicological effects of dietary NiCl2 on IgA+ B cells and the immunoglobulins including sIgA, IgA, IgG and IgM in the small intestine and cecal tonsil of broilers by the methods of immunohistochemistry and enzyme-linked immunosorbent assay (ELISA). Two hundred and forty one-day-old avian broilers were randomly divided into four groups and fed on a control diet and three experimental diets supplemented with 300, 600, and 900 mg/kg NiCl2 for 42 days. Compared with the control group, the IgA+ B cell number and the sIgA, IgA, IgG, and IgM contents in the NiCl2-treated groups were significantly decreased (p < 0.05 or p < 0.01). It was concluded that dietary NiCl2 in the excess of 300 mg/kg had negative effects on the IgA+ B cell number and the abovementioned immunoglobulin contents in the small intestine and the cecal tonsil. NiCl2-reduced sIgA, IgA, IgG and IgM contents is due to decrease in the population and/or the activation of B cell. The results suggest that NiCl2 at high levels has intestinal mucosal humoral immunotoxicity in animals. PMID:25116637

  6. Silk wrapping of nuptial gifts as visual signal for female attraction in a crepuscular spider

    NASA Astrophysics Data System (ADS)

    Trillo, Mariana C.; Melo-González, Valentina; Albo, Maria J.

    2014-02-01

    An extensive diversity of nuptial gifts is known in invertebrates, but prey wrapped in silk is a unique type of gift present in few insects and spiders. Females from spider species prefer males offering a gift accepting more and longer matings than when males offered no gift. Silk wrapping of the gift is not essential to obtain a mating, but appears to increase the chance of a mating evidencing a particularly intriguing function of this trait. Consequently, as other secondary sexual traits, silk wrapping may be an important trait under sexual selection, if it is used by females as a signal providing information on male quality. We aimed to understand whether the white color of wrapped gifts is used as visual signal during courtship in the spider Paratrechalea ornata. We studied if a patch of white paint on the males' chelicerae is attractive to females by exposing females to males: with their chelicerae painted white; without paint; and with the sternum painted white (paint control). Females contacted males with white chelicerae more often and those males obtained higher mating success than other males. Thereafter, we explored whether silk wrapping is a condition-dependent trait and drives female visual attraction. We exposed good and poor condition males, carrying a prey, to the female silk. Males in poor condition added less silk to the prey than males in good condition, indicating that gift wrapping is an indicator of male quality and may be used by females to acquire information of the potential mate.

  7. Predation risk causes oxidative damage in prey

    PubMed Central

    Janssens, Lizanne; Stoks, Robby

    2013-01-01

    While there is increasing interest in non-consumptive effects of predators on prey, physiological effects are understudied. While physiological stress responses play a crucial role in preparing escape responses, the increased metabolic rates and shunting of energy away from other body functions, including antioxidant defence, may generate costs in terms of increased oxidative stress. Here, we test whether predation risk increases oxidative damage in Enallagma cyathigerum damselfly larvae. Under predation risk, larvae showed higher lipid peroxidation, which was associated with lower levels of superoxide dismutase, a major antioxidant enzyme in insects, and higher superoxide anion concentrations, a potent reactive oxygen species. The mechanisms underlying oxidative damage are likely to be due to the shunting of energy away from antioxidant defence and to an increased metabolic rate, suggesting that the observed increased oxidative damage under predation risk may be widespread. Given the potentially severe fitness consequences of oxidative damage, this largely overlooked non-consumptive effect of predators may be contributing significantly to prey population dynamics. PMID:23760170

  8. Behavioral response races, predator-prey shell games, ecology of fear, and patch use of pumas and their ungulate prey.

    PubMed

    Laundré, John W

    2010-10-01

    The predator-prey shell game predicts random movement of prey across the landscape, whereas the behavioral response race and landscape of fear models predict that there should be a negative relationship between the spatial distribution of a predator and its behaviorally active prey. Additionally, prey have imperfect information on the whereabouts of their predator, which the predator should incorporate in its patch use strategy. I used a one-predator-one-prey system, puma (Puma concolor)-mule deer (Odocoileus hemionus) to test the following predictions regarding predator-prey distribution and patch use by the predator. (1) Pumas will spend more time in high prey risk/low prey use habitat types, while deer will spend their time in low-risk habitats. Pumas should (2) select large forage patches more often, (3) remain in large patches longer, and (4) revisit individual large patches more often than individual smaller ones. I tested these predictions with an extensive telemetry data set collected over 16 years in a study area of patchy forested habitat. When active, pumas spent significantly less time in open areas of low intrinsic predation risk than did deer. Pumas used large patches more than expected, revisited individual large patches significantly more often than smaller ones, and stayed significantly longer in larger patches than in smaller ones. The results supported the prediction of a negative relationship in the spatial distribution of a predator and its prey and indicated that the predator is incorporating the prey's imperfect information about its presence. These results indicate a behavioral complexity on the landscape scale that can have far-reaching impacts on predator-prey interactions. PMID:21058559

  9. Piscivore-prey fish interactions: mechanisms behind diurnal patterns in prey selectivity in brown and clear water.

    PubMed

    Ranåker, Lynn; Persson, Jens; Jönsson, Mikael; Nilsson, P Anders; Brönmark, Christer

    2014-01-01

    Environmental change may affect predator-prey interactions in lakes through deterioration of visual conditions affecting foraging success of visually oriented predators. Environmental change in lakes includes an increase in humic matter causing browner water and reduced visibility, affecting the behavioural performance of both piscivores and prey. We studied diurnal patterns of prey selection in piscivorous pikeperch (Sander lucioperca) in both field and laboratory investigations. In the field we estimated prey selectivity and prey availability during day and night in a clear and a brown water lake. Further, prey selectivity during day and night conditions was studied in the laboratory where we manipulated optical conditions (humic matter content) of the water. Here, we also studied the behaviours of piscivores and prey, focusing on foraging-cycle stages such as number of interests and attacks by the pikeperch as well as the escape distance of the prey fish species. Analyses of gut contents from the field study showed that pikeperch selected perch (Perca fluviatilis) over roach (Rutilus rutilus) prey in both lakes during the day, but changed selectivity towards roach in both lakes at night. These results were corroborated in the selectivity experiments along a brown-water gradient in day and night light conditions. However, a change in selectivity from perch to roach was observed when the optical condition was heavily degraded, from either brown-stained water or light intensity. At longer visual ranges, roach initiated escape at distances greater than pikeperch attack distances, whereas perch stayed inactive making pikeperch approach and attack at the closest range possible. Roach anti-predatory behaviour decreased in deteriorated visual conditions, altering selectivity patterns. Our results highlight the importance of investigating both predator and prey responses to visibility conditions in order to understand the effects of degrading optical conditions on piscivore-prey interaction strength and thereby ecosystem responses to brownification of waters. PMID:25379665

  10. Stonefly nymphs use hydrodynamic cues to discriminate between prey

    Microsoft Academic Search

    Barbara L. Peckarsky; R. Stimson Wilcox

    1989-01-01

    Playback experiments conducted in a Rocky Mountain, USA, stream determined whether predatory stonefly nymphs (Kogotus modestus; Plecoptera: PerlodiMae) used hydrodynamic cues to discriminate prey species from nonprey species. In the laboratory we recorded pressure wave patterns associated with swimming escape behavior of Baetis bicaudatus (Baetidae), the favored mayfly prey species, and those of a nonprey mayfly, Ephemerella infrequens (Ephemerellidae). We

  11. Prey bacteria shape the community structure of their predators.

    PubMed

    Chen, Huan; Athar, Rana; Zheng, Guili; Williams, Henry N

    2011-08-01

    Although predator-prey interactions among higher organisms have been studied extensively, only few examples are known for microbes other than protists and viruses. Among the bacteria, the most studied obligate predators are the Bdellovibrio and like organisms (BALOs) that prey on many other bacteria. In the macroscopical world, both predator and prey influence the population size of the other's community, and may have a role in selection. However, selective pressures among prey and predatory bacteria have been rarely investigated. In this study, Bacteriovorax, a predator within the group of BALOs, in environmental waters were fed two prey bacteria, Vibrio vulnificus and Vibrio parahaemolyticus. The two prey species yielded distinct Bacteriovorax populations, evidence that selective pressures shaped the predator community and diversity. The results of laboratory experiments confirmed the differential predation of Bacteriovorax phylotypes on the two bacteria species. Not only did Bacteriovorax Cluster IX exhibit the versatility to be the exclusive efficient predator on Vibrio vulnificus, thereby, behaving as a specialist, but was also able to prey with similar efficiency on Vibrio parahaemolyticus, indicative of a generalist. Therefore, we proposed a designation of versatilist for this predator. This initiative should provide a basis for further efforts to characterize the predatory patterns of bacterial predators. The results of this study have revealed impacts of the prey on Bacteriovorax predation and in structuring the predator community, and advanced understanding of predation behavior in the microbial world. PMID:21326335

  12. Unusual predator-prey dynamics under reciprocal phenotypic plasticity.

    PubMed

    Mougi, Akihiko

    2012-07-21

    Recent theories and experiments have shown that plasticity, such as an inducible defense or an inducible offense in predator-prey interactions, strongly influences the stability of the population dynamics. However, such plastic adaptation has not been expected to cause unusual dynamics such as antiphase cycles, which occur in experimental predator-prey systems with evolutionary adaptation in the defensive trait of prey. Here I show that antiphase cycles and cryptic cycles (a large population fluctuation in one species with almost no change in the population of the other species) can occur in a predator-prey system when both member species can change their phenotypes through adaptive plasticity (inducible defenses and offenses). I consider a familiar type of predator-prey system in which both species can change their morphology or behavior through phenotypic plasticity. The plasticity, that is, the ability to change between distinct phenotypes, is assumed to occur so as to maximize their fitness. I examined how the reciprocal adaptive plasticity influences the population dynamics. The results show that unusual dynamics such as antiphase population cycles and cryptic cycles can occur when both species show inducible plasticity. The unusual dynamics are particularly likely to occur when the carrying capacity of the prey is small (the density dependence of the prey's growth is strong). The unusual predator-prey dynamics may be induced by phenotypic plasticity as long as the phenotypic change occurs to maximize fitness. PMID:22575552

  13. An analysis of prey selection by Mesocyclops edax

    Microsoft Academic Search

    Anthony Janicki; John DeCosta

    1990-01-01

    The results of four laboratory experiments suggest that Mesocyclops edax selectively preyed upon Bosmina longirostris, given Daphnia parvula and Diaptomus pallidus as alternative prey. These results support an earlier hypothesis (DeCosta & Janicki, 1978) that M. edax may act as an important determinant of the crustacean plankton community structure in an acid lake devoid of planktivorous fishes.

  14. The impact on tigers of poaching versus prey depletion

    Microsoft Academic Search

    Guillaume Chapron; Dale G. Miquelle; Amaury Lambert; John M. Goodrich; Stéphane Legendre; Jean Clobert

    2008-01-01

    Summary 1. There exists a continuing dilemma in prioritizing conservation actions for large carnivores. Habitat loss, poaching, and prey depletion have often been cited as the three primary threats, but there is debate over the relative importance of each. 2. We assess the relative importance of poaching and prey depletion rates, and use existing information in the literature and multi-type

  15. Ambient temperature influences birds' decisions to eat toxic prey?

    PubMed Central

    Chatelain, M.; Halpin, C.G.; Rowe, C.

    2013-01-01

    Aposematic prey warn predators of their toxicity using conspicuous signals. However, predators regularly include aposematic prey in their diets, particularly when they are in a poor energetic state and in need of nutrients. We investigated whether or not an environmental factor, ambient temperature, could change the energetic state of predators and lead to an increased intake of prey that they know to contain toxins. We found that European starlings, Sturnus vulgaris, increased their consumption of mealworm, Tenebrio molitor, prey containing quinine (a mild toxin) when the ambient temperature was reduced below their thermoneutral zone from 20 °C to 6 °C. The birds differed in their sensitivity to changes in ambient temperature, with heavier birds increasing the number of toxic prey they ate more rapidly with decreasing temperature compared to birds with lower body mass. This could have been the result of their requiring more nutrients at lower temperatures or being better able to detoxify quinine. Taken together, our results suggest that conspicuous coloration may be more costly at lower temperatures, and that aposematic prey may need to invest more in chemical defences as temperatures decline. Our study also provides novel insights into what factors affect birds' decisions to eat toxic prey, and demonstrates that selection pressures acting on prey defences can vary with changing temperature across days, seasons, climes, and potentially in response to climate change. PMID:24109148

  16. Uniform persistence for sigmoidal diet selection with keystone prey species.

    PubMed

    Sikder, A

    2000-07-01

    In this paper we discuss uniform persistence (UP) criteria of two prey- one predator systems, where we consider that the predator's diet selection is a sigmoidal function of the most profitable prey type in place of a step function of conventional diet choice theory. We also derive UP results of the system with direct interspecific competition between the prey. The role of the most profitable prey item as a keystone species, the magnitude of its carrying capacity, the ability to withstand predation of both prey species, and the ratios of their profitability values (to predators) are important to whether or not adaptive foraging may promote UP. In general, foraging decision rules play no role in UP if the alternative prey item is the keystone species. The result is also not affected by the effect of direct competitive coexistence or dominance relationship of the prey. In some cases, dominance of one of the prey species provides the most advantageous situation for ensuring UP. PMID:10958414

  17. Dietary shifts of sympatric buteos during a prey decline

    Microsoft Academic Search

    K. Steenhof; M. N. Kochert

    1985-01-01

    Diets of nesting Red-tailed Hawks (Buteo jamaicensis) and Ferruginous Hawks (Buteo regalis) were sampled before and after a decline in the hawks' principal prey species. Diets of pairs that shared their foraging ranges with interspecifics were contrasted with those of pairs whose home ranges did not overlap with interspecifics. Current theory predicts that diets should diverge during prey shortages and

  18. Relaxation oscillations in a class of predator–prey systems

    Microsoft Academic Search

    Weishi Liu; Dongmei Xiao; Yingfei Yi

    2003-01-01

    We consider a class of three-dimensional, singularly perturbed predator–prey systems having two predators competing exploitatively for the same prey in a constant environment. By using dynamical systems techniques and the geometric singular perturbation theory, we give precise conditions which guarantee the existence of stable relaxation oscillations for systems within the class. Such result shows the coexistence of the predators and

  19. RELAXATION OSCILLATIONS IN A CLASS OF PREDATOR-PREY SYSTEMS

    Microsoft Academic Search

    Weishi Liu

    Abstract. We consider a class of three dimensional, singularly perturbed predator-prey systems having two predators competing exploitatively for the same prey in a constant environment. By using dynamical systems techniques and the geometric singular perturbation theory, we give precise conditions which guarantee the existence of stable relaxation oscillations for systems within the class. Such result shows the coexistence of the

  20. Dynamics and Equilibria of Ecological Predator-Prey Networks

    E-print Network

    Nagurney, Anna

    Dynamics and Equilibria of Ecological Predator-Prey Networks as Nature's Supply Chains Anna, Connecticut 06117 58th Annual North American Meetings of the Regional Science Association International Miami, Florida, November 9-12, 2011 Anna and Ladimer S. Nagurney Ecological Predator-Prey Networks #12

  1. PATTERNS OF TEMPORAL VARIATION IN GOSHAWK REPRODUCTION AND PREY RESOURCES

    Microsoft Academic Search

    SUSAN R. SALAFSKY; RICHARD T. R EYNOLDS; BARRY R. NOON

    To investigate whether Northern Goshawk (Accipiter gentilis) reproduction is food-limited, we evaluated the reproductive output from 401 goshawk breeding opportunities on the Kaibab Plateau, Arizona during 1999-2002. Concurrently, we estimated densities of 10 goshawk prey species (seven birds, three mammals) using distance sampling. We then assessed the relationship between goshawk produc- tivity (number of fledglings produced) and prey density within

  2. Coexisting glomerular IgA deposition and IgG-kappa multiple myeloma.

    PubMed

    Wang, Feng; Xing, Tao; Li, Junhui; Zhang, Zhi-Gang; Wang, Niansong

    2014-09-01

    Multiple myeloma (MM) is a common malignancy that often results in many kinds of kidney injuries for the abnormal monoclonal immunoglobulin. Here, we present an IgG-kappa type MM case accompanied by renal IgA deposition combined with IgG-kappa. The patient was treated with prednisone plus mycophenolate mofetil, and got a satisfactory remission. Although it cannot be determined whether the IgA deposition was secondary to MM, this was the first report of coexisting mesangial proliferative nephritis with IgA deposition and IgG-kappa type MM. PMID:24958510

  3. IgE-binding epitopes: a reappraisal.

    PubMed

    Aalberse, R C; Crameri, R

    2011-10-01

    Here, we discuss various questions related to IgE epitopes: What are the technical possibilities and pitfalls, what is currently known, how can we put this information into hypothetical frameworks and the unavoidable question: how useful is this information for patient care or allergenicity prediction? We discuss the information obtained by (i) 3D structures of allergen-antibody complexes; (ii) analysis of allergen analogues; (iii) mimics without obvious structural similarity; (iv) mAbs competing with IgE; (v) repertoire analysis of cloned IgEs, and other developments. Based on limited data, four suggestions are presented in the literature: (i) IgE might be more cross-reactive than IgG; (ii) IgE might be more often directed to immunologically 'uninviting' surfaces; (iii) IgE epitopes may tend to cluster and (iv) IgE paratopes might have a higher intrinsic flexibility. While these are not proven facts, they still can generate hypotheses for future research. The hypothesis is put forward that the IgE repertoire of switched B-cells is less influenced by positive selection, because positive selection might not be able to rescue IgE-switched B cells. While this might be of interest for the discussion about mechanisms leading to allergen-sensitization, we need to be modest in answering the 'clinical relevance' question. Current evidence indicates the IgE-epitope repertoire is too big to make specific IgE epitopes a realistic target for diagnosis, treatment or allergenicity prediction. In-depth analysis of a few selected IgE epitope-peptides or mimitopes derived from allergen-sequences and from random peptide libraries, respectively, might well prove rewarding in relation to diagnosis and prognosis of allergy, particularly food allergy. PMID:21623828

  4. Effects of aerobic conditioning on salivary IgA and plasma IgA, IgG and IgM in older men and women.

    PubMed

    Martins, R A; Cunha, M R; Neves, A P; Martins, M; Teixeira-Veríssimo, M; Teixeira, A M

    2009-12-01

    As people age, they experience a decline in immune responses. Unusually heavy acute or chronic exercise could increase the risk of upper respiratory tract infection (URTI) whereas regular moderate physical activity may reduce URTI symptomatology. The purpose of the present study was to determine whether an aerobic exercise program would promote chronic adaptations in plasma IgA, IgG and IgM, and salivary IgA (Sal-IgA) in both elderly women and men. Forty-three independently living men and women, aged between 65 and 96 years, were randomly assigned to an aerobic exercising or a control group. Each participant underwent three evaluations (pre, post at 16 weeks and follow-up at 32 weeks). The aerobic exercise group increased resting plasma IgA concentration from 1.08 g. L (-1)+/-0.50 g. L (-1) to 2.29 g. L (-1)+/-0.93 g. L (-1), whereas salivary IgA concentration was unchanged. The control group maintained the plasma IgA values but experienced a decrease in Sal-IgA. The IgG and IgM plasma concentrations increased in both groups, however, only the exercise group maintained higher values in the final follow-up evaluation. Regular aerobic exercise may be effective in promoting IgA immunity and protecting against the deterioration in Sal-IgA values observed in the control group. No gender differences in the immunoglobulin responses to aerobic training were observed. PMID:19941250

  5. Birth Timing for Mountain Lions (Puma concolor); Testing the Prey Availability Hypothesis

    PubMed Central

    Jansen, Brian D.; Jenks, Jonathan A.

    2012-01-01

    We investigated potential advantages in birth timing for mountain lion (Puma concolor) cubs. We examined cub body mass, survival, and age of natal dispersal in relation to specific timing of birth. We also investigated the role of maternal age relative to timing of births. We captured mountain lion cubs while in the natal den to determine birth date, which allowed for precise estimates of the population birth pulse and age of natal dispersal. A birth pulse occurred during June–August. Body mass of cubs was related to litter size and timing of birth; heaviest cubs occurred in litters of 2, and those born after 1 July. Cubs born within pulse months exhibited similar survival to those born out of the pulse. We found that cubs born April–June dispersed at younger ages than those born after 1 July. There was less variation in birth timing for 1st litters of females than older females. We hypothesize that cubs born after the peak in births of neonate prey are advantaged by the abundance of vulnerable prey and those cubs and mothers realize an evolutionary advantage. PMID:23028569

  6. An Overlapping Case of Lupus Nephritis and IgG4-Related Kidney Disease

    PubMed Central

    Zaarour, Mazen; Weerasinghe, Chanudi; Eter, Ahmad; El-Sayegh, Suzanne; El-Charabaty, Elie

    2015-01-01

    We report a case of a 71-year-old Filipino female who was admitted to the hospital for abdominal pain, vomiting and diarrhea of 8 days duration. The patient was found to have marked acute kidney injury (AKI), which required hemodialysis in the next 3 days. Extensive workup revealed hematuria, subnephrotic range proteinuria, elevated anti-nuclear antibody (ANA) and elevated total immunoglobulin G (IgG) levels, with normal IgG4 and anti-dsDNA levels. On kidney biopsy, mild membranous glomerulonephritis was found, along with autoimmune tubulointerstitial nephritis (TIN) with a “full-house” pattern of immune deposits. These findings were suggestive of lupus interstitial nephritis. However, IgG4+ plasma cells were detected in the interstitium by immunostaining, favoring a diagnosis of IgG4-related kidney disease (IgG4-RKD). Our case highlights the difficulty in differentiating lupus nephritis (LN) from IgG4-RKD in some patients, raising the suspicion that these two entities can co-exist. PMID:26015827

  7. An Overlapping Case of Lupus Nephritis and IgG4-Related Kidney Disease.

    PubMed

    Zaarour, Mazen; Weerasinghe, Chanudi; Eter, Ahmad; El-Sayegh, Suzanne; El-Charabaty, Elie

    2015-07-01

    We report a case of a 71-year-old Filipino female who was admitted to the hospital for abdominal pain, vomiting and diarrhea of 8 days duration. The patient was found to have marked acute kidney injury (AKI), which required hemodialysis in the next 3 days. Extensive workup revealed hematuria, subnephrotic range proteinuria, elevated anti-nuclear antibody (ANA) and elevated total immunoglobulin G (IgG) levels, with normal IgG4 and anti-dsDNA levels. On kidney biopsy, mild membranous glomerulonephritis was found, along with autoimmune tubulointerstitial nephritis (TIN) with a "full-house" pattern of immune deposits. These findings were suggestive of lupus interstitial nephritis. However, IgG4+ plasma cells were detected in the interstitium by immunostaining, favoring a diagnosis of IgG4-related kidney disease (IgG4-RKD). Our case highlights the difficulty in differentiating lupus nephritis (LN) from IgG4-RKD in some patients, raising the suspicion that these two entities can co-exist. PMID:26015827

  8. Mesangial IgA deposits indicate pathogenesis of anti-glomerular basement membrane disease.

    PubMed

    Wang, Aifeng; Wang, Yongping; Wang, Guobao; Zhou, Zhanmei; Xun, Zhang; Tan, Xiaohui

    2012-05-01

    Anti-glomerular basement membrane (anti-GBM) disease is characterized by crescentic glomerulonephritis with immunoglobulin G (IgG) autoantibodies to the non-collagenous (NC1) domain of ?3(IV) collagen presenting along the GBM. The patient clinically manifests with rapidly progressive glomerulonephritis (RPGN) with pulmonary hemorrhage (Goodpasture syndrome). In rare cases, other immunocomplexes of IgA or IgM are involved, but their specificities have not been determined. We report a rare case of a 31-year-old female who was diagnosed as having anti-GBM disease with extensive IgA deposits in the mesangium. This patient presented heavy hematuria, proteinuria with increasing creatinine, but no lung hemorrhage. Renal biopsy showed crescentic glomerulonephritis (type ?) with strong IgA (3+) as lump and branch shape. Therapies with pulse methylprednisolone, plasmapheresis and cyclophosphamide administration were less effective. This case is different from the present type ? crescentic glomerulonephritis and the specificity of IgA deposits may implicate the pathogenesis of anti-GBM disease. PMID:22366925

  9. IgG4-Related Disease without Overexpression of IgG4: Pathogenesis Implications.

    PubMed

    Nishina, Naoshi; Kaneko, Yuko; Kuwana, Masataka; Hanaoka, Hironari; Kameda, Hideto; Mikami, Shuji; Takeuchi, Tsutomu

    2012-01-01

    IgG4-related disease is a new disease group that affects multiple organs. It is characterized by high serum IgG4 and abundant infiltration of IgG4-bearing plasma cells in the affected organ. Here, we describe an intriguing case that suggested that IgG4-related disease might present without IgG4 overexpression or infiltration, at least during a relapse. A 47-year-old man had been diagnosed with systemic lupus erythematosus 15 years. He was admitted due to a pituitary mass, systemic lymphadenopathy, and multiple nodules in the lungs and kidneys. The serum IgG4 level was normal and histopathological examination of the pituitary mass showed abundant lymphocyte and plasma cell infiltration with very few IgG4-positive cells. When we examined specimens preserved from 15 years ago, we found high serum IgG4 levels and IgG4-bearing plasma cell infiltration. This resulted in a diagnosis of IgG4-related disease, and we considered the current episode to be a relapse without IgG4 overexpression. This case indicated that, to clarify the pathogenesis of IgG4-related disease, current cases should repeat specimen evaluations over the course of IgG4-related disease to define diagnostic markers. PMID:22937457

  10. Modelling the effects of prey size and distribution on prey capture rates of two sympatric marine predators.

    PubMed

    Thaxter, Chris B; Daunt, Francis; Grémillet, David; Harris, Mike P; Benvenuti, Silvano; Watanuki, Yutaka; Hamer, Keith C; Wanless, Sarah

    2013-01-01

    Understanding how prey capture rates are influenced by feeding ecology and environmental conditions is fundamental to assessing anthropogenic impacts on marine higher predators. We compared how prey capture rates varied in relation to prey size, prey patch distribution and prey density for two species of alcid, common guillemot (Uria aalge) and razorbill (Alca torda) during the chick-rearing period. We developed a Monte Carlo approach parameterised with foraging behaviour from bird-borne data loggers, observations of prey fed to chicks, and adult diet from water-offloading, to construct a bio-energetics model. Our primary goal was to estimate prey capture rates, and a secondary aim was to test responses to a set of biologically plausible environmental scenarios. Estimated prey capture rates were 1.5 ± 0.8 items per dive (0.8 ± 0.4 and 1.1 ± 0.6 items per minute foraging and underwater, respectively) for guillemots and 3.7 ± 2.4 items per dive (4.9 ± 3.1 and 7.3 ± 4.0 items per minute foraging and underwater, respectively) for razorbills. Based on species' ecology, diet and flight costs, we predicted that razorbills would be more sensitive to decreases in 0-group sandeel (Ammodytes marinus) length (prediction 1), but guillemots would be more sensitive to prey patches that were more widely spaced (prediction 2), and lower in prey density (prediction 3). Estimated prey capture rates increased non-linearly as 0-group sandeel length declined, with the slope being steeper in razorbills, supporting prediction 1. When prey patches were more dispersed, estimated daily energy expenditure increased by a factor of 3.0 for guillemots and 2.3 for razorbills, suggesting guillemots were more sensitive to patchier prey, supporting prediction 2. However, both species responded similarly to reduced prey density (guillemot expenditure increased by 1.7; razorbill by 1.6), thus not supporting prediction 3. This bio-energetics approach complements other foraging models in predicting likely impacts of environmental change on marine higher predators dependent on species-specific foraging ecologies. PMID:24260318

  11. Modelling the Effects of Prey Size and Distribution on Prey Capture Rates of Two Sympatric Marine Predators

    PubMed Central

    Thaxter, Chris B.; Daunt, Francis; Grémillet, David; Harris, Mike P.; Benvenuti, Silvano; Watanuki, Yutaka; Hamer, Keith C.; Wanless, Sarah

    2013-01-01

    Understanding how prey capture rates are influenced by feeding ecology and environmental conditions is fundamental to assessing anthropogenic impacts on marine higher predators. We compared how prey capture rates varied in relation to prey size, prey patch distribution and prey density for two species of alcid, common guillemot (Uria aalge) and razorbill (Alca torda) during the chick-rearing period. We developed a Monte Carlo approach parameterised with foraging behaviour from bird-borne data loggers, observations of prey fed to chicks, and adult diet from water-offloading, to construct a bio-energetics model. Our primary goal was to estimate prey capture rates, and a secondary aim was to test responses to a set of biologically plausible environmental scenarios. Estimated prey capture rates were 1.5±0.8 items per dive (0.8±0.4 and 1.1±0.6 items per minute foraging and underwater, respectively) for guillemots and 3.7±2.4 items per dive (4.9±3.1 and 7.3±4.0 items per minute foraging and underwater, respectively) for razorbills. Based on species' ecology, diet and flight costs, we predicted that razorbills would be more sensitive to decreases in 0-group sandeel (Ammodytes marinus) length (prediction 1), but guillemots would be more sensitive to prey patches that were more widely spaced (prediction 2), and lower in prey density (prediction 3). Estimated prey capture rates increased non-linearly as 0-group sandeel length declined, with the slope being steeper in razorbills, supporting prediction 1. When prey patches were more dispersed, estimated daily energy expenditure increased by a factor of 3.0 for guillemots and 2.3 for razorbills, suggesting guillemots were more sensitive to patchier prey, supporting prediction 2. However, both species responded similarly to reduced prey density (guillemot expenditure increased by 1.7; razorbill by 1.6), thus not supporting prediction 3. This bio-energetics approach complements other foraging models in predicting likely impacts of environmental change on marine higher predators dependent on species-specific foraging ecologies. PMID:24260318

  12. Predator-induced changes of female mating preferences: innate and experiential effects

    PubMed Central

    2011-01-01

    Background In many species males face a higher predation risk than females because males display elaborate traits that evolved under sexual selection, which may attract not only females but also predators. Females are, therefore, predicted to avoid such conspicuous males under predation risk. The present study was designed to investigate predator-induced changes of female mating preferences in Atlantic mollies (Poecilia mexicana). Males of this species show a pronounced polymorphism in body size and coloration, and females prefer large, colorful males in the absence of predators. Results In dichotomous choice tests predator-naïve (lab-reared) females altered their initial preference for larger males in the presence of the cichlid Cichlasoma salvini, a natural predator of P. mexicana, and preferred small males instead. This effect was considerably weaker when females were confronted visually with the non-piscivorous cichlid Vieja bifasciata or the introduced non-piscivorous Nile tilapia (Oreochromis niloticus). In contrast, predator experienced (wild-caught) females did not respond to the same extent to the presence of a predator, most likely due to a learned ability to evaluate their predators' motivation to prey. Conclusions Our study highlights that (a) predatory fish can have a profound influence on the expression of mating preferences of their prey (thus potentially affecting the strength of sexual selection), and females may alter their mate choice behavior strategically to reduce their own exposure to predators. (b) Prey species can evolve visual predator recognition mechanisms and alter their mate choice only when a natural predator is present. (c) Finally, experiential effects can play an important role, and prey species may learn to evaluate the motivational state of their predators. PMID:21726456

  13. Present and Future IGS Ionospheric Products

    NASA Astrophysics Data System (ADS)

    Krankowski, Andrzej; Wielgosz, Pawel; Hernández-Pajares, Manuel; García-Rigo, Alberto

    2010-05-01

    The purpose of this paper is, on one hand, to show the present performance of the combined final and rapid IGS global ionosphere maps (GIMs), and on the other hand to inform the geodetic community on new product - predicted IGS GIMs. In addition, information on future development of IGS ionospheric products will be also presented. Nowadays, the Ionosphere Working Group of IGS generates three types of ionospheric products: final, rapid and predicted, respectively. There are currently four IGS Associate Analysis Centres (IAACs) for the ionospheric products: CODE (Center for Orbit Determination in Europe, University of Berne, Switzerland), ESA/ESOC (European Space Operations Center of ESA, Darmstadt, Germany), JPL (Jet Propulsion Laboratory, Pasadena, U.S.A) and gAGE/UPC (Technical University of Catalonia, Barcelona, Spain). These centres provide ionosphere maps computed with different approaches. Their maps are uploaded to IGS Ionosphere Product Coordinator, who computes official IGS combined products. Since January 2008, this coordination is carried out by the GRL/UWM (Geodynamics Research Laboratory of the University of Warmia and Mazury in Olsztyn, Poland). The IGS GIMs are provided in Ionosphere Exchange (IONEX) format with spatial resolution of 5.0 degrees in longitude and 2.5 degrees in latitude, and temporal resolution of 2 hours. Latency of the final and rapid GIMs is 10 days and 1 day, respectively. In November 2009, the IGS Iono WG started to generate predicted ionospheric products 1 and 2 days in advance (requested for ESA's SMOS mission). These new IGS products are currently based on predicted ionosphere maps prepared by UPC and ESA. During period of more than 10 years of continuous IGS ionosphere operation, the techniques used by the IAACs and the strategies of combination have improved in such a way that the combined IGS GIMs are now significantly more accurate and robust. Future plans include, among others, increasing temporal resolution to 1 hour and studies on taking advantage of COSMIC occultation data.

  14. Competing conservation objectives for predators and prey: estimating killer whale prey requirements for Chinook salmon.

    PubMed

    Williams, Rob; Krkošek, Martin; Ashe, Erin; Branch, Trevor A; Clark, Steve; Hammond, Philip S; Hoyt, Erich; Noren, Dawn P; Rosen, David; Winship, Arliss

    2011-01-01

    Ecosystem-based management (EBM) of marine resources attempts to conserve interacting species. In contrast to single-species fisheries management, EBM aims to identify and resolve conflicting objectives for different species. Such a conflict may be emerging in the northeastern Pacific for southern resident killer whales (Orcinus orca) and their primary prey, Chinook salmon (Oncorhynchus tshawytscha). Both species have at-risk conservation status and transboundary (Canada-US) ranges. We modeled individual killer whale prey requirements from feeding and growth records of captive killer whales and morphometric data from historic live-capture fishery and whaling records worldwide. The models, combined with caloric value of salmon, and demographic and diet data for wild killer whales, allow us to predict salmon quantities needed to maintain and recover this killer whale population, which numbered 87 individuals in 2009. Our analyses provide new information on cost of lactation and new parameter estimates for other killer whale populations globally. Prey requirements of southern resident killer whales are difficult to reconcile with fisheries and conservation objectives for Chinook salmon, because the number of fish required is large relative to annual returns and fishery catches. For instance, a U.S. recovery goal (2.3% annual population growth of killer whales over 28 years) implies a 75% increase in energetic requirements. Reducing salmon fisheries may serve as a temporary mitigation measure to allow time for management actions to improve salmon productivity to take effect. As ecosystem-based fishery management becomes more prevalent, trade-offs between conservation objectives for predators and prey will become increasingly necessary. Our approach offers scenarios to compare relative influence of various sources of uncertainty on the resulting consumption estimates to prioritise future research efforts, and a general approach for assessing the extent of conflict between conservation objectives for threatened or protected wildlife where the interaction between affected species can be quantified. PMID:22096495

  15. IgG4-Related Esophageal Disease Presenting as Esophagitis Dissecans Superficialis With Chronic Strictures.

    PubMed

    Dumas-Campagna, Myriam; Bouchard, Simon; Soucy, Genevieve; Bouin, Mickael

    2014-08-01

    IgG4-related disease is a recently recognized autoimmune systemic disorder that has been described in various organs. The disease is characterized histologically by a dense lymphoplasmocytic infiltrate of IgG4-positive cells, storiform fibrosis and can be associated with tumefactive lesions. IgG4-related disease involving the upper gastrointestinal tract is rare and only two previous case reports have reported IgG4-related esophageal disease. We report the case of a 63-year-old female patient with a long-standing history of severe dysphagia and odynophagia with an initial diagnosis of reflux esophagitis. Symptoms persisted despite anti-acid therapy and control esophagogastroduodenoscopy (EGD) revealed endoscopic images consistent with esophagitis dissecans superficialis (sloughing esophagitis). An underlying autoimmune process was suspected and immunosuppressant agents were tried to control her disease. The patient eventually developed disabling dysphagia secondary to multiple chronic esophageal strictures. A diagnosis of IgG4-related disease was eventually made after reviewing esophageal biopsies and performing an immunohistochemical study with an anti-IgG4 antibody. Treatment attempts with corticosteroids and rituximab was not associated with a significant improvement of the symptoms of dysphagia and odynophagia, possibly because of the chronic nature of the disease associated with a high fibrotic component. Our case report describes this unique case of IgG4-related esophageal disease presenting as chronic esophagitis dissecans with strictures. We also briefly review the main histopathological features and treatment options in IgG4-related disease. PMID:24883156

  16. Organ Correlation in IgG4-Related Diseases.

    PubMed

    Koizumi, Satomi; Kamisawa, Terumi; Kuruma, Sawako; Tabata, Taku; Chiba, Kazuro; Iwasaki, Susumu; Kuwata, Go; Fujiwara, Takashi; Fujiwara, Junko; Arakawa, Takeo; Koizumi, Koichi; Momma, Kumiko

    2015-06-01

    IgG4-related disease (IgG4-RD) is a potentially multiorgan disorder. In this study, clinical and serological features from 132 IgG4-RD patients were compared about organ correlations. Underlying pathologies comprised autoimmune pancreatitis (AIP) in 85 cases, IgG4-related sclerosing cholangitis (IgG4-SC) in 12, IgG4-related sialadenitis (IgG4-SIA) in 56, IgG4-related dacryoadenitis (IgG4-DAC) in 38, IgG4-related lymphadenopathy (IgG4-LYM) in 20, IgG4-related retroperitoneal fibrosis (IgG4-RF) in 19, IgG4-related kidney disease (IgG4-KD) in 6, IgG4-related pseudotumor (IgG4-PT) in 3. Sixty-five patients (49%) had multiple IgG4-RD (two affected organs in 36 patients, three in 19, four in 8, five in 1, and six in 1). Serum IgG4 levels were significantly higher with multiple lesions than with a single lesion (P<0.001). The proportion of association with other IgG4-RD was 42% in AIP, the lowest of all IgG4-RDs. Serum IgG4 level was lower in AIP than in other IgG4-RDs. Frequently associated IgG4-RDs were SIA (25%) and DAC (12%) for AIP; AIP (75%) for IgG4-SC; DAC (57%), AIP (38%) and LYM (27%) for IgG4-SIA; AIP (26%) and LYM (26%) for IgG4-DAC; SIA (75%), DAC (50%) and AIP (45%) for IgG4-LYM; SIA (58%), AIP (42%) and LYM (32%) for IgG4-RF; AIP (100%) and SIA (67%) for IgG4-KID; and DAC (67%) and SIA (67%) for IgG4-PT. Most associated IgG4-RD lesions were diagnosed simultaneously, but IgG4-SIA and IgG4-DAC were sometimes identified before other lesions. About half of IgG4-RD patients had multiple IgG4-RD lesions, and some associations were seen between specific organs. PMID:26028927

  17. [Parasites of Austrian birds of prey (Falconiformes)].

    PubMed

    Kutzer, E; Frey, H; Kotremba, J

    1980-11-01

    During the examination of 158 birds of prey -- Buteo buteo (85), Falco tinnunculus (30), Accipiter gentilis (19), Accipiter nisus (18), Circus aeruginosus (2), Circus pygargus (1), Pandion haliaetus (1), Pernis apivorus (1), Falco subbuteo (1) and faeces samples of Falco tinnunculus 4 protozoan species, 1 trematode species, 2 cestode species, 13 nematode species, 2 acanthocephalan species and 5 mallophaga species could be detected. In the buzzard, kestrel and goshawk a new species of Capillaria could be found and described as Eucoleus suppereri spec. nov. A new species of Synhimantus, Synhimantus (Dispharynx) falconis spec. nov. was diagnosed. The infestation frequency of endo- and ectoparasites was relatively high, whereas the infestation intensity was small or mediocre on an average. The highest rate of infestation was found with trematodes and cestodes. The significance of the analysis of crop- and stomach-cntents as a guarantee of diagnosis "psuedoparasitism" was pointed out. PMID:7212374

  18. Chemotaxis by Bdellovibrio bacteriovorus toward prey.

    PubMed Central

    Straley, S C; Conti, S F

    1977-01-01

    A chemotaxis assay system that uses a modified Boyden chamber was characterized and used for measurements of chemotaxis by Bdellovibrio bacteriovorus strain UKi2 toward several bacterial species. Bacteria tested included both susceptible and nonsusceptible cells (Escherichia coli, Pseudomonas fluorescens, Bacillus megaterium, and B. bacteriovorus strains UKi2 and D). None was attractive to bdellovibrios when present at densities below 10(7) cells per ml. Chemotaxis toward E. coli was studied most extensively; under conditions that minimized effects of osmotic shock to the cells, E. coli and exudates from E. coli at densities as high as 10(8) cells per ml failed to elicit a chemotactic response. Cell-free filtrates from mixed cultures of bdellovibrios and E. coli neither attracted nor repelled bdellovibrios. The data indicate that bdellovibrios do not use chemotaxis to locate prey cells. PMID:410796

  19. Specific IgG subclasses in pollinosis.

    PubMed

    García, B E; Sanz, M L; Diéguez, I; de las Marinas, M D; Oehling, A

    1992-01-01

    We studied IgG subclasses in pollinosis in order to determine the possible immunopathological role of these antibodies, especially antigen-specific IgG4. The selection of pollinosic patients allowed us to observe the influence natural antigenic exposure exerts upon antibodies. On the other hand, we intended to study the possible modifications immunotherapy produces on IgG subclasses. For this purpose, we selected 266 patients who were classified into the following groups: Group I, 65 patients without immunotherapy, 35 of whom were studied during the pollen season and 30 outside the pollen season; Group II, 40 nonpollinosic patients with hypersensitization to Dermatophagoides pteronyssinus were taken as atopic controls; Group III, 161 pollinosic patients with from 3 to 42 months of immunotherapy. For every patient, IgG1, IgG2 and IgG3 against Phleum pratense were determined by means of ELAST (Leti), and IgG4 against the same allergen by means of the ELISA technique developed by us. Our results confirm, first, that untreated pollinosic patients present higher concentrations of IgG4 against Phleum than nonpollinosic patients, and second, that immunotherapy produces significant modifications in the production of antigen-specific IgG. PMID:1342913

  20. IgG and IgM Antibodies to Rubella Quantitated by Enzyme Immunoassay

    Microsoft Academic Search

    Roy B. Johnson Jr; Fred C. Jensen; Christopher R. Peter; Robert M. Nakamura

    1982-01-01

    A solid-phase enzyme immunoassay for rubella antibodies (of IgG, H & L type, IgM-type) is described that requires assay at usually one dilution of serum. Results are reportable in milligrams IgG (or IgM) - equivalents per liter serum and in approximate hemagglutination inhibition (HAI) titers. The method uses purified rubella virus immobilized by a special process in excess, a 16

  1. Experimental evolution of a microbial predator's ability to find prey

    PubMed Central

    Hillesland, Kristina L.; Velicer, Gregory J.; Lenski, Richard E.

    2008-01-01

    Foraging theory seeks to explain how the distribution and abundance of prey influence the evolution of predatory behaviour, including the allocation of effort to searching for prey and handling them after they are found. While experiments have shown that many predators alter their behaviour phenotypically within individual lifetimes, few have examined the actual evolution of predatory behaviour in light of this theory. Here, we test the effects of prey density on the evolution of a predator's searching and handling behaviours using a bacterial predator, Myxococcus xanthus. Sixteen predator populations evolved for almost a year on agar surfaces containing patches of Escherichia coli prey at low or high density. Improvements in searching rate were significantly greater in those predators that evolved at low prey density. Handling performance also improved in some predator populations, but prey density did not significantly affect the magnitude of these gains. As the predators evolved greater foraging proficiency, their capacity diminished to produce fruiting bodies that enable them to survive prolonged periods of starvation. More generally, these results demonstrate that predators evolve behaviours that reflect at least some of the opportunities and limitations imposed by the distribution and abundance of their prey. PMID:18832061

  2. Predator pursuit strategies: how do falcons and hawks chase prey?

    NASA Astrophysics Data System (ADS)

    Kane, Suzanne Amador; Zamani, Marjon; Fulton, Andrew; Rosenthal, Lee

    2014-03-01

    This study reports on experiments on falcons, goshawks and red-tailed hawks wearing miniature videocameras mounted on their backs or heads while pursuing flying or ground-based prey. Videos of hunts recorded by the raptors were analyzed to determine apparent prey positions on their visual fields during pursuits. These video data then were interpreted using computer simulations of pursuit steering laws observed in insects and mammals. A comparison of the empirical and modeling data indicates that falcons use cues due to the apparent motion of prey on the falcon's visual field to track and capture flying prey via a form of motion camouflage. The falcons also were found to maintain their prey's image at visual angles consistent with using their shallow fovea. Results for goshawks and red-tailed hawks were analyzed for a comparative study of how pursuits of ground-based prey by accipeters and buteos differ from those used by falcons chasing flying prey. These results should prove relevant for understanding the coevolution of pursuit and evasion, as well as the development of computer models of predation on flocks,and the integration of sensory and locomotion systems in biomimetic robots.

  3. Tactile experience shapes prey-capture behavior in Etruscan shrews

    PubMed Central

    Anjum, Farzana; Brecht, Michael

    2012-01-01

    A crucial role of tactile experience for the maturation of neural response properties in the somatosensory system is well established, but little is known about the role of tactile experience in the development of tactile behaviors. Here we study how tactile experience affects prey capture behavior in Etruscan shrews, Suncus etruscus. Prey capture in adult shrews is a high-speed behavior that relies on precise attacks guided by tactile Gestalt cues. We studied the role of tactile experience by three different approaches. First, we analyzed the hunting skills of young shrews' right after weaning. We found that prey capture in young animals in most, but not all, aspects is similar to that of adults. Second, we performed whisker trimming for 3–4 weeks after birth. Such deprivation resulted in a lasting disruption of prey capture even after whisker re-growth: attacks lacked precise targeting and had a lower success rate. Third, we presented adult shrews with an entirely novel prey species, the giant cockroach. The shape of this roach is very different from the shrew's normal (cricket) prey and the thorax—the preferred point of attack in crickets—is protected by a heavy cuticle. Initially shrews attacked giant roaches the same way they attack crickets and targeted the thoracic region. With progressive experience, however, shrews adopted a new attack strategy targeting legs and underside of the roaches while avoiding other body parts. Speed and efficiency of attacks improved. These data suggest that tactile experience shapes prey capture behavior. PMID:22701408

  4. Social Familiarity Governs Prey Patch-Exploitation, - Leaving and Inter-Patch Distribution of the Group-Living Predatory Mite Phytoseiulus persimilis

    PubMed Central

    Zach, Gernot J.; Peneder, Stefan; Strodl, Markus A.; Schausberger, Peter

    2012-01-01

    Background In group-living animals, social interactions and their effects on other life activities such as foraging are commonly determined by discrimination among group members. Accordingly, many group-living species evolved sophisticated social recognition abilities such as the ability to recognize familiar individuals, i.e. individuals encountered before. Social familiarity may affect within-group interactions and between-group movements. In environments with patchily distributed prey, group-living predators must repeatedly decide whether to stay with the group in a given prey patch or to leave and search for new prey patches and groups. Methodology/Principal Findings Based on the assumption that in group-living animals social familiarity allows to optimize the performance in other tasks, as for example predicted by limited attention theory, we assessed the influence of social familiarity on prey patch exploitation, patch-leaving, and inter-patch distribution of the group-living, plant-inhabiting predatory mite Phytoseiulus persimilis. P. persimilis is highly specialized on herbivorous spider mite prey such as the two-spotted spider mite Tetranychus urticae, which is patchily distributed on its host plants. We conducted two experiments with (1) groups of juvenile P. persimilis under limited food on interconnected detached leaflets, and (2) groups of adult P. persimilis females under limited food on whole plants. Familiar individuals of both juvenile and adult predator groups were more exploratory and dispersed earlier from a given spider mite patch, occupied more leaves and depleted prey more quickly than individuals of unfamiliar groups. Moreover, familiar juvenile predators had higher survival chances than unfamiliar juveniles. Conclusions/Significance We argue that patch-exploitation and -leaving, and inter-patch dispersion were more favorably coordinated in groups of familiar than unfamiliar predators, alleviating intraspecific competition and improving prey utilization and suppression. PMID:22900062

  5. Identification of Prey Captures in Australian Fur Seals (Arctocephalus pusillus doriferus) Using Head-Mounted Accelerometers: Field Validation with Animal-Borne Video Cameras

    PubMed Central

    Volpov, Beth L.; Hoskins, Andrew J.; Battaile, Brian C.; Viviant, Morgane; Wheatley, Kathryn E.; Marshall, Greg; Abernathy, Kyler; Arnould, John P. Y.

    2015-01-01

    This study investigated prey captures in free-ranging adult female Australian fur seals (Arctocephalus pusillus doriferus) using head-mounted 3-axis accelerometers and animal-borne video cameras. Acceleration data was used to identify individual attempted prey captures (APC), and video data were used to independently verify APC and prey types. Results demonstrated that head-mounted accelerometers could detect individual APC but were unable to distinguish among prey types (fish, cephalopod, stingray) or between successful captures and unsuccessful capture attempts. Mean detection rate (true positive rate) on individual animals in the testing subset ranged from 67-100%, and mean detection on the testing subset averaged across 4 animals ranged from 82-97%. Mean False positive (FP) rate ranged from 15-67% individually in the testing subset, and 26-59% averaged across 4 animals. Surge and sway had significantly greater detection rates, but also conversely greater FP rates compared to heave. Video data also indicated that some head movements recorded by the accelerometers were unrelated to APC and that a peak in acceleration variance did not always equate to an individual prey item. The results of the present study indicate that head-mounted accelerometers provide a complementary tool for investigating foraging behaviour in pinnipeds, but that detection and FP correction factors need to be applied for reliable field application. PMID:26107647

  6. Diet of a polyphagous arthropod predator affects refuge seeking of its thrips prey

    Microsoft Academic Search

    Madelaine Venzon; Arne Janssen; Angelo Pallini; Maurice W. Sabelis

    2000-01-01

    Antipredator behaviour of prey costs time and energy, at the expense of other activities. However, not all predators are equally dangerous to all prey; some may have switched to feeding on another prey species, making them effectively harmless. To minimize costs, prey should therefore invest in antipredator behaviour only when dangerous predators are around. To distinguish these from harmless predators,

  7. KINEMATICS OF AQUATIC PREY CAPTURE IN THE SNAPPING TURTLE CHELYDRA SERPENTINA

    Microsoft Academic Search

    G. V. LAUDER; T. PRENDERGAST

    1992-01-01

    Summary The kinematics of feeding on two prey types is studied quantitatively in the common snapping turtle, Chelydra serpentina, to provide a description of prey capture mechanisms and to determine whether kinematic patterns can be altered in response to prey that vary in escape capability. High-speed video recordings of prey capture (200 fields s\\

  8. Apostatic selection by blue jays produces balanced polymorphism in virtual prey

    Microsoft Academic Search

    Alan B. Bond; Alan C. Kamil

    1998-01-01

    Apostatic selection, in which predators overlook rare prey types while consuming an excess of abundant ones, has been assumed to contribute to the maintenance of prey polymorphisms. Such an effect requires predators to respond to changes in the relative abundance of prey, switching to alternatives when a focal prey type becomes less common,. Apostatic selection has often been investigated using

  9. Effect of predator density dependent dispersal of prey on stability of a predatorprey system

    E-print Network

    Poggiale, Jean-Christophe

    predator­prey interaction on each patch. Thus, we take advantage of two time scales in order to reduce of two parts, one describ- ing the local predator­prey interaction and one describing the dispersal fromEffect of predator density dependent dispersal of prey on stability of a predator­prey system

  10. REVISITING THE CLASSICS: CONSIDERING NONCONSUMPTIVE EFFECTS IN TEXTBOOK EXAMPLES OF PREDATOR–PREY INTERACTIONS

    Microsoft Academic Search

    Barbara L. Peckarsky; Peter A. Abrams; Daniel I. Bolnick; Lawrence M. Dill; Jonathan H. Grabowski; Barney Luttbeg; John L. Orrock; Scott D. Peacor; Evan L. Preisser; Oswald J. Schmitz; Geoffrey C. Trussell

    2008-01-01

    Predator effects on prey dynamics are conventionally studied by measuring changes in prey abundance attributed to consumption by predators. We revisit four classic examples of predator-prey systems often cited in textbooks and incorporate subsequent studies of nonconsumptive effects of predators (NCE), defined as changes in prey traits (e.g., behavior, growth, development) measured on an ecological time scale. Our review revealed

  11. Functional response and prey defence level in an experimental predatorprey system

    E-print Network

    Altwegg, Res

    interaction, random effects. INTRODUCTION Prey express inducible defences only if they perceive predation risk, the paradox of enrichment predicts that predator­prey interactions become less stable with increasing nutrientFunctional response and prey defence level in an experimental predator­prey system Res Altwegg

  12. OSCILLATIONS IN A SIZE-STRUCTURED PREY-PREDATOR SOUVIK BHATTACHARYA AND MAIA MARTCHEVA

    E-print Network

    Martcheva, Maia

    model, predator escape mechanism 1. Introduction Predator-prey interactions have fascinated mathematical be responsible for the oscillations observed in the predator-prey interactions in nature. The interactions the opposite perspective: we look at the impact of the size of the prey on the predator-prey interaction and we

  13. Effect of pentachlorophenol on predator-prey interaction of two rotifers

    Microsoft Academic Search

    Africa Gómez; Gary Cecchine; Terry W Snell

    1997-01-01

    The effect of pentachlorophenol (PCP) on the predator-prey relationship of two rotifers (Asplanchna girodi and Brachionus calyciflorus) was studied using Asplanchna predatory behavior as an endpoint. The experimental design included three treatments: prey and predator exposure, only prey exposure, and only predator exposure. This enabled us to distinguish toxic effects on the predator from those on the prey and to

  14. A reduced model for spatially structured predator-prey systems with fast spatial migrations and slow

    E-print Network

    Paris-Sud XI, Université de

    migrations, and under the effect of prey-predator interaction. We consider situations where prey-predator bounded domain. On the one hand, we choose to describe prey-predator interaction through a simple Lotka-scale of predator-prey interaction is naturally of the order of several weeks up to one year (it corresponds

  15. A nonlocal kinetic model for predator-prey interactions R. C. Fetecau

    E-print Network

    Fetecau, Razvan C.

    A nonlocal kinetic model for predator-prey interactions R. C. Fetecau J. Meskas April 28, 2013 and by including a second species. The two species, assumed to have a predator-prey relationship, have dynamics as predator-prey relationships. We illustrate numerically a diverse set of predator-prey behaviours that can

  16. SCARED TO DEATH? THE EFFECTS OF INTIMIDATION AND CONSUMPTION IN PREDATOR–PREY INTERACTIONS

    Microsoft Academic Search

    Evan L. Preisser; Daniel I. Bolnick; Michael F. Benard

    2005-01-01

    Predation is a central feature of ecological communities. Most theoretical and empirical studies of predation focus on the consequences of predators consuming their prey. Predators reduce prey population densities through direct consumption (a density- mediated interaction, DMI), a process that may indirectly affect the prey's resources, com- petitors, and other predators. However, predators can also affect prey population density by

  17. Accepted Manuscript Qualitative behaviour of n-dimensional ratio-dependent predator-prey systems

    E-print Network

    Tóth, János

    -dependent predator-prey interaction. Key words and phrases: Predator-prey system, Functional response, Sign stabilityAccepted Manuscript Qualitative behaviour of n-dimensional ratio-dependent predator-prey systems Pleasecitethisarticleas: K. Kiss,S.Kovács, Qualitativebehaviour of n-dimensional ratio-dependent predator-prey systems

  18. Sensory exploitation of prey: manipulation of the initial direction of prey escapes by a conspicuous "rare enemy".

    PubMed Central

    Jab?onski, P. G.

    2001-01-01

    The painted redstart (Myioborus pictus) represents a group of non-cryptic predators, the flush pursuers, who visually trigger prey escapes by spreading and pivoting their conspicuously patterned tails and wings. The prey are then chased in aerial pursuits. Such an exploitation of prey may be possible because the predation risk from redstarts is smaller than that from the predatory guild of insectivores and their neural pathways are adapted to helping prey avoid common predators rather than "rare enemies". I propose that the pivoting movements of flush pursuers direct insect escapes across the central field of vision of a predator, where it is easier to track and intercept the prey. Eighty per cent of chases by wild redstarts were in a direction suggesting that prey were entering the birds' area of stereoscopic vision. The redstart's fanned and raised tail creates a stronger visual stimulus than a redstart's head. Flies escaped away from the section of the fly's field of vision in which the model's tail was located and towards the area where the predator's stereoscopic vision is likely to be located, in front of a bird's forehead. The experiments suggested that redstarts may not only exploit the sensitivity of typical neural escape pathways, which are non-directionally sensitive, but that they may also exploit the sensitivity of some directionally sensitive neural pathways in prey. PMID:11375085

  19. Sensory exploitation of prey: manipulation of the initial direction of prey escapes by a conspicuous "rare enemy".

    PubMed

    Jab?onski, P G

    2001-05-22

    The painted redstart (Myioborus pictus) represents a group of non-cryptic predators, the flush pursuers, who visually trigger prey escapes by spreading and pivoting their conspicuously patterned tails and wings. The prey are then chased in aerial pursuits. Such an exploitation of prey may be possible because the predation risk from redstarts is smaller than that from the predatory guild of insectivores and their neural pathways are adapted to helping prey avoid common predators rather than "rare enemies". I propose that the pivoting movements of flush pursuers direct insect escapes across the central field of vision of a predator, where it is easier to track and intercept the prey. Eighty per cent of chases by wild redstarts were in a direction suggesting that prey were entering the birds' area of stereoscopic vision. The redstart's fanned and raised tail creates a stronger visual stimulus than a redstart's head. Flies escaped away from the section of the fly's field of vision in which the model's tail was located and towards the area where the predator's stereoscopic vision is likely to be located, in front of a bird's forehead. The experiments suggested that redstarts may not only exploit the sensitivity of typical neural escape pathways, which are non-directionally sensitive, but that they may also exploit the sensitivity of some directionally sensitive neural pathways in prey. PMID:11375085

  20. Long-Term Treatment and Transfusion of Normal Blood Components Following Tolerance Induction in Patients with Anti-IgA Anaphylactic Reactions

    PubMed Central

    Salama, Abdulgabar; Kardashi, Romina; Arbach, Olga

    2014-01-01

    Summary Background In general, patients with significant anti-Ig-A do not tolerate intravenous (i.v.) administration of normal blood products. Here, we present our experiences in the induction of immune tolerance (IIT) and long-term treatment in a series of such patients affected in such a way. The question whether blood components from IgA-deficient donors are required will be discussed. Methods Ten adult patients (4 females and 6 males; age ranging from 36 to 75 years) with anti-IgA were included in this study. All patients required long-term treatment with blood components. One patient had IgA deficiency and paroxysmal nocturnal hemoglobinuria (PNH), and all other patients had common variable immunodeficiency (CVID). The particle gel immunoassay was used for the detection of anti-IgA. Immune tolerance to IgA was induced by controlled subcutaneous (s.c.) and/or i.v. infusions of IgG preparations. Results Prior to IIT, anti-IgA was detectable in plasma samples of all patients and significantly diminished or abolished by controlled s.c. and/or i.v. infusions of IgG. Multiple transfusions with normal blood components could be repeatedly performed with the patient suffering from PNH without any complications. As long as i.v. IgG (IVIgG) infusions were consequently administered as individually required (intervals 2–8 weeks), none of the patients developed reactions during observation (up to 10 years). However, interruption of treatment and re-exposure to IVIgG resulted in adverse reactions. Conclusion Patients with significant anti-IgA can be safely desensitized and tolerate long-term IgG substitutions independent of the IgA concentration of the used blood component. PMID:25538541

  1. [IgG4-related disease that presented cranial, cervical, lumbar and sacral hypertrophic pachymeningitis associated with infundibulo-hypophysitis].

    PubMed

    Sakai, Toshiyuki; Kondo, Masahide; Yoshii, Shintaro; Tomimoto, Hidekazu

    2014-01-01

    We report a patient of 32-year-old female with central IgG4-related disease. She developed headache and visual disturbance. On examination, she revealed diabetes insipidus, retrobulbar neuritis, hyperreflexia and limb weakness. Her laboratory findings showed serum IgG4 elevation, pleocytosis and protein elevation in cerebrospinal fluid. Chest CT showed a nodular lesion in the S8 of the left lung. Cranial and spinal magnetic resonance images with gadolinium contrast material showed cranial, cervical and lumbosacral hypertrophic pachymeningitis associated with infundibulo-hypophysitis. Pathological findings of the left frontal dura mater revealed lymphoplasmacytic inflammatory cell infiltrate with dense fibrosis. IgG4 immunohistochemistry showed no IgG4 + plasma cells within the inflammatory infiltrate. During treatment with intravenous pulse methylprednisolone followed by oral prednisolone, she revealed recovery of visual acuity with improvement of hypertrophic pachymeningitis and normalization of serum IgG4. This is a first report of IgG4-related hypertrophic pachymeningitis which involved cranial, cervical and lumbosacral regions as well as infundibulo-hypophysitis in a young female. PMID:25142540

  2. Paraplegia in a Patient With IgG4-Related Sclerosing Disease: A Case Report

    PubMed Central

    Kim, Sung Heon; Oh, Sung Han; Paik, Soya; Kim, Joo Sup

    2014-01-01

    Immunoglobulin G4 (IgG4)-related sclerosing disease is a systemic disease, characterized by mass forming inflammatory lesions which respond well to steroid therapy. Pancreas is the most common site of involvement, and other organ involvements are also common. However, there are only a few reports about central nervous system involvement. We report a case of IgG4-related sclerosing disease which involves spinal cord causing paraplegia. A middle-aged female presented with sudden lower limb weakness. Magnetic resonance imaging showed a soft tissue mass which was diffusely compressing spinal cord along the C7 to T5 levels. Intravenous steroid pulse therapy and emergent operation was performed. The immunopathologic findings revealed IgG4-related sclerosing pachymeningitis postoperatively. There was no evidence of other organ involvement. Her neurologic deficit remained unchanged after two months of comprehensive rehabilitation therapy. PMID:25566488

  3. Transfer of selenium from prey to predators in a simulated terrestrial food chain.

    PubMed

    Hopkins, William A; Staub, Brandon P; Baionno, Jennifer A; Jackson, Brian P; Talent, Larry G

    2005-04-01

    Little is known about the accumulation and effects of selenium in reptiles. We developed a simplified laboratory food chain where we fed commercial feed laden with seleno-D,L-methionine (30 microg/g dry mass) to crickets (Acheta domestica) for 5-7 d. Se-enriched crickets (approximately 15 microg/g Se [dry mass]) were fed to juvenile male and female lizards (Sceloporus occidentalis) for 98 d while conspecifics were fed uncontaminated crickets. Lizards fed contaminated prey accumulated Se concentrations ranging from 9.3 (in female carcass) to 14.1 (in female gonad) microg/g compared to <1.5 microg/g in tissues of controls. Female gonad concentrations approached the highest of thresholds for reproductive toxicity in oviparous vertebrates. However, we observed no consistent effect of dietary treatment on sublethal parameters or survival. Our simplified food chain proved to be an ecologically relevant method of exposing lizards to Se, and forms the foundation for future studies on maternal transfer and teratogenicity of Se. PMID:15620590

  4. IgG "detoxes" the intestinal mucosa.

    PubMed

    Eckmann, Lars; Stappenbeck, Thaddeus S

    2015-05-13

    Secretory IgA is important in mucosal defense, but other, incompletely understood effectors exist. In this issue of Cell Host & Microbe, Kamada et al. (2015) show that IgG antibodies are produced against surface virulence factors of an intestinal attaching/effacing pathogen, bind to bacteria localized at the epithelium, and direct their destruction by mucosal and translocated neutrophils. PMID:25974292

  5. Differential glycosylation of polymeric and monomeric IgA: a possible role in glomerular inflammation in IgA nephropathy.

    PubMed

    Oortwijn, Beatrijs D; Roos, Anja; Royle, Louise; van Gijlswijk-Janssen, Daniëlle J; Faber-Krol, Maria C; Eijgenraam, Jan-Willem; Dwek, Raymond A; Daha, Mohamed R; Rudd, Pauline M; van Kooten, Cees

    2006-12-01

    IgA nephropathy (IgAN) is characterized by mesangial deposition of polymeric IgA1 (pIgA1) and complement. Complement activation via mannose-binding lectin and the lectin pathway is associated with disease progression. Furthermore, recent studies have indicated a possible role for secretory IgA. IgAN is associated with abnormalities in circulating IgA, including aberrant O-linked glycosylation. This study characterized and compared functional properties and N-linked glycosylation of highly purified monomeric IgA (mIgA) and pIgA from patients with IgAN and control subjects. Total serum IgA was affinity-purified from patients (n = 11) and control subjects (n = 11) followed by size separation. pIgA but not mIgA contained secretory IgA, and its concentration was significantly higher in patients with IgAN than in control subjects. Both in patients with IgAN and in control subjects, IgA binding to the GalNAc-specific lectin Helix Aspersa and to mannose-binding lectin was much stronger for pIgA than for mIgA. Furthermore, binding of IgA to mesangial cells largely was restricted to polymeric IgA. Binding of pIgA to mesangial cells resulted in increased production of IL-8, predominantly with IgA from patients with IgAN. Quantitative analysis of N-linked glycosylation of IgA heavy chains showed significant differences in glycan composition between mIgA and pIgA, including the presence of oligomannose exclusively on pIgA. In conclusion, binding and activation of mesangial cells, as well as lectin pathway activation, is a predominant characteristic of pIgA as opposed to mIgA. Furthermore, pIgA has different N-glycans, which may recruit lectins of the inflammatory pathway. These results underscore the role of pIgA in glomerular inflammation in IgAN. PMID:17050773

  6. The riddle of the dual expression of IgM and IgD.

    PubMed

    Geisberger, Roland; Lamers, Marinus; Achatz, Gernot

    2006-08-01

    Signalling through the B cell antigen receptor (BCR) is required for peripheral B lymphocyte maturation, maintenance, activation and silencing. In mature B cells, the antigen receptor normally consists of two isotypes, membrane IgM and IgD (mIgM, mIgD). Although the signals initiated from both isotypes differ in kinetics and intensity, in vivo, the BCR of either isotype seems to be able to compensate for the loss of the other, reflected by the mild phenotypes of mice deficient for mIgM or mIgD. Thus, it is still unclear why mature B cells need expression of mIgD in addition to mIgM. In the current review we suggest that the view that IgD has a simply definable function centred around the basic signalling function should be replaced by the assumption that IgD fine tunes humoral responses, modulates B cell selection and homeostasis and thus shapes the B cell repertoire, defining IgD to be a key modulator of the humoral immune response. PMID:16895553

  7. The riddle of the dual expression of IgM and IgD

    PubMed Central

    Geisberger, Roland; Lamers, Marinus; Achatz, Gernot

    2006-01-01

    Signalling through the B cell antigen receptor (BCR) is required for peripheral B lymphocyte maturation, maintenance, activation and silencing. In mature B cells, the antigen receptor normally consists of two isotypes, membrane IgM and IgD (mIgM, mIgD). Although the signals initiated from both isotypes differ in kinetics and intensity, in vivo, the BCR of either isotype seems to be able to compensate for the loss of the other, reflected by the mild phenotypes of mice deficient for mIgM or mIgD. Thus, it is still unclear why mature B cells need expression of mIgD in addition to mIgM. In the current review we suggest that the view that IgD has a simpIy definable function centred around the basic signalling function should be replaced by the assumption that IgD fine tunes humoral responses, modulates B cell selection and homeostasis and thus shapes the B cell repertoire, defining IgD to be a key modulator of the humoral immune response. PMID:16895553

  8. Assessment of lead uptake in reptilian prey species.

    PubMed

    Inouye, Laura S; Yoo, Leslie J; Talent, Larry G; Clarke, Joan U; Jones, Robert P; Steevens, Jeffery A; Boyd, Robert E

    2007-07-01

    As part of an investigation determining the trophically available fraction of metals in a model terrestrial food web, i.e., invertebrate prey to Western fence lizards (Sceloporus occidentalis), we evaluated the ability of several invertebrate prey to bioaccumulate lead and to form metals-rich granules, which are hypothesized to be non-available to predators. Crickets (Acheta domestica), tenebroid beetle larvae (Tenebrio molitor), and isopods (Porcellio scaber) were selected as model prey organisms. Lack of standard exposure methodologies for these species has presented a barrier to trophic transfer evaluations, as each species has particular requirements that create challenges for designing exposure conditions. We were able to devise exposure conditions for all three species that allow long-term exposure studies. All prey organisms accumulated lead from contaminated food, and for all species the majority of the accumulated Pb was associated with the exoskeleton (>50%), with metals-rich granules accounting for most of the remaining accumulated lead. PMID:17490716

  9. Can prey behaviour induce spatially synchronic aggregation of solitary predators?

    E-print Network

    range of coordinated behaviours, as for example when foraging. Relationships between predators (forCan prey behaviour induce spatially synchronic aggregation of solitary predators? Vincenzo generally, foraging patches) were studied. By integrating the main behavioural rules of juveniles of Spanish

  10. [IgG4-related sclerosing disease].

    PubMed

    Kazantsev, I A; Lishchuk, S V

    2011-01-01

    IgG4-related sclerosing disease (IgG4-RSD) is a systemic one in which IgG4-positive plasma cells and T lymphocytes extensively infiltrate various organs. The clinical manifestations of the disease include autoimmune pancreatitis, sclerosing cholangitis, cholecystitis, sialodenitis, retroperitoneal fibrosis, tubulointestitial nephritis, interstitial pneumonia, prostatitis, inflammatory pseudotumors and lymphadenopathy, all related with significantly elevated serum IgG4 levels. Tissue fibrosis with obliterative phlebitis of the affected organs is pathologically induced. The disease occurs predominantly in elderly men and responds well to steroid therapy. Since malignant tumors are frequently suspected on initial presentation, IgG4-RSD should be considered in the differential diagnosis to avoid unnecessary surgery. PMID:21853923

  11. IgG4-related ophthalmic disease

    PubMed Central

    Mejico, Luis J.

    2014-01-01

    IgG4-related disease is a fibro-inflammatory condition with tendency to form tumors with inflammatory infiltrate with IgG4 rich plasma cells and elevation of IgG4 level in serum, which may affect virtually every organ and tissue in the organism. IgG4-related ophthalmic disease may present as dacryoadenitis, myositis, other orbital tissues, hypophysitis or pachymeningitis causing cranial neuropathies. The diagnosis of IgG4-related disease is based on a typical clinical scenario, supportive laboratory data, expected radiological characteristics and distinct histopathological and immunohistochemical features. Corticosteroid followed by the use of long-term immunosuppressive therapy is the most commonly attempted treatment. PMID:25859140

  12. Regulation of intestinal IgA responses.

    PubMed

    Xiong, Na; Hu, Shaomin

    2015-07-01

    The intestine harbors enormous numbers of commensal bacteria and is under frequent attack from food-borne pathogens and toxins. A properly regulated immune response is critical for homeostatic maintenance of commensals and for protection against infection and toxins in the intestine. Immunoglobulin A (IgA) isotype antibodies function specifically in mucosal sites such as the intestines to help maintain intestinal health by binding to and regulating commensal microbiota, pathogens and toxins. IgA antibodies are produced by intestinal IgA antibody-secreting plasma cells generated in gut-associated lymphoid tissues from naïve B cells in response to stimulations of the intestinal bacteria and components. Research on generation, migration, and maintenance of IgA-secreting cells is important in our effort to understand the biology of IgA responses and to help better design vaccines against intestinal infections. PMID:25837997

  13. SENSITIVITY TO ASSUMPTIONS IN MODELS OF GENERALIST PREDATION ON A CYCLIC PREY

    Microsoft Academic Search

    Jason Matthiopoulos; Kate Graham; Sophie Smout; Christian Asseburg; Stephen Redpath; Simon Thirgood; Peter Hudson; John Harwood

    2007-01-01

    Abstract. Ecological theory predicts that generalist predators,should,damp,or suppress long-term periodic fluctuations (cycles) in their prey populations,and,depress their average densities. However, the magnitude of these impacts is likely to vary depending on the availability of alternative prey species and,the nature of ecological mechanisms,driving the prey cycles. These multispecies effects can be modeled,explicitly if parameterized,functions relating prey consumption to prey abundance, and

  14. Mean free-path length theory of predator–prey interactions: Application to juvenile salmon migration

    Microsoft Academic Search

    James J. Anderson; Eliezer Gurarie; Richard W. Zabel

    2005-01-01

    Ecological theory traditionally describes predator–prey interactions in terms of a law of mass action in which the prey mortality rate depends on the density of predators and prey. This simplifying assumption makes population-based models more tractable but ignores potentially important behaviors that characterize predator–prey dynamics. Here, we expand traditional predator–prey models by incorporating directed and random movements of both predators

  15. Seroepidemiology and risk factors of Toxoplasma gondii infection in undergraduate university female students in Jordan.

    PubMed

    Obaidat, M M; Al-Sheyab, N A; Bani Salman, A E; Lafi, S Q

    2015-07-01

    This study estimated the seroprevalence and risk factors for acquiring Toxoplasma gondii infection by undergraduate female university students in Jordan. A cross-sectional study from September 2013 to July 2014 analysed 202 blood samples for IgG and IgM antibodies by enzyme-linked immunosorbent assay and a semi-constructed questionnaire was completed by participants to gather information about Toxoplasma infection risk factors. T. gondii IgG antibodies were detected in 66·5% of the females. Only one sample was positive for both IgG and IgM. Using ? 2 test, six factors showed significant association with T. gondii infection (P ? 0·01). The multivariate logistic regression model showed that female students living in houses, wet areas, with income >US$750/month and using spring (untreated) water were 47·42, 10·20, 5·00, 3·25 more times at risk to be seropositive for T. gondii, respectively, compared to female students living in apartments, dry areas, with income ?US$750/month and using treated water, respectively. This study concluded that T. gondii infection in female university students in Jordan is high and most women become infected before marriage; however, congenital toxoplasmosis is still likely to occur in Jordan. Thus, dissemination of protective measures and knowledge by healthcare professionals is essential especially for pregnant women. PMID:25543692

  16. Interactions between the leech Glossiphonia complanata and its gastropod prey

    Microsoft Academic Search

    Christer Briinmark; Bjiirn Malmqvist

    1986-01-01

    Predator-prey interactions between the predatory leech, Glossiphonia complanata, and its gastropod prey were investigated in laboratory experiments, including behavioural observations with the aid of time-lapse video technique. Six gastropod species were investigated, viz. Lymnaea peregra, Planorbis planorbis, Physa fontinalis, Ancylus fluviatilis, Bithynia tentaculata, and Theodoxus fluviatilis. The species studied exhibited anti-predator defences, which had their maximum efficiency at different stages

  17. Predator Dispersal Determines the Effect of Connectivity on Prey Diversity

    PubMed Central

    Limberger, Romana; Wickham, Stephen A.

    2011-01-01

    Linking local communities to a metacommunity can positively affect diversity by enabling immigration of dispersal-limited species and maintenance of sink populations. However, connectivity can also negatively affect diversity by allowing the spread of strong competitors or predators. In a microcosm experiment with five ciliate species as prey and a copepod as an efficient generalist predator, we analysed the effect of connectivity on prey species richness in metacommunities that were either unconnected, connected for the prey, or connected for both prey and predator. Presence and absence of predator dispersal was cross-classified with low and high connectivity. The effect of connectivity on local and regional richness strongly depended on whether corridors were open for the predator. Local richness was initially positively affected by connectivity through rescue of species from stochastic extinctions. With predator dispersal, however, this positive effect soon turned negative as the predator spread over the metacommunity. Regional richness was unaffected by connectivity when local communities were connected only for the prey, while predator dispersal resulted in a pronounced decrease of regional richness. The level of connectivity influenced the speed of richness decline, with regional species extinctions being delayed for one week in weakly connected metacommunities. While connectivity enabled rescue of prey species from stochastic extinctions, deterministic extinctions due to predation were not overcome through reimmigration from predator-free refuges. Prey reimmigrating into these sink habitats appeared to be directly converted into increased predator abundance. Connectivity thus had a positive effect on the predator, even when the predator was not dispersing itself. Our study illustrates that dispersal of a species with strong negative effects on other community members shapes the dispersal-diversity relationship. When connections enable the spread of a generalist predator, positive effects of connectivity on prey species richness are outweighed by regional extinctions through predation. PMID:22194992

  18. Winter Prey Selection of Canada Lynx in Northwestern Montana

    Microsoft Academic Search

    JOHN R. SQUIRES; LEONARD F. RUGGIERO

    2007-01-01

    ABSTRACT The roles that diet and prey abundance,play in habitat selection of Canada,lynx (Lynx canadensis) in the contiguous,United States is poorly understood. From 1998–2002, we back-tracked radiocollared lynx (6 F, 9 M) for a distance of 582 km and we located 86 kills in northwestern Montana, USA. Lynx preyed on 7 species that included blue grouse (Dendragapus obscurus), spruce grouse

  19. The effect of background cuing on prey detection

    Microsoft Academic Search

    HENRY KONO; PAMELA J. REID; ALAN C. KAMIL

    1998-01-01

    Studies of prey detection have typically focused on how search image affects the capture of cryptic items. This study also considers how background vegetation influences cryptic prey detection. Blue jays,Cyanocitta cristata, searched digitized images for twoCatocalamoths:C.ilia, which is cryptic on oak, andC.relicta, which is cryptic on birch. Some images contained moths while others did not. The ability of blue jays

  20. Novel predator-prey interactions: is resistance futile?

    Microsoft Academic Search

    Jennifer E. Smith; Christopher J. Whelan; Steven J. Taylor; Michael L. Denight; Mike M. Stake

    2007-01-01

    Premise: Prey species may possess inappropriate behavioural, morphological, and\\/or physiological responses to introduced, novel predators. Thus, introduced predators may exert strong selection on prey species. Organisms: Black-capped vireo, Vireo atricapilla, and the fire ant, Solenopsis invicta. Data: Behavioural response of and time-energy budget for parental vireo defence against nest predation by fire ants. Field site: Fort Hood, Texas, an 88,500-hectare

  1. IgA and IgG hypogammaglobulinemia in Waldenström’s macroglobulinemia

    PubMed Central

    Hunter, Zachary R.; Manning, Robert J.; Hanzis, Christine; Ciccarelli, Bryan T.; Ioakimidis, Leukothea; Patterson, Christopher J.; Lewicki, Megan C.; Tseng, Hsuiyi; Gong, Ping; Liu, Xia; Zhou, Yangsheng; Yang, Guang; Sun, Jenny; Xu, Lian; Sheehy, Patricia; Morra, Massimo; Treon, Steven P.

    2010-01-01

    Background Hypogammaglobulinemia is common in Waldenström’s macroglobulinemia. The etiology of this finding remains unclear, but it has been speculated to be based on tumor-induced suppression of the ‘uninvolved’ immunoglobulin production Design and Methods We evaluated the incidence of IgA and IgG hypogammaglobulinemia in 207 untreated patients with Waldenström’s macroglobulinemia and investigated the associated clinicopathological findings and impact of therapy. We also sequenced eight genes (AICDA, BTK, CD40, CD154, NEMO, TACI, SH2D1A, UNG) implicated in immunoglobulin deficiency in 19 Waldenström’s macroglobulinemia patients with IgA and/or IgG hypogammaglobulinemia. Results At baseline 63.3%, 58.0% and 49.3% of the 207 patients had abnormally low serum levels of IgA, IgG, or both. No association between IgA and IgG hypogammaglobulinemia and disease burden, serum IgM levels, ?2-microglobulin, International Prognostic Scoring System score, or incidence of recurrent infections was observed, although the presence of adenopathy and/or splenomegaly was associated with a lower incidence of hypogammaglobulinemia. Lower IgA and IgG levels were associated with disease progression in patients managed with a ‘watch and wait’ strategy. IgA and/or IgG levels remained abnormally low despite response to treatment, including complete remissions. A missense mutation in the highly conserved catalytic site of UNG was observed in a patient with hypogammaglobulinemia, warranting further study of this pathway in Waldenström’s macroglobulinemia. Conclusions IgA and IgG hypogammaglobulinemia is common in Waldenström’s macroglobulinemia and persists despite therapeutic intervention and response. IgA and IgG hypogammaglobulinemia does not predict the risk of recurrent infections in patients with Waldenström’s macroglobulinemia, although lower levels of serum IgA and IgG are associated with disease progression in Waldenström’s macroglobulinemia patients being managed with a ‘watch and wait’ strategy. PMID:19903677

  2. Impacts of human disturbance on large prey species: do behavioral reactions translate to fitness consequences?

    PubMed

    Leblond, Mathieu; Dussault, Christian; Ouellet, Jean-Pierre

    2013-01-01

    Anthropogenic disturbances have been demonstrated to affect animal behavior, distribution, and abundance, but assessment of their impacts on fitness-related traits has received little attention. We hypothesized that human activities and infrastructure cause a decrease in the individual performance of preys because of anthropogenically enhanced predation risk. We evaluated the impacts of commercial logging and road networks on the fitness of a large herbivore known to be sensitive to human disturbance: the forest-dwelling woodland caribou (Rangifer tarandus caribou). For 8 consecutive years (2004-2011) we monitored 59 individuals using GPS telemetry in the Charlevoix region of Québec, Canada. We also used Very High Frequency telemetry locations collected on 28 individuals from 1999-2000. We related habitat selection of adult caribou at various spatio-temporal scales to their probability of dying from predation, and to indices of their reproductive success and energy expenditure. The probability that adult caribou died from predation increased with the proportion of recent disturbances (including cutblocks ? 5 years old) in their annual home range. The respective effects of increasing paved and forestry road densities depended upon the overall road density within the home range of caribou. At a finer scale of 10 to 15 days before their death, caribou that were killed by a predator selected for recent disturbances more than individuals that survived, and avoided old mature conifer stands. The home range area of caribou increased with road density. Finally, the composition of the home range of females had no effect on their reproductive success. We show that human activities and infrastructure may influence the individual performance of large prey species in highly managed regions. We outline the need to consider the full set of impacts that human development may have on threatened animal populations, with particular emphasis on predator-prey relationships and population dynamics. PMID:24040029

  3. Impacts of Human Disturbance on Large Prey Species: Do Behavioral Reactions Translate to Fitness Consequences?

    PubMed Central

    Leblond, Mathieu; Dussault, Christian; Ouellet, Jean-Pierre

    2013-01-01

    Anthropogenic disturbances have been demonstrated to affect animal behavior, distribution, and abundance, but assessment of their impacts on fitness-related traits has received little attention. We hypothesized that human activities and infrastructure cause a decrease in the individual performance of preys because of anthropogenically enhanced predation risk. We evaluated the impacts of commercial logging and road networks on the fitness of a large herbivore known to be sensitive to human disturbance: the forest-dwelling woodland caribou (Rangifer tarandus caribou). For 8 consecutive years (2004–2011) we monitored 59 individuals using GPS telemetry in the Charlevoix region of Québec, Canada. We also used Very High Frequency telemetry locations collected on 28 individuals from 1999–2000. We related habitat selection of adult caribou at various spatio-temporal scales to their probability of dying from predation, and to indices of their reproductive success and energy expenditure. The probability that adult caribou died from predation increased with the proportion of recent disturbances (including cutblocks ?5 years old) in their annual home range. The respective effects of increasing paved and forestry road densities depended upon the overall road density within the home range of caribou. At a finer scale of 10 to 15 days before their death, caribou that were killed by a predator selected for recent disturbances more than individuals that survived, and avoided old mature conifer stands. The home range area of caribou increased with road density. Finally, the composition of the home range of females had no effect on their reproductive success. We show that human activities and infrastructure may influence the individual performance of large prey species in highly managed regions. We outline the need to consider the full set of impacts that human development may have on threatened animal populations, with particular emphasis on predator-prey relationships and population dynamics. PMID:24040029

  4. The impact of environmental toxins on predator-prey dynamics.

    PubMed

    Huang, Qihua; Wang, Hao; Lewis, Mark A

    2015-08-01

    Predators and prey may be simultaneously exposed to environmental toxins, but one may be more susceptible than the other. To study the effects of environmental toxins on food web dynamics, we develop a toxin-dependent predator-prey model that combines both direct and indirect toxic effects on two trophic levels. The direct effects of toxins typically reduce organism abundance by increasing mortality or reducing fecundity. Such direct effects, therefore, alter both bottom-up food availability and top-down predatory ability. However, the indirect effects, when mediated through predator-prey interactions, may lead to counterintuitive effects. This study investigates how the balance of the classical predator-prey dynamics changes as a function of environmental toxin levels. While high toxin concentrations are shown to be harmful to both species, possibly leading to extirpation of both species, intermediate toxin concentrations may affect predators disproportionately through biomagnification, leading to reduced abundance of predators and increased abundance of the prey. This counterintuitive effect significantly increases biomass at the lower trophic level. Environmental toxins may also reduce population variability by preventing populations from fluctuating around a coexistence equilibrium. Finally, environmental toxins may induce bistable dynamics, in which different initial population levels produce different long-term outcomes. Since our toxin-dependent predator-prey model is general, the theory developed here not only provides a sound foundation for population or community effects of toxicity, but also could be used to help develop management strategies to preserve and restore the integrity of contaminated habitats. PMID:25916557

  5. Predator interference and stability of predator-prey dynamics.

    PubMed

    P?ibylová, Lenka; Berec, Lud?k

    2015-08-01

    Predator interference, that is, a decline in the per predator consumption rate as predator density increases, is generally thought to promote predator-prey stability. Indeed, this has been demonstrated in many theoretical studies on predator-prey dynamics. In virtually all of these studies, the stabilization role is demonstrated as a weakening of the paradox of enrichment. With predator interference, stable limit cycles that appear as a result of environmental enrichment occur for higher values of the environmental carrying capacity of prey, and even a complete absence of the limit cycles can happen. Here we study predator-prey dynamics using the Rosenzweig-MacArthur-like model in which the Holling type II functional response has been replaced by a predator-dependent family which generalizes many of the commonly used descriptions of predator interference. By means of a bifurcation analysis we show that sufficiently strong predator interference may bring about another stabilizing mechanism. In particular, hysteresis combined with (dis)appearance of stable limit cycles imply abrupt increases in both the prey and predator densities and enhanced persistence and resilience of the predator-prey system. We encourage refitting the previously collected data on predator consumption rates as well as for conducting further predation experiments to see what functional response from the explored family is the most appropriate. PMID:25108420

  6. Horned lizards (Phrynosoma) incapacitate dangerous ant prey with mucus.

    PubMed

    Sherbrooke, Wade C; Schwenk, Kurt

    2008-10-01

    Horned lizards (Iguanidae, Phrynosomatinae, Phrynosoma) are morphologically specialized reptiles characterized by squat, tank-like bodies, short limbs, blunt snouts, spines and cranial horns, among other traits. They are unusual among lizards in the degree to which they specialize on a diet of ants, but exceptional in the number of pugnacious, highly venomous, stinging ants they consume, especially harvester ants (genus Pogonomyrmex). Like other iguanian lizards, they capture insect prey on the tongue, but unlike other lizards, they neither bite nor chew dangerous prey before swallowing. Instead, they employ a unique kinematic pattern in which prey capture, transport and swallowing are combined. Nevertheless, horned lizards consume dozens of harvester ants without harm. We show that their derived feeding kinematics are associated with unique, mucus-secreting pharyngeal papillae that apparently serve to immobilize and incapacitate dangerous ants as they are swallowed by compacting them and binding them in mucus strands. Radially branched esophageal folds provide additional mucus-secreting surfaces the ants pass through as they are swallowed. Ants extracted from fresh-killed horned lizard stomachs are curled ventrally into balls and bound in mucus. We conclude that the pharyngeal papillae, in association with a unique form of hyolingual prey transport and swallowing, are horned lizard adaptations related to a diet of dangerous prey. Harvester ant defensive weapons, along with horned lizard adaptations against such weapons, suggest a long-term, predator-prey, co-evolutionary arms race between Phrynosoma and Pogonomyrmex. PMID:18570329

  7. Shiga toxin-induced apoptosis is more efficiently inhibited by dimeric recombinant hybrid-IgG/IgA immunoglobulins than by the parental IgG monoclonal antibodies.

    PubMed

    Kurohane, Kohta; Nagano, Kyoko; Nakanishi, Katsuhiro; Iwata, Koki; Miyake, Masaki; Imai, Yasuyuki

    2014-11-17

    Shiga toxin 1 (Stx1) is a virulence factor of enterohaemorrhagic Escherichia coli strains such as O157:H7 and Shigella dysenteriae. To prevent entry of Stx1 from the mucosal surface, an immunoglobulin A (IgA) specific for Stx1 would be useful. Due to the difficulty of producing IgA monoclonal antibodies (mAb) against the binding subunit of Stx1 (Stx1B) in mice, we took advantage of recombinant technology that combines the heavy chain variable region from Stx1B-specific IgG1 mAb and the Fc region from IgA. The resulting hybrid IgG/IgA was stably expressed in Chinese hamster ovary cells as a dimeric hybrid IgG/IgA. We separated the dimeric hybrid IgG/IgA from the monomeric one by size-exclusion chromatography. The dimer fraction, confirmed by immunoblot analyses, was used for toxin neutralization assays. The dimeric IgG/IgA was shown to neutralize Stx1 toxicity toward Vero cells by assaying their viability. To compare the relative effectiveness of the dimeric hybrid IgG/IgA and parental IgG1 mAb, Stx1-induced apoptosis was examined using 2 different cell lines, Ramos and Vero cells. The hybrid IgG/IgA inhibited apoptosis more efficiently than the parental IgG1 mAb in both cases. The results indicated that the use of high affinity binding sites as variable regions of IgA would increase the utility of IgA specific for virulence factors. PMID:25469594

  8. Prey preference by Delphastus catalinae (Coleoptera: Coccinellidae) on Bemisia argentifolii (Homoptera: Aleyrodidae): effects of host plant and prey stages.

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Host plant and insect host stage preference were studied in the predator Delphastus catalinae (Horn) (= pusillus) (Coleoptera: Coccinellidae) feeding on the silverleaf whitefly (Bemisia argentifolii Bellows and Perring) (Homoptera: Aleyrodidae). To study host plant preference, immature whitefly prey...

  9. Enhanced immune response against pertussis toxoid by IgA-loaded chitosan-dextran sulfate nanoparticles.

    PubMed

    Sharma, Sameer; Mukkur, Trilochan Ks; Benson, Heather Ae; Chen, Yan

    2012-01-01

    The objective of the present study was to evaluate immunological activities of chitosan-dextran sulfate (CS-DS) nanoparticle formulation of pertussis toxoid (PTXd) and its combination with a potential immunological adjuvant, immunoglobulin A (IgA). CS-DS nanoparticles were prepared using a complex coacervation (polyelectrolyte complexation) technique. CS-DS nanoparticle formulations with size and zeta potential in a range of 300-350 nm and +40-+55 mV, respectively, were obtained. An entrapment efficiency of more than 90% was obtained for pertussis toxin and IgA in CS-DS nanoparticles. All loaded nanoparticle formulations showed less than 20% of release within 24 h in in vitro release studies. The immunological evaluation of developed formulations in female Balb/c mice groups showed that the CS-DS nanoparticles formulations induced significantly higher serum IgG and IgG1 titers (p < 0.05) as compared with conventional alum-adjuvanted PTXd formulation administered by subcutaneous route. This study indicated the potential of CS-DS nanoparticles to be a simple and effective particulate delivery system with in-built immunological adjuvant property for acellular protein antigens. The study also revealed the potential important role of IgA-loaded CS-DS nanoparticles as a novel immunological adjuvant for vaccine delivery. PMID:21953499

  10. Dynamical complexities in the Leslie–Gower predator–prey model as consequences of the Allee effect on prey

    Microsoft Academic Search

    Eduardo González-Olivares; Jaime Mena-Lorca; Alejandro Rojas-Palma; José D. Flores

    2011-01-01

    This work deals with the analysis of a predator–prey model derived from the Leslie–Gower type model, where the most common mathematical form to express the Allee effect in the prey growth function is considered.It is well-known that the Leslie–Gower model has a unique globally asymptotically stable equilibrium point. However, it is shown here the Allee effect significantly modifies the original

  11. Bifurcation and stability analysis of a temperature-dependent mite predator-prey interaction model incorporating a prey refuge

    Microsoft Academic Search

    John B. Collings; Grand Forks

    1995-01-01

    The non-linear behavior of a differential equations-based predator-prey model, incorporating a spatial refuge protecting a\\u000a consant proportion of prey and with temperature-dependent parameters chosen appropriately for a mite interaction on fruit\\u000a trees, is examined using the numerical bifurcation code AUTO 86. The most significant result of this analysis is the existence\\u000a of a temperature interval in which increasing the amount

  12. Serum levels of immunoglobulins (IgG, IgA, IgM) in Antarctic summer expeditioners and their relationship with seasickness.

    PubMed

    Mishra, K P; Yadav, A P; Shweta; Chanda, Sudipta; Majumdar, D; Ganju, Lilly

    2011-01-01

    The Antarctic continent is full of environmental extremes like isolation, cold, UV exposure, and blizzards etc. The present study was conducted to analyze the effect of ship borne journey and the impact of Antarctic harsh environment on serum immunoglobulin (IgG, IgM, IgA) levels and their relationship with seasickness in Indian expeditioners. It was observed that one month onboard ship journey induced an increase in serum IgA levels and decrease in IgG levels while after being one month off board at the Indian research station Maitri, decreased levels of IgG and increased levels of IgA were found. IgM levels were not altered in comparison to the base line control. Moreover, serum IgG level showed a positive correlation while IgA level showed a negative correlation with seasickness. The stimulation of human peripheral blood mononuclear cells (PBMCs) with serum of expeditioner at different places showed that IgA at lower dose induces the release of pro-inflammatory IL-1?, and IL-6 cytokines from PBMCs while higher dose of IgA decreases proinflammatory cytokine production. The release of anti-inflammatory cytokines TGF-?1 and IL-10 was not significantly altered. Thus, the present study concluded that ship borne journey and Antarctic environment lead to increased serum IgA levels while decreased IgG levels. It also suggests that serum IgA level could be a possible biomarker for environmental stress. PMID:21714963

  13. Differentiation of acute and chronic hepatitis B in IgM anti-HBc positive patients

    PubMed Central

    Park, Ji Won; Kwak, Kyeong Min; Kim, Sung Eun; Jang, Myoung Kuk; Kim, Dong Joon; Lee, Myung Seok; Kim, Hyoung Su; Park, Choong Kee

    2015-01-01

    AIM: To identify the factors that differentiate acute hepatitis B (AHB) from chronic hepatitis B with acute exacerbation (CHB-AE). METHODS: From 2004 to 2013, a total of 82 patients (male n = 52, 63.4%; female n = 30, 36.6%) with clinical features of acute hepatitis with immunoglobulin M antibodies to the hepatitis B core antigen (IgM anti-HBc) were retrospectively enrolled and divided into two groups; AHB (n = 53) and CHB-AE (n = 29). The AHB group was defined as patients without a history of hepatitis B virus (HBV) infection before the episode and with loss of hepatitis B surface antigen within 6 mo after onset of acute hepatitis. Biochemical and virological profiles and the sample/cutoff (S/CO) ratio of IgM anti-HBc were compared to determine the differential diagnostic factors. RESULTS: The multivariate analysis demonstrated that, the S/CO ratio of IgM anti-HBc and HBV DNA levels were meaningful factors. The S/CO ratio of IgM anti-HBc was significantly higher in the AHB group, while the HBV DNA level was significantly higher in the CHB-AE group. The optimal cutoff values of IgM anti-HBc and HBV DNA levels for differentiating the two conditions were 8 S/CO ratio and 5.5 log10 IU/mL, respectively. The sensitivity and specificity were 96.2% and 89.7% for the S/CO ratio of IgM anti-HBc and 81.1% and 72.4% for HBV DNA levels, respectively. The area under receiver operating characteristic curves of both the S/CO ratio of IgM anti-HBc and HBV DNA levels were not significantly different (0.933 vs 0.844, P = 0.105). When combining IgM anti-HBc and HBV DNA, the diagnostic power significantly improved compared to HBV DNA alone (P = 0.0056). The combination of these factors yielded a sensitivity and specificity of 98.1% and 86.2%, respectively. CONCLUSION: The combination of the S/CO ratio of IgM anti-HBc and HBV DNA levels was a useful tool for differentiating AHB from CHB-AE in patients with positive IgM anti-HBc. PMID:25852281

  14. Do lions Panthera leo actively select prey or do prey preferences simply reflect chance responses via evolutionary adaptations to optimal foraging?

    PubMed

    Hayward, Matt W; Hayward, Gina J; Tambling, Craig J; Kerley, Graham I H

    2011-01-01

    Research on coursing predators has revealed that actions throughout the predatory behavioral sequence (using encounter rate, hunting rate, and kill rate as proxy measures of decisions) drive observed prey preferences. We tested whether similar actions drive the observed prey preferences of a stalking predator, the African lion Panthera leo. We conducted two 96 hour, continuous follows of lions in Addo Elephant National Park seasonally from December 2003 until November 2005 (16 follows), and compared prey encounter rate with prey abundance, hunt rate with prey encounter rate, and kill rate with prey hunt rate for the major prey species in Addo using Jacobs' electivity index. We found that lions encountered preferred prey species far more frequently than expected based on their abundance, and they hunted these species more frequently than expected based on this higher encounter rate. Lions responded variably to non-preferred and avoided prey species throughout the predatory sequence, although they hunted avoided prey far less frequently than expected based on the number of encounters of them. We conclude that actions of lions throughout the predatory behavioural sequence, but particularly early on, drive the prey preferences that have been documented for this species. Once a hunt is initiated, evolutionary adaptations to the predator-prey interactions drive hunting success. PMID:21915261

  15. The Human IgE Repertoire

    PubMed Central

    Gadermaier, Elisabeth; Levin, Mattias; Flicker, Sabine; Ohlin, Mats

    2015-01-01

    IgE is a key mediator in allergic diseases. However, in strong contrast to other antibody isotypes, many details of the composition of the human IgE repertoire are poorly defined. The low levels of human IgE in the circulation and the rarity of IgE-producing B cells are important reasons for this lack of knowledge. In this review, we summarize the current knowledge on these repertoires both in terms of their complexity and activity, i.e. knowledge which despite the difficulties encountered when studying the molecular details of human IgE has been acquired in recent years. We also take a look at likely future developments, for instance through improvements in sequencing technology and methodology that allow the isolation of additional allergen-specific human antibodies mimicking IgE, as this certainly will support our understanding of human IgE in the context of human disease in the years to come. PMID:24296690

  16. Immunoglobulin G (IgG) subclasses and human disease.

    PubMed

    Oxelius, V A

    1984-03-30

    The isotypes of IgG, IgG1, IgG2, IgG3, and IgG4 were determined in immunoglobulin preparations and the effect on serum levels of treated patients. Serum IgG subclass deficiencies were recorded in different patient groups: (1) IgG2-IgG4 deficiency was associated with IgA deficiency. (2) IgG2-IgG4 deficiency was found in patients with ataxia telangiectasia. (3) Low IgG2 levels were recorded in patients with SLE; one of these patients with recurrent pericarditis was treated with immunoglobulin with good results. (4) Low IgG2 and/or low IgG3 levels were found in patients with juvenile diabetes mellitus. (5) Mothers giving birth to severely group B streptococci infected infants showed low levels of IgG subclasses indicating that the newborns were IgG subclass deficient at birth. (6) In a prospective study of children with recurrent otitis media aged 12 and 32 months the IgG2 levels were significantly reduced in the group with considerably high otitis proneness. In patients with IgG2-IgG4 deficiency, absence of antibodies to polysaccharide antigen teichoic acid and the protein antigen alpha-toxin of staphylococci was demonstrated. Imbalanced IgG subclass pattern with increased IgG4 was recorded in patients with different diseases such as atopic diseases and also in combination with increased IgE, Henoch-Schönlein vasculitis, idiopathic pulmonary hemosiderosis, chronic mucocutaneous candidiasis, and in patients with Trichuris trichiura infection. PMID:6369977

  17. Predators choose prey over prey habitats: evidence from a lynx-hare system.

    PubMed

    Keim, Jonah L; DeWitt, Philip D; Lele, Subhash R

    2011-06-01

    Resource selection is grounded in the understanding that animals select resources based on fitness requirements. Despite uncertainty in how mechanisms relate to the landscape, resource selection studies often assume, but rarely demonstrate, a relationship between modeled variables and fitness mechanisms. Using Canada lynx (Lynx canadensis) and snowshoe hare (Lepus americanus) as a model system, we assess whether prey habitat is a viable surrogate for encounters between predators and prey. We simultaneously collected winter track data for lynx and hare in two study areas. We used information criteria to determine whether selection by lynx is best characterized by a hare resource selection probability function (RSPF) or by the amount of hare resource use. Results show that lynx selection is better explained by the amount of hare use (SIC = -21.9; Schwarz's Information Criterion) than by hare RSPF (SIC = -16.71), and that hare RSPF cannot be assumed to reveal the amount of resource use, a primary mechanism of predator selection. Our study reveals an obvious but important distinction between selection and use that is applicable to all resource selection studies. We recommend that resource selection studies be coupled with mechanistic data (e.g., metrics of diet, forage, fitness, or abundance) when investigating mechanisms of resource selection. PMID:21774407

  18. Mosquitocidal properties of IgG targeting the glutamate-gated chloride channel in three mosquito disease vectors (Diptera: Culicidae).

    PubMed

    Meyers, Jacob I; Gray, Meg; Foy, Brian D

    2015-05-15

    The glutamate-gated chloride channel (GluCl) is a highly sensitive insecticide target of the avermectin class of insecticides. As an alternative to using chemical insecticides to kill mosquitoes, we tested the effects of purified immunoglobulin G (IgG) targeting the extracellular domain of GluCl from Anopheles gambiae (AgGluCl) on the survivorship of three key mosquito disease vectors: Anopheles gambiae s.s., Aedes aegypti and Culex tarsalis. When administered through a single blood meal, anti-AgGluCl IgG reduced the survivorship of A. gambiae in a dose-dependent manner (LC50: 2.82?mg?ml(-1), range 2.68-2.96?mg?ml(-1)) but not A. aegypti or C. tarsalis. We previously demonstrated that AgGluCl is only located in tissues of the head and thorax of A. gambiae. To verify that AgGluCl IgG is affecting target antigens found outside the midgut, we injected it directly into the hemocoel via intrathoracic injection. A single, physiologically relevant concentration of anti-AgGluCl IgG injected into the hemocoel equally reduced mosquito survivorship of all three species. To test whether anti-AgGluCl IgG was entering the hemocoel of each of these mosquitoes, we fed mosquitoes a blood meal containing anti-AgGluCl IgG and subsequently extracted their hemolymph. We only detected IgG in the hemolymph of A. gambiae, suggesting that resistance of A. aegypti and C. tarsalis to anti-AgGluCl IgG found in blood meals is due to deficient IgG translocation across the midgut. We predicted that anti-AgGluCl IgG's mode of action is by antagonizing GluCl activity. To test this hypothesis, we fed A. gambiae blood meals containing anti-AgGluCl IgG and the GluCl agonist ivermectin (IVM). Anti-AgGluCl IgG attenuated the mosquitocidal effects of IVM, suggesting that anti-AgGluCl IgG antagonizes IVM-induced activation of GluCl. Lastly, we stained adult, female A. aegypti and C. tarsalis for GluCl expression. Neuronal GluCl expression in these mosquitoes was similar to previously reported A. gambiae GluCl expression; however, we also discovered GluCl staining on the basolateral surface of their midgut epithelial cells, suggesting important physiological differences in Culicine and Anopheline mosquitoes. PMID:25994632

  19. Sequential assessment of prey through the use of multiple sensory cues by an eavesdropping bat

    NASA Astrophysics Data System (ADS)

    Page, Rachel A.; Schnelle, Tanja; Kalko, Elisabeth K. V.; Bunge, Thomas; Bernal, Ximena E.

    2012-06-01

    Predators are often confronted with a broad diversity of potential prey. They rely on cues associated with prey quality and palatability to optimize their hunting success and to avoid consuming toxic prey. Here, we investigate a predator's ability to assess prey cues during capture, handling, and consumption when confronted with conflicting information about prey quality. We used advertisement calls of a preferred prey item (the túngara frog) to attract fringe-lipped bats, Trachops cirrhosus, then offered palatable, poisonous, and chemically manipulated anurans as prey. Advertisement calls elicited an attack response, but as bats approached, they used additional sensory cues in a sequential manner to update their information about prey size and palatability. While both palatable and poisonous small anurans were readily captured, large poisonous toads were approached but not contacted suggesting the use of echolocation for assessment of prey size at close range. Once prey was captured, bats used chemical cues to make final, post-capture decisions about whether to consume the prey. Bats dropped small, poisonous toads as well as palatable frogs coated in toad toxins either immediately or shortly after capture. Our study suggests that echolocation and chemical cues obtained at close range supplement information obtained from acoustic cues at long range. Updating information about prey quality minimizes the occurrence of costly errors and may be advantageous in tracking temporal and spatial fluctuations of prey and exploiting novel food sources. These findings emphasize the sequential, complex nature of prey assessment that may allow exploratory and flexible hunting behaviors.

  20. Host plant mediates foraging behavior and mutual interference among adult Stethorus gilvifrons (Coleoptera: Coccinellidae) preying on Tetranychus urticae (Acari: Tetranychidae).

    PubMed

    Bayoumy, Mohamed H; Osman, Mohamed A; Michaud, J P

    2014-10-01

    Physical plant characteristics can influence predator foraging and their behavioral responses to each other. This study examined the searching efficiency and functional response of adult female Stethorus gilvifrons Mulsant foraging for Tetranychus urticae Koch (Acari: Tetranychidae) on castor bean, common bean, and cucumber leaves. Experiments conducted on leaf discs in arenas for 12 h revealed a type II functional response for S. gilvifrons on all host plants. Per capita searching efficiency and killing power decreased with increasing predator density on all plants, but most notably on common bean, the plant with the highest prey consumption rates, due to greater mutual interference. Attack rates were highest on common bean and lowest on castor bean, whereas handling times were shortest on common bean and longest on cucumber, such that the daily predation rate was maximal on common bean. Host plant interacted with predator and prey densities to affect searching efficiency and functional response, the differences in mite consumption among host plants increasing with predator and prey densities. The waxy layers of castor bean leaves and high trichome counts of cucumber leaves appeared to reduce predator foraging efficiency. Thus, the efficacy of S. gilvifrons against T. urticae is likely to be greatest on plants such as Phaeseolus vulgaris L. that have relatively smooth leaves. PMID:25259694

  1. “Auto-anti-IgE”: Naturally occurring IgG anti-IgE antibodies may inhibit allergen-induced basophil activation

    PubMed Central

    Chan, Yih-Chih; Ramadani, Faruk; Santos, Alexandra F.; Pillai, Prathap; Ohm-Laursen, Line; Harper, Clare E.; Fang, Cailong; Dodev, Tihomir S.; Wu, Shih-Ying; Ying, Sun; Corrigan, Christopher J.; Gould, Hannah J.

    2014-01-01

    Background Naturally occurring IgE-specific IgG autoantibodies have been identified in patients with asthma and other diseases, but their spectrum of functions is poorly understood. Objective Address the hypothesis that: (i) IgG anti-IgE autoantibodies are detectable in the serum of all subjects but elevated in asthmatic patients regardless of atopic status as compared with controls; (ii) some activate IgE-sensitized basophils; and (iii) some inhibit allergen-induced basophil activation. Methods IgE-specific IgG autoantibodies were detected and quantified in sera using ELISA. Sera were examined for their ability to activate IgE-sensitized human blood basophils in the presence and absence of allergen using a basophil activation test, and to inhibit allergen binding to specific IgE on a rat basophilic cell line stably expressing human Fc?RI. Results IgG autoantibodies binding to both free and Fc?RI-bound IgE were detected in patients with atopic and non-atopic asthma, as well as controls. While some were able to activate IgE-sensitised basophils, others inhibited allergen-induced basophil activation, at least partly by inhibiting binding of IgE to specific allergen. Conclusion Naturally occurring IgG anti-IgE autoantibodies may inhibit, as well as induce, basophil activation. They act in a manner distinct from therapeutic IgG anti-IgE antibodies such as omalizumab. They may at least partly explain why atopic subjects who make allergen-specific IgE never develop clinical symptoms, and why omalizumab therapy is of variable clinical benefit in severe atopic asthma. PMID:25112697

  2. Galactosylation of N- and O-linked carbohydrate moieties of IgA1 and IgG in IgA nephropathy.

    PubMed Central

    Allen, A C; Harper, S J; Feehally, J

    1995-01-01

    The mechanism of IgA deposition in the kidneys in IgA nephropathy is unknown. Mesangial IgA is of the IgA1 subclass, and since no consistent antigenic target for the IgA1 has been described, we have investigated the glycosylation of the molecule, as a potential non-immunological abnormality which may contribute to its deposition. IgA1 is rich in carbohydrate, carrying N-linked moieties in common with IgG, but also O-linked sugars, which are rare in serum proteins, and not expressed by IgG or IgA2. Lectin binding assays were designed to examine the expression of terminal galactose on the N-linked carbohydrate chains of purified serum IgG and IgA1, and the O-linked sugars of IgA1 and C1 inhibitor (one of the very few other serum proteins with O-linked glycosylation). No evidence was found for abnormalities of N-linked glycosylation of either isotype in IgA nephropathy compared with matched controls. However, in IgA nephropathy, reduced terminal galactosylation of the hinge region O-linked moieties was demonstrated; this was not seen in C1 inhibitor, which showed normal or increased galactosylation of the O-linked sugars. This abnormality of IgA1 has considerable implications for the pathogenesis of IgA nephropathy, since the O-linked sugars lie in an important functional location within the IgA1 molecule, close to the ligand of Fc receptors. Changes in the carbohydrates in this site may therefore affect interactions with receptors and extracellular proteins, leading to anomalous handling of the IgA1 protein in this condition, including failure of normal clearance mechanisms, and mesangial deposition. Images Fig. 1 PMID:7774058

  3. Genistein Enhancement of Respiratory Allergen Trimellitic Anhydride-induced IgE Production by Adult B6C3F1 Mice Following In Utero and Postnatal Exposure

    PubMed Central

    Guo, Tai L.; Auttachoat, W.; Chi, Rui P.

    2005-01-01

    The objective of the present study was to determine if exposure to the phytoestrogen genistein (GEN) during immune development had any effects on the production of IgE by adult mice following dermal treatment with trimellitic anhydride (TMA), a respiratory allergen. B6C3F1 mice were exposed to GEN either by feeding at 500 ppm or by gavage (20 mg/kg) for varied periods from gestation day (GD) 14 to postnatal day (PND) 84. In utero exposure to GEN by feeding increased the production of IgE at PND84 in male mice but not in female mice. In male mice, continuous exposure to GEN postnatally diminished the in utero exposure-induced enhancement in serum total IgE production. However, continuous exposure to GEN from GD14 to PND84 was required to increase serum total IgE production in female mice. In utero exposure to GEN by gavage increased the production of IgE at PND84 in female mice but not in male mice when the mice were maintained on the NIH-07 rodent diet in which a medium level of phytoestrogens was present. The enhancement in IgE production following GEN exposure in females but not in males was associated with decreases in the percentages of CD4+CD25+ T suppressor cells, and increases in the NK cell activity, the basal splenocyte proliferation, the expression of CD86 by B cells and the production of IL-2 and IL-4. Overall, the results demonstrated that GEN differentially modulated the developing immune system in male and female mice, and that more IgE was produced upon exposure to TMA in the adult. PMID:16049267

  4. Supernova 2009ig Has Brightened

    NASA Astrophysics Data System (ADS)

    Waagen, Elizabeth O.

    2009-09-01

    The Type-Ia Supernova 2009ig in NGC 1015 has brightened from its discovery magnitude of 17.5 on Aug. 20.48 UT (I. Kleiser, S. B. Cenko, W. Li, and A. V. Filippenko, University of California; LOSS discovery on unfiltered KAIT images) to unfiltered CCD magnitude 14.0 on Sep. 20.646 UT (Yoshiteru Matsuura, Nada-ku, Kobe, Japan). H. Navasardyan, E. Cappellaro, and S. Benetti, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Padova, report that a spectrogram obtained on Aug. 21.08 UT with the Asiago 1.82-m telescope indicates that the object is a type-Ia supernova caught soon after explosion. They note some similarity to early spectra of SN 2002bo (Benetti et al. 2004, MNRAS 348, 261), although Si II 597.2-nm and S II 564.0-nm are not yet present. Instructions for CCD observing are given in accordance with AAVSO policy on the observation of Type-Ia supernovae brighter than magnitude 15.0. Data should be submitted to the AAVSO International Database; FITS images should be uploaded to ftp.aavso.org.

  5. Patterns in prey use among fur seals and seabirds in the Pribilof Islands

    NASA Astrophysics Data System (ADS)

    Sinclair, E. H.; Vlietstra, L. S.; Johnson, D. S.; Zeppelin, T. K.; Byrd, G. V.; Springer, A. M.; Ream, R. R.; Hunt, G. L., Jr.

    2008-08-01

    We explored correlation in diet trends for five piscivorous predators that reproduce on the Pribilof Islands as illustrative of the shifting structure of the Bering Sea ecosystem. We evaluated the size and species of prey consumed by adult female and juvenile northern fur seals ( Callorhinus ursinus) and adults and chicks of black-legged kittiwakes ( Rissa tridactyla), red-legged kittiwakes ( Rissa brevirostris), thick-billed murres ( Uria lomvia), and common murres ( Uria aalge) from data collected between July and October 1960-2000. Sample sources included stomachs from seals and seabirds collected on pelagic foraging grounds in the eastern Bering Sea, seal scats from rookeries and seabird regurgitations and whole prey from nest sites on St. Paul and St. George Islands of the Pribilof Island archipelago. Typical prey included small fish and invertebrates (?20 cm for seals and ?12 cm for seabirds) that concentrate along frontal boundaries of the continental shelf/slope and in the epi-pelagic zone. Squids and fishes including walleye pollock ( Theragra chalcogramma), capelin ( Mallotus villosus), and sand lance ( Ammodytes hexapterus) were variably important in the diet of all five predators. Some prey, such as capelin, were principal in predator diets during the 1960s (seals) and into the early 1980s (seabirds), but declined or disappeared from all predator diets thereafter while others, such as walleye pollock, occurred with increasing frequency from the 1970s forward. As the number of individuals consuming walleye pollock increased, the overall volume of pollock in seabird diets declined. This decline was coincident with a decrease in the age and body size of pollock consumed by both seabirds and fur seals. Squid and pollock were negatively correlated in the diets of their primary consumers, northern fur seals (Pearson's coefficient -0.71, p=0.016) and thick-billed murres (Pearson's coefficient=-0.74, p=0.015) from the 1970s forward. Inter-island variation in diet was evident to varying degrees for all predators, with a prevalence of fish on St. Paul Island and invertebrates on St. George Island. Bayesian time-series analysis of synthesized data described significant temporal cross-correlation in diet among northern fur seals, red- and black-legged kittiwakes, and thick-billed murres. For all correlated predators except common murres, beta-binomial modeling indicated that trends in the occurrence of four of the five primary prey (sand lance, capelin, squid, and pollock) evaluated, were significantly associated with eastern Bering Sea time-series trends in sea surface temperature, ice retreat or a combination of both. Data synthesis highlighted potential competition and a scenario for the effects of an altered prey field on the population stability of predators. The association between correlated diet changes among predators and indices of oceanographic shifts in the 1970s and the 1990s allow scrutiny of hypotheses concerning causal mechanisms in population declines.

  6. Capture success and efficiency of dragonflies pursuing different types of prey.

    PubMed

    Combes, S A; Salcedo, M K; Pandit, M M; Iwasaki, J M

    2013-11-01

    The dynamics of predator-prey interactions vary enormously, due both to the heterogeneity of natural environments and to wide variability in the sensorimotor systems of predator and prey. In addition, most predators pursue a range of different types of prey, and most organisms are preyed upon by a variety of predators. We do not yet know whether predators employ a general kinematic and behavioral strategy, or whether they tailor their pursuits to each type of prey; nor do we know how widely prey differ in their survival strategies and sensorimotor capabilities. To gain insight into these questions, we compared aerial predation in 4 species of libelluid dragonflies pursuing 4 types of dipteran prey, spanning a range of sizes. We quantified the proportion of predation attempts that were successful (capture success), as well as the total time spent and the distance flown in pursuit of prey (capture efficiency). Our results show that dragonfly prey-capture success and efficiency both decrease with increasing size of prey, and that average prey velocity generally increases with size. However, it is not clear that the greater distances and times required for capturing larger prey are due solely to the flight performance (e.g., speed or evasiveness) of the prey, as predicted. Dragonflies initiated pursuits of large prey when they were located farther away, on average, as compared to small prey, and the total distance flown in pursuit was correlated with initial distance to the prey. The greater initial distances observed during pursuits of larger prey may arise from constraints on dragonflies' visual perception; dragonflies typically pursued prey subtending a visual angle of 1°, and rarely pursued prey at visual angles greater than 3°. Thus, dragonflies may be unable to perceive large prey flying very close to their perch (subtending a visual angle greater than 3-4°) as a distinct target. In comparing the performance of different dragonfly species that co-occur in the same habitat, we found significant differences that are not explained by body size, suggesting that some dragonflies may be specialized for pursuing particular types of prey. Our results underscore the importance of performing comparative studies of predator-prey interactions with freely behaving subjects in natural settings, to provide insight into how the behavior of both participants influences the dynamics of the interaction. In addition, it is clear that gaining a full understanding of predator-prey interactions requires detailed knowledge not only of locomotory mechanics and behavior, but also of the sensory capabilities and constraints of both predator and prey. PMID:23784698

  7. Abnormalities in IgA and IgM are associated with treatment-resistant ITP.

    PubMed

    Arnason, Jon E; Campigotto, Federico; Neuberg, Donna; Bussel, James B

    2012-05-24

    We hypothesized that immune dysregulation, as represented by abnormal immunoglobulin (Ig) levels, may increase immune thrombocytopenia (ITP) severity. A cross-sectional analysis was performed encompassing patients with ITP seen at the New York Presbyterian Platelet Disorder Center in the past 10 years. The subjects' Ig levels were measured, and subjects were analyzed for differences in treatment response. Subjects with an IgA level greater than median had a significantly increased chance of failing to respond to standard treatment (steroids, intravenous Ig, and intravenous anti-D) than did subjects with an IgA level lower than median (37 of 271, 14%; vs 22 of 281, 8%; P = .03) and an increased risk for bleeding (36 of 378, 10%; vs 19 of 386, 5%; P = .02). Subjects with an IgM less than 56 (lower limit of normal) failed to respond to standard treatment more often than patients with a normal IgM (12 of 67, 18%; vs 44 of 467, 9%; P = .05) with a trend toward worsened response to splenectomy (3 of 18, 17%; vs 36 of 86, 42%; P = .06). These observations suggest that immune dysregulation, as represented by elevations in IgA or decreased levels of IgM, are associated with ITP that is more resistant to treatment. PMID:22490683

  8. IgG4-related cardiovascular disorders.

    PubMed

    Tajima, Miyu; Nagai, Ryozo; Hiroi, Yukio

    2014-01-01

    Immunoglobulin4 (IgG4)-related disease is a systemic inflammatory disease characterized by elevation of serum IgG4. It involves various organs such as the pancreas (autoimmune pancreatitis), lacrimal gland (Mikulicz's disease), retroperitoneum (retroperitoneal fibrosis), aorta (aortic aneurysm and aortitis), heart (constrictive pericarditis), and pseudotumors around the coronary arteries. These disorders often coexist in accordance with progression of the disease. Because IgG4-related cardiovascular disorder affects the patient's prognosis, early detection and treatment is important. Coronary CT imaging and echocardiography accidentally detect IgG4-related disorders and (18)FDG-PET imaging can identify active inflammation in the lesions. Measurement of serum IgG4 levels and tissue biopsy are necessary for diagnosis. Minor salivary gland biopsy is recommended even though (18)FDG uptake is not detected when it is difficult to obtain a biopsy specimen from IgG4-related cardiovascular lesions. The first-line treatment is high-dose corticosteroid therapy, however, relapse is often reported. Corticosteroids suppress the development of active inflammatory diseases such as aortitis, pericarditis, and pseudotumors, but already-developed lesions do not respond. A large developed aneurysm can rupture even during or after corticosteroid therapy, therefore, additional surgical treatment may be needed. Treatment of IgG4-related cardiovascular disorders might require higher doses of corticosteroids than IgG4-related extracardiovascular disorders. The adequate dose of corticosteroid, type and dose of immunosuppressant, and surgical intervention should be carefully considered on a case-by-case basis. PMID:24898599

  9. Pathogenesis of Hyper IgE Syndrome

    Microsoft Academic Search

    Jennifer Heimall; Alexandra Freeman; Steven M. Holland

    2010-01-01

    Hyper IgE syndrome (HIES) is a rare primary immunodeficiency characterized by the triad of elevated IgE and eosinophilia,\\u000a eczema, and recurrent skin and pulmonary infections. The autosomal dominant (AD) form of HIES results from mutations in STAT3 and is characterized by disordered inflammation, connective tissue, and skeletal abnormalities. Tissue-specific STAT3 deficiency in animals, cytokine and transcriptional array data, and careful

  10. The IgG Fc receptor family

    Microsoft Academic Search

    J. E. Gessner; H. Heiken; A. Tamm; R. E. Schmidt

    1998-01-01

    .   IgG immune complexes are of central importance in the humoral immune system and strongly implicated in the pathogenesis of\\u000a hematologic and rheumatic autoimmune disorders. Cross-linking of receptors for the Fc domain of IgG antibodies (Fc?Rs) triggers\\u000a a wide variety of effector functions including phagocytosis, antibody-dependent cellular cytotoxicity, and release of inflammatory\\u000a mediators, as well as immune complex clearance and

  11. Prey Capture Behavior in an Arboreal African Ponerine Ant

    PubMed Central

    Dejean, Alain

    2011-01-01

    I studied the predatory behavior of Platythyrea conradti, an arboreal ponerine ant, whereas most species in this subfamily are ground-dwelling. The workers, which hunt solitarily only around dusk, are able to capture a wide range of prey, including termites and agile, nocturnal insects as well as diurnal insects that are inactive at that moment of the Nyctemeron, resting on tree branches or under leaves. Prey are captured very rapidly, and the antennal palpation used by ground-dwelling ponerine species is reduced to a simple contact; stinging occurs immediately thereafter. The venom has an instant, violent effect as even large prey (up to 30 times the weight of a worker) never struggled after being stung. Only small prey are not stung. Workers retrieve their prey, even large items, singly. To capture termite workers and soldiers defending their nest entrances, ant workers crouch and fold their antennae backward. In their role as guards, the termites face the crouching ants and end up by rolling onto their backs, their legs batting the air. This is likely due to volatile secretions produced by the ants' mandibular gland. The same behavior is used against competing ants, including territorially-dominant arboreal species that retreat further and further away, so that the P. conradti finally drive them from large, sugary food sources. PMID:21589941

  12. Predator-prey relationships on Apiaceae at an organic farm.

    PubMed

    Shirk, Paul D; Shapiro, Jeffrey P; Reitz, Stuart R; Thomas, Jean M G; Koenig, Rosalie L; Hay-Roe, Mirian M; Buss, Lyle J

    2012-06-01

    Orius insidiosus (Say) and O. pumilio (Champion) were confirmed to be sympatric in north central Florida as the major predators of the Florida flower thrips, Frankliniella bispinosa (Morgan), on flowers of Queen Anne's lace, Daucus carota L. and false Queen Anne's lace, Ammi majus L. F. bispinosa was the predominant thrips observed on both flowers but colonized D. carota to a greater extent and earlier in the season than A. majus. Despite differences in the abundance of F. bispinosa on the two plants, neither Orius species showed host plant affinities. Population profiles for the thrips and Orius spp. followed a density dependent response of prey to predator with a large initial prey population followed by a rapid decline as the predator populations increased. The temporal increases in Orius spp. populations during the flowering season suggest that they were based on reproductive activity. As observed in a previous study, O. insidiosus had a larger population than O. pumilio and also had a predominantly male population on the flowers. By examining carcasses of the prey, there appeared to be no sexual preference of the thrips as prey by the Orius spp. as the prey pattern followed the demographics of the thrips sex ratio. Few immatures of either thrips or Orius spp. were observed on D. carota or A. majus, which suggests that oviposition and nymphal development occurred elsewhere. Based on these findings, D. carota and A. majus could serve as a banker plant system for Orius spp. PMID:22732606

  13. Prey-dependent retention of dimethylsulfoniopropionate (DMSP) by mixotrophic dinoflagellates

    PubMed Central

    Lee, Hyunwoo; Park, Ki-Tae; Lee, Kitack; Jeong, Hae Jin; Yoo, Yeong Du

    2012-01-01

    Summary We investigated the retention of dimethylsulfoniopropionate (DMSP) in phototrophic dinoflagellates arising from mixotrophy by estimating the cellular content of DMSP in Karlodinium veneficum (mixotrophic growth) fed for 7–10 days on either DMSP-rich Amphidinium carterae (phototrophic growth only) or DMSP-poor Teleaulax sp. (phototrophic growth only). In K. veneficum fed on DMSP-poor prey, the cellular content of DMSP remained almost unchanged regardless of the rate of feeding, whereas the cellular content of DMSP in cells of K. veneficum fed on DMSP-rich prey increased by as much as 21 times the cellular concentration derived exclusively from phototrophic growth. In both cases, significant fractions (10–32% in the former case and 55–65% in the latter) of the total DMSP ingested by K. veneficum were transformed into dimethylsulfide and other biochemical compounds. The results may indicate that the DMSP content of prey species affects temporal variations in the cellular DMSP content of mixotrophic dinoflagellates, and that mixotrophic dinoflagellates produce DMS through grazing on DMSP-rich preys. Additional studies should be performed to examine the universality of our finding in other mixotrophic dinoflagellates feeding on diverse prey species. PMID:21958033

  14. Dynamics of a predator-prey model with Allee effect and prey group defense

    NASA Astrophysics Data System (ADS)

    Saleh, Khairul

    2015-02-01

    Dynamical properties of a Gauss type of planar predator-prey system with Allee effect and non-monotonic response function are discussed. We are interested in persistent features lying in the first quadrant, which amount to structurally stable phase portraits. We show that all positive solutions are uniformly bounded. It is also proved that the system has at most two equilibria in the interior of the first quadrant and can exhibit interesting bifurcation phenomena, including Bogdanov-Takens, Hopf, transcritical and saddle-node bifurcations. The system may have a stable periodic orbit, or a homoclinic loop, or a heteroclinic connection, a saddle point, or a stable focus, depending on parameter values. Biologically, both populations may survive for certain values of parameters. Computer simulations are also given in support of the conclusions.

  15. Sympatric Masticophis flagellum and Coluber constrictor select vertebrate prey at different levels of taxonomy

    USGS Publications Warehouse

    Halstead, B.J.; Mushinsky, H.R.; McCoy, E.D.

    2008-01-01

    Masticophis flagellum (Coachwhip) and Coluber constrictor (Eastern Racer) are widespread North American snakes with similar foraging modes and habits. Little is known about the selection of prey by either species, and despite their apparently similar foraging habits, comparative studies of the foraging ecology of sympatric M. flagellum and C. constrictor are lacking. We examined the foraging ecology and prey selection of these actively foraging snakes in xeric, open-canopied Florida scrub habitat by defining prey availability separately for each snake to elucidate mechanisms underlying geographic, temporal, and interspecific variation in predator diets. Nineteen percent of M. flagellum and 28% of C. constrictor contained stomach contents, and most snakes contained only one prey item. Mean relative prey mass for both species was less than 10%. Larger C. constrictor consumed larger prey than small individuals, but this relationship disappeared when prey size was scaled to snake size. Masticophis flagellum was selective at the prey category level, and positively selected lizards and mammals; however, within these categories it consumed prey species in proportion to their availability. In contrast, C. constrictor preyed upon prey categories opportunistically, but was selective with regard to species. Specifically, C. constrictor positively selected Hyla femoralis (Pine Woods Treefrog) and negatively selected Bufo querclcus (Oak Toad), B. terrestris (Southern Toad), and Gastrophryne carolinensis (Eastern Narrowmouth Toad). Thus, despite their similar foraging habits, M. flagellum and C. constrictor select different prey and are selective of prey at different levels of taxonomy. ?? 2008 by the American Society of Ichthyologists and Herpetologists.

  16. Prevalence of and risk factors for increased serum levels of allergen-specific IgE in a population of Norwegian dogs.

    PubMed

    Bjelland, Annelin A; Dolva, Frederik L; Nødtvedt, Ane; Sævik, Bente K

    2014-12-01

    BackgroundThe importance of different allergens in association with IgE production and canine atopic dermatitis (CAD) has been poorly studied and few studies exist on factors influencing allergen-specific IgE antibodies in serum. The aim of this cross-sectional study was to investigate the prevalence of elevated IgE levels to different environmental allergens in Norwegian dogs with a suspicion of CAD. The secondary aim was to identify risk factors associated with elevated serum levels of allergen-specific IgE.ResultsThe study sample consisted of serum from 1313 dogs of 161 different breeds. All samples were submitted for serologic IgE-testing (Fc epsilon R1 alpha-based ELISA) based on suspicion of CAD. Overall, 84.3% of the dogs had elevated IgE levels to one or more of the allergen(s). The predominant allergens amongst the positive results were the indoor allergens (Acarus siro 84.0%, Dermatophagoides farinae 80.2%, Tyrophagus putrescentiae 79.9%). Sheep sorrel was the most commonly encountered outdoor allergen (40.0%). Only 2.6% of the dogs with elevated IgE levels were positive to flea saliva.The test results varied significantly depending on when the serum samples were taken. Samples taken during summer and autumn more often came out positive than samples taken during winter and spring. Geographical variations were also demonstrated. A greater proportion of females than males had positive test results, and more females than males tested positive to outdoor allergens. The mean age was significantly higher in the dogs testing positive than amongst the dogs testing negative. The allergen-specific IgE levels varied with breed. The boxer was the only breed with a significantly higher proportion of positive test results compared to the other breeds. Boxers also had a higher prevalence of elevated IgE levels to outdoor allergens, whereas the Rottweiler had a higher prevalence of elevated IgE levels to indoor allergens compared to the other breeds.ConclusionsIgE hypersensitivity was most often associated with indoor allergens. Outdoor allergens were of minor importance and IgE reactivity to flea saliva was rare. Breed differences in allergen-specific IgE levels were identified. Season of sampling, and the dogs¿ geographical localisation, sex and age also affected the results of the IgE analysis. PMID:25475748

  17. IgA in the horse: cloning of equine polymeric Ig receptor and J chain and characterization of recombinant forms of equine IgA.

    PubMed

    Lewis, M J; Wagner, B; Irvine, R M; Woof, J M

    2010-11-01

    As in other mammals, immunoglobulin A (IgA) in the horse has a key role in immune defense. To better dissect equine IgA function, we isolated complementary DNA (cDNA) clones for equine J chain and polymeric Ig receptor (pIgR). When coexpressed with equine IgA, equine J chain promoted efficient IgA polymerization. A truncated version of equine pIgR, equivalent to secretory component, bound with nanomolar affinity to recombinant equine and human dimeric IgA but not with monomeric IgA from either species. Searches of the equine genome localized equine J chain and pIgR to chromosomes 3 and 5, respectively, with J chain and pIgR coding sequence distributed across 4 and 11 exons, respectively. Comparisons of transcriptional regulatory sequences suggest that horse and human pIgR expression is controlled through common regulatory mechanisms that are less conserved in rodents. These studies pave the way for full dissection of equine IgA function and open up possibilities for immune-based treatment of equine diseases. PMID:20631692

  18. Fear on the move: predator hunting mode predicts variation in prey mortality and plasticity in prey spatial response.

    PubMed

    Miller, Jennifer R B; Ament, Judith M; Schmitz, Oswald J

    2014-01-01

    Ecologists have long searched for a framework of a priori species traits to help predict predator-prey interactions in food webs. Empirical evidence has shown that predator hunting mode and predator and prey habitat domain are useful traits for explaining predator-prey interactions. Yet, individual experiments have yet to replicate predator hunting mode, calling into question whether predator impacts can be attributed to hunting mode or merely species identity. We tested the effects of spider predators with sit-and-wait, sit-and-pursue and active hunting modes on grasshopper habitat domain, activity and mortality in a grassland system. We replicated hunting mode by testing two spider predator species of each hunting mode on the same grasshopper prey species. We observed grasshoppers with and without each spider species in behavioural cages and measured their mortality rates, movements and habitat domains. We likewise measured the movements and habitat domains of spiders to characterize hunting modes. We found that predator hunting mode explained grasshopper mortality and spider and grasshopper movement activity and habitat domain size. Sit-and-wait spider predators covered small distances over a narrow domain space and killed fewer grasshoppers than sit-and-pursue and active predators, which ranged farther distances across broader domains and killed more grasshoppers, respectively. Prey adjusted their activity levels and horizontal habitat domains in response to predator presence and hunting mode: sedentary sit-and-wait predators with narrow domains caused grasshoppers to reduce activity in the same-sized domain space; more mobile sit-and-pursue predators with broader domains caused prey to reduce their activity within a contracted horizontal (but not vertical) domain space; and highly mobile active spiders led grasshoppers to increase their activity across the same domain area. All predators impacted prey activity, and sit-and-pursue predators generated strong effects on domain size. This study demonstrates the validity of utilizing hunting mode and habitat domain for predicting predator-prey interactions. Results also highlight the importance of accounting for flexibility in prey movement ranges as an anti-predator response rather than treating the domain as a static attribute. PMID:24028410

  19. Predatory fish select for coordinated collective motion in virtual prey.

    PubMed

    Ioannou, C C; Guttal, V; Couzin, I D

    2012-09-01

    Movement in animal groups is highly varied and ranges from seemingly disordered motion in swarms to coordinated aligned motion in flocks and schools. These social interactions are often thought to reduce risk from predators, despite a lack of direct evidence. We investigated risk-related selection for collective motion by allowing real predators (bluegill sunfish) to hunt mobile virtual prey. By fusing simulated and real animal behavior, we isolated predator effects while controlling for confounding factors. Prey with a tendency to be attracted toward, and to align direction of travel with, near neighbors tended to form mobile coordinated groups and were rarely attacked. These results demonstrate that collective motion could evolve as a response to predation, without prey being able to detect and respond to predators. PMID:22903520

  20. How predation can slow, stop or reverse a prey invasion.

    PubMed

    Owen, M R; Lewis, M A

    2001-07-01

    Observations on Mount St Helens indicate that the spread of recolonizing lupin plants has been slowed due to the presence of insect herbivores and it is possible that the spread of lupins could be reversed in the future by intense insect herbivory [Fagan, W. F. and J. Bishop (2000). Trophic interactions during primary sucession: herbivores slow a plant reinvasion at Mount St. Helens. Amer. Nat. 155, 238-251]. In this paper we investigate mechanisms by which herbivory can contain the spatial spread of recolonizing plants. Our approach is to analyse a series of predator-prey reaction-diffusion models and spatially coupled ordinary differential equation models to derive conditions under which predation pressure can slow, stall or reverse a spatial invasion of prey. We focus on models where prey disperse more slowly than predators. We comment on the types of functional response which give such solutions, and the circumstances under which the models are appropriate. PMID:11497163

  1. How sailfish use their bills to capture schooling prey

    PubMed Central

    Domenici, P.; Wilson, A. D. M.; Kurvers, R. H. J. M.; Marras, S.; Herbert-Read, J. E.; Steffensen, J. F.; Krause, S.; Viblanc, P. E.; Couillaud, P.; Krause, J.

    2014-01-01

    The istiophorid family of billfishes is characterized by an extended rostrum or ‘bill’. While various functions (e.g. foraging and hydrodynamic benefits) have been proposed for this structure, until now no study has directly investigated the mechanisms by which billfishes use their rostrum to feed on prey. Here, we present the first unequivocal evidence of how the bill is used by Atlantic sailfish (Istiophorus albicans) to attack schooling sardines in the open ocean. Using high-speed video-analysis, we show that (i) sailfish manage to insert their bill into sardine schools without eliciting an evasive response and (ii) subsequently use their bill to either tap on individual prey targets or to slash through the school with powerful lateral motions characterized by one of the highest accelerations ever recorded in an aquatic vertebrate. Our results demonstrate that the combination of stealth and rapid motion make the sailfish bill an extremely effective feeding adaptation for capturing schooling prey. PMID:24759865

  2. Resilient silk captures prey in black widow cobwebs

    NASA Astrophysics Data System (ADS)

    Argintean, S.; Chen, J.; Kim, M.; Moore, A. M. F.

    2006-02-01

    The gumfoot thread of a black widow ( Latrodectus hesperus) spider’s cob web is a spring-loaded trap that yanks walking insects into the web. Since spider silks are known as energy dissipating materials, we investigated this trap to find out where the energy is stored. Using previously measured material properties, we modeled the gumfoot thread as a damped harmonic oscillator and compared it to high speed video analysis of prey capture. These measurements show that the gumfoot thread is plastically deformed during prey capture and cannot be the site of energy storage. We then measured the material properties of scaffolding silk that makes up the upper portion of the cob web. Scaffolding silk is highly resilient (90%) at strains less than 3%. This energy storage is sufficient to drive the oscillations seen in prey capture and is consistent with the measured kinematics. This study is the first demonstration of energy-storage as a primary biological function for spider silk.

  3. Efficient generation of human IgA monoclonal antibodies.

    PubMed

    Lorin, Valérie; Mouquet, Hugo

    2015-07-01

    Immunoglobulin A (IgA) is the most abundant antibody isotype produced in humans. IgA antibodies primarily ensure immune protection of mucosal surfaces against invading pathogens, but also circulate and are present in large quantities in blood. IgAs are heterogeneous at a molecular level, with two IgA subtypes and the capacity to form multimers by interacting with the joining (J) chain. Here, we have developed an efficient strategy to rapidly generate human IgA1 and IgA2 monoclonal antibodies in their monomeric and dimeric forms. Recombinant monomeric and dimeric IgA1/IgA2 counterparts of a prototypical IgG1 monoclonal antibody, 10-1074, targeting the HIV-1 envelope protein, were produced in large amounts after expression cloning and transient transfection of 293-F cells. 10-1074 IgAs were FPLC-purified using a novel affinity-based resin engrafted with anti-IgA chimeric Fabs, followed by a monomers/multimers separation using size exclusion-based FPLC. ELISA binding experiments confirmed that the artificial IgA class switching of 10-1074 did not alter its antigen recognition. In summary, our technical approach allows the very efficient production of various forms of purified recombinant human IgA molecules, which are precious tools in dissecting IgA B-cell responses in physiological and pathophysiological conditions, and studying the biology, function and therapeutic potential of IgAs. PMID:25910833

  4. The Many Faces of Fear: Comparing the Pathways and Impacts of Nonconsumptive Predator Effects on Prey Populations

    Microsoft Academic Search

    Evan L. Preisser; Daniel I. Bolnick; Andy Hector

    2008-01-01

    BackgroundMost ecological models assume that predator and prey populations interact solely through consumption: predators reduce prey densities by killing and consuming individual prey. However, predators can also reduce prey densities by forcing prey to adopt costly defensive strategies.Methodology\\/Principal FindingsWe build on a simple Lotka-Volterra predator-prey model to provide a heuristic tool for distinguishing between the demographic effects of consumption (consumptive

  5. Insulin-like growth factor binding protein-1 levels are increased in patients with IgA nephropathy

    SciTech Connect

    Tokunaga, Koki [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan)] [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Uto, Hirofumi, E-mail: hirouto@m2.kufm.kagoshima-u.ac.jp [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan)] [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan); Takami, Yoichiro; Mera, Kumiko; Nishida, Chika; Yoshimine, Yozo; Fukumoto, Mayumi; Oku, Manei; Sogabe, Atsushi; Nosaki, Tsuyoshi; Moriuchi, Akihiro; Oketani, Makoto; Ido, Akio; Tsubouchi, Hirohito [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan)] [Department of Digestive and Life-Style Related Disease, Health Research Course, Human and Environmental Sciences, Kagoshima University Graduate School of Medical and Dental Sciences, 8-35-1 Sakuragaoka, Kagoshima 890-8520 (Japan)

    2010-08-20

    Research highlights: {yields} IGFBP-1 mRNA over express in kidneys obtained from mice model of IgA nephropathy. {yields} Serum IGFBP-1 levels are high in patients with IgA nephropathy. {yields} Serum IGFBP-1 levels correlate with renal function and the severity of renal injury. -- Abstract: The mechanisms underlying the pathogenesis of immunoglobulin A (IgA) nephropathy (IgAN) are not well understood. In this study, we examined gene expression profiles in kidneys obtained from mice with high serum IgA levels (HIGA mice), which exhibit features of human IgAN. Female inbred HIGA, established from the ddY line, were used in these experiments. Serum IgA levels, renal IgA deposition, mesangial proliferation, and glomerulosclerosis were increased in 32-week-old HIGA mice in comparison to ddY animals. By microarray analysis, five genes were observed to be increased by more than 2.5-fold in 32-week-old HIGA in comparison to 16-week-old HIGA; these same five genes were decreased more than 2.5-fold in 32-week-old ddY in comparison to 16-week-old ddY mice. Of these five genes, insulin-like growth factor (IGF) binding protein (IGFBP)-1 exhibited differential expression between these mouse lines, as confirmed by quantitative RT-PCR. In addition, serum IGFBP-1 levels were significantly higher in patients with IgAN than in healthy controls. In patients with IgAN, these levels correlated with measures of renal function, such as estimated glomerular filtration rate (eGFR), but not with sex, age, serum IgA, C3 levels, or IGF-1 levels. Pathologically, serum IGFBP-1 levels were significantly associated with the severity of renal injury, as assessed by mesangial cell proliferation and interstitial fibrosis. These results suggest that increased IGFBP-1 levels are associated with the severity of renal pathology in patients with IgAN.

  6. Ocean Acidification Affects Prey Detection by a Predatory Reef Fish

    PubMed Central

    Cripps, Ingrid L.; Munday, Philip L.; McCormick, Mark I.

    2011-01-01

    Changes in olfactory-mediated behaviour caused by elevated CO2 levels in the ocean could affect recruitment to reef fish populations because larval fish become more vulnerable to predation. However, it is currently unclear how elevated CO2 will impact the other key part of the predator-prey interaction – the predators. We investigated the effects of elevated CO2 and reduced pH on olfactory preferences, activity levels and feeding behaviour of a common coral reef meso-predator, the brown dottyback (Pseudochromis fuscus). Predators were exposed to either current-day CO2 levels or one of two elevated CO2 levels (?600 µatm or ?950 µatm) that may occur by 2100 according to climate change predictions. Exposure to elevated CO2 and reduced pH caused a shift from preference to avoidance of the smell of injured prey, with CO2 treated predators spending approximately 20% less time in a water stream containing prey odour compared with controls. Furthermore, activity levels of fish was higher in the high CO2 treatment and feeding activity was lower for fish in the mid CO2 treatment; indicating that future conditions may potentially reduce the ability of the fish to respond rapidly to fluctuations in food availability. Elevated activity levels of predators in the high CO2 treatment, however, may compensate for reduced olfactory ability, as greater movement facilitated visual detection of food. Our findings show that, at least for the species tested to date, both parties in the predator-prey relationship may be affected by ocean acidification. Although impairment of olfactory-mediated behaviour of predators might reduce the risk of predation for larval fishes, the magnitude of the observed effects of elevated CO2 acidification appear to be more dramatic for prey compared to predators. Thus, it is unlikely that the altered behaviour of predators is sufficient to fully compensate for the effects of ocean acidification on prey mortality. PMID:21829497

  7. Tissue Deposits of IgA-Binding Streptococcal M Proteins in IgA Nephropathy and Henoch-Schönlein Purpura

    PubMed Central

    Schmitt, Roland; Carlsson, Fredric; Mörgelin, Matthias; Tati, Ramesh; Lindahl, Gunnar; Karpman, Diana

    2010-01-01

    IgA nephropathy (IgAN) and Henoch-Schönlein purpura (HSP) are diseases characterized by IgA deposits in the kidney and/or skin. Both may arise after upper respiratory tract infections, but the pathogenic mechanisms governing these diseases remain unclear. Patients with IgAN (n = 16) and HSP (n = 17) were included in this study aimed at examining whether IgA-binding M proteins of group A streptococci could be involved. As M proteins vary in sequence, the study focused on the IgA-binding-region (IgA-BR) of three different M proteins: M4, M22, and M60. Renal tissue from IgAN and HSP patients and skin from HSP patients were examined for deposits of streptococcal IgA-BR by immunohistochemistry and electron microscopy using specific antibodies, and a skin sample from a HSP patient was examined by mass spectrometry. IgA-BR deposits were detected in 10/16 IgAN kidneys and 7/13 HSP kidneys. Electron microscopy demonstrated deposits of IgA-BRs in the mesangial matrix and glomerular basement membrane, which colocalized with IgA. Skin samples exhibited IgA-BR deposits in 4/5 biopsies, a result confirmed by mass spectrometry in one patient. IgA-BR deposits were not detected in normal kidney and skin samples. Taken together, these results demonstrate IgA-BR from streptococcal M proteins in patient tissues. IgA-BR, would on gaining access to the circulation, encounter circulatory IgA and form a complex with IgA-Fc that could deposit in tissues and contribute to the pathogenesis of IgAN and HSP. PMID:20056836

  8. IgG transport across mucosal barriers by neonatal Fc receptor for IgG and mucosal immunity

    Microsoft Academic Search

    Masaru Yoshida; Atsuhiro Masuda; Timothy T. Kuo; Kanna Kobayashi; Steven M. Claypool; Tetsuya Takagawa; Hiromu Kutsumi; Takeshi Azuma; Wayne I. Lencer; Richard S. Blumberg

    2006-01-01

    Mucosal secretions of the human gastrointestinal, respiratory, and genital tracts contain significant quantities of IgG. The neonatal Fc receptor for IgG (FcRn) plays a major role in regulating host IgG levels and transporting IgG and associated antigens across polarized epithelial barriers. The FcRn can then recycle the IgG\\/antigen complex back across the intestinal barrier into the lamina propria for processing

  9. Dietary perilla oil lowers serum lipids and ovalbumin-specific IgG1, but increases total IgE levels in ovalbumin-challenged mice.

    PubMed

    Chang, Hui-Hsiang; Chen, Chin-Shuh; Lin, Jin-Yuarn

    2009-04-01

    Our previous studies indicated that alpha-linolenic acid (ALA)-rich perilla oil might alleviate bronchoalveolar inflammation. However, it failed to modulate the Th1/Th2 balance toward the Th1 pole during Th2-skewed allergic airway inflammation in mice. This study attempts to further investigate the effects of dietary perilla oil on serum lipids and immunoglobulin profiles using an ovalbumin (OVA)-challenged mouse model. The inbred female BALB/c mice were randomly divided into four groups and fed different AIN-76 feeds containing 5% corn oil (rich in linoleic acid, 18:2n-6 polyunsaturated fatty acids (PUFA), as a control diet), 5% perilla oil (rich in alpha-linolenic acid, 18:3n-3 PUFA) or 5% compound oil containing 50% corn oil and 50% perilla oil, respectively, for 35 consecutive days ad libitum. Experimental mice were sensitized by an intraperitoneal injection of alum-precipitated antigen containing ovalbumin on 7, 14 and 21 days after supply of the specified experimental diets. One week later, the mice were then challenged by aerosolized OVA. The results showed that dietary perilla oil administration significantly (P < 0.05) decreased the relative liver tissue weight (RTW) and serum lipid levels including triglycerides, total cholesterol, HDL- and LDL-cholesterol. However, the HDL/LDL ratio was also significantly lowered by dietary perilla oil. Dietary perilla oil markedly decreased serum OVA-specific IgG1 level and total IgA antibodies (Th2 antibodies). Unfortunately, it also increased non-specific serum IgE (Th2 antibody) levels. The results suggest that dietary perilla oil might have a moderately beneficial effect on asthmatic allergy via lowering serum lipids and OVA-specific IgG1, as well as total IgA levels. However, it failed to obviously modulate Th1/Th2 antibody levels via isotype switching of B cells from Th2 antibody to Th1 antibody. PMID:19271319

  10. Bacteroides gingivalis-specific serum IgG and IgA subclass antibodies in periodontal diseases.

    PubMed Central

    Ogawa, T; Kusumoto, Y; Hamada, S; McGhee, J R; Kiyono, H

    1990-01-01

    The level of serum IgM, IgG and IgA antibodies including IgG1, IgG2, IgG3, IgG4, IgA1 and IgA2 subclass-specific antibodies to Bacteroides (Porphyromonas) gingivalis fimbriae and to lipopolysaccharide (LPS) were analysed in patients with different forms of periodontal disease (PD) and control subjects by ELISA. Among PD subjects, sera obtained from adult periodontitis (AP), rapidly progressive periodontitis (RPP) and gingivitis contained high titres of fimbriae-specific IgG antibodies (7500-15,000 ELISA units) followed by IgA (90-700 units) and IgM (30-90 units). In contrast, sera from localized juvenile periodontitis (LJP) subjects exhibited much lower titres of fimbriae-specific IgG (89 +/- 11 units), IgA (31 +/- 5 units) and IgM (17 +/- 3 units) antibodies. A similar response pattern was also seen in sera from normal subjects aged 35-41 years who practice normal oral hygiene, while sera of younger adults (aged 18-24) with superior hygiene did not have any antigen-specific antibodies. Analysis of IgG subclass anti-fimbriae responses revealed that the major response was IgG3 followed by IgG1, IgG2 and IgG4 in AP, RPP and gingivitis. Although lower, a similar pattern of IgG subclass titre was seen in LJP and normal subjects aged 35-41 years. When IgA subclass responses were measured in AP and RPP, higher titres of the fimbriae-specific response were noted with IgA1 when compared with IgA2. However, lower but approximately equal levels of fimbriae-specific IgA1 and IgA2 titres were seen in other PD groups. When anti-B. gingivalis LPS-specific responses were measured, the sera of AP patients contained high levels of IgG antibodies (2265 +/- 224 units) followed by IgA (411 +/- 90 units) and IgM (214 +/- 56 units). Further, IgG anti-LPS responses were mainly IgG2 followed by IgG4, IgG3 and IgG1. For IgA subclass responses, higher titres of anti-LPS-specific antibodies were noted in IgA2 subclass over IgA1. These results showed that higher anti-B. gingivalis antibody responses occur in PD when compared with healthy individuals and protein and lipid-carbohydrate antigens of B. gingivalis induce distinct patterns of antigen-specific IgG and IgA subclass responses. PMID:1978704

  11. Prey choice and cannibalistic behaviour in the theropod Coelophysis

    PubMed Central

    Nesbitt, Sterling J; Turner, Alan H; Erickson, Gregory M; Norell, Mark A

    2006-01-01

    Abstract Direct evidence of prey choice in carnivorous dinosaurs is rare in the fossil record. The most celebrated example pertains to purported stomach contents in the carnivorous dinosaur Coelophysis bauri, which besides revealing prey choice, also points to cannibalistic behaviour as being commonplace (Colbert 1989, 1995). Here, we test this hypothesis by conducting the first comprehensive anatomical and histological examination of the famed Coelophysis ‘cannibals’. The results unequivocally show that the gut contents derive from early crocodylomorphs rather than juveniles of Coelophysis. These findings suggest that this taxon is not cannibalistic and bring into question the commonality of this behaviour among non-avian dinosaurs. PMID:17148302

  12. PREY ECOLOGY OF MEXICAN SPOTTED OWLS IN PINEOAK FORESTS OF NORTHERN ARIZONA

    E-print Network

    of primarily the deer mouse (Peromyscus maniculatus), brush mouse (P. boylii), Mexican woodrat (Neotoma, Peromyscus boylii, P. maniculatus, ponderosa pine­Gambel oak forest, prey abundance, prey habitat, Strix

  13. OIKOS 101: 591601, 2003 Assessing differential prey selection patterns between two

    E-print Network

    . Elk (Cer6us elephus) were the primary prey for both predators, followed by mule deer (Odocoileus hemionus). Both predators preyed disproportionately on elk calves and old individu- als; among mule deer

  14. Comparison of Antiviral Activity between IgA and IgG Specific to Influenza Virus Hemagglutinin: Increased Potential of IgA for Heterosubtypic Immunity

    PubMed Central

    Yokoyama, Ayaka; Miyamoto, Hiroko; Kajihara, Masahiro; Maruyama, Junki; Nao, Naganori; Manzoor, Rashid; Takada, Ayato

    2014-01-01

    Both IgA and IgG antibodies are known to play important roles in protection against influenza virus infection. While IgG is the major isotype induced systemically, IgA is predominant in mucosal tissues, including the upper respiratory tract. Although IgA antibodies are believed to have unique advantages in mucosal immunity, information on direct comparisons of the in vitro antiviral activities of IgA and IgG antibodies recognizing the same epitope is limited. In this study, we demonstrate differences in antiviral activities between these isotypes using monoclonal IgA and IgG antibodies obtained from hybridomas of the same origin. Polymeric IgA-producing hybridoma cells were successfully subcloned from those originally producing monoclonal antibody S139/1, a hemaggulutinin (HA)-specific IgG that was generated against an influenza A virus strain of the H3 subtype but had cross-neutralizing activities against the H1, H2, H13, and H16 subtypes. These monoclonal S139/1 IgA and IgG antibodies were assumed to recognize the same epitope and thus used to compare their antiviral activities. We found that both S139/1 IgA and IgG antibodies strongly bound to the homologous H3 virus in an enzyme-linked immunosorbent assay, and there were no significant differences in their hemagglutination-inhibiting and neutralizing activities against the H3 virus. In contrast, S139/1 IgA showed remarkably higher cross-binding to and antiviral activities against H1, H2, and H13 viruses than S139/1 IgG. It was also noted that S139/1 IgA, but not IgG, drastically suppressed the extracellular release of the viruses from infected cells. Electron microscopy revealed that S139/1 IgA deposited newly produced viral particles on the cell surface, most likely by tethering the particles. These results suggest that anti-HA IgA has greater potential to prevent influenza A virus infection than IgG antibodies, likely due to increased avidity conferred by its multivalency, and that this advantage may be particularly important for heterosubtypic immunity. PMID:24465606

  15. COMPARATIVE ABSORPTION OF COLOSTRAL IgG1 AND IgM IN THE NEWBORN CALF

    E-print Network

    Boyer, Edmond

    COMPARATIVE ABSORPTION OF COLOSTRAL IgG1 AND IgM IN THE NEWBORN CALF EFFECTS OF THYROXINE, CORTISOL PAR LE VEAU NOUVEAU-NÉ. INFLUENCE DE LA THYROXINE, DU CORTISOL ET DE LA TEMPÉRATURE AMBIANTE À LA. Furthermore, a negative correlation existed between the levels of thyroid hormone in the plasma at birth

  16. Lynx body size in Norway is related to its main prey (Roe deer) density, climate, and latitude.

    PubMed

    Yom-Tov, Yoram; Kvam, Tor; Wiig, Øystein

    2011-02-01

    We studied the effect of various factors on body size variation of the Eurasian lynx in Norway, using data from 374 lynx collected between 1960 and 1976 and whose locality of capture, year of birth, sex, and age were known. Body size of lynx in Norway was mainly affected by sex and age. Female skull size (and by implication body size) was also positively affected by the availability of its main prey (roe deer) and by latitude, and negatively by the North Atlantic Oscillation (NAO). Male size was not affected by any of the environmental factors examined. We interpret the effects of NAO and latitude on body size through their effect on the local climate and particularly snow conditions. We suggest that females are more sensitive to environmental factors than males. PMID:21404822

  17. Advanced glycation end-product (AGE)-damaged IgG and IgM autoantibodies to IgG-AGE in patients with early synovitis

    Microsoft Academic Search

    Marianna M Newkirk; Raphaela Goldbach-Mansky; Jennifer Lee; Joseph Hoxworth; Angie McCoy; Cheryl Yarboro; John Klippel; Hani S El-Gabalawy

    2003-01-01

    Advanced glycation end-product (AGE)-damaged IgG occurs as a result of hyperglycemia and\\/or oxidative stress. Autoantibodies to IgG-AGE were previously demonstrated in patients with severe, longstanding rheumatoid arthritis (RA). We investigated whether IgG-AGE and anti-IgG-AGE antibodies were present early in the course of RA and other inflammatory arthropathies. We prospectively followed a cohort of 238 patients with inflammatory arthritis of duration

  18. Detection of IgA and IgG but not IgE antibody to respiratory syncytial virus in nasal washes and sera from infants with wheezing

    Microsoft Academic Search

    Alessandro de Alarcon; Edward E. Walsh; Holliday T. Carper; Joseph B. La Russa; Brent A. Evans; Gary P. Rakes; Thomas A. E. Platts-Mills; Peter W. Heymann

    2001-01-01

    Background and Objective: The capacity of respiratory syncytial virus (RSV) to stimulate an IgE antibody response and enhance the development of atopy and asthma remains controversial. Nasal washes and sera from 40 infants (20 with wheezing, 9 with rhinitis, and 11 without respiratory tract symptoms) were obtained to measure IgE, IgA, and IgG antibody to the immunodominant, F and G,

  19. The bigger they come, the harder they fall: body size and prey abundance influence predator–prey ratios

    PubMed Central

    Carbone, Chris; Pettorelli, Nathalie; Stephens, Philip A.

    2011-01-01

    Large carnivores are highly threatened, yet the processes underlying their population declines are still poorly understood and widely debated. We explored how body mass and prey abundance influence carnivore density using data on 199 populations obtained across multiple sites for 11 carnivore species. We found that relative decreases in prey abundance resulted in a five- to sixfold greater decrease in the largest carnivores compared with the smallest species. We discuss a number of possible causes for this inherent vulnerability, but also explore a possible mechanistic link between predator size, energetics and population processes. Our results have important implications for carnivore ecology and conservation, demonstrating that larger species are particularly vulnerable to anthropogenic threats to their environment, especially those which have an adverse affect on the abundance of their prey. PMID:21106569

  20. Eye movements and target fixation during dragonfly prey-interception flights

    Microsoft Academic Search

    R. M. Olberg; R. C. Seaman; M. I. Coats; A. F. Henry

    2007-01-01

    The capture of flying insects by foraging dragonflies is a highly accurate, visually guided behavior. Rather than simply aiming\\u000a at the prey’s position, the dragonfly aims at a point in front of the prey, so that the prey is intercepted with a relatively\\u000a straight flight trajectory. To better understand the neural mechanisms underlying this behavior, we used high-speed video\\u000a to

  1. Piscivore efficiency and refuging prey: the importance of predator search mode

    Microsoft Academic Search

    Peter Eklöv; Sebastian Diehl

    1994-01-01

    In predator-prey interactions, the efficiency of the predator is dependent on characteristics of both the predator and the prey, as well as the structure of the environment. In a field enclosure experiment, we tested the effects of a prey refuge on predator search mode, predator efficiency and prey behaviour. Replicated enclosures containing young of the year (0+) and 1-year-old (1+)

  2. Cannibalism in a Zoophytophagous Omnivore is Mediated by Prey Availability and Plant Substrate

    Microsoft Academic Search

    Amie Laycock; Edith Camm; Sherah Van Laerhoven; Dave Gillespie

    2006-01-01

    Cannibalism is a dietary option, the frequency of which, in most predator-prey systems, is inversely proportional to the abundance of primary prey. Under conditions of prey scarcity, in food webs involving plant-feeding omnivores, cannibals may choose to feed on either conspecifics or on the continuously-available but less nourishing plant substrate. We tested the effects of prey limitation and plant species

  3. Insect predator-prey coevolution via enantiomeric specificity in a kairomone-pheromone system

    Microsoft Academic Search

    T. L. Payne; J. C. Dickens; J. V. Richerson

    1984-01-01

    Insect predators can be guided to their prey by a kairomonal response to the prey pheromone. We found this phenomenon to be highly specific in the bark beetle predatorThanasimus dubius. Olfactory responses and behavioral tests revealed that the predator is guided to its major preyDendroctonusfrontalis by the primary enantiomer of the pheromone of the prey, (1S, 5R)-(-)-frontalin. These and other

  4. Prey preferences of Portia fimbriata , an araneophagic, web-building jumping spider (Araneae: Salticidae) from Queensland

    Microsoft Academic Search

    Daiqin Li I; Robert R. Jackson

    1996-01-01

    Portia fimbriata from Queensland, a previously studied jumping spider (Salticidae), routinely includes web-building spiders and cursorial salticids in its diet, both of these types of prey being dangerous and unusual prey for a salticid. The present paper is the first detailed study ofP. fimbriata's prey preferences. Three basic types of tests of prey preference were used, providing evidence that (1)P.

  5. Predator-Prey Interactions of Fishes under the Influence of Ammonia

    Microsoft Academic Search

    D. M. Woltering; J. L. Hedtke; L. J. Weber

    1978-01-01

    Food consumption and growth rates of a predator, the largemouth bass (Micropterus salmoides), and the behavior of both the predator and its prey, the mosquitofish (Gambusia affinis), were sensitive indices of sublethal effects of ammonia on predator-prey interactions. Prey consumption and growth rates of bass in control tests increased with increasing prey densities. Ammonia concentrations of 0.63 and 0.86 mg\\/liter

  6. Crime, Females and Statistics

    Microsoft Academic Search

    Dennis Challinger

    1982-01-01

    Inspection of Victoria Police data shows that females proceeded against account for an increasing volume of crime, and have higher offending rates over 1960–1979. The bulk of female offences remain in the property area and in particular theft from shops accounts for most female activity. Changes in retail security procedures may explain some of the increase and that, in turn,

  7. Decreased Levels of Bisecting GlcNAc Glycoforms of IgG Are Associated with Human Longevity

    PubMed Central

    Ruhaak, L. Renee; Uh, Hae-Won; Beekman, Marian; Koeleman, Carolien A. M.; Hokke, Cornelis H.; Westendorp, Rudi G. J.; Wuhrer, Manfred; Houwing-Duistermaat, Jeanine J.

    2010-01-01

    Background Markers for longevity that reflect the health condition and predict healthy aging are extremely scarce. Such markers are, however, valuable in aging research. It has been shown previously that the N-glycosylation pattern of human immunoglobulin G (IgG) is age-dependent. Here we investigate whether N-linked glycans reflect early features of human longevity. Methodology/Principal Findings The Leiden Longevity Study (LLS) consists of nonagenarian sibling pairs, their offspring, and partners of the offspring serving as control. IgG subclass specific glycosylation patterns were obtained from 1967 participants in the LLS by MALDI-TOF-MS analysis of tryptic IgG Fc glycopeptides. Several regression strategies were applied to evaluate the association of IgG glycosylation with age, sex, and longevity. The degree of galactosylation of IgG decreased with increasing age. For the galactosylated glycoforms the incidence of bisecting GlcNAc increased as a function of age. Sex-related differences were observed at ages below 60 years. Compared to males, younger females had higher galactosylation, which decreased stronger with increasing age, resulting in similar galactosylation for both sexes from 60 onwards. In younger participants (<60 years of age), but not in the older age group (>60 years), decreased levels of non-galactosylated glycoforms containing a bisecting GlcNAc reflected early features of longevity. Conclusions/Significance We here describe IgG glycoforms associated with calendar age at all ages and the propensity for longevity before middle age. As modulation of IgG effector functions has been described for various IgG glycosylation features, a modulatory effect may be expected for the longevity marker described in this study. PMID:20830288

  8. IL-4 upregulates Ig? and Ig? protein, resulting in augmented IgM maturation and BCR-triggered B cell activation1

    PubMed Central

    Guo, Benchang; Rothstein, Thomas L.

    2015-01-01

    Interleukin 4 (IL-4) is critical for optimal B cell activation and germinal center B cell expansion in T-dependent immune responses; however, the underlying mechanism remains elusive. In the present study, we found that primary B cells express little Ig? and Ig? protein despite substantial levels of messenger RNA. IL-4 markedly up-regulates Ig? and Ig? protein expression that requires STAT6. Elevated Ig? and Ig? protein form heterodimers that associate with IgM and significantly promote IgM maturation and surface IgM expression, resulting in amplified BCR-initiated signaling that is Lyn-dependent. In vivo, we found that pre-germinal center B cells express upregulated Ig?, Ig?, and surface IgM expression, in conjunction with elevated BCR-triggered pERK ex vivo, that are dependent on IL-4 and reversed by in vivo administration of neutralizing anti-IL-4 antibody. Thus, this study elucidates a novel mechanism for crosstalk between the IL-4 and B cell receptors that programs enhancement of subsequent BCR signaling. PMID:23776171

  9. Comparison of the Specificities of IgG, IgG-Subclass, IgA and IgM Reactivities in African and European HIV-Infected Individuals with an HIV-1 Clade C Proteome-Based Array

    PubMed Central

    Gallerano, Daniela; Ndlovu, Portia; Makupe, Ian; Focke-Tejkl, Margarete; Fauland, Kerstin; Wollmann, Eva; Puchhammer-Stöckl, Elisabeth; Keller, Walter; Sibanda, Elopy; Valenta, Rudolf

    2015-01-01

    A comprehensive set of recombinant proteins and peptides of the proteome of HIV-1 clade C was prepared and purified and used to measure IgG, IgG-subclass, IgA and IgM responses in HIV-infected patients from Sub-Saharan Africa, where clade C is predominant. As a comparison group, HIV-infected patients from Europe were tested. African and European patients showed an almost identical antibody reactivity profile in terms of epitope specificity and involvement of IgG, IgG subclass, IgA and IgM responses. A V3-peptide of gp120 was identified as major epitope recognized by IgG1>IgG2 = IgG4>IgG3, IgA>IgM antibodies and a C-terminal peptide represented another major peptide epitope for the four IgG subclasses. By contrast, gp41-derived-peptides were mainly recognized by IgG1 but not by the other IgG subclasses, IgA or IgM. Among the non-surface proteins, protease, reverse transcriptase+RNAseH, integrase, as well as the capsid and matrix proteins were the most frequently and strongly recognized antigens which showed broad IgG subclass and IgA reactivity. Specificities and magnitudes of antibody responses in African patients were stable during disease and antiretroviral treatment, and persisted despite severe T cell loss. Using a comprehensive panel of gp120, gp41 peptides and recombinant non-surface proteins of HIV-1 clade C we found an almost identical antibody recognition profile in African and European patients regarding epitopes and involved IgG-sublass, IgA- and IgM-responses. Immune recognition of gp120 peptides and non-surface proteins involved all four IgG subclasses and was indicative of a mixed Th1/Th2 immune response. The HIV-1 clade C proteome-based test allowed diagnosis and monitoring of antibody responses in the course of HIV-infections and assessment of isotype and subclass responses. PMID:25658330

  10. Teleost fish mount complex clonal IgM and IgT responses in spleen upon systemic viral infection.

    PubMed

    Castro, Rosario; Jouneau, Luc; Pham, Hang-Phuong; Bouchez, Olivier; Giudicelli, Véronique; Lefranc, Marie-Paule; Quillet, Edwige; Benmansour, Abdenour; Cazals, Frédéric; Six, Adrien; Fillatreau, Simon; Sunyer, Oriol; Boudinot, Pierre

    2013-01-01

    Upon infection, B-lymphocytes expressing antibodies specific for the intruding pathogen develop clonal responses triggered by pathogen recognition via the B-cell receptor. The constant region of antibodies produced by such responding clones dictates their functional properties. In teleost fish, the clonal structure of B-cell responses and the respective contribution of the three isotypes IgM, IgD and IgT remain unknown. The expression of IgM and IgT are mutually exclusive, leading to the existence of two B-cell subsets expressing either both IgM and IgD or only IgT. Here, we undertook a comprehensive analysis of the variable heavy chain (VH) domain repertoires of the IgM, IgD and IgT in spleen of homozygous isogenic rainbow trout (Onchorhynchus mykiss) before, and after challenge with a rhabdovirus, the Viral Hemorrhagic Septicemia Virus (VHSV), using CDR3-length spectratyping and pyrosequencing of immunoglobulin (Ig) transcripts. In healthy fish, we observed distinct repertoires for IgM, IgD and IgT, respectively, with a few amplified ? and ? junctions, suggesting the presence of IgM- and IgT-secreting cells in the spleen. In infected animals, we detected complex and highly diverse IgM responses involving all VH subgroups, and dominated by a few large public and private clones. A lower number of robust clonal responses involving only a few VH were detected for the mucosal IgT, indicating that both IgM(+) and IgT(+) spleen B cells responded to systemic infection but at different degrees. In contrast, the IgD response to the infection was faint. Although fish IgD and IgT present different structural features and evolutionary origin compared to mammalian IgD and IgA, respectively, their implication in the B-cell response evokes these mouse and human counterparts. Thus, it appears that the general properties of antibody responses were already in place in common ancestors of fish and mammals, and were globally conserved during evolution with possible functional convergences. PMID:23326228

  11. The interaction of ruminant IgG with receptor type II for IgG on human phagocytes.

    PubMed Central

    Jungi, T W; Peterhans, E; Pfister, H; Fey, H

    1989-01-01

    The interaction of ruminant IgG with human phagocytes was assessed using Fc receptor (FcR)-mediated ingestion and the triggering of a respiratory burst as effector functions indicative of receptor-specific interaction. In monomeric form, ruminant IgG was three to five orders of magnitude less potent than homologous IgG in inhibiting FcR-specific phagocytosis by monocytes. However, when attached to tanned sheep erythrocytes (Es-T), ruminant IgG was opsonic, as it promoted enhanced phagocytosis of Es-T, comparable to ingestion of rabbit IgG-coated Es. This phagocytosis was inhibitable by high concentrations of human IgG in the fluid phase. Moreover, Es-T precoated with ferritin could be opsonized to a similar degree by anti-ferritin IgG from rabbit and cow. However, only bovine IgG1, but not IgG2, was opsonic. Bovine and goat IgG of some, but not other, suppliers were inactive. Similar results were obtained by measuring the respiratory burst triggered by heat-aggregated IgG, using a luminol-enhanced chemiluminescence assay. Thus, human IgG and ruminant IgG stimulated monocytes and, to a lesser extent, polymorphonuclear leucocytes (PMN), to generate CL. Depending on the manufacturer, some preparations of bovine and goat IgG were inactive, and bovine IgG2 failed to induce CL. These findings prove that certain ruminant IgG preparations, including bovine IgG1 interacting weakly with homologous PMN and monocytes, do interact with human PMN, monocytes and macrophages in a FcR-specific manner when offered in complexed form. Inhibition studies suggest that bovine IgG1 interacts mainly with human FcR type II. In contrast, bovine IgG2, regarded as cytophilic for homologous PMN, fails to interact with human PMN, monocytes and macrophages. PMID:15493277

  12. Decreased cervicovaginal production of both IgA1 and IgA2 subclasses in women with AIDS.

    PubMed Central

    Belec, L; Meillet, D; Gaillard, O; Prazuck, T; Michel, E; Ngondi Ekome, J; Pillot, J

    1995-01-01

    Paired sera and cervicovaginal secretions from 35 HIV-1-infected women representing different CDC stages of HIV infection were evaluated for total IgA, IgA1 and IgA2, for IgA, IgA1 and IgA2 to gp160, and for albumin. Age-matched healthy women (n = 45) served as controls. The secretion rates of total IgA, IgA1 and IgA2 were evaluated by calculating their relative coefficients of excretion by reference to albumin. In HIV-infected women, total IgA1 and IgA2 in sera and in cervicovaginal secretions increased proportionately as early as stages II + III and more markedly at stage IV. By contrast, the secretion rates of total IgA IgA1 and IgA2 were markedly reduced in AIDS women, the IgA2 secretion rate decreasing significantly as early as stages II + III. This apparent discrepancy was probably the result of increased transudation of serum-borne immunoglobulins into the vaginal cavity, since albumin levels in cervicovaginal secretions increased significantly according to the stages of disease. HIV-reactive IgA antibodies in serum, as in cervicovaginal secretions, were principally found within the IgA1 subclass. In women at stage IV, a high local production of IgA1 to gp160 occurred in spite of the impairment of cervicovaginal IgA synthesis, probably because of marked genital HIV replication at advanced stages. PMID:7621578

  13. Abnormal IgD and IgA1 O-glycosylation in hyperimmunoglobulinaemia D and periodic fever syndrome.

    PubMed

    de Wolff, Jacob F; Dickinson, Stephen J; Smith, Alice C; Molyneux, Karen; Feehally, John; Simon, Anna; Barratt, Jonathan

    2009-12-01

    In order to determine the glycosylation pattern for IgD, and to examine whether there are changes in the pattern of IgD and IgA1 O-glycosylation in patients with hyperimmunoglobulinaemia D and periodic fever syndrome (HIDS) during acute febrile attacks and during periods of quiescence, serum was obtained from 20 patients with HIDS and 20 control subjects. In the HIDS group, serum was obtained either during an acute febrile episode (n = 9) or during a period of quiescence (n = 11). The O-glycosylation profiles of native and desialylated IgA1 and IgD were measured in an ELISA-type system using the lectins Helix aspersa and peanut agglutinin, which bind to alternative forms of O-glycan moieties. IgD is more heavily O-galactosylated and less O-sialylated than IgA1 in healthy subjects. HIDS is associated with more extensive O-galactosylation of IgD and a reduction in O-sialylation of both IgD and IgA1. These changes are present both during acute febrile attacks and periods of quiescence. The T cell IgD receptor is a lectin with binding affinity for the O-glycans of both IgD and IgA1. The observed changes in IgD and IgA1 O-glycosylation are likely to have a significant effect on IgD/IgA1-T cell IgD receptor interactions including basal immunoglobulin synthesis, and possibly myeloid IgD receptor-mediated cytokine release. PMID:19543954

  14. Seasonality of prey size selection in adult Sympetrum vicinum (Odonata: Libellulidae)

    Microsoft Academic Search

    Andrea Worthington; Kristen Haggert; Michael Loosemore

    2005-01-01

    Sympetrum vicinum is a sit and wait predator, which takes off and pursues small flying insects during its long flying season (July to November). We investigated whether foraging individuals become less discriminating regarding prey size selection during the fall season because the changeable fall weather has an impact on the prey population. To investigate the seasonality of prey size selection,

  15. Predatory Bdellovibrio bacteria use gliding motility to scout for prey on surfaces.

    PubMed

    Lambert, Carey; Fenton, Andrew K; Hobley, Laura; Sockett, R Elizabeth

    2011-06-01

    Bdellovibrio bacteriovorus is a famously fast, flagellate predatory bacterium, preying upon Gram-negative bacteria in liquids; how it interacts with prey on surfaces such as in medical biofilms is unknown. Here we report that Bdellovibrio bacteria "scout" for prey bacteria on solid surfaces, using slow gliding motility that is present in flagellum-negative and pilus-negative strains. PMID:21515772

  16. Steller sea lion foraging response to seasonal changes in prey availability

    Microsoft Academic Search

    Michael F. Sigler; Dominic J. Tollit; Johanna J. Vollenweider; John F. Thedinga; David J. Csepp; Jamie N. Womble; Mandy A. Wong; Michael J. Rehberg; Andrew W. Trites

    2009-01-01

    We hypothesized that: (1) Steller sea lion Eumetopias jubatus diet choice is a function of prey availability, (2) sea lions move to take advantage of times and locations of seasonal prey concen- trations and (3) the number present depends on the amount of prey available (numerical response). Over 3 yr, typically on a quarterly basis, in Frederick Sound, SE Alaska,

  17. THE MODULATION OF FEEDING BEHAVIOR IN RESPONSE TO PREY TYPE IN THE FROG RANA PIPIENS

    Microsoft Academic Search

    CURTIS W. ANDERSON

    1993-01-01

    Summary Using high-speed video motion analysis, the kinematics of feeding behavior was studied in Rana pipiens. Rana pipiens exhibits differing behavior patterns depending upon prey type. When feeding on small prey such as waxworms, R. pipiens uses tongue protraction to catch prey, minimizing head and body movements. When feeding on the larger earthworm, it arches its body, flexes the head

  18. Prey consumption and energy transfer by marine birds in the Gulf of Alaska

    Microsoft Academic Search

    George L. Hunt; Gary S. Drew; Jaime Jahncke; John F. Piatt

    2005-01-01

    We investigated prey consumption by marine birds and their contribution to cross-shelf fluxes in the northern Gulf of Alaska. We utilized data from the North Pacific Pelagic Seabird Database for modeling energy demand and prey consumption. We found that prey consumption by marine birds was much greater over the continental shelf than it was over the basin. Over the shelf,

  19. 77 FR 42327 - Proposed Supplementary Rules for the Morley Nelson Snake River Birds of Prey National...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-07-18

    ...Supplementary Rules for the Morley Nelson Snake River Birds of Prey National Conservation...approximately 483,700-acre Morley Nelson Snake River Birds of Prey National Conservation...and Record of Decision (ROD). The Snake River Birds of Prey NCA RMP...

  20. Diet of Common Nighthawks (Chordeiles minor: Caprimulgidae) Relative to Prey Abundance

    Microsoft Academic Search

    L. Danielle Todd; Ray G. Poulin; R. Mark Brigham

    1998-01-01

    Optimal foraging theory predicts that when prey density is low, predators should employ a generalist feeding strategy and take prey in proportion to their abundance. The purpose of this study was to compare the diet of common nighthawks (Chordeiles minor: Caprimulgidae) with a measure of prey abundance. Relative to the proportion of insects available, nighthawks consumed Coleoptera and Hymenoptera more

  1. PRIMARY RESEARCH PAPER Microhabitat use and prey selection of the coral-feeding

    E-print Network

    Zuschin, Martin

    PRIMARY RESEARCH PAPER Microhabitat use and prey selection of the coral-feeding snail Drupella of coral reef, prey preferences have never been analyzed with respect to prey availability, and juvenile ecology and food selectivity remain largely unknown. Here, the influ- ence of water depth, coral abundance

  2. Dietary supplementation with non-prey food enhances fitness of a predatory arthropod

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Uncertainties exist about the value of non-prey food for natural enemies that are commonly food limited, and the dietary conditions where non-prey foods are beneficial for carnivorous species. We examined the nutritional role of a non-prey food using a ground dwelling, tangle web-building spider tha...

  3. Experimental evidence of cannibalism and prey specialization in Arctic charr, Salvelinus alpinus

    Microsoft Academic Search

    Per-Arne Amundsen; Arne Mikal Arnesen; Malcolm Jobling; Even H. Jørgensen

    1995-01-01

    Use of a radiographic technique enabled the study of prey selection and individual specialization in Arctic charr, Salvelinus alpinus, fed with small charr and dry pellets under laboratory conditions. Both naive and experienced fish (mean weight 475 g, mean length 34.9 cm), selected the smallest individuals when offered juvenile charr (6–16 cm) as prey. The selected prey were, on average,

  4. Teams in social insects: group retrieval of prey by army ants ( Eciton burchelli , Hymenoptera: Formicidae)

    Microsoft Academic Search

    Nigel R. Franks

    1986-01-01

    Eciton burchelli workers frequently form groups to retrieve large prey items. Such groups have a definite structure. There is a constant relationship between total ant dry weight and prey item dry weight for both individual porters and groups, and this relation is such that a larger weight of ant or ants can carry disproportionately heavy items. Furthermore, all prey items

  5. Predator versus prey: on aerial hunting and escape strategies in birds

    Microsoft Academic Search

    Anders Hedenstrom; Mikael Rosen

    2001-01-01

    Predator and prey attack-escape performance is likely to be the outcome of an evolutionary arms race. Predatory birds are typically larger than their prey, suggesting different flight performances. We analyze three idealized attack-escape situations between predatory and prey birds: climbing flight escape, horizontal speeding, and turning and escape by diving. Generally a smaller bird will outclimb a larger predator and

  6. RELATIONSHIPS OF THE BLUE SHARK, PRZONACE GLAUCA, AND ITS PREY SPECIES NEAR SANTA CATALINA ISLAND, CALIFORNIA'

    E-print Network

    Tricas, Timothy C.

    RELATIONSHIPS OF THE BLUE SHARK, PRZONACE GLAUCA, AND ITS PREY SPECIES NEAR SANTA CATALINA ISLAND the major prey for the blue shark, Prionace glauca, near Santa Catalina Island, Calif. The northern anchovy, Engraulis mordm, was the predominant prey for sharks in the immediate study area while at least 13 speciesof

  7. A generalized functional response for predators that switch between multiple prey species

    E-print Network

    observations of prey switching and is based on the behavioural assumption that a predator tends to continue, defences, location, habitat choice, or behaviour. From a predator's dietary history and the assumed observations for predators feeding only on pairs of prey species. (5) Predators foraging on more prey species

  8. Foraging modes in an assemblage of odonate larvae — effects of prey and interference

    Microsoft Academic Search

    Frank Johansson

    1991-01-01

    The foraging behaviour of four coexisting odonate larvae; Coenagrion hastulatum (Charp.) Zygoptera, Aeshna juncea (L.) Anisoptera, Cordulia aenea (L.) Anisoptera and Leucorrhinia dubia (v d Lind.) Anisoptera was analysed under various conditions of prey type and abundance. Coenagrion and Aeshna used a sit and wait mode when the prey density was high and when the prey was evasive. When the

  9. Prey consumption by the mealybug predator Spalgis epius on pink hibiscus mealybug ( Maconellicoccus hirsutus )

    Microsoft Academic Search

    Anegunda S. Dinesh; Melally G. Venkatesha

    2011-01-01

    The pink hibiscus mealybug Maconellicoccus hirsutus (Green) (Hemiptera: Pseudococcidae) is a major pest of economically important crops. The apefly Spalgis epius (Westwood) (Lepidoptera: Lycaenidae) is a potential predator of various species of mealybugs. Studies of its preying potential\\u000a and preference for prey stages on M. hirsutus are incomplete. An investigation was undertaken to determine the daily prey consumption and preference

  10. The Cost of Capturing Prey: Measuring Largemouth Bass Foraging Activity using Glycolytic Enzymes (Lactate Dehydrogenase)

    E-print Network

    The Cost of Capturing Prey: Measuring Largemouth Bass Foraging Activity using Glycolytic Enzymes THE COST OF CAPTURING PREY: MEASURING LARGEMOUTH BASS FORAGING ACTIVITY USING GLYCOLYTIC ENZYMES (LACTATE #12;11 The Cost of Capturing Prey: Measuring Largemouth Bass Foraging Activity using Glycolytic

  11. A reduced model for spatially structured predator-prey systems with fast spatial migrations and slow

    E-print Network

    Castella, François

    evolving both under the effect of spatial migrations, and under the effect of prey-predator interaction. We interaction through a simple Lotka- Volterra system: we stress that any other realistic model of prey-predator, in this context, while the typical time-scale of predator-prey interaction is naturally of the order of several

  12. Computational Science Technical Note CSTN-010 Defensive Spiral Emergence in a Predator-Prey Model

    E-print Network

    Hawick, Ken

    behaviour that arises from the predator- prey interactions. We believe the emergent patterns from predator-prey interaction between randomly initialised groups of animal automata. We believe we0 Computational Science Technical Note CSTN-010 Defensive Spiral Emergence in a Predator-Prey Model

  13. Wave Train Selection Behind Invasion Fronts in Reaction-Diffusion Predator-Prey Models

    E-print Network

    Nagata, Wayne

    is that this oscillatory behaviour arises from the interaction between a predator population and its prey, and many modelsWave Train Selection Behind Invasion Fronts in Reaction-Diffusion Predator-Prey Models Sandra M in oscillatory reaction-diffusion models for predator-prey systems. Although there is a one-parameter family

  14. GLOBAL ANALYSIS IN A PREDATOR-PREY SYSTEM WITH NONMONOTONIC FUNCTIONAL RESPONSE

    E-print Network

    Ruan, Shigui

    and by Volterra in 1926 in modeling a predator-prey interaction. However, the curve defined by the Lotka­ VolterraGLOBAL ANALYSIS IN A PREDATOR-PREY SYSTEM WITH NONMONOTONIC FUNCTIONAL RESPONSE SHIGUI RUAN. 1445­1472 Abstract. A predator-prey system with nonmonotonic functional response is considered. Global

  15. Effects of an Infectious Fungus, Batrachochytrium dendrobatidis, on Amphibian Predator-Prey Interactions

    E-print Network

    Blaustein, Andrew R.

    , on Amphibian Predator-Prey Interactions. PLoS ONE 6(2): e16675. doi:10.1371/journal.pone.0016675 Editor: Howard-predatory behaviors with important consequences for predator-prey interactions. For example, several studies revealEffects of an Infectious Fungus, Batrachochytrium dendrobatidis, on Amphibian Predator-Prey

  16. Water shrews detect movement, shape, and smell to find prey underwater

    Microsoft Academic Search

    Kenneth C. Catania; James F. Hare; Kevin L. Campbell

    2008-01-01

    American water shrews (Sorex palustris) are aggressive predators that feed on a variety of terrestrial and aquatic prey. They often forage at night, diving into streams and ponds in search of food. We investigated how shrews locate submerged prey using high-speed videography, infrared lighting, and stimuli designed to mimic prey. Shrews attacked brief water movements, indicating motion is an important

  17. 1999 Macmillan Magazines Ltd ost snakes transport prey through

    E-print Network

    Brainerd, Elizabeth

    . This mechanism, which we call `mandibular rak- ing', is the only vertebrate feeding mecha- nism known in which to study their feeding mechanics. We used an inverted dissecting micro- scope coupled to a high-speed video, allowing the lower jaw to conform more closely to the shape of large vertebrate prey, thereby maximizing

  18. Dynamics of Prey Capture and Escape Wednesday, March 6th

    E-print Network

    Eddy, Sean

    processing during predation? 10:15 am Sheila Patek, University of Massachusetts Power and the evolution: Cynthia Moss 11:10 am Karin Nordström, Uppsala University Neural mechanisms underlying target tracking, University pf Maryland Latency and stochasticity in prey capture 3:05 pm Cynthia F. Moss, University

  19. Cooperative prey herding by the pelagic dolphin, Stenella longirostris

    E-print Network

    Benoit-Bird, Kelly J.

    , Corvallis, Oregon 97330 Whitlow W. L. Au Hawaii Institute of Marine Biology, University of Hawaii, P.O. Box 1106, Kailua, Hawaii 96734 Received 7 January 2008; revised 20 June 2008; accepted 23 June 2008 Sonar consuming an estimated 1.25 prey items per minute through- out the night Benoit-Bird, 2004 . Spinner

  20. Conservation Status of North America's Birds of Prey

    Microsoft Academic Search

    Christopher J. Farmer; Laurie J. Goodrich; Ernesto Ruelas Inzunza; Jeff P. Smith

    We assessed the conservation status of 20 species of North American birds of prey by examining historical and recent estimates of trends in counts of raptors at migration watchsites. We compared these trend estimates with trends in Breeding Bird Surveys (BBSs), Christmas Bird Counts (CBCs) (terms in italics are defi ned in the book's glossary), and other available population indexes

  1. Testing for Camouflage Using Virtual Prey and Human "Predators"

    ERIC Educational Resources Information Center

    Todd, Peter A.

    2009-01-01

    Camouflage is a prevalent feature of the natural world and as such has a ready appeal to students; however, it is a difficult subject to study using real predators and prey. This paper focuses how one fundamental type of camouflage, disruptive colouration (bold markings that break up the outline of the organism), can be tested using paper…

  2. Prey selection by the scyphomedusan predator Aurelia aurita

    Microsoft Academic Search

    B. K. Sullivan; J. R. Garcia; G. Klein-MacPhee

    1994-01-01

    We describe feeding behavior of Aurelia aurita (Linnaeus) using gut content analyses of field-collected specimens and a mesocosm experiment. The field studies were conducted in Narragansett Bay, Rhode Island, USA from March to April 1988, and the mesocosm studies were done at the Marine Ecosystems Research Laboratory at the University of Rhode Island. Patterns of prey selection changed with medusa

  3. Changes in water chemistry can disable plankton prey defenses

    PubMed Central

    Riessen, Howard P.; Linley, Robert Dallas; Altshuler, Ianina; Rabus, Max; Söllradl, Thomas; Clausen-Schaumann, Hauke; Laforsch, Christian; Yan, Norman D.

    2012-01-01

    The effectiveness of antipredator defenses is greatly influenced by the environment in which an organism lives. In aquatic ecosystems, the chemical composition of the water itself may play an important role in the outcome of predator–prey interactions by altering the ability of prey to detect predators or to implement defensive responses once the predator’s presence is perceived. Here, we demonstrate that low calcium concentrations (<1.5 mg/L) that are found in many softwater lakes and ponds disable the ability of the water flea, Daphnia pulex to respond effectively to its predator, larvae of the phantom midge, Chaoborus americanus. This low-calcium environment prevents development of the prey’s normal array of induced defenses, which include an increase in body size, formation of neck spines, and strengthening of the carapace. We estimate that this inability to access these otherwise effective defenses results in a 50–186% increase in the vulnerability of the smaller juvenile instars of Daphnia, the stages most susceptible to Chaoborus predation. Such a change likely contributes to the observed lack of success of daphniids in most low-calcium freshwater environments, and will speed the loss of these important zooplankton in lakes where calcium levels are in decline. PMID:22949653

  4. Cyclic Genetic Algorithm with Conditional Branching PredatorPrey Scenario

    E-print Network

    Parker, Gary B.

    Cyclic Genetic Algorithm with Conditional Branching Predator­Prey Scenario Gary Parker Computer Science Connecticut College New London, 06320 parker@conncoll.edu Parashkevov Computer Science Connecticut) found to a successful method evolving single control programs legged robots. major limitation

  5. Are Kissing Gourami Specialized for Substrate-Feeding? Prey

    E-print Network

    Gibb, Alice C.

    Are Kissing Gourami Specialized for Substrate-Feeding? Prey Capture Kinematics of Helostoma The Kissing gourami, Helostoma temminckii, has an unusual jaw morphology, which is used in a peculiar way: two the tips of their jaws against one another. This eponymous "kissing" behavior is an intraspecific

  6. Visual Detection of Cryptic Prey by Blue Jays (Cyanocitta cristata).

    PubMed

    Pietrewicz, A T; Kamil, A C

    1977-02-11

    Blue jays learned to respond differentially to the presence or absence of Catocala moths in slides. This detection of the moths by the jays was affected by the background upon which the moth was placed and its body orientation, thus providing an objective measure of crypticity. These procedures are useful for the study of visual detection of prey. PMID:17732294

  7. Visual predators select for crypticity and polymorphism in virtual prey

    Microsoft Academic Search

    Alan B. Bond; Alan C. Kamil

    2002-01-01

    Cryptically coloured animals commonly occur in several distinct pattern variants. Such phenotypic diversity may be promoted by frequency-dependent predation, in which more abundant variants are attacked disproportionately often, but the hypothesis has never been explicitly tested. Here we report the first controlled experiment on the effects of visual predators on prey crypticity and phenotypic variance, in which blue jays (Cyanocitta

  8. Visual Detection of Cryptic Prey by Blue Jays (Cyanocitta cristata)

    Microsoft Academic Search

    Alexandra T. Pietrewicz; Alan C. Kamil

    1977-01-01

    Blue jays learned to respond differentially to the presence or absence of Catocala moths in slides. This detection of the moths by the jays was affected by the background upon which the moth was placed and its body orientation, thus providing an objective measure of crypticity. These procedures are useful for the study of visual detection of prey.

  9. Research Article Winter Prey Selection of Canada Lynx in

    E-print Network

    abundance play in habitat selection of Canada lynx (Lynx canadensis) in the contiguous United States.2193/2005-445 KEY WORDS alternative prey, Canada lynx, food habits, Lepus americanus, Lynx canadensis, Montana, snowshoe hare. Northern populations of Canada lynx (Lynx canadensis) exhibit both numeric (Elton

  10. Signal conict in spider webs driven by predators and prey

    E-print Network

    Blackledge, Todd

    Signal con¯ict in spider webs driven by predators and prey Todd A. Blackledge Department silk designs, stabilimenta, in the centre of their webs. Stabilimenta can be highly visible signals to predators, warning them of the presence of a noxious, sticky silk web. However, stabilimenta can also

  11. Evolution of dispersal in a predator-prey metacommunity.

    PubMed

    Pillai, Pradeep; Gonzalez, Andrew; Loreau, Michel

    2012-02-01

    Dispersal is crucial to allowing species inhabiting patchy or spatially subdivided habitats to persist globally despite the possibility of frequent local extinctions. Theoretical studies have repeatedly demonstrated that species that exhibit a regional metapopulation structure and are subject to increasing rates of local patch extinctions should experience strong selective pressures to disperse more rapidly despite the costs such increased dispersal would entail in terms of decreased local fitness. We extend these studies to consider how extinctions arising from predator-prey interactions affect the evolution of dispersal for species inhabiting a metacommunity. Specifically, we investigate how increasing a strong extinction-prone interaction between a predator and prey within local patches affects the evolution of each species' dispersal. We found that for the predator, as expected, evolutionarily stable strategy (ESS) dispersal rates increased monotonically in response to increasing local extinctions induced by strong predator top-down effects. Unexpectedly for the prey, however, ESS dispersal rates displayed a nonmonotonic response to increasing predator-induced extinction rates-actually decreasing for a significant range of values. These counterintuitive results arise from how extinctions resulting from trophic interactions play out at different spatial scales: interactions that increase extinction rates of both species locally can, at the same time, decrease the frequency of interaction between the prey and predator at the metacommunity scale. PMID:22218310

  12. Lateralisation in birds of prey: adaptive and phylogenetic considerations

    Microsoft Academic Search

    Davide Csermely

    2004-01-01

    Lateralisation, the different use of one or other side or appendix of the body, is basically determined by brain asymmetry which, in turn, is likely to be due to adaptive reasons. Several studies have been carried out on birds in general. However, birds of prey in particular, although they are very good candidates, have not been investigated from the sensory

  13. Quantifying the effects of prey abundance on killer whale reproduction

    Microsoft Academic Search

    Eric J. Ward; Elizabeth E. Holmes; Ken C. Balcomb

    2009-01-01

    Summary 1. Management decisions for threatened and endangered species require risks to be identified and prioritized, based on the degree to which they influence population dynamics. The potential for recovery of small populations at risk may be determined by multiple factors, including intrinsic population characteristics (inbreeding, sex ratios) and extrinsic variables (prey availability, disease, human disturbance). Using Bayesian statistical methods,

  14. Population dynamics, production, and prey consumption of fathead minnows (Pimephales

    E-print Network

    Population dynamics, production, and prey consumption of fathead minnows (Pimephales promelas of fathead minnows (Pimephales promelas) in prairie wetlands and developed a bioenergetics model to estimate-de-boules (Pimephales promelas) dans les milieux humides des prairies et mis au point un modèle de bioénergétique pour

  15. Evolution of forelimb movement patterns for prey manipulation in anurans

    Microsoft Academic Search

    Lucie A. Gray; James C. O'Reilly; Kiisa C. Nishikawa

    1997-01-01

    Unlike other amphibians, frogs often use their forelimbs to capture and transport prey. In the present study, high-speed videography was used to observe forelimb use during feed- ing in a diverse group of anurans in order to determine the evolution of forelimb movement pat- terns among anuran taxa. Data were gathered from 488 individuals representing 104 species, 55 genera, and

  16. PRAIRIE FALCON PREY IN THE MOJAVE DESERT, CALIFORNIA

    Microsoft Academic Search

    DOUGLAS A. BOYCE

    Twenty-five species of birds, 9 species of mammals, 5 species of reptiles and 1 species of insect were represented in prey remains and castings from 19 Prairie Falcon (Falco mexicanus) nests in the Mojave Desert, California, during 1977 and 1978. Reptiles represented a greater proportion in the diet than is reported in most other Prairie Falcon food studies in the

  17. Body masses, functional responses and predator-prey stability.

    PubMed

    Kalinkat, Gregor; Schneider, Florian D; Digel, Christoph; Guill, Christian; Rall, Björn C; Brose, Ulrich

    2013-09-01

    The stability of ecological communities depends strongly on quantitative characteristics of population interactions (type-II vs. type-III functional responses) and the distribution of body masses across species. Until now, these two aspects have almost exclusively been treated separately leaving a substantial gap in our general understanding of food webs. We analysed a large data set of arthropod feeding rates and found that all functional-response parameters depend on the body masses of predator and prey. Thus, we propose generalised functional responses which predict gradual shifts from type-II predation of small predators on equally sized prey to type-III functional-responses of large predators on small prey. Models including these generalised functional responses predict population dynamics and persistence only depending on predator and prey body masses, and we show that these predictions are strongly supported by empirical data on forest soil food webs. These results help unravelling systematic relationships between quantitative population interactions and large-scale community patterns. PMID:23819684

  18. A global mathematical investigation of a predator-prey model

    E-print Network

    S. A. Treskov; E. P. Volokitin

    2009-11-05

    We construct a global bifurcation diagram of the plane differential system $$ {l} \\dot x = x(1-x)-x y/(a+x^2), \\dot y = y(\\delta-\\beta y/x), x(t)>0, y(t)>0, a>0, \\delta>0, \\beta>0, $$ which describes the predator-prey interaction.

  19. Detection of Serum IgG4 Levels in Patients with IgG4-Related Disease and Other Disorders

    PubMed Central

    Wang, Chenqiong; Wu, Xuefen; Miao, Ye; Xiong, Hui; Bai, Lin; Dong, Lingli

    2015-01-01

    Objective Elevated serum IgG4 levels are an important hallmark for diagnosing IgG4-related disease (IgG4-RD), but can also be observed in other diseases. This study aimed to compare two different testing methods for IgG4: ELISA and nephelometric assay. Both assays were used to measure serum IgG4 concentrations, and to assess the prevalence of high serum IgG4 levels in both IgG4-RD and non-IgG4-RD diseases. Methods A total of 80 serum samples were tested using the nephelometric assay and ELISA method that we established. Serum IgG4 concentrations were determined by ELISA for 957 patients with distinct diseases, including 12 cases of IgG4-RD and 945 cases of non-IgG4-RD. Results IgG4 levels from 80 selected serum samples examined by ELISA were in agreement with those detected using the nephelometry assay. Meanwhile, the serum IgG4 concentrations measured by ELISA were also consistent with the clinical diagnoses of patients with IgG4-RD during the course of disease. The Elevated levels of serum IgG4 (>1.35 g/L) were detected in all IgG4-RD (12/12) patients, and the prevalence of high IgG4 serum levels was 3.39% in non-IgG4-RD cases. Among them, the positive rates of serum IgG4 were 2.06% in patients with carcinoma and 6.3% in patients with other non-IgG4 autoimmune diseases. Conclusion Our established ELISA method is a reliable and convenient technique, which could be extensively used in the clinic to measure serum IgG4 levels. High levels of IgG4 were observed in IgG4-RD. However, this phenomenon could also be observed in other diseases, such as carcinomas and other autoimmune diseases. Thus, a diagnosis of IgG4 disease cannot only be dependent on the detection of elevated serum IgG4 levels. PMID:25885536

  20. The genetics and immunobiology of IgA nephropathy

    PubMed Central

    Kiryluk, Krzysztof; Novak, Jan

    2014-01-01

    IgA nephropathy (IgAN) represents the leading cause of kidney failure among East Asian populations and the most frequent form of primary glomerulonephritis among Europeans. Patients with IgAN develop characteristic IgA1-containing immune complexes that deposit in the glomerular mesangium, producing progressive kidney injury. Recent studies define IgAN as an autoimmune trait of complex architecture with a strong genetic determination. This Review summarizes new insights into the role of the O-glycosylation pathway, anti-glycan immune response, mucosal immunity, antigen processing and presentation, and the alternative complement pathway in the pathogenesis of IgAN. PMID:24892706

  1. Membrane IgM influences membrane IgD mediated antigen internalization in the B cell line Bcl1.

    PubMed

    Geisberger, Roland; Königsberger, Sebastian; Achatz, Gernot

    2006-02-15

    Signalling through the B cell antigen receptor (BCR) is required for peripheral B lymphocyte maturation, maintenance, activation and silencing. In mature B cells, the antigen receptor normally consists of two isotypes: membrane IgM and IgD (mIgM, mIgD). Although the signals initiated from both isotypes differ in kinetics and intensity, in vivo, the BCR of either isotype seems to be able to compensate for the loss of the other, reflected by the mild phenotypes of mice deficient for mIgM or mIgD. Thus, it is still unclear why mature B cells need expression of mIgD in addition to mIgM. In the present paper, we used the B cell line Bcl1 and investigated the isotype-specific antigen internalization in dependence of co-stimulation of the reciprocal isotype and analysed whether the signal initiated from mIgM is modulated through signalling from mIgD and vice versa. We clearly showed that cross-linkage of mIgM decreases the rate of mIgD mediated antigen internalization and interpret this influence as a unilateral mIgM mediated control on signals initiated at mIgD. PMID:16219364

  2. Marine predators and persistent prey in the southeast Bering Sea

    NASA Astrophysics Data System (ADS)

    Sigler, Michael F.; Kuletz, Kathy J.; Ressler, Patrick H.; Friday, Nancy A.; Wilson, Christopher D.; Zerbini, Alexandre N.

    2012-06-01

    Predictable prey locations reduce search time and energetic costs of foraging; thus marine predators often exploit locations where prey concentrations persist. In our study, we examined whether this association is influenced by differences among predator species in foraging modes (travel cost, surface feeder or diver) or whether the predator species is a central place forager or not. We examined distributions of two seabird species during their nesting period, the surface-feeding black-legged kittiwake (Rissa tridactyla) and the pursuit-diving thick-billed murre (Uria lomvia), and two baleen whale species, the humpback whale (Megaptera novaeangliae) and the fin whale (Balaenoptera physalus), in relation to two key prey, age-1 walleye pollock (Theragra chalcogramma) and euphausiids (Euphausiidae). Prey surveys were conducted once each year during 2004 and 2006-2010. Concurrent predator surveys were conducted in 2006-2010 (seabirds) and 2008 and 2010 (whales). We compared the seabird and whale foraging locations to where age-1 pollock and euphausiids were concentrated and considered the persistence of these concentrations, where the time-scale of persistence is year (i.e., a comparison among surveys that are conducted once each year). Euphausiids were widespread and concentrations often were reliably found within specific 37 km×37 km blocks ('persistent hot spots of prey'). In contrast, age-1 pollock were more concentrated and their hot spots were persistent only on coarser scales (>37 km). Both seabird species, regardless of foraging mode, were associated with age-1 pollock but not with euphausiids, even though age-1 pollock were less persistent than euphausiids. The higher travel cost central place foragers, thick-billed murres, foraged at prey concentrations nearer their island colonies than black-legged kittiwakes, which were more widespread foragers. Humpback whales were not tied to a central place and mostly were located only where euphausiids were concentrated, and further, often in locations where these concentrations were persistent. Fin whales were associated with locations where age-1 pollock were more likely, similar to black-legged kittiwakes and thick-billed murres, but their association with euphausiids was unclear. Our results suggest that a predator's foraging mode and their restrictions during breeding affect their response to prey persistence.

  3. CNES-CLS IGS Analysis Center Activities

    NASA Astrophysics Data System (ADS)

    Sylvain, L.; F., P.; H., C.; L., S.

    2008-12-01

    GRGS and CLS teams process regularly GPS data from a worldwide network of IGS permanent stations. We compute precise GPS orbits together with Earth rotation parameters and stations coordinates at the highest level of precision using the CNES-GRGS GINS software. Our solutions are being submitted to the International Earth Rotation Service since January 2004 and to the IGS since July 2007. This poster gives a summary of our processing strategy as well as the status of the quality of our products. In addition, the source of a systematic scale factor between our orbit solution and the IGS ones is discussed. Special interest is paid on the radiation pressure modelization which includes in our case the Earth albedo contribution. The processing of SLR tracking data from GPS satellite SVN35 and 36 is included in this study.

  4. Heat sensitivity of porcine IgG.

    PubMed

    Metzger, J J; Bourdieu, C; Rouze, P; Houdayer, M

    1975-09-01

    The sensitivity to heat of porcine IgG was studied. The serum from immunized pigs was heated at 56 degrees C for 30 min as for decomplementation. The elution pattern of the serum proteins on an agarose gel column showed a dramatic change with the appearance of a large peak of the gel-excluded material. This peak contained mainly IgG molecules which still retained its antibody activity. This fact points to misinterpretations which can easily occur in 7S and 19S antibody recognition during the porcine immune response. Correlation is suggested of this property with the large number of interheavy chain disulfide bridges present in porcine IgG. PMID:810517

  5. Preference and Prey Switching in a Generalist Predator Attacking Local and Invasive Alien Pests

    PubMed Central

    Jaworski, Coline C.; Bompard, Anaïs; Genies, Laure; Amiens-Desneux, Edwige; Desneux, Nicolas

    2013-01-01

    Invasive pest species may strongly affect biotic interactions in agro-ecosystems. The ability of generalist predators to prey on new invasive pests may result in drastic changes in the population dynamics of local pest species owing to predator-mediated indirect interactions among prey. On a short time scale, the nature and strength of such indirect interactions depend largely on preferences between prey and on predator behavior patterns. Under laboratory conditions we evaluated the prey preference of the generalist predator Macrolophus pygmaeus Rambur (Heteroptera: Miridae) when it encounters simultaneously the local tomato pest Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and the invasive alien pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). We tested various ratios of local vs. alien prey numbers, measuring switching by the predator from one prey to the other, and assessing what conditions (e.g. prey species abundance and prey development stage) may favor such prey switching. The total predation activity of M. pygmaeus was affected by the presence of T. absoluta in the prey complex with an opposite effect when comparing adult and juvenile predators. The predator showed similar preference toward T. absoluta eggs and B. tabaci nymphs, but T. absoluta larvae were clearly less attacked. However, prey preference strongly depended on prey relative abundance with a disproportionately high predation on the most abundant prey and disproportionately low predation on the rarest prey. Together with the findings of a recent companion study (Bompard et al. 2013, Population Ecology), the insight obtained on M. pygmaeus prey switching may be useful for Integrated Pest Management in tomato crops, notably for optimal simultaneous management of B. tabaci and T. absoluta, which very frequently co-occur on tomato. PMID:24312646

  6. The Nutritional Content of Prey Affects the Foraging of a Generalist Arthropod Predator

    PubMed Central

    Schmidt, Jason M.; Sebastian, Peter; Wilder, Shawn M.; Rypstra, Ann L.

    2012-01-01

    While foraging theory predicts that predatory responses should be determined by the energy content and size of prey, it is becoming increasingly clear that carnivores regulate their intake of specific nutrients. We tested the hypothesis that prey nutrient composition and predator nutritional history affects foraging intensity, consumption, and prey selection by the wolf spider, Pardosa milvina. By altering the rearing environment for fruit flies, Drosophila melanogaster, we produced high quality flies containing more nitrogen and protein and less lipid than low quality fruit flies. In one experiment, we quantified the proportion of flies taken and consumption across a range of densities of either high or low quality flies and, in a second experiment, we determined the prey capture and consumption of spiders that had been maintained on contrasting diets prior to testing. In both cases, the proportion of prey captured declined with increasing prey density, which characterizes the Type II functional response that is typical of wolf spiders. Spiders with similar nutritional histories killed similar numbers of each prey type but consumed more of the low quality prey. Spiders provided high quality prey in the weeks prior to testing killed more prey than those on the low quality diet but there was no effect of prior diet on consumption. In the third experiment, spiders were maintained on contrasting diets for three weeks and then allowed to select from a mixture of high and low quality prey. Interestingly, feeding history affected prey preferences: spiders that had been on a low quality diet showed no preference but those on the high quality diet selected high quality flies from the mixture. Our results suggest that, even when prey size and species identity are controlled, the nutritional experience of the predator as well as the specific content of the prey shapes predator-prey interactions. PMID:23145130

  7. Preference and prey switching in a generalist predator attacking local and invasive alien pests.

    PubMed

    Jaworski, Coline C; Bompard, Anaïs; Genies, Laure; Amiens-Desneux, Edwige; Desneux, Nicolas

    2013-01-01

    Invasive pest species may strongly affect biotic interactions in agro-ecosystems. The ability of generalist predators to prey on new invasive pests may result in drastic changes in the population dynamics of local pest species owing to predator-mediated indirect interactions among prey. On a short time scale, the nature and strength of such indirect interactions depend largely on preferences between prey and on predator behavior patterns. Under laboratory conditions we evaluated the prey preference of the generalist predator Macrolophus pygmaeus Rambur (Heteroptera: Miridae) when it encounters simultaneously the local tomato pest Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) and the invasive alien pest Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae). We tested various ratios of local vs. alien prey numbers, measuring switching by the predator from one prey to the other, and assessing what conditions (e.g. prey species abundance and prey development stage) may favor such prey switching. The total predation activity of M. pygmaeus was affected by the presence of T. absoluta in the prey complex with an opposite effect when comparing adult and juvenile predators. The predator showed similar preference toward T. absoluta eggs and B. tabaci nymphs, but T. absoluta larvae were clearly less attacked. However, prey preference strongly depended on prey relative abundance with a disproportionately high predation on the most abundant prey and disproportionately low predation on the rarest prey. Together with the findings of a recent companion study (Bompard et al. 2013, Population Ecology), the insight obtained on M. pygmaeus prey switching may be useful for Integrated Pest Management in tomato crops, notably for optimal simultaneous management of B. tabaci and T. absoluta, which very frequently co-occur on tomato. PMID:24312646

  8. Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.

    USGS Publications Warehouse

    Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.

    2009-01-01

    We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

  9. Construction of an sIgE:FLAG-mIgE:GFP reporter mouse strain.

    PubMed

    Achatz-Straussberger, Gertrude; Geisberger, Roland; Oberndorfer, Iris; Inführ, Daniela; Luger, Elke; Fallon, Padraic; Lamers, Marinus; Achatz, Gernot

    2003-04-01

    Like all other immunoglobulins, IgE can be secreted into the blood or expressed as a membrane receptor on the surface of B lymphocytes. Secreted immunoglobulins trace the antigen and contribute to its destruction. Membrane immunoglobulins accompany the B cell along its differentiation pathway, regulating processes like the induction and maintenance of immunological memory and differentiation of plasma cells. The regulation of the expression of IgE is very complex. A lot of positive and negative regulators influence the synthesis of IgE. In previous publications, we were able to show that the membrane IgE (mIgE) antigen receptor itself controls the quantity and quality of serum IgE produced. However, the knowledge about the regulatory function of the antigen receptor on these processes is at best limited. In the present paper, we present the construction of a reporter mouse strain, which will help us to follow an mIgE-bearing B cell during the immune response more precisely. PMID:12740529

  10. A novel chimeric Ig heavy chain from a teleost fish shares similarities to?IgD

    PubMed Central

    Wilson, Melanie; Bengtén, Eva; Miller, Norman W.; Clem, L. William; Du Pasquier, Louis; Warr, Gregory W.

    1997-01-01

    IgD is considered to be a recently evolved Ig, being previously found only in primates and rodents. Here we describe, from a teleost fish (the channel catfish, Ictalurus punctatus), a novel complex chimeric Ig heavy chain, homologous, in part, to the heavy chain (?) of IgD. In addition to alternative secretory or membrane-associated C termini, this chimeric molecule contains a rearranged variable domain, the first constant domain of ?, and seven constant domains encoded by a ? gene homolog. Identification of the catfish gene as ? is based on the following properties: sequence relatedness to mammalian ?; a location within the IgH locus that is immediately downstream of the ? gene; separate terminal exons for the secretory and membrane forms; coexpression with the complete ? chain in some but not all B cells. These results (i) suggest that IgD is an ancient immunoglobulin that was present in vertebrates ancestral to both the mammals and the ray-finned fishes, and (ii) raise the possibility that this Ig isotype may have served an as yet unidentified important function early in the evolution of the immune system. PMID:9114035

  11. Nitrogen uptake from prey and substrate as affected by prey capture level and plant reproductive status in four carnivorous plant species

    Microsoft Academic Search

    H. M. Hanslin; P. S. Karlsson

    1996-01-01

    Uptake of nitrogen from prey and substrate and partitioning of prey-derived nitrogen were studied in the carnivorous plant species Pinguicula alpina, P. villosa, P. vulgaris and Drosera rotundifolia in a subarctic environment. Efficiency in nitrogen uptake from prey was evaluated by tracing 15N from 15N-enriched Drosophila flies fed to the plants. The in situ uptake efficiency differed somewhat between species

  12. Cloning and structural analysis of two highly divergent IgA isotypes, IgA1 and IgA2 from the duck billed platypus, Ornithorhynchus anatinus.

    PubMed

    Vernersson, M; Belov, K; Aveskogh, M; Hellman, L

    2010-01-01

    To trace the emergence of modern IgA isotypes during vertebrate evolution we have studied the immunoglobulin repertoire of a model monotreme, the platypus. Two highly divergent IgA-like isotypes (IgA1 and IgA2) were identified and their primary structures were determined from full-length cDNAs. A comparative analysis of the amino acid sequences for IgA from various animal species showed that the two platypus IgA isotypes form a branch clearly separated from their eutherian (placental) counterparts. However, they still conform to the general structure of eutherian IgA, with a hinge region and three constant domains. This indicates that the deletion of the second domain and the formation of a hinge region in IgA did occur very early during mammalian evolution, more than 166 million years ago. The two IgA isotypes in platypus differ in primary structure and appear to have arisen from a very early gene duplication, possibly preceding the metatherian eutherian split. Interestingly, one of these isotypes, IgA1, appears to be expressed in only the platypus, but is present in the echidna based on Southern blot analysis. The platypus may require a more effective mucosal immunity, with two highly divergent IgA forms, than the terrestrial echidna, due to its lifestyle, where it is exposed to pathogens both on land and in the water. PMID:19913303

  13. Molecular and cellular targets of anti-IgE antibodies.

    PubMed

    Inführ, D; Crameri, R; Lamers, R; Achatz, G

    2005-08-01

    Immunoglobulin E (IgE) was the last of the immunoglobulins discovered. It is present in very low amounts (nano- to micro-gram per ml range) in the serum of normal healthy individuals and normal laboratory mouse strains and has a very short half-life. This contrasts with the other immunoglobulin classes, which are present in much higher concentrations (micro- to milligram per ml range) and form a substantial component of serum proteins. Immunoglobulins play a role in homeostatic mechanisms and they represent the humoral arm of defence against pathogenic organisms. Since IgE antibodies play a key role in allergic disorders, a number of approaches to inhibit IgE antibody production are currently being explored. In the recent past the use of nonanaphylactic, humanized anti-IgE antibodies became a new therapeutic strategy for allergic diseases. The therapeutic rational beyond the idea derives from the ability of the anti-IgE antibodies to bind to the same domains on the IgE molecule that interact with the high-affinity IgE receptor, thereby interfering with the binding of IgE to this receptor without cross-linking the IgE on the receptor (nonanaphylactic anti-IgE antibodies). Treatment with anti-IgE antibodies leads primarily to a decrease in serum IgE levels. As a consequence thereof, the number of high-affinity IgE receptors on mast cells and basophils decreases, leading to a lower excitability of the effector cells reducing the release of inflammatory mediator such as histamine, prostaglandins and leukotrienes. Experimental studies in mice indicate that injection of some monoclonal anti-IgE antibodies also inhibited IgE production in vivo. The biological mechanism behind this reduction remains speculative. A possible explanation may be that these antibodies can also interact with membrane bound IgE on B cells, which could interfere the IgE production. PMID:15969677

  14. Multiple myeloma with monoclonal IgG and IgD of lambda type exhibiting, under treatment, a shift from mainly IgG to mainly IgD.

    PubMed Central

    Gallart, T; Bladé, J; Martínez-Quesada, J; Sierra, J; Rozman, C; Vives, J

    1985-01-01

    A patient with multiple myeloma (MM), who initially presented with a predominant IgG lambda and a minor IgD lambda paraprotein pattern, is described. After chemotherapy, levels of the IgD lambda protein increased and the IgG lambda levels decreased. The following results were obtained when serum IgD was predominant. In the bone marrow, there were three plasma cell populations: a major one containing only delta chains, a minor one containing only gamma chains, and another minor one containing both delta and gamma chains. All these plasma cell populations contained lambda chains. Stimulation of circulating mononuclear cells with pokeweed mitogen (PWM) achieved differentiation of circulating B lymphocytes into plasma cells: 30% with only cytoplasmic delta lambda chains and 10% with only cytoplasmic gamma lambda chains. These IgG-containing plasma cells showed cytoplasmic reactivity with rabbit antiserum raised against monoclonal IgD which was shown to contain specificities recognizing both delta chains and idiotypic determinants present in both serum IgD lambda and IgG lambda. Circulating B lymphocytes were 'monoclonal': almost all expressed surface delta lambda chains, and a small proportion of them expressed both delta gamma and lambda chains. High levels of IgD were detected in the supernatants of all cultures, but high concentrations of IgG were only detected in those from PWM-stimulated cultures with very low levels of IgM and IgA. These findings suggest that plasma cells producing either IgD or IgG were derived from a common B-cell clone. Double paraproteinaemia exhibiting a shift in immunoglobulin production from IgG to IgD has not been previously described. Images Figure 1 Figure 2 Figure 3 Figure 4 PMID:3922877

  15. Suppression of IgE B cells and IgE binding to Fc?RI by gene therapy with single chain anti-IgE1

    PubMed Central

    Ota, Takayuki; Aoki-Ota, Miyo; Duong, Bao Hoa; Nemazee, David

    2010-01-01

    This is an author-produced version of a manuscript accepted for publication in The Journal of Immunology (The JI). The American Association of Immunologists, Inc. (AAI), publisher of The JI, holds the copyright to this manuscript. This version of the manuscript has not yet been copyedited or subjected to editorial proofreading by The JI; hence, it may differ from the final version published in The JI (online and in print). AAI (The JI) is not liable for errors or omissions in this author-produced version of the manuscript or in any version derived from it by the U.S. National Institutes of Health or any other third party. The final, citable version of record can be found at www.jimmunol.org. Immunoglobulin E (IgE) plays a pivotal role in allergic reactions and asthma through its ability to bind to the mast cell Fc receptor for IgE (Fc?RI). Current therapies to suppress such reactions include passive treatment with neutralizing antibodies to IgE that block its binding to Fc?RI. In theory, induction of immune tolerance in the B lymphocytes that carry IgE antigen receptors and give rise to IgE secreting cells should provide longer term efficacy. However, recent data have suggested that such memory cells may lack cell surface IgE. Using a gene therapy approach, we show that a recombinant single-chain neutralizing anti-IgE could not only neutralize circulating IgE, but also reduce IgE+ B cell numbers and H-chain transcripts. Therapeutic anti-IgE stimulated a calcium response in primary B cells or in a B cell line expressing membrane IgE and suppressed IgE secretion in vitro suggesting that active signaling through membrane IgE likely promoted tolerance. Interestingly, upon subsequent challenge of anti-IgE treated mice with an IgE crosslinking reagent capable of inducing activation of IgE-decorated mast cells, an anaphylaxis reaction was induced, apparently via a Fc?RIII pathway involving recognition of anti-IgE antibody itself. These studies have important implications for the optimal design of safe and effective anti-IgE therapies and suggest that the IgE memory B cells may be targeted by such genetic antibody therapies. PMID:19494337

  16. Prey preferences of the snow leopard (Panthera uncia): regional diet specificity holds global significance for conservation.

    PubMed

    Lyngdoh, Salvador; Shrotriya, Shivam; Goyal, Surendra P; Clements, Hayley; Hayward, Matthew W; Habib, Bilal

    2014-01-01

    The endangered snow leopard is a large felid that is distributed over 1.83 million km(2) globally. Throughout its range it relies on a limited number of prey species in some of the most inhospitable landscapes on the planet where high rates of human persecution exist for both predator and prey. We reviewed 14 published and 11 unpublished studies pertaining to snow leopard diet throughout its range. We calculated prey consumption in terms of frequency of occurrence and biomass consumed based on 1696 analysed scats from throughout the snow leopard's range. Prey biomass consumed was calculated based on the Ackerman's linear correction factor. We identified four distinct physiographic and snow leopard prey type zones, using cluster analysis that had unique prey assemblages and had key prey characteristics which supported snow leopard occurrence there. Levin's index showed the snow leopard had a specialized dietary niche breadth. The main prey of the snow leopard were Siberian ibex (Capra sibrica), blue sheep (Pseudois nayaur), Himalayan tahr (Hemitragus jemlahicus), argali (Ovis ammon) and marmots (Marmota spp). The significantly preferred prey species of snow leopard weighed 55±5 kg, while the preferred prey weight range of snow leopard was 36-76 kg with a significant preference for Siberian ibex and blue sheep. Our meta-analysis identified critical dietary resources for snow leopards throughout their distribution and illustrates the importance of understanding regional variation in species ecology; particularly prey species that have global implications for conservation. PMID:24533080

  17. Sensory-based niche partitioning in a multiple predator - multiple prey community.

    PubMed

    Falk, Jay J; ter Hofstede, Hannah M; Jones, Patricia L; Dixon, Marjorie M; Faure, Paul A; Kalko, Elisabeth K V; Page, Rachel A

    2015-06-01

    Many predators and parasites eavesdrop on the communication signals of their prey. Eavesdropping is typically studied as dyadic predator-prey species interactions; yet in nature, most predators target multiple prey species and most prey must evade multiple predator species. The impact of predator communities on prey signal evolution is not well understood. Predators could converge in their preferences for conspicuous signal properties, generating competition among predators and natural selection on particular prey signal features. Alternatively, predator species could vary in their preferences for prey signal properties, resulting in sensory-based niche partitioning of prey resources. In the Neotropics, many substrate-gleaning bats use the mate-attraction songs of male katydids to locate them as prey. We studied mechanisms of niche partitioning in four substrate-gleaning bat species and found they are similar in morphology, echolocation signal design and prey-handling ability, but each species preferred different acoustic features of male song in 12 sympatric katydid species. This divergence in predator preference probably contributes to the coexistence of many substrate-gleaning bat species in the Neotropics, and the substantial diversity in the mate-attraction signals of katydids. Our results provide insight into how multiple eavesdropping predator species might influence prey signal evolution through sensory-based niche partitioning. PMID:25994677

  18. Effects of the heterogeneous landscape on a predator-prey system

    NASA Astrophysics Data System (ADS)

    Lee, Sang-Hee

    2010-01-01

    In order to understand how a heterogeneous landscape affects a predator-prey system, a spatially explicit lattice model consisting of predators, prey, grass, and landscape was constructed. The predators and preys randomly move on the lattice space and the grass grows in its neighboring site according to its growth probability. When predators and preys meet at the same site at the same time, a number of prey, equal to the number of predators are eaten. This rule was also applied to the relationship between the prey and grass. The predator (prey) could give birth to an offspring when it ate prey (grass), with a birth probability. When a predator or prey animal was initially introduced, or newly born, its health state was set at a given high value. This health state decreased by one with every time step. When the state of an animal decreased to less than zero, the animal died and was removed from the system. The heterogeneous landscape was characterized by parameter H, which controlled the heterogeneity according to the neutral model. The simulation results showed that H positively or negatively affected a predator’s survival, while its effect on prey and grass was less pronounced. The results can be understood by the disturbance of the balance between the prey and predator densities in the areas where the animals aggregated.

  19. Pneumococcal meningitis in a young adult female with common variable immunodeficiency

    PubMed Central

    Cooper, Chad J.; Said, Sarmad; Quansah, Raphael; Khalillullah, Sayeed; Alozie, Ogechika

    2013-01-01

    Patient: Female, 22 Final Diagnosis: Pneumococcal meningitis Symptoms: Fever • headache • neck stiffness • nuchal rigidity • photophobia Medication: Ceftriaxone Clinical Procedure: — Specialty: Neurology Objective: Rare disease Background: Common variable immunodeficiency (CVID) is a primary immunodeficiency associated with hypogammaglobulinemia and other various clinical manifestations. It is a rare disease with a prevalence of CVID is approximately 1: 50,000–200,000. Clinical manifestations of CVID include recurrent bacterial infections, autoimmune, gastrointestinal, lymphoproliferative, granulomatous, and malignancy. Case Report: Twenty-two year-old Hispanic female presented with a throbbing headache, nuchal rigidity, photophobia and a high grade fever. Lumbar puncture with CSF assessment revealed a turbid fluid with WBC of 6937 per uL, polymorphnuclear cells of 81%, protein 248 mg/dL, glucose <3 mg/Dl. CSF antigens were positive for Streptococcus pneumonia and CSF culture grew pansensitive Strepococcus pneumonia. Immunoglobin (Ig) levels of IgA, IgE, IgG and IgM were all decreased. Absolute cell counts of CD3, CD4 and CD8 were all low. Bone marrow biopsy was normocellular. Excisional lymph node biopsy revealed lymph nodes with reactive follicular hyperplasia. Common variable immunodeficiency disease (CVID) was diagnosed based on exclusion. IVIG therapy was given and patient received a two-week course of ceftriaxone. Conclusions: The diagnosis of CVID is made based on the following criteria: 1) Marked decrease of IgG and at least one of the IgM or IgA isotypes. 2) The onset of immunodeficiency at greater than 2 years old. 3) Absence of isohemagglutinins and/or poor response to vaccines 4) Exclusion of other defined causes of hypogammaglobulinemia. A definite diagnosis is often late because it is wrongly assumed that primary immunodeficiencies are extremely rare, hence many patients are already seriously ill at the time of presentation. PMID:24265845

  20. Morphology of seahorse head hydrodynamically aids in capture of evasive prey.

    PubMed

    Gemmell, Brad J; Sheng, Jian; Buskey, Edward J

    2013-01-01

    Syngnathid fish (seahorses, pipefish and sea dragons) are slow swimmers yet capture evasive prey (copepods) using a technique known as the 'pivot' feeding, which involves rapid movement to overcome prey escape capabilities. However, this feeding mode functions only at short range and requires approaching very closely to hydrodynamically sensitive prey without triggering an escape. Here we investigate the role of head morphology on prey capture using holographic and particle image velocimetry (PIV). We show that head morphology functions to create a reduced fluid deformation zone, minimizing hydrodynamic disturbance where feeding strikes occur (above the end of the snout), and permits syngnathid fish to approach highly sensitive copepod prey (Acartia tonsa) undetected. The results explain how these animals can successfully employ short range 'pivot' feeding effectively on evasive prey. The need to approach prey with stealth may have selected for a head shape that produces lower deformation rates than other fish. PMID:24281430

  1. Tie them up tight: wrapping by Philoponella vicina spiders breaks, compresses and sometimes kills their prey

    NASA Astrophysics Data System (ADS)

    Eberhard, William G.; Barrantes, Gilbert; Weng, Ju-Lin

    2006-05-01

    We show that uloborid spiders, which lack the poison glands typical of nearly all other spiders, employ thousands of wrapping movements with their hind legs and up to hundreds of meters of silk line to make a shroud that applies substantial compressive force to their prey. Shrouds sometimes break the prey’s legs, buckle its compound eyes inward, or kill it outright. The compressive force apparently results from the summation of small tensions on sticky lines as they are applied to the prey package. Behavioral details indicate that wrapping is designed to compact prey; in turn, compaction probably functions to facilitate these spiders’ unusual method of feeding. This is the first demonstration that prey wrapping by spiders compacts and physically damages their prey, rather than simply restraining them.

  2. IgG4 and IgE transcripts in childhood allergic asthma reflect divergent antigen-driven selection.

    PubMed

    Rogosch, Tobias; Kerzel, Sebastian; Dey, Friederike; Wagner, Johanna-Josophina; Zhang, Zhixin; Maier, Rolf F; Zemlin, Michael

    2014-12-15

    The physiologic function of the "odd" Ab IgG4 remains enigmatic. IgG4 mediates immunotolerance, as, for example, during specific immunotherapy of allergies, but it mediates tissue damage in autoimmune pemphigus vulgaris and "IgG4-related disease." Approximately half of the circulating IgG4 molecules are bispecific owing to their unique ability to exchange half-molecules. Better understanding of the interrelation between IgG4 and IgE repertoires may yield insight into the pathogenesis of allergies and into potential novel therapies that modulate IgG4 responses. We aimed to compare the selective forces that forge the IgG4 and IgE repertoires in allergic asthma. Using an IgG4-specific RT-PCR, we amplified, cloned, and sequenced IgG4 H chain transcripts of PBMCs from 10 children with allergic asthma. We obtained 558 functional IgG4 sequences, of which 286 were unique. Compared with previously published unique IgE transcripts from the same blood samples, the somatic mutation rate was significantly enhanced in IgG4 transcripts (62 versus 83%; p < 0.001), whereas fewer IgG4 sequences displayed statistical evidence of Ag-driven selection (p < 0.001). On average, the hypervariable CDRH3 region was four nucleotides shorter in IgG4 than in IgE transcripts (p < 0.001). IgG4 transcripts in the circulation of children with allergic asthma reflect some characteristics of classical Ag-driven B2 immune responses but display less indication of Ag selection than do IgE transcripts. Although allergen-specific IgG4 can block IgE-mediated allergen presentation and degranulation of mast cells, key factors that influence the Ag-binding properties of the Ab differ between the overall repertoires of circulating IgG4- and IgE-expressing cells. PMID:25385824

  3. IgA- and secretory IgA-opsonized S. aureus induce a respiratory burst and phagocytosis by polymorphonuclear leucocytes.

    PubMed Central

    Gorter, A; Hiemstra, P S; Leijh, P C; van der Sluys, M E; van den Barselaar, M T; van Es, L A; Daha, M R

    1987-01-01

    The aim of the present study was to investigate whether corpuscular immune complexes containing human IgA were able to interact with human polymorphonuclear leucocytes (PMN). As a model for corpuscular IgA immune complexes (IgA IC), heat-killed Staphylococcus aureus (S. aureus) opsonized with either purified human serum IgA or purified secretory IgA (sIgA) isolated from human colostrum was used. In order to determine the capacity of IgA and sIgA to opsonize S. aureus the phagocytosis of these IgA IC by PMN was measured. S. aureus opsonized with IgA, sIgA, IgG, heat-inactivated serum or fresh serum was ingested by 23 +/- 8%; 28 +/- 9%; 39 +/- 7%; 31 +/- 10% and 78 +/- 10% of the PMN (S. aureus:PMN = 10:1, n = 4), respectively. These results were significantly different (P less than 0.05) from the percentage obtained with unopsonized S. aureus (9 +/- 3%), indicating that IgA and sIgA induce ingestion of S. aureus. The phagocytic index for PMN incubated with S. aureus opsonized with sIgA (231) was higher than for S. aureus opsonized with IgA (119), indicating a better uptake of S. aureus opsonized with sIgA in our system. Bacteria opsonized with either IgA or sIgA were also capable of triggering H2O2 release of PMN in a dose-dependent manner. The H2O2 release by PMN triggered with S. aureus opsonized with IgA could not be inhibited with a F(ab')2 anti-Fe gamma receptor monoclonal antibody, whereas the H2O2 release triggered with S. aureus opsonized with IgG was fully inhibited. Soluble heat-aggregated IgA (AIgA) also induced H2O2 release of PMN, suggesting that the IgA itself is essential for the induction of a respiratory burst. PMID:3610212

  4. Avoidance of unpalatable prey by predaceous diving beetle larvae: The role of hunger level and experience (Coleoptera: Dytiscidae)

    Microsoft Academic Search

    Kendra S. Hileman; Edmund D. Brodie; Daniel R. Formanowicz

    1994-01-01

    The effects of hunger and experience on the avoidance of unpalatable prey were examined. Larvae of the predaceous diving beetle,Dytiscus verticalis, after feeding on one of two feeding regimes, were offered palatable and unpalatable prey during a series of trials. Consumption of palatable prey (calf heart) was not affected by hunger or experience. Avoidance of unpalatable prey (tails of the

  5. The sensory basis of prey location by the California leaf-nosed bat Macrotus californicus (Chiroptera: Phyllostomidae)

    Microsoft Academic Search

    Gary P. Bell

    1985-01-01

    Macrotus californicus, an insectivorous bat, captures prey on the ground, and shows great sensory flexibility in hunting for prey: it uses high frequency, low intensity, frequency modulated echolocation to locate prey in total darkness, however data from this study suggest that it uses vision preferentially, and switches off its echolocation when adequate illumination is available. When souncs of prey are

  6. Quasi-soliton interaction of pursuit-evasion waves in a predator-prey system M. A. Tsyganov

    E-print Network

    Biktashev, Vadim N.

    Quasi-soliton interaction of pursuit-evasion waves in a predator-prey system M. A. Tsyganov differential equations describing two spatially distributed populations in a "predator-prey" interaction the gradient of prey (pursuit), negative taxis of prey down the gradient of predators (evasion) and diffusion

  7. Quasicycles in a spatial predator-prey model Carlos A. Lugo and Alan J. McKane*

    E-print Network

    McKane, Alan

    models of simple predator-prey interactions to predict that predator and prey numbers oscillate in time- tem where the interaction between individuals of those spe- cies is of the predator-prey typeQuasicycles in a spatial predator-prey model Carlos A. Lugo and Alan J. McKane* Theoretical Physics

  8. Subclass distribution of human IgG autoantibodies in pemphigus

    Microsoft Academic Search

    Christian C. Jones; Robert G. Hamilton; Robert E. Jordon

    1988-01-01

    The distribution of IgG subclasses in the intercellular substance (ICS) reactive autoantibodies in serum of 10 patients with pemphigus was analyzed by semiquantitative indirect immunofluorescence (IF) using the HP series of monoclonal antibodies specific for the four human IgG subclasses. IgG4 ICS specific autoantibody was present in all 10 sera at a titer of 10 to 320, while IgG1 antibodies

  9. The immune geography of IgA induction and function

    Microsoft Academic Search

    A J Macpherson; K D McCoy; F-E Johansen; P Brandtzaeg

    2008-01-01

    The production of immunoglobulin A (IgA) in mammals exceeds all other isotypes, and it is mostly exported across mucous membranes. The discovery of IgA and the realization that it dominates humoral mucosal immunity, in contrast to the IgG dominance of the systemic immune system, was early evidence for the distinct nature of mucosal immunology. It is now clear that IgA

  10. Alcohol Consumption and Kidney Function in IgA Glomerulonephritis

    Microsoft Academic Search

    Kati Kaartinen; Onni Niemelä; Jaana Syrjänen; Ilkka Pörsti; Aimo Harmoinen; Amos Pasternack; Heini Huhtala; Jukka Mustonen

    2009-01-01

    Background: IgA glomerulonephritis (IgAGN) is a kidney disease with variable prognosis. Several known risk factors exist for a more progressive course. Some population studies indicate that moderate alcohol consumption might protect kidney function, but the relationship between alcohol intake and IgAGN has not previously been examined. Methods: We examined 158 (95 men) IgAGN patients (37 abstainers, 80 light drinkers, 25

  11. Sensitivity to assumptions in models of generalist predation on a cyclic prey.

    PubMed

    Matthiopoulos, Jason; Graham, Kate; Smout, Sophie; Asseburg, Christian; Redpath, Stephen; Thirgood, Simon; Hudson, Peter; Harwood, John

    2007-10-01

    Ecological theory predicts that generalist predators should damp or suppress long-term periodic fluctuations (cycles) in their prey populations and depress their average densities. However, the magnitude of these impacts is likely to vary depending on the availability of alternative prey species and the nature of ecological mechanisms driving the prey cycles. These multispecies effects can be modeled explicitly if parameterized functions relating prey consumption to prey abundance, and realistic population dynamical models for the prey, are available. These requirements are met by the interaction between the Hen Harrier (Circus cyaneus) and three of its prey species in the United Kingdom, the Meadow Pipit (Anthus pratensis), the field vole (Microtus agrestis), and the Red Grouse (Lagopus lagopus scoticus). We used this system to investigate how the availability of alternative prey and the way in which prey dynamics are modeled might affect the behavior of simple trophic networks. We generated cycles in one of the prey species (Red Grouse) in three different ways: through (1) the interaction between grouse density and macroparasites, (2) the interaction between grouse density and male grouse aggressiveness, and (3) a generic, delayed density-dependent mechanism. Our results confirm that generalist predation can damp or suppress grouse cycles, but only when the densities of alternative prey are low. They also demonstrate that diametrically opposite indirect effects between pairs of prey species can occur together in simple systems. In this case, pipits and grouse are apparent competitors, whereas voles and grouse are apparent facilitators. Finally, we found that the quantitative impacts of the predator on prey density differed among the three models of prey dynamics, and these differences were robust to uncertainty in parameter estimation and environmental stochasticity. PMID:18027760

  12. Restricting Prey Dispersal Can Overestimate the Importance of Predation in Trophic Cascades

    PubMed Central

    Geraldi, Nathan R.; Macreadie, Peter I.

    2013-01-01

    Predators can affect prey populations and, via trophic cascades, predators can indirectly impact resource populations (2 trophic levels below the predator) through consumption of prey (density-mediated indirect effects; DMIEs) and by inducing predator-avoidance behavior in prey (trait-mediated indirect effects; TMIEs). Prey often employ multiple predator-avoidance behaviors, such as dispersal or reduced foraging activity, but estimates of TMIEs are usually on individual behaviors. We assessed direct and indirect predator effects in a mesocosm experiment using a marine food chain consisting of a predator (toadfish – Opsanus tau), prey (mud crab - Panopeus herbstii) and resource (ribbed mussel – Geukensia demissa). We measured dispersal and foraging activity of prey separately by manipulating both the presence and absence of the predator, and whether prey could or could not disperse into a predator-free area. Consumption of prey was 9 times greater when prey could not disperse, probably because mesocosm boundaries increased predator capture success. Although predator presence did not significantly affect the number of crabs that emigrated, the presence of a predator decreased resource consumption by prey, which resulted in fewer resources consumed for each prey that emigrated in the presence of a predator, and reduced the overall TMIE. When prey were unable to disperse, TMIEs on mussel survival were 3 times higher than the DMIEs. When prey were allowed to disperse, the TMIEs on resource survival increased to 11-times the DMIEs. We found that restricting the ability of prey to disperse, or focusing on only one predator-avoidance behavior, may be underestimating TMIEs. Our results indicate that the relative contribution of behavior and consumption in food chain dynamics will depend on which predator-avoidance behaviors are allowed to occur and measured. PMID:23408957

  13. CODE's contribution to the IGS MGEX

    NASA Astrophysics Data System (ADS)

    Prange, Lars; Dach, Rolf; Lutz, Simon; Schaer, Stefan; Jäggi, Adrian

    2014-05-01

    The Center for Orbit Determination in Europe (CODE) is contributing as a global analysis center to the International GNSS Service (IGS) since many years. The processing of GPS and GLONASS data is well established in CODE's ultra-rapid, rapid, and final product lines. Since 2012 CODE contributes to the "Multi GNSS EXperiment" (MGEX), launched by the IGS as a testbed for the incorporation of new GNSS and their signals into the existing IGS processing chains and software packages. The focus of CODE's MGEX activities was on Galileo so far. Comparisons with other groups results proved the quality of CODE's Galileo orbit (based on a 3-day long-arc solution) and clock products. The MGEX processing at CODE is currently extended to the BeiDou system, which will result in a fully consistent quadruple-system solution including GPS, GLONASS, Galileo, and BeiDou. We present the latest status of the CODE MGEX processing. The quality of the orbit and clock solutions will be evaluated. The characteristics and the impact of the contributing GNSS on the products will be assessed. The CODE MGEX orbit and clock products are publicly available in the IGS MGEX products directory at the CDDIS data center: ftp://cddis.gsfc.nasa.gov/gnss/products/mgex (the solution ID "com" stands for CODE-MGEX).

  14. IG Workshop 2006 The Genetics of Disease

    E-print Network

    Mayfield, John

    be submitted to the faculty member who is hosting the speaker. Chalk Talks Students enrolled in GENET 591 onlyIG Workshop 2006 The Genetics of Disease Discussion Wednesdays, 3:10 p.m. to 4:00 p.m. in 105 Matthew Ellinwood Stephen O'Brien, National Cancer Institute, MD mellinwo@iastate.edu Students must attend

  15. IgE levels in intestinal juice

    Microsoft Academic Search

    D. Belut; D. A. Moneret-Vautrin; J. P. Nicolas; J. P. Grilliat

    1980-01-01

    This investigation was performed to determine the possible significance of the IgE levels in intestinal secretions for the recognition of type I food allergy (immediate hypersensitivity). Four groups of individuals were studied and compared with each other: (1) healthy controls and patients with gastrointestinal disorders not affecting the small intestine; (2) patients with small intestinal disease; (3) patients with various

  16. Female competition in chimpanzees

    PubMed Central

    Pusey, Anne E.; Schroepfer-Walker, Kara

    2013-01-01

    Female chimpanzees exhibit exceptionally slow rates of reproduction and raise their offspring without direct paternal care. Therefore, their reproductive success depends critically on long-term access to high-quality food resources over a long lifespan. Chimpanzee communities contain multiple adult males, multiple adult females and their offspring. Because males are philopatric and jointly defend the community range while most females transfer to new communities before breeding, adult females are typically surrounded by unrelated competitors. Communities are fission–fusion societies in which individuals spend time alone or in fluid subgroups, whose size depends mostly on the abundance and distribution of food. To varying extents in different populations, females avoid direct competition by foraging alone or in small groups in distinct, but overlapping core areas within the community range to which they show high fidelity. Although rates of aggression are low, females compete for space and access to food. High rank correlates with high reproductive success, and high-ranking females win direct contests for food and gain preferential access to resource-rich sites. Females are aggressive to immigrant females and even kill the newborn infants of community members. The intensity of such aggression correlates with population density. These patterns are compared to those in other species, including humans. PMID:24167307

  17. Oxford-MEST classification in IgA nephropathy patients: A report from Iran

    PubMed Central

    Nasri, Hamid; Mortazavi, Mojgan; Ghorbani, Ali; Shahbazian, Heshmatollah; Kheiri, Soleiman; Baradaran, Azar; Emami-Naieni, Afsoon; Saffari, Maryam; Mardani, Saeed; Momeni, Ali; Madihi, Yahya; Baradaran-Ghahfarokhi, Milad; Rafieian-Kopaie, Mahmoud; Hedayati, Parin; Baradaran, Shahzad; Ardalan, Mohammadreza; Sajjadieh, Shahram; Assarzadegan, Naziheh; Ahmadi Soleimani, Seyed Mohammad; Tamadon, Mohamad Reza

    2012-01-01

    Background There is a limited knowledge about the morphological features of IgA nephropathy (IgAN)in the middle east region. Objectives The objective of this study was to evaluate the spectrum of histopathological findings in IgAN patients at our laboratory. Patients and Methods At this work, an observational study reported which was conducted on IgAN patients using the Oxford-MEST classification system. Results In this survey, of 102 patients 71.6 % were male. The mean age of the patients was 37.7 ± 13.6 years. Morphologic variables of MEST classification was as follows; M1: 90.2 %, E: 32 %, S: 67 % also,T in grads I and II were in 30% and 19% respectively, while 51% were in grade zero. A significant difference was observed in segmental glomerulosclerosis (P=0.003) and interstitial fibrosis/tubular atrophy frequency distribution (P= 0.045), between males and females . Furthermore, it was found that mesangial hypercellularity was more prevalent in yonger patients. Moreover, there was a significant correlation between serum creatinine and crescents (P<0.001). There was also significant correlation of serum creatinine with segmental glomerulosclerosis (P<0.001). Conclusions Higher prevalence of segmental glomerulosclerosis and interstitial fibrosis/ tubular atrophy, as the two of, four variables of Oxford-MEST classification of IgAN in male patients further attests that male gender is a risk factor in this disease.In this study the significant correlation between serum creatinine and crescent was in an agreement with previous studies and suggests for the probable accomodation of extracapillary proliferation as a new variable in MEST system. PMID:24475384

  18. Receptor-mediated transport of IgG

    Microsoft Academic Search

    R. Rodewald; JEAN-PIERRE KRAEHENBUHL

    1984-01-01

    ABSTRACT ? The intestinalepitheliumof the neonatalratisa model,system,forthe study,of receptor-mediated endocytosis,inwhich,largeamounts,of IgG are transferredintactacross polarizedcells.This review,summarizes,the ultrastructural pathway,followed,by IgG during cellulartransitand severalimportantpropertiesofthe membrane,receptorthatrecognizesthe IgG. The smallintestine ofnewborn,ratsishighlyadaptedfor

  19. A novel clinical entity, IgG4-related disease (IgG4RD): general concept and details.

    PubMed

    Umehara, Hisanori; Okazaki, Kazuichi; Masaki, Yasufumi; Kawano, Mitsuhiro; Yamamoto, Motohisa; Saeki, Takako; Matsui, Shoko; Sumida, Takayuki; Mimori, Tsuneyo; Tanaka, Yoshiya; Tsubota, Kazuo; Yoshino, Tadashi; Kawa, Shigeyuki; Suzuki, Ritsuro; Takegami, Tsutomu; Tomosugi, Naohisa; Kurose, Nozomu; Ishigaki, Yasuhito; Azumi, Atsushi; Kojima, Masaru; Nakamura, Shigeo; Inoue, Dai

    2012-02-01

    IgG4-related disease (IgG4RD) is a novel clinical disease entity characterized by elevated serum IgG4 concentration and tumefaction or tissue infiltration by IgG4-positive plasma cells. IgG4RD may be present in a certain proportion of patients with a wide variety of diseases, including Mikulicz's disease, autoimmune pancreatitis, hypophysitis, Riedel thyroiditis, interstitial pneumonitis, interstitial nephritis, prostatitis, lymphadenopathy, retroperitoneal fibrosis, inflammatory aortic aneurysm, and inflammatory pseudotumor. Although IgG4RD forms a distinct, clinically independent disease category and is attracting strong attention as a new clinical entity, many questions and problems still remain to be elucidated, including its pathogenesis, the establishment of diagnostic criteria, and the role of IgG4. Here we describe the concept of IgG4RD and up-to-date information on this emerging disease entity. PMID:21881964

  20. Serum IgG and IgM anticardiolipin antibodies in neurological diseases.

    PubMed

    Rombos, A; Evangelopoulou-Katsiri, E; Leventakou, A; Voumvourakis, K; Triantafyllou, N; Papageorgiou, C

    1990-03-01

    To determine whether anti-cardiolipin antibodies (ACA) are associated with multiple sclerosis (MS) or myasthenia gravis (MG), sera from 42 patients suffering from MS and from 21 patients with myasthenia were studied, using an enzyme-linked immunosorbent assay (ELISA). No significant difference in IgG or IgM immunoglobulin isotypes between the MS myasthenic patients and controls was found. PMID:2112819

  1. Extensive diversification of IgD-, IgY-, and truncated IgY(?Fc)-encoding genes in the red-eared turtle (Trachemys scripta elegans).

    PubMed

    Li, Lingxiao; Wang, Tao; Sun, Yi; Cheng, Gang; Yang, Hui; Wei, Zhiguo; Wang, Ping; Hu, Xiaoxiang; Ren, Liming; Meng, Qingyong; Zhang, Ran; Guo, Ying; Hammarström, Lennart; Li, Ning; Zhao, Yaofeng

    2012-10-15

    IgY(?Fc), containing only CH1 and CH2 domains, is expressed in the serum of some birds and reptiles, such as ducks and turtles. The duck IgY(?Fc) is produced by the same ? gene that expresses the intact IgY form (CH1-4) using different transcriptional termination sites. In this study, we show that intact IgY and IgY(?Fc) are encoded by distinct genes in the red-eared turtle (Trachemys scripta elegans). At least eight IgY and five IgY(?Fc) transcripts were found in a single turtle. Together with Southern blotting, our data suggest that multiple genes encoding both IgY forms are present in the turtle genome. Both of the IgY forms were detected in the serum using rabbit polyclonal Abs. In addition, we show that multiple copies of the turtle ? gene are present in the genome and that alternative splicing is extensively involved in the generation of both the secretory and membrane-bound forms of the IgD H chain transcripts. Although a single ? gene was identified, the ? gene was not identified in this species. PMID:22972932

  2. Red trap colour of the carnivorous plant Drosera rotundifolia does not serve a prey attraction or camouflage function.

    PubMed

    Foot, G; Rice, S P; Millett, J

    2014-01-01

    The traps of many carnivorous plants are red in colour. This has been widely hypothesized to serve a prey attraction function; colour has also been hypothesized to function as camouflage, preventing prey avoidance. We tested these two hypotheses in situ for the carnivorous plant Drosera rotundifolia. We conducted three separate studies: (i) prey attraction to artificial traps to isolate the influence of colour; (ii) prey attraction to artificial traps on artificial backgrounds to control the degree of contrast and (iii) observation of prey capture by D. rotundifolia to determine the effects of colour on prey capture. Prey were not attracted to green traps and were deterred from red traps. There was no evidence that camouflaged traps caught more prey. For D. rotundifolia, there was a relationship between trap colour and prey capture. However, trap colour may be confounded with other leaf traits. Thus, we conclude that for D. rotundifolia, red trap colour does not serve a prey attraction or camouflage function. PMID:24740904

  3. Red trap colour of the carnivorous plant Drosera rotundifolia does not serve a prey attraction or camouflage function

    PubMed Central

    Foot, G.; Rice, S. P.; Millett, J.

    2014-01-01

    The traps of many carnivorous plants are red in colour. This has been widely hypothesized to serve a prey attraction function; colour has also been hypothesized to function as camouflage, preventing prey avoidance. We tested these two hypotheses in situ for the carnivorous plant Drosera rotundifolia. We conducted three separate studies: (i) prey attraction to artificial traps to isolate the influence of colour; (ii) prey attraction to artificial traps on artificial backgrounds to control the degree of contrast and (iii) observation of prey capture by D. rotundifolia to determine the effects of colour on prey capture. Prey were not attracted to green traps and were deterred from red traps. There was no evidence that camouflaged traps caught more prey. For D. rotundifolia, there was a relationship between trap colour and prey capture. However, trap colour may be confounded with other leaf traits. Thus, we conclude that for D. rotundifolia, red trap colour does not serve a prey attraction or camouflage function. PMID:24740904

  4. O-glycosylation of serum IgA1 antibodies against mucosal and systemic antigens in IgA nephropathy.

    PubMed

    Smith, Alice C; Molyneux, Karen; Feehally, John; Barratt, Jonathan

    2006-12-01

    In IgA nephropathy (IgAN), serum IgA1 with abnormal O-glycosylation deposits in the glomerular mesangium. The underlying mechanism of this IgA1 O-glycosylation abnormality is poorly understood, but recent evidence argues against a generic defect in B cell glycosyltransferases, suggesting that only a subpopulation of IgA1-committed B cells are affected. For investigation of whether the site of antigen encounter influences IgA1 O-glycosylation, the O-glycosylation of serum IgA1 antibodies against a systemic antigen, tetanus toxoid (TT), and a mucosal antigen, Helicobacter pylori (HP), was studied in patients with IgAN and control subjects. Serum IgA1 was purified from cohorts of patients with IgAN and control subjects with HP infection and after systemic TT immunization. The IgA1 samples were applied to HP- and TT-coated immunoplates to immobilize specific antibodies, and IgA1 O-glycosylation profiles were assessed by binding of the O-glycan-specific lectin Vicia villosa using a modified ELISA technique. Although total serum IgA1 had raised lectin binding in IgAN, the O-glycosylation of the specific IgA1 antibodies to TT and HP did not differ between patients and control subjects. In both groups, IgA1 anti-HP had higher lectin binding than IgA1 anti-TT. This study demonstrates that IgA1 O-glycosylation normally varies in different immune responses and that patients produce the full spectrum of IgA1 O-glycoforms. IgA1 with high lectin binding was produced in response to mucosal HP infection in all subjects. The raised circulating level of this type of IgA1 in IgAN is likely to be a consequence of abnormal systemic responses to mucosally encountered antigens rather than a fundamental defect in B cell O-glycosylation pathways. PMID:17093066

  5. IgG galactosylation aberrancy precedes disease onset, correlates with disease activity and is prevalent in autoantibodies in rheumatoid arthritis

    PubMed Central

    Ercan, Altan; Cui, Jing; Chatterton, Dereck E.W.; Deane, Kevin D.; Hazen, Melissa M.; Brintnell, William; O’Donnell, Colin I.; Derber, Lezlie A.; Weinblatt, Michael E.; Shadick, Nancy A.; Bell, David A.; Cairns, Ewa; Solomon, Daniel H.; Holers, V. Michael; Rudd, Pauline M.; Lee, David M.

    2014-01-01

    Objective To examine the association of IgG galactosylation aberrancy with disease parameters in rheumatoid arthritis (RA). Methods N-glycan analysis of serum from multiple cohorts was performed. IgG N-glycan content and timing of N-glycan aberrancy relative to disease onset was compared in healthy and RA subjects. Correlations between aberrant galactosylation and disease activity were assessed in the RA cohorts. The impact of disease activity, gender, age, anti-CCP titer, disease duration, and CRP on aberrant galactosylation was determined using multivariate analysis. N-glycan content was also compared between epitope affinity purified autoantibodies and the remaining repertoire IgG in RA subjects. Results Our results confirm the aberrant galactosylation of IgG in RA (1.36 ± 0.43) compared to healthy controls (1.01 ± 0.23) (P < 0.0001). We observe a significant correlation between levels of aberrant IgG galactosylation and disease activity (Spearman rho = 0.37, p<0.0001). This correlation is higher in females [Spearman rho = 0.60 (P<0.0001)] than males [Spearman rho = 0.16 (P = 0.10)]. Further, IgG galactosylation aberrancy substantially predates onset of arthritis and the diagnosis of RA (3.5 years) and resides selectively in the anti-citrullinated peptide autoantibody fraction. Conclusions Our findings identify aberrant IgG galactosylation as a dysregulated component of the humoral immune response in RA that begins prior to disease onset, that associates with disease activity in a gender specific manner, and that resides preferentially in autoantibodies. PMID:20506563

  6. Saliva and sera IgA and IgG in Egyptian Giardia-infected children.

    PubMed

    El-Gebaly, Naglaa Saad M; Halawa, Eman Fawzy; Moussa, Hanaa M Ezzat; Rabia, Ibrahim; Abu-Zekry, Maha

    2012-08-01

    Giardiasis is a gastrointestinal infection of wide distribution that is more prevalent in childhood. Easy and rapid diagnosis of giardiasis is essential for reduction of this infection. This cross-sectional study included 62 children in which collection of saliva, stool and serum samples was performed. An enzyme-linked immunosorbent assay (ELISA) technique was evaluated to detect IgA and IgG responses in both saliva and serum samples. Twenty-two children were positive for Giardia duodenalis infection by direct examination of faecal specimens, 20 non-infected and 20 infected with other parasites. Salivary and serum IgA and IgG responses against G. duodenalis infection were significantly higher in Giardia parasitized than non-Giardia parasitized children (p?IgA may serve as a diagnostic tool and specific salivary IgG as a screening tool in monitoring the exposure of various populations to Giardia duodenalis. The advantage of salivary assays over serum immunoglobulin assay is being easy and non-invasive in sampling technique which is important especially for young children. PMID:22402609

  7. The Chemistry of the Postpharyngeal Gland of Female European Beewolves

    PubMed Central

    Herzner, Gudrun; Kaltenpoth, Martin; Boland, Wilhelm; Schreier, Peter; Geiselhardt, Sven; Peschke, Klaus; Schmitt, Thomas

    2008-01-01

    Females of the European beewolf, Philanthus triangulum, possess a large glove-shaped gland in the head, the postpharyngeal gland (PPG). They apply the content of the PPG to their prey, paralyzed honeybees, where it delays fungal infestation. Here, we describe the chemical composition of the gland by using combined GC-MS, GC-FTIR, and derivatization. The PPG of beewolves contains mainly long-chain unsaturated hydrocarbons (C23–C33), lower amounts of saturated hydrocarbons (C14–C33), and minor amounts of methyl-branched hydrocarbons (C17–C31). Additionally, the hexane-soluble gland content is comprised of small amounts of an unsaturated C25 alcohol, an unknown sesquiterpene, an octadecenylmethylester, and several long-chain saturated (C25, C27) and unsaturated (C23–C27) ketones, some of which have not yet been reported as natural products. Surprisingly, we found a dimorphism with regard to the major component of the PPG with some females having (Z)-9-pentacosene, whereas others have (Z)-9-heptacosene as their predominant component. The biological relevance of the compounds for the prevention of fungal growth on the prey and the significance of the chemical dimorphism are discussed. PMID:18415061

  8. Viability selection on prey morphology by a generalist predator.

    PubMed

    Møller, A P; Couderc, G; Nielsen, J T

    2009-06-01

    Prey use their locomotory capacity to escape predators, and there should thus be strong viability selection on locomotory morphology of prey. We compared feather morphology of wood pigeons Columba palumbus killed by goshawks Accipiter gentilis with that of survivors to quantify directional and quadratic selection on primary and rectrix feathers. The goshawk is mainly a predator attacking by surprise, leaving wood pigeons with an ability to accelerate fast at a selective advantage. There was directional selection for light primary feathers with a narrow calamus. In addition, there was directional selection for increased area of rectrices. These patterns of natural selection were confirmed in multivariate analyses of selection that showed selection for light primary feathers with a large area and narrow calamus and for a large area of rectrix feathers. These results provide evidence of selection on different aspects of feather morphology directly related to flight performance and thus escape ability from predators. PMID:19344382

  9. Predator fitness increases with selectivity for odd prey.

    PubMed

    Rutz, Christian

    2012-05-01

    The fundamental currency of normative models of animal decision making is Darwinian fitness. In foraging ecology, empirical studies typically assess foraging strategies by recording energy intake rates rather than realized reproductive performance. This study provides a rare empirical link, in a vertebrate predator-prey system, between a predator's foraging behavior and direct measures of its reproductive fitness. Goshawks Accipiter gentilis selectively kill rare color variants of their principal prey, the feral pigeon Columba livia, presumably because targeting odd-looking birds in large uniform flocks helps them overcome confusion effects and enhances attack success. Reproductive performance of individual hawks increases significantly with their selectivity for odd-colored pigeons, even after controlling for confounding age effects. Older hawks exhibit more pronounced dietary preferences, suggesting that hunting performance improves with experience. Intriguingly, although negative frequency-dependent predation by hawks exerts strong selection against rare pigeon phenotypes, pigeon color polymorphism is maintained through negative assortative mating. PMID:22503502

  10. Visual predators select for crypticity and polymorphism in virtual prey.

    PubMed

    Bond, Alan B; Kamil, Alan C

    2002-02-01

    Cryptically coloured animals commonly occur in several distinct pattern variants. Such phenotypic diversity may be promoted by frequency-dependent predation, in which more abundant variants are attacked disproportionately often, but the hypothesis has never been explicitly tested. Here we report the first controlled experiment on the effects of visual predators on prey crypticity and phenotypic variance, in which blue jays (Cyanocitta cristata) searched for digital moths on computer monitors. Moth phenotypes evolved via a genetic algorithm in which individuals detected by the jays were much less likely to reproduce. Jays often failed to detect atypical cryptic moths, confirming frequency-dependent selection and suggesting the use of searching images, which enhance the detection of common prey. Over successive generations, the moths evolved to become significantly harder to detect, and they showed significantly greater phenotypic variance than non-selected or frequency-independent selected controls. PMID:11832937

  11. Environmental versus demographic variability in stochastic predator-prey models

    NASA Astrophysics Data System (ADS)

    Dobramysl, U.; Täuber, U. C.

    2013-10-01

    In contrast to the neutral population cycles of the deterministic mean-field Lotka-Volterra rate equations, including spatial structure and stochastic noise in models for predator-prey interactions yields complex spatio-temporal structures associated with long-lived erratic population oscillations. Environmental variability in the form of quenched spatial randomness in the predation rates results in more localized activity patches. Our previous study showed that population fluctuations in rare favorable regions in turn cause a remarkable increase in the asymptotic densities of both predators and prey. Very intriguing features are found when variable interaction rates are affixed to individual particles rather than lattice sites. Stochastic dynamics with demographic variability in conjunction with inheritable predation efficiencies generate non-trivial time evolution for the predation rate distributions, yet with overall essentially neutral optimization.

  12. Crystal structure of deglycosylated human IgG4-Fc

    PubMed Central

    Davies, Anna M.; Jefferis, Roy; Sutton, Brian J.

    2014-01-01

    The Fc region of IgG antibodies, important for effector functions such as antibody-dependent cell-mediated cytotoxicity, antibody-dependent cellular phagocytosis and complement activation, contains an oligosaccharide moiety covalently attached to each CH2 domain. The oligosaccharide not only orients the CH2 domains but plays an important role in influencing IgG effector function, and engineering the IgG-Fc oligosaccharide moiety is an important aspect in the design of therapeutic monoclonal IgG antibodies. Recently we reported the crystal structure of glycosylated IgG4-Fc, revealing structural features that could explain the anti-inflammatory biological properties of IgG4 compared with IgG1. We now report the crystal structure of enzymatically deglycosylated IgG4-Fc, derived from human serum, at 2.7 ? resolution. Intermolecular CH2-CH2 domain interactions partially bury the CH2 domain surface that would otherwise be exposed by the absence of oligosaccharide, and two Fc molecules are interlocked in a symmetric, open conformation. The conformation of the CH2 domain DE loop, to which oligosaccharide is attached, is altered in the absence of carbohydrate. Furthermore, the CH2 domain FG loop, important for Fc? receptor and C1q binding, adopts two different conformations. One loop conformation is unique to IgG4 and would disrupt binding, consistent with IgG4's anti-inflammatory properties. The second is similar to the conserved conformation found in IgG1, suggesting that in contrast to IgG1, the IgG4 CH2 FG loop is dynamic. Finally, crystal packing reveals a hexameric arrangement of IgG4-Fc molecules, providing further clues about the interaction between C1q and IgG. PMID:24956411

  13. PERFUMED FEMALE'S SEX APPEAL

    Microsoft Academic Search

    Yfke van Bergen; Jean-Francois Ferveur

    2004-01-01

    When a male fruit fly wants to track down a gal, he follows his nose along her attractive scent trail. Jean-François Ferveur explains that this alluring bouquet is a complicated mixture of 16 hydrocarbon compounds, but it wasn't clear which of the cocktail's components turns a female fruit fly into a femme fatale. He adds that two of the female's

  14. Female infanticide and amniocentesis

    Microsoft Academic Search

    Roger Jeffery; Patricia Jeffery; Andrew Lyon

    1984-01-01

    Clinical services offering amniocentesis to inform women of the sex of their foetuses have appeared in North India in the past 10 years. They fit into cultural patterns in which girls are devalued, and some authors have seen direct links between female infanticide (assumed to have been eradicated by 1900), female neglect leading to higher infant and child mortality rates

  15. The Female Athlete Triad

    ERIC Educational Resources Information Center

    Sherman, Roberta Trattner; Thompson, Ron A.

    2004-01-01

    The Female Athlete Triad is a syndrome of the interrelated components of disordered eating, amenorrhea, and osteoporosis. Sometimes inadvertently, but more often by willful dietary restriction, many female athletes do not ingest sufficient calories to adequately fuel their physical or sport activities, which can disrupt menstrual functioning,…

  16. Understanding the Female Offender

    ERIC Educational Resources Information Center

    Cauffman, Elizabeth

    2008-01-01

    Although boys engage in more delinquent and criminal acts than do girls, female delinquency is on the rise. In 1980, boys were four times as likely as girls to be arrested; today they are only twice as likely to be arrested. In this article, the author explores how the juvenile justice system is and should be responding to the adolescent female

  17. Prognostic value of glomerular C4d staining in patients with IgA nephritis

    PubMed Central

    Sahin, Osman Zikrullah; Yavas, Hakan; Tasl?, Funda; Gibyeli, Dilek Genek; Ersoy, R?fk?; Uzum, Atilla; Cirit, Mustafa

    2014-01-01

    Introduction: Mesangial IgA deposition is the initiative factor in the pathogenesis of IgA nephropathy (IgAN). Glomerular IgA depositon leads to activation local complement system. C4d positivity shows that complement activation occurs via alternative pathway. C4d positivity at the time of renal biopsy can be associated with poor prognosis in IgA nephropathy. We aimed to evaluate C4d deposition and renal outcome in patients with IgA nephritis. Methods: Between January 2005 and December 2009, 40 patients with IgA nephritis were enrolled. Renal biopsy specimens of 33 patients have been evaluated. C4d immunohistochemical staining was performed 3-?m deparaffinized and rehydrated sections of formaldehyde-fixed renal tissues, using rabbit polyclonal anti-human C4d as the antibody. Baseline demographical, clinical and laboratory data were recorded retrospectively. Results: Mean age of the patients was 35.9 ± 12.9 years and female/male ratio was 19/21. Mean duration of follow-up was 32.8 (12-60) months. Baseline glomerular filtration ratio (GFR) and proteinuria were 55.8 ml/min and 2.44 gr/day respectively at the time of renal biopsy. Eleven patients were C4d positive. Presence of hypertension (p=0.133), proteinuria (p=0.007), serum creatinine levels (p=0.056) and glomerulosclerosis (p=0.004), mesengial hypersellularity (p=0.0001) and interstitial fibrosis (p=0.006) at the time of renal biopsy were higher in C4d positive group rather than negative group. Evolution to renal failure were 63.6% in C4d positive group and 13.6% in negative group (p=0.006). Renal survival at 3 years was 39% in C4d-positive patients versus 66.7% in the C4d-negative patients (log rank- p=0.0072). PMID:25031752

  18. Modelling encounter rates and distribution of mobile predators and prey

    NASA Astrophysics Data System (ADS)

    Huse, Geir; Fiksen, Øyvind

    2010-01-01

    Marine ecosystem models often contain modules for two phytoplankton compartments (flagellates and diatoms) and two zooplankton groups (micro- and mesozooplankton). The models rarely include fish, not even as an agent in zooplankton mortality, which is often formulated as a constant rate. This mortality rate is treated as a free parameter, which can be used to tune or stabilize the model. There are major gaps in our knowledge and modelling capabilities of interactions at the higher trophic levels for example with regards to movement of fish at different scales, prey selection, and zooplankton responses to predators. Here, we argue that there are good reasons for making zooplankton mortality dependent on some key environmental variables known to affect the interaction strength between zooplankton and fish. In addition, since fish are highly mobile organisms, often moving in large groups, there is a need to better understand and model their horizontal migration and to include this in ecosystem models. We present basic models for light-dependent encounters between fish and their zooplankton prey and illustrate how predator-prey interactions can be modelled for herring- Calanus and cod-capelin interactions using individual-based models with super-individuals. In the latter two cases individual displacement is determined by movement behaviour and ocean circulation, and growth and mortality become emergent properties resulting from local encounters between predators and prey. Similarly movement behaviours emerge from simple adaptive rules or more complex models where behavioural strategies are evolved using a genetic algorithm. Such models are versatile and we argue that emergent mortality and growth rates resulting from adaptive behaviours and key environmental forcing are essential for realistic representation of fish-zooplankton interactions.

  19. [Occurrence of parasites in indigenous birds of prey and owls].

    PubMed

    Lierz, M; Göbel, T; Schuster, R

    2002-01-01

    In the present paper a general overview on parasites in birds of prey and owls is given. This part is followed by a study investigating the prevalences and species of parasites in free-ranging birds of prey and owls in Berlin and Brandenburg State, Germany. Over a one year period, 84 birds of prey and owls of the following species were examined for the presence of endo- and ectoparasites: Common Buzzard (Buteo buteo) (n = 32), Kestrel (Falco tinnunculus) (n = 20), Sparrowhawk (Accipiter nisus) (n = 9), Goshawk (Accipiter gentilis) (n = 8), Black Kite (Milvus migrans) (n = 4), Peregrine Falcon (Falco peregrinus) (n = 3), Marsh Harrier (Circus aeruginosus) (n = 1), White-tailed-Sea Eagle (Haliaeetus albicilla) (n = 1), Tawny Owl (Strix aluco) (n = 4), Long-eared Owl (Asio otus) (n = 1) and Barn Owl (Tyto alba) (n = 1). In 97.6% of the cases, ectoparasites (feather mites and hippoboscid flies) were found. Especially eyasses (93.3%) were positive for hippoboscid flies. Trichomonas was detected in 28.6% of all birds of prey and owls examined. A prevalence of 100% was established in the Sparrow Hawks as well as Peregrine Falcons. Leucozytozoon sp. and Hemoproteus sp. as blood parasites were found in 26.9% of the birds in total. Common Buzzards showed the highest prevalence (44.8%). 58.3% of birds examined were positive for endoparasites. Flukes were found in 16.7%, tapeworms in 14.3%, round-worms in 48.8% and acanthocephales in 2.4% of the cases. Interestingly, Tylodelphis clavata (in a Common Buzzard) and Hovorkonema variegatum (in a Goshawk) were found for the first time in raptors. The results of this study underline the importance of a parasitological examination in the process of raptor rehabilitation. PMID:11852683

  20. Predator-Prey Model for Haloes in Saturn's Rings

    NASA Astrophysics Data System (ADS)

    Esposito, L. W.; Bradley, E. T.; Colwell, J. E.; Madhusudhanan, P.; Sremcevic, M.

    2013-09-01

    ISS, VIMS, UVIS spectroscopy and occultations show haloes around the strongest density waves. Based on a predator-prey model for ring dynamics, we offer the following explanation: •Cyclic velocity changes cause the perturbed regions to reach higher collision speeds at some orbital phases, which preferentially removes small regolith particles; •This forms a bright halo around the ILR, if the forcing is strong enough; •Surrounding particles diffuse back too slowly to erase the effect; they diffuse away to form the halo.

  1. Cascade of Complexity in Evolving Predator-Prey Dynamics

    NASA Astrophysics Data System (ADS)

    Guttenberg, Nicholas; Goldenfeld, Nigel

    2008-02-01

    We simulate an individual-based model that represents both the phenotype and genome of digital organisms with predator-prey interactions. We show how open-ended growth of complexity arises from the invariance of genetic evolution operators with respect to changes in the complexity, and that the dynamics which emerges shows scaling indicative of a nonequilibrium critical point. The mechanism is analogous to the development of the cascade in fluid turbulence.

  2. Modulation of predator–prey interactions by the Allee effect

    Microsoft Academic Search

    Ariane Verdy

    2010-01-01

    An Allee effect arising from density-dependent mating success can have significant impacts at the ecosystem level when considered in the context of predator–prey interactions. These are captured by a mathematical model for the exchange of biomass between a structured predator population (continuous weight distribution) and a resource. Because the predator’s mating success affects the amount of resources required for the

  3. Predator and prey activity levels jointly influence the outcome of long-term foraging bouts

    PubMed Central

    2013-01-01

    Consistent interindividual differences in behavior (i.e., “behavioral types”) may be a key factor in determining the outcome of species interactions. Studies that simultaneously account for the behavioral types of individuals in multiple interacting species, such as predator–prey systems, may be particularly strong predictors of ecological outcomes. Here, we test the predator–prey locomotor crossover hypothesis, which predicts that active predators are more likely to encounter and consume prey with the opposing locomotor tendency. We test this hypothesis using intraspecific behavioral variation in both a predator and prey species as predictors of foraging outcomes. We use the old field jumping spider, Phidippus clarus (Araneae, Salticidae), and the house cricket, Acheta domesticus (Orthoptera, Gryllidae), as a model predator–prey system in laboratory mesocosm trials. Stable individual differences in locomotor tendencies were identified in both P. clarus and A. domesticus, and the outcome of foraging bouts depended neither on the average activity level of the predator nor on the average activity level of prey. Instead, an interaction between the activity level of spiders and crickets predicted spider foraging success and prey survivorship. Consistent with the locomotor crossover hypothesis, predators exhibiting higher activity levels consumed more prey when in an environment containing low-activity prey items and vice versa. This study highlights 1) the importance of intraspecific variation in determining the outcome of predator–prey interactions and 2) that acknowledging behavioral variation in only a single species may be insufficient to characterize the performance consequences of intraspecific trait variants. PMID:23935257

  4. When hawks attack: animal-borne video studies of goshawk pursuit and prey-evasion strategies.

    PubMed

    Kane, Suzanne Amador; Fulton, Andrew H; Rosenthal, Lee J

    2015-01-15

    Video filmed by a camera mounted on the head of a Northern Goshawk (Accipiter gentilis) was used to study how the raptor used visual guidance to pursue prey and land on perches. A combination of novel image analysis methods and numerical simulations of mathematical pursuit models was used to determine the goshawk's pursuit strategy. The goshawk flew to intercept targets by fixing the prey at a constant visual angle, using classical pursuit for stationary prey, lures or perches, and usually using constant absolute target direction (CATD) for moving prey. Visual fixation was better maintained along the horizontal than vertical direction. In some cases, we observed oscillations in the visual fix on the prey, suggesting that the goshawk used finite-feedback steering. Video filmed from the ground gave similar results. In most cases, it showed goshawks intercepting prey using a trajectory consistent with CATD, then turning rapidly to attack by classical pursuit; in a few cases, it showed them using curving non-CATD trajectories. Analysis of the prey's evasive tactics indicated that only sharp sideways turns caused the goshawk to lose visual fixation on the prey, supporting a sensory basis for the surprising frequency and effectiveness of this tactic found by previous studies. The dynamics of the prey's looming image also suggested that the goshawk used a tau-based interception strategy. We interpret these results in the context of a concise review of pursuit-evasion in biology, and conjecture that some prey deimatic 'startle' displays may exploit tau-based interception. PMID:25609783

  5. When hawks attack: animal-borne video studies of goshawk pursuit and prey-evasion strategies

    PubMed Central

    Kane, Suzanne Amador; Fulton, Andrew H.; Rosenthal, Lee J.

    2015-01-01

    Video filmed by a camera mounted on the head of a Northern Goshawk (Accipiter gentilis) was used to study how the raptor used visual guidance to pursue prey and land on perches. A combination of novel image analysis methods and numerical simulations of mathematical pursuit models was used to determine the goshawk's pursuit strategy. The goshawk flew to intercept targets by fixing the prey at a constant visual angle, using classical pursuit for stationary prey, lures or perches, and usually using constant absolute target direction (CATD) for moving prey. Visual fixation was better maintained along the horizontal than vertical direction. In some cases, we observed oscillations in the visual fix on the prey, suggesting that the goshawk used finite-feedback steering. Video filmed from the ground gave similar results. In most cases, it showed goshawks intercepting prey using a trajectory consistent with CATD, then turning rapidly to attack by classical pursuit; in a few cases, it showed them using curving non-CATD trajectories. Analysis of the prey's evasive tactics indicated that only sharp sideways turns caused the goshawk to lose visual fixation on the prey, supporting a sensory basis for the surprising frequency and effectiveness of this tactic found by previous studies. The dynamics of the prey's looming image also suggested that the goshawk used a tau-based interception strategy. We interpret these results in the context of a concise review of pursuit–evasion in biology, and conjecture that some prey deimatic ‘startle’ displays may exploit tau-based interception. PMID:25609783

  6. Selection and capture of prey in the African ponerine ant Plectroctena minor (Hymenoptera: Formicidae)

    NASA Astrophysics Data System (ADS)

    Schatz, Bertrand; Suzzoni, Jean-Pierre; Corbara, Bruno; Dejean, Alain

    2001-02-01

    Prey selection by Plectroctena minor workers is two-fold. During cafeteria experiments, the workers always selected millipedes, their essential prey, while alternative prey acceptance varied according to the taxa and the situation. Millipedes were seized by the anterior part of their body, stung, and retrieved by single workers that transported them between their legs. They were rarely snapped at, and never abandoned. When P. minor workers were confronted with alternative prey they behaved like generalist species: prey acceptance was inversely correlated to prey size. This was not the case vis-à-vis millipedes that they selected and captured although larger than compared alternative prey. The semi-specialised diet of P. minor permits the colonies to be easily provisioned by a few foraging workers as millipedes are rarely hunted by other predatory arthropods, while alternative prey abound, resulting in low competition pressure in both cases. Different traits characteristic of an adaptation to hunting millipedes were noted and compared with the capture of alternative prey. We also noted the parsimony of the behavioural phases during their capture compared to the capture of alternative prey.

  7. Predator and prey activity levels jointly influence the outcome of long-term foraging bouts.

    PubMed

    Sweeney, Kayla; Cusack, Brian; Armagost, Fawn; O'Brien, Timothy; Keiser, Carl N; Pruitt, Jonathan N

    2013-09-01

    Consistent interindividual differences in behavior (i.e., "behavioral types") may be a key factor in determining the outcome of species interactions. Studies that simultaneously account for the behavioral types of individuals in multiple interacting species, such as predator-prey systems, may be particularly strong predictors of ecological outcomes. Here, we test the predator-prey locomotor crossover hypothesis, which predicts that active predators are more likely to encounter and consume prey with the opposing locomotor tendency. We test this hypothesis using intraspecific behavioral variation in both a predator and prey species as predictors of foraging outcomes. We use the old field jumping spider, Phidippus clarus (Araneae, Salticidae), and the house cricket, Acheta domesticus (Orthoptera, Gryllidae), as a model predator-prey system in laboratory mesocosm trials. Stable individual differences in locomotor tendencies were identified in both P. clarus and A. domesticus, and the outcome of foraging bouts depended neither on the average activity level of the predator nor on the average activity level of prey. Instead, an interaction between the activity level of spiders and crickets predicted spider foraging success and prey survivorship. Consistent with the locomotor crossover hypothesis, predators exhibiting higher activity levels consumed more prey when in an environment containing low-activity prey items and vice versa. This study highlights 1) the importance of intraspecific variation in determining the outcome of predator-prey interactions and 2) that acknowledging behavioral variation in only a single species may be insufficient to characterize the performance consequences of intraspecific trait variants. PMID:23935257

  8. Using predator-prey theory to predict outcomes of broadscale experiments to reduce apparent competition.

    PubMed

    Serrouya, Robert; Wittmann, Meike J; McLellan, Bruce N; Wittmer, Heiko U; Boutin, Stan

    2015-05-01

    Apparent competition is an important process influencing many ecological communities. We used predator-prey theory to predict outcomes of ecosystem experiments aimed at mitigating apparent competition by reducing primary prey. Simulations predicted declines in secondary prey following reductions in primary prey because predators consumed more secondary prey until predator numbers responded to reduced prey densities. Losses were exacerbated by a higher carrying capacity of primary prey and a longer lag time of the predator's numerical response, but a gradual reduction in primary prey was less detrimental to the secondary prey. We compared predictions against two field experiments where endangered woodland caribou (Rangifer tarandus caribou) were victims of apparent competition. First, when deer (Odocoileus sp.) declined suddenly following a severe winter, cougar (Puma concolor) declined with a 1-2-year lag, yet in the interim more caribou were killed by cougars, and caribou populations declined by 40%. Second, when moose (Alces alces) were gradually reduced using a management experiment, wolf (Canis lupus) populations declined but did not shift consumption to caribou, and the largest caribou subpopulation stabilized. The observed contrasting outcomes of sudden versus gradual declines in primary prey supported theoretical predictions. Combining theory with field studies clarified how to manage communities to mitigate endangerment caused by apparent competition that affects many taxa. PMID:25905509

  9. Prey size selection and distance estimation in foraging adult dragonflies.

    PubMed

    Olberg, R M; Worthington, A H; Fox, J L; Bessette, C E; Loosemore, M P

    2005-09-01

    To determine whether perching dragonflies visually assess the distance to potential prey items, we presented artificial prey, glass beads suspended from fine wires, to perching dragonflies in the field. We videotaped the responses of freely foraging dragonflies (Libellula luctuosa and Sympetrum vicinum-Odonata, suborder Anisoptera) to beads ranging from 0.5 mm to 8 mm in diameter, recording whether or not the dragonflies took off after the beads, and if so, at what distance. Our results indicated that dragonflies were highly selective for bead size. Furthermore, the smaller Sympetrum preferred beads of smaller size and the larger Libellula preferred larger beads. Each species rejected beads as large or larger than their heads, even when the beads subtended the same visual angles as the smaller, attractive beads. Since bead size cannot be determined without reference to distance, we conclude that dragonflies are able to estimate the distance to potential prey items. The range over which they estimate distance is about 1 m for the larger Libellula and 70 cm for the smaller Sympetrum. The mechanism of distance estimation is unknown, but it probably includes both stereopsis and the motion parallax produced by head movements. PMID:16034603

  10. Blue whale habitat and prey in the California Channel Islands

    NASA Astrophysics Data System (ADS)

    Fiedler, Paul C.; Reilly, Stephen B.; Hewitt, Roger P.; Demer, David; Philbrick, Valerie A.; Smith, Susan; Armstrong, Wesley; Croll, Donald A.; Tershy, Bernie R.; Mate, Bruce R.

    1998-08-01

    Whale Habitat and Prey Studies were conducted off southern California during August 1995 (WHAPS95) and July 1996 (WHAPS96) to (1) study the distribution and activities of blue whales and other large whales, (2) survey the distribution of prey organisms (krill), and (3) measure physical and biological habitat variables that influence the distribution of whales and prey. A total of 1307 cetacean sightings included 460 blue whale, 78 fin whale and 101 humpback whale sightings. Most blue whales were found in cold, well-mixed and productive water that had upwelled along the coast north of Point Conception and then advected south. They were aggregated in this water near San Miguel and Santa Rosa Islands, where they fed on dense, subsurface layers of euphausiids both on the shelf and extending off the shelf edge. Two species of euphausiids were consumed by blue whales, Thysanoessa spinifera and Euphausia pacifica, with evidence of preference for the former, a larger and more coastal species. These krill patches on the Channel Island feeding grounds are a resource exploited during summer-fall by the world's largest stock of blue whales.

  11. Long-term nutrient enrichment decouples predator and prey production

    PubMed Central

    Davis, John M.; Rosemond, Amy D.; Eggert, Susan L.; Cross, Wyatt F.; Wallace, J. Bruce

    2009-01-01

    Increased nutrient mobilization by human activities represents one of the greatest threats to global ecosystems, but its effects on ecosystem productivity can differ depending on food web structure. When this structure facilitates efficient energy transfers to higher trophic levels, evidence from previous large-scale enrichments suggests that nutrients can stimulate the production of multiple trophic levels. Here we report results from a 5-year continuous nutrient enrichment of a forested stream that increased primary consumer production, but not predator production. Because of strong positive correlations between predator and prey production (evidence of highly efficient trophic transfers) under reference conditions, we originally predicted that nutrient enrichment would stimulate energy flow to higher trophic levels. However, enrichment decoupled this strong positive correlation and produced a nonlinear relationship between predator and prey production. By increasing the dominance of large-bodied predator-resistant prey, nutrient enrichment truncated energy flow to predators and reduced food web efficiency. This unexpected decline in food web efficiency indicates that nutrient enrichment, a ubiquitous threat to aquatic ecosystems, may have unforeseen and unpredictable effects on ecosystem structure and productivity. PMID:20018677

  12. Prey transport in "palatine-erecting" elapid snakes.

    PubMed

    Deufel, Alexandra; Cundall, David

    2003-12-01

    Cobras and mambas are members of a group of elapid snakes supposedly united by the morphology and inferred behavior of their palatine bone during prey transport (palatine erectors). The palatine erectors investigated (Dendroaspis polylepis, Naja pallida, Ophiophagus hannah, Aspidelaps scutatus, A. lubricus) show differences in the morphology of their feeding apparatus that do not affect the overall behavior of the system. We delineated the structures directly involved in producing palatine erection during prey transport. Palatine erection can be achieved by a colubroid muscle contraction pattern acting on a palato-pterygoid bar with a movable palato-pterygoid joint and a palatine that is stabilized against the snout. The palatine characters originally proposed to cause palatine erection are not required to produce the behavior and actually impede it in Naja pallida. Palatine-erecting elapids share a fundamental design of the palato-maxillary apparatus with all higher snakes. A set of plesiomorphic core characters is functionally integrated to function in prey transport using the pterygoid walk. Variant characters are either part of a structural periphery unrelated to the core structures that define function or patterns of variation are subordinate character sets operating within functional thresholds of a single system. PMID:14584037

  13. Coexistence of structured populations with size-based prey selection.

    PubMed

    Hartvig, Martin; Andersen, Ken Haste

    2013-11-01

    Species with a large adult-offspring size ratio and a preferred predator-prey mass ratio undergo ontogenetic trophic niche shift(s) throughout life. Trophic interactions between such species vary throughout life, resulting in different species-level interaction motifs depending on the maximum adult sizes and population size distributions. We explore the assembly and potential for coexistence of small communities where all species experience ontogenetic trophic niche shifts. The life-history of each species is described by a physiologically structured model and species identity is characterised by the trait: size at maturation. We show that a single species can exist in two different states: a 'resource driven state' and a 'cannibalistic state' with a large scope for emergent Allee effects and bistable states. Two species can coexist in two different configurations: in a 'competitive coexistence' state when the ratio between sizes at maturation of the two species is less than a predator-prey mass ratio and the resource level is low to intermediate, or in a 'trophic ladder' state if the ratio of sizes at maturation is larger than the predator-prey mass ratio at all resource levels. While there is a large scope for coexistence of two species, the scope for coexistence of three species is limited and we conclude that further trait differentiation is required for coexistence of more species-rich size-structured communities. PMID:23927897

  14. Electroreceptive Prey-Location Coding by the Juvenile Paddlefish

    NASA Astrophysics Data System (ADS)

    van Hemmen, J. Leo

    2003-03-01

    The long rostrum of the paddlefish (Polyodon spathula), a Mississippi river inhabitant, supports an extensive array of ampullary electroreceptors that are used to locate its favorite prey, water fleas, in dark and muddy water. Neuronal coding of such real-world events is often considered to be optimal in the sense of minimizing a mean-square reconstruction error or maximizing likelihood. Implementation of these theoretically motivated optimality criteria is, however, computationally very costly. For the juvenile paddlefish we exhibit [1] a computationally cheap and geometrically simple algorithm with the neuronal activity ?n of its electroreceptors 1<= n <= N as input and evaluating the turning direction \\varphi required to catch the prey through the so-called population-vector code \\varphi^estimate = arg [sumn ?n exp(i \\varphi_n)]. This explains experimentally found prey-detection statistics more convincingly than minimization of the mean-square reconstruction error. The only assumption concerns the neuronal time scale of the sensory organs. [1] C. Leibold, K.B. Reuter, L. Voigts, W. Wojtenek, and J.L. van Hemmen, manuscript in preparation.

  15. Sublethal effects and predator-prey interactions: implications for ecological risk assessment.

    PubMed

    Brooks, Amy C; Gaskell, Paul N; Maltby, Lorraine L

    2009-11-01

    Ecological risk assessments tend to focus on contaminant effects on single species in isolation. However, additional effects from interactions between species (e.g., predator-prey interactions) may also occur in natural systems. The present study investigated the consequences of sublethal contaminant effects in prey on predator-prey interactions, particularly the interaction between prey behavioral changes and predation by predators with different hunting strategies. Ambush (Ischnura elegans Vander Linden [Insecta, Odonata]) and active (Notonecta glauca Linnaeus [Insecta, Heteroptera]) predator species were used in conjunction with three prey species (Asellus aquaticus Linnaeus [Crustacea, Isopoda], Cloion dipterum Linnaeus [Insecta, Ephemeroptera], and Chironomus riparius Meigen [Insecta, Diptera]). Immobilized prey demonstrated the importance of prey behavior for determining predation rates for both single- and multiple-prey species. Chironomus riparius was less responsive following exposure to cadmium, becoming more vulnerableto attack by the active but not the ambush predator. Some evidence was also observed for reduced general activity in C. dipterum following cadmium exposure. Sublethal exposure of prey did not affect the prey choice of active predators, possibly because of prey behavioral changes being insufficient to influence their relative availabilities. However, cadmium exposure of prey did alter their susceptibility to ambush predators. There was a reduced proportion of C. dipterum and an increased proportion of A. aquaticus in the diet of ambush predators, possibly because of reduced activity in C. dipterum affecting their relative encounter rates with predators. Sublethal exposures can therefore result in reduced prey survival that would not be predicted by single-species toxicity tests. PMID:19572771

  16. Immunoglobulin G kappa [IgG kappa] and IgG lambda paraproteinemia in a child with AIDS and response to highly active antiretroviral therapy.

    PubMed

    Seeborg, Filiz Odabasi; Gay, Hannah; Schmiege, Lorenz M; Bernard, David; Shearer, William T

    2005-11-01

    We report an 8-year-old boy with AIDS, extremely elevated serum immunoglobulin G (IgG) concentration and IgG kappa [IgG(kappa)] and IgG lambda [IgG(lambda)] paraproteinemia. This paraproteinemia partially responded to highly active antiretroviral therapy. This case emphasizes the importance of controlling B-cell activation. PMID:16275950

  17. Serum immunoglobulin concentrations in preschool children measured by laser nephelometry: reference ranges for IgG, IgA, IgM

    Microsoft Academic Search

    D Isaacs; D G Altman; C E Tidmarsh; H B Valman; A D Webster

    1983-01-01

    Serum immunoglobulin concentrations were determined on sera from 298 healthy children aged six months to six years using the Hyland laser nephelometer PDQ system. Age-specific 95% reference ranges for serum IgG, IgA and IgM are presented; considerable care has been taken to ensure statistical validity of the reference ranges. The wide range of values in children under two years suggest

  18. Interactions of the IGS reprocessing and the IGS antenna phase center model (Invited)

    NASA Astrophysics Data System (ADS)

    Schmid, R.; Steigenberger, P.; Dach, R.; Schmitz, M.; Dilssner, F.; Hugentobler, U.

    2009-12-01

    Since November 2006 an absolute phase center correction model for GNSS satellite and receiver antennas has been used within the International GNSS Service (IGS). This model, called igs05.atx, comprises consistent phase center offset (PCO) and variation (PCV) values given in ANTEX format. Generally, these correction values have not been changed in the meantime.For most of the receiver antenna types dominating the IGS network, absolute robot calibrations provided by Geo++ GmbH are available. Those comprise azimuth- and zenith-dependent PCVs down to the horizon. For the remaining antenna types converted field calibrations from the National Geodetic Survey are applied that are purely zenith-dependent. The impact of radomes is taken into account, if calibration results are available. So far, igs05.atx only contains calibrations for the GPS frequencies.The GPS satellite antenna corrections contained in igs05.atx were estimated by Deutsches GeoForschungsZentrum and by TUM by reprocessing more than ten years of IGS data. The corresponding GLONASS corrections were provided by the Center for Orbit Determination in Europe (CODE) after processing more than one year of data. Although azimuth-dependent PCVs are present, the igs05.atx model is limited to block-specific purely nadir-dependent PCVs. In contrast, satellite-specific z-offsets are given.At the time the satellite antenna corrections were estimated, the solutions could only be aligned to IGb00, the IGS realization of ITRF2000, that was based on relative receiver antenna corrections. Moreover, the impact of radomes had to be ignored, as calibration results were not available. So, the IGS reprocessing campaign is an excellent possibility to improve the consistency between both satellite and receiver antenna corrections and the terrestrial reference frame.Several analysis centers (ACs) of the IGS provide z-offset estimates within their weekly SINEX files. By back-solving those files with selected station coordinates fixed to ITRF2008, consistent z-offsets for all GPS satellites can be estimated. As PCV estimates are not contained in the SINEX files, the block-specific igs05.atx values for the GPS satellites will have to be kept fixed. As GLONASS observations were not reprocessed by the IGS ACs, a separate solution by CODE and ESOC will be necessary. This allows the simultaneous update of PCO and PCV values for GLONASS.As regards the receiver antennas, the overall update of igs05.atx provides the opportunity to consider the latest calibration results. As the accuracy of type-mean calibrations depends on the number of individually calibrated antennas, it is worth taking all calibrations from recent years into account. Whereas the update of robot calibrations will have minor influence on the coordinate estimates, the replacement of converted field calibrations probably requires the elimination of several reference frame stations. Besides, GLONASS-specific PCVs will be considered.The presentation will focus on the timeline of the various updates as well as on their impact on the coordinate results. We will highlight the benefit for the overall consistency of IGS products, but also demonstrate several remaining consistency problems.

  19. A novel heterophilic antibody interaction involves IgG4.

    PubMed

    Ito, T; Kitahara, K; Umemura, T; Ota, M; Shimozuru, Y; Kawa, S; Bahram, S

    2010-02-01

    IgG4 has been implicated in a diverse set of complex pathologies - e.g. autoimmune pancreatitis (AIP), idiopathic membranous nephropathy - and carries unique features including lack of activation of the classical complement pathway and a dynamic Fab-arm exchange. We recently showed that the rheumatoid factor (RF)-like activity of IgG4 is achieved through a hitherto unknown, Fc-Fc (and not Fab-Fc as is the case in classical RF; CRF) interaction; hence the name, novel RF (NRF). Here, we further explore the resemblance/difference between CRF and NRF. As heterophilic interactions of human IgM RF (CRF) are well known, we checked whether this is the case for IgG4. Human IgG4 showed variable reactivity to animal IgGs: reacting intensely with rabbit and mouse IgGs, but weakly with others. The binding to rabbit IgG was not through the Fab (as in CRF) but via the Fc piece, as was recently shown for human IgG (NRF). This binding correlates with the IgG4 concentration per se and could therefore be of diagnostic usage and incidentally explain some observed interferences in biological assays. In conclusion, here is defined a novel heterophilic antibody interaction and is established the universality of the unique Fc-Fc binding, both involving IgG4. PMID:20384862

  20. HSV-IgA serum antibodies in cervical intraepithelial neoplasia and invasive cancer patients, and in their spouses: a case control study.

    PubMed

    Gupta, M M; Jain, R; Parashari, A; Singh, V; Satyanarayana, L

    1992-07-01

    Class-specific IgG and IgA antibodies to HSV were assayed in women with CIN (76), invasive cancer (52) (histological diagnosis) and age-matched controls (119), employing HSV-2-infected HEp-2 cells as antigen during IFA assay. We observed an elevated geometric mean titre (GMT) of serum antibody (IgG five-to eight-fold and IgA four-to five-fold) for the entire spectrum of cervical lesions, as compared to controls. The odds of finding HSV-IgA antibodies were highest with CIN III (OR = 22.0), followed by invasive carcinoma, and CIN I & II (OR = 9.5 and 5.2), respectively. Furthermore, the investigations with respect to married couples (husbands and wives) who volunteered to participate in this study (33 cases and 47 control group) also indicated relatively high antibody titres and increased frequency of HSV sero positivity amongst husbands of cases as compared to their wives, as well as the control group males and females. The contribution of HSV infection in women and/or their husbands to the risk of developing abnormal cervical lesions was analysed after adjusting for the same in respective counterparts. It was observed that the risk was increased 14-fold with HSV-IgA positivity of women, and that HSV-IgA positivity of husbands (male partners) further increased the risk 16-fold. This preliminary observation shows the importance of serum HSV-IgA antibodies as a risk indicator in cervical precancer and cancer lesions in women without a history of recent genital herpes lesions. The serum HSV-IgA may also be taken as an indicator of "high risk" males. PMID:1322678

  1. Astragalus membranaceus up-regulate Cosmc expression and reverse IgA dys-glycosylation in IgA nephropathy

    PubMed Central

    2014-01-01

    Background Decreased Core I ?3-Gal-T-specific molecular chaperone (Cosmc) expression induced IgA1 aberrant glycosylation is the main characteristic of IgA nephropathy (IgAN). This study tried to elucidate the effect of Astragalus membranaceus on Cosmc expression and IgA O-glycosylation of peripheral B lymphocytes in IgAN patients. Methods Peripheral B lymphocytes of 21 IgAN patients and 10 normal controls were isolated and cultured with or without lipopolysaccharide (LPS) and Astragalus membranaceus injection (AMI). Cosmc mRNA and protein expression levels were measured by real-time RT-PCR and Western blot. IgA1 and glycosylation level were determined by enzyme-linked immunosorbent assay (ELISA) and VV lectin-binding method. Results Cosmc mRNA expression and IgA1 O-glycosylation level in IgAN patients was significantly lower than normal controls at baseline. Treatment of LPS could obviously inhibit Cosmc expression and increase the IgA1 secretion in peripheral B lymphocytes of IgAN patients, which resulted in a significantly increase in IgA1 aberrant glycosylation level. Addition of AMI could remarkably up regulated Cosmc expression, decrease IgA1 secretion, and reverse glycosylation level in a dose related manner. Conclusion AMI can up-regulate Cosmc expression of peripheral B lymphocytes and reverse IgA1 aberrant O-glycosylation level, which might be the underlying mechanism of AMI therapy in treating IgAN. Trial registration TCTR20140515001 (Registration Date: 2014-05-15) PMID:24942185

  2. Egg Yolk Antibodies (IgY) in Routine Diagnostic Work.

    PubMed

    Staak, Christian

    1996-01-01

    According to Linscott"s Directory of Immunological and Biological Reagents (1994/95) the commercial availability of egg-yolk antibodies (IgY) is extremely low. For preparation, cleaning and detection of IgY it would be of advantage to have a "Protein Y" available analogous to protein A and protein G for mammalian antibodies. Until now, the search for "Protein Y" was unsuccessful. IgY has been used for routine diagnostic work covering the following subjects: 1.Identification of the host species from abdominal blood of haematophageous insects; 2.IgY-anti-horse-Ig-PO conjugate for ELISA on dourine; 3.FITC-conjugated IgY-antirabies for diagnostic work on rabies; 4.FITC-conjugated IgY against avian virus diseases (Newcastle dis., Infectious bronchitis, Gumboro). In all cases satisfactory results have been achieved. PMID:11178478

  3. The proteolytic activity of milk fat, whey and casein for iodinated, extrinsic bovine IgG1, IgG2, SIgA and IgM.

    PubMed

    Frenyo, V L; Butler, J E

    1986-11-01

    Purified, iodinated bovine immunoglobulins (Igs) were incubated with fresh Guernsey milk or with the casein, fat and whey fraction of such milk for up to 12 hr at 37 degrees C. Igs incubated in whole milk, showed little evidence of proteolysis in either the whey, fat or casein fractions although the amount of radioactivity which became associated with the latter two fractions prevented adequate analysis. When the individual milk fractions were first prepared and then incubated with iodinated Igs, we found no evidence for proteolysis of any Ig in whey or casein but ca. 25% breakdown or dissociation of the IgM and SIgA which had been incubated with milk fat. Breakdown of these Igs in fat was not inhibited with benzamidine-HCl, sodium azide or EDTA. These data show that: only those Igs which associate with milk fat are degraded or dissociated by it and the Ig fragments described from cows milk or recovered during studies on Ig transport cannot be ascribed to the proteolytic activity of fresh milk. PMID:3492071

  4. Fate of Predator and Prey Proteins during Growth of Bdellovibrio bacteriovorus on Escherichia coli and Pseudomonas syringae Prey

    Microsoft Academic Search

    Gilli Barel; Alexandra Sirota; Hanne Volpin; Edouard Jurkevitch

    2005-01-01

    A two-dimensional electrophoretic analysis of protein distribution followed by identification of selected proteins by mass spectrometry was performed on fresh bdellovibrio cultures containing attack phase cells of the predatory bacterium Bdellovibrio bacteriovorus strain 109J-1 and the remains of an Escherichia coli or a Pseudomonas syringae pv. tomato prey. Cleavage of the peptidoglycan-associated outer membrane proteins (OMPs) OmpA in E. coli

  5. Reciprocity in predator–prey interactions: exposure to defended prey and predation risk affects intermediate predator life history and morphology

    Microsoft Academic Search

    Edd Hammill; Andrew P. Beckerman

    2010-01-01

    A vast body of literature exists documenting the morphological, behavioural and life history changes that predators induce\\u000a in prey. However, little attention has been paid to how these induced changes feed back and affect the predators’ life history\\u000a and morphology. Larvae of the phantom midge Chaoborus flavicans are intermediate predators in a food web with Daphnia pulex as the basal

  6. Echolocating Bats Cry Out Loud to Detect Their Prey

    PubMed Central

    Surlykke, Annemarie; Kalko, Elisabeth K. V.

    2008-01-01

    Echolocating bats have successfully exploited a broad range of habitats and prey. Much research has demonstrated how time-frequency structure of echolocation calls of different species is adapted to acoustic constraints of habitats and foraging behaviors. However, the intensity of bat calls has been largely neglected although intensity is a key factor determining echolocation range and interactions with other bats and prey. Differences in detection range, in turn, are thought to constitute a mechanism promoting resource partitioning among bats, which might be particularly important for the species-rich bat assemblages in the tropics. Here we present data on emitted intensities for 11 species from 5 families of insectivorous bats from Panamá hunting in open or background cluttered space or over water. We recorded all bats in their natural habitat in the field using a multi-microphone array coupled with photographic methods to assess the bats' position in space to estimate emitted call intensities. All species emitted intense search signals. Output intensity was reduced when closing in on background by 4–7 dB per halving of distance. Source levels of open space and edge space foragers (Emballonuridae, Mormoopidae, Molossidae, and Vespertilionidae) ranged between 122–134 dB SPL. The two Noctilionidae species hunting over water emitted the loudest signals recorded so far for any bat with average source levels of ca. 137 dB SPL and maximum levels above 140 dB SPL. In spite of this ten-fold variation in emitted intensity, estimates indicated, surprisingly, that detection distances for prey varied far less; bats emitting the highest intensities also emitted the highest frequencies, which are severely attenuated in air. Thus, our results suggest that bats within a local assemblage compensate for frequency dependent attenuation by adjusting the emitted intensity to achieve comparable detection distances for prey across species. We conclude that for bats with similar hunting habits, prey detection range represents a unifying constraint on the emitted intensity largely independent of call shape, body size, and close phylogenetic relationships. PMID:18446226

  7. The influence of habitat, prey abundance, sex, and breeding success on the ranging behavior of Prairie Falcons

    USGS Publications Warehouse

    Marzluff, J.M.; Kimsey, Bryan A.; Schueck, Linda S.; McFadzen, Mary E.; Vekasy, M.S.; Bednarz, James C.

    1997-01-01

    We studied the ranging behavior and habitat selection of radio-tagged Prairie Falcons (Falco mexicanus) during the breeding season in southwestern Idaho. The distribution and numbers of Townsend's ground squirrels (Spermophilus townsendii), the primary prey of Prairie Falcons in our study area, varied in response to drought during the study period. Prairie Falcons ranged over large areas (ca. 300 km2) and increased their foraging ranges in response to declining ground squirrels. Reptiles and birds were preyed upon most frequently when squirrels were rare. Males and females differed little in their use of space. Successful pairs ranged over smaller areas than non-nesters and unsuccessful pairs. Falcons nesting near habitat most suitable for ground squirrels ranged over smaller areas than those nesting farther from such habitat. Home ranges contained significantly more winterfat (Ceratoides lanata) and native perennial grasses (especially Poa secunda), and significantly less salt desert shrubs and exotic annual grasses than expected based on availability. Salt desert shrubs were found less than expected, based on availability in core areas within home ranges. Selection for winterfat and bluegrass in core areas was contingent upon selection at the larger scale of the home range; falcons with home ranges containing more winterfat and bluegrass than expected based on availability were less selective in their placement of core areas with respect to these habitats. We believe salient features of Prairie Falcon home ranges result largely from patchy distribution of landscape features associated with different densities and availabilities of Townsend's ground squirrels.

  8. Lunar cycles in diel prey migrations exert a stronger effect on the diving of juveniles than adult Galápagos fur seals.

    PubMed Central

    Horning, M; Trillmich, F

    1999-01-01

    In our study of the development of diving in Galápagos fur seals, we analysed changes in diving activity and body mass trends over the lunar cycle. Based on previously observed lunar cycles in colony attendance patterns, we hypothesized a greater impact of prey migrations of deep scattering layer organisms on younger fur seals. Using electronic dive recorders, we determined that seals dived less and deeper on moonlit nights than at new moon, and incurred body mass losses. These changes in foraging over the lunar cycle correlate with the suppression of the vertical migration of prey by lunar light. All effects were more pronounced in juveniles than adult females, with greater relative mass loss during full moon, which must (i) negatively affect long-term juvenile growth rates, (ii) lengthen periods of maternal dependence, and (iii) contribute to the lowest reproductive rate reported for seals. This underlines the importance of studying ontogeny in order to understand life histories, and for determining the susceptibility of animal populations to fluctuations in food availability. PMID:10406130

  9. IgA and temperature dependent IgG complex formation in a patient with Waldenström's hypergammaglobulinaemic purpura.

    PubMed Central

    Roberts-Thomson, P J; Kemp, A S

    1980-01-01

    We describe a patient with hypergammaglobulinaemic purpura and show that the serum contains IgG and IgA immune complexes sedimenting between IgM and IgG on ultracentrifugation. The complexes containing IgG were markedly temperature dependent. A drop in temperature from 37 degrees C to 28 degrees C gave a seventeen-fold increase in the quantity of these complexes. This temperature dependency may be an important factor in localizing the major pathological manifestation of this disease to the skin. PMID:7389190

  10. Corticosteroid therapy in IgA nephropathy.

    PubMed

    Lv, Jicheng; Xu, Damin; Perkovic, Vlado; Ma, Xinxin; Johnson, David W; Woodward, Mark; Levin, Adeera; Zhang, Hong; Wang, Haiyan

    2012-06-01

    The benefits and risks of steroids for the treatment of IgA nephropathy remain uncertain. We systematically searched MEDLINE, EMBASE, and the Cochrane Library for randomized, controlled trials of corticosteroid therapy for IgA nephropathy published between 1966 and March 2011. We identified nine relevant trials that included 536 patients who had urinary protein excretion >1 g/d and normal renal function. Forty-six (8.6%) of these patients developed a kidney failure event, defined as doubling of the serum creatinine/halving of the GFR or ESRD. Overall, steroid therapy was associated with a lower risk for kidney failure (relative risk, 0.32 [95% confidence interval [CI], 0.15-0.67]; P=0.002) and a reduction in proteinuria (weighted mean difference, -0.46 g/d [95% CI, -0.63 to -0.29 g/d]), with no evidence of heterogeneity in these outcomes. Subgroup analysis suggested that the dose modifies the effect of steroids for renal protection (P for heterogeneity=0.030): Relatively high-dose and short-term therapy (prednisone >30 mg/d or high-dose pulse intravenous methylprednisolone with duration ?1 year) produced significant renal protection, whereas low-dose, long-term steroid use did not. Steroid therapy was associated with a 55% higher risk for adverse events. The quality of included studies was low, however, limiting the generalizability of the results. In conclusion, steroids appear to provide renal protection in patients with IgA nephropathy but increase the risk for adverse events. Reliably defining the efficacy and safety of steroids in IgA nephropathy requires a high-quality trial with a large sample size. PMID:22539830

  11. Corticosteroid Therapy in IgA Nephropathy

    PubMed Central

    Xu, Damin; Perkovic, Vlado; Ma, Xinxin; Johnson, David W.; Woodward, Mark; Levin, Adeera; Zhang, Hong; Wang, Haiyan

    2012-01-01

    The benefits and risks of steroids for the treatment of IgA nephropathy remain uncertain. We systematically searched MEDLINE, EMBASE, and the Cochrane Library for randomized, controlled trials of corticosteroid therapy for IgA nephropathy published between 1966 and March 2011. We identified nine relevant trials that included 536 patients who had urinary protein excretion >1 g/d and normal renal function. Forty-six (8.6%) of these patients developed a kidney failure event, defined as doubling of the serum creatinine/halving of the GFR or ESRD. Overall, steroid therapy was associated with a lower risk for kidney failure (relative risk, 0.32 [95% confidence interval [CI], 0.15–0.67]; P=0.002) and a reduction in proteinuria (weighted mean difference, ?0.46 g/d [95% CI, ?0.63 to ?0.29 g/d]), with no evidence of heterogeneity in these outcomes. Subgroup analysis suggested that the dose modifies the effect of steroids for renal protection (P for heterogeneity=0.030): Relatively high-dose and short-term therapy (prednisone >30 mg/d or high-dose pulse intravenous methylprednisolone with duration ?1 year) produced significant renal protection, whereas low-dose, long-term steroid use did not. Steroid therapy was associated with a 55% higher risk for adverse events. The quality of included studies was low, however, limiting the generalizability of the results. In conclusion, steroids appear to provide renal protection in patients with IgA nephropathy but increase the risk for adverse events. Reliably defining the efficacy and safety of steroids in IgA nephropathy requires a high-quality trial with a large sample size. PMID:22539830

  12. Hyper-IgE syndrome update

    PubMed Central

    Sowerwine, Kathryn J.; Holland, Steven M.; Freeman, Alexandra F.

    2014-01-01

    Autosomal dominant hyper-IgE syndrome (AD-HIES) or Job’s syndrome is a primary immunodeficiency with a wide array of clinical features caused by dominant negative mutations in STAT3. In recent years, not only the clinical phenotype of the disease has been expanded with recognition of features such as arterial aneurysms, but also our understanding of the pathogenesis of the disease has greatly improved. PMID:22268731

  13. Male sexual harassment alters female social behaviour towards other females.

    PubMed

    Darden, Safi K; Watts, Lauren

    2012-04-23

    Male harassment of females to gain mating opportunities is a consequence of an evolutionary conflict of interest between the sexes over reproduction and is common among sexually reproducing species. Male Trinidadian guppies Poecilia reticulata spend a large proportion of their time harassing females for copulations and their presence in female social groups has been shown to disrupt female-female social networks and the propensity for females to develop social recognition based on familiarity. In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with female only shoals. Our work provides direct evidence that the presence of sexually harassing males alters female-female social behaviour, an effect that we expect will be recurrent across taxonomic groups. PMID:21976624

  14. Male sexual harassment alters female social behaviour towards other females

    PubMed Central

    Darden, Safi K.; Watts, Lauren

    2012-01-01

    Male harassment of females to gain mating opportunities is a consequence of an evolutionary conflict of interest between the sexes over reproduction and is common among sexually reproducing species. Male Trinidadian guppies Poecilia reticulata spend a large proportion of their time harassing females for copulations and their presence in female social groups has been shown to disrupt female–female social networks and the propensity for females to develop social recognition based on familiarity. In this study, we investigate the behavioural mechanisms that may lead to this disruption of female sociality. Using two experiments, we test the hypothesis that male presence will directly affect social behaviours expressed by females towards other females in the population. In experiment one, we tested for an effect of male presence on female shoaling behaviour and found that, in the presence of a free-swimming male guppy, females spent shorter amounts of time with other females than when in the presence of a free-swimming female guppy. In experiment two, we tested for an effect of male presence on the incidence of aggressive behaviour among female guppies. When males were present in a shoal, females exhibited increased levels of overall aggression towards other females compared with female only shoals. Our work provides direct evidence that the presence of sexually harassing males alters female–female social behaviour, an effect that we expect will be recurrent across taxonomic groups. PMID:21976624

  15. Clinical evaluation of new automated cytomegalovirus IgM and IgG assays for the Elecsys(®) analyser platform.

    PubMed

    Revello, M G; Vauloup-Fellous, C; Grangeot-Keros, L; van Helden, J; Dickstein, Y; Lipkin, I; Mühlbacher, A; Lazzarotto, T

    2012-12-01

    Cytomegalovirus (CMV) is a leading cause of physical and neurological abnormalities in newborns. Hence, the diagnosis of CMV infection in pregnant women is necessary in order to allow appropriate management of their pregnancy. New assays have been developed for the Roche Elecsys® immunoassay platform that detect CMV-specific immunoglobulin (Ig)M and IgG, with the IgM assay designed to target IgM produced at the start of infection rather than IgM persisting later in infection. This study aimed to evaluate the performance of the new assays compared with other commercial kits widely distributed in laboratories. The performance of the Elecsys and comparator CMV IgM and IgG assays was assessed using 967 preselected patient samples characterised by CMV infection status, as well as being compared using 1,668 unselected clinical samples. The Elecsys CMV IgM and IgG assays performed consistently with comparator assays using the preselected samples. The Elecsys CMV IgM assay showed improved sensitivity compared with the Enzygnost® assay in primary infection (91.2 % vs. 79.4 %) and improved specificity over the Architect® assay in potentially cross-reacting samples (94.1 % vs. 82.4 %). The Elecsys IgM assay reported fewer positive results in the later stages of CMV infection compared with ETI-CYTOK-M ELISA, while the Elecsys IgG assay reported slightly fewer negative results in the early stages of infection compared with ETI-CYTOK-G ELISA. There was good agreement between Elecsys and comparator assays using unselected clinical samples (range 90.4-99.4 %). The Elecsys CMV IgM and IgG assays compare well with routinely used assays and are suitable for clinical use. PMID:22850741

  16. Prey Selection by an Apex Predator: The Importance of Sampling Uncertainty

    PubMed Central

    Davis, Miranda L.; Stephens, Philip A.; Willis, Stephen G.; Bassi, Elena; Marcon, Andrea; Donaggio, Emanuela; Capitani, Claudia; Apollonio, Marco

    2012-01-01

    The impact of predation on prey populations has long been a focus of ecologists, but a firm understanding of the factors influencing prey selection, a key predictor of that impact, remains elusive. High levels of variability observed in prey selection may reflect true differences in the ecology of different communities but might also reflect a failure to deal adequately with uncertainties in the underlying data. Indeed, our review showed that less than 10% of studies of European wolf predation accounted for sampling uncertainty. Here, we relate annual variability in wolf diet to prey availability and examine temporal patterns in prey selection; in particular, we identify how considering uncertainty alters conclusions regarding prey selection. Over nine years, we collected 1,974 wolf scats and conducted drive censuses of ungulates in Alpe di Catenaia, Italy. We bootstrapped scat and census data within years to construct confidence intervals around estimates of prey use, availability and selection. Wolf diet was dominated by boar (61.5±3.90 [SE] % of biomass eaten) and roe deer (33.7±3.61%). Temporal patterns of prey densities revealed that the proportion of roe deer in wolf diet peaked when boar densities were low, not when roe deer densities were highest. Considering only the two dominant prey types, Manly's standardized selection index using all data across years indicated selection for boar (mean?=?0.73±0.023). However, sampling error resulted in wide confidence intervals around estimates of prey selection. Thus, despite considerable variation in yearly estimates, confidence intervals for all years overlapped. Failing to consider such uncertainty could lead erroneously to the assumption of differences in prey selection among years. This study highlights the importance of considering temporal variation in relative prey availability and accounting for sampling uncertainty when interpreting the results of dietary studies. PMID:23110122

  17. Predation risk assessment by green frog ( Rana clamitans ) tadpoles through chemical cues produced by multiple prey

    Microsoft Academic Search

    Michael E. Fraker

    2009-01-01

    Many prey assess predation risk through predator chemical cues. Numerous studies have shown that (1) prey sometimes respond\\u000a to chemical cues produced by heterospecifics and (2) that many species are capable of associative learning. This study extends\\u000a this research by focusing on predation risk assessment and antipredator behavior in environments containing chemical cues\\u000a produced by multiple prey species. The results

  18. Effect of temperature, prey density, vegetation, and BTI on development and predation by Psorophora ciliata (Fabricius) 

    E-print Network

    Atwood, Donald Wayne

    1985-01-01

    times as larger prey are depleted. Cannibalism may also serve as a source of nutrients for P. ciliata. According to Steffan and Evenhuis (1981), cannibalism may be viewed as a survival strategy which allows at least one predator to complete... development in the absence of a suitable prey source. Trpis (1979) reported that cannibalism in Toxorhynchites may occur even when prey are abundant, indicating that the predatory nature of mosquito larvae may be indiscriminate. Steffan and Evenhui s ( 1981...

  19. The response of prey to the risk of predation: proximate cues for refuging juvenile fish

    Microsoft Academic Search

    PETER EKLÖV; LENNART PERSSON

    1996-01-01

    When prey encounter predators, they use different cues to indicate how to respond to minimize the predation risk. How such proximate cues in the environment correspond to the ultimate behaviour of the prey are important for understanding the outcome of predator–prey interactions. The precision of the anti-predator response of juvenile perch,Perca fluviatilis, and roach,Rutilus rutilus, when subjected to predation by

  20. Prey Preference by the Stinkbug Perillus bioculatus,a Predator of the Colorado Potato Beetle

    Microsoft Academic Search

    Jean-François Saint-Cyr; Conrad Cloutier

    1996-01-01

    Perillus bioculatus(F.) is sometimes considered a generalist but has most often been recorded as predator of Colorado potato beetle (CPB),Leptinotarsa decemlineata.(Say). This study was designed to analyze prey selection inP. bioculatuswith respect to factors that may lead to specialization. To establish if parental prey determines preference in na??ve progeny, prey selection experiments were conducted with the CPB and two unusual