These are representative sample records from Science.gov related to your search topic.
For comprehensive and current results, perform a real-time search at Science.gov.
1

Prey  

NSDL National Science Digital Library

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.

2011-01-01

2

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 ...

3

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

Microsoft Academic Search

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

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

2010-01-01

4

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

USGS Publications Warehouse

Intraguild (IG) predation is an important factor influencing community structure, yet factors allowing coexistence of IG predator and IG prey are not well understood. The existence of spatial refuges for IG prey has recently been noted for their importance in allowing coexistence. However, reduction in basal prey availability might lead IG prey to leave spatial refuges for greater access to prey, leading to increased IG predation and fewer opportunities for coexistence. We determined how the availability of prey affected space-use patterns of bobcats (Lynx rufus, IG prey) in relation to coyote space-use patterns (Canis latrans, IG predators). We located animals from fall 2007 to spring 2009 and estimated bobcat home ranges and core areas seasonally. For each bobcat relocation, we determined intensity of coyote use, distance to water, small mammal biomass, and mean small mammal biomass of the home range during the season the location was collected. We built generalized linear mixed models and used Akaike Information Criteria to determine which factors best predicted bobcat space use. Coyote intensity was a primary determinant of bobcat core area location. In bobcat home ranges with abundant prey, core areas occurred where coyote use was low, but shifted to areas intensively used by coyotes when prey declined. High spatial variability in basal prey abundance allowed some bobcats to avoid coyotes while at the same time others were forced into more risky areas. Our results suggest that multiple behavioral strategies associated with spatial variation in basal prey abundance likely allow IG prey and IG predators to coexist. ?? 2010 Springer-Verlag.

Wilson, R.R.; Blankenship, T.L.; Hooten, M.B.; Shivik, J.A.

2010-01-01

5

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

PubMed

Intraguild (IG) predation is an important factor influencing community structure, yet factors allowing coexistence of IG predator and IG prey are not well understood. The existence of spatial refuges for IG prey has recently been noted for their importance in allowing coexistence. However, reduction in basal prey availability might lead IG prey to leave spatial refuges for greater access to prey, leading to increased IG predation and fewer opportunities for coexistence. We determined how the availability of prey affected space-use patterns of bobcats (Lynx rufus, IG prey) in relation to coyote space-use patterns (Canis latrans, IG predators). We located animals from fall 2007 to spring 2009 and estimated bobcat home ranges and core areas seasonally. For each bobcat relocation, we determined intensity of coyote use, distance to water, small mammal biomass, and mean small mammal biomass of the home range during the season the location was collected. We built generalized linear mixed models and used Akaike Information Criteria to determine which factors best predicted bobcat space use. Coyote intensity was a primary determinant of bobcat core area location. In bobcat home ranges with abundant prey, core areas occurred where coyote use was low, but shifted to areas intensively used by coyotes when prey declined. High spatial variability in basal prey abundance allowed some bobcats to avoid coyotes while at the same time others were forced into more risky areas. Our results suggest that multiple behavioral strategies associated with spatial variation in basal prey abundance likely allow IG prey and IG predators to coexist. PMID:20953798

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

2010-12-01

6

[Rubella virus IgG and IgM antibody levels in 17-20 year old female students using ELISA and fluorescent antibody tests].  

PubMed

In this study Rubella virus antibody levels were investigated by using ELISA and IFAT in 94 sera obtained from girl students in Gülhane Military Medical Academy nursing college. We have propagated Rubella virus in BHK-21 cell line for production Rubella virus antigen in order to use IFAT. 81 sera IgG (86.2%) and 29 sera IgM (30.9%) were found positive in ELISA. However 76 sera (80.9%) IgG and 27 sera (28.7%) were positive in IFAT. On the other hand we have obtained suspected results in 8 sera (8.5%) with 1/10 dilution in IgG ELISA and in 3 sera (3.2%) with the same dilution in IgM ELISA. One of 29 sera which are ELISA IgM positive have established 80 IU/ml RF. We can say that ELISA is more reliable sensitive and practical than IFAT. It may be considered 29 student who have Rubella IgM antibody may be infected or reinfected by Rubella virus with in the last six months. On the other hand they may also infected with Parvovirus or some other viruses. We believe that the causes of false positive Rubella IgM antibody results should be investigated well enough. PMID:3078789

Kocabeyo?lu, O; Gün, H; Yilmaz, E; Güngör, S; Emekda?, G; Yücel, N

1988-01-01

7

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

PubMed

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

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

2014-10-01

8

IgG Avidity Antibodies against Toxoplasma gondii in High Risk Females of Reproductive Age Group in India  

PubMed Central

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

Shujatullah, Fatima; Khan, Haris M.; Rabbani, Tamkin; Khan, Parvez A.

2014-01-01

9

Quantitative anti-F1 and anti-V IgG ELISAs as serological correlates of protection against plague in female Swiss Webster mice.  

PubMed

A recombinant fusion protein composed of Yersinia pestis fraction 1 capsule (F1) and virulence-associated V antigen (V) (F1-V) has been developed as the next-generation vaccine against plague. In this study, female Swiss Webster mice received a single intramuscular vaccination with one of eight doses of the F1-V vaccine and exposed 4 weeks later to either Y. pestis CO92 or C12 organisms by the subcutaneous or aerosol routes of infection. Quantitative anti-F1 and anti-V immunoglobulin G (IgG) ELISAs were used to examine the relationship between survival outcome and antibody titers to F1 and V. Results suggested that each 1log(10) increase in week 4 quantitative anti-F1 and anti-V IgG ELISA titers were associated with a 1.7-fold (p=0.0051) and 2.5-fold (p=0.0054) increase in odds of survival, respectively, against either bubonic or pneumonic plague and may serve as serological correlates of protection. PMID:19925906

Little, S F; Webster, W M; Wilhelm, H; Fisher, D; Norris, S L W; Powell, B S; Enama, J; Adamovicz, J J

2010-01-22

10

Mixed-mode oscillations and chaos in a prey-predator system with dormancy of  

E-print Network

that significantly impact individual growth, reproduction, and survivorship. In particular, zooplankton mainly prey in microcosms increases when a portion of females producing resting eggs is replaced by asexually

11

Birds of Prey  

NSDL National Science Digital Library

This activity allows the student to independently research several birds of prey and compare the predator/prey relationship. Although the research questions are limited, the background reading should lead the student to make a connection between these birds and the ecosystem in which they live. This may also lead to a discussion of food webs and food chains.

Science Netlinks;

2001-10-20

12

Predator-Prey Models  

NSDL National Science Digital Library

Using Maple, Mathmatica, or MatLab, learner should be able to develop and explore the Lotka-Volterra model for predator-prey interactions as a prototypical first-order system of differential equations.

Smith, David

2001-01-30

13

Predator-Prey Models  

NSDL National Science Digital Library

Using Maple, Mathmatica, or MatLab, learner should be able to develop the Lotka-Volterra model for predator-prey interactions and a two-populaton version of Eulers Method for solving a system of differential equations.

Smith, David

2001-01-22

14

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

PubMed

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

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

2013-01-01

15

Effects of rapid prey evolution on predator–prey cycles  

Microsoft Academic Search

We study the qualitative properties of population cycles in a predator–prey system where genetic variability allows contemporary\\u000a rapid evolution of the prey. Previous numerical studies have found that prey evolution in response to changing predation risk\\u000a can have major quantitative and qualitative effects on predator–prey cycles, including: (1) large increases in cycle period,\\u000a (2) changes in phase relations (so that

Laura E. Jones; Stephen P. Ellner

2007-01-01

16

Quantitative anti-F1 and anti-V IgG ELISAs as serological correlates of protection against plague in female Swiss Webster mice  

Microsoft Academic Search

A recombinant fusion protein composed of Yersinia pestis fraction 1 capsule (F1) and virulence-associated V antigen (V) (F1–V) has been developed as the next-generation vaccine against plague. In this study, female Swiss Webster mice received a single intramuscular vaccination with one of eight doses of the F1–V vaccine and exposed 4 weeks later to either Y. pestis CO92 or C12

S. F. Little; W. M. Webster; H. Wilhelm; D. Fisher; S. L. W. Norris; B. S. Powell; J. Enama; J. J. Adamovicz

2010-01-01

17

Predator–prey fuzzy model  

Microsoft Academic Search

In this work we have used fuzzy rule-based systems to elaborate a predator–prey type of model to study the interaction between aphids (preys) and ladybugs (predators) in citriculture, where the aphids are considered as transmitter agents of the Citrus Sudden Death (CSD). Simulations were performed and a graph was drawn to show the prey population, the potentiality of the predators,

Magda da Silva Peixoto; Laécio Carvalho de Barros; Rodney Carlos Bassanezi

2008-01-01

18

IGS 2000 Annual Report  

NASA Technical Reports Server (NTRS)

Contents: The IGS Governing Board 2000; Central Bureau Status 2000; Growth of the IGS Network in 2000; Analysis Activities; Data Center Activities 2000; The International Terrestrial Reference Frame; IGS Reference Frame Coordination and Working Group Activities; The IGS/BIPM Time and Frequency Pilot Project; IGS Activities in the Area of the Ionosphere 2000; IGS Tropospheric Products; IGS International GLONASS Service Pilot Project; IGS LEO Pilot Project; Continuous GPS Positioning of Tide Gauges.

2003-01-01

19

Predator-Prey Models  

NSDL National Science Digital Library

Created by David Smith for the Connected Curriculum Project, the purpose of this module is to develop the Lotka-Volterra model for predator-prey interactions and a two-populaton version of Euler's Method for solving a system of differential equations. This is one within a much larger set of learning modules hosted by Duke University.

Smith, David

20

Predator-Prey Models  

NSDL National Science Digital Library

Created by Lang Moore and David Smith for the Connected Curriculum Project, this module develops and explores the Lotka-Volterra model for predator-prey interactions as a prototypical first-order system of differential equations. This is part of a larger collection of modules hosted by Duke University.

Moore, Lang

21

Serum levels of IgG and IgG4 in Hashimoto thyroiditis.  

PubMed

Although IgG4-related disease is characterized by extensive infiltration of IgG4-positive plasma cells and lymphocytes of various organs, the details of this systemic disease are still unclear. We screened serum total IgG levels in the patients with Hashimoto thyroiditis (HT) to illustrate the prevalence of IgG4-related thyroiditis in HT. Twenty-four of 94 patients with HT (25.5%) had elevated serum IgG levels and their serum IgG4 was measured. Five of the 24 cases had more than 135 mg/dL of IgG4, which is the serum criterion of IgG4-related disease. One was a female patient who was initially treated as Graves' disease and rapidly developed a firm goiter and hypothyroidism. The biopsy of her thyroid gland revealed that follicular cells were atrophic with squamous metaplasia, replaced with fibrosis, which was compatible with the fibrous variant of HT. Immunohistochemical examination revealed diffuse infiltration of IgG4-positive plasma cells, and the serum IgG4 level was 179 mg/dL. The levels of IgG and IgG4 were positively correlated with the titers of anti-thyroglobulin antibody or anti-thyroid peroxidase antibody. In conclusion, at least a small portion of patients with HT with high titers of anti-thyroid antibodies may overlap the IgG4-related thyroiditis. PMID:23695895

Kawashima, Sachiko-Tsukamoto; Tagami, Tetsuya; Nakao, Kanako; Nanba, Kazutaka; Tamanaha, Tamiko; Usui, Takeshi; Naruse, Mitsuhide; Minamiguchi, Sachiko; Mori, Yusuke; Tsuji, Jun; Tanaka, Issei; Shimatsu, Akira

2014-03-01

22

The Allometry of Prey Preferences  

PubMed Central

The distribution of weak and strong non-linear feeding interactions (i.e., functional responses) across the links of complex food webs is critically important for their stability. While empirical advances have unravelled constraints on single-prey functional responses, their validity in the context of complex food webs where most predators have multiple prey remain uncertain. In this study, we present conceptual evidence for the invalidity of strictly density-dependent consumption as the null model in multi-prey experiments. Instead, we employ two-prey functional responses parameterised with allometric scaling relationships of the functional response parameters that were derived from a previous single-prey functional response study as novel null models. Our experiments included predators of different sizes from two taxonomical groups (wolf spiders and ground beetles) simultaneously preying on one small and one large prey species. We define compliance with the null model predictions (based on two independent single-prey functional responses) as passive preferences or passive switching, and deviations from the null model as active preferences or active switching. Our results indicate active and passive preferences for the larger prey by predators that are at least twice the size of the larger prey. Moreover, our approach revealed that active preferences increased significantly with the predator-prey body-mass ratio. Together with prior allometric scaling relationships of functional response parameters, this preference allometry may allow estimating the distribution of functional response parameters across the myriads of interactions in natural ecosystems. PMID:21998724

Kalinkat, Gregor; Rall, Björn Christian; Vucic-Pestic, Olivera; Brose, Ulrich

2011-01-01

23

Individual variation in prey selection by sea otters: patterns, causes and implications  

Microsoft Academic Search

Summary 1. Longitudinal records of prey selection by 10 adult female sea otters on the Monterey Peninsula, California, from 1983 to 1990 demonstrate extreme inter-individual vari- ation in diet. Variation in prey availability cannot explain these differences as the data were obtained from a common spatial-temporal area. 2. Individual dietary patterns persisted throughout our study, thus indicating that they are

J. A. Estes; M. L. Riedman; M. M. Staedler; M. T. Tinker; B. E. Lyon

2003-01-01

24

Prey preference in stoneflies: a comparative analysis of prey vulnerability  

Microsoft Academic Search

Laboratory feeding trials were conducted with the predaceous stonefly Hesperoperla pacifica and a number of mayfly and dipteran prey species to investigate the effects of predator size, and prey size and morphology, on the predator's success. Observations under dim red light permitted estimation of encounter rate (E\\/min), attack propensity (A\\/E), capture success (C\\/A) and handling time (HT). For prey of

J. D. Allan; A. S. Flecker

1988-01-01

25

ORIGINAL PAPER Problems with studying wolf predation on small prey  

E-print Network

predation on various-sized prey by a male and female wolf (Canis lupus) with global positioning system (GPS with trying to conduct such a study. Keywords Canis lupus . Global positioning system (GPS) collars for the scarcity of summer predation studies. Recently, use of global positioning system (GPS) collars

Boyer, Edmond

26

Predators and Prey  

NSDL National Science Digital Library

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 Âbecome 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.

Consortium, The C.

2011-12-11

27

Predator-prey systems depend on a prey refuge.  

PubMed

Models of near-exclusive predator-prey systems such as that of the Canadian lynx and snowshoe hare have included factors such as a second prey species, a Holling Type II predator response and climatic or seasonal effects to reproduce sub-sets of six signature patterns in the empirical data. We present an agent-based model which does not require the factors or constraints of previous models to reproduce all six patterns in persistent populations. Our parsimonious model represents a generalised predator and prey species with a small prey refuge. The lack of the constraints of previous models, considered to be important for those models, casts doubt on the current hypothesised mechanisms of exclusive predator-prey systems. The implication for management of the lynx, a protected species, is that maintenance of an heterogeneous environment offering natural refuge areas for the hare is the most important factor for the conservation of this species. PMID:25058806

Chivers, W J; Gladstone, W; Herbert, R D; Fuller, M M

2014-11-01

28

Birds of Prey of Wisconsin.  

ERIC Educational Resources Information Center

This copiously illustrated document is designed to be a field quide to birds of prey that are common to Wisconsin, as well as to some that enter the state occasionally. An introduction discusses birds of prey with regard to migration patterns, the relationship between common names and the attitudes of people toward certain birds, and natural signs…

Hamerstrom, Frances

29

The discerning predator: decision rules underlying prey classification by a mosquito-eating jumping spider  

PubMed Central

SUMMARY Evarcha culicivora is an East African jumping spider that feeds indirectly on vertebrate blood by choosing blood-fed female Anopheles mosquitoes as prey. Previous studies have shown that this predator can identify its preferred prey even when restricted to using only visual cues. Here, we used lures and virtual mosquitoes to investigate the optical cues underlying this predator's prey-choice behaviour. We made lures by dissecting and then reconstructing dead mosquitoes, combining the head plus thorax with different abdomens. Depending on the experiment, lures were either moving or motionless. Findings from the lure experiments suggested that, for E. culicivora, seeing a blood-fed female mosquito's abdomen on a lure was a necessary, but not sufficient, cue by which preferred prey was identified, as cues from the abdomen needed to be paired with cues from the head and thorax of a mosquito. Conversely, when abdomens were not visible or were identical, spiders based their decisions on the appearance of the head plus thorax of mosquitoes, choosing prey with female characteristics. Findings from a subsequent experiment using animated 3D virtual mosquitoes suggest that it is specifically the mosquito's antennae that influence E. culicivora's prey-choice decisions. Our results show that E. culicivora uses a complex process for prey classification. PMID:22675186

Nelson, Ximena J.; Jackson, Robert R.

2012-01-01

30

Phase transitions in predator-prey systems.  

PubMed

The relationship between predator and prey plays an important role in ecosystem conservation. However, our understanding of the principles underlying the spatial distribution of predators and prey is still poor. Here we present a phase diagram of a predator-prey system and investigate the lattice formation in such a system. We show that the production of stable lattice structures depends on the limited diffusion or migration of prey as well as higher carrying capacity for the prey. In addition, when the prey's growth rate is lower than the birth rate of the predator, global prey lattice formation is initiated by microlattices at the center of prey spirals. The predator lattice is later formed in the predator spirals. But both lattice formations proceed together as the prey growth rate increases. PMID:22400599

Nagano, Seido; Maeda, Yusuke

2012-01-01

31

Subepithelial corneal deposits in IgG lambda myeloma.  

PubMed Central

A 46-year-old female presented with disseminated IgG lambda myeloma and unusual, translucent, subepithelial deposits in the periphery of both corneas. Electrophoretic studies showed that the deposits consisted of an IgG lambda paraprotein identical to that found in the serum. Minute amounts of the papaprotein were also present in the tears. Images PMID:2503029

Hill, J C; Mulligan, G P

1989-01-01

32

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

PubMed

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

Kojima, Yosuke; Mori, Akira

2015-01-01

33

Predator-Prey Simulation Exercises for the Classroom  

NSDL National Science Digital Library

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.

James Waddell (University of Maine at Orono; )

2009-08-26

34

Tigers and their prey: Predicting carnivore densities from prey abundance  

USGS Publications Warehouse

The goal of ecology is to understand interactions that determine the distribution and abundance of organisms. In principle, ecologists should be able to identify a small number of limiting resources for a species of interest, estimate densities of these resources at different locations across the landscape, and then use these estimates to predict the density of the focal species at these locations. In practice, however, development of functional relationships between abundances of species and their resources has proven extremely difficult, and examples of such predictive ability are very rare. Ecological studies of prey requirements of tigers Panthera tigris led us to develop a simple mechanistic model for predicting tiger density as a function of prey density. We tested our model using data from a landscape-scale long-term (1995-2003) field study that estimated tiger and prey densities in 11 ecologically diverse sites across India. We used field techniques and analytical methods that specifically addressed sampling and detectability, two issues that frequently present problems in macroecological studies of animal populations. Estimated densities of ungulate prey ranged between 5.3 and 63.8 animals per km2. Estimated tiger densities (3.2-16.8 tigers per 100 km2) were reasonably consistent with model predictions. The results provide evidence of a functional relationship between abundances of large carnivores and their prey under a wide range of ecological conditions. In addition to generating important insights into carnivore ecology and conservation, the study provides a potentially useful model for the rigorous conduct of macroecological science.

Karanth, K.U.; Nichols, J.D.; Kumar, N.S.; Link, W.A.; Hines, J.E.

2004-01-01

35

SHIFTING PREY SELECTION GENERATES CONTRASTING HERBIVORE DYNAMICS WITHIN A LARGE-MAMMAL PREDATOR–PREY WEB  

Microsoft Academic Search

Shifting prey selection has been identified as a mechanism potentially regulating predator-prey interactions, but it may also lead to different outcomes, especially in more complex systems with multiple prey species available. We assessed changing prey selection by lions, the major predator for 12 large herbivore species in South Africa's Kruger National Park. The database was provided by records of found

Norman Owen-Smith; M. G. L. Mills

2008-01-01

36

Mechanisms of prey selection by predaceous stoneflies: roles of prey morphology, behavior and predator hunger  

Microsoft Academic Search

Laboratory feeding experiments using Hesperoperla pacifica (Banks), Perlidae, and Megarcys signata (Hagen), Perlodidae, as predators and Baetis tricaudatus Dodds and Ephemerella altana Allen as prey indicate a strong effect of prey morphology and mobility and predator hunger on prey selection by stoneflies. Knowledge of both dietary composition and feeding behavior was necessary to fully understand prey selection by these stoneflies.

Manuel C. Molles; Robert D. Pietruszka

1983-01-01

37

Prey selection by a stonefly: the influence of hunger and prey size  

Microsoft Academic Search

The influences of hunger and prey size on prey selection by the stonefly Hesperoperla pacifica (Perlidae) were explored in the laboratory by observing behavioral responses toward ten prey taxa and three nonprey taxa. Patterns of behavior were consistent with most assumptions and predictions of optimal foraging theory predicting sizebased prey selection by pursuing predators. Handling time appeared to increase as

M. C. Molles Jr; R. D. Pietruszka

1987-01-01

38

Resource partitioning in a ladybird, Menochilus sexmaculatus: function of body size and prey density.  

PubMed

In the present study, resource partitioning by natural conspecific size variants (small and large) of ladybird, Menochilus sexmaculatus (Fabricius) females, in response to varying prey densities was assessed using functional and numerical responses as measures of prey density. The prey provided was small (second) and large (fourth) instars of Aphis craccivora Koch. Results revealed that under choice condition, small and large females of M. sexmaculatus consumed higher number of small and large instars, respectively. Small females exhibited a modified Type II functional response on small aphid instars and a Type II functional response on fourth aphid instars. Large females exhibited a Type II functional response when provided either second or fourth aphid instars. Numerical response in terms of numbers of eggs laid by both the females increased with increase in the density of either of the aphid instars. However, in small females, oviposition had a positive correlation with the numbers of small and large aphid instars consumed; being strong for the small aphid instars. While in large females, oviposition was positively correlated with the numbers of large aphid instars consumed and not small aphid instars. It therefore seems that intraspecific resource partitioning in M. sexmaculatus occurs prominently in large females than the small females. PMID:25467186

Chaudhary, D D; Kumar, B; Mishra, G; Omkar

2015-02-01

39

Mountain lions prey selectively on prion-infected mule deer.  

PubMed

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

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

2010-04-23

40

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

PubMed Central

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

Shah, Mohd Abas; Khan, Akhtar Ali

2014-01-01

41

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

PubMed

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

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

2010-10-01

42

Impact of diet-index selection and the digestion of prey hard remains on determining the diet of the Steller sea lion ( Eumetopias jubatus )  

Microsoft Academic Search

Nine prey species (n = 7431) were fed to four captive female Steller sea lions (Eumetopias jubatus (Schreber, 1776)) in 11 feeding trials over 75 days to investigate the effectiveness of different methods used to determine diet from prey hard remains. Trials aimed to replicate short (1-2 days) and long feeding bouts, and consisted of single species and mixed daily

D. J. Tollit; S. G. Heaslip; R. L. Barrick; A. W. Trites

2007-01-01

43

Investigating Predator-Prey Interactions  

NSDL National Science Digital Library

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

Ethel D. Stanley (Beloit College; Biology)

2006-05-20

44

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

PubMed

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

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

2014-12-01

45

Reproductive tradeoff limits the predatory efficiency of female Arizona Bark Scorpions (Centruroides sculpturatus)  

PubMed Central

Background Life history tradeoffs may result from temporal and physiological constraints intrinsic to an organism. When faced with limited time and energy, compromises occur and these resources are allocated among essential activities, such as body growth, maintenance, foraging, mating, and offspring care. We investigated potential tradeoffs that may occur between reproductive activities and feeding performance in female Arizona Bark Scorpions (Centruroides sculpturatus) by comparing the time taken to capture prey between non-reproductive and reproductive females (gravid females and females exhibiting maternal care, i.e. carrying offspring on their backs). Results Gravid females were as efficient at catching prey as non-gravid females. To control for variation in the duration of the maternal care period, we removed all offspring from all post-parturient females after 5 days. Brooding females and females 24 hours following offspring removal (FOR) did not successfully capture prey within the 900-second trial period. Twenty-eight days FOR, females caught prey faster than females displaying maternal care and females 24 hours FOR, but were not as efficient at catching prey as non-gravid and gravid females. When pursuing prey, C. sculpturatus exhibiting maternal care used an active foraging strategy more frequently than non-gravid, gravid, and females 28 days FOR. In contrast, non-gravid, gravid, and females 28 days FOR used active and ambush foraging with similar frequency. Conclusions Our data suggest that reproduction does not significantly reduce the predatory efficiency of gravid C. sculpturatus, and that these females can cope with increasing body mass and the physiological costs of gestation. However, the observation that brooding females and females 24 hours FOR did not catch prey within the trial period indicates that maternal care significantly reduces predatory efficiency in these scorpions. Females 28 days FOR were still not as efficient at catching prey as non-gravid and gravid females, suggesting that reproductive costs extend for at least 4 weeks after the end of the maternal care period. Preferential use of an active foraging strategy by brooding females may increase prey encounter rates, allowing the scorpions to more rapidly replenish energy reserves depleted during reproduction. However, active foraging may be energetically costly and increase predation risk for brooding females. Our findings regarding antagonistic interactions between reproduction and feeding in female C. sculpturatus demonstrate the pervasive nature of reproductive costs for viviparous females, and may provide insight on factors that influence the diversity of reproductive strategies observed in nature. PMID:24034444

2013-01-01

46

The Role of Ciscoes as Prey in the Trophy Growth Potential of Walleyes  

Microsoft Academic Search

Analysis of the growth characteristics of 215 populations of walleye Sander vitreus across Ontario revealed that female walleyes reached larger asymptotic lengths in lakes in which ciscoes Coregonus artedi provided a relatively large prey species for them. The stomach contents of walleyes from a set of intensively studied lakes revealed that walleyes of all sizes depended on ciscoes but that

Scott D. Kaufman; George E. Morgan; John M. Gunn

2009-01-01

47

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

Microsoft Academic Search

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

Marc Théry; Martine Debut; Doris Gomez; Jérôme Casas

2005-01-01

48

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

Microsoft Academic Search

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

E. J. Temeles

1989-01-01

49

Coevolution can reverse predator-prey cycles.  

PubMed

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

Cortez, Michael H; Weitz, Joshua S

2014-05-20

50

NEST OCCUPATION AND PREY GRABBING BY SAKER FALCON (FALCO CHERRUG) ON POWER LINES IN the province of VOJVODINA (SERBIA)  

E-print Network

Abstract — Research on nest occupation and prey grabbing by saker falcon (Falco cherrug) on power lines in Vojvodina (Serbia) was done in the period from 1986 to 2004. During three specially analyzed periods, saker falcon took the nests of raven (Corvus corax) in 91 % of a total of 22 cases of nest occupation, and those of hooded crow (Corvus corone cornix) in only 9%. Saker falcon regularly grabs prey from different birds that occasionally or constantly spend time around power lines [Kestrel (Falco tinnunculus), hobby (Falco subbuteo), hooded crow (Corvus corone cornix), jackdaw (Corvus monedula), marsh harrier (Circus aeruginosus), hen harrier (Circus cyaneus), buzzard (Buteo buteo), and raven (Corvus corax)]. One year a studied pair of saker falcons on a power line in Donji Srem, Serbia grabbed prey from five different species of birds. Out of a total of 40 cases of prey grabbing in the period from January to December, as much 70 % of the grabbed prey was taken from kestrel (Falco tinnunculus). During the winter and early spring, prey was grabbed predominantly by males; after May, prey was sometimes grabbed by females as well. Most of the grabbed prey was common vole (Microtus arvalis).

S. Puzovi?

51

Consequences of size structure in the prey for predator–prey dynamics: the composite functional response  

Microsoft Academic Search

Summary 1. Current formulations of functional responses assume that the prey is homogeneous and independent of intraspecific processes. Most prey populations consist of different coexisting size classes that often engage in asymmetrical intraspecific interactions, including cannibalism, which can lead to nonlinear interaction effects. This may be important as the size structure with the prey could alter the overall density-dependent predation

Volker H. W. Rudolf

2008-01-01

52

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

PubMed

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

Mulvany, Samantha; Motta, Philip J

2014-11-01

53

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

ERIC Educational Resources Information Center

"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…

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

2012-01-01

54

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

ERIC Educational Resources Information Center

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…

Kar, Tapan Kumar

2006-01-01

55

Availability of prey resources drives evolution of predator–prey interaction  

PubMed Central

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 prey selection lines to become more diverse. On average, prey became most defensive in the high-resource environment and suffered from reduced resource use ability more in the low-resource environment. As a result, the evolution of stronger prey defence in the high-resource environment led to a strong decrease in predator-to-prey ratio. Predation increased temporal variability of populations and traits of prey. However, this destabilizing effect was less pronounced in the high-resource environment. Our results demonstrate that prey resource availability can shape the trade-off allocation of prey traits, which in turn affects multiple properties of the evolving predator–prey system. PMID:18430643

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

2008-01-01

56

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

ERIC Educational Resources Information Center

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…

Maiti, Alakes; Samanta, G. P.

2005-01-01

57

Tracking prey or tracking the prey's resource? Mechanisms of movement and optimal habitat selection by predators  

Microsoft Academic Search

We synthesize previous theory on ideal free habitat selection to develop a model of predator movement mechanisms, when both predators and prey are mobile. We consider a continuous environment with an arbitrary distribution of resources, randomly diffusing prey that consume the resources, and predators that consume the prey. Our model introduces a very general class of movement rules in which

Samuel M. Flaxman; Yuan Lou

2009-01-01

58

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

PubMed

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

Hermann, Sara L; Thaler, Jennifer S

2014-11-01

59

IGS Network Coordinator Report - 2002  

NASA Technical Reports Server (NTRS)

The IGS network is a set of permanent, continuously-operating, dual-frequency GPS stations operated by over 100 worldwide agencies. The dataset is pooled at IGS Data Centers for routine use by IGS Analysis Centers in creating precise IGS products, as well as free access by other analysts around the world. The IGS Central Bureau hosts the IGS Network Coordinator, who assures adherence to standards and provides information regarding the IGS network via the Central Bureau Information System website at http://igscb.jpl.nasa.gov.

Moore, Angelyn

2004-01-01

60

Respiratory Exposure to Diesel Exhaust Particles Decreases the Spleen IgM Response to a T Cell-Dependent Antigen in Female B6C3F1 Mice  

Microsoft Academic Search

We investigated the systemic immunotoxic potential of respira- tory exposure to diesel exhaust particles (DEP) in this study. Female B6C3F1 mice (8 weeks old) were exposed to increasing concentrations of DEP intratracheally, 3 times every two weeks, and sacrificed 2 or 4 weeks after the first exposure. The systemic toxicity and immune status in mice were evaluated. Mice exposed to

H.-M. Yang; L. Butterworth; A. E. Munson; B. Jean

2003-01-01

61

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),

62

Managing fisheries involving predator and prey species  

Microsoft Academic Search

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

Villy Christensen; Lake Victoria; Lake Tanganyika

1996-01-01

63

Optimal intermittent search strategies: smelling the prey  

NASA Astrophysics Data System (ADS)

We study the kinetics of the search of a single fixed target by a searcher/walker that performs an intermittent random walk, characterized by different states of motion. In addition, we assume that the walker has the ability to detect the scent left by the prey/target in its surroundings. Our results, in agreement with intuition, indicate that the prey's survival probability could be strongly reduced (increased) if the predator is attracted (or repelled) by the trace left by the prey. We have also found that, for a positive trace (the predator is guided towards the prey), increasing the inhomogeneity's size reduces the prey's survival probability, while the optimal value of ? (the parameter that regulates intermittency) ceases to exist. The agreement between theory and numerical simulations is excellent.

Revelli, J. A.; Rojo, F.; Budde, C. E.; Wio, H. S.

2010-05-01

64

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

USGS Publications Warehouse

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.

Palacios, Vicente; Mech, L. David

2010-01-01

65

Shifting prey selection generates contrasting herbivore dynamics within a large-mammal predator-prey web.  

PubMed

Shifting prey selection has been identified as a mechanism potentially regulating predator-prey interactions, but it may also lead to different outcomes, especially in more complex systems with multiple prey species available. We assessed changing prey selection by lions, the major predator for 12 large herbivore species in South Africa's Kruger National Park. The database was provided by records of found carcasses ascribed to kills by lions assembled over 70 years, coupled with counts of changing prey abundance extending over 30 years. Wildebeest and zebra constituted the most favored prey species during the early portion of the study period, while selection for buffalo rose in the south of the park after a severe drought increased their vulnerability. Rainfall had a negative influence on the proportional representation of buffalo in lion kills, but wildebeest and zebra appeared less susceptible to being killed under conditions of low rainfall. Selection by lions for alternative prey species, including giraffe, kudu, waterbuck, and warthog, was influenced by the changing relative abundance and vulnerability of the three principal prey species. Simultaneous declines in the abundance of rarer antelope species were associated with a sharp increase in selection for these species at a time when all three principal prey species were less available. Hence shifting prey selection by lions affected the dynamics of herbivore populations in different ways: promoting contrasting responses by principal prey species to rainfall variation, while apparently being the main cause of sharp declines by alternative prey species under certain conditions. Accordingly, adaptive responses by predators, to both the changing relative abundance of the principal prey species, and other conditions affecting the relative vulnerability of various species, should be taken into account to understand the interactive dynamics of multispecies predator-prey webs. PMID:18481536

Owen-Smith, Norman; Mills, M G L

2008-04-01

66

IgE immunotherapy  

PubMed Central

The importance of antibodies in activating immune responses against tumors is now better appreciated with the emergence of checkpoint blockade antibodies and with engineered antibody Fc domains featuring enhanced capacity to focus potent effector cells against cancer cells. Antibodies designed with Fc regions of the IgE class can confer natural, potent, long-lived immune surveillance in tissues through tenacious engagement of high-affinity cognate Fc receptors on distinct, often tumor-resident immune effector cells, and through ability to activate these cells under tumor-induced Th2-biased conditions. Here, we review the properties that make IgE a contributor to the allergic response and a critical player in the protection against parasites, which also support IgE as a novel anti-cancer modality. We discuss IgE-based active and passive immunotherapeutic approaches in disparate in vitro and in vivo model systems, collectively suggesting the potential of IgE immunotherapies in oncology. Translation toward clinical application is now in progress. PMID:24423620

Josephs, Debra H; Spicer, James F; Karagiannis, Panagiotis; Gould, Hannah J; Karagiannis, Sophia N

2014-01-01

67

Seasonal Diet and Prey Preference of the African Lion in a Waterhole-Driven Semi-Arid Savanna  

PubMed Central

Large carnivores inhabiting ecosystems with heterogeneously distributed environmental resources with strong seasonal variations frequently employ opportunistic foraging strategies, often typified by seasonal switches in diet. In semi-arid ecosystems, herbivore distribution is generally more homogeneous in the wet season, when surface water is abundant, than in the dry season when only permanent sources remain. Here, we investigate the seasonal contribution of the different herbivore species, prey preference and distribution of kills (i.e. feeding locations) of African lions in Hwange National Park, Zimbabwe, a semi-arid African savanna structured by artificial waterholes. We used data from 245 kills and 74 faecal samples. Buffalo consistently emerged as the most frequently utilised prey in all seasons by both male (56%) and female (33%) lions, contributing the most to lion dietary biomass. Jacobs’ index also revealed that buffalo was the most intensively selected species throughout the year. For female lions, kudu and to a lesser extent the group “medium Bovidae” are the most important secondary prey. This study revealed seasonal patterns in secondary prey consumption by female lions partly based on prey ecology with browsers, such as giraffe and kudu, mainly consumed in the early dry season, and grazers, such as zebra and suids, contributing more to female diet in the late dry season. Further, it revealed the opportunistic hunting behaviour of lions for prey as diverse as elephants and mice, with elephants taken mostly as juveniles at the end of the dry season during droughts. Jacobs’ index finally revealed a very strong preference for kills within 2 km from a waterhole for all prey species, except small antelopes, in all seasons. This suggested that surface-water resources form passive traps and contribute to the structuring of lion foraging behaviour. PMID:23405121

Van Kesteren, Freya; Loveridge, Andrew J.; Hunt, Jane E.; Murindagomo, Felix; Macdonald, David W.

2013-01-01

68

Male courtship vibrations delay predatory behaviour in female spiders  

PubMed Central

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

Wignall, Anne E.; Herberstein, Marie E.

2013-01-01

69

Fluorescent prey traps in carnivorous plants.  

PubMed

Carnivorous plants acquire most of their nutrients by capturing ants, insects and other arthropods through their leaf-evolved biological traps. So far, the best-known attractants in carnivorous prey traps are nectar, colour and olfactory cues. Here, fresh prey traps of 14 Nepenthes, five Sarracenia, five Drosera, two Pinguicula species/hybrids, Dionaea muscipula and Utricularia stellaris were scanned at UV 366 nm. Fluorescence emissions of major isolates of fresh Nepenthes khasiana pitcher peristomes were recorded at an excitation wavelength of 366 nm. N. khasiana field pitcher peristomes were masked by its slippery zone extract, and prey capture rates were compared with control pitchers. We found the existence of distinct blue fluorescence emissions at the capture spots of Nepenthes, Sarracenia and Dionaea prey traps at UV 366 nm. These alluring blue emissions gradually developed with the growth of the prey traps and diminished towards their death. On excitation at 366 nm, N. khasiana peristome 3:1 CHCl3–MeOH extract and its two major blue bands showed strong fluorescence emissions at 430–480 nm. Masking of blue emissions on peristomes drastically reduced prey capture in N. khasiana pitchers. We propose these molecular emissions as a critical factor attracting arthropods and other visitors to these carnivorous traps. Drosera, Pinguicula and Utricularia prey traps showed only red chlorophyll emissions at 366 nm. PMID:23696970

Kurup, R; Johnson, A J; Sankar, S; Hussain, A A; Sathish Kumar, C; Sabulal, B

2013-05-01

70

Biochemical prey recognition by planktonic protozoa.  

PubMed

Planktonic flagellates and ciliates are the major consumers of phytoplankton and bacterioplankton in aquatic environments, playing a pivotal role in carbon cycling and nutrient regeneration. Despite certain unicellular predators using chemosensory responses to locate and select their prey, the biochemical mechanisms behind prey reception and selection have not been elucidated. Here we identify a Ca(2+)-dependent, mannose-binding lectin on the marine dinoflagellate Oxyrrhis marina, which is used as a feeding receptor for recognizing prey. Blocking the receptor using 20 microM mannose-BSA inhibited ingestion of phytoplankton prey, Isochrysis galbana, by 60%. In prey selection studies, O. marina ingested twice as many 6 mum diameter beads coated with mannose-BSA as those coated with galNac-BSA. When pre-incubated with mannose-BSA, O. marina was no longer able to discriminate between different sugar-coated beads. Thus, these findings reveal molecular mechanisms of protozoan prey recognition. Our results also indicate the functional similarity between cellular recognition used by planktonic protozoa to discriminate between different prey items, and those used by metazoan phagocytic blood cells to recognize invading microorganisms. PMID:17227426

Wootton, Emma C; Zubkov, Mikhail V; Jones, D Hugh; Jones, Ruth H; Martel, Claire M; Thornton, Catherine A; Roberts, Emily C

2007-01-01

71

Group formation stabilizes predator-prey dynamics.  

PubMed

Theoretical ecology is largely founded on the principle of mass action, in which uncoordinated populations of predators and prey move in a random and well-mixed fashion across a featureless landscape. The conceptual core of this body of theory is the functional response, predicting the rate of prey consumption by individual predators as a function of predator and/or prey densities. This assumption is seriously violated in many ecosystems in which predators and/or prey form social groups. Here we develop a new set of group-dependent functional responses to consider the ecological implications of sociality and apply the model to the Serengeti ecosystem. All of the prey species typically captured by Serengeti lions (Panthera leo) are gregarious, exhibiting nonlinear relationships between prey-group density and population density. The observed patterns of group formation profoundly reduce food intake rates below the levels expected under random mixing, having as strong an impact on intake rates as the seasonal migratory behaviour of the herbivores. A dynamical system model parameterized for the Serengeti ecosystem (using wildebeest (Connochaetes taurinus) as a well-studied example) shows that grouping strongly stabilizes interactions between lions and wildebeest. Our results suggest that social groups rather than individuals are the basic building blocks around which predator-prey interactions should be modelled and that group formation may provide the underlying stability of many ecosystems. PMID:17960242

Fryxell, John M; Mosser, Anna; Sinclair, Anthony R E; Packer, Craig

2007-10-25

72

[Mesangial IgA-glomerulonephritis].  

PubMed

IgA-glomerulonephritis represents the most frequent glomerulonephritis (GN; 20%) among our patients. In contrast to data from the literature the prognosis is not benign. Renal insufficiency developed in 17 out of 50 investigated patients within 4 to 96 months, 3 of these patients had to undergo dialysis. Eleven of the 17 patients still had a normal renal function at the time of diagnosis. Malignant hypertension was present in 5 patients. An unfavourable course was predictable in cases of male gender, proteinuria, hypertension, age above 30 years, and histological changes indicating glomerulosclerosis, tubular atrophy, interstitial fibrosis and vascular lesions. Increased serum IgA levels, circulating IgA complexes, association with certain HLA-B or -Dr antigens as well as clinical symptoms and signs of haematuria, dysuria and kidney pains were not helpful either for diagnosis or for prognosis. The value of skin biopsy was comparatively small. Positive IgA demonstration was possible in 12 out of 41 cases with IgA-GN, however, also in 4 out of 21 patients with non-IgA-GN. None of 50 probands without renal disease showed IgA. Five out of 7 skin biopsies demonstrated IgA2, one IgA1 and one both IgA1 and IgA2. Increased serum IgA levels were found in a high percentage (21 out of 38 patients). The same applied to circulating IgA-complexes (8 out of 33 patients). PMID:6825588

Rambausek, M; Seelig, H P; Andrassy, K; Waldherr, R; Kehry, I; Lenhard, V; Ritz, E

1983-01-28

73

Introduction IG Progress  

E-print Network

Introduction IG Progress Summary and Future Work Overview of the PSI-Center Interfacing Group B. A. Nelson, C. C. Kim, A. P. Cassidy, S. D. Griffith, and the PSI-Center Team Plasma Science and Innovation Center PSI-Center Meeting 2007 University of Washington August 13­14, 2007 B. A. Nelson et al., PSI

74

Predators' decisions to eat defended prey depend on the size of undefended prey.  

PubMed

Predators that have learned to associate warning coloration with toxicity often continue to include aposematic prey in their diet in order to gain the nutrients and energy that they contain. As body size is widely reported to correlate with energetic content, we predicted that prey size would affect predators' decisions to eat aposematic prey. We used a well-established system of wild-caught European starlings, Sturnus vulgaris, foraging on mealworms, Tenebrio molitor, to test how the size of undefended (water-injected) and defended (quinine-injected) prey, on different coloured backgrounds, affected birds' decisions to eat defended prey. We found that birds ate fewer defended prey, and less quinine, when undefended prey were large compared with when they were small, but that the size of the defended prey had no effect on the numbers eaten. Consequently, we found no evidence that the mass of the defended prey or the overall mass of prey ingested affected the amount of toxin that a predator was willing to ingest, and instead the mass of undefended prey eaten was more important. This is a surprising finding, challenging the assumptions of state-dependent models of aposematism and mimicry, and highlighting the need to understand better the mechanisms of predator decision making. In addition, the birds did not learn to discriminate visually between defended and undefended prey based on size, but only on the basis of colour. This suggests that colour signals may be more salient to predators than size differences, allowing Batesian mimics to benefit from aposematic models even when they differ in size. PMID:23814280

Halpin, Christina G; Skelhorn, John; Rowe, Candy

2013-06-01

75

Predators' decisions to eat defended prey depend on the size of undefended prey?  

PubMed Central

Predators that have learned to associate warning coloration with toxicity often continue to include aposematic prey in their diet in order to gain the nutrients and energy that they contain. As body size is widely reported to correlate with energetic content, we predicted that prey size would affect predators' decisions to eat aposematic prey. We used a well-established system of wild-caught European starlings, Sturnus vulgaris, foraging on mealworms, Tenebrio molitor, to test how the size of undefended (water-injected) and defended (quinine-injected) prey, on different coloured backgrounds, affected birds’ decisions to eat defended prey. We found that birds ate fewer defended prey, and less quinine, when undefended prey were large compared with when they were small, but that the size of the defended prey had no effect on the numbers eaten. Consequently, we found no evidence that the mass of the defended prey or the overall mass of prey ingested affected the amount of toxin that a predator was willing to ingest, and instead the mass of undefended prey eaten was more important. This is a surprising finding, challenging the assumptions of state-dependent models of aposematism and mimicry, and highlighting the need to understand better the mechanisms of predator decision making. In addition, the birds did not learn to discriminate visually between defended and undefended prey based on size, but only on the basis of colour. This suggests that colour signals may be more salient to predators than size differences, allowing Batesian mimics to benefit from aposematic models even when they differ in size. PMID:23814280

Halpin, Christina G.; Skelhorn, John; Rowe, Candy

2013-01-01

76

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

PubMed Central

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

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

2014-01-01

77

Campylobacter spp. and birds of prey.  

PubMed

A total of 170 birds of prey admitted to two Wildlife Rescue and Rehabilitation Centers of Italy were examined. Birds were divided by diurnal (n = 15) and nocturnal (n = 7) species, sampled by cloacal swabs, and examined for Campylobacter spp. by cultural and molecular methods. Campylobacter spp. were isolated in 43 out of the 170 (25.3%) birds of prey examined. Among these, 43/43 (100%) were identified as Campylobacter jejuni and 10/43 (23.3%) were identified as Campylobacter coli recovered from mixed infections. Diurnal birds of prey showed a significantly higher prevalence value (P = 0.0006) for Campylobacter spp. than did nocturnal birds of prey. PMID:25055637

Dipineto, Ludovico; De Luca Bossa, Luigi Maria; Russo, Tamara Pasqualina; Cutino, Eridania Annalisa; Gargiulo, Antonio; Ciccarelli, Francesca; Raia, Pasquale; Menna, Lucia Francesca; Fioretti, Alessandro

2014-06-01

78

PREY OF NESTING BALD EAGLES IN TEXAS  

Microsoft Academic Search

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),

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

79

Individual variation in space use by female spotted hyenas  

USGS Publications Warehouse

Large carnivores range more widely than many other terrestrial mammals, and this behavior tends to bring them into frequent conflict with humans. Within any carnivore population, individual variation in patterns of space use should be expected to make some animals more vulnerable than others to risks of mortality from humans and other sources. In this study, our goal was to document variation among individuals in space use by female spotted hyenas (Crocuta crocuta). We examined predictions of hypotheses suggesting that space use by female hyenas is affected by reproductive state, social rank, and local prey abundance. Home-range size, distance at which females were found from the current communal den, and distance at which they were found from the nearest territorial boundary all varied significantly with the 3 independent variables. Females with den-dwelling cubs had smaller home ranges, were found closer to the communal den, and were found farther from the territorial boundary than were females with no den-dwelling cubs. Neither social rank nor prey availability significantly influenced the space-use patterns of females with den-dwelling cubs. Among females with no den-dwelling cubs, high-ranking females had smaller home ranges, were closer to the communal den, and were farther from the territorial boundary than were low-ranking females. The females ranging most widely were low-ranking individuals with no den-dwelling cubs when they were observed during periods of prey scarcity.

Boydston, E.E.; Kapheim, K.M.; Szykman, M.; Holekamp, K.E.

2003-01-01

80

Ig Nobel Prizes  

NSDL National Science Digital Library

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).

2000-01-01

81

Flexibility in assessment of prey cues: frog-eating bats and frog calls  

Microsoft Academic Search

Predators use cues associated with their prey to assess prey quality and to avoid consuming poisonous prey. Considerable attention has been given to predators' use of aposematic cues to assess prey quality, but little is known about predators that eavesdrop on prey cues that are not intended for them. Here we investigate the prey-cue\\/prey-quality associations of a predator that eavesdrops

Rachel A. Page; Michael J. Ryan

2005-01-01

82

Tennis, incidence of URTI and salivary IgA.  

PubMed

Tennis played at an elite level requires intensive training characterized by repeated bouts of brief intermittent high intensity exercise over relatively long periods of time (1 - 3 h or more). Competition can place additional stress on players. The purpose of this study was to investigate the temporal association between specific components of tennis training and competition, the incidence of upper respiratory tract infections (URTI), and salivary IgA, in a cohort of seventeen elite female tennis players. Timed, whole unstimulated saliva samples were collected before and after selected 1-h training sessions at 2 weekly intervals, over 12 weeks. Salivary IgA concentration was measured by ELISA and IgA secretion rate calculated (microg IgA x ml -1 x ml saliva x min -1). Players reported URTI symptoms and recorded training and competition in daily logs. Data analysis showed that higher incidence of URTI was significantly associated with increased training duration and load, and competition level, on a weekly basis. Salivary IgA secretion rate (S-IgA) dropped significantly after 1 hour of tennis play. Over the 12-week period, pre-exercise salivary IgA concentration and secretion rate were directly associated with the amount of training undertaken during the previous day and week (p < 0.05). However, the decline in S-IgA after 1 h of intense tennis play was also positively related to the duration and load of training undertaken during the previous day and week (p < 0.05). Although exercise-induced suppression of salivary IgA may be a risk factor, it could not accurately predict the occurrence of URTI in this cohort of athletes. PMID:12740744

Novas, A M P; Rowbottom, D G; Jenkins, D G

2003-04-01

83

Olfactive detection of fig wasps as prey by the ant Crematogaster scutellaris (Formicidae; Myrmicinae).  

PubMed

In the species-specific and obligate mutualism between the fig (Ficus carica) and its pollinator (the fig wasps Blastophaga psenes), a third participant, the ant Crematogaster scutellaris, is a predator of the wasps. Here, we ask how ant workers can rapidly localise such prey, whose availability is limited in time and space. Using a Y-tube olfactometer, we tested ant response to odours emitted by different types of figs (receptive female, ripe female or male figs) and by fig wasps (pollinators or non-pollinators). We demonstrate that ants were significantly attracted only to odours emitted by pollinators, either alone or associated with odours of male figs (releasing wasps). Detection of prey odour by ants is an important trait that can explain their observed high rate of predation on pollinators, and could have important implications on the stability of the fig/fig wasp mutualism. PMID:14564404

Schatz, Bertrand; Anstett, Marie-Charlotte; Out, Welmoed; Hossaert-McKey, Martine

2003-10-01

84

Influence of plumage colour on prey response: does habitat alter heron crypsis to prey?  

Microsoft Academic Search

The foraging strategies of wading birds may be influenced by their degree of crypsis to aquatic prey. White plumage has been hypothesized to be adaptive for herons hunting in open water habitats. We tested this hypothesis with laboratory and field experiments with multiple prey species. We investigated the response of crayfish, Procambarus spp., and mosquitofish, Gambusia affinis, to white- and

M. Clay Green; Paul L. Leberg

2005-01-01

85

Ecological consequences of chemically mediated prey perception.  

PubMed

To locate food, mobile consumers in aquatic habitats perceive and move towards sources of attractive chemicals. There has been much progress in understanding how consumers use chemicals to identify and locate prey despite the elusive identity of odor signals and the complex effects of turbulence on chemical dispersion. This review highlights how integrative studies on behavior, fluid physics, and chemical isolation can be fundamental in elucidating mechanisms that regulate species composition and distribution. We suggest three areas where further research may yield important ecological insights. First, although basic aspects of stimulatory molecules are known, our understanding of how consumers identify prey from a distance remains poor, and the lack of studies examining the influence of distance perception on food preference may result in inaccurate estimation of foraging behavior in the field. Second, the ability of many animals to find prey is greatest in unidirectional, low turbulence flow environments, although recent evidence indicates a trade-off in movement speed versus tracking ability in turbulent conditions. This suggests that predator foraging mode may affect competitive interactions among consumers, and that turbulence provides a hydrodynamic refuge in space or time, leading to particular associations between predator success, prey distributions, and flow. Third, studies have been biased towards examining predator tracking. Current data suggest a variety of mechanisms prey may use to disguise their presence and avoid predation; these mechanisms also may produce associations between prey distributions and flow environments. These examples of how chemical attraction may mediate interactions between consumers and their resources suggest that the ecology of chemically mediated prey perception may be as fundamental to the organization of aquatic communities as the ecology of chemical deterrence. PMID:12474893

Weissburg, Marc J; Ferner, Matthew C; Pisut, Daniel P; Smee, Delbert L

2002-10-01

86

A new antibody in rheumatoid arthritis targeting glycated IgG: IgM anti- IgG-AGE  

Microsoft Academic Search

SUMMARY Hyperglycaemia and\\/or oxidative stress can cause IgG to be modified by advanced glycation end products (AGE). Three patients with aggressive rheumatoid arthritis (RA) and vasculitis are described who have high titres of IgM antibodies against AGE-modified IgG (IgM anti-IgG-AGE ). Diabetics and randomly selected patients with rheumatic diseases, including 50 additional RA patients, were tested for IgM and IgA

S. LIGIER; P. R. FORTIN; M. M. NEWKIRK

1998-01-01

87

Prey Responses to Predator Chemical Cues: Disentangling the Importance of the Number and Biomass of Prey Consumed  

PubMed Central

To effectively balance investment in predator defenses versus other traits, organisms must accurately assess predation risk. Chemical cues caused by predation events are indicators of risk for prey in a wide variety of systems, but the relationship between how prey perceive risk in relation to the amount of prey consumed by predators is poorly understood. While per capita predation rate is often used as the metric of relative risk, studies aimed at quantifying predator-induced defenses commonly control biomass of prey consumed as the metric of risk. However, biomass consumed can change by altering either the number or size of prey consumed. In this study we determine whether phenotypic plasticity to predator chemical cues depends upon prey biomass consumed, prey number consumed, or both. We examine the growth response of red-eyed treefrog tadpoles (Agalychnis callidryas) to cues from a larval dragonfly (Anax amazili). Biomass consumed was manipulated by either increasing the number of prey while holding individual prey size constant, or by holding the number of prey constant and varying individual prey size. We address two questions. (i) Do prey reduce growth rate in response to chemical cues in a dose dependent manner? (ii) Does the magnitude of the response depend on whether prey consumption increases via number or size of prey? We find that the phenotypic response of prey is an asymptotic function of prey biomass consumed. However, the asymptotic response is higher when more prey are consumed. Our findings have important implications for evaluating past studies and how future experiments should be designed. A stronger response to predation cues generated by more individual prey deaths is consistent with models that predict prey sensitivity to per capita risk, providing a more direct link between empirical and theoretical studies which are often focused on changes in population sizes not individual biomass. PMID:23082171

McCoy, Michael W.; Touchon, Justin C.; Landberg, Tobias; Warkentin, Karen M.; Vonesh, James R.

2012-01-01

88

Penguins, fur seals, and fishing: prey requirements and potential competition in the South Shetland Islands, Antarctica  

Microsoft Academic Search

Antarctic and sub-Antarctic seabirds, marine mammals, and human fisheries concentrate their foraging efforts on a single\\u000a species, Antarctic krill (Euphausiasuperba). Because these predators may have a significant effect on krill abundance, we estimated the energy and prey requirements\\u000a of Adelie (Pygoscelisadeliae), chinstrap (Pygoscelisantarctica), and gentoo (Pygoscelispapua) penguins and female Antarctic fur seals (Arctocephalusgazella) breeding on the South Shetland Islands, Antarctica

D. A. Croll; B. R. Tershy

1998-01-01

89

The physiology of predator stress in free-ranging prey.  

PubMed

Ecologists have only begun to understand the physiological mechanisms underlying individual- and population-level responses of prey- to predator-related stress. Sheriff, Krebs and Boonstra advance this field by providing evidence that predator-induced increases in glucorticoid concentrations in wild female snowshoe hares (Lepus americanus) impact both litter size and offspring condition. They hypothesize that the glucocorticoid-mediated effects on reproduction provides an adaptive benefit: mothers 'programming' their offspring to be timid and risk-averse in high-risk environments should increase their survival probability. This research illuminates the connection between stress physiology and population-level changes and demonstrates the surprisingly far-reaching impact of predation risk. PMID:19840173

Preisser, Evan L

2009-11-01

90

Foraging technique and prey-handling time in black-necked stork (Ephippiorhynchus asiaticus).  

PubMed

The foraging technique and prey-handling time of the black-necked stork (Ephippiorhynchus asiaticus) was studied in Dudhwa National Park, India, from January 1996 to June 1997. The habitat in which the storks foraged played an important role in selecting a particular technique to procure food. Black-necked storks mostly foraged using a tactile technique (>90%), but sometimes foraged visually. When the water level was estimated to be less than 60 cm, the storks foraged using tactile techniques. There was no difference in the feeding techniques of male and female storks. Foraging attempt rates varied between the sexes in summer (May) and during late winter (February) in 1997. The search time for prey increased when the water level was high and fish were widely distributed. Decreases in water level resulted in concentration offish in certain areas and this contributed to high fish-catching rates by black-necked storks. Males had a higher success rate offish capture than females. However, females captured longer fish than males. Prey-handling time increased in both sexes as fish length increased. Fish 4-6 cm long were most frequently taken by the foraging storks. PMID:21396077

Maheswaran, Gopinathan; Rahmani, Asad R

2008-12-01

91

The clinical spectrum of IgG4-related disease.  

PubMed

IgG4-related disease (IgG4-RD) is an emerging immune-mediated disease with the capability of involving essentially any organ. The epidemiology of this disease has not been explored in detail. A majority of patients reported in the literature to date are from Japan, but the condition has been described all across the world and there is no strong evidence to suggest a predilection for Asian populations. The mean age at diagnosis is approximately 60years and there is a decided male predominance for many clinical features, with an overall male:female ratio of 8:3. A cardinal feature of IgG4-RD is single or multiple organ swelling that often raises concern for malignancy. IgG4-RD should be suspected in patients presenting with unexplained enlargement or swelling of one or more organs. Presenting features vary substantially according to the specialty to which patients present first; in addition, the disease can be diagnosed unexpectedly in pathological specimens or identified incidentally on radiology studies. Involvement of major organs is common and IgG4-RD may lead to organ failure, particularly in the pancreas, liver and biliary tree, kidneys, thyroid gland, lungs, and aorta. The diagnosis of IgG4-RD relies on the coexistence of various clinical, laboratory and histopathological findings, although none is pathognomonic by itself. PMID:25151972

Brito-Zerón, Pilar; Ramos-Casals, Manuel; Bosch, Xavier; Stone, John H

2014-12-01

92

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

USGS Publications Warehouse

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.

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

2013-01-01

93

Complex-to-Predict Generational Shift between Nested and Clustered Organization of Individual Prey Networks in Digger Wasps  

PubMed Central

Although diet has traditionally been considered to be a property of the species or populations as a whole, there is nowadays extensive knowledge that individual specialization is widespread among animal populations. Nevertheless, the factors determining the shape of interactions within food webs remain largely undiscovered, especially in predatory insects. We used an aggregation of the digger wasp Bembix merceti to 1) analyse patterns of individual prey use across three flying seasons in a network–based context; and 2) test the effect of four potential factors that might explain network topologies (wasp mass, nest spatial distribution, simultaneous nest-provisioning, prey availability). Inter-individual diet variation was found in all three years, under different predator-prey network topologies: Individuals arranged in dietary clusters and displayed a checkerboard pattern in 2009, but showed nestedness in 2008 and 2010. Network topologies were not fully explained by the tested factors. Larger females consumed a higher proportion of the total number of prey species captured by the population as a whole, in such a way that nested patterns may arise from mass-dependent prey spectrum width. Conversely, individuals with similar body mass didn’t form clusters. Nested patterns seemed to be associated with a greater availability of the main prey species (a proxy for reduced intra-specific competition). Thus, according with theory, clusters seemed to appear when competition increased. On the other hand, the nests of the individuals belonging to a given cluster were not more closely located, and neither did individuals within a cluster provision their nests simultaneously. Thus, a female-female copying behaviour during foraging was unlikely. In conclusion, wasp populations can maintain a considerable individual variation across years under different food web organizations. The tested factors only partially accounted for the shift in network properties, and new analyses should be carried out to elucidate how diet network topologies arise in wasp populations. PMID:25019164

Ballesteros, Yolanda; Polidori, Carlo; Tormos, José; Bańos-Picón, Laura; Asís, Josep Daniel

2014-01-01

94

Diurnal and nocturnal prey detection by Dunlins Calidris alpina  

Microsoft Academic Search

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.

K. N. Mouritsen

1993-01-01

95

Prey escaping wolves, Canis lupus, despite close proximity  

USGS Publications Warehouse

We describe attacks by wolf (Canis lupus) packs in Minnesota on a white-tailed deer (Odocoileus virginianus) and a moose (Alces alces) in which wolves were within contact distance of the prey but in which the prey escaped.

Nelson, M.E.; Mech, L.D.

1993-01-01

96

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

PubMed

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

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

2004-05-01

97

A meal or a male: the ‘whispers’ of black widow males do not trigger a predatory response in females  

PubMed Central

Introduction Female spiders are fine-tuned to detect and quickly respond to prey vibrations, presenting a challenge to courting males who must attract a female’s attention but not be mistaken for prey. This is likely particularly important at the onset of courtship when a male enters a female’s web. In web-dwelling spiders, little is known about how males solve this conundrum, or about their courtship signals. Here we used laser Doppler vibrometry to study the vibrations produced by males and prey (house flies and crickets) on tangle webs of the western black widow Latrodectus hesperus and on sheet webs of the hobo spider Tegenaria agrestis. We recorded the vibrations at the location typically occupied by a hunting female spider. We compared the vibrations produced by males and prey in terms of their waveform, dominant frequency, frequency bandwidth, amplitude and duration. We also played back recorded male and prey vibrations through the webs of female L. hesperus to determine the vibratory parameters that trigger a predatory response in females. Results We found overlap in waveform between male and prey vibrations in both L. hesperus and T. agrestis. In both species, male vibrations were continuous, of long duration (on average 6.35 s for T. agrestis and 9.31 s for L. hesperus), and lacked complex temporal patterning such as repeated motifs or syllables. Prey vibrations were shorter (1.38 - 2.59 s), sporadic and often percussive. Based on the parameters measured, courtship signals of male L. hesperus differed more markedly from prey cues than did those of T. agrestis. Courtship vibrations of L. hesperus males differed from prey vibrations in terms of dominant frequency, amplitude and duration. Vibrations of T. agrestis males differed from prey in terms of duration only. During a playback experiment, L. hesperus females did not respond aggressively to low-amplitude vibrations irrespective of whether the playback recording was from a prey or a male. Conclusions Unlike courtship signals of other spider species, the courtship signals of L. hesperus and T. agrestis males do not have complex temporal patterning. The low-amplitude ‘whispers’ of L. hesperus males at the onset of courtship are less likely to trigger a predatory response in females than the high-amplitude vibrations of struggling prey. PMID:24433544

2014-01-01

98

Blue whale habitat and prey in the California Channel Islands  

Microsoft Academic Search

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

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

99

SCIENCE IN ACTION! Nature's Partners: predators, prey & you  

E-print Network

& Prey Partnerships revising mental models creating mental models O3 Wild Wolves OBSERVATIONS Module 3. Wolf & Prey Partnerships O3 Wild Wolves A3 Field studies Q3 Social Function seeking to better what I observed; my hypothesis about cause/effect MAP FAQ SOURCES O3 Wild wolves- sharing prey

Packard, Jane M.

100

Prey bacteria shape the community structure of their predators  

Microsoft Academic Search

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

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

2011-01-01

101

Molecular assessment of heterotrophy and prey digestion in zooxanthellate cnidarians.  

PubMed

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

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

2014-08-01

102

Prey preferences of the lion ( Panthera leo )  

Microsoft Academic Search

Lions Panthera leo are generally thought to prey on medium to large ungulates. Knowledge of which species are actually preferred and which are avoided is lacking, however, as is an understanding of why such preference or avoidance may arise. An analysis of 32 studies over 48 different spatial locations or temporal periods throughout the distribution of the lion shows that

Matt W. Hayward; Graham I. H. Kerley

2005-01-01

103

Apparent decoupling of prey recognition ability with prey availability in an insular snake population  

Microsoft Academic Search

Numerous studies on the feeding behavior of snakes have reported the consistency of tongue-flick responses with their natural\\u000a diets. For representatives of widely distributed, dietary generalist species from particular localities, we can expect that\\u000a their tongue-flick responses to potential prey unavailable in their original habitats have been reduced whereas those to prey\\u000a common in the habitats have been enhanced. To

Koji Tanaka; Akira Mori; Masami Hasegawa

2001-01-01

104

Activity Budget, Field Metabolic Rate, and Foraging Ecology of Female Sea Otters (Enhydra lutris kenyoni) with Dependent Pups in Alaska  

E-print Network

Sea otter (Enhydra lutris kenyoni) foraging behavior and prey preference (2001- 2004) and the behavior and activity budgets of females with dependent pups (2005- 2010) were studied during the summer (June-August) in Simpson Bay, Prince William Sound...

Wolt, Ryan C.

2014-04-30

105

Alterations in carbohydrate composition of serum IgG from patients with rheumatoid arthritis and from pregnant women.  

PubMed

The carbohydrate composition of IgG purified from serum of patients with rheumatoid arthritis (RA), pregnant women, and blood donors has been determined by gas-liquid chromatography. Comparison of the results indicates that IgG from patients with RA contains significantly less galactose but more N-acetylglucosamine than normal IgG, whereas the fucose and sialic acid contents are not changed. The carbohydrate content of IgG in RA is reduced. IgG in pregnancy contains more galactose and more sialic acid than normal IgG, whereas fucose, N-acetylglucosamine, and the total carbohydrate content are not changed. These data suggest a temporal compensation of the RA associated undergalactosylation of IgG in female patients with RA during pregnancy, a period during which remission of the disease is often observed. PMID:3355256

Pekelharing, J M; Hepp, E; Kamerling, J P; Gerwig, G J; Leijnse, B

1988-02-01

106

Alterations in carbohydrate composition of serum IgG from patients with rheumatoid arthritis and from pregnant women.  

PubMed Central

The carbohydrate composition of IgG purified from serum of patients with rheumatoid arthritis (RA), pregnant women, and blood donors has been determined by gas-liquid chromatography. Comparison of the results indicates that IgG from patients with RA contains significantly less galactose but more N-acetylglucosamine than normal IgG, whereas the fucose and sialic acid contents are not changed. The carbohydrate content of IgG in RA is reduced. IgG in pregnancy contains more galactose and more sialic acid than normal IgG, whereas fucose, N-acetylglucosamine, and the total carbohydrate content are not changed. These data suggest a temporal compensation of the RA associated undergalactosylation of IgG in female patients with RA during pregnancy, a period during which remission of the disease is often observed. PMID:3355256

Pekelharing, J M; Hepp, E; Kamerling, J P; Gerwig, G J; Leijnse, B

1988-01-01

107

A predator-prey model with diseases in both prey and predator  

NASA Astrophysics Data System (ADS)

In this paper, we present and analyze a predator-prey model, in which both predator and prey can be infected. Each of the predator and prey is divided into two categories, susceptible and infected. The epidemics cannot be transmitted between prey and predator by predation. The predation ability of susceptible predators is stronger than infected ones. Likewise, it is more difficult to catch a susceptible prey than an infected one. And the diseases cannot be hereditary in both of the predator and prey populations. Based on the assumptions above, we find that there are six equilibrium points in this model. Using the base reproduction number, we discuss the stability of the equilibrium points qualitatively. Then both of the local and global stabilities of the equilibrium points are analyzed quantitatively by mathematical methods. We provide numerical results to discuss some interesting biological cases that our model exhibits. Lastly, we discuss how the infectious rates affect the stability, and how the other parameters work in the five possible cases within this model.

Gao, Xubin; Pan, Qiuhui; He, Mingfeng; Kang, Yibin

2013-12-01

108

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

SciTech Connect

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.

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

2000-04-01

109

Signal transduction by immunoglobulin is mediated through Ig alpha and Ig beta  

PubMed Central

Immunoglobulin (Ig) antigen receptors are composed of a noncovalently- associated complex of Ig and two other proteins, Ig alpha and Ig beta. The cytoplasmic domain of both of these Ig associated proteins contains a consensus sequence that is shared with the signaling proteins of the T cell and Fc receptor. To test the idea that Ig alpha-Ig beta heterodimers are the signaling components of the Ig receptor, we have studied Ig mutations that interfere with signal transduction. We find that specific mutations in the transmembrane domain of Ig that inactivate Ca2+ and phosphorylation responses also uncouple IgM from Ig alpha-Ig beta. These results define amino acid residues that are essential for the assembly of the Ig receptor. Further, receptor activity can be fully reconstituted in Ca2+ flux and phosphorylation assays by fusing the cytoplasmic domain of Ig alpha with the mutant Igs. In contrast, fusion of the cytoplasmic domain of Ig beta to the inactive Ig reconstitutes only Ca2+ responses. Thus, Ig alpha and Ig beta are both necessary and sufficient to mediate signal transduction by the Ig receptor in B cells. In addition, our results suggest that Ig alpha and Ig beta can activate different signaling pathways. PMID:7688784

1993-01-01

110

The influence of sublethal deposits of agricultural mineral oil on the functional and numerical responses of Phytoseiulus persimilis (Acari: Phytoseiidae) to its prey, Tetranychus urticae (Acari: Tetranychidae).  

PubMed

Occasional pesticide application in integrated pest management to at least part of a crop requires that any biological control agents must re-invade previously sprayed areas in order that resurgent pests can be constrained. The ability of the phytoseiid predatory mite Phytoseiulus persimilis to feed on adult two-spotted spider mite (TSSM) Tetranychus urticae on excised leaf discs in both control conditions and in a treatment with a sub lethal residue of agricultural mineral oil (AMO) was assessed. The predator exhibited a Type II functional response with the asymptote significantly higher in the AMO conditions due to the fact that the prey grew slower and reached a smaller size in this treatment. In terms of prey volume eaten, the satiation level of the predator was unchanged by the AMO deposits. The numbers of eggs produced by adult P. persimilis females at densities of 4, 8 and 16 TSSM adult females/disc in the control were significantly higher than those in the AMO treatment, but were similar for the higher density levels, 32 and 64 prey per disc. Thus the functional response in terms of volume of prey eaten explained the numerical response in terms of predator eggs produced. The presence of AMO deposits when the prey were at high density had no effect on predator efficiency (volume eaten) but resulted in a lower intake than that in control conditions when there was a greater distance between prey. PMID:19184467

Xue, Yingen; Meats, Alan; Beattie, G Andrew C; Spooner-Hart, Robert; Herron, Grant A

2009-08-01

111

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

Microsoft Academic Search

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

Jeanine C. Bond; Daniel Esler

2006-01-01

112

Body size matters for aposematic prey during predator aversion learning.  

PubMed

Aposematic prey advertise their toxicity to predators using conspicuous warning signals, which predators learn to use to reduce their intake of toxic prey. Like other types of prey, aposematic prey often differ in body size, both within and between species. Increasing body size can increase signal size, which make larger aposematic prey more detectable but also gives them a more effective and salient deterrent. However, increasing body size also increases the nutritional value of prey, and larger aposematic prey may make a more profitable meal to predators that are trading off the costs of eating toxins with the benefits of ingesting nutrients. We tested if body size, independent of signal size, affected predation of toxic prey as predators learn to reduce their attacks on them. European starlings (Sturnus vulgaris) learned to discriminate between defended (quinine-injected) and undefended (water-injected) mealworm prey (Tenebrio molitor) using visual signals. During this process, we found that birds attacked and ate more defended prey the larger they were. Body size does affect the probability that toxic prey are attacked and eaten, which has implications for the evolutionary dynamics of aposematism and mimicry (where species share the same warning pattern). PMID:25256160

Smith, Karen E; Halpin, Christina G; Rowe, Candy

2014-11-01

113

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

PubMed

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

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

2014-07-01

114

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

USGS Publications Warehouse

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.

Palacios, V.; Mech, L.D.

2011-01-01

115

Female Infertility  

MedlinePLUS

Infertility is a term doctors use if a woman hasn't been able to get pregnant after ... woman keeps having miscarriages, it is also called infertility. Female infertility can result from physical problems, hormone ...

116

Deposition of polymeric IgA 1 in idiopathic mesangial IgA-glomerulonephritis  

Microsoft Academic Search

Summary IgA deposits in kidney and skin biopsies from patients with idiopathic mesangial IgA-glomerulonephritis were characterized with immunofluorescence microscopy using monoclonal antibodies against the IgA subclasses IgA1 and IgA2. IgA1 was the major constituent in all biopsy specimens. Double immunofluorescence microscopy showed that IgA deposits were constantly associated with J-chain. Secretory component was never found in the deposited material. In

R. Waldherr; H. P. Seelig; M. Rambausek; K. Andrassy; E. Ritz

1983-01-01

117

Inflammatory pseudotumors of the kidney due to IgG4-related tubulointerstitial nephritis.  

PubMed

The paper presents the case of a female patient who was admitted to our department because of prolonged febrile syndrome, altered general status and renal tumoral masses revealed by thoracic and abdominal CT. After thorough histological examination, including immunohisto-chemistry and in situ hybridization studies, we reached the diagnosis of renal pseudotumoral masses due to IgG4-related tubulointerstitial nephritis. The kidney is a distinct target organ affected by IgG4-related sclerosing disease, and the most frequent manifestation is tubulo-interstitial nephritis. We described the clinical, imagistic and histopathological features of kidney and urological involvement in IgG4-related sclerosing disease, especially focusing on IgG4-related tubulointerstitial nephritis. This is a rare case of IgG4-related sclerosing disease without extrarenal features, excepting lumboaortic lymphadenopathy. PMID:24969995

Hârza, Mihai; Ismail, Gener; Mitroi, George; Gherghiceanu, Mihaela; Preda, Adrian; Sinescu, Ioanel

2014-01-01

118

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

Microsoft Academic Search

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

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

1999-01-01

119

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

E-print Network

Approach Strategy by which Male Mediterranean Tarantulas Adjust to the Cannibalistic Behaviour spiders, Lycosa tarantula (L.) (Araneae, Lycosidae), decides to approach females in periods when experiments, we offered a grasshopper (typical prey) or a male L. tarantula to females at night and during

Illinois at Chicago, University of

120

A dinoflagellate exploits toxins to immobilize prey prior to ingestion.  

PubMed

Toxins produced by the harmful algal bloom (HAB) forming, mixotrophic dinoflagellate Karlodinium veneficum have long been associated with fish kills. To date, the perceived ecological role for toxins has been relief from grazing pressures. Here, we demonstrate that karlotoxins also serve as a predation instrument. Using high-speed holographic microscopy, we measure the swimming behavior of several toxic and nontoxic strains of K. veneficum and their prey, Storeatula major, within dense suspensions. The selected strains produce toxins with varying potency and dosages, including a nontoxic one. Results clearly show that mixing the prey with the predatory, toxic strains causes prey immobilization at rates that are consistent with the karlotoxins' potency and dosage. Even prey cells that continue swimming slow down after exposure to toxic predators. The swimming characteristics of predators vary substantially in pure suspensions, as quantified by their velocity, radii of helical trajectories, and direction of helical rotation. When mixed with prey, all toxic strains that are involved in predation slow down. Furthermore, they substantially reduced their predominantly vertical migration, presumably to remain in the vicinity of their prey. Conversely, the nontoxic control strain does not alter its swimming and does not affect prey behavior. In separate experiments, we show that exposing prey to exogenous toxins also causes prey immobilization at rates consistent with potency. Clearly, the toxic predatory strains use karlotoxins as a means of stunning their prey, before ingesting it. These findings add a substantiated critical understanding for why some HAB species produce such complex toxin molecules. PMID:20133853

Sheng, Jian; Malkiel, Edwin; Katz, Joseph; Adolf, Jason E; Place, Allen R

2010-02-01

121

Prey selection by the Lake Superior fish community  

USGS Publications Warehouse

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.

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

2012-01-01

122

Increased predation of nutrient-enriched aposematic prey.  

PubMed

Avian predators readily learn to associate the warning coloration of aposematic prey with the toxic effects of ingesting them, but they do not necessarily exclude aposematic prey from their diets. By eating aposematic prey 'educated' predators are thought to be trading-off the benefits of gaining nutrients with the costs of eating toxins. However, while we know that the toxin content of aposematic prey affects the foraging decisions made by avian predators, the extent to which the nutritional content of toxic prey affects predators' decisions to eat them remains to be tested. Here, we show that European starlings (Sturnus vulgaris) increase their intake of a toxic prey type when the nutritional content is artificially increased, and decrease their intake when nutritional enrichment is ceased. This clearly demonstrates that birds can detect the nutritional content of toxic prey by post-ingestive feedback, and use this information in their foraging decisions, raising new perspectives on the evolution of prey defences. Nutritional differences between individuals could result in equally toxic prey being unequally predated, and might explain why some species undergo ontogenetic shifts in defence strategies. Furthermore, the nutritional value of prey will likely have a significant impact on the evolutionary dynamics of mimicry systems. PMID:24598424

Halpin, Christina G; Skelhorn, John; Rowe, Candy

2014-04-22

123

Concealed by conspicuousness: distractive prey markings and backgrounds  

PubMed Central

High-contrast markings, called distractive or dazzle markings, have been suggested to draw and hold the attention of a viewer, thus hindering detection or recognition of revealing prey characteristics, such as the body outline. We tested this hypothesis in a predation experiment with blue tits (Cyanistes caeruleus) and artificial prey. We also tested whether this idea can be extrapolated to the background appearance and whether high-contrast markings in the background would improve prey concealment. We compared search times for a high-contrast range prey (HC-P) and a low-contrast range prey (LC-P) in a high-contrast range background (HC-B) and a low-contrast range background (LC-B). The HC-P was more difficult to detect in both backgrounds, although it did not match the LC-B. Also, both prey types were more difficult to find in the HC-B than in the LC-B, in spite of the mismatch of the LC-P. In addition, the HC-P was more difficult to detect, in both backgrounds, when compared with a generalist prey, not mismatching either background. Thus, we conclude that distractive prey pattern markings and selection of microhabitats with distractive features may provide an effective way to improve camouflage. Importantly, high-contrast markings, both as part of the prey coloration and in the background, can indeed increase prey concealment. PMID:19324754

Dimitrova, Marina; Stobbe, Nina; Schaefer, H. Martin; Merilaita, Sami

2009-01-01

124

A dinoflagellate exploits toxins to immobilize prey prior to ingestion  

PubMed Central

Toxins produced by the harmful algal bloom (HAB) forming, mixotrophic dinoflagellate Karlodinium veneficum have long been associated with fish kills. To date, the perceived ecological role for toxins has been relief from grazing pressures. Here, we demonstrate that karlotoxins also serve as a predation instrument. Using high-speed holographic microscopy, we measure the swimming behavior of several toxic and nontoxic strains of K. veneficum and their prey, Storeatula major, within dense suspensions. The selected strains produce toxins with varying potency and dosages, including a nontoxic one. Results clearly show that mixing the prey with the predatory, toxic strains causes prey immobilization at rates that are consistent with the karlotoxins’ potency and dosage. Even prey cells that continue swimming slow down after exposure to toxic predators. The swimming characteristics of predators vary substantially in pure suspensions, as quantified by their velocity, radii of helical trajectories, and direction of helical rotation. When mixed with prey, all toxic strains that are involved in predation slow down. Furthermore, they substantially reduced their predominantly vertical migration, presumably to remain in the vicinity of their prey. Conversely, the nontoxic control strain does not alter its swimming and does not affect prey behavior. In separate experiments, we show that exposing prey to exogenous toxins also causes prey immobilization at rates consistent with potency. Clearly, the toxic predatory strains use karlotoxins as a means of stunning their prey, before ingesting it. These findings add a substantiated critical understanding for why some HAB species produce such complex toxin molecules. PMID:20133853

Sheng, Jian; Malkiel, Edwin; Katz, Joseph; Adolf, Jason E.; Place, Allen R.

2010-01-01

125

Immunoglobulin M Serum Levels in Females and Pups of Southern Elephant Seal ( Mirounga leonina) During the Suckling Period  

Microsoft Academic Search

This paper reports Immunoglobulin M (IgM) levels in serum samples from eight female-pup pairs of southern elephant seals (Mirounga leonina), at King George Island, Antarctica. IgM levels were determined on sera obtained from sequential sampling throughout the suckling period (approximately 23 days). The IgM concentration in southern elephant seal serum was measured by single radial immunodiffusion on agarose plates. Female

M. E. I Marquez; A. R Carlini; N. H Slobodianik; P. A. Ronayne de Ferrer; M. F Godoy

1998-01-01

126

Hemolytic uremic syndrome complicated with IgA nephropathy: a case report and literature review.  

PubMed

A previously healthy young female, presenting with nausea, vomiting, diarrhea, anemia, thrombocytopenia, and acute renal failure, was admitted to our hospital. Her clinical and histological features were consistent with both hemolytic uremic syndrome and IgA nephropathy, and she responded to steroid treatment, plasma transfusion, and gamma globulin therapy and did not need hemodialysis. In the following months, she achieved clinical remission except for low complement C3. Since hemolytic uremic syndrome is rarely associated with IgA nephropathy, we present this case and discuss potential connection between hemolytic uremic syndrome and IgA nephropathy. PMID:24290408

Wang, Rong; Zhang, Yiyan; Li, Shijun; Chen, Hao; Zeng, Caihong; Chen, Huiping; Tang, Zheng; Liu, Zhihong

2015-01-01

127

IgG4-related disease.  

PubMed

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is an immune-mediated condition that can affect almost any organ and is now being recognized with increasing frequency. IgG4-RD is characterized by a lymphoplasmacytic infiltrate composed of IgG4(+) plasma cells, storiform fibrosis, obliterative phlebitis, and mild to moderate eosinophilia. The diagnosis of IgG4-RD unifies many eponymous fibroinflammatory conditions that had previously been thought to be confined to single organs. IgG4-RD lesions are infiltrated by T helper cells, which likely cause progressive fibrosis and organ damage. IgG4 antibodies are generally regarded as noninflammatory. Although autoreactive IgG4 antibodies are observed in IgG4-RD, there is no evidence that they are directly pathogenic. Rituximab-induced B cell depletion in IgG4-RD leads to rapid clinical and histological improvement accompanied by swift declines in serum IgG4 concentrations. Although IgG autoantibodies against various exocrine gland antigens have been described in IgG4-RD, whether they are members of the IgG4 subclass is unknown. The contribution of autoantibodies to IgG4-RD remains unclear. PMID:24111912

Mahajan, Vinay S; Mattoo, Hamid; Deshpande, Vikram; Pillai, Shiv S; Stone, John H

2014-01-01

128

Nash Equilibria in Noncooperative Predator-Prey Games  

SciTech Connect

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.

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

129

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

Microsoft Academic Search

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

C. Gilbert

1997-01-01

130

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

Microsoft Academic Search

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

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

2010-01-01

131

Foraging mode, prey chemical discrimination, and phylogeny in lizards  

Microsoft Academic Search

The long-held hypothesis that active foragers should use chemical senses to detect food more than do ambush foragers is verified for lizards. In actively foraging and herbivorous families, tongue-flicking permits sampling of chemicals for detection and identification of prey, but in ambush-foraging families the tongue does not participate even in detection of prey. Because foraging mode and prey chemical discrimination

William E. Cooper

1995-01-01

132

Predator size and phenology shape prey survival in temporary ponds  

Microsoft Academic Search

Theoretical efforts suggest that the relative sizes of predators and their prey can shape community dynamics, the structure\\u000a of food webs, and the evolution of life histories. However, much of this work has assumed static predator and prey body sizes.\\u000a The timing of recruitment and the growth patterns of both predator and prey have the potential to modify the strength

Mark C. Urban

2007-01-01

133

Prey caloric value and predator energy needs: foraging predictions for wild spinner dolphins  

Microsoft Academic Search

Spinner dolphins ( Stenella longirostris) feed on individual small (2–10 cm long) prey that undergo diel vertical migrations, presumably making them inaccessible to dolphins during the day. To examine how time, prey behavior, prey distribution, and energy needs constrain dolphin foraging, a calorimeter was used to measure the caloric content of prey items. These data were combined with information on prey

K. J. Benoit-Bird

2004-01-01

134

The Coevolution of "Tyrannosaurus" & Its Prey: Could "Tyrannosaurus" Chase down & Kill a "Triceratops" for Lunch?  

ERIC Educational Resources Information Center

Students will analyze the coevolution of the predator-prey relationships between "Tyrannosaurus rex" and its prey species using analyses of animal speeds from fossilized trackways, prey-animal armaments, adaptive behaviors, bite marks on prey-animal fossils, predator-prey ratios, and scavenger competition. The students will be asked to…

May, S. Randolph

2014-01-01

135

COMPARATIVE ABSORPTION OF COLOSTRAL IgG1 AND IgM IN THE NEWBORN CALF  

E-print Network

COMPARATIVE ABSORPTION OF COLOSTRAL IgG1 AND IgM IN THE NEWBORN CALF EFFECTS OF THYROXINE, CORTISOL Nutritionnelles, l.N.R.A., Centre de Theix, 63110 Beaumont France Résumé ABSORPTION DES IgGl ET IgM COLOSTRALES conditions. Les résultats suivants ont été obtenus : - la capacité d'absorption des IgGl et des IgM varie

Boyer, Edmond

136

Hypertension in mesangial IgA glomerulonephritis.  

PubMed

Blood pressure in 75 patients with IgA nephropathy (IgA-GN), confirmed by renal biopsy, was related to clinical, immunological and morphological findings. The findings were compared with an age-matched control group of patients with non-IgA-GN. Overall prevalence of hypertension (HT) was similar in IgA-GN and non-IgA-GN (38.7% vs 38.2%). The presence of HT in IgA-GN was related to age, renal function, immunohistological pattern and degree of glomerular sclerosis or vascular lesions respectively. No correlation was found between HT and elevated serum IgA, circulating IgA immune complexes and IgA skin deposits. The current observations underline the value of hypertension for predicting development of renal failure. Vascular lesions are not only strongly correlated with, but may even precede development of, hypertension as confirmed by longitudinal observations. PMID:3991561

Rambausek, M; Waldherr, R; Andrassy, K; Ritz, E

1985-01-01

137

Aquatic predation alters a terrestrial prey subsidy.  

PubMed

Organisms with complex life histories (CLH) often cross habitat or ecosystem boundaries as they develop from larvae to adults, coupling energy flow between ecosystems as both prey (bottom-up) and consumers (top-down). Predation effects on one stage of this life cycle can therefore cascade across ecosystems, magnifying the impact of local predation. The majority of predation studies have assessed effects only on a local level, within the habitat of the predator. I used large outdoor stream mesocosms to test the hypothesis that predation in an aquatic habitat alters the magnitude and trophic structure of a prey assemblage in a terrestrial habitat. I also tested how a consumer in the terrestrial habitat (web-weaving spiders) responded to these changes in prey export. Two fish species were the predators (red shiner, Cyprinella lutrensis and orangethroat darter, Etheostoma spectabile) in an experiment with three treatments: both fish species monocultures plus a fishless control. Fish predation reduced aquatic insect emergence biomass by 50% compared to the fishless control and altered the trophic structure of the emergent community, reducing emerging insect predator biomass by 50%, but had no effect on other insect trophic groups. Spiders captured only insects that were unaffected by fish predation (mostly chironomids) and therefore did not respond numerically to overall changes in insect abundance or biomass. Patterns of insect emergence were largely driven by a strong negative relationship between fish and a predatory dragonfly (Pantala flavescens). The results of this experiment show that predation in one habitat can have strong effects on the biomass and trophic structure of subsidies entering adjacent habitats, resulting in contrasting predictions for the role of these subsidies in recipient food webs. In the absence of fish, aquatic habitats produced terrestrial insect communities with higher biomass (bottom-up potential) and a higher proportion of predators (top-down potential) than when fish were present. PMID:20503875

Wesner, Jeff Scott

2010-05-01

138

Peripherin-IgG Association with Neurologic and Endocrine Autoimmunity  

PubMed Central

Peripherin-IgG has been reported a pertinent autoantibody in non-obese type 1 diabetic (NOD) mice. However, it has not previously been recognized in any human disease. In blinded evaluation of serum for markers of neurological autoimmunity in a high-volume diagnostic laboratory, we incidentally identified 26 patients (61% female) with an IgG that bound selectively to neural elements in enteric ganglia, sympathetic nerve trunks and discrete nerve tracts in mid-brain and hind-brain. The target antigen was identified as peripherin, a 55 kDa-type III intermediate filament protein. Review of clinical histories revealed that 54% of seropositive patients had dysautonomia (predominantly gastrointestinal dysmotility), 30% had neuropathies with varied sensory symptoms and 35% had clinical or serological evidence of endocrinopathy (type 1 diabetes, thyroiditis or premature ovarian failure). Collectively, 73% had autonomic dysfunction or endocrinopathy. None of 173 healthy subjects was seropositive. Subsequent western blot evaluation of archival sera from patients with small fiber/autonomic neuropathies (with or without endocrinopathy) revealed a 33% seropositivity rate for peripherin IgG. Our further demonstration that peripherin-immunoreactive autonomic fibers in pancreas, thyroid and ovary are juxtaposed to endocrine epithelium, complement our clinical observations in suggesting that neuronal elements may be a pertinent initial target for immune attack in multiple forms of endocrine autoimmunity (intermolecular epitope spreading). It remains to be determined whether or not peripherin-IgG is predictive for development of small fiber neuropathy (autonomic or somatic). PMID:20061119

Chamberlain, Jayne L.; Pittock, Sean J.; Oprescu, Anna-Maria; Dege, Carissa; Apiwattanakul, Metha; Kryzer, Thomas J.; Lennon, Vanda A.

2010-01-01

139

Serum levels of IgM, IgD, IgA and IgG before and during rejection of renal allotransplants.  

PubMed

In recipients of renal allotransplants the relationship of IgM, IgA and IgG serum levels to 26 rejections was investigated, as well as the relationship of IgD and 22 rejection. For IgM and IgG a significant decline was found in the whole group (p less than 0.05) and in the sub-group of rejections after a period longer than one month following transplantation (p less than 0.05 in IgM and p less than 0.02 in IgD). As compared with values before rejection, a decline of IgM occurred in 11 rejections which amounted to more than 20% and a decline of IgD in 10 rejections by more than 50%. Changes of the serum levels of IgA and IgG were not statistically significant (p greater than 0.05). In recipients of renal allotransplants serum immunoglobulin (Ig) levels of the main classes were investigated for two reasons: (1) as part of a check-up of the condition of the graft and screening of rejection and (2) to detect possible deficiencies of humoral immunity with increased liability to infections. As regards monitoring of the risk of the rejection crisis, hitherto assembled experience did not provide an unequivocal answer in which class of Ig the greatest change may be expected, whether a rise or fall, and it is not even clear whether investigations of serum Ig levels will be a positive contribution. There is only agreement on the point that IgA levels are not related to rejection; according to some authors this applies also to IgM and IgG (8, 11). Other authors (1, 15, 17) appreciate in conjunction with rejections the importance of high IgM and IgG levels, while other workers observed a significant decline of IgM (13, 16, 19). IgD levels were investigated in our previous work on the relationship of renal functions and serum Ig levels in recipients of renal allotransplants (7); we found no reports on the relationship between IgD and rejection. PMID:394945

Hrncír, Z; Erben, J; Tichý, M

1979-01-01

140

Evaluating prey switching in wolf-ungulate systems.  

PubMed

Wolf restoration has become a widely accepted conservation and management practice throughout North America and Europe, though the ecosystem effects of returning top carnivores remain both scientific and societal controversies. Mathematical models predicting and describing wolf-ungulate interactions are typically limited to the wolves' primary prey, with the potential for prey switching in wolf-multiple-ungulate systems only suggested or assumed by a number of investigators. We used insights gained from experiments on small taxa and field data from ongoing wolf-ungulate studies to construct a model of predator diet composition for a wolf-elk-bison system in Yellowstone National Park, Wyoming, USA. The model explicitly incorporates differential vulnerability of the ungulate prey types to predation, predator preference, differences in prey biomass, and the possibility of prey switching. Our model demonstrates wolf diet shifts with changes in relative abundance of the two prey, with the dynamics of this shift dependent on the combined influences of preference, differential vulnerability, relative abundances of prey, and whether or not switching occurs. Differences in vulnerability between elk and bison, and strong wolf preference for elk, result in an abrupt dietary shift occurring only when elk are very rare relative to bison, whereas incorporating switching initiates the dietary shift more gradually and at higher bison-elk ratios. We demonstrate how researchers can apply these equations in newly restored wolf-two-prey systems to empirically evaluate whether prey switching is occurring. Each coefficient in the model has a biological interpretation, and most can be directly estimated from empirical data collected from field studies. Given the potential for switching to dramatically influence predator-prey dynamics and the wide range of expected prey types and abundances in some systems where wolves are present and/or being restored, we suggest that this is an important and productive line of research that should be pursued by ecologists working in wolf-ungulate systems. PMID:17913125

Garrott, Robert A; Bruggeman, Jason E; Becker, Matthew S; Kalinowski, Steven T; White, P J

2007-09-01

141

Insect prey foraging strategies in Callicebus oenanthe in northern Peru.  

PubMed

Titi monkeys (genus Callicebus) are small-bodied platyrrhines that supplement their predominantly frugivorous diet with variable amounts of leaves, seeds, and/or arthropod prey. Notable interspecific variation in the amount of insect prey in the diet has been observed in Callicebus, ranging from 0% to 20%. In this study, I investigate the degree and type of prey foraging in a little-known species, Callicebus oenanthe inhabiting a fragmented, secondary forest on the foothills of the Andes in northern Peru. I present data on prey type, prey search and capture techniques, substrate/vegetation use, foraging height, prey capture efficiency, and seasonal variation of insect prey foraging in one group of C. oenanthe observed from January to August 2005. Insect prey accounted for 22% of the diet, the highest amount reported for any Callicebus species to date, and insects from at least six different orders were included. C. oenanthe was mainly an investigative forager of hidden prey, manipulating easy-to-open substrates such as rolled up leaves, and hunted ant swarms and larger insects opportunistically. Insect foraging was predominant during the dry season (26%) and decreased during the wet season (13%). The study group foraged mostly in the understory (2-6 m) within vine-laden shrubs and trees, which may conform to an anti-predator strategy of crypticity. Overall the group had an 83% insect capture success rate. These data suggest that insect prey is an important part of the diet of C. oenanthe and may be especially notable during periods of resource scarcity. This study adds to the knowledge concerning insect prey foraging in Callicebus, which can have an important role in defining ecological strategies in the selection of secondary protein food resources within a given ecosystem. PMID:22311736

Deluycker, Anneke M

2012-05-01

142

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

PubMed

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

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

2011-07-01

143

Predation risk causes oxidative damage in prey  

PubMed Central

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

Janssens, Lizanne; Stoks, Robby

2013-01-01

144

Predation risk causes oxidative damage in prey.  

PubMed

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

Janssens, Lizanne; Stoks, Robby

2013-08-23

145

O-Glycosylated IgA Rheumatoid Factor Induces IgA Deposits and Glomerulonephritis  

PubMed Central

Structural aberrations of O-linked glycans present in the IgA1 hinge region are associated with IgA nephropathy, but their contribution to its pathogenesis remains incompletely understood. In this study, mice implanted with hybridoma secreting 6-19 IgA anti-IgG2a rheumatoid factor, but not 46-42 IgA rheumatoid factor bearing the same IgA allotype, developed mesangial deposits consisting of IgA, IgG2a, and C3. Studies in immunoglobulin- and C3-deficient mice revealed that the development of these glomerular lesions required the formation of IgA-IgG2a immune complexes and subsequent activation of complement. The proportion of polymeric and monomeric forms, the IgG2a-binding affinity, and the serum levels of IgA-IgG2a immune complexes were similar between 6-19 IgA– and 46-42 IgA–injected mice. In contrast, the analysis of oligosaccharide structures revealed highly galactosylated O-linked glycans in the hinge region of 6-19 IgA and poorly O-glycosylated in the hinge region of 46-42 IgA. Furthermore, the structure of N-linked glycans in the CH1 domain was the complex type in 6-19 IgA and the hybrid type in 46-42 IgA. In summary, this study demonstrates the presence of O-linked glycans in the hinge region of mouse IgA and suggests that 6-19 IgA rheumatoid factor–induced GN could serve as an experimental model for IgA nephropathy. PMID:22193386

Otani, Masako; Nakata, Junichiro; Kihara, Masao; Leroy, Valérie; Moll, Solange; Wada, Yoshinao

2012-01-01

146

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

PubMed

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

Antczak, Marcin; Hromada, Martin; Tryjanowski, Piotr

2012-09-01

147

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

PubMed

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

Laundré, John W

2010-10-01

148

PATTERNS OF TEMPORAL VARIATION IN GOSHAWK REPRODUCTION AND PREY RESOURCES  

Microsoft Academic Search

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

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

149

ENERGETIC REQUIREMENTS AND PREY CONSUMPTION OF HARBOR SEALS (PHOCA VITULINA)  

E-print Network

ENERGETIC REQUIREMENTS AND PREY CONSUMPTION OF HARBOR SEALS (PHOCA VITULINA) IN THE SAN JUAN __________________________________ #12;ENERGETIC REQUIREMENTS AND PREY CONSUMPTION OF HARBOR SEALS (PHOCA VITULINA) IN THE SAN JUAN with production costs to estimate total energetic requirements, which were in turn used to estimate consumption

Acevedo, Alejandro

150

Aggregative response in bats: prey abundance versus habitat.  

PubMed

In habitats where prey is either rare or difficult to predict spatiotemporally, such as open habitats, predators must be adapted to react effectively to variations in prey abundance. Open-habitat foraging bats have a wing morphology adapted for covering long distances, possibly use information transfer to locate patches of high prey abundance, and would therefore be expected to show an aggregative response at these patches. Here, we examined the effects of prey abundance on foraging activities of open-habitat foragers in comparison to that of edge-habitat foragers and closed-habitat foragers. Bat activity was estimated by counting foraging calls recorded with bat call recorders (38,371 calls). Prey abundance was estimated concurrently at each site using light and pitfall traps. The habitat was characterized by terrestrial laser scanning. Prey abundance increased with vegetation density. As expected, recordings of open-habitat foragers clearly decreased with increasing vegetation density. The foraging activity of edge- and closed-habitat foragers was not significantly affected by the vegetation density, i.e., these guilds were able to forage from open habitats to habitats with dense vegetation. Only open-habitat foragers displayed a significant and proportional aggregative response to increasing prey abundance. Our results suggest that adaptations for effective and low-cost foraging constrains habitat use and excludes the guild of open-habitat foragers from foraging in habitats with high prey abundance, such as dense forest stands. PMID:22218944

Müller, Jörg; Mehr, Milenka; Bässler, Claus; Fenton, M Brock; Hothorn, Torsten; Pretzsch, Hans; Klemmt, Hans-Joachim; Brandl, Roland

2012-07-01

151

Red fox prey demands and implications to prairie duck production  

USGS Publications Warehouse

Experiments were conducted during spring and summer with 33 red foxes (Vulpes vulpes) to determine prey demands, feeding characteristics, and growth rates using natural foods. Pups began eating prey the 4th week after birth. Then, prey consumption averaged 1.38 and 1.90 kg/pup/week for weeks 5-8 and 9-12 of the denning season respectively, and 2.54 kg/pup/week for the postdenning period. Feeding by adults averaged 2.25 kg/adult/week. Free water was not needed by either pups or adults. About 90 percent of the prey offered to pups on simulated natural diets was consumed, remains varied with prey availability and prey type. Prey biomass required by a typical fox family was estimated at 18.5 kg/km2 for the 12-week denning season and 2.4 kg/km2/week for the postdenning period. Because of the large prey demands, ducks could represent a small part of the foxes' diet and yet be of consequence to the productivity of particular species. An example is provided for the mallard (Anas platyrhynchos).

Sargeant, A.B.

1978-01-01

152

Ambient temperature influences birds' decisions to eat toxic prey.  

PubMed

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

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

2013-10-01

153

ORIGINAL PAPER The causes and consequences of partial prey consumption  

E-print Network

ORIGINAL PAPER The causes and consequences of partial prey consumption by wolves preying on moose: wolves (Canis lupus) feeding on moose (Alces alces). Previous theoretical assessments indicate carcasses is uncorrelated with time between kills. Wolves exhibit exactly this pattern. We explore how

154

Some aspects of prey capture by Chaoborus larvae  

Microsoft Academic Search

The effects of prey size, shape, and locomotion on capture, ingestion, and handling time were investigated in second-, third-, and fourth&star larvae of Chaoborus americanus and Chaoborus trivittutus from Eunice Lake, British Columbia. Before contact, densities and swimming speeds of predators and prey determine the number of interactions and hence availability. After contact is made, successful capture is determined largely

MICHAEL C. SWIFT; Alice Y. Fedorenlcoz

1975-01-01

155

Prey bacteria shape the community structure of their predators  

PubMed Central

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

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

2011-01-01

156

Prey behavior, age-dependent vulnerability, and predation rates.  

PubMed

Variation in the temporal pattern of vulnerability can provide important insights into predator-prey relationships and the evolution of antipredator behavior. We illustrate these points with a system that has coyotes (Canis latrans) as a predator and two species of congeneric deer (Odocoileus spp.) as prey. The deer employ different antipredator tactics (aggressive defense vs. flight) that result in contrasting patterns of age-dependent vulnerability in their probability of being captured when encountered by coyotes. We use long-term survival data and a simple mathematical model to show that (1) species differences in age-dependent vulnerability are reflected in seasonal predation rates and (2) seasonal variation in prey vulnerability and predator hunt activity, which can be associated with the availability of alternative prey, interact to shape seasonal and annual predation rates for each prey species. Shifting hunt activity from summer to winter, or vice versa, alleviated annual mortality on one species and focused it on the other. Our results indicate that seasonal variation in prey vulnerability and hunt activity interact to influence the impact that a predator has on any particular type of prey. Furthermore, these results indicate that seasonal variation in predation pressure is an important selection pressure shaping prey defenses. PMID:18840071

Lingle, Susan; Feldman, Alex; Boyce, Mark S; Wilson, W Finbarr

2008-11-01

157

Energy and protein content of coyote prey in southeastern Idaho  

SciTech Connect

Gross energy, digestible energy, crude protein, and digestible crude protein were estimated for two leporids and five rodents that were the primary prey of coyotes (Canis latrans) in southeastern Idaho. Digestible protein estimates differed (38%-54%) more than digestible energy (3.5-4.4 kcal), in the prey examined. 15 references, 1 table.

MacCracken, J.G.; Hansen, R.M.

1986-04-30

158

The impact on tigers of poaching versus prey depletion  

Microsoft Academic Search

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

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

2008-01-01

159

Dietary shifts of sympatric buteos during a prey decline  

Microsoft Academic Search

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

K. Steenhof; M. N. Kochert

1985-01-01

160

Predatory Bacteriovorax Communities Ordered by Various Prey Species  

PubMed Central

The role of predation in altering microbial communities has been studied for decades but few examples are known for bacterial predators. Bacteriovorax are halophilic prokaryotes that prey on susceptible Gram-negative bacteria. We recently reported novel observations on the differential selection of Bacteriovorax phylotypes by two different prey, Vibrio parahaemolyticus and Vibrio vulnificus. However, the conclusion is restricted by the limited number of prey tested. In this study, we have conducted two independent investigations involving eight species of prey bacteria while using V. vulnificus and V. parahaemolytics as reference strains. Water samples collected from Dry Bar, Apalachicola Bay were used to establish microcosms which were respectively spiked with prey strains Vibrio cholerae, Escherichia coli or Pseudomonas putida to examine the response of native Bacteriovorax to freshwater bacteria. Indigenous Vibrio sp., Pseudoalteromonas sp., Photobacterium sp. and a clinical strain of V. vulnificus were also tested for the impact of saltwater prey on the Bacteriovorax community. At 24 hour intervals, optical density of the microcosm samples and the abundance of Bacteriovorax were measured over five days. The predominant Bacteriovorax plaques were selected and analyzed by 16S rRNA gene amplification and sequencing. In addition, the impacts of prey on predator population and bacterial community composition were investigated using culture independent denaturing gradient gel electrophoresis. Strikingly, Cluster IV was found consistently as the predominant phylotype produced by the freshwater prey. For all saltwater prey, subgroups of Bacteriovorax phylotype IX were the major predators recovered. The results suggest that prey is an important factor along with temperature, salinity and other environmental parameters in shaping Bacteriovorax communities in aquatic systems. PMID:22461907

Chen, Huan; Young, Shanterial; Berhane, Timkhite-Kulu; Williams, Henry N.

2012-01-01

161

Acoustic behaviour of echolocating porpoises during prey capture.  

PubMed

Porpoise echolocation has been studied previously, mainly in target detection experiments using stationed animals and steel sphere targets, but little is known about the acoustic behaviour of free-swimming porpoises echolocating for prey. Here, we used small onboard sound and orientation recording tags to study the echolocation behaviour of free-swimming trained porpoises as they caught dead, freely drifting fish. We analysed porpoise echolocation behaviour leading up to and following prey capture events, including variability in echolocation in response to vision restriction, prey species, and individual porpoise tested. The porpoises produced echolocation clicks as they searched for the fish, followed by fast-repetition-rate clicks (echolocation buzzes) when acquiring prey. During buzzes, which usually began when porpoises were about 1-2 body lengths from prey, tag-recorded click levels decreased by about 10 dB, click rates increased to over 300 clicks per second, and variability in body orientation (roll) increased. Buzzes generally continued beyond the first contact with the fish, and often extended until or after the end of prey handling. This unexplained continuation of buzzes after prey capture raises questions about the function of buzzes, suggesting that in addition to providing detailed information on target location during the capture, they may serve additional purposes such as the relocation of potentially escaping prey. We conclude that porpoises display the same overall acoustic prey capture behaviour seen in larger toothed whales in the wild, albeit at a faster pace, clicking slowly during search and approach phases and buzzing during prey capture. PMID:19749102

Deruiter, Stacy L; Bahr, Alexander; Blanchet, Marie-Anne; Hansen, Sabina Fobian; Kristensen, Jakob Hřjer; Madsen, Peter T; Tyack, Peter L; Wahlberg, Magnus

2009-10-01

162

Effects of symbiotic status, flow speed, and prey type on prey capture by the facultatively symbiotic temperate coral Oculina arbuscula  

Microsoft Academic Search

Symbiotic temperate corals can supplement prey capture by the coelenterate host with autotrophic carbon production by endosymbiotic zooxanthellae. To test the relationship between heterotrophic consumption and photosynthetic energy, prey capture by symbiotic and aposymbiotic specimens of the temperate scleractinian coral Oculina arbuscula (Verrill) was measured in January-April 2001. Corals were tested in a laboratory flume at five flow speeds, using

G. A. Piniak

2002-01-01

163

Effects of Prey and Predator Abundances on Prey Consumption and Growth of Walleyes in Western Lake Erie  

Microsoft Academic Search

Declining growth and delayed age at maturity of walleye Stizostedion vitreum from 1965 to 1984 indicated that the species' large Lake Erie population was taxing the capacity of the prey fish community to support it. We examined the effects of prey and predator abundances on walleye diets and estimated the total predatory demand of age-0 through age-6 walleyes in western

Kyle J. Hartman; F. Joseph Margraf

1992-01-01

164

[Three cases of IgG4-related disease associated with urinary tract obstruction].  

PubMed

IgG4-related disease (IgG4RD) is a novel clinical entity characterized by tissue infiltration of IgG4-positive plasma cells. We report here 3 cases of IgG4RD associated with urinary tract obstruction. Patient 1 was a 59-year-old male who complained of difficulty on urination. A CT scan showed bilateral ureteral wall thickness, hydronephrosis, and an enlarged prostate. His serum IgG4 was 817 mg/dl. We made a diagnosis of IgG4RD and performed bilateral ureteral stenting and steroid therapy. A significant reduction in the size of the lesion was detected, and IgG4 was decreased to 272 mg/dl. He was doing well after removal of the ureteral stent. Patient 2 was a 51-year-old female who complained of bilateral swelling of the submaxillary gland. A CT scan showed left ureteral wall thickness and hydronephrosis. Her serum IgG4 was 1,020 mg/dl. We made a diagnosis of IgG4RD and performed left ureteral stenting and steroid therapy. A significant reduction in the size of the lesion was detected, and IgG4 was decreased to 337 mg/dl. She was doing well after removal of the ureteral stent. Patient 3 was a 64-year-old male who underwent evaluation for autoimmune pancreatitis. He complained of back pain and bilateral hydronephrosis was detected. His serum IgG4 level was 649 mg/dl. Bilateral ureteral stenting was performed based on a diagnosis of IgG4RD. He did not receive steroid therapy because of poorly-controlled diabetes mellitus. After insertion of the ureteral stent, hydronephrosis and back pain were relieved. We could only find a few case reports in the literature on IgG4RD associated with urinary tract obstruction. It is important for clinicians to bear in mind that IgG4RD sometimes causes urinary tract obstruction. PMID:23971373

Yazawa, Satoshi; Ohara, Rei; Maeda, Takahiro; Kanao, Kent; Hattori, Seiya; Nakajima, Yosuke; Oya, Mototsugu

2013-07-01

165

Seasonal variability in otariid energetics: implications for the effects of predators on localized prey resources.  

PubMed

Otariids, like other wild mammals, contend with a wide variety of energetic demands across seasons. However, due to the cryptic behaviors of this marine group, few studies have been able to examine longitudinal energetic costs or the potential impact of these costs on seasonal or annual prey requirements. Here we evaluated the changes in energy demand and intake of female California sea lions (Zalophus californianus) during reproductive (n=2 sea lions) and nonreproductive (n=3) periods. Monthly measurements included resting metabolic rate, blood hormone levels, body condition (blubber thickness and body mass), and caloric intake for adult sea lions throughout molting, late pregnancy, lactation, and postweaning. We found that maintenance energy demands decreased from 32.0 to 23.1 MJ d(-1) before pupping, remaining stable at 19.4+/-0.6 MJ d(-1) during lactation and postweaning. Energy intake rates to meet these demands showed marked changes with activity level and the reproductive cycle, reaching a peak intake of 3.6 times baseline levels during lactation. Translating this into prey demands, we find that 20,000 reproductively active females on San Nicolas Island rookeries would maximally require 4,950 metric tons of Pacific whiting during a month of the breeding season. This localized impact is reduced significantly with postbreeding dispersal and demonstrates the importance of considering spatial and temporal factors driving the energetic requirements of predators when designing marine protected areas. PMID:17508338

Williams, Terrie M; Rutishauser, M; Long, B; Fink, T; Gafney, J; Mostman-Liwanag, H; Casper, D

2007-01-01

166

Birth timing for mountain lions (Puma concolor); testing the prey availability hypothesis.  

PubMed

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 1(st) 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

Jansen, Brian D; Jenks, Jonathan A

2012-01-01

167

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

PubMed Central

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

Jansen, Brian D.; Jenks, Jonathan A.

2012-01-01

168

Competing Conservation Objectives for Predators and Prey: Estimating Killer Whale Prey Requirements for Chinook Salmon  

Microsoft Academic Search

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

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

2011-01-01

169

Competing Conservation Objectives for Predators and Prey: Estimating Killer Whale Prey Requirements for Chinook Salmon  

PubMed Central

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

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

170

Total IgE plasma levels vary according to gender and age in Brazilian patients with allergic rhinitis  

PubMed Central

OBJECTIVE: Allergic rhinitis is a disease that affects the upper airways and causes inflammation of the nasal mucosa and it is mediated by IgE antibodies produced after sensitization to environmental allergens. Previous reports have indicated that this disease affects males more often than females. The objective of this study was to verify whether total IgE plasma levels vary between genders in patients suffering from allergic rhinitis. METHODS: A total of 171 adult patients suffering from allergic rhinitis (55 males and 116 females) were enrolled. Total IgE plasma levels were determined using commercial kits, with 140 IU/mL considered as a reference value. The mean total IgE plasma levels were compared according to gender and age. RESULTS: The mean age of the overall patient group with allergic rhinitis was 38.4±19.0 years and a significant difference in age was observed between genders (males: 32.2±17.8 years; females: 41.4±18.9 years; p?=?0.0027). Additionally, the mean total IgE plasma levels were higher in males (413.0±143.0 IU/mL) than in females (147.9±98.0 IU/mL) (p<0.0001). These differences persisted even when males and females were stratified by age (up to or older than 20 years of age). CONCLUSIONS: In conclusion, total IgE plasma levels are higher in young adult males than in females suffering from allergic rhinitis. Evaluating total IgE plasma levels can be useful to identify patients at risk of allergic rhinitis in areas with low industrial pollution. PMID:25518031

de Paula Couto, Thaís Amarante Peres; Falsarella, Nelson; de Cássia Brandăo de Mattos, Cinara; de Mattos, Luiz Carlos

2014-01-01

171

Degraded Environments Alter Prey Risk Assessment  

PubMed Central

Elevated water temperatures, a decrease in ocean pH, and an increasing prevalence of severe storms have lead to bleaching and death of the hard corals that underpin coral reef ecosystems. As coral cover declines, fish diversity and abundance declines. How degradation of coral reefs affects behavior of reef inhabitants is unknown. Here, we demonstrate that risk assessment behaviors of prey are severely affected by coral degradation. Juvenile damselfish were exposed to visual and olfactory indicators of predation risk in healthy live, thermally bleached, and dead coral in a series of laboratory and field experiments. While fish still responded to visual cues in all habitats, they did not respond to olfactory indicators of risk in dead coral habitats, likely as a result of alteration or degradation of chemical cues. These cues are critical for learning and avoiding predators, and a failure to respond can have dramatic repercussions for survival and recruitment. PMID:23403754

Lönnstedt, Oona M; McCormick, Mark I; Chivers, Douglas P

2013-01-01

172

The effect of structural complexity, prey density, and "predator-free space" on prey survivorship at created oyster reef mesocosms  

USGS Publications Warehouse

Interactions between predators and their prey are influenced by the habitat they occupy. Using created oyster (Crassostrea virginica) reef mesocosms, we conducted a series of laboratory experiments that created structure and manipulated complexity as well as prey density and “predator-free space” to examine the relationship between structural complexity and prey survivorship. Specifically, volume and spatial arrangement of oysters as well as prey density were manipulated, and the survivorship of prey (grass shrimp, Palaemonetes pugio) in the presence of a predator (wild red drum, Sciaenops ocellatus) was quantified. We found that the presence of structure increased prey survivorship, and that increasing complexity of this structure further increased survivorship, but only to a point. This agrees with the theory that structural complexity may influence predator-prey dynamics, but that a threshold exists with diminishing returns. These results held true even when prey density was scaled to structural complexity, or the amount of “predator-free space” was manipulated within our created reef mesocosms. The presence of structure and its complexity (oyster shell volume) were more important in facilitating prey survivorship than perceived refugia or density-dependent prey effects. A more accurate indicator of refugia might require “predator-free space” measures that also account for the available area within the structure itself (i.e., volume) and not just on the surface of a structure. Creating experiments that better mimic natural conditions and test a wider range of “predator-free space” are suggested to better understand the role of structural complexity in oyster reefs and other complex habitats.

Humphries, Austin T.; La Peyre, Megan K.; Decossas, Gary A.

2011-01-01

173

Prey risk allocation in a grazing ecosystem.  

PubMed

Understanding the behaviorally mediated indirect effects of predators in ecosystems requires knowledge of predator-prey behavioral interactions. In predator-ungulate-plant systems, empirical research quantifying how predators affect ungulate group sizes and distribution, in the context of other influential variables, is particularly needed. The risk allocation hypothesis proposes that prey behavioral responses to predation risk depend on background frequencies of exposure to risk, and it can be used to make predictions about predator-ungulate-plant interactions. We determined non-predation variables that affect elk (Cervus elaphus) group sizes and distribution on a winter range in the Greater Yellowstone Ecosystem (GYE) using logistic and log-linear regression on surveys of 513 1-km2 areas conducted over two years. Employing model selection techniques, we evaluated risk allocation and other a priori hypotheses of elk group size and distributional responses to wolf (Canis lupus) predation risk while accounting for influential non-wolf-predation variables. We found little evidence that wolves affect elk group sizes, which were strongly influenced by habitat type and hunting by humans. Following predictions from the risk allocation hypothesis, wolves likely created a more dynamic elk distribution in areas that they frequently hunted, as elk tended to move following wolf encounters in those areas. This response should dilute elk foraging pressure on plant communities in areas where they are frequently hunted by wolves. We predict that this should decrease the spatial heterogeneity of elk impacts on grasslands in areas that wolves frequently hunt. We also predict that this should decrease browsing pressure on heavily browsed woody plant stands in certain areas, which is supported by recent research in the GYE. PMID:16705980

Gude, Justin A; Garrott, Robert A; Borkowski, John J; King, Fred

2006-02-01

174

Female sterilization.  

PubMed

There has been considerable development and implementation of new contraceptive methods over the last 15 years. However, sterilization has remained the most widely used method around the world. Ideally, the procedure should be safe, have a high efficacy, be readily accessible, and be personally and culturally acceptable. The cost for each procedure would be low and the method would be simple, quick, easily learned and be able to be performed in an outpatient setting without general anesthesia. A transuterine method of female sterilization has long been the ideal for the gynecologist. The Essure system fulfils many of the criteria, and is the first one to be approved by the US FDA. However, there is still a need for further research to find a device with the success rate of the Essure but without its irreversibility. PMID:18573050

Chapman, Lynne; Magos, Adam

2008-07-01

175

Flexibility in assessment of prey cues: frog-eating bats and frog calls  

PubMed Central

Predators use cues associated with their prey to assess prey quality and to avoid consuming poisonous prey. Considerable attention has been given to predators' use of aposematic cues to assess prey quality, but little is known about predators that eavesdrop on prey cues that are not intended for them. Here we investigate the prey-cue/prey-quality associations of a predator that eavesdrops on the sexual advertisement signals of its prey. Stability is expected in prey-cue/prey-quality associations when mistakes in prey assessment are lethal. Conversely, flexibility is possible when mistakes are less costly. Predators that must respond to temporal and spatial fluctuations in prey availability should be more flexible in their assessment of prey quality. Given these predictions, we examined flexibility in the ability of wild-caught bats to reverse prey-cue/prey-quality associations for a preferred prey and a poisonous one. We found that the predatory bat, Trachops cirrhosus, has a heretofore undescribed ability to reverse its evaluations of the cues that signal preferred prey. PMID:15888417

Page, Rachel A; Ryan, Michael J

2005-01-01

176

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

NASA Astrophysics Data System (ADS)

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.

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

2014-02-01

177

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

PubMed

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. PMID:24424786

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

2014-02-01

178

A link between water availability and nesting success mediated by predator-prey interactions in the Arctic.  

PubMed

Although water availability is primarily seen as a factor affecting food availability (a bottom-up process), we examined its effect on predator-prey interactions through an influence on prey behavior (a top-down process). We documented a link between water availability, predation risk, and reproductive success in a goose species (Chen caerulescens atlantica) inhabiting an Arctic environment where water is not considered a limited commodity. To reach water sources during incubation recesses, geese nesting in mesic tundra (low water availability) must move almost four times as far from their nest than those nesting in wetlands, which reduced their ability to defend their nest against predators and led to a higher predation rate. Nesting success was improved in high rainfall years due to increased water availability, and more so for geese nesting in the low water availability habitat. Likewise, nesting success was improved in years where the potential for evaporative water loss (measured by the atmospheric water vapor pressure) was low, presumably because females had to leave their nest less often to drink. Females from water-supplemented nests traveled a shorter distance to drink, and their nesting success was enhanced by 20% compared to the control. This shows that water availability and rainfall can have a strong effect on predator-prey dynamics and that changes in precipitation brought by climate change could have an impact on some Arctic species through a top-down effect. PMID:19323230

Lecomte, Nicolas; Gauthier, Gilles; Giroux, Jean-François

2009-02-01

179

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

PubMed Central

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

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

2008-01-01

180

Prey detection by vomeronasal chemoreception in a plethodontid salamander.  

PubMed

While chemoreception is involved in a wide variety of salamander behaviors, the chemosensory system that mediates specific behaviors is rarely known. We investigated the role of the vomeronasal system (VNS) in foraging behavior of the red-backed salamander (Plethodon cinereus) by manipulating salamanders' abilities to detect nonvolatile chemical cues emitted by potential prey. Subjects received one of three treatments: (1) impaired vomeronasal system, (2) sham manipulation, and (3) no manipulation. The role of the VNS in mediating foraging on motile prey (Drosophila melanogaster) was investigated under three light conditions (bright, dim, dark). Salamanders with impaired VNSs foraged less efficiently than either of the other experimental groups by displaying the longest latency to attack and the lowest rate of prey capture, especially in the absence of visual cues. A second experiment utilized freshly killed prey to determine whether the VNS takes on added importance in the absence of visual or tactile cues associated with moving prey. Animals with impaired VNSs showed a decreased foraging efficiency on stationary prey under both dark and light conditions. In addition, a mark-recapture study of VNS-impaired and sham salamanders in the field also indicated that salamanders with impaired VNSs consumed fewer stationary prey compared to shams. The study indicates that the VNS plays a substantial role in the foraging behavior of the plethodontid salamander, P. cinereus. PMID:12049224

Placyk, John S; Graves, Brent M

2002-05-01

181

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

PubMed Central

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

Vojdani, Aristo

2009-01-01

182

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

PubMed Central

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

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

2014-01-01

183

Deposition of polymeric IgA1 in idiopathic mesangial IgA-glomerulonephritis.  

PubMed

IgA deposits in kidney and skin biopsies from patients with idiopathic mesangial IgA-glomerulonephritis were characterized with immunofluorescence microscopy using monoclonal antibodies against the IgA subclasses IgA1 and IgA2. IgA1 was the major constituent in all biopsy specimens. Double immunofluorescence microscopy showed that IgA deposits were constantly associated with J-chain. Secretory component was never found in the deposited material. In vitro fixation of free secretory component, however, was observed in some biopsies. These findings indicate that most if not all of the deposited IgA in patients with idiopathic IgA-glomerulonephritis is polymeric in nature. PMID:6415341

Waldherr, R; Seelig, H P; Rambausek, M; Andrassy, K; Ritz, E

1983-09-15

184

KINEMATICS OF AQUATIC PREY CAPTURE IN THE SNAPPING TURTLE CHELYDRA SERPENTINA  

Microsoft Academic Search

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\\

G. V. LAUDER; T. PRENDERGAST

1992-01-01

185

Production and storage of mealworm beetle as prey for predatory stinkbug  

Microsoft Academic Search

Arthropod predators can be produced using alternative prey, but the availability of a constant supply of prey at low cost is necessary to support large-scale production. The use of stored prey can be advantageous for maintaining a constant food supply, but its quality may decline in storage. Thus, we tested the effect of using stored pupae of the alternative prey

Robério Carlos dos Santos Neves; Jorge Braz Torres; José Cola Zanuncio

2010-01-01

186

Prey selection by the common dolphin: fulfilling high energy1 requirements with high quality food2  

E-print Network

1 Prey selection by the common dolphin: fulfilling high energy1 requirements with high quality food prey organisms of poor energy content even32 when abundant in the environment.33 34 Keyworld: field reflected prey availability or a22 selection shaped by prey energy densities (ED). To do this, the community

Boyer, Edmond

187

Neuro-Evolution for competitive co-evolution of biologically canonical predator and prey behaviors  

Microsoft Academic Search

This paper presents a simulation of predator (pursuer) and prey (evader) agents operating within a competitive co-evolution process. The aim of the study was to investigate the effects of different resource (food for the prey) distributions and amounts on the adaptation of predator (pursuit) and prey (evasion) behaviors. Predator and prey use Artificial Neural Network (ANN) controllers to simulate behavior,

Geoff S. Nitschke; Leo H. Langenhoven

2010-01-01

188

Territory size in wintering Sanderlings: the effects of prey abundance and intruder density  

Microsoft Academic Search

Winter territory size in the Sanderling (Calidris alba) on marine beaches varies inversely with prey density. Multivariate analyses suggest that the inverse correlation results indirectly because more intruders are attracted to areas of higher prey density, and increased intruder frequency makes territorial defense more costly. Once the interaction between prey density and intruder density is controlled statistically, prey density has

J. P. Myers; P. G. Connors; F. A. Pitelka

1979-01-01

189

Prey abundance and food habits of San Joaquin kit fox (Vulpes velox macrotis) at Camp Roberts Army National Guard Training site, California  

SciTech Connect

Prey abundance and food habits of the San Joaquin kit fox (Vulpes velox macrotis) were investigated at Camp Roberts Army National Guard Training site, California, from November 1988 through September 1991. The sampling methods initially used to assess abundance of prey species resulted in indices too low to be of value. Because of this, the relationship between relative abundance and frequency of occurrence of prey species could not be examined. Six hundred forty-nine fecal samples (scats) were analyzed to determine the frequency of occurrence of prey items. California ground squirrels (Spermophilus beecheyi) and lagomorphs primarily desert cottontails (Sylvilagus audubonii) and black-tailed jackrabbits (Lepus californicus) were the most frequently occurring mammalian prey items found in scats (35.0% and 12.2%, respectively). The frequency of occurrence of ground squirrel (but not lagomorph) remains in scats collected from juveniles was significantly higher than in scats collected from adults. The frequency of occurrence of ground squirrel and lagomorph remains in scats collected from males was not significant different than in scats collected from females. There were significant variations in the frequency of ground squirrel remains among the years 1989--1991 and during the June--November periods between 1989 and 1990 and between 1990 and 1991. The frequency of lagomorph remains collected during the June--November period differed significantly among the years 1989--1991 and between 1990 and 1991.

Logan, C.G.; Berry, W.H.; Standley, W.G.; Kato, T.T.

1992-09-01

190

Nonlinearity in the predation risk of prey mobility.  

PubMed Central

Odorous waste products such as urine and faeces are unavoidable for most animals and are widely exploited by predators and their prey. Consequently, waste accumulations can be risky and prey which increase their mobility in order to disperse and dilute their waste should avoid a high predation risk until this benefit is balanced by the increasing risks of random predator encounter. This hypothesis was tested for voles (Microtus spp.) in Finland which are vulnerable to predation due to the scent and ultraviolet attractiveness of their urine. The mortality and mobility of radio-collared voles showed a U-shaped relationship, regardless of vole sex, species or population cycle phase. The low risks for prey making intermediate movements suggest that predation risk can exert strong selective pressures on prey such that they have little respite from the risk of being killed. PMID:11467424

Banks, P B; Norrdahl, K; Korpimäki, E

2000-01-01

191

Craniodental indicators of prey size preference in the Felidae  

E-print Network

and dentition to explore the association between craniodental shape and prey size among 35 species of living: crania ­ dentition ­ morphology. INTRODUCTION Subsequent to their first appearance in the fossil record

Meachen-Samuels, Julie

192

Diversity and repertoire of IgW and IgM VH families in the newborn nurse shark  

Microsoft Academic Search

BACKGROUND: Adult cartilaginous fish express three immunoglobulin (Ig) isotypes, IgM, IgNAR and IgW. Newborn nurse sharks, Ginglymostoma cirratum, produce 19S (multimeric) IgM and monomeric\\/dimeric IgM1gj, a germline-joined, IgM-related VH, and very low amounts of 7S (monomeric) IgM and IgNAR proteins. Newborn IgNAR VH mRNAs are diverse in the complementarity-determining region 3 (CDR3) with non-templated nucleotide (N-region) addition, which suggests that,

Lynn L Rumfelt; Rebecca L Lohr; Helen Dooley; Martin F Flajnik

2004-01-01

193

Molecular basis for prey relocation in viperid snakes  

PubMed Central

Background Vertebrate predators use a broad arsenal of behaviors and weaponry for overcoming fractious and potentially dangerous prey. A unique array of predatory strategies occur among snakes, ranging from mechanical modes of constriction and jaw-holding in non-venomous snakes, to a chemical means, venom, for quickly dispatching prey. However, even among venomous snakes, different prey handling strategies are utilized, varying from the strike-and-hold behaviors exhibited by highly toxic elapid snakes to the rapid strike-and-release envenomation seen in viperid snakes. For vipers, this mode of envenomation represents a minimal risk predatory strategy by permitting little contact with or retaliation from prey, but it adds the additional task of relocating envenomated prey which has wandered from the attack site. This task is further confounded by trails of other unstruck conspecific or heterospecific prey. Despite decades of behavioral study, researchers still do not know the molecular mechanism which allows for prey relocation. Results During behavioral discrimination trials (vomeronasal responsiveness) to euthanized mice injected with size-fractionated venom, Crotalus atrox responded significantly to only one protein peak. Assays for enzymes common in rattlesnake venoms, such as exonuclease, L-amino acid oxidase, metalloproteinase, thrombin-like and kallikrein-like serine proteases and phospholipase A2, showed that vomeronasal responsiveness was not dependent on enzymatic activity. Using mass spectrometry and N-terminal sequencing, we identified the proteins responsible for envenomated prey discrimination as the non-enzymatic disintegrins crotatroxin 1 and 2. Our results demonstrate a novel and critical biological role for venom disintegrins far beyond their well-established role in disruption of cell-cell and cell-extracellular matrix interactions. Conclusions These findings reveal the evolutionary significance of free disintegrins in venoms as the molecular mechanism in vipers allowing for effective relocation of envenomated prey. The presence of free disintegrins in turn has led to evolution of a major behavioral adaptation (strike-and-release), characteristic of only rattlesnakes and other vipers, which exploits and refines the efficiency of a pre-existing chemical means of predation and a highly sensitive olfaction system. This system of a predator chemically tagging prey represents a novel trend in the coevolution of predator-prey relationships. PMID:23452837

2013-01-01

194

Novel predator-prey interactions: is resistance futile?  

Microsoft Academic Search

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

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

2007-01-01

195

Prey size selection and distance estimation in foraging adult dragonflies  

Microsoft Academic Search

To determine whether perching dragonflies visually assess the distance to potential prey items, we presented artificial prey,\\u000a glass beads suspended from fine wires, to perching dragonflies in the field. We videotaped the responses of freely foraging\\u000a 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\\u000a took

R. M. Olberg; A. H. Worthington; J. L. Fox; C. E. Bessette; M. P. Loosemore

2005-01-01

196

Winter Prey Selection of Canada Lynx in Northwestern Montana  

Microsoft Academic Search

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

JOHN R. SQUIRES; LEONARD F. RUGGIERO

2007-01-01

197

Prey detection with electrical sense in the paddlefish (Polydon spathula)  

Microsoft Academic Search

Paddlefish,Polyodon spathula, is a threatened species which inhabits major mid-western river systems. Paddlefishes are plankton feeders, preying on small crustaceans including Daphnia sp.. Their rostrum is elongated and flattened into a paddle shape on which many electro-sensitive ampullary receptor cells are located. We demonstrate that the paddlefishes use their electrical sense to locate prey in its food searching behavior. Our

Xing Pei; Lon Wilkens; David Russell; Frank Moss

1997-01-01

198

Interactions between the leech Glossiphonia complanata and its gastropod prey  

Microsoft Academic Search

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

Christer Briinmark; Bjiirn Malmqvist

1986-01-01

199

Habitat fragmentation and the stability of predator-prey interactions  

Microsoft Academic Search

Mathematical models1-3, field observations4,5, and laboratory studies6 all suggest that habitat patchiness (or 'fragmentation') profoundly affects species interactions. One especially widely cited idea is that patchiness stabilizes predator-prey dynamics7,8. I performed the first test of this idea in a natural community by experimentally manipulating the degree of patchiness in goldenrod fields that were the setting for a predator-prey interaction between

P. Kareiva

1987-01-01

200

Predator Dispersal Determines the Effect of Connectivity on Prey Diversity  

PubMed Central

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

Limberger, Romana; Wickham, Stephen A.

2011-01-01

201

Prey capture kinematics of ant-eating lizards.  

PubMed

While morphological and behavioral feeding specializations are obvious in many vertebrate groups, among lizards there appear to be few dietary specialists. By comparing the prey capture kinematics and overall feeding behavior in two highly specialized ant-eating lizards (Moloch horridus and Phrynosoma platyrhinos) with those of two closely related dietary generalists (Pogona vitticeps and Uma notata), we investigate whether dietary specialization has been accompanied by changes in the function and use of the feeding system. We quantified kinematic variables from high-speed video recordings (200-250 frames s(-1)) of each species feeding on ants. Prey capture was strikingly different in M. horridus to that of other species, being characterized by a suite of unusual behaviors including the lack of a body lunge, faster tongue protrusion, reduced prey processing and, most notably, the ability to modulate the slow open phase of the gape cycle. In concert, these traits make a single feeding event in M. horridus faster than that in any other iguanian lizard studied to date. Prey capture behavior in P. platyrhinos is kinematically more similar to U. notata and P. vitticeps than to M. horridus, but the ant specialists are similar in that both lack distinct prey processing behaviors, resulting in faster overall capture and feeding events. While ant feeding in P. vitticeps is faster than feeding on other prey, the duration of a single feeding event is still four times longer than in either ant specialist, because of extensive prey processing. Additionally, a phylogenetic comparison of ant specialist lizards with dietary generalists revealed that ant-eating lizards require significantly less time to capture and process prey. Thus there are not only significant behavioral modifications in these ant-eating lizards, but also multiple strategies among specialists, suggesting differing selective pressures or phylogenetic constraints in the evolution of ant eating in lizards. PMID:15601883

Meyers, Jay J; Herrel, Anthony

2005-01-01

202

Predation on two vole species by a shared predator: antipredatory response and prey preference  

Microsoft Academic Search

In prey communities with shared predators, variation in prey vulnerability is a key factor in shaping community dynamics.\\u000a Conversely, the hunting efficiency of a predator depends on the prey community structure, preferences of the predator and\\u000a antipredatory behavioural traits of the prey. We studied experimentally, under seminatural field conditions, the preferences\\u000a of a predator and the antipredatory responses of prey

Janne Sundell; Lenka Trebatická; Tarja Oksanen; Otso Ovaskainen; Marko Haapakoski; Hannu Ylönen

2008-01-01

203

Effects of Predator–prey Body Size Ratios on the Stability of Food Chains  

Microsoft Academic Search

The effects of predator-prey body size ratios on the resilience and probability of stability in linear Lotka–Volterra food chains have been analysed. The prey per capita interaction strengths of the model is assumed to be negatively correlated to the relative size difference between a predator and its prey. The relationship between prey interaction strength and predator–prey body size ratios is

Tomas Jonsson; Bo Ebenman

1998-01-01

204

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

Microsoft Academic Search

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

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

2007-01-01

205

Prey selection by resident common bottlenose dolphins ( tursiops truncatus ) in Sarasota Bay, Florida  

Microsoft Academic Search

Prey selection was investigated in wild, resident common bottlenose dolphins, Tursiops truncatus, during the summer months in Sarasota Bay, Florida, USA. Stomach content analyses of 15 dolphins with extensive sighting\\u000a histories and well-documented distributions were used to determine prey use. Prey availability was assessed by purse seine\\u000a surveys. We compared the relative abundances of prey available to estimates of prey

Elizabeth J. Berens McCabe; Damon P. Gannon; Nélio B. Barros; Randall S. Wells

2010-01-01

206

Naďve prey exhibit reduced antipredator behavior and survivorship.  

PubMed

Prey naiveté has been hypothesized to be one of the major driving forces behind population declines following the introduction of novel predators or release of inexperienced prey into predator rich environments. In these cases, naďve prey may lack sufficient antipredator behavior and, as a result, suffer increased mortality. Despite this, some evidence suggests that many prey utilize a generalized response to predators. Here, the naiveté hypothesis is tested using a predator-prey pair sharing an evolutionary history: the red swamp crayfish (Procambarus clarkii Girard, 1852) and largemouth bass (Micropterus salmoides Lacépčde, 1802). Using farm-reared, naďve crayfish and wild-caught, experienced individuals, laboratory experiments demonstrated that naďve, farmed crayfish lack behavioral responses to chemical cues from bass, both in terms of movement and use of structural refuge. In contrast, experienced crayfish responded strongly to the same cues. In a subsequent field tethering experiment, these naďve individuals suffered a three-fold increase in predation rate. Based on these results, recognition of predators may not be innate in all prey, and previous experience and learning likely play a key role in the development of antipredator behavior. PMID:25392763

Martin, Charles W

2014-01-01

207

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

PubMed

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

Sherbrooke, Wade C; Schwenk, Kurt

2008-10-01

208

Integrated pest management with stochastic birth rate for prey species  

PubMed Central

Song and Xiang (2006) developed an impulsive differential equations model for a two-prey one-predator model with stage structure for the predator. They demonstrate the conditions on the impulsive period for which a globally asymptotically stable pest-eradication periodic solution exists, as well as conditions on the impulsive period for which the prey species is permanently maintained under an economically acceptable threshold. We extend their model by including stage structure for both predator and prey as well as by adding stochastic elements in the birth rate of the prey. As in Song and Xiang (2006), we find the conditions under which a globally asymptotically stable pest eradication periodic solution exists. In addition, we numerically show the relationship between the stochastically varying birth rate of the prey and the necessary efficacy of the pesticide for which the probability of eradication of the prey species is above 90%. This is significant because the model recognizes varying environmental and climatic conditions which affect the resources needed for pest eradication. PMID:23964194

Akman, Olcay; Comar, Timothy D.; Hrozencik, Daniel

2013-01-01

209

Snake modulates constriction in response to prey's heartbeat  

PubMed Central

Many species of snakes use constriction—the act of applying pressure via loops of their trunk—to subdue and kill their prey. Constriction is costly and snakes must therefore constrict their prey just long enough to ensure death. However, it remains unknown how snakes determine when their prey is dead. Here, we demonstrate that boas (Boa constrictor) have the remarkable ability to detect a heartbeat in their prey and, based on this signal, modify the pressure and duration of constriction accordingly. We monitored pressure generated by snakes as they struck and constricted warm cadaveric rats instrumented with a simulated heart. Snakes responded to the beating heart by constricting longer and with greater total pressure than when constricting rats with no heartbeat. When the heart was stopped midway through the constriction, snakes abandoned constriction shortly after the heartbeat ceased. Furthermore, snakes naive to live prey also responded to the simulated heart, suggesting that this behaviour is at least partly innate. These results are an example of how snakes integrate physiological cues from their prey to modulate a complex and ancient behavioural pattern. PMID:22258447

Boback, Scott M.; Hall, Allison E.; McCann, Katelyn J.; Hayes, Amanda W.; Forrester, Jeffrey S.; Zwemer, Charles F.

2012-01-01

210

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...

211

IgG4-related skin disease.  

PubMed

IgG4-related disease (IgG4-RD) is a recently established clinical entity characterized by high levels of circulating IgG4, and tissue infiltration of IgG4(+) plasma cells. IgG4-RD exhibits a distinctive fibroinflammatory change involving multiple organs, such as the pancreas and salivary and lacrimal glands. The skin lesions of IgG4-RD have been poorly characterized and may stem not only from direct infiltration of plasma cells but also from IgG4-mediated inflammation. Based on the documented cases together with ours, we categorized the skin lesions into seven subtypes: (1) cutaneous plasmacytosis (multiple papulonodules or indurations on the trunk and proximal part of the limbs), (2) pseudolymphoma and angiolymphoid hyperplasia with eosinophilia (plaques and papulonodules mainly on the periauricular, cheek and mandible regions), (3) Mikulicz disease (palpebral swelling, sicca syndrome and exophthalmos), (4) psoriasis-like eruption (strikingly mimicking psoriasis vulgaris), (5) unspecified maculopapular or erythematous eruptions, (6) hypergammaglobulinaemic purpura (bilateral asymmetrical palpable purpuric lesions on the lower extremities) and urticarial vasculitis (prolonged urticarial lesions occasionally with purpura) and (7) ischaemic digit (Raynaud phenomenon and digital gangrene). It is considered that subtypes 1-3 are induced by direct infiltration of IgG4(+) plasma cells, while the other types (4-7) are caused by secondary mechanisms. IgG4-related skin disease is defined as IgG4(+) plasma-cell-infiltrating skin lesions that form plaques, nodules or tumours (types 1-3), but may manifest secondary lesions caused by IgG4(+) plasma cells and/or IgG4 (types 4-7). PMID:25065694

Tokura, Y; Yagi, H; Yanaguchi, H; Majima, Y; Kasuya, A; Ito, T; Maekawa, M; Hashizume, H

2014-11-01

212

Lymphoplasmacytic sclerosing pancreatitis without IgG4 tissue infiltration or serum IgG4 elevation: IgG4-related disease without IgG4.  

PubMed

Type 1 autoimmune pancreatitis can be diagnosed by and is synonymous with its pathognomonic histopathologic appearance called lymphoplasmacytic sclerosing pancreatitis. Type 1 autoimmune pancreatitis, also called IgG4-related pancreatitis, is the pancreatic manifestation of IgG4-related disease. However, the role of IgG4 in the pathogenesis of IgG4-related disease is unclear. We describe patients with LPSP without serum or tissue IgG4 abnormalities. From the Mayo Clinic database of autoimmune pancreatitis patients, we identified three patients with histologically confirmed type 1 autoimmune pancreatitis (lymphoplasmacytic sclerosing pancreatitis) who had normal serum IgG4 and no increase in IgG4-positive plasma cells in tissue. We reviewed original clinical records and pathologic specimens, and describe the clinical and histologic features of these three patients. All patients (age/gender: 63/F, 70/M and 68/M) had normal serum IgG and IgG4 levels, and multiple sections of pancreatic histology did not show increased IgG4-positive plasma cells. Two patients were diagnosed retrospectively following pancreatic surgery, one relapsed in another organ and one has remained relapse free. Another patient was diagnosed by pancreatic core biopsy and has suffered multiple relapses that have been controlled by rituximab. These cases highlight the fact that although the currently agreed upon name for type 1 autoimmune pancreatitis is IgG4-related pancreatitis, serum and tissue IgG4 abnormalities are best considered characteristic, but not essential for the diagnosis of this enigmatic condition.Modern Pathology advance online publication, 1 August 2014; doi:10.1038/modpathol.2014.91. PMID:25081756

Hart, Phil A; Smyrk, Thomas C; Chari, Suresh T

2014-08-01

213

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

PubMed

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

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

2013-01-01

214

Biopsy-proven recurrence of unilateral IgG4-related orbital inflammation after 20 years.  

PubMed

A 38-year-old female patient presented with a painful swelling in the lateral part of the upper eyelid, a diffuse scleritis and slight hypoglobus of the right eye. An orbital biopsy showed a fibrotic idiopathic orbital inflammation (IOI) with, on immunohistochemical staining, an increased number of IgG4-positive plasma cells scored as >200 per high-power field, with IgG4/IgG ratio >0.50, indicating orbital IgG4 related autoimmune disease. On treatment with oral prednisone and azathioprine the symptoms resolved within 6 months. Twenty years prior, the patient had been diagnosed with an IOI of at the same side, for which at that time a biopsy had been taken similarly. Reclassification of the previous biopsy specimen with immunohistological staining also showed evidence of orbital IgG4 related disease. To our knowledge this is the first report of a biopsy-proven unilateral IgG4-related orbitopathy that recurred after 20 years. PMID:24911364

Heidari, Pegah; Verdijk, Robert M; van den Bosch, W A; Paridaens, Dion

2014-10-01

215

Rosai-Dorfman Disease in the Breast with Increased IgG4 Expressing Plasma Cells: A Case Report  

PubMed Central

Rosai-Dorfman disease (RDD) can present in any anatomic site, but breast involvement is rarely reported. Recently, a relationship between RDD and IgG4-related sclerosing disease has been suggested. Here we report another case of RDD with overlapping features of IgG4-related sclerosing disease occurring in a right breast of a 62-year-old female. On microscopic examination, the mass demonstrated a characteristic zonal pattern of proliferation of large polygonal histiocytes and lymphoplasma cells with stromal fibrosis. Emperipolesis was observed in histiocytes with abundant cytoplasm, which showed immunoreactivity for S-100 protein and CD68; the diagnosis of RDD was made. Sheets of plasma cells in the fibrotic stroma demonstrated positive reactions for IgG and IgG4. The mean count of IgG4-positive plasma cells was 100.2/high power field, and the ratio of IgG4/IgG was 56.7%. Additional findings of stromal fibrosis and obliteration of preexisting breast lobules suggested overlapping features with IgG4-related sclerosing disease. PMID:23136577

Cha, Yoon Jin; Yang, Woo Ick; Park, Se Ho

2012-01-01

216

Female siskins choose mates by the size of the yellow wing stripe  

Microsoft Academic Search

Commonly, female birds use the brightly coloured patches on males to choose the best-quality mates. Coloured wing patches, however, have received little attention or have been previously related to social behaviour (as a signal to recruit conspecific individuals at feeding patches) or foraging (to flush prey) contexts, rather than to sexual selection. Here we provide evidence that in siskins (Carduelis

J. C. Senar; J. Domčnech; M. Camerino

2005-01-01

217

Space-use strategies of female polar bears in a dynamic sea ice habitat  

Microsoft Academic Search

In environments with high spatiotemporal variability in resources, animals may exhibit nomadic movements for resource tracking as opposed to long-term area fidelity. Polar bears ( Ursus maritimus) inhabit the dynamic sea ice, preying on seals, and demonstrate considerable intraspecific variation in space use. We studied patterns of fidelity and annual range size for 74 adult female polar bears captured in

Mette Mauritzen; Andrew E. Derocher; Řystein Wiig

2001-01-01

218

Concomitant occurrence of IgG4-related pleuritis and periaortitis: a case report with review of the literature  

PubMed Central

IgG4-related sclerosing disease is an established disease entity with characteristic clinicopathological features. Some recent reports have demonstrated that this disease can occur in the respiratory system including the pleura. Herein, we describe the first documented case of concomitant occurrence of IgG4-related pleuritis and periaortitis. A 71-year-old Japanese female with a history of essential thrombocythemia presented with persistent cough and difficulty in breathing. Computed tomography demonstrated thickening of the right parietal pleura, pericardium, and periaortic tissue and pleural and cardiac effusions. Histopathological study of the surgical biopsy specimen of the parietal pleura revealed marked fibrous thickening with lymphoplasmacytic infiltration. Phlebitis was noted, however, only a few eosinophils had infiltrated. Immunohistochemical study revealed abundant IgG4-positive plasma cell infiltration and high ratio of IgG4-/IgG-positive plasma cells (84%). Therefore, a diagnosis of IgG4-related pleuritis was made with consideration of the elevated serum IgG4 level (684 mg/dL). Recently, the spectrum of IgG4-related sclerosing disease has expanded, and this disease can occur in the pleura, pericardium, and periaortic tissue. Although histopathological analysis of the pericardium and periaortic tissue was not performed in the present case, it was suspected that thickening of the pericardium and periaortic tissue was clinically due to IgG4-related sclerosing disease. Our clinicopathological analyses of IgG4-related pleuritis and pericarditis reveal that this disease can present as dyspnea and pleural and pericardial effusion as seen in the present case, therefore, it is important to recognize that IgG4-related sclerosing disease can occur in these organs for accurate diagnosis and treatment. PMID:24551308

Ishida, Mitsuaki; Hodohara, Keiko; Furuya, Aya; Fujishiro, Aya; Okuno, Hiroko; Yoshii, Miyuki; Horinouchi, Akiko; Shirakawa, Ayaka; Harada, Ayumi; Iwai, Muneo; Yoshida, Keiko; Kagotani, Akiko; Yoshida, Takashi; Okabe, Hidetoshi

2014-01-01

219

Natural History of Perceived Food Hypersensitivity and IgE Sensitisation to Food Allergens in a Cohort of Adults  

PubMed Central

Background No longitudinal studies exist on the natural history of food hypersensitivity and IgE sensitisation to food allergens in adults. Objective To examine the natural history of food hypersensitivity, the natural history of IgE sensitisation to food allergens and to investigate the risk factors for new onset food hypersensitivity. Methods Food hypersensitivity was questionnaire-assessed in 2307 individuals (aged 20–45 years) from Iceland and Sweden during the European Community Respiratory Health Survey both at baseline and follow-up 9 years later. IgE food and aeroallergen sensitisation were assessed in a subgroup of these individuals (n?=?807). Values of 0.35 kU/L and above were regarded as positive sensitisation. Results Food hypersensitivity was reported by 21% of the subjects and this proportion remained unchanged at follow-up (p?=?0.58). Fruits, nuts and vegetables were the three most common causes of food hypersensitivity, with a similar prevalence at baseline and follow-up. The prevalence IgE sensitisation to food allergens decreased in general by 56% (p<0.001) and IgE sensitisation to peanut decreased in particular by 67% (p?=?0.003). The prevalence of timothy grass IgE sensitisation decreased by 15% (p?=?0.003) while cat, mite and birch IgE sensitisation did not decrease significantly. Female sex, rhinitis, eczema and presence of IgE sensitisation to aeroallergens were independently associated with new onset food hypersensitivity. Conclusion The prevalence of food hypersensitivity remained unchanged while the prevalence of IgE sensitisation to food allergens decreased in adults over a 9-year follow-up period. The decrease in prevalence of IgE sensitisation to food allergens was considerably larger than the change in prevalence of IgE sensitisation to aeroallergens. PMID:24427301

Patelis, Antonios; Gunnbjörnsdottir, Maria; Borres, Magnus P.; Burney, Peter; Gislason, Thorarinn; Torén, Kjell; Forsberg, Bertil; Alving, Kjell

2014-01-01

220

IgG4-associated cholangitis.  

PubMed

IgG4-associated cholangitis (IAC) is the hepatobiliary manifestation of immunoglobulin G4-related disease (IgG4-RD), a systemic fibroinflammatory disorder with a wide variety of clinical presentations and organ manifestations. IgG4-RD predominantly affects the hepatobiliary tract (IAC) and pancreas (autoimmune pancreatitis) and mimics hepatobiliary, pancreatic and other malignancies. Patients typically are 60-80 years old and 80-85% are male. They often present with painless obstructive jaundice and organ swelling that can be mistaken for pancreatic or bile duct cancer, as well as primary or secondary sclerosing cholangitis. An accurate diagnostic marker is lacking and extensive surgery for presumed malignant hepatobiliary or pancreatic disease leads to the diagnosis of IgG4-RD in 1 of 3 patients. Early effective immunosuppressive treatment is often missed. The pathogenesis of IgG4-RD has been enigmatic. We recently identified dominant IgG4+ B-cell receptor clones in blood and tissue of patients with IAC, but not in healthy or disease controls, and hypothesized that specific B-cell responses are pivotal to the pathogenesis of IAC and IgG4-RD. Analysis of our Amsterdam cohort and blinded extramural validation of the Oxford cohort of patients with IgG4-RD disclosed a remarkable association with 'blue-collar work'. Thus, long-term exposure to solvents and other organic agents might predispose to IgG4-RD. PMID:25034294

Beuers, Ulrich; Maillette de Buy Wenniger, Lucas J; Doorenspleet, Marieke; Hubers, Lowiek; Verheij, Joanne; van Gulik, Thomas; van de Graaf, Stan F J; de Vries, Niek

2014-01-01

221

Measurement of Human Serum IgE and IgA by Reverse Passive Antiglobulin Haemagglutination  

Microsoft Academic Search

Serum IgE levels can be measured by reverse passive antiglobulin haemagglutination (RPAH) of trypsin-treated human or sheep red cells coupled to sheep IgG anti-human IgE by chromic chloride. The results show a high correlation with those obtained by the radioactive single radial immunodiffusion method. Interfering anti-sheep IgG factors can be easily removed by absorption with small amounts of whole sheep

M. L. Scott; Margaret J. Thornley; R. R. A. Coombs; A. R. Bradwell

1981-01-01

222

Changes in IgG and IgE Antibody Levels to Bee Venom during Immunotherapy  

Microsoft Academic Search

IgE and IgG antibodies to bee venom were measured in sera of patients receiving bee venom immunotherapy. All patients selected for therapy had suffered severe reactions to bee stings. The results showed that within 2–3 months from the commencement of immunotherapy there was a marked rise in IgG antibodies and a slight but not significant rise in IgE antibodies. After

Antonio Ferrante; Frances Mocatta; David H. B. Goh

1986-01-01

223

IgG and IgE Antibodies after Immunotherapy with Bee and Wasp Venom  

Microsoft Academic Search

IgG and IgE antibody levels have been followed for a period of 2 years in patients receiving immunotherapy with bee and wasp venom. 106 adult patients who had had anaphylactic reactions to wasp stings had initially low IgG antibody levels to wasp venom which rose with therapy (p < 0.001). IgE antibody levels also showed an initial rise but subsequently

D. M. Kemeny; M. H. Lessof; S. Patel; L. J. F. Youlten; A. Williams; E. Lambourn

1989-01-01

224

Do Lions Panthera leo Actively Select Prey or Do Prey Preferences Simply Reflect Chance Responses via Evolutionary Adaptations to Optimal Foraging?  

PubMed Central

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

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

2011-01-01

225

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

PubMed

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

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

2011-06-01

226

Prevalence of atopy, eosinophilia, and IgE elevation in IgG4-related disease.  

PubMed

IgG4-related disease (IgG4-RD) is a fibroinflammatory disorder that can affect virtually every organ system. T-helper type 2 responses have been presumed to be pathogenic in this disease, and a high proportion of patients with IgG4-RD are reported to have longstanding allergies, peripheral blood eosinophilia, and serum IgE elevation. It has therefore been proposed that allergic mechanisms drive IgG4-RD. However, no epidemiological assessment of atopy, peripheral blood eosinophilia, and serum IgE concentrations has ever been undertaken in patients with IgG4-RD. In this study, we evaluated these parameters in a large cohort of patients with IgG4-RD in whom a wide range of organs were affected by disease. Our results demonstrate that the majority of patients with IgG4-RD are nonatopic. Nevertheless, a subset of nonatopic subjects exhibit peripheral blood eosinophilia and elevated IgE, suggesting that processes inherent to IgG4-RD itself rather than atopy per se contribute to the eosinophilia and IgE elevation observed in the absence of atopy. PMID:24266692

Della Torre, E; Mattoo, H; Mahajan, V S; Carruthers, M; Pillai, S; Stone, J H

2014-02-01

227

Incidence and clinical significance of bcl-2/IgH rearrangements in follicular lymphoma.  

PubMed

Bcl-2/IgH rearrangement is the molecular hallmark of follicular lymphoma (FL) which is present in 70-90% of the cases at diagnosis. The clinical significance of this feature is controversial. The aim of this study was to analyze the bcl-2/IgH rearrangement by means of a PCR technique, and to correlate molecular findings with clinical characteristics and outcome. Sixty-nine patients (median age, 53 years; male/female ratio: 35/34) diagnosed with FL in a single institution were included in the study. A total of 77 DNA samples were analyzed, 54 were obtained from lymph node biopsy and 23 from peripheral blood or bone marrow. Bcl-2/IgH rearrangement was assessed for both the major breakpoint region (MBR) and the minor cluster region (mcr) breakpoints by a PCR technique. Thirty-nine out of sixty patients (65%) with assessable samples were found to have a bcl-2/IgH rearrangement in the MBR breakpoint, whereas bcl-2/IgH rearrangement in mcr was observed in one patient (2%) and no rearrangement at MBR or mcr in the remaining 20 patients (33%). Regarding the initial characteristics, patients with bcl-2/IgH rearrangements at MBR or mcr were younger (<65 years) than those with no rearrangement at these sites (p = 0.0001). No differences were found according to bcl-2/IgH rearrangement in terms of complete response rate, time to treatment failure and overall survival. In our series bcl-2/IgH rearrangement at MBR or mcr, which was found in 67% of the patients, was not correlated with response to treatment, survival nor time-to-treatment-failure. PMID:12691144

Montoto, Silvia; López-Guillermo, Armando; Colomer, Dolors; Esteve, Jordi; Bosch, Francesc; Ferrer, Ana; Villamor, Neus; Moreno, Carolina; Campo, Elías; Montserrat, Emili

2003-01-01

228

Abnormalities of the IgA immune system in members of unrelated pedigrees from patients with IgA nephropathy.  

PubMed Central

In the last few years many investigators have reported the recurrence of primary IgA nephropathy (IgAN) or the presence of persistent microhaematuria and/or proteinuria in family members of patients with IgAN. Our study was undertaken to investigate the relevance of abnormalities in the regulation of the IgA and IgM immune system in microhaematuric and asymptomatic family members of IgAN patients. Fifty-four out of 120 members of nine unrelated pedigrees were examined by urinalysis; polymeric IgA (pIgA), IgA rheumatoid factor (IgARF), IgA1-IgG immune complexes (IgA 1-IgG IC) and IgA 1-IgM IC, and other immunoglobulins were measured in serum samples. Moreover, we studied the production of immunoglobulins, pIgA and IgARF by peripheral blood mononuclear cells (PBMC) in basal conditions and after pokeweed mitogen (PWM) stimulation. Our data demonstrate that persistent microhaematuria was present in 24% of relatives. High serum levels of IgA, mainly pIgA and IgARF, IgA 1-IgG IC and IgA 1-IgM IC occurred in 66% of relatives. Abnormal spontaneous production of IgA by PBMC and after PWM stimulation was present in 64% of family members. Interestingly, high serum levels of IgM and abnormal production of this immunoglobulin by PBMC were observed in relatives. However, the immunological abnormalities did not correlate in any way with the presence of urinary abnormalities such as microhaematuria, which was most likely determined by an underlying glomerular alteration. PMID:8467558

Schena, F P; Scivittaro, V; Ranieri, E; Sinico, R; Benuzzi, S; Di Cillo, M; Aventaggiato, L

1993-01-01

229

Visually guided gradation of prey capture movements in larval zebrafish.  

PubMed

A mechanistic understanding of goal-directed behavior in vertebrates is hindered by the relative inaccessibility and size of their nervous systems. Here, we have studied the kinematics of prey capture behavior in a highly accessible vertebrate model organism, the transparent larval zebrafish (Danio rerio), to assess whether they use visual cues to systematically adjust their movements. We found that zebrafish larvae scale the speed and magnitude of turning movements according to the azimuth of one of their standard prey, paramecia. They also bias the direction of subsequent swimming movements based on prey azimuth and select forward or backward movements based on the prey's direction of travel. Once within striking distance, larvae generate either ram or suction capture behaviors depending on their distance from the prey. From our experimental estimations of ocular receptive fields, we ascertained that the ultimate decision to consume prey is likely a function of the progressive vergence of the eyes that places the target in a proximal binocular 'capture zone'. By repeating these experiments in the dark, we demonstrate that paramecia are only consumed if they contact the anterior extremities of larvae, which triggers ocular vergence and tail movements similar to close proximity captures in lit conditions. These observations confirm the importance of vision in the graded movements we observe leading up to capture of more distant prey in the light, and implicate somatosensation in captures in the absence of light. We discuss the implications of these findings for future work on the neural control of visually guided behavior in zebrafish. PMID:23619412

Patterson, Bradley W; Abraham, Aliza O; MacIver, Malcolm A; McLean, David L

2013-08-15

230

Influence of cues from the anterior medial eyes of virtual prey on Portia fimbriata, an araneophagic jumping spider  

Microsoft Academic Search

Portia fimbriata from Queensland, Australia, is a jumping spider (Salticidae) that preys on other spiders, including other salticids. Cryptic stalking (palps retracted, walking very slowly and freezing when faced) is a prey- specific tactic deployed exclusively against salticid prey. Using vision alone, P. fimbriata discriminates salticid from non-salticid prey, with the prey salticid's large anterior median (AM) eyes providing critical

Duane P. Harland; Robert R. Jackson

231

Normal Female Reproductive Anatomy  

MedlinePLUS

... Search Quick Search Image Details Reproductive System, Female, Anatomy View/Download: Small: 720x756 View Download Add to My Pictures Title: Reproductive System, Female, Anatomy Description: Anatomy of the female reproductive system; drawing ...

232

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

NASA Astrophysics Data System (ADS)

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.

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

2012-06-01

233

Comparative Growth and Development of Spiders Reared on Live and Dead Prey  

PubMed Central

Scavenging (feeding on dead prey) has been demonstrated across a number of spider families, yet the implications of feeding on dead prey for the growth and development of individuals and population is unknown. In this study we compare the growth, development, and predatory activity of two species of spiders that were fed on live and dead prey. Pardosa astrigera (Lycosidae) and Hylyphantes graminicola (Lyniphiidae) were fed live or dead fruit flies, Drosophila melanogaster. The survival of P. astrigera and H. graminicola was not affected by prey type. The duration of late instars of P. astrigera fed dead prey were longer and mature spiders had less protein content than those fed live prey, whereas there were no differences in the rate of H. graminicola development, but the mass of mature spiders fed dead prey was greater than those fed live prey. Predation rates by P. astrigera did not differ between the two prey types, but H. graminicola had a higher rate of predation on dead than alive prey, presumably because the dead flies were easier to catch and handle. Overall, the growth, development and reproduction of H. graminicola reared with dead flies was better than those reared on live flies, yet for the larger P. astrigera, dead prey may suit smaller instars but mature spiders may be best maintained with live prey. We have clearly demonstrated that dead prey may be suitable for rearing spiders, although the success of the spiders fed such prey appears size- and species specific. PMID:24386248

Peng, Yu; Zhang, Fan; Gui, Shaolan; Qiao, Huping; Hose, Grant C.

2013-01-01

234

IgA Antibodies in Rett Syndrome  

ERIC Educational Resources Information Center

The level of IgA antibodies to gluten and gliadin proteins found in grains and to casein found in milk, as well as the level of IgG to gluten and gliadin, have been examined in 23 girls with Rett syndrome and 53 controls. Highly statistically significant increases were found for the Rett population compared to the controls. The reason for this…

Reichelt, K. L.; Skjeldal, O.

2006-01-01

235

IgG4-related diseases.  

PubMed

Immunoglobulin G4 (IgG4)-related disease (IgG4-RD) is a fascinating condition recognised as a systemic disease in 2003 [1,2]. The first link between autoimmunity affecting the pancreas, elevated serum IgG4 concentrations and large numbers of IgG4-positive plasma cells in pancreatic tissue was described only 2 years earlier [3]. Since then, many diseases that have long been viewed organ-specific are now considered within the spectrum of IgG4-RD. Practically any organ can be affected, having in common a key pathological feature consisting in dense lymphocyte and plasma cell infiltrate rich in IgG4-positive plasma cells, storiform fibrosis and often an elevated serum IgG4 concentration. While good clinical response to steroid therapy is observed, immunosuppressive or B-cell depleting therapy can be required. It is important to distinguish the IgG4-RD from traditional organ-specific autoimmune disease to guide therapy. PMID:23040358

Guma, Monica; Firestein, Gary S

2012-08-01

236

A monomeric chicken IgY receptor binds IgY with 2:1 stoichiometry.  

PubMed

IgY is the principal serum antibody in birds and reptiles, and an IgY-like molecule was the evolutionary precursor of both mammalian IgG and IgE. A receptor for IgY on chicken monocytes, chicken leukocyte receptor AB1 (CHIR-AB1), lies in the avian leukocyte receptor cluster rather than the classical Fc receptor cluster where the genes for mammalian IgE and IgG receptors are found. IgG and IgE receptors bind to the lower hinge region of their respective antibodies with 1:1 stoichiometry, whereas the myeloid receptor for IgA, FcalphaRI, and the IgG homeostasis receptor, FcRn, which are found in the mammalian leukocyte receptor cluster, bind with 2:1 stoichiometry between the heavy chain constant domains 2 and 3 of each heavy chain. In this paper, the extracellular domain of CHIR-AB1 was expressed in a soluble form and shown to be a monomer that binds to IgY-Fc with 2:1 stoichiometry. The two binding sites have similar affinities: K(a)(1) = 7.22 +/- 0.22 x 10(5) m(-1) and K(a)(2) = 3.63 +/- 1.03 x 10(6) m(-1) (comparable with the values reported for IgA binding to its receptor). The affinity constants for IgY and IgY-Fc binding to immobilized CHIR-AB1 are 9.07 +/- 0.07 x 10(7) and 6.11 +/- 0.02 x 10(8) m(-1), respectively, in agreement with values obtained for IgY binding to chicken monocyte cells and comparable with reported values for human IgA binding to neutrophils. Although the binding site for CHIR-AB1 on IgY is not known, the data reported here with a monomeric receptor binding to IgY at two sites with low affinity suggest an IgA-like interaction. PMID:19592496

Taylor, Alexander I; Beavil, Rebecca L; Sutton, Brian J; Calvert, Rosaleen A

2009-09-01

237

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

PubMed

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

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

2012-03-01

238

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

PubMed Central

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

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

2012-01-01

239

Prey Capture Behavior in an Arboreal African Ponerine Ant  

PubMed Central

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

Dejean, Alain

2011-01-01

240

A dedicated visual pathway for prey detection in larval zebrafish  

PubMed Central

Zebrafish larvae show characteristic prey capture behavior in response to small moving objects. The neural mechanism used to recognize objects as prey remains largely unknown. We devised a machine learning behavior classification system to quantify hunting kinematics in semi-restrained animals exposed to a range of virtual stimuli. Two-photon calcium imaging revealed a small visual area, AF7, that was activated specifically by the optimal prey stimulus. This pretectal region is innervated by two types of retinal ganglion cells, which also send collaterals to the optic tectum. Laser ablation of AF7 markedly reduced prey capture behavior. We identified neurons with arbors in AF7 and found that they projected to multiple sensory and premotor areas: the optic tectum, the nucleus of the medial longitudinal fasciculus (nMLF) and the hindbrain. These findings indicate that computations in the retina give rise to a visual stream which transforms sensory information into a directed prey capture response. DOI: http://dx.doi.org/10.7554/eLife.04878.001 PMID:25490154

Semmelhack, Julia L; Donovan, Joseph C; Thiele, Tod R; Kuehn, Enrico; Laurell, Eva; Baier, Herwig

2014-01-01

241

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

PubMed

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

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

2014-12-01

242

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

PubMed Central

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.

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

2014-01-01

243

Density of wild prey modulates lynx kill rates on free-ranging domestic sheep.  

PubMed

Understanding the factors shaping the dynamics of carnivore-livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB) models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed. PMID:24278123

Odden, John; Nilsen, Erlend B; Linnell, John D C

2013-01-01

244

Density of Wild Prey Modulates Lynx Kill Rates on Free-Ranging Domestic Sheep  

PubMed Central

Understanding the factors shaping the dynamics of carnivore–livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB) models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed. PMID:24278123

Odden, John; Nilsen, Erlend B.; Linnell, John D. C.

2013-01-01

245

Chemical defense of an Asian snake reflects local availability of toxic prey and hatchling diet  

PubMed Central

Species that sequester toxins from prey for their own defense against predators may exhibit population-level variation in their chemical arsenal that reflects the availability of chemically defended prey in their habitat. Rhabdophis tigrinus is an Asian snake that possesses defensive glands in the skin of its neck (‘nuchal glands’), which typically contain toxic bufadienolide steroids that the snakes sequester from consumed toads. In this study, we compared the chemistry of the nuchal gland fluid of R. tigrinus from toad-rich and toad-free islands in Japan and determined the effect of diet on the nuchal gland constituents. Our findings demonstrate that captive-hatched juveniles from toad-rich Ishima Island that had not been fed toads possess defensive bufadienolides in their nuchal glands, presumably due to maternal provisioning of these sequestered compounds. Wild-caught juveniles from Ishima possess large quantities of bufadienolides, which could result from a combination of maternal provisioning and sequestration of these defensive compounds from consumed toads. Interestingly, juvenile females from Ishima possess larger quantities of bufadienolides than do juvenile males, whereas a small sample of field-collected snakes suggests that adult males contain larger quantities of bufadienolides than do adult females. Captive-born hatchlings from Kinkasan Island lack bufadienolides in their nuchal glands, reflecting the absence of toads on that island, but they can sequester bufadienolides by feeding on toads (Bufo japonicus) in captivity. The presence of large quantities of bufadienolides in the nuchal glands of R. tigrinus from Ishima may reduce the risk of predation by providing an effective chemical defense, whereas snakes on Kinkasan may experience increased predation due to the lack of defensive compounds in their nuchal glands. PMID:23853424

Hutchinson, D A; Savitzky, A H; Burghardt, G M; Nguyen, C; Meinwald, J; Schroeder, F C; Mori, A

2013-01-01

246

Sexual Cannibalism: High Incidence in a Natural Population with Benefits to Females  

PubMed Central

Background Sexual cannibalism may be a form of extreme sexual conflict in which females benefit more from feeding on males than mating with them, and males avoid aggressive, cannibalistic females in order to increase net fitness. A thorough understanding of the adaptive significance of sexual cannibalism is hindered by our ignorance of its prevalence in nature. Furthermore, there are serious doubts about the food value of males, probably because most studies that attempt to document benefits of sexual cannibalism to the female have been conducted in the laboratory with non-natural alternative prey. Thus, to understand more fully the ecology and evolution of sexual cannibalism, field experiments are needed to document the prevalence of sexual cannibalism and its benefits to females. Methodology/Principal Findings We conducted field experiments with the Mediterranean tarantula (Lycosa tarantula), a burrowing wolf spider, to address these issues. At natural rates of encounter with males, approximately a third of L. tarantula females cannibalized the male. The rate of sexual cannibalism increased with male availability, and females were more likely to kill and consume an approaching male if they had previously mated with another male. We show that females benefit from feeding on a male by breeding earlier, producing 30% more offspring per egg sac, and producing progeny of higher body condition. Offspring of sexually cannibalistic females dispersed earlier and were larger later in the season than spiderlings of non-cannibalistic females. Conclusions/Significance In nature a substantial fraction of female L. tarantula kill and consume approaching males instead of mating with them. This behaviour is more likely to occur if the female has mated previously. Cannibalistic females have higher rates of reproduction, and produce higher-quality offspring, than non-cannibalistic females. Our findings further suggest that female L. tarantula are nutrient-limited in nature and that males are high-quality prey. The results of these field experiments support the hypothesis that sexual cannibalism is adaptive to females. PMID:18941517

Rabaneda-Bueno, Rubén; Rodríguez-Gironés, Miguel Á.; Aguado-de-la-Paz, Sara; Fernández-Montraveta, Carmen; De Mas, Eva; Wise, David H.; Moya-Larańo, Jordi

2008-01-01

247

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

PubMed Central

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

Salama, Abdulgabar; Kardashi, Romina; Arbach, Olga

2014-01-01

248

Therapeutic potential of anti-IgE antibodies  

Microsoft Academic Search

Anti-IgE antibodies directed against the Fc?RI-binding region on IgE inhibit binding of IgE to IgE receptors without inducing mediator release from IgE sensitized cells. In mice these antibodies selectively reduce serum IgE, inhibit antigen induced skin reactions, cytokine production by lung Th2 cells, and pulmonary eosinophil infiltration. Clinical trials in humans reveal that such antibodies are well tolerated and reduce

Christoph Heusser; Paula Jardieu

1997-01-01

249

Reproductive age-related changes in the blood brain barrier: Expression of IgG and tight junction proteins  

PubMed Central

We previously demonstrated that there is significantly greater transfer of intravenously-injected Evan’s blue dye into the forebrain of acyclic (reproductive senescent) females compared to young adult females, indicating that blood brain barrier permeability is compromised in the reproductive senescent forebrain. The present study examined brain IgG expression and microvessel tight junction proteins to assess ovarian age-related changes in microvascular permeability, and further compared young and senescent females with age-matched males to distinguish changes attributable to age and reproductive senescence. Blood brain barrier breakdown are often associated with increased extravasation of plasma proteins and high levels of immunoglobulin G (IgG) in brain. In the present study, IgG expression was dramatically increased in the hippocampus and thalamus, but not the hypothalamus of reproductive senescent females compared to young adult females. In males, IgG expression was increased in all these regions in middle aged animals (aged-matched to senescent females) as compared to young males (age-matched to the young adult females). Furthermore, the proportion of hippocampal microvessels with perivascular IgG immunoreactivity was significantly greater in reproductive senescent females as compared to young adult females, while middle aged males and young adult males did not differ. The tight junctions between adjacent microvascular endothelial cells regulated by transmembrane proteins such as claudin-5 and occludin play a critical role in maintaining the blood brain barrier integrity. Increased hippocampal IgG expression in senescent females was paralleled by poor junctional localization of the tight junction protein claudin-5 in hippocampal microvessels. However, there was no difference in hippocampal claudin-5 localization between young adult and middle aged males, indicating that dysregulation of this junctional protein was associated with ovarian aging. Parallel studies in human brain microvessels also revealed age-dependent disruption in claudin-5 distribution in post-menopausal women compared to premenopausal women. Collectively, these data support the hypothesis that constitutive loss of barrier integrity in the forebrain during reproductive senescence may be due, in part, to the selective loss of tight junction proteins in endothelial junctions. PMID:19591848

Bake, Shameena; Friedman, Jonathan A; Sohrabji, Farida

2009-01-01

250

Resilient silk captures prey in black widow cobwebs  

NASA Astrophysics Data System (ADS)

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.

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

2006-02-01

251

How sailfish use their bills to capture schooling prey.  

PubMed

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

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

2014-06-01

252

Serological Profile of HSV-2 in STD Patients: Evaluation of Diagnostic Utility of HSV-2 IgM and IgG Detection  

PubMed Central

Background and Objectives:The present study was undertaken to determine Herpes Simplex Virus-2 seroprevalence in sexually active adults aged 20-49 and to investigate the correlation with sociodemographic characteristics and to find its association with other sexually transmitted diseases especially HIV and also to assess the proportion of primary and reactivated HSV-2 cases. Materials and Methods:This prospective study was carried out for a period of six months in a tertiary care hospital. Serum samples were taken from 91 patients attending the out Patient clinic of the Department of Venereology. The serological testing for HSV-2 was performed on all the specimens by using Euroimmun anti-HSV2 (gG2) IgM ELISA and IgG ELISA. Results: Out of the 91 STD patients in the study group, 18 males (34.62%) and 14 females (36.84%) tested positive for HSV-2 antibodies. Seropositivity rate is 35.16%. More number of HSV-2 positive cases were seen among males, older age, rural residence, low socioeconomic status, single marital status, irregular condom usage during the sexual intercourses with new partners and with higher number of sexual partners during lifetime. HSV-2 IgM alone was positive in three cases, HSV-2 IgG alone was positive in 26 cases and three had a positive HSV-2 IgM and IgG result. Addition of IgM testing increased rate of detecting seroconversion, 31.87%, when only IgG ELISA was used, to 35.16 % patients when IgM test was added. In the study group four cases tested positive for VDRL, and one of them was a known positive case. Among the 55 HIV positive cases in the study group, HSV 2 was positive in 17 cases and among the 36 HIV negative cases HSV 2 was positive in 15 cases. (30.91% and 47.22%).Though the number of HIV cases were high, HSV 2 positivity among them was statistically not significant. Conclusion:The purpose of screening for HSV-2 is not only to identify seropositivity, but to help seropositive people identify symptoms and protect themselves from acquiring HIV and to protect their partners and seronegative people from acquiring HSV-2 and/or HIV. PMID:25653947

Rashetha; Sucilathangam, G.; Cinthujah, B.; Revathy, C.

2014-01-01

253

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

USGS Publications Warehouse

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.

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

2008-01-01

254

Stomach fullness modulates prey size choice in the frillfin goby, Bathygobius soporator.  

PubMed

Behaviours related to foraging and feeding in predator-prey systems are fundamental to our understanding of food webs. From the perspective of a predator, the selection of prey size depends upon a number of factors including prey vulnerability, prey size, and the predator's motivation to eat. Thus, feeding motivation and prey visual cues are supposed to influence predator decisions and it is predicted that prey selection by visual cues is modulated by the predator's stomach fullness prior to attacking a prey. This study was conducted using an animal model from the rocky shores ecosystem, a predatory fish, the frillfin goby Bathygobius soporator, and a benthic prey, the mottled shore crab Pachygrapsus transversus. Our results demonstrate that frillfin gobies are capable of visually evaluating prey size and that the size evaluation process is modulated by the level of stomach fullness. Predators with an empty stomach (0% fullness) attacked prey that was larger than the predicted optimal size. Partially satiated predators (50% stomach fullness) selected prey close to the optimal size, while fully satiated predators (100% stomach fullness) showed no preference for size. This finding indicates an integrative response of the predator that depends on the input of both internal and external sensory information when choosing prey. Predator perceptions of visual cues (prey size) and stomach fullness modulate foraging decisions. As a result, a flexible feeding behaviour emerges, evidencing a clearly adaptive response in line with optimal foraging theory predictions. PMID:22951273

Tomida, Leonardo; Lee, James T; Barreto, Rodrigo E

2012-10-01

255

Ocean Acidification Affects Prey Detection by a Predatory Reef Fish  

PubMed Central

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

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

2011-01-01

256

Predator-prey quasicycles from a path-integral formalism.  

PubMed

The existence of beyond mean-field quasicycle oscillations in a simple spatial model of predator-prey interactions is derived from a path-integral formalism. The results agree substantially with those obtained from analysis of similar models using system size expansions of the master equation. In all of these analyses, the discrete nature of predator-prey populations and finite-size effects lead to persistent oscillations in time, but spatial patterns fail to form. The path-integral formalism goes beyond mean-field theory and provides a focus on individual realizations of the stochastic time evolution of population not captured in the standard master-equation approach. PMID:19392001

Butler, Thomas; Reynolds, David

2009-03-01

257

FCRLA is a resident endoplasmic reticulum protein that associates with intracellular Igs, IgM, IgG and IgA  

PubMed Central

Fc receptor-like A (FCRLA) is an unusual member of the extended Fc receptor family. FCRLA has homology to receptors for the Fc portion of Ig (FCR) and to other FCRL proteins. However, unlike these other family representatives, which are typically transmembrane receptors with extracellular ligand-binding domains, FCRLA has no predicted transmembrane domain or N-linked glycosylation sites and is an intracellular protein. We show by confocal microscopy and biochemical assays that FCRLA is a soluble resident endoplasmic reticulum (ER) protein, but it does not possess the amino acid sequence KDEL as an ER retention motif in its C-terminus. Using a series of deletion mutants, we found that its ER retention is most likely mediated by the amino terminal partial Ig-like domain. We have identified ER-localized Ig as the FCRLA ligand. FCRLA is unique among the large family of Fc receptors, in that it is capable of associating with multiple Ig isotypes, IgM, IgG and IgA. Among hemopoietic cells, FCRLA expression is restricted to the B lineage and is most abundant in germinal center B lymphocytes. The studies reported here demonstrate that FCRLA is more broadly expressed among human B lineage cells than originally reported; it is found at significant levels in resting blood B cells and at varying levels in all B-cell subsets in tonsil. PMID:21149418

Santiago, Teresa; Kulemzin, Sergei V.; Reshetnikova, Evdokia S.; Chikaev, Nikolai A.; Volkova, Olga Y.; Mechetina, Ludmila V.; Zhao, Meina; Davis, Randall S.; Taranin, Alexander V.; Najakshin, Alexander M.; Hendershot, Linda M.

2011-01-01

258

Immunoglobulin M serum levels in females and pups of southern elephant seal (Mirounga leonina) during the suckling period.  

PubMed

This paper reports Immunoglobulin M (IgM) levels in serum samples from eight female-pup pairs of southern elephant seals (Mirounga leonina), at King George Island, Antarctica. IgM levels were determined on sera obtained from sequential sampling throughout the suckling period (approximately 23 days). The IgM concentration in southern elephant seal serum was measured by single radial immunodiffusion on agarose plates. Female IgM levels (123.5-613.0 mg/dL, n = 8) were significantly higher than pup levels (5.9-123.6 mg/dL, n = 8). Both groups showed an increasing trend throughout the entire suckling period, with significant differences in relation to stages of lactation. Pup IgM levels on the first day of life (mean +/- SD, 7.6 +/- 2.9 mg/dL, n = 3) suggest that endogenous synthesis takes place before birth. PMID:9683413

Marquez, M E; Carlini, A R; Slobodianik, N H; Ronayne de Ferrer, P A; Godoy, M F

1998-03-01

259

Evaluation of Anti-Toxoplasma IgG, IgM, and IgA in Mothers with Spontaneous Abortion in Zanjan, Northwest Iran  

PubMed Central

Toxoplasma gondii is one of the major agents of infectious abortions and due to its worldwide distribution can threat healthy pregnant women who had no previous exposure to this parasite. The present study was designed to investigate the contribution of T. gondii to spontaneous abortions in Zanjan, Northwest of Iran, using ELISA method. Blood Samples were collected from 264 mothers referred to the provincial hospitals of Zanjan due to spontaneous abortion. The sera were isolated and subjected to evaluate the anti-Toxoplasma IgG, IgM and IgA antibodies. The results showed IgG positive (IgG+) in 99 cases (37.5%). A total of 68 women (25.8%) showed seroconversion with IgM or IgA or both IgM and IgA. They included: IgM+ in 21 (8.0%), IgA+ in 23 (8.7%) and both IgM+ and IgA+ in 24 (9.1%) subjects. In 23 cases, positive titers of IgM and IgG were accompanied. In general, the analysis of anti-Toxoplasma antibody patterns, showed that about 17% of the spontaneous abortions were associated with serological patterns of acute infection. According to these findings, a considerable proportion of spontaneous abortions can be attributed to T. gondii in the study area. PMID:23230339

Amin, Abbas; Mazloomzadeh, S.; Haniloo, A.; Mohammadian, F.

2012-01-01

260

Antigen endocytosis and presentation mediated by human membrane IgG1 in the absence of the Ig(alpha)/Ig(beta) dimer.  

PubMed Central

Membrane immunoglobulin (mIg) M and D heavy chains possess minimal (KVK) cytoplasmic tails and associate with the Ig alpha/Ig beta (CD79) dimer to achieve surface expression and antigen presentation function. In contrast, the cytoplasmic tail of mIgG is extended by 25 residues (gamma ct). We have tested the possibility that mIgG can perform antigen capture and presentation functions independently of the Ig(alpha)/beta dimer. We show that CD4/(gamma)ct chimeras are efficiently endocytosed partially dependent on a tyrosine residue in (gamma)ct. In addition, human mIgG was expressed on the surface of Ig(alpha)/Ig(beta)-negative non-lymphoid cells and mediated antigen capture and endocytosis. Antigen-specific human mIgG targeted antigen to MIIC-type vesicles in the Ig(alpha)/beta negative melanoma Mel JuSo and augmented antigen presentation 1000-fold, identical to the augmentation seen in Ig(alpha)/beta-positive B-cells expressing the same transfected mIgG. Thus, unlike mIgM, mIgG has autonomous antigen capture and presentation capacity, which may have evolved to reduce or eliminate the BCR's dependence on additional accessory molecules. PMID:9233794

Knight, A M; Lucocq, J M; Prescott, A R; Ponnambalam, S; Watts, C

1997-01-01

261

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

262

Effect of an exotic prey on the feeding pattern of a predatory snail  

E-print Network

to prey upon the invasive mussel over all indigenous species offered (e.g. barnacles and mussels on smaller prey, mostly barnacles. We suggest that this differential foraging activity in the two zones

Benayahu, Yehuda

263

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

264

Anti-alpha-galactosyl immunoglobulin A (IgA), IgG, and IgM in human secretions.  

PubMed Central

Anti-alpha-galactosyl (anti-Gal) is a natural human serum antibody that binds to the carbohydrate Gal alpha 1,3Gal beta 1,4GlcNAc-R (alpha-galactosyl epitope) and is synthesized by 1% of circulating B lymphocytes in response to immune stimulation by enteric bacteria. We were able to purify secretory anti-Gal from human colostrum and bile by affinity chromatography on silica-linked Gal alpha 1,3Gal beta 1,4GlcNAc. We found similar secretory anti-Gal antibodies in human milk, saliva, and vaginal washings. Secretory anti-Gal from milk and saliva was exclusively immunoglobulin A (IgA); that from colostrum and bile also contained IgG and IgM isotypes. Serum was also found to contain anti-Gal IgM and IgA in addition to the previously reported IgG. Anti-Gal IgA purified from colostrum and bile had both IgA1 and IgA2. Secretory anti-Gal from saliva, milk, colostrum, and bile agglutinated rabbit erythrocytes (RRBC) and bound to bovine thyroglobulin, both of which have abundant alpha-galactosyl epitopes. The RRBC-hemagglutinating capacity of human saliva, milk, bile, and serum was specifically adsorbed by immobilized Gal alpha 1,3Gal beta 1,4GlcNAc but not by Gal alpha 1,4Gal beta 1,4GlcNAc, Gal beta 1,3GalNAc, Gal beta 1,4GlcNAc, Gal beta 1,4GlcNAc alpha 1,2Man, or Fuc alpha 1,2Gal beta 1,4GlcNAc. No RRBC-hemagglutinating activity could be detected in rat milk, rat bile, cow milk, or rabbit bile, suggesting a restricted species distribution for secretory anti-Gal similar to that found for serum anti-Gal. Colostral anti-GaI IgA bound strongly to a sample of gram-negative bacteria isolated from the throats and stools of well children as well as to an Escherichia coli K-1 blood isolate. Colostral anti-GaI IgA inhibited the binding of a Neisseria meningitidis strain to human buccal epithelial cells, suggesting that this antibody may play a protective role at the mucosal surface. PMID:7697518

Hamadeh, R M; Galili, U; Zhou, P; Griffiss, J M

1995-01-01

265

Testing the effects of resource distribution and inherent habitat riskiness on simultaneous habitat selection by predators and prey  

E-print Network

dace Phoxinus eos predation risk predator­prey interaction Semotilus atromaculatus structural habitat laboratory experiments in which both predators (creek chub, Semotilus atromaculatus) and prey (northern

Sorenson, Michael

266

Generation and Characterization of Antibodies against Asian Elephant (Elephas maximus) IgG, IgM, and IgA.  

PubMed

Asian elephant (Elephas maximus) immunity is poorly characterized and understood. This gap in knowledge is particularly concerning as Asian elephants are an endangered species threatened by a newly discovered herpesvirus known as elephant endotheliotropic herpesvirus (EEHV), which is the leading cause of death for captive Asian elephants born after 1980 in North America. While reliable diagnostic assays have been developed to detect EEHV DNA, serological assays to evaluate elephant anti-EEHV antibody responses are lacking and will be needed for surveillance and epidemiological studies and also for evaluating potential treatments or vaccines against lethal EEHV infection. Previous studies have shown that Asian elephants produce IgG in serum, but they failed to detect IgM and IgA, further hampering development of informative serological assays for this species. To begin to address this issue, we determined the constant region genomic sequence of Asian elephant IgM and obtained some limited protein sequence information for putative serum IgA. The information was used to generate or identify specific commercial antisera reactive against IgM and IgA isotypes. In addition, we generated a monoclonal antibody against Asian elephant IgG. These three reagents were used to demonstrate that all three immunoglobulin isotypes are found in Asian elephant serum and milk and to detect antibody responses following tetanus toxoid booster vaccination or antibodies against a putative EEHV structural protein. The results indicate that these new reagents will be useful for developing sensitive and specific assays to detect and characterize elephant antibody responses for any pathogen or vaccine, including EEHV. PMID:25658336

Humphreys, Alan F; Tan, Jie; Peng, RongSheng; Benton, Susan M; Qin, Xiang; Worley, Kim C; Mikulski, Rose L; Chow, Dar-Chone; Palzkill, Timothy G; Ling, Paul D

2015-01-01

267

Generation and Characterization of Antibodies against Asian Elephant (Elephas maximus) IgG, IgM, and IgA  

PubMed Central

Asian elephant (Elephas maximus) immunity is poorly characterized and understood. This gap in knowledge is particularly concerning as Asian elephants are an endangered species threatened by a newly discovered herpesvirus known as elephant endotheliotropic herpesvirus (EEHV), which is the leading cause of death for captive Asian elephants born after 1980 in North America. While reliable diagnostic assays have been developed to detect EEHV DNA, serological assays to evaluate elephant anti-EEHV antibody responses are lacking and will be needed for surveillance and epidemiological studies and also for evaluating potential treatments or vaccines against lethal EEHV infection. Previous studies have shown that Asian elephants produce IgG in serum, but they failed to detect IgM and IgA, further hampering development of informative serological assays for this species. To begin to address this issue, we determined the constant region genomic sequence of Asian elephant IgM and obtained some limited protein sequence information for putative serum IgA. The information was used to generate or identify specific commercial antisera reactive against IgM and IgA isotypes. In addition, we generated a monoclonal antibody against Asian elephant IgG. These three reagents were used to demonstrate that all three immunoglobulin isotypes are found in Asian elephant serum and milk and to detect antibody responses following tetanus toxoid booster vaccination or antibodies against a putative EEHV structural protein. The results indicate that these new reagents will be useful for developing sensitive and specific assays to detect and characterize elephant antibody responses for any pathogen or vaccine, including EEHV. PMID:25658336

Humphreys, Alan F.; Tan, Jie; Peng, RongSheng; Benton, Susan M.; Qin, Xiang; Worley, Kim C.; Mikulski, Rose L.; Chow, Dar-Chone; Palzkill, Timothy G.; Ling, Paul D.

2015-01-01

268

The purification and characterisation of cervine IgM and IgG.  

PubMed

A procedure is described for the isolation of immunoglobulin G (IgG) and immunoglobulin M (IgM) from hyperimmune cervine serum. Hybrids of red deer (Cervus elaphus) and wapiti (Cervus canadensis) were immunised with keyhole limpet hemocyanin (KLH). An immunoglobulin-containing fraction was precipitated from the hyperimmune serum using ammonium sulphate. The antigen-specific immunoglobulins were purified by KLH-conjugated sepharose affinity chromatography and further separated into IgM and IgG by gel-filtration chromatography. Purified immunoglobulin was analysed by polyacrylamide gel electrophoresis and isoelectric focusing. The molecular weights and isoelectric points of the composite chains of cervine IgG and IgM are presented. PMID:2075697

Hibma, M H; Griffin, J F

1990-12-01

269

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

PubMed

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

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

2011-02-01

270

Damage, digestion, and defence: the roles of alarm cues and kairomones for inducing prey defences  

Microsoft Academic Search

Inducible defences are widely used for studying phenotypic plasticity, yet frequently we know little about the cues that induce these defences. For aquatic prey, defences are induced by chemical cues from predators (kairomones) and injured prey (alarm cues). Rarely has anyone determined the separate and combined effects of these cues, particularly across phylogenetically diverse prey types. We examined how tadpoles

Nancy M. Schoeppner; A. Relyea

2005-01-01

271

Predatory Bdellovibrio Bacteria Use Gliding Motility To Scout for Prey on Surfaces ? §  

PubMed Central

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

Lambert, Carey; Fenton, Andrew K.; Hobley, Laura; Sockett, R. Elizabeth

2011-01-01

272

Along Came a Spider: Using Live Arthropods in a Predator–Prey Activity  

Microsoft Academic Search

We developed a predator–prey activity with eighth-grade students in which they used wolf spiders (Lycosa carolinensis), house crickets (Acheta domestica), and abiotic factors to address how (1) adaptations in predators and prey shape their interaction and (2) abiotic factors modify the interaction between predators and prey. We tested student understanding with pre- and postquizzes, written observations, and interpretations of graphical

Matthew L. Richardson; Janice Hari

2011-01-01

273

The Return of the Wolf Effects on Prey, Competitors and Scavengers  

E-print Network

The Return of the Wolf Effects on Prey, Competitors and Scavengers Camilla Wikenros Faculty on Prey, Competitors and Scavengers Abstract Apex predators may have both direct and indirect effects) on prey species, competitors (including humans) and the scavenging guild after the re- colonization

274

Period Doubling Cascades in a Predator-Prey Model with a Scavenger  

E-print Network

Period Doubling Cascades in a Predator-Prey Model with a Scavenger Joseph P. Previte Kathleen A-prey model are well understood. We introduce a scavenger species, who scavenges the predator and is also goal is to introduce a third scavenger species to the classical predator-prey equations

Previte, Joseph P.

275

Claw morphology, prey size selection and foraging efficiency in generalist and specialist shell-breaking crabs  

Microsoft Academic Search

Claw morphology, and claw-closing forces of four species of intertidal crabs from San Juan Island, Washington were compared and related these findings were related to prey size selection, shell breaking times and total handling times on their snail prey, Littorina sitkana Philippi. Two functional groups of crabs emerged: generalists and specialists on hard-shelled prey. The generalist, Hemigrapsus nudus (Dana), has

Sylvia Behrens Yamada; Elizabeth G. Boulding

1998-01-01

276

Nonselective Harvesting of a Prey-Predator Fishery with Gompertz Law of Growth  

ERIC Educational Resources Information Center

This paper develops a mathematical model for the nonselective harvesting of a prey-predator system in which both the prey and the predator obey the Gompertz law of growth and some prey avoid predation by hiding. The steady states of the system are determined, and the dynamical behaviour of both species is examined. The possibility of existence of…

Purohit, D.; Chaudhuri, K. S.

2002-01-01

277

Examining the potential for nutritional stress in young Steller sea lions: physiological effects of prey composition  

Microsoft Academic Search

The effects of high- and low-lipid prey on the body mass, body condition, and metabolic rates of young captive Steller sea lions (Eumetopias jubatus) were examined to better understand how changes in prey composition might impact the physiology and health of wild sea lions and contribute to their population decline. Results of three feeding experiments suggest that prey lipid content

David A. S. Rosen; Andrew W Trites

2005-01-01

278

Functional feeding responses of coyotes, Canis latrans, to fluctuating prey abundance in the  

E-print Network

Functional feeding responses of coyotes, Canis latrans, to fluctuating prey abundance in the Curlew interactions between coyotes (Canis latrans Say, 1823) and prey in the Curlew Valley, Utah, by comparing prey coyotes (Canis latrans Say, 1823) et leurs proies dans la vallée Curlew, Utah, en comparant l

Bartel, Becky

279

Prey skeletal remnants from stom-ach samples and more recently from  

E-print Network

ways to deal with the effect of diges- tion on estimates of prey size. One is to measure only-Berset, 1996). In the past, sag- ittal otoliths were commonly used to estimate prey size (Frost and Lowry, 1981 fisheries (Beverton, 1985). Accurate estimates of size of prey consumed by pinnipeds are also important

280

Diet and Prey Selection by Lake Superior Lake Trout during Spring, 1986–2001  

Microsoft Academic Search

We describe the diet and prey selectivity of lean (Salvelinus namaycush namaycush) and siscowet lake trout (S. n. siscowet) collected during spring (April–June) from Lake Superior during 1986–2001. We estimated prey selectivity by comparing prey numerical abundance estimates from spring bottom trawl surveys and lake trout diet information in similar areas from spring gill net surveys conducted annually in Lake

Bradley A. Ray; Thomas R. Hrabik; Mark P. Ebener; Owen T. Gorman; Donald R. Schreiner; Stephen T. Schram; Shawn P. Sitar; William P. Mattes; Charles R. Bronte

2007-01-01

281

Aposematic coloration enhances chemosensory recognition of noxious prey in the garter snake Thamnophis radix  

Microsoft Academic Search

Considerable recent research has suggested that predators learn to avoid noxious or unpalatable prey more rapidly if those prey have conspicuous (aposematic) colour patterns. However, the precise psychological mechanisms by which predators associate conspicuous coloration with unpalatability remain poorly understood. In this study, the relative importance of visual and chemosensory information in learned aversions to noxious prey was examined by

TIMOTHY D. TERRICK; RONALD L. MUMME; GORDON M. BURGHARDT

1995-01-01

282

77 FR 42327 - Proposed Supplementary Rules for the Morley Nelson Snake River Birds of Prey National...  

Federal Register 2010, 2011, 2012, 2013

...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...

2012-07-18

283

IgE Immunotherapy Against Cancer.  

PubMed

The success of antibody therapy in cancer is consistent with the ability of these molecules to activate immune responses against tumors. Experience in clinical applications, antibody design, and advancement in technology have enabled antibodies to be engineered with enhanced efficacy against cancer cells. This allows re-evaluation of current antibody approaches dominated by antibodies of the IgG class with a new light. Antibodies of the IgE class play a central role in allergic reactions and have many properties that may be advantageous for cancer therapy. IgE-based active and passive immunotherapeutic approaches have been shown to be effective in both in vitro and in vivo models of cancer, suggesting the potential use of these approaches in humans. Further studies on the anticancer efficacy and safety profile of these IgE-based approaches are warranted in preparation for translation toward clinical application. PMID:25553797

Leoh, Lai Sum; Daniels-Wells, Tracy R; Penichet, Manuel L

2015-01-01

284

Predators Are Attracted to the Olfactory Signals of Prey  

PubMed Central

Background Predator attraction to prey social signals can force prey to trade-off the social imperatives to communicate against the profound effect of predation on their future fitness. These tradeoffs underlie theories on the design and evolution of conspecific signalling systems and have received much attention in visual and acoustic signalling modes. Yet while most territorial mammals communicate using olfactory signals and olfactory hunting is widespread in predators, evidence for the attraction of predators to prey olfactory signals under field conditions is lacking. Methodology/Principal Findings To redress this fundamental issue, we examined the attraction of free-roaming predators to discrete patches of scents collected from groups of two and six adult, male house mice, Mus domesticus, which primarily communicate through olfaction. Olfactorily-hunting predators were rapidly attracted to mouse scent signals, visiting mouse scented locations sooner, and in greater number, than control locations. There were no effects of signal concentration on predator attraction to their prey's signals. Conclusions/Significance This implies that communication will be costly if conspecific receivers and eavesdropping predators are simultaneously attracted to a signal. Significantly, our results also suggest that receivers may be at greater risk of predation when communicating than signallers, as receivers must visit risky patches of scent to perform their half of the communication equation, while signallers need not. PMID:20927352

Hughes, Nelika K.; Price, Catherine J.; Banks, Peter B.

2010-01-01

285

PRAIRIE FALCON PREY IN THE MOJAVE DESERT, CALIFORNIA  

Microsoft Academic Search

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

DOUGLAS A. BOYCE

286

Hydrodynamic effects on a predator approaching a group of preys  

NASA Astrophysics Data System (ADS)

A numerical approach to predict the hydrodynamics involving a predator approaching a group of 100 preys is presented. A collective behavioural model is adopted to predict the two-dimensional space-time evolution of the predator-preys system that is supposed to be immersed in a fluid. The preys manifest mutual repulsion, attraction and orientation, while the predator is idealized as an individual to be strongly repulsed. During the motion, the predator experiences a resistance induced by the encompassing fluid. Such effect is accounted for by computing the hydrodynamic force and by modifying the predator’s velocity given by the behavioural equations. A numerical campaign is carried out by varying the predator’s drag coefficient. Moreover, analyses characterized by progressively wider predator’s perception areas are performed, thus highlighting the role of the hydrodynamics over the behavioural interactions. In order to estimate the predator’s performance, an ad-hoc parameter is proposed. Moreover, findings in terms of trajectories and angular momentum of the group of preys are discussed. Present findings show that the sole collective behavioural equations are insufficient to predict the performance of a predator that is immersed in a fluid, since its motion is drastically affected by the resistance of the surrounding fluid.

De Rosis, Alessandro

2014-11-01

287

Diet of intraguild predators affects antipredator behavior in intraguild prey  

E-print Network

on other diets, including a diet of conspecifics. When intraguild prey were foraging on a patch, detection they encounter intraguild predators in the field and not to different degrees of danger. Key words: food webs, 2003; Okuyama, 2002; Wissinger and McGrady, 1993; Yurewicz, 2004), or move to safe sites or refuges

MagalhĂŁes, Sara

288

Predator-Prey Role Reversal in a Marine Benthic Ecosystem  

Microsoft Academic Search

Two closely located islands on the west coast of South Africa support widely different benthic communities. The biota at Malgas Island is dominated by seaweeds and by rock lobsters that consume settling mussels, thereby preventing the establishment of the mussels. They also prey on whelks, although one species, Burnupena papyracea, is protected from predation by a commensal bryozoan that covers

Amos Barkai; Christopher McQuaid

1988-01-01

289

Testing for Camouflage Using Virtual Prey and Human "Predators"  

ERIC Educational Resources Information Center

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…

Todd, Peter A.

2009-01-01

290

Predator-Prey Population Dynamics By Victor Piotrowicz  

E-print Network

into PPPD has practical implications in management of endangered species. Topically, it is important-Evolutionary System with Predator-Prey Interactions to Solving Multi-Objective Optimization Problems [http://ieeexplore.ieee.org/Xplore/login.jsp?reload=true&url=http%3A%2F%2Fieeexplore.ieee.org%2 Fiel5%2F4222970%2F

Goldschmidt, Christina

291

Prey Detection by Vomeronasal Chemoreception in a Plethodontid Salamander  

Microsoft Academic Search

While chemoreception is involved in a wide variety of salamander behaviors, the chemosensory system that mediates specific behaviors is rarely known. We investigated the role of the vomeronasal system (VNS) in foraging behavior of the red-backed salamander (Plethodon cinereus) by manipulating salamanders' abilities to detect nonvolatile chemical cues emitted by potential prey. Subjects received one of three treatments: (1) impaired

John S. Placyk; Brent M. Graves

2002-01-01

292

More than the kill: hunters' relationships with landscape and prey  

Microsoft Academic Search

Through a discussion of the perceptions of hunters within a New Zealand tourism context, this article explores how different perspectives of the ‘connection’ between hunter and prey are performed by participants and analysed by scholars using distinct ethical approaches. It attempts to contribute to the conversation about hunting ethics within the tourism and recreation fields by discussing the limitations of

Arianne Carvalhedo Reis

2009-01-01

293

Prey Capture and Phagocytosis in the Choanoflagellate Salpingoeca rosetta  

PubMed Central

Choanoflagellates are unicellular and colonial aquatic microeukaryotes that capture bacteria using an apical flagellum surrounded by a feeding collar composed of actin-filled microvilli. Flow produced by the apical flagellum drives prey bacteria to the feeding collar for phagocytosis. We report here on the cell biology of prey capture in rosette-shaped colonies and unicellular “thecate” or substrate attached cells from the choanoflagellate S. rosetta. In thecate cells and rosette colonies, phagocytosis initially involves fusion of multiple microvilli, followed by remodeling of the collar membrane to engulf the prey, and transport of engulfed bacteria into the cell. Although both thecate cells and rosette colony cells produce ?70 nm “collar links” that connect and potentially stabilize adjacent microvilli, only thecate cells were observed to produce a lamellipod-like “collar skirt” that encircles the base of the collar. This study offers insight into the process of prey ingestion by S. rosetta, and provides a context within which to consider potential ecological differences between solitary cells and colonies in choanoflagellates. PMID:24806026

Dayel, Mark J.; King, Nicole

2014-01-01

294

Prolonged prey suppression by carnivores — predator-removal experiments  

Microsoft Academic Search

The hypothesis that carnivores can significantly suppress prey populations after they collapse during drought was tested by predator-removal experiments. Low populations of rabbits (Oryctolagus cuniculus) responded with significantly accelerated growth where foxes (Vulpes vulpes) and feral cats (Felis catus) were continually shot. Experiments in years of good pasture and poor were confirmatory. After only 14 months, the rabbits were well

A. E. Newsome; I. Parer; P. C. Catling

1989-01-01

295

CHLORINATED HYDROCARBON POLLUTANTS IN ALASKAN GYRFALCONS AND THEIR PREY  

Microsoft Academic Search

ABSTACT.---Analyses of biopsy fat samples and addled eggs of Gyrfalcons (Falco rusticolus) and selected prey items collected during 1970 and 1971 from the Seward Peninsula, Alaska show that all samples contained both industrial and agricultural contaminants. A pathway of aerial transport to this remote arctic ecosystem is indicated. Geometric mean levels of DDE, the principal insec- ticide derivative in both

WAYMAN WALKER

296

Brown pelican siblicide and the prey-size hypothesis  

Microsoft Academic Search

We asked whether the brown pelican (Pelecanus occidentalis) practices facultative brood reduction and tested two predictions of Mock's (1985) prey-size hypothesis: (1) if chicks take food directly from the parental mouth, nestmates should compete aggressively; (2) aggression between nestmates should increase during the developmental transition from indirect feeding (parents deposit food on the substrate) to direct feeding (parents pass food

D. Pinson; H. Drummond

1993-01-01

297

Antarctic jaws: cephalopod prey of sharks in Kerguelen waters  

Microsoft Academic Search

Only five species of sharks have been recorded in the Southern Ocean, where their biology is essentially unknown. We investigated the feeding habits of the three commonest species from stomach content analysis of specimens taken as bycatches of the fishery targeting the Patagonian toothfish (Dissostichus eleginoides) in upper slope waters of the Kerguelen Archipelago. The three species prey upon a

Yves Cherel; Guy Duhamel

2004-01-01

298

Signal conict in spider webs driven by predators and prey  

E-print Network

Signal conÂŻict 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

Blackledge, Todd

299

Functional Morphology of Prey Capture in the Sturgeon, Scaphirhynchus albus  

E-print Network

Functional Morphology of Prey Capture in the Sturgeon, Scaphirhynchus albus Andrew M. Carroll Scaphirhynchus albus, the pallid sturgeon. Feeding pallid sturgeon were filmed in lateral and ventral views. albus resemble those of other aquatic vertebrates: maximum hyoid depression follows maxi- mum gape

Wainwright, Peter C.

300

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

PubMed Central

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

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

1995-01-01

301

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

PubMed Central

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

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

302

IgE, IgG4 and IgA specific to Bet v 1-related food allergens do not predict oral allergy syndrome  

PubMed Central

Background Birch pollen-associated plant food allergy is caused by Bet v 1-specific IgE, but presence of cross-reactive IgE to related allergens does not predict food allergy. The role of other immunoglobulin isotypes in the birch pollen-plant food syndrome has not been investigated in detail. Methods Bet v 1-sensitized birch pollen-allergic patients (n = 35) were diagnosed for food allergy by standardized interviews, skin prick tests, prick-to-prick tests and ImmunoCAP. Concentrations of allergen-specific IgE, IgG1, IgG4 and IgA to seven Bet v 1-related food allergens were determined by ELISA. Results Bet v 1, Cor a 1, Mal d 1 and Pru p 1 bound IgE from all and IgG4 and IgA from the majority of sera. Immunoglobulins to Gly m 4, Vig r 1 and Api g 1.01 were detected in <65% of the sera. No significant correlation was observed between plant food allergy and increased or reduced levels of IgE, IgG1, IgG4 or IgA specific to most Bet v 1-related allergens. Api g 1-specific IgE was significantly (P = 0.01) elevated in celeriac-allergic compared with celeriac-tolerant patients. Likewise, frequencies of IgE (71% vs 15%; P = 0.01) and IgA (86% vs 38%; P = 0.04) binding to Api g 1.01 were increased. Conclusion Measurements of allergen-specific immunoglobulins are not suitable for diagnosing Bet v 1-mediated plant food allergy to hazelnut and Rosaceae fruits. In contrast, IgE and IgA to the distantly related allergen Api g 1 correlate with allergy to celeriac. PMID:25327982

Guhsl, E E; Hofstetter, G; Lengger, N; Hemmer, W; Ebner, C; Fröschl, R; Bublin, M; Lupinek, C; Breiteneder, H; Radauer, C

2015-01-01

303

Human IgG/Fc?R Interactions Are Modulated by Streptococcal IgG Glycan Hydrolysis  

PubMed Central

Background The human pathogen Streptococcus pyogenes produces an endoglycosidase, EndoS that hydrolyzes the chitobiose core of the asparagine-linked glycan on the heavy chain of human IgG. IgG-binding to Fc gamma receptors (Fc?R) on leukocytes triggers effector functions including phagocytosis, oxidative burst and the release of inflammatory mediators. The interactions between Fc?R and the Fc domain of IgG depend on the IgG glycosylation state. Methodology/Principal Findings Here we show for the first time that EndoS hydrolyzes the heavy chain glycan of all four human IgG subclasses (IgG1-4), in purified form and in a plasma environment. An inactive form of EndoS, obtained by site-directed mutagenesis, binds IgG with high affinity, in contrast to wild type EndoS that only transiently interacts with IgG, as shown by Slot-blotting and surface plasmon resonance technology. Furthermore, EndoS hydrolysis of the IgG glycan influences the binding of IgG to immobilized soluble Fc?R and to an erythroleukemic cell line, K562, expressing Fc?RIIa. Incubation of whole blood with EndoS results in a dramatic decrease of IgG binding to activated monocytes as analyzed by flow cytometry. Moreover, the IgG bound to K562 cells dissociates when cells are treated with EndoS. Likewise, IgG bound to immobilized Fc?RIIa and subsequently treated with EndoS, dissociates from the receptor as analyzed by surface plasmon resonance and Western blot. Conclusions/Significance We provide novel information about bacterial enzymatic modulation of the IgG/Fc?R interaction that emphasizes the importance of glycosylation for antibody effector functions. Moreover, EndoS could be used as a biochemical tool for specific IgG N-glycan hydrolysis and IgG purification/detection, or as a potential immunosuppressing agent for treatment of antibody-mediated pathological processes. PMID:18183294

Allhorn, Maria; Olin, Anders I.; Nimmerjahn, Falk; Collin, Mattias

2008-01-01

304

Production of Hybrid-IgG/IgA Plantibodies with Neutralizing Activity against Shiga Toxin 1  

PubMed Central

Shiga toxin 1 (Stx1) is a virulence factor of enterohemorrhagic Escherichia coli, such as the O157:H7 strain. In the intestines, secretory IgA (SIgA) is a major component of the immune defense against pathogens and toxins. To form SIgA, the production of dimeric IgA that retains biological activity is an important step. We previously established hybrid-IgG/IgA having variable regions of the IgG specific for the binding subunit of Stx1 (Stx1B) and the heavy chain constant region of IgA. If hybrid-IgG/IgA cDNAs can be expressed in plants, therapeutic or preventive effects may be expected in people eating those plants containing a “plantibody”. Here, we established transgenic Arabidopsis thaliana expressing dimeric hybrid-IgG/IgA. The heavy and light chain genes were placed under the control of a bidirectional promoter and terminator of the chlorophyll a/b-binding protein of Arabidopsis thaliana (expression cassette). This expression cassette and the J chain gene were subcloned into a single binary vector, which was then introduced into A. thaliana by means of the Agrobacterium method. Expression and assembly of the dimeric hybrid-IgG/IgA in plants were revealed by ELISA and immunoblotting. The hybrid-IgG/IgA bound to Stx1B and inhibited Stx1B binding to Gb3, as demonstrated by ELISA. When Stx1 holotoxin was pre-treated with the resulting plantibody, the cytotoxicity of Stx1 was inhibited. The toxin neutralization was also demonstrated by means of several assays including Stx1-induced phosphatidylserine translocation on the plasma membrane, caspase-3 activation and 180 base-pair DNA ladder formation due to inter-nucleosomal cleavage. These results indicate that edible plants containing hybrid-IgG/IgA against Stx1B have the potential to be used for immunotherapy against Stx1-caused food poisoning. PMID:24312238

Nakanishi, Katsuhiro; Narimatsu, Sanshiro; Ichikawa, Shiori; Tobisawa, Yuki; Kurohane, Kohta; Niwa, Yasuo; Kobayashi, Hirokazu; Imai, Yasuyuki

2013-01-01

305

Pathologies Associated with Serum IgG4 Elevation  

PubMed Central

Statement of Purpose. IgG4-related disease (IgG4-RD) is usually associated to an increase of serum IgG4 levels. However other conditions have also been associated to high serum IgG4 levels. Methods. All IgG subclasses analyses performed in our hospital over a one-year period were analyzed. When IgG4 level were over 1.35?g/L, the patient's clinical observation was analyzed and both final diagnosis and reason leading to IgG subclasses analysis were recorded. Only polyclonal increases of IgG4 were considered. Summary of the Results. On 646 IgG subclass analysis performed, 59 patients had serum IgG4 over 1.35?g/L. The final diagnosis associated to serum IgG4 increase was very variable. Most patients (25%) presented with repeated infections, 13.5% with autoimmune diseases, and 10% with IgG4-RD. Other patients presented with cancer, primary immune deficiencies, idiopathic interstitial lung disease, cystic fibrosis, histiocytosis, or systemic vasculitis and 13.5% presented with various pathologies or no diagnosis. Mean IgG4 levels and IgG4/IgG ratio were higher in IgG4-RD than in other pathologies associated to elevated IgG4 levels. Conclusions. Our study confirms that elevation of serum IgG4 is not specific to IgG4-RD. Before retaining IgG4-RD diagnosis in cases of serum IgG4 above 1.35?g/L, several other pathological conditions should be excluded. PMID:22966232

Ebbo, Mikael; Grados, Aurélie; Bernit, Emmanuelle; Vély, Frederic; Boucraut, José; Harlé, Jean-Robert; Daniel, Laurent; Schleinitz, Nicolas

2012-01-01

306

IgE antibodies in toxoplasmosis.  

PubMed

Toxoplasmosis is a worldwide infection caused by the intracellular parasite Toxoplasma gondii. At least a third of the world human population is infected with the parasite, making it one of the most successful parasitic infections. Primary maternal infection may cause health-threatening sequelae for the fetus, or even cause death of the uterus. Reactivation of a latent infection in immune deficiency conditions such as AIDS and organ transplantation can cause fatal toxoplasmic encephalitis. Toxoplasmosis is a major cause of chorioretinitis, especially in individuals with impaired immune systems. In the acute phase, directly after invading the body, T. gondii begins to multiply rapidly. In the majority of cases acquired toxoplasmosis is asymptomatic. In the second week of infection, specific IgM antibodies are present in the blood. IgE antibodies appear at the same time, slightly preceding specific IgA antibodies. The concentration of IgE can be one of the parameters used for diagnosing an infection with T. gondii. Laboratory diagnosis, i.e. IgE and serologic assays, plays the main role in the diagnosis of congenital infection and assists in the confirmatory diagnosis of toxoplasmic encephalitis and ocular toxoplasmosis. This article is a review of IgE in toxoplasmosis. PMID:24864110

Matowicka-Karna, Joanna; Kemona, Halina

2014-01-01

307

Predator size and phenology shape prey survival in temporary ponds.  

PubMed

Theoretical efforts suggest that the relative sizes of predators and their prey can shape community dynamics, the structure of food webs, and the evolution of life histories. However, much of this work has assumed static predator and prey body sizes. The timing of recruitment and the growth patterns of both predator and prey have the potential to modify the strength of predator-prey interactions. In this study, I examined how predator size dynamics in 40 temporary ponds over a 3-year period affected the survival of spotted salamander (Ambystoma maculatum) larvae. Across communities, gape-limited predator richness, but not size, was correlated with habitat duration (pond permanence). Within communities, mean gape-limited predator size diminished as the growing season progressed. This size reduction occurred because prey individuals grew into a body size refuge and because the largest of the predators left ponds by mid-season. Elevated gape-limited predation risk across time and space was predicted by the occurrence of two large predatory salamanders: marbled salamander larvae (Ambystoma opacum) and red-spotted newt adults (Notophthalmus viridescens). The presence of the largest gape-limited predator, A. opacum, predicted A. maculatum larval survival in the field. The distribution of large predatory salamanders among ponds and across time is expected to lead to differing community dynamics and to generate divergent natural selection on early growth and body size in A. maculatum. In general, a dynamic perspective on predator size often will be necessary to understand the ecology and evolution of species interactions. This will be especially true in frequently disturbed or seasonal habitats where phenology and ontogeny interact to determine body size asymmetries. PMID:17891545

Urban, Mark C

2007-12-01

308

Preference and Prey Switching in a Generalist Predator Attacking Local and Invasive Alien Pests  

PubMed Central

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

Jaworski, Coline C.; Bompard, Anaďs; Genies, Laure; Amiens-Desneux, Edwige; Desneux, Nicolas

2013-01-01

309

Preference and prey switching in a generalist predator attacking local and invasive alien pests.  

PubMed

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

Jaworski, Coline C; Bompard, Anaďs; Genies, Laure; Amiens-Desneux, Edwige; Desneux, Nicolas

2013-01-01

310

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

PubMed Central

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

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

2005-01-01

311

Foraging success of juvenile pike Esox lucius depends on visual conditions and prey pigmentation.  

PubMed

Young-of-the-year pike Esox lucius foraging on copepods experienced different foraging success depending on prey pigmentation in water visually degraded by brown colouration or algae. Both attack rate and prey consumption rate were higher for E. lucius foraging on transparent prey in brown water, whereas the opposite was true in algal turbid water. Pigments in copepod prey may have a cryptic function in brown water instead of a photo-protective function even if prey-size selectivity was stronger than selection based on pigmentation in juvenile E. lucius. PMID:21722125

Jönsson, M; Hylander, S; Ranĺker, L; Nilsson, P A; Brönmark, C

2011-07-01

312

High intestinal IgA associates with reduced risk of IgE-associated allergic diseases.  

PubMed

Development of oral tolerance and its stimulation by probiotics are still incomprehensible. Microbial stimulation of the gut may induce a subtle inflammation and induce secretion of mucosal IgA, which participates in antigen elimination. In a cohort of allergy-prone infants receiving probiotics and prebiotics or placebo we studied intestinal IgA and inflammation in the development of eczema, food allergy, asthma, and rhinitis (allergic diseases). We performed a nested unmatched case-control study of 237 infants participating in a randomized double-blind placebo-controlled allergy-prevention trial using a combination of four probiotic strains pre-natally and during 6 months form birth. We measured faecal IgA, alpha1-antitrypsin (alpha1-AT), tumour necrosis factor-alpha (TNF-alpha), and calprotectin at the age of 3 and 6 months. By age 2 yr, 124 infants had developed allergic disease or IgE-sensitization (cases) and 113 had not (controls). In infants with high faecal IgA concentration at the age of 6 months, the risk of having any allergic disease before the age of 2 yr tended to reduce [odds ratio (OR: 0.52)] and the risk for any IgE-associated (atopic) disease reduced significantly (OR: 0.49). High faecal calprotectin at the age of 6 months associated also with lower risk for IgE-associated diseases up to age 2 yr (OR: 0.49). All faecal inflammation markers (alpha1-AT, TNF-alpha, and calprotectin) correlated positively with faecal IgA (p < 0.001). Probiotics tended to augment faecal IgA (p = 0.085) and significantly increased faecal alpha1-AT (p = 0.001). High intestinal IgA in early life associates with minimal intestinal inflammation and indicates reduced risk for IgE-associated allergic diseases. PMID:19566584

Kukkonen, Kaarina; Kuitunen, Mikael; Haahtela, Tari; Korpela, Riitta; Poussa, Tuija; Savilahti, Erkki

2010-02-01

313

High prevalence of NMDA receptor IgA/IgM antibodies in different dementia types  

PubMed Central

Objective To retrospectively determine the frequency of N-Methyl-D-Aspartate (NMDA) receptor (NMDAR) autoantibodies in patients with different forms of dementia. Methods Clinical characterization of 660 patients with dementia, neurodegenerative disease without dementia, other neurological disorders and age-matched healthy controls combined with retrospective analysis of serum or cerebrospinal fluid (CSF) for the presence of NMDAR antibodies. Antibody binding to receptor mutants and the effect of immunotherapy were determined in a subgroup of patients. Results Serum NMDAR antibodies of IgM, IgA, or IgG subtypes were detected in 16.1% of 286 dementia patients (9.5% IgM, 4.9% IgA, and 1.7% IgG) and in 2.8% of 217 cognitively healthy controls (1.9% IgM and 0.9% IgA). Antibodies were rarely found in CSF. The highest prevalence of serum antibodies was detected in patients with “unclassified dementia” followed by progressive supranuclear palsy, corticobasal syndrome, Parkinson’s disease-related dementia, and primary progressive aphasia. Among the unclassified dementia group, 60% of 20 patients had NMDAR antibodies, accompanied by higher frequency of CSF abnormalities, and subacute or fluctuating disease progression. Immunotherapy in selected prospective cases resulted in clinical stabilization, loss of antibodies, and improvement of functional imaging parameters. Epitope mapping showed varied determinants in patients with NMDAR IgA-associated cognitive decline. Interpretation Serum IgA/IgM NMDAR antibodies occur in a significant number of patients with dementia. Whether these antibodies result from or contribute to the neurodegenerative disorder remains unknown, but our findings reveal a subgroup of patients with high antibody levels who can potentially benefit from immunotherapy. PMID:25493273

Doss, Sarah; Wandinger, Klaus-Peter; Hyman, Bradley T; Panzer, Jessica A; Synofzik, Matthis; Dickerson, Bradford; Mollenhauer, Brit; Scherzer, Clemens R; Ivinson, Adrian J; Finke, Carsten; Schöls, Ludger; Müller vom Hagen, Jennifer; Trenkwalder, Claudia; Jahn, Holger; Höltje, Markus; Biswal, Bharat B; Harms, Lutz; Ruprecht, Klemens; Buchert, Ralph; Höglinger, Günther U; Oertel, Wolfgang H; Unger, Marcus M; Körtvélyessy, Peter; Bittner, Daniel; Priller, Josef; Spruth, Eike J; Paul, Friedemann; Meisel, Andreas; Lynch, David R; Dirnagl, Ulrich; Endres, Matthias; Teegen, Bianca; Probst, Christian; Komorowski, Lars; Stöcker, Winfried; Dalmau, Josep; Prüss, Harald

2014-01-01

314

An IgG subclass imbalance in connective tissue disease  

Microsoft Academic Search

A group of 16 patients with a disproportionate polyclonal increase in their serum IgG1, resulting in raised concentrations of total IgG immunoglobulin, has been discovered. The other IgG subclasses in these patients are either normal or slightly reduced, resulting in an IgG1:IgG2 ratio of at least 10:1. Most cases are marked by the presence of anti-extractable nuclear antigen (anti-ENA) antibodies

R A Kay; K J Wood; R M Bernstein; P J Holt; R S Pumphrey

1988-01-01

315

Serum IgG subclasses in autoimmune diseases.  

PubMed

To characterize serum IgG subclass levels in several autoimmune diseases, including primary Sjogren syndrome (pSS), systemic sclerosis (SSc), systemic lupus erythematosus (SLE), and primary biliary cirrhosis (PBC). We aimed to analyze serum IgG subclass distribution and to test whether serum IgG4 levels are elevated in these diseases.Serum IgG subclass levels from 102 pSS, 102 SSc, 100 SLE, and 59 PBC patients, as well as 40 healthy controls (HCs), were measured using the immunonephelometric assay. The distribution of IgG subclasses among these autoimmune diseases was analyzed.In this cross-sectional study, serum IgG1 (IgG1/IgG) and/or IgG3 (IgG3/IgG) were significantly increased, compared with those in HCs. Only 6.34% of patients had levels of serum IgG4 >135?mg/dL. There were no significant differences in the frequency of elevated serum IgG4 levels between patients and HC. In pSS, serum IgG1 levels were much higher than those in other disease groups, whereas serum IgG2 and IgG3 levels were most prominently increased in PBC.A strikingly different serum IgG subclass distribution was detected in patients with autoimmune diseases compared with HCs. Serum IgG subclass levels also showed distinct characteristics among different autoimmune diseases. Serum IgG4 levels in these patients were lower or not much higher than those in HCs, which differed from IgG4-related diseases. PMID:25590841

Zhang, Haoze; Li, Ping; Wu, Di; Xu, Dong; Hou, Yong; Wang, Qian; Li, Mengtao; Li, Yongzhe; Zeng, Xiaofeng; Zhang, Fengchun; Shi, Qun

2015-01-01

316

Potential Impact of Different Cytomegalovirus (CMV) IgM Assays on an Algorithm Requiring IgM Reactivity as a Criterion for Measuring CMV IgG Avidity  

PubMed Central

The measurement of cytomegalovirus (CMV) IgG avidity is a powerful tool for identifying individuals with recent CMV infection. Because such patients are expected to be positive for CMV IgM, several investigators have suggested that CMV IgG-positive sera first be screened for CMV IgM and then only the IgM-reactive sera be tested for avidity. We investigated the impact of different CMV IgM assays on such a reflexing algorithm using a panel of 369 consecutive IgG-positive serum samples submitted for avidity testing. A bead-based immunofluorescent assay (BIFA) identified 105 IgM-positive serum samples, whereas an IgM-capture enzyme immunoassay (EIA) identified 48 IgM-positive serum samples; this marked difference led us to evaluate additional CMV IgM assays. An enzyme-linked immunofluorescent assay (ELFA) and a chemiluminescent immunoassay (CIA) were used to test all sera with discordant BIFA/EIA results, all sera with concordant positive results, and selected sera with concordant negative results. The findings indicated that the ELFA would identify 74 CMV IgM-positive samples and the CIA would identify 64. Of the 23 low-avidity serum samples, 2 were IgM negative by BIFA, 3 by ELFA and CIA, and 4 by EIA; of the 23 intermediate-avidity serum samples, 6 were IgM negative by BIFA, 10 by ELFA, and 15 by EIA and CIA. In both these avidity groups, BIFA IgM-negative sera were also negative by the other 3 assays. These findings demonstrate that an algorithm requiring CMV IgM reactivity as a criterion for CMV IgG avidity testing does not identify all low-avidity sera and thus misses some cases of acute CMV infection. PMID:24671558

Lapé-Nixon, Mary; Brenner, Andrew; Pitstick, Nancy; Couturier, Marc Roger

2014-01-01

317

Biotin-avidin amplified enzyme-linked immunosorbent assay (ELISA) for the measurement of canine serum IgA, IgG and IgM.  

PubMed

An amplified capture enzyme-linked immunosorbent assay (ELISA) has been developed by the use of the biotin-avidin detection system, for the measurement of canine plasma immunoglobulins (Ig) A, G and M. Test responses of dilutions of both the Ig standards and test plasma samples were consistently linear (r > 0.987) for the three Ig classes. The within-assay variation was 3.53 per cent for IgG, 5.84 per cent for IgM and 6.34 per cent for IgA. The analytical recoveries were 95 per cent for IgA, 97 per cent for IgG and 98 per cent for IgM. The lower detection limits of the assay were 38.4 ng ml-1 for IgG, 20.3 ng ml-1 for IgM and 41.2 ng ml-1 for IgA. The results indicate that this ELISA has a much higher sensitivity than the single radial immunodiffusion assay or the non-amplified ELISA for measurements of canine Igs, but has a comparable specificity and precision. PMID:8685529

Ginel, P J; Margarito, J M; Molleda, J M; López, R; Novales, M; Bernadina, W E

1996-03-01

318

CHAPTER THREE Female Behavioral  

E-print Network

53 CHAPTER THREE Female Behavioral Strategies of Hybrid Baboons in the Awash National Park of hamadryas baboons has been attrib- uted primarily to the predisposition of hamadryas males to herd females-like morphological phe- notypes exhibited behaviors characteristic of hamadryas baboons, while females with more

319

Female Prisoners in Malaysia  

ERIC Educational Resources Information Center

This is a study on 422 female prisoners in peninsular Malaysia. More than half of the female prisoners are foreigners, mainly from Indonesia and Thailand. This study surveys the background of the respondents and identifies factors that may have influenced them to commit the offences. Female prisoners in Malaysia, particularly those who are…

Teh, Yik Koon

2006-01-01

320

Female Prisoners in Malaysia  

Microsoft Academic Search

This is a study on 422 female prisoners in peninsular Malaysia. More than half of the female prisoners are foreigners, mainly from Indonesia and Thailand. This study surveys the background of the respondents and identifies factors that may have influenced them to commit the offences. Female prisoners in Malaysia, particularly those who are foreigners, still fit the stereotypical image of

Yik Koon Teh

2006-01-01

321

Cholangiocarcinoma with respect to IgG4 Reaction  

PubMed Central

IgG4 reactions marked by infiltration of IgG4-positive plasma cells in affected organs occur in cancer patients and in patients with IgG4-related diseases. Extrahepatic cholangiocarcinomas including gall bladder cancer are often accompanied by significant IgG4 reactions; these reactions show a negative correlation with CD8-positive cytotoxic T cells, suggesting that the evasion of immune surveillance is associated with cytotoxic T cells. The regulatory cytokine IL-10 may induce IgG4-positive plasma cell differentiation or promote B cell switching to IgG4 in the presence of IL-4. Cholangiocarcinoma cells may function as nonprofessional antigen presenting cells that indirectly induce IgG4 reactions via the IL-10-producing cells and/or these may act as Foxp3-positive and IL-10-producing cells that directly induce IgG4 reactions. Moreover, IgG4-related disease is a high-risk factor for cancer development; IgG4-related sclerosing cholangitis (IgG4-SC) cases associated with cholangiocarcinoma or its precursor lesion biliary intraepithelial neoplasia (BilIN) have been reported. IgG4-positive cell infiltration is an important finding of IgG4-SC but is not a histological hallmark of IgG4-SC. For the diagnosis of IgG4-SC, its differentiation from cholangiocarcinoma remains important. PMID:25132998

Nakanuma, Yasuni

2014-01-01

322

Dolphin underwater bait-balling behaviors in relation to group and prey ball sizes.  

PubMed

We characterized dusky dolphin (Lagenorhynchus obscurus) feeding behaviors recorded on underwater video, and related behaviors to variation in prey ball sizes, dolphin group sizes, and study site (Argentina versus New Zealand, NZ). Herding behaviors most often involved dolphins swimming around the side or under prey balls, but dolphins in Argentina more often swam under prey balls (48% of passes) than did dolphins in NZ (34% of passes). This result may have been due to differences in group sizes between sites, since groups are larger in Argentina. Additionally, in NZ, group size was positively correlated with proportion of passes that occurred under prey balls (p<0.001). Prey-capture attempts most often involved capturing fish from the side of prey balls, but dolphins in Argentina more often swam through prey balls (8% of attempts) than did dolphins in NZ (4% of attempts). This result may have been due to differences in prey ball sizes between sites, since dolphins fed on larger prey balls in Argentina (>74m(2)) than in NZ (maximum 33m(2)). Additionally, in NZ, dolphins were more likely to swim through prey balls to capture fish when they fed on larger prey balls (p=0.025). PMID:23608148

Vaughn-Hirshorn, Robin L; Muzi, Elisa; Richardson, Jessica L; Fox, Gabriella J; Hansen, Lauren N; Salley, Alyce M; Dudzinski, Kathleen M; Würsig, Bernd

2013-09-01

323

Prey preferences of the snow leopard (Panthera uncia): regional diet specificity holds global significance for conservation.  

PubMed

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

Lyngdoh, Salvador; Shrotriya, Shivam; Goyal, Surendra P; Clements, Hayley; Hayward, Matthew W; Habib, Bilal

2014-01-01

324

Prey Preferences of the Snow Leopard (Panthera uncia): Regional Diet Specificity Holds Global Significance for Conservation  

PubMed Central

The endangered snow leopard is a large felid that is distributed over 1.83 million km2 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

Lyngdoh, Salvador; Shrotriya, Shivam; Goyal, Surendra P.; Clements, Hayley; Hayward, Matthew W.; Habib, Bilal

2014-01-01

325

Do we need to measure total serum IgA to exclude IgA deficiency in coeliac disease?  

Microsoft Academic Search

Background: Screening for IgA deficiency in patients with coeliac disease is essential because of the increased incidence of IgA deficiency associated with the disease, which usually relies on the estimation of IgA levels in each case.Aim: To devise a method of excluding IgA deficiency without measuring total serum IgA in each case.Materials and methods: The optical density readings on enzyme-linked

D Sinclair; M Saas; A Turk; M Goble; D Kerr

2006-01-01

326

How predatory mites find plants with whitefly prey.  

PubMed

We investigated the searching behaviour of two species of predatory mites, Typhlodromips swirskii (Athias-Henriot) and Euseius scutalis (Athias-Henriot), both known to feed on immature stages of the whitefly Bemisia tabaci Gennadius. When released in a greenhouse inside a circle of cucumber plants that were alternatingly clean or infested with immature whiteflies, the mites took several days to find plants. Both species were recaptured significantly more on plants with whiteflies. This suggests that the mites are able to discriminate between plants with and without whiteflies. The predators may either have been attracted to plants with whiteflies from a distance or arrested on plants with whiteflies. Typhlodromips swirskii that had previously fed on whitefly immatures on cucumber leaves were significantly attracted by volatiles from cucumber plants with whiteflies in a Y-tube olfactometer. This suggests that the mites use volatile cues to discriminate between infested and clean plants. However, this response waned rapidly; if predators, experienced as above, were starved for 3-4 h in absence of cucumber leaves, they no longer preferred volatiles of infested plants to clean plants. Furthermore, T. swirskii that had no experience with immature whiteflies on cucumber plants also did not prefer odours of infested plants to those of clean plants. Because the release experiment with this species in the greenhouse was done with inexperienced predators, this suggests that the aggregation of mites on plants with whiteflies was mainly caused by differential arrestment of mites on plants with prey and clean plants. For T. swirskii, this was in agreement with the finding that the fraction of predators on plants with prey increased with time to levels higher than 70%. A less clear trend was found for E. scutalis, for which the fraction of predators on plants with prey stabilized soon after release to levels from 54-70%. Hence, the predatory mites may find plants with prey by random searching, but they are subsequently arrested on these plants. An earlier study showed that 87% of all whiteflies released in a set-up as used here were recaptured within 1 day. Hence, the effectiveness with which predatory mites locate plants with whiteflies is low compared with that of their prey. We expect this to generate spatial patterns in the dynamics of predator and prey and this may have consequences for biological control of whiteflies with predatory mites. PMID:16132740

Nomikou, Maria; Meng, Ruixia; Schraag, Ruud; Sabelis, Maurice W; Janssen, Arne

2005-01-01

327

Sabretoothed Carnivores and the Killing of Large Prey  

PubMed Central

Sabre-like canines clearly have the potential to inflict grievous wounds leading to massive blood loss and rapid death. Hypotheses concerning sabretooth killing modes include attack to soft parts such as the belly or throat, where biting deep is essential to generate strikes reaching major blood vessels. Sabretoothed carnivorans are widely interpreted as hunters of larger and more powerful prey than that of their present-day nonsabretoothed relatives. However, the precise functional advantage of the sabretooth bite, particularly in relation to prey size, is unknown. Here, we present a new point-to-point bite model and show that, for sabretooths, depth of the killing bite decreases dramatically with increasing prey size. The extended gape of sabretooths only results in considerable increase in bite depth when biting into prey with a radius of less than ?10 cm. For sabretooths, this size-reversed functional advantage suggests predation on species within a similar size range to those attacked by present-day carnivorans, rather than “megaherbivores” as previously believed. The development of the sabretooth condition appears to represent a shift in function and killing behaviour, rather than one in predator-prey relations. Furthermore, our results demonstrate how sabretoothed carnivorans are likely to have evolved along a functionally continuous trajectory: beginning as an extension of a jaw-powered killing bite, as adopted by present-day pantherine cats, followed by neck-powered biting and thereafter shifting to neck-powered shear-biting. We anticipate this new insight to be a starting point for detailed study of the evolution of pathways that encompass extreme specialisation, for example, understanding how neck-powered biting shifts into shear-biting and its significance for predator-prey interactions. We also expect that our model for point-to-point biting and bite depth estimations will yield new insights into the behaviours of a broad range of extinct predators including therocephalians (gorgonopsian + cynodont, sabretoothed mammal-like reptiles), sauropterygians (marine reptiles) and theropod dinosaurs. PMID:22039403

Andersson, Ki; Norman, David; Werdelin, Lars

2011-01-01

328

Restricting Prey Dispersal Can Overestimate the Importance of Predation in Trophic Cascades  

PubMed Central

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

Geraldi, Nathan R.; Macreadie, Peter I.

2013-01-01

329

Sensitivity to assumptions in models of generalist predation on a cyclic prey.  

PubMed

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

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

2007-10-01

330

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

PubMed

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 dogsż geographical localisation, sex and age also affected the results of the IgE analysis. PMID:25475748

Bjelland, Annelin A; Dolva, Frederik L; Nřdtvedt, Ane; Sćvik, Bente K

2014-12-01

331

Total serum IgE and specific IgE antibodies in children with bronchial asthma.  

PubMed

Correlation between total serum IgE levels and RAST scores in a total of 342 asthmatic children were evaluated. The median and range of serum IgE were 1,050 IU/mL and 20 to 10,000 IU/mL respectively. Positive rates of RAST were highest for mites and house dust (87% to 91%) and lowest for milk, dogs, buckwheat, and eggs (2% to 8%). In general, patients with higher RAST scores had higher serum IgE (P less than .05, Mann-Whitney test). In individual cases, however, serum IgE levels did not significantly correlate with RAST scores and RAST was mandatory to estimate the levels of specific IgE antibodies. PMID:3717715

Kuno-Sakai, H

1986-06-01

332

Serum IgG responses to food antigens in the italian population evaluated by highly sensitive and specific ELISA test.  

PubMed

Using an optimized and validated ELISA method, we performed a serum test for assaying the binding capacity of serum IgG to proteins extracted from approx. 160 different foods to investigate the reactivity of specific IgG antibodies in the Italian population composed of 6,879 subjects (4,551 females and 2,328 males). 44 antigens showed an IgG response greater than 10% and only 14 aliments had an elevated reactivity greater than 20%, in particular, milk, from cow and goat, and several milk derivatives, along with egg albumen and yeasts. The IgG response to the high reactive food antigens depending on the age of the 6880 subjects was also analyzed. We demonstrated a high IgG response in a very large subject group to milk and milk derivatives, and egg albumin antigens, and we conclude that the validated ELISA test may be applied for the serum/plasma IgG antibody level determination as a useful indicator of adverse reactions to food and food hypersensitivity. PMID:19117202

Volpi, Nicola; Maccari, Francesca

2009-01-01

333

IgG, IgA, and lysozyme in Martina Franca donkey jennies and their foals.  

PubMed

Because immune transfer from jenny to donkey foal is mostly unknown, the aim of the present study was to evaluate, from 5 days before to 10 days after foaling, immunoglobulin (Ig)G, IgA, and lysozyme peripartal concentrations in serum and mammary secretions of 10 healthy, spontaneously foaling Martina Franca jennies and in serum of their mature, viable, healthy foals, in the first 10 days after birth. The results showed that, in jennies, mammary secretion of IgG levels (ranging between 16 and 75 mg/mL) and IgA (0.9-2 mg/mL), and IgG (6.8-13.5 mg/mL) and IgA (0.5-2.4 mg/mL) serum concentrations were not different along the time of study. Also, IgG concentrations in serum of foals did not show significant differences although a high level was observed at 12 hours after birth (8 mg/mL), and IgA concentrations in serum of foals did not show any significant difference, although a high level was observed at 12 hours after birth (1.2 mg/mL). Lysozyme increased significantly at Day 2 after parturition in mammary secretions of jennies (551.9 ?g/mL) and at 12 hours in serum of foals (25.9 ?g/mL). The study demonstrated that the pattern of passive immune transfer in donkey foals seems to be similar to that reported for the horse foal, with IgG predominating IgA in serum and mammary secretions of the jenny and also in serum of foals. The most significant early increase in foals' serum concerns lysozyme, which probably plays an important role in the innate immunity of the donkey foal in the first challenging hours after birth. PMID:24462298

Veronesi, Maria C; Dall'Ara, Paola; Gloria, Alessia; Servida, Francesco; Sala, Elisabetta; Robbe, Domenico

2014-04-01

334

Metabolic Syndrome in IgA Glomerulonephritis  

PubMed Central

Background/Aims Metabolic syndrome (MetS) may have an independent impact on the development of chronic kidney disease. This study examines the prevalence of MetS in subjects with IgA glomerulonephritis (IgAGN) and its impact on disease progression in a retrospective fashion. Patients and Methods Altogether, 174 subjects (104 males) were examined 11 years (first visit) after IgAGN diagnosis and again after 16 years (second visit; 144 subjects responded). Different glomerular filtration markers were utilized. The MetS criteria by Alberti et al. [Circulation 2009;120:1640-1645] were applied, in which the presence of any three of five risk factors (elevated waist circumference, triglycerides, glucose, existence of hypertension, or reduced high-density lipoprotein cholesterol) constitutes the diagnosis. Results The prevalence of MetS at the first visit was 39%, corresponding to that of the general Finnish population. In univariate analyses, MetS was significantly associated with the progression of IgAGN at the second visit. However, in multivariate analyses, the existence of MetS was not a significant prognostic determinant. Conclusion The number of subjects with MetS among IgAGN patients and the general population is equal in Finland. MetS does not seem to be an independent prognostic variable. PMID:25337083

Kaartinen, Kati; Syrjänen, Jaana; Pörsti, Ilkka; Harmoinen, Aimo; Huhtala, Heini; Mustonen, Jukka

2014-01-01

335

Red trap colour of the carnivorous plant Drosera rotundifolia does not serve a prey attraction or camouflage function.  

PubMed

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

Foot, G; Rice, S P; Millett, J

2014-01-01

336

IgA antibody response during acquired and congenital toxoplasmosis.  

PubMed Central

Toxoplasma gondii specific IgA and IgM antibodies were quantitated by an antibody capture agglutination assay in 260 patients with acquired toxoplasmosis and from 94 fetuses suspected of congenital toxoplasmosis and 30 infected children. In acquired toxoplasmosis, IgA antibodies to T gondii were found in 95% of the cases. In congenital toxoplasmosis IgA antibodies were more frequently detected (75%) in cord blood than IgM antibodies (61%). They persisted after birth, in some cases for up to 24 months. IgA antibodies were also detected in fetuses whose mothers had toxoplasmosis during their pregnancy. In infected fetuses IgM and IgA antibodies were detected in fetal blood as early as week 24 of pregnancy. Detection of IgA T gondii antibodies may be useful for the diagnosis of some recently acquired infection and for the diagnosis and follow up of the infection in the fetus and neonate. PMID:1517461

Bessičres, M. H.; Roques, C.; Berrebi, A.; Barre, V.; Cazaux, M.; Séguéla, J. P.

1992-01-01

337

Clinical and serological features of mesangial IgA glomerulonephritis.  

PubMed

IgA-glomerulonephritis (IgA-GN) accounts for approximately 20 per cent of all glomerulonephritis in our unit. Seventeen out of 50 patients with IgA-GN developed renal failure, which appeared in 11 out of 17 over the course of a mean follow-up of 68 months. Haemodialysis was required in three patients. Twenty-two out of 50 patients had hypertension, five with malignant hypertension. Perivascular IgA deposits were found in skin biopsies of 29 per cent of patients with IgA-GN and also in 19 per cent of patients with other GN, but not in healthy controls. Mucosal (salivary and nasal) secretory IgA concentrations were normal. In cutaneous and glomerular IgA/IgM deposits, IgA1 was demonstrated using monoclonal antibodies. No excess of HLA-A, B or DR antigens and no relation of clinical course and HLA-Bw35 were found. PMID:6348757

Rambausek, M; Seelig, H P; Andrassy, K; Waldherr, R; Lenhard, V; Ritz, E

1983-01-01

338

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

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

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

339

Teleost Fish Mount Complex Clonal IgM and IgT Responses in Spleen upon Systemic Viral Infection  

PubMed Central

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

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

340

Web-building spiders attract prey by storing decaying matter  

NASA Astrophysics Data System (ADS)

The orb-weaving spider Nephila edulis incorporates into its web a band of decaying animal and plant matter. While earlier studies demonstrate that larger spiders utilise these debris bands as caches of food, the presence of plant matter suggests additional functions. When organic and plastic items were placed in the webs of N. edulis, some of the former but none of the latter were incorporated into the debris band. Using an Y-maze olfactometer, we show that sheep blowflies Lucilia cuprina are attracted to recently collected debris bands, but that this attraction does not persist over time. These data reveal an entirely novel foraging strategy, in which a sit-and-wait predator attracts insect prey by utilising the odours of decaying organic material. The spider's habit of replenishing the debris band may be necessary to maintain its efficacy for attracting prey.

Bjorkman-Chiswell, Bojun T.; Kulinski, Melissa M.; Muscat, Robert L.; Nguyen, Kim A.; Norton, Briony A.; Symonds, Matthew R. E.; Westhorpe, Gina E.; Elgar, Mark A.

341

Environmental versus demographic variability in stochastic predator-prey models  

NASA Astrophysics Data System (ADS)

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.

Dobramysl, U.; Täuber, U. C.

2013-10-01

342

IgG4-related kidney disease – an update  

PubMed Central

Purpose of review IgG4-related disease (IgG4-RD) is a recently recognized systemic inflammatory disorder that can affect most organs/tissues such as sarcoidosis. The kidney is a frequently affected organ with tubulointerstitial nephritis (TIN), the representative lesion of IgG4-RD. This review focuses on the latest knowledge of IgG4-related kidney disease (IgG4-RKD). Recent findings A wide range of renal manifestations of IgG4-RD, that is TIN, membranous glomerulonephritis (MGN) and other glomerular lesions, and pyelitis, are collectively referred to as IgG4-RKD. Clinically, decreased renal function, or characteristic imaging findings such as multiple low-density lesions on contrast-enhanced computed tomography or diffuse thickening of the renal pelvic wall, are typical presenting features. Although a rapid response to corticosteroid therapy is a very important feature of IgG4-TIN, in cases in which renal function is moderately to severely decreased before therapy, only partial recovery of renal function is obtained. Summary TIN with characteristic imaging findings is a typical manifestation of IgG4-RKD in the interstitium, while MGN is a representative manifestation of the glomerular lesions. Although IgG4 is a central feature of IgG4-RD, the recent discovery of IgG4-negative IgG4-RD raises questions about the causative role of the IgG4 molecule in this context. PMID:25594543

Kawano, Mitsuhiro; Saeki, Takako

2015-01-01

343

Elevated IgD antibodies to wheat in celiac disease.  

PubMed

Sera of 17 patients with gluten-induced celiac disease were studied. Total serum IgE and IgD, as well as specific IgE and IgD antibodies to selected food antigens, were determined. Total IgE levels were within the normal range. Specific IgE antibodies to wheat, alpha-gliadin, cows's milk, rice and buckwheat were comparable to those of normal controls. In the celiac subjects total IgD levels were also within the normal range but IgD antibodies to wheat were high whereas IgD antibodies to milk were lower than in pooled normal sera. The levels of IgE or IgD antibodies to either wheat or milk showed no relationship to the presence of precipitins to the antigens of these two foods. The study did not demonstrate a role for IgE in celiac disease. That IgD antibodies may play a role is suggested by the elevated serum IgD antibodies to wheat antigens. PMID:7362093

Bahna, S L; Tateno, K; Heiner, D C

1980-03-01

344

Recolonizing Carnivores and Naďve Prey: Conservation Lessons from Pleistocene Extinctions  

Microsoft Academic Search

The current extinction of many of Earth's large terrestrial carnivores has left some extant prey species lacking knowledge about contemporary predators, a situation roughly parallel to that 10,000 to 50,000 years ago, when naďve animals first encountered colonizing human hunters. Along present-day carnivore recolonization fronts, brown (also called grizzly) bears killed predator-naďve adult moose at disproportionately high rates in Scandinavia,

Joel Berger; Jon E. Swenson; Inga-Lill Persson

2001-01-01

345

PREY OF NESTING BALD EAGLES IN NORTHERN CALIFORNIA  

Microsoft Academic Search

ABSTRACT.---Inland nesting Bald Eagles (Haliaeetus leucocephalus) in northern California preyed on both native and introduced freshwater fish species, primarily brown bullhead (Ameiurus nebulosus), Sacramen- to sucker (Cat0st0mus occidentalis), common carp (Cyprinus carpio) and tui chub (Gila bicolor). At most locations, eagles ate mainly fish; however, birds, principally American Coots (Fulica americana) and Mal- lards (Anas platyrhynchos), were more important than

Ronald E. Jackman; W. Grainger Hunt; Phillip J. Detrich

346

Stability of the unfolding of the predator-prey model  

Microsoft Academic Search

We prove a conjecture of Zeeman that any generic unfolding of the Volterra's original predator-prey model is stable. This well-known two-dimensional model has co-dimension one in the planar Lotka- Volterra system and all its orbits are closed in the region of physical interest. Any generic unfolding of the model locally induces a degenerate Hopf bifurcation, but the presence of a

Abbas Edalat

1994-01-01

347

Cheetah mothers' vigilance: looking out for prey or for predators?  

Microsoft Academic Search

Free-living cheetah (Acinonyx jubatus) cubs are killed by a number of predators, thus vigilance in cheetah mothers may be a form of anti-predator behaviour as well as a means of locating prey. Mothers' vigilance during the day was closely associated with measures of hunting but not with measures of anti-predator behaviour. In contrast, mothers' vigilance at kills was not related

T. M. Caro

1987-01-01

348

Ocean Acidification Affects Prey Detection by a Predatory Reef Fish  

Microsoft Academic Search

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

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

2011-01-01

349

The influence of nutritional history on the functional response of Geocoris pallidipennis to its prey, Myzus persicae.  

PubMed

Insect artificial diets are the foundation for mass production of insect predators. Whether there is an influence of long-term rearing with artificial diet on the control ability of predators should be considered. Here, we focused on the effect of nutritional history on the functional response of Geocoris pallidipennis to Myzus persicae. The influence of nutritional history (artificial diet versus natural prey, M. persicae) on the functional response of third to fifth instar nymphs and female G. pallidipennis was examined in the laboratory. The results showed that the functional response curve of both the nymphs and the adult female of G. pallidipennis to M. persicae reflected similar trends on both nutritional histories and confirmed the type II response. Adult female G. pallidipennis reared on either M. persicae or artificial diet produced a significantly better performance than the juvenile stages tested. We estimated that adult female G. pallidipennis can consume 141.6 (artificial diet) or 131.6 (M. persicae) aphids per day, respectively. This indicated that G. pallidipennis reared on both artificial diet and M. persicae displayed high rates of predation. PMID:24990177

Liu, F; Zeng, F

2014-12-01

350

IgG1 Is Pathogenic in Leishmania mexicana Infection  

PubMed Central

There are over 2 million new cases of leishmaniasis annually, and no effective vaccine has been developed to prevent infection. In murine infection, Leishmania mexicana, which lives intracellularly in host macrophages, has developed pathways to hijack host IgG to induce a suppressive IL-10 response through Fc?Rs, the cell-surface receptors for IgG. To guide vaccine development away from detrimental Ab responses, which can accompany attempts to induce cell-mediated immunity, it is crucial to know which isotypes of IgG are pathogenic in this infection. We have found that IgG1 and IgG2a/c induce IL-10 from macrophages in vitro equally well but through different Fc?R subtypes: IgG1 through Fc?RIII, and IgG2a/c through Fc?RI primarily, but also through Fc?RIII. In sharp contrast, mice lacking IgG1 develop earlier and stronger IgG2a/c, IgG3, and IgM responses to L. mexicana infection and yet are more resistant to the infection. Thus, IgG1, but not IgG2a/c or IgG3, is pathogenic in vivo, in agreement with prior studies indicating that Fc?RIII is required for chronic disease. This calls into question the assumption that macrophages, which should secrete IL-10 in response to both IgG1 and IgG2a/c immune complexes, are the most important source of IL-10 generated by IgG-Fc?R engagement in L. mexicana infection. Further investigations are required to better determine the cell type responsible for this immunosuppressive Fc?RIII-induced IL-10 pathway and whether IgG2a/c is protective. PMID:21037092

Chu, Niansheng; Thomas, Bolaji N.; Patel, Supriya R.; Buxbaum, Laurence U.

2010-01-01

351

The Female Gametophyte  

PubMed Central

The angiosperm female gametophyte is critical for plant reproduction. It contains the egg cell and central cell that become fertilized and give rise to the embryo and endosperm of the seed, respectively. Female gametophyte development begins early in ovule development with the formation of a diploid megaspore mother cell that undergoes meiosis. One resulting haploid megaspore then develops into the female gametophyte. Genetic and epigenetic processes mediate specification of megaspore mother cell identity and limit megaspore mother cell formation to a single cell per ovule. Auxin gradients influence female gametophyte polarity and a battery of transcription factors mediate female gametophyte cell specification and differentiation. The mature female gametophyte secretes peptides that guide the pollen tube to the embryo sac and contains protein complexes that prevent seed development before fertilization. Post-fertilization, the female gametophyte influences seed development through maternal-effect genes and by regulating parental contributions. Female gametophytes can form by an asexual process called gametophytic apomixis, which involves formation of a diploid female gametophyte and fertilization-independent development of the egg into the embryo. These functions collectively underscore the important role of the female gametophyte in seed and food production. PMID:22303279

Drews, Gary N.; Koltunow, Anna M.G

2011-01-01

352

Antarctic jaws: cephalopod prey of sharks in Kerguelen waters  

NASA Astrophysics Data System (ADS)

Only five species of sharks have been recorded in the Southern Ocean, where their biology is essentially unknown. We investigated the feeding habits of the three commonest species from stomach content analysis of specimens taken as bycatches of the fishery targeting the Patagonian toothfish ( Dissostichus eleginoides) in upper slope waters of the Kerguelen Archipelago. The three species prey upon a diversity of fishes and cephalopods. They segregate by feeding on different species of squids of different sizes. The small lanternsharks ( Etmopterus cf. granulosus; 0.3 m on average) feed on small-sized Mastigoteuthis psychrophila, while the large porbeagles ( Lamna nasus; 1.9 m) feed on small-sized histioteuthids ( Histioteuthis atlantica and H. eltaninae) and on medium-sized juvenile ommastrephids of the genus Todarodes. Finally, the huge sleeper sharks ( Somniosus cf. microcephalus; 3.9 m) prey upon large-sized cephalopods ( Kondakovia longimana and Taningia danae) and giant squids ( Mesonychoteuthis hamiltoni and Architeuthis dux). Thus sleeper shark is a fish with sperm whale-like feeding habits and, hence, the second top predator known to science to rely significantly on giant squids. Prey species and biology indicate that porbeagles are pelagic predators in the entire water column, while sleeper sharks are mainly benthic top predators and scavengers. The present study also underlines the diversity and biomass of the poorly known cephalopod fauna, including giant squids, occurring in outer shelf and upper slope waters surrounding subantarctic islands.

Cherel, Yves; Duhamel, Guy

2004-01-01

353

Potential Landscape and Probabilistic Flux of a Predator Prey Network  

PubMed Central

Predator-prey system, as an essential element of ecological dynamics, has been recently studied experimentally with synthetic biology. We developed a global probabilistic landscape and flux framework to explore a synthetic predator-prey network constructed with two Escherichia coli populations. We developed a self consistent mean field method to solve multidimensional problem and uncovered the potential landscape with Mexican hat ring valley shape for predator-prey oscillations. The landscape attracts the system down to the closed oscillation ring. The probability flux drives the coherent oscillations on the ring. Both the landscape and flux are essential for the stable and coherent oscillations. The landscape topography characterized by the barrier height from the top of Mexican hat to the closed ring valley provides a quantitative measure of global stability of system. The entropy production rate for the energy dissipation is less for smaller environmental fluctuations or perturbations. The global sensitivity analysis based on the landscape topography gives specific predictions for the effects of parameters on the stability and function of the system. This may provide some clues for the global stability, robustness, function and synthetic network design. PMID:21423576

Li, Chunhe; Wang, Erkang; Wang, Jin

2011-01-01

354

Blue whale habitat and prey in the California Channel Islands  

NASA Astrophysics Data System (ADS)

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.

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

355

Spreading of families in cyclic predator-prey models.  

PubMed

We study the spreading of families in two-dimensional multispecies predator-prey systems, in which species cyclically dominate each other. In each time step randomly chosen individuals invade one of the nearest sites of the square lattice eliminating their prey. Initially all individuals get a family name which will be carried on by their descendants. Monte Carlo simulations show that the systems with several species (N=3,4,5) are asymptotically approaching the behavior of the voter model, i.e., the survival probability of families, the mean size of families, and the mean-square distance of descendants from their ancestor exhibits the same scaling behavior. The scaling behavior of the survival probability of families has a logarithmic correction. In case of the voter model this correction depends on the number of species, while cyclic predator-prey models behave like the voter model with infinite species. It is found that changing the rates of invasions does not change this asymptotic behavior. As an application a three-species system with a fourth-species intruder is also discussed. PMID:15324103

Ravasz, Mária; Szabó, György; Szolnoki, Attila

2004-07-01

356

Effects of mosquito larvicide on mallard ducklings and prey  

USGS Publications Warehouse

We determined the effects of a commonly used mosquito (Culicidae) larvicide (California Golden Bear Oil??, also GB-1111) on body mass and survival of mallard (Anas platyrhynchos) ducklings and on target and nontarget invertebrates. Field studies conducted on natural ponds located in salt marshes in south San Francisco Bay indicated that GB-1111 had an initial impact on potential invertebrate prey of birds that dissipated rapidly 3 days post-spray. Over-spray, spray drift, or treatment of more extensive areas would likely delay recovery of nontarget prey. Ducklings held intermittently on the ponds over an 8-day period showed no significant effects of weight loss due to invertebrate prey depletion, although initial effects of exposure to GB-1111 were observed (i.e., matting of feathers and mild hypothermia). These results emphasize the importance of avoiding application of GB-1111 during cold temperatures and adherence to recommended use of this larvicide. Otherwise, GB-1111 had a short-term impact on wetland communities.

Miles, A.K.; Lawler, S.P.; Dritz, D.; Spring, S.

2002-01-01

357

Long-term nutrient enrichment decouples predator and prey production  

PubMed Central

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

Davis, John M.; Rosemond, Amy D.; Eggert, Susan L.; Cross, Wyatt F.; Wallace, J. Bruce

2009-01-01

358

Functional morphology of prey capture in the sturgeon, Scaphirhynchus albus.  

PubMed

Acipenseriformes (sturgeon and paddlefish) are basal actinopterygians with a highly derived cranial morphology that is characterized by an anatomical independence of the jaws from the neurocranium. We examined the morphological and kinematic basis of prey capture in the Acipenseriform fish Scaphirhynchus albus, the pallid sturgeon. Feeding pallid sturgeon were filmed in lateral and ventral views and movement of cranial elements was measured from video sequences. Sturgeon feed by creating an anterior to posterior wave of cranial expansion resulting in prey movement through the mouth. The kinematics of S. albus resemble those of other aquatic vertebrates: maximum hyoid depression follows maximum gape by an average of 15 ms and maximum opercular abduction follows maximum hyoid depression by an average of 57 ms. Neurocranial rotation was not a part of prey capture kinematics in S. albus, but was observed in another sturgeon species, Acipenser medirostris. Acipenseriformes have a novel jaw protrusion mechanism, which converts rostral rotation of the hyomandibula into ventral protrusion of the jaw joint. The relationship between jaw protrusion and jaw opening in sturgeon typically resembles that of elasmobranchs, with peak upper jaw protrusion occurring after peak gape. PMID:12655610

Carroll, Andrew M; Wainwright, Peter C

2003-06-01

359

Piscivory in Juvenile Walleyes: Relative Importance of Prey Species, Timing of Spawning of Prey Fish, and Density on Growth and Survival  

Microsoft Academic Search

We examined the effect of the timing of spawning by prey fish and the species of prey fish on the growth and survival of juvenile walleye Stizostedion vitreum. We expected that age-0 walleyes would grow more in ponds when stocked about the same time as the spawning of gizzard shad Dorosoma cepedianum than when stocked about 6 weeks after spawning.

Cynthia S. Kolar; David H. Wahl; Michael L. Hooe

2003-01-01

360

Molecular identification of the prey range of the invasive Asian paper wasp  

PubMed Central

The prey range of the invasive Asian paper wasp, Polistes chinensis antennalis, was studied using molecular diagnostics. Nests of paper wasps were collected from urban residential and salt marsh habitats, larvae were removed and dissected, and DNA in the gut of the paper wasp larvae was amplified and sequenced with cytochrome c oxidase subunit I (COI). Seventy percent of samples (211/299) yielded medium-to high-quality sequences, and prey identification was achieved using BLAST searches in BOLD. A total of 42 taxa were identified from 211 samples. Lepidoptera were the majority of prey, with 39 taxa from 91% of samples. Diptera was a relatively small component of prey (three taxa, 19 samples). Conclusive species-level identification of prey was possible for 67% of samples, and genus-level identification, for another 12% of samples. The composition of prey taken was different between the two habitats, with 2.5× more native prey species being taken in salt marsh compared with urban habitats. The results greatly extend the prey range of this invasive species. The technique is a more effective and efficient approach than relying on the collection of “prey balls”, or morphological identification of prey, for the study of paper wasps. PMID:24340182

Ward, Darren F; Ramón-Laca, Ana

2013-01-01

361

Better the devil you know: avian predators find variation in prey toxicity aversive.  

PubMed

Toxic prey that signal their defences to predators using conspicuous warning signals are called 'aposematic'. Predators learn about the toxic content of aposematic prey and reduce their attacks on them. However, through regulating their toxin intake, predators will include aposematic prey in their diets when the benefits of gaining the nutrients they contain outweigh the costs of ingesting the prey's toxins. Predators face a problem when managing their toxin intake: prey sharing the same warning signal often vary in their toxicities. Given that predators should avoid uncertainty when managing their toxin intake, we tested whether European starlings (Sturnus vulgaris) preferred to eat fixed-defence prey (where all prey contained a 2% quinine solution) to mixed-defence prey (where half the prey contained a 4% quinine solution and the other half contained only water). Our results support the idea that predators should be more 'risk-averse' when foraging on variably defended prey and suggest that variation in toxicity levels could be a form of defence. PMID:25392317

Barnett, Craig A; Bateson, Melissa; Rowe, Candy

2014-11-01

362

When hawks attack: animal-borne video studies of goshawk pursuit and prey-evasion strategies.  

PubMed

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

Kane, Suzanne Amador; Fulton, Andrew H; Rosenthal, Lee J

2015-01-15

363

The genetics and immunobiology of IgA nephropathy  

PubMed Central

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

Kiryluk, Krzysztof; Novak, Jan

2014-01-01

364

Specialist predator in a multi-species prey community: boreal voles and weasels.  

PubMed

Dissimilar vulnerabilities of different prey types and preferences of predators are factors likely to contribute to community dynamics. This may happen via differential individual properties of prey animals (e.g. vigilance, escape) or via habitat effects making hunting by a predator easier and more rewarding in some habitats, or both. Furthermore, community dynamics may be influenced by predator mediated apparent competition, in which an increase in one prey type has negative effects on another prey type indirectly via the shared predator. We summarize the current knowledge from the field in a model predator-prey system consisting of sympatric boreal vole species and their common specialist predator and review field studies using predator manipulation and studies on the responses of individuals in the laboratory and in outdoor enclosures. The vole species studied represent different prey types that are thought to have different vulnerabilities. Our observations on the main resident specialist predator, the least weasel (Mustela nivalis nivalis L.), show that it hunts according to prey availability and suitability of the hunting habitat. Prey voles respond to the presence of the predator behaviorally in various ways to avoid predation. We conclude that even if the least weasel is a specialized predator of small rodents it acts like a generalist predator within the small rodent guild and may facilitate the coexistence of prey species via predator switching. This may lead to interspecific synchrony between prey populations, which has often been observed. We suggest that the processes determining the community impact of predator-prey interactions are driven by the behavioral arms race between the predator and the prey, together with the habitat-dependent density of prey and net gain for the predator. PMID:21396051

Sundell, Janne; Ylönen, Hannu

2008-03-01

365

Non-classical forms of pemphigus: pemphigus herpetiformis, IgA pemphigus, paraneoplastic pemphigus and IgG/IgA pemphigus*  

PubMed Central

The pemphigus group comprises the autoimmune intraepidermal blistering diseases classically divided into two major types: pemphigus vulgaris and pemphigus foliaceous. Pemphigus herpetiformis, IgA pemphigus, paraneoplastic pemphigus and IgG/IgA pemphigus are rarer forms that present some clinical, histological and immunopathological characteristics that are different from the classical types. These are reviewed in this article. Future research may help definitively to locate the position of these forms in the pemphigus group, especially with regard to pemphigus herpetiformis and the IgG/ IgA pemphigus. PMID:24626654

Porro, Adriana Maria; Caetano, Livia de Vasconcelos Nasser; Maehara, Laura de Sena Nogueira; Enokihara, Milvia Maria dos Santos

2014-01-01

366

Female competition in chimpanzees  

PubMed Central

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

Pusey, Anne E.; Schroepfer-Walker, Kara

2013-01-01

367

Measurement of anti-IgA antibodies by a two-site immunoradiometric assay  

SciTech Connect

To enable the detection of IgG class, anti-IgA antibodies and to investigate the possible occurrence of IgE class, anti-IgA antibodies, we developed a solid phase immunoradiometric assay, which uses purified IgA coupled covalently to microcrystalline cellulose as an immunosorbent. Radiolabeled, Fc specific anti-IgG and anti-IgE antibodies were used to detect specific aIgA after incubation of test sera or controls with the immunosorbent. IgG-aIgA were detected by the IRA in 100 and 67% of control sera with class specific and limited specificity aIgA. The IRA was sensitive to approximately two ng of class specific IgG-aIgA. IgG-aIgA also were detected by IRA in 7.9% of sera from patients with urticarial transfusion reactions and 73% of sera from patients with ataxia telangiectasia and IgA deficiency. Sera from 50 normal blood donors did not have detectable IgG-aIgA. Tests for IgE-aIgA were negative in all cases, including control sera with class specific IgG-aIgA. We conclude that the IRA is a sensitive and reproducible method for detection of class specific and limited specificity IgG-aIgA, and that IgE-aIgA do not mediate urticarial transfusion reactions.

Homburger, H.A.; Smith, J.R.; Jacob, G.L.; Laschinger, C.; Naylor, D.H.; Pineda, A.A.

1981-01-01

368

Molecular sexing of prey remains permits a test of sex-biased predation in a wintering population of western sandpipers.  

PubMed

Population sex ratios in monogamous birds are often male biased. One factor that can affect population sex ratios is sex-biased predation. However, most estimates of sex-biased predation in birds have focused on species with obvious sexual colour dimorphism or body size dimorphism. Data on sexually monomorphic birds are generally lacking. In the present study, we adopt a PCR-based sexing procedure to help test for sex-biased predation in a wintering population of western sandpipers (Calidris mauri), a shorebird that shows only subtle sexual size dimorphism. Specifically, by comparing the a priori determined sex ratio of live birds wintering at a site in western Mexico to the molecular estimate obtained from depredated birds at this same site, we were able to perform a population-specific test for sex bias in predator-induced mortality. The proportion of females estimated from living (ca. 25%) versus dead (ca. 24%) individuals was in fact not significantly different, indicating that the strong male bias in this population is not due to differential predation. However, molecular sexing of prey remains is a hitherto unexploited test of sex-biased predation in birds, and is potentially applicable to any species for which prey remains can be gathered. We discuss our results in the context of alternate ecological hypotheses for population sex biases. PMID:15504006

Nebel, Silke; Cloutier, Alison; Thompson, Graham J

2004-08-01

369

Availability and abundance of prey for the red-cockaded woodpecker.  

SciTech Connect

Red-cockaded woodpecker; Road to Recovery. Proceedings of the 4th Red-cockaded woodpecker Symposium. Ralph Costa and Susan J. Daniels, eds. Savannah, Georgia. January, 2003. Chapter 11. Prey, Fire, and Community Ecology. Pp 633-645. Abstract: Over a 10-year period we investigated red-cockaded woodpecker (Picoides borealis) prey use, sources of prey, prey distribution within trees and stands, and how forest management decisions affect prey abundance in South Carolina, Alabama, Georgia and Florida. Cameras were operated at 31 nest cavities to record nest visits with prey in 4 locations that ranged in foraging habitat from pine stands established in old fields to an old-growth stand in South Georgia. Examination of nearly 12,000 photographs recorded over 5 years revealed that, although red-cockaded woodpeckers used over 40 arthropods for food, the majority of the nestling diet is comprised of a relatively small number of common arthropods.

Hanula, James, L.; Horn, Scott.

2004-12-31

370

Evaluating prey capture by larval mummichogs (Fundulus heteroclitus) as a potential biomarker for contaminants.  

PubMed

We evaluated larval prey capture as a "behavioral biomarker" of contamination by examining feeding behavior of larval mummichogs (Fundulus heteroclitus) from many different sites, including a severely contaminated "Superfund" site, moderately contaminated sites, and reference areas. Prey capture ability was related to sediment contaminant levels. The levels of contaminants at a site were highly correlated with each other, so that the impact of individual contaminants was confounded. The number of captures of brine shrimp by mummichog larvae from all sites was highly variable, but significant negative correlations of prey capture were seen with mercury, lead, zinc, cadmium, and PCBs. As observed previously with adults, polyaromatic hydrocarbons (PAHs) did not appear to impair prey capture ability. The only site in which prey capture rates of 8-day old larvae were severely affected was the most highly contaminated Superfund site, Berry's Creek, NJ. This implies that larval prey capture is not as sensitive a behavioral biomarker for contamination as adult behavior studied previously. PMID:12469774

Weis, Judith S; Samson, Jennifer; Zhou, Tong; Skurnick, Joan; Weis, Peddrick

2003-02-01

371

A fluid mechanical model for mixing in a plankton predator-prey system  

NASA Astrophysics Data System (ADS)

A Lagrangian method is developed to study mixing of small particles in open flows. Particle Lagrangian Coherent Structures (pLCS) are identified as transport barriers in the dynamical systems of particles. We apply this method to a planktonic predator-prey system in which moon jellyfish Aurelia aurita uses its body motion to generate fluid currents which carry their prey to the vicinity of their capture appendages. With the flow generated by the jellyfish experimentally measured and the dynamics of prey particles in the flow described by a modified Maxey-Riley equation, we use pLCS to identify the capture region in which prey can be captured. The properties of the capture region enable analysis of the effects of several physiological and mechanical parameters on the predator-prey interaction, such as prey size, escape force, predator perception, etc. The method provides a new methodology to study dynamics and mixing of small organisms in general.

Peng, J.; Dabiri, J. O.

2009-04-01

372

Polychlorinated biphenyl accumulation differs among pumpkinseed sunfish during experimental field exposure: the role of invertebrate prey.  

PubMed

The relative importance of aqueous vs. trophic exposure of fish to polychlorinated biphenyls (PCBs) was investigated. The potential role of different invertebrate prey upon PCB accumulation by fish was also investigated. Pumpkinseed sunfish (Lepomis gibbosus) were exposed in the upper Hudson River under conditions that either permitted feeding upon different local prey assemblages, or excluded local prey from fish diets. Total [PCB] was 5x greater in fish exposed to local prey versus those not permitted to feed on local prey. Further, fish with trophic exposure to PCBs exhibited a chlorine shift, a significantly higher proportion of more chlorinated isomers than fish with only aqueous exposure. Total [PCB] differed among benthic invertebrate assemblages. Phytophilous invertebrates had lower [PCB] than benthic invertebrates, and also had lower concentrations of the more chlorinated isomers. Short-term (7-day) exposure of fish did not permit differentiation of PCB accumulation in fish according to differences in diet of native prey assemblages. PMID:11090898

Feldman, R S; Titus, J E

2001-02-01

373

IgA producing primary intracerebral lymphoma.  

PubMed Central

The first case of a primary and solitary IgA (lambda) producing tumour (possibly a non-Hodgkin's lymphoma) in the CNS is reported. Clinical and neuroimaging findings are described. Early diagnosis without brain biopsy and successful therapy were possible by CSF and serum immunoglobulin analysis which proved local paraprotein production restricted to the CNS. Images PMID:1640243

Burkhardt, D; Schipper, H I; Kaboth, U; Felgenhauer, K

1992-01-01

374

The IGS Real-Time Service  

NASA Astrophysics Data System (ADS)

The IGS Real-Time Service (RTS) is being rolled out in 2013 following the successful completion of the IGS Real-Time Pilot Project. The RTS has recently completed beta testing and is now operating at the level of initial operating capability. The service will reach full operating capability by the end of 2013. RTS products include GNSS data streams and GNSS orbit and clock correction streams. These products are available in real-time in accordance with the IGS open-data policy using RTCM standard formats and the NTRIP transportation protocol. The RTS is key to IGS's support of the GGOS Natural Hazards theme. Of particular importance in this context is the high degree of redundancy that is build into the RTS in order to reliably support public-good scientific applications commonly associated with natural hazards; for example, precise-point positioning applications requiring high accuracy and low latency related to earthquakes and tsunamis . This presentation will illustrate the data gathering through product generation to user distribution design of the RTS, highlighting built-in robustness at various stages. The presentation will also present an assessment of the performance of the service to date.

Caissy, Mark; Agrotis, Loukis; Weber, Georg; Fisher, Steven

2013-04-01

375

IgG4-related disease.  

PubMed

IgG4-related disease is a protean condition that mimics many malignant, infectious, and inflammatory disorders. This multi-organ immune-mediated condition links many disorders previously regarded as isolated, single-organ diseases without any known underlying systemic condition. It was recognised as a unified entity only 10 years ago. Histopathology is the key to diagnosis. The three central pathology features of IgG4-related disease are lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis. The extent of fibrosis is an important determinant of responsiveness to immunosuppressive therapies. IgG4-related disease generally responds to glucocorticoids in its inflammatory stage, but recurrent or refractory cases are common. Important mechanistic insights have been derived from studies of patients treated by B-cell depletion. Greater awareness of this disease is needed to ensure earlier diagnoses, which can prevent severe organ damage, disabling tissue fibrosis, and even death. Identification of specific antigens and T-cell clones that drive the disease will be the first steps to elucidate the pathogenesis of IgG4-related disease. PMID:25481618

Kamisawa, Terumi; Zen, Yoh; Pillai, Shiv; Stone, John H

2014-12-01

376

The Chemistry of the Postpharyngeal Gland of Female European Beewolves  

PubMed Central

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

Herzner, Gudrun; Kaltenpoth, Martin; Boland, Wilhelm; Schreier, Peter; Geiselhardt, Sven; Peschke, Klaus; Schmitt, Thomas

2008-01-01

377

Inducible offences affect predator-prey interactions and life-history plasticity in both predators and prey.  

PubMed

Phenotypic plasticity can have strong impacts on predator-prey interactions. Although much work has examined the effects of inducible defences, less understood is how inducible offences in predators affect predator-prey interactions and predator and prey phenotypes. Here, we examine the impacts of an inducible offence on the interactions and life histories of a cohort of predatory Hynobius retardatus salamander larvae and their prey, Rana pirica tadpoles. We examined larval (duration, survival) and post-metamorphic (size) traits of both species after manipulating the presence/absence of tadpoles and salamanders with offensive (broadened gape width) or non-offensive phenotypes in pond enclosures. Offensive phenotype salamanders reduced tadpole survival and metamorph emergence by 58% compared to tadpole-only treatments, and by over 30% compared to non-offensive phenotypes. Average time to metamorphosis of frogs was delayed by 30% in the presence of salamanders, although this was independent of salamander phenotype. Thus, offensive phenotype salamanders reduced the number of tadpoles remaining in the pond over time by reducing tadpole survival, not by altering patterns of metamorph emergence. Offensive phenotypes also caused tadpoles to metamorphose 19% larger than no salamander treatments and 6% larger than non-offensive phenotype treatments. Pooled across salamander treatments, tadpoles caused salamanders to reach metamorphosis faster and larger. Moreover, in the presence of tadpoles, offensive phenotype salamanders metamorphosed 25% faster and 5% larger than non-offensive phenotype salamanders, but in their absence, neither their size nor larval period differed from non-offensive phenotype individuals. To our knowledge, this study is the first to demonstrate that inducible offences in predators can have strong impacts on predator and prey phenotypes across multiple life stages. Since early metamorphosis at a larger size has potential fitness advantages, the impacts of offensive phenotypes on frog and salamander life histories likely have significant consequences for individuals and populations. Furthermore, increased predation on tadpoles likely causes offensive phenotype individuals to have strong impacts on pond communities. Future studies should examine the fitness consequences of morphological and life-history plasticity across multiple life stages and should address the population and community level consequences of offensive phenotypes. PMID:24320092

Kishida, Osamu; Costa, Zacharia; Tezuka, Ayumi; Michimae, Hirofumi

2013-12-01

378

Differential binding of IgG and IgA antibodies to antigenic determinants of bovine serum albumin  

PubMed Central

The aim of this study was to investigate the recognition pattern of bovine serum albumin (BSA), a major dietary protein by serum IgG and IgA antibodies. Anti-BSA IgG and IgA antibodies were measured by ELISA technique in 3 different cohorts: 578 unselected persons, 84 new-onset insulin-dependent diabetes mellitus (IDDM) patients and 103 atopic persons. In order to characterize the recognition pattern of the different BSA domains, recombinant BSA and recombinant fragments covering the 3 BSA domains were produced. BSA digestion was monitored in simulated gastric fluid experiments by means of domain specific monoclonal antibodies. IgG and IgA antibody titres to native BSA were highest in IDDM patients. The three major BSA domains were equally well recognized by IgG antibodies of the three cohorts. Interestingly all three study groups showed a dissociation of their IgG and IgA antibody response to the first BSA domain. The ratio of IgG to IgA antibodies recognizing this domain was 93%/42% in controls, 92%/37% in IDDM patients and 80%/47% in atopic persons. In simulated gastric fluid experiments, the first BSA domain was the first to become undetectable to specific monoclonal antibodies during digestion. In conclusion humoral IgG and IgA antibodies recognize the major BSA domains with different frequencies. The N-terminal domain of BSA, the first to be degraded during simulated gastric digestion is less well recognized by IgA antibodies. This suggests that early digestion is negatively correlated to the IgA antibody response and that the IgA response associated to the gut associated lymphoid tissue (GALT) and the systemic IgG antibody responses are independent. PMID:11298124

Hilger, C; Grigioni, F; De Beaufort, C; Michel, G; Freilinger, J; Hentges, F

2001-01-01

379

Absence of IgD-CD27(+) memory B cell population in X-linked hyper-IgM syndrome.  

PubMed Central

The present study analyzed peripheral blood B cell populations separated by IgD and CD27 expression in six males with X-linked hyper-IgM syndrome (XHIM). Costimulation of mononuclear cells from most of the patients induced no to low levels of class switching from IgM to IgG and IgA with Staphylococcus aureus Cowan strain (SAC) plus IL-2 or anti-CD40 mAb (anti-CD40) plus IL-10. Measurable levels of IgE were secreted in some of the patients after stimulation with anti-CD40 plus IL-4. Costimulation with SAC plus IL-2 plus anti-CD40 plus IL-10 yielded secretion of significant levels of IgG in addition to IgM, but not IgA. The most striking finding was that peripheral blood B cells from all of the six patients were composed of only IgD+ CD27(-) and IgD+ CD27(+) B cells; IgD- CD27(+) memory B cells were greatly decreased. IgD+ CD27(+) B cells from an XHIM patient produced IgM predominantly. Our data indicate that the low response of IgG production in XHIM patients is due to reduced numbers of IgD- CD27(+) memory B cells. However, the IgG production can be induced by stimulation of immunoglobulin receptors and CD40 in cooperation with such cytokines as IL-2 and IL-10 in vitro. PMID:9710455

Agematsu, K; Nagumo, H; Shinozaki, K; Hokibara, S; Yasui, K; Terada, K; Kawamura, N; Toba, T; Nonoyama, S; Ochs, H D; Komiyama, A

1998-01-01

380

IgA- and secretory IgA-opsonized S. aureus induce a respiratory burst and phagocytosis by polymorphonuclear leucocytes.  

PubMed

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

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

1987-07-01

381

IgA- and secretory IgA-opsonized S. aureus induce a respiratory burst and phagocytosis by polymorphonuclear leucocytes.  

PubMed Central

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

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

382

Helicobacter pylori Antibodies and Iron Deficiency in Female Adolescents  

PubMed Central

Objective Iron deficiency (ID) is a common clinical problem worldwide, affecting primarily females. Helicobacter pylori (HP) infection has been shown to be associated with ID. The objective of this study was to define the prevalence of HP antibodies in female adolescents, and to find out if there was a correlation between HP infection and ID. The secondary aim was to study if regularly performed sporting activity, have any association to HP infection, in itself. Design A controlled clinical trial. Setting A senior high school in Gothenburg, Sweden. Subjects All female athletes at a senior high school for top-level athletes were offered to take part, and 56 athletes took part in the study. The control group consisted of a random sample of age-matched non-athlete students of which 71 entered the study. Main outcome measures Iron deficiency (ID) and iron deficiency anaemia (IDA) were defined by the use of levels of haemoglobin, serum iron, total iron-binding capacity, transferrin saturation, and serum ferritin, as previously described. HP IgG-antibodies were detected by ELISA. Results 18 of 127 (14%) adolescent females had antibodies against HP. Only 3% had IDA, while 50% had ID. In total, 66% of the HP positive females had ID compared to 48% of the negative females (p?=?0.203). No correlation between sporting activity and HP infection was found. Regarding ethnicity, 11/28 of subjects from medium-high risk areas were HP-positive, compared to 7/99 coming from low-risk areas (p<0.001). Conclusion The main finding of this study is that the prevalence of HP IgG antibodies was 14% in adolescent females. We could not find any difference regarding frequency of ID and IDA, between HP positive and negative individuals. Ethnicity is of great importance for the risk of HP infection, while sporting activity itself seems to have no association to HP-infection. PMID:25409451

Sandström, Göran; Rödjer, Stig; Kaijser, Bertil; Börjesson, Mats

2014-01-01

383

Killer whale ( Orcinus orca ) predation in a multi-prey system  

Microsoft Academic Search

Predation can regulate prey numbers but predator behaviour in multiple-prey systems can complicate understanding of control\\u000a mechanisms. We investigate killer whale (Orcinus orca) predation in an ocean system where multiple marine mammal prey coexist. Using stochastic models with Monte-Carlo simulations,\\u000a we test the most likely outcome of predator selection and compare scenarios where killer whales: (1) focus predation on larger

Steven H. FergusonMichael; Michael C. S. Kingsley; Jeff W. Higdon

384

Solving ratio-dependent predator-prey system with constant effort harvesting using Adomian decomposition method  

Microsoft Academic Search

In this paper, an algorithm based on Adomian’s decomposition method is developed to approximate the solution of the ratio-dependent predator–prey system with constant effort harvesting. The convergence of the decomposition series is enhanced using Padé approximation technique. The qualitative analysis of the model reveals that constant effort prey harvesting may contribute to mutual extinction as a possible outcome of predator–prey

Oluwole Daniel Makinde

2007-01-01

385

Food Habits and Prey Specificity of the Common Barn Owl in Ohio1  

Microsoft Academic Search

Pellets from common barn owls (Tyto alba) were collected in 1976 and 1979-1981 from seven different locations in Ohio, yielding 14 distinct samples. A total of 12,589 prey items, including 21 mammal species, was identified. The meadow vole (Microtus pennsylvanicus) was 63.9% of all prey and 75.7% of all biomass of mammalian prey. Two species, the meadow vole and short-tailed

BRUCE A. COLVIN; E. BRUCE MCLEAN

386

Prey Selection by an Apex Predator: The Importance of Sampling Uncertainty  

PubMed Central

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

Davis, Miranda L.; Stephens, Philip A.; Willis, Stephen G.; Bassi, Elena; Marcon, Andrea; Donaggio, Emanuela; Capitani, Claudia; Apollonio, Marco

2012-01-01

387

Allergen dose dependent cytokine production regulates specific IgE and IgG antibody production.  

PubMed

The elicitation of a specific immune response against allergens depends on the recognition of antigenic determinants (epitopes) by specific T and B lymphocytes. In order to determine the relevant epitopes for human T and B cells and their features in the regulation and production of specific IgE and/or IgG antibodies, we have investigated the immune response to bee venom phospholipase A2 (PLA) in allergic and non-allergic subjects. This enzyme represents the major allergen in bee sting allergy. It consists of 134 amino acid residues with a carbohydrate side chain at position 13 and is available as recombinant protein. We have developed PLA-specific T-cell clones from bee sting allergic and non-allergic human subjects. Using a panel of dodecapeptides overlapping in 10 residues and a large set of 18-25 mer overlapping peptides, we detected three epitopes that were recognized by peripheral blood T-cells and T-cell clones. A fourth determinant involved the carbohydrate moiety on Asn13 of PLA. Whereas the CHO-depending epitope seems to be mostly active in allergics, the other three epitopes are equally recognized by peripheral blood mononuclear cells (PBMC) of both allergic and non-allergic individuals. In T-cell clones, the ratio of IL-4/IFN gamma cytokines and the quality of the activating signal depend on the strength of the binding of the MHC-II/Ag/TcR complex between APC and T-cells. The number of antigen-specific APC-T-cell contact sites can be varied in vitro by changing the dose of antigen added to the cell culture. While isotype switch for both IgE and IgG4 requires IL-4, this cytokine suppresses antigen-specific IgG4 production by already switched B-cells. Therefore, IL-4 and IFN gamma display counter-regulatory effects on the production of IgE being responsible for atopic states and IgG4 antibodies which are signs of a normal immune response to allergen and act as protective antibodies. The combination of this counter-regulation of IgE and IgG4 antibodies with the fundamental law of mass action for chemical equilibrium reactions revealed that the antigen concentration governs to a great part the ratio of IL-4/IFN gamma secretion and therefore the formation of IgE and IgG and allergy or protection, together with the equilibrium constant K, which represents immunological individuality and a measure of Ag presentation. PMID:9095257

Blaser, K

1996-01-01

388

IgA antibody response during acquired and congenital toxoplasmosis  

Microsoft Academic Search

Toxoplasma gondii specific IgA and IgM antibodies were quantitated by an antibody capture agglutination assay in 260 patients with acquired toxoplasmosis and from 94 fetuses suspected of congenital toxoplasmosis and 30 infected children. In acquired toxoplasmosis, IgA antibodies to T gondii were found in 95% of the cases. In congenital toxoplasmosis IgA antibodies were more frequently detected (75%) in cord

M H Bessičres; C Roques; A Berrebi; V Barre; M Cazaux; J P Séguéla

1992-01-01

389

The Female Athlete Triad  

ERIC Educational Resources Information Center

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,…

Sherman, Roberta Trattner; Thompson, Ron A.

2004-01-01

390

Female Sexuality: An Enigma.  

ERIC Educational Resources Information Center

Describes constructions of sexuality that have occurred within social context in which language, culture, and behavior interact to reinforce male power. Against backdrop of these patriarchal examples of female sexual expression and experience, discusses difficulties of female clients. Addresses critical counseling concerns in terms of contextual…

Daniluk, Judith

1991-01-01

391

Female Pattern Hair Loss  

MedlinePLUS

... Hormonal changes are a common cause of female hair loss. Many women do not realize that hair loss can occur ... available for female pattern hair loss. The other hair loss medication, Propecia, just doesn't work in women at all. Spironolactone pills help many women, especially ...

392

Well-informed foraging: damage-released chemical cues of injured prey signal quality and size to predators.  

PubMed

Predators use a variety of information sources to locate potential prey, and likewise prey animals use numerous sources of information to detect and avoid becoming the meal of a potential predator. In freshwater environments, chemosensory cues often play a crucial role in such predator/prey interactions. The importance of chemosensory information to teleost fish in marine environments is not well understood. Here, we tested whether coral reef fish predators are attracted to damage-released chemical cues from already wounded prey in order to find patches of prey and minimize their own costs of obtaining food. Furthermore, we tested if these chemical cues would convey information about status of the prey. Using y-maze experiments, we found that predatory dottybacks, Pseudochromis fuscus, were more attracted to skin extracts of damselfish, Pomacentrus amboinensis, prey that were in good condition compared to prey in poor body condition. Moreover, in both the laboratory and field, we found that predators could differentiate between skin extracts from prey based on prey size, showing a greater attraction to extracts made from prey that were the appropriate size to consume. This suggests that predators are not attracted to any general substance released from an injured prey fish instead being capable of detecting and distinguishing relatively small differences in the chemical composition of the skin of their prey. These results have implications for understanding predator foraging strategies and highlights that chemical cues play a complex role in predator-prey interactions in marine fish. PMID:21947496

Lonnstedt, Oona M; McCormick, Mark I; Chivers, Douglas P

2012-03-01

393

Chromaticity in the UV/blue range facilitates the search for achromatically background-matching prey in birds  

PubMed Central

A large variety of predatory species rely on their visual abilities to locate their prey. However, the search for prey may be hampered by prey camouflage. The most prominent example of concealing coloration is background-matching prey coloration characterized by a strong visual resemblance of prey to the background. Even though this principle of camouflage was recognized to efficiently work in predator avoidance a long time ago, the underlying mechanisms are not very well known. In this study, we assessed whether blue tits (Cyanistes caeruleus) use chromatic cues in the search for prey. We used two prey types that were achromatically identical but differed in chromatic properties in the UV/blue range and presented them on two achromatically identical backgrounds. The backgrounds had either the same chromatic properties as the prey items (matching combination) or differed in their chromatic properties (mismatching combination). Our results show that birds use chromatic cues in the search for mismatching prey, whereupon chromatic contrast leads to a ‘pop-out’ of the prey item from the background. When prey was presented on a matching background, search times were significantly higher. Interestingly, search for more chromatic prey on the matching background was easier than search for less chromatic prey on the matching background. Our results indicate that birds use both achromatic and chromatic cues when searching for prey, and that the combination of both cues might be helpful in the search task. PMID:19000974

Stobbe, Nina; Dimitrova, Marina; Merilaita, Sami; Schaefer, H. Martin

2008-01-01

394

Modulation of prey capture kinematics and the role of lingual sensory feedback in the lizard Pogona vitticeps.  

PubMed

Most organisms feed on a variety of prey that may differ dramatically in their physical and behavioural characteristics (e.g. mobility, mass, texture, etc.). Thus the ability to modulate prey capture behaviour in accordance with the characteristics of the food appears crucial. In animals that use rapid tongue movements to capture prey (frogs and chameleons), the coordination of jaws and tongue is based on visual cues gathered prior to the prey capture event. However, most iguanian lizards have much slower tongue-based prey capture systems suggesting that sensory feedback from the tongue may play an important role in coordinating jaw and tongue movements. We investigated the modulation of prey capture kinematics in the agamid lizard Pogona vitticeps when feeding on a range of food items differing in their physical characteristics. As the lizard is a dietary generalist, we expected it to be able to modulate its prey capture kinematics as a function of the (mechanical) demands imposed by the prey. Additionally, we investigated the role of lingual sensory feedback by transecting the trigeminal sensory afferents. Our findings demonstrated that P. vitticeps modulates its prey capture kinematics according to specific prey properties (e.g. size). In addition, transection of the trigeminal sensory nerves had a strong effect on prey capture kinematics. However, significant prey type effects and prey type by transection effects suggest that other sources of sensory information are also used to modulate the prey capture kinematics in P. vitticeps. PMID:17368008

Schaerlaeken, Vicky; Meyers, Jay J; Herrel, Anthony

2007-01-01

395

IgA and IgG immune complexes increase human macrophage C3 biosynthesis.  

PubMed Central

We have studied the effect of IgA- and IgG-containing immune complexes on the production of complement proteins C3, factor B and C2 by human monocyte-derived macrophages, using biosynthetic labelling, immunoprecipitation, sodium dodecyl sulphate-polyacrylamide gel (SDS-PAGE) and autoradiography. There was a consistent increase in C3 production and secretion with both IgA and IgG immune complexes. This increase appeared after a 24-hr incubation period of the macrophages in the presence of immune complexes. No change in the biosynthesis of factor B and C2 proteins was observed in these experiments. Concomitant with the enhanced C3 biosynthesis, the immune complexes caused an increase in macrophage tumour necrosis factor (TNF) production; 310 + 24 U/ml/5 x 10(5) cells and 430 + 51 U/ml/5 x 10(5) cells for IgA and IgG immune complexes, respectively, versus 12 + 8 U/ml/5 x 10(5) cells in the control cells. The presence of prednisolone (2 x 10(-5) M) or dexamethasone (1 x 10(-7) M) inhibited the immune complex-induced TNF production, but had no effect on C3-increased synthesis, suggesting that the effect of immune complexes was not mediated by endogenous TNF production. These findings may be relevant to the local inflammatory response in IgA immune complex-mediated diseases, including IgA nephropathy. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 7 PMID:7750996

Laufer, J; Boichis, H; Farzam, N; Passwell, J H

1995-01-01

396

Shedding light on microbial predator-prey population dynamics using a quantitative bioluminescence assay.  

PubMed

This study assessed the dynamics of predation by Bdellovibrio bacteriovorus HD 100. Predation tests with two different bioluminescent strains of Escherichia coli, one expressing a heat-labile bacterial luciferase and the other a heat-stable form, showed near identical losses from both, indicating that protein expression and stability are not responsible for the "shutting-off" of the prey bioluminescence (BL). Furthermore, it was found that the loss in the prey BL was not proportional with the predator-to-prey ratio (PPR), with significantly greater losses seen as this value was increased. This suggests that other factors also play a role in lowering the prey BL. The loss in BL, however, was very consistent within nine independent experiments to the point that we were able to reliably estimate the predator numbers within only 1 h when present at a PPR of 6 or higher, Using a fluorescent prey, we found that premature lysis of the prey occurs at a significant level and was more prominent as the PPR ratio increased. Based upon the supernatant fluorescent signal, even a relatively low PPR of 10-20 led to approximately 5% of the prey population being prematurely lysed within 1 h, while a PPR of 90 led to nearly 15% lysis. Consequently, we developed a modified Lotka-Volterra predator-prey model that accounted for this lysis and is able to reliably estimate the prey and bdelloplast populations for a wide range of PPRs. PMID:24272279

Im, Hansol; Kim, Dasol; Ghim, Cheol-Min; Mitchell, Robert J

2014-01-01

397

Chlorophacinone residues in mammalian prey at a black-tailed prairie dog colony  

USGS Publications Warehouse

Black-tailed prairie dogs (BTPDs), Cynomys ludovicianus, are an important prey for raptors; therefore, the use of the rodenticide Rozol (0.005% chlorophacinone active ingredient) to control BTPDs raises concern for secondary poisonings resulting from the consumption of contaminated prey by raptors. In the present study, the authors observed Rozol exposure and adverse effects to mammalian prey on 11 of 12 search days of the study. Mammalian hepatic chlorophacinone residues ranged from 0.44 to 7.56 µg/g. Poisoned prey availability was greater than previously reported.

Vyas, Nimish B.; Hulse, Craig S.; Rice, Clifford P.

2012-01-01

398

Temperature and prey quality effects on growth of juvenile walleye pollock Theragra chalcogramma  

E-print Network

: bioenergetics; energy budgets; food consumption; model evaluation; prey energy content; spatially explicit, 1990; Sogard & Olla, 2000). The relationship between body size and predator vulner- ability, energy

399

Interactions between benthic predators and zooplanktonic prey are affected by turbulent waves.  

PubMed

Predators capture prey in complex and variable environments. In the ocean, bottom-dwelling (benthic) organisms are subjected to water currents, waves, and turbulent eddies. For benthic predators that feed on small animals carried in the water (zooplankton), flow not only delivers prey, but can also shape predator-prey interactions. Benthic passive suspension feeders collect prey delivered by movement of ambient water onto capture-surfaces, whereas motile benthic predators, such as burrow-dwelling fish, dart out to catch passing zooplankton. How does the flow of ambient water affect these contrasting modes of predation by benthic zooplanktivores? We studied the effects of turbulent, wavy flow on the encounter, capture, and retention of motile zooplanktonic prey (copepods, Acartia spp.) by passive benthic suspension feeders (sea anemones, Anthopleura elegantissima). Predator-prey interactions were video-recorded in a wave-generating flume under two regimes of oscillating flow with different peak wave velocities and levels of turbulent kinetic energy ("weak" and "strong" waves). Rates of encounter (number of prey passing through a sea anemone's capture zone per time), capture (prey contacting and sticking to tentacles per time), and retention (prey retained on tentacles, without struggling free or washing off, per time) were measured at both strengths of waves. Strong waves enhanced encounter rates both for dead copepods and for actively swimming copepods, but there was so much variability in the behavior of the live prey that the effect of wave strength on encounter rates was not significant. Trapping efficiency (number of prey retained per number encountered) was the same in both flow regimes because, although fewer prey executed maneuvers to escape capture in strong waves, more of the captured prey was washed off the predators' tentacles. Although peak water velocities and turbulence of waves did not affect feeding rates of passive suspension-feeding sea anemones, increases in these aspects of flow have been shown to enhance feeding rates and efficiency of motile benthic fish that lunge out of their burrows to catch zooplankton. Faster, more turbulent flow interferes with the ability of prey to detect predators and execute escape maneuvers, and thus enhances capture rates both for passive suspension-feeding predators and for actively swimming predators. However, prey captured in the mouths of fish are not washed away by ambient flow, whereas prey captured on the tentacles of suspension feeders can be swept off before they are ingested. Therefore, the effects of flowing water on predation on zooplankton by benthic animals depend on the feeding mode of the predator. PMID:23942646

Robinson, H E; Finelli, C M; Koehl, M A R

2013-11-01

400

Horseshoe bats make adaptive prey-selection decisions, informed by echo cues  

PubMed Central

Foragers base their prey-selection decisions on the information acquired by the sensory systems. In bats that use echolocation to find prey in darkness, it is not clear whether the specialized diet, as sometimes found by faecal analysis, is a result of active decision-making or rather of biased sensory information. Here, we tested whether greater horseshoe bats decide economically when to attack a particular prey item and when not. This species is known to recognize different insects based on their wing-beat pattern imprinted in the echoes. We built a simulation of the natural foraging process in the laboratory, where the bats scanned for prey from a perch and, upon reaching the decision to attack, intercepted the prey in flight. To fully control echo information available to the bats and assure its unambiguity, we implemented computer-controlled propellers that produced echoes resembling those from natural insects of differing profitability. The bats monitored prey arrivals to sample the supply of prey categories in the environment and to inform foraging decisions. The bats adjusted selectivity for the more profitable prey to its inter-arrival intervals as predicted by foraging theory (an economic strategy known to benefit fitness). Moreover, unlike in previously studied vertebrates, foraging performance of horseshoe bats was not limited by costly rejections of the profitable prey. This calls for further research into the evolutionary selection pressures that sharpened the species's decision-making capacity. PMID:21367788

Koselj, Klemen; Schnitzler, Hans-Ulrich; Siemers, Björn M.

2011-01-01

401

Influence of prey abundance on size-selective predation by bluegills  

SciTech Connect

Bluegills Lepomis macrochirus in Lake Wingra consume zooplankton in a size-selective fashion. Length-frequency distributions of ingested and available prey demonstrated that bluegills feed on a smaller range of ever larger Daphnia galeata and Bosmina longirostris as these prey species increased in abundance. The same was not apparent for Cyclops bicuspidatus as prey. Regression of intensity-of-selection indices for Daphnia and Bosmina versus their combined abundance suggests that these prey species are not differentiated by bluegills in Lake Wingra.

Bartell, S.M.

1982-01-01

402

When cormorants go fishing: the differing costs of hunting for sedentary and motile prey.  

PubMed

Cormorants hunt both benthic (sedentary) and pelagic (motile) prey but it is not known if the energy costs of foraging on these prey differ. We used respirometry to measure the costs of diving in double-crested cormorants (Phalacrocorax auritus) foraging either for sedentary (fish pieces) or motile (juvenile salmon) prey in a deep dive tank. Short dives for sedentary prey were more expensive than dives of similar duration for motile prey (e.g. 20% higher for a 10s dive) whereas the reverse was true for long dives (i.e. long dives for motile prey were more expensive than for sedentary prey). Across dives of all durations, the foraging phase of the dive was more expensive when the birds hunted motile prey, presumably due to pursuit costs. The period of descent in all the dives undertaken appears to have been more expensive when the birds foraged on sedentary prey, probably due to a higher swimming speed during this period. PMID:17623631

Halsey, Lewis G; White, Craig R; Enstipp, Manfred R; Jones, David R; Martin, Graham R; Butler, Patrick J

2007-10-22

403

Chlorophacinone residues in mammalian prey at a black-tailed prairie dog colony.  

PubMed

Black-tailed prairie dogs (BTPDs), Cynomys ludovicianus, are an important prey for raptors; therefore, the use of the rodenticide Rozol (0.005% chlorophacinone active ingredient) to control BTPDs raises concern for secondary poisonings resulting from the consumption of contaminated prey by raptors. In the present study, the authors observed Rozol exposure and adverse effects to mammalian prey on 11 of 12 search days of the study. Mammalian hepatic chlorophacinone residues ranged from 0.44 to 7.56 µg/g. Poisoned prey availability was greater than previously reported. PMID:22865654

Vyas, Nimish B; Hulse, Craig S; Rice, Clifford P

2012-11-01

404

Predator-Prey Interactions Shape Thermal Patch Use in a Newt Larvae-Dragonfly Nymph Model  

PubMed Central

Thermal quality and predation risk are considered important factors influencing habitat patch use in ectothermic prey. However, how the predator’s food requirement and the prey’s necessity to avoid predation interact with their respective thermoregulatory strategies remains poorly understood. The recently developed ‘thermal game model’ predicts that in the face of imminent predation, prey should divide their time equally among a range of thermal patches. In contrast, predators should concentrate their hunting activities towards warmer patches. In this study, we test these predictions in a laboratory setup and an artificial environment that mimics more natural conditions. In both cases, we scored thermal patch use of newt larvae (prey) and free-ranging dragonfly nymphs (predators). Similar effects were seen in both settings. The newt larvae spent less time in the warm patch if dragonfly nymphs were present. The patch use of the dragonfly nymphs did not change as a function of prey availability, even when the nymphs were starved prior to the experiment. Our behavioral observations partially corroborate predictions of the thermal game model. In line with asymmetric fitness pay-offs in predator-prey interactions (the ‘life-dinner’ principle), the prey’s thermal strategy is more sensitive to the presence of predators than vice versa. PMID:23755175

Gvoždík, Lumír; ?ernická, Eva; Van Damme, Raoul

2013-01-01

405

Stage-specific predator species help each other to persist while competing for a single prey  

PubMed Central

Prey in natural communities are usually shared by many predator species. How predators coexist while competing for the same prey is one of the fundamental questions in ecology. Here, we show that competing predator species may not only coexist on a single prey but even help each other to persist if they specialize on different life history stages of the prey. By changing the prey size distribution, a predator species may in fact increase the amount of prey available for its competitor. Surprisingly, a predator may not be able to persist at all unless its competitor is also present. The competitor thus significantly increases the range of conditions for which a particular predator can persist. This “emergent facilitation” is a long-term, population-level effect that results from asymmetric increases in the rate of prey maturation and reproduction when predation relaxes competition among prey. Emergent facilitation explains observations of correlated increases of predators on small and large conspecific prey as well as concordance in their distribution patterns. Our results suggest that emergent facilitation may promote the occurrence of complex, stable, community food webs and that persistence of these communities could critically depend on diversity within predator guilds. PMID:18779580

De Roos, A. M.; Schellekens, T.; Van Kooten, T.; Persson, L.

2008-01-01

406

Prey-size selection by Triops longicaudatus (Notostraca: Triopsidae) feeding on immature stages of Culex quinquefasciatus.  

PubMed

The tadpole shrimp, Triops longicaudatus, was found to be a size-dependent predator of Culex quinquefasciatus larvae in the laboratory. However, changes in tadpole shrimp size were accompanied by changes in prey-size preference: larger-sized predators consumed an increasing proportion of larger prey items. Very large tadpole shrimp may be nonselective predators of this mosquito species. Quantified behavioral observations indicated that while second instar mosquito larvae were encountered significantly less frequently than were fourth instar larvae or pupae, they were captured at significantly greater rates and with shorter handling times. It is hypothesized that prey vulnerability has an important influence on tadpole shrimp prey size "preferences." PMID:2584973

Tietze, N S; Mulla, M S

1989-09-01

407

Extensive diversification of IgD-, IgY-, and truncated IgY(?Fc)-encoding genes in the red-eared turtle (Trachemys scripta elegans).  

PubMed

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

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

408

Increased sodium-lithium countertransport activity in red cells of IgA nephropathy patients.  

PubMed

The aim of this work was to analyze Na,Li countertransport activity in the erythrocytes from patients with IgA nephropathy, in relationship with their blood pressure status and lipid profile. Forty-nine patients (32 males, 17 females) with biopsy-proven IgA nephropathy and without significant impairment of renal function (serum creatinine less than or equal to 1.4 mg/dl) and 36 normal subjects (21 males, 15 females) were evaluated. Twenty-nine patients with IgA nephropathy were normotensive and 20 hypertensive (diastolic pressure greater than or equal to 95 mm Hg or treated by antihypertensive drugs). Na,Li countertransport was significantly higher in red cells from hypertensive than from normotensive patients (P = 0.002) and normal subjects (P = 0.0001), (values respectively 309 +/- 17; 241 +/- 12 and 211 +/- 11 mumol/liter RBC/hr); normotensive patients with IgA nephropathy did not differ from controls regarding the Na,Li countertransport rate. A multiple stepwise logistic regression analysis with blood pressure status as the dependent variable and Na,Li countertransport activity, age, serum creatinine, proteinuria, cholesterol, triglycerides, plasma potassium and time from onset as independent variables, indicated an independent significant association for Na,Li countertransport (P = 0.002) proteinuria (P = 0.006), plasma potassium (P = 0.006) and age (P = 0.029). Other tested variables were not independently related to blood pressure status. Hyperlipidemic patients (plasma total cholesterol concentration greater than 200 mg/dl and/or plasma triglycerides greater than 172 mg/dl) had an erythrocyte Na,Li countertransport activity significantly higher than normolipidemic (P = 0.005) and controls (P = 0.001) (values respectively 295 +/- 14; 226 +/- 12 and 211 +/- 11 mumol/liter RBC/hr).(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1762312

Boero, R; Degli Esposti, E; Fabbri, A; Guarena, C; Forneris, G; Quarello, F; Fusaroli, M; Piccoli, G

1991-12-01

409

Charge distribution of plasma IgA in IgA nephropathy.  

PubMed Central

The spectrotype of plasma IgA in patients with IgA nephropathy was studied by isoelectric focussing. Densitometry of the gels showed a significant increase in the anionic region at isoelectric points (pI) 4.7-5.1 (P = 0.02) and a reduction in the cationic region pI 5.8-6.0 (P = 0.03) in patients (n = 15) compared with controls (n = 8). Measurement of the IgA concentration in eluates of sequential slices of the gels showed that the ratio of anionic-to-cationic IgA, using pI 5.6 as the dividing point, was significantly greater in patients (n = 10) than in controls (n = 10) (P = 0.03). Two different methods of analysis have therefore demonstrated an increased proportion of anionic and decreased proportion of cationic IgA in the plasma of patients with IgA nephropathy. Images Fig. 1 PMID:2776359

Harada, T; Hobby, P; Courteau, M; Knight, J F; Williams, D G

1989-01-01

410

Polymeric IgA increases the synthesis of macrophage migration inhibitory factor by human mesangial cells in IgA nephropathy  

Microsoft Academic Search

Background. It has been suggested that polymeric IgA (pIgA) or IgA immune complexes play a significant pathogenic role in IgA nephropathy (IgAN). Macro- phage migration inhibitory factor (MIF) shares many activities with other pro-inflammatory cytokines. In human glomerulonephritis, including IgAN, glome- rular expression of MIF is found to correlate with progressive renal injury. We hypothesized that deposi- tion of pIgA

Joseph C. K. Leung; Sydney C. W. Tang; Loretta Y. Y. Chan; Anita W. L. Tsang; Hui Yao Lan; Kar Neng Lai

411

Using Time-Resolved Fluorescence to Measure Serum Venom-Specific IgE and IgG  

PubMed Central

We adapted DELFIA™ (dissociation-enhanced lanthanide fluoroimmunoassay), a time resolved fluorescence method, to quantitate whole venom specific and allergenic peptide-specific IgE (sIgE), sIgG1 and sIgG4 in serum from people clinically allergic to Australian native ant venoms, of which the predominant cause of allergy is jack jumper ant venom (JJAV). Intra-assay CV was 6.3% and inter-assay CV was 13.7% for JJAV sIgE. DELFIA and Phadia CAP JJAV sIgE results correlated well and had similar sensitivity and specificity for the detection of JJAV sIgE against intradermal skin testing as the gold standard. DELFIA was easily adapted for detecting sIgE to a panel of other native ant venoms. PMID:21304970

van Eeden, Pauline E.; Wiese, Michael D.; Aulfrey, Susan; Hales, Belinda J.; Stone, Shelley F.; Brown, Simon G. A.

2011-01-01

412

Using time-resolved fluorescence to measure serum venom-specific IgE and IgG.  

PubMed

We adapted DELFIA™ (dissociation-enhanced lanthanide fluoroimmunoassay), a time resolved fluorescence method, to quantitate whole venom specific and allergenic peptide-specific IgE (sIgE), sIgG(1) and sIgG(4) in serum from people clinically allergic to Australian native ant venoms, of which the predominant cause of allergy is jack jumper ant venom (JJAV). Intra-assay CV was 6.3% and inter-assay CV was 13.7% for JJAV sIgE. DELFIA and Phadia CAP JJAV sIgE results correlated well and had similar sensitivity and specificity for the detection of JJAV sIgE against intradermal skin testing as the gold standard. DELFIA was easily adapted for detecting sIgE to a panel of other native ant venoms. PMID:21304970

van Eeden, Pauline E; Wiese, Michael D; Aulfrey, Susan; Hales, Belinda J; Stone, Shelley F; Brown, Simon G A

2011-01-01

413

Choroidoretinal granuloma in a young female patient.  

PubMed

A 16-year-old Brazilian female patient presented with blurring of vision in the right eye. Corrected visual acuity was OD 2/20, OS 20/20. Afferent pupillary defect was absent and anterior segment examination revealed anterior uveitis. Fundus examination showed light vitritis and a raised grey-white granuloma located at posterior pole with focal serous retinal detachment on optical coherence. Indocyacnine green angiography disclosed a complete mask effect in granuloma's area. Differential diagnoses were infectious (bacterial, viral, fungal and parasites) diseases, systemic inflammatory diseases, tumours. Blood serologies (HIV, toxoplasma, Borrelia, cytomegalovirus (CMV), herpes simplex virus (HSV), varicella-zoster virus (VZV), rubeola) showed positive results for IgM and IgG for toxoplasma, and anterior chamber tap (PCR for toxoplasma, CMV, HSV, VZV) revealed toxoplasma DNA. Anti-toxoplasma therapy, pyrimethamine, sulfadiazine and calcium folinate, was administered immediately. On follow-up granuloma regression was observed, with complete visual restoration. This case demonstrates a clinically challenging posterior pole granuloma. PMID:24744062

Massa, Horace F; Gatzioufas, Zisis; Mangioris, Georgios; Panos, Georgios D

2014-01-01

414

O-glycosylation of serum IgA1 antibodies against mucosal and systemic antigens in IgA nephropathy.  

PubMed

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

Smith, Alice C; Molyneux, Karen; Feehally, John; Barratt, Jonathan

2006-12-01

415

IgG and IgE Collaboratively Accelerate Expulsion of Strongyloides venezuelensis in a Primary Infection  

PubMed Central

The host deploys a subset of immune responses to expel helminths, which differs depending on the nature of the helminth. Strongyloides venezuelensis, a counterpart of the human pathogen S. stercoralis, naturally infects rodents and has been used as an experimental model. Here we show that induction of immunoglobulin G (IgG) and IgE is a prerequisite for rapid expulsion of S. venezuelensis during a primary infection. Activation-induced cytidine deaminase-deficient (AID?/?) mice, which lack the ability to switch IgM to other isotypes, normally developed T-helper 2 (Th2) cells and intestinal mastocytosis after infection with S. venezuelensis. Although AID?/? mice expelled Nippostrongylus brasiliensis normally, they required a much longer period to expel S. venezuelensis than wild-type (WT) mice. Adoptive transfers of immune sera from S. venezuelensis-infected but not N. brasiliensis-infected mice restored the ability of AID?/? mice to promptly expel S. venezuelensis. Immune serum-derived IgG and IgE induced worm expulsion via Fc ? receptor III (Fc?RIII) and Fc ? receptor I (Fc?RI), respectively, and a mixture of IgG and IgE showed collaborative effects. Whereas Fc?RIII?/? mice or Fc?RI??/? mice normally could expel S. venezuelensis, Fc?RIII?/? mice, when their IgE was neutralized by anti-IgE, or Fc?RI??/? mice, when their IgG binding to Fc?RIII was blocked by anti-Fc?RIII, showed a markedly reduced ability to expel S. venezuelensis. These data reveal that IgG and IgE play redundant roles but act in concert to accelerate S. venezuelensis expulsion. Mast cell-deficient mice, even those equipped with immune serum-derived IgG or IgE, failed to expel S. venezuelensis promptly, suggesting that mast cells are cellular targets of IgG and IgE. PMID:23630966

Matsumoto, Makoto; Sasaki, Yuki; Yasuda, Koubun; Takai, Toshiyuki; Muramatsu, Masamichi; Yoshimoto, Tomohiro

2013-01-01

416

Anti-annexin V IgM and IgG autoantibodies and the risk of idiopathic recurrent spontaneous miscarriage.  

PubMed

Anti-annexin V antibodies have been identified as risk factors for recurrent spontaneous miscarriage (RSM) in some, but not all previous studies. We investigated the association between anti-annexin IgM and IgG in RSM cases and control women. Blood samples from 244 women with idiopathic RSM, and 283 multi-parous control women were tested for anti-annexin V antibodies by ELISA. A significant elevation in anti-annexin V IgM and IgG was seen in the RSM cases. An increased prevalence of elevated anti-annexin V IgM and to a lesser extent anti-annexin V IgG was seen in RSM patients. Receiver operating characteristic analysis indicated that the area under the curve for anti-annexin V IgM was 0.916, and for anti-annexin V IgG was 0.725. A systematic shift in anti-annexin V IgM and IgG distributions toward higher values occurred in RSM women, which was confirmed by percentile analysis. For each of the anti-annexin V isotypes, the adjusted odds ratio increased as the percentile value increased; the strongest risk was for anti-annexin V IgM, in which the 99th percentile (P99) was associated with a 165-fold higher risk than P50, and for anti-annexin V IgG where P99 was associated with a 38-fold higher risk than P50. In addition, a higher prevalence of elevated anti-annexin V IgM and anti-annexin V IgG was seen in RSM cases than in control women. We conclude that anti-annexin V IgM and IgG antibody positivity are independent risk factors for RSM. PMID:21466898

Sater, Mai S; Finan, Ramzi R; Mustafa, Fekria E; Al-Khateeb, Ghada M; Almawi, Wassim Y

2011-04-01

417

Detection of IgG and IgE antibodies to Aspergillus fumigatus in human sera by immunogold assay  

Microsoft Academic Search

An immunogold assay (IGA) was developed to detect IgG and IgE antibodies to Aspergillus fumigatus. Sixteen sera from patients with allergic bronchopulmonary aspergillosis (ABPA), aspergilloma, and normal controls were studied. All sera were also evaluated for antibodies against A. fumigatus by biotin-avidin linked enzyme immunosorbent assay (BALISA) and by agar gel double diffusion method. A. fumigatus specific IgG and IgE

Harish C. Gugnani; Kari E. Reijula; Viswanath P. Kurup; Jordan N. Fink

1990-01-01

418

Hydrodynamics of jumping for prey capture in Archer fish  

NASA Astrophysics Data System (ADS)

The prey capture behavior by jumping Archer fish (Toxotes microlepisis) was investigated using high speed imaging and particle imaging velocimetry (PIV). Archer fish are renowned for their ability to spit jets of water at insects and also to jump out of the water to capture their prey. Our investigations reveal that the fish typically fail to reach their prey by jumping when the bait is placed at a height above 3.5 body lengths. After jumping and failing, the fish do not typically jump again, only spit. For our experiments bait was placed between 0.5 and 3.5 body lengths (BL) above the free surface, within reach of jumping, and thus the fish rarely spit unless they missed first by jumping. It is observed that the fish typically position their bodies under the bait with a slight angle, hover momentarily, snap in their pectoral fins, and then flap their tail in an "S-start"-type maneuver with a fixed number of cycles, which increases as a function of bait height. High speed imaging, including time-resolved PIV, was used to capture the kinematics of the jumping behavior and compare the fluid impulse generated during the fast start, jump maneuver with the total change in momentum of the fish body. Maximum acceleration was observed in the early stages of the jump maneuver and was often on the order of 5 to 15 times gravity. Correlations between the maximum energy, power in, number of tail beats, jump height and overall jumping kinematics will be discussed.

Techet, A. H.; Shih, A. M.

2010-11-01

419

Secreted major Venus flytrap chitinase enables digestion of Arthropod prey.  

PubMed

Predation plays a major role in energy and nutrient flow in the biological food chain. Plant carnivory has attracted much interest since Darwin's time, but many fundamental properties of the carnivorous lifestyle are largely unexplored. In particular, the chain of events leading from prey perception to its digestive utilization remains to be elucidated. One of the first steps after the capture of animal prey, i.e. the enzymatic breakup of the insects' chitin-based shell, is ref