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1

Risk assessment of non-target effects caused by releasing two exotic phytoseiid mites in Japan: can an indigenous phytoseiid mite become IG prey?  

PubMed

Two exotic phytoseiid mites, Neoseiulus cucumeris and Amblyseius swirskii, are commercially available in Japan for the control of thrips and other pest insects. As part of a risk assessment of the non-target effects of releasing these two species, we investigated intraguild predation (IGP) between these exotic phytoseiid mites and an indigenous phytoseiid mite Gynaeseius liturivorus, which is promising as an indigenous natural enemy for the control of thrips in Japan. To understand IGP relations between the exotic and indigenous phytoseiid mites after use of the exotic mites for biological control, we investigated IGP between them in the absence of their shared prey. When an IG prey was offered to an IG predator, both exotic and indigenous females consumed the IG prey at all immature stages (egg, larva, protonymph, deutonymph), especially at its larval stages. The propensity for IGP in a no-choice test was measured by the survival time of IG prey corrected using the survival time of thrips offered to the IG predator. There was no significant difference in the propensity for IGP between N. cucumeris and G. liturivorus, but the propensity was significantly higher in A. swirskii than G. liturivorus. The propensity for IGP in a choice test was measured by the prey choice of the IG predator when a conspecific and a heterospecific larva were offered simultaneously as IG prey. Both exotic females consumed the heterospecific larva only. The indigenous female preferentially consumed the heterospecific larva when the heterospecific larva was N. cucumeris, but consumed the conspecific larva when the heterospecific larva was A. swirskii. We concluded that further investigation would be necessary for the exotic mites' risk assessment, since the propensity for IGP of the two exotic females was similar to or higher than that of the indigenous female in both the no-choice and choice tests. PMID:21465332

Sato, Yukie; Mochizuki, Atsushi

2011-08-01

2

WHY ARE FEMALE BIRDS OF PREY LARGER THAN MALES?  

Microsoft Academic Search

The males of most birds are larger than the females, but the opposite is true of birds of prey-the hawks and owls of the orders Falconiformes and Strigiformes. In these females are, with few exceptions, larger than males-sometimes markedly so. These two orders are only distantly related, and one may assume that this reversed sexual dimorphism evolved indepen- dently in

Dean Amadon; H. L. Mencken

1975-01-01

3

A spider that feeds indirectly on vertebrate blood by choosing female mosquitoes as prey.  

PubMed

Spiders do not feed directly on vertebrate blood, but a small East African jumping spider (Salticidae), Evarcha culicivora, feeds indirectly on vertebrate blood by choosing as preferred prey female mosquitoes that have had recent blood meals. Experiments show that this spider can identify its preferred prey by sight alone and by odor alone. When presented with two types of size-matched motionless lures, E. culicivora consistently chose blood-fed female mosquitoes in preference to nonmosquito prey, male mosquitoes, and sugar-fed female mosquitoes (i.e., females that had not been feeding on blood). When the choice was between mosquitoes of different sizes (both blood- or both sugar-fed), small juveniles chose the smaller prey, whereas adults and larger juveniles chose the larger prey. However, preference for blood took precedence over preference for size (i.e., to get a blood meal, small individuals took prey that were larger than the preferred size, and larger individuals took prey that were smaller than the preferred size). When presented with odor from two prey types, E. culicivora approached the odor from blood-fed female mosquitoes significantly more often the odor of the prey that were not carrying blood. PMID:16217015

Jackson, Robert R; Nelson, Ximena J; Sune, Godfrey O

2005-10-18

4

Prey resources before spawning influence gonadal investment of female, but not male, white crappie  

USGS Publications Warehouse

In this study, an outdoor pool experiment was used to evaluate the effect of prey resources during 4 months before spawning on the gonadal investments of male and female white crappie Pomoxis annularis, a popular freshwater sportfish that exhibits erratic recruitment. Fish were assigned one of three feeding treatments: starved, fed once every 5 days (intermediate) or fed daily (high). All measurements of male testes (i.e. wet mass, energy density and spermatocrit) were similar across treatments. Conversely, high-fed females produced larger ovaries than those of intermediate-fed and starved fish, and invested more energy in their ovaries than starved fish. Compared to pre-experiment fish, starved and intermediate-fed females appeared to increase their ovary size by relying on liver energy stores ('capital' spawning). Conversely, high-fed females increased liver and gonad mass, implying an 'income'-spawning strategy (where gonads are built from recently acquired energy). Fecundity did not differ among treatments, but high-fed fish built larger eggs than those starved. Females rarely 'skipped' spawning opportunities when prey resources were low, as only 8% of starved females and 8% of intermediate-fed females lacked vitellogenic eggs. These results suggest that limited prey resources during the months before spawning can limit ovary production, which, in turn, can limit reproductive success of white crappies.

Bunnell, D. B.; Thomas, S. E.; Stein, R. A.

2007-01-01

5

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

PubMed Central

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

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

2013-01-01

6

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

7

Cues of intraguild predators affect the distribution of intraguild prey.  

PubMed

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

Choh, Yasuyuki; van der Hammen, Tessa; Sabelis, Maurice W; Janssen, Arne

2010-06-01

8

Malignant amelanotic melanoma behind the left eye in a female Crj:CD(SD)IGS rat: a case report.  

PubMed

A tumor behind the left eye in a female Crj:CD(SD)IGS rat was investigated histopathologically, immunohistopathologically, and electron microscopically. The tumor invaded and destroyed orbital tissues and bones. It consisted of various tumor cells; namely, spindle-shaped, epithelioid, anaplastic melanoma cells, and had prominent eosinophilic cytoplasm and nuclei with a greater variation in size. Immunohistochemically, almost all of the tumor cells were positive for antimelanoma, PNL2 antibody. Ultrastructurally, the tumor cells were rich in small vesicles containing fine granules and filamentous structures. This is the first report describing an amelanotic melanoma in the head of an albino rat. PMID:18725473

Kurotaki, T; Tomonari, Y; Kanno, T; Wako, Y; Tsuchitani, M

2008-09-01

9

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

10

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

11

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

12

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

Microsoft Academic Search

Rationale: The basis for gender influences on allergen-specific IgEs is unclear. Objectives: To perform regular and sex-stratified genomewide link- age analyses of IgE to each of three allergens (Ascaris lumbricoides, Blatella germanica (German cockroach)), and Dermatophagoides pteronyssinus (dust mite)) and to conduct an association study of a candidate gene in a linked genomic region. Methods: Genomewide linkage analyses of allergen-specific

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

2008-01-01

13

IGS Directory  

NASA Technical Reports Server (NTRS)

The International GPS (Global Positioning System) Service for Geodynamics (IGS) supports and helps coordinate GPS data production and parameters useful for generating more accurate data products. The IGS has operated a GPS tracking system for several years. It contains more than 100 stations worldwide and has produced a combined GPS ephemeris that has become the standard for geodesists and geophysicists worldwide. IGS data and products are freely available to all, thanks to the cooperation and participation of all the IGS members. This directory provides data on the stations and provides names and contact information with personnel involved with the IGS.

1997-01-01

14

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

Microsoft Academic Search

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

Yixin Zhang; John S. Richardson

2007-01-01

15

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

16

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

Microsoft Academic Search

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

Robert R. Jackson; R. Stimson Wilcox

1990-01-01

17

Prey attack and predators defend: counterattacking prey trigger parental care  

E-print Network

Prey attack and predators defend: counterattacking prey trigger parental care in predators Sara and predators alike, creating a cascade of predator attack, prey counterattack and predator defence. Therefore of Amsterdam, PO Box 94084, 1090 GB Amsterdam, The Netherlands That predators attack and prey defend

Magalhães, Sara

18

Testing of bovine sera by ELISA for IgG, IgM and IgA rheumatoid factors.  

PubMed

Sera from 19 colostrum-deprived calves less than 1 week old, 24 colostrum-supplemented calves less than 1 week old, 36 3-5-month-old calves and 200 females greater than 9 months of age were tested by ELISA for the presence of IgM, IgG and IgA rheumatoid factors (RF). An increasing level of IgM- and IgG-RF with age was found. IgG-RF levels in the colostrum-supplemented calves were significantly higher than in the non-supplemented calves (p < 0.001). Individual IgG-RF values correlated with serum IgG levels, as determined by zinc sulphate turbidity testing (r=0.59, p < 0.01). No IgA-RF was detected. The cross-reactivity of IgM-RF with heterologous IgG was found to be greatest with rabbit IgG, followed by mouse and chicken IgG. The significance of rheumatoid factors in relation to diagnostic testing is discussed. PMID:9613438

Graham, D A; Mawhinney, K A; Adair, B M; Merza, M

1998-02-27

19

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

20

Seasonal Foraging Ecology of Non-Migratory Cougars in a System with Migrating Prey  

PubMed Central

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

21

Predators induce egg retention in prey.  

PubMed

To prevent predation on their eggs, prey often avoid patches occupied by predators. As a result, they need to delay oviposition until they reach predator-free patches. Because many species allocate energy to egg production in a continuous fashion, it is not clear what kind of mechanism prey use to delay oviposition. We used females of the phytoseiid mite Neoseiulus cucumeris to study these mechanisms. Females were placed in patches with pollen, a food source they use for egg production, and they were exposed to another phytoseiid mite, Iphiseius degenerans, which is an intraguild predator of N. cucumeris juveniles. We found that the oviposition of N. cucumeris females on patches with the predator was lower than on patches without the predator. Cues left by the intraguild predator were not sufficient to elicit such behaviour. Females of N. cucumeris reduced oviposition when exposed to the predator by retaining the egg inside their body, resulting in a lower developmental rate once these eggs were laid. Hence, females are capable of retaining eggs, but the development of these eggs continues inside the mother's body. In this way, females gain some time to search for less risky oviposition sites. PMID:16955289

Montserrat, Marta; Bas, Cristina; Magalhães, Sara; Sabelis, Maurice W; de Roos, André M; Janssen, Arne

2007-01-01

22

Cladocera: Predators and prey  

Microsoft Academic Search

Among the freshwater zooplankton community, Cladocera represent one of the most common elements of pelagic populations. Being\\u000a almost exclusively filter feeders and algae users and, at the same time, the favourite prey of invertebrate and vertebrate\\u000a predators, Cladocera represent the most important group in the plankton community of lakes as regards energy transfer along\\u000a the food chain. Because of their

R. de Bernardi; G. Giussani; M. Manca

1987-01-01

23

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

24

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

Microsoft Academic Search

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

Daiqin Li; Robert R. Jackson

2003-01-01

25

Seasonal Consumptive Demand and Prey Use by Stocked Saugeyes in Ohio Reservoirs  

Microsoft Academic Search

Community structure and species composition may be strongly influenced by predator– prey interactions resulting from and leading to episodes of population abundance or scarcity. We quantified diets of stocked saugeyes (female walleye Sander vitreus × male sauger S. canadensis) and estimated biomass of their primary prey, gizzard shad Dorosoma cepedianum, in three Ohio reservoirs at quarterly intervals during July 2002–July

Jonathan C. Sieber Denlinger; R. Scott Hale; Roy A. Stein

2006-01-01

26

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

PubMed

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

Zhang, Yixin; Richardson, John S

2007-06-22

27

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

E-print Network

Competing Conservation Objectives for Predators and Prey: Estimating Killer Whale Prey Requirements for southern resident killer whales (Orcinus orca) and their primary prey, Chinook salmon (Oncorhynchus individual killer whale prey requirements from feeding and growth records of captive killer whales

28

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

29

Prey choice by marten during a decline in prey abundance  

Microsoft Academic Search

We examined variation in diet choice by marten (Martes americana) among seasons and between sexes and ages from 1980–1985. During this period prey populations crashed simultaneously, except for ruffed grouse (Bonasa umbellus) which was common at the beginning and end of the study, and masked shrews (Sorex cinereus) which were abundant in 1983. Marten were catholic in selection of prey

Ian D. Thompson; Patrick W. Colgan

1990-01-01

30

Goshawk prey have more bacteria than non-prey.  

PubMed

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

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

2012-03-01

31

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

32

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

33

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

Microsoft Academic Search

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

Jesusa Crisostomo Legaspi; Benjamin C. Legaspi

2004-01-01

34

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

35

Does Sex-Selective Predation Stabilize or Destabilize Predator-Prey Dynamics?  

PubMed Central

Background Little is known about the impact of prey sexual dimorphism on predator-prey dynamics and the impact of sex-selective harvesting and trophy hunting on long-term stability of exploited populations. Methodology and Principal Findings We review the quantitative evidence for sex-selective predation and study its long-term consequences using several simple predator-prey models. These models can be also interpreted in terms of feedback between harvesting effort and population size of the harvested species under open-access exploitation. Among the 81 predator-prey pairs found in the literature, male bias in predation is 2.3 times as common as female bias. We show that long-term effects of sex-selective predation depend on the interplay of predation bias and prey mating system. Predation on the ‘less limiting’ prey sex can yield a stable predator-prey equilibrium, while predation on the other sex usually destabilizes the dynamics and promotes population collapses. For prey mating systems that we consider, males are less limiting except for polyandry and polyandrogyny, and male-biased predation alone on such prey can stabilize otherwise unstable dynamics. On the contrary, our results suggest that female-biased predation on polygynous, polygynandrous or monogamous prey requires other stabilizing mechanisms to persist. Conclusions and Significance Our modelling results suggest that the observed skew towards male-biased predation might reflect, in addition to sexual selection, the evolutionary history of predator-prey interactions. More focus on these phenomena can yield additional and interesting insights as to which mechanisms maintain the persistence of predator-prey pairs over ecological and evolutionary timescales. Our results can also have implications for long-term sustainability of harvesting and trophy hunting of sexually dimorphic species. PMID:18628951

Boukal, David S.; Berec, Lud?k; K?ivan, Vlastimil

2008-01-01

36

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

PubMed

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

2012-07-01

37

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

38

Ambulatory dispersal behavior of Neoseiulus fallacis (Acarina: Phytoseiidae) in relation to prey density and temperature  

Microsoft Academic Search

Ambulatory dispersal behavior ofNeoseiulus fallacis (Garman) was studied in the laboratory to evaluate within-plant movement in relation to temperature and prey density. Adult femaleN. fallacis were confined in 2.5-cm-diameter arenas on the abaxial surface of excised corn leaves. Four temperatures (23, 28, 33, and 39° C) and prey densities ranging from 0 to 55 spider mite eggs per cm2 were

James S. Berry; Thomas O. Holtzer

1990-01-01

39

Integrity monitoring of IGS products  

NASA Technical Reports Server (NTRS)

The IGS has successfully produced precise GPS and GLONASS transmitter parameters, coordinates of IGS tracking stations, Earth rotation parameters, and atmospheric parameters. In this paper we discuss the concepts of integrity monitoring, system monitoring, and performance assessment, all in the context of IGS products. We report on a recent survey of IGS product users, and propose an integrity strategy for the IGS.

Zumberge, James F.; Plag, H. -P.

2005-01-01

40

IgA nephropathy  

MedlinePLUS

... glomerulonephritis). Risk factors include: A personal or family history of IgA nephropathy or Henoch Schonlein purpura , a form of vasculitis that affects many parts of the body Caucasian or Asian ethnicity IgA nephropathy can occur in people of ...

41

PredatorPrey Relationships 933 PredatorPrey  

E-print Network

and prey have shaped each other's behaviors, physiologies, morphologies, and life-history strategies-feeding bivalves; (16) sand dollars; (17) sea stars; (18) crabs; (19) bottom feeding fishes; (20) poly- chaetes; (21) predatory gastropods; and (22) deposit feeding bivalves. From McConnaughey and McRoy (1976). Sea

42

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

43

Prey pursuit and interception in dragonflies  

Microsoft Academic Search

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

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

2000-01-01

44

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

45

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

46

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

47

Predatory mites avoid ovipositing near counterattacking prey  

Microsoft Academic Search

Attacking prey is not without risk; predators may endure counterattackby the prey. Here, we study the oviposition behaviour of a predatory mite(Iphiseius degenerans) in relation to its prey, thewesternflower thrips (Frankliniella occidentalis). This thrips iscapable of killing the eggs of the predator. Thrips and predatory mites - apartfrom feeding on each other - can also feed and reproduce on a

Farid Faraji; Arne Janssen; Maurice W. Sabelis

2001-01-01

48

Prey availability and selective foraging in shorebirds  

Microsoft Academic Search

Accurate measurements of prey availability are vital to our understanding of foraging behaviour, particularly prey selectivity. In the present study, observations of shorebirds foraging for fiddler crabs on intertidal mudflats demonstrate that prey availability depends both on the temporal variation in crab activity and on the crabs’ responses to the presence of foraging shorebirds. Our results suggest that measurements of

PATRICIA R. Y. BACKWELL; PATRICK D O’HARA; JOHN H. CHRISTY

1998-01-01

49

Dragonfly Production and Prey Turnover  

Microsoft Academic Search

Annual production was calculated for three dominant larval odonate populations (Ladona deplanata, Epitheca spp., and Celithemis fasciata) coexisting in the littoral zone of an abandoned farm pond. Dragonfly populations and their prey were collected simultaneously with an Ekman grab at 2-wk to 1-mo intervals. Production for each dragonfly species was calculated using both the Allen curve method and the removal-summation

Arthur C. Benke

1976-01-01

50

2D immunoblots show differential response of mouse IgG and IgM antibodies to antigens of mammary carcinoma 4 T1 cells  

PubMed Central

Background Immunosuppression in breast cancer has been reported in women and in the highly metastatic mouse mammary tumor model 4 T1. The immunosuppressive environment complicates the use of the humoral response against the tumor as an immunodiagnostic tool. IgM has not been used in immunodiagnostic in part because its antitumor responses, both innate and adaptive, have not been studied in function of time in breast cancer. We show a new approach to analyzing the mouse humoral immune response, and compare the evolution with time of IgG and IgM responses against the antigens of 4 T1 cells. Methods The study is based on 2-dimensional immunoblotting detection of antigens from 4 T1 cells by the IgG and IgM antibodies in the serum of female mice injected with 4 T1 cells. Results There was a high variability in the intra-and inter-mouse response. Variability in the IgM response was manifested as a pattern of spots that could become a multibinomial variable of 0 and 1, which could represent a signature of the immune response. Different numbers of spots was found in the IgG and IgM responses from week 1 to 5. On average, the IgM had more but the IgG response decrease with the time. The natural IgM at t?=?0 responds stronger than w1; the adaptive response of both IgM and IgG were elicited where, with the former being stronger better than the latter. Antigens that are recognized by some female mice in the first week are also recognized by other female mice at time 0. Contamination of the natural IgM makes difficult use the adaptive IgM as a tool for immunodiagnostic. Conclusions IgM and IgG response varied with the time and individuals. Spot variation in 2D pattern for the natural IgM could be expressed as a binomial signature, which opens up the way to correlate a particular pattern with resistance or susceptibility. This uncovers a battery of IgMs for each individual to confront cancer or infections. The possibility to differentiate between adaptive IgM antibodies from the natural IgM will allow investigation of the adaptive IgM for early immunodiagnosis. PMID:24467921

2014-01-01

51

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

52

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

53

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

54

Qualitative and quantitative prey requirements of two aphidophagous coccinellids,Adalia tetraspilota and Hippodamia variegata.  

PubMed

The suitability of two prey species, Aphis pomi De Geer (Hemiptera: Aphididae) and Brevicoryne brassicae (L.), for two generalist aphidophagous coccinellids, Adalia tetraspilota (Hope) (Cole- optera: 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 (preoviposition and postoviposition 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

55

Prey attack and predators defend: counterattacking prey trigger parental care in predators.  

PubMed

That predators attack and prey defend is an oversimplified view. When size changes during development, large prey may be invulnerable to predators, and small juvenile predators vulnerable to attack by prey. This in turn may trigger a defensive response in adult predators to protect their offspring. Indeed, when sizes overlap, one may wonder "who is the predator and who is the prey"! Experiments with "predatory" mites and thrips "prey" showed that young, vulnerable prey counterattack by killing young predators and adult predators respond by protective parental care, killing young prey that attack their offspring. Thus, young individuals form the Achilles' heel of prey and predators alike, creating a cascade of predator attack, prey counterattack and predator defence. Therefore, size structure and relatedness induce multiple ecological role reversals. PMID:16191599

Magalhães, Sara; Janssen, Arne; Montserrat, Marta; Sabelis, Maurice W

2005-09-22

56

Prey attack and predators defend: counterattacking prey trigger parental care in predators  

PubMed Central

That predators attack and prey defend is an oversimplified view. When size changes during development, large prey may be invulnerable to predators, and small juvenile predators vulnerable to attack by prey. This in turn may trigger a defensive response in adult predators to protect their offspring. Indeed, when sizes overlap, one may wonder ‘who is the predator and who is the prey’! Experiments with ‘predatory’ mites and thrips ‘prey’ showed that young, vulnerable prey counterattack by killing young predators and adult predators respond by protective parental care, killing young prey that attack their offspring. Thus, young individuals form the Achilles' heel of prey and predators alike, creating a cascade of predator attack, prey counterattack and predator defence. Therefore, size structure and relatedness induce multiple ecological role reversals. PMID:16191599

Magalhaes, Sara; Janssen, Arne; Montserrat, Marta; Sabelis, Maurice W

2005-01-01

57

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

58

Separating the effects of prey size and speed on the kinematics of prey capture in the omnivorous lizard Gerrhosaurus major  

Microsoft Academic Search

Feeding behavior is known to be modulated as prey properties change. During prey capture, external prey properties, including\\u000a size and mobility, are likely some of the most important components in predator–prey interactions. Whereas prey size has been\\u000a demonstrated to elicit modulation of jaw movements during capture, how prey speed affects the approach and capture of prey\\u000a remains unknown. We quantified

Stéphane J. Montuelle; Anthony Herrel; Paul-Antoine Libourel; Lionel Reveret; Vincent L. Bels

2010-01-01

59

IGS Data Flow  

NASA Technical Reports Server (NTRS)

The IGS analysis centers and user community in general need to be assured that the data centers archive a consistent set of files. Changes to the archives can occur because of the re-publishing of data, the transmission of historic data, and the resulting re-distribution (or lack thereof) of these data from data center to data center. To ensure the quality of the archives, a defined data flow and method of archive population needs to be established. This poster will diagram and review the current IGS data flow, discuss problems that have occurred, and provide recommendations for improvement.

Noll, Carey

2006-01-01

60

Coevolution can reverse predator–prey cycles  

PubMed Central

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.

2014-01-01

61

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

62

Specific IgE and IgG Responses and Cytokine Profile in Subjects with Allergic Reactions to Biting Midge Forcipomyia taiwana  

Microsoft Academic Search

Background:Forcipomyia taiwana is a tiny blood-sucking midge whose habitat covers large parts of Taiwan and southern China. Female midges bite during the day, causing intense pruritis and swelling in allergic individuals. In this study, we investigated the immune responses of different allergic reactions to midge bites. Methods:F. taiwana (midge)-specific IgE, -IgG and -IgG subclasses were examined by ELISA in 62

Yi-Hsing Chen; Mey-Fann Lee; Jaw-Ji Tsai; Hsin-Ju Wu; Guang-Yuh Hwang

2009-01-01

63

Prey selection by dragonflies in relation to prey size and wasp-like colours and patterns  

E-print Network

Prey selection by dragonflies in relation to prey size and wasp-like colours and patterns ARASH and patterns were important in deterring attacks by dragonflies, using pairwise and single presentations of both natural and artificial prey in the field. Dragonflies were more likely to attack smaller natural

Beatty, Christopher

64

Prey attack and predators defend: counterattacking prey trigger parental care in predators  

Microsoft Academic Search

That predators attack and prey defend is an oversimplified view. When size changes during development, large prey may be invulnerable to predators, and small juvenile predators vulnerable to attack by prey. This in turn may trigger a defensive response in adult predators to protect their offspring. Indeed, when sizes overlap, one may wonder 'who is the predator and who is

S. Magalhaes; A. Janssen; M. Montserrat Larrosa; M. W. Sabelis

2005-01-01

65

Australian Fur Seals (Arctocephalus pusillus doriferus) Use Raptorial Biting and Suction Feeding When Targeting Prey in Different Foraging Scenarios  

PubMed Central

Foraging behaviours used by two female Australian fur seals (Arctocephalus pusillus doriferus) were documented during controlled feeding trials. During these trials the seals were presented with prey either free-floating in open water or concealed within a mobile ball or a static box feeding device. When targeting free-floating prey both subjects primarily used raptorial biting in combination with suction, which was used to draw prey to within range of the teeth. When targeting prey concealed within either the mobile or static feeding device, the seals were able to use suction to draw out prey items that could not be reached by biting. Suction was followed by lateral water expulsion, where water drawn into the mouth along with the prey item was purged via the sides of the mouth. Vibrissae were used to explore the surface of the feeding devices, especially when locating the openings in which the prey items had been hidden. The mobile ball device was also manipulated by pushing it with the muzzle to knock out concealed prey, which was not possible when using the static feeding device. To knock prey out of this static device one seal used targeted bubble blowing, where a focused stream of bubbles was blown out of the nose into the openings in the device. Once captured in the jaws, prey items were manipulated and re-oriented using further mouth movements or chews so that they could be swallowed head first. While most items were swallowed whole underwater, some were instead taken to the surface and held in the teeth, while being vigorously shaken to break them into smaller pieces before swallowing. The behavioural flexibility displayed by Australian fur seals likely assists in capturing and consuming the extremely wide range of prey types that are targeted in the wild, during both benthic and epipelagic foraging. PMID:25390347

Hocking, David P.; Salverson, Marcia; Fitzgerald, Erich M. G.; Evans, Alistair R.

2014-01-01

66

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

67

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

E-print Network

Transfer of selenium from prey to predators in a simulated terrestrial food chain William A, USA Received 28 May 2004; accepted 10 September 2004 Partitioning of selenium among tissues differs between male and female lizards. Abstract Little is known about the accumulation and effects of selenium

Hopkins, William A.

68

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

Microsoft Academic Search

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

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

2007-01-01

69

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

70

SUPPORTING ONLINE MATERIAL Cyclic dynamics in a simple vertebrate predator-prey community  

E-print Network

, the main alternate prey are birds (ptarmigan, waders and passerines) for the snowy owl, small birds, fishes at snowmelt (N') based on the density of winter nests for 1988-2002 and on direct live-trapping for 1998 to be looked for since only the male snowy owl hunts (and feeds the female) while the skuas take turns

Helsinki, University of

71

Whole Body Inhalation Exposure to 1-Bromopropane Suppresses the IgM Response to Sheep Red Blood Cells in Female B6C3F1 Mice and Fisher 344/N Rats  

PubMed Central

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

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

2010-01-01

72

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),

73

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

74

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

75

IgG deposition in IgA nephropathy patients  

PubMed Central

IgA nephropathy is the most common form of glomerular disease among young adults. The aim of this study is to determine the correlation of IgG deposition with morphologic variables of Oxford classification and some clinical data of patients with IgA nephropathy (IgAN).A total of 114 biopsies were enrolled to the study (70.2% were male). Mean age of the patients was 37.7±13.6 years. This study showed that, IgG deposition intensity had not significant correlation with serum creatinine. No significant association of sex with IgG was found. There was not significant association of IgG deposits with age below and more that 40 years. There was not significant association of IgG deposit intensity with four morphologic variables of Oxford classification. Less studied published regarding the immunostaining findings in IgA nephropathy patients. Location of deposited immunoglobulin (mesangial versus mesangial-capillary) or the type of immunoglobulin (IgG or IgM) may have prognostic significant. More studies needs to find the clinical significance of immunostaining data. PMID:25340115

Nasri, Hamid

2013-01-01

76

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

77

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

78

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

79

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

80

Swarming Behavior, Sexual Dimorphism, and Female Reproductive Status in the Sex Role-Reversed Dance Fly Species Rhamphomyia marginata  

Microsoft Academic Search

Dance flies are predaceous insects which often form male mating swarms. In many species males prior to swarming catch an insect prey, which is presented to the female at mating. In Rhamphomyia marginata, females in contrast to males gather to swarm, while males carrying a prey visit swarms for mating. Here I describe the swarming and courtship behavior in R.

Bo G. Svensson

1997-01-01

81

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

82

Seasonal diet and prey preference of the African lion in a waterhole-driven semi-arid savanna.  

PubMed

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

Davidson, Zeke; Valeix, Marion; Van Kesteren, Freya; Loveridge, Andrew J; Hunt, Jane E; Murindagomo, Felix; Macdonald, David W

2013-01-01

83

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

84

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. J. Exp. Zool. 321A: 515-530, 2014. © 2014 Wiley Periodicals, Inc. PMID:25074721

Mulvany, Samantha; Motta, Philip J

2014-11-01

85

Human Activity Helps Prey Win the Predator-Prey Space Race  

Microsoft Academic Search

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

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

2011-01-01

86

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

87

Predators Drive Evolution of Virtual Prey Appearance  

NSF Publications Database

... Predators Drive Evolution of Virtual Prey Appearance Two University of Nebraska-Lincoln biologists ... display mimicking the appearance of live moths on a tree trunk. The appearance of the moths was ...

88

Effects of predator species, vegetation and prey assemblage on prey preferences of predators with  

E-print Network

and community dynamics. For example, common carp, Cyprinus carpio L., is an invasive species that can become, Cyprinus carpio, fathead minnow, foraging, prey selection, yellow perch. Introduction Predation

89

IGS 1996 Analysis Center Workshop  

NASA Technical Reports Server (NTRS)

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

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

1996-01-01

90

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

91

Reproductive responses of invasive and native predatory lady beetles (Coleoptera: Coccinellidae) to varying prey availability.  

PubMed

As adults, many predatory insects must adjust to a constantly changing prey environment while balancing between survival and reproduction. Two laboratory experiments were conducted to compare reproductive responses of females of two species of lady beetles, invasive Coccinella septempunctata L. and native C. transversoguttata richardsoni (Brown), in Utah alfalfa fields to varying availability of prey. When both lady beetles were placed immediately on experimental diets after being collected from the field (first experiment) and when they were provided excess prey for 14 d before being placed on experimental diets (second experiment), C. septempunctata produced more but individually smaller eggs than C. transversoguttata. Overall, however, in both experiments, C. septempunctata and C. transversoguttata responded similarly when they consumed pea aphids in varying amounts, by laying fewer and less viable eggs when fewer prey were consumed. In particular, the experiments provided no evidence that C. septempunctata converts pea aphids into eggs at a relatively higher rate than C. transversoguttata under limited prey availability. However, C. septempunctata had greater ability than C. transversoguttata to maintain body weight, even as they were producing eggs at low rates. This suggests that low aphid availability is less stressful for C. septempunctata, perhaps because it has more physiological ability than C. transversoguttata to assimilate pea aphid nutrients at low aphid availability. Such ability might contribute to the numerical dominance of the introduced C. septempunctata in alfalfa fields, which have supported low numbers of aphids in recent years. PMID:19689911

Kajita, Y; Evans, E W; Yasuda, H

2009-08-01

92

Is Tetranychus urticae suitable prey for development and reproduction of naïve Coleomegilla maculata?  

PubMed

The lady beetle Coleomegilla maculata De Geer is an omnivorous predator that could help suppress aphid and spider mite populations on plants in greenhouses, plantscapes or interiorscapes. We are assessing the nutritional requirements and feeding behavior of C. maculata on target prey (spider mites) and factitious (unnatural) food. Our ultimate goal is to develop an efficacious diet to mass produce C. maculata. In this study, we tested the hypothesis that Tetranychus urticae Koch (two-spotted spider mite) is not suitable prey for development and reproduction of naïve C. maculata (i.e., with no prior exposure to T. urticae). Our objectives were to (i) provide baseline data on the effects of consuming T. urticae on C. maculata life history, (ii) to compare the effects of consuming all stages of T. urticae versus eggs of Musca domestica L. (common housefly), and (iii) to determine if the consumption of plant products was beneficial. We used C. maculata from a colony reared only on Ephestia kuehniella Zeller (Mediterranean flour moth) eggs. In experiments, C. maculata larvae were reared from the first instar to adult stage with prey/food in replicated arenas; adult females were paired with a single male with prey/food. The results showed that naïve C. maculata readily attacked and consumed T. urticae. Nevertheless, T. urticae was less suitable than M. domestica eggs for C. maculata development and reproduction. Applying a synthetic pollen-Chlorella alga powder (SPCA) in arenas containing T. urticae appeared to boost C. maculata female development and reproduction. PMID:23955814

Riddick, Eric W; Wu, Zhixin; Rojas, M Guadalupe

2014-02-01

93

Firefly "femmes fatales" acquire defensive steroids (lucibufagins) from their firefly prey  

PubMed Central

Female fireflies of the genus Photuris, the so-called firefly “femmes fatales,” prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus. PMID:9275191

Eisner, Thomas; Goetz, Michael A.; Hill, David E.; Smedley, Scott R.; Meinwald, Jerrold

1997-01-01

94

Firefly "femmes fatales" acquire defensive steroids (lucibufagins) from their firefly prey.  

PubMed

Female fireflies of the genus Photuris, the so-called firefly "femmes fatales," prey on male fireflies of the genus Photinus. The females are able to entrap the males by faking the flash signal characteristics of the Photinus female. We found that by feeding on Photinus males, Photuris females gain more than nutrients. They also acquire defensive steroidal pyrones called lucibufagins, which are contained in Photinus but which Photuris fireflies are unable to produce on their own. Photuris females that eat Photinus males or lucibufagin are rejected by Phidippus jumping spiders. Lucibufagin itself proved to be a deterrent to such spiders. Field-collected Photuris females contain lucibufagin in varying amounts. The more lucibufagin they contain the more unacceptable they are to Phidippus. PMID:9275191

Eisner, T; Goetz, M A; Hill, D E; Smedley, S R; Meinwald, J

1997-09-01

95

A stochastic simulation model for Anelosimus studiosus during prey capture: A case study for determination of optimal spacing Pages : 1411 - 1429.  

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

96

Separating the effects of prey size and speed on the kinematics of prey capture in the omnivorous lizard Gerrhosaurus major.  

PubMed

Feeding behavior is known to be modulated as prey properties change. During prey capture, external prey properties, including size and mobility, are likely some of the most important components in predator-prey interactions. Whereas prey size has been demonstrated to elicit modulation of jaw movements during capture, how prey speed affects the approach and capture of prey remains unknown. We quantified the kinematics associated with movements of both the feeding and locomotor systems during prey capture in a lizard, Gerrhosaurus major, while facing prey differing in size and mobility (newborn mice, grasshoppers, and mealworms). Our data show that the feeding and locomotor systems were recruited differently in response to changes in the size or speed of the prey. The timing of jaw movements and of the positioning of the head are affected by changes in prey size-and speed, to a lesser extent. Changes in prey speed resulted in concomitant changes in the speed of strike and an early and greater elevation of the neck. External prey properties, and prey mobility in particular, are relevant in predator-prey interactions and elicit specific responses in different functional systems. PMID:20521149

Montuelle, Stéphane J; Herrel, Anthony; Libourel, Paul-Antoine; Reveret, Lionel; Bels, Vincent L

2010-07-01

97

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

NASA Astrophysics Data System (ADS)

Understanding the interspecific interactions of Procambarus clarkii with other aquatic macroinvertebrates will help to unveil the mechanisms and processes underlying biological invasiveness. The purpose of this study was to investigate predator-prey interactions of two ontogenic phases of P. clarkii with native and exotic species of aquatic macroinvertebrates at a single and multiple prey level. We performed laboratory experiments to determine the consumption and the behavioral responses of Chironomus riparius, Physa acuta and Corbicula fluminea to P. clarkii. The presence of P. clarkii significantly affected the abundance of C. riparius and P. acuta, but not of C. fluminea whether prey species were provided singly or simultaneously. The consumption of C. riparius by P. clarkii was higher than P. acuta for both crayfish sizes and situations (single/multiple prey systems) and C. fluminea was never consumed. Physa acuta was the only species that exhibited an anti-predator behavior to P. clarkii. Our results show that P. clarkii can have strong consumptive and trait effects on aquatic macroinvertebrate prey at a single and multiple prey level, resulting in differential impacts on different prey species. This study clarifies some aspects of the predator-prey interactions between P. clarkii and native as well as other exotic macroinvertebrate species that have invaded freshwater biocenosis worldwide.

Correia, Alexandra Marçal; Bandeira, Nuno; Anastácio, Pedro Manuel

2005-11-01

98

Male courtship vibrations delay predatory behaviour in female spiders.  

PubMed

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

99

Selective IgA Deficiency  

E-print Network

calcium modulator and cyclo- philin ligand interactor gene appear to act as disease- modifying mutations in both IgA deficiencycalcium-modulator and cyclophilin ligand interactor (TACI, TNFRSF13B) have been found both in a subset of patients with IgA deficiency

Yel, Leman

2010-01-01

100

Selective IgA Deficiency  

MedlinePLUS

... Asthma Quiz Atopic Dermatitis (Eczema) Atopic March Atopy Autoimmune Disease Back to School Interactive Game Beta2-agonists (bronchodilators) ... problem in IgA deficiency is increased occurrence of autoimmune diseases. Also, many people with Selective IgA Deficiency also ...

101

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

102

Assessment of fetal exposure risk following seminal excretion of a therapeutic IgG4 (T-IgG4) monoclonal antibody using a rabbit model.  

PubMed

Studies were conducted in New Zealand White rabbits to assess the seminal transfer, vaginal absorption, and placental transfer of a therapeutic monoclonal antibody (T-IgG4). T-IgG4 was administered by intravenous injection (IV) in males and by IV and intravaginal routes in females. Low levels of T-IgG4 were excreted into seminal plasma (100- to 370-fold lower than serum concentrations) and absorbed following vaginal dosing (three orders of magnitude lower than IV administration). On gestation day 29 (GD29), fetal serum T-IgG4 levels were 1.5-fold greater than maternal levels following IV dosing. The fetal T-IgG4 exposure ratio for seminal transfer vs. direct maternal IV dosing was estimated to be 1.3×10(-8). Applying human serum T-IgG4 exposure data to the model, the estimated human T-IgG4 serum concentration from seminal transfer was 3.07×10(-7)?g/mL, an exposure level at least 1000-fold lower than the T-IgG4-ligand dissociation constant (Kd) and at least seven orders of magnitude lower than the in vivo concentration producing 20% inhibition of the target (EC20). These data indicate that excretion of a T-IgG4 into semen would not result in a biologically meaningful exposure risk to the conceptus of an untreated partner. PMID:24863471

Breslin, William J; Hilbish, Kim G; Page, Todd J; Coutant, David E

2014-09-01

103

IgG, IgM, and IgA antinuclear antibodies in discoid and systemic lupus erythematosus patients.  

PubMed

IgG antinuclear antibodies (ANAs) are elevated in patients with systemic lupus erythematosus (SLE) compared with patients with discoid lupus erythematosus (DLE). To provide an expanded immunologic view of circulating ANAs in lupus patients, we compared the expressions of IgG, IgM, and IgA ANAs in DLE and SLE patients. In this cross-sectional study, sera from age-, gender-, and ethnic-matched SLE (N = 35), DLE (N = 23), and normal patients (N = 22) were tested for IgG, IgM, and IgA ANAs using enzyme-linked immunosorbent assays (ELISAs) and indirect immunofluorescence (IIF) with monkey esophagus as substrate. ELISAs showed elevated levels of IgG ANA, IgM ANA, and IgG/IgM ANA ratios in SLE patients compared with DLE and normal patients. IgA ANA expression was higher in SLE and DLE patients versus normal patients. IIF studies showed higher percentages of patients positive for IgG, IgM, and IgA ANAs in the SLE group. Higher IgG/IgM ANA ratios in SLE than DLE show enhanced class-switching and a more sustained humoral response in SLE. They also suggest a potential connection of IgM ANAs with disease containment. PMID:24741342

Jost, Sheridan A; Tseng, Lin-Chiang; Matthews, Loderick A; Vasquez, Rebecca; Zhang, Song; Yancey, Kim B; Chong, Benjamin F

2014-01-01

104

Increased urinary IgM excretion in patients with chest pain due to coronary artery disease  

PubMed Central

Background Micro-albuminuria is a recognized predictor of cardiovascular morbidity and mortality in patients with coronary artery disease. We have previously reported, in diabetic and non-diabetic patients, that an increased urinary excretion of IgM is associated with higher cardiovascular mortality. The purpose of this study was to investigate the pattern of urinary IgM excretion in patients with acute coronary syndrome (ACS) and its correlation to cardiovascular outcome. Methods Urine albumin, and IgM to creatinine concentration ratios were determined in 178 consecutive patients presenting with chest pain to the Department of Emergency Medicine (ED) at the University Hospital of Lund. Fifty eight (23 female) patients had ACS, 55 (19 female) patients had stable angina (SA), and 65 (35 female) patients were diagnosed as non-specific chest pain (NS). Results Urine albumin and IgM excretions were significantly higher in patients with ACS (p?=?0.001, and p?=?0.029, respectively) compared to patients with NS-chest pain. During the 2 years follow-up time, 40 (19 female) patients suffered a new major cardiovascular event (ACS, acute heart failure, stroke) and 5 (4 male/1 female) patients died of cardiovascular cause. A high degree of albuminuria and IgM-uria significantly predicted cardiovascular mortality and morbidity (HR?=?2.89, 95% CI: 1.48 - 5.66, p?=?0.002). Microalbuminuric patients (?3?mg/mmol) with high IgM-uria (?0.005?mg/mmol) had a 3-fold higher risk for cardiovascular new events compared to patients with low IgM-uria (RR?=?3.3, 95% CI: 1.1 - 9.9, p?=?0.001). Conclusion In patients with chest pain, an increased urine IgM excretion, is associated with coronary artery disease and long-term cardiovascular complications. Measuring urine IgM concentration could have a clinical value in risk stratification of patients with ACS. PMID:24028208

2013-01-01

105

Anti-dsDNA Antibody Isotypes in Systemic Lupus Erythematosus: IgA in Addition to IgG Anti-dsDNA Help to Identify Glomerulonephritis and Active Disease  

PubMed Central

Objectives To evaluate the role of serum IgG, IgM and IgA anti-dsDNA antibody isotypes in the diagnosis of systemic lupus erythematosus (SLE), and their association with clinical features and disease activity, in a large cohort of SLE patients. Methods Sera of 200 SLE patients (mean age 34±10.3 years; 26 male and 174 female; median duration of disease 115 months, range 7–378), and of 206 controls, including 19 Sjögren's syndrome, 27 rheumatoid arthritis, 26 psoriatic arthritis, 15 idiopathic inflammatory myopathies (IIM), 13 systemic sclerosis, 49 infectious diseases and 57 healthy subjects, were tested for anti-dsDNA IgG, IgM and IgA isotypes. Results Selecting a cutoff corresponding to 95% specificity, the sensitivity of IgG, IgM and IgA anti-dsDNA antibodies in SLE was 55%, 30% and 49%, respectively; 12.5%, 1% and 7.5% of SLE patients had positive IgG, IgM or IgA isotype alone, respectively. SLE patients with glomerulonephritis showed higher levels of IgA anti-dsDNA (p?=?0.0002), anti-dsDNA IgG/IgM (p?=?0.001) and IgA/IgM (p<0.0001) ratios than patients without renal disease. No significant associations have been found between anti-dsDNA isotypes and other clinical features. IgA anti-dsDNA (p?=?0.01) (but not IgG or IgM) and IgG/IgM ratio (p?=?0.005) were significantly higher in patients with more active disease (ECLAM score >4). Conclusions The detection of IgA anti-dsDNA autoantibodies seems to improve our ability to diagnose SLE and to define lupus nephritis phenotype and active disease. By contrast, IgM anti-dsDNA antibodies might be protective for renal involvement. These data support the hypothesis that anti-dsDNA antibody class clustering may help to refine SLE diagnosis and prognosis. PMID:23951169

Villalta, Danilo; Bizzaro, Nicola; Bassi, Nicola; Zen, Margherita; Gatto, Mariele; Ghirardello, Anna; Iaccarino, Luca; Punzi, Leonardo; Doria, Andrea

2013-01-01

106

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

107

Predator-prey interactions, resource depression and patch revisitation  

USGS Publications Warehouse

Generalist predators may be confronted by different types of prey in different patches: sedentary and conspicuous, cryptic (with or without refugia), conspicuous and nonsocial, or conspicuous and social. I argue that, where encounter rates with prey are of most importance, patch revisitation should be a profitable tactic where prey have short 'recovery' times (conspicuous, nonsocial prey), or where anti-predator response (e.g. shoaling) may increase conspicuousness. Predictions are made for how temporal changes in prey encounter rates should affect revisit schedules and feeding rates for the 4 different prey types.

Erwin, R.M.

1989-01-01

108

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

PubMed

1. Predation plays an integral role in many community interactions, with the number of predators and the rate at which they consume prey (i.e. their functional response) determining interaction strengths. Owing to the difficulty of directly observing predation events, attempts to determine the functional response of predators in natural systems are limited. Determining the forms that predator functional responses take in complex systems is important in advancing understanding of community interactions. 2. Prey survival has a direct relationship to the functional response of their predators. We employed this relationship to estimate the functional response for bald eagle Haliaeetus leucocepalus predation of Canada goose Branta canadensis nests. We compared models that incorporated eagle abundance, nest abundance and alternative prey presence to determine the form of the functional response that best predicted intra-annual variation in survival of goose nests. 3. Eagle abundance, nest abundance and the availability of alternative prey were all related to predation rates of goose nests by eagles. There was a sigmoidal relationship between predation rate and prey abundance and prey switching occurred when alternative prey was present. In addition, predation by individual eagles increased as eagle abundance increased. 4. A complex set of interactions among the three species examined in this study determined survival rates of goose nests. Results show that eagle predation had both prey- and predator-dependent components with no support for ratio dependence. In addition, indirect interactions resulting from the availability of alternative prey had an important role in mediating the rate at which eagles depredated nests. As a result, much of the within-season variation in nest survival was due to changing availability of alternative prey consumed by eagles. 5. Empirical relationships drawn from ecological theory can be directly integrated into the estimation process to determine the mechanisms responsible for variation in observed survival rates. The relationship between predator functional response and prey survival offers a flexible and robust method to advance our understanding of predator-prey interactions in many complex natural systems where prey populations are marked and regularly visited. PMID:16903047

Miller, David A; Grand, James B; Fondell, Thomas F; Anthony, Michael

2006-01-01

109

Prey preference and life tables of the predatory mite Parasitus bituberosus (Acari: Parasitidae) when offered various prey combinations.  

PubMed

Parasitus bituberosus Karg (Acari: Parasitidae) is one of the predatory mite species inhabiting mushroom houses. It is known to accept a wide range of prey, suggesting that it may be a promising candidate for the biological control of key pests of mushroom culture. In our study it did not show any prey preference among four groups of small organisms often occurring in mushroom growth medium, namely rhabditid nematodes, pygmephorid mites, and sciarid and phorid fly larvae. Nevertheless, the type of food these predators fed on affects their development. The shortest egg-to-adult development time was obtained on a nematode diet. On a diet of phorid larvae, mite development stopped at the deutonymph stage; none reached adulthood. All other diets sufficed to reach the adult phase. Female fecundity when fed nematodes and sciarid larvae did not differ, but it was much lower when fed pygmephorid mites. Other life table parameters confirmed that pygmephorid mites constituted the worst diet for P. bituberosus. The highest intrinsic rate of population increase (r m = 0.34) was obtained on the nematode diet; when fed sciarid larvae and pygmephorid mites it was 0.25 and 0.14, respectively. Our study provides good reasons to further test P. bituberosus as biocontrol agent of especially sciarid flies and nematodes, especially when the compost is well colonized by mushroom mycelium (which retards nematode growth). PMID:23640712

Szafranek, Piotr; Lewandowski, Mariusz; Kozak, Marcin

2013-09-01

110

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

111

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

112

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

Microsoft Academic Search

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\\u000a of Minnesota. During May to August 2007, we investigated 147 clusters of locations (31% of the total) and found evidence of\\u000a predation on a white-tailed deer (Odocoileus

Vicente Palacios; L. David Mech

2011-01-01

113

Prey aggregation is an effective olfactory predator avoidance strategy  

PubMed Central

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

Dunn, Alison M.; Morrell, Lesley J.

2014-01-01

114

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

115

Active Touch During Shrew Prey Capture  

PubMed Central

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

Munz, Martin; Brecht, Michael; Wolfe, Jason

2010-01-01

116

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

117

Why are predator urines aversive to prey?  

PubMed

Predator odors often repel prey species. In the present experiments, we investigated whether changes in the diet of a predator, the coyote (Canis latrans) would affect the repellency of its urine. Furthermore, because predator odors have a high sulfur content, reflecting large amounts of meat in the diet, we investigated the contribution of sulfurous odors to repellency. Our results were consistent with the hypothesis that diet composition and sulfurous metabolites of meat digestion are important for the repellency of predator odors to potential prey. PMID:24242647

Nolte, D L; Mason, J R; Epple, G; Aronov, E; Campbell, D L

1994-07-01

118

How the owl tracks its prey - II  

PubMed Central

Barn owls can capture prey in pitch darkness or by diving into snow, while homing in on the sounds made by their prey. First, the neural mechanisms by which the barn owl localizes a single sound source in an otherwise quiet environment will be explained. The ideas developed for the single source case will then be expanded to environments in which there are multiple sound sources and echoes – environments that are challenging for humans with impaired hearing. Recent controversies regarding the mechanisms of sound localization will be discussed. Finally, the case in which both visual and auditory information are available to the owl will be considered. PMID:20889819

Takahashi, Terry T.

2010-01-01

119

Human activity helps prey win the predator-prey space race.  

PubMed

Predator-prey interactions, including between large mammalian wildlife species, can be represented as a "space race", where prey try to minimize and predators maximize spatial overlap. Human activity can also influence the distribution of wildlife species. In particular, high-human disturbance can displace large carnivore predators, a trait-mediated direct effect. Predator displacement by humans could then indirectly benefit prey species by reducing predation risk, a trait-mediated indirect effect of humans that spatially decouples predators from prey. The purpose of this research was to test the hypothesis that high-human activity was displacing predators and thus indirectly creating spatial refuge for prey species, helping prey win the "space race". We measured the occurrence of eleven large mammal species (including humans and cattle) at 43 camera traps deployed on roads and trails in southwest Alberta, Canada. We tested species co-occurrence at camera sites using hierarchical cluster and nonmetric multidimensional scaling (NMS) analyses; and tested whether human activity, food and/or habitat influenced predator and prey species counts at camera sites using regression tree analysis. Cluster and NMS analysis indicated that at camera sites humans co-occurred with prey species more than predator species and predator species had relatively low co-occurrence with prey species. Regression tree analysis indicated that prey species were three times more abundant on roads and trails with >32 humans/day. However, predators were less abundant on roads and trails that exceeded 18 humans/day. Our results support the hypothesis that high-human activity displaced predators but not prey species, creating spatial refuge from predation. High-human activity on roads and trails (i.e., >18 humans/day) has the potential to interfere with predator-prey interactions via trait-mediated direct and indirect effects. We urge scientist and managers to carefully consider and quantify the trait-mediated indirect effects of humans, in addition to direct effects, when assessing human impacts on wildlife and ecosystems. PMID:21399682

Muhly, Tyler B; Semeniuk, Christina; Massolo, Alessandro; Hickman, Laura; Musiani, Marco

2011-01-01

120

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

121

Divergent outcomes following transcytosis of IgG targeting intracellular and extracellular chlamydial antigens.  

PubMed

Antibodies can have a protective but non-essential role in natural chlamydial infections dependent on antigen specificity and antibody isotype. IgG is the dominant antibody in both male and female reproductive tract mucosal secretions, and is bi-directionally trafficked across epithelia by the neonatal Fc receptor (FcRn). Using pH-polarized epididymal epithelia grown on Transwells, IgG specifically targeted at an extracellular chlamydial antigen; the major outer membrane protein (MOMP), enhanced uptake and translocation of infection at pH 6-6.5 but not at neutral pH. This was dependent on FcRn expression. Conversely, FcRn-mediated transport of IgG targeting the intracellular chlamydial inclusion membrane protein A (IncA), induced aberrant inclusion morphology, recruited autophagic proteins independent of lysosomes and significantly reduced infection. Challenge of female mice with MOMP-specific IgG-opsonized Chlamydia muridarum delayed infection clearance but exacerbated oviduct occlusion. In male mice, MOMP-IgG elicited by immunization afforded no protection against testicular chlamydial infection, whereas the transcytosis of IncA-IgG significantly reduced testicular chlamydial burden. Together these data show that the protective and pathological effects of IgG are dependent on FcRn-mediated transport as well as the specificity of IgG for intracellular or extracellular antigens. PMID:24445600

Armitage, Charles W; O'Meara, Connor P; Harvie, Marina C G; Timms, Peter; Blumberg, Richard S; Beagley, Kenneth W

2014-01-01

122

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

PubMed

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

123

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, Jose; Banos-Picon, Laura; Asis, Josep Daniel

2014-01-01

124

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

125

Chemosensory detection of prey by Nephelopsis obscura (Hirudinoidea: Erpobdellidae)  

Microsoft Academic Search

The chemosensory detection of prey by the freshwater leech Nephelopsis obscura (Erpobdellidae) was investigated in the laboratory. Without direct tactile contact N. obscura of all three size classes tested were unable to detect and react to any of the prey types (Gammarus lacustris, Chironomus sp., Tubifex sp) or prey conditions (live, asphyxiated, homogenate) tested. The length of the starvation period

Ronald W. Davies; L. R. Linton; W. Parsons; E. S. Edgington

1982-01-01

126

Ant foraging behavior: ambient temperature influences prey selection  

Microsoft Academic Search

When prey of two sizes (6 and 32 mg) were offered in a choice situation to foragers of the ant Formica schaufussi at different ambient temperatures, significantly more workers rejected the smaller prey at low temperatures, whereas at high temperatures workers accepted the less profitable smaller item. Foragers scavenge for arthropod prey over a temperature range of 15–40°C, and increasing

James F. A. Traniello; Marty S. Fujita; Rhys V. Bowen

1984-01-01

127

SPRING AND SUMMER PREY OF CALIFORNIA SEA LIONS, ZALOPHUS CAUFORNIANUS,  

E-print Network

SPRING AND SUMMER PREY OF CALIFORNIA SEA LIONS, ZALOPHUS CAUFORNIANUS, AT SAN MIGUEL ISLAND lion, Zalophus califomianus, at San Miguel Island for the purpose of identifying prey species. A total prey of the California sea lion. Thec"california sea lion,Zalophus cali{ornianus, is the most abundant

128

Gastropods as Predators and Prey at Easter Island  

Microsoft Academic Search

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

ALAN J. KOHN

129

WINTER PREY CACHING BY NORTHERN HAWK OWLS IN MINNESOTA  

Microsoft Academic Search

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

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

2007-01-01

130

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

131

Does Dysdera crocata (Araneae Dysderidae) prefer woodlice as prey?  

Microsoft Academic Search

Three different types of prey-preference tests were carried out using Dysdera crocata, a spider frequently described as a specialist predator of woodlice. None of these tests provided evidence that Dysdera crocata prefers woodlice over a variety of insect prey (house flies, beetle larvae, mirid bugs, moths and crickets). We also ran prey preference tests with two species of woodlice that

S. D. Pollard; R. R. Jackson; A. Van Olphen; M. W. Robertson

1995-01-01

132

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

133

Hydrodynamics of prey capture in sharks: effects  

E-print Network

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

Nauwelaerts, Sandra

134

Predators & Prey BIO3176 -University of Ottawa  

E-print Network

J Lin Soc 30: 31-44 16 · Great tits (Parus major), twigs (twine in opaque straw), big worms in opaque straw, and small worms in clear straw · Twigs are not edible · Big worms are cryptic · Small worms are conspicuous Advantage twigs = 4 x big worms opposite 0% 20% 40% 60% 80% A B conspicuous prey taken Erichsen et

Blouin-Demers, Gabriel

135

Prey processing in central place foragers.  

PubMed

The importance of prey processing as an integral part of foraging behaviour has long been acknowledged, but little theoretical consideration has been given to the optimization of the processing behaviour itself. Processing renders food down to ingestible, palatable portions, and also removes non-essential mass thus reducing transport costs. Here, several models of processing are developed for a central place forager. When the forager has to make a simple choice between processing the prey and not, a critical distance from the central place can be calculated, beyond which it is optimal to process prey. If the forager also decides on how much of the prey to remove, the optimal amount to be removed can also be calculated. Imposing a ceiling on overall metabolic expenditure is shown to reduce the distances at which processing becomes the optimal strategy. The models are tested using parameters derived for a provisioning merlin, Falco columbarius, and alternative explanations as to why observed behaviours should differ from the optimal behaviour predicted are discussed. PMID:10640435

Rands, S A; Houston, A I; Gasson, C E

2000-01-21

136

Prey Processing in Central Place Foragers  

Microsoft Academic Search

The importance of prey processing as an integral part of foraging behaviour has long been acknowledged, but little theoretical consideration has been given to the optimization of the processing behaviour itself. Processing renders food down to ingestible, palatable portions, and also removes non-essential mass thus reducing transport costs. Here, several models of processing are developed for a central place forager.

SEAN A. RANDS; ALASDAIR I. HOUSTON; CATHERINE E. GASSON

2000-01-01

137

Diet, prey delivery rates, and prey biomass of Northern Goshawks in East-Central Arizona  

USGS Publications Warehouse

Recent concern over persistence of Northern Goshawk (Accipiter gentilis) populations in Arizona has stemmed from two long-term demography studies that report substantial yearly fluctuations in productivity and evidence of a declining population. Although many factors could be involved in changes in productivity and population declines, availability of food is one such factor. As part of a demography study on the Sitgreaves portion of the Apache-Sitgreaves National Forest in Arizona, we used remote cameras to assess diets of goshawks. Northern Goshawks preyed upon 22 species during two nesting seasons. Adult pairs tended to specialize on particular species of prey. Prey delivery rates decreased throughout the nesting season with a corresponding increase in biomass in the latter stages of the nestling and fledgling periods. Adults appeared to take larger prey as nestlings increased in age.

Rogers, A.S.; DeStefano, S.; Ingraldi, M.F.

2006-01-01

138

Prey size, prey nutrition, and food handling by shrews of different body sizes  

Microsoft Academic Search

We tested some predictions relating metabolic constraints of foraging behavior and prey selection by comparing food handling and utilization in four sympatric shrew species: Sorex minutus (mean body mass = 3.0 g), S. araneus (8.0 g), Neomys anomalus (10.0 g), and N. fodiens (14.4 g). Live fly larvae, mealworm larvae, and aquatic arthropods were offered to shrews as small prey

Leszek Rychlik

2002-01-01

139

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

140

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

141

Rubella-Specific IgM Antibodies in Postnatal Infection  

Microsoft Academic Search

A total of 214 serum specimens of postnatal rubella infected cases were determined for persistence of rubella-specific IgM antibodies, using solid-phase immunosorbent hemadsorp­ tion (SPIHAd) test and enzyme-linked immunosorbent assay (ELISA). Initially, 148 blood samples were obtained from 77 patients comprising 74 females and 3 males. All patients were clinical rubella cases whose sera were confirmed by serodiagnosis. The remaining

Uraiwan Kositanont; Pilaipan Puthavathana; Chantapong Wasi

142

Use of prey hotspots by an avian predator: purposeful unpredictability?  

PubMed

The use of space by predators in relation to their prey is a poorly understood aspect of predator-prey interactions. Classic theory suggests that predators should focus their efforts on areas of abundant prey, that is, prey hotspots, whereas game-theoretical models of predator and prey movement suggest that the distribution of predators should match that of their prey's resources. If, however, prey are spatially anchored to one location and these prey have particularly strong antipredator responses that make them difficult to capture with frequent attacks, then predators may be forced to adopt alternative movement strategies to hunt behaviorally responsive prey. We examined the movement patterns of bird-eating sharp-shinned hawks (Accipiter striatus) in an attempt to shed light on hotspot use by predators. Our results suggest that these hawks do not focus on prey hotspots such as bird feeders but instead maintain much spatial and temporal unpredictability in their movements. Hawks seldom revisited the same area, and the few frequently used areas were revisited in a manner consistent with unpredictable returns, giving prey little additional information about risk. PMID:17211809

Roth, Timothy C; Lima, Steven L

2007-02-01

143

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

144

Predator-Prey Interactions of Marine Invaders  

Microsoft Academic Search

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

Gil Rilov

145

Models of prey capture in larval fish  

Microsoft Academic Search

The food uptake of larval carp and pike is described from high speed movies with synchronous lateral and ventral views.During prey intake by larval fishes the velocities of the created suction flow are high relative to their own size: 0.3 m\\/s for carp larvae of 6 mm.Starting from the first feeding carp larvae have morphological adaptations to suction feeding: the

M. R. Drost

1986-01-01

146

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

PubMed

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

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

2011-11-01

147

David and Goliath: potent venom of an ant-eating spider (Araneae) enables capture of a giant prey.  

PubMed

It is rare to find a true predator that repeatedly and routinely kills prey larger than itself. A solitary specialised ant-eating spider of the genus Zodarion can capture a relatively giant prey. We studied the trophic niche of this spider species and investigated its adaptations (behavioural and venomic) that are used to capture ants. We found that the spider captures mainly polymorphic Messor arenarius ants. Adult female spiders captured large morphs while tiny juveniles captured smaller morphs, yet in both cases ants were giant in comparison with spider size. All specimens used an effective prey capture strategy that protected them from ant retaliation. Juvenile and adult spiders were able to paralyse their prey using a single bite. The venom glands of adults were more than 50 times larger than those of juvenile spiders, but the paralysis latency of juveniles was 1.5 times longer. This suggests that this spider species possesses very potent venom already at the juvenile stage. Comparison of the venom composition between juvenile and adult spiders did not reveal significant differences. We discovered here that specialised capture combined with very effective venom enables the capture of giant prey. PMID:24879352

Pekár, Stano; Šedo, On?ej; Líznarová, Eva; Korenko, Stanislav; Zdráhal, Zden?k

2014-07-01

148

Female circumcision.  

PubMed

It is uncertain when female circumcision was first practiced, but it certainly preceded the founding of both Christianity and Islam. A review of past and current historical, popular and professional literature was undertaken, and 4 types of female circumcision were identified. Typically female circumcision is performed by a local village practitioner, lay person or by untrained midwives. Female genital mutilation is not accepted by any religious or medical opinion, and is a violation of human rights against helpless individuals who are unable to provide informed consent and who must therefore be protected through education and legislation. Complications of female circumcision can present after many years. Any medical practitioner (either for adult or pediatric) can be confronted with this issue of female circumcision, even in countries where this custom is not present, thus mandating the understanding of this complex issue. PMID:11369952

Abu Daia, J M

2000-10-01

149

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

150

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

151

Increased predation of nutrient-enriched aposematic prey  

PubMed Central

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

2014-01-01

152

Coupled predator-prey oscillations in a chaotic food web.  

PubMed

Coupling of several predator-prey oscillations can generate intriguing patterns of synchronization and chaos. Theory predicts that prey species will fluctuate in phase if predator-prey cycles are coupled through generalist predators, whereas they will fluctuate in anti-phase if predator-prey cycles are coupled through competition between prey species. Here, we investigate predator-prey oscillations in a long-term experiment with a marine plankton community. Wavelet analysis of the species fluctuations reveals two predator-prey cycles that fluctuate largely in anti-phase. The phase angles point at strong competition between the phytoplankton species, but relatively little prey overlap among the zooplankton species. This food web architecture is consistent with the size structure of the plankton community, and generates highly dynamic food webs. Continued alternations in species dominance enable coexistence of the prey species through a non-equilibrium 'killing-the-winner' mechanism, as the system shifts back and forth between the two predator-prey cycles in a chaotic fashion. PMID:19845726

Benincà, Elisa; Jöhnk, Klaus D; Heerkloss, Reinhard; Huisman, Jef

2009-12-01

153

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

154

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

PubMed Central

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

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

2013-01-01

155

Integration of multiple intraguild predator cues for oviposition decisions by a predatory mite  

PubMed Central

In mutual intraguild predation (IGP), the role of individual guild members is strongly context dependent and, during ontogeny, can shift from an intraguild (IG) prey to a food competitor or to an IG predator. Consequently, recognition of an offspring's predator is more complex for IG than classic prey females. Thus, IG prey females should be able to modulate their oviposition decisions by integrating multiple IG predator cues and by experience. Using a guild of plant-inhabiting predatory mites sharing the spider mite Tetranychus urticae as prey and passing through ontogenetic role shifts in mutual IGP, we assessed the effects of single and combined direct cues of the IG predator Amblyseius andersoni (eggs and traces left by a female on the substrate) on prey patch selection and oviposition behaviour of naïve and IG predator-experienced IG prey females of Phytoseiulus persimilis. The IG prey females preferentially resided in patches without predator cues when the alternative patch contained traces of predator females or the cue combination. Preferential egg placement in patches without predator cues was only apparent in the choice situation with the cue combination. Experience increased the responsiveness of females exposed to the IG predator cue combination, indicated by immediate selection of the prey patch without predator cues and almost perfect oviposition avoidance in patches with the cue combination. We argue that the evolution of the ability of IG prey females to evaluate offspring's IGP risk accurately is driven by the irreversibility of oviposition and the functionally complex relationships between predator guild members. PMID:23264692

Walzer, Andreas; Schausberger, Peter

2012-01-01

156

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

157

Nonconsumptive predator-driven mortality causes natural selection on prey.  

PubMed

Predators frequently exert natural selection through differential consumption of their prey. However, predators may also cause prey mortality through nonconsumptive effects, which could cause selection if different prey phenotypes are differentially susceptible to this nonconsumptive mortality. Here we present an experimental test of this hypothesis, which reveals that nonconsumptive mortality imposed by predatory dragonflies causes selection on their damselfly prey favoring increased activity levels. These results are consistent with other studies of predator-driven selection, however, they reveal that consumption alone is not the only mechanism by which predators can exert selection on prey. Uncovering this mechanism also suggests that prey defensive traits may represent adaptations to not only avoid being consumed, but also for dealing with other sources of mortality caused by predators. Demonstrating selection through both consumptive and nonconsumptive predator mortality provides us with insight into the diverse effects of predators as an evolutionary force. PMID:24152082

Siepielski, Adam M; Wang, Jason; Prince, Garrett

2014-03-01

158

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

Microsoft Academic Search

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,

Aristo Vojdani

2009-01-01

159

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

160

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

161

Prey selection by experienced and naive juvenile Atlantic salmon  

Microsoft Academic Search

Both in foraging groups and in a sequential prey encounter context, learning had a visible eVect on the pattern of selection for three live prey types (Ecdyonurus larvae, Hydropsyche larvae, and Gammarus) by juvenile Atlantic salmon Salmo salar. Compared to wild-caught fish, naive, hatchery-reared fish that had not been exposed to natural prey ate Hydropsyche larvae in a remarkably low

L. Reiriz; A. G. Nicieza; F. Branta

1998-01-01

162

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

163

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

PubMed Central

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

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

1994-01-01

164

Meat-eating by adult female Sumatran orangutans (Pongo pygmaeus abelii).  

PubMed

Information about meat-eating behavior by wild orangutans (Pongo pygmaeus) is scant. The first article about such a case dates from 1981. Since 1989, seven incidents of adult female Sumatran orangutans eating slow lorises (Nycticebus coucang) have been witnessed. Three females from two study sites were involved. In three cases the females were seen catching the prey. There are too few cases to conclude whether this behavior is typically female. PMID:9327098

Utami, S S; Van Hooff, J A

1997-01-01

165

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

PubMed Central

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

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

1995-01-01

166

International standards for IgG and IgM anti-?2glycoprotein antibody measurement.  

PubMed

International standards for anti-beta2 glycoprotein I (anti-?2GPI) testing are needed. We evaluated the suitability of polyclonal/monoclonal candidate reference materials (RM) for the assay. IgG/IgM anti-?2GPI were affinity-purified (AP) from high-positive antiphospholipid syndrome sera and IgG from HCAL clone supernatant. Igs were tested for purity by SDS-PAGE, pooled, concentrated, sterile-filtered and the protein concentration determined. One unit was defined as the binding activity of 1?µg/ml of AP anti-?2GPI Ig. IgG/IgM RM were each assigned a unit value using the respective AP material as a calibrator. Polyclonal/monoclonal RM and 30 samples were evaluated for linearity, unit equivalency and commutability. Polyclonal AP material was assigned a value of 100 U IgG and 15?U IgM anti-?2GPI, respectively. IgG-RM had a value of 270 IgG and the IgM-RM of 220.3 IgM anti-?2GPI U. The linearity (R (2)) of each RM curve for the various assays ranged from 0.96 to 0.99. Commutability samples fit very well within 95% prediction intervals and had excellent correlation when comparing assays. IgG and IgM polyclonal and IgG monoclonal RM displayed excellent linearity and commutability, being good candidates for better standardization of anti-?2GPI immunoassays. PMID:25228737

Willis, R; Grossi, C; Orietta Borghi, M; Martos-Sevilla, G; Zegers, I; Sheldon, J; Meroni, Pl

2014-10-01

167

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

PubMed

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

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

2013-07-01

168

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

169

Predation: Prey plumage adaptation against falcon attack.  

PubMed

Several plumage types are found in feral pigeons (Columba livia), but one type imparts a clear survival advantage during attacks by the swiftest of all predators--the peregrine falcon (Falco peregrinus). Here we use quantitative field observations and experiments to demonstrate both the selective nature of the falcon's choice of prey and the effect of plumage coloration on the survival of feral pigeons. This plumage colour is an independently heritable trait that is likely to be an antipredator adaptation against high-speed attacks in open air space. PMID:15846334

Palleroni, Alberto; Miller, Cory T; Hauser, Marc; Marler, Peter

2005-04-21

170

Prey detection of aquatic predators: Assessing the identity of chemical cues eliciting prey behavioral plasticity  

E-print Network

Dragonfly larvae a b s t r a c t Chemical cues transmitted through the environment are thought to underlie of such cues, their basic composition are poorly understood. Using anuran tadpoles (prey) and dragonfly larvae spectrometry of the extracts. We found that dragonfly larvae predators consistently produced a negative ion, m

171

Effects of predator removal on vertebrate prey populations: birds of prey and small mammals  

Microsoft Academic Search

We studied the effects of removal of breeding nomadic avian predators (the kestrel, Falco tinnunculus and Tengmalm's owl, Aegolius funereus) on small mammals (voles of the genera Microtus and Clethrionomys and the common shrew, Sorex araneus) during 1989–1992 in western Finland to find out if these predators have a regulating or limiting impact on their prey populations. We removed potential

Kai Norrdahl; Erkki Korpimäki

1995-01-01

172

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

PubMed Central

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

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

2013-01-01

173

Female Infertility  

MedlinePLUS

... keeps having miscarriages, it is also called infertility. Female infertility can result from physical problems, hormone problems, ... or environmental factors. Most cases of infertility in women result from problems with producing eggs. One problem ...

174

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

175

Functional responses: a question of alternative prey and predator density.  

PubMed

Throughout the study of ecology, there has been a growing realization that indirect effects among species cause complexity in food webs. Understanding and predicting the behavior of ecosystems consequently depends on our ability to identify indirect effects and their mechanisms. The present study experimentally investigates indirect interactions arising between two prey species that share a common predator. In a natural field experiment, we introduced different densities of mealworms (Tenebrio molitor), an alternative prey, to a previously studied predator-prey system in which paper wasps (Polistes dominulus) preyed on shield beetle larvae (Cassida rubiginosa). We tested if alternative prey affects predation on the first prey (i.e., the predator-dependent functional response of paper wasps) by modifying either interference among predators or the effective number of predators foraging on shield beetles. Presence of mealworms significantly reduced the effective number of predators, whereas predator interference was not affected. In this way, the experimentally introduced alternative prey altered the wasps' functional response and thereby indirectly influenced C. rubiginosa density. In all prey-density combinations offered, paper wasps constantly preferred T. molitor. This led to an asymmetrical, indirect interaction between both prey species: an increase in mealworm density significantly relaxed predation on C. rubiginosa, whereas an increase in C. rubiginosa density intensified predation on mealworms. Such asymmetrical outcomes of a fixed food preference can significantly affect the population dynamics of the species involved. In spite of the repeated finding of a Type III functional response in this system, our experiment did not reveal switching behavior in paper wasps. The variety of mechanisms underlying direct and indirect interactions within our study system exemplifies the importance of incorporating alternative prey when investigating the impact of a generalist predator on a focal prey population under realistic field conditions. PMID:17536415

Tschanz, Britta; Bersier, Louis-Felix; Bacher, Sven

2007-05-01

176

Status of IGS Core Products  

NASA Astrophysics Data System (ADS)

The International GNSS Service (IGS) generally aims to provide ~1 cm satellite orbits and ~1 mm terrestrial frame products to meet the most demanding user needs. While the goal has not yet been met, the IGS has made good progress. The current Global Positioning System (GPS) Final orbits have accuracies better than 2.5 cm; the Rapids are of similar quality; and the near real-time parts of the Ultra-rapids have an accuracy of ~3.0 cm, while the real-time parts have an accuracy of about 5 cm. About half of the total error in the GPS orbits can be attributed to systematic time-varying rotational misalignment of the orbital frames; the other half is dominated by sub-daily tidal variations in Earth orientation. Near-field multi-path errors, anthropogenic changes at tracking stations, and the presence of uncalibrated GNSS antenna radomes at multi-technique sites continue to be a significant source of error in the terrestrial frame products. While recent model and analysis changes have reduced some errors, others will remain for the foreseeable future. This paper will summarize the current quality state of the IGS Final, Rapid and Ultra-rapid products as preparations for the next reprocessing campaign continue.

Griffiths, J.

2013-12-01

177

Sensory biology: listening in the dark for echoes from silent and stationary prey.  

PubMed

New research shows how bats use echolocation unexpectedly to detect silent and stationary prey in darkness. Bats may use acoustic search images to identify potential prey when prey-generated noises, visual and olfactory cues are absent. PMID:23518059

Jones, Gareth

2013-03-18

178

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

179

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

180

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

181

Effect of temperature, prey density, vegetation, and BTI on development and predation by Psorophora ciliata (Fabricius)  

E-print Network

. Depletion prey density studies (where missing or dead larvae were not replaced) demonstrated that prey densities ranging from 100 to 250 larvae per pan were needed for completion of predator development. Total consumption and killing in both constant... and depletion prey densities ranged from 74 to 159 prey per predator depending upon temperature and prey density tested. Neither prey species nor presence or absence of vegetation in rearing pans appeared to influence rate of development or predation...

Atwood, Donald Wayne

2012-06-07

182

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

183

Piscivore-Prey Fish Interactions: Mechanisms behind Diurnal Patterns in Prey Selectivity in Brown and Clear Water  

PubMed Central

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

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

2014-01-01

184

Predator induced defenses in prey with diverse predators  

E-print Network

PREDATOR INDUCED DEFENSES IN PREY WITH DIVERSE PREDATORS A Thesis by MARK ISAAC GARZA Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements... for the degree of MASTER OF SCIENCE December 2005 Major Subject: Wildlife and Fisheries Sciences PREDATOR INDUCED DEFENSES IN PREY WITH DIVERSE PREDATORS A Thesis by MARK ISAAC GARZA...

Garza, Mark Isaac

2006-04-12

185

Dynamics of Prey Capture and Escape Wednesday, March 6th  

E-print Network

-selective visual neurons in the dragonfly 12:00 pm Anthony Leonardo, Janelia Farm Research Campus/HHMI Guidance laws underlying prey capture in the dragonfly 12:25 pm Jérôme Casas, UMR CNRS Search games in predator general are predator-prey interactions? Comparative flight mechanics and strategy of dragonflies pursuing

Eddy, Sean

186

Dynamics of Prey Capture and Escape Wednesday, March 6th  

E-print Network

-selective visual neurons in the dragonfly 12:00 pm Anthony Leonardo, Janelia Farm Research Campus/HHMI Guidance laws underlying prey capture in the dragonfly 12:25 pm Jérôme Casas, UMR CNRS Search games in predator flight mechanics and strategy of dragonflies pursuing dipteran prey 10:40 am Break 11:10 am Session 6

Eddy, Sean

187

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

188

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

189

Avian prey-dropping behavior. II. American crows and walnuts  

Microsoft Academic Search

Complex and energetically expensive foraging tasks should be shaped by natural selection to be efficient. Many species of birds open hard-shelled prey by dropping the prey repeatedly onto the ground from considerable heights. Urban-dwelling American crows (Corvus brachyrhynchos) forage in this way on two species of walnuts in central California, USA. As predicted from a theoretical model, crows dropped nuts

Daniel A. Cristola; Paul V. Switzer

190

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

191

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

192

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

193

Tactile guidance of prey capture in Etruscan shrews  

PubMed Central

Whereas visuomotor behaviors and visual object recognition have been studied in detail, we know relatively little about tactile object representations. We investigate a new model system for the tactile guidance of behavior, namely prey (cricket) capture by one of the smallest mammals, the Etruscan shrew, Suncus etruscus. Because of their high metabolic rate and nocturnal lifestyle, Etruscan shrews are forced to detect, overwhelm, and kill prey in large numbers in darkness. Crickets are exquisitely mechanosensitive, fast-moving prey, almost as big as the shrew itself. Shrews succeed in hunting by lateralized, precise, and fast attacks. Removal experiments demonstrate that both macrovibrissae and microvibrissae are required for prey capture, with the macrovibrissae being involved in attack targeting. Experiments with artificial prey replica show that tactile shape cues are both necessary and sufficient for evoking attacks. Prey representations are motion- and size-invariant. Shrews distinguish and memorize prey features. Corrective maneuvers and cricket shape manipulation experiments indicate that shrew behavior is guided by Gestalt-like prey descriptions. Thus, tactile object recognition in Etruscan shrews shares characteristics of human visual object recognition, but it proceeds faster and occurs in a 20,000-times-smaller brain. PMID:17060642

Anjum, Farzana; Turni, Hendrik; Mulder, Paul G. H.; van der Burg, Johannes; Brecht, Michael

2006-01-01

194

Ambient temperature influences birds' decisions to eat toxic prey?  

PubMed Central

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.

2013-01-01

195

Prey abundance and food habit of tigers (Panthera tigris tigris)  

Microsoft Academic Search

Abstract Food habits of tigers Panthera tigris and population attributes of prey species (population structure, density and biomass) were studied in the tropical dry deciduous forest of Pench National Park, Central India, from November 1998 to April 1999. Scat analysis and line transect method were used to estimate tiger food habits and density of major prey species, respectively. The 61.1

S. Biswas; K. Sankar

196

Extirpation of alternative prey during a small rodent crash  

Microsoft Academic Search

We document two episodes, in different years, of Barn Owls (Tyto alba) preying on a winter population of Burrowing Owls (Athene cunicularia) on a southern California island. The predation in each case followed a marked shift in the diet of the Barn Owls, due to the cyclic decline of their normal small mammal prey. Heavy predation in the first year

Charles A. Drost; Reed C. McCluskey

1992-01-01

197

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

198

Size-dependent prey selection in piscivorous pikeperch Sander lucioperca and Volga pikeperch Sander volgensis shaped by bimodal prey size distribution.  

PubMed

Prey size and species selection of pikeperch Sander lucioperca and Volga pikeperch Sander volgensis were investigated in relation to predator size in the shallow Lake Balaton, Hungary. Although their gape sizes were similar, S. lucioperca shifted to piscivory earlier and consumed fewer, but larger, prey than S. volgensis. Prey species preference of the two piscivores also differed. A bimodal prey size distribution resulted in a reclining sigmoid curve for the life span predator size to prey size relationship with inflexion points between 266 and 284 mm predator standard length (L(S) ) in S. lucioperca. In S. volgensis, as well as in S. lucioperca L(S) ? 350 mm, prey size increased monotonically with predator L(S) , following a power trend for all prey size variables. Prey depth to predator L(S) relationship varied significantly with prey species and prey number in both piscivores, and prey depth tended to be smaller in predators consuming more than one prey. Both predator species characteristically selected less active, benthic prey fishes in spite of their spiny fin rays, and small- and mid-sized predators selected for small prey. Relatively large prey were also eaten, however, especially by the smallest and largest S. lucioperca. PMID:22141894

Specziár, A

2011-12-01

199

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

200

CUES BY WHICH PORTIA FIMBRIATA, AN ARANEOPHAGIC JUMPING SPIDER, DISTINGUISHES JUMPING-SPIDER PREY FROM OTHER PREY  

Microsoft Academic Search

Portia fimbriata from Queensland, Australia, is an araneophagic jumping spider (Salticidae) that includes in its predatory strategy a tactic (cryptic stalking) enabling it to prey effectively on a wide range of salticids from other genera. Optical cues used by P. fimbriata to identify the salticid species on which it most commonly preys, Jacksonoides queenslandicus, were investigated experimentally in the laboratory

DUANE P. HARLAND; ROBERT R. JACKSON

201

Predation by xanthid crabs on early post-settlement gastropods: the role of prey size, prey density, and habitat complexity  

Microsoft Academic Search

Small predators in marine benthic communities create a hazardous environment for newly settled invertebrates, especially for the smallest individuals. To explore the effects of predation on a newly settled gastropod, queen conch (Strombus gigas Linnaeus), by a xanthid crab (Micropanope sp.), prey size, prey density, and habitat complexity were manipulated in five laboratory experiments. All crabs >3.1 mm CW killed

Melody Ray-Culp; Megan Davis; Allan W Stoner

1999-01-01

202

Effects of Predation by Nonnative Smallmouth Bass on Native Salmonid Prey: The Role of Predator and Prey Size  

Microsoft Academic Search

The size of predators that consume the most fish and the size of prey fish that are the most vulnerable to predation are important factors to consider when assessing the predation risks to valued prey fish such as Chinook salmon Oncorhynchus tshawytscha in the Pacific Northwest. We found that native salmonids' risk of predation by nonnative smallmouth bass Micropterus dolomieu

Anthony L. Fritts; Todd N. Pearsons

2006-01-01

203

Occurrence of IgA Subclasses (IgA1 and IgA2) in the Human Nervous System  

Microsoft Academic Search

The occurrence of IgA subclasses in pathological conditions of the nervous system was studied by means of monoclonal antibodies and an indirect immunofluorescence technique. IgA1- and\\/or IgA2-positive lymphoid (plasma) cells were found in demyelinating diseases comprising multiple sclerosis, Guillain-Barré syndrome, and adrenoleukodystrophy, in various inflammatory diseases, and in tumors, some of which exhibited labeling of tumor cells. Demyelinating and inflammatory

H. Budka; H. Bernheimer; J. J. Haaijman; J. Radl

1985-01-01

204

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

PubMed Central

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

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

2013-01-01

205

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

PubMed

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

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

2013-01-01

206

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

207

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

PubMed

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

Kutzer, E; Frey, H; Kotremba, J

1980-11-01

208

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

2011-01-01

209

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

210

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

211

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

PubMed

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. PMID:22145037

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

2011-01-01

212

Low molecular weight IgM in selective IgA deficiency.  

PubMed Central

Thirty-nine persons with selective IgA deficiency were studied. These comprised 27 subjects found by population screening and 12 by other means. Low molecular weight (LMW) serum IgM was sought in 28 of the 39 persons. Nine of the 28 (32%) had LMW IgM detectable by a sensitive gel filtration technique. Of 17 patients discovered by screening, five (29%) had LMW IgM. In the nine positive persons, LMW IgM constituted up to 17% of the total serum IgM concentration. Eight of the nine IgA deficient persons with LMW IgM, had clinical disease while associated disease in the entire IgA deficient population was less frequent. Serum immune complexes were demonstrated in five of seven subjects with LMW IgM using a C1q-dependent radioimmunoassay; four of these had immune complex associated disorders, three with polyarthritis and one with glomerulonephritis. Because circulating immune complexes are frequently detected in IgA deficient persons without disease, it is proposed that the presence of LMW serum IgM in IgA deficiency may be associated with disease due to the formation of specific pathogenic immune complexes. PMID:7172505

Kwitko, A O; Roberts-Thomson, P J; Shearman, D J

1982-01-01

213

Allergen-specific IgE and IgGd antibodies in atopic and normal dogs.  

PubMed

Intradermal skin tests (IDSTs) were performed on 65 atopic and 24 normal dogs. The levels of allergen-specific IgE and IgGd antibodies were determined in serum samples by enzyme-linked immunosorbent assay (ELISA) using the same 12 allergens that were used in the IDST on normal dogs. The correlation between the levels of IgE and IgGd to Dermatophagoides farinae (DF) and Dermatophagoides pteronyssinus (DP) was examined. The sensitivity, specificity and positive and negative predictive values of allergen-specific IgE and IgGd levels in the total dog population were also compared. Results were consistent and reproducible for 9/12 allergens, but in the case of house dust, flea and Alternaria tenuis, a less discriminating standard curve and the fact that the negative control gave positive results, suggests non-specific binding and that these allergens are complex and should not be employed without further purification. A high percentage of atopic dogs had positive IDSTs and detectable IgE and IgGd antibodies to DF, DP and house dust. Similar results were obtained in the normal dog population. There were significant correlations between allergen-specific IgE and IgGd levels to DF and DP. However, in contrast to IgE, allergen-specific IgGd in normal dogs was higher than in atopic dogs. Furthermore, a high percentage of the atopic population had detectable IgGd to unrelated allergens, despite negative IDSTs. Overall, the negative predictive values were similar for both IgE and IgGd. Sensitivities were higher in the allergen-specific IgGd assays, but the specificities and positive predictive values were higher in the allergen-specific IgE assays. In conclusion, the concordance of IDSTs with ELISA results to DF and DP in normal dogs without clinical signs implied the possible heterogeneity of IgE in dogs. The presence of IgGd directed against apparently irrelevant allergens in atopic patients and the high levels of IgGd in normal dogs to the most common allergens, DF and DP, implied an uncertain role of IgGd in canine atopic disease. Therefore, the detection of allergen-specific IgE is a more useful adjunct to the diagnosis of atopic disease in the dog than IgGd. PMID:9880099

Lian, T M; Halliwell, R E

1998-12-11

214

Porcine allergy and IgE  

Microsoft Academic Search

Anaphylaxis was reported in 1963 in pigs experimentally sensitized with ovalbumin and was subsequently associated indirectly with IgE-related antibodies by functional assays to confirm heat-labile passive cutaneous anaphylaxis (PCA), reverse passive anaphylaxis (RPA) and Prausnitz–Küstner (PK) reactions to this and other allergens. The immunoglobulin mediating immediate hypersensitivity could be cross-adsorbed with anti-human IgE. Porcine IgE epsilon chain has been cloned

Prithy Rupa; Julie Schmied; Bruce N. Wilkie

2009-01-01

215

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

216

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

217

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

218

Tonically immobilized selfish prey can survive by sacrificing others.  

PubMed

Death-feigning, also called tonic immobility, is found in a number of animal species across vertebrate and invertebrate taxa. To date, five hypotheses have been proposed for the adaptive significance of tonic immobility. These are that tonic immobility is effective for prey because (i) avoiding dead prey is safer for predators, (ii) immobility plays a role in physical defence, (iii) immobility plays a role in concealment and/or background matching, (iv) predators lose interest in unmoving prey, and (v) the characteristic immobilization posture signals a bad taste to predators. The fourth and fifth hypotheses have been considered suitable explanations for tonic immobility of the red flour beetle against its predator, the jumping spider. In the present study, we used chemical analyses of secretions by the red flour beetles under attack by the jumping spider to reject the fifth hypothesis for this system. More importantly, we tested a selfish-prey hypothesis for the adaptive significance of death-feigning as an anti-predator strategy, in which individuals adopting tonic immobility survive by sacrificing neighbours. Findings showed that survival rates of feigners were higher when in the presence of non-feigners or prey of a different species, compared to when alone, thus confirming our selfish-prey hypothesis. In summary, our results suggest that immobility following a spider attack is selfish; death-feigning prey increase their probability of survival at the expense of more mobile neighbours. PMID:19403540

Miyatake, Takahisa; Nakayama, Satoshi; Nishi, Yusuke; Nakajima, Shuhei

2009-08-01

219

Tactile experience shapes prey-capture behavior in Etruscan shrews  

PubMed Central

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

Anjum, Farzana; Brecht, Michael

2012-01-01

220

Effect of prey richness on a consumer's intrinsic growth rate.  

PubMed

The intrinsic growth rate of non-selective microbivores increases asymptotically with increasing prey biomass, but we do not know how intrinsic growth rate is affected by prey richness. The objective of this experiment was to determine the effect of prey richness on the growth kinetics of nematode predators while grazing on mixed bacterial lawns. We found that the intrinsic growth rate of Caenorhabditis elegans in laboratory culture increased asymptotically with prey richness. The mechanism of this pattern was primarily due to the best available prey species in the mixture: the intrinsic growth rate of the consumer feeding on a mixture of prey was approximately equal to the intrinsic growth rate of the predator when feeding on the single best prey in monoculture. This was analogous to the selection effect observed in biodiversity-ecosystem functioning relationships. Generation time, and not reproductive output, was the life history trait component that was most consistent with the pattern of intrinsic growth rate. Our results suggest that in order to link invertebrate consumers' growth rates to their microbial species composition in the field, it will be necessary to determine the ability of microbivorous invertebrates to selectively forage in natural environments and to better understand the micro-scale distribution of microbial communities in their natural environments. PMID:24453006

Darby, Brian J; Herman, Michael A

2014-05-01

221

Tonically immobilized selfish prey can survive by sacrificing others  

PubMed Central

Death-feigning, also called tonic immobility, is found in a number of animal species across vertebrate and invertebrate taxa. To date, five hypotheses have been proposed for the adaptive significance of tonic immobility. These are that tonic immobility is effective for prey because (i) avoiding dead prey is safer for predators, (ii) immobility plays a role in physical defence, (iii) immobility plays a role in concealment and/or background matching, (iv) predators lose interest in unmoving prey, and (v) the characteristic immobilization posture signals a bad taste to predators. The fourth and fifth hypotheses have been considered suitable explanations for tonic immobility of the red flour beetle against its predator, the jumping spider. In the present study, we used chemical analyses of secretions by the red flour beetles under attack by the jumping spider to reject the fifth hypothesis for this system. More importantly, we tested a selfish-prey hypothesis for the adaptive significance of death-feigning as an anti-predator strategy, in which individuals adopting tonic immobility survive by sacrificing neighbours. Findings showed that survival rates of feigners were higher when in the presence of non-feigners or prey of a different species, compared to when alone, thus confirming our selfish-prey hypothesis. In summary, our results suggest that immobility following a spider attack is selfish; death-feigning prey increase their probability of survival at the expense of more mobile neighbours. PMID:19403540

Miyatake, Takahisa; Nakayama, Satoshi; Nishi, Yusuke; Nakajima, Shuhei

2009-01-01

222

Omalizumab may decrease IgE synthesis by targeting membrane IgE+ human B cells  

E-print Network

Omalizumab, is a humanized anti-IgE monoclonal antibody used to treat allergic asthma. Decreased serum IgE levels, lower eosinophil and B cell counts have been noted as a result of treatment. In vitro studies and animal ...

Chan, Marcia A.; Gigliotti, Nicole M.; Dotson, Abby Louise; Rosenwasser, Lanny J.

2013-09-02

223

Predator size, prey size and threshold food densities of diving ducks: does a common prey base support fewer large animals?  

PubMed

1. Allometry predicts that a given habitat area or common prey biomass supports fewer numbers of larger than smaller predators; however, birds from related taxa or the same feeding guild often deviate from this pattern. In particular, foraging costs of birds may differ among locomotor modes, while intake rates vary with accessibility, handling times and energy content of different-sized prey. Such mechanisms might affect threshold prey densities needed for energy balance, and thus relative numbers of different-sized predators in habitats with varying prey patches. 2. We compared the foraging profitability (energy gain minus cost) of two diving ducks: smaller lesser scaup (Aythya affinis, 450-1090 g) and larger white-winged scoters (Melanitta fusca, 950-1800 g). Calculations were based on past measurements of dive costs with respirometry, and of intake rates of a common bivalve prey ranging in size, energy content and burial depth in sediments. 3. For scaup feeding on small prey <12 mm long, all clams buried deeper than 5 cm were unprofitable at realistic prey densities. For clams buried in the top 5 cm, the profitability threshold decreased from 216 to 34 clams m(-2) as energy content increased from 50 to 300 J clam(-1). 4. For larger scoters feeding on larger prey 18-24 mm long, foraging was profitable for clams buried deeper than 5 cm, with a threshold density of 147 m(-2) for clams containing 380 J clam(-1). For clams <5 cm deep, the threshold density decreased from 86 to 36 clams m(-2) as energy content increased from 380 to 850 J clam(-1). If scoters decreased dive costs by swimming with wings as well as feet (not an option for scaup), threshold prey densities were 11-12% lower. 5. Our results show that threshold densities of total prey numbers for different-sized ducks depend on prey size structure and depth in the sediments. Thus, heterogeneity in disturbance regimes and prey population dynamics can create a mosaic of patches favouring large or small predators. Whether a given area or total prey biomass will support greater numbers of larger or smaller predators will vary with these effects. PMID:19426253

Richman, Samantha E; Lovvorn, James R

2009-09-01

224

Galactose-deficient IgA1 in sera of IgA nephropathy patients is present in complexes with IgG  

Microsoft Academic Search

Galactose-deficient IgA1 in sera of IgA nephropathy patients is present in complexes with IgG. IgA1 proteins from sera of patients with IgA nephropathy (IgAN) are galactosylated to a lesser degree than those from healthy controls. The increased reactivity of intact or de-sialylated serum IgA1 with N-acetylgalactosamine (GalNAc)-specific lectins, Helix aspersa (HAA) and Caragana arborescens (CAA) and de-sialylated IgA1 with Helix

Milan Tomana; Karel Matousovic; Bruce A Julian; Jiri Radl; Karel Konecny; Jiri Mestecky

1997-01-01

225

Aberrant IgA1 Glycosylation Is Inherited in Familial and Sporadic IgA Nephropathy  

Microsoft Academic Search

IgA nephropathy (IgAN) is a complex trait determined by genetic and environmental factors. Most IgAN patients exhibit a characteristic undergalactosylation of the O-glycans of the IgA1 hinge region, which promotes formation and glomerular deposition of immune complexes. It is not known whether this aberrant glycosylation is the result of an acquired or inherited defect, or whether the presence of aberrant

Ali G. Gharavi; Zina Moldoveanu; Robert J. Wyatt; Catherine V. Barker; Susan Y. Woodford; Richard P. Lifton; Jiri Mestecky; Jan Novak; Bruce A. Julian

2008-01-01

226

A Novel Chimeric Ig Heavy Chain from a Teleost Fish Shares Similarities to IgD  

Microsoft Academic Search

IgD is considered to be a recently evolved Ig, being previously found only in primates and rodents. Here we describe, from a teleost fish (the channel catfish, Ictalurus punctatus), a novel complex chimeric Ig heavy chain, homologous, in part, to the heavy chain (delta ) of IgD. In addition to alternative secretory or membrane-associated C termini, this chimeric molecule contains

Melanie Wilson; Eva Bengten; Norman W. Miller; L. William Clem; Louis Du Pasquier; Gregory W. Warr

1997-01-01

227

IgA glycosylation and IgA immune complexes in the pathogenesis of IgA Nephropathy  

PubMed Central

Circulating immune complexes containing aberrantly glycosylated IgA1 play a pivotal role in the pathogenesis of IgAN. A portion of IgA1 secreted by IgA1-producing cells in patients with IgAN is galactose-deficient and consequently recognized by anti-glycan IgG or IgA1 antibodies. Some of the resultant immune complexes in the circulation escape normal clearance mechanisms, deposit in the renal mesangium, and induce glomerular injury. Recent studies of the origin of these aberrant molecules, their glycosylation profiles, and mechanisms of biosynthesis have provided new insight into the autoimmune nature of the pathogenesis of this common renal disease. An imbalance in the activities of the pertinent glycosyltransferases in the IgA1-producing cells favors production of molecules with galactose-deficient O-linked glycans at specific sites in the hinge region of the alpha heavy chains. Using sophisticated analytical methods, it may be possible to define biomarkers for diagnostic purposes and identify new therapeutic targets for a future disease-specific therapy. PMID:18222349

Novak, Jan; Julian, Bruce A.; Tomana, Milan; Mestecky, Jiri

2008-01-01

228

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

PubMed Central

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

Jablonski, P. G.

2001-01-01

229

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

PubMed

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

Jab?onski, P G

2001-05-22

230

Cannibalism and intraguild predation among phytoseiid mites: are aggressiveness and prey preference related to diet specialization?  

PubMed

We tested whether specialist and generalist phytoseiid mites differ in aggressiveness and prey choice in cannibalism and intraguild predation. Specialists tested were Galendromus occidentalis, Neoseiulus longispinosus, Phytoseiulus persimilis, and P. macropilis; generalists tested were Amblyseius andersoni, Euseius finlandicus, E. hibisci, Kampimodromus aberrans, Neoseiulus barkeri, N. californicus, N. cucumeris, NM fallacis, and Typhlodromus pyri. Aggressiveness of cannibalistic females against larvae was not related to diet specialization except that highly aggressive species were exclusively generalists. Seldom to moderately cannibalizing species occurred in both generalist and specialist phytoseiids. In contrast to aggressiveness in cannibalism, generalists and specialists differed in aggressiveness in intraguild predation. Adult females of specialists were only slightly aggressive against heterospecific larvae, whereas adult females of all generalists except T. pyri were highly aggressive. Adult females of generalists were able to discriminate between con- and heterospecific larvae and preferentially consumed the latter when given a choice. Adult females of specialists except G. occidentalis showed no preference when given a choice between con- and heterospecific larvae. We conclude that aggressiveness in intraguild predation, species recognition and subsequent preferential consumption of heterospecifics when given a choice is common in generalist but not specialist phytoseiids. We discuss the evolutionary pathways that might have led to the difference between specialists and generalists in species discrimination. PMID:11227828

Schausberger, P; Croft, B A

2000-01-01

231

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

232

Biopsy-Proven Recurrence of Unilateral IgG4-Related Orbital Inflammation after 20 years.  

PubMed

Abstract 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

233

Capture Success and Efficiency of Dragonflies Pursuing Different Types of Prey  

E-print Network

SYMPOSIUM Capture Success and Efficiency of Dragonflies Pursuing Different Types of Prey S. A of libelluid dragonflies pursuing 4 types of dipteran prey, spanning a range of sizes. We quantified and the distance flown in pursuit of prey (capture efficiency). Our results show that dragonfly prey

Combes, Stacey A.

234

Factors determining the prey size of the orb-web spider, Argiope amoena (L. Koch) (Argiopidae)  

Microsoft Academic Search

Argiope amoena is a common web spider in southwestern Japan. Surveys were made of prey size by use of prey traps and by direct observations, and of potential prey size by use of the sweeping method. The web size, web mesh size, spider size, and spider's effective size on prey capture were also measured. Hymenoptera, Coleoptera, and Hemiptera were important

Yasuaki Murakami

1983-01-01

235

DOES THE PRESENCE OF POTENTIAL PREY AFFECT WEB DESIGN IN ARGIOPE KEYSERLINGI (ARANEAE, ARANEIDAE)?  

Microsoft Academic Search

Orb-web spiders may anticipate their future prey environment by detecting the presence of prey and adjusting their web building behavior accordingly. Here we investigate the effect of different prey sizes and density on the web size and mesh height of the orb webs constructed by Argiope keyserlingi. The experimental design allowed the transmission of prey vibrations but prevented any capture.

Marie E. Herberstein; Anne C. Gaskett; Deborah Glencross; Simon Hart; Sue Jaensch; Mark A. Elgar

2000-01-01

236

Availability of Clupeid Prey to Primary Piscivores in Smith Mountain Lake, Virginia  

Microsoft Academic Search

Prey supply to predators is limited by the morphology, behavior, and spatial distributions of both predator and prey. To be eaten, prey must co-occur spatially and temporally with the predator (distribution), the predator must recognize the prey as potential food and successfully capture it (behavior), and the predator must have a mouth large enough to ingest its target (morphology). We

Michael J. Cyterski; John J. Ney

2005-01-01

237

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

238

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

E-print Network

Flexibility in assessment of prey cues: frog-eating bats and frog calls Rachel A. Page1; Physalaemus pustulosus 1. INTRODUCTION It is critical that predators do not eat poisonous prey. Towards- fulness. Many studies of aposematism have investigated predators' associations of prey cue and prey

Ryan, Michael J.

239

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

240

Ecology of fear: Foraging games between predators and prey with pulsed resources  

Microsoft Academic Search

We model the foraging game between a prey and predator when the prey experiences a temporally pulsed resource (e.g., seed-eating gerbils). Animals have the options of foraging or remaining inactive. Prey harvest resources and incur a mortality risk only while foraging. ESS levels of prey and predator activity have three distinct phases over the time course of a resource pulse.

Joel S. Brown; Burt P. Kotler; Amos Bouskila

241

Evolving predator and prey behaviours with co-evolution using genetic programming and decision trees  

Microsoft Academic Search

Developing artificial behaviours to control artificial creatures or vehicles is a task that can be solved by means of Evolu- tionary Algorithms. The Predator and Prey is a problem where it is possible to evolve behaviours for both predator and prey, using artificial co-evolution: the predator must capture the prey and the prey must evade the predator. Both predator and

Tiago Francisco; Gustavo Miguel Jorge Dos Reis

2008-01-01

242

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

PubMed

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

243

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; Gunnbjornsdottir, Maria; Borres, Magnus P.; Burney, Peter; Gislason, Thorarinn; Toren, Kjell; Forsberg, Bertil; Alving, Kjell

2014-01-01

244

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

245

IgA antibodies in Rett syndrome  

Microsoft Academic Search

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

K. L. Reichelt; O. Skjeldal

2006-01-01

246

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; Korpimaki, E

2000-01-01

247

Recolonizing carnivores and naïve prey: conservation lessons from Pleistocene extinctions.  

PubMed

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 naive animals first encountered colonizing human hunters. Along present-day carnivore recolonization fronts, brown (also called grizzly) bears killed predator-naive adult moose at disproportionately high rates in Scandinavia, and moose mothers who lost juveniles to recolonizing wolves in North America's Yellowstone region developed hypersensitivity to wolf howls. Although prey that had been unfamiliar with dangerous predators for as few as 50 to 130 years were highly vulnerable to initial encounters, behavioral adjustments to reduce predation transpired within a single generation. The fact that at least one prey species quickly learns to be wary of restored carnivores should negate fears about localized prey extinction. PMID:11161215

Berger, J; Swenson, J E; Persson, I L

2001-02-01

248

Prey preferences of specialized jumping spiders (Araneae : Salticidae).  

E-print Network

??I studied prey preferences of two groups of specialized jumping spiders (Salticidae), ant-eating ('myrmicophagic') species and spider-eating ('araneophagic') species, in the laboratory. Spiders and ants… (more)

Daiquin, Li

1996-01-01

249

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

250

[IgG4-related sclerosing disease].  

PubMed

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

Kazantsev, I A; Lishchuk, S V

2011-01-01

251

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

252

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

253

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

254

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

255

IgG2 antibodies block IgE antibody-induced asthma in guinea pigs.  

PubMed

In order to examine the blocking activity of IgG2 antibodies to guinea pig for IgE antibodies-induced guinea pig asthma, experiments were carried out as follows. Guinea pigs were passively sensitized intravenously with guinea pig serum containing IgE antibodies to ovalbumin (OA). 8 days after sensitization, IgG2 purified from guinea pigs hyperimmunized with OA was intravenously injected. One hour later, the guinea pigs were challenged by inhalation of OA solution. Asthma attacks were not observed in the guinea pigs, whereas the attacks were observed in guinea pigs passively sensitized with the IgE antibodies but injected IgG2 fraction from normal guinea pigs 1 h before inhalation. These observations suggested that IgG antibodies that increased after immunotherapy might block asthma caused by inhalation of allergens in humans. PMID:3957447

Yamauchi, N; Ito, K; Suko, M; Ishii, A; Miyamoto, T

1986-01-01

256

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

257

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

258

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

Microsoft Academic Search

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

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

2005-01-01

259

Naïve prey exhibit reduced antipredator behavior and survivorship  

PubMed Central

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, naïve 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 Lacépède, 1802). Using farm-reared, naïve crayfish and wild-caught, experienced individuals, laboratory experiments demonstrated that naïve, 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 naïve 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

2014-01-01

260

Trait-mediated diversification in nematode predator-prey systems.  

PubMed

Nematodes are presumably the most numerous Metazoans in terrestrial habitats. They are represented at all trophic levels and are known to respond to nutrient limitation, prey availability, and microbial resources. Predatory nematodes reside at the highest trophic level, and as such their feeding habits could have a major impact on soil food web functioning. Here, we investigate the effects of gender and developmental stage on the nematode body sizes in coarse and loamy soils. Besides Neodiplogasteridae, our predators are much larger than other soil-dwelling nematodes from their early developmental stage onwards. From juvenile to adult, the predatory Aporcelaimellus (Kruskal-Wallis P < 0.001), Dorylaimoides, and Tripyla (both P < 0.01) show great length increases during their developmental growth, in contrast to their possible prey (almost all P < 0.001). Less than 4% of the prey exceeds the length of the predatory adults, but more than 30% of the prey exceeds the length of the predatory juveniles. Potential body size ratios and some physical problems experienced by small fluid feeders attacking large prey are discussed in an attempt to summarize different prey-searching mechanisms and aggregative predatory responses in the soil system. PMID:22393508

Mulder, Christian; Helder, Johannes; Vervoort, Mariëtte T W; Arie Vonk, J

2011-11-01

261

Honest signaling and the uses of prey coloration.  

PubMed

Abstract Although signal reliability is of fundamental importance to the understanding of animal communication, the extent of signal honesty in relation to antipredator warning signals has received relatively little attention. A recent theoretical model that assumed a physiological linkage between pigmentation and toxicity suggested that (aposematic) warning signals may often be reliable, in the sense that brightness and toxicity are positively correlated within prey populations. Two shortcomings of the model were (1) the requirement among predators for an innate aversion to brightly colored prey and (2) the assumption that prey can generate only bright coloration and not cryptic coloration. We evaluated the generality of predictions of reliable signaling when these shortcomings were removed. Without innate avoidance of bright prey, we found a positive brightness-toxin correlation when conspicuous prey coloration provided an additional fitness benefit unrelated to predation. Initially, this correlation could evolve for reasons unrelated to prey signaling; hence, aposematism might represent a striking example of exaptation. Given a choice between using pigmentation for bright or for cryptic coloration, crypsis was favored only in conditions of very low or very high resource levels. In the latter case, toxicity correlated positively with degree of cryptic coloration. Predictions of toxin-signal correlation appear robust, but we can identify interesting conditions in which signal reliability is not predicted. PMID:21670571

Lee, Thomas J; Speed, Michael P; Stephens, Philip A

2011-07-01

262

Galactose-deficient IgA1 in sera of IgA nephropathy patients is present in complexes with IgG.  

PubMed

IgA1 proteins from sera of patients with IgA nephropathy (IgAN) are galactosylated to a lesser degree than those from healthy controls. The increased reactivity of intact or de-sialylated serum IgA1 with N-acetylgalactosamine (GalNAc)-specific lectins, Helix aspersa (HAA) and Caragana arborescens (CAA) and de-sialylated IgA1 with Helix pomatia (HPA) and Bauhinia purpurea (BPA) indicated that the Gal deficiency is in glycans located in the hinge region of IgA1 molecules. De-sialylated IgA from sera of 81 IgAN patients bound biotin-labeled lectin HAA more effectively than did de-sialylated IgA from 56 healthy controls (P < 0.0001). Similar results were observed for 67 IgAN patients and 52 controls with second lectin, CAA (P < 0.001). The binding patterns for 9 patients with mesangial proliferative glomerulonephritis of non-IgA origin were similar to those for controls. Incompletely galactosylated IgA1 capable of binding GalNAc-specific lectins was detected in complexes with IgG as demonstrated by ELISA, size-exclusion chromatography and sucrose gradient ultracentrifugation. The formation of IgA1-IgG complexes may affect the serum level of IgA1 by reducing the rate of its elimination and catabolic degradation by the liver. PMID:9264010

Tomana, M; Matousovic, K; Julian, B A; Radl, J; Konecny, K; Mestecky, J

1997-08-01

263

IgG, IgM and IgA antibodies against the novel polyprotein in active tuberculosis  

PubMed Central

Background The present study was aimed to evaluate whether IgG, IgM and IgA antibodies levels detected against a novel Mycobacterium tuberculosis polyprotein 38 F-64 F (with 38 F being the abbreviation for 38kD-ESAT6-CFP10 and 64 F for Mtb8.4-MPT64-TB16.3-Mtb8) are suitable for diagnosing active tuberculosis, and for monitoring the efficacy of chemotherapy on TB patients. Methods In this study, a total of 371 active TB patients without treatment were selected and categorized into S+/C+?group (n?=?143), S-/C+?group (n?=?106) or S-/C- group (n?=?122). A series of serum samples were collected from 82 active TB patients who had undergone anti-TB chemotherapy for 0–6 months at one month interval. Humoral responses (IgG, IgM and IgA) were determined for the novel Mycobacterium tuberculosis polyprotein using indirect ELISA methods in all of serum samples. Results For S+/C+, S-/C+?and S-/C- active tuberculosis patients before anti-TB chemotherapy, the sensitivities of tests based on IgG were 65.7%, 46.2% and 52.5% respectively; the sensitivities based on IgM were 21.7%, 24.5% and 18.9%; and the sensitivities based on IgA were 25.2%, 17.9% and 23.8%. By combination of three isotypes, for all active tuberculosis patients, the test sensitivity increased to 70.4% with the specificity being 91.5%. After anti-TB chemotherapy, there were no significant differences between groups with different courses of anti-TB chemotherapy. Conclusions The novel Mycobacterium tuberculosis polyprotein 38 F-64 F represents potential antigen suitable for measuring IgG, IgM and IgA antibodies. However, the serodiagnostic test based on the 38 F-64 F polyprotein appears unsuitable for monitoring the efficacy of chemotherapy. PMID:24939009

2014-01-01

264

The three-dimensional prey field of the northern krill, Meganyctiphanes norvegica , and the escape responses of their copepod prey  

Microsoft Academic Search

In the north Atlantic, Meganyctiphanes norvegica feeds predominantly on copepods, including Calanus spp. To quantify its perceptual field for prey, and the sensory systems underlying prey detection, the responses of tethered\\u000a krill to free-swimming Calanus spp. were observed in 3D using silhouette video imaging. An attack–which occurred despite the krill’s being tethered—was\\u000a characterized by a pronounced movement of the krill’s

Mari B. Abrahamsen; Howard I. Browman; David M. Fields; Anne Berit Skiftesvik

2010-01-01

265

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

266

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

267

Who's for dinner? High-throughput sequencing reveals bat dietary differentiation in a biodiversity hotspot where prey taxonomy is largely undescribed.  

PubMed

Effective management and conservation of biodiversity requires understanding of predator-prey relationships to ensure the continued existence of both predator and prey populations. Gathering dietary data from predatory species, such as insectivorous bats, often presents logistical challenges, further exacerbated in biodiversity hot spots because prey items are highly speciose, yet their taxonomy is largely undescribed. We used high-throughput sequencing (HTS) and bioinformatic analyses to phylogenetically group DNA sequences into molecular operational taxonomic units (MOTUs) to examine predator-prey dynamics of three sympatric insectivorous bat species in the biodiversity hotspot of south-western Australia. We could only assign between 4% and 20% of MOTUs to known genera or species, depending on the method used, underscoring the importance of examining dietary diversity irrespective of taxonomic knowledge in areas lacking a comprehensive genetic reference database. MOTU analysis confirmed that resource partitioning occurred, with dietary divergence positively related to the ecomorphological divergence of the three bat species. We predicted that bat species' diets would converge during times of high energetic requirements, that is, the maternity season for females and the mating season for males. There was an interactive effect of season on female, but not male, bat species' diets, although small sample sizes may have limited our findings. Contrary to our predictions, females of two ecomorphologically similar species showed dietary convergence during the mating season rather than the maternity season. HTS-based approaches can help elucidate complex predator-prey relationships in highly speciose regions, which should facilitate the conservation of biodiversity in genetically uncharacterized areas, such as biodiversity hotspots. PMID:24118181

Burgar, Joanna M; Murray, Daithi C; Craig, Michael D; Haile, James; Houston, Jayne; Stokes, Vicki; Bunce, Michael

2014-08-01

268

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

PubMed Central

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

269

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

270

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

PubMed

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

271

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

272

The Hitchner B1 strain of Newcastle disease virus induces high levels of IgA, IgG and IgM in newly hatched chicks  

Microsoft Academic Search

Reaseheath line C chicks produced IgA, IgG and IgM in their serum, tears, spleen and Harderian gland (HG) as a consequence of oculotopical vaccination with the Hitchner B1 strain of Newcastle disease virus. The IgM response was seen first, at 5 days after vaccination, and antiviral IgM levels in the tears and serum were negatively correlated to the level of

P. H. Russell; G. O. Ezeifeka

1995-01-01

273

IgA-binding factor suppresses synthesis of IgA in MOPC-315 plasmacytoma cells  

SciTech Connect

T cells with Fc receptors for IgA (T/sup ..cap alpha../ cells) and their products, IgA-binding factors (IgABF), have been implicated in the regulation of IgA expression by B cells. They have previously shown that an IgABF produced by IgA induced normal T cells or constitutively by the Fc/sup ..cap alpha../ R+ T cell lymphoma, BALENTL 8, is capable of suppressing the proliferation and the amount of secreted IgA by MOPC-315 cells. In the present studies, they demonstrate that: (a) suppression of proliferation and secretion requires surface membrane IgA on the target cell, (b) suppression exhibits rapid kinetics with maximal effect occurring by 3-4 hours, (c) suppression is reversible, and (d) suppression of secretion involves selective suppression of IgA synthesis as measured by /sup 3/H-leucine incorporation into immunoprecipitable IgA(non-IgA protein is unaffected). These findings indicate that IgA-isotype-specific effector molecules interact directly with their B cell targets through surface membrane immunoglobulin and cause a down regulation of immunoglobulin synthesis by the target. Current studies are underway to address whether this selective suppression of IgA is mediated at the transcriptional, translational or post-translational level. The use of MOPC-315 tumor cells as targets of T cell produced, isotype-specific, effector molecules should provide a unique model for the further analysis of isotype regulation at the molecular level.

Darby, C.; Moore, J.S.; Muller, S.; Aaronsen, D.; Madianos, E.; Hoover, R.G.

1986-03-05

274

IgY pharmacokinetics in rabbits: Implications for IgY use as antivenoms.  

PubMed

This paper presents the first study of chicken IgY pharmacokinetics (PK) in rabbits. We measured IgY blood serum concentrations using a specific high sensitivity ELISA method. The fast initial component observed when studying horse Fab, F(ab')2 or IgG was absent from IgY PK. During the first 80 min of observation there was only a single slow exponential decay, which sped up afterward to the point that IgY became undetectable after 216 h of observation; due to this time course, PK parameters were determined with trapezoidal integration. The most significant IgY pharmacokinetic parameters determined were (all presented as medians and their 95% confidence interval): Area Under the Curve = 183.8 (135.2, 221.5) mg·h·L(-1); Distribution volume of the central compartment·[Body Weight (BW)](-1) = 46.0 (21.7, 70.3) mL·kg(-1); Distribution volume in steady state·BW(-1) = 56.8 (44.4, 68.5) mLkg(-1); Mean Residence Time = 40.1 (33.6, 48.5) h; Total plasma clearance·BW(-1) = 1.44 (1.15, 1.66) mL·h(-1)·kg(-1). Anti IgY IgG titers determined by ELISA increased steadily after 72 h, and reached 2560 (1920, 5760) dilution(-1) at 264 h; anti-chicken IgG concentrations rose up to 3.19 (2.31, 6.17) ?g/mL in 264 h. Our results show that IgY PK lacks the fast initial decay observed in other PK studies using horse IgG, F(ab')2 or Fab, remains in the body 39.0 (28.7, 47.2) % much as IgG and is ?3 times more immunogenic that horse IgG in rabbits. PMID:25111201

Díaz, Patricia; Malavé, Caridad; Zerpa, Noraida; Vázquez, Hilda; D'Suze, Gina; Montero, Yuyibeth; Castillo, Cecilia; Alagón, Alejandro; Sevcik, Carlos

2014-11-01

275

Neuromuscular control of prey capture in frogs.  

PubMed Central

While retaining a feeding apparatus that is surprisingly conservative morphologically, frogs as a group exhibit great variability in the biomechanics of tongue protraction during prey capture, which in turn is related to differences in neuromuscular control. In this paper, I address the following three questions. (1) How do frog tongues differ biomechanically? (2) What anatomical and physiological differences are responsible? (3) How is biomechanics related to mechanisms of neuromuscular control? Frog species use three non-exclusive mechanisms to protract their tongues during feeding: (i) mechanical pulling, in which the tongue shortens as its muscles contract during protraction; (ii) inertial elongation, in which the tongue lengthens under inertial and muscular loading; and (iii) hydrostatic elongation, in which the tongue lengthens under constraints imposed by the constant volume of a muscular hydrostat. Major differences among these functional types include (i) the amount and orientation of collagen fibres associated with the tongue muscles and the mechanical properties that this connective tissue confers to the tongue as a whole; and (ii) the transfer of intertia from the opening jaws to the tongue, which probably involves a catch mechanism that increases the acceleration achieved during mouth opening. The mechanisms of tongue protraction differ in the types of neural mechanisms that are used to control tongue movements, particularly in the relative importance of feed-forward versus feedback control, in requirements for precise interjoint coordination, in the size and number of motor units, and in the afferent pathways that are involved in coordinating tongue and jaw movements. Evolution of biomechanics and neuromuscular control of frog tongues provides an example in which neuromuscular control is finely tuned to the biomechanical constraints and opportunities provided by differences in morphological design among species. PMID:10382226

Nishikawa, K C

1999-01-01

276

Evaluation of anti-toxoplasma IgG, IgM, and IgA in mothers with spontaneous abortion in Zanjan, Northwest Iran.  

PubMed

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; Fazaeli, Asghar

2012-12-01

277

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

278

IgA antibodies in Rett syndrome.  

PubMed

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 remains unknown, but because IgA antibodies reflect the uptake of proteins and/or epitopes of proteins from the gut, this may be indicative of increased protein uptake. PMID:16613867

Reichelt, K L; Skjeldal, O

2006-03-01

279

Visually guided gradation of prey capture movements in larval zebrafish  

PubMed Central

SUMMARY 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.

2013-01-01

280

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

281

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

282

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

283

Wuchereria bancrofti filariasis in French Polynesia: age-specific patterns of microfilaremia, circulating antigen, and specific IgG and IgG4 responses according to transmission level.  

PubMed

The age-specific patterns of microfilaremia, Og4C3 antigenemia, anti-Brugia malayi IgG and IgG4 were assessed in 3 villages of low, medium and high transmission level for Wuchereria bancrofti filariasis. The prevalence rates for each of the 4 markers were clearly age dependent and their patterns strongly associated with the transmission level. The antigenemia prevalence rate was consistently higher than the microfilaremia prevalence rate, in all age groups. The prevalences of anti-B. malayi IgG and IgG4 responses were very similar and much higher than those of microfilaremia or antigenemia. Antibody responses reached the plateau at an earlier age and at a higher prevalence with increased intensity of transmission. For all the markers, the prevalence rates were significantly higher in males than in females. PMID:7797377

Chanteau, S; Glaziou, P; Plichart, C; Luquiaud, P; Moulia-Pelat, J P; N'Guyen, L; Cartel, J L

1995-01-01

284

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

285

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

PubMed

Cuttlefish have a large repertoire of body patterns that are used for camouflage and interspecific signaling. Intraspecific signaling by male cuttlefish has been well documented but studies on signaling by females are lacking. We found that females displayed a newly described body pattern termed Splotch toward their mirror image and female conspecifics, but not to males, prey or inanimate objects. Female cuttlefish may use the Splotch body pattern as an intraspecific signal, possibly to reduce agonistic interactions. The ability of females to produce a consistent body pattern in response to conspecifics and mirrors suggests that they can recognize same-sex conspecifics using visual cues, despite the lack of sexual dimorphism visible to human observers. PMID:16408230

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

2006-04-01

286

Visceral leishmaniasis in Somalia. Significance of IgG subclasses and of IgE response  

Microsoft Academic Search

We have determined the levels of IgG subclasses and IgE as well as specific antibodies of these isotypes in sera from 22 patients with clinical visceral leishmaniasis (VL) from Somalia. The results are compared with those obtained from 30 Somali and 23 Swedish controls. We found markedly increased concentrations of IgG1 in the VL sera, indicating that the pronounced increase

S. A. Shiddo; G. Huldt; L. Å. Nilsson; Ö. Ouchterlony; R. Thorstensson

1996-01-01

287

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

288

IgA Nephropathy in Children  

Microsoft Academic Search

It is becoming evident that IgA nephropathy is the commonest variety of primary glomerulonephritis in the world today [1]. IgA nephropathy was initially considered a benign disease with a favorable prognosis; however, as data from long-term follow-up studies became available, progression of the disease to renal failure in 20–50% of the adult patients was recognized. In children, a more benign

Nirishige Yoshikawa; Kazumoto Iijima; Hiroshi Ito

1999-01-01

289

Demonstration of IgG subclass (IgG1 and IgG3) in patients with positive direct antiglobulin tests.  

PubMed

Serologic characterization of autoantibodies helps in the management and monitoring of the course of autoimmune hemolytic anemia (AIHA). The purpose of this study was to evaluate gel centrifugation test (GCT) cards for immunoglobulin G (IgG) titer and determination of IgG subclasses IgG1 and IgG3 and their influence on hemolysis. Eighty direct antiglobulin test (DAT)-positive patients were examined with the help of GCT cards for IgG titer and IgG subclasses. The results were correlated with the presence and absence of hemolysis. A statistically significant (p < 0.005) association of hemolysis with increasing anti-IgG titer was observed. When IgG titer was 30 or less, 28 (50.91%) patients had no hemolysis, whereas 15 (93.75%) patients had features of hemolysis when titer was at least 300. Statistically significant (p < 0.005) association of subclass of IgG (IgG1, IgG3) coating the red blood cells with intravascular hemolysis was also seen. Twenty-nine (80.56%) patients had evidence of hemolysis when IgG1 or IgGl-IgG3 both were present. Gel technology is helpful to demonstrate red blood cell-bound autoantibodies and their characterization with regard to class, subclass, and titer. This information is useful to identify patients with AIHA who are at risk of severe hemolysis with adverse prognosis. PMID:25238241

Singh, A; Solanki, A; Chaudhary, R

2014-01-01

290

Effects of serial plasmapheresis on serum IgA levels in IgA-deficient blood donors with IgA-suppressor T cells.  

PubMed

Seventeen IgA-deficient blood donors, without antibodies to IgA, underwent plasmapheresis four to eight consecutive times at intervals of 8 weeks or less to provide fresh-frozen plasma for patients with anti-IgA. Blood samples, drawn for analysis no more than 1 hour before plasmapheresis and again at the conclusion of each procedure, were analyzed for lymphocyte subpopulations and serum IgA levels. Five lymphocyte subpopulations, including natural killer cells, the suppressor-inducer CD4 subset, the suppressor-precursor CD8 subset, non-major histocompatibility complex (MHC)-restricted cytotoxic T cells, and CD5+ B cells, were all decreased significantly after plasmapheresis (p less than 0.05). In a subgroup of IgA-deficient donors with excessive IgA-suppressor T-cell activity, serum IgA increased to levels exceeding 0.05 g per L following the fourth consecutive plasmapheresis procedure. Serum IgA levels did not similarly increase in IgA-deficient donors without excessive IgA-suppressor T-cell activity or in controls without IgA deficiency. Our study shows the potential, in a subpopulation of IgA-deficient donors who undergo frequent plasmapheresis, for a transient increase in serum IgA to a level no longer considered IgA deficient. PMID:1531902

Paglieroni, T G; Holland, P V

1992-02-01

291

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

PubMed Central

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

2011-01-01

292

Predatory capacity and prey selectivity of nymphs of the dragonfly Pantala hymenaea.  

PubMed

Predatory capacity and prey selectivity of nymphs of the dragonfly Pantala hymenaea (Odonata: Libellulidae) were evaluated on larvae of the mosquito Culex quinquefasciatus (Diptera: Culicidae) and larvae of the midge Chironomus plumosus (Diptera: Chironomidae) as prey. With functional response methodology, 7 larval densities were exposed to predator individuals in a glass jar under laboratory conditions. The study was performed in 2 experiments. The 1st was a test system with each prey species alone. The 2nd tested a mixture of both prey species in a 1:1 ratio. Prey selectivity and prey capacity were significantly greater on midge larvae than on mosquito larvae. PMID:16252528

Quiroz-Martínez, Humberto; Rodríguez-Castro, Violeta Ariadna; Solís-Rojas, Carlos; Maldonado-Blanco, María Guadalupe

2005-09-01

293

The effect of institutionalisation on elevated IgD and IgG levels in patients with Down's syndrome.  

PubMed

Serum levels of IgA, IgD, IgE, IgG, IgM and levels of secretory IgA (S-IgA) in nasal specimens were quantitated by radial immunodiffusion in a group of forty-one institutionalised patients with Down's syndrome (all non-disjunctive trisomy-G karyotype) and their age, sex and race matched controls, consisting of institutionalised non-mongols and normal non-institutionalised subjects. Analysis of levels of all immunoglobulins by age and sex showed no differences within the populations. However, levels of IgA, IgD and IgG were found significantly higher in mongols than in the other two populations. The concentrations of IgM were lower in mongols than in other institutionalised retardates but higher than non-institutionalised normal controls. Levels of S-IgA or IgE were similar in all populations. It was shown that the length of institutionalisation was associated with elevated levels of IgA and depressed levels of IgM in mongols. However, elevated IgG levels in mongols did not appear to be associated with their length of institutionalisation. Similarly, elevated levels of IgD in mongols were not associated with their length of institutionalisation. PMID:129572

McMillan, B C; Hanson, R P; Golubjatnikov, G; Sinha, S K

1975-01-01

294

Production of hybrid-IgG/IgA plantibodies with neutralizing activity against Shiga toxin 1.  

PubMed

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

295

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

296

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

297

Porcine allergy and IgE.  

PubMed

Anaphylaxis was reported in 1963 in pigs experimentally sensitized with ovalbumin and was subsequently associated indirectly with IgE-related antibodies by functional assays to confirm heat-labile passive cutaneous anaphylaxis (PCA), reverse passive anaphylaxis (RPA) and Prausnitz-Küstner (PK) reactions to this and other allergens. The immunoglobulin mediating immediate hypersensitivity could be cross-adsorbed with anti-human IgE. Porcine IgE epsilon chain has been cloned and sequenced. Rabbit anti-pig IgE has been described by two groups, as has cross reactivity with pig IgE of various heterologous polyclonal and monoclonal anti-IgEs. Pigs develop transient post-weaning food allergy to soy allergens which can be prevented by pre-weaning feeding of soy proteins in sufficient quantity. Natural hypersensitivity also occurs to nematodes. Recently, experimental allergy has been induced in outbred pigs to peanut and to egg allergens which manifest as respiratory, cutaneous and enteric signs similar to those of human food allergy. These models are platforms for comparative allergy research as realistic alternatives to use of inbred mice or humans for investigation of pathogenesis, prophylaxis and therapy. PMID:19854520

Rupa, Prithy; Schmied, Julie; Wilkie, Bruce N

2009-11-15

298

The Pathophysiology of IgA Nephropathy  

PubMed Central

Here we discuss recent advances in understanding the biochemical, immunologic, and genetic pathogenesis of IgA nephropathy, the most common primary glomerulonephritis. Current data indicate that at least four processes contribute to development of IgA nephropathy. Patients with IgA nephropathy often have a genetically determined increase in circulating levels of IgA1 with galactose-deficient O-glycans in the hinge-region (Hit 1). This glycosylation aberrancy is, however, not sufficient to induce renal injury. Synthesis and binding of antibodies directed against galactose-deficient IgA1 are required for formation of immune complexes that accumulate in the glomerular mesangium (Hits 2 and 3). These immune complexes activate mesangial cells, inducing proliferation and secretion of extracellular matrix, cytokines, and chemokines, which result in renal injury (Hit 4). Recent genome-wide association studies identify five distinct susceptibility loci—in the MHC on chromosome 6p21, the complement factor H locus on chromosome 1q32, and in a cluster of genes on chromosome 22q22—that potentially influence these processes and contain candidate mediators of disease. The significant variation in prevalence of risk alleles among different populations may also explain some of the sizable geographic variation in disease prevalence. Elucidation of the pathogenesis of IgA nephropathy provides an opportunity to develop disease-specific therapies. PMID:21949093

Suzuki, Hitoshi; Kiryluk, Krzysztof; Novak, Jan; Moldoveanu, Zina; Herr, Andrew B.; Renfrow, Matthew B.; Wyatt, Robert J.; Scolari, Francesco; Mestecky, Jiri; Gharavi, Ali G.

2011-01-01

299

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

PubMed

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

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

2012-01-01

300

Host Plant Mediates Foraging Behavior and Mutual Interference Among Adult Stethorus gilvifrons (Coleoptera: Coccinellidae) Preying on Tetranychus urticae (Acari: Tetranychidae).  

PubMed

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

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

2014-10-01

301

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

NASA Astrophysics Data System (ADS)

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

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

2008-08-01

302

Prey preferences of Portia labiata, P. africana, and P. schultzi, araneophagic jumping spiders (Araneae: Salticidae) from the Philippines, Sri Lanka, Kenya, and Uganda  

Microsoft Academic Search

Prey?preference behaviour of three species of araneophagic salticid (P. labiata from the Philippines and Sri Lanka, P. africana from Kenya and Uganda, and P. schultzi from Kenya) is studied in the laboratory for the first time. “Well?fed” (7 day fast) and “starved” (14 day fast) males and females of each species have a pronounced preference for web?building spiders over insects,

Daiqin Li; Robert R. Jackson; Alberto Barrion

1997-01-01

303

Aggregation increases prey survival time in group chase and escape  

NASA Astrophysics Data System (ADS)

Recently developed chase-and-escape models have addressed a fascinating pursuit-and-evasion problem that may have both theoretical significance and potential applications. We introduce three aggregation strategies for the prey in a group chase model on a lattice. Simulation results show that aggregation dramatically increases the group survival time, even allowing immortal prey. The average survival time ? and the aggregation probability P have a power-law dependence of \\tau \\sim {{(1-P)}^{-1}} for P\\in [0.9,0.997]. With increasing numbers of predators, there is still a phase transition. When the number of predators is less than the critical point value, the prey group survival time increases significantly.

Yang, Sicong; Jiang, Shijie; Jiang, Li; Li, Geng; Han, Zhangang

2014-08-01

304

Anim. Behav., 1995, 49, 11221124 Predation on females or males: who pays for bright male traits?  

E-print Network

deaths. Guppies are com- monly found in mixed-sex groups (Haskins et al. 1961) and predators that detect number of fish possible because the experiment resulted in the death of the prey. The guppies were from a choice, pike cichlids first attack female guppies (Fig. 1). We found both sexes were cap- tured

Dill, Lawrence M.

305

The stabilizing effects of genetic diversity on predator-prey dynamics  

PubMed Central

Heterogeneity among prey in their susceptibility to predation is a potentially important stabilizer of predator-prey interactions, reducing the magnitude of population oscillations and enhancing total prey population abundance. When microevolutionary responses of prey populations occur at time scales comparable to population dynamics, adaptive responses in prey defense can, in theory, stabilize predator-prey dynamics and reduce top-down effects on prey abundance. While experiments have tested these predictions, less explored are the consequences of the evolution of prey phenotypes that can persist in both vulnerable and invulnerable classes. We tested this experimentally using a laboratory aquatic system composed of the rotifer Brachionus calyciflorus as a predator and the prey Synura petersenii, a colony-forming alga that exhibits genetic variation in its propensity to form colonies and colony size (larger colonies are a defense against predators). Prey populations of either low initial genetic diversity and low adaptive capacity or high initial genetic diversity and high adaptive capacity were crossed with predator presence and absence. Dynamics measured over the last 127 days of the 167-day experiment revealed no effects of initial prey genetic diversity on the average abundance or temporal variability of predator populations. However, genetic diversity and predator presence/absence interactively affected prey population abundance and stability; diversity of prey had no effects in the absence of predators but stabilized dynamics and increased total prey abundance in the presence of predators. The size structure of the genetically diverse prey populations diverged from single strain populations in the presence of predators, showing increases in colony size and in the relative abundance of cells found in colonies. Our work sheds light on the adaptive value of colony formation and supports the general view that genetic diversity and intraspecific trait variation of prey can play a vital role in the short-term dynamics and stability of planktonic predator-prey systems. PMID:25339982

Steiner, Christopher F; Masse, Jordan

2013-01-01

306

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

307

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

308

Kinematics of prey capture in a flatfish, Pleuronichthys verticalis  

PubMed

Hornyhead turbot, Pleuronichthys verticalis (Pleuronectiformes: Pleuronectidae), are morphologically asymmetrical teleosts with substantial bilateral asymmetry in the neurocranium, suspensorium and anterior jaws. In order to quantify the kinematics of prey capture and to test for functional bilateral asymmetries, four individuals of this species were video-taped feeding using a high-speed video system at 200 fields s-1. Frame-by-frame analysis revealed several features not commonly found in prey capture behavior of previously studied ray-finned fishes. These features include (1) extreme lateral compression of the suspensorium and opercular series prior to mouth opening, indicating the consistent presence of a preparatory phase during feeding, (2) apparent dissociation of hyoid retraction and lower jaw depression, (3) prolonged hyoid retraction throughout much of the feeding cycle, and (4) concomitant dorsal rotation of the neurocranium and closing of the jaws. P. verticalis also demonstrate a significant degree of functional bilateral asymmetry during prey capture. When approaching prey, fish flex their heads towards the ocular (anatomically the right) side of the body. During prey capture, their jaws bend out of the midline towards the blind (left) side. Comparisons of the displacement and timing for movements of homologous anatomical features on the ocular and blind sides of the head reveal that maximum gape is always larger on the blind side of the head than on the ocular side. In contrast, other kinematic variables measured are similar on both sides of the head. These results suggest that P. verticalis possess unique functional features of prey capture behavior and that morphological bilateral asymmetry of the head and jaws is associated with, and perhaps causally related to, the functional bilateral asymmetry present during feeding. PMID:9319016

Gibb

1995-01-01

309

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

310

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

311

How the owl tracks its prey--II.  

PubMed

Barn owls can capture prey in pitch darkness or by diving into snow, while homing in on the sounds made by their prey. First, the neural mechanisms by which the barn owl localizes a single sound source in an otherwise quiet environment will be explained. The ideas developed for the single source case will then be expanded to environments in which there are multiple sound sources and echoes--environments that are challenging for humans with impaired hearing. Recent controversies regarding the mechanisms of sound localization will be discussed. Finally, the case in which both visual and auditory information are available to the owl will be considered. PMID:20889819

Takahashi, Terry T

2010-10-15

312

Specific IgE, IgG, and IgA antibody response to oral immunotherapy in birch pollinosis.  

PubMed

Thirty-nine patients with birch pollinosis participated in a double-blind, placebo-controlled trial of oral immunotherapy (OIT) for 18 months. They were treated with increasing doses of freeze-dried birch-pollen antigens for 16 months, reaching a cumulative dose of 280 x 10(6) biologic units. This is about 200 times more than the dose used in conventional subcutaneous immunotherapy (IT). In the placebo-treated group, but not in the actively treated group, there was a rise in postseasonal birch-specific IgE antibody levels. A significant decline in postseasonal values after 1 year of treatment was recorded in the actively treated, but not in the placebo-treated, group. Compared to the placebo treatment, there was a significant rise in birch-specific IgG antibodies in patients administered active treatment; however, the rise was less than that usually observed during subcutaneous IT. No significant change in birch-specific serum IgA was found in either group. The changes in IgE and IgG antibody levels demonstrate that OIT affects the immune system. This supports our recent findings that OIT demonstrates a beneficial effect in the treatment of birch pollinosis in adults. But, as with subcutaneous IT, there was no clear relationship between antibody response and clinical findings in the patients. The underlying mechanisms responsible for the relief of symptoms thus remain unknown. PMID:2647818

Taudorf, E; Laursen, L; Lanner, A; Björkstén, B; Dreborg, S; Weeke, B

1989-03-01

313

Metabolism of IgM in the tropical splenomegaly syndrome.  

PubMed

IgM metabolism was studied in five patients with the tropical splenomegaly syndrome and in five controls. The half-life and turnover time of I125 IgM was similar in the two groups. We conclude that the raised serum IgM levels found in patients with the tropical splenomegaly syndrome are not due to decreased IgM catabolism but are due to increased IgM production. PMID:1006767

Fakunle, Y M; Greenwood, B M

1976-01-01

314

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

PubMed Central

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

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

2011-01-01

315

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

316

EVOLVING PREDATOR CONTROL PROGRAMS FOR A HEXAPOD ROBOT PURSUING A PREY  

E-print Network

EVOLVING PREDATOR CONTROL PROGRAMS FOR A HEXAPOD ROBOT PURSUING A PREY GARY PARKER, CONNECTICUT for an autonomous hexapod robot, the predator, which allowed it to catch another autonomous robot, the prey

Parker, Gary B.

317

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

318

Predator-prey role reversals, juvenile experience and adult antipredator behaviour  

PubMed Central

Although biologists routinely label animals as predators and prey, the ecological role of individuals is often far from clear. There are many examples of role reversals in predators and prey, where adult prey attack vulnerable young predators. This implies that juvenile prey that escape from predation and become adult can kill juvenile predators. We show that such an exposure of juvenile prey to adult predators results in behavioural changes later in life: after becoming adult, these prey killed juvenile predators at a faster rate than prey that had not been exposed. The attacks were specifically aimed at predators of the species to which they had been exposed. This suggests that prey recognize the species of predator to which they were exposed during their juvenile stage. Our results show that juvenile experience affects adult behaviour after a role reversal. PMID:23061011

Choh, Yasuyuki; Ignacio, Maira; Sabelis, Maurice W.; Janssen, Arne

2012-01-01

319

Fibrosis of the thyroid gland caused by an IgG4-related sclerosing disease: three years of follow-up.  

PubMed

Immunoglobulin G4-related sclerosing disease (IgG4-RSD) represents a recently identified inflammatory disorder in which infiltration of IgG4 plasma cells causes fibrosis in organs. While IgG4-RSD is well documented in the pancreas and other organs, it is poorly characterized in the thyroid gland. We report a case of a 48-year-old female with a fibrotic thyroid mass associated with a retroperitoneal fibrosis. Diagnosed early as Riedel disease, the high serum IgG4, immunohistopathology and decreased fibrosis with corticosteroid therapy, finally confirm for the first time, the origin of IgG4-RSD fibrosis of the thyroid. PMID:25224542

Oriot, P; Amraoui, A; Rousseau, E; Malvaux, P; Dechambre, S; Delcourt, A

2014-12-01

320

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

Microsoft Academic Search

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

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

2006-01-01

321

Mixotrophy in the phototrophic harmful alga Cochlodinium polykrikoides (Dinophycean): prey species, the effects of prey concentration, and grazing impact.  

PubMed

We first reported here that the harmful alga Cochlodinium polykrikoides, which had been previously known as an autotrophic dinoflagellate, was a mixotrophic species. We investigated the kinds of prey species and the effects of the prey concentration on the growth and ingestion rates of C. polykrikoides when feeding on an unidentified cryptophyte species (Equivalent Spherical Diameter, ESD = 5.6 microm). We also calculated grazing coefficients by combining field data on abundances of C. polykrikoides and co-occurring cryptophytes with laboratory data on ingestion rates obtained in the present study. Cocholdinium polykrikoides fed on prey cells by engulfing the prey through the sulcus. Among the phytoplankton prey offered, C. polykrikoides ingested small phytoplankton species that had ESD's < or = 11 microm (e.g. the prymnesiophyte Isochrysis galbana, an unidentified cryptophyte, the cryptophyte Rhodomonas salina, the raphidophyte Heterosigma akashiwo, and the dinoflagellate Amphidinium carterae). It did not feed on larger phytoplankton species that had ESD's > or = 12 microm (e.g. the dinoflagellates Heterocapsa triquetra, Prorocentrum minimum, Scrippsiella sp., Alexandrium tamarense, Prorocentrum micans, Gymnodinium catenatum, Akashiwo sanguinea, and Lingulodinium polyedrum). Specific growth rates of C. polykrikoides on a cryptophyte increased with increasing mean prey concentration, with saturation at a mean prey concentration of approximately 270 ng C ml(-1) (i.e. 15,900 cells ml(-1)). The maximum specific growth rate (mixotrophic growth) of C. polykrikoides on a cryptophyte was 0.324 d(-1), under a 14:10 h light-dark cycle of 50 microE m(-2) s(-1), while its growth rate (phototrophic growth) under the same light conditions without added prey was 0.166 d(-1). Maximum ingestion and clearance rates of C. polykrikoides on a cryptophyte were 0.16 ng C grazer(-1)d(-1) (9.4 cells grazer(-1)d(-1)) and 0.33 microl grazer(-1)h(-1), respectively. Calculated grazing coefficients by C. polykrikoides on cryptophytes were 0.001-0.745 h(-1) (i.e. 0.1-53% of cryptophyte populations were removed by a C. polykrikoides population in 1 h). The results of the present study suggest that C. polykrikoides sometimes has a considerable grazing impact on populations of cryptophytes. PMID:15537091

Jeong, Hae Jin; Du Yoo, Yeong; Kim, Jae Seong; Kim, Tae Hoon; Kim, Jong Hyeok; Kang, Nam Seon; Yih, Wonho

2004-01-01

322

Comparison of antiviral activity between IgA and IgG specific to influenza virus hemagglutinin: increased potential of IgA for heterosubtypic immunity.  

PubMed

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

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

2014-01-01

323

The chemosensory ability of the predatory leech Whitmania laevis (Arhynchobdellida: Haemopidae) for prey searching  

Microsoft Academic Search

Although prey-detecting and searching abilities of predatory leeches of rhynchobdellid or the Erpobdelliformes of arhynchobdellid\\u000a species have been studied in the past, hirudiniformes leeches are rarely mentioned. In this study, we investigated the chemosensory\\u000a ability for prey-detecting and searching in Whitmania laevis, a hirudiniformes species that mainly preys on freshwater snails, and examined if such ability aided in their prey

Yi-Te Lai; Jiun-Hong Chen; Ling-Ling Lee

2011-01-01

324

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

Microsoft Academic Search

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

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

2006-01-01

325

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

Microsoft Academic Search

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

Daiqin Li I; Robert R. Jackson

1996-01-01

326

[IgA nephropathy in pediatrics].  

PubMed

IgA nephropathy is a primitive cronic idiopatic glomerulonephritis, characterized by diffuse depositis of IgA in the glomeruler mesangium. Familial cases are also descripted. IgA nephropaty is more frequent in males and in white rase. In Italy it's the most frequently recognized glomerulonephritis in renal biopsia (20%), especially in patients with dismorfic micro or macroematuria and nephrotic proteinuria. Clinical presentation is often in association with respiratory tract or gastrointestinal disorders. The most relevant pathogenetic hypothesis suggest an IgA abnormal glycosilation, with mesangial IgA aggregation, increased mesangial reactivity and release of inflammatory mediators and fibrotic agents. Treatment is considered in rapidly progressing forms. At the present, there is no treatment of proven value in all patients, althoug interesting results have been published with prednison, ACE-inhibitors or fish-oil in decresing renal deterioration rate. Natural history varies in different series. Renal survival at 10 years is 85% in Italy, 94% in France, 97% in the USA. Poor prognostic factor are heavy proteinuria and hypertension. However a wide inter-individual variability is observed. PMID:15279364

Marinaki, M; Benini, D; Fasoli, E; Fanos, V

2003-01-01

327

Regionalization in hereditary IgA nephropathy.  

PubMed Central

The genealogies of 80 patients with IgA nephropathy who were born in central or eastern Kentucky or whose parents were born in this region were researched. At a minimum, 48 of these patients were related to at least one other patient. On the basis of presence or absence of established kinships, the patients were divided into three groups. Twenty-nine patients in group 1 belonged to one large pedigree. Their birthplaces and those of their parents, grandparents, and great-grandparents clustered in the extreme eastern portion of the state. Seventeen other patients, group 2, were related to at least one other patient but not to a patient in group 1. Their birthplaces and those of their ancestors did not show significant clustering. With the exception of two siblings, the 34 patients of group 3 had no family members with IgA nephropathy. The birthplaces for these patients and ancestors were widely scattered. These data suggest that one or more genetically determined factors are important in the pathogenesis of IgA nephropathy in some patients. A founder effect, whereby a gene(s) conveying susceptibility to IgA nephropathy was carried into eastern Kentucky by one or more of the early settlers, would explain the geographic clustering of the birthplaces of the patients in group 1 and their ancestors. The characteristic immunopathology of IgA nephropathy may represent the histologic result of separate disease processes, one or more of which could be genetically influenced. PMID:3605095

Wyatt, R J; Rivas, M L; Julian, B A; Quiggins, P A; Woodford, S Y; McMorrow, R G; Baehler, R W

1987-01-01

328

Uncoupling of Glomerular IgA Deposition and Disease Progression in Alymphoplasia Mice with IgA Nephropathy  

PubMed Central

Previous clinical and experimental studies have indicated that cells responsible for IgA nephropathy (IgAN), at least in part, are localized in bone marrow (BM). Indeed, we have demonstrated that murine IgAN can be experimentally reconstituted by bone marrow transplantation (BMT) from IgAN prone mice in not only normal mice, but also in alymphoplasia mice (aly/aly) independent of IgA+ cells homing to mucosa or secondary lymphoid tissues. The objective of the present study was to further assess whether secondary lymph nodes (LN) contribute to the progression of this disease. BM cells from the several lines of IgAN prone mice were transplanted into aly/aly and wild-type mice (B6). Although the transplanted aly/aly showed the same degree of mesangial IgA and IgG deposition and the same serum elevation levels of IgA and IgA-IgG immune-complexes (IC) as B6, even in extent, the progression of glomerular injury was observed only in B6. This uncoupling in aly/aly was associated with a lack of CD4+ T cells and macrophage infiltration, although phlogogenic capacity to nephritogenic IC of renal resident cells was identical between both recipients. It is suggested that secondary LN may be required for the full progression of IgAN after nephritogenic IgA and IgA/IgG IC deposition. PMID:24743510

Aizawa, Masashi; Suzuki, Yusuke; Suzuki, Hitoshi; Pang, Huihua; Kihara, Masao; Nakata, Junichiro; Yamaji, Kenji; Horikoshi, Satoshi; Tomino, Yasuhiko

2014-01-01

329

Prey Detectability Mediates Selectivity in a Zooplanktivorous Cyprinid (Alburnus alburnus (L.))  

Microsoft Academic Search

Summary To examine if prey choice in the bleak Alburnus alburnus, a planktivorous cyprinid of lake Neusiedler See, is affected by prey detectability, the foraging behaviour and selectivity in response to two cladoceran prey, L eptodora kindti and Diaphanosoma mongolianum, was investigated. In the field, bleak Alburnus showed negative selectivities for the smaller size- classes and a positive selectivity for

Z. Liu; F. Uiblein

1996-01-01

330

Two prey capture strategies are generally recognised in lizards: tongue and jaw prehension (Schwenk and  

E-print Network

prey prehension mechanism. Using high-speed video recordings, cineradiography, electromyography, nerve of epithelial glands and possesses numerous papillae that can lock into surface irregularities on the prey by the surface area of the tongue contacting the prey (Emerson and Diehl, 1980), this system places severe

Nishikawa, Kiisa

331

Optimal prey choice and discrimination time in the great tit ( Parus major L.)  

Microsoft Academic Search

1.We tested the predictions of an optimal diet model which incorporated time taken to discriminate between prey types. Five captive great tits were presented with a choice of two prey types. The prey were large (profitable) and small (unprofitable) pieces of mealworm inside pieces of plastic drinking straw.2.When the worms were inside clear plastic straws, the birds selected only large

Alasdair I. Houston; John R. Krebs; Jonathan T. Erichsen

1980-01-01

332

Prey Handling Behavior of Eumeces gilberti with Comments on Headfirst Ingestion in Squamates  

Microsoft Academic Search

Captive Gilbert's skinks (Eumeces gilbertù almost always swallowed prey that were rela- tively difficult to ingest (crickets) headfirst, regardless of whether they initially grasped the anterior or posterior half of the prey. Skinks took longer to handle (subdue and swallow) crickets attacked posteriorly than those attacked anteriorly. The skinks tended to swallow prey that were relatively easy to ingest (mealworms)

ALAN DE QUEIROZ; KEVIN DE QUEIROZ

1987-01-01

333

Sizes of Prey Consumed by Age0 Brown Trout in Douglas Creek, Wyoming  

Microsoft Academic Search

We identified and measured invertebrate prey from 234 age-0 brown trout (Salmo trutta) captured in Douglas Creek, Wyoming during summer 1990. The mean length of invertebrate prey increased as the fish increased from 21 to 65 mm total length. The low variability of invertebrate prey lengths found within individual 5-mm length groups of age-0 brown trout indicates that fish of

Wayne A. Hubert; Howard A. Rhodes

1992-01-01

334

RELATIONSHIPS OF THE BLUE SHARK, PRZONACE GLAUCA, AND ITS PREY SPECIES NEAR SANTA CATALINA ISLAND, CALIFORNIA'  

E-print Network

the major prey for the blue shark, Prionace glauca, near Santa Catalina Island, Calif. The northern anchovy to prey behavior. The blue shark,Prionace glauca (Carcharhinidae) (Figure 11,is a pelagic carnivoreRELATIONSHIPS OF THE BLUE SHARK, PRZONACE GLAUCA, AND ITS PREY SPECIES NEAR SANTA CATALINA ISLAND

Tricas, Timothy C.

335

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

336

Diet of Common Nighthawks (Chordeiles minor: Caprimulgidae) Relative to Prey Abundance  

Microsoft Academic Search

Optimal foraging theory predicts that when prey density is low, predators should employ a generalist feeding strategy and take prey in proportion to their abundance. The purpose of this study was to compare the diet of common nighthawks (Chordeiles minor: Caprimulgidae) with a measure of prey abundance. Relative to the proportion of insects available, nighthawks consumed Coleoptera and Hymenoptera more

L. Danielle Todd; Ray G. Poulin; R. Mark Brigham

1998-01-01

337

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

338

Water shrews detect movement, shape, and smell to find prey underwater  

Microsoft Academic Search

American water shrews (Sorex palustris) are aggressive predators that feed on a variety of terrestrial and aquatic prey. They often forage at night, diving into streams and ponds in search of food. We investigated how shrews locate submerged prey using high-speed videography, infrared lighting, and stimuli designed to mimic prey. Shrews attacked brief water movements, indicating motion is an important

Kenneth C. Catania; James F. Hare; Kevin L. Campbell

2008-01-01

339

Owls and rabbits: predation against substandard individuals of an easy prey  

Microsoft Academic Search

The interactions among the multiple factors regulating predator-prey relationships make predation a more complex process than previously thought. The degree to which substandard individuals are captured disproportionately seems to be better a function of the difficulty of prey capture than of the hunting techniques (coursing vs. ambushing predators). That is, when the capture and killing of a prey species is

Vincenzo Penteriani; Maria Del Mar Delgado; Paola Bartolommei; Carlotta Maggio; Carlos Alonso-Alvarez; Graham J. Holloway

2008-01-01

340

ORIGINAL PAPER Joint evolution of predator body size and prey-size  

E-print Network

combinations, the island rule, and the difference in predator­prey size ratios between filter feedersORIGINAL PAPER Joint evolution of predator body size and prey-size preference Tineke A. Troost � of predator body size and prey-size preference based on dynamic energy budget theory. The predators

Dieckmann, Ulf

341

Predator versus prey: on aerial hunting and escape strategies in birds  

Microsoft Academic Search

Predator and prey attack-escape performance is likely to be the outcome of an evolutionary arms race. Predatory birds are typically larger than their prey, suggesting different flight performances. We analyze three idealized attack-escape situations between predatory and prey birds: climbing flight escape, horizontal speeding, and turning and escape by diving. Generally a smaller bird will outclimb a larger predator and

Anders Hedenstrom; Mikael Rosen

2001-01-01

342

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

343

Hard prey, soft jaws and the ontogeny of feeding mechanics in the spotted ratfish  

E-print Network

Hard prey, soft jaws and the ontogeny of feeding mechanics in the spotted ratfish Hydrolagus colliei is a holocephalan fish that consumes hard prey (durophagy) but lacks many morphological characters (Chondrichthyes: Holocephali) have branded them as hard prey specialists (Didier 1995; Grogan & Lund 2004

Summers, Adam P.

344

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

345

FUNCTIONAL RESPONSES: A QUESTION OF ALTERNATIVE PREY AND PREDATOR DENSITY  

Microsoft Academic Search

Throughout the study of ecology, there has been a growing realization that indirect effects among species cause complexity in food webs. Understanding and predicting the behavior of ecosystems consequently depends on our ability to identify indirect effects and their mechanisms. The present study experimentally investigates indirect interactions arising between two prey species that share a common predator. In a natural

Britta Tschanz; Louis-Félix Bersier; Sven Bacher

2007-01-01

346

Status of the Nemertea as prey in marine ecosystems  

Microsoft Academic Search

Nemerteans are predators of a wide variety of animals, but little is known of their role as prey for other animals. The presence of toxins in the tissues and secretions of these worms has led to the assumption usually suggested that they are ingested only rarely. However, analysis of a Food Habits Data Base from the United States National Marine

John J. McDermott

2001-01-01

347

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

348

ORIGINAL PAPER The causes and consequences of partial prey consumption  

E-print Network

range of taxa, partial prey consumption (PPC) is a frequent occurrence. PPC may arise from physiological constraints to gut capacity or digestive rate. Alternatively, PPC may represent an optimal foraging strategy the first strong test for the cause of PPC in a cursorial vertebrate predator with intestinal digestion

349

Signal conict in spider webs driven by predators and prey  

E-print Network

of webs is capable of entangling predators such as jumping spiders (Salticidae) and wasps (SphecidaeSignal con¯ict in spider webs driven by predators and prey Todd A. Blackledge Department for crypsis of the signal to unintended receivers. Several genera of orb- weaving spiders include conspicuous

Blackledge, Todd

350

When predators become prey: flight decisions in jumping spiders  

Microsoft Academic Search

Current optimal escape theory focuses on economic distance-based models that predict that animals will flee at greater distances when risk of capture is greater. Although these models have been tested extensively on vertebrate prey animals using large approaching stimuli (e.g., humans), it has never been tested on an invertebrate generalist predator with a stimulus that is in the size range

Theodore Stankowich

2009-01-01

351

Population dynamics, production, and prey consumption of fathead minnows (Pimephales  

E-print Network

Population dynamics, production, and prey consumption of fathead minnows (Pimephales promelas of fathead minnows (Pimephales promelas) in prairie wetlands and developed a bioenergetics model to estimate-de-boules (Pimephales promelas) dans les milieux humides des prairies et mis au point un modèle de bioénergétique pour

352

Research Article Winter Prey Selection of Canada Lynx in  

E-print Network

abundance play in habitat selection of Canada lynx (Lynx canadensis) in the contiguous United States.2193/2005-445 KEY WORDS alternative prey, Canada lynx, food habits, Lepus americanus, Lynx canadensis, Montana, snowshoe hare. Northern populations of Canada lynx (Lynx canadensis) exhibit both numeric (Elton

353

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

354

Conservation Status of North America's Birds of Prey  

Microsoft Academic Search

We assessed the conservation status of 20 species of North American birds of prey by examining historical and recent estimates of trends in counts of raptors at migration watchsites. We compared these trend estimates with trends in Breeding Bird Surveys (BBSs), Christmas Bird Counts (CBCs) (terms in italics are defi ned in the book's glossary), and other available population indexes

Christopher J. Farmer; Laurie J. Goodrich; Ernesto Ruelas Inzunza; Jeff P. Smith

355

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

356

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

357

Ecological Role of Sea Lions as Predators, Competitors, and Prey  

E-print Network

Ecological Role of Sea Lions as Predators, Competitors, and Prey · Sea Lion Species · California Sea Lions (not listed) - increasing · Steller Sea Lions eDPS (threatened) ­ increasing (delisting review under way, June 2010) · Steller Sea Lions wDPS (endangered) - decreasing · Predators ­ varied diet

358

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

359

Antagonistic evolution in an aposematic predator-prey signaling system.  

PubMed

Warning signals within species, such as the bright colors of chemically defended animals, are usually considered mutualistic, monomorphic traits. Such a view is however increasingly at odds with the growing empirical literature, showing nontrivial levels of signal variation within prey populations. Key to understanding this variation, we argue, could be a recognition that toxicity levels frequently vary within populations because of environmental heterogeneity. Inequalities in defense may undermine mutualistic monomorphic signaling, causing evolutionary antagonism between loci that determine appearance of less well-defended and better defended prey forms within species. In this article, we apply a stochastic model of evolved phenotypic plasticity to the evolution of prey signals. We show that when toxicity levels vary, then antagonistic interactions can lead to evolutionary conflict between alleles at different signaling loci, causing signal evolution, "red queen-like" evolutionary chase, and one or more forms of signaling equilibria. A key prediction is that variation in the way that predators use information about toxicity levels in their attack behaviors profoundly affects the evolutionary characteristics of the prey signaling systems. Environmental variation is known to cause variation in many qualities that organisms signal; our approach may therefore have application to other signaling systems. PMID:25132560

Speed, Michael P; Franks, Daniel W

2014-10-01

360

Prey odor discrimination by ingestively naive coachwhip snakes (Masticophis flagellum)  

Microsoft Academic Search

Summary Ingestively naive hatchling coachwhip snakes(Masticophis flagellum) detected integumentary chemicals from several potential prey species and discriminated them from chemical stimuli from other animals and from distilled water, strongly suggesting a genetic basis for these abilities. The strongest responses were to lizard and snake stimuli, which form a major part of the diet. Variable responses to chemical cues from other

William E. Cooper; Donald G. Buth; Laurie J. Vitt

1990-01-01

361

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

362

Marine predators and persistent prey in the southeast Bering Sea  

NASA Astrophysics Data System (ADS)

Predictable prey locations reduce search time and energetic costs of foraging; thus marine predators often exploit locations where prey concentrations persist. In our study, we examined whether this association is influenced by differences among predator species in foraging modes (travel cost, surface feeder or diver) or whether the predator species is a central place forager or not. We examined distributions of two seabird species during their nesting period, the surface-feeding black-legged kittiwake (Rissa tridactyla) and the pursuit-diving thick-billed murre (Uria lomvia), and two baleen whale species, the humpback whale (Megaptera novaeangliae) and the fin whale (Balaenoptera physalus), in relation to two key prey, age-1 walleye pollock (Theragra chalcogramma) and euphausiids (Euphausiidae). Prey surveys were conducted once each year during 2004 and 2006-2010. Concurrent predator surveys were conducted in 2006-2010 (seabirds) and 2008 and 2010 (whales). We compared the seabird and whale foraging locations to where age-1 pollock and euphausiids were concentrated and considered the persistence of these concentrations, where the time-scale of persistence is year (i.e., a comparison among surveys that are conducted once each year). Euphausiids were widespread and concentrations often were reliably found within specific 37 km×37 km blocks ('persistent hot spots of prey'). In contrast, age-1 pollock were more concentrated and their hot spots were persistent only on coarser scales (>37 km). Both seabird species, regardless of foraging mode, were associated with age-1 pollock but not with euphausiids, even though age-1 pollock were less persistent than euphausiids. The higher travel cost central place foragers, thick-billed murres, foraged at prey concentrations nearer their island colonies than black-legged kittiwakes, which were more widespread foragers. Humpback whales were not tied to a central place and mostly were located only where euphausiids were concentrated, and further, often in locations where these concentrations were persistent. Fin whales were associated with locations where age-1 pollock were more likely, similar to black-legged kittiwakes and thick-billed murres, but their association with euphausiids was unclear. Our results suggest that a predator's foraging mode and their restrictions during breeding affect their response to prey persistence.

Sigler, Michael F.; Kuletz, Kathy J.; Ressler, Patrick H.; Friday, Nancy A.; Wilson, Christopher D.; Zerbini, Alexandre N.

2012-06-01

363

Responses of IgE, IgG1, and IgG4 to concanavalin A-binding Blomia tropicalis antigens in allergic patients.  

PubMed

Blomia tropicalis (Bt) and Dermatophagoides pteronyssinus (Dp) are the prevalent house dust mites in tropical countries and are associated with allergic diseases. Glycosylated antigens are highly immunogenic and involved in different pathologies. We evaluated the presence of IgE, IgG1, and IgG4 to concanavalin A-binding antigens (Bt-Con-A) isolated from Bt-total extract in sera of allergic and non-allergic subjects. Bt-total and Bt-Con-A extracts were evaluated by SDS-PAGE and ELISA for reacting with IgE, IgG1, and IgG4 in sera of 121 patients with allergic rhinitis and 36 non-allergic individuals. All subjects were skin prick tested with Bt-total extract and inhibition tests were performed for IgE, IgG1, and IgG4 using both extracts (Bt-total and Bt-Con-A). Skin prick test showed that 58% of the patients were sensitized to Bt (Bt+), with 52% reactive to both mites (Bt and Dp) and 6% to Bt only. A broad spectrum of proteins (14-152 kDa) was visualized in Bt-total and components >27 kDa for the Bt-Con-A extract. ELISA showed a similar profile of IgE, IgG1 and IgG4 levels in response to Bt-total and Bt-Con-A extracts in different groups, although Bt+ patients showed a lower IgG4 reactivity to Bt-Con-A extract. Specific IgG1 levels were higher in Bt+ patients than in control subjects, and IgG4 levels showed no significant difference among groups. ELISA inhibition showed a partial IgE and total IgG1 and IgG4 cross-reactivity with Dp extract for Bt-total and Bt-Con-A extracts. We conclude that Con-A-binding components isolated from Bt constitute major allergens and are involved in both allergen sensitization (IgE response) and homeostasis maintenance (IgG1 and IgG4 responses). PMID:17146557

Almeida, K C; Silva, D A O; Gennari-Cardoso, M L; Cunha-Júnior, J P; Alves, R; Ynoue, L H; Resende, R O; Sung, S J; Taketomi, E A

2006-11-01

364

CNES-CLS IGS Analysis Center Activities  

NASA Astrophysics Data System (ADS)

GRGS and CLS teams process regularly GPS data from a worldwide network of IGS permanent stations. We compute precise GPS orbits together with Earth rotation parameters and stations coordinates at the highest level of precision using the CNES-GRGS GINS software. Our solutions are being submitted to the International Earth Rotation Service since January 2004 and to the IGS since July 2007. This poster gives a summary of our processing strategy as well as the status of the quality of our products. In addition, the source of a systematic scale factor between our orbit solution and the IGS ones is discussed. Special interest is paid on the radiation pressure modelization which includes in our case the Earth albedo contribution. The processing of SLR tracking data from GPS satellite SVN35 and 36 is included in this study.

Sylvain, L.; F., P.; H., C.; L., S.

2008-12-01

365

Low molecular weight IgM in primary biliary cirrhosis.  

PubMed Central

Low molecular weight IgM is the monomeric subunit of pentameric IgM and is not generally found in the blood of healthy individuals. Using a sensitive immunoblotting technique, low molecular weight IgM was detected in all 17 patients with primary biliary cirrhosis and constituted up to 5% of the total circulating IgM. This low molecular weight IgM moiety correlated significantly with total IgM (p less than 0.01) but not with the specific biliary cirrhosis mitochondrial autoantibody anti-M2. Furthermore it was not possible to show that a partially purified sample of low molecular weight IgM contained M2 binding activity. Mitogen stimulated peripheral blood mononuclear cells from two of four patients were observed to secrete low molecular weight IgM in vitro, a finding seen in only one of six healthy subjects. Immunoblot analysis of patients sera revealed the presence of other oligomers of IgM in addition to low molecular weight IgM. In conclusion this study suggests that during the enhanced IgM synthesis observed in primary biliary cirrhosis a defect occurs in the assembly of the IgM pentamer with release of monomeric and oligomeric IgM into the circulation. The pathogenic significance of these circulating low molecular weight IgM species is unknown. Images Figure 1 PMID:2318435

Roberts-Thomson, P J; Shepherd, K

1990-01-01

366

Cellular Signaling and Production of Galactose-Deficient IgA1 in IgA Nephropathy, an Autoimmune Disease  

PubMed Central

Immunoglobulin A (IgA) nephropathy (IgAN), the leading cause of primary glomerulonephritis, is characterized by IgA1-containing immunodeposits in the glomeruli. IgAN is a chronic disease, with up to 40% of patients progressing to end-stage renal disease, with no disease-specific treatment. Multiple studies of the origin of the glomerular immunodeposits have linked elevated circulating levels of aberrantly glycosylated IgA1 (galactose-deficient in some O-glycans; Gd-IgA1) with formation of nephritogenic Gd-IgA1-containing immune complexes. Gd-IgA1 is recognized as an autoantigen in susceptible individuals by anti-glycan autoantibodies, resulting in immune complexes that may ultimately deposit in the kidney and induce glomerular injury. Genetic studies have revealed that an elevated level of Gd-IgA1 in the circulation of IgAN patients is a hereditable trait. Moreover, recent genome-wide association studies have identified several immunity-related loci that associated with IgAN. Production of Gd-IgA1 by IgA1-secreting cells of IgAN patients has been attributed to abnormal expression and activity of several key glycosyltransferases. Substantial evidence is emerging that abnormal signaling in IgA1-producing cells is related to the production of Gd-IgA1. As Gd-IgA1 is the key autoantigen in IgAN, understanding the genetic, biochemical, and environmental aspects of the abnormal signaling in IgA1-producing cells will provide insight into possible targets for future disease-specific therapy. PMID:25152896

Huang, Zhi-Qiang; Mestecky, Jiri; Julian, Bruce A.

2014-01-01

367

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

368

Frequency of IgE-dependent hypersensitivity to moulds in patients with chronic rhinosinusitis with polyps  

PubMed Central

Introduction The complicated etiology of chronic sinusitis with polyps and frequent allergy to mould is established. Aim We aimed to investigate the frequency of the IgE-dependent hypersensitivity in this group of patients and prove the need of surgery in allergic chronic rhinosinusitis patients. Material and methods Forty-two patients (19 females, 23 males) aged 34–73 years (55 ±12.6 years), with chronic sinusitis with polyps were included into the study. Functional endoscopic sinus surgery, laryngological examination, sinus computed tomography scans, and smear from maxillary sinus for microbiological examination were done in all patients. Skin prick tests with common perennial and seasonal inhalant allergens, tIgE and sIgE against moulds were required. Results Thirty-two of 42 patients (71.4%) were allergic to at least one inhalant allergen. A mean concentration of total IgE was 241.2 ±186.3 kU/l (35.0–708.0 kU/l) and was lower in patients with fungal culture found in sinus mucin than in patients without fungal presence 75.1 ±54.6 kU/l vs. 284.3 ±204.1 kU/l. We found no difference in the number of positive skin prick tests in a group with and without fungal culture. None of patients with fungal culture found in sinuses presented a detectable level of mold sIgE. All patients with fungal vegetation in sinuses required at least two polypectomy procedures. Conclusions The total IgE concentration was significantly lower in patients with fungal presence in sinuses. Nasal polyps occurred more frequently in patients with fungal presence in sinuses. PMID:25097487

Czecior, Eugeniusz; Jarzab, Jerzy; Grzanka, Alicja; Cichecka, Ewelina; Sowa, Pawel; Scierski, Wojciech

2014-01-01

369

Female Reproductive System  

MedlinePLUS

... and female reproductive systems. Continue What Is the Female Reproductive System? Most species have two sexes: male ... some reason other than pregnancy. Infections of the Female Reproductive System Sexually transmitted diseases (STDs) . Also called ...

370

The Nutritional Content of Prey Affects the Foraging of a Generalist Arthropod Predator  

PubMed Central

While foraging theory predicts that predatory responses should be determined by the energy content and size of prey, it is becoming increasingly clear that carnivores regulate their intake of specific nutrients. We tested the hypothesis that prey nutrient composition and predator nutritional history affects foraging intensity, consumption, and prey selection by the wolf spider, Pardosa milvina. By altering the rearing environment for fruit flies, Drosophila melanogaster, we produced high quality flies containing more nitrogen and protein and less lipid than low quality fruit flies. In one experiment, we quantified the proportion of flies taken and consumption across a range of densities of either high or low quality flies and, in a second experiment, we determined the prey capture and consumption of spiders that had been maintained on contrasting diets prior to testing. In both cases, the proportion of prey captured declined with increasing prey density, which characterizes the Type II functional response that is typical of wolf spiders. Spiders with similar nutritional histories killed similar numbers of each prey type but consumed more of the low quality prey. Spiders provided high quality prey in the weeks prior to testing killed more prey than those on the low quality diet but there was no effect of prior diet on consumption. In the third experiment, spiders were maintained on contrasting diets for three weeks and then allowed to select from a mixture of high and low quality prey. Interestingly, feeding history affected prey preferences: spiders that had been on a low quality diet showed no preference but those on the high quality diet selected high quality flies from the mixture. Our results suggest that, even when prey size and species identity are controlled, the nutritional experience of the predator as well as the specific content of the prey shapes predator-prey interactions. PMID:23145130

Schmidt, Jason M.; Sebastian, Peter; Wilder, Shawn M.; Rypstra, Ann L.

2012-01-01

371

A novel chimeric Ig heavy chain from a teleost fish shares similarities to IgD  

PubMed Central

IgD is considered to be a recently evolved Ig, being previously found only in primates and rodents. Here we describe, from a teleost fish (the channel catfish, Ictalurus punctatus), a novel complex chimeric Ig heavy chain, homologous, in part, to the heavy chain (?) of IgD. In addition to alternative secretory or membrane-associated C termini, this chimeric molecule contains a rearranged variable domain, the first constant domain of ?, and seven constant domains encoded by a ? gene homolog. Identification of the catfish gene as ? is based on the following properties: sequence relatedness to mammalian ?; a location within the IgH locus that is immediately downstream of the ? gene; separate terminal exons for the secretory and membrane forms; coexpression with the complete ? chain in some but not all B cells. These results (i) suggest that IgD is an ancient immunoglobulin that was present in vertebrates ancestral to both the mammals and the ray-finned fishes, and (ii) raise the possibility that this Ig isotype may have served an as yet unidentified important function early in the evolution of the immune system. PMID:9114035

Wilson, Melanie; Bengten, Eva; Miller, Norman W.; Clem, L. William; Du Pasquier, Louis; Warr, Gregory W.

1997-01-01

372

IgG and IgA antibodies specific for Chlamydia trachomatis in acute epididymitis.  

PubMed

The possibility of using elevated Chlamydia trachomatis-specific serum IgG and IgA as a screening test for Chlamydia-associated epididymitis was analyzed in 28 acute epididymitis patients and 42 apparently healthy men by the single antigen (L2) immunoperoxidase assay. The prevalence rates of C. trachomatis IgG antibody titer greater than or equal to 64 and elevated C. trachomatis IgG titers (greater than or equal to 128) were significantly higher in the epididymitis patients (75 vs. 40%, p less than 0.01, and 39 vs. 14%, p less than 0.025, respectively) than in controls. The prevalence rate of C. trachomatis IgA antibodies (titer greater than or equal to 8) was significantly higher (p less than 0.001) in epididymitis patients as compared to controls (46 vs. 10%, respectively). The potential application of elevated serum C. trachomatis IgG and IgA antibodies as a noninvasive screening marker in epididymitis patients is discussed. PMID:3049107

Kaneti, J; Sarov, B; Sarov, I

1988-01-01

373

Rain, prey and predators: climatically driven shifts in frog abundance modify reproductive allometry in a tropical snake.  

PubMed

To predict the impacts of climate change on animal populations, we need long-term data sets on the effects of annual climatic variation on the demographic traits (growth, survival, reproductive output) that determine population viability. One frequent complication is that fecundity also depends upon maternal body size, a trait that often spans a wide range within a single population. During an eight-year field study, we measured annual variation in weather conditions, frog abundance and snake reproduction on a floodplain in the Australian wet-dry tropics. Frog numbers varied considerably from year to year, and were highest in years with hotter wetter conditions during the monsoonal season ("wet season"). Mean maternal body sizes, egg sizes and post-partum maternal body conditions of frog-eating snakes (keelback, Tropidonophis mairii, Colubridae) showed no significant annual variation over this period, but mean clutch sizes were higher in years with higher prey abundance. Larger females were more sensitive to frog abundance in this respect than were smaller conspecifics, so that the rate at which fecundity increased with body size varied among years, and was highest when prey availability was greatest. Thus, the link between female body size and reproductive output varied among years, with climatic factors modifying the relative reproductive rates of larger (older) versus smaller (younger) animals within the keelback population. PMID:17724615

Brown, Gregory P; Shine, Richard

2007-11-01

374

IgG and IgM autoantibody differences in discoid and systemic lupus patients  

PubMed Central

Systemic lupus (SLE) patients with discoid lupus (DLE) were reported to have milder disease. To test this observation, we employed sandwich arrays containing 98 autoantigens to compare autoantibody profiles of SLE subjects without DLE (DLE?SLE+) (N=9), SLE subjects with DLE (DLE+SLE+) (N=10), DLE subjects without SLE (DLE+SLE?) (N=11), and healthy controls (N=11). We validated differentially expressed autoantibodies using immunoassays in DLE?SLE+ (N=18), DLE+SLE+ (N=17), DLE+SLE? (N=23), and healthy subjects (N=22). Arrays showed 15 IgG autoantibodies (ten against nuclear antigens) and four IgM autoantibodies that were differentially expressed (q-value<0.05). DLE?SLE+ subjects had higher IgG autoantibodies against dsDNA, ssDNA, dsRNA, histone H2A and H2B, and SS-A (52 kDa) than all other groups including DLE+SLE+ subjects (p<0.05). Immunoassays measuring anti-dsDNA, -ssDNA, and -SS-A (52 kDa) IgG autoantibodies showed similar trends (p<0.05). Healthy and DLE+SLE?subjects expressed higher IgM autoantibodies against alpha beta crystallin, lipopolysaccharide, heat shock cognate 70, and desmoglein-3 than DLE+SLE+ and DLE?SLE+ subjects. IgG:IgM ratios of autoantibodies against nuclear antigens progressively rose from healthy to DLE?SLE+ subjects. In conclusion, lower IgG autoantibodies against nuclear antigens in DLE+SLE+ versus DLE?SLE+ subjects suggest that DLE indicates lower disease severity. Higher IgM autoantibodies against selected antigens in healthy and DLE+SLE?subjects may be non-pathogenic. PMID:22763789

Chong, Benjamin F.; Tseng, Lin-chiang; Lee, Thomas; Vasquez, Rebecca; Li, Quan Z.; Zhang, Song; Karp, David R.; Olsen, Nancy J.; Mohan, Chandra

2012-01-01

375

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, Øystein

2011-02-01

376

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; Ranåker, L; Nilsson, P A; Brönmark, C

2011-07-01

377

Administration of an anti-IgE antibody inhibits CD23 expression and IgE production in vivo.  

PubMed Central

High IgE responder BDF1 mice were immunized intraperitoneally (i.p.) with dinitrophenol4 (DNP4)-ovalbumin (OVA) in alum concomitant with intravenous (i.v.) administration of an anti-IgE monoclonal antibody (mAb). IgE levels were undetectable in mice treated with the anti-IgE antibody, whereas mice treated with isotype-matched irrelevant mAb had IgE levels comparable to that of untreated, immunized mice. Subsequent antigen challenges with DNP4-OVA, either at weekly or monthly intervals, failed to evoke an IgE response for greater than 2 months in mice treated with anti-IgE during the primary sensitization, even though the terminal half-life of the anti-IgE antibody was 7 days. This inhibition was specific for DNP4-OVA since the DNP4-OVA-suppressed mice were able to respond to keyhole limpet haemocyanin (KLH). To investigate the effects of antibody treatment at the cellular level, passive transfer experiments were performed. The primary DNP-specific IgE response of adoptive transfer recipient mice was the same whether the donor cells were from mice treated with IgG or anti-IgE. Transfer of enriched T- or B-cell populations indicated that T-cell help was not compromised by administration of the anti-IgE mAb. However, splenocytes from the anti-IgE-treated mice failed to synthesize IgE in vitro, and flow cytometric analysis of B cells from anti-IgE-treated mice showed a dose-dependent decrease in CD23+ cells following antibody treatment, which correlated with decreased serum IgE levels. Taken together, the results of these studies suggest that anti-IgE treatment suppresses IgE responses via effects on B cells rather than T cells, possibly through effects on CD23-dependent pathways. PMID:7927502

Haak-Frendscho, M; Robbins, K; Lyon, R; Shields, R; Hooley, J; Schoenhoff, M; Jardieu, P

1994-01-01

378

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, Ruben; Rodriguez-Girones, Miguel A.; Aguado-de-la-Paz, Sara; Fernandez-Montraveta, Carmen; De Mas, Eva; Wise, David H.; Moya-Larano, Jordi

2008-01-01

379

Effects of the heterogeneous landscape on a predator-prey system  

NASA Astrophysics Data System (ADS)

In order to understand how a heterogeneous landscape affects a predator-prey system, a spatially explicit lattice model consisting of predators, prey, grass, and landscape was constructed. The predators and preys randomly move on the lattice space and the grass grows in its neighboring site according to its growth probability. When predators and preys meet at the same site at the same time, a number of prey, equal to the number of predators are eaten. This rule was also applied to the relationship between the prey and grass. The predator (prey) could give birth to an offspring when it ate prey (grass), with a birth probability. When a predator or prey animal was initially introduced, or newly born, its health state was set at a given high value. This health state decreased by one with every time step. When the state of an animal decreased to less than zero, the animal died and was removed from the system. The heterogeneous landscape was characterized by parameter H, which controlled the heterogeneity according to the neutral model. The simulation results showed that H positively or negatively affected a predator’s survival, while its effect on prey and grass was less pronounced. The results can be understood by the disturbance of the balance between the prey and predator densities in the areas where the animals aggregated.

Lee, Sang-Hee

2010-01-01

380

Early exposure to odors changes later visual prey preferences in cuttlefish.  

PubMed

Developmental studies have shown that environmental stimulation received by a developing sensory system can alter the developmental outcome of both that sensory system and other aspects of the nervous system. We investigated the ecologically relevant question of whether prior exposure to prey early in development within one sensory modality could influence later prey choice within a different sensory modality. Cuttlefish are visual predators; they can detect prey odors but attacks on prey cannot be elicited without visual stimulation. Cuttlefish eggs were exposed to the odor of shrimp (preferred prey), crabs (non-preferred prey), mollusks (non-prey), or a seawater control (no prey). Seven days after hatching, prey preferences were tested with a visual choice test between crabs and shrimp. Hatchlings exposed to crabs odors and the seawater control were significantly more likely to attack shrimp. Hatchlings exposed to mollusk odors showed no visual prey preference, while those exposed to shrimp preferentially attacked crabs. These results demonstrate a complex relationship between an early sensory exposure and later prey preference PMID:21157990

Guibé, Mathieu; Boal, Jean G; Dickel, Ludovic

2010-12-01

381

Morphology of seahorse head hydrodynamically aids in capture of evasive prey.  

PubMed

Syngnathid fish (seahorses, pipefish and sea dragons) are slow swimmers yet capture evasive prey (copepods) using a technique known as the 'pivot' feeding, which involves rapid movement to overcome prey escape capabilities. However, this feeding mode functions only at short range and requires approaching very closely to hydrodynamically sensitive prey without triggering an escape. Here we investigate the role of head morphology on prey capture using holographic and particle image velocimetry (PIV). We show that head morphology functions to create a reduced fluid deformation zone, minimizing hydrodynamic disturbance where feeding strikes occur (above the end of the snout), and permits syngnathid fish to approach highly sensitive copepod prey (Acartia tonsa) undetected. The results explain how these animals can successfully employ short range 'pivot' feeding effectively on evasive prey. The need to approach prey with stealth may have selected for a head shape that produces lower deformation rates than other fish. PMID:24281430

Gemmell, Brad J; Sheng, Jian; Buskey, Edward J

2013-01-01

382

Short-term sublethal hypoxia affects a predator-prey system in northern Adriatic transitional waters  

NASA Astrophysics Data System (ADS)

Predation intensity depends on factors that affect both the predator's ability to locate prey as well as defensive responses by prey to approaching predators. The interactive effects of short-term hypoxia and predation were tested on the survival of two bivalves ( Tapes philippinarum and Musculista senhousia) through laboratory experiments using the crab Carcinus aestuarii as predator. We found M. senhousia to be a focal prey of C. aestuarii but, after non-lethal hypoxia, the crabs' preference for the focal prey was influenced by the presence of the other prey, T. philippinarum. We observed an environmentally-mediated, non-reciprocal indirect interaction between the two prey species, probably caused by differences in specific traits. Identifying the influence of short-term disturbance on predator-prey relationships is critical for predicting the effects of changes in water quality on trophic interactions and food web dynamics in transitional systems.

Munari, Cristina; Mistri, Michele

2012-01-01

383

Blood Test: Immunoglobulin A (IgA)  

MedlinePLUS

... Español Teachers - Looking for Health Lessons? Visit KidsHealth in the Classroom What Other Parents Are Reading Getting Kids Ready ... well as in saliva and tears. IgA also plays a role in allergic reactions. Its levels rise in response to ...

384

Pathology of IgA nephropathy.  

PubMed

IgA nephropathy is defined by the presence of IgA-dominant or co-dominant immune deposits within glomeruli. Biopsy specimens meeting these diagnostic criteria have a range of histological changes that are reflected in the variable clinical course of IgA nephropathy. The impact of histology on outcomes in IgA nephropathy has been clarified in a number of large retrospective clinicopathological studies. These studies have consistently demonstrated that the stage of disease at presentation, as indicated by the extent of interstitial fibrosis and tubular atrophy in the biopsy, is the strongest histological predictor of renal survival. The effect of active proliferative lesions on the disease course is less clear cut, owing in part to considerable treatment bias in most published retrospective studies. There is evidence that endocapillary hypercellularity and cellular crescents are responsive to immunosuppressive therapy, but this observation requires confirmation in prospective randomized controlled trials. Future challenges include improving the reproducibility of histological scoring, particularly for the presence and extent of endocapillary lesions, and to improve prognostic modelling by combining histological data with clinical variables and biomarker data. PMID:24861083

Roberts, Ian S D

2014-08-01

385

Egg fatty acid composition from lake trout fed two Lake Michigan prey fish species.  

USGS Publications Warehouse

We previously demonstrated that there were significant differences in the egg thiamine content in lake trout Salvelinus namaycush fed two Lake Michigan prey fish (alewife Alosa pseudoharengus and bloater Coregonus hoyi). Lake trout fed alewives produced eggs low in thiamine, but it was unknown whether the consumption of alewives affected other nutritionally important components. In this study we investigated the fatty acid composition of lake trout eggs when females were fed diets that resulted in different egg thiamine concentrations. For 2 years, adult lake trout were fed diets consisting of four combinations of captured alewives and bloaters (100% alewives; 65% alewives, 35% bloaters; 35% alewives, 65% bloaters; and 100% bloaters). The alewife fatty acid profile had higher concentrations of arachidonic acid and total omega-6 fatty acids than the bloater profile. The concentrations of four fatty acids (cis-13, 16-docosadienoic, eicosapentaenoic, docosapentaenoic, and docosahexaenoic acids) were higher in bloaters than in alewives. Although six fatty acid components were higher in lake trout eggs in 2001 than in 2000 and eight fatty acids were lower, diet had no effect on any fatty acid concentration measured in lake trout eggs in this study. Based on these results, it appears that egg fatty acid concentrations differ between years but that the egg fatty acid profile does not reflect the alewife-bloater mix in the diet of adults. The essential fatty acid content of lake trout eggs from females fed alewives and bloaters appears to be physiologically regulated and adequate to meet the requirements of developing embryos.

Honeyfield, D.C.; Fitzsimons, J.D.; Tillitt, D.E.; Brown, S.B.

2009-01-01

386

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

387

Plasticity in extended phenotypes: orb web architectural responses to variations in prey parameters.  

PubMed

A spider orb web is an extended phenotype; it modifies and interacts with the environment, influencing spider physiology. Orb webs are plastic, responding to variations in prey parameters. Studies attempting to understand how nutrients influence spider orb-web plasticity have been hampered by the inability to decouple prey nutrients from other, highly correlated, prey factors and the intrinsic link between prey protein and prey energy concentration. I analyzed the nutrient concentrations of cockroaches, and adult and juvenile crickets to devise experiments that controlled prey protein concentration while varying prey size, ingested mass, energy concentration and feeding frequency of the orb web spider Argiope keyserlingi. I found that A. keyserlingi alters overall architecture according to feeding frequency. Decoration length was inversely related to ingested prey mass and/or energy density in one experiment but directly related to ingested prey mass in another. These contradictory results suggest that factors not examined in this study have a confounding influence on decoration plasticity. As decorations attract prey as well as predators decreasing decoration investment may, in some instances, be attributable to benefits no longer outweighing the risks. Web area was altered according to feeding frequency, and mesh size altered according to feeding frequency and prey length. The number of radii in orb webs was unaffected by prey parameters. A finite amount of silk can be invested in the orb web, so spiders trade-off smaller mesh size with larger web capture area, explaining why feeding frequency influenced both web area and mesh size. Mesh size is additionally responsive to prey size via sensory cues, with spiders constructing webs suitable for catching the most common or most profitable prey. PMID:20802123

Blamires, Sean J

2010-09-15

388

Restricting prey dispersal can overestimate the importance of predation in trophic cascades.  

PubMed

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 musse--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

389

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

390

The sensory basis of prey location by the California leaf-nosed bat Macrotus californicus (Chiroptera: Phyllostomidae)  

Microsoft Academic Search

Macrotus californicus, an insectivorous bat, captures prey on the ground, and shows great sensory flexibility in hunting for prey: it uses high frequency, low intensity, frequency modulated echolocation to locate prey in total darkness, however data from this study suggest that it uses vision preferentially, and switches off its echolocation when adequate illumination is available. When souncs of prey are

Gary P. Bell

1985-01-01

391

IgD, like IgM, is a primordial immunoglobulin class perpetuated in most jawed vertebrates  

PubMed Central

IgD has remained a mysterious Ig class and a bane to immunology students since its discovery >40 years ago. Its spotty occurrence in mammals and birds and the discovery of an isotype with similarities to IgD in bony fish are perplexing. We have identified IgD heavy (H) chain (?) from the amphibian Xenopus tropicalis during examination of the IgH locus. The Xenopus ? gene is in the same position, immediately 3? of the IgM gene, as in mammals, and it is expressed only in the spleen at low levels, primarily as a transmembrane receptor by surface IgM+ cells. Our data suggest that frog IgD is expressed on mature B cells, like in mouse/human. Unexpectedly, Xenopus IgD is orthologous to IgW, an Ig isotype found only in cartilaginous fish and lungfish, demonstrating that IgD/W, like IgM, was present in the ancestor of all living jawed vertebrates. In striking contrast to IgM, IgD/W is evolutionarily labile, showing many duplications/deletions of domains, the presence of multiple splice forms, existence as predominantly a secretory or transmembrane form, or loss of the entire gene in a species-specific manner. Our study suggests that IgD/W has played varied roles in different vertebrate taxa since the inception of the adaptive immune system, and it may have been preserved as a flexible locus over evolutionary time to complement steadfast IgM. PMID:16818885

Ohta, Yuko; Flajnik, Martin

2006-01-01

392

Cleavage of immunoglobulin G (IgG) and IgA around the hinge region by proteases from Serratia marcescens.  

PubMed Central

Seven clinical and two nonclinical isolates of Serratia marcescens were examined for their ability to produce extracellular enzymes that cleave immunoglobulin G (IgG) and IgA molecules. All seven clinical isolates excreted a large amount of a 56-kilodalton (kDa) protease (56K protease) and small amounts of a 60-kDa and a 73-kDa protease (60K and 73K proteases, respectively) in culture medium during growth. All purified proteases cleaved IgG and IgA effectively if the level of protease production exceeded 2 to 5 micrograms/ml. The proteolytic activity in the culture supernatant was inhibited by about 85% by a chelating agent (EDTA), which indicated that the major immunoglobulin-cleaving enzyme is the metalloprotease(s) reported previously. Immunological quantification of proteases by single radial immunodiffusion showed similar results: the amount of 56K protease was about 65% and those of the 60K and 73K proteases were about 20 and 5%, respectively. Incubation for 3 h at 37 degrees C was required to generate immunoreactive Fab and Fc fragments. Further analysis of the cleavage products of IgG or IgA demonstrated that the 56K protease, as well as the 60K and 73K proteases, cleaves only the heavy chain of these immunoglobulins near the hinge region to generate Fab and Fc fragments. The susceptibilities of the subclasses of IgG and IgA to the 56K protease were as follows: IgG3 greater than IgG1 greater than IgG2 greater than IgG4 and IgA1 greater than IgA2. IgG2, IgG4, and IgA2 were relatively resistant to the 56K protease. Images PMID:3126147

Molla, A; Kagimoto, T; Maeda, H

1988-01-01

393

The utility of IgG, IgM, and CD138 immunohistochemistry in the evaluation of autoimmune liver diseases.  

PubMed

Primary biliary cirrhosis (PBC) and autoimmune hepatitis (AIH) present with distinct clinical features. The term "PBC-AIH overlap syndrome (OS)" has been adopted to describe the condition characterized by occurrence of both PBC and AIH, although this clinical entity is difficult to define. This study aimed to assess the utility of IgG, IgM, and CD138 immunohistochemistry in the evaluation of AIH, PBC, and OS. Immunohistochemistry was performed with anti-human IgG, IgM, and CD138 to detect specific plasma cells in the liver. Predominant IgG staining was observed in AIH (85.7 %), while equivocal (46.1 %) or predominant (38.5 %) IgM staining was observed in PBC. In OS, equivocal (20 %) or predominant (80 %) IgG staining was observed. The IgM/IgG ratio was significantly higher in PBC than in AIH or OS (P < 0.005). Histological findings revealed significantly higher IgM expression in PBC at cholangitis activity grades 2-3 compared to those at cholangitis activity grades 0-1. In contrast, a significantly higher IgG expression was observed in PBC at hepatitis activity and fibrosis grades 2-3 compared to those at hepatitis activity and fibrosis grades 0-1. Taken together, periportal plasmacytic infiltrates with variable immunohistochemistry patterns of IgG and IgM expression characterized different autoimmune liver diseases. PMID:24969678

Abe, Kazumichi; Takahashi, Atsushi; Nozawa, Yoshihiro; Imaizumi, Hiromichi; Hayashi, Manabu; Okai, Ken; Kanno, Yukiko; Watanabe, Hiroshi; Ohira, Hiromasa

2014-09-01

394

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

395

Immunoglobulin G (IgG) attenuates neuroinflammation and improves neurobehavioral recovery after cervical spinal cord injury  

PubMed Central

Background Evidence suggests that the inflammatory events in the acute phase of spinal cord injury (SCI) exacerbate the initial trauma to the cord leading to poor functional recovery. As a result, minimizing the detrimental aspects of the inflammatory response after SCI is a promising treatment strategy. In this regard, immunoglobulin G (IgG) from pooled human serum is a promising treatment candidate. Due to its putative, though poorly characterized immuno-modulatory effects, IgG has been used clinically to treat neuroinflammatory disorders such as Guillain-Barré syndrome, but its effects in neurotrauma remain largely unexplored. Methods This study examines the potential neuroprotective effects of IgG in a well-characterized cervical model of SCI. Female Wistar rats were subject to moderate-severe clip compression injury at the C7-T1 level. IgG (0.4?g/kg) or saline was injected intravenously to randomly selected animals at 15?min post SCI. At several time points post SCI, biochemical assays, histology and immunohistochemistry analyses, and neurobehavioral assessments were used to examine the neuroprotective effects of IgG at the molecular, cellular, and neurobehavioral levels. Results We found that intravenous treatment of IgG following acute clip-compression SCI at C7-T1 significantly reduced two important inflammatory cytokines: interleukin (IL)-1? and IL-6. This early reduction in pro-inflammatory signaling was associated with significant reductions in neutrophils in the spinal cord and reductions in the expression of myeloperoxidase and matrix metalloproteinase-9 in the injured spinal cord at 24?h after SCI. These beneficial effects of IgG were associated with enhanced tissue preservation, improved neurobehavioral recovery as measured by the BBB and inclined plane tests, and enhanced electrophysiological evidence of central axonal conduction as determined by motor-evoked potentials. Conclusion The findings from this study indicate that IgG is a novel immuno-modulatory therapy which shows promise as a potential treatment for SCI. PMID:22998664

2012-01-01

396

Alcohol Consumption and Kidney Function in IgA Glomerulonephritis  

Microsoft Academic Search

Background: IgA glomerulonephritis (IgAGN) is a kidney disease with variable prognosis. Several known risk factors exist for a more progressive course. Some population studies indicate that moderate alcohol consumption might protect kidney function, but the relationship between alcohol intake and IgAGN has not previously been examined. Methods: We examined 158 (95 men) IgAGN patients (37 abstainers, 80 light drinkers, 25

Kati Kaartinen; Onni Niemelä; Jaana Syrjänen; Ilkka Pörsti; Aimo Harmoinen; Amos Pasternack; Heini Huhtala; Jukka Mustonen

2009-01-01

397

Complex dynamics in a prey predator system with multiple delays  

NASA Astrophysics Data System (ADS)

The complex dynamics is explored in a prey predator system with multiple delays. Holling type-II functional response is assumed for prey dynamics. The predator dynamics is governed by modified Leslie-Gower scheme. The existence of periodic solutions via Hopf-bifurcation with respect to both delays are established. An algorithm is developed for drawing two-parametric bifurcation diagram with respect to two delays. The domain of stability with respect to ?1 and ?2 is thus obtained. The complex dynamical behavior of the system outside the domain of stability is evident from the exhaustive numerical simulation. Direction and stability of periodic solutions are also determined using normal form theory and center manifold argument.

Gakkhar, Sunita; Singh, Anuraj

2012-02-01

398

Viability selection on prey morphology by a generalist predator.  

PubMed

Prey use their locomotory capacity to escape predators, and there should thus be strong viability selection on locomotory morphology of prey. We compared feather morphology of wood pigeons Columba palumbus killed by goshawks Accipiter gentilis with that of survivors to quantify directional and quadratic selection on primary and rectrix feathers. The goshawk is mainly a predator attacking by surprise, leaving wood pigeons with an ability to accelerate fast at a selective advantage. There was directional selection for light primary feathers with a narrow calamus. In addition, there was directional selection for increased area of rectrices. These patterns of natural selection were confirmed in multivariate analyses of selection that showed selection for light primary feathers with a large area and narrow calamus and for a large area of rectrix feathers. These results provide evidence of selection on different aspects of feather morphology directly related to flight performance and thus escape ability from predators. PMID:19344382

Møller, A P; Couderc, G; Nielsen, J T

2009-06-01

399

Predator fitness increases with selectivity for odd prey.  

PubMed

The fundamental currency of normative models of animal decision making is Darwinian fitness. In foraging ecology, empirical studies typically assess foraging strategies by recording energy intake rates rather than realized reproductive performance. This study provides a rare empirical link, in a vertebrate predator-prey system, between a predator's foraging behavior and direct measures of its reproductive fitness. Goshawks Accipiter gentilis selectively kill rare color variants of their principal prey, the feral pigeon Columba livia, presumably because targeting odd-looking birds in large uniform flocks helps them overcome confusion effects and enhances attack success. Reproductive performance of individual hawks increases significantly with their selectivity for odd-colored pigeons, even after controlling for confounding age effects. Older hawks exhibit more pronounced dietary preferences, suggesting that hunting performance improves with experience. Intriguingly, although negative frequency-dependent predation by hawks exerts strong selection against rare pigeon phenotypes, pigeon color polymorphism is maintained through negative assortative mating. PMID:22503502

Rutz, Christian

2012-05-01

400

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

401

Human-IgE-induced degranulation of mouse mast cells.  

PubMed

The relations between human IgE and mouse peritoneal mast cells were studied in vitro. Non-heated human IgE sensitizes the mouse mast cells for degranulation on challenge with anti-human IgE. This capacity is lost after heating of human IgE at 56 degrees C. The degranulation only occurs in determined quantitative IgE-anti-IgE relationships, an excess of one or the other reagent inhibiting the reaction. Sensitization is practically instanteneous, and the degranulation is independent on the order of addition of the human IgE and anti-IgE. The human IgE can be removed from mouse peritoneal mast cells by a single washing. The results show that human IgE is unable to bind firmly to mouse peritoneal mast cells in vitro. It seems to induce the formation of biologically active human IgE-anti-human IgE complexes, which act on mouse mast cells and induce their degranulation. PMID:1244207

Wyczolkowska, J; Prouvost-Danon, A

1976-01-01

402

RAST-specific IgE in Nigerian asthmatic patients.  

PubMed

This first study of the pattern of allergen-specific IgE in Nigerian asthmatic patients in Zaria shows a significant percentage with specific IgE to Dermatophagoides pteronnyssinus, Aspergillus fumigatus, and Cynodon dactylon (Bermuda grass). Total serum IgE varied in both urban and rural asthmatics with a pattern of low and high levels in all groups. PMID:3484920

Onyemelukwe, G C; Shakib, F; Saeed, T K; Salloum, Z A; Lawande, R V; Obineche, E

1986-02-01

403

Thermoinactivation of human IgE: antigenic and functional modifications.  

PubMed Central

The thermoinactivation kinetics of IgE were studied in experimental models revealing the antigenic properties and the basophil-sensitizing capacity of these immunoglobulins. A pool of human sera containing anti-Dactylis glomerata (Dg) IgE was heated from 5 min up to 4 hr at 56 degrees. The IgE antigenicity was tested by two polyclonal 125I-labelled anti-IgE antibodies; one anti-IgE was specific of the whole Fc epsilon region, while the other had a specificity restricted to the D epsilon 2 domain. Radioimmunoassays showed that the D epsilon 2 epitopes were more rapidly altered than the D epsilon 1 epitopes. The capacity of IgE to bind to basophil Fc epsilon receptors was assayed by passive sensitization experiments. Basophil sensitivity towards the Dg pollen extract was tested by histamine release experiments in the presence of this allergen. A progressive decrease in cell sensitivity was observed when IgE samples used for cell sensitization were heated for longer than 5 min. Thermoinactivation kinetics of IgE revealed an unexpected increase in the apparent quantity and biological activity of IgE heated for 5 min at 56 degrees. This fact could be due to auto-anti-IgE antibodies linked to the unheated IgE and which interfere with the biological activities of IgE and their quantification. Images Figure 2 PMID:2420711

Demeulemester, C; Weyer, A; Peltre, G; Laurent, M; Marchand, F; David, B

1986-01-01

404

Khishchnik i zhertva v zvezdno-kosmicheskoj i kalendarno-sezonnoj reprezentatsii %t Prey and predator in starry and calendar-seasonal representation  

NASA Astrophysics Data System (ADS)

The paper deals with the semantics of hunting calendars from northern Eurasia and Siberia. It is shown that traditional economic and hunting activities were based on observations of seasonal changes in nature and animal life, as well as of the Sun's and Moon's yearly or monthly movement and several stars' positions. There is reason to assume that in the world view of the ancient populaton of Eurasia the winter season corresponding to the southern part of the Sun's yearly motion on the ecliptic was related to the images of beasts of prey (a bear, wolf, dog, fox, felines) and birds of prey (crow, eagle) with male personification, underworld symbolism, and mediatory functions. The summer period, associated with images of horned hoofed animals (deer, elk, cow, etc.) or with functionally similar characters (horse, aquatic birds - ducks, geese, swans; ermine, weasel, etc.) that have female personification, symbolises the upper part of the model of the Universe.

Lushnikova, A. V.

405

KINEMATICS OF PREY CAPTURE IN A FLATFISH, PLEURONICHTHYS VERTICALIS  

Microsoft Academic Search

Hornyhead turbot, Pleuronichthys verticalis (Pleuronectiformes: Pleuronectidae), are morphologically asymmetrical teleosts with substantial bilateral asymmetry in the neurocranium, suspensorium and anterior jaws. In order to quantify the kinematics of prey capture and to test for functional bilateral asymmetries, four individuals of this species were video-taped feeding using a high-speed video system at 200 fields s21. Frame-by-frame analysis revealed several features not

ALICE C. GIBB

406

Effects of Turbidity on Prey Consumption by Prairie Stream Fishes  

Microsoft Academic Search

Reduced suspended-sediment loads (i.e., turbidity) in many Midwestern prairie rivers have been hypothesized as contributing to the replacement of species that historically occupied highly turbid main-channel habitats by visually feeding species that are competitively superior in less-turbid waters. We examined the relationship between prey consumption and turbidity for six fish species from the Canadian River (New Mexico, Oklahoma, and Texas)

Timothy H. Bonner; Gene R. Wilde

2002-01-01

407

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

408

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

409

[Occurrence of parasites in indigenous birds of prey and owls].  

PubMed

In the present paper a general overview on parasites in birds of prey and owls is given. This part is followed by a study investigating the prevalences and species of parasites in free-ranging birds of prey and owls in Berlin and Brandenburg State, Germany. Over a one year period, 84 birds of prey and owls of the following species were examined for the presence of endo- and ectoparasites: Common Buzzard (Buteo buteo) (n = 32), Kestrel (Falco tinnunculus) (n = 20), Sparrowhawk (Accipiter nisus) (n = 9), Goshawk (Accipiter gentilis) (n = 8), Black Kite (Milvus migrans) (n = 4), Peregrine Falcon (Falco peregrinus) (n = 3), Marsh Harrier (Circus aeruginosus) (n = 1), White-tailed-Sea Eagle (Haliaeetus albicilla) (n = 1), Tawny Owl (Strix aluco) (n = 4), Long-eared Owl (Asio otus) (n = 1) and Barn Owl (Tyto alba) (n = 1). In 97.6% of the cases, ectoparasites (feather mites and hippoboscid flies) were found. Especially eyasses (93.3%) were positive for hippoboscid flies. Trichomonas was detected in 28.6% of all birds of prey and owls examined. A prevalence of 100% was established in the Sparrow Hawks as well as Peregrine Falcons. Leucozytozoon sp. and Hemoproteus sp. as blood parasites were found in 26.9% of the birds in total. Common Buzzards showed the highest prevalence (44.8%). 58.3% of birds examined were positive for endoparasites. Flukes were found in 16.7%, tapeworms in 14.3%, round-worms in 48.8% and acanthocephales in 2.4% of the cases. Interestingly, Tylodelphis clavata (in a Common Buzzard) and Hovorkonema variegatum (in a Goshawk) were found for the first time in raptors. The results of this study underline the importance of a parasitological examination in the process of raptor rehabilitation. PMID:11852683

Lierz, M; Göbel, T; Schuster, R

2002-01-01

410

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

411

Electroreceptive Prey-Location Coding by the Juvenile Paddlefish  

NASA Astrophysics Data System (ADS)

The long rostrum of the paddlefish (Polyodon spathula), a Mississippi river inhabitant, supports an extensive array of ampullary electroreceptors that are used to locate its favorite prey, water fleas, in dark and muddy water. Neuronal coding of such real-world events is often considered to be optimal in the sense of minimizing a mean-square reconstruction error or maximizing likelihood. Implementation of these theoretically motivated optimality criteria is, however, computationally very costly. For the juvenile paddlefish we exhibit [1] a computationally cheap and geometrically simple algorithm with the neuronal activity ?n of its electroreceptors 1<= n <= N as input and evaluating the turning direction \\varphi required to catch the prey through the so-called population-vector code \\varphi^estimate = arg [sumn ?n exp(i \\varphi_n)]. This explains experimentally found prey-detection statistics more convincingly than minimization of the mean-square reconstruction error. The only assumption concerns the neuronal time scale of the sensory organs. [1] C. Leibold, K.B. Reuter, L. Voigts, W. Wojtenek, and J.L. van Hemmen, manuscript in preparation.

van Hemmen, J. Leo

2003-03-01

412

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

413

Pythons metabolize prey to fuel the response to feeding.  

PubMed Central

We investigated the energy source fuelling the post-feeding metabolic upregulation (specific dynamic action, SDA) in pythons (Python regius). Our goal was to distinguish between two alternatives: (i) snakes fuel SDA by metabolizing energy depots from their tissues; or (ii) snakes fuel SDA by metabolizing their prey. To characterize the postprandial response of pythons we used transcutaneous ultrasonography to measure organ-size changes and respirometry to record oxygen consumption. To discriminate unequivocally between the two hypotheses, we enriched mice (= prey) with the stable isotope of carbon (13C). For two weeks after feeding we quantified the CO2 exhaled by pythons and determined its isotopic 13C/12C signature. Ultrasonography and respirometry showed typical postprandial responses in pythons. After feeding, the isotope ratio of the exhaled breath changed rapidly to values that characterized enriched mouse tissue, followed by a very slow change towards less enriched values over a period of two weeks after feeding. We conclude that pythons metabolize their prey to fuel SDA. The slowly declining delta13C values indicate that less enriched tissues (bone, cartilage and collagen) from the mouse become available after several days of digestion. PMID:15255044

Starck, J. Matthias; Moser, Patrick; Werner, Roland A.; Linke, Petra

2004-01-01

414

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