Search results for "host"

Contrasting reproductive traits of competing parasitoids facilitate coexistence on a shared host pest in a biological control perspective

2022

BACKGROUND: Interspecific competition in insect parasitoids is an important ecological phenomenon that has relevant implications for biological pest control. To date, interspecific intrinsic (=larval) competition has been intensively studied, while investigations on extrinsic (=adult) competition have often lagged behind. In this study we examined the role played by parasitoid reproductive traits and host clutch size on the outcome of extrinsic competition between Trissolcus basalis (Wollaston) and Ooencyrtus telenomicida (Vassiliev), two egg parasitoids of the pest Nezara viridula (L). Laboratory experiments were conducted by allowing both parasitoid species to exploit an egg mass made of …

THE EFFECTS OF MATING SYSTEM AND GENETIC VARIABILITY ON SUSCEPTIBILITY TO TREMATODE PARASITES IN A FRESHWATER SNAIL, LYMNAEA STAGNALIS

2004

The amount and distribution of genetic variability in host populations can have significant effects on the outcome of host-parasite interactions. We studied the effect of mating system and genetic variability on susceptibility of Lymnaea stagnalis snails to trematode parasites. Mating system of snails from eight populations differing in the amount of genetic variability was manipulated, and self- and cross-fertilized offspring were exposed to naturally occurring trematode parasites in a controlled lake experiment. Susceptibility of snails varied between populations, but mating-system treatment did not have a significant effect. Heterozygosity of snails was negatively correlated with the pro…

On the zero crossing of the three-gluon vertex

2016

We report on new results on the infrared behaviour of the three-gluon vertex in quenched Quantum Chormodynamics, obtained from large-volume lattice simulations. The main focus of our study is the appearance of the characteristic infrared feature known as 'zero crossing', the origin of which is intimately connected with the nonperturbative masslessness of the Faddeev-Popov ghost. The appearance of this effect is clearly visible in one of the two kinematic configurations analyzed, and its theoretical origin is discussed in the framework of Schwinger-Dyson equations. The effective coupling in the momentum subtraction scheme that corresponds to the three-gluon vertex is constructed, revealing t…

Exploration of extracellular vesicles from Ascaris suum provides evidence of parasite–host cross talk

2019

The prevalent porcine helminth, Ascaris suum, compromises pig health and reduces farm productivity worldwide. The closely related human parasite, A. lumbricoides, infects more than 800 million people representing a disease burden of 1.31 million disability-adjusted life years. The infections are often chronic in nature, and the parasites have a profound ability to modulate their hosts' immune responses. This study provides the first in-depth characterisation of extracellular vesicles (EVs) from different developmental stages and body parts of A. suum and proposes the role of these vesicles in the host-parasite interplay. The release of EVs from the third- (L3) and fourth-stage (L4) larvae a…

Sequence, evolution and tissue expression patterns of an epidermal type I keratin from the shark Scyliorhinus stellaris.

2004

From the shark Scyliorhinus stellaris we cloned and sequenced a cDNA encoding a novel type I keratin, termed SstK10. By MALDI-MS peptide mass fingerprinting of cytoskeletal proteins separated on polyacrylamide gels, we assigned SstK10 to a 46-kDa protein which is the major epidermal type I (“IE”) keratin in this fish and is specifically expressed in stratified epithelia. In a phylogenetic tree based on type I keratin sequences and with lamprey keratins applied as outgroup, SstK10 branches off in a rather basal position. This tree strongly supports the concept that teleost keratins and tetrapod keratins resulted from two independent gene radiation processes. The only exception is human K18 b…

Extracellular vesicles in parasitic diseases

2014

Parasitic diseases affect billions of people and are considered a major public health issue. Close to 400 species are estimated to parasitize humans, of which around 90 are responsible for great clinical burden and mortality rates. Unfortunately, they are largely neglected as they are mainly endemic to poor regions. Of relevance to this review, there is accumulating evidence of the release of extracellular vesicles (EVs) in parasitic diseases, acting both in parasite parasite inter-communication as well as in parasite host interactions. EVs participate in the dissemination of the pathogen and play a role in the regulation of the host immune systems. Production of EVs from parasites or paras…

The geography of the Rendiconti del Circolo Matematico di Palermo: local and international aspect

The Mathematical Circle of Palermo, founded in 1884 by 27 mathematicians all living in Palermo, became the publisher of the prestigious magazine "Rendiconti", which in thirty years became one of the leading international mathematical journals. In this talk, we will analyze the evolution of the components of the Societies and of Rendiconti towards internationalization from 1884 to 1914. Moreover, we will try to extract from the statistical data some considerations about the possible causes of the identified internationalization process

Enfermar lejos de casa : la atención médica y veterinaria en los hostales de la Corona de Aragón durante la Baja Edad Media

2013

During the late Middle Ages the mobility of people was intense, for various reasons. Frequently, people stayed in hostels, which were abundant in all cities and in the countryside and where they could rest, eat and receive medical care for themselves and their horses. These hostels were favourable environments to the intervention of barbers and surgeons, because many fights resulting in injuries took place there.Durante la baja Edad Media la movilidad de las personas fue muy intensa, por razones diversas. Frecuentemente la gente se alojaba en hostales, abundantes en todas las ciudades y también en el mundo rural, donde podían descansar, alimentarse y recibir atención médica para ellos y par…

Olympic Games-Related Values and Host Country Residents’ Pre-event Evaluations in the Run-Up to the 2016 Olympic Games

2019

The goal of this study is to examine the relationship between perceived values in relation to the Olympic Games and individuals’ attitudes toward, and intended support of hosting the Olympic Games ...

Echinostomes in the definitive host: a model for the study of host-parasite relationships.

2008

Echinostomes are hermaphroditic digeneans that parasitize, as adults, numerous vertebrate hosts of all classes. In this chapter, the main features of the development of adult echinostome in the definitive host are analyzed in detail. The stage of the echinostome in the definitive host undergoes a number of features such as metacercarial excystment, establishment, habitat location, adult development, mate, and release of eggs. These features are documented with an emphasis in their potential use as experimental models. The analysis is focused on members of the genus Echinostoma, although members of other genera of the Echinostomatidae are mentioned when they are relevant to the discussion. A…