Long-term fluctuation of population in the system of host-parasite interaction

1956 ◽  
Vol 3 (1) ◽  
pp. 52-59 ◽  
Author(s):  
Syunro Utida
Keyword(s):  
Host Parasite ◽  
Term Fluctuation

scholarly journals Long-Term Sea Level Cycle Affects Predictions of Future Rise

Eos ◽  
2021 ◽  
Vol 102 ◽  
Author(s):  
Sarah Stanley
Keyword(s):  
Sea Level ◽  
Earth’S Core ◽  
Earth's Core ◽  
New Research ◽  
Term Fluctuation

New research confirms the existence of a regular, long-term fluctuation in sea level, perhaps caused by processes in Earth’s core.

scholarly journals Long-term spatiotemporal stability and dynamic changes in helminth infracommunities of spiny mice (Acomys dimidiatus) in St. Katherine's Protectorate, Sinai, Egypt

Parasitology ◽  
2018 ◽  
Vol 146 (1) ◽  
pp. 50-73
Author(s):  
Jerzy M. Behnke ◽  
Anna Bajer ◽  
Jolanta Behnke-Borowczyk ◽  
Natalie Clisham ◽  
Francis Gilbert ◽  
...  
Keyword(s):  
Rank Order ◽  
Spatial Effects ◽  
Spiny Mice ◽  
Age Dependent ◽  
Female Bias ◽  
Temporal And Spatial ◽  
Host Evolution ◽  
Host Parasite ◽  
Acomys Dimidiatus

AbstractThe importance of parasites as a selective force in host evolution is a topic of current interest. However, short-term ecological studies of host–parasite systems, on which such studies are usually based, provide only snap-shots of what may be dynamic systems. We report here on four surveys, carried out over a period of 12 years, of helminths of spiny mice (Acomys dimidiatus), the numerically dominant rodents inhabiting dry montane wadis in the Sinai Peninsula. With host age (age-dependent effects on prevalence and abundance were prominent) and sex (female bias in abundance in helminth diversity and in several taxa including Cestoda) taken into consideration, we focus on the relative importance of temporal and spatial effects on helminth infracommunities. We show that site of capture is the major determinant of prevalence and abundance of species (and higher taxa) contributing to helminth community structure, the only exceptions beingStreptopharausspp. andDentostomella kuntzi.We provide evidence that most (notably the Spiruroidea,Protospirura muricola,Mastophorus murisandGongylonema aegypti, but with exceptions among the Oxyuroidae, e.g.Syphacia minuta), show elements of temporal-site stability, with a rank order of measures among sites remaining similar over successive surveys. Hence, there are some elements of predictability in these systems.

Onchocerca ochengi infections in cattle as a model for human onchocerciasis: recent developments

Parasitology ◽  
2000 ◽  
Vol 120 (7) ◽  
pp. 133-142 ◽  
Author(s):  
A. J. TREES ◽  
S. P. GRAHAM ◽  
A. RENZ ◽  
A. E. BIANCO ◽  
V. TANYA
Keyword(s):  
Vaccine Development ◽  
Parasite Development ◽  
Field Exposure ◽  
Adult Cattle ◽  
Experimental Infections ◽  
Long Term Treatment ◽  
Onchocerca Ochengi ◽  
Drug Development Research ◽  
Host Parasite

The bovine parasite Onchocerca ochengi is a nodule-dwelling filarial nematode, closely related to O. volvulus, the causal agent of human River Blindness, and, sharing with it, the same vector. This brief review, based on a presentation at the BSP Autumn Symposium 1999, describes recent work supported by the WHO Drug Development Research Macrofil programme and the Edna McConnell Clark Foundation vaccine development programme, to research the chemotherapy and immunology of onchocerciasis utilising this model system, with experimental infections in Liverpool and field infections in northern Cameroon. In a series of chemotherapeutic trials involving 10 compounds in 20 treatment regimes, the comparability of drug efficacy against O. ochengi with that described against O. volvulus has been demonstrated. Repeated, long-term treatment with oxytetracycline has been shown to be macrofilaricidal and the effect is hypothesized to be related to action on Wolbachia endobacteria, abundant in O. ochengi. Avermectins/milbemycins are not macrofilaricidal (even in high and repeated long-term treatments) but induce sustained abrogation of embryogenesis. In prospective, field exposure experiments with naive calves, prophylactic treatments with ivermectin and moxidectin prevented the development of adult worm infection, raising the possibility that drug-attenuated larval challenge infections may induce immunity. Putatively immune adult cattle exist in endemically exposed populations, and these have been shown to be significantly less susceptible to challenge than age-matched naive controls, whereas radically drug-cured, previously patently-infected cattle were not. Experimental infections with O. ochengi have revealed the kinetics of the immune response in relation to parasite development and demonstrate analogous responses to those reported in O. volvulus infection in humans and chimpanzees. In an immunization experiment with irradiated L3 larvae, cattle were significantly protected against experimental challenge – the first such demonstration of the experimental induction of immunity in a natural Onchocerca host–parasite system. Taken collectively, these studies not only demonstrate the similarity between the host–parasite relationships of O. ochengi in cattle and O. volvulus in humans, but promise to advance options for the control of human onchocerciasis.

Subcellular distribution of the Entamoeba histolytica 140 kDa FN-binding molecule during host-parasite interaction

Parasitology ◽  
2006 ◽  
Vol 134 (2) ◽  
pp. 169-177 ◽  
Author(s):  
V. I. HERNÁNDEZ-RAMÍREZ ◽  
A. RIOS ◽  
A. ANGEL ◽  
M. A. MAGOS ◽  
L. PÉREZ-CASTILLO ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Entamoeba Histolytica ◽  
Cdna Clone ◽  
Subcellular Distribution ◽  
Cultured Cells ◽  
Receptor Molecule ◽  
Specific Regulation ◽  
Host Parasite ◽  
Adhesion Process

Entamoeba histolytica trophozoites recovered from the host-parasite interface during abscess development obtain different stimuli compared with long-term cultured cells. In order to have a better understanding about the mechanisms in which the 140 kDa fibronectin (FN)-binding molecule (EhFNR) is involved during the invasive process, we decided to compare the regulation process of this molecule among long-term cultured trophozoites, FN-stimulated trophozoites, and trophozoites recently recovered from a liver abscess. A cDNA clone (5A) containing a fragment of the EhFNR that shows identity to the C-terminal region of the intermediate galactose lectin subunit Igl, was selected with a mAb (3C10). Identity of EhFNR with Igl was confirmed by immunoprecipitation with 3C10 and EH3015 (against the Gal/GalNAc intermediate subunit) mAbs. The 3C10 mAb was used as a tool to explore the modulation of the amoebic receptor (EhFNR). Our results showed specific regulation of the EhFNR in FN-interacted amoebas, as well as in trophozoites recovered at different stages of abscess development. This regulation involved mobilization of the receptor molecule from internal vesicles to the plasma membrane. Therefore, we suggest that in the host-parasite interface, the EhFNR (Igl) plays an important role in the adhesion process during abscess development.

Covariates of the Long-term Fluctuation of the Differential Light Threshold

1984 ◽  
Vol 102 (6) ◽  
pp. 880-882 ◽  
Author(s):  
J. Flammer ◽  
S. M. Drance ◽  
M. Schulzer
Keyword(s):  
Term Fluctuation

Longevity ofEchinostoma caproniin Balb/c mice

2008 ◽  
Vol 82 (1) ◽  
pp. 95-96 ◽  
Author(s):  
B. Fried ◽  
R.C. Peoples
Keyword(s):  
The Other ◽  
Term Survival ◽  
Long Term Survival ◽  
Echinostoma Caproni ◽  
Host Parasite Relationship ◽  
Parasite Relationship ◽  
The Mean ◽  
Host Parasite ◽  
Relationship Of

AbstractThis study used Balb/c mice to examine the longevity ofEchinostoma caproni. Five mice each exposed to 75 encysted metacercariae (cysts) were necropsied at 23 weeks postinfection (PI) (160 days PI). Two of the 5 were infected with a total of 33 worms; 23 in one mouse and 10 in the other. Body and organ area measurements showed that these worms were robust and normal in appearance. No signs of atrophy of any of the genital structures were observed. The mean ± SE of eggs/uterus per worm (n = 10) was 243 ± 6. This strain of mouse will be suitable to study the effect of long-term survival on the host–parasite relationship ofE. caproniin Balb/c mice.

scholarly journals NUMERICAL SIMULATIONS ON INFLUENCE OF LONG-TERM FLUCTUATION OF MEAN WATER LEVEL ON SAND WAVES IN THE KANMON WATERWAY, JAPAN

2020 ◽  
pp. 45
Author(s):  
Shiro Yamagata ◽  
Shouya Orishikise ◽  
Masaru Yamashiro ◽  
Yasuyuki Nakagawa ◽  
Noriaki Hashimoto ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Water Level ◽  
Tidal Current ◽  
Ocean Model ◽  
Spatial Difference ◽  
Sand Waves ◽  
Mean Water Level ◽  
Simulation Results ◽  
Term Fluctuation

In this study, the numerical simulation of tidal current and sediment transport in the Kanmon Waterway were performed by using a numerical simulation model FVCOM (Finite Volume Community Ocean Model (Chen et al. 2003)), in order to discuss the influence of the long-term fluctuation of mean water level on the sand waves. The numerical simulation results suggested that the spatial difference of the long-term fluctuation of mean water level in the Kanmon Straits slightly changes the tidal current around Tanoura Area, and consequently affects the development of sand waves.Recorded Presentation from the vICCE (YouTube Link): https://youtu.be/kfMfIVGiLKM

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