Search results for "STING"
showing 10 items of 3756 documents
Mixis strategies and resting eeg production of rotifers living in temporally-varying habitats
1993
A dynamic model based on six differential equations has been developed to explore the control of mixis of rotifers living in temporally-varying habitats. The equations give variation rates of amictic females, three stages of mictic females, males and resting eggs. The model takes into account some constraints on mixis (e.g., male-female encounter probability and effort involved in resting egg production) and its predictions have been generated by computer simulation using parameter values from the literature. For simulation, a time-dependent birth rate function was assumed to account for changes in the environment, and several mixis patterns (i.e., moment of mixis induction and mictic rate …
About the Influences of Some Major Biotic Drivers on the Population Dynamics in Host-parasite Systems: Interpretative Lessons from an Extended Nichol…
2020
Population dynamics within host-parasite systems in insects is governed by a series of factors, both endogenous and exogenous. Among them, five factors may be considered as major drivers: the respective inherent rates of increase of the host and of the parasite, the level of resource available to the host, the respective immigration rates of the host and of the parasite. While only the first two (the inherent rates of increase of host and parasite) are considered in the original Nicholson and Bailey model, an extended version of the model includes also the other three parameters, thus providing a broader (although still schematic) approach to the host-parasite population dynamics. A brief a…
The Severe Asthma Registry – German data
2018
Patients with severe persistent asthma represent the highest unmet medical need among the asthmatic population. To improve the understanding of underlying mechanisms and disease progression the German Asthma Net (GAN, www.german-asthma-net.de) launched a Severe Asthma Registry in December 2011. Enrolled patients undergo detailed clinical and physiologic evaluations, including patients’ medical history, allergy and lung function tests, blood analyses as well as past and concomitant medication and comorbidities. Patients are followed up every year. As of February 2018, 1097 subjects were recruited in Germany, Austria, and Slovenia. The mean age±SEM of the 839 German adult patients is 50.6±0.5…
O início de uma nova era: teste sistemático para patógenos causadores de infecções agudas das vias aéreas superiores (IVAS) em crianças
2007
On average humans get sick ten times per year. About six times the illness is due to an acute respiratory tract infection (ARI). Morbidity is especially high in children since they usually encounter the offending organism for the first time in their life; the lack of immunity results in shedding of the offending organisms in high numbers of prolonged time as compared to adults; their airways are smaller than those of adults and thus the inflammatory response leads to a more significant narrowing of the airways resulting in more severe disease; on average they have a high number of social contacts and also a more intimate contact with peers and caregivers alike resulting in a higher attack r…
Socially Responsible Investing and Public Pension Fund Performance in Latvia
2018
Currently Latvia runs a three-pillar pension system. Despite positive dynamics of change of net assets of pension schemes, investments into pension programs are not regarded as financial products that could be popular amongst the population of Latvia. This problem is one of the key social economic issues in society and therefore its solution, which should be developed with consideration of ethical principles of investment, is socially important, which is why it should be addressed by the state. The aim of this research is to consider social and economic aspects of activities of the 2nd pillar pension fund in Latvia and to identify the attitude of Latvian residents to investments into pensio…
Seasonal population dynamics of Zeuxapta seriolae (Monogenea: Heteraxinidae) parasitising Seriola dumerili (Carangidae) in the Western Mediterranean.
2013
We examined the seasonal and yearly population dynamics of the monogenean pathogen Zeuxapta seriolae on juvenile fish from wild populations of Seriola dumerili. The study is based on bimonthly monitoring between April, 2005 and April, 2007 off Majorca, and newly obtained monogenean population data for juvenile fish from three additional localities in the Western Mediterranean (off Alicante, Corsica and Sardinia). We documented the highest intensities and abundances of Z. seriolae, with mean abundance values similar to or higher than those reported in the single case of wild fish mortalities reported to date. There was a recurrent pattern of seasonal change in infection with Z. seriolae in t…
On the infracommunity structure of adult cestodes in freshwater fishes.
1990
The distribution–co-occurrence and exchange of adult cestode species in two fish communities (the Bothnian Bay and Lake Yli-Kitka both in Finland) was studied. Coexistence of two or more mature cestode species in the same fish host population was zero for all fish species studied (33) except pike in the Bothnian Bay and whitefish in the lake. It was found that 60% of the fish species studied in the Bothnian Bay and 80% of the fish species studied from Lake Yli-Kitka harboured only 1 mature cestode species. Exchange of adult cestode species between the different fish species in these two fish communities was found to be as rare as coexistence. The infra-community structure of adult cestodes …
Host‐parasite relationships between two seal populations and two species of Corynosoma (Acanthocephala) in Finland
1988
Ringed seals (Phoea hispida botnica), from the Bothnian Bay, north-eastern Baltic Sea were examined for acanthocephalan parasites in 1977-1982, and specimens from Lake Saimaa in south-eastern Finland (P. h. saimensis) were examined in 1980-1981. The two seal stocks have been isolated from Arctic stock for 11,000 years and from each other for 8,000 years. Corynosoma strumosum and C. semerme were found in the Baltic seals, but only C. strumosurn in those from the lake. Eighty two of the ringed seals caught in the Bothruan Bay were infected with both Corynosoma species, one with a single infection of C. strumosum and one with C. semerme inautumn. The total number of C. semerme increased in rel…
Differences in parasite susceptibility and costs of resistance between naturally exposed and unexposed host populations
2009
It is generally assumed that resistance to parasitism entails costs. Consequently, hosts evolving in the absence of parasites are predicted to invest less in costly resistance mechanisms than hosts consistently exposed to parasites. This prediction has, however, rarely been tested in natural populations. We studied the susceptibility of three naïve, three parasitized and one recently isolated Asellus aquaticus isopod populations to an acanthocephalan parasite. We found that parasitized populations, with the exception of the isopod population sympatric with the parasite strain used, were less susceptible to the parasite than the naïve populations. Exposed but uninfected (resistant) isopods f…
Parasitic infracommunities of the Aegean wall lizard Podarcis erhardii (Lacertidae, Sauria): isolation and impoverishment in small island populations
2009
AbstractThe Aegean wall lizard Podarcis erhardii, is widely distributed across the islands of the Aegean Sea (Greece). While there exists a relatively substantial body of knowledge on the ecology and life history of the species, the parasite communities of the taxon remain almost completely unknown. Quantifying the composition of these communities in P. erhardii is not only important for autoecological reasons, but also because inter-island comparisons of this lizard's parasite communities can shed light on the factors that structure parasite diversity in general. Here we investigate the gastrointestinal parasite communities of P. erhardii populations occurring on 16 landbridge islands of t…