Search Results

1 - 10 of 14 items :

  • "ecological factor" x
Clear All
Ecological Factors of Transmission, Persistence and Circulation of Pathogens In Bat Populations

Abstract

The existence of bats is crucial for all ecosystem units as they fulfil numerous ecological roles. However, they are also considered to be natural reservoirs of a wide range of zoonotic microorganisms, especially viruses. In this review article we briefly summarize current knowledge about various ecological factors that facilitate bat pathogen dispersal and about the current approaches to monitoring viral communities present within bat populations. On the basis of the cited papers, we suggest that the increased focus on complex viral populations in bats and their interactions with other populations and the environment is necessary to fully comprehend the relationship between emerging infectious diseases, the environment and their toll on human health.

Open access
Looking for the causes of and solutions to the issue of honey bee colony losses

: do pollen quality and diversity matter? PLoS ONE 2013, 8:e72016. 21. Asensio I, Vicente-Rubiano M, Muñoz MJ, Fernández-Carrión E, Sánchez-Vizcaíno JM, Carballo M: Importance of ecological factors and colony handling for optimizing health status of apiaries in Mediterranean ecosystems. PLoS ONE 2016, 11:e0164205. 22. Stanimirović Z, Soldatović B, Vučinić M: Honey bee – Biology of the bees [in Serbian] Beograd, Srbija: Medicinska knjiga – Medicinske komunikacije 2000, 1-375. 23. Cirkovic D, Stanimirovic Z: Beekeeping manual [in Serbian] Državni

Open access
Evaluation of the Loss of Assimilation Apparatus and Its Causes in Scots Pine Stands (Pinus Sylvestris L.) of the Kampinos National Park

Abstract

The Kampinos National Park (KNP), in terms of ecology, is an exceptionally valuable place in the Polish lowland region. Until the 20th century, as a result of limited human influence on the natural resources of the Kampinos Forest, it can be presumed that the 100-year-old tree stands were shaped by natural ecological processes. This study contains a detailed assessment of crown conditions, dendrometric measurements and visible disease symptoms in the oldest fragments of the KNP, as well as statistical evaluation of the relationships between these factors. Results were correlated with ecological factors such as precipitation and temperature. For the purpose of the study, five tree stands, each over 130 years old, were selected. In each stand, the level of defoliation was assessed, based on the forest monitoring methodology performed in Poland for the State Environmental Monitoring. Tree height, circumference, and diameter at breast height measurements were performed for all the trees, and any visible disease symptoms were described. Defoliation data were used to classify 93.6% of the trees as the second level of stand damage (the so-called ‘warning’ level) according to the monitoring methodology. Observed disease factors confirm the physiological weakening of the trees. The populations studied exhibited a range of mean height and stem volume, and these were not significantly related to the level of defoliation or visible disease symptoms. Ecological factors, especially the drought in 2015, probably did not have a negative impact on the examined stands. The analysed pine populations demonstrate physiological weakness, but this appears to be related to their age and natural ecological processes.

Open access
Infection patterns of helminths in Norops brasiliensis (Squamata, Dactyloidae) from a humid forest, Northeastern Brazil and their relation with body mass, sex, host size, and season

Summary

Climatic and ecological factors can influence the parasite load of a host. Variation in rainfall, body size, and sex of the hosts may be related to the abundance of parasites. This study investigated the helminth fauna associated with a population of Norops brasiliensis, together with the effect of host biology (sex, body size, and mass) and variation in rainfall regime on the abundance of helminths. Species of three groups of endoparasites were found (Nematoda, Cestoda, and Trematoda), with nematodes as the most representative taxa with eight species, prevalence of 63.2 %, mean intensity of 4.0 ± 0.58 (1 – 25), and mean abundance of 2.66 ± 0.44 (0 – 25). Nine helminth species are new host records for N. brasiliensis. The nematode Rhabdias sp. had the highest prevalence (53.3 %). There was no significant relationship between abundance of the trematode Mesocoelium monas and host sex or season, although the abundance of this parasite increased significantly with host body size and mass, while abundance of nematodes was related to season and host mass. This study increases the knowledge about the diversity of helminth fauna associated with N. brasiliensis, revealing infection levels of hosts from northeastern Brazil.

Open access
Endoparasites of red fox (Vulpes vulpes) in the Slovak Republic with the emphasis on zoonotic species Echinococcus multilocularis and Trichinella spp.

Abstract

Due to specific geographical localization, climatic and geomorphologic conditions, several serious parasitic diseases circulate in the territory of the Slovak Republic that makes this area an ideal model territory of the central European red fox system. The red fox is an important reservoir host of parasites, which can be spread to another animals and humans. Our study was aimed at determining the current prevalence of certain parasites in red foxes from the entire territory of the Slovak Republic and identifies some ecological factors influencing their epidemiology. Within the first systematic investigation of red foxes carried out between the years 2000 and 2006 in total 4026 foxes were examined for Echinococcus multilocularis (prevalence 31.1 %) and 4699 foxes were investigated for the presence of Trichinella spp. larvae (10.4 % infected). The results of the next separate study revealed that 83.3 % of 1198 red foxes in the Slovak Republic had coccidian oocysts and helminth eggs in their faeces. Fifteen helminth species including two trematode, four cestode and nine nematode species were detected by coprological examination. Nine of these parasite taxa have zoonotic potential: Capillaria spp. (prevalence 22.4 %), Ancylostoma caninum (18.1 %), Toxocara canis (12.5 %), Taenia spp. (12.2 %), Mesocestoides spp. (5.8 %), Strongyloides stercoralis (1.6 %), Hymenolepis diminuta (0.6 %), Dipylidium caninum (0.4 %) and Opisthorchis felineus (0.3 %). Toxascaris leonina was the most common helminth species found in this survey (42.9 %).

Open access
Observations on the Influence of Temperature Of Second Stage Juveniles (Meloidogyne Spp.) in the Absence of the Host Plant

Abstract

The knowledge of root-knot nematodes behavior in different habitats and especially the knowledge of their reaction to major ecologic factors (humidity, temperature) are important for the assessment of pathogen potential in a specific area, being at the same time an important criterion for understanding the behavior towards host plants. The temperature is the most important factor, not just in the development of the entire biological cycle of root-knot nematodes, but at the same time it also affects their distribution, spread and survival under thermic stress conditions (excessive heat or cold). Alongside with the water and oxygen, the temperature is the triggering factor of hatching and running all stages until the adult stage. The articles aims to determine the survival of juveniles stages for Meloidogyne species, in the absence of host plants, and by exposing second stage juveniles to different temperatures. The juveniles survival and mobility decreases quite much at relative low temperatures (4°C and 10°C). Forward movements, mobility, hatching and lifetime were accentuated at higher temperatures (20°C) for a few weeks, so that after a period to decrease drastically (in 10 and 12 week) for the species considered for the study.

Open access
Transplanting date adjustment in Boro rice cultivation as a strategy to reduce groundwater withdrawal in Bangladesh

Abstract

Due to intensive irrigated rice cultivation during dry season, declining trend of groundwater level is observed in many parts of Bangladesh. Field experiments were conducted in 2015 and 2016 at four experimental stations of Bangladesh Institute of Nuclear Agriculture, Bangladesh to evaluate the performance of some Boro rice cultivars in different planting dates with respect to yield and irrigation water requirement, and to optimize between yield and irrigation water requirement, with a view to reduce groundwater withdrawal and hence reducing mining of groundwater. The transplanting dates were 21th January (T1), 15th February (T2), 7th March and 30th March. Four rice cultivars were used. The results showed that the rice growth period was shortened with the later dates of transplanting. Generally, the yield of all cultivars at first and second transplanting (i.e. in T1 & T2) are good, and decrease at the later transplanting dates (T3, T4) and hence could not be recommended among farmers. When we consider the irrigation savings in T2 compare to T1, the irrigation savings varies with location and year, but the general tendency is that the second transplanting can save irrigation water. By considering economic (intrusion of additional rabi crop between two rice crops) and ecological factor (irrigation reduction, and hence reducing groundwater withdrawal), we recommend that the most suitable transplanting time for Boro rice should be 15th February. As such, we can effectively achieve good yield, reduce irrigation requirement, and creating opportunity for possible intrusion of addition Rabi crop between two rice crops. Overall, the findings of the present study can provide effective transplanting time and cultivar to reduce groundwater withdrawal in the present agro-ecosystem of northwestern Bangladesh and other similar areas.

Open access
Helminthofauna of Pelophylax kl. esculentus (Linne, 1758) from Petrovaradinski Rit Marsh (Serbia)

Anura (Amphibia) from the Petrovaradinski Rit marsh. Prirodno-matematički fakultet-Univerzitet u Novom Sadu, Magistarska teza, Novi Sad. (In Serbian) [13] Plasota, K. (1969): The effect of some ecological factors on the parasitofauna of frogs. Acta Parasitol. Polonica, 16(6): 48–60 [14] Popović, E. (1992): Fauna and Ecology of Trematoda of tailless amphibians (Amphibia: Anura) of Vojvodina Province. Prirodno-matematički fakultet-Univerzitet u Novom Sadu, Doktorska disertacija, Novi Sad. (In Serbian

Open access
New data on an exotic Nippotaenia mogurndae (Cestoda), newly introduced to Europe

–335 http://dx.doi.org/10.1016/S0304-4017(99)00039-4 [31] Terek, J. (1990): Net zooplankton of hydromeliorational canals and its relation to selected ecological factors. Biologia, Bratislava, 45: 801–814

Open access
Mallard duck (Anas platyrhynchos) as a potential link in the epidemiological chain mycoses originating from water reservoirs

migratory birds. J Wild Dis 2004, 40 , 639-659. 17. Korniłłowicz-Kowalska T., Kitowski I.: Diversity of fungi in nests and pellets of Montagu’s harrier ( Circus pygargus ) from eastern Poland- importance of chemical and ecological factors. Import Chemic and Ecol Fact 2009, 16 , 453-471. 18. Kurnatowski P., Rózga A., Wójcik A.: Potentially pathogenic yeast-like fungi in lowland water reservoir. Mycoses 2001, 55 , 40-41. 19. Kreger-van Rij N.J.W.: The yeasts. A taxonomic study. Elsevier, Amsterdam, 1984, pp. 1082

Open access