A 38-year study on Trichinella spp. in wild boar (Sus scrofa) of Latvia shows a stable incidence with an increased parasite biomass in the last decade

BACKGROUND: Trichinella spp. are zoonotic parasites transmitted to humans by the consumption of raw or insufficiently cooked meat of different animal species. The most common source of infection for humans is meat from pigs and wild boar (Sus scrofa). The aim of the present work was to evaluate the incidence of Trichinella spp. infections in wild boar hunted in Latvia over a 38 year interval (1976 to 2013). METHODS: A total 120,609 wild boars were individually tested for Trichinella spp. by trichinoscopy and, in case of negativity, by artificial digestion of 25 g muscles, in the 1976–2005 period, and by artificial digestion of 25–50 g muscles in the 2006–2013 period. Trichinella spp. larvae were identified at the species level by multiplex PCR. RESULTS: In the study period, the overall prevalence of infected wild boar was 2.5%. Trichinella britovi was the predominant (90%) species. The incidence of Trichinella spp. infection in wild boar exhibited two different trends. From 1976 to 1987, the incidence of infected/hunted wild boar increased from 0.23% to 2.56%, then it decreased to 0.19 in 1994. Thereafter, the incidence fluctuated between 0.05% and 0.37%. A statistically significant (P < 0.05) correlation (r = 0.54; p = 0.0199) was found between the trend of Trichinella spp. incidence in hunted wild boar and the number of snow cover days from 1976 to 1993. From 1997 to 2013, the estimated wild boar population of Latvia increased by 4.9 times and the hunting bag by 9.7 times, with a stable incidence of Trichinella spp. in the population. It follows that the biomass of Trichinella spp. larvae and of T. britovi, in particular, increased. CONCLUSIONS: The incidence trends of Trichinella spp. in wild boar could be related to the role played by the snow in reducing the thermal shock and muscle putrefaction which increases the survival of the larvae in muscle tissues of carrion in the 1976–1993 period; and, in the 1997–2013 period, to the increased biomass of Trichinella spp. due to the increased carnivore populations, which are the main reservoirs of these parasites

Acquirement of speech skills in the process of getting acquainted with literary works among six-years old children

Kvalifikācijas darba autors: Inese Daukšte. Kvalifikācijas darba vadītāja: Aija Kalve Ineses Daukštes kvalifikācijas darba tēma ir „Sešgadīgu bērnu runas prasmju apguve literāro darbu iepazīšanas procesā”. Kvalifikācijas darba mērķis ir teorētiski noskaidrot un praktiski pētīt bērnu runas prasmju sekmēšanas iespējas literāro darbu iepazīšanas procesā. Lai mērķis tiktu sasniegts, bērni tika novēroti daiļdarbu lasīšanas laikā, tika spēlētas lomu rotaļas, lai sekmētu bērnu stāstītprasmi, raksturojot notikumus un tēlus literārajos darbos. Kvalifikācijas darbā autore iepazīstas un analizē pedagoģijas un psiholoģijas literatūru par runas un valodas attīstību. Tika izmantotas pārrunas, novērošanas metode, kā arī tika veikts pedagoģiskais izmēģinājums. Apstiprinājies, ka sešgadīgu bērnu runa literāro darbu iepazīšanas procesā tiks sekmēta, ja •ja izvēlētie literārie darbi būs atbilstoši vecumposmam; •ja izvēlētie metodiskie paņēmieni sekmēs runas attīstību; •ja literārie darbi tiks lasīti regulāri; Pētījums tika veikts Rīgas X pirmsskolas izglītības iestādē Pētījuma bāzi veido vecākās grupas( 6 gadi )bērni Pētījuma darbu veido divas nodaļas, secinājumi, literatūras avoti un pielikumi. Pētījuma darbs izklāstīts ir 55 lapaspusēs. Atslēgvārdi: Runa, valoda, literārie darbi, pirmsskola Anotation Author of the qualification paper: Inese Daukšte. Supervisor of the qualification paper: Aija Kalve The theme for the qualification paper of Inese Daukšte is “Acquirement of speech skills in the process of getting acquainted with literary works among six-years old children”. Purpose of the qualification paper is to theoretically clarify and practically research the ability to improve children’s mutual speech skills through acquaintance with literary works. In order to obtain the necessary information, the children were observed while they were reading, role-play games were played to improve children’s narrative skills by describing events and characters from the literary works. In the qualification paper the author analyzes pedagogy and psychology literature on speech and language development. Discussions, observation method, as well as pedagogical trial were conducted in the process. Through the research it was confirmed that the acquirement of speech skills in the process of getting acquainted with literary works among six years old children will be successful if •the chosen literary works are suitable for the according age group; •the chosen methodological techniques contribute to the development of speech; •the literary works are being read on a regular basis. The research was conducted in the Riga Preschool Educational Institution X. The research base was formed on six-years old children. The research consists of two chapters, conclusions, literature sources and annexes The research work is presented in 55 pages. Keywords – language, speech, literary works, pre-schoo

Data from: Senescence in immune priming and attractiveness in a beetle

Age-related decline in immune activity is referred to as immunosenescence and has been observed for both the adaptive immune response of vertebrates and the innate immune system of invertebrates. Since maintaining a basic level of immune defence and mounting an immune response is costly, optimal investment in immune function should vary over a wide range of individual states such as the individual’s age. In this study we tested whether the immune response and immunological priming within individuals become less efficient with age using mealworm beetles, Tenebrio molitor, as a model organism. We also tested whether aging and immunological priming affected the odours produced by males. We found that young males of T.molitor were capable of mounting an immune response a sterile nylon monofilament implant with the potential to exhibit a simple form of immune memory through mechanisms of immune priming. Older males did not increase their immune response to a second immune challenge, which negatively affected their sexual attractiveness and remaining life span. Our results indicate that the immune system of older males in T.molitor is less effective, suggesting complex evolutionary trade-offs between ageing, immune response and sexual attractiveness

Senescence of immunity in Tenebrio molitor - J Evol Biol

This excel file contains the data on encapsulation response of young and old males and their attractiveness. The attractiveness was measured as the total time females spent (s) and number of visits of females on pheromone discs of the males

Terminal investment in Tenebrio molitor

Encapsulation responses, resting metabolic rate before activation of the immune system and after the activation, attractiveness of male odours to females before activation of the immune system and after its activation, and survival of males in relation to their immune response (encapsulation rate), sexual attractiveness and metabolic rate

Data from: Male mealworm beetles increase resting metabolic rate under terminal investment

Harmful parasite infestation can cause energetically costly behavioural and immunological responses, with the potential to reduce host fitness and survival. It has been hypothesized that the energetic costs of infection cause resting metabolic rate (RMR) to increase. Furthermore, under terminal investment theory, individuals exposed to pathogens should allocate resources to current reproduction when life expectancy is reduced, instead of concentrating resources on an immune defence. In this study, we activated the immune system of Tenebrio molitor males via insertion of nylon monofilament, conducted female preference tests to estimate attractiveness of male odours and assessed RMR and mortality. We found that attractiveness of males coincided with significant down-regulation of their encapsulation response against a parasite-like intruder. Activation of the immune system increased RMR only in males with heightened odour attractiveness and that later suffered higher mortality rates. The results suggest a link between high RMR and mortality and support terminal investment theory in T. molitor

A 38-year study on Trichinella spp. in wild boar (Sus scrofa) of Latvia shows a stable incidence with an increased parasite biomass in the last decade

Publisher Copyright: © 2015 Kirjušina et al.; licensee BioMed Central.Background: Trichinella spp. are zoonotic parasites transmitted to humans by the consumption of raw or insufficiently cooked meat of different animal species. The most common source of infection for humans is meat from pigs and wild boar (Sus scrofa). The aim of the present work was to evaluate the incidence of Trichinella spp. infections in wild boar hunted in Latvia over a 38 year interval (1976 to 2013). Methods: A total 120,609 wild boars were individually tested for Trichinella spp. by trichinoscopy and, in case of negativity, by artificial digestion of 25 g muscles, in the 1976-2005 period, and by artificial digestion of 25-50 g muscles in the 2006-2013 period. Trichinella spp. larvae were identified at the species level by multiplex PCR. Results: In the study period, the overall prevalence of infected wild boar was 2.5%. Trichinella britovi was the predominant (90%) species. The incidence of Trichinella spp. infection in wild boar exhibited two different trends. From 1976 to 1987, the incidence of infected/hunted wild boar increased from 0.23% to 2.56%, then it decreased to 0.19 in 1994. Thereafter, the incidence fluctuated between 0.05% and 0.37%. A statistically significant (P∈<∈0.05) correlation (r∈=∈0.54; p∈=∈0.0199) was found between the trend of Trichinella spp. incidence in hunted wild boar and the number of snow cover days from 1976 to 1993. From 1997 to 2013, the estimated wild boar population of Latvia increased by 4.9 times and the hunting bag by 9.7 times, with a stable incidence of Trichinella spp. in the population. It follows that the biomass of Trichinella spp. larvae and of T. britovi, in particular, increased. Conclusions: The incidence trends of Trichinella spp. in wild boar could be related to the role played by the snow in reducing the thermal shock and muscle putrefaction which increases the survival of the larvae in muscle tissues of carrion in the 1976-1993 period; and, in the 1997-2013 period, to the increased biomass of Trichinella spp. due to the increased carnivore populations, which are the main reservoirs of these parasites.publishersversionPeer reviewe

Terminal investment in Tenebrio molitor

Encapsulation responses, resting metabolic rate before activation of the immune system and after the activation, attractiveness of male odours to females before activation of the immune system and after its activation, and survival of males in relation to their immune response (encapsulation rate), sexual attractiveness and metabolic rate