The acanthocephalan parasite Pomphorhynchus laevis (Müller, 1776) uses freshwater amphipods as its intermediate host. In order to complete the life cycle, the infected amphipod must be consumed by a fish, where the acanthocephalan will mature and reproduce. Parasite transmission, and therefore fitness, could be enhanced if infected amphipods fail to detect or avoid predatory fish. We compared the activity levels of infected and non-infected amphipods, Echinogammarus stammeri (Karaman, 1931), in both the presence and absence of odours from its natural, definitive host, the fish Leuciscus cephalus (L.). Throughout the experiment, infected amphipods were more active than were non-infected individuals. The non-infected amphipods reduced their activity after the addition of fish odours, but the infected amphipods failed to show a significant decrease. The failure of infected amphipods to reduce activity levels in the presence of fish odour may reflect a parasite strategy to increase its chances of transmission by making its amphipod host more vulnerable to predation by fish.
The pattern of activity of 1-aminocyclopropane carboxylic acid synthase (ACS) was similar to photosynthetic and growth traits observed at 30, 45, and 60 d after sowing in mustard (Brassica juncea L.) cultivars Varuna and RH 30 differing in photosynthetic capacity. Higher activity of ACS and therefore ethylene release in Varuna than RH 30 increased stomatal conductance, intercellular CO2 concentration, carboxylation rate (carbonic anhydrase and intrinsic water use efficiency), and thus net photosynthetic rate (PN) and leaf and plant dry masses (DM) at all sampling times. Moreover, Varuna also had larger leaf area which contributed to higher PN and DM. A positive correlation between ACS activity and PN and leaf area was found in both the cultivars. Thus ACS activity may affect PN through ethylene-induced changes on foliar gas exchange and leaf growth.
The activity of enzymes characteristic for C4-type photosynthesis was determined in different organs of two herbaceous plants: Reynoutria japonica Houtt. and Helianthus tuberosus L. The activity of phosphoenolpyruvate carboxylase (PEPC) was usually higher in the roots, some of the stem tissues and petioles in comparison to the leaf blades. The highest activity of malic enzymes (NAD-ME, NADP-ME) and phosphoenolpyruvate carboxykinase (PEPCK) was in the petioles and stem tissues of both plants and the lowest in the leaf blades and the pith of Helianthus tuberosus L. and M. Kocurek, J. Pilarski.
Paraoxonase 1 (PON1) seems to have a relevant role in detoxifying processes and in atherosclerosis. The aim of this study was to determine PON1 activity, the total antioxidant capacity, as well as entire lipid profile in children for screening of possible risk of atherosclerosis development. Serum PON1 arylesterase/paraoxonase activities were determined spectrophotometrically. The total antioxidant capacity of the serum was measured by TEAC method. Parameters of lipid profile were analyzed by routine laboratory methods. It has been shown that PON1 arylesterase/ paraoxonase activities were very similar to values found in adults. In children, no significant correlation between PON1 arylesterase activity and HDL was observed. PON1 paraoxonase activity correlated only with atherogenic index. PON1 arylesterase activity was significantly higher in girls than in boys. The antioxidant capacity was inversely related to the body mass index. In this study, PON1 activity was determined in healthy children aged 11 to 12 years and we found a similarity in PON1 activities of children and adults. Moreover, the results of our study support the hypothesis that higher body weight of children may contribute to a greater risk for development of atherosclerosis in which oxidative stress plays a role., K. Sumegová, Z. Nagyová, I. Waczulíková, I. Žitňanová, Z. Ďuračková., and Obsahuje bibliografii a bibliografické odkazy
The impact of heat shock on minimising the activity of photosystem 2 (PS2) initiating high lipid peroxidation (POL) level and consequently changes in the enzymatic-antioxidant protective system was studied in seedlings of two Egyptian cultivars of barley (Giza 124 and 125). Heat doses (35 and 45 °C for 2, 4, 6, and 8 h) decreased chlorophyll (Chl) contents coupled with an increase in Chl a/b ratio, diminished Hill reaction activity, and quenched Chl a fluorescence emission spectra. These parameters reflect the disturbance of the structure, composition, and function of the photosynthetic apparatus as well as the activity of PS2. POL level, as dependent on the balance between pro- and anti-oxidant systems, was directly correlated with temperature, exposure time, and their interaction. Heat shock caused an increase in the electric conductivity of cell membrane, and malonyldialdehyde content (a peroxidation product) coupled with the disappearance of the polyunsaturated linolenic acid (C18:3), reflecting the peroxidation of membrane lipids which led to the loss of membrane selective permeability. Moreover, it induced distinct and significant changes in activities of antioxidant enzymes. Superoxide dismutase and peroxidase activities have been progressively enhanced by moderate and elevated heat doses, but the most elevated one (45 °C for 8 h) showed a decrease in activities of both enzymes. In contrast, catalase activity was reduced with all heat shocks. and F. El-Shintinawy ... [et al.].
We studied the temporal relationships and the patterns of electromyographic activities of the posterior cricoarytenoid and thyreoarytenoid muscles (laryngeal abductor and adductor), the diaphragm and abdominal muscles in anesthetized cats during mechanically induced tracheobronchial and laryngopharyngeal coughs, expiration and aspiration reflexes. The posterior cricoarytenoid muscle activity reached the maxima just before the peak of diaphragmatic activity in both types of cough and aspiration reflexes and slightly before the top of abdominal muscle activity in coughs and the expiration reflex. Thus, this muscle contributes to the inspiratory phase of coughs and aspiration reflex and also to the expulsive phase of coughs and the expiration reflex. The thyreoarytenoid muscle presented strong discharges in the compressive phase of coughs and expiration reflex (during the rising part of the abdominal muscle activity) and in the subsequent laryngoconstriction (following the diaphragmal and/or abdominal muscle activity) in all four reflexes. This muscle was also slightly activated at the beginning of the aspiration reflex. The existence of four phases of the cough reflex is also discussed., I. Poliaček, A. Stránsky, J. Jakuš, H. Baráni, Z. Tomori, E. Halašová., and Obsahuje bibliografii
Eleven calves from the European bison breeding centres of Białowieża National Park (Poland) were observed during the first 3 months of life to investigate their integration patterns into a group. Spatial relations of the calf with other bison in a group were reflected in the distance to group members of various categories and in the extent to which individuals synchronized their behaviour. Data on changes in the calf’s activity pattern provided information on the transformation in feeding habits. Three main phases were identified in the early period of European bison’s life: (1) establishment of mother-infant bond, (2) incorporation of a calf into a calf subgroup, and (3) integration of the calf into the whole group. Incorporation of the calf into a herd started in week 2. The pattern of calf’s integration was determined by transformation of its activity pattern. At first similarity of activity patterns among calves resulted in synchronization of their behaviour and proximate company. In the next phase, the change in the primary source of nutrition from nursing to grazing and gradual alteration of activity pattern towards an adult’s one led to non-specific spatial relations with group members and integration of the calf into the herd.
With solitary-living species, such as the European roe deer (Capreolus capreolus), high individuality is also expected to influence activity. Here we studied the annual activity patterns of European roe deer in the Bavarian Forest National Park. We investigated the influence of age and sex, the weather, and the individuality. We used sex-specific generalized additive models with variables that considered the age of the animal and also the high-resolution site-specific parameters temperature, precipitation, and snow depth. Data from 20 males and 9 females were gathered continuously with GPS-GSM collars carrying a dual-axis acceleration sensor. Our results indicated that the main factors influencing the activity patterns of the crepuscular roe deer in the Bavarian Forest National Park are the individual, the season, and the time of day, and that weather parameters are secondary. GPS-GSM collars with a dual-axis acceleration sensor allow long-term, continuous, and remote activity monitoring of European roe deer.
This study investigated whether the males of the Tengmalm’s owl change their activity patterns, evaluated based on delivering prey to nestlings in respect of different food supply. During two breeding seasons 12 owl nests were continuously monitored by a camera system to obtain data on the time of male prey delivery and identification of prey items brought to nestlings. Even though the abundance of food supply differed in both years, there was no difference in the number of prey items delivered by males to their nests. Nevertheless, the species composition of food supply as well as the species composition of prey delivered by males to the nests differed between 2004 and 2006. Yet male activity patterns were the same in both years; they showed a monophasic cycle with one peak at the beginning of the night, around 22:00 and 23:00. Moreover, the males delivered prey to their chicks strictly at night time in both years and they started (the first evening arrival at the nest) and ended (the last morning arrival at the nest) their nest visiting in the same time in 2004 and 2006. The results of this study suggest that activity patterns of Tengmalm’s owl males in central Europe do not depend on varying food conditions.
To study annual and circadian activity proportion and activity allocation during the pup rearing period we analysed VHF telemetry-based data from the invasive, socially monogamous raccoon dog in North Eastern Germany. Proportions of active fixes for 26 adults indicate a mean annual activity level
of 58.3 %. There was no difference between males and females in mean annual activity or in the mean activity in each of the different seasons. A mean winter-activity level of 47.0 % ± 32.4 active fixes indicates that raccoon dogs did not hibernate; however, they became less active as the temperature decreases in winter. There were clear differences in the
proportion of active fixes observed in the biological seasons, with the
highest activity level (70.3 %) during the pup rearing period. Circadian
activity rhythm, sampled on a daily basis, indicates that raccoon
dogs were mainly crepuscular and nocturnal with a mean activity
level of 86.8 %. The mean diurnal activity level across the seasons was 32.4 %, ranging from 15.0 % in winter to 56.6 % during the pup rearing period. Allocation of active fixes for 24-h continuous observations during the first six weeks after parturition showed that males were mostly inactive, resting with the pups in the den, while females foraged to satisfy their
increased energy requirements. This point to a clear division of labour between parents, during the pup rearing period.