Contamination of soil with Toxocara eggs in urban (Prague) and rural areas in the Czech Republic

Contamination of soil with feline and canine ascarid eggs in public parks, backyards and sand pits in Prague, Czech Republic was investigated in this work. Soil samples from shelters and rural areas were also collected. The comparison of soil from different areas (urban, rural, backyards and shelters) exhibited significant difference (chi(2)=32.16, d.f.=3 and p<0.0001). The highest rate of contamination (45%) was found in backyards inhabited by feral cats. The eggs of Toxocara spp. were found in 20.4% of parks, 10% of shelters and 5% of rural samples. Mean egg density per sample from Prague parks was 6.2 eggs/100g of soil. In 126 composite samples from children's and pits, the prevalence of Toxocara eggs was 11.90%. The number of eggs in positive samples varied from 2 to 22 (per 100g). A high proportion (46.9%) of eggs was fully embryonated. There was no difference between the sand pits with or without formal exclusion of dogs (chi(2)=0.6, d.f.=1 and p<0.0001).     

Behavior, preference for, and use of alfalfa, tall fescue, white clover, and buffalograss by pregnant gilts in an outdoor production system

Sustainable outdoor pig production requires vegetation that can maintain ground cover, assimilate manure nutrients, and prevent soil erosion. Two experiments were conducted to evaluate the suitability of four forages: alfalfa (Medicago sativa), tall fescue (Festuca arundinacea), white clover (Trifolium repens), and buffalograss (Buchloe dactyloides) for grazing or ground cover in pastures for pigs. Each forage plot covered 7.5 m2, with nine replicates in a randomized block design. In Exp. 1, eight pregnant gilts had free access to all forages during a 2-d adjustment period. Immediately thereafter, pairs of gilts were assigned randomly to one of each of four blocks of the four forages during a 2-d measurement period. The percentage of ground cover for each forage was visually estimated at 0, 24, and 48 h of study. Behavioral data, including walking, eating, grazing, rooting, drinking, standing, lying, and time spent in hut were video-monitored continuously for 48 h. Initial percentage of ground cover was 100% for all species. By 48 h, percentage of ground cover decreased (P < 0.001) for white clover (11.3 +/- 0.88%) and alfalfa (36.3 +/- 0.88%), but not for tall fescue (98.0 +/- 0.88%) or buffalograss (98.0 +/- 0.88%). Gilts spent more (P < 0.01) time grazing white clover (16.3 +/- 1.97 min/d) and alfalfa (11.2 +/- 1.97) than tall fescue (0.8 +/- 1.97) or buffalograss (0.3 +/- 1.97), and rooted more (P < 0.04) white clover than other forages. In Exp. 2, six gilts from the initial group were put on six blocks of the four forages. Each gilt was assigned randomly to three replicates of each forage, including alfalfa, tall fescue, or buffalograss (white clover was excluded because of damage by gilts during Exp. 1), and gilts grazed single forages for 2 d. After this grazing period, the percentage of ground cover was less (P < 0.01) for alfalfa than for buffalograss or tall fescue (37.5 +/- 0.38, 96.7 +/- 0.39, 96.3 +/- 0.39%, respectively). With access to a single forage, pregnant gilts spent more (P < 0.01) time grazing alfalfa (15.8 +/- 2.36 min/d) than buffalograss (1.5 +/- 2.36) or tall fescue (0.7 +/- 2.37). These gilts clearly preferred grazing white clover and alfalfa, and rooting and eating white clover compared with buffalograss or tall fescue. Rates of ground cover loss were less (P < 0.01) for tall fescue and buffalograss than for the more preferred forages. Less preferred forages could have potential as pasture for swine when the primary objective is ground cover maintenance rather than nutrient supply.     

Intestinal Contents Supernatant Viscosity of Rats Fed Oat-Based Muffins and Cereal Products

The intestinal contents viscosities of oat-based breakfast cereals and muffins were examined. Male Sprague-Dawley rats were adapted for four days to a semipurified diet (AIN-76A). Following an overnight fast, the animals were meal-fed 5 g of either the AIN-76A diet (containing 5% cellulose), the AIN-76A diet containing 2% guar gum, whole-grain oat flour, one of five cereals (corn flakes, cooked oatmeal, uncooked oatmeal, cooked oat bran, or Cheerios), or one of two types of muffins (containing whole-grain oat flour or oatmeal). Two hours after presentation of the meal, the animals were killed, the small intestines removed, and the contents collected. The contents were centrifuged, and the viscosity values of the undiluted supernatants were determined. The supernatant viscosity from rats fed the AIN-76A diet was negligible (<5 mPa·sec), whereas that from rats fed guar gum was high (396 ± 117 mPa·sec). Of the cereals fed, corn flakes resulted in the lowest viscosity (<5 mPa·sec). However, all oat-based cereals resulted in high intestinal contents supernatant viscosity levels (cooked oatmeal 368 ± 128, uncooked oatmeal 307 ± 107, cooked oat bran 301 ± 85, Cheerios 199 ± 58, mPa·sec) with no statistically significant differences. The intestinal contents viscosity values for the whole-grain oat flour muffin and oatmeal muffin were 233 ± 52 and 111 ± 26 mPa·sec, respectively, a statistically significant difference (P < 0.05). This suggests that the form of the oat within a food may influence the degree of viscosity produced within the small intestine after that food is consumed.     

Estimation of the effect of lead and cadmium ions on fluctuating asymmetry in leaves of the common bean (Phaseolus vulgaris L.)

The effect of lead and cadmium ions on the fluctuating asymmetry of the side leaflets’ central veins of the common bean (Phaseolus vulgaris L.) was estimated. The impact of heavy metals on the parameter with the lead or cadmium content in the ground in the concentration of 650 mg/kg or 10 mg/kg respectively was not revealed.     

Susceptibility of Mastomys natalensis to Brugia malayi following pretreatment with antifilarials

Mastomys natalensis pretreated with diethylcarbamazine (DEC), levamisole or centperazine were exposed to the standard inoculum of infective larvae of Brugia malayi. Percentage 'take' of infection, duration of prepatent period, course of microfilaraemia and number of adult worms recovered were compared with those of untreated infected Mastomys (control). DEC and centperazine did not alter the 'take' (DEC/centperazine: 100%; control: 88.24%) and the average prepatent period (DEC: 105.44 days; centperazine: 105.18 days, control: 109.20 days). In levamisole pretreated animals on the other hand, the 'take' was much lower (68.18%) with extended prepatent period (125.87 days). However, unlike centperazine and control, the course of microfilaraemia was identical in DEC and levamisole pretreated animals. The average adult worm recovery was significantly high in centperazine pretreated animals being 14.09 as against 8.12, 7.46 and 8.42 in DEC, levamisole pretreated and control animals, respectively.     

Arbovirus isolations from mosquitoes in South Slovakia.

In the years 1973 and 1975 mosquitoes and some other Diptera (Tabanidae, Simuliidae, Hippoboscidae) were tested for virus. 13,924 mosquitoes, 75 horseflies and 60 blackflies were processed in 1973. Five strains of Tahyna virus were isolated from mosquito species Aedes vexans. 3,378 mosquitoes and 12 sheep keds were tested for virus in 1975. Twelve strains of Calovo virus were isolated from Anopheles maculipennis and one strain of Tahyna virus was obtained from Aedes vexans mosquitoes.     

The effect of wind on foraging activity of the tenebrionid beetle Lepidochora discoidalis in the sand dunes of the Namib Desert

The foraging activity of the tenebrionid beetle, Lepidochora discoidalis, was studied in the sand dunes of the Namib Desert. The surface activity of this beetle species was found to be correlated both with time of day and wind speed. Higher numbers were observed on the dune surface between 17:00–19:00 h when wind speeds were consistently higher than 9 m/s. Noise and vibrations in the dune sand were found to be highly dependent on wind speed. Wind blowing at speeds higher than 5 m/s lifts the surface sand grains and generates vibrations in the sand. The peak frequency of these vibrations is in the range of 700–1000 Hz. The vibrational amplitude at the peak frequency is on average 40 dB higher at those wind speeds when the beetles are active compared to lower wind speeds. The results indicate that wind is an important cue for these beetles and can be perceived by buried beetles through substrate vibrations.     

Host plant stimulation of detoxifying enzymes in a phytophagous insect

The midgut microsomal aldrin epoxidase of variegated cutworm larvae (Peridroma saucia, Hübner) fed bean or peppermint leaves was up to 10 and 45 times more active, respectively, than that of larvae fed a basic control diet. Large increases in oxidase activity and cytochrome P-450 levels also occurred in larvae fed mint plant constituents such as menthol menthone, α-pinene, and β-pinene. Mint-fed larvae were more tolerant of the insecticide, carbaryl, than bean-fed larvae.