The production of pheromone clouds by spraying in the melon fly,Dacus cucurbitae coquillett (Diptera: Tephritidae)

Pheromone clouds sprayed by melon fly males were visually detected by focusing a beam of light at them during dusk when the males were vibrating their wings. The clouds were sprayed to the front, rear and upper sides of the male. We found that special morphological structures are used for spraying the pheromone clouds. When a male melon fly engages in calling behavior, sex pheromone droplets are excreted from his anus. This excretion is wiped off with the tarsus of his hind leg, and then it is deposited on the sexually dimorphic cubital cell hairs on the wing. During wing vibration, the targal bristles on the 3rd abdominal segment, which are peculiar to males, are rubbed against the specialized hairs of the cubital cell. Calling males sprayed clouds of pheromone with these actions. This paper was presented at the 32nd Annual Meeting of the Japanese Society of Applied Entomology and Zoology (Kochi, April, 1988).     

A metabolic model for biological phosphorus removal by denitrifying organisms

A metabolic model for biological phosphorus removal under denitrifying conditions has been established. The model is based on previous work with aerobic phosphorus removal. The form of the kinetic equations used is the same as for the aerobic model. The main difference is the value of P/NADH(2) ratio in the electron transport phosphorylation with nitrate (delta(N)). This value was determined independently from batch tests with an enriched culture of denitrifying phosphorus-removing bacteria. The measured delta(N) was approximately 1.0 mol ATP/mol NADH(2). This indicates that the energy production efficiency with nitrate compared to oxygen is approximately 40% lower. These batch tests were also used to identify a proper set of kinetic parameters. The obtained model was subsequently applied for the simulation of cyclic behavior in an anaerobic-anoxic sequencing batch reactor at different biomass retention times. The simulation results showed that the metabolic model can be used successfully for the denitrifying dephosphatation process. The obtained kinetic parameters for denitrifying enrichment cultures, however, deviated from those obtained for the aerobic enrichment cultures. (c) 1996 John Wiley & Sons, Inc.     

Characterization of N omega-phosphoarginine hydrolase from rat liver.

N omega-Phosphoarginine hydrolase from rat liver hydrolyzed N omega-phosphoarginine into arginine and inorganic phosphate, whereas it did not release inorganic phosphate from 19 other phosphorylated compounds containing a N-P bond, an O-P bond or a C-P bond. In addition, it was not able to transfer the phosphoryl moiety from N omega-phosphoarginine to ADP. These results indicated that this enzyme was distinct from both phosphoamidase and arginine kinase. Its properties were as follows: thiol compounds were essential for its activity; it was stimulated by 1.5-2-fold in the presence of 0.001% Lubrol, Tween 20, poly(oxyethylene) 9-lauryl ether and Nonidet P-40, while 0.004% sodium lauryl sulfate inhibited the activity completely; concentrations of sodium molybdate and sodium vanadate necessary for 50% inhibition were 7 microM and 12 microM, respectively; some proteins stimulated the activity, while lysophosphatidic acid, lysophosphatidylinositol, and phosphatidic acid suppressed the activity even in the presence of poly(oxyethylene) 9-lauryl ether.     

Changes in vulvar and vestibular tissue of the bovine during the estrous cycle as determined by the use of near-infrared interactance

Near-infrared interactance spectra of the vulva and vestibule of cows were analyzed throughout the estrous cycle to determine if they could be used to detect tissue changes that are associated with estrus. The spectra were collected daily from 16 cyclic Holstein cows beginning at 40 days post partum and continuing for 3 estrous cycles, or until pregnancy was verified. Spectra collected on the day when estrus was exhibited were compared with spectra collected on the nonestrous days. There were spectral differences at 1695 to 1705, at 1790 to 1800 and at 1880 to 1900 nm (P<0.05), regions that are associated with changes in carbohydrate, protein, and water content of the tissues, respectively. Discriminant analysis of interactance measurements at the significant wavelengths was used to develop an equation to predict the day of estrus. The error rate associated with the equation was 26%. Results indicate that near-infrared analysis can detect changes in vestibular and vulvar tissue during the estrous cycle. However, accurate estrus detection using near-infrared interactance techniques will require additional study to reduce variation in the results.     

Enterocin M-Producing Enterococcus faecium CCM 8558 Demonstrating Probiotic Properties in Horses

The effects of non-authochtonous Enterococcus faecium AL41 = CCM 8558, enterocin M-producing and probiotic strain were tested on the microbiota, phagocytic activity, hydrolytic enzymes, biochemical parameters and dry matter in horses based on its previous benefits demonstrated in other animals. E. faecium CCM 8558 sufficiently colonized the digestive tract of horses. At day 14, its counts reached 2.35 ± 0.70 CFU/g (log 10) on average. The identity of CCM 8558 was confirmed by means of PCR after its re-isolation from horse faeces. The inhibition activity of CCM 8558 was demonstrated against Gram-negative aeromonads, counts of which were significantly reduced (P < 0.001). After 14 days application of CCM 8558, a tendency towards increased phagocytic activity (PA) was measured; PA value was 73.13% ± 8.55 on average at day 0/1; at day 14, it was 75.11 ± 8.66%. Cellulolytic, xylanolytic and pectinolytic activity in horse faeces was significantly increased (P < 0.001) at day 14 (after CCM 8558 application) and amylolytic activity as well (P < 0.01) compared to day 0/1. Inulolytic activity increased with mathematical difference 1.378. Dry matter value reached 20.81 ± 2.29% on average at day 0/1; at day 14, it was 20.77 ± 2.59% (P = 0.9725). Biochemical parameters were influenced mostly in the physiological range. These results achieved after application of CCM 8558 in horses are original, giving us further opportunity to continue these studies, to measure additional parameters and to show the benefits of CCM 8558 application in horses.

     

Pull or Push? Octopuses Solve a Puzzle Problem

Octopuses have large brains and exhibit complex behaviors, but relatively little is known about their cognitive abilities. Here we present data from a five-level learning and problem-solving experiment. Seven octopuses (Octopus vulgaris) were first trained to open an L shaped container to retrieve food (level 0). After learning the initial task all animals followed the same experimental protocol, first they had to retrieve this L shaped container, presented at the same orientation, through a tight fitting hole in a clear Perspex partition (level 1). This required the octopuses to perform both pull and release or push actions. After reaching criterion the animals advanced to the next stage of the test, which would be a different consistent orientation of the object (level 2) at the start of the trial, an opaque barrier (level 3) or a random orientation of the object (level 4). All octopuses were successful in reaching criterion in all levels of the task. At the onset of each new level the performance of the animals dropped, shown as an increase in working times. However, they adapted quickly so that overall working times were not significantly different between levels. Our findings indicate that octopuses show behavioral flexibility by quickly adapting to a change in a task. This can be compared to tests in other species where subjects had to conduct actions comprised of a set of motor actions that cannot be understood by a simple learning rule alone.     

Visual event-related potentials to moving stimuli: normative data

Visual cognitive responses (P300) to moving stimuli were tested in 36 subjects with the aim to find the normal range of P300 parameters. Concomitantly, the circadian intra-individual variability of the P300 was studied in a subgroup of 6 subjects. Visual stimuli consisted of either coherent (frequent stimulus) or non-coherent motion (random stimulus). The oddball paradigm was applied for recording cognitive responses. P300 to rare stimuli had an average latency of 447.3 +/- 46.6 ms and amplitude of 12.9 +/- 6.0 microV. The average reaction time was in the range from 322 to 611 ms and there was no correlation between the reaction time and P300 latency. We did not find any significant circadian changes of the P300 parameters in the 6 subjects tested four times during the same day. Cognitive (event-related) responses (P300) displayed distinctly greater inter-individual variability (S.D. of 50 ms) when compared with pattern-reversal and motion-onset VEPs (S.D. of 6.0 ms and 14 ms, respectively). For this reason, the clinical use of P300 elicited by this kind of visual stimuli seems to be rather restricted and the evaluation of its intra-individual changes is preferable.     

Functional coupling of Ca(2+) channels to ryanodine receptors at presynaptic terminals. Amplification of exocytosis and plasticity

Ca(2+)-induced Ca(2+) release (CICR) enhances a variety of cellular Ca(2+) signaling and functions. How CICR affects impulse-evoked transmitter release is unknown. At frog motor nerve terminals, repetitive Ca(2+) entries slowly prime and subsequently activate the mechanism of CICR via ryanodine receptors and asynchronous exocytosis of transmitters. Further Ca(2+) entry inactivates the CICR mechanism and the absence of Ca(2+) entry for >1 min results in its slow depriming. We now report here that the activation of this unique CICR markedly enhances impulse-evoked exocytosis of transmitter. The conditioning nerve stimulation (10-20 Hz, 2-10 min) that primes the CICR mechanism produced the marked enhancement of the amplitude and quantal content of end-plate potentials (EPPs) that decayed double exponentially with time constants of 1.85 and 10 min. The enhancement was blocked by inhibitors of ryanodine receptors and was accompanied by a slight prolongation of the peak times of EPP and the end-plate currents estimated from deconvolution of EPP. The conditioning nerve stimulation also enhanced single impulse- and tetanus-induced rises in intracellular Ca(2+) in the terminals with little change in time course. There was no change in the rate of growth of the amplitudes of EPPs in a short train after the conditioning stimulation. On the other hand, the augmentation and potentiation of EPP were enhanced, and then decreased in parallel with changes in intraterminal Ca(2+) during repetition of tetani. The results suggest that ryanodine receptors exist close to voltage-gated Ca(2+) channels in the presynaptic terminals and amplify the impulse-evoked exocytosis and its plasticity via CICR after Ca(2+)-dependent priming.