There is very little information on the importance of fleshy fruit in the diet of the nestlings and fledglings of partially frugivorous Holarctic passerines. In an area of 0.6 km2 in northwestern Spain, it was verified during 2001–2003 that at least one blackcap Sylvia atricapilla pair and five blackbird Turdus merula pairs fed their offspring on a certain proportion of ivy Hedera helix fruit. Observations made on a blackcap nest in May showed that the parents fed older nestlings on animal prey on 60.7% of occasions and 39.3% on fruit (n = 140 total number of identified feeds). The female fed nestlings on fruit more often than the male. According to observations carried out on five ivy plants in May, blackcaps brought fruit in their bills to feed nestlings or fledglings on 40.3% of 67 feeding visits and blackbirds on at least 22.1% of 86 feeding visits. The blackcaps consistently carried one fruit and the blackbirds between three and five. Both species fed their young on fruit under very different meteorological conditions. Seeds found in the faecal sacs of their nestlings showed high potential germination viability (95.6% undamaged seeds and 4.4% cracked seeds; n = 46 total seeds except for those gnawed by rodents), so the adults probably acted as indirect vectors in dispersing ivy whilst carrying faecal sacs away from the nest.
The corpora cardiaca (CC) of the pneumorid grasshopper species Bullacris discolor contain at least one substance that causes hyperlipaemia in the migratory locust. Isolation of neuropeptides belonging to the adipokinetic hormone (AKH) family was achieved by single-step reversed-phase high performance liquid chromatography (RP-HPLC) of CC extracts and monitoring tryptophan fluorescence. The material of the bladder grasshopper showed three distinct fluorescence peaks with adipokinetic activity in the migratory locust. The peptide sequences were identified by Edman degradation after the N-terminal pyroglutamate residue had been cleaved off enzymatically, and the exact peptide masses were determined by matrix-assisted laser desorption/ionisation time-of-flight mass spectrometry. Moreover, the assigned peptides were synthesised and natural and synthetic peptides were compared in their behaviour in RP-HPLC. B. discolor stores three AKH peptides in its CC: two of those are octapeptides, Schgr-AKH-II (pELNFSTGWamide) and Peram-CAH-II (pELTFTPNWamide), whereas the third peptide is a decapeptide, Phyle-CC (pELTFTPNWGSamide. The concentration of carbohydrates in the haemolymph of B. discolor is about 3 times higher than the lipid concentration. Upon injection with synthetic Schgr-AKH-II no adipokinetic or hypertrehalosaemic effect was measurable. A literature survey appears to indicate that an active role of these AKH peptides in substrate mobilisation is only overtly displayed in those caeliferan species that undertake well-defined flight periods.
Blaena tamasi sp. n., the first species of Cydnidae with staphylinoid modification of wings, is described from Western Australia. The rare cases of wing modifications in Cydnidae and Pentatomoidea are briefly discussed. A key to all known species of the genus Blaena Walker is also provided.
It is known that, under very general conditions, Blaschke products generate branched covering surfaces of the Riemann sphere. We are presenting here a method of finding fundamental domains of such coverings and we are studying the corresponding groups of covering transformations.
The paper follows from the theory of explosion and interaction of an impact wave formed by the explosion and a structure..As a rule, a number of simplifying assumptions must be applied as regards the characteristics of the explosion and of the threatened structure to analyze the structure. As example of dynamic analysis of a new reinforced concrete structure, loaded with a blast wave was used to apply the principles of simpflified ingineering analysis of an explosion-loaded structure. The way of structure failure was analyzed based on time courses of calculated internal forces and displacenets of individual structure elements. The criteria of structural elements failure due to explosion load effects were determined as a part of the dynamic structure response assessment. and Obsahuje seznam literatury
This paper describes an implementation of the Kurtosis and InfoMax algorithms for an independent components analysis in mixed-signal CMOS. Our design uses on-chip calibration techniques and local adaptation to compensate for the effect of device mismatch in arithmetic blocks and analog memory cells. We use our design to perform two-input blind source-separation on mixtures of audio signals and mixtures of EEG signals. Our experiments show that the hardware implementation of InfoMax consistently separates the signals within a normalized reconstruction error of less than 10%, while the reconstruction error of Kurtosis varies between 25% and 60%, due to its higher sensitivity to device mismatch and input statistics. Each circuit has a settling time of 8 ms, occupies a die area of 0.016-0.022 mm² and dissipates 15-20 mW of power.
We study block diagonalization of matrices induced by resolutions of the unit matrix into the sum of idempotent matrices. We show that the block diagonal matrices have disjoint spectra if and only if each idempotent matrix in the inducing resolution double commutes with the given matrix. Applications include a new characterization of an eigenprojection and of the Drazin inverse of a given matrix.
The influence of chronic angiotensin ATi receptor blockade by specific antibody on the development of genetic hypertension was studied in young spontaneously hypertensive rats (SHR). The immunization of 4-week-old SHR with a small part of the angiotensin ATi receptor molecule attenuated the development of hypertension in these animals. After five subcutaneous injections of the antigen both systolic and diastolic blood pressures were significantly lower (p<0.005) in immunized SHR compared to sham- immunized SHR. No effect on blood pressure was seen in immunized Wistar-Kyoto control rats. We conclude that renin-angiotensin system might be partially involved in the development of hypertension in young spontaneously hypertensive rats because it can be attenuated by a specific antibody raised against a part of the angiotensin ATi receptor.
The study investigated the role of α2-adrenergic receptors of the caudal raphe region in the sympathetic and cardiovascular responses to the acute intermittent hypercapnia (AIHc). Urethane-anesthetized, vagotomized, mechanically ventilated Sprague-Dawley rats (n=38) were exposed to the AIHc protocol (5×3 min, 15 % CO2+50 % O2) in hyperoxic background (50 % O2). α2-adrenergic receptor antagonist-yohimbine was applied intravenously (1 mg/kg, n=9) or microinjected into the caudal raphe region (2 mM, n=12) prior to exposure to AIHc. Control groups of animals received saline intravenously (n=7) or into the caudal raphe region (n=10) prior to exposure to AIHc. Renal sympathetic nerve activity (RSNA), mean arterial pressure (MAP) and heart rate (HR) were monitored before exposure to the AIHc protocol (T0), during five hypercapnic episodes (THc1-5) and at 15 min following the end of the last hypercapnic episode (T15). Following intravenous administration of yohimbine, RSNA was significantly greater during THc1-5 and at T15 than in the control group (P<0.05). When yohimbine was microinjected into the caudal raphe region, AIHc elicited greater increases in RSNA during THc1-5 when compared to the controls (THc1: 138.0±4.0 % vs. 123.7±4.8 %, P=0.032; THc2: 137.1±5.0 % vs. 124.1±4.5 %, P=0.071; THc3: 143.1±6.4 % vs. 122.0±4.8 %, P=0.020; THc4: 146.1±6.2 % vs. 120.7±5.7 %, P=0.007 and THc5: 143.2±7.7 % vs. 119.2±7.2 %, P=0.038). During THc1-5, significant decreases in HR from T0 were observed in all groups, while changes in MAP were observed in the group that received yohimbine intravenously. These findings suggest that blockade of the α2-adrenegic receptors in the caudal raphe region might have an important role in sympathetic responses to AIHc.