Chaotic variations of electrical conductance in powdered Pd correlating with oscillatory sorption of D2.

A microcalorimetric method has been combined with a potentiostatic method to measure simultaneously the rate of heat evolution and the electrical current in a powdered sample of palladium during thermokinetic oscillations accompanying the sorption of deuterium in the metal. Deterministic chaos has been confirmed in the temporal variations in current (of ca. 1-4 mA) on the onset of both the sorption and the desorption of deuterium from Pd. It has been found that the first derivative of the current in time, dI/dt, turns out to be correlated precisely with the periodicity of thermokinetic oscillations. The dI/dt curves consist of regularly timed outbursts of aperiodic, high frequency (HF) fluctuations, interlinked by calm periods. The calm periods correlate with the descending slopes of thermokinetic oscillations (i.e., with decrease in the rate of heat evolution) and their lengths depend on the frequency of thermokinetic oscillations. In turn, the outbursts of aperiodic HF fluctuations in the dI/dt derivatives correlate with the ascending slopes of thermokinetic oscillations (i.e., with increasing rate of heat production), but their length is practically constant, irrespective of the thermokinetic frequency. We propose a periodic mechanism of sorption including a collective action of adsorbed deuterium taking place on the Pd surface. The periodicity of this mechanism arises from the temporal separation of its two sub-processes. The sub-process (1) involves only the adsorption of molecular D2 on the Pd surface and proceeds with little heat evolution until a critical coverage of D2 is achieved. The sub-process (2) initiates the dissociation of the adsorbed D2 and the penetration of the dissociated atomic D species into the Pd lattice. It is the more energetic of the two, but it only begins after a threshold coverage of D2 on the Pd surface has been achieved. We suggest that these sub-processes occurring alternatingly may provide a kernel for the oscillatory behavior observed in Pd/H(D) systems.

Antireflection TiO x Coating with Plasmonic Metal Nanoparticles for Silicon Solar Cells.

It is known that the light scattering from the metal particles deposited on the surfaces of cells can be used for increasing light trapping in the solar cells. In this work, plasmonic structures are composite materials that consisted of silver nanoparticles embedded in dielectric films of TiO x -used as cell antireflection coating. The films are deposited by sol-gel method using spin-on technique. Microstructure of prepared samples is analyzed by SEM observation. Good homogenity and particles density was obtained by this simple, cheap, and short time-demanding method. We demonstrate that due to light scattering by metal particles, the plasmonic-ARC layer is more effective than TiO x layer without Ag nanoparticles. Implementation of nanoparticles on bare cell surface was carried out too. The influence of the plasmonic structures on the silicon solar cells parameters is presented as well. We announce about 5 % additional growth in short circuit current for cells with nanoparticles.

Development of amplified fragment length polymorphism-derived functional strain-specific markers to assess the persistence of 10 bacterial strains in soil microcosms.

To augment the information on commercial microbial products, we investigated the persistence patterns of high-priority bacterial strains from the Canadian Domestic Substance List (DSL). Specific DNA markers for each of the 10 DSL bacterial strains were developed using the amplified fragment length polymorphism (AFLP) technique, and the fates of DSL strains introduced in soil were assessed by real-time quantitative PCR (qPCR). The results indicated that all DNA markers had high specificity at the functional strain level and that detection of the target microorganisms was sensitive at a detection limitation range from 1.3 × 10² to 3.25 × 105 CFU/g of dry soil. The results indicated that all introduced strains showed a trend toward a declining persistence in soil and could be categorized into three pattern types. The first type was long-term persistence exemplified by Pseudomonas stutzeri (ATCC 17587) and Pseudomonas denitrificans (ATCC 13867) strains. In the second pattern, represented by Bacillus subtilis (ATCC 6051) and Escherichia hermannii (ATCC 700368), the inoculated strain populations dropped dramatically below the detection threshold after 10 to 21 days, while in the third pattern there was a gradual decrease, with the population falling below the detectable level within the 180-day incubation period. These patterns indicate a selection effect of a microbial community related to the ecological function of microbial strains introduced in soil. As a key finding, the DSL strains can be quantitatively tracked in soil with high sensitivity and specificity at the functional strain level. This provides the basic evidence for further risk assessment of the priority DSL strains.

Differential allocation of protein resources to flight muscles and reproductive organs in the flightless wing-polymorphic bug, Pyrrhocoris apterus (L.) (Heteroptera).

Differences in the growth of dorsolongitudinal flight muscles and gonads in 1-28 days old long-winged (macropterous) and short-winged (brachypterous) adults of the firebug (Pyrrhocoris apterus L.) and the resource allocation to these organs were studied by means of total protein analysis. We found predominant allocation of food resources to flight muscles compared to reproductive organs in both macropterous males and females during the first 5 days of adult life. Subsequent histolysis of developed flight muscles coincided with increased total protein content in some reproductive organs. Initiation of intensive food intake after starvation or application of higher dose of methoprene on macropterous adults changed the resource allocation in favour of growth of reproductive organs and induced precocious histolysis of flight muscles. It indicates an involvement of juvenile hormone in wing morph-related differential allocation of resources in the bug. Increased total protein contents in the ovaries and accessory glands of starved macropterous females and males treated with methoprene, respectively, indicate that proteins derived from the methoprene-induced histolysis of the flight muscles are re-utilized for the growth of the reproductive organs. It is the first report of persistence of differential resource allocation to flight muscles and reproductive organs in the wing-polymorphic insects with non-functional macropterism.

Developmental and diel changes of adipokinetic hormone in CNS and haemolymph of the flightless wing-polymorphic bug, Pyrrhocoris apterus (L.).

We have used an enzyme-linked immunoassay (ELISA) for determination of the AKH content in CNS (brain + corpora cardiaca + corpora allata) and haemolymph of adult macropterous and brachypterous females of the bug Pyrrhocoris apterus. The tests revealed that the AKH content fluctuates between 1 and almost 4 pmol/CNS during the first 14 days of adult life and significantly increased in order diapausing brachypters

The effect of feeding status on sexual attractiveness of Ixodes ricinus (Acari: Ixodidae) females.

Sexual attractiveness of unengorged, semiengorged and fully engorged females of both field and laboratory populations of Ixodes ricinus was studied under laboratory conditions by means of a computerised video tracking system. A male and a female were allowed to walk freely in a glass arena during 1 h and their behavioural interactions were observed. Obtained results revealed that the feeding status of L. ricinus females affects their sexual attractiveness. The highest attractiveness was observed in engorged females, the lowest in unengorged females of the field population. Copulation occurred in all experimental groups with the highest frequency observed in the unengorged virgin laboratory females. Despite engorged females being highly attractive for males on distance, the frequency of copulation was low. Differences between field and laboratory populations were found in both behavioural parameters and frequency of copulation.

A new member of the AKH/RPCH family that stimulates locomotory activity in the firebug, Pyrrhocoris apterus (Heteroptera).

A new member of the AKH/RPCH family was isolated and identified from the corpora cardiaca of the firebug Pyrrhocoris apterus. The peptide was isolated in a single step by reversed phase HPLC and the structure deduced from the multiple MS (MS(N)) electrospray mass spectra and amino acid analysis as that of an octapeptide with the sequence pGlu-Leu-Asn-Phe-Thr-Pro-Asn-Trp-NH(2): this sequence was confirmed by synthesis. The synthetic peptide induced lipid mobilisation and stimulated locomotory activity in macropterous females. This peptide, designated as Pyrrhocoris apterus adipokinetic hormone (Pya-AKH), is the first identified adipokinetic hormone described in a representative species of the suborder Heteroptera.

Wing morph-related physiological differences in adults of temperate population of Pyrrhocoris apterus (L.) (Heteroptera: Pyrrhocoridae).

The reproductive and diapausing adult females of brachypterous morph and macropterous females with reproductive arrest of non-diapause type, originating from the laboratory cultures of Pyrrhocoris apterus, were studied for their feeding and drinking behaviour, digestive enzyme activities, and carbohydrate and lipid contents. The highest feeding and drinking activities were observed in reproductive brachypters, the lowest in macropters. Macropters also differed from brachypters by lower activities of gut lipase, peptidase and protease, lower concentration of haemolymph sugars, and lower weight of fat body, which probably reflects their low feeding activity. The total content of fat body lipids was also lower in macropters (0.6 mg) than in reproductive and diapausing brachypters (4.6 and 7.5 mg, respectively) on day 14. A very high amount of glycogen was found in the fat body of diapausing brachypters, 363 micrograms on day 14, as opposed to 15 and 80 micrograms in macropterous and reproductive brachypterous females, respectively. The obtained data indicate that the most important difference between macropterous and brachypterous females with different types of reproductive arrest consists of an enhanced mobilization of lipids for dispersal in macropters and accumulation of energetic reserves for hibernation in brachypters.

The role of executive and physician representative calling programs in TQM/CQI.

Many hospital Total Quality Management/Continuous Quality Improvement programs focus on the patient as the ultimate consumer of the hospital's service. Recent research utilizing data provided by Hospital Corporation of America has shown that "quality, as measured by patient satisfaction, is associated with financial strength as measured by earnings, net revenues, and return on assets ... Relatively small increases in the level of patient satisfaction are associated with millions of dollars in year-end earnings for the average hospital. "However, there are other significant customer groups on which hospitals need to focus. Chief among these are physicians, who still play a major role in determining which hospital a patient will utilize. It is reasonable to assume that the positive financial impact that has been demonstrated for the patient market also exists for the physician market.

Genotoxicity of the anti-juvenile hormone agent precocene II as revealed by the Drosophila wing spot test.

The anti-juvenile hormone agent, precocene II, designated as a prototype of potential fourth-generation insecticides, was subjected to genotoxicity screening by means of the somatic mutation and recombination test in Drosophila melanogaster. Larvae heterozygous for recessive wing trichome mutations, mwh and flr3, were exposed to sublethal concentrations of precocene II, and wings of emerged adult females were inspected for the presence of phenotypically mutant mosaic spots. The compound significantly increased the frequency of mosaic spots in mwh/flr3 wings, but revealed only a slight effect in mwh/TM2 wings. The results suggest that the main sources of genotoxic activity of precocene II are due to chromosome-breakage phenomena resulting from mitotic recombination. The possible mechanism of this effect is discussed.

Mutagenicity testing of the juvenoid methoprene (ZR-515) by means of the Drosophila wing spot test.

The juvenile hormone analogue methoprene, which is used in insect pest control, was subjected to mutagenicity testing by means of the Drosophila wing spot test. Larvae heterozygous for recessive wing trichome mutations were exposed to a sublethal dose of methoprene. Wings of emerged adult females were inspected for the presence of phenotypically mutant mosaic spots. Methoprene exhibited a weak mutagenic effect. The fact that only small mosaic clones were induced is discussed.