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M Rossetto

Publications and source records attributed to M Rossetto.

18 recordsLinked to original sources
PubMed2002

Evaluating the potential of SSR flanking regions for examining taxonomic relationships in the Vitaceae.

Three EST-derived microsatellite loci from Vitis vinifera were amplified and sequenced across eight species of Vitaceae from four different genera. Phylogenetic analysis of the microsatellite's flanking regions produced informative results in congruence with previous studies. Generic relationships were respected and the data produced sufficient inter-specific variation to distinguish between Cayratia acris and Cayratia saponaria, two very closely related species. Overall, the sequence alignments showed that priming sites were conserved, whereas microsatellite repeats were present in most cases but structurally variable. The sequence data provided information on the evolutionary patterns of various microsatellite repeats and their correlation to evolutionary relationships among taxa.

Journal Article↗
PubMed2002

Ultrasonic testing of anaerobic bonded joints.

The paper deals with ultrasonic testing of adhesive joints between sheets of thickness greater than 1 mm, bonded by a "zero thickness" layer of anaerobic adhesive. In the case of equally thick sheets, interference phenomena can arise that make impossible the use of the "decay method" (a method previously developed by the authors for the case of non-zero adhesive thickness). Consequently an alternative method, termed "first peak", has been proposed. In order to evaluate the applicability of the two methods, a series of tests has been carried out on specimens having geometry suitable for both types of inspection. Also two different levels of surface roughness have been considered. The results allow for evaluating the defect detection capability of each method, accounting for the roughness effect, and give information on the suitable control procedures.

Journal Article↗
PubMed2001

Stable free radicals as ubiquitous components of red wines.

A stable ESR signal, centred at g = 2.0037 +/- 0.0002, characterised by a single resonance and assignable to a free radical, was found in all the bottled red wines, both commercial and experimental, that we have examined. The radical concentration was calculated to be in the range of 5-82 nM. After exposure of the wines to air for a few minutes a two fold increase of the ESR signal, followed by a slow decrease with time, was observed. The intensity of ESR signal in experimental red wines, was found to increase with the ageing of the wines and was strictly correlated to the total content of polyphenols. The formation of semiquinone radicals of polyphenols is suggested as one possible mechanism leading to the presence of stable free radicals in red wines.

Electron Spin Resonance Spectroscopy↗
PubMed2001

Molecular Dissection of the 5' Region of no-on-transientA of Drosophila melanogaster Reveals cis-Regulation by Adjacent dGpi1 Sequences.

The nonA gene of Drosophila melanogaster is important for normal vision, courtship song, and viability and lies approximately 350 bp downstream of the dGpi1 gene. Full rescue of nonA mutant phenotypes can be achieved by transformation with a genomic clone that carries approximately 2 kb of 5' regulatory material and that encodes most of the coding sequence of dGpi1. We have analyzed this 5' region by making a series of deleted fragments, fusing them to yeast GAL4 sequences, and driving UAS-nonA expression in a mutant nonA background. Regions that both silence and enhance developmental tissue-specific expression of nonA and that are necessary for generating optomotor visual responses are identified. Some of these overlap the dGpi1 sequences, revealing cis-regulation by neighboring gene sequences. The largest 5' fragment was unable to rescue the normal electroretinogram (ERG) consistently, and no rescue at all was observed for the courtship song phenotype. We suggest that sequences within the nonA introns that were missing in the UAS-nonA cDNA may carry enhancer elements for these two phenotypes. Finally, we speculate on the striking observation that some of the cis-regulatory regions of nonA appear to be embedded within the coding regions of dGpi1.

Alleles↗
PubMed2000

Contribution of proanthocyanidins to the peroxy radical scavenging capacity of some Italian red wines.

Highly reactive radicals, ROO(*), were generated from 2, 2'-azobis[2-(2-imidazolin-2-yl)propane] and linoleic acid. The ROO(*) scavenging capacity of some Italian red wines was evaluated following the changes in oxygen consumption. Under the experimental conditions the time course of oxygen consumption shows two typical behaviors: trolox-like (class I) and gallic acid-like (class II). Usually the time course of wine was similar to that of gallic acid. The rate of oxygen consumption was found to decrease exponentially with the amount of wine or gallic acid added to the test solution. On this basis the capacity of red wines to scavenge peroxy radicals was expressed as content of gallic acid (S(GA)). The S(GA) values were found to be correlated to the amount of total proanthocyanidins and total polyphenols of some Italian red wines (p < 0.01). The proanthocyanidins extracted from seeds were shown to make a major contribution to the peroxy radical scavenging capacity of red wines, whereas, interestingly, the chemical class of the low molecular weight tannins reactive to vanillin did not correlate with the S(GA) values.

Anthocyanins↗
PubMed1999

Microsatellite variation and assessment of genetic structure in tea tree (Melaleuca alternifolia-Myrtaceae).

Analysis of five microsatellite loci in 500 Melaleuca alternifolia individuals produced 98 alleles that were useful for population genetic studies. Considerable levels of observed heterozygosity were recorded (HO = 0.724), with approximately 90% of the variability being detected within populations. A low level of selfing (14%) was suggested to be the principal cause of excess homozygosity in a number of populations (overall FIS = 0.073). This study showed low levels of inbreeding in certain populations as well as a significant isolation-by-distance model. Only two groups of populations (Queensland and New South Wales) constituted different genetic provenances as a result of geographical isolation. The M. alternifolia data suggest that microsatellite loci did not always arise by a stepwise mutation process but that larger jumps in allele size may be involved in their evolution.

Australia↗
PubMed1999

Plasma and urine carnitine concentrations in well-trained athletes at rest and after exercise. Influence of L-carnitine intake.

L-carnitine is essential to cellular energy production mainly because of its acyl- and acetyl-carrier properties. Athletes commonly take L-carnitine, which is thought to improve exercise performance. There are no reports on carnitine plasma concentrations and carnitine excretion in short-duration maximal exercise in well-trained athletes taking this substance. We measured plasma and urine carnitine concentrations before and 10 min after maximal treadmill ergometry in nine well-trained sportsmen with and without oral supplementation with 1 g L-carnitine. In athletes without L-carnitine intake, plasma free carnitine concentration decreased significantly from 45.2 +/- 5.3 to 41.6 +/- 5.0 mumol/l (mean +/- SD, p < 0.001) 10 min after exercise compared with baseline. In athletes with oral L-carnitine supplementation, plasma free carnitine concentration at baseline was 71.3 +/- 10.2 mumol/l and did not change after maximal exercise (71.8 mumol/l +/- 10.7 mumol/l). The elevated plasma concentration of free carnitine without decrease after maximal exercise in well-trained athletes taking L-carnitine could be important in view of the newly postulated direct vascular effects of L-carnitine in improving skeletal muscle performance.

Administration, Oral↗
PubMed1995

Use of RAPD analysis in devising conservation strategies for the rare and endangered Grevillea scapigera (Proteaceae).

Extensive human impact in south western Australia has resulted in a high incidence of rarity throughout the highly endemic flora of the region. Grevillea scapigera (Proteaceae) is a typical example, with 27 plants (represented by four extant populations) remaining in the wild. In order to devise an appropriate strategy for the conservation of this species, its population genetics were studied using RAPD analysis, which enabled the discrimination of individual plants and the detection of a relatively high amount of variability (V = 0.32) within G. scapigera. This variability was found to be evenly distributed within the plants analysed despite the clear distinction between most populations (87% of the variability being attributable to single plant difference and 13% to population difference). Finally, RAPD analysis was used to select a small group of plants that captured maximum genetic variability to be used in the recovery program of the species. Because of the low genetic difference between populations, the mixing of these selected plants during the recovery process should not create genetic imbalances. The methods used in this study provide a useful model for future projects involving the recovery of rare flora.

Australia↗
PubMedDate not supplied

Light-evoked changes in near-infrared transmission by the ON and OFF channels of the anuran retina.

We have developed an optical method to monitor the activity of the ON and OFF channels in the anuran retina. The change in the fraction of near infrared that is transmitted transversely through the retina in an eyecup slice is monitored during stimulation by visible, green light. Near-infrared transmission increases both at the onset and at the termination of a step stimulus. This "ON/OFF" response is maximal in the neural retina. Sodium L-aspartate, which blocks the light-evoked activity of post-photoreceptor neurons, abolishes the "ON/OFF" response. L-AP4, used as a selective blocker of the ON channel, reduces the "ON" component and has little or no effect on the "OFF" component. The "ON" and "OFF" processes observed optically are distinct from those that generate the b- and d-waves of the electroretinogram, and the "ON" and "OFF" components may be superior to the b- and d-waves as indicators of ON and OFF channel activity. The optical method is almost as simple as electroretinography and has the advantages that responses can be spatially localized with ease.

Aminobutyrates↗