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E Stella

Publications and source records attributed to E Stella.

13 recordsLinked to original sources
PubMed1993

SIMD parallelization of the WORDUP algorithm for detecting statistically significant patterns in DNA sequences.

The development of new techniques in sequencing nuclei acids has produced a great amount of sequence data and has led to the discovery of new relationships. In this paper, we study a method for parallelizing the algorithm WORDUP, which detects the presence of statistically significant patterns in DNA sequences. WORDUP implements an efficient method to identify the presence of statistically significant oligomers in a non-homologous group of sequences. It is based on a modified version of the Boyer-Moore algorithm, which is one of the fastest algorithms for string matching available in the literature. The aim of the parallel version of WORDUP presented here is to speed up the computational time and allow the analysis of a greater set of longer nucleotide sequences, which is usually impractical with sequential algorithms.

Algorithms↗
PubMed1988

Rickettsiae of the spotted fever group associated with the host-parasite system Oryctolagus cuniculi/Rhipicephalus pusillus.

Wild rabbits--Oryctolagus cuniculi--living in large numbers in a protected zone of Tuscany, the park of Migliarino--San Rossore--Massaciuccoli, showed to be carriers of the hard tick Rhipicephalus pusillus, previously observed in North Africa and Sicily. Antibodies to Rickettsia conorii and R. slovaca were detected in 78.9 per cent of the wild rabbits captured in that area. Seroconversion towards R. conorii was also observed in guinea pigs inoculated with homogenates of R. pusillus parasitizing the wild rabbits. These results identify an ecological niche of rickettsiae of the Spotted fever group in the host-parasite system O. cuniculi/R. pusillus. Attempts to isolate rickettsiae from the ticks and the wild rabbits were unsuccessful both in the egg yolk sac and in the guinea pig. This failure probably shows the low pathogenicity of the rickettsiae parasitizing the biosystem O. cuniculi/R. pusillus.

Animals↗
PubMed1985

[Preliminary studies on the occurrence of Rickettsiae of the spotted fever group in Rhipicephalus sanguineus captured in suburban areas].

In the urban periphery of Rome, two sub-zones could be distinguished, characterized by uncultivated steppeland and by small shacks with large quantities of domestic refuse, respectively. Rhipicephalus sanguineus appeared to be typical of this second sub-zone. R. sanguineus adults and nymphae were captured in different seasonal periods and were checked for the prevalence of rickettsiae of the Spotted Fever (SF) group. Moreover, larvae from hatched eggs, laid by captured R. sanguineus females, were checked for the transovarial transmission of rickettsiae. Ten lots each of three guinea-pigs, seronegative to rickettsiae of the SF group, were inoculated with R. sanguineus extracts, prepared from adults or larvae. Clinical signs of infection, fever and scrotal reaction, could be observed only in one lot of guinea-pigs inoculated with adult parasites. On the other hand, in 8 out of 10 guinea pig lots, antibodies to the soluble antigens of R. conori and R. slovaca were observed by the complement fixation (CF) test. In the remaining two lots only antibodies to R. slovaca were detected. No antibodies to Coxiella burneti could be demonstrated in the same sera.

Animals↗
PubMed1978

[Haemaphysalis concinna Koch, 1844 in Italy].

The authors provide here the data concerning the first italian finding of tick Hemaphysalis concinna (Ixodidae). Two males of this species--which has a large geographic diffusion--were actually caught for the first time in Italy, in July 1977. They were found on the ground of the Castel Porziano estate (Rome) at sealevel, in two different grassy places. The authors describe their morphological characters and provide some essential data on the environment of Castel Porziano.

Animals↗
PubMed1975

Inhibition of amylases from different origins by albumins from the wheat kernel.

The amylase activity of water extracts from 18 insect species, from 23 marine species and from 17 different species of birds and mammals was determined quantitatively. The inhibition of amylase in these extracts by three albumin fractions from the mature wheat kernel, which had been separated according to their molecular weights (60 000, 24 000 and 12 500 D), was determined as well. The inhibition activity of the three albumin fractions toward amylases extracted from a number of cereal species or from immature and germinating wheat kernel was also tested. The extracts from insects that are destructive of wheat grain and stored wheat products showed much higher amylase activities as compared to the other insect species that do not attack wheat and wheat products. On the basis of the effectiveness with which the three albumin fractions inhibit their activities, the amylase preparations tested were divided into susceptible, partially susceptible and resistent. Susceptible amylases, inhibited by any of the three albumin fractions, were found mainly in insects that attack wheat and in marine species. Partially susceptible amylases, inhibited by only one or two of the three albumin fractions, were present in a few avain and mammalian species including man. Resistent amylases were largely distributed in cereal, avian and mammalian species as well as in insect species that do not usually attack wheat grain or wheat flour products. At no stage of development, wheat alpha-amylase was inhibited by the albumin fractions from the mature kernel. The 12 500 dalton albumin fraction was the most effective in inhibiting insect amylases, but it was inactive toward avian and mammalian amylases. The 24 000 dalton albumin fraction was the most effective in inhibiting amylases from marine avian and mammalian species and inhibited as much as 33 amylases over 66 different amylases tested. It is suggested that protein inhibitors of amylase contributed to natural selection of polyploid wheats by giving some insect resistence to such wheats, even though some insect species were able to overcome this biochemical defense toa large degree by producing higher amylase activities.

Albumins↗