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PubMed2000

Large scale population structure and gene flow in the planktonic developing periwinkle, Littorina striata, in Macaronesia (Mollusca: Gastropoda).

Allozymes were used to investigate the genetic structure of 42 populations of the planktonic developing, Macaronesian periwinkle Littorina striata, throughout its entire geographic range (Azores, Madeira, Canary Islands and Cape Verde Islands). This periwinkle is presumed to have a high dispersal and gene flow potential, because it has a planktonic development. It is therefore expected to show little population genetic differentiation. Indeed, based on Wright's hierarchical F-statistics, no significant genetic differentiation could be detected among populations, at any of the specified hierarchical levels (i.e. population, island, and archipelago). Nevertheless, the Cape Verde Islands seemed genetically more diverse (highest mean number of alleles per locus). The number of loci revealing a significant genetic heterogeneity increased with increasing distance between populations, while private alleles based gene flow (Nm) estimates also revealed a tendency towards a geographical pattern. The distribution of rare and private alleles, might account for these observations which suggested some geographical effect. Because of the low frequency at which these alleles occur, their influence on the genetic population structure is negligible, and not picked up by F-statistics.

Journal Article↗

PubMed2003

Tonsillectomy: cold dissection versus bipolar electrodissection.

OBJECTIVES: to compare the technique and post-operative morbidity of two different tonsillectomy methods: cold dissection and bipolar electrodissection. MATERIAL AND METHODS: prospective study including children (3> age <14) undergoing tonsillectomy in ORL Department of the main hospital in Azores, Portugal, from September 2000 to March 2001. Patients alternately selected to cold dissection tonsillectomy group (CDT) or bipolar electrodissection tonsillectomy group (BET). Duration of surgery; amount of blood loss; duration of hospitalization; aspect of tonsillar fossa on 10th post-operative day and intensity of pain after surgery were recorded and compared. RESULTS: Sixty tonsillectomies were performed. Blood loss and duration of surgery were significantly decreased in BET group (P<0.001), but the healing process, directly assessed by the aspect of tonsillar fossa on the 10th day was markedly delayed. The intensity of pain was slightly higher in the BET group compared with the CDT group, and no difference on duration of hospitalization was found between the two groups. Two post-operative hemorrhages occurred (one in each group), and no major complications were registered. CONCLUSIONS: BET reduces the duration of surgery and amount of blood loss when compared with cold dissection, but post-operative morbidity is increased. We believe the best patient indication for this method are small children where total circulating blood volume is reduced and patients with bleeding disorders.

Adolescent↗

PubMed1997

Nucleotide sequences and gene organization of TaqI endonuclease isoschizomers from Thermus sp. SM32 and Thermus filiformis Tok6A1.

Eight TaqI isoschizomer genes, two from Yellowstone National Park, one from Japan, two from New Zealand, two from Portugal, and one from the Azores (1000 miles west of Portugal), were PCR-amplified and sequenced. Sequence alignment of isoschizomers isolated from close geographical locations shows identical or almost identical protein sequences, while isoschizomers from distant sites demonstrate considerable diversity, ranging from 54 to 75% in amino acid identity. Accordingly, these isoschizomers were arranged into four geographical groups, i.e., USA as represented by Thermus aquaticus YT1, Japan by Thermus thermophilus HB8, New Zealand by Thermus filiformis Tok6A1, Portugal by Thermus sp. SM32. The complete ORFs of two new representative genes, tfiTok6A1I and tsp32IR, were obtained by bubble PCR. Unlike M . TaqI-R.TaqI and M . TthHB8I-R . TthHB8I which exhibit an unusual 13-codon overlap, the methylase and endonuclease genes are each separated by 15 nucleotides in the TfiTok6A1I and Tsp32IR restriction-modification systems. Phylogenetic analysis suggests that initially TfiTok6A1I diverged from a common ancestor, then Tsp32IR branched out, and finally TaqI and TthHB8I diverged from each other during evolution.

Amino Acid Sequence↗

PubMed2006

Biogeography: molecular trails from hitch-hiking snails.

Darwin was fascinated by the transportation of land snails across great swathes of open ocean by birds--he even immersed snails in sea water to see how long they would survive. Here we follow a molecular phylogenetic trail that reveals the incredible transequatorial dispersal of the land snail Balea from Europe to the Azores and the Tristan da Cunha islands, and back again. This long-distance dispersal is unexpected for what are proverbially considered the most pedestrian of creatures.

Animal Migration↗

PubMed2006

Insights into the dynamics of mantle plumes from uranium-series geochemistry.

The long-standing paradigm that hotspot volcanoes such as Hawaii or Iceland represent the surface expression of mantle plumes--hot, buoyant upwelling regions beneath the Earth's lithosphere--has recently been the focus of controversy. Whether mantle plumes exist or not is pivotal for our understanding of the thermal, dynamic and compositional evolution of the Earth's mantle. Here we show that uranium-series disequilibria measured in hotspot lavas indicate that hotspots are indeed associated with hot and buoyant upwellings and that weaker (low buoyancy flux) hotspots such as Iceland and the Azores are characterized by lower excess temperatures than stronger hotspots such as Hawaii. This direct link between buoyancy flux and mantle temperature is evidence for the existence of mantle plumes.

Journal Article↗

PubMed2026

Stability in the face of global decline: a 20-year study of arthropods in an oceanic archipelago.

Insect declines are of global concern, yet no long-term ecological studies (LTER) have confirmed this trend on islands. This study utilises the first available LTER data on island arthropods, targeting epigeal and canopy species from the Azores Archipelago (Portugal), and covering over 20 years in three distinct sampling events from 30 standard sites. We investigate changes in abundance, biomass, and species richness within native forest arthropod communities, focusing on the proportions of endemic and introduced species, and temporal patterns among single-island endemics and forest-dependent endemics. Results reveal significant temporal variability, but overall abundance, biomass, and species richness remain stable across endemic and native non-endemic taxa. Among the species studied, 28% declined, 17% increased, and 55% showed no significant differences. Exotic invasions and related extinctions appear minimal. Forest-dependent endemic species declined below anticipated levels, suggesting that the extinction debt for these species may be less severe than initially expected. Nonetheless, some forest specialists have declined significantly, and seven species, not seen over 20 years, are considered to be extinct. The three-decade-long conservation of Azorean native forests may have contributed to the stability of some populations, thus these findings underscore the need for continued and enhanced conservation efforts of insular forest-associated diversity.

Animals↗

PubMed1995

Two different isoschizomers of the type-II restriction endonuclease Taq I (T/CGA) within the same Thermus isolate: Tsp32 I, an enzyme with similar heat stability properties to the prototype enzyme Taq I, and Tsp32 II, a hyperthermostable isoschizomer of Taq I.

We have recently screened 112 separate isolates of the genus Thermus, collected from neutral and alkaline hot water springs on four continents, for the presence of the Type-II restriction endonuclease Taq I (T/CGA). One particular isolate from the Azores (strain 32) was found to contain high levels of a restriction endonuclease with the same recognition and cleavage site as Taq I. Initial studies revealed that the partially purified enzyme from strain 32 was considerably more resistant to heat inactivation than the prototype enzyme Taq I, being able to withstand temperatures at least 10 degrees C higher than Taq I, before showing evidence of heat inactivation. Subsequently it became clear that the partially purified extract from strain 32 contains two separate enzymes, both of which are isoschizomers of Taq I. One of the enzymes, Tsp32 I, has similar thermal stability characteristics to Taq I, whereas the second Taq I isoschizomer, Tsp32 II, found in the same Thermus isolate as Tsp32 I, is considerably more thermostable than Taq I, retaining full enzyme activity up to a temperature of 85 degrees C. Tsp32 I and Tsp32 II were further distinguished by virtue of their different requirements for magnesium ions.

Base Sequence↗

PubMed1998

Cloning and thermostability of TaqI endonuclease isoschizomers from Thermus species SM32 and Thermus filiformis Tok6A1.

Two TaqI endonuclease (hereafter referred to as TaqI) isoschizomer genes, tsp32IR from Thermus species SM32 of Azores and tfiTok6A1I from T. filiformis Tok6A1 of New Zealand, were cloned in Escherichia coli. The overexpressed enzymes were partly purified and their thermostability was determined. In the medium-salt buffer, Tsp32IR, TfiTok6A1I and one previously cloned TaqI isoschizomer (TthHB8I) were more thermostable than TaqI. Tsp32IR remained partly active up to 90 degreesC in the low-salt buffer. Six amino acid residues that are identical in the three high thermostability isoschizomers (Tsp32IR, TfiTok6A1I and TthHB8I) but differ in TaqI might provide added rigidity for thermostabilization. These include four proline residues located in or near loop regions, and one alanine and one arginine located at helix regions in the predicted TaqI endonuclease secondary structure. The possible role of these residues in thermostabilization was evaluated by mutagenizing the TaqI enzyme. Mutants generated at these six positions were less thermostable than wild-type TaqI. The results suggest that the surrounding sequence or structural context might be as important as the mutation itself.

Amino Acid Sequence↗

PubMed1999

Molecular evidence for multiple origins of woodiness and a new world biogeographic connection of the Macaronesian island endemic Pericallis (Asteraceae: senecioneae).

The prevalence of woody species in oceanic islands has attracted the attention of evolutionary biologists for more than a century. We used a phylogeny based on sequences of the internal-transcribed spacer region of nuclear ribosomal DNA to trace the evolution of woodiness in Pericallis (Asteraceae: Senecioneae), a genus endemic to the Macaronesian archipelagos of the Azores, Madeira, and Canaries. Our results show that woodiness in Pericallis originated independently at least twice in these islands, further weakening some previous hypotheses concerning the value of this character for tracing the continental ancestry of island endemics. The same data suggest that the origin of woodiness is correlated with ecological shifts from open to species-rich habitats and that the ancestor of Pericallis was an herbaceous species adapted to marginal habitats of the laurel forest. Our results also support Pericallis as closely related to New World genera of the tribe Senecioneae.

Asteraceae↗

PubMed2002

Morphometric and molecular analysis of the Encarsia inaron species-group (Hymenoptera: Aphelinidae), parasitoids of whiteflies (Hemiptera: Aleyrodidae).

Several series of host-reared specimens of an Encarsia species, initially thought to be the cosmopolitan Encarsia inaron (Walker), were collected in the Azores Islands (Portugal). Subsequent morphometric analysis supported the presence of two species: E. inaron and a new species, described herein as Encarsia estrellae Manzari & Polaszek sp. n. Encarsia estrellae was reared from Aleyrodes singularis Danzig, A. ?singularis, and Bemisia sp. afer-group on several host plants. In addition, the D2 region of the 28S rDNA gene was sequenced in eight individuals belonging to these species, as well as single representatives of two closely related and one distantly related species. Phylogenetic analysis of these DNA sequences, together with 23 additional Encarsia sequences retrieved from the European Molecular Biology Laboratory (EMBL) and GenBank databases, further supported the specific status of E. estrellae, and the placement of E. dichroa (Mercet) in the E. inaron species-group. Additionally, E. inaron is redescribed and some taxonomic problems in the E. inaron species-group are discussed.

Animals↗

PubMed2003

Urban photochemical pollution in the Iberian Peninsula: Lisbon and Barcelona airsheds.

Numerical simulations with photochemical transport models were independently performed for two domains situated in the Iberian Peninsula covering the Lisbon and Barcelona airsheds. Although the days chosen for simulation of the two cities are not the same, the synoptic situations in both cases, known as typical summertime situations, were similar, which allowed the development of typical mesoscale circulations, such as sea breezes and mountain and valley winds dominated by the Azores anticyclone. Emission inventories for the two areas were developed. The O3 concentrations recorded in both cities have a similar level. Nevertheless, O(x) values in Barcelona are higher than in Lisbon, which may, at a first glance, indicate an apparently more oxidant atmosphere in Barcelona. Photochemical modeling for the two cities has shown that the behavior of the circulatory patterns in both urban areas is rather different, which mainly has to do with the different strengths of the sea breeze and the topography, inducing an important offshore vertical layered dimension of pollutant transport in Barcelona versus an important inland horizontal transport in Lisbon.

Air Movements↗

PubMed2005

Efficacy of Bacillus thuringiensis against Phyllocnistis citrella (Lepidoptera: Phyllocnistidae).

The purpose of this work was to analyze the efficacy of Bacillus thuringiensis Berliner on the control of Phyllocnistis citrella Stainton (Lepidoptera: Phyllocnistidae) in laboratory and field trials. In the laboratory, four B. thuringiensis were used: Dipel (commercial formulation) tested at the concentrations of 25 x 10(6) and 25 x 10(8) spores/ml and the isolates K, 6, and 15 (collections of the University of Azores) at the concentration of 25 x 10(6) spores/ ml. A surfactant solution of nonoxinol also was tested with or without the different suspensions of B. thuringiensis. Leaves of Citrus sinensis (L.) Osbeck with second or third instars of leafminer larvae were used in all tests. Bacterial suspensions were applied topically on the surface of intact leaf mines or by injection inside the mine, near the head of the leafminer. When injecting both concentrations of Dipel into the mines, mortality of the leafminers increased compared with the topical application, although no significant differences were observed. The addition of the nonoxinol to the Dipel suspension, applied topically, increased the effect of B. thuringiensis, but differences were not significant. The mortality of the leafminers treated only with the nonoxinol solution increased significantly 48 h after treatment, compared with the control group, suggesting an insecticidal effect of this surfactant when used at a concentration of 0.01%. All the tested B. thuringiensis were equally active against the leafminer, either when applied topically or by mine injection. Field trials showed a significant difference between larval mortality of the control group and the results observed at the trees treated with B. thuringiensis 48 h after treatments.

Animals↗

PubMed1996

Thermothrix azorensis sp. nov., an obligately chemolithoautotrophic, sulfur-oxidizing, thermophilic bacterium.

A new aerobic, obligately chemolithoautotrophic, thermophilic, sulfur-oxidizing bacterium, Thermothrix azorensis, was isolated from a hot spring on Sao Miguel Island in the Azores. The cells of this organism are gram negative, nonsporulating, and rod shaped. Filament formation appears to occur as a response to nonoptimal growth conditions. Growth occurs at 63 to 86 degrees C, and the optimum temperature is 76 to 78 degrees C. The optimum pH range for growth is 7.0 to 7.5. The G+C content of the DNA of our isolate is 39.7 mol%. This isolate uses thiosulfate, tetrathionate, hydrogen sulfide, and elemental sulfur as energy sources. Of particular interest are the absence of Calvin cycle enzymes and the initial appearance of sulfide during the lag phase of growth of aerobic cultures grown on elemental sulfur. The subsequent formation of thiosulfate is followed by oxidation of the thiosulfate to sulfate. T. azorensis differs from the only other Thermothrix species that has been described, Thermothrix thiopara, by having higher optimum and maximum growth temperatures, by being an obligate chemolithoautotroph, and by its close but separate position on a 16S rRNA sequence-based phylogenetic tree. Our T. azorensis isolate has been deposited in the American Type Culture Collection as strain ATCC 51754T (T = type strain).

Bacteriological Techniques↗

PubMed1998

Isoschizomers of the restriction endonuclease TaqI (T/CGA) requiring different metal ion concentrations and having a range of thermal stabilities from Thermus species from different continents.

One-hundred-and-fifty-two isolates of the genus Thermus, collected from hot springs on four continents, were screened for evidence of the presence of the thermophilic Type II restriction endonuclease TaqI (T/CGA). The presence of isoschizomers of TaqI in 27 of the isolates, originating from hot springs in New Zealand, Iceland, USA, Japan, mainland Portugal and the island of São Miguel in the Azores, is reported. Six of the TaqI-containing isolates from diverse geographical locations, identified by means of DNA/DNA homology and 16S rRNA sequence alignment as belonging to the Thermus species T. aquaticus, T. filiformis, T. thermophilus, T. scotoductus and T. brockianus, were selected for comparative studies. The TaqI isoschizomers from each of the six isolates were partially purified. They differed in their magnesium ion requirements, isoelectric points, subunit molecular masses and thermal stability.

Base Sequence↗

PubMed2006

Tepidicella xavieri gen. nov., sp. nov., a betaproteobacterium isolated from a hot spring runoff.

Strains TU-16T and TU-18, two non-pigmented bacterial isolates with an optimum growth temperature of about 45 degrees C and an optimum pH of about 8.5-9.0, were recovered from the Furnas geothermal area on the Island of São Miguel in the Azores. Phylogenetic analysis of the 16S rRNA gene sequence of these strains indicated that they represent a novel species in a new genus of the phylum Betaproteobacteria. The major fatty acids of strains TU-16T and TU-18 were 16 : 0 and 18 : 1omega7c. Ubiquinone 8 was the major respiratory quinone and the major polar lipids were phosphatidylethanolamine and phosphatidylglycerol. The novel isolates were aerobic; thiosulfate was oxidized to sulfate in the presence of a metabolizable carbon source. The organism assimilated organic acids and amino acids, but did not assimilate carbohydrates or polyols. Based on phylogenetic analyses and physiological and biochemical characteristics, it is proposed that strain TU-16T (=LMG 23030T = CIP 108724T) represents the type strain of a novel species in a new genus, Tepidicella xavieri gen. nov., sp. nov.

Betaproteobacteria↗

PubMed1988

Transferrin (Tf) polymorphism in wild rabbit, Oryctolagus cuniculus.

Evidence for two new alleles (TfC and TfD) at the transferrin locus (Tf) in wild rabbit, Oryctolagus cuniculus, is presented. Blood samples were collected in Continental Portugal (178 individuals), and in the Azores Islands of Terceira (52) and S. Miguel (59). The frequency of TfA, which is the only allele detected up to now in domestic rabbits, varied from 0.20 +/- 0.13 to 0.95 +/- 0.05 in the populations sampled in Continental Portugal. In the island populations sampled the frequency of TfA was greater than 0.8.

Alleles↗

PubMed1986

Relation between suicide and homicide in Portugal from 1970 to 1982.

To evaluate to what extent a suicide can be considered a hetero-aggression converted into self-aggression, this study analyses whether the increase in suicides corresponds to a decrease in homicides and vice-versa. Rates of suicide and homicide from 1970 to 1982 have been analysed in Portugal, Azores and Maderia, and the district and city of Lisbon; age and sex groups have also been compared. There is no inverse variation between suicides and homicides either globally or for males or females. There is also a difference in age distribution for suicides and homicides - suicides being mainly over 50 years, homicides mainly under. This suggests that it is not very plausible that self- and hetero-aggressive behaviours alternate in the same individual, although it is possible that, with increasing age, he may move from hetero- or potential hetero-aggression to self-aggression.

Age Factors↗

PubMed2001

The intensity coherence function of time for partially saturated acoustic propagation through ocean internal waves.

The intensity coherence function of time for partially saturated acoustic propagation through internal waves is calculated with a method that is improved over previous treatments. Two specific improvements are introduced: the usual expansion in (1/lambdaphi2) is carried out to a higher order, and then the terms of that expansion are calculated with a new perturbative method. The method is applied to propagation without a sound channel, for both phase-screen and continuous-medium cases. The validity of the new perturbative method is estimated by calculating the next order error terms. Accuracies at the few-percent level are found. The new analytic formulas are also corroborated with numerical integration. Finally, the method is applied to a specific ocean-acoustic experiment [Azores Fixed Acoustic Range (AFAR)]. In order to achieve good agreement with experiment it will be necessary to add an accurate treatment of the sound channel to the present perturbation method.

Acoustics↗