Perífrasis verbales de infinitivo en la norma lingüística culta de Las Palmas de Gran Canaria

[ES] Inserto dentro del Estudio de la norma lingüística culta del español de Las Palmas de Gran Canaria, este trabajo pretende contribuir al mejor conocimiento de la morfosintaxis dialectal canaria.

Frecuencia de los formantes de las vocales medias en sílaba final de palabra con elisión de -/s/: un estudio con materiales de la norma culta de Las Palmas de Gran Canaria

[ES]El propósito de este artículo es comprobar si la supresión de -/s/ final de palabra condiciona la articulación de las vocales medias pronunciadas por hablantes con estudios universitarios de Las Palmas de Gran Canaria. Para ello, no solo se calculan las frecuencias de los formantes de /e/ y /o/ y se establecen sus campos de dispersión, sino que, además, se examina si la información gramatical de la consonante elidida o los factores sexo y edad pueden influir en la altura frecuencial de los formantes.

Individuazione dei valori ottimali di crescita di dinoflagellate bentoniche, valutazione della tossicità e di interazioni allopatiche.

Individuazione dei valori ottimali di crescita di dinoflagellate bentoniche, valutazione della tossicità e di interazioni allelopatiche. Il fitoplancton rappresenta la base della catena trofica in ambiente marino, nonché oltre la metà  della produzione primaria a livello mondiale. Le dinoflagellate, assieme alle diatomee, costituiscono la maggior parte del fitoplancton, comprendendo numerose e diversificate specie di microalghe dalla differente distribuzione, ecologia e fisiologia. Alcune specie appartenenti a tale gruppo sono in grado di dare luogo, in determinate condizioni, a estesi fenomeni di fioriture algali, che diventano particolarmente impattanti se le specie coinvolte sono responsabili della produzione di biotossine, le quali possono direttamente uccidere altri organismi o accumularsi nei loro tessuti. Gli effetti nocivi di questi fenomeni si ripercuotono pesantemente sull'ecosistema marino, con ingenti morie di organismi acquatici (da pesci a molluschi, dal bentos al necton) e profonde alterazioni nelle comunità specifiche. Un forte coinvolgimento si ha di conseguenza anche per le attività umane, in seguito a forti esternalità negative su pesca, turismo, attività ricreative, o spesso con rischi direttamente correlati alla salute umana, dovuti perlopiù ad ingestione di organismi contaminati o all'inalazione di tossine per via aerea. Negli ultimi anni le fioriture algali tossiche si sono fortemente intensificate in distribuzione, estensione e frequenza, attirando l'interesse globale della comunità scientifica. Diversi studi condotti in questo senso hanno portato all'identificazione di numerose specie di dinoflagellate tossiche e all'isolamento di una lunga serie di composti chimici con effetti dannosi da esse sintetizzate. Tuttavia si conosce ancora ben poco sull'ecologia di queste specie, in particolare su quali siano i fattori che possano indurre o regolare la proliferazione e lo sviluppo di un bloom algale. Questo studio si è focalizzato su due specie di dinoflagellate bentoniche tossiche, Ostreopsis ovata e Coolia monotis, entrambe appartenenti alla famiglia Ostreopsidaceae, note già da tempo nei paesi tropicali poiché associate alla sindrome da ciguatera. Negli ultimi anni, Ostreopsis ovata è stata oggetto di numerose ricerche in Europa, poiché ha dato luogo a fenomeni di bloom, collegati con danni respiratori nell'uomo, anche lungo i litorali italiani; soltanto recentemente grazie ad una tecnica analitica basata sulla combinazione di cromatografia liquida e spettrometria di massa (LC-MS), è stato possibile isolare la diverse tossine responsabili. Durante i vari monitoraggi e campionamenti delle acque, questa dinoflagellata è stata sempre riscontrata in presenza di Coolia monotis (e Prorocentrum lima), di cui invece si conosce ben poco, visto che la sua tossicità in Mediterraneo non è ancora stata dimostrata, né la sua tossina caratterizzata. Il primo step di questo studio è stato quello di valutare, attraverso il mantenimento di colture in vitro, l'importanza della temperatura nella crescita di O. ovata e C. monotis (singolarmente) provenienti dalla zona del monte Conero (Ancona, Marche). Esistono già studi di questo tipo su ceppi adriatici di O. ovata, tuttavia è stato effettuato un esperimento similare utilizzando un nuovo ceppo, isolato in anni recenti; per C. monotis invece non sono presenti molti studi in letteratura, in particolare nessuno riguardante ceppi italiani. La valutazione della crescita è stata effettuata attraverso conteggio delle cellule, misura dell'efficienza fotosintetica e consumo dei macronutrienti. Quindi, visto che le due specie vivono in associazione nell'ambiente marino, si è cercato di evidenziare l'instaurarsi di eventuali processi competitivi o di fenomeni di allelopatia. Dall'analisi dei risultati è emerso che, se coltivate individualmente, sia C. monotis che O. ovata mostrano un optimum di crescita alla temperatura di 20°C, con tasso di crescita, numero di cellule e rendimento fotosintetico raggiunti più elevati, seppure non di molto rispetto alle colture a 25°C. Le colture a 30°C al contrario hanno mostrato valori sensibilmente inferiori. Se fatte crescere assieme, invece, C. monotis mantiene lo stesso pattern riscontrato nella monoculture a 20 e 25°C, seppur raggiungendo numeri di cellule inferiori, mentre a 30°C ha una crescita bassissima. Al contrario, O. ovata alla temperatura più elevata raggiunge lo stesso numero di cellule della monocultura, alla temperatura intermedia registra il tasso di crescita, ma non il numero di cellule, più elevato, mentre alla temperatura più bassa (che era l'optimum per la monocultura) si ha il maggior stress per la specie, evidenziando forti fenomeni di competizione. Esperimenti su C. monotis fatta crescere in un filtrato di O. ovata non hanno invece chiarito l'esistenza o meno di eventuali effetti allelopatici di Ostreopsis su Coolia, dato che non sono apparse differenze evidenti tra il controllo e il filtrato, mentre hanno messo in luce l'importanza dei batteri associati alle microalghe come supporto alla loro crescita, poiché le colture cresciute in filtrato sterile hanno manifestato tutte quante un rendimento quantico fotosintetico inferiore.

Harmful algae and their potential impacts on the coastal ecosystem: growth and toxin production dynamics

The main goal of the present thesis was to study some harmful algal species which cause blooms in Italian coastal waters, leading to consequences for human health, coastal ecosystem, fishery and tourism. In particular, in the first part of this thesis the toxicity of Adriatic strains of the raphidophyte Fibrocapsa japonica was investigated. Despite several hypotheses have been proposed for the toxic mechanism of the raphidophytes, especially for the species Chattonella antiqua and C. marina, which have been studied more extensively, just a few studies on the toxic effects of these species for different organisms were reported. Moreover, a careful reading of the literature evidenced as any ichthyotoxic events reported worldwide can be linked to F. japonica blooms. Although recently several studies were performed on F. japonica strains from the USA, Japan, Australia, New Zealand, the Netherlands, Germany, and France in order to characterize their growth and toxicity features, the work reported in this thesis results one of the first investigation on the toxic effects of F. japonica for different organisms, such as bacteria, crustaceans and fish. Mortality effects, together with haemolysis of fish erythrocytes, probably due to the relatively high amount of PUFAs produced by this species, were observed. Mortality for fish, however, was reported only at a high cell density and after a long exposition period (9-10 days); moreover a significant increase of H2O2 obtained in the tanks where sea basses were exposed to F. japonica was also relevant. This result may justify the absence of ichthyotoxic events in the Italian coasts, despite F. japonica blooms detected in these areas were characterized by high cell densities. This work reports also a first complete characterization of the fatty acids produced and extracellularly released by the Adriatic F. japonica, and results were also compared with the fatty acid profile of other strains. The absence of known brevetoxins in F. japonica algal extracts was also highlighted, leading to the hypothesis that the toxicity of F. japonica may be due to a synergic effect of PUFAs and ROS. Another microalgae that was studied in this thesis is the benthic dinoflagellate Ostreopsis cf. ovata. This species was investigated with the aim to investigate the effect of environmental parameters on its growth and toxicity. O. cf. ovata, in fact, shows different blooming periods along the Italian coasts and even the reported toxic effects are variable. The results of this work confirmed the high variability in the growth dynamic and toxin content of several Italian strains which were isolated in recent years along the Adriatic and Tyrrhenian Seas. Moreover, the effects of temperature and salinity on the behaviour of the different isolates are in good agreement with the results obtained from field surveys, which evidence as the environmental parameters are important factors modulating O. cf. ovata proliferation. Another relevant result that was highlighted is the anomaly in the production of palytoxin-like compounds reported by one of the studied isolate, in particular the one isolated in 2008 in Ancona (Adriatic Sea). Only this strain reported the absence of two (ovatoxin-b and –c) of the five ovatoxins so far known in the toxin profile and a different relative abundance of the other toxins. The last aspect that was studied in this thesis regards the toxin biosythesis. In fact, toxins produced (palytoxin-like compounds) or supposed to be produced (brevetoxin-like compounds) by O. cf. ovata and F. japonica, respectively, are polyketides, which are highly oxygenated compounds synthesized by complex enzymes known as polyketide synthase (PKS) enzymes. These enzymes are multi-domain complexes that structurally and functionally resemble the fatty acid synthases (FASs). This work reports the first study of PKS proteins in the dinoflagellates O. cf. ovata, C. monotis and in the raphidophyte F. japonica. For the first time some PKSs were identified in these species, confirming the presence of PKS proteins predicted by the in silico translation of the transcripts found in K. brevis also in other species. The identification of O. cf. ovata PKSs and the localization of the palytoxin-like compounds produced by this dinoflagellate in a similar location (chloroplast) as that observed for other dinoflagellate and cyanobacterial toxins provides some indication that these proteins may be involved in polyketide biosynthesis. However, their potential function as fatty acid synthases cannot be ruled out, as plant fatty acid synthesis also occurs within chloroplasts. This last hypothesis is also supported by the fact that in all the investigated species, and in particular in F. japonica, PKS proteins were present. Therefore, these results provide an important contribution to the study of the polyketides and of the involvement of PKS proteins in the toxin biosynthesis.

CHARACTERIZATION OF ASPHALT MATERIALS CONTAINING BIO OIL FROM MICHIGAN WOOD

The objective of this research is to develop sustainable wood-blend bioasphalt and characterize the atomic, molecular and bulk-scale behavior necessary to produce advanced asphalt paving mixtures. Bioasphalt was manufactured from Aspen, Basswood, Red Maple, Balsam, Maple, Pine, Beech and Magnolia wood via a 25 KWt fast-pyrolysis plant at 500 °C and refined into two distinct end forms - non-treated (5.54% moisture) and treated bioasphalt (1% moisture). Michigan petroleum-based asphalt, Performance Grade (PG) 58-28 was modified with 2, 5 and 10% of the bioasphalt by weight of base asphalt and characterized with the gas chromatography-mass spectroscopy (GC-MS), Fourier Transform Infra-red (FTIR) spectroscopy and the automated flocculation titrimetry techniques. The GC-MS method was used to characterize the Carbon-Hydrogen-Nitrogen (CHN) elemental ratio whiles the FTIR and the AFT were used to characterize the oxidative aging performance and the solubility parameters, respectively. For rheological characterization, the rotational viscosity, dynamic shear modulus and flexural bending methods are used in evaluating the low, intermediate and high temperature performance of the bio-modified asphalt materials. 54 5E3 (maximum of 3 million expected equivalent standard axle traffic loads) asphalt paving mixes were then prepared and characterized to investigate their laboratory permanent deformation, dynamic mix stiffness, moisture susceptibility, workability and constructability performance. From the research investigations, it was concluded that: 1) levo, 2, 6 dimethoxyphenol, 2 methoxy 4 vinylphenol, 2 methyl 1-2 cyclopentandione and 4-allyl-2, 6 dimetoxyphenol are the dominant chemical functional groups; 2) bioasphalt increases the viscosity and dynamic shear modulus of traditional asphalt binders; 3) Bio-modified petroleum asphalt can provide low-temperature cracking resistance benefits at -18 °C but is susceptible to cracking at -24 °C; 3) Carbonyl and sulphoxide oxidation in petroleum-based asphalt increases with increasing bioasphalt modifiers; 4) bioasphalt causes the asphaltene fractions in petroleum-based asphalt to precipitate out of the solvent maltene fractions; 5) there is no definite improvement or decline in the dynamic mix behavior of bio-modified mixes at low temperatures; 6) bio-modified asphalt mixes exhibit better rutting performance than traditional asphalt mixes; 7) bio-modified asphalt mixes have lower susceptibility to moisture damage; 8) more field compaction energy is needed to compact bio-modified mixes.

The new Southeast Asian goblin spider genus Aposphragisma (Araneae, Oonopidae): diversity and phylogeny

The new genus Aposphragisma (Araneae, Oonopidae, Oonopinae) comprising the new species A. baltenspergerae, A. borgulai, A. brunomanseri, A. confluens, A. dayak, A. dentatum, A. draconigenum, A. hausammannae, A. helvetiorum, A. kolleri, A. menzi, A. monoceros, A. nocturnum, A. retifer, A. rimba, A. salewskii, A. scimitar, A. sepilok and A. stannum is described. It is characterised by very hard bodied, strongly sclerotized species with completely armoured prosoma and strongly sclerotized ventral and dorsal abdominal scuta. Aposphragisma gen. nov. is placed within the Gamasomorpha-group sensu Saaristo (2001). Descriptions and illustrations are given for all new species. A phylogenetic analysis based on 40 characters using Prethopalpus fosuma, Gamasomorpha asterobothros, G. cataphracta, G. seximpressa, Xestaspis biflocci, X. kandy and X. paulina as outgroup-taxa and Cortestina thaleri (Oonopidae, Sulsulinae) as the root is presented and discussed. Furthermore it is shown that females of Aposphragisma gen. nov. possess complex internal genitalia. The members of the new genus are ground-dwelling litter inhabitants restricted to Southeast Asian lowland and montane forests, with more than 60% of the species only known from single localities. They are presumed to be negatively affected by the massive destruction of pristine forest habitats within their range. This work has been conducted within the framework of the Planetary Biodiversity Inventory (PBI) of Oonopidae (see http://research.amnh.org/oonopidae).

Moderate concentrations of 4-O-methylhonokiol potentiate GABAA receptor currents stronger than honokiol

BACKGROUND Magnolia bark preparations from Magnolia officinalis of Asian medicinal systems are known for their muscle relaxant effect and anticonvulsant activity. These CNS related effects are ascribed to the presence of the biphenyl-type neolignans honokiol and magnolol that exert a potentiating effect on GABAA receptors. 4-O-methylhonokiol isolated from seeds of the North-American M. grandiflora was compared to honokiol for its activity to potentiate GABAA receptors and its GABAA receptor subtype-specificity was established. METHODS Different recombinant GABAA receptors were functionally expressed in Xenopus oocytes and electrophysiological techniques were used determine to their modulation by 4-O-methylhonokiol. RESULTS 3μM 4-O-methylhonokiol is shown here to potentiate responses of the α₁β₂γ₂ GABAA receptor about 20-fold stronger than the same concentration of honokiol. In the present study potentiation by 4-O-methylhonokiol is also detailed for 12 GABAA receptor subtypes to assess GABAA receptor subunits that are responsible for the potentiating effect. CONCLUSION The much higher potentiation of GABAA receptors at identical concentrations of 4-O-methylhonokiol as compared to honokiol parallels previous observations made in other systems of potentiated pharmacological activity of 4-O-methylhonokiol over honokiol. GENERAL SIGNIFICANCE The results point to the use of 4-O-methylhonokiol as a lead for GABAA receptor potentiation and corroborate the use of M. grandiflora seeds against convulsions in Mexican folk medicine.

Diversity and faunal composition of benthic foraminifera in Hole 44-390A on the Blake Nose Plateau

Benthic foraminiferal assemblages are a widespread tool to understand changes in organic matter flux and bottom-water oxygenation and their relation to paleoceanographic changes in the Upper Cretaceous oceans. In this study, assemblage data (diversity, total number, and number per species and gram) from Deep Sea Drilling Project (DSDP) Site 390 (Blake Nose, western North Atlantic) were processed for the lower Maastrichtian (Globotruncana falsostuarti - Gansserina gansseri Planktic Foraminiferal Zone). These data document significant changes in nutrient flux to the sea floor as well as bottom-water oxygenation during this time interval. Parallel to the observed changes in the benthic foraminiferal assemblages the number of inoceramid shells decreases, reflecting also a significant increase in bottom-water oxygenation. We speculate, that these data could reflect the onset of a shift from warmer low-latitude to cooler high-latitude deep-water sources. This speculation will predate the major reorganization of the oceanic circulation resulting in a circulation mode similar to today at the Early/Late Maastrichtian boundary by ~1 Ma and therefore improves our understanding of Late Cretaceous paleoceanography.

Abundance of mesozooplankton in the western part of the Black Sea in summer 1998 during the National Monitoring Programme

The dataset is based on samples collected in the summer of 1998 in the Western Black Sea in front of Bulgaria coast. The whole dataset is composed of 69 samples (from 22 stations of National Monitoring Grid) with data of mesozooplankton species composition abundance and biomass. Samples were collected in discrete layers 0-10, 0-20, 0-50, 10-25, 25-50, 50-100 and from bottom up to the surface at depths depending on water column stratification and the thermocline depth. Zooplankton samples were collected with vertical closing Juday net,diameter - 36cm, mesh size 150 µm. Tows were performed from surface down to bottom meters depths in discrete layers. Samples were preserved by a 4% formaldehyde sea water buffered solution. Sampling volume was estimated by multiplying the mouth area with the wire length. Mesozooplankton abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Lyudmila Kamburska using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972). Taxon-specific abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Copepods and Cladoceras were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Lyudmila Kamburska using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972).

Abundance of mesozooplankton in the western part of the Black Sea in summer 2001 during the National Monitoring Programme of the Bulgarian Institute of Oceanography

The dataset is based on samples collected in the summer of 2001 in the Western Black Sea in front of Bulgaria coast (transects at c. Kaliakra and c. Galata). The whole dataset is composed of 26 samples (from 10 stations of National Monitoring Grid) with data of mesozooplankton species composition abundance and biomass. Samples were collected in discrete layers 0-10, 10-20, 10-25, 25-50, 50-75, 75-90. Zooplankton samples were collected with vertical closing Juday net,diameter - 36cm, mesh size 150 µm. Tows were performed from surface down to bottom meters depths in discrete layers. Samples were preserved by a 4% formaldehyde sea water buffered solution. Sampling volume was estimated by multiplying the mouth area with the wire length. Mesozooplankton abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Lyudmila Kamburska and Kremena Stefanova using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972). Taxon-specific abundance: The collected material was analysed using the method of Domov (1959). Samples were brought to volume of 25-30 ml depending upon zooplankton density and mixed intensively until all organisms were distributed randomly in the sample volume. After that 5 ml of sample was taken and poured in the counting chamber which is a rectangle form for taxomomic identification and count. Copepods and Cladoceras were identified and enumerated; the other mesozooplankters were identified and enumerated at higher taxonomic level (commonly named as mesozooplankton groups). Large (> 1 mm body length) and not abundant species were calculated in whole sample. Counting and measuring of organisms were made in the Dimov chamber under the stereomicroscope to the lowest taxon possible. Taxonomic identification was done at the Institute of Oceanology by Lyudmila Kamburska and Kremena Stefanova using the relevant taxonomic literature (Mordukhay-Boltovskoy, F.D. (Ed.). 1968, 1969,1972).