202 research outputs found
A preliminary plan for the study of zooplankton in the gulf of Vlorë (Albania)
ItIl Golfo di Vlorë è l’unico mare "interno" della costa albanese. Presenta una profondità massima di 55 m ed è separato dal Canale d’Otranto dalla penisola Karaburun. Il sito è di particolare interesse per la nascente economia peschereccia albanese, rappresentando un sito nursery naturale sia per le specie pelagiche che per quelle rivierasche.Un survey sulla distribuzione e la composizione dello zooplankton è stato organizzato a scopo dimostrativo, nell’ambito del progetto per la fondazione di un Dipartimento di Ecologia (all’interno del Protocollo di Cooperazione scientifica e culturale tra Italia e Albania) presso l’Università di Vlorë. La campagna di prelievo è stata organizzata in una sola data (26 Giugno 2003). L’area è stata suddivisa in 7 stazioni di campionamento (6 nel Golfo,1 nel Canale d’Otranto).I campioni sono stati prelevati per trascinamento di retini da plancton in acqua. In ciascuna stazione sono stati usati due retini a differente maglia (50 e 200 mm), per un totale di 14 campioni. La composizione di specie, la loro abbondanza, e la distribuzione spaziale sono state studiate statisticamente. Un totale di 94 categorie tassonomiche è stato riconosciuto nei campioni. Solo per 34 di loro si è potuti giungere a livello di specie, a causa della abbondante presenza di stadi larvali. Copepoda (43 catego-rie)e Tintinnina (16 categorie) erano i gruppi più rappresentati. Le differenze tra le stazioni del Golfo sono risultate inferiori di quelle con la stazione esterna (canale d’Otranto).La presenza di uova e larve di pesci (soprattutto appartenenti al gen. Engraulis) è stata documentata. Anche larve di Stomatopoda sono state raccolte,a testimonianza del potenziale ruolo di nursery per specie economicamente importanti della baia. La composizione del plankton ha consentito di separare le stazioni (1 e 2) a Nord (ricche di veliger di Bivalvia) come influenzate dalla presenza dei piani sabbiosi. L’abbondanza di Acartia italica, Paracartia latisetosa, Centropages kroyeri, e Oithona nana, ci ha consentito di individuare nella stazione 6 il polo di maggiore confinamento.EnThe Gulf of Vlorë is the only internal sea of the Albanian coastline. It has a maximum depth of 55 m and is separated from the Otranto Channel by the Peninsula Karaburun. The site is of paramount interest for the Albanian fishing,being a natural nursery for many fish species of economic importance.In the framework of a plan for the foundation of a Department of Ecology at the Technological University of Vlorë, a first demonstrative survey on the zooplankton composition and distribution has been carried out in the Gulf of Vlorë,to standardise investigation methods.The demonstrative survey was performed on a single date (June 2003), on 7 different sampling stations (six in the Gulf of Vlorë, one in the Otranto Channel), on the superficial water layer, and with two different mesh sized nets (50 and 200 mm, for a total of 14 samples) to collect micro and meso-zooplankton. Species composition, abundance, and distribution were statistically studied (Analysis of Variance). A total of 94 categories were recognised. Only 34 of them were recognised at the species level,due to the abundance of larval stages. Copepoda (43 categories) and Tintinnina (16 categories) were the most representative components. Differences between the “Gulf” stations were less significant than those resulting from the comparison with the “Otranto Channel” station. The presence of fish larvae and eggs (with the genus Engraulis well recognisable) was recorded. Also stomatopod larvae (erichteus of Squillidae) were found, which contributed to affirm the potential role of this inlet as nursery area. The confinement degree of stations was described on the basis of indicator species belonging to the copepod families Acartiidae (Calanoida) and Oithonidae (Cyclopoida), and of the body size of adults belonging to different copepod populations of the same genus (Centropages). Station 2 showed the highest number of zooplankton categories (61),and and the co-presence of Acartia clausi, Paracartia latisetosa, Centropages kroyeri, and Oithona nana, which allowed to define it as the most confined station. Micro-zooplankton resulted more abundant in stations 1, and 2, along the North coast of the Gulf, owing this result essentially to Bivalvia (veliger), early stages of Oithonidae, and Tintinnina. A plan for future studies has been proposed to monitor the presence (either in space and in time) of economically important larvae to understand life cycle timing of their species in the Gulf of Vlorë
Calanoida (Crustacea Copepoda) from the inland waters of Apulia (south-eastern Italy)
The currently available knowledge on biodiversity and species distribution of Italian fauna still presents some gaps to be filled, in particular in the southern part of the country. This study represents the first survey aimed at assessing the presence and distribution of Calanoida in inland waters of Apulia (south-eastern Italy). The research lasted five years and led to the mapping of 121 inland water bodies, most of which are characterized by temporary hydroperiods. Fifty-five of the sampled sites hosted at least one calanoid species, and 48 sites (among the 55 sites hosting Calanoida) are temporary water bodies. Thirteen calanoid species were detected in total; several of these are first records for Apulia and three species are new records for mainland Italy. The efficiency of the sampling effort was tested for both the entire Apulian territory and its main subareas, namely Gargano (in northern Apulia), and Salento (southern Apulia). Central Apulia showed the lowest species richness among the three sampled subareas. This is probably due to the scarcity of inland water bodies. Species composition of Apulian calanoid fauna was compared to the ones of the geographically close areas for which data are available: the other Italian faunal provinces (Alpine, Apennine, Padanian, Sardinian and Sicilian provinces) and the Balkans (Albania, Corfu, Croatia, Greece and Turkish Trace, Macedonia, Slovenia). Gargano and Salento showed a different assemblage of vicariant species but both the areas showed a remarkable presence of Mediterranean elements that, in fact, characterize the whole Apulian faunal province. The highest similarities for inland water calanoid fauna, which were observed between Gargano and the Apennine province, and between Salento and Sicily, are discussed, along with the total assessment of the whole Apulian calanoid fauna
Egg banks in hypersaline lakes of the South-East Europe
The cyst banks of 6 coastal hypersaline lakes of South-East Europe have been investigated. The study concerned the bottom sediments of Khersonesskoe and Koyashskoe lakes in the Crimea (Ukraine), Nartë saltworks (Albania), Vecchia Salina at Torre Colimena (Apulia, Italy), Pantano Grande and Pantano Roveto at Vendicari (Sicily, Italy). A total of 19 cyst types were recognised. The cyst banks of lakes were found to be well separated in the representation derived from a statistical multivariate data analysis. For all the lakes examined a comparison was possible between the resting community in sediments (cyst bank) and the active one in the water. The cyst banks contained more species than those recorded over a multi-year sampling effort in the water column. The study of cyst hatching, performed on 5 cyst types under lab conditions, demonstrated that cysts do not hatch under the same conditions. Furthermore, each cyst type shows a wide range of preferential hatching conditions, which allow us to confirm the ecological generalism of salt lake species
An infra-red beam device for the study of the motor activity rhythms on groundwater mysidacea
ItL’attività motoria o locomotoria è un parametro utile per comprendere il funzionamento degli orologi biologici. Gli animali cavernicoli rappresentano un eccellente modello per gli studi cronobiologici oltre che per comprendere l’evoluzione e l’adattamento alla vita sotterranea.Le ricerche in ambito cronobiologico richiedono spesso monitoraggi molto lunghi per i quali è necessario ricorrere all’utilizzo di sistemi automatici. L’obbiettivo primario del presente lavoro consiste nel testare, con animali vivi, il prototipo di un apparato elettronico ad infrarossi appositamente costruito per il monitoraggio dell’attività motoria di animali acquatici di piccole dimensioni. La specie utilizzata in questa ricerca è un misidaceo, Spelaeomysis bottazzii Caroli 1924, proveniente dalla Grotta di San Isidoro (Nardò – LE, Pu/507). La registrazione dell’attività motoria ha riguardato animali mantenuti singolarmente in celle di coltura da 30 ml (5x3x2 cm). L’attività motoria è stata rilevata con un sistema di 9 barriere a luce infrorossa (ciascuna barriera composta da una sorgente e un sensore alle sue estremità). I sensori erano collegati ad un circuito elettronico che inviava i segnali ad un personal computer che a sua volta li archiviava. È stata eseguita un’analisi qualitativa dell’attività motoria dei singoli animali, rappresentandola graficamente per mezzo di attogrammi. Inoltre è stata eseguita un’ analisi quantitativa esplorativa di questi primi dati sull’attività motoria dei misidacei. A tal fine tutte le serie temporali sono state analizzate applicando la trasformata discreta di Fourier (DFT). Sono state eseguite registrazioni per un totale di 20 giorni, 24 ore su 24 (12 gg il primo animale, 4 gg il secondo ed il terzo animale). Durante tale periodo non sono stati riportati problemi di eccessivo surriscaldamento dell’acqua, la componente elettronica (in particolare quella optoelettronica) si è rivelata altamente sensibile e non ha mostrato segni di usura dovuti alle condizioni di utilizzo. Gli animali sono rimasti vivi sino alla conclusione dell’esperimento. L’ispezione visiva degli attogrammi ha evidenziato una continua e costante rilevazione dell’attività locomotoria dei misidacei. L’analisi cronobiologia si è concentrata sul calcolo della lunghezza del periodo circadiano in free-running, trovando un periodo medio di 24,7 h. La DFT ha rilevato la presenza di un picco a circa 24 h in tutte le registrazioni esaminate, evidenziando inoltre una bassa potenza spettrale.Oltre al ritmo circadiano, in tutte le registrazioni ricorrevano ritmi ultradiani nell’attività motoria. Nonostante le repliche sperimentali non siano sufficienti a giustificare conclusioni circa i ritmi dell’attività motoria di Speleomysis bottazzii, i ritmi individuati e la loro differente intensità, testimoniano di un incoraggiante funzionamento dell’apparato progettato.EnLocomotor activity and cave animals represent excellent models for study of biological clocks. An infrared-based detection device for recording motor activity has been tested on the stigobitic Spelaeomysis bottazzii Caroli, 1924 (Crustacea: Mysidacea). The individual activity of mysidaceans was monitored in continuous darkness. Data were analyzed by a DFT and chi-square periodogram. The apparatus was able to read rhythms of activity, in particular a lower circadian rhythm and some ultradian ones
Floating Objects of Non Marine Origin, Rafting of Marine Organisms, and the Interfering Role of Man in Mediterranean Sea
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Distribution of mesozooplankton resting eggs in seabottom sediments of Thermaikos gulf (NW Aegean Sea, Greece) and possible effects of sediment resuspension.
The distribution of mesozooplankton resting eggs was studied in the bottom sediments of Thermaikos Gulf (Aegean Sea, Greece), to study possible effects of sediment resuspension on egg assemblages, due to physical forcing (storm events) and/or anthropogenic activity (trawling). The total abundance of eggs in sediments was higher at stations located close to the rivers’ mouths, with muddy sediments, and with the water column richer of zooplankton, than at stations located at greater depths and with muddy-sand bed sediments. At the former stations the vertical distribution of eggs has revealed a trend of homogenization within the sediment column, from September to February. This is related probably to the sediment re-suspension. At the latter stations, no clear temporal variability in the vertical distribution was detected. The eggs found in the bottom sediments of Thermaikos Gulf were assigned to 16 morpho-types. Amongst these, those assigned to Paracartia latisetosa and Labidocera wollastoni (as well as one type called Calanoida 3), were found to be dominant at all the stations and during all the sampling periods, both as full and empty eggs
Wax and monoglyceride interactions towards flaxseed oil structuring
Orientadores: Rosiane Lopes da Cunha, Paula Kiyomi OkuroDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia de AlimentosResumo: A combinação de diferentes oleogelators para a formação de oleogéis apresenta um potencial ainda pouco explorado, uma vez que pares efetivos geralmente são encontrados empiricamente. O objetivo deste trabalho foi avaliar a estruturação de óleo de linhaça (FXO) em duas temperaturas de armazenamento diferentes (5 e 25 °C), explorando-se a combinação entre cera de berry (BEW) ou cera de girassol hidrolisada (SHW), com baixa e alta temperatura de fusão, respectivamente, e monoestearato de glicerol (GMS). As propriedades térmicas e mecânicas, a microestrutura e a estabilidade dos oleogéis foram investigadas para se compreender o papel desempenhado pelas diferentes combinações de ceras-monoestearato de glicerol. Géis autossustentáveis e translúcidos foram obtidos a partir da dispersão de BEW em FXO. No entanto, observou-se uma interação negativa decorrente da adição de GMS aos oleogéis de BEW, o que foi confirmado pela redução das propriedades viscoelásticas. Além disso, foram detectadas alterações na rede cristalina através de microscopia de luz polarizada (PLM), que foram correlacionadas com a diminuição da capacidade de retenção de óleo (OBC). Este resultado indicou que o GMS impediu a organização completa do BEW nas cadeias poli-insaturadas do FXO. Por outro lado, uma interação positiva entre GMS e SHW foi encontrada, uma vez que ambos componentes por si só não foram capazes de estruturar o óleo a 25 °C. Curiosamente, a formação de gel foi promovida mesmo com uma pequena adição de GMS, embora uma proporção ideal de 1:1 (GMS50:50SHW) tenha sido observada. Neste caso, oleogéis com propriedades elásticas notáveis, decorrentes da formação de uma rede de cristalina densa e coesa com alta capacidade de retenção de óleo, foram formados tanto a 5 como a 25 °C. Tal interação positiva pode estar associada ao fato de que as porções polares de GMS interagiram com as regiões polares de álcoois graxos presentes em SHW, uma vez que esses álcoois estão em menor quantidade em BEW, aumentando a afinidade entre os gelators. A análise de estabilidade oxidativa mostrou que, apesar do aquecimento durante a preparação do oleogel, todos os géis apresentaram comportamento semelhante ao do óleo de linhaça não estruturado (~ 12,00 meqO2/kg), mesmo após 30 dias de armazenamento. Dessa forma, sistemas semi-sólidos com alegação nutricional e diferentes texturas foram desenvolvidos a partir da mistura de ceras com diferentes pontos de fusão e um oleogelator derivado de ácido graxo, abrindo a oportunidade de personalizar as propriedades dos géis abrangendo uma ampla gama de tecno-funcionalidadesAbstract: The combination of different oleogelators aiming the formation of oleogels has an untapped potential, since effective pairs are usually found by serendipity. The objective of this work was to evaluate the structure of flaxseed oil (FXO) by evaluating the combination of berry wax (BEW) or hydrolyzed sunflower wax (SHW), with low and high melting temperature, respectively, and glycerol monostearate (GMS) at two different storage temperatures (5 and 25 °C). The thermal and mechanical properties, microstructure and stability of oleogels were investigated to understand the role played by different wax-glycerol monostearate combinations. Self-standing and translucent gels were obtained from BEW dispersed in FXO. However, a negative interaction was observed with GMS addition in BEW-based oleogels, which was confirmed by the reduction of the viscoelastic properties. In addition, changes in a crystal network were disclosed by polarized light microscopy (PLM) and correlated to the decrease of oil binding capacity (OBC). This result indicated that the GMS prevented the complete organization of BEW in polyunsaturated chains of FXO. Conversely, a positive interaction was found for GMS and SHW, since both components alone were not able to impart structure in FXO at 25 °C. Interestingly, gel formation was promoted even with a small addition of GMS, although an ideal ratio of 1:1 (GMS50:50SHW) was observed. In this case, oleogels with remarkable elastic properties related with the formation of a dense and cohesive crystalline network, and with high ability to entrap liquid oil, were formed at both 5 and 25 °C. Such a positive interaction may be associated with the fact that the polar portions of GMS interacted with the polar regions of fatty alcohols present in SHW, since these alcohols are in lower amount in BEW, increasing the affinity between gelators. Oxidative stability analysis showed that despite heating exposure during oleogel preparation, all gels resembled to the behavior of fresh liquid oil (~12.00 meqO2/kg) even after 30 days of storage. In this way, semi-solid systems with nutritional claim and different textures were developed from the mixture of waxes with different melting points and a fatty acid derivative oleogelator, opening the opportunity to customize the properties of the gels covering a wide range of techno-functionalitiesMestradoEngenharia de AlimentosMestra em Engenharia de Alimentos88882.329557/2019-01CAPE
Plankton Resting Stages in the Marine Sediments of the Bay of Vlorë (Albania)
In the frame of the INTERREG III CISM project, sediment cores were collected at 2 stations in the Gulf of Vlorë to study the plankton resting stage assemblages. A total of 87 morphotypes were identified and produced by Dinophyta, Ciliophora, Rotifera, and Crustacea. In 22 cases, the cyst belonged to a species absent from the plankton of the same period. The most abundant resting stages were those produced byScrippsiellaspecies (Dinophyta). Some calcareous cysts were identified as fossil species associated with Pleistocene to Pliocene sediment, although they were also found in surface sediments and some of them successfully germinated, thus proving their modern status. Total abundance generally decreased with sediment depth at station 40, while station 45 showed distinct maxima at 3 and 8 cm below the sediment surface. The depth of peak abundance in the sediment varied with species. This paper presents the first study of the plankton resting stages in the Bay of Vlorë. The study confirmed the utility of this type of investigation for a more correct evaluation of species diversity. In addition, the varying distribution with sediment depth suggests that this field could be of some importance in determining the history of species assemblages
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