Analysis of the olive fruit fly Bactrocera oleae transcriptome and phylogenetic classification of the major detoxification gene families

he olive fruit fly Bactrocera oleae has a unique ability to cope with olive flesh, and is the most destructive pest of olives worldwide. Its control has been largely based on the use of chemical insecticides, however, the selection of insecticide resistance against several insecticides has evolved. The study of detoxification mechanisms, which allow the olive fruit fly to defend against insecticides, and/or phytotoxins possibly present in the mesocarp, has been hampered by the lack of genomic information in this species. In the NCBI database less than 1,000 nucleotide sequences have been deposited, with less than 10 detoxification gene homologues in total. We used 454 pyrosequencing to produce, for the first time, a large transcriptome dataset for B. oleae. A total of 482,790 reads were assembled into 14,204 contigs. More than 60% of those contigs (8,630) were larger than 500 base pairs, and almost half of them matched with genes of the order of the Diptera. Analysis of the Gene Ontology (GO) distribution of unique contigs, suggests that, compared to other insects, the assembly is broadly representative for the B. oleae transcriptome. Furthermore, the transcriptome was found to contain 55 P450, 43 GST-, 15 CCE- and 18 ABC transporter-genes. Several of those detoxification genes, may putatively be involved in the ability of the olive fruit fly to deal with xenobiotics, such as plant phytotoxins and insecticides. In summary, our study has generated new data and genomic resources, which will substantially facilitate molecular studies in B. oleae, including elucidation of detoxification mechanisms of xenobiotic, as well as other important aspects of olive fruit fly biology

DOA ESTIMATION WITH HISTOGRAM ANALYSIS OF SPATIALLY CONSTRAINED ACTIVE INTENSITY VECTORS

The active intensity vector (AIV) is a common descriptor of the sound field. In microphone array processing, AIV is commonly approximated with beamforming operations and uti- lized as a direction of arrival (DOA) estimator. However, in its original form, it provides inaccurate estimates in sound field conditions where coherent sound sources are simultane- ously active. In this work we utilize a higher order intensity- based DOA estimator on spatially-constrained regions (SCR) to overcome such limitations. We then apply 1-dimensional (1D) histogram processing on the noisy estimates for mul- tiple DOA estimation. The performance of the estimator is shown with a 7-channel microphone array, fitted on a rigid mobile-like device, in reverberant conditions and under dif- ferent signal-to-noise ratios

Real-time multiple sound source localization using a circular microphone array based on single-source confidence measures

International audienceWe propose a novel real-time adaptative localization approach for multiple sources using a circular array, in order to suppress the localization ambiguities faced with linear arrays, and assuming a weak sound source sparsity which is derived from blind source separation methods. Our proposed method performs very well both in simulations and in real conditions at 50% real-time

Source counting in real-time sound source localization using a circular microphone array

International audienceRecently, we proposed an approach inspired by Sparse Component Analysis for real-time localization of multiple sound sources using a circular microphone array. The method was based on identifying time-frequency zones where only one source is active, reducing the problem to single-source localization for these zones. A histogram of estimated Directions of Arrival (DOAs) was formed and then processed to obtain improved DOAestimates, assuming that the number of sources was known. In this paper, we extend our previous work by proposing three different methods for counting the number of sources by looking for prominent peaks in the derived histogram based on: (a) performing a peak search, (b) processing an LPC-smoothed version of the histogram, (c) employing a matching pursuit-based approach. The third approach is shown to perform very accurately in simulated reverberant conditions and additive noise, and its computational requirements are very small

Transcriptomic responses of the olive fruit fly Bactrocera oleae and its symbiont Candidatus Erwinia dacicola to olive feeding

The olive fruit fly, Bactrocera oleae, is the most destructive pest of olive orchards worldwide. The monophagous larva has the unique capability of feeding on olive mesocarp, coping with high levels of phenolic compounds and utilizing non-hydrolyzed proteins present, particularly in the unripe, green olives. On the molecular level, the interaction between B. oleae and olives has not been investigated as yet. Nevertheless, it has been associated with the gut obligate symbiotic bacterium Candidatus Erwinia dacicola. Here, we used a B. oleae microarray to analyze the gene expression of larvae during their development in artificial diet, unripe (green) and ripe (black) olives. The expression profiles of Ca. E. dacicola were analyzed in parallel, using the Illumina platform. Several genes were found overexpressed in the olive fly larvae when feeding in green olives. Among these, a number of genes encoding detoxification and digestive enzymes, indicating a potential association with the ability of B. oleae to cope with green olives. In addition, a number of biological processes seem to be activated in Ca. E. dacicola during the development of larvae in olives, with the most notable being the activation of amino-acid metabolism

On the Deque and Rique Numbers of Complete and Complete Bipartite Graphs

Several types of linear layouts of graphs are obtained by leveraging known data structures; the most notable representatives are the stack and the queue layouts. In this content, given a data structure, one seeks to specify an order of the vertices of the graph and a partition of its edges into pages, such that the endpoints of the edges assigned to each page can be processed by the given data structure in the underlying order. In this paper, we study deque and rique layouts of graphs obtained by leveraging the double-ended queue and the restricted-input double-ended queue (or deque and rique, for short), respectively. Hence, they generalize both the stack and the queue layouts. We focus on complete and complete bipartite graphs and present bounds on their deque- and rique-numbers, that is, on the minimum number of pages needed by any of these two types of linear layouts

Φωνολογική επίγνωση σε παιδιά με Διαταραχή Αυτιστικού Φάσματος

Στην έρευνα της παρούσας εργασίας μελετάται η φωνολογική επίγνωση των παιδιών που βρίσκονται στο αυτιστικό φάσμα. Τα παιδιά που μελετήθηκαν έχουν ανεπτυγμένο λόγο και είναι σε θέση να διαβάσουν και να γράψουν. Το πρώτο μέρος αφορά τη σχετική θεωρία και τους ορισμούς ενώ το δεύτερο μέρος αφορά την έρευνα. Η έρευνα είναι ποιοτική και αφορά μελέτη περίπτωσης τεσσάρων ατόμων. Πραγματοποιήθηκε σε ένα ειδικό σχολείο της Αττικής και οι συμμετέχοντες ήταν τέσσερα παιδιά στο φάσμα του αυτισμού με επαρκώς αναπτυγμένο προφορικό λόγο. Τα αποτελέσματα της έρευνας έδειξαν ότι παρόλο που τα παιδία έχουν αναπτυγμένο προφορικό λόγο δεν είναι σε θέση να κατανοήσουν τα δομικά στοιχεία των λέξεων. Δεν μπορούν να αντιληφθούν τις συλλαβές και τα φωνήματα των λέξεων και να τα ξεχωρίσουν. Μία επιπλέον δυσκολία ήταν ότι τα περισσότερα από τα παιδιά δεν μπορούσαν να καταλάβουν τι ακριβώς του ζητείται να κάνουν, δηλαδή δεν μπορούσαν να καταλάβουν ούτε την εκφώνηση. Άλλα ενώ καταλάβαιναν την εκφώνηση δεν μπόρεσαν να αποδώσουν στην άσκηση και μονάχα ένα παιδί κατάφερε να ολοκληρώσει τη διαδικασία.In the present study, the phonological awareness of children in the autistic spectrum is studied. The children studied have a developed speech and are able to read and write. The first part concerns the relevant theory and definitions while the second part concerns the research. The research is qualitative and involves a case study of four people. The research was conducted at a special school in Attica and the participants were four children in the spectrum of autism with a sufficiently developed spoken word. The results of the research showed that although children have developed spoken language they are not able to understand the syllables of words. They cannot grasp the syllables and phonics of words and distinguish them. One additional difficulty was that most of the children could not understand what they were asked to do, that is, they could not even understand the pronunciation. But while they understood the guidelines of the exercises they could not perform the exercise and only one child managed to solve the task

Substrate specificity and promiscuity of horizontally transferred UDP-glycosyltransferases in the generalist herbivore Tetranychus urticae

Uridine diphosphate (UDP)-glycosyltransferases (UGTs) catalyze the addition of UDP-sugars to small hydrophobic molecules, turning them into more water-soluble metabolites. While their role in detoxification is well documented for vertebrates, arthropod UGTs have only recently been linked to the detoxification and sequestration of plant toxins and insecticides. The two-spotted spider mite Tetranychus urticae is a generalist herbivore notorious for rapidly developing resistance to insecticides and acaricides. We identified a set of eight UGT genes that were overexpressed in mites upon long-term acclimation or adaptation to a new host plant and/or in mite strains highly resistant to acaricides. Functional expression revealed that they were all catalytically active and that the majority preferred UDP-glucose as activated donor for glycosylation of model substrates. A high-throughput substrate screening of both plant secondary metabolites and pesticides revealed patterns of both substrate specificity and promiscuity. We further selected nine enzyme-substrate combinations for more comprehensive analysis and determined steady-state kinetic parameters. Among others, plant metabolites such as capsaicin and several flavonoids were shown to be glycosylated. The acaricide abamectin was also glycosylated by two UGTs and one of these was also overexpressed in an abamectin resistant strain. Our study corroborates the potential role of T. urticae UGTs in detoxification of both synthetic and natural xenobiotic compounds and paves the way for rapid substrate screening of arthropod UGTs

Reconstruction of the submerged landscape of Vatika Bay (SE Peloponnese, Greece)

Ο κόλπος των Βατίκων, στη ΝΑ Πελοπόννησο, ανήκει στο Ελληνικό Τόξο και χαρακτηρίζεται από έντονες ενεργές τεκτονικές κινήσεις και σεισμικότητα. Η παρουσία αλλεπάλληλων ανυψωμένων θαλάσσιων αναβαθμίδων του Ανώτερου Τεταρτογενούς ιδιαίτερα στην δυτική πλευρά του Κόλπου και την Ελαφόνησο αποτελεί μαρτυρία μακροπρόθεσμης τεκτονικής ανύψωσης της περιοχής. Σε αυτό το τεκτονικό καθεστώς, η παρουσία της βυθισμένης προϊστορικής πόλης του Παυλοπετρίου, η οποία βρίσκεται σε βάθος μέχρι στα 3-4 μέτρα στην παραλία Πούντα, στα Βιγκλάφια, αποτελεί ένα παράδοξο που δεν έχει εξηγηθεί επαρκώς μέχρι σήμερα Σκοπός αυτής της εργασίας είναι η κατανόηση των γεωλογικών-τεκτονικών διεργασιών σε συνδυασμό με τις διακυμάνσεις της στάθμης της θάλασσας στο Ανώτερο Πλειστόκαινο και Ολόκαινο με στόχο την αναπαράσταση της εξέλιξης του βυθισμένου προϊστορικού ανάγλυφου και την ερμηνεία της σημερινής γεωμορφολογικής διάταξης. Στην παρούσα εργασία χρησιμοποιήθηκαν δεδομένα πολυδιαυλικής βυθομετρίας, τομογράφου υποδομής πυθμένα και ηχοβολιστή πλευρικής σάρωσης, που συλλέχθηκαν σε δύο ερευνητικούς πλόες του σκάφους ΑΛΚΥΩΝ του ΕΛΚΕΘΕ το 2010 και το 2015. Ο κόλπος των Βατίκων παρουσιάζει μορφολογία κοιλάδας. Σεισμικά προφίλ υψηλής ανάλυσης κατά μήκος του δυτικού απότομου υποθαλάσσιου πρανούς δείχνουν ότι σχετικές βυθιζόμενες και ανυψωμένες περιοχές ελέγχονται από ενεργά ρήγματα. Το ανατολικό πρανές του κόλπου εμφανίζει σημαντικές διαφορές: κλίνει ομαλά προς τα δυτικά, ενώ οι υποθαλάσσιες αναβαθμίδες που ανήκουν σε αυτό το τμήμα δε συμπίπτουν με αυτές που χαρτογραφήθηκαν στο δυτικό πρανές. Οι μορφολογικές αναβαθμίδες που χαρτογραφήθηκαν βρίσκονται σε διάφορα βάθη, από 40 έως 104 μέτρα. Ο ρυθμός ιζηματογένεσης κατά το Ολόκαινο είναι πολύ μικρός. Στη βόρεια ακτή του κόλπου παρατηρούνται πολλαπλά παλαιο-κανάλια, θαμμένα κάτω από πρόσφατα, Ολοκαινικά ιζήματα. Τα μακροπρόθεσμα ανυψωμένα τμήματα της περιοχής μελέτης διαχωρίζονται από το σχετικά βυθιζόμενο πυθμένα του κόλπου των Βατίκων μέσω ενεργών ρηγμάτων. Τα τρία beachrock σε διαφορετικά βάθη κατά μήκος της βόρειας ακτής υποδεικνύουν σταδιακά γρήγορη βύθιση λόγω τεκτονικών κινήσεων σε ιστορικό χρόνο. Η βυθισμένη αρχαία πόλη του Παυλοπετρίου βρίσκεται στο βυθιζόμενο τμήμα του κυρίαρχου ρήγματος. Διαφορικές κάθετες τεκτονικές κινήσεις δημιούργησαν μορφολογικές αναβαθμίδες χαμηλής στάθμης σε διάφορα βάθη κατά μήκος του κόλπου των Βατίκων.Vatika Bay is located in SE Peloponnese and belongs to Laconia peninsula. The area is seismically active because it is part of the Hellenic Arc and is characterized by long term uplift, also postulated by a sequence of uplifted Late Quaternary marine terraces. This fact contrasts with the subsidence by about 3-4 m bellow the present sea level of the prehistoric city of Pavlopetri, located at Punta beach, Viglafia, in the strait of Elaphonisos. That is what is called the “Laconia Paradox”: a submerged archaeological site within a long term uplifting area. Thus, the aim of this thesis is to reconstruct the submerged prehistoric landscapes and provide understanding of the geological processes and sea-level fluctuation, which led to the present geomorphological configuration. A marine geological survey, carried out in 2015 aboard the 14m long RV Alkyon of HCMR and positioned with GPS and differential GPS, allowed to obtain complete high resolution swath bathymetry coverage of the area. Both Multi Beam 200/400 kHz and Single Beam echosounders have been used. Bathymetric data were integrated with the acquisition of high-resolution seismic profiling data, such as Chirp, Pinger and Boomer and side scan sonar data. The bay displays valley-like morphology. High resolution seismic profiles across the western steep slope of the Bay provide evidence that relative subsiding and uplifting areas are controlled by active faulting. The eastern slope of the Bay displays marked differences: it dips smoothly westwards, while the observed submarine terraces do not match with the ones mapped along the western slope. Holocene sediment deposition is fairly limited across the bay. A series of submerged paleo-channels occurs running off the northern shore of the Bay and buried below the recent sediments. Evidence on morphological terraces has been found at several depths ranging roughly between 40 m and 104 m bsl. Active faulting separates the long-term uplifting parts of the surveyed area from the relative subsiding seafloor of Vatika Bay. The occurrence of three beachrock bands at different depths indicates rapid, incremental subsidence due to tectonic activity in historical times. The submerged ancient city of Pavlopetri is located on the subsiding, hanging wall of the dominant fault. Differential vertical tectonics has led to the occurrence of low sea-level terraces at different depths across the Vatika Bay