A non-abelian quasi-particle model for gluon plasma

We propose a quasi-particle model for the thermodynamic description of the gluon plasma which takes into account non-abelian characteristics of the gluonic field. This is accomplished utilizing massive non-linear plane wave solutions of the classical equations of motion with a variable mass parameter, reflecting the scale invariance of the Yang-Mills Lagrangian. For the statistical description of the gluon plasma we interpret these non-linear waves as quasi-particles with a temperature dependent mass distribution. Quasi-Gaussian distributions with a common variance but different temperature dependent mean masses for the longitudinal and transverse modes are employed. We use recent Lattice results to fix the mean transverse and longitudinal masses while the variance is fitted to the equation of state of pure $SU(3)$ on the Lattice. Thus, our model succeeds to obtain both a consistent description of the gluon plasma energy density as well as a correct behaviour of the mass parameters near the critical point.Comment: 7 pages, 2 figure

First record of the invasive species Parasaissetia nigra in Greece

Στην παρούσα εργασία γίνεται η πρώτη καταγραφή του είδους Parasaissetia nigra (Nietner) (Hemiptera: Coccidae) επί της ροδιάς στην Ελλάδα. Η παρουσία του είδους αυτού διαπιστώθηκε σε καλλωπιστική ροδιά, τον Ιούνιο του 2014, εντός της Πανεπιστημιούπολης του Γεωπονικού Πανεπιστημίου Αθηνών. Δίδονται πληροφορίες σχετικά με τα μορφολογικά και βιολογικά χαρακτηριστικά, όπως και για την εξάπλωση του εντόμου.In June 2014, the nigra scale Parasaissetia nigra (Nietner) (Hemiptera: Coccidae) was recorded for the first time in Greece on pomegranate, Punica granatum. Its occurrence was observed in an ornamental pomegranate tree in the campus of the Agricultural University of Athens. Information on its morphology, biology and distribution is presented

Population fluctuation of Phyllocnistis citrella and its parasi-toids in two citrus species in Western Crete (Greece)

Μελετήθηκαν η διακύμανση του πληθυσμού, το ποσοστό παρασιτισμού και η πληθυσμιακή σύνθεση των παρασιτοειδών του φυλλορύκτη των εσπεριδοειδών Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), ιθαγενών και εισαγόμενων, που βρέθηκαν σε δύο από τα σπουδαιότερα είδη εσπεριδοειδών που καλλιεργούνται στην Ελλάδα την πορτοκαλιά (Citrus sinensis) και τη μανταρινιά (Citrus reticulata). Η μελέτη πραγματοποιήθηκε το 1999 σε βιολογικό εσπεριδοειδώνα του νομού Χανίων. Από τα αποτελέσματα της μελέτης προκύπτει ότι σημαντικά υψηλότερος πληθυσμός του φυλλορύκτη των εσπεριδοειδών ανευρέθηκε στην πορτοκαλιά σε σχέση με την μανταρινιά. Από τα πέντε είδη εξωτικών παρασιτοειδών (Citrostichus phyllocnistoides, Quadrastichus sp., Semielacher petiolatus, Ageniaspis citricola, και Cirrospilus quadristriatus), που είχαν στο παρελθόν εισαχθεί και εξαπολυθεί, βρέθηκαν στα δείγματα μόνο τα τρία πρώτα, εκ των οποίων σημαντικά πολυπληθέστερο βρέθηκε να είναι το C. phyllocnistoides σημειώνοντας τα υψηλότερα ποσοστά παρασιτισμού σε σχέση με τα υπόλοιπα. Το S. petiolatus όμως βρέθηκε σε μικρότερους πληθυσμούς σημειώνοντας σημαντικά χαμηλότερο ποσοστό παρασιτισμού σε σχέση με αυτό του C. phyllocnistoides. Αμφότερα τα παραπάνω εξωτικά είδη προτιμούν να παρασιτούν κυρίως προνύμφες 2ης και 3ης ηλικίας του φυλλορύκτη, γεγονός που πιθανώς οδηγεί σε ανταγωνισμό μεταξύ τους με αποτέλεσμα την επικράτηση του C. phyllocnistoides. Από τα δύο ιθαγενή παρασιτοειδή που ανευρέθησαν, τα Pnigalio pectinicornis και Neochrysocharis formosa, πολυπληθέστερο ήταν το πρώτο, ενώ η εν γένει δράση τους συνέβαλε ελάχιστα στη μείωση του πληθυσμού του φυλλορύκτη.Population fluctuation, percentage of parasitism and parasitoid species composition of Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) were studied in a citrus orchard with orange and mandarin trees in Chania (Greece), in 1999, three years after the release of the in-troduced parasitoids Citrostichus phyllocnistoides (Narayanan), Quadrastichus sp., Semielacher petiolatus (Girault), Cirrospilus quadristriatus (Subba Rao and Ramamani) and Ageniaspis citricola Logvinovskaya. Results showed that significantly more P. citrella individuals per leaf were recorded on orange than on mandarin trees. Regarding the parasitoid complex composition, the exotic species C. phyllocnistoides, S. petiolatus and Quadrastichus sp., as well as the natives Pnigalio pectinicornis L. and Neochrysocharis formosa (Westwood) were recorded. Among them, C. phyllocnistoides was the most abundant, followed by S. petiolatus. The average percentage of parasitism reached 17% and 22% on orange and mandarin, respectively

First record of Stenodiplosis sorghicola on sorghum in Greece

Στην παρούσα εργασία γίνεται η πρώτη καταγραφή του είδους Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae), εχθρού του σόργου, στην Ελλάδα. Η παρουσία του είδους αυτού διαπιστώθηκε από δειγματοληψία που  πραγματοποιήθηκε τον Οκτώβριο του 2007 στον πειραματικό αγρό του Γεωπονικού Πανεπιστημίου Αθηνών, στον Αλίαρτο Βοιωτίας. Επίσης, δίδονται πληροφορίες σχετικά με τα μορφολογικά και βιολογικά χαρακτηριστικά, όπως και για την γεωγραφική εξάπλωση του εντόμου.In October 2007, the sorghum midge Stenodiplosis sorghicola (Coquillett) (Diptera: Cecidomyiidae) was recorded for the first time in Greece. Its occurrence was noticed in an experimental sorghum cultivar at Aliartos, near Athens, in Viotia region. Information on its morphology, biology and distribution is given

Oscillons and oscillating kinks in the Abelian-Higgs model

We study the classical dynamics of the Abelian Higgs model employing an asymptotic multiscale expansion method, which uses the ratio of the Higgs to the gauge field amplitudes as a small parameter. We derive an effective nonlinear Schr\"{o}dinger equation for the gauge field, and a linear equation for the scalar field containing the gauge field as a nonlinear source. This equation is used to predict the existence of oscillons and oscillating kinks for certain regimes of the ratio of the Higgs to the gauge field masses. Results of numerical simulations are found to be in very good agreement with the analytical findings, and show that the oscillons are robust, while kinks are unstable. It is also demonstrated that oscillons emerge spontaneously as a result of the onset of the modulational instability of plane wave solutions of the model. Connections of the obtained solutions with the phenomenology of superconductors is discussed.Comment: arXiv admin note: substantial text overlap with arXiv:1306.386

First record of the nesting whitefly, Paraleyrodes minei, in Greece

Στα τέλη Ιουνίου του 2015 εντοπίστηκε προσβολή από τον αλευρώδη Paraleyrodes minei Ιaccarino (Hemiptera: Aleyrodidae) σε εσπεριδοειδώνα με πορτοκαλιές, ποικιλίας Washighton Navel, στην περιοχή του Πλατανιά, Χανίων (35o30´50.47´´N, 23o53´24.00´´E). Η παρουσία του διαπιστώθηκε στην κάτω επιφάνεια ανεπτυγμένων φύλλων της τρέχουσας βλάστησης. Στα δείγματα που εξετάστηκαν βρέθηκαν διάφορα στάδια ανάπτυξης του εντόμου (νύμφες 2ης, 3ης και 4ης ηλικίας, καθώς και ενήλικα). Συχνά στα ίδια φύλλα βρέθηκε επίσης προσβολή από τον εριώδη αλευρώδη, Aleurothrixus floccosus Meskell (Hemiptera: Aleyrodidae), γεγονός που βοήθησε να αποδειχθεί ότι μακροσκοπικά είναι δυνατή η αναγνώριση της παρουσίας του νέου είδους αλευρώδη στην καλλιέργεια, διότι τα κηρώδη νημάτια που εκκρίνονται από τα δύο αυτά είδη διαφέρουν μορφολογικά. Ένα μήνα αργότερα (τέλη Ιουλίου) στον ίδιο εσπεριδοειδώνα βρέθηκε επίσης και το Dialeurodes citri (Ashmead) (Hemiptera: Aleyrodidae). To P. minei θεωρείται ιθαγενές είδος της κεντρικής Αμερικής. Είναι πολυφάγο είδος αφού έχει καταγραφεί να προσβάλλει είδη φυτών που ανήκουν σε 14 οικογένειες. Δίδονται πληροφορίες σχετικά με τα μορφολογικά και βιολογικά χαρακτηριστικά, καθώς και για την εξάπλωση του εντόμου.On late June 2015, the nesting whitefly Paraleyrodes minei Ιaccarino (Hemiptera: Aleyrodidae) was recorded for first time in Greece. Its occurrence was observed on leaves of sweet orange [Citrus sinensis (L.) Osbeck] trees at Platanias, Chania, on the underside of which tiny white “nests” were observed, due to the woolly waxy material secreted by females, around themselves, as well as by the filamentous translucent wax rods extending from the dorsum of late nymphal instars. In our surveys P. minei was observed at low or moderate population densities. Information on its morphology, biology and present geographical distribution is provided

Sampling and distribution pattern of Trioza erytreae Del Guercio, 1918 (Hemiptera: Triozidae) in citrus orchard

Developing efficient sampling protocols is essential to monitor crop pests. One vector of the citrus disease HLB, the African citrus psyllid Trioza erytreae Del Guercio, 1918 (Hemiptera: Triozidae), currently threatens the lemon industry throughout the Mediterranean region. In this work, a pool of sampling methods devoted to monitoring the population of T. erytreae was compared, its spatial distribution in the orchard was assessed, and the minimum sampling effort for the best sampling method was estimated. Three lemon orchards in North-western Portugal were sampled for one year using two types of yellow sticky traps (standard yellow and fluorescent Saturn yellow), B-vac sampling and sweep net sampling. The method that best performed, in terms of cost-efficiency, was the yellow sticky traps. The two colours of the sticky traps tested did not yield a significantly different number of catches. The spatial distribution throughout the orchards was found to be aggregated towards the borders. A minimum of three sticky traps per hectare was found to be enough to estimate the population at 90% accuracy for the mean during the outbreak. These results should help to monitor and anticipate outbreaks that may even colonize neighbour orchards. Studies on the local dispersion patterns of T. erytreae throughout the orchard are mandatory to further refine and optimize efficient monitoring protocols.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal), for financial support through national funds FCT/MCTES to CIMO (UIDB/00690/2020) and to the project PRE-HLB-Preventing HLB epidemics for ensuring citrus survival in Europe (H2020-SFS-2018-2 Topic SFS-05-2018-2019-2020, proj. No. 817526).info:eu-repo/semantics/publishedVersio

Fatalities from a Greek Burn Unit—A clinicopathological correlation of 129 cases

Introduction: This is a retrospective study of the hospital data and autopsy reports of burn patients who died in the Burn Unit of the Department of Plastic and Reconstructive Surgery, Microsurgery and Burn Center of “G. Gennimatas” Hospital of Athens, Greece during the period 1999–2005. Materials and methods: The records of the burn victims deceased during the period 1999–2005 were reviewed and the cause of injury, percentage of body surface area (BSA) burned, age, gender, and co-morbidities were documented. Moreover, the autopsy findings per system were recorded and compared to clinical reports to analyze any inconsistencies. Results: Between 1999 and 2005, 368 patients were hospitalized in the Burn Unit of “G. Gennimatas” Hospital of Athens, Greece. One-hundred and twenty-nine patients died. The first three causes of death in autopsy reports were: pneumonia (30 patients), myocardial infarction (17 cases) and multiple organ failure (15 patients). Three patients had class I diagnostic discrepancies, 5 patients had class II diagnostic discrepancies and minor diagnostic errors (class III and IV) were documented in 20 patients. Conclusions: Although the percentage of discrepancies of premortem compared to postmortem diagnosis in this series of deceased burn patients is small (2.3%), we believe that it is sufficient to justify the performance of autopsies. © 2017 Elsevier Ltd and ISB

Oscillons and oscillating kinks in the Abelian-Higgs model

We study the classical dynamics of the Abelian Higgs model employing an asymptotic multiscale expansion method, which uses the ratio of the Higgs to the gauge field amplitudes as a small parameter. We derive an effective nonlinear Schrödinger equation for the gauge field, and a linear equation for the scalar field containing the gauge field as a nonlinear source. This equation is used to predict the existence of oscillons and oscillating kinks for certain regimes of the ratio of the Higgs to the gauge field masses. Results of direct numerical simulations are found to be in very good agreement with the analytical findings, and show that the oscillons are robust, while kinks are unstable. It is also demonstrated that oscillons emerge spontaneously as a result of the onset of the modulational instability of plane wave solutions of the model. Connections of the results with the phenomenology of superconductors is discussed. © 2013 American Physical Society