Nucleon to Delta Weak Excitation Amplitudes in the Non-relativistic Quark Model

We investigate the nucleon to Delta(1232) vector and axial vector amplitudes in the non-relativistic quark model of the Isgur-Karl variety. A particular interest is to investigate the SU(6) symmetry breaking, due to color hyperfine interaction. We compare the theoretical estimates to recent experimental investigation of the Adler amplitudes by neutrino scattering.Comment: \documentstyle[aps]{revtex}, 21pages; 11 postscript figures. Accepted for publication by Phys. Rev.

Critical Analysis of Theoretical Estimates for BB to Light Meson Form Factors and the B→ψK(K∗)B \to \psi K(K^{\ast}) Data

We point out that current estimates of form factors fail to explain the non-leptonic decays $B \to \psi K(K^{\ast})$ and that the combination of data on the semi-leptonic decays $D \to K(K^{\ast})\ell \nu$ and on the non-leptonic decays $B \to \psi K(K^{\ast})$ (in particular recent po\-la\-ri\-za\-tion data) severely constrain the form (normalization and $q^2$ dependence) of the heavy-to-light meson form factors, if we assume the factorization hypothesis for the latter. From a simultaneous fit to \bpsi and \dk data we find that strict heavy quark limit scaling laws do not hold when going from $D$ to $B$ and must have large corrections that make softer the dependence on the masses. We find that $A_1(q^2)$ should increase slower with \qq than $A_2, V, f_+$. We propose a simple parametrization of these corrections based on a quark model or on an extension of the \hhs laws to the \hl case, complemented with an approximately constant $A_1(q^2)$. We analyze in the light of these data and theoretical input various theoretical approaches (lattice calculations, QCD sum rules, quark models) and point out the origin of the difficulties encountered by most of these schemes. In particular we check the compatibility of several quark models with the heavy quark scaling relations.Comment: 48 pages, DAPNIA/SPP/94-24, LPTHE-Orsay 94/1

Verified and potential pathogens of predatory mites (Acari: Phytoseiidae)

Several species of phytoseiid mites (Acari: Phytoseiidae), including species of the genera Amblyseius, Galendromus, Metaseiulus, Neoseiulus, Phytoseiulus and Typhlodromus, are currently reared for biological control of various crop pests and/or as model organisms for the study of predator¿prey interactions. Pathogen-free phytoseiid mites are important to obtain high efficacy in biological pest control and to get reliable data in mite research, as pathogens may affect the performance of their host or alter their reproduction and behaviour. Potential and verified pathogens have been reported for phytoseiid mites during the past 25 years. The present review provides an overview, including potential pathogens with unknown host effects (17 reports), endosymbiotic Wolbachia (seven reports), other bacteria (including Cardinium and Spiroplasma) (four reports), cases of unidentified diseases (three reports) and cases of verified pathogens (six reports). From the latter group four reports refer to Microsporidia, one to a fungus and one to a bacterium. Only five entities have been studied in detail, including Wolbachia infecting seven predatory mite species, other endosymbiotic bacteria infecting Metaseiulus (Galendromus, Typhlodromus) occidentalis (Nesbitt), the bacterium Acaricomes phytoseiuli infecting Phytoseiulus persimilis Athias-Henriot, the microsporidium Microsporidium phytoseiuli infecting P. persimilis and the microsporidium Oligosproridium occidentalis infecting M. occidentalis. In four cases (Wolbachia, A. phytoseiuli, M. phytoseiuli and O. occidentalis) an infection may be connected with fitness costs of the host. Moreover, infection is not always readily visible as no obvious gross symptoms are present. Monitoring of these entities on a routine and continuous basis should therefore get more attention, especially in commercial mass-production. Special attention should be paid to field-collected mites before introduction into the laboratory or mass rearing, and to mites that are exchanged among rearing facilities. However, at present general pathogen monitoring is not yet practical as effects of many entities are unknown. More research effort is needed concerning verified and potential pathogens of commercially reared arthropods and those used as model organisms in research

Human adipose stem cells cell sheet constructs impact epidermal morphogenesis in full-thickness excisional wounds

Among the wide range of strategies to target skin repair/regeneration, tissue engineering (TE) with stem cells at the forefront, remains as the most promising route. Cell sheet (CS) engineering is herein proposed, taking advantage of particular cell-cell and cell-extracellular matrix (ECM) interactions and subsequent cellular milieu, to create 3D TE constructs to promote full-thickness skin wound regeneration. Human adipose derived stem cells (hASCs) CS were obtained within five days using both thermoresponsive and standard cell culture surfaces. hASCs-based constructs were then built by superimposing three CS and transplanted into full-thickness excisional mice skin wounds with delayed healing. Constructs obtained using thermoresponsive surfaces were more stable than the ones from standard cell culture surfaces due to the natural adhesive character of the respective CS. Both CS-generating strategies lead to prolonged hASCs engraftment, although no transdifferentiation phenomena were observed. Moreover, our findings suggest that the transplanted hASCs might be promoting neotissue vascularization and extensively influencing epidermal morphogenesis, mainly through paracrine actions with the resident cells. The thicker epidermis, with a higher degree of maturation characterized by the presence of rete ridges-like structures, as well as a significant number of hair follicles observed after transplantation of the constructs combining the CS obtained from the thermoresponsive surfaces, reinforced the assumptions of the influence of the transplanted hASCs and the importance of the higher stability of these constructs promoted by cohesive cell-cell and cell-ECM interactions. Overall, this study confirmed the potential of hASCs CS-based constructs to treat full-thickness excisional skin wounds and that their fabrication conditions impact different aspects of skin regeneration, such as neovascularisation, but mainly epidermal morphogenesis.We would like to thank Hospital da Prelada (Porto), in particular, to Dr. Paulo Costa for the lipoaspirates collection and for financial support by Skingineering (PTDC/SAU-OSM/099422/2008), Portuguese Foundation for Science and Technology (FCT) funded project. The research leading to these results has also received funding from the European Union's Seventh Framework Programme (FP7/2007-2013) under Grant Agreement No. REGPOT-CT2012-316331-POLARIS

Wound myiasis caused by Lucilia sericata in an open femoral fracture treated with external fixation

Η μυΐαση είναι η τέταρτη πιο κοινή δερματική ασθένεια στον άνθρωπο που σχετίζεται με ταξίδια ενώ η δερματική μυΐαση είναι η συνηθέστερη κλινική μορφή. Αναφέρεται σε μη-ιατρογενή μόλυνση των ιστών από προνύμφες διπτέρων εντόμων και εμφανίζεται κυρίως σε ασθενείς που έχουν κακή υγιεινή, με συνθήκες κακής στέγασης, διανοητική καθυστέρηση, προχωρημένη ηλικία, διαβήτη, ακινητοποίηση και χαμηλό ανοσοποιητικό σύστημα. Ασθενής 14 ετών, ο οποίος είχε υποβληθεί πριν 6 μήνες σε εξωτερική οστεοσύνθεση μηριαίου λόγω κατάγματος διάφυσης μηριαίου, προσήλθε στα επείγοντα ιατρεία με άλγος στην περιοχή των βελονών. Κατά την εξέταση του τραύματος διαπιστώθηκε ερυθρότητα, οίδημα αλλά και η παρουσία ζωντανών προνυμφών διπτέρων εντόμων. Αφού ελέγχθηκε ακτινολογικά το κάταγμα της διάφυσης αφαιρέθηκε σε πρώτο χρόνο το σώμα της εξωτερικής οστεοσύνθεσης και έγινε σχολαστικότατος καθαρισμός. Με κατάλληλα χειρουργικά εργαλεία, απομονώθηκαν όλες οι προνύμφες από το τραύμα και τοποθετήθηκαν σε κατάλληλο υπόστρωμα για περαιτέρω εξέταση και προσδιορισμό του είδους. Έπειτα από μικροσκοπική εξέταση των προνυμφών και με βάση κατάλληλες μορφολογικές κλείδες προσδιορίστηκαν ως προνύμφες 3ης ηλικίας του είδους Lucilia sericata (Meigen) (Diptera: Calliphoridae). Έπειτα από 7 ημέρες αντιβιοτικής αγωγής ευρέως φάσματος, κλινοστατισμού, σχολαστικής περιποίησης των τραυμάτων και αφού είχαμε σαφή βελτίωση της περιοχής γύρω από τις βελόνες έγινε αφαίρεση αυτών. Κατά τις επανεξετάσεις έως και 6 μήνες μετά, τόσο κλινικά όσο και ακτινολογικά τα αποτελέσματα ήταν πολύ καλά.On examination of the wound of a patient who was treated previously with external fixation for a diaphysial fracture of the femur, we observed the presence of multiple living larvae (maggots) of dipterous flies. Treatment included removal of the maggots and use of antibiotic. The importance of hygiene and sanitation is discussed

Wound myiasis caused by Lucilia sericata in an open femoral fracture treated with external fixation

Η μυΐαση είναι η τέταρτη πιο κοινή δερματική ασθένεια στον άνθρωπο που σχετίζεται με ταξίδια ενώ η δερματική μυΐαση είναι η συνηθέστερη κλινική μορφή. Αναφέρεται σε μη-ιατρογενή μόλυνση των ιστών από προνύμφες διπτέρων εντόμων και εμφανίζεται κυρίως σε ασθενείς που έχουν κακή υγιεινή, με συνθήκες κακής στέγασης, διανοητική καθυστέρηση, προχωρημένη ηλικία, διαβήτη, ακινητοποίηση και χαμηλό ανοσοποιητικό σύστημα. Ασθενής 14 ετών, ο οποίος είχε υποβληθεί πριν 6 μήνες σε εξωτερική οστεοσύνθεση μηριαίου λόγω κατάγματος διάφυσης μηριαίου, προσήλθε στα επείγοντα ιατρεία με άλγος στην περιοχή των βελονών. Κατά την εξέταση του τραύματος διαπιστώθηκε ερυθρότητα, οίδημα αλλά και η παρουσία ζωντανών προνυμφών διπτέρων εντόμων. Αφού ελέγχθηκε ακτινολογικά το κάταγμα της διάφυσης αφαιρέθηκε σε πρώτο χρόνο το σώμα της εξωτερικής οστεοσύνθεσης και έγινε σχολαστικότατος καθαρισμός. Με κατάλληλα χειρουργικά εργαλεία, απομονώθηκαν όλες οι προνύμφες από το τραύμα και τοποθετήθηκαν σε κατάλληλο υπόστρωμα για περαιτέρω εξέταση και προσδιορισμό του είδους. Έπειτα από μικροσκοπική εξέταση των προνυμφών και με βάση κατάλληλες μορφολογικές κλείδες προσδιορίστηκαν ως προνύμφες 3ης ηλικίας του είδους Lucilia sericata (Meigen) (Diptera: Calliphoridae). Έπειτα από 7 ημέρες αντιβιοτικής αγωγής ευρέως φάσματος, κλινοστατισμού, σχολαστικής περιποίησης των τραυμάτων και αφού είχαμε σαφή βελτίωση της περιοχής γύρω από τις βελόνες έγινε αφαίρεση αυτών. Κατά τις επανεξετάσεις έως και 6 μήνες μετά, τόσο κλινικά όσο και ακτινολογικά τα αποτελέσματα ήταν πολύ καλά.On examination of the wound of a patient who was treated previously with external fixation for a diaphysial fracture of the femur, we observed the presence of multiple living larvae (maggots) of dipterous flies. Treatment included removal of the maggots and use of antibiotic. The importance of hygiene and sanitation is discussed

British container breeding mosquitoes: the impact of urbanisation and climate change on community composition and phenology

The proliferation of artificial container habitats in urban areas has benefitted urban adaptable mosquito species globally. In areas where mosquitoes transmit viruses and parasites, it can promote vector population productivity and fuel mosquito-borne disease outbreaks. In Britain, storage of water in garden water butts is increasing, potentially expanding mosquito larval habitats and influencing population dynamics and mosquito-human contact. Here we show that the community composition, abundance and phenology of mosquitoes breeding in experimental water butt containers were influenced by urbanisation. Mosquitoes in urban containers were less species-rich but present in significantly higher densities (100.4±21.3) per container than those in rural containers (77.7±15.1). Urban containers were dominated by Culex pipiens (a potential vector of West Nile Virus [WNV]) and appear to be increasingly exploited by Anopheles plumbeus (a human-biting potential WNV and malaria vector). Culex phenology was influenced by urban land use type, with peaks in larval abundances occurring earlier in urban than rural containers. Among other factors, this was associated with an urban heat island effect which raised urban air and water temperatures by 0.9°C and 1.2°C respectively. Further increases in domestic water storage, particularly in urban areas, in combination with climate changes will likely alter mosquito population dynamics in the UK

Global snow mass measurements and the effect of stratigraphic detail on inversion of microwave brightness temperatures

Snow provides large seasonal storage of freshwater, and information about the distribution of snow mass as Snow Water Equivalent (SWE) is important for hydrological planning and detecting climate change impacts. Large regional disagreements remain between estimates from reanalyses, remote sensing and modelling. Assimilating passive microwave information improves SWE estimates in many regions but the assimilation must account for how microwave scattering depends on snow stratigraphy. Physical snow models can estimate snow stratigraphy, but users must consider the computational expense of model complexity versus acceptable errors. Using data from the National Aeronautics and Space Administration Cold Land Processes Experiment (NASA CLPX) and the Helsinki University of Technology (HUT) microwave emission model of layered snowpacks, it is shown that simulations of the brightness temperature difference between 19 GHz and 37 GHz vertically polarised microwaves are consistent with Advanced Microwave Scanning Radiometer-Earth Observing System (AMSR-E) and Special Sensor Microwave Imager (SSM/I) retrievals once known stratigraphic information is used. Simulated brightness temperature differences for an individual snow profile depend on the provided stratigraphic detail. Relative to a profile defined at the 10 cm resolution of density and temperature measurements, the error introduced by simplification to a single layer of average properties increases approximately linearly with snow mass. If this brightness temperature error is converted into SWE using a traditional retrieval method then it is equivalent to ±13 mm SWE (7% of total) at a depth of 100 cm. This error is reduced to ±5.6 mm SWE (3 % of total) for a two-layer model