Revision of the Megaselia giraudii and M. densior species complexes of Europe, including ecological notes (Diptera, Phoridae).

Die Megaselia giraudii/densior-Artengruppe umfaßt 21 beschriebene Arten in Europa. Acht Arten werden neu beschrieben: M. citrinella Buck sp. n., M. glabrimargo Buck sp. n., M. hexanophila Buck sp. n., M. immodensior Disney sp. n. (= M. densior auctt., nec Schmitz), M. labellaspinata Disney sp. n. (= M. septentrionalis auctt., nec Schmitz), M. mimodensior Buck sp. n., M. raruvesiculae Disney sp. n. und M. xanthophila Buck sp. n. Megaselia phoenicura (Schmitz), M. badia Schmitz und M. hayleyensis Disney (alle allein von Männchen beschrieben) werden synonymisiert mit M. quadriseta (Schmitz) (bisher nur bekannt im weiblichen Geschlecht). Viele Individuen, die früher für M. badia gehalten wurden, gehören tatsächlich zu M. densior Schmitz, und M. coulsoni Disney wird mit letzterer synonymisiert. Lectotypen werden festgelegt für M. albicans (Wood), M. densior, M. offuscata Schmitz, M. phoenicura und M. quadriseta, sowie ein Neotyp für M. comosa (Schmitz). Die Männchen von M. rubricornis (Schmitz) und Weibchen von M. correlata (Schmitz), M. haraldlundi Disney und M. parnassia Disney werden erstmals beschrieben. Das mutmaßliche Männchen von M. sanguinea (Schmitz) und wahrscheinliche Weibchen von M. albicans werden ebenfalls zum ersten Mal beschrieben. Die Identität anderer Arten wird aufgeklärt inklusive vier Arten, die nicht zum giraudii/ densior-Komplex gehören (M. nigrescens (Wood), M. opacicornis Schmitz, M. rubida (Schmitz) und M. ustulata (Schmitz)). Ein revidierter Bestimmungsschlüssel für Männchen und ein neuer Schlüssel für Weibchen werden vorgestellt. Dabei wird neuen taxonomischen Merkmalen wie den subkutikularen Sensillen innerhalb des dritten Fühlersegments sowie der Morphologie des weiblichen Ovipositors bzw. Vaginalsklerite besondere Beachtung geschenkt. Für die meisten Arten werden außerdem Informationen zur Biologie mitgeliefert (Brutsubstrate der Larven, Köder-, Farb- und Biotoppräferenzen der Imagines).StichwörterDiptera, Phoridae, Megaselia, taxonomy, rearing, saprophages, bait trap, Europe.Nomenklatorische Handlungencomosa Santos Abréu, 1921 (Aphiochaeta), Neotype; syn. n. of Megaselia giraudii (Egger, 1862)phoenicura Schmitz, 1926 (Aphiochaeta), Lectotype; syn. n. of Megaselia quadriseta (Schmitz, 1918)albicans Wood, 1908 (Megaselia), Lectotype described as Phora albicansbadia Schmitz, 1938 (Megaselia), syn. n. of Megaselia quadriseta (Schmitz, 1918)bayleyensis Disney, 1987 (Megaselia), syn. n. of Megaselia quadriseta (Schmitz, 1918)citrinella Buck, 2001 (Megaselia), spec. n.coulsoni Disney, 1987 (Megaselia), syn. n. of Megaselia densior Schmitz, 1927densior Schmitz, 1926 (Megaselia), Lectotypeglabrimargo Buck, 2001 (Megaselia), spec. n.hexanophila Buck, 2001 (Megaselia), spec. n.immodensior Disney, 2001 (Megaselia), spec. n.labellaspinata Disney, 2001 (Megaselia), spec. n.mimodensior Buck, 2001 (Megaselia), spec. n.offuscata (Schmitz, 1921) (Megaselia), Lectotype described as Phiochaeta offuscataquadriseta (Schmitz, 1918) (Megaselia), Lectotype described as Aphiochaeta lutea var. quadrisetararuvesiculae Disney, 2001 (Megaselia), spec. n.xanthophila Buck, 2001 (Megaselia), spec. n.rata Collin in Wood, 1908 (Phora), Lectotype now a synonym of Megaselia giraudii (Egger, 1862)The Megaselia giraudii and M. densior species groups are revised to include a total of twenty-one described European species. Eight species are new to science: M. citrinella Buck sp. n., M. glabrimargo Buck sp. n., M. hexanophila Buck sp. n., M. immodensior Disney sp. n. (= M. densior auctt., nec Schmitz), M. labellaspinata Disney sp. n. (= M. septentrionalis auctt., nec Schmitz), M. mimodensior Buck sp. n., M. raruvesiculae Disney sp. n., and M. xanthophila Buck sp. n.. Megaselia phoenicura (Schmitz), M. badia Schmitz and M. hayleyensis Disney (all described from males only) are synonymised with M. quadriseta (Schmitz) (previously only known in the female sex). Many specimens previously assigned to M. badia are recognised as being M. densior Schmitz, and M. coulsoni Disney is synonymised with this species. Lectotypes are designated for M. albicans (Wood), M. densior, M. offuscata Schmitz, M. phoenicura and M. quadriseta, and a neotype is designated for M. comosa (Schmitz). The males of M. rubricornis (Schmitz) and females of M. correlata (Schmitz), M. haraldlundi Disney and M. parnassia Disney are described for the first time. The putative male of M. sanguinea (Schmitz) and the putative female of M. albicans are also described for the first time. The recognition of other species is clarified including four species that do not belong to the giraudii/densior complex (M. nigrescens (Wood), M. opacicornis Schmitz, M. rubida (Schmitz), and M. ustulata (Schmitz)). A revised key to males and a new key to females is provided, utilising the novel taxonomic character of the subcuticular sensilla inside the third antennal segment, and giving special attention to the morphology of the female ovipositor and vaginal sclerite. Biological data (breeding substrates of larvae, bait, colour and habitat preference of adults) are reported for most species.KeywordsDiptera, Phoridae, Megaselia, taxonomy, rearing, saprophages, bait trap, Europe.Nomenclatural Actscomosa Santos Abréu, 1921 (Aphiochaeta), Neotype; syn. n. of Megaselia giraudii (Egger, 1862)phoenicura Schmitz, 1926 (Aphiochaeta), Lectotype; syn. n. of Megaselia quadriseta (Schmitz, 1918)albicans Wood, 1908 (Megaselia), Lectotype described as Phora albicansbadia Schmitz, 1938 (Megaselia), syn. n. of Megaselia quadriseta (Schmitz, 1918)bayleyensis Disney, 1987 (Megaselia), syn. n. of Megaselia quadriseta (Schmitz, 1918)citrinella Buck, 2001 (Megaselia), spec. n.coulsoni Disney, 1987 (Megaselia), syn. n. of Megaselia densior Schmitz, 1927densior Schmitz, 1926 (Megaselia), Lectotypeglabrimargo Buck, 2001 (Megaselia), spec. n.hexanophila Buck, 2001 (Megaselia), spec. n.immodensior Disney, 2001 (Megaselia), spec. n.labellaspinata Disney, 2001 (Megaselia), spec. n.mimodensior Buck, 2001 (Megaselia), spec. n.offuscata (Schmitz, 1921) (Megaselia), Lectotype described as Phiochaeta offuscataquadriseta (Schmitz, 1918) (Megaselia), Lectotype described as Aphiochaeta lutea var. quadrisetararuvesiculae Disney, 2001 (Megaselia), spec. n.xanthophila Buck, 2001 (Megaselia), spec. n.rata Collin in Wood, 1908 (Phora), Lectotype now a synonym of Megaselia giraudii (Egger, 1862

Remaining Fatigue Lifetime Prediction for Retirement-for-Cause in Metals

A methodology is evaluated to predict the probability of specimen failure with subsequent fatigue, after a short surface crack has been detected in Al 2219-T851 alloy. Cracks are detected and tracked to failure using optical microscopy. Predictions of remaining lifetime distributions are made with a Monte Carlo procedure in conjunction with growth laws which model the effect of grains of differing size, shape and crystallographic orientation in the crack path on propagation rate. Because the surface of the alloy cyclically hardens, the average rate of crack growth is less for cracks formed later during fatigue. The predictive methodology successfully describes this phenomenon, as well as predicts the probability of early failure arising from the statistical nature of the growth process, for failure probabilities substantially smaller than conveniently measureable in the laboratory

Crack Depth Measurements with the Aid of SAW NDE

This report presents results of measurements of crack depth with the aid of acoustic bulk and surface waves. Both simulated and real fatigue cracks were examined. Two techniques were employed, one took advantage of the very efficient mode conversion between acoustic surface waves and shear waves at the crack tip; the other technique used the diffraction of shear waves at the crack tip. Both techniques were used on a number of simulated {spark eroded) and real cracks in Al 2024. In one fatigue specimen which contained an elliptical crack 4.5 mm in length and 1.25 mm in depth, crack closure studies were carried out. The precision of crack depth determination was judged to be better than 10%

Surface Wave Techniques for Predicting the Remaining Life of Fatigue Damaged Metals

In our continuing efforts to investigate methods to characterize the state of fatigue nondestructively and to apply these observations to lifetime predictions, we have initiated acoustic surface wave studies using Al 2024-T351. A smooth bar specimen was designed which can be tested in tension-compression fatigue. Acoustic wedge transducers were mounted on the specimen to sample fatigue induced changes within the gauge section. Data on acoustic harmonic generation were taken as a function of applied external load at any point of the sample\u27s fatigue life. An optical microscope was attached to the load frame to monitor microcrack formation in the gauge section. Significant changes of the second harmonic have been observed as a function of stress and fatigue. First results indicate a decrease of the second harmonic as a function of stress. At about 50% of the fatigue life microcracks initiated at surface intermetallics and a substantial increase of the second harmonic amplitude in the vicinity of zero external applied load was observed

Gene Expression and the Diversity of Identified Neurons

Nervous systems consist of diverse populations of neurons that are anatomically and functionally distinct. The diversity of neurons and the precision with which they are interconnected suggest that specific genes or sets of genes are activated in some neurons but not expressed in others. Experimentally, this problem may be considered at two levels. First, what is the total number of genes expressed in the brain, and how are they distributed among the different populations of neurons? Second, can we identify specific genes expressed in individual neurons and relate the expression of these genes to the unique functional properties of these neurons

Characterization of Knots and Links Arising From Site-specific Recombination on Twist Knots

We develop a model characterizing all possible knots and links arising from recombination starting with a twist knot substrate, extending previous work of Buck and Flapan. We show that all knot or link products fall into three well-understood families of knots and links, and prove that given a positive integer $n$, the number of product knots and links with minimal crossing number equal to $n$ grows proportionally to $n^5$. In the (common) case of twist knot substrates whose products have minimal crossing number one more than the substrate, we prove that the types of products are tightly prescribed. Finally, we give two simple examples to illustrate how this model can help determine previously uncharacterized experimental data.Comment: 32 pages, 7 tables, 27 figures, revised: figures re-arranged, and minor corrections. To appear in Journal of Physics

The S0_0(0) structure in highly compressed hydrogen and the orientational transition

A calculation of the rotational S$_0$(0) frequencies in high pressure solid para-hydrogen is performed. Convergence of the perturbative series at high density is demonstrated by the calculation of second and third order terms. The results of the theory are compared with the available experimental data to derive the density behaviour of structural parameters. In particular, a strong increase of the value of the lattice constant ratio $c/a$ and of the internuclear distance is determined. Also a decrease of the anisotropic intermolecular potential is observed which is attributed to charge transfer effects. The structural parameters determined at the phase transition may be used to calculate quantum properties of the rotationally ordered phase.Comment: accepted Europhysics Letter

Isomorphic classical molecular dynamics model for an excess electron in a supercritical fluid

Ring polymer molecular dynamics (RPMD) is used to directly simulate the dynamics of an excess electron in a supercritical fluid over a broad range of densities. The accuracy of the RPMD model is tested against numerically exact path integral statistics through the use of analytical continuation techniques. At low fluid densities, the RPMD model substantially underestimates the contribution of delocalized states to the dynamics of the excess electron. However, with increasing solvent density, the RPMD model improves, nearly satisfying analytical continuation constraints at densities approaching those of typical liquids. In the high density regime, quantum dispersion substantially decreases the self-diffusion of the solvated electron. In this regime where the dynamics of the electron is strongly coupled to the dynamics of the atoms in the fluid, trajectories that can reveal diffusive motion of the electron are long in comparison to $\beta\hbar$.Comment: 24 pages, 4 figure

Clarification of the relationship between bound and scattering states in quantum mechanics: Application to 12C + alpha

Using phase-equivalent supersymmetric partner potentials, a general result from the inverse problem in quantum scattering theory is illustrated, i.e., that bound-state properties cannot be extracted from the phase shifts of a single partial wave, as a matter of principle. In particular, recent R-matrix analyses of the 12C + alpha system, extracting the asymptotic normalization constant of the 2+ subthreshold state, C12, from the l=2 elastic-scattering phase shifts and bound-state energy, are shown to be unreliable. In contrast, this important constant in nuclear astrophysics can be deduced from the simultaneous analysis of the l=0, 2, 4, 6 partial waves in a simplified potential model. A new supersymmetric inversion potential and existing models give C12=144500+-8500 fm-1/2.Comment: Expanded version (50% larger); three errors corrected (conversion of published reduced widths to ANCs); nine references added, one remove