Causal sites as quantum geometry

We propose a structure called a causal site to use as a setting for quantum geometry, replacing the underlying point set. The structure has an interesting categorical form, and a natural "tangent 2-bundle," analogous to the tangent bundle of a smooth manifold. Examples with reasonable finiteness conditions have an intrinsic geometry, which can approximate classical solutions to general relativity. We propose an approach to quantization of causal sites as well.Comment: 21 pages, 3 eps figures; v2: added references; to appear in JM

The health status of Irish honeybee colonies in 2006

peer-reviewedThis study assessed the health status of Irish honeybee colonies and provides a snapshot of the incidence of a number of important colony parasites/pathogens including: the mite Varroa destructor; three associated viruses (deformed wing virus (DWV), acute bee paralysis virus (ABPV) and Kashmir virus (KBV)); the tracheal mite Acarapis woodi; the microsporidian Nosema spp., and the insect Braula coeca. During June/July 2006, 135 samples of adult bees were collected from productive colonies throughout Ireland and standard techniques were used to determine the presence and absence of the parasites and pathogens. Varroa destructor was positively identified in 72.6% of the samples and was widely distributed. Although the samples were analysed for three viruses, DWV, ABPV and KBV, only DWV was detected (frequency = 12.5%). Acarapis woodi and Nosema spp. occurred in approximately 11% and 22% of the samples, respectively, while B. coeca, a wingless dipteran that was once common in Irish honeybee colonies, was very rare (3.7%). Samples where all the pathogens/parasites were jointly absent were statistically under-represented in Leinster and DWV was statistically over-represented in Munster. In Ulster, there was over-representation of the categories where all parasites/pathogens were jointly absent and for A. woodi, and underrepresentation of V. destructor.The project was funded by EU FEOGA and the National Apiculture Programme 2007–2010 of the Department of Agriculture, Food and the Marine

Direct observation of the picosecond dynamics of I_2-Ar fragmentation

Picosecond real‐time observations of the dynamics of I_2–Ar fragmentation are reported. The state‐to‐state rates, k(ν^i,,ν^f,), are directly measured and related to the homogeneous broadening of the initial state, and to product state distributions in the exit channel. Comparisons with different theories of vibrational (and electronic) predissociation are made

12.2-GHz methanol maser MMB follow-up catalogue - II. Longitude range 186 to 330 degrees

We present the second portion of a catalogue of 12.2-GHz methanol masers detected towards 6.7-GHz methanol masers observed in the unbiased Methanol Multibeam (MMB) Survey. Using the Parkes radio telescope we have targeted all 207 6.7-GHz methanol masers in the longitude range 186 to 330 degrees for 12.2-GHz counterparts. We report the detection of 83 12.2-GHz methanol masers, and one additional source which we suspect is thermal emission, equating to a detection rate of 40 per cent. Of the 83 maser detections, 39 are reported here for the first time. We discuss source properties, including variability and highlight a number of unusual sources. We present a list of 45 candidates that are likely to harbor methanol masers in the 107.0-GHz transition.Comment: Accepted MNRAS 19 July 201

Repetition enhances the musicality of speech and tone stimuli to similar degrees

Certain spoken phrases, when removed from context and repeated, begin to sound as if they were sung. Prior work has uncover ed several acoustic factors which determine wh ether a phrase sounds sung after repetition . However, the reason why repetition is necessary for song to be perceived in speech is unclear . One possibility is that by default pitch is not a salient attribute of speech in non - tonal languages, as spectral information is more vital for determining meaning. However, repetition may satiate lexical processing , increas ing pitch salience. A second possibility is that it takes time to e stablish the precise pitch perception necessary for as signing each syllable a musical scale degree . Here we tested these hypotheses by asking participants to rate the musicality of spoken phrases and complex tones with matching pitch contours after each of eight repetitions. Although musicality ratings were overall higher for the tone stimuli, both the speech and complex tone stimuli increased in musicality to a similar degree with repetition. Thus, although the rapid spectral variation of speech may inhibi t pitch salience , this inhibition does not decrease with repetition. Instead, repetition may be necessary for the perception of song in speech because the perception of exact pitch intervals takes time

37 GHz methanol masers : Horsemen of the Apocalypse for the class II methanol maser phase?

We report the results of a search for class II methanol masers at 37.7, 38.3 and 38.5 GHz towards a sample of 70 high-mass star formation regions. We primarily searched towards regions known to show emission either from the 107 GHz class II methanol maser transition, or from the 6.035 GHz excited OH transition. We detected maser emission from 13 sources in the 37.7 GHz transition, eight of these being new detections. We detected maser emission from three sources in the 38 GHz transitions, one of which is a new detection. We find that 37.7 GHz methanol masers are only associated with the most luminous 6.7 and 12.2 GHz methanol maser sources, which in turn are hypothesised to be the oldest class II methanol sources. We suggest that the 37.7 GHz methanol masers are associated with a brief evolutionary phase (of 1000-4000 years) prior to the cessation of class II methanol maser activity in the associated high-mass star formation region.Comment: 14 pages, 4 figures, accepted for publication in Ap