Ensemble prediction of a severe weather event: a study of the 2009 Southern Ontario storm

The tornadic storm of August 20, 2009 of Southern Ontario is studied using a numerical prediction model. It is found that a 3km resolution simulation works as well as a 1km resolution model to model the storms underlying physical processes relevant to supercell mesocyclone formation and storm propagation, although both models showed a significant phase bias in the storm system's squall line position. A 3m resolution ensemble of 20 members is used to model the storm system further, and it is found that the ensemble mean shows the same bias that the 1km and 3km resolution models exhibited. Investigation of ensemble perturbation growth rates from ensemble mean values reveals differing growth rates for baroclinic and convective modes. Ensemble-based sensitivity analyses reveal that there are strong correlations of squall line position with model variables up to 12 hours previously

The ecology of the Chironomidae in a Phragmites reedbed at Cop Mere (Staffordshire, England)

The Chironomidae occupying a Phragmites reedbed at Cop Mere, Staffordshire were studied during 1981 and 1982. In 1981, reedstem-dwelling larvae were sampled at monthly intervals from three zones running parallel with the reedbed/open-water interface, lying at the front (lakeward edge) (Zone 1), middle (Zone 2) and back (landward edge) (Zone 3) of the aquatic part of the reedbed. The highest monthly chironomid larval density and biomass usually existed in Zone 1 and the lowest in Zone 3. Significant interzonal density and biomass variation occurred at various times of the year; such variation was consistently manifest between Zones 1 and 3, except in density during April. Seventeen chironomid taxa were identified on reedstems, Glyptotendipes pallens and Camptochironomus tentans being the most abundant of the nine Chironominae taxa found; eight Orthocladiinae taxa were represented, Cricotopus sylvestris accounting for over 95% of all reedstem-dwelling chironomid larvae. For each taxon, ecologically significant interzonal abundance differences were often found. These were largely attributed to interzonal variation in epiphytic shelter. In some species (e. g. Cconptochironomus tentans, Cricotopus syZvestris and Parachironomus arcuatus), higher densities towards open water may have reflected a positive phototactic response in early instars. The benthic-dwelling larval community showed interzonal variation: the predominant species, Camptochironomus tentans, was most abundant towards the reedbed front, whereas Glyptotendipes pallens favoured the area around Zone 3. Interzonal substrate variation may have been the biggest influence on species distribution. The semi-aquatic reedbed area supported a distinctive larval community; Tanytarsus, Metriocnemus sp. A and Pentaneurini sp. A predominated. Adult chironomid population data derived from emergence trap catches was used principally to supplement and corroborate information relating to larval populations. Temporal chironomid density patterns appeared to be determined primarily by intrinsic species characteristics, especially those which govern seasonal patterns of egg-laying

La cooperación internacional en la crisis de los refugiados norcoreanos

El mayor reto en lo que concierne a los refugiados norcoreanos es que, por el momento, no existe un marco internacional que marque las pautas sobre cómo responder una vez que estas personas cruzan la frontera

Corporate religiosity and individual decision on conducting entrepreneurial activity : The contingent effects of institutional environments in China

Feng Zhang acknowledges the financial support from the Research Project of Ministry of Education of China (Grant No. 18JJD630003) and the Fundamental Research Funds for the Central Universities (Grant No. 63185009 and 63,185,011), and Haina Zhang acknowledges the financial support from Skills Acquisition Award received from the British Academy (award reference: SQ140008). Open Access via Springer Compact Agreement.Peer reviewedPublisher PD

Assessing the marginal dollar value losses to an estuarine ecosystem from an aggressive alien invasive crab

This paper reports on a case study to establish dollar values for loss of biodiversity in the New Zealand coastal marine environment. The study uses the European Shore Crab (Carcinas maenas) as the example alien invasive species and the Pauatahanui Inlet, Wellington, New Zealand, as the ecosystem representative of the coastal marine environment. Choice modelling is the stated preference tool used to elicit marginal dollar values for these various attributes of the inlet. Reallocation of existing government expenditure is used as the payment mechanism. Results indicate a wide range of dollar values for the marginal losses to the environment, with no clear trend on a distance-decay relationship. The probability distributions of the dollar values of the environmental attributes tended to have a concentration around the median with very wide tails, especially on the high side. This indicates that most people generally agreed on a dollar value, but a very few individuals expressed extremely high values. The study concludes that the dollar values for loss of biodiversity and other environmental attributes do provide useful information to decision makers, but considerable caution needs to be exercised when applying these values in benefit cost studies. Marginal rate of substitution estimates between environmental attributes will be useful for estimating money values for attributes identified given future work estimates a statistically significant money value for one

Exploring the Case for Expanded Remote Texter Liability for Employers

In 2013, the New Jersey Appellate Court decided the potentially landmark case of Kubert v. Best, recognizing for the first time that a sender of a text may be held liable to an innocent third party injured in an automobile accident caused by a driver who was distracted by receiving the text. Other subsequent cases have both confirmed and limited the Kubert ruling. In this article, we explore possible further extensions of the Kubert ruling, anticipating that because of expanding employer liability for acts undertaken by their employees, the next step in the evolution of texting and driving law may likely hold employers liable for accidents caused by their employees whose employment-related texts to others result in accident and harm

Establishing Pine Monocultures and Mixed Pine-Hardwood Stands on Reclaimed Surface Mined Land in Eastern Kentucky: Implications for Forest Resilience in a Changing Climate

Surface mining and mine reclamation practices have caused significant forest loss and forest fragmentation in Appalachia. Shortleaf pine (Pinus echinata) is threatened by a variety of stresses, including diseases, pests, poor management, altered fire regimes, and climate change, and the species is the subject of a widescale restoration effort. Surface mines may present opportunity for shortleaf pine restoration; however, the survival and growth of shortleaf pine on these harsh sites has not been critically evaluated. This paper presents first-year survival and growth of native shortleaf pine planted on a reclaimed surface mine, compared to non-native loblolly pine (Pinus taeda), which has been highly successful in previous mined land reclamation plantings. Pine monoculture plots are also compared to pine-hardwood polyculture plots to evaluate effects of planting mix on tree growth and survival, as well as soil health. Initial survival of shortleaf pine is low (42%), but height growth is similar to that of loblolly pine. No differences in survival or growth were observed between monoculture and polyculture treatments. Additional surveys in coming years will address longer-term growth and survival patterns of these species, as well as changes to relevant soil health endpoints, such as soil carbon

On the mathematical Structure of Quantum Measurement Theory

We show that the key problems of quantum measurement theory, namely the reduction of the wave packet of a microsystem and the specification of its quantum state by a macroscopic measuring instrument, may be rigorously resolved within the traditional framework of the quantum mechanics of finite conservative systems. The argument is centred on the generic model of a microsystem, S, coupled to a finite macroscopic measuring instrument, I, which itself is an N-particle quantum system. The pointer positions of I correspond to the macrostates of this instrument, as represented by orthogonal subspaces of the Hilbert space of its pure states. These subspaces, or 'phase cells', are the simultaneous eigenspaces of a set of coarse grained intercommuting macroscopic observables, M, and, crucially, are of astronomically large dimensionalities, which incease exponentially with N. We formulate conditions on the conservative dynamics of the composite (S+I) under which it yields both a reduction of the wave packet describing the state of S and a one-to-one correspondence, following a measurement, between the pointer position of I and the resultant state of S; and we show that these conditions are fulfilled by the finite version of the Coleman-Hepp model.Comment: 20 pages, minor correstions installed, to appear in Rep. Math. Phy

The JCMT Transient Survey: An Extraordinary Submillimetre Flare in the T Tauri Binary System JW 566

The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of $L_{\nu}=8\times10^{19}$ erg/s/Hz, approximately one order of magnitude brighter (in terms of $\nu L_{\nu}$) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of $\alpha = 0.11$ is broadly consistent with non-thermal emission. The brightness temperature was in excess of $6\times10^{4}$ K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Comment: Accepted in ApJ. 16 pages (single column), 6 figure

The JCMT Transient Survey: An Extraordinary Submillimeter Flare in the T Tauri Binary System JW 566

© 2019 The American Astronomical Society. All rights reserved.The binary T Tauri system JW 566 in the Orion Molecular Cloud underwent an energetic, short-lived flare observed at submillimetre wavelengths by the SCUBA-2 instrument on 26 November 2016 (UT). The emission faded by nearly 50% during the 31 minute integration. The simultaneous source fluxes averaged over the observation are 500 +/- 107 mJy/beam at 450 microns and 466 +/- 47 mJy/beam at 850 microns. The 850 micron flux corresponds to a radio luminosity of $L_{\nu}=8\times10^{19}$ erg/s/Hz, approximately one order of magnitude brighter (in terms of $\nu L_{\nu}$) than that of a flare of the young star GMR-A, detected in Orion in 2003 at 3mm. The event may be the most luminous known flare associated with a young stellar object and is also the first coronal flare discovered at sub-mm wavelengths. The spectral index between 450 microns and 850 microns of $\alpha = 0.11$ is broadly consistent with non-thermal emission. The brightness temperature was in excess of $6\times10^{4}$ K. We interpret this event to be a magnetic reconnection that energised charged particles to emit gyrosynchrotron/synchrotron radiation.Peer reviewedFinal Published versio