Timed logic conformance and its application

Journal ArticleTimed Logic Conformance _x000B_TLC_x000C_ is a bisimulation-style partial order relationship defined over the statespace of Timed Safety Automata _x000B_TSA_x000C_ with real-valued clocks. In contrast to timed simulation. Calculus of Timed Refine- ment _x000B_CTR_x000C_, and Time-Abstracted bisimulation. TLC defines when one system is an acceptable implementation of another by asymmetric bisimulation-style requirements for specification inputs and implementation outputs. While TLC does not necessarily preserve timed properties, it intuitively and pragmatically supports writing abstract specifications and verifying them against implementations. TLC scales up by substituting verified specifications for implementations and hierarchically verifying larger systems. TLC verification is an alternative to assumes-guarantees reasoning process. TLC verification depends on explicitly capturing environmental timing properties in the specification and insuring they are satisfied in the TLC relation. The region-automata-based TLC System (_x000B_TLCS) implements TSA parallel composition and a TLC decision procedure which is used to hierarchically verify the STARI queue

Attracting Preservice Teachers to Remote Locations

Teaching in rural/remote regions poses many challenges to teachers and is identified as a priority research area by the state government. Despite initiatives by the state government and university providers to solve the issue through various incentives designed to attract teachers, the problem remains significant. This research describes and analyses the impact of a regional university initiative to attract teachers to rural and remote locations in Queensland. The data was gathered through analysis of responses from preservice teachers completing education degrees at a regional university in Queensland. The data revealed that a pre-graduation teaching placement to a rural/remote region resulted in positive attitudinal changes towards applying for such a placement upon graduation. The results are significant and suggest that universities have a major role to play in work force planning for graduate teachers

Calcium and magnesium absorption and retention by growing goats offered diets with different calcium sources

Calcium addition is necessary in order to balance the high phosphorus concentrations that are characteristic of high-concentrate ruminant diets. However, calcium sources differ in their bioavailability. Our objective was to determine apparent calcium and magnesium absorption and retention in goats offered diets containing different sources of calcium. Spanish-Boer goats (n = 18; 19.6 ± 1.88 kg) were stratified by body weight (BW) and sex and randomized to dietary treatments consisting of Purina Antlermax 16 containing either calcium carbonate (CC), Calmin (CM) or Milk Cal (MC). Goats were adapted to a control, corn-based high-concentrate diet on pasture and then moved to individual 1.0 × 1.5-m pens with plastic coated expanded metal floors, and adjusted to their respective diets along with removal of hay from the diet over a 7-d period. Goats were then offered their respective diets at a total of 2% of BW in equal feedings at 8:30 AM and 5:00 PM for an additional 14-d adaption period to diet and facilities followed by a 7-d collection of total urine and feces. Data were analyzed using PROC MIXED of SAS. Calcium and magnesium intake were not different (P ≥ 0.12) among diets. Calcium and magnesium apparent absorption and retention (g/d and % of intake) were greatest (P \u3c 0.05) in goats offered CC and did not differ (P ≥ 0.20) between goats offered the CM and MC diets. Therefore, calcium and magnesium were more available for goats from the diet containing calcium carbonate compared with diets containing Calmin and Milk Cal

Andean Land Use And Biodiversity: Humanized Landscapes In A Time Of Change

Some landscapes Cannot be understood without reference., to the kinds. degrees, kinds, degrees, and history of human-caused modifications to the Earth's surface. The tropical latitudes of the Andes represent one such place, with agricultural land-use systems appearing in the Early Holocene. Current land use includes both intensive and extensive grazing and crop- or tree-based agricultural systems found across virtually the, entire range of possible elevations and humidity regimes. Biodiversity found in or adjacent to such humanized landscapes will have been altered in abundance. composition, and distribution in relation to the resiliency of the native Species to harvest, hold cover modifications, and other deliberate or inadvertent human land uses. In addition, the geometries of land cover, resulting flout difference among the shapes, sizes, connectivities, and physical structures of the patches, corridors, and matrices that compose landscape mosaics, will constrain biodiversity, often in predictable ways. This article proposes a conceptual model that alter ins that the Continued persistence of native species may depend as much oil the shifting Of Andean landscape mosaics as on species characteristics, themselves. Furthermore, mountains such as the Andes display long gradients of environmental Conditions that after in relation to latitude, soil moisture, aspect, and elevation. Global environmental change will shift these, especially temperature and humidity regimes along elevational gradients, causing Changes outside the historical range of variation for some species. Both land-use systems and Conservation efforts will need to respond spatially to these shifts in the future, at both landscape and regional scales.Geography and the Environmen

Tissue Doppler imaging following paediatric cardiac surgery : early patterns of change and relationship to outcome

In this study, tissue Doppler imaging (TDI) was used to assess changes in ventricular function following repair of congenital heart defects. The relationship between TDI indices, myocardial injury and clinical outcome was explored. Forty-five children were studied; 35 withcardiac lesions and 10 controls. TDI was performed preoperatively, on admission to paediatric intensive care unit (PICU) and day 1. Regional myocardial Doppler signals were acquired from the right ventricle (RV), left ventricle (LV) and septum. TDI indices included: peak systolicvelocities, isovolumetric velocities (IVV) and isovolumetric acceleration (IVA). Preoperatively, bi-ventricular TDI velocities in the study groupwere reduced compared with normal controls. Postoperatively, RV velocities were significantly reduced and this persisted to day-1 (PreOp vs. PICU and day-1: 7.7+2.2 vs. 3.4+1.0, P < 0.0001 and 3.55+1.29, P < 0.0001). LV velocities initially declined but recovered towards baseline by day-1 (PreOp vs. PICU: 5.31+1.50 vs. 3.51+1.23, P < 0.0001). Isovolumetric parameters in all regions were reduced throughout the postoperative period. Troponin-I release correlated with longer X-clamp times (r=0.82, P < 0.0001) and reduced RV velocities (r=0.42, P=0.028). Reduced pre- and postoperative LV velocities correlated with longer ventilation (PreOp: r=0.54, P=0.002; PostOp: r=0.42, P=0.026). This study identified reduced postoperative RV velocities correlated with myocardial injury while reduced LV TDI correlated with longer postoperative ventilation

Calcium puffs are generic InsP₃-activated elementary calcium signals and are downregulated by prolonged hormonal stimulation to inhibit cellular calcium responses

Elementary Ca2+ signals, such as "Ca2+ puffs", which arise from the activation of inositol 1,4,5-trisphosphate receptors, are building blocks for local and global Ca2+ signalling. We characterized Ca2+ puffs in six cell types that expressed differing ratios of the three inositol 1,4,5-trisphosphate receptor isoforms. The amplitudes, spatial spreads and kinetics of the events were similar in each of the cell types. The resemblance of Ca2+ puffs in these cell types suggests that they are a generic elementary Ca2+ signal and, furthermore, that the different inositol 1,4,5-trisphosphate isoforms are functionally redundant at the level of subcellular Ca2+ signalling. Hormonal stimulation of SH-SY5Y neuroblastoma cells and HeLa cells for several hours downregulated inositol 1,4,5-trisphosphate expression and concomitantly altered the properties of the Ca2+ puffs. The amplitude and duration of Ca2+ puffs were substantially reduced. In addition, the number of Ca2+ puff sites active during the onset of a Ca2+ wave declined. The consequence of the changes in Ca2+ puff properties was that cells displayed a lower propensity to trigger regenerative Ca2+ waves. Therefore, Ca2+ puffs underlie inositol 1,4,5-trisphosphate signalling in diverse cell types and are focal points for regulation of cellular responses

Transient absorption and reshaping of ultrafast XUV light by laser-dressed helium

We present a theoretical study of transient absorption and reshaping of extreme ultraviolet (XUV) pulses by helium atoms dressed with a moderately strong infrared (IR) laser field. We formulate the atomic response using both the frequency-dependent absorption cross section and a time-frequency approach based on the time-dependent dipole induced by the light fields. The latter approach can be used in cases when an ultrafast dressing pulse induces transient effects, and/or when the atom exchanges energy with multiple frequency components of the XUV field. We first characterize the dressed atom response by calculating the frequency-dependent absorption cross section for XUV energies between 20 and 24 eV for several dressing wavelengths between 400 and 2000 nm and intensities up to 10^12 W/cm^2. We find that for dressing wavelengths near 1600 nm, there is an Autler-Townes splitting of the 1s ---> 2p transition that can potentially lead to transparency for absorption of XUV light tuned to this transition. We study the effect of this XUV transparency in a macroscopic helium gas by incorporating the time-frequency approach into a solution of the coupled Maxwell-Schr\"odinger equations. We find rich temporal reshaping dynamics when a 61 fs XUV pulse resonant with the 1s ---> 2p transition propagates through a helium gas dressed by an 11 fs, 1600 nm laser pulse.Comment: 13 pages, 8 figures, 1 table, RevTeX4, revise

High-resolution Near-Infrared Images and Models of the Circumstellar Disk in HH 30

We present Hubble Space Telescope (HST) Near-Infrared Camera and Multi-object Spectrometer (NICMOS) observations of the reflection nebulosity associated with the T Tauri star HH 30. The images show the scattered light pattern characteristic of a highly inclined, optically thick disk with a prominent dustlane whose width decreases with increasing wavelength. The reflected nebulosity exhibits a lateral asymmetry in the upper lobe on the opposite side to that reported in previously published Wide Field Planetary Camera 2 (WFPC2) images. The radiation transfer model which most closely reproduces the data has a flared accretion disk with dust grains larger than standard interstellar medium grains by a factor of approximately 2.1. A single hotspot on the stellar surface provides the necessary asymmetry to fit the images and is consistent with previous modeling of the light curve and images. Photometric analysis results in an estimated extinction of Av>~80; however, since the photometry measures only scattered light rather than direct stellar flux, this a lower limit. The radiative transfer models require an extinction of Av = 7,900.Comment: Accepted for publication in Ap.

Student abstracts of selected articles

Vowel Nasality in Sudanese by Ron Trail, abstracted from Robins, R. H. 1957. Vowel Nasality in Sudanese, A Phonological and Grammatical Study. Studies in Linguistic Analysis, J.R. Firth ed. London: The Philological Society, 87-103. Style in Huichol by Nancy Freiberger, abstracted from Grimes, Joseph E. 1955. Style in Huichol Structure, Language 31.31-35. Trique Tone by Richard Bergman, abstracted from Longacre, Robert E. 1952. Five Phonemic Pitch Levels in Trique, Acta Linguistica 7.62-82. Tonme Representation in Mazatec Orthography by Ron Trail, abstracted from Gudschinsky, Sarah. 1959. Toneme Representation in Mazatec Orthography, Word, 15.446-52. Totonac Verb Inflection by Kenneth D. Smith, abstracted from Aschmann, Herman, and Wonderly, William L. 1952. Affixes and Implicit Categories in Totonac Verb Inflections, IJAL 18.130-45. Have as a Function Word by Jean Haggar, abstracted from Fries, Charles C. 1948. Have as a Function Word, Language Learning, 1.3,4-8. Bella Coola Phonology by Margie Griffin, abstracted from Newman, Stanley, 1947. Bella Coola I: Phonology, IJAL 13.129-34. Old High German Umlaut by Elwood Jacobson, abstracted from Twaddell, W. Freeman. 1938. A Note on Old High German Umlaut, Monatshefte für deutschen Unterricht, 30:177-81. Reprinted in Readings in Linguistics, edited by Martin Joos, 1958. Washington: American Council of Learned Societies, 85-87. The Phonemic Principle by Nancy Freiberger, abstracted from Swadesh, Morris, 1934. The Phonemic Principle, Language 10.117-29. Reprinted in Readings in Linguistics, edited by Martin Joos. 1958. Washington: American Council of Learned Societies, 1957, 32-37. Meaning and Dictionary Making by Nancy Freiberger, abstracted from Nida, Eugene A. 1958. Analysis of Meaning and Dictionary Making, IJAL 24.279-92. Mazateco Whistle Speech by Nancy Freiberger, abstracted from Cowan, George M. 1948. Mazateco Whistle Speech, Language 24.280-86. Voiceless Vowels in Comanche by Bob Beadle, abstracted from Canonge, Elliot D. 1957. Voiceless Vowels in Comanche, IJAL, 23.63-67. Noun Possession in Villa Alta Zapotec by Gwen Young, abstracted from Mary Leal and Otis Leal, 1954. Noun Possession in Villa Alta Zapotec, IJAL 20.215-216. Sound Patterns by Richard Bergman, abstracted from Sapir, Edward. 1925. Sound Patterns in Language. Language, 1.37-51