A computerized fault tree construction methodology

A new approach to automating the fault tree construction process is proposed. The methodology has features which make it applicable to binary state systems and also to process control systems. Previous attempts to model the failure generation in systems have worked well on only a small sub-class of system types and have failed to produce a generally applicable method. Thus in some previous approaches there are desirable features which are worth retaining in a new construction method. The new method is based on the flexibility of the decision table method but incorporates a way of detecting, classifying and analysing control loops, similar to that used with operators in the digraph approach. As well as using operators to deal with control loops a new operator is introduced that deals with two-state circuits. This will mean that when constructing the fault trees, the difficulty of handling repeated events will be eliminated and the size of the tree structures will be significantly reduced. The developed algorithm can produce a tree format appropriate for direct input to an analysis code. The method is demonstrated in this paper by its application to a simplified safety system from the railway industry. This system has been selected as it exhibits features that are typical of two-state circuitry but is also small enough to illustrate the new developments introduced

Applications of the ACGT Master Ontology on Cancer

In this paper we present applications of the ACGT Master Ontology (MO) which is a new terminology resource for a transnational network providing data exchange in oncology, emphasizing the integration of both clinical and molecular data. The development of a new ontology was necessary due to problems with existing biomedical ontologies in oncology. The ACGT MO is a test case for the application of best practices in ontology development. This paper provides an overview of the application of the ontology within the ACGT project thus far

Explosive dome eruptions modulated by periodic gas-driven inflation

Volcan Santiaguito (Guatemala) "breathes" with extraordinary regularity as the edifice's conduit system accumulates free gas, which periodically vents to the atmosphere. Periodic pressurization controls explosion timing, which nearly always occurs at peak inflation, as detected with tiltmeters. Tilt cycles in January 2012 reveal regular 26 ± 6 min inflation/deflation cycles corresponding to at least ~101 kg/s of gas fluxing the system. Very long period (VLP) earthquakes presage explosions and occur during cycles when inflation rates are most rapid. VLPs locate ~300 m below the vent and indicate mobilization of volatiles, which ascend at ~50 m/s. Rapid gas ascent feeds pyroclast-laden eruptions lasting several minutes and rising to ~1 km. VLPs are not observed during less rapid inflation episodes; instead, gas vents passively through the conduit producing no infrasound and no explosion. These observations intimate that steady gas exsolution and accumulation in shallow reservoirs may drive inflation cycles at open-vent silicic volcanoes. Key Points Regular 26 min inflation/deflation cycles are observed at silicic volcanoInflation rates control whether volcano explodes or passively degassesLocation of gas reservoir and flux of gas through the volcano are quantifie

Anomalous rotational properties of Bose-Einstein condensates in asymmetric traps

We study the rotational properties of a Bose-Einstein condensate confined in a rotating harmonic trap for different trap anisotropies. Using simple arguments, we derive expressions for the velocity field of the quantum fluid for condensates with or without vortices. While the condensed gas describes open spiraling trajectories, on the frame of reference of the rotating trap the motion of the fluid is against the trap rotation. We also find explicit formulae for the angular momentum and a linear and Thomas-Fermi solutions for the state without vortices. In these two limits we also find an analytic relation between the shape of the cloud and the rotation speed. The predictions are supported by numerical simulations of the mean field Gross-Pitaevskii model.Comment: 4 RevTeX pages, 2 EPS figures; typos fixed, reference adde

Use of Pregnancy Associated Glycoproteins to Determine Fetal Age Throughout Gestation in Cattle

Objective The objective of the current study was to determine if a commercially available blood pregnancy test could be modified to detect differences in pregnancy-associated glycoprotein (PAG) concentrations to indicate stage of pregnancy or fetal age in cattle. Study Description Previously identified pregnant females were grouped by age (pre-primiparous or multiparous). Blood samples were collected between day 27 and 190 of pregnancy (n = 176 from pre-primiparous and n = 240 from multiparous) and serum was tested in duplicate using a commercially available blood pregnancy test, IDEXX Alertys Pregnancy Test. Procedures were adapted to allow concentrations to fall within the detectible range of the assay. Animals were grouped by parity (pre-primiparous vs multiparous) into 4 gestational groups (group 1 - \u3c 30 days, group 2 - 30 to 90 days, group 3 - 91 to 178 days, and group 4 - \u3e178 days). Data were analyzed using the MIXED procedure of SAS with parity and gestational age in the model. There was an effect of parity, gestational age, and a parity by gestational age interaction (P \u3c 0.01). Pre-primiparous animals had greater concentrations of PAGs compared to multiparous animals. Among pre-primiparous animals, serum PAG concentrations did not differ between gestational age groups 1, 2, or 3 (P \u3e 0.37), but group 4 had greater PAG concentrations than all other groups (P \u3c 0.01). Among multiparous animals, serum PAG concentrations decreased from group 1 to 2 (P \u3c 0.01), and then increased throughout gestation (P \u3c 0.01). Data were then analyzed using the REG procedure in SAS within gestational age group. There was a positive correlation between gestational age and PAG concentrations among both pre-primiparous (P \u3c 0.01; R2 = 0.25) and multiparous (gestational age 30 and greater P \u3c 0.01; R2 = 0.64)

Use of Pregnancy Associated Glycoproteins to Determine Fetal Age Throughout Gestation and Clearance Rate in Postpartum Beef Cattle

Study Description: Previously identified pregnant females from four different herds and postpartum females from one herd were utilized. Blood samples were collected (n = 1,753; study 1) between d 28 and 285 of gestation and (heifers n = 418 and cows n = 657; study 2) once a week for up to 12 weeks after calving. Serum was tested in duplicate using a commercially available blood pregnancy test, IDEXX Alertys Pregnancy Test. In study 1, procedures were modified to allow PAG concentrations to fall within the detectible range of the assay. Data were analyzed using the MIXED procedure of SAS with cow age and gestational age (also divided into four gestational age groups: 1) \u3c 30 d; 2) 30-90 d; 3) 91-180 d; 4) \u3e 180 d) in the model and then analyzed further using the REG procedure in SAS within gestational age group. In study 2, data were analyzed as repeated measure using the MIXED procedure of SAS with cow age, days postpartum (dpp), and cow age by dpp in the model, then data were analyzed further using the REG procedure in SAS. In study 1, there was a significant effect of gestational age and cow age by gestational age interaction (P \u3c 0.01) as well as a tendency of cow age (P = 0.08). Among heifers and cows, serum PAG concentrations did not differ between gestational age groups 1 and 2 (P \u3e 0.84), however, PAG concentrations differed between groups 2 and 3 (P \u3c 0.0001) and 3 and 4 (P \u3c 0.0001). There was a positive correlation between gestational age and PAG concentrations (P \u3c 0.01; r2 = 0.2604). In study 2, there was a significant effect of days postpartum (dpp; P \u3c 0.01) on PAG concentrations; however, PAG concentrations were not influenced by cow age (P = 0.73) or cow age by dpp (P = 0.55). Concentrations of PAGs rapidly decreased from d 0 to 50 postpartum and then continued to gradually decrease (P \u3c 0.01; r2 = 0.8083). Prior to 42 dpp, PAG concentrations were sufficiently elevated which resulted in false positive readings

On manifolds with nonhomogeneous factors

We present simple examples of finite-dimensional connected homogeneous spaces (they are actually topological manifolds) with nonhomogeneous and nonrigid factors. In particular, we give an elementary solution of an old problem in general topology concerning homogeneous spaces

Towards a sustainable and equitable blue economy

The global rush to develop the \u2018blue economy\u2019 risks harming both the marine environment and human wellbeing. Bold policies and actions are urgently needed. We identify five priorities to chart a course towards an environmentally sustainable and socially equitable blue economy

Comparison of Lateral Flow to Other Pregnancy Determination Methods in Order to Determine Accuracy of Pregnancy Status in Beef Cattle Pre and Postpartum

Study Description: Blood samples were collected from six different Bos taurus herds between day 27 and 285 of gestation (heifers n = 1,205 and cows n = 1,539). Blood samples to determine PAG clearance interval were collected weekly postpartum for up to 12 weeks (heifers n = 418 and cows n = 657). Serum was tested using the lateral flow test and were read by two technicians who were blind to pregnancy status. Level of agreement between the tests were determined by Pearson’s correlation coefficients and Kappa scores. The MIXED procedure of SAS was used to evaluate the effect of dpp and age (heifers or cows) on postpartum test results. There was a positive correlation between transrectal ultrasonography and the lateral flow test (r2 = 0.71; P \u3c 0.01), and agreement between the two tests was very good (Kappa = 0.84). Of the animals that were diagnosed nonpregnant by transrectal ultrasonography, 5.61% were called pregnant by the lateral flow test. Of the animals diagnosed pregnant by transrectal ultrasonography, 2.00% were called not pregnant by the lateral flow test. Thus, a 92.38% agreement occurred between the two methods. For postpartum samples, there was no effect (P = 0.21) of age, but there was an effect of dpp (P \u3c 0.01) and a tendency for a dpp by age interaction (P = 0.06). All animals were still considered pregnant from the previous pregnancy through 35 dpp (100 ± 2.58%). The percentage of females receiving a false positive test result further decreased with time postpartum, by 77 dpp there were 13.72 ± 3.16% of the females positive for pregnancy and at 84 dpp there were 4.11 ± 4.39% positive for pregnancy detection

Askey-Wilson Type Functions, With Bound States

The two linearly independent solutions of the three-term recurrence relation of the associated Askey-Wilson polynomials, found by Ismail and Rahman in [22], are slightly modified so as to make it transparent that these functions satisfy a beautiful symmetry property. It essentially means that the geometric and the spectral parameters are interchangeable in these functions. We call the resulting functions the Askey-Wilson functions. Then, we show that by adding bound states (with arbitrary weights) at specific points outside of the continuous spectrum of some instances of the Askey-Wilson difference operator, we can generate functions that satisfy a doubly infinite three-term recursion relation and are also eigenfunctions of $q$-difference operators of arbitrary orders. Our result provides a discrete analogue of the solutions of the purely differential version of the bispectral problem that were discovered in the pioneering work [8] of Duistermaat and Gr\"unbaum.Comment: 42 pages, Section 3 moved to the end, minor correction