174 research outputs found

    Real-time task attributes and temporal constraints

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    Real-time tasks need attributes for monitoring their execution and performing recovery actions in case of failures. Temporal constraints are a class of real-time task attributes where the constraints relate the status of the task to temporal entities. Violating temporal constraints can produce consequences of unknown severity. This paper is part of our on-going research on real-time multi agent systems constraints. We discuss the importance of temporal constraints and present a task model that explicitly represents temporal constraints. We also present our preliminary results from our initial implementation in the domain of Meeting Schedules Management involving multiple users assisted by agents

    Unintended Consequences Of Equal Employment Opportunity: Unequal Parties In The Selection Process?

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    There arevarious regulations that are intended to promote equal employment opportunityand avoid illegal discrimination in the employment process. These regulationsdetermine what information employers may seek, and require that informationsought be job-related or it is illegal to seek such information as age, maritalstatus, or religion. Information that is not a bona fide occupationalqualification (BFOQ) is usually out of bounds as employers gather informationto determine the suitability of applicants for employment.  Since one of thebedrock laws affecting the employment relationship is the “at will” doctrinethat assumes both employer and applicant come together as equal partners in theformation of the employment contract, this paper raises the issues aboutwhether such regulations unintentionally leave the employer at an informationdisadvantage by negating the concept of equality assumed by the “at will”doctrine. Some suggestions for practical ways of reducing the identifiedemployer information disadvantages are provided

    A requirement modelling framework for real-time multi-agent systems

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    University of Technology Sydney. Faculty of Engineering and Information Technology.Real-time constraints are a subset of abstract temporal constraints, which are a class of constraints that are often placed on real world tasks during a problem-solving activity. Violating temporal constraints can produce consequences of unknown severity. Real-time constraints research is extremely useful in environments that require a high degree of availability and reliability, which are the main characteristics of real-time multi-agent systems (RTMAS). Domains currently using RTMAS include, but are not limited to, rescue systems, scheduling applications, electricity, infrastructure systems, flight control systems, marine systems, automotive systems. This thesis synthesises a framework to support RTMAS requirements analysis to enhance system design identifying real-time and fault tolerance requirements in the early phase of the software development life cycle. The framework consists of a sufficient set of constraints and an associated process to identify and apply the modelling units. The analysts identify the applicable modelling units during the system analysis phase of the sought RTMAS. A design science approach was applied to construct the framework systematically. The framework was validated incrementally as it was constructed using a call centre case study, a meeting scheduling application and an iPhone scheduling application. These case studies have illustrated that the early identification of the real-time constraints and their even distribution among different agent, significantly reduce the chance of an agent failing. These also enhance the system stability and redundancy by providing an extra level of fault tolerance at the agent and task level, as well as at the overall system level

    The Dosimetric Effects of Photon Energy on the Quality of Volumetric Modulated Arc Therapy for Lung Stereotactic Body Radiation Therapy

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    Purpose: There is little published data on the optimal energy to use to minimize doses to Organs at Risk (OARs), while maintaining adequate Planning Target Volume (PTV) coverage in lung volumetric-modulated arc therapy (VMAT) stereotactic body radiation therapy (SBRT).Methods: 35 lung lesions in 33 patients were treated at our institution by VMAT SBRT. Dosimetric plans using 6-Megavoltage (6-MV) and 10-Megavoltage (10-MV) energies were generated for each lesion. The median dose was 5000cGy delivered over 3-5 daily fractions. Various dosimetric parameters were recorded for both the 6-MV and 10-MV plans and the patients were stratified according to the tumor to chest wall distance (TCW), the tumor location (central versus peripheral), patient anterior-posterior (AP) diameter, and the diameter of an equivalent sphere encompassing the patient's body over the distance of the PTV (ESD).Results: There was a statistically significant difference between 6-MV and 10-MV with respect to the sum lung dose, which favored 6-MV plans (p=0.04). For those stratified by TCW, there was a difference in conformity index (CI) for patients with peripheral tumors (p=0.04). For the group stratified by AP separation, there was a difference in mean sum lung dose favoring 6-MV (p=0.01). In the group stratified by ESD, there were statistically significant (SS) differences in the volume of lung receiving at least 13Gy (V13), mean sum lung dose, and CI, all favoring 6-MV plans (p=0.05, p<0.01, and p<0.01). For the cohort overall, and within each subgroup, there was a SS difference in the total number of monitor units (MUs), which consistently favored planning with 10-MV.Conclusion: With the exception of thinner patients, for which 6-MV plans was superior with respect to OARs and conformity index, 10-MV should be considered for use in lung VMAT SBRT. 10-MV plans consistently resulted in fewer total MUs. Fewer MUs results in shorter treatment times, with the potential for improved target accuracy due to less intrafractional tumor motion

    Real or imagined women? Staff representations of international women postgraduate students

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    In Australia\u27s globalising universities many support staff and teaching staff now work with international women postgraduate students. But are they aware of the issues facing these women, and is their understanding of them adequate? Indeed, how do they represent them? In this paper we draw on a small-scale pilot study involving key university personnel. We argue that the ways in which such staff represent this group of students is problematic. Focusing primarily on academic issues and on the literature on learning styles, we analyse these staff members\u27 representations of international women postgraduate students from a postcolonial perspective. We explore the extent to which such representations, and the learning styles literature that reflects and informs them, are what Edward Said calls \u27Orientalist\u27. In so doing, we point to both the constitution of the international woman student as postcolonial female subject and show how this situates her in relation to the prevalent learning styles discourse. Further we argue that such representations of the students differ in crucial ways from the students\u27 self-representations, suggesting that in certain subtle ways such staff members are engaging with \u27imagined\u27 rather than \u27real\u27 women. <br /

    Comparison of CT and PET-CT based planning of radiation therapy in locally advanced pancreatic carcinoma

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    Abstract Background To compare computed tomography (CT) with co-registered positron emission tomography-computed tomography (PET-CT) as the basis for delineating gross tumor volume (GTV) in unresectable, locally advanced pancreatic carcinoma (LAPC). Methods Fourteen patients with unresectable LAPC had both CT and PET images acquired. For each patient, two three-dimensional conformal plans were made using the CT and PET-CT fusion data sets. We analyzed differences in treatment plans and doses of radiation to primary tumors and critical organs. Results Changes in GTV delineation were necessary in 5 patients based on PET-CT information. In these patients, the average increase in GTV was 29.7%, due to the incorporation of additional lymph node metastases and extension of the primary tumor beyond that defined by CT. For all patients, the GTVCT versus GTVPET-CT was 92.5 ± 32.3 cm3 versus 104.5 ± 32.6 cm3 (p = 0.009). Toxicity analysis revealed no clinically significant differences between two plans with regard to doses to critical organs. Conclusion Co-registration of PET and CT information in unresectable LAPC may improve the delineation of GTV and theoretically reduce the likelihood of geographic misses.</p

    Hyperbaric treatment for children with autism: a multicenter, randomized, double-blind, controlled trial

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    <p>Abstract</p> <p>Background</p> <p>Several uncontrolled studies of hyperbaric treatment in children with autism have reported clinical improvements; however, this treatment has not been evaluated to date with a controlled study. We performed a multicenter, randomized, double-blind, controlled trial to assess the efficacy of hyperbaric treatment in children with autism.</p> <p>Methods</p> <p>62 children with autism recruited from 6 centers, ages 2–7 years (mean 4.92 ± 1.21), were randomly assigned to 40 hourly treatments of either hyperbaric treatment at 1.3 atmosphere (atm) and 24% oxygen ("treatment group", n = 33) or slightly pressurized room air at 1.03 atm and 21% oxygen ("control group", n = 29). Outcome measures included Clinical Global Impression (CGI) scale, Aberrant Behavior Checklist (ABC), and Autism Treatment Evaluation Checklist (ATEC).</p> <p>Results</p> <p>After 40 sessions, mean physician CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0008), receptive language (p < 0.0001), social interaction (p = 0.0473), and eye contact (p = 0.0102); 9/30 children (30%) in the treatment group were rated as "very much improved" or "much improved" compared to 2/26 (8%) of controls (p = 0.0471); 24/30 (80%) in the treatment group improved compared to 10/26 (38%) of controls (p = 0.0024). Mean parental CGI scores significantly improved in the treatment group compared to controls in overall functioning (p = 0.0336), receptive language (p = 0.0168), and eye contact (p = 0.0322). On the ABC, significant improvements were observed in the treatment group in total score, irritability, stereotypy, hyperactivity, and speech (p < 0.03 for each), but not in the control group. In the treatment group compared to the control group, mean changes on the ABC total score and subscales were similar except a greater number of children improved in irritability (p = 0.0311). On the ATEC, sensory/cognitive awareness significantly improved (p = 0.0367) in the treatment group compared to the control group. Post-hoc analysis indicated that children over age 5 and children with lower initial autism severity had the most robust improvements. Hyperbaric treatment was safe and well-tolerated.</p> <p>Conclusion</p> <p>Children with autism who received hyperbaric treatment at 1.3 atm and 24% oxygen for 40 hourly sessions had significant improvements in overall functioning, receptive language, social interaction, eye contact, and sensory/cognitive awareness compared to children who received slightly pressurized room air.</p> <p>Trial Registration</p> <p>clinicaltrials.gov NCT00335790</p

    Mitochondrial Protease ClpP is a Target for the Anticancer Compounds ONC201 and Related Analogues

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    ONC201 is a first-in-class imipridone molecule currently in clinical trials for the treatment of multiple cancers. Despite enormous clinical potential, the mechanism of action is controversial. To investigate the mechanism of ONC201 and identify compounds with improved potency, we tested a series of novel ONC201 analogues (TR compounds) for effects on cell viability and stress responses in breast and other cancer models. The TR compounds were found to be ∼50-100 times more potent at inhibiting cell proliferation and inducing the integrated stress response protein ATF4 than ONC201. Using immobilized TR compounds, we identified the human mitochondrial caseinolytic protease P (ClpP) as a specific binding protein by mass spectrometry. Affinity chromatography/drug competition assays showed that the TR compounds bound ClpP with ∼10-fold higher affinity compared to ONC201. Importantly, we found that the peptidase activity of recombinant ClpP was strongly activated by ONC201 and the TR compounds in a dose- and time-dependent manner with the TR compounds displaying a ∼10-100 fold increase in potency over ONC201. Finally, siRNA knockdown of ClpP in SUM159 cells reduced the response to ONC201 and the TR compounds, including induction of CHOP, loss of the mitochondrial proteins (TFAM, TUFM), and the cytostatic effects of these compounds. Thus, we report that ClpP directly binds ONC201 and the related TR compounds and is an important biological target for this class of molecules. Moreover, these studies provide, for the first time, a biochemical basis for the difference in efficacy between ONC201 and the TR compounds

    Changes in Intracellular Na+ following Enhancement of Late Na+ Current in Virtual Human Ventricular Myocytes

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    The slowly inactivating or late Na+ current, INa-L, can contribute to the initiation of both atrial and ventricular rhythm disturbances in the human heart. However, the cellular and molecular mechanisms that underlie these pro-arrhythmic influences are not fully understood. At present, the major working hypothesis is that the Na+ influx corresponding to I(Na-L)significantly increases intracellular Na+, [Na]; and the resulting reduction in the electrochemical driving force for Na+ reduces and (may reverse) Na+/Ca2+ exchange. These changes increase intracellular Ca2+, [Ca2+]; which may further enhance I(Na-L)due to calmodulindependent phosphorylation of the Na+ channels. This paper is based on mathematical simulations using the O'Hara et al (2011) model of baseline or healthy human ventricular action potential waveforms(s) and its [Ca2(+)]; homeostasis mechanisms. Somewhat surprisingly, our results reveal only very small changes (<= 1.5 mM) in [Na] even when INa-L is increased 5-fold and steady-state stimulation rate is approximately 2 times the normal human heart rate (i.e. 2 Hz). Previous work done using well-established models of the rabbit and human ventricular action potential in heart failure settings also reported little or no change in [Na] when I(Na-L)was increased. Based on our simulations, the major short-term effect of markedly augmenting I(Na-L)is a significant prolongation of the action potential and an associated increase in the likelihood of reactivation of the L-type Ca2+ current, Ica-L. Furthermore, this action potential prolongation does not contribute to [Na]; increase.This work was supported by (i) the "VI Plan Nacional de Investigacion Cientifica, Desarrollo e Innovacion Tecnologica" from the Ministerio de Economia y Competitividad of Spain (grant number TIN2012-37546-C03-01) and the European Commission (European Regional Development Funds-ERDF-FEDER), (ii) by the Direccion General de Politica Cientifica de la Generalitat Valenciana (grant number GV/2013/119), and by (iii), Programa Prometeo (PROMETEO/2016/088) de la Conselleria d'Educacio Formacio I Ocupacio, Generalitat Valenciana. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.K Cardona; Trénor Gomis, BA.; W Giles (2016). Changes in Intracellular Na+ following Enhancement of Late Na+ Current in Virtual Human Ventricular Myocytes. PLoS ONE. 11(11). https://doi.org/10.1371/journal.pone.0167060S111
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