2,002 research outputs found
Domain independent goal recognition
Goal recognition is generally considered to follow plan recognition. The plan recognition problem is typically defined to be that of identifying which plan in a given library of plans is being executed, given a sequence of observed actions. Once a plan has been identified, the goal of the plan can be assumed to follow. In this work, we address the problem of goal recognition directly, without assuming a plan library. Instead, we start with a domain description, just as is used for plan construction, and a sequence of action observations. The task, then, is to identify which possible goal state is the ultimate destination of the trajectory being observed. We present a formalisation of the problem and motivate its interest, before describing some simplifying assumptions we have made to arrive at a first implementation of a goal recognition system, AUTOGRAPH. We discuss the techniques employed in AUTOGRAPH to arrive at a tractable approximation of the goal recognition problem and show results for the system we have implemented
Active regulator of SIRT1 is required for cancer cell survival but not for SIRT1 activity
The NAD+-dependent deacetylase SIRT1 is involved in diverse cellular processes, and has also been linked with multiple disease states. Among these, SIRT1 expression negatively correlates with cancer survival in both laboratory and clinical studies. Active regulator of SIRT1 (AROS) was the first reported post-transcriptional regulator of SIRT1 activity, enhancing SIRT1-mediated deacetylation and downregulation of the SIRT1 target p53. However, little is known regarding the role of AROS in regulation of SIRT1 during disease. Here, we report the cellular and molecular effects of RNAi-mediated AROS suppression, comparing this with the role of SIRT1 in a panel of human cell lines of both cancerous and non-cancerous origins. Unexpectedly, AROS is found to vary in its modulation of p53 acetylation according to cell context. AROS suppresses p53 acetylation only following the application of cell damaging stress, whereas SIRT1 suppresses p53 under all conditions analysed. This supplements the original characterization of AROS but indicates that SIRT1 activity can persist following suppression of AROS. We also demonstrate that knockdown of AROS induces apoptosis in three cancer cell lines, independent of p53 activation. Importantly, AROS is not required for the viability of three non-cancer cell lines indicating a putative role for AROS in specifically promoting cancer cell survival
Sea Otter, Enhydra lutris, mortalities in California, 1968 through 1993
Sea otter, Enhydra lutris, mortality in California and the relative contribution from specific causes was assessed for the 26 years from 1968 through 1993. There were 2,082 dead sea otters recorded from Tomales Bay (Marin County) south to Bluff Cove (Los Angeles County) during that period. The average number of carcasses recorded was 80 per year and seven per month. Sex was identified in 87% (n=1,819) of the cases and was composed of 47% female and 53% male. A relative age was assigned to 97% (n=2,017) of the cases and was composed of 28% pup, 18% subadult and 54% adult.
Specific causes of death were determined for 26% (n=55 1) of the cases. The majority of these (n=381) were considered to be due to natural causes and included the following specific causes: shark bitten (n=78), probably shark bitten (n=106), other natural causes (n=140), and mating wounds (n=57). The remaining (n=170) were considered to be due to human-related causes and included the following specific causes: shot
(n=72), probably shot (n=8), net drowned (n=76), and other human causes (n=14).
The large proportion of carcasses without an identified specific cause of death prompted a more detailed necropsy effort in 1992 and 1993. During that period, 78 of the 232 recovered carcasses were examined by veterinary pathologists and a specific cause of death was determined in 76% (n=59) of the cases. This effort identified a wide range of specific causes of death that otherwise may have been categorized as "unknown without trauma". Considering the variety of diseases diagnosed in this expanded necropsy program, it would be prudent to continue this level of examination to refine our knowledge of sea otter pathology. (48pp.
Hydrogen: A Framework for Analyzing Software Revision Histories
Hydrogen is a framework used for analyzing software revision histories for such applications as verifying bug fixes and identifying changes that cause bugs. The framework uses a graph representation of multiple versions of a program in a software revision history called a multi-version interprocedural control flow graph (MVICFG). The MVICFG integrates the control flow for multiple versions of a program into a single graph and provides a convenient way to represent semantic (i.e. control flow) change in a program. The MVICFG can also reduce the storage demands for representing the control flow for multiple versions of a program. Hydrogen implements an algorithm that uses data mined from source code repositories to construct the MVICFG. The MVICFG is analyzed using demand driven analysis for patch verification in multiple releases of software
Structural disorder versus chiral magnetism in CrNbS
The crystal structure of a disordered form of CrNbS has been
characterized using diffraction and inelastic scattering of synchrotron
radiation. In contrast to the previously reported symmetry (P622), the
crystal can be described by a regular twinning of an average P6 structure
with three disordered positions of the Cr ions. Short-range correlations of the
occupational disorder result in a quite intense and structured diffuse
scattering; a static nature of the disorder was unambiguously attributed by the
inelastic x-ray scattering. The diffuse scattering has been modeled using a
reverse Monte-Carlo algorithm assuming a disorder of the Cr sub-lattice only.
The observed correlated disorder of the Cr sub-lattice reduces the temperature
of the magnetic ordering from 130 K to 88 K and drastically modifies the field
dependence of the magnetization as it is evidenced by the SQUID magnetometery.
We conclude, that in contrast to the helicoidal spin structure assumed for
P622 form, the compound under study is ferromagnetically ordered with a
pronounced in-plane anisotropy
Investigation on the sampling size optimisation in gear tooth surface measurement using a Co-ordinate Measuring Machine
Co-ordinate Measuring Machines (CMMs) are widely used in gear manufacturing industry. One of the main issues for contact inspection using a CMM is the sampling technique. In this paper the gear tooth surfaces are expressed by series of parameters and inspection error compensation and initial value optimisation method are presented. The minimum number of measurement points for 3D tooth surfaces are derived. If high precision is required, more points need to be inspected. The sampling size optimisation is obtained from the criterion equation. The surface form deviation and initial values are optimised using the minimum zone method and Genetic Algorithms. A feature based inspection system for spur/helical gears is developed and trials and simulations demonstrated the developed method is very effective and suitable
Systematic review of the current status of cadaveric simulation for surgical training
Background:
There is growing interest in and provision of cadaveric simulation courses for surgical trainees. This is being driven by the need to modernize and improve the efficiency of surgical training within the current challenging training climate. The objective of this systematic review is to describe and evaluate the evidence for cadaveric simulation in postgraduate surgical training.
Methods:
A PRISMA‐compliant systematic literature review of studies that prospectively evaluated a cadaveric simulation training intervention for surgical trainees was undertaken. All relevant databases and trial registries were searched to January 2019. Methodological rigour was assessed using the widely validated Medical Education Research Quality Index (MERSQI) tool.
Results:
A total of 51 studies were included, involving 2002 surgical trainees across 69 cadaveric training interventions. Of these, 22 assessed the impact of the cadaveric training intervention using only subjective measures, five measured impact by change in learner knowledge, and 23 used objective tools to assess change in learner behaviour after training. Only one study assessed patient outcome and demonstrated transfer of skill from the simulated environment to the workplace. Of the included studies, 67 per cent had weak methodology (MERSQI score less than 10·7).
Conclusion:
There is an abundance of relatively low‐quality evidence showing that cadaveric simulation induces short‐term skill acquisition as measured by objective means. There is currently a lack of evidence of skill retention, and of transfer of skills following training into the live operating theatre
Site-selective quantum correlations revealed by magnetic anisotropy in the tetramer system SeCuO3
We present the investigation of a monoclinic compound SeCuO3 using x-ray
powder diffraction, magnetization, torque and electron-spin-resonance (ESR).
Structurally based analysis suggests that SeCuO3 can be considered as a 3D
network of tetramers. The values of intra-tetramer exchange interactions are
extracted from the temperature dependence of the susceptibility and amount to
~200 K. The inter-tetramer coupling leads to the development of long-range
antiferromagnetic order at TN = 8 K. An unusual temperature dependence of the
effective g-tensors is observed, accompanied with a rotation of macroscopic
magnetic axes. We explain this unique observation as due to site-selective
quantum correlations
Letter from William D. Pattison to Alfred L. Shoemaker, September 20, 1959
A letter from William D. Pattison to Alfred L. Shoemaker, dated September 20, 1959. Within, Pattison informs Shoemaker of Walter Horn\u27s lectures about the history of Western barns and how they may relate to Pennsylvania barns.https://digitalcommons.ursinus.edu/shoemaker_documents/1222/thumbnail.jp
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