Thought and qualia

I present a theory of the nature and basis of the conscious experience characteristic of occurent propositional attitudes: thinking this or that. As a preliminary I offer an extended criticism of Paul Schweizer's treatment of such consciousness as unexplained secondary qualities of neural events. I also attempt to rebut arguments against the possibility of functionalist accounts of conscious experience and qualia.     

New class of one-bit digital autocorrelator

A new incoherent optical approach to processing one-bit digital signals is described. Autocorrelation of such signals is demonstrated using light-emitting diodes and a photodiode array as the logical units.     

The MMPI and chronic pain.

112 chronic pain patients (mean age 48.4 yrs) completed the MMPI upon entering either an anesthesiologic or a psychiatric treatment program. Pretreatment MMPI performance was found to be successful in predicting patient outcome an average of 20 mo following treatment, with the K (Test-Taking Attitude), Hypochondriasis, Hysteria, and Masculinity and Femininity scales accounting for most of the variance. The strength of this relationship varied as a function of the measure of outcome and type of treatment received. Substantial MMPI differences were found when Ss with only one part of their body in pain were compared with those with multiple pain complaints. Significant MMPI differences were also found in comparisons based on Ss' sex, type of pain (e.g., head vs back), and type of treatment for which was referred (i.e., psychiatric vs anesthesiologic). Clinical implications of the observed MMPI differences are discussed. Results are seen as demonstrating the value of the MMPI as a clinical and research instrument within this population. (14 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A Bayesian Reliability Assessment of Complex Systems for Binomial Sampling

This paper presents a reliability assessment procedure that systematically combines complete system binomial test data with lower level binomial test data obtained from either partial system or component tests. The procedure uses beta prior distributions of all reliabilities, Bayes theorem, and probability moments. The result is a posterior distribution of system reliability that can be used to determine Bayes point and interval estimates. The beta prior distributions evolve from data on predecessor systems similar to the system in question and engineering knowledge about what the various test-alternatives measure.     

Designing mobile technologies to support co-present collaboration

Mobile technologies offer new opportunities for childrens educational activities in that they can be used across different locations and times. Naturally, some instances of mobile technology use will necessitate, or be enhanced by, the sharing of information. Social interaction is important for sharing ideas, constructing and shaping understanding and fundamental for educational development. However the physical size of mobile technologies presents interesting challenges when designing for collaborative activities. When designing mobile technologies the importance of collaborative tasks has often been overlooked. The replacement of low-tech artefacts with digital devices, for supporting multiple users, can inhibit the shareability of information. We present three projects where mobile technologies have been used as part of a larger mixed reality experience. Novel technologies were used to support childrens collaborative activities in storytelling, an adventure game and during an outdoor field trip. Interaction with mobile devices within each project is reviewed and the authors highlight important considerations for their design and use across multiple contexts.     

Effectiveness of customised neutron shielding in the maze of radiotherapy accelerators

An investigation was performed to examine the neutron dose equivalent in a radiotherapy maze lined with a customised neutron shielding material. The accelerator investigated was a Varian Clinac 2100C/D using 18 MV photons, and the neutron shielding utilised at this centre was Premadex commercially available neutron shielding. Based on Monte Carlo simulations, properly installed customised neutron shielding may reduce the neutron dose equivalent by up to a factor of 8 outside the maze, depending upon the installation. In addition, it was determined that the neutron dose near the entrance to the maze may be reduced by approximately 40% by using customised neutron shielding in the maze, as compared with a facility not using this shielding. This would have a positive dose-saving effect in doorless maze designs.     

Shifts in peptide and protein charge state distributions with varying spray tip orifice diameter in nanoelectrospray Fourier transform ion cyclotron resonance mass spectrometry

The influence of the diameter of the spray tip employed for nano-electrospray mass spectrometry (nano-ES-MS) upon mass spectral charge state distributions was investigated using angiotensin I (M(r) = 1296), insulin (M(r) = 5774), and ubiquitin (M(r) = 8560) as test analytes. Under a variety of experimental conditions, the charge state distributions of the test peptides and protein consistently shifted toward higher values as the tip orifice diameter decreased. This finding indicates that the use of narrow diameter capillaries can promote the formation of higher charge state ions that are more reactive precursors in tandem mass spectrometry experiments. A detailed comparison of charge state distributions obtained for nanospray capillaries of varying diameters was undertaken while systematically varying experimental parameters such as sample flow rate, analyte concentration, solvent composition, and electrospray current. The general tendency to obtain higher charge states from narrow diameter capillaries was conserved throughout, but tips with smaller orifices were more sensitive to sample flow rate (the average charge state was lowered significantly as flow was raised), whereas tips with bigger orifices were more sensitive to analyte concentration and pH of the solution (as each was lowered, the average charge state increased).     

Modeling the growth boundary of Staphylococcus aureus for risk assessment purposes

Knowing the precise boundary for growth of Staphylococcus aureus is critical for food safety risk assessment, especially in the formulation of safe, shelf-stable foods with intermediate relative humidity (RH) values. To date, most studies and resulting models have led to the presumption that S. aureus is osmotolerant. However, most studies and resulting models have focused on growth kinetics using NaCl as the humectant. In this study, glycerol was used to investigate the effects of a glass-forming nonionic humectant to avoid specific metabolic aspects of membrane ion transport. The experiments were designed to produce a growth boundary model as a tool for risk assessment. The statistical effects and interactions of RH (84 to 95% adjusted by glycerol), initial pH (4.5 to 7.0 adjusted by HC1), and potassium sorbate (0, 500, or 1,000 ppm) or calcium propionate (0, 500, or 1,000 ppm) on the aerobic growth of a five-strain S. aureus cocktail in brain heart infusion broth were explored. Inoculated broths were distributed into microtiter plates and incubated at 37 degrees C over appropriate saturated salt slurries to maintain RH. Growth was monitored by turbidity during a 24-week period. Toxin production was explored by enterotoxin assay. The 1,280 generated data points were analyzed by SAS LIFEREG procedures, which showed all studied parameters significantly affected the growth responses of S. aureus with interactions between RH and pH. The resulting growth/no growth boundary is presented.     

Algorithms for discrete and continuous multicommodity flow network interdiction problems

We consider a network interdiction problem on a multicommodity flow network, in which an attacker disables a set of network arcs in order to minimize the maximum profit that can be obtained from shipping commodities across the network. The attacker is assumed to have some budget for destroying (or “interdicting”) arcs, and each arc is associated with a positive interdiction expense. In this paper, we examine problems in which interdiction must be discrete (i.e., each arc must either be left alone or completely destroyed), and in which interdiction can be continuous (the capacities of arcs may be partially reduced). For the discrete problem, we describe a linearized model for optimizing network interdiction that is similar to previous studies in the field, and compare it to a penalty model that does not require linearization constraints. For the continuous case, we prescribe an optimal partitioning algorithm along with a heuristic procedure for estimating the optimal objective function value. We demonstrate on a set of randomly generated test data that our penalty model for the discrete interdiction problem significantly reduces computational time when compared to that consumed by the linearization model.