Inhibition of human eye blink by brief acoustic stimulus.

A corneal air puff (S2) which elicited eye blinks in 10 undergraduates either appeared alone (control) or was preceded by a brief acoustic stimulus (S1) at a variety of temporal intervals (50-2,020 msec). Amplitude of the eye-blink response to S2 was depressed by S1 at short intervals as compared with control trials; peak inhibition appeared at about 70 msec of S1-S2 separation and declined at longer intervals. An intense S1 was more effective than a weak S1 at short intervals. Inhibition was independent of prior experience with S1 and S2 and of overt responding to S1, and no systematic change in inhibition occurred during testing. The temporal course of inhibition was the same as that previously obtained with the acoustic-startle reflex in rats and the nictitating membrane reflex to circumorbital shock in rabbits. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of eye,head and trunk coordination during target tracking tasks

This study tested the feasibility of a method to synchronise and to evaluate eye, head and trunk movement patterns during target tracking tasks performed by 10 subjects. A projected central target was randomly repositioned at 40° and 70° of rotation to the left and right. Subjects were instructed to change gaze as quickly as possible. Head and trunk motion was measured using a motion analysis system, and eye movement was measured using an eye-tracker; all data were synchronised. For healthy subjects, the eye moved faster than the head, there was no trunk movement and the head moved more than the eye to reach further displaced targets. The method tested was feasible, and it could be used to evaluate eye, head and trunk movement patterns of subjects with injuries such as whiplash and concussions.

Practitioner Summary: Studies of eye, head and trunk movements using synchronised methods are needed. We tested the feasibility of a method to synchronise and evaluate eye, head and trunk movement patterns. The method tested was feasible, and it could be used to evaluate movement patterns of subjects with injuries such as whiplash.     

An investigation into irreducible autocatalytic sets and power law distributed catalysis

RAF theory has been established as a useful and formal framework for studying the emergence and evolution of autocatalytic sets. Here, we present several new and additional results on RAF sets. In particular, we investigate in more detail the existence, expected sizes, and composition of the smallest possible, or irreducible, RAF sets. Furthermore, we study a more realistic variant of the well-known binary polymer model in which the catalysis events are assigned according to a power law distribution. Together, these results provide further insights into the existence and structure of autocatalytic sets in simple models of chemical reaction systems, with possible implications for theories on the origin of life.     

Investigations Regarding the Determination of Glass Transition Temperatures from Moisture Sorption Isotherms

Moisture sorption isotherm and glass transition temperature (T_g data on polyvinylpyrrolidone (PVP) of molecular weights less than or equal to 40,000 as well as PVP containing added plasticizers were collected to examine the possibility of extracting T, values from moisture sorption data. Moisture sorption isotherms generated for PVP of various molecular weights were similar to those previously reported. The moisture sorption isotherm for PVP-K15 containing added vinylpyrrolidone (VP) and methylpyrrolidone (MP) were predicted reasonably well by simple addition of their respective isotherms with that of PVP-K15. The T_g values for PVP as a function of moisture was similar to that found previously. Decreasing polymer molecular weight or the addition of plasticizers (VP or MP) reduced the T_g of the polymer system, displacing the T_g to lower temperatures. When the moisture content to give a T_g of 25°C (W_g) was indicated on the isotherm, W_g shifted downward with decreasing molecular weight or increasing plasticization by VP or MP while the shape of the isotherm was not distinguishably altered. Consequently, W_g, and thus T_g, would be difficult to extract from the moisture sorption isotherm.     

Conceptual designs of AI-based systems for local prediction ofvoltage collapse

Vulnerability of modern power systems to locally initiated voltage collapse gives rise to a need for methods to measure local voltage security and to predict voltage instability. The paper presents a novel architecture based on a suite of AI technologies and three-dimensional PQV surfaces which provides prediction of local voltage collapse and indices of system voltage security. Robustness and adaptation are demonstrated on difficult and realistic power system simulation models     

Visual Spatial Learning Test: Normative data and further validation.

The Visual Spatial Learning Test (VSLT) is a nonverbal memory test that requires minimal language and motor abilities. Normative data are presented for VSLT measures of learning, delayed memory, and intrusion errors for 455 Ss (aged 56–97 yrs). The normative sample is an open community sample that was not screened for memory impairment using psychometric procedures. Validity of these normative data was then assessed by application to a group of patients with dementia. Sequential application of cutoff scores for intrusion errors, learning, and delayed memory correctly identified 87.9% of demented and 78.9% of normal Ss. The VSLT appears to be a test of recognition and cued memory that may be appropriately included in a psychometric battery for the assessment of dementia. (PsycINFO Database Record (c) 2010 APA, all rights reserved)