Distinguishing a ‘hit’ from a ‘view’: Using the access durations of lecture recordings to tell whether learning might have happened

Audiovisual recordings of lectures are available to many students in all disciplines. The use of lecture recordings has been studied extensively, but it is still not clear how, or how much, they are actually used. Previous analysis of their use has been based on either survey data or computer logs of access. In the latter case, measurements of actual use have usually been based on counts of the number of times recordings have been accessed. This does not distinguish those that happen accidentally (‘hits’), from those that might permit learning (‘views’). This distinction is essential to the meaningful analysis of the log of the actual use of recorded lectures. Using the access logs of undergraduate science students, we show that the distribution of the durations of the access of recordings of scheduled lectures has two distinct components. The most rapid of these is complete within three minutes and we infer that it reflects the behaviour of students searching among recordings. This inference is based on a comparison of these distributions with those of (i) recordings made automatically during a non-teaching period and (ii) individual users. This is also consistent with the pattern of usage by students searching for a specific recording

Assessment of a carbon dioxide laser for the measurement of thermal nociceptive thresholds following intramuscular administration of analgesic drugs in pain-free female cats

Objective: To assess the potential for using a thermal carbon dioxide (CO2) laser to 8 assess anti-nociception in pain-free cats. Animals: Sixty healthy adult female cats with a mean weight (± SD) of 3.3 k g (± 0. 6 11 kg). Methods: This is a prospective, blinded and randomised study. Cats were systematically allocated to one of six treatments 1) saline 0.2 ml/cat; 2) morphine 0.5 mg/kg; 3) buprenorphine 20 μg/kg; 4) medetomidine 2 μg/kg; 5) tramadol 2mg/kg; 6) ketoprofen 2 mg/kg. Latency to respond to thermal stimulation was assessed prior to intramuscular injection and at 6 time periods following injection (15-30; 30-45; 45- 18 60; 60-75; 90-105; 120-135 min). Thermal thresholds were assessed using time to respond behaviourally to stimulation with a 500 mW CO2 laser with maximum latency to respond set at 60 seconds. Differences in response latency for each treatment across the duration of the experiment were assessed using a Friedman's test. Differences between treatments at any given time were assessed using an independent Kruskal-Wallis test. Where significant effects were identified, pair-wise comparisons were conducted at 30-45, 60-75 and 120-135 min to further explain the direction of the effect. Results: Cats treated with morphine (χ2 = 12.90; df = 6; P = 0.045) and tramadol (χ2 = 20.28; df = 6; P = 0.002) showed significant increases in latency to respond over the duration of the test period. However, subsequent pairwise comparisons indicated that latencies at specific time points were only significantly different (P < 0.05) for tramadol at 60-75 and 90-105 min after administration. No significant pairwise comparisons were found within the morphine treatment group. Injection of saline, ketoprofen, medetomidine or buprenorphine showed no significant effect on latency to respond. Conclusions: This project further validates the CO 2 laser technique for use in cats. It can be used for assessment of thermal nociceptive thresholds in pain-free cats after analgesic administration and shows some promise in differentiating amongst analgesic treatments. It may provide a simpler alternative to existing systems although further exploration is required both in terms of its sensitivity and comparative utility (i.e. relative to other thermal threshold systems). Future experiments should seek to quantify the effects of skin temperature and sedation on latency to respond. Given that this technique was found to cause minor skin blistering in individuals that reached the 60 s exposure limit, a cut off time of <45 s is recommended

Body weight affects behavioural indication of thermal nociceptive threshold in adult domestic cats (Felis catus)

Carbon dioxide (CO2 ) thermal lasers have previously been validated for the assessment of nociception in cats. This experiment sought to assess the potential impact of factors associated with age, sex, body weight and sterilisation upon nociceptive threshold as measured by latency to display a behavioural response. Cats (N = 113) were exposed to a CO2 thermal laser three times during a 45–60 min test period depending upon the interval between tests. A minimum of 15 min elapsed between consecutive tests on any one individual. Time to display either a skin twitch or withdrawal was measured. Intra-class correlations showed the three measurements to be repeatable across tests for any given cat (ICC = 0.482; P < 0.001). Males had a significantly longer mean latency to respond than females (14.83 s and 12.59 s respectively; P = 0.028). Analyses of co-variance established that the body weight of females significantly affected response threshold (P = 0.013) but for males this effect was marginal (P = 0.058). All other factors included in the analyses were non-significant. A post hoc test for males and females with overlapping body weights found no significant differences between the sexes (P = 0.721). The precise reason for the effect of body weight on latency to respond is unknown and further exploration is needed particularly as it relates to sub-cutaneous fat deposition and skin temperature. It is concluded that, for cats, the body weight of the subject should be standardised or included in any analyses for assessment of nociception. Inclusion of body weight data in analyses may also prove useful when using a CO2 laser protocol in other species