Estimating the Male to Female Ratio in Autistic Spectrum Disorder, Defining and Calculating the Biases and Finding the True Number of Girls.

The ratio of males to females with ASD is generally quoted as 4:1 though it is believed that there are biases preventing females being diagnosed and that the true ratio is lower. These biases have not been clearly identified or quantified. Starting with a clinical dataset of 1711 children <18 years old four different methods were employed in an inductive study to identify and quantify the biases and calculate the proportion of females missed. A mathematical model was constructed to compare the findings with current published data. The true male to female ratio appears to be 3:4. Eighty per cent of females remain undiagnosed at age 18 which has serious consequences for the mental health of young women.

Enhancing banknote authentication by guiding attention to security features and manipulating prevalence expectancy

All banknotes have security features which are intended to help determine whether they are false or genuine. Typically, however, the general public has limited knowledge of where on a banknote these security features can be found. Here, we tested whether counterfeit detection can be improved with the help of salient elements, designed to guide bottom-up visuospatial attention. We also tested the influence of the participant’s a priori level of trust in the authenticity of the banknote. In an online study (N = 422), a demographically diverse panel of Dutch participants distinguished genuine banknotes from banknotes with one (left- or right-sided) counterfeited security feature. Either normal banknotes (without novel design elements) or banknotes that contained a salient element (a pink rectangular frame) were presented for 1 s. To manipulate the participant’s level of trust, trials were administered in three blocks, whereby at the start of each block, participants were instructed that either one third, one half, or two thirds of the upcoming banknotes were counterfeit (though the true ratio was always 1:1). We hypothesized (i) that in the presence of a salient element, counterfeits would be better detected when the location of the salient element aligned with the location of the counterfeited security feature—i.e. that it would act as an attentional cue; and (ii) that this effect would be stronger with lower trust. Our hypotheses were partly confirmed: counterfeit detection improved with ‘valid cues’ and decreasing trust, but the level of trust did not modulate the cueing effect. As the overall detection performance was rather poor, we replicated the study with a sample of university students (N = 66), this time presenting stimuli until response. While indeed observing better overall performance, all other patterns were replicated. Our results provide evidence that attention can be guided to enhance banknote authentication.

The Golden Section: The “True” Ratio?

Seven rectangles with different ratios of the lengths of their sides but of approximately equal areas were presented to 120 subjects to assess their aesthetic preferences for each rectangle. The method of pair comparisons was used for presentation of the rectangles. Subjects tended to prefer the golden rectangle. Also rectangles in the vicinity of the golden rectangle were preferred to those deviating markedly from it.

An Explanation of the Discrepancy between Direct and Indirect Platelet Counts

The indirect platelet count is higher than the direct count because the red cells, which are used as a point of reference in the indirect method, are not randomly distributed beneath the coverslip. The red cells are concentrated at the edge of the coverslip so that the true ratio of red cells to platelets cannot be accurately established. Indirect platelet counts based on the ratio in the central areas of the coverslip are too high.

X. Bakerian lecture. - on the mechanical equivalent of heat

1. The determination by Joule, in 1849, of the expenditure of mechanical effect (7 72’69 lbs. falling 1 foot) necessary to raise the temperature of 1 lb. of water, weighed in vacuo, 1° Fahr. between the temperatures of 50° and 60° Fahr. (at Manchester), together with the second, in 1878, 772’55 ft.-lbs., to raise the temperature of 1 lb. (weighed in vacuo) from 60° to 6L° Fahr., at the latitude of Greenwich, established once for all the existence of a physically constant ratio between the work expended in producing heat and the heat produced; while the extreme simplicity of his methods, his marvellous skill as an experimenter, and the complete system of checks he adopted, have led to the universal acceptance of the numbers he obtained as being within the limits he himself assigned (1 foot), of the true ratio of work expended in his experiments in producing heat and the heat produced as measured on the scale of the thermometer on which he spent so much time and care.