The advantage of mixing examples in inductive learning: a comparison of three hypotheses

Mixing examples of different categories (interleaving) has been shown to promote inductive learning as compared with presenting examples of the same category together (massing). In three studies, we tested whether the advantage of interleaving is exclusively due to the mixing of examples from different categories or to the temporal gap introduced between presentations. In addition, we also tested the role of working memory capacity (WMC). Results showed that the mixing of examples might be the key component that determines improved induction. WMC might also be involved in the interleaving effect: participants with high spans seemed to profit more than participants with low spans from interleaved presentations. Our findings have relevant implications for education. Practice schedules should be individually customised so society as a whole can profit from differences between learners.     

The impacts of fundraising periods and geographic distance on financing music production via crowdfunding in Brazil

We conduct an analysis of 1835 pledges to 10 music production projects hosted on the largest Brazilian crowdfunding platform, namely the Catarse Web site, and we assess the relation between the fundraising accumulation period, the donor–entrepreneur distance and the propensity of donors to back projects. Our results suggest a significantly negative association between distance and the value of capital pledged to projects, which is consistent with the notion that the entrepreneur’s network of close contacts might play a central role in funding. Furthermore, our results contradict the idea that crowdfunding reduces the inhibiting effect of donor–entrepreneur distance. In addition, the results show that a long project exposure is associated with higher values of pledges. These results suggest practical implications for the study of crowdfunding as a financing platform. This study contributes to the literature on the use of crowdfunding as an alternative funding source in a major emerging market.     

Effects of identical context on visual pattern recognition by pigeons

The effects of identical context on pattern recognition by pigeons for outline drawings of faces were investigated by training pigeons to identify (Experiment 1) and categorize (Experiment 2) these stimuli according to the orientation of the mouth—an upright U shape representing a smiling mouth or an inverted U shape representing a sad mouth. These target stimuli were presented alone (Pair 1), with three dots in a triangular orientation to represent a nose and eyes (Pair 2), and with the face pattern surrounded by an oval (Pair 3). In Experiment 1, the pigeons trained with Pair 1 were most accurate, those trained with Pair 2 were less so, and those trained with Pair 3 failed to acquire the discrimination within eighty 100-trial sessions. The same ordering was found in Experiment 2 for pigeons trained on the three pairs simultaneously. The authors suggest that a contrasting finding in humans, the face superiority effect, might be due to a gain in discriminability resulting from recognition of the pattern as a face. An exemplar model of information processing that excludes linguistic coding accounts for the present results.     

Effect of verbal instructions and image size on visual search strategies in basketball free throw shooting

We assessed the effects on basketball free throw performance of two types of verbal directions with an external attentional focus. Novices (n = 16) were pre-tested on free throw performance and assigned to two groups of similar ability (n = 8 in each). Both groups received verbal instructions with an external focus on either movement dynamics (movement form) or movement effects (e.g. ball trajectory relative to basket). The participants also observed a skilled model performing the task on either a small or large screen monitor, to ascertain the effects of visual presentation mode on task performance. After observation of six videotaped trials, all participants were given a post-test. Visual search patterns were monitored during observation and cross-referenced with performance on the pre- and post-test. Group effects were noted for verbal instructions and image size on visual search strategies and free throw performance. The 'movement effects' group saw a significant improvement in outcome scores between the pre-test and post-test. These results supported evidence that this group spent more viewing time on information outside the body than the 'movement dynamics' group. Image size affected both groups equally with more fixations of shorter duration when viewing the small screen. The results support the benefits of instructions when observing a model with an external focus on movement effects, not dynamics.     

Use of sexuality-focused entertainment media in sex education

The literature on the impact of entertainment media on sex education is typically pathology-focused, unclear regarding the effects of such usage, and void of dialogue between those who actually work in the areas of sexuality education and entertainment. To address this gap, this paper is the product of joint authorship between media figures from varied sexually-focused programming fields and academics who teach and conduct research in the areas of sexuality and relational health. The authors focus on the role that various forms of entertainment media play in educating members of the public and college classrooms in the areas of sex and sexuality. Additionally, examples of the inclusion of entertainment media in educational contexts are discussed.     

Optimal control of eutrophication processes in a moving domain

This work deals with an environmental problem related to controlling eutrophication inside a sensitive zone, by means of a regulation of the wastewater discharges in the region. After setting a detailed mathematical formulation of the optimal control problem posed on a free-boundary moving domain, we present several theoretical results on existence-regularity of optimal solutions, and their characterization by a first order optimality system. In the second part of the work a complete numerical algorithm for the resolution of the control problem is proposed, and several numerical examples are also given.     

A deep vein thrombosis caused by 20209C>T mutation in homozygosis of the prothrombin gene in a Caucasian patient

Introduction:

Additional nucleotide substitutions in the 3′-untranslated region of prothrombin gene could explain some thrombotic events and also adverse pregnancy outcomes. We describe the first case of a homozygous 20209C>T mutation as the cause of deep vein thrombosis in a Spanish patient.

Case and methods:

The 56-year-old male patient with a partial tear of the Achilles tendon developed calf (tibial) deep vein thrombosis after immobilization and was treated with an anticoagulant. To determine if the deep vein thrombosis was of genetic origin, a peripheral blood DNA sample was analysed for the presence of the three most frequent mutations associated with thrombotic events: factor V Leiden (1691G>A), prothrombin (20210G>A) and methylene tetrahydrofolate reductase (677C>T). The presence or absence of the normal allele of prothrombin could not be determined using the PTH-FV-MTHFR StripAssay (Vienna Lab).

Results:

Comprehensive analysis showed that the patient had a variant interfering with the polymerase chain reaction product, we sequenced the entire prothrombin gene and found that the patient had a homozygous C>T mutation at position 20209; this interfered with the polymerase chain reaction product, which needs a C at this position to be able to bind to the wild-type probe present in the test strip.

Conclusion:

The homozygous 20209C>T mutation and the presence of the mutation 677C>T in heterozygosity explained the patient’s deep vein thrombosis because the combination of mutations would increase the risk of thrombosis. Suitable genetic counselling should be provided to the patient and first-degree relatives as it important to detect prothrombin gene variants that could increase risk for thrombotic events.