Indicators of letter visual similarity have been used for controlling the design of empirical and neuropsychological studies and for rigorously determining the factors that underlie reading ability and literacy acquisition. Additionally, these letter similarity/confusability matrices have been useful for studies examining more general aspects of human cognition, such as perception. Despite many letter visual-similarity matrices being available, they all have two serious limitations if they are to be used by researchers in the reading domain: (1) They have been constructed using atypical reading data obtained from speeded reading-aloud tasks and/or under degraded presentation conditions; (2) they only include letters from the English alphabet. Although some letter visual-similarity matrices have been constructed using data gathered from normal reading conditions, these either are based on old fonts, which may not resemble the letters found in modern print, or were never published. For the first time, this article presents a comprehensive letter visual-similarity/confusability matrix that has been constructed based on untimed responses to clearly presented upper-and lowercase letters that are present in many languages that use Latin-based alphabets, including Catalan, Dutch, English, French, Galician, German, Italian, Portuguese, and Spanish. Such a matrix will be useful for researchers interested in the processes underpinning reading and literacy acquisition.Keywords Letter visual-similarity/confusability matrix . Latin alphabets . Reading . Literacy acquisitionIn an extensive review of the literature spanning over 120 years, Mueller and Weidemann (2012) identified more than 70 published articles that had in one way or another sought to measure letter similarity (or confusability). From this review, the authors identified three main motivations for studying letter similarity: (1) practical attempts to make written text more comprehensible, and thereby allow learners to acquire reading skill more easily; (2) empirical investigations with the goal of understanding how the visual system functions; and (3) theoretical research attempting to explain how letters are represented by the visual system or, in abstract form, by the cognitive system. Regardless of the motivations for studying letter similarity, in the majority of these studies the same basic paradigm has been used-that of presenting single letters to participants, with the task being to name the presented item. A confusion matrix is then constructed by noting how often each letter was (incorrectly) given as a response to the presented letter. The number of responses given for each stimulus-response letter pair has been assumed to be an indication of the level of similarity (or confusability) between the two letters, with more errors on a pair indicating higher similarity/confusability. One problem with this paradigm is that if the letters are presented in a visually clear manner and no time limit to make a response is imposed on the participants, fe...

The World Health Organization (WHO) estimates that 50-80 x 10(6) couples in the world are infertile, i.e. 7-15% of all couples of reproductive age (15-45 years old). The term infertility refers to couples who have been unable to conceive children for at least 1 year of regular unprotected intercourse. Although the frequency and origin of infertility varies, approximately 40-60% of the aetiology of infertility in the population studied is due to female causes. The introduction of assisted reproduction techniques, which offer couples the best opportunities for pregnancy, has opened a vast field of knowledge in reproductive biology. The medical history must be taken meticulously, with enough time to obtain the largest possible amount of relevant information. It is recommended that both partners be included in the initial work-up. In recent decades, technological progress has been favoured with the development of a great variety of diagnostic tests. Moreover, a very valuable tool helping to solve this problem has gained strength and is available to everybody - so-called 'evidence-based medicine'. There are three categories in infertility diagnostic tests. The first category includes tests showing a well-established correlation with pregnancy, e.g. semen analysis, tubal patency with hysterosalpingography or laparoscopy, and ovulation detection. The second category includes patients whose results are not consistently related to pregnancy. Here, these tests include sperm penetration assay in the zona-free hamster oocyte, post-coital tests, sperm penetration into cervical mucus, and tests to detect anti-sperm antibodies. The third group includes patients whose tests are not correlated with pregnancy. The relevant tests include endometrial biopsy, the presence of varicocele, and Chlamydia detection tests. Tests for infertility are often expensive. Since these patients are usually anxious and eager and will do almost anything to have a child, care must be taken to avoid exploitation of their hopes with unnecessary procedures. This text now reviews and updates the procedures used to investigate infertility.

Readers' rhetorical competence is related to reading comprehension and moderates the impact of rhetorical devices in expository texts. In this cross-sectional study, we examine the differences in four measures of rhetorical competence (knowledge of anaphors, organizational signals, refutations, and a total score) in grades three through to six, we determine its contribution to expository text comprehension after controlling the effect of a wide set of linguistic and cognitive variables, and we study whether this contribution is moderated by grade or any of our control variables. First, although we found evidence for some level of rhetorical competence at early ages, data suggest that rhetorical competence development takes many years. Second, we found that knowledge of some rhetorical devices is acquired before knowledge of others. Finally, rhetorical competence was a unique predictor of expository text comprehension, and its influence was evident regardless of grade and all of the control variables. Most research on rhetorical competence concerns students at the end of the primary school or older. This is surprising given that, typically from third grade, children are expected to learn from expository texts across a wide range of subject matter (Best et al., 2008). For this reason, we conducted a cross-sectional study of Spanish students to determine how rhetorical competence develops and its role in the comprehension of expository texts during the elementary school years. The aims of this study were: (1) to describe Spanish students' rhetorical competence from grade three (8-9 years) to six (11-12 years), (2) to determine whether rhetorical competence makes a unique contribution to children's comprehension of expository text in this age range, Rhetorical competence and expository text comprehension in primary 4 above and beyond variables known to be strongly related to comprehension (namely word decoding, integration/inference skills, prior knowledge, and working memory), and (3) to examine whether the contribution of rhetorical competence to expository text comprehension was moderated by grade, or the other variables outlined above. 1.1. Rhetorical devices and rhetorical competence Rhetorical devices are signals that work as ''potential processing instructions'' for understanding the meaning of a discourse without affecting its organization or

No abstract

Under a contract with the GRANTECAN, the Commissioning Instrument is a project developed by a team of Mexican scientists and engineers from the Instrumentation Department of the Astronomy Institute at the UNAM and the CIDESI Engineering Center. This paper will discuss in some detail the final Commissioning Instrument (CI) mechanical design and fabrication. We will also explain the error budget and the barrels design as well as their thermal compensation. The optical design and the control system are discussed in other papers (Cuevas', Flores3).The CI will just act as a diagnostic tool for image quality verification during the GTC Commissioning Phase. This phase is a quality control process for achieving, verifying, and documenting the performance of each GTC sub-systems. This is a very important step for the telescope life. It will begin on starting day and will last for a year.The CI project started in December 2000. The critical design phase was reviewed in July 2001. The CI manufacturing is currently in progress and most parts are finished. We are now approaching the factory acceptance stage.