Hemispheric differences in visual recognition of two Kanji characters

The purpose of the present study was to examine hemispheric differences in visual recognition of two kanji letters. Kanji phrases and nonsense kanji letters were presented unilaterally to the left or right visual hemifield in thirty normal right-handed men by a tachistoscope. The experiments were separated into three conditions; the mixing tasks (ten phrases and ten sets of nonsense letters are presented by mixture), the phase task (twenty phrases are presented), and the nonsense letters task (twenty sets of nonsense letters are presented). Under all conditions, significant right visual hemifield superiorities for the accuracy of recognition of phrase and nonsense letters were observed.     

Referral letters and replies from orthopaedic departments: opportunities missed.

OBJECTIVE--To study delays between sending referral letters and the outpatient appointment and to assess the content of referral and reply letters, their educational value, and the extent to which questions asked are answered by reply letters. DESIGN--Retrospective review of referrals to 16 consultant orthopaedic surgeons at five hospitals, comprising 288 referral letters with corresponding replies, by scoring contents of letters. SETTING--Orthopaedic teaching hospitals in Nottingham, Derby, and Mansfield. MAIN OUTCOME MEASURES--Weighted scores of contents of referral and reply letters, assessment of their educational value, and responses to questions in referral letters. RESULTS--Median outpatient delay was 23.4 weeks. There was no significant decrease in waiting time if the referral letter was marked "urgent" but a significantly greater delay (p less than 0.01) if referrals were directed to an unnamed consultant. The content score was generally unsatisfactory for both referrals and replies, and there was no correlation for the content scores of the referral letter and its reply (r = 0.13). Items of education were rare in the referral letters (8/288; 3%) and significantly more common in replies (75/288; 26%) (p much less than 0.001). Senior registrars were significantly more likely to attempt education than other writers (p less than 0.02). Education in replies was significantly related to increased length of the letter (p less than 0.05) and was more likely to occur if the referral was addressed to a named consultant (p less than 0.03). 48 (17%) Referral letters asked questions, of which 21 (44%) received a reply. No factor was found to influence the asking of or replying to questions. CONCLUSIONS--The potential for useful communication in the referral letter and in the reply from orthopaedic surgeons is being missed at a number of levels. The content is often poor, the level of mutual education is low, and the use of the referral letter to determine urgency is deficient. Most questions asked by general practitioners are not answered.     

Is communication improving between general practitioners and psychiatrists?

General practitioners and psychiatrists communicate mainly by letter. To ascertain the most important items of information that should be included in these letters ("key items") questionnaires were sent to 80 general practitioners and 80 psychiatrists. A total of 120 referral letters sent to psychiatric clinics in 1973 and 1983 were studied, together with the psychiatrists'' replies, and these were rated for the inclusion of "key items." General practitioners'' letters contain less information about the family but more about psychiatric history than they did a decade ago. Overall, psychiatrists'' letters have not changed. Registrars, however, now include noticeably more "key items" than they did 10 years ago, but their letters remain twice the length of those written by consultants. It is suggested that letter writing skills are vital to good patient management and should be taught to postgraduate trainees in general practice and psychiatry.     

A validation study of appropriate phonological verbal fluency stimulus letters for use with croatian speaking individuals

The aim of this study is to determine the word frequency for all thirty letters of the Croatian alphabet and to collect normative data for the letter fluency task in Croatian speakers. Ninety two healthy participants were given each of the Croatian letters, and asked to generate as many words as possible in 60 seconds for each letter Results suggested that participants generated most frequently words starting with the letters as follows: "K", "P", "S" and "M".     

Influence of the Emotional Factor on EEG Correlates of the Recognition of a Significant Light Stimulus

Spatiotemporal EEG characteristics of an operator were analyzed at different stages of visual recognition of letters under conditions of exposure to negative emotional factors: the threat of electrodermal stimulation and an information deficit produced by a decrease in the time of stimulus presentation. It was shown that, during exposure to the emotional factors under study, recognition sensorimotor performance was associated with decreased intra- and interhemispheric crosscorrelation coefficients. The most prominent changes in this parameter were observed under the conditions of an information deficit. Under these complicated conditions, the stimulus recognition was characterized by differently directed redistributions of potentials in the - and frequency ranges in the rostral and caudal regions of the brain. It is suggested that, under the influence of emotional factors, a functional system with decreased interrelation of the brain structures is formed. Such a system provides optimal sensorimotor performance during exposure to emotional factors.     

A sharp minimum on the mean number of steps taken in adaptive walks

It was recently conjectured by H.A. Orr that from a random initial point on a random fitness landscape of alphabetic sequences with one-mutation adjacency, chosen from a larger class of landscapes, no adaptive algorithm can arrive at a local optimum in fewer than on average e-1 steps. Here, using an example in which the mean number of steps to a local optimum equals (A-1)/A, where A is the number of distinct "letters" in the "alphabet" from which sequences are constructed, it is shown that as originally stated, the conjecture does not hold. It is also demonstrated that (A-1)/A is a sharp minimum on the mean number of steps taken in adaptive walks on fitness landscapes of alphabetic sequences with one-mutation adjacency. As the example that achieves the new lower bound has properties that are not often considered as potential attributes for fitness landscapes-non-identically distributed fitnesses and negative fitness correlations for adjacent points-a weaker set of conditions characteristic of more commonly studied fitness landscapes is proposed under which the lower bound on the mean length of adaptive walks is conjectured to equal e-1.     

A preprocessor for shotgun assembly of large genomes.

The whole-genome shotgun (WGS) assembly technique has been remarkably successful in efforts to determine the sequence of bases that make up a genome. WGS assembly begins with a large collection of short fragments that have been selected at random from a genome. The sequence of bases at each end of the fragment is determined, albeit imprecisely, resulting in a sequence of letters called a "read." Each letter in a read is assigned a quality value, which estimates the probability that a sequencing error occurred in determining that letter. Reads are typically cut off after about 500 letters, where sequencing errors become endemic. We report on a set of procedures that (1) corrects most of the sequencing errors, (2) changes quality values accordingly, and (3) produces a list of "overlaps," i.e., pairs of reads that plausibly come from overlapping parts of the genome. Our procedures, which we call collectively the "UMD Overlapper," can be run iteratively and as a preprocessor for other assemblers. We tested the UMD Overlapper on Celera's Drosophila reads. When we replaced Celera's overlap procedures in the front end of their assembler, it was able to produce a significantly improved genome.     

Efficacy and Safety of Intravitreal Therapy in Macular Edema Due to Branch and Central Retinal Vein Occlusion: a Systematic Review

Background

Intravitreal agents have replaced observation in macular edema in central (CRVO) and grid laser photocoagulation in branch retinal vein occlusion (BRVO). We conducted a systematic review to evaluate efficacy and safety outcomes of intravitreal therapies for macular edema in CRVO and BRVO.

Methods

And Findings: MEDLINE, Embase, and the Cochrane Library were systematically searched for RCTs with no limitations of language and year of publication. 11 RCTs investigating anti-VEGF agents (ranibizumab, bevacizumab, aflibercept) and steroids (triamcinolone, dexamethasone implant) with a minimum follow-up of 1 year were evaluated.

Efficacy: CRVO

Greatest gain in visual acuity after 12 months was observed both under aflibercept 2 mg: +16.2 letters (8.5 injections), and under bevacizumab 1.25 mg: +16.1 letters (8 injections). Ranibizumab 0.5 mg improved vision by +13.9 letters (8.8 injections). Triamcinolone 1 mg and 4 mg stabilized visual acuity at a lower injection frequency (-1.2 letters, 2 injections).

BRVO

Ranibizumab 0.5 mg resulted in a visual acuity gain of +18.3 letters (8.4 injections). The effect of dexamethasone implant was transient after 1.9 implants in both indications.

Safety

Serious ocular adverse events were rare, e.g., endophthalmitis occurred in 0.0-0.9%. Major differences were found in an indirect comparison between steroids and anti-VEGF agents for cataract progression (19.8-35.0% vs. 0.9-7.0%) and in required treatment of increased intraocular pressure (7.0-41.0% vs. none). No major differences were identified in systemic adverse events.

Conclusions

Anti-VEGF agents result in a promising gain of visual acuity, but require a high injection frequency. Dexamethasone implant might be an alternative, but comparison is impaired as the effect is temporary and it has not yet been tested in PRN regimen. The ocular risk profile seems to be favorable for anti-VEGF agents in comparison to steroids. Because comparative data from head-to-head trials are missing currently, clinicians and patients should carefully weigh the benefit-harm ratio.     

An audit of the BMJ's correspondence columns.

OBJECTIVE--To see whether some sections of the BMJ attract more comment than others, whether letters submitted in response to different sections of the journal are rejected at different rates, and whether the balance between letters that agree and disagree with articles in the published correspondence reflects that in submitted letters. DESIGN--Retrospective audit of letters submitted for publication in the correspondence columns of the BMJ in response to articles published between 1 January and 21 May 1989. SUBJECTS--A total of 1319 letters received by the journal, 974 submitted in response to the 1501 published articles and a further 345 raising new issues. MAIN OUTCOME MEASURES--The total numbers of letters submitted in response to the four main sections of the journal--editorials, news, papers, and middles--and the numbers published. Submitted and published letters were analysed according to whether they agreed or disagreed with articles. RESULTS--The overall rejection rate was 63% (831/1319), but among letters relating to articles it was 56% (543/974). Editorials and middles attracted proportionately more letters than papers, but letters relating to papers had a lower rejection rate (43% v 57% for editorials and 43% v 66% for middles). For all sections more letters disagreed than agreed, but a higher proportion of letters in response to editorials and middles disagreed than those submitted in response to papers (64% and 72% v 53%). Among the published letters, however, broadly equal numbers of letters agreed and disagreed with articles, irrespective of section. CONCLUSION--Those sections of the journal that aim at stimulating debate succeeded in attracting the most comment. The relative importance of original scientific research papers was reflected by the priority given to letters submitted in response to papers, and the final correspondence column was a balanced platform of debate despite an unequal submitted response in terms of letters that agreed and disagreed with different sections of the journal.     

Topography of visual event-related potentials during geometric and phonetic discriminations

Event-related potentials (ERPs) were obtained to letters during 3 tasks that involved a SIMPLE RESPONSE (SR) to each letter presentation, a FORM discrimination of the letters that formed a closed loop, and a RHYME discrimination of the letters that rhymed with the letter ‘v’. The first task only required detection of the letters, the FORM task required a visual-spatial analysis. and the RHYME task, a grapheme-phoneme conversion of the letters followed by a determination of rhyming characteristics. The SR ERPs were morphologically different from the discriminative ERPs, notably by the absence of N2 and P3. The difference wave forms between the discrimination and SR conditions and between the targets and non-targets indicated differential topographies of components associated with the FORM and RHYME tasks in the 300 msec latency region. In both of these tasks, components exhibited distributions localized primarily in the occipital regions, whereas in the RHYME task they extended more anteriorly and encompassed temporo-parietal regions. Thus, although the stimulus presentation was visual, the requirement of a visual-auditory conversion in the RHYME task resulted in activity that was more proximal to auditory regions than when only a FORM analysis of the letters was required.     

Recognizing Words and Reading Sentences with Microsecond Flash Displays

Strings of dots can be used to construct easily identifiable letters, and these in turn can be used to write words and sentences. Prior work found that respondents could identify individual letters when all the dots were simultaneously flashed for an ultra-brief duration. Four of the experiments reported here constructed five-letter words with these dot-letters and a fifth experiment used them to write complete sentences. Respondents were able to recognize individual words that were displayed with a single, simultaneous ultra-brief flash of all the letters. Further, sentences could be efficiently read with a sequence of simultaneous flashes at a frequency that produced perceptual fusion. One experiment determined the frequency range that would produce flicker-fusion. Two experiments established the relation of intensity to probability of recognition with single flashes and with fused-flicker frequencies. Another established the intensities at which flicker-fused and steady displays were judged to be equal in brightness. The final experiment used those flicker-fused and steady intensities to display sentences. The two display conditions were read with equal efficiency, even though the flicker-fused displays provided light stimulation only 0.003% of the time.     

Influenza vaccination in the elderly: 2. The economics of sending reminder letters

Reminder letters and follow-up telephone calls were used to increase influenza vaccination acceptance by 273 well elderly registered at an urban community health centre. The net effect of the reminder letters was to increase overall coverage to 43%, from 17% in the previous year. Follow-up telephone calls to patients who had not responded to the letters increased coverage to only 55%. Calculation of costs per additional vaccination given revealed that the use of reminder letters alone was much more cost-effective than follow-up telephone calls in increasing coverage. However, with the current fee-for-service reimbursement by medical care insurance in Ontario, neither means of improving vaccination coverage would result in net practice earnings. The implications for an effective and efficient annual influenza program in Canada are discussed.     

Letter Position Coding Across Modalities: The Case of Braille Readers

Background

The question of how the brain encodes letter position in written words has attracted increasing attention in recent years. A number of models have recently been proposed to accommodate the fact that transposed-letter stimuli like jugde or caniso are perceptually very close to their base words.

Methodology

Here we examined how letter position coding is attained in the tactile modality via Braille reading. The idea is that Braille word recognition may provide more serial processing than the visual modality, and this may produce differences in the input coding schemes employed to encode letters in written words. To that end, we conducted a lexical decision experiment with adult Braille readers in which the pseudowords were created by transposing/replacing two letters.

Principal Findings

We found a word-frequency effect for words. In addition, unlike parallel experiments in the visual modality, we failed to find any clear signs of transposed-letter confusability effects. This dissociation highlights the differences between modalities.

Conclusions

The present data argue against models of letter position coding that assume that transposed-letter effects (in the visual modality) occur at a relatively late, abstract locus.     

Reading between Eye Saccades

Background

Skilled adult readers, in contrast to beginners, show no or little increase in reading latencies as a function of the number of letters in words up to seven letters. The information extraction strategy underlying such efficiency in word identification is still largely unknown, and methods that allow tracking of the letter information extraction through time between eye saccades are needed to fully address this question.

Methodology/Principal Findings

The present study examined the use of letter information during reading, by means of the Bubbles technique. Ten participants each read 5,000 five-letter French words sampled in space-time within a 200 ms window. On the temporal dimension, our results show that two moments are especially important during the information extraction process. On the spatial dimension, we found a bias for the upper half of words. We also show for the first time that letter positions four, one, and three are particularly important for the identification of five-letter words.

Conclusions/Significance

Our findings are consistent with either a partially parallel reading strategy or an optimal serial reading strategy. We show using computer simulations that this serial reading strategy predicts an absence of a word-length effect for words from four- to seven letters in length. We believe that the Bubbles technique will play an important role in further examining the nature of reading between eye saccades.     

JUZBOX: A web server for extracting biomedical words from the protein sequence

The recognition of gene/protein names in literature is one of the pivotal steps in the processing of biological literatures for information extraction or data mining. We have compiled a lexicon of biomedical words (conserved patterns/ potential motifs) which has the combination of only 20 alphabets of amino acids. The remaining 6 letters of the English alphabets (B, J, O, U, X, Z) are treated as invalid amino acid characters (to our context), We have jumbled the 6 letters for the sake of usage and convenience and termed as ’JUZBOX‘ and these characters were filtered in the biomedical lexicon. Undoubtedly, the generation of biomedical words from protein sequence using JUZBOX have applications specific for functional annotation.

Availability

JUZBOX is available freely at http://www.spices.res.in/juzbox     

Essay: Letters,numbers, symbols and words: how to communicate grades of evidence and recommendations

THE GRADE WORKING GROUP IS DEVELOPING and evaluating a common, sensible approach to grading quality of evidence and strength of recommendations in health care. In this article, we discuss the advantages and disadvantages of using letters, numbers, symbols or words to represent grades of evidence and recommendations. Using multiple strategies, we searched for comparative studies of alternative ways of representing ordered categories in any context. In addition, we contacted experts and reviewed theoretical work and qualitative research on how best to communicate grades of any kind quickly and clearly. We were unable to identify health care research that addressed, either directly or indirectly, the best way to present grades of evidence and recommendations. We found examples of symbols used by government, commercial and consumer organizations to communicate quality of evidence or strength of recommendations, but no comparative studies. Although a number of grading systems are used in health care and other fields, there is little or no evidence of how well various presentations are understood. Before promoting the use of specific symbols, numbers, letters or words, the extent to which the intended message is comprehended should be evaluated. Organizations such as the Canadian Task Force on Preventive Health Care¹ and more than 100 other groups² use various systems of codes to communicate grades of evidence and recommendations. The codes fall primarily into 3 categories: letters (e.g., A, B, C, etc.), numbers (e.g., I, II, III, etc.) and mixed letters and numbers (e.g., Ia, Ib, IIa, etc.).Health care practitioners, especially students, are often puzzled by the message a grade conveys. For example, the administration of oral anticoagulation in patients with atrial fibrillation and rheumatic mitral valve disease receives various grades of recommendation from different organizations: Class I based on level B evidence by the American Heart Association,³ grade C recommendation based on level IV evidence by SIGN² and grade 1C+ (where the 1 indicates the balance between benefit and harm and C+ the methodological quality of the underlying evidence) by the American College of Chest Physicians.⁴ Thus, the various grading systems may not be fulfilling their intended function: to communicate a clear message, quickly and concisely. Indeed, if the same code, used by different systems, represents different meanings, bewilderment and incomprehension may result.We formed the GRADE Working Group with the hope of reaching agreement on a common, sensible approach to grading quality of evidence and strength of recommendations. We consider here the advantages and disadvantages of using letters, numbers, symbols or words to represent different grades.     

A Meta-Analysis of Anti-Vascular Endothelial Growth Factor Remedy for Macular Edema Secondary to Central Retinal Vein Occlusion

Background

Central retinal vein occlusion (CRVO) associates with severe vision outcome and no proven beneficial treatment. Our meta-analysis intended to appraise the efficacy and safety of anti-vascular endothelial growth factor (anti-VEGF) agents in macular edema (ME) following CRVO.

Methods

Data were collected and analyzed by Review Manager 5.2.1. We employed a random-effects model to eliminate between-study heterogeneity. N_fs (called fail-safe number) was calculated to evaluate the publication bias.

Results

We included 5 trials consisting 323 cases and 281 controls. Primary outcomes showed that overall comparison of anti-VEGF agents with placebo control yielded a 374% and 136% increased tendency for a gain of 15 letters or more on Early Treatment Diabetic Retinopathy Study (ETDRS) chart (95% confidence interval [95% CI]: 2.43–9.23; P<0.00001; I² = 59%, 95% CI: 1.60–3.49; P<0.0001; I² = 0%, respectively) at 6 and 12 months. Secondary outcomes showed that a 90% and 77% decreased risk at 6 and 12 months for a loss of 15 letters or more. The overall mean difference showed a statistically significance in best-corrected visual acuity (BCVA) on each time point. However, changes of central retinal thickness (CRT) lost significance at 12 months after 6-month as-needed treatment. The incidence of adverse events (AEs) had no statistical difference between anti-VEGF and placebo groups. Subgroup analyses indicated that patients receiving Aflibercept got the highest tendency to gain 15 letters or more (OR = 9.78; 95% CI: 4.43–21.56; P<0.00001). Age controlled analysis suggested a weaken tendency of BCVA improvement in age over 50 (MD = 12.26; 95% CI: 7.55–16.98; P<0.00001). Subgroup analysis by clinical classification showed a strengthen difference of BCVA changes at 6 months in ischemic type (MD = 19.65 letters, 95% CI: 13.15 to 26.14 letters, P<0.00001).

Conclusions

Our results showed that anti-VEGF agents were superior to placebo in CRVO-ME treatment with no statistically significant AEs, especially in younger people and for ischemic type.     

Communication between general practitioners and consultants: what should their letters contain?

OBJECTIVE--To canvass the views of all general practitioners and consultants working in Newcastle upon Tyne on the content of referral letters and replies, the feasibility of standardising certain aspects of referral letters, and the use of communications data for audit purposes. DESIGN--A postal questionnaire was sent to all general practitioners and consultants in Newcastle upon Tyne in May 1991. Questions were asked about the clinical and administrative content of letters, the utility of standard categories to state the reason for referral, the idea of using letters for feedback purposes, and communications as a potential topic for professionally led audit. SETTING--Area served by Newcastle upon Tyne Family Health Services Authority and District Health Authority. RESULTS--Replies were received from 274 (77%) doctors (115 general practitioners and 159 consultants). A majority (225; 82%) were in favour of items defined as "always important" forming a minimum requirement for referral letters and for consultants'' replies. Using standardised categories to state the reason for referral was not endorsed: 102 (89%) general practitioners and 132 (83%) consultants preferred referrers to use their own words. Using referral communications to provide feedback was less popular with consultants (54; 34%) than general practitioners (72; 63%). Finally, a majority of doctors (179; 65%) were in favour of using written communications as a topic for professionally led audit. CONCLUSIONS--A high degree of consensus exists among clinicians about the content of referral communications. Although doctors may still reject the concept of standardised communications, they have unambiguously endorsed a standard for communication that they can aspire to, and they are prepared to use it as a yardstick for their actual performance.