Two models of the recognition and detection of texture-defined letters compared

We quantified texture segregation by measuring psychophysically the percentage correct detection scores for each of a set of 10 texture-defined (TD) letters using the temporal two-alternative forced choice method, and at the same time quantified spatial discrimination of the TD form of measuring psychophysically the percentage correct letter recognition scores for the 10 letters. Ten levels of task difficulty were created by adding noise dots to the texture patterns. The resulting psychophysical data were used to test and compare models of the detection and recognition of texture-defined letters. Each model comprised a sequence of physiologically plausible stages in early visual processing. Each had the same first, second and third stages, namely linear orientation-tuned spatial filters followed by rectification and smoothing. Model 1 had only one non-linear stage. Model 2 had two non-linear stages. In model 2 the second non-linear stage was cross-orientation inhibition. This second non-linear stage enhanced the texture borders by, in effect, comparing textures at different locations in the texture pattern. In both models, the last stage modelled either letter detection or letter recognition. Letter recognition was modelled as follows. We passed a given letter stimulus through the first several stages of a model and, in 10 separate calculations, cross-correlated the output with a template of each of the 10 letters. From these 10 correlations we obtained a predicted percentage correct letter recognition score for the given letter stimulus. The predicted recognition scores closely agreed with the experimental data at all 10 levels of task difficulty for model 2, but not for model 1. We conclude that a borderenhancing algorithm is necessary to model letter recognition. The letter-detection algorithm modelled detection of part of a letter (a single letter stroke) in terms of the signal-to-noise ratio of a letter-segment detector. The predicted letter detection scores fitted the data closely for both models.     

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.     

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.     

我院医疗信息服务平台建设的实践探索

医院搭建并应用12582120医疗信息服务平台,对于健康咨询、就医指导、疑难病会诊及预约挂号管理都具有重要意义。主要介绍搭建12582120医疗信息服务平台,包括12582120医疗服务热线平台、易农宝手机APP预约挂号系统、远程医疗服务平台、农村平价医药平台和易复诊医患信息管理APP系统平台为会员服务情况,并针对平台运用中存在的问题提出整改措施,使平台功能最大化,以利于推进分级诊疗体系建设,从而达到方便患者就医的目的。     

Interpretative commenting

* Clinical laboratories should be able to offer interpretation of the results they produce. * At a minimum, contact details for interpretative advice should be available on laboratory reports.Interpretative comments may be verbal or written and printed. * Printed comments on reports should be offered judiciously, only where they would add value; no comment preferred to inappropriate or dangerous comment. * Interpretation should be based on locally agreed or nationally recognised clinical guidelines where available. * Standard tied comments ("canned" comments) can have some limited use.Individualised narrative comments may be particularly useful in the case of tests that are new, complex or unfamiliar to the requesting clinicians and where clinical details are available. * Interpretative commenting should only be provided by appropriately trained and credentialed personnel. * Audit of comments and continued professional development of personnel providing them are important for quality assurance.     

Does paramedic-base hospital contact result in beneficial deviations from standard prehospital protocols?

We reviewed written and audio records of paramedic-base hospital radio contact to determine whether care differed from that suggested in standard prehospital care protocols. Records of all 659 contacts for seizure, syncope, abdominal pain, or altered mental state during 1987 (28.4% of all contacts) were scored for the use of standard therapies (such as intravenous access, oxygen, naloxone hydrochloride) and unanticipated therapies (intubation, nitroglycerin). Cases that involved unanticipated treatments were reviewed to determine whether they could have been prospectively identified by simple clinical findings. Standard therapies were used in the majority of patients. Unanticipated therapies were administered to 13 patients, all of whom had abnormal vital signs, diaphoresis, respiratory distress, or a second prominent symptom. Data suggest that protocols could replace radio contact for most patients and that the few who might benefit from radio contact can be easily identified. A 90% reduction in radio contacts in Los Angeles county could save $3 million each year.     

Letter constraints within words in printed English

Summary Due to the manner in which the English language is used, words exhibit strong internal constraints on letters, but some additional constraint may be imposed by the context in which words appear. In order to estimate the internal constraints of words and the overall effect of context, an experiment was carried out using 225 human subjects who predicted letters in each of the first four positions within words, both with and without context prior to the words. It was found that as more letters at the beginning of words are given, prediction of the following letters increases monotonically, but the increase is not smooth. Prediction of the third letter of words given the first two letters is only a little better than prediction of the second letter given only the first. This effect may be explained by the probable combinations of vowels and consonants at the beginning of words. Letters in the first two positions show no improvement due to long context but prediction of later letters is increased by such context so that prediction rises smoothly from the initial letter to the fourth letter. Also, the type of word in which the letters are to be predicted affects the prediction, function words showing more constraint on letters than content words. The difference between function and content words does not take effect, however, until the first two letters of the word are given. Using the prediction data from words preceded by long context, extrapolations of constraint out to the tenth letter were obtained. From the values of constraint at the first ten letter positions it was possible to estimate the maximum unilateral sequential constraint in English. A value of about 48% was obtained which compares with previous estimates of 50%. A further evaluation of the overall effect of context indicates that about 81% of the constraint in English is contained within the words themselves, and the other 19% is due to any additional context.This paper is based on a dissertation submitted to the Department of Psychology, The Johns Hopkins University, in partial fulfillment of the requirements for the Ph. D. degree. The research was done under Contract Nonr-248(55) between the Office of Naval Research and The Johns Hopkins University. This is Report No. 13 under that contract. Reproduction in whole or in part is permitted for any purpose of the United States Government.During the period of this investigation the author was a National Institutes of Health Fellow. The author wishes to thank Wendell R. Garner for his encouragement and advice.     

An unanswered 2003 letter appealing on behalf of all mankind to Nobel Laureate Roderick McKinnon to use his newfound fame and visibility to begin restoring honesty and integrity to basic biomedical science by rebutting or correcting suspected plagiarism in his Nobel-Prize-winning work

The centerpiece of this document is an unanswered letter of appeal from the author to Professor Roderick MacKinnon of the Rockefeller University dated November 17, 2003. The aim of the appeal is summarized in the title of this communication. In addition to the 2003 letter, there are also two follow-up letters in this communication, each containing a copy of the 2003 letter and each repeating the appeal. The follow-up letters, dated February 22, 2008 and April 2, 2008 respectively, were also unanswered. To make sure that these letters reached their destination, each was certified with delivery time and date affirmed. Thus the February 22 letter was delivered on the February 24 by the US Postal Service. Two copies of the April 2 follow-up letter were sent. The first copy was delivered by Federal Express on April 4. The second copy of the April 2 letter was delivered by the US Postal Service on the same day. Thus all told three additional copies of the 2003 letters were delivered to, and must be in the hand of Professor MacKinnnon. All these efforts were made to make certain that Professor MacKinnon's refusal to answer my registered 2003 letter was not due to his not having received a copy of that letter.     

An Australian Based Study on the Readability of HIV/AIDS and Type 2 Diabetes Clinical Trial Informed Consent Documents

The aims of this study were to measure the readability of Australian based informed consent documents and determine whether informed consent readability guidelines have been established by Australian human research ethics committees (HRECs). A total of 20 informed consent documents, 10 HIV/AIDS and 10 type 2 diabetes, were measured for readability using the Simple Measure of Gobbledygook (SMOG) and Gunning Fog Index (Fog). Published guidelines and policy statements of the two local HREC who approved the 20 clinical trials under study where examined to identify whether they had any formal policies/guidelines on the readability of informed consent documents. The two HRECs were contacted via e-mail to also determine whether they utilised any informal readability standards or “rules of thumb” that may not have been mentioned in the published documents. The HIV/AIDS and type 2 diabetes informed consent documents were, on average, written at a grade 13 reading level. Formal readability standards had not been established by the two local HRECs, however, they did verify the use of informal rules for assessing readability of informed consent documents. Based on Australian literacy data, the majority of informed consent documents were written well beyond the reading ability of many Australians. Unreadable informed consent documents may result in patients rejecting trial participation altogether or conversely may result in their participating in a trial with inadequate consent. Therefore, a step toward reducing the complexity of informed consent documents may be to implement objective readability assessments into the human research ethics application and review process.     

Unconscious letter discrimination is enhanced by association with conscious color perception in visual form agnosia

Adaptive behavior guided by unconscious visual cues occurs in patients with various kinds of brain damage as well as in normal observers, all of whom can process visual information of which they are fully unaware [1] [2] [3] [4] [5] [6] [7] [8]. Little is known on the possibility that unconscious vision is influenced by visual cues that have access to consciousness [9]. Here we report a 'blind' letter discrimination induced through a semantic interaction with conscious color processing in a patient who is agnosic for visual shapes, but has normal color vision and visual imagery. In seeing the initial letters of color names printed in different colors, it is normally easier to name the print color when it is congruent with the initial letter of the color name than when it is not [10]. The patient could discriminate the initial letters of the words 'red' and 'green' printed in the corresponding colors significantly above chance but without any conscious accompaniment, whereas he performed at chance with the reverse color-letter mapping as well as in standard tests of letter reading. We suggest that the consciously perceived colors activated a representation of the corresponding word names and their component letters, which in turn brought out a partially successful, unconscious processing of visual inputs corresponding to the activated letter representations.     

Uptake of cystic fibrosis testing in primary care: supply push or demand pull?

OBJECTIVE--To determine the acceptability and feasibility of screening for carriers of cystic fibrosis in a primary care setting. DESIGN--Follow up study over 15 months of patients offered carrier testing by mouthwash. SETTING--A general practice in inner London. SUBJECTS--5529 patients aged 18-45 invited by various methods and combinations of methods (letter, booklet, personal approach) for testing. MAIN OUTCOME MEASURES--Uptake of screening, anxiety, and knowledge of test. RESULTS--957 (17%) invitees were screened over the 15 months. 28 carriers and no carrier couples were detected. Uptake rates were 12% (59/502 patients) among patients invited by letter and tested by appointment; 9% (47/496) among patients invited by letter, with leaflet, and tested by appointment; 4% (128/2953) among patients invited by letter six weeks before the end of the study and tested by appointment; 17% (81/471) among patients offered passive opportunistic testing; 70% (453/649) among patients offered active opportunistic testing; and 25% (22/88) among patients offered active opportunistic testing by appointment. A short term rise in anxiety among those given a positive test result had dissipated by three months. At three months about one fifth and one third of those given positive and negative results respectively did not understand their results correctly. CONCLUSION--These results suggest that the strongest variable in determining uptake of screening is the active approach by a health professional offering immediate testing. It remains to be resolved whether the high uptake rates achieved by active recruitment indicate a supply push for this new test rather than a demand from the population.     

Effectiveness of a call/recall system in improving compliance with cervical cancer screening: a randomized controlled trial

OBJECTIVE: To determine the effectiveness of a simple call/recall system in improving compliance with cervical cancer screening among women not screened in the previous 3 years. DESIGN: Prospective randomized controlled study. SETTING: Two family medicine clinics (1 urban, 1 rural) affiliated with Memorial University of Newfoundland, St. John''s. PARTICIPANTS: A sample of women aged 18-69 years who were listed as patients of the clinics but who had not had a Papanicolaou test (Pap test) within the 3 years before the start of the study. Of 9071 women listed as patients 1360 (15.0%) had not undergone screening in the previous 3 years. A random sample of 650 were selected, 209 of whom were excluded because they had had a hysterectomy, had had a recent Pap test, had moved or had records containing clerical errors. This left 441 women for the study. INTERVENTION: The 221 women in the intervention group were sent a letter asking them to seek a Pap test and a reminder letter 4 weeks later. The 220 in the control group were sent no letters. MAIN OUTCOME MEASURES: Number of women who had a Pap test within 2 months and 6 months after the first letter was sent. RESULTS: Within 2 months, more women in the intervention group than in the control group had been screened (2.8% [5/178] and 1.9% (4/208] respectively). There was also a difference between the overall proportions at 6 months (10.7% [19/178] and 6.3% [13/208] respectively). None of the differences was statistically significant. CONCLUSION: A letter of invitation is not sufficient to encourage women who have never or have infrequently undergone a Pap test to come in for cervical cancer screening. The effectiveness of added recruitment methods such as opportunistic screening by physicians, follow-up by telephone and the offer of a specific appointment should be evaluated.     

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.     

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.     

The Standard Genetic Code can Evolve from a Two-Letter GC Code Without Information Loss or Costly Reassignments

It is widely agreed that the standard genetic code must have been preceded by a simpler code that encoded fewer amino acids. How this simpler code could have expanded into the standard genetic code is not well understood because most changes to the code are costly. Taking inspiration from the recently synthesized six-letter code, we propose a novel hypothesis: the initial genetic code consisted of only two letters, G and C, and then expanded the number of available codons via the introduction of an additional pair of letters, A and U. Various lines of evidence, including the relative prebiotic abundance of the earliest assigned amino acids, the balance of their hydrophobicity, and the higher GC content in genome coding regions, indicate that the original two nucleotides were indeed G and C. This process of code expansion probably started with the third base, continued with the second base, and ended up as the standard genetic code when the second pair of letters was introduced into the first base. The proposed process is consistent with the available empirical evidence, and it uniquely avoids the problem of costly code changes by positing instead that the code expanded its capacity via the creation of new codons with extra letters.     

Increasing Partner Attendance in Antenatal Care and HIV Testing Services: Comparable Outcomes Using Written versus Verbal Invitations in an Urban Facility-Based Controlled Intervention Trial in Mbeya,Tanzania

In many Sub-Saharan African settings male partner involvement in antenatal care (ANC) remains low, although great benefits for maternal and infant health outcomes have been long recognised, in particular regarding the prevention of HIV transmission. Yet there is paucity on evidence regarding the effectiveness of strategies to increase male partner involvement. This controlled intervention trial in Ruanda Health Centre in Mbeya, Tanzania, assessed the effectiveness of invitation letters for male involvement in ANC. Pregnant women approaching ANC without partners received official letters inviting the partner to attend ANC. A control group was instructed to verbally invite partners. Partner attendance was recorded at two subsequent ANC visits. Rates for male partner return, couple voluntary counselling and testing (CVCT), and influencing factors were analysed. From 199 ANC clients in total, 97 were assigned to the invitation letter group; 30 of these (30.9%) returned with their male partners for ANC. In the control group of 102 women, 28 (27.5%) returned with their partner. In both groups CVCT rates among jointly returning couples were 100%. Partner return/CVCT rate was not statistically different in intervention and control group (OR 1.2, p = 0.59). Former partner attendance at ANC during a previous pregnancy was the only factor found to be significantly linked with partner return (p = 0.03). Our study demonstrates that rather simple measures to increase male partner attendance in ANC and CVCT can be effective, with written and verbal invitations having comparable outcomes. In terms of practicability in Sub-Saharan African settings, we recommend systematic coaching of ANC clients on how to verbally invite male partners in the first instance, followed by written invitation letters for partners in case of their non-attendance. Further studies covering both urban and rural settings will be more informative for effective translation into policy.     

Evaluating Letter Recognition,Flicker Fusion,and the Talbot-Plateau Law using Microsecond-Duration Flashes

Four experiments examined the ability of respondents to identify letters that were displayed on an LED array with flashes lasting little more than a microsecond. The first experiment displayed each letter with a single, simultaneous flash of all the dots forming the letter and established the relation of flash intensity to the probability of letter identification. The second experiment displayed the letters with multiple flashes at different frequencies to determine the probability that the sequence of flashes would be perceived as fused. The third experiment displayed the letters at a frequency that was above the flicker-fusion frequency, varying flash intensity to establish the amount needed to elicit a given probability of letter identification. The fourth experiment displayed each letter twice, once at a frequency where no flicker was perceived and also with steady light emission. The intensity of each flash was fixed and the steady intensity was varied; respondents were asked to judge whether the fused-flicker display and the steady display appeared to be the same brightness. Steady intensity was about double the average flash intensity where the two conditions were perceived as being equal in brightness. This is at odds with Talbot-Plateau law, which predicts that these two values should be equal. The law was formulated relative to a flash lasting half of each period, so it is surprising that it comes this close to being correct where the flash occupies only a millionth of the total period.     

Neural Correlates of Letter Reversal in Children and Adults

Children often make letter reversal errors when first learning to read and write, even for letters whose reversed forms do not appear in normal print. However, the brain basis of such letter reversal in children learning to read is unknown. The present study compared the neuroanatomical correlates (via functional magnetic resonance imaging) and the electrophysiological correlates (via event-related potentials or ERPs) of this phenomenon in children, ages 5–12, relative to young adults. When viewing reversed letters relative to typically oriented letters, adults exhibited widespread occipital, parietal, and temporal lobe activations, including activation in the functionally localized visual word form area (VWFA) in left occipito-temporal cortex. Adults exhibited significantly greater activation than children in all of these regions; children only exhibited such activation in a limited frontal region. Similarly, on the P1 and N170 ERP components, adults exhibited significantly greater differences between typical and reversed letters than children, who failed to exhibit significant differences between typical and reversed letters. These findings indicate that adults distinguish typical and reversed letters in the early stages of specialized brain processing of print, but that children do not recognize this distinction during the early stages of processing. Specialized brain processes responsible for early stages of letter perception that distinguish between typical and reversed letters may develop slowly and remain immature even in older children who no longer produce letter reversals in their writing.     

Are Individual Differences in Reading Speed Related to Extrafoveal Visual Acuity and Crowding?

Readers differ considerably in their speed of self-paced reading. One factor known to influence fixation durations in reading is the preprocessing of words in parafoveal vision. Here we investigated whether individual differences in reading speed or the amount of information extracted from upcoming words (the preview benefit) can be explained by basic differences in extrafoveal vision—i.e., the ability to recognize peripheral letters with or without the presence of flanking letters. Forty participants were given an adaptive test to determine their eccentricity thresholds for the identification of letters presented either in isolation (extrafoveal acuity) or flanked by other letters (crowded letter recognition). In a separate eye-tracking experiment, the same participants read lists of words from left to right, while the preview of the upcoming words was manipulated with the gaze-contingent moving window technique. Relationships between dependent measures were analyzed on the observational level and with linear mixed models. We obtained highly reliable estimates both for extrafoveal letter identification (acuity and crowding) and measures of reading speed (overall reading speed, size of preview benefit). Reading speed was higher in participants with larger uncrowded windows. However, the strength of this relationship was moderate and it was only observed if other sources of variance in reading speed (e.g., the occurrence of regressive saccades) were eliminated. Moreover, the size of the preview benefit—an important factor in normal reading—was larger in participants with better extrafoveal acuity. Together, these results indicate a significant albeit moderate contribution of extrafoveal vision to individual differences in reading speed.     

Quality of life measures in health care. I: Applications and issues in assessment.

Many clinicians remain unsure of the relevance of measuring quality of life to their clinical practice. In health economics quality of life measures have become the standard means of assessing the results of health care interventions and, more controversially, the means of prioritising funding; but they have many other applications. This article--the first of three on measuring quality of life--reviews the instruments available and their application in screening programmes, audit, health care research, and clinical trials. Using the appropriate instrument is essential if outcome measures are to be valid and clinically meaningful.