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Preserved reading aloud with semantic deficits: evidence for a non-semantic lexical route for reading Chinese.

This article describes a Cantonese dyslexic patient with a dissociation between reading ability and oral naming, similar to previously reported cases of Chinese dyslexia. Additional semantic tests without pictorial input were given to localize his impairment to the semantic system. His largely preserved reading performance vis-à-vis semantic deficits, together with the absence of assembled phonology in Chinese, support a model of the Chinese lexicon in which reading can be achieved via two different lexical routes, one with semantic mediation and one without. The patient's poor ability to make homophony judgments of written characters and the high rate of tonal errors suggest that brain injury may have a more detrimental effect on suprasegmental than segmental features of phonological representations.

Asian People↗

Modeling the mind: very-high-field functional magnetic resonance imaging activation during cognition.

This article describes how fMRI can be used to examine the large-scale networks of cortical areas that subserve high-level cognition, such as sentence comprehension and visual thinking. The findings from a number of studies show that the qualitative and quantitative nature of the cognitive processes determines which cortical areas are activated (the network constituency) and the degree to which each network member is activated. For example, during sentence comprehension, activation in the left posterior temporal region and the inferior frontal gyrus, as well as their right hemisphere homologs, increases as a function of the linguistic complexity of the sentence. Such findings indicate that cognition emerges from the collaboration among the multiple cortical areas that compose the large-scale networks, rather than from the aggregate of autonomously functioning modules. The patterns of activation also show systematic shifts in the activity of a network during the spontaneous recovery of function by stroke patients, demonstrating cortical plasticity in adults. Finally, the article describes some simulation models that relate the information processing activity of a computational system to its resource consumption. This construct enables a mapping from the functional properties of the cognitive systems to the biological substrate that is reflected in fMRI.

Adult↗

Effect of periodontal treatment on serum C-reactive protein levels: a systematic review and meta-analysis.

BACKGROUND: Systemic inflammation is increasingly being recognized as a risk factor for adverse cardiovascular events. Evidence is accumulating that associates periodontal disease with a higher risk for atherosclerotic plaque formation. A positive association between circulating C-reactive protein (CRP) levels and periodontal disease may be responsible for these observations. We undertook a systematic review and conducted a meta-analysis of the available evidence to examine the effect of periodontal treatment on systemic CRP levels and to assess the quality of the available evidence. METHODS: We conducted a systematic search of the English-language literature on the effect of periodontal treatment on CRP levels, as assessed by high-sensitivity assays, at least 2 months after periodontal treatment. The search was conducted in MEDLINE between 1966 and July 2005 and the Cochrane Central Register of Controlled Trials. We performed a meta-analysis using the DerSimonian and Laird random-effects model. RESULTS: The literature search yielded 814 citations of which 10 met the inclusion criteria. The meta-analysis of the randomized controlled trials (RCTs) showed that the difference in serum CRP levels is not significantly different between the two arms. Similarly, results from the single-cohort studies showed that the difference on serum CRP levels was not significantly different before and after treatment. CONCLUSIONS: There is now a large body of evidence to indicate that systemic inflammation is present in patients with periodontal disease. Thus, information from RCTs and single-cohort studies does not support the hypothesis that periodontal treatment can reduce systemic CRP levels.

C-Reactive Protein↗

Recursive domains in proteins.

The domain is a fundamental unit of protein structure. Numerous studies have analyzed folding patterns in protein domains of known structure to gain insight into the underlying protein folding process. Are such patterns a haphazard assortment or are they similar to sentences in a language, which can be generated by an underlying grammar? Specifically, can a small number of intuitively sensible rules generate a large class of folds, including feasible new folds? In this paper, we explore the extent to which four simple rules can generate the known all-beta folds, using tools from graph theory. As a control, an exhaustive set of beta-sandwiches was tested and found to be largely incompatible with such a grammar. The existence of a protein grammar has potential implications for both the mechanism of folding and the evolution of domains.

Dimerization↗

Automation of a procedure to find the polynomial which best fits (kappa, c1, c2, T) data of electrolyte solutions by non-linear regression analysis using MATHEMATICA software.

A MATHEMATICA package, 'CONDU.M', has been developed to find the polynomial in concentration and temperature which best fits conductimetric data of the type (kappa, c, T) or (kappa, c1, c2, T) of electrolyte solutions (kappa: specific conductivity; ci: concentration of component i; T: temperature). In addition, an interface, 'TKONDU', has been written in the TCL/Tk language to facilitate the use of CONDU.M by an operator not familiarised with MATHEMATICA. All this software is available on line (UPV/EHU, 2001). 'CONDU.M' has been programmed to: (i) select the optimum grade in c1 and/or c2; (ii) compare models with linear or quadratic terms in temperature; (iii) calculate the set of adjustable parameters which best fits data; (iv) simplify the model by elimination of 'a priori' included adjustable parameters which after the regression analysis result in low statistical significance; (v) facilitate the location of outlier data by graphical analysis of the residuals; and (vi) provide quantitative statistical information on the quality of the fit, allowing a critical comparison among different models. Due to the multiple options offered the software allows testing different conductivity models in a short time, even if a large set of conductivity data is being considered simultaneously. Then, the user can choose the best model making use of the graphical and statistical information provided in the output file. Although the program has been initially designed to treat conductimetric data, it can be also applied for processing data with similar structure, e.g. (P, c, T) or (P, c1, c2, T), being P any appropriate transport, physical or thermodynamic property.

Journal Article↗

Habituation to irrelevant speech: effects on a visual short-term memory task.

The Baddeley and Hitch (1974) formulation of short-term or working memory embodied a phonological store within the articulatory loop component of the model. Later formulations specifically postulated an acoustic filter that endowed only speech-like stimuli with obligatory access to this phonological store. This paper presents evidence that this phonological store may have two filters, one of which is subject to habituation and can therefore attenuate the entry of irrelevant speech, thus undermining the obligatory access assumption of the model. An experiment is reported in which subjects were presented with a habituation period comprising 20 min of irrelevant speech--speech to be ignored by the subject--before a test phase in which a visually presented serial recall task with concurrent irrelevant speech was performed. The effect of irrelevant speech, which impairs performance on the primary task when there is no habituation phase, is reduced markedly in those conditions where the speech used in the habituation phase is the same as that used in the test phase, if the irrelevant speech is in a language different from that presented during the subsequent trials or if the habituator is a hummed version of the irrelevant speech passage. When a nonspeech sound (pink noise) is used in the habituation phase, a large irrelevant speech effect is found in the test phase. Morris, Quayle, and Jones (1989) found that humming did not produce an irrelevant speech effect, which suggests that the first filter is permeable to humming but that the second filter is not.(ABSTRACT TRUNCATED AT 250 WORDS)

Attention↗

Physician gender effects in medical communication: a meta-analytic review.

CONTEXT: Physician gender has been viewed as a possible source of variation in the interpersonal aspects of medical practice, with speculation that female physicians facilitate more open and equal exchange and a different therapeutic milieu from that of male physicians. However, studies in this area are generally based on small samples, with conflicting results. OBJECTIVE: To systematically review and quantify the effect of physician gender on communication during medical visits. DATA SOURCES: Online database searches of English-language abstracts for the years 1967 to 2001 (MEDLINE, AIDSLINE, PsycINFO, and Bioethics); a hand search was conducted of reprint files and the reference sections of review articles and other publications. STUDY SELECTION: Studies using a communication data source, such as audiotape, videotape, or direct observation, and large national or regional studies in which physician report was used to establish length of visit, were identified through bibliographic and computerized searches. Twenty-three observational studies and 3 large physician-report studies reported in 29 publications met inclusion criteria and were rated. DATA EXTRACTION: The Cohen d was computed based on 2 reviewers' (J.A.H. and Y.A.) independent extraction of quantitative information from the publications. Study heterogeneity was tested using Q statistics and pooled effect sizes were computed using the appropriate effects model. The characteristics of the study populations were also extracted. DATA SYNTHESIS: Female physicians engage in significantly more active partnership behaviors, positive talk, psychosocial counseling, psychosocial question asking, and emotionally focused talk. There were no gender differences evident in the amount, quality, or manner of biomedical information giving or social conversation. Medical visits with female physicians are, on average, 2 minutes (10%) longer than those with male physicians. Obstetrics and gynecology may present a different pattern than that of primary care, with male physicians demonstrating higher levels of emotionally focused talk than their female colleagues. CONCLUSIONS: Female primary care physicians engage in more communication that can be considered patient centered and have longer visits than their male colleagues. Limited studies exist outside of primary care, and gender-related practice patterns in some subspecialties may differ from those evident in primary care.

Communication↗

ARIANE: integration of information databases within a hospital intranet.

Large information systems handle massive volume of data stored in heterogeneous sources. Each server has its own model of representation of concepts with regard to its aims. One of the main problems end-users encounter when accessing different servers is to match their own viewpoint on biomedical concepts with the various representations that are made in the databases servers. The aim of the project ARIANE is to provide end-users with easy-to-use and natural means to access and query heterogeneous information databases. The objectives of this research work consist in building a conceptual interface by means of the Internet technology inside an enterprise Intranet and to propose a method to realize it. This method is based on the knowledge sources provided by the Unified Medical Language System (UMLS) project of the US National Library of Medicine. Experiments concern queries to three different information servers: PubMed, a Medline server of the NLM; Thériaque, a French database on drugs implemented in the Hospital Intranet; and a Web site dedicated to Internet resources in gastroenterology and nutrition, located at the Faculty of Medicine of Nice (France). Accessing to each of these servers is different according to the kind of information delivered and according to the technology used to query it. Dealing with health care professional workstation, the authors introduced in the ARIANE project quality criteria in order to attempt a homogeneous and efficient way to build a query system able to be integrated in existing information systems and to integrate existing and new information sources.

Computer Communication Networks↗

New evidence for phonological processing during visual word recognition: the case of Arabic.

Lexical decision and naming were examined with words and pseudowords in literary Arabic and with transliterations of words in a Palestinian dialect that has no written form. Although the transliterations were visually unfamiliar, they were not easily rejected in lexical decision, and they were more slowly accepted in phonologically based lexical decision. Naming transliterations of spoken words was slower than naming of literary words and pseudowords. Apparently, phonological computation is mandatory for both lexical decision and naming. A large frequency effect in both lexical decision and naming suggests that addressed phonology is an option for familiar orthographic patterns. The frequency effect on processing transliterations indicated that lexical phonology is involved with prelexical phonological computation even if addressed phonology is not possible. These data support a combination between a cascade-type process, in which partial products of the grapheme-to-phoneme translation activate phonological units in the lexicon, and an interactive model, in which the activated lexical units feed back, shaping the prelexical phonological computation process.

Adolescent↗

Vulnerable but strong: deaf people challenge established understandings of deafness.

BACKGROUND: In the last 35 years, hearing majorities have, in variable degree, gradually recognized that deaf people can be strong and able and a common knowledge of deaf people as linguistic minorities is partly embraced in public life. This is by and large a result of a long-time deaf struggle for the recognition of sign language and against paternalistic policies of pity. AIM: This article aims at showing how contemporary deaf identities are crafted by balancing vulnerability and empowering forces. METHODS: In the presentation of life narratives from one deaf Norwegian and one deaf American, different aspects of being deaf are explored. These two stories have emerged from two related deaf research projects. They are deliberately chosen because they illustrate central insights gained within this research. RESULTS: The empowering aspects of being sign language users are in focus, as well as the joys of being connected to a global deaf movement. Difficulties and hardship are also part and parcel of the deaf lives displayed, and strong arguments are put forward against the medical model of deafness in particular. CONCLUSION: One conclusion is that deaf identities are vulnerable but at the same time can be strongly rewarding.

Adaptation, Psychological↗

Integrality in the perception of tongue root position and voice quality in vowels.

In English and a large number of African and Southeast Asian languages, voice quality along a tense-lax dimension covaries with advancement of the tongue root in vowels: a laxer voice quality co-occurs with a more advanced tongue root. As laxing the voice increases energy in the first harmonic relative to higher ones and advancing the tongue root lowers F1, the acoustic consequences of these two articulations may integrate perceptually into a higher-level perceptual property, here called spectral "flatness." Two Garner-paradigm experiments evaluated this interaction across nearly the entire range of tense-lax voice qualities and a narrow range of F1 values. The acoustic consequences of laxness and advanced tongue root integrated into spectral flatness for tenser and laxer but not for intermediate voice qualities. Detection-theoretic models developed in earlier work proved highly successful in representing the perceptual interaction between these dimensions.

Humans↗

A quarter-long exercise that introduces general education students to neurophysiology and scientific writing.

Providing large numbers of general education students with an introduction to science is a challenge. To meet this challenge, a quarter-long neurophysiology project was developed for use in an introductory biology course. The primary goals of this multistep project were to introduce students to the scientific method, scientific writing, on-line scientific bibliographic databases, and the scientific literature, while improving their academic literacy skills. Students began by collecting data on their own circadian rhythms in autonomic, motor, and cognitive function, reliably demonstrating the predicted circadian changes in heart rate, eye-hand coordination, and adding speed. Students wrote a journal-style article using pooled class data. Students were prepared to write the paper by several methods that were designed to improve academic language skills, including a library training exercise, "modeling" of the writing assignment, and drafting of subsections of the paper. This multistep neurophysiology project represents a significant commitment of time by both students and instructors, but produces a valuable finished product and ideally gives introductory students a positive first experience with science.

Circadian Rhythm↗

Algorithmic and complexity results for decompositions of biological networks into monotone subsystems.

A useful approach to the mathematical analysis of large-scale biological networks is based upon their decompositions into monotone dynamical systems. This paper deals with two computational problems associated to finding decompositions which are optimal in an appropriate sense. In graph-theoretic language, the problems can be recast in terms of maximal sign-consistent subgraphs. The theoretical results include polynomial-time approximation algorithms as well as constant-ratio inapproximability results. One of the algorithms, which has a worst-case guarantee of 87.9% from optimality, is based on the semidefinite programming relaxation approach of Goemans-Williamson [Goemans, M., Williamson, D., 1995. Improved approximation algorithms for maximum cut and satisfiability problems using semidefinite programming. J. ACM 42 (6), 1115-1145]. The algorithm was implemented and tested on a Drosophila segmentation network and an Epidermal Growth Factor Receptor pathway model, and it was found to perform close to optimally.

Algorithms↗

Treatment of chronic headache with antidepressants: a meta-analysis.

BACKGROUND: Although antidepressants are often used for preventing chronic headache, their effectiveness is uncertain. METHODS: We performed a meta-analysis of English-language, randomized placebo-controlled trials of antidepressants as prophylaxis for chronic headache. RESULTS: Thirty-eight trials were included. Because some compared more than one drug with placebo, 44 study arms were combined using a random effects model. Twenty-five studies focused on migraines, 12 on tension headaches, and 1 on both. Nineteen used tricyclic antidepressants, 18 serotonin antagonists, and 7 selective serotonin reuptake inhibitors. Patients receiving antidepressants were twice as likely to report headache improvement (rate ratio [RR]: 2.0; 95% confidence interval [CI]: 1.6 to 2.4). Because 31% (95% CI: 23% to 40%) more treated patients improved than those receiving placebo, clinicians would need to treat 3.2 patients for 1 patient to improve. The average amount of improvement (standardized mean difference) was 0.94 (95% CI: 0.65 to 1.2), an effect considered large. Treated patients also consumed less analgesic medication (standardized mean difference, -0.7; 95% CI: -0.5 to -0.94). There were no differences in outcomes among the three classes of agents studied or by the type of headache (migraine vs. tension), quality score, length of treatment, or percentage of patients lost to follow-up. Assessment of depression across studies was insufficient to determine if the effects were independent of depression. CONCLUSION: Antidepressants are effective in preventing chronic headaches. Whether this is independent of depression and whether there are differences in efficacy by class of agent needs further study.

Antidepressive Agents↗

Role of osmolality of contrast media in the development of post-ERCP pancreatitis: a metanalysis.

The role of osmolality of contrast media (CM) in the development of post-ERCP pancreatitis (PEP) is debated. We therefore performed a metanalysis to determine whether osmolality affects the incidence of PEP. A literature search of English-language studies was performed using computerized databases and manual searching of abstracts and article bibliographies. Randomized controlled trials comparing the incidence of PEP associated with high- and low-osmolality contrast media (HOCM, LOCM) were considered. The outcome assessed was clinical pancreatitis as evidenced by both elevation of pancreatic enzymes and pain. Data were analyzed using logistic regression with terms for study and osmolality. Fisher's exact test was done to compare PEP rates. Homogeneity between studies was indicated by the nonsignificance of the study effect in the logistic regression model. Logistic regression also indicated no difference in PEP rates between LOCM and HOCM (P = 0.399). Comparison of PEP rates in both groups using Fisher's exact test did not indicate a difference in any individual study (all P values > 0.05). Due to the large variation of study sample sizes, we repeated the analysis by creating three study groups. The effect of osmolality was invariant to how the data were combined. The results of this metanalysis indicate that there is no significant difference between HOCM and LOCM with respect to clinical PEP.

Cholangiopancreatography, Endoscopic Retrograde↗

Does "callosal relay" explain ear advantage in dichotic monitoring?

Pairs of consonant-vowel (CV) syllables were dichotically presented to a large sample of healthy subjects (n = 263) who were instructed to monitor for the presence of a target CV (/ta/) which could occur in either ear. The subjects responded by pressing a response button, allowing the recording of reaction times (RTs) and number of correct responses. The investigated sample comprised consistent right-handers (CRH), consistent left-handers (CLH), and mixed-handers (MH). It was found that right-ear targets were detected more frequently and faster than left-ear targets, both in CRH and MH subjects. CLH subjects, on the other hand, responded faster to targets presented to the left ear but there was no ear advantage in terms of the correct responses. The RT data were used to examine whether they are compatible with the callosal relay model of language lateralisation. It was found that the predictions made by the callosal relay model were supported by the RT data for all groups.

Journal Article↗

Inferring the impact of linguistic boundaries on population differentiation: application to the Afro-Asiatic-Indo-European case.

We present here a quantitative way to assess the impact of language-family boundaries on population differentiation and to evaluate the homogeneity of the genetic processes along these boundaries. Our estimator (delta a) of the impact of the boundary is based on an isolation by distance (IBD) model and measures the added genetic distance between populations located on different sides of the boundary. We compare this statistic with another estimator of group differentiation (F(CT)) computed under an analysis of variance framework that does not assume any particular spatial structure of the populations. Monte Carlo simulations are used to study the behaviour of these statistics under a two-dimensional stepping-stone model. Simulations show that F(CT) can suggest the existence of a frontier when populations only differ because of IBD. This spurious behaviour is much less frequent for the delta a statistic. However, the large variance associated with the delta a statistic, and the fact that it should only be computed in the presence of IBD, may limit the use of this statistic. Overall, the origin and the effect of the boundary is best understood by comparing different statistics and by testing for the presence of IBD on each side of the boundary as well as across the boundary. We illustrate our approach by examining the boundary between Afro-Asiatic and Indo-European populations. These populations are globally genetically differentiated, but the effect of the linguistic boundary on gene flow seems geographically very heterogeneous. This boundary appears to be the result of a secondary contact between two differentiation centres rather than an enhancer of population differentiation.

Africa↗

Yet another application of the Monte Carlo method for modeling in the field of biomedicine.

By means of Monte Carlo simulations performed in the C programming language, an example of scientific programming for the generation of pseudorandom numbers relevant to both teaching and research in the field of biomedicine is presented. The relatively simple algorithm proposed makes possible the statistical analysis of sequences of random numbers. The following three generators of pseudorandom numbers were used: the rand function contained in the stdlib.h library of the C programming language, Marsaglia's generator, and a chaotic function. The statistical properties of the sequences generated were compared, identical parameter values being adopted for this purpose. The properties of two estimators in finite samples of the pseudorandom numbers were also evaluated and, under suitable conditions, both the maximum-likelihood and method of moments proved to be good estimators. The findings demonstrated that the proposed algorithm appears to be suitable for the analysis of data from random experiments, indicating that it has a large variety of possible applications in the clinical practice.

Algorithms↗