Flexible composition and execution of high performance, high fidelity multiscale biomedical simulations.

Multiscale simulations are essential in the biomedical domain to accurately model human physiology. We present a modular approach for designing, constructing and executing multiscale simulations on a wide range of resources, from laptops to petascale supercomputers, including combinations of these. Our work features two multiscale applications, in-stent restenosis and cerebrovascular bloodflow, which combine multiple existing single-scale applications to create a multiscale simulation. These applications can be efficiently coupled, deployed and executed on computers up to the largest (peta) scale, incurring a coupling overhead of 1-10% of the total execution time.

The preparticipation athletic evaluation.

A comprehensive medical history that includes questions about a personal and family history of cardiovascular disease is the most important initial component of the preparticipation athletic evaluation. Additional questions should focus on any history of neurologic or musculoskeletal problems. A limited physical examination should emphasize cardiac auscultation with provocative maneuvers to screen for hypertrophic cardiomyopathy. This condition is the most common cause of sudden death in young male athletes. Other components of the physical examination include an evaluation of the spine and extremities. Screening tests such as electrocardiography, treadmill stress testing and urinalysis are not indicated in the absence of symptoms or a significant history of risk factors. Specific conditions that would exclude or limit athletic participation include hypertrophic cardiomyopathy, long QT interval syndrome, concussion, significant knee injury, sickle cell disease and uncontrolled seizures. Overall, about 1 percent of athletes who are screened are completely disqualified from sports participation.

The mapping from sound structure to the lexicon in aphasia: evidence from rhyme and repetition priming.

Two studies were conducted to explore the hypothesis that Broca's and Wernicke's aphasics have deficits arising from the processes involved in activating the lexicon from phonological form. The first study explored whether phonologically similar lexical entries differing only in their initial consonants show "rhyme priming." Results revealed that Broca's aphasics failed to show facilitation when the target was identical to the prime (i.e. identity priming) and they showed significant inhibition when targets were preceded by rhyming words. Wernicke's aphasics showed a pattern of results similar to that of normal subjects, i.e., identity priming and rhyme priming as well as significantly slower reaction-times in the rhyming condition compared to the identity condition. The second study investigated form-based repetition priming in aphasic patients at a number of intervals including when no other stimuli intervened between repeated stimuli (0 lag) or when 4, 8, or 12 stimuli intervened. Results showed that, unlike old normal subjects who showed repetition priming for both words and nonwords, both Broca's and Wernicke's aphasics showed repetition priming for word targets only. Moreover, in contrast to old normal subjects who showed a greater magnitude of priming at 0 lag for word targets, neither Broca's aphasics or Wernicke's aphasics showed priming at 0 lag. Implications of these findings are considered with respect to the hypotheses that Broca's and Wernicke's aphasics have deficits in the nature of the activation patterns within the lexicon itself and in auditory (working) memory.

Clarithromycin-induced alterations in vaginal flora.

Many antibiotics have been shown to alter both the bacterial and the fungal flora of the vagina, in some cases potentially increasing a woman's propensity toward urinary tract infections and vaginal candidiasis. The effects of some of the newer macrolide antibiotics on women's vaginal flora have not been previously studied, and almost none of the previous studies specifically cultured for effects on vaginal lactobacillus. Young women (ages 18-45 years) who were about to go onto therapy with clarithromycin, who did not have any conditions known to affect the vaginal flora (eg, diabetes mellitus, spermicide use, menopausal status without hormone replacement therapy), and who agreed to participate in the study were cultured with aerobic and anaerobic and fungal vaginal cultures before starting the antibiotic. These same women were then retested about 4 to 6 weeks after the start of their antibiotic course, and the results of their preantibiotic and postantibiotic cultures were compared. Lactobacillus was present in 33% of patients by vaginal culture before treatment, but this decreased to 0% after treatment. Escherichia coli was present in only 8% of patients before treatment, but this increased to 17% of patients after treatment. Enterococcus was present in 25% of patients before treatment but in only 8% of patients after treatment. The incidence of Gardnerella vaginalis was not affected by the treatment. Candida species incidence increased from 17% to 33% with treatment. The overall effects of clarithromycin on the vaginal flora are similar to other older antibiotics that have been tested.

Consonant and vowel production of right hemisphere patients.

Recent reports of subclinical phonetic deficits in posterior and most particularly in Wernicke's aphasics have challenged the traditional dichotomy which characterized speech deficits in aphasia as anterior/phonetic and posterior/phonological. It is unclear whether the basis of the phonetic deficit in posterior aphasics reflects the fact that the speech production system extends to more posterior regions of the left hemisphere than previously thought or alternatively is the result of generalized brain damage effects. The present study explores the latter possibility by investigating the patterns of speech production in right hemisphere brain-damaged, non-aphasic patients with anterior and posterior lesions. Acoustic analyses conducted on a range of consonant and vowel parameters showed differences between the speech patterns of both anterior and posterior right hemisphere patients and that of Wernicke's aphasics. These findings suggest that the subclinical deficit of Wernicke's aphasics can not simply be ascribed to a generalized brain-damage effect and raise the possibility that the right hemisphere also plays some role, if only a minor one, in the phonetic implementation of speech.

[Congenital esophago-tracheal fistula in an adult]. / Wrodzona przetoka przelykowo-tchawicza u doroslego.

A 33 year old man with recurrent respiratory tract infections was admitted to surgery ward. During esophagoscopy and bronchoscopy--esophago-tracheal fistula was found. Diagnosis was confirmed by radiologic examination of esophagus. Surgical treatment was performed with good result.

The women with dysuria.

Bacterial cystitis is the most common bacterial infection occurring in women. Thirty percent of women will experience at least one episode of cystitis during their lifetime. About one third of patients presenting with symptoms of cystitis have upper urinary tract infection. A careful history to identify risk factors for subclinical pyelonephritis is important. Symptoms of chronic cystitis accompanied by sterile urine without pyuria may represent interstitial cystitis. Dysuria may also be the principal complaint of women with vaginitis (infectious, atrophic or chemical) or urethritis. A stepwise diagnostic approach, accompanied by inexpensive office laboratory testing, is usually sufficient to determine the cause of dysuria.

On-line processing of filler-gap construction in aphasia.

Two experiments were conducted exploring on-line processing of filler-gap construction in aphasia. An auditory-auditory lexical decision paradigm was used to investigate whether Broca's and Wernicke's aphasic patients show, as do normals, reactivation of the filler at the gap site. Experiment I investigated the processing of a number of filler-gap constructions including wh-questions, relative clauses as subject, relative clauses as object, and embedded wh-questions. Broca's aphasics showed reactivation of the filler at the gap site, whereas Wernicke's aphasics did not. Experiment II examined object relative clauses and their processing by Broca's aphasics. In addition, we investigated whether the presence (or absence) of the relative pronoun played any role in on-line processing. Broca's aphasics performed as did normals. In addition, their performance was unaffected by the presence or absence of the relative pronoun. The results of these experiments suggest that Broca's aphasics do not have an impairment in processing or representing thematic relationships of NP arguments to predicates or relating traces to their antecedents.

The characteristics of voicing in syllable-initial fricatives in American English.

This study investigated the acoustic characteristics of voicing in the production of fricative consonants. The fricatives [f v s z] were used in combination with the vowels [i e a o u] to create CV syllables, which were produced by four subjects both in a context condition (following voiced and voiceless velar stops) and in isolation. Analyses were conducted of the time course of glottal excitation during the fricative noise interval in the voiced and voiceless fricative stimuli. Results showed that the patterns of voicing in the fricative noise interval were influenced by the voicing characteristics of preceding stop consonants. Nonetheless, these carryover coarticulatory effects were short-lived, influencing only the first 10's of ms of the following segment. Despite the influence of phonetic context on the patterns of voicing, an acoustic measure relating to the presence or absence of glottal excitation at the acoustic boundaries of the fricative noise reliably classified a majority (93%) of the fricative consonants in terms of the phonetic category of voicing. Thus, while phonetic context affected the patterns of glottal excitation in the fricative noise interval, it did not affect the criterial attribute associated with the phonetic category of voicing.

The foreign accent syndrome: a reconsideration.

This study compared the post-CVA speech of a patient presenting with the foreign accent syndrome (FAS) to both a premorbid baseline for that patient and to similarly analyzed data from an earlier reported case of FAS. The object of this research was to provide quantitative acoustic data to determine whether: (1) the constellation of phonetic features associated with FAS is the same across patients and (2) a common neural mechanism underlies FAS. Acoustic parameters investigated included features of consonant production (voicing, place and manner of articulation), vowel production (formant frequency and duration), and prosody. Results supported the characterization of FAS patients as having a "generic" foreign accent and the hypothesis that FAS deficits are qualitatively different from that of Broca's aphasia. However, comparison of this case with recent studies revealed the extent to which the constellation of phonetic features may vary among FAS patients, challenging the notion that a general prosodic disturbance is the sole underlying mechanism in FAS.

Acoustic and perceptual characteristics of voicing in fricatives and fricative clusters.

Several types of measurements were made to determine the acoustic characteristics that distinguish between voiced and voiceless fricatives in various phonetic environments. The selection of measurements was based on a theoretical analysis that indicated the acoustic and aerodynamic attributes at the boundaries between fricatives and vowels. As expected, glottal vibration extended over a longer time in the obstruent interval for voiced fricatives than for voiceless fricatives, and there were more extensive transitions of the first formant adjacent to voiced fricatives than for the voiceless cognates. When two fricatives with different voicing were adjacent, there were substantial modifications of these acoustic attributes, particularly for the syllable-final fricative. In some cases, these modifications leads to complete assimilation of the voicing feature. Several perceptual studies with synthetic vowel-consonant-vowel stimuli and with edited natural stimuli examined the role of consonant duration, extent and location of glottal vibration, and extent of formant transitions on the identification of the voicing characteristics of fricatives. The perceptual results were in general consistent with the acoustic observations and with expectations based on the theoretical model. The results suggest that listeners base their voicing judgments of intervocalic fricatives on an assessment of the time interval in the fricative during which there is no glottal vibration. This time interval must exceed about 60 ms if the fricative is to be judged as voiceless, except that a small correction to this threshold is applied depending on the extent to which the first-formant transitions are truncated at the consonant boundaries.

[Hypertension in a case of pancreatic pseudocyst]. / Nadcisnienie tetnicze w przebiegu torbieli rzekomej trzustki.

A 33-year-old male is described in whom compression of the renal artery by a pancreatic pseudocyst caused hypertension refractory to conservative treatment. After operation with removal of the contents of the cyst and Roux-type enterostomy the arterial blood pressure fell to normal level.

Acoustic properties for place of articulation in nasal consonants.

The goal of this study was to determine whether acoustic properties could be derived for English labial and alveolar nasal consonants that remain stable across vowel contexts, speakers, and syllable positions. In experiment I, critical band analyses were conducted of five tokens each of [m] and [n] followed by the vowels [i e a o u] spoken by three speakers. Comparison of the nature of the changes in the spectral patterns from the murmur to the release showed that, for labials, there was a greater change in energy in the region of Bark 5-7 relative to that of Bark 11-14, whereas, for alveolars, there was a greater change in energy from the murmur to the release in the region of Bark 11-14 relative to that of Bark 5-7. Quantitative analyses of each token indicated that over 89% of the utterances could be appropriately classified for place of articulation by comparing the proportion of energy change in these spectral regions. In experiment II, the spectral patterns of labial and alveolar nasals produced in the context of [s] + nasal ([ m n]) + vowel ([ i e a o u]) by two speakers were explored. The same analysis procedures were used as in experiment I. Eighty-four percent of the utterances were appropriately classified, although labial consonants were less consistently classified than in experiment I. The properties associated with nasal place of articulation found in this study are discussed in relation to those associated with place of articulation in stop consonants and are considered from the viewpoint of a more general theory of acoustic invariance.

Perceptual integration of the murmur and formant transitions for place of articulation in nasal consonants.

This study reassessed the role of the nasal murmur and formant transitions as perceptual cues for place of articulation in nasal consonants across a number of vowel environments. Five types of computer-edited stimuli were generated from natural utterances consisting of [m n] followed by [i e a o u]: (1) full murmurs; (2) transitions plus vowel segments; (3) the last six pulses of the murmur; (4) the six pulses starting from the beginning of the formant transitions; and (5) the six pulses surrounding the nasal release (three pulses before and three pulses after). Results showed that the murmur provided as much information for the perception of place of articulation as did the transitions. Moreover, the highest performance scores for place of articulation were obtained in the six-pulse condition containing both murmur and transition information. The data support the view that it is the combination of nasal murmur plus formant transitions which forms an integrated property for the perception of place of articulation.