Manipulation of temporal localized structures in a vertical external-cavity surface-emitting laser with optical feedback.

We analyze the effect of optical feedback on the dynamics of an external-cavity passively mode-locked surface-emitting laser operating in the regime of temporal localized structures. Depending on the ratio between the cavity round trip time and the feedback delay, we show experimentally that feedback acts as a solution selector that either reinforces or hinders the appearance of one of the multistable harmonic arrangements of pulses. Our theoretical analysis reproduces well the experiment and allows us to evidence asymmetrical resonance tongues due to the parity symmetry-breaking induced by gain depletion.

Assessing the ideal microwave duration for disinfection of sinus irrigation bottles-A quantitative study.

OBJECTIVES: Saline irrigation of the nasal cavity and paranasal sinuses has a recognised role in the management of chronic rhinosinusitis. However, bacterial recontamination of irrigation bottles through backflow from the sinonasal cavity is a concern in recurrent sinus cavity infections. While patients are encouraged to clean the irrigation bottles regularly, there remains significant concern that the use of contaminated bottles may perpetuate chronic rhinosinusitis. This study assesses the optimal microwave duration to achieve decontamination for each irrigation bottle component part (reservoir, tube and nozzle) using a standard, commercially available microwave. In addition, the irrigation fluid was also tested for contamination after each microwave cycle. STUDY DESIGN: Laboratory-based experimental study. PARTICIPANTS: No patients were involved in this study. MAIN OUTCOME MEASURES: The percentage in vitro decontamination of the bottles' components was determined following 30, 60, 90, 120, 150 seconds of microwave cycles. RESULTS: Complete decontamination of the bottles was not achieved at any of the tested microwave cycles. Levels of decontamination differed for the different bottle components, and the greatest degree of decontamination for all bottle components occurred at 90 seconds. Although higher levels of decontamination were observed at microwave durations exceeding 90 seconds, this was at the expense of thermal degradation and deformation of the reservoir plastic component of the irrigation bottle. Similarly, lowest contamination of irrigation fluid was observed at 120 seconds. CONCLUSIONS: This study highlights the importance of establishing precise decontamination procedures and recommends a microwave cycle of 90 seconds for optimal decontamination.

Pantomimes are special gestures which rely on working memory.

The case of a patient is reported who presented consistently with overt deficits in producing pantomimes in the absence of any other deficits in producing meaningful gestures. This pattern of spared and impaired abilities is difficult to reconcile with the current layout of cognitive models for praxis. This patient also showed clear impairment in a dual-task paradigm, a test taxing the co-ordination aspect of working memory, though performed normally in a series of other neuropsychological measures assessing language, visuo-spatial functions, reasoning function, and executive function. A specific working memory impairment associated with a deficit of pantomiming in the absence of any other disorders in the production of meaningful gestures suggested a way to modify the model to account for the data. Pantomimes are a particular category of gestures, meaningful, yet novel. We posit that by their very nature they call for the intervention of a mechanism to integrate and synthesise perceptual inputs together with information made available from the action semantics (knowledge about objects and functions) and the output lexicon (stored procedural programmes). This processing stage conceived as a temporary workspace where gesture information is actively manipulated, would generate new motor programmes to carry out pantomimes. The model of gesture production is refined to include this workspace.

An arrhythmia detector and heart rate estimator for overnight polysomnography studies.

We present an algorithm for automatic on-line analysis of the electrocardiography (ECG) channel acquired during overnight polysomnography (PSG) studies. The system is independent of ECG morphology, requires no manual initialization, and operates automatically throughout the night. It highlights likely occurrences of arrhythmias and intervals of bad signal quality while outputting a continual estimate of heart rate. Algorithm performance is validated against standard ECG databases and PSG data. Results demonstrate a minimal false negative rate and a low false positive rate for arrhythmia detection, and robustness over a wide range of noise contamination.

The polysomnogram assay: a method to represent the overnight polysomnogram in a condensed format.

We present the polysomnogram assay (PSGA), a new representation format for the polysomnogram (PSG), designed to assist in the interpretation of overnight PSG studies. The technique condenses the PSG record by a factor of 30 while preserving the ability to portray PSG features of diagnostic relevance, including sleep architecture, arousals, movement, leg jerks, cyclic alternating pattern, and increased breathing effort. The PSGA patterns associated with these events are described and illustrated by examples. The new format considerably reduces the effort required to evaluate sleep quality and continuity, making it more practicable for the polysomnographer to interpret the entire overnight PSG study. The compressed time scale also facilitates analysis of relatively long PSG episodes and allows assessment of signal activity surrounding critical PSG events. The PSGA appears capable of improving identification of arousals, leg jerks, and upper airway resistance, and may be especially amenable for automatic analysis of PSG data.

[Acute pericarditis in childhood. The 9-year experience of a tertiary referral center]. / Pericardite aguda na criança. Experiencia de 9 anos de um centro de referencia terciário.

Sixteen children, aged 7 months to 12 years, with acute pericarditis, admitted between 1985 and 1993 to a tertiary referral centre were analyzed retrospectively for their presentation, etiology, work-up, management and prognosis. It was found that most of the presenting signs were not specific and were often related to associated diseases such as respiratory tract infections. In 50% of the cases a cause was not found, the others had viral infections (12.5%), tuberculosis (12.5%), Haemophilus influenzae infection (6.25%), Toxocara canis infection (6.25%) and collagen diseases (12.5%). In eight cases non-steroidal anti-inflammatory drugs associated with steroids were given, 7 patients received non-steroidal anti-inflammatory drugs and 1 steroids. The mean follow-up time was 3 years (1 to 5). Six patients had one or more relapses. Five of the 6 patients with relapses were in the group which received steroids. The two patients with tuberculosis underwent pericardiectomy. One child died due to complex heart disease and the remaining 15 were cured. It was concluded that in pericarditis an extensive work-up may not reveal the major etiologies and that long term prognosis is good.

Analysis of diaphragm EMG signals: comparison of gating vs. subtraction for removal of ECG contamination.

The diaphragm electromyogram (EMGdi) conveys information relating to the mechanisms of respiration; however, electrocardiogram (ECG) contamination can compromise the accuracy of data derived from this signal. We examine the EMGdi recorded from anesthetized spontaneously breathing dogs via implanted electrodes to assess the extent of the error introduced by the ECG contamination and the effectiveness of ECG gating in reducing this error. Because ECG subtraction has been shown to generate accurate results for such applications, it is used as the gold standard. Analysis of variance methods are employed to compare results derived from the EMGdi data after ECG subtraction with corresponding results derived from the original data and from the data after ECG gating. Estimates of EMGdi variables obtained by using subtraction and gating techniques were not significantly different, indicating that gating can be employed on these signals to reduce ECG contamination without affecting the accuracy of the derived data. Results also show that at EMG-to-ECG power ratios > 13.3 dB, ECG contamination does not significantly affect estimates of the EMGdi variables.

[Detection of Chlamydia trachomatis in urine samples. Possibility of a non-invasive screening]. / Ricerca di Chlamydia trachomatis in campioni di urine. Possibilità di uno screening non invasivo.

In clinic practice urethral specimens from a big proportion of patients are inadequate or swabbing if not undertaken at all because for the discomfort experienced. Moreover, such an experience sometimes discourages patients for reattending. It is clear that having a urine sample from patients is incomparably preferable to having an inadequate urethral swab or none. 250 women attending our gynecology clinic had a urinary sample (20 ml first-voided urine minimum 4-hours from prior menstruation) analysed with an enzyme immunoassay (IDEIA-Dako) for the detection of Chlamydia trachomatis. They also had sample taken from cervix, and urethra for testing with IDEIA. The urinary samples, compared with urethral samples, showed a optimal correspondence to final results. It is concluded that the urinary samples could be used for screening programs to detect Chlamydia trachomatis.