Characterization of the complexity in short oscillating time series: An application to seismic airgun detonations.

Extracting frequency-derived parameters allows for the identification and characterization of acoustic events, such as those obtained in passive acoustic monitoring applications. Situations where it is difficult to achieve the desired frequency resolution to distinguish between similar events occur, for example, in short time oscillating events. One feasible approach to make discrimination among such events is by measuring the complexity or the presence of non-linearities in a time series. Available techniques include the delay vector variance (DVV) and recurrence plot (RP) analysis, which have been used independently for statistical testing, however, the similarities between these two techniques have so far been overlooked. This work suggests a method that combines the DVV method with the recurrence quantification analysis parameters of the RP graphs for the characterization of short oscillating events. In order to establish the confidence intervals, a variant of the pseudo-periodic surrogate algorithm is proposed. This allows one to eliminate the fine details that may indicate the presence of non-linear dynamics, without having to add a large amount of noise, while preserving more efficiently the phase-space shape. The algorithm is verified on both synthetic and real world time series.

Does breathing type influence electromyographic activity of obligatory and accessory respiratory muscles?

Craniomandibular electromyographic (EMG) studies frequently include several parameters, e.g. resting, chewing and tooth-clenching. EMG activity during these parameters has been recorded in the elevator muscles, but little is known about the respiratory muscles. The aim of this study was to compare EMG activity in obligatory and accessory respiratory muscles between subjects with different breathing types. Forty male subjects were classified according to their breathing type into two groups of 20 each: costo-diaphragmatic breathing type and upper costal breathing type. Bipolar surface electrodes were placed on the sternocleidomastoid, diaphragm, external intercostal and latissimus dorsi muscles. EMG activity was recorded during the following tasks: (i) normal quiet breathing, (ii) maximal voluntary clenching in intercuspal position, (iii) natural rate chewing until swallowing threshold, (iv) short-time chewing. Diaphragm EMG activity was significantly higher in the upper costal breathing type than in the costo-diaphragmatic breathing type in all tasks (P < 0·05). External intercostal EMG activity was significantly higher in the upper costal breathing type than in the costo-diaphragmatic breathing type in tasks 3 and 4 (P < 0·05). Sternocleidomastoid and latissimus dorsi EMG activity did not show significant differences between breathing types in the tasks studied (P > 0·05). The significantly higher EMG activity observed in subjects with upper costal breathing than in the costo-diaphragmatic breathing type suggests that there could be differences in motor unit recruitment strategies depending on the breathing type. This may be an expression of the adaptive capability of muscle chains in subjects who clinically have a different thoraco-abdominal expansion during inspiration at rest.

Clonal interference and the evolution of RNA viruses.

In asexual populations, beneficial mutations that occur in different lineages compete with one another. This phenomenon, known as clonal interference, ensures that those beneficial mutations that do achieve fixation are of large effect. Clonal interference also increases the time between fixations, thereby slowing the adaptation of asexual populations. The effects of clonal interference were measured in the asexual RNA virus vesicular stomatitis virus; rates and average effects of beneficial mutations were quantified.

Frailty, Falls and Osteoporosis: Learning in Elderly Patients Using a Theatrical Performance in the Classroom.

OBJECTIVE: To ascertain the usefulness of a simulated clinical scene with actors in the classroom (theatrical performance) as a teaching tool for the management of falls and their related injuries. DESIGN: Experimental design of two related groups. SETTING: Spain. PARTICIPANTS: A group of 12 students attended a seminar in which the approach to a clinical case was made using a simulated scene with actors in the classroom (scene group); a non-scene group of 34 students attended the seminar, without a theatrical performance (the same clinical case was read and presented in a traditional manner, oral presentation). MEASUREMENTS: Before and after the seminar, students answered a questionnaire [five questions on theoretical knowledge of falls and osteoporosis (score 0-10) and two on subjective learning perception (linear scale: 0-10) (score 0-20)]. In the scene group were two further questions included at the end on their opinion of the scene and on the seminar overall. RESULTS: Both groups significantly improved in all questionnaire scores after the seminar (p=0.001). The scene group had a greater rise in mean points of the questionnaire before and after the seminar than the non-scene group: theoretical knowledge [3.81±1.69 versus 2.75±1.33 (p=0.033)], subjective questions [6.08±4.10 versus 4.97±2.24 (p=0.247)], and the questionnaire overall [9.89±4.98 versus 7.72±2.66 (p=0.060)]. The scene group had a very good opinion of the usefulness of the scene and of the overall opinion of the seminar: 9.08±0.95 and 9.41±0.79. CONCLUSIONS: Theatrical performance in the classroom seems to promote better learning than classic oral presentation, providing qualitative value by adding creativity and different approaches to the teaching of medicine.

Laterotrusive occlusal schemes and their effect on supra- and infrahyoid electromyographic activity.

The objective of this study was to determine the effects of canine guidance and group function on supra- and infrahyoid electromyographic (EMG) activity. The sample included 40 healthy subjects, 20 with bilateral canine guidance and 20 with bilateral group function. Surface electrodes were used to record the integrated EMG (IEMG) activity of the left supra- and infrahyoid muscles during (1) grinding from intercuspal position to lateral edge-to-edge contact position (with canine guidance or group function), (2) static clenching in edge-to-edge lateral contact position with canine guidance or group function, and (3) grinding from lateral edge-to-edge contact position (with canine guidance or group function) to intercuspal position. IEMG activity in the suprahyoid or infrahyoid muscles was not significantly different with canine guidance or group function. Supra- and infrahyoid IEMG activity in condition 2 was significantly higher than in condition 3, which was significantly higher than in condition 1. Supra- and infrahyoid IEMG activity was not significantly different with canine guidance and group function. Supra- and infrahyoid IEMG activity during the static recording (clenching) was significantly higher than during the dynamic recordings (grinding). Activity during grinding from the lateral edge-to-edge contact position to the intercuspal position was higher than vice versa.

Optimized ultrasonic attenuation measures for non-homogeneous materials.

In this paper the study of frequency-dependent ultrasonic attenuation in strongly heterogeneous materials is addressed. To determine the attenuation accurately over a wide frequency range, it is necessary to have suitable excitation techniques. Three kinds of transmitted signals have been analysed, grouped according to their bandwidth: narrowband and broadband signals. The mathematical formulation has revealed the relation between the distribution of energy in their spectra and their immunity to noise. Sinusoidal and burst signals have higher signal-to-noise ratios (SNRs) but need many measurements to cover their frequency range. However, linear swept-frequency signals (chirp) improve the effective bandwidth covering a wide frequency range with a single measurement and equivalent accuracy, at the expense of a lower SNR. In the case of highly attenuating materials, it is proposed to use different configurations of chirp signals, enabling injecting more energy, and therefore, improving the sensitivity of the technique without a high time cost. Thus, if the attenuation of the material and the sensitivity of the measuring equipment allows the use of broadband signals, the combination of this kind of signal and suitable signal processing results in an optimal estimate of frequency-dependent attenuation with a minimum measurement time.

Laparoscopic diverticulectomy: A systemised technique. / Diverticulectomía laparoscópica: técnica sistematizada.

OBJECTIVES: To present an original technique for laparoscopic vesical diverticulectomy without the need for dissecting the diverticular wall, thereby making the procedure safe and significantly simpler. MATERIAL AND METHODS: Four patients were operated on between September 2014 and April 2016. The diagnosis was made by ultrasonography in all cases, and the study included blood and urine analyses with urine cultures, urine cytology, contrast-enhanced CT scans, prostate symptom questionnaire (International Prostate Symptom Score), flowmetry and cystoscopy. One case required transurethral prostate resection in a first time. RESULTS: The mean age of the patients was 64 years (range: 56-71). The mean diverticulum size was 4cm (range: 3-6). The location was retrotrigonal in all cases, on the left side in 2 cases, right retromeatic in 1 case and near the midline in 1 case. The mean surgical time was 146min (range, 120-180), shortening for each new case. There were no significant bleeding, complications or conversion to open surgery in any of the cases. The postoperative period had no incidences. The hospital stay was 3 days in 3 cases and 48h in the other case (mean, 3.5 days). The catheter was withdrawn in the outpatient clinic at 14 days. CONCLUSIONS: The initial experience with the technique described above shows it to be safe and reproducible, with results similar to other current laparoscopic techniques. Avoiding the dissection of the diverticular wall significantly reduces the technical difficulty of the procedure.

Ultrasonic characterization of GRC with high percentage of fly ash substitution.

New applications of non-destructive techniques (NDT) with ultrasonic tests (attenuation and velocity by means of ultrasonic frequency sweeps) have been developed for the characterization of fibre-reinforced cementitious composites. According to new lines of research on glass-fibre reinforced cement (GRC) matrix modification, two similar GRC composites with high percentages of fly ash and different water/binder ratios will be studied. Conventional techniques have been used to confirm their low Ca(OH)(2) content (thermogravimetry), fibre integrity (Scanning Electron Microscopy), low porosity (Mercury Intrusion Porosimetry) and good mechanical properties (compression and four points bending test). Ultrasound frequency sweeps allowed the estimation of the attenuation and pulse velocity as functions of frequency. This ultrasonic characterization was correlated successfully with conventional techniques.

Pulmonary tuberculosis in HIV-infected patients with normal chest radiographs.

SUBJECTS: Three HIV-infected patients with active pulmonary non-disseminated tuberculosis and normal chest radiograph at clinical presentation and during follow-up are reported. Patients had cough and fever but no other specific symptoms. Löwenstein cultures of specimens from bronchoalveolar lavage in two cases and induced sputum in one yielded Mycobacterium tuberculosis. CONCLUSIONS: The diagnosis of tuberculosis in HIV-infected patients depends greatly on clinical suspicion by the physician, because of its atypical presentation. Failure to perform appropriate diagnostic tests in HIV-infected patients who present with suspected pulmonary disease will result in underdiagnosis and undertreatment of tuberculosis.

PIP: Between 1984-1991, physicians at Hospital del Mar in Barcelona, Spain and the area with the highest prevalence of tuberculosis (TB) diagnosed active pulmonary nondisseminated TB in 57 HIV infected patients. 3 of these patients consistently had normal chest radiographs. All 3 patients had fever and cough. Case 1 was a 26 year old female intravenous (IV) drug user. She had generalized lymphadenopathy. Hematologic tests revealed an HIV positive status. Her CD4+ lymphocyte count was 782 x 10 to the 6th power/1. Her tuberculin skin test was negative. Mycobacterium tuberculosis in her sputum grew in Lowenstein medium. Acid fast bacilli were detected in her sputum with Ziehl-Nielsen stain. Physicians began antiTB therapy (isoniazid, pyrazinamide, rifampin, and ethambutol). She improved within a few weeks. Case 2 was an HIV positive IV drug user and 33 years old. The CD4+ lymphocyte count was 645 x 10 to the 6th power/1. Acid fast bacilli were detected in his bronchoalveolar lavage with Ziehl-Nielsen stain. M. Tuberculosis in the lavage grew in Lowenstein medium. The physicians started him on the same antiTB therapy as Case 1. His condition improved with therapy. Case 3 was a 50 year old bisexual man. Hematologic tests showed HIV positivity. His CD4+ lymphocyte count was 790 x 10 to the 6th power/1. Further his tuberculin skin test was negative. Fibre optic bronchoscopic samples were negative for acid fast bacilli, but M. tuberculosis grew in Lowenstein culture. Blood, urine, bone marrow and gastric aspirates tested negative for M. tuberculosis. He began the same antiTB therapy as Cases 1 and 2. His condition improved. In conclusion, physicians should aggressively pursue a diagnosis to TB in HIV infected patients presenting with fever and cough. Their rate of hospitalization should fall with early diagnosis and treatment which will in turn prevent the spread of TB among the population.

Response to repeated phlebotomies in patients with non-insulin-dependent diabetes mellitus.

Regardless of type, uncontrolled diabetes represents a serious disruption of fuel homeostasis with consequences throughout the body. This may hamper the applicability of predeposited autologous blood transfusion in diabetic patients because metabolic changes are expected as a consequence of repeated bleeding. We undertook this study to determine whether the presence of non-insulin-dependent diabetes mellitus (NIDDM) influences the erythropoietin (EPO) response to repeated phlebotomies with respect to normal subjects. We included 22 consecutive patients scheduled for major surgery during a 2-year period in which clinical and metabolic complications were excluded and renal and liver function was considered unaffected. Selected biochemical and hematologic variables were serially measured during donation of several units of blood in a 12- to 29-day period. Bleeding produced a significant decrease in serum glucose, cholesterol, triglyceride, and apoprotein B concentration in diabetic patients. Except for glucose, this effect was not observed in controls. Both groups were comparable with respect to initial hemoglobin concentrations and all hematologic variables measured. The decrease in hemoglobin concentration did not produce clinical symptoms in these patients, and recovery was regarded as normal in both groups. Serum EPO levels in diabetic patients were negatively influenced by the initial hemoglobin A1c (HbA1c) proportion. Moreover, three nonrespondent diabetic patients with poor glycemic control responded normally 6 to 13 months later, in a second operation, when glycemic control had improved significantly. In conclusion, NIDDM may limit the donation of requested units for major surgery only if poor glycemic control is present. When possible, phlebotomies should be delayed and metabolic control reinforced.

Heparin cofactor II: a new marker for pre-eclampsia.

The plasma levels of heparin cofactor II were determined in pregnant women who were either normotensive, or had essential hypertension, gestational hypertension or pre-eclampsia during the third trimester and 72 h after delivery. Heparin cofactor II levels in the pre-eclampsia group were depressed. The clinical relevance of this finding is the potential utility of heparin cofactor II plasma levels in the differential diagnostic between non-proteinuric hypertension and pre-eclampsia.

Radiographic findings in pulmonary tuberculosis: the influence of human immunodeficiency virus infection.

The chest radiographs and medical records of 166 patients diagnosed as having clinically active pulmonary tuberculosis were reviewed. Forty-nine patients (group I) were seropositives to human immunodeficiency virus (HIV), and 117 patients (group II) did not have known risk factors for HIV infection. Roentgenographic abnormalities were analysed in the two groups, according to nine different radiographic patterns previously defined. The seropositive group had a significantly higher proportion of hilar and/or mediastinal adenopathy (P less than 0.001), infiltrates confined to the lower lung fields (P less than 0.05), and miliary tuberculosis (P less than 0.005). Otherwise, single cavitation and destructive pattern were more frequent in the group II. These data suggest that patients with pulmonary tuberculosis and HIV infection are much more likely to have atypical radiographic findings.

Pelvic masses and endoscopic surgery: diagnosis.

Most adnexal masses are benign but a careful preoperative evaluation is necessary to exclude malignancy. Pelvic examination is considered to be of limited importance Ultrasonography is of prime importance and also tumor marker's assays. The last step of evaluation to exclude malignancy is the laparoscopic inspection of the tumor. If any signs of malignancy are found, laparotomy is performed immediately. The majority of patients with a benign adnexal cyst can be treated by operative endoscopy.

Metastatic cancer spread at the laparoscopic puncture site. Report of a case in a patient with carcinoma of the ovary. Case report.

The aim of this study is to draw attention to the possibility of the occurrence of a metastatic spread at the laparoscopic entrance site in patients suffering from a carcinoma of the ovary. This event has rarely been mentioned in medical literature before. A case is presented here in which a localized tumoral lesion appeared after a laparoscopic staging study in the abdominal wall, exactly at the site used for the introduction of the accessory laparoscopic trocar in a patient suffering from a carcinoma of the ovary.

On estimating the center frequency of ultrasonic pulses.

In this paper we propose a new technique for estimating the center frequency of the ultrasound pulse from records of backscattering noise. We start by considering that the conventional maximum frequency method can be seen as a filtering (differentiator) of the pulse spectrum magnitude followed by a searching for the zero-crossing value. The new approach replaces the differentiator by a Hilbert transformer. We show in the paper that the proposed method has less variance than the maximum frequency method. In particular, we analyse the performance assuming that the real cepstrum method is used for extracting pulse spectrum magnitude. We give an upper bound for the variance reduction when practical criteria are applied for fitting the cepstrum cut-off frequency. The analytical work is verified by real and simulated data.

[Study of the antimicrobial sensitivity, auxotype, serotype and plasmid analysis of 75 strains of Neisseria gonorrhoeae isolated in Barcelona]. / Estudio de la sensibilidad antimicrobiana, auxotipia, serotipia y análisis plasmídico de 75 cepas de Neisseria gonorrhoeae aisladas en Barcelona.

The sensitivity of five antimicrobials (penicillin, cefoxitin, tetracycline, ceftazidime and spectinomycin) was assayed in 75 Neisseria gonorrhoeae strains, isolated from May 1986 to December 1987 in a general hospital in Barcelona. Auxotype, serotype and plasmid analysis studies were also performed on these strains. Twenty-six (34%) penicillinase-producing strains were found. 49% of the non-penicillinase-producing strains showed intermediate resistance to penicillin and 12% were resistant with MIC greater than 1 mg/1. 6% were resistant to tetracycline and cefoxitin, respectively, and all were sensitive to ceftazidime and spectinomycin. All the penicillinase-producing strains had the plasmid Africa and three of them had a diffuser plasmid of 24.5 mD. With regard to the auxotype study, most of the strains were prototrophic (38%) followed by the proline dependent ones (38%). 64% of the penicillinase-producing strains belonged to the serogroup W I, while 77% of the non-penicillinase-producing strains were in the W II/III serogroup.

[Exhaustion syndromes in a popular marathon]. / Síndromes por agotamiento en una maratón popular.

The clinical characteristics of seven healthy subjects who required hospital care for an exhaustion syndrome due to extenuated physical exercise during participation in a public marathon are presented. All the patients were used to practising sports activities and in all the cases the symptoms of exhaustion appeared in the last few kilometers of the race. The most frequent symptom found in all the patients was lipothymia with falling to the ground followed by gastrointestinal manifestations, muscle cramping and fever. Upon analysis the signs of rhabdomyolysis and others suggestive of dehydration were observed in all the cases. Leukocytosis was observed in four and hypopotassemia in two. Evolution was good in all the cases with rest and hydroelectrolytic reposition. Finally, the preventive measures to avoid heat stroke and exhaustion syndromes in public marathons are reported.

[Acquired immunodeficiency syndrome: a descriptive study and analysis of survival in 73 cases]. / Síndrome de inmunodeficiencia adquirida: estudio descriptivo y análisis de la supervivencia en 73 casos.

The clinical features and prognostic factors influencing survival in 73 patients diagnosed of acquired immunodeficiency syndrome (AIDS) from June 1984 to November 1988 were evaluated. Mean age was 32 years. The predominant risk group were drug abusers (67%). The most common opportunistic infections were extrapulmonary tuberculosis and esophageal candidiasis. After 6 months, with 42 patients followed up, the probability of survival was 69% +/- 11 (95% confidence interval); after 12 months, with 28 patients, it was 65% +/- 12 (95% confidence interval); and after 18 months, with 11 patients, it was 54% +/- 15 (95% confidence interval). Patients younger than 30 years and those with extrapulmonary tuberculosis had a longer survival than the rest (p = 0.046 and p = 0.014, respectively). The remaining evaluated variables did not have any influence on survival.

[Incidence of nosocomial infections. Comparison of 2 surveillance systems: clinical vs microbiological follow-up]. / Incidencia de la infección nosocomial. Comparación de dos sistemas de vigilancia: seguimiento clínco frente a seguimiento microbiológico.

The effectiveness of a clinical and a microbiological follow-up systems for the detection of hospital-acquired infection (HI), both independently and simultaneously applied, were prospectively evaluated. The observed incidence rate was 11.4%. The clinical follow-up detected 81.3% of HI while microbiological follow-up detected 59.7%. This difference was statistically significant (p less than 0.001). It took 43 and 45 minutes to detect each instance of HI with the clinical and microbiological methods, respectively. Clinical methods are the most adequate to obtain maximal sensitivity in the overall surveillance of hospital-acquired infection, whereas microbiological follow-up may be useful for the detection of some types of HI such as bacteremia or urinary tract infection.