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The overall dependability of an interactive system is one of its weakest components, which is usually its user interface. The presented approach integrates techniques from the dependable computing field and elements of the user-centered design. Risk analysis and fault-tolerance techniques are used in combination with task analysis and modeling to describe and analyze the impact of system faults on human activities and the impact of human deviation or errors on system performance and overall mission performance. A technique for systematic analysis of human errors, effects, and criticality (HEECA) is proposed. It is inspired and adapted from the Failure Mode, Effects, and Criticality Analysis technique. The key points of the approach are: 1) the HEECA technique combining a systematic analysis of the effects of system faults and of human errors; and 2) a task modeling notation to describe and to assess the impact of system faults and human errors on operators' activities and system performance. These key points are illustrated on an example extracted from a case study of the space domain. It demonstrates the feasibility of this approach as well as its benefits in terms of identifying opportunities for redesigning the system, redesigning the operations, and for modifying operators' training.

Laparoscopic common bile duct (CBD) exploration was attempted in 115 of 121 consecutive unselected patients with choledocholithiasis (mean age 69 (range 21–92) years) found during routine intraoperative cholangiography. The CBD was successfully cleared of all stones in 100 patients (87 per cent). Ten of 11 patients referred for surgery after failure of endoscopic sphincterotomy had complete laparoscopic choledocholithiasis. Eleven patients (10 per cent) required conversion to open CBD exploration, and laparoscopic exploration was not attempted in six (5 per cent) because of inflammation or fibrosis. Postoperative endoscopic sphincterotomy was required in four patients (4 per cent) for retained stones after laparoscopic exploration. There were no postoperative deaths (39 per cent of patients were aged 75 years or more). Routine intraoperative cholangiography, and when required laparoscopic CBD exploration, should be compared in randomized trials with preoperative endoscopic retrograde cholangiography in patients with suspected choledocholithiasis.

The immunoelectron microscopy (IEM) technique has been used for the detection of a rabbit enteric coronavirus (RECV). Immune serum was prepared in guinea pigs; the viral antigen used for the immunization procedure was obtained from the caecum of a sick rabbit, concentrated by centrifugation and purified on Percoll gradient. In order to identify the viral particles used in the immunization procedure, the protein pattern of the particles was determined by electrophoresis and compared with the pattern of other known coronaviruses. Analysis of structural polypeptides of the purified viral particles revealed a pattern similar to that reported for other coronaviruses. These polypeptides cross reacted with two other coronavirus specific immune sera (IBV and TGE). IEM assay of fecal samples collected from healthy and sick rabbits showed the presence of immune aggregates in specimens from both sick and healthy rabbits. Those aggregates contained viral particules sharing morphological characteristics with other coronaviruses. Furthermore, IEM assay was shown to be more sensitive than a direct EM procedure to detect coronavirus particles in rabbit feces. This assay also allowed the detection of a larger number of chronic carriers.

Insertion of bulky tertiobutyl groups into the sequence of [D-Ser2,Leu5]enkephalyl-Thr6 leads to a conformationally induced large increase in selectivity toward rat brain delta-opioid binding sites, as shown by the ratio of apparent affinities for mu and delta receptors of [D-Ser2(O-tert-butyl),Leu5]enkephalyl-Thr6,KI(mu)/KI(delta) = 130, and [D-Ser2(O-tert-butyl),Leu5]enkephalyl-Thr6 (O-tert-butyl),KI(mu)/KI(delta) = 280. In addition to a selectivity similar to that of the cyclic compounds [D-Pen2, D-Pen5]enkephalin and [D-Pen2,L-Pen5]enkephalin, the affinity of [3H][D-Ser2(O-tert-butyl),Leu5]enkephalyl-Thr6 for the delta sites of rat brain membranes is significantly better (KD = 2.2 nM) than that of [3H][D-Pen2,D-Pen5]enkephalin (KD approximately 8.5 nM). Therefore, [3H][D-Ser2(O-tert-butyl),Leu5]enkephalyl-Thr6 seems to be the most appropriate delta-probe currently available for binding studies. Moreover, the lipophilic and protected peptide [D-Ser2(O-tert-butyl),Leu5]enkephalyl-Thr6(O-tert-butyl) behaves as the most specific ligand for the delta-opioid binding sites and appears appropriate for in vivo investigations. The inactive analogue [D-Thr2(O-tert-butyl),Leu5]enkephalyl-Thr6 might serve as a negative control in biochemical or pharmacological studies.

Xenopus laevis embryos of stages 14–20 were subjected, for periods of 5–330 min, to hydrostatic pressures ranging from 500 to 10000 psi. The specimens were fixed under corresponding pressures and their neuroepithelium was studied under light and electron microscopy. A pressure of 3000 psi, maintained for as long as 180 min, did not inhibit neurulation though it induced slight deformities of the neuroepithelium. A pressure of 4000 psi, applied for 180 min, disrupted the apical ring of microfilaments and blocked neurulation. The cells lost their dissymmetry. The effect was reversible. Lengthening the duration of treatment to 330 min caused the neuroepithelial cells to loose their microtubules and to become round. This situation was not reversible. Our results indicated that microfilaments are more sensitive than microtubules, that both organelles became increasingly sensitive as the exerted pressure was increased and that microtubules of older embryos exhibited a better resistance. Finally, we showed a correlation between the presence of microfilaments and the constricted state of the cellular apices and a relationship between the presence of microtubules and cell elongation.

Fifty three arteriosclerotic and senile patients were studied from both the EEG and the clinical points of view. The EEG's were classified according to previously defined criteria The following clinical symptoms proved to be particularly important in relation to this study confusion, irritability, agitation, anxiety, delusions, depression, and hallucinations. Memory disorders had to be disregarded, being obscured by confusion. However, they have been taken into consideration in making the diagnosis of these patients.

Electroencephalographic examinations were performed on 118 patients aged between 13 and 23 years, suffering from all types of mental disease. Thirteen of these patients had a personal history of a neurological disorder. These patients were classified in different groups according to the presence and importance of the abnormal hereditary factors.