Interruption of a Monotonous Activity with Complex Tasks: Effects of Individual Differences

The fluctuations of vigilance and performance for operators working in monotonous conditions were studied in laboratory. Three experimental designs were achieved on 20 subjects:

— one reference condition with a vigilance task of 3 hours 30 during day time, — one experimental condition with interruptions of monotony during the vigilance task by a sustained task, during the same day time period, — the same experimental condition during night time.

The purpose was to analyse the effect of breakdown in monotony on arousal and human performance and to look for individual differences in human performance. Physiological data were collected in order to study the variation of arousal. Response times and omissions were used as performance index. Individual differences can be observed for performance and vigilance. Two kinds of behavior are defined: stable subjects and subjects characterized by fluctuations both for arousal and performance during the task. During day time period, breakdown of monotony has a positive effect on performance especially for subjects with fluctuations of arousal. Night time condition creates a sleep deprivation and the consequence is that the efficiency of the reactivation due to breakdown by sustained task is not demonstrated. Results are discussed in regard of the theory of Fisk and Schneider on automated and controlled mental processing during monotonous activities.

Human Force Exertion: The Significance of the Measure?

A basic research was conducted on a sample of twelve right-handed young males for pull actions of the upper limb on a gauge handle. The general purpose is to constitute an atlas of forces for french males, useful for ergonomics studies. Different conditions were tested before to select a standard protocol. Main difficulties concern the elimination of lower limbs contribution, the stability of the posture, the motivation of the subject and the choice of the parameters for the measure. Intra-individual variability in function of the protocols is in a range of 20-30%. With the usual standard protocol, this variability still remains if we try to evaluate maximal pull force during a week period. The interpretation of these data is not clear, and a more accurate definition of the measure is necessary before recommendations for normative data. Time duration of 5 seconds, real-time display of the force and maximal peak value seem to be an acceptable solution by comparison with a functional effort on a torque wrench that reflects a realistic action. It is proposed to use this procedure for the next experiments.

A new way to apply ultrasound in cross-flow ultrafiltration: application to colloidal suspensions

A new coupling of ultrasound device with membrane process has been developed in order to enhance cross-flow ultrafiltration of colloidal suspensions usually involved in several industrial applications included bio and agro industries, water and sludge treatment. In order to reduce mass transfer resistances induced by fouling and concentration polarization, which both are main limitations in membrane separation process continuous ultrasound is applied with the help of a vibrating blade (20 kHz) located in the feed channel all over the membrane surface (8mm between membrane surface and the blade). Hydrodynamic aspects were also taking into account by the control of the rectangular geometry of the feed channel. Three colloidal suspensions with different kinds of colloidal interaction (attractive, repulsive) were chosen to evaluate the effect of their physico-chemical properties on the filtration. For a 90 W power (20.5 W cm(-2)) and a continuous flow rate, permeation fluxes are increased for each studied colloidal suspension, without damaging the membrane. The results show that the flux increase depends on the initial structural properties of filtered dispersion in terms of colloidal interaction and spatial organizations. For instance, a Montmorillonite Wyoming-Na clay suspension was filtered at 1.5 × 10(5)Pa transmembrane pressure. Its permeation flux is increased by a factor 7.1, from 13.6 L m(-2)h(-1) without ultrasound to 97 L m(-2)h(-1) with ultrasound.

Colonization and maintenance of murine embryonic stem cells on poly(alpha-hydroxy esters)

The aim of this study was to determine the ability of various poly(alpha-hydroxy esters) to support the in vitro propagation of murine embryonic stem (ES) cells in an undifferentiated state. To this end, ES cell colonization, growth and Oct-4 immunoreactivity following a 48 h culture period upon poly((D,L)-lactide), poly((L)-lactide), poly(glycolide) and poly((D,L)-lactide-co-glycolide) (PLGA) were assessed. By the analysis of live and dead cell number indices and Oct-4 immunoreactivity, ES cell colonization rate during a 48 h culture period was found to be significantly greater on PLGA compared to all the other unmodified poly(alpha-hydroxy esters) tested. Surface treatment of all polymers with 0.1m potassium hydroxide revealed a significant increase in ES cell live numbers when compared to all unmodified polymers, thus revealing a correlation between polymer content, hydrophilicity and colonization rate. These data suggest that surface treated poly(alpha-hydroxy esters) may be employed for ES cell scale up procedures and in tissue engineering applications requiring the colonization of scaffolds by ES cells in an undifferentiated state. According to such applications, once the designated scaffold has been colonized, ES cell directed differentiation into the desired and fully differentiated, functional adult tissue may then be effected.

Sintered hydroxyfluorapatites--IV: The effect of fluoride substitutions upon colonisation of hydroxyapatites by mouse embryonic stem cells

Biodegradable scaffolds serve a central role for tissue engineering scaffolds and guiding tissue regeneration. Some of these scaffolds, including apatites, display a significant effect upon cell adhesion and cell proliferation. The incorporation of scaffold technology with the developing embryonic stem (ES) cell field and the capacity of ES cells for self-renewal and differentiation are believed to hold enormous potential for applications in biomedical research and regenerative medicine. The purpose of this work was to determine the effect of hydroxyapatite (HAP) and fluoride substitutions of HAP upon ES cell growth and colonisation. Sintered hydroxyfluorapatite discs were found to support cellular proliferation and colonisation, and the ES cells displayed a tendency for differentiation on the apatite surface as determined by reductions in colony Oct4 immunoreactivity. Fluoride-containing HAPs were found to provide equivalent support to gelatin in terms of cell numbers, yet superior support for cellular colonisation when compared to HAP. This study indicates that fluoride substitutions of HAP may represent a viable strategy for the development of certain engineered tissue replacements and tissue regeneration systems using ES cells.

Do morphological anomalies reflect chromosomal aneuploidies?: case report

In cases of severe teratozoospermia, the current morphological criteria used to assess chromosomal status is insufficient for the selection of spermatozoa for intracytoplasmic sperm injection (ICSI). Case histories are reported of four patients presenting 100% teratozoospermia, and the integrity of their individual chromosomal statuses is determined using a three-colour fluorescence in-situ hybridization (FISH) technique. Patient 1 presented shortened flagella syndrome, patient 2 globozoospermia, patient 3 spermatozoa with irregular acrosomes, and patient 4 macrocephalic spermatozoa with associated multiple flagella. Three-colour FISH analysis using chromosome X, Y and 1-specific probes showed that approximately 95% of the spermatozoa analysed from patients 1, 2 and 3 presented X,1 and Y,1 signals, X,Y ratios and aneuploidy/diploidy rates comparable with those observed in normal controls. In contrast, patient 4 showed a highly elevated Y to X sex ratio and a highly elevated aneuploidy/diploidy rate. Three-colour FISH analysis thus demonstrates an increased incidence of chromosomal abnormalities in association with macrocephalic spermatozoa. Moreover, the analysis shows that in patients affected with either globozoospermia, shortened flagella syndrome or a condition of abnormal acrosomal spermatozoa, no association exists between chromosomal status and phenotype. Since these patients display normal haploid, sex chromosome and aneuploidy status, ICSI can be conceivably offered as a treatment for their infertility.

Stage-dependent responses of the developing lung to retinoic acid signaling

Morphological analysis of vitamin A-deficient rat fetuses and of retinoic acid receptor (RAR and RXR) mutant mice have demonstrated that retinoic acid (RA) is essential for lung development. To gainfurther insight into RA signaling pathways during primary lung budformation and lung branching, we have investigated the effects of RA and of a pan-RAR antagonist in cultures of whole embryos and lung explants. Treatment of E8.0 embryos with the pan-RAR antagonist inhibits the formation of the primitive respiratory system. On the other hand, treatment of E11.75 and E12.5 lung explants with RA inhibits branching morphogenesis, whereas treatment with the pan-RAR antagonist at the same developmental stages stimulates formation of distal buds. The inhibitory effect of RA on branching is strongly decreased in RARbeta null lungs, while enhancement of budding by the pan-RAR antagonist is not affected by an RARgamma null mutation. Additionally, cellular retinol binding protein one (CRBPI) null lungs are more sensitive than wild type lungs to the pan-RAR antagonist-induced stimulation of branching. These data indicate that retinoid signaling is indispensable for the formation of primary lung buds and the oesophagotracheal septum from the primitive foregut. They also suggest that at the pseudoglandular stage, RA signaling through RARbeta, but not RARgamma, inhibits distal bud formation thereby promoting the formation of conducting airways. Moreover, the level of CRBPI in the pseudoglandular lung appears to participate in the control of branching morphogenesis.

Histological and genetic analysis and risk assessment for chromosomal aberration after ICSI for patients presenting with CBAVD

Intracytoplasmic sperm injection (ICSI) has opened a new field in the treatment of male infertility, leading to a debate concerning its genetic safety. In this study we present an analysis of 11 patients presenting congenital bilateral absence of the vas deferens (CBAVD). In all 11 cases, genetic counselling, histological analysis of testicular biopsies, cystic fibrosis transmembrane conductance regulator (CFTR) mutation screenings of both partners and spermatozoa three-colour fluorescent in-situ hybridization (FISH) analysis were performed. A total of 31 CFTR mutations were screened and mutations were found in eight out of 11 cases, with DeltaF508 being the most common mutation found. Histological analyses showed that seven out of 11 patients had normal tubule/membrane/interstitium (TMI) and Johnsen scores, while the remaining four patients had mild impairment of testicular parenchyma. The average aneuploidy rate was 6.8 +/- 3.9% compared with two control subjects with 4.4 and 5.4% aneuploidy rates respectively, using FISH analysis. After ICSI, the fertilization and pregnancy rates were 66.2 and 22.7% respectively. Thus, in our case of CBAVD, the risk of chromosomal aberration following ICSI, in the absence of a CFTR mutation in the male patient and/or in his partner, was not higher than in normal fertile men. Furthermore, the pregnancy success rate following ICSI of these CBAVD patients was comparable to the general ICSI population, even when histological analysis showed limited spermatogenesis.

Tissue-specific expression of retinoic acid receptor isoform transcripts in the mouse embryo

The three murine retinoic acid receptor (RAR) genes each contain two distinct promoters which give rise to protein isoforms differing in their N-terminal regions. This study used in situ hybridization to describe the expression patterns of RARalpha1, RARalpha2, RARbeta1/3, RARbeta2/4, RARgamma1 and RARgamma2 isoform transcripts during mouse embryogenesis. RARalpha1 transcripts are widely distributed, with the exception of the central nervous system. Highest expression is found in developing muscle, pituitary gland and various epithelia. On the other hand, RARalpha2 is essentially expressed along the spinal cord up to the hindbrain 7th rhombomere and in the 4th rhombomere, pons and developing basal ganglia (corpus striatum and pallidum). RARbeta2/4 transcripts account for most of the previously described RARbeta expression features being expressed specifically, or more prominently than RARbeta1/3, in foregut endoderm and its derivatives, olfactory and periocular mesenchyme, urogenital region, proximal limb bud mesenchyme and later within interdigital regions. RARbeta1/3 is more prominently expressed in the developing heart outflow tract mesenchyme, intervertebral disks, midgut loop mesenchyme and umbilical vessel walls. RARbeta1/3 and RARbeta2/4 are coexpressed in the developing corpus striatum. They exhibit, however, distinct dorsoventral distributions along the spinal cord and caudal hindbrain. RARgamma2 is the RARgamma isoform expressed at high levels in the caudal neural groove at embryonic day 8.5. At later stages, both RARgamma isoforms are essentially coexpressed, although the progressive restriction of RARgamma1 transcripts to craniofacial or limb precartilaginous condensations appears to precede that of RARgamma2.

A correlation between epithelial proliferation rates, basement membrane component localization patterns, and morphogenetic potential in the embryonic mouse lung

Lung epithelial branching morphogenesis results from a repetitive series of cleft and bud formation, a process dependent upon a complex interaction with the surrounding mesenchyme. The present study describes these cleft- and bud-forming regions as autonomous morphogenetic compartments within the embryonic day 11.5 (E11.5) mouse lung and directly correlates their identity with differences in epithelial proliferation rates and the localization pattern of specific basement membrane components. Lung buds were cultured in vitro, in two-dimensional planes, and labeled with a series of 5-bromo-2'-deoxyuridine (BrdU) pulses. Collectively, epithelial cells within actively budding regions of the bronchiolar tree demonstrated an at least 2.5-fold greater proliferation rate than those situated in the adjacent cleft-forming regions. Epithelial proliferation rates showed an inverse relationship with the degree of immunoreactivity of nidogen, laminin-1, fibronectin, and collagen IV within the underlying basement membrane. Epithelial cells dissected free from mesenchyme demonstrated cell-cell contact-dependent proliferation, thus revealing a hierarchy between mesenchymal signaling and direct epithelial cell-cell communication during branch formation. Dissection of the E11.5 bronchiolar tree into specific distalbud and interbud regions and their in vitro culture demonstrated differences in their autonomous morphogenetic potential. Tissue dissected from the distal tips of the lung continued to branch, whereas tissue dissected from immediately adjacent cleft regions seldom branched. Isolated distalbud tissue also continued to correlate regional differences in epithelial proliferation rates and immunolocalization patterns of nidogen, laminin-1, fibronectin, and collagen IV with branch formation. These results support the basement membrane remodeling hypothesis, thus connecting nidogen, collagen type IV, fibronectin, and laminin-1 localization with the molecular processes directing epithelial proliferation and supporting bud outgrowth and cleft formation/stabilization during lung morphogenesis.

Homeobox genes from clusters A and B demonstrate characteristics of temporal colinearity and differential restrictions in spatial expression domains in the branching mouse lung

Lung branching morphogenesis is accomplished by reciprocal morphogenetic interactions between the epithelium and its mesenchyme. In order to better understand the molecular mechanisms regulating these interactions in time and space, the expression patterns of Hox genes isolated exclusively from the branching region of the developing lung have been investigated. Reverse transcriptase PCR identified Hoxa-1, Hoxa-3, Hoxa-5, Hoxb-3, Hoxb-4, Hoxb-6, Hoxb-7, and Hoxb-8 transcripts from within this tissue at 11.5 day post coitum (E11.5). Northern blot, in situ hybridization and PCR analyses demonstrated qualitative and quantitative differences in expression patterns for each gene assessed in this region thus providing evidence for Hox gene temporal colinearity. Furthermore, although not within the context of strict anteroposterior definition, Hox genes located within a more 5' region in both clusters were found to have greater spatial expression constrictions when compared to their more 3' counterparts. These Hox genes were also differentially expressed both between and within specific germ cell lineage derivatives. Such patterns of expression suggest that Hox genes play a role in the specification and maturation of lung cell lineage derivatives throughout the pseudoglandular, canalicular and terminal sac phases of lung development.

Micromotion, fit, and fill of custom made femoral stems designed with an automated process

This study presents an automated process for the design of custom made femoral stems. Two software programs have been developed to obtain the inner bone contours from computed tomography scan images and to design the optimal stem that can be inserted into the femur. This process requires only 2 hours of computer use, therefore reducing the price of the stem. It is also possible to control the amount of bone sacrifice necessary to facilitate the insertion of the stem. Micromotion for 6 specimens was measured using a special machine simulating the load supported by the hip joint during single-limb stance. Three prostheses were tested successively: anatomic cementless stem, custom made stem, and modified custom made stem in which the distal part was thinned out. To be stabilized, the anatomic prosthesis required a greater number of cycles than custom made stems associated with a more important total vertical migration. The micromotion of custom made prostheses was significantly less than that of the other prostheses. The fill of custom made stems also was measured, having a range from 93% to 100% (mean, 97.5%-98.8%) of the medullary canal. The metaphyseal fill was significantly linked with the vertical and rotational components of instability. These results showed that it was possible, using a computerized automated and controlled process, to obtain low price femoral stems well fitted to the medullary canal that provide an excellent primary stability.

Appropriate use of bright light promotes a durable adaptation to night-shifts and accelerates readjustment during recovery after a period of night-shifts

The present study examines the stability of bright light circadian readjustment during two consecutive dim light night-work periods and circadian synchronization during the recovery after a night-shift period. A sample of 10 subjects was divided into 2 groups (control group : 6 subjects; experimental group: 4 subjects). All subjects worked during 5 days, between 23:00 and 07:00 h and then went to sleep. Subjects received 2500-3000 lux between 02:00 and 05:00 h during 5 days for the control group and 3 days for the experimental group. During recovery after the night-shift periods, three cycles of bright light were administered at two different times: 12:00-15:00 h for two of six subjects from the control group and 10:00-13:00 h for all subjects (4) of the experimental group. By the fifth cycle of night-work the maximum of urinary aMT6s excretion that occurs at 05:00 h in the baseline condition was shifted to 12:00 h for the control and experimental groups (delay in hours: 7 +/- 1.6 (control); 7 +/- 1(experimental)). This result suggests that three cycles of bright light are sufficient to induce a significant phase delay and that this delay remained stable when night-work proceeded under dim light. The phase delay of the circadian aMT6s excretion by exposure to bright light was accompanied by an improvement of the quality of day sleep and level of cognitive and psychomotor performances for control and experimental groups. No significant difference was observed in the two groups for daytime sleep and nocturnal performance. The two bright light periods used during the three days of recovery induced a complete synchronization in five of six subjects. One subject showed a partial sychronization probably because he remained at the laboratory under dim light during the day and had few family and social contacts.

Human vigilance in railway and long-haul flight operation

Human operators in transport operations are often confronted with monotony, boredom, and irregular work schedules. This situation has become increasingly more acute because of the growing automation of systems. This paper presents methodology and preliminary results for two field studies on the vigilance of train drivers and long-range aircrews. The aim of these studies was to identify factors that can modify vigilance and to elaborate several specific solutions for reactivation. The method is based on the collection of physiological data in the field and on task observation of the operators. The recorded physiological data (EEG, EOG, EKG) permit an evaluation of vigilance and mental workload. The rest-activity cycles are estimated by actometry. The use of EEG and EOG are discussed in relation to monotony and sleep deprivation. For pilots, results show a high occurrence of decreased vigilance, particularly during phases of low workload (i.e., when cruising). Furthermore, it was shown that these periods of lowered vigilance can occur at the same time for two crew members. A great number of incidents of decreased vigilance were also observed for the train drivers. These incidents occurred even though the operators sometimes had high levels of activity. A direct relation was also noted between sleep duration and the onset of rest. These studies provide several means for maintaining vigilance during activities and improving the system of work schedule rotation.

An assessment of the deflecting effect on human movement due to the Coriolis inertial forces in a space vehicle

Under conditions of prolonged space flight, it may be feasible to restore gravity artificially using centrifugal inertial forces in a spinning vehicle. As a result, the motion of the passengers relative to the vehicle is affected by Coriolis forces. The aim of this study is to propose a theoretical method to evaluate the extent of these effects compared to other inertial or motor forces affecting movement. We investigated typical right upper limb movement in a numerical model with a two-solid-links mechanism, including a spherical joint for the shoulder and a hinge joint for the elbow. The inertial and dimensional characteristics of this model derive from measurements and computations obtained on laboratory subjects. The same is true for the movements assigned to the model. These were inferred from actual recordings of arm movement when the subject presses a button placed in front of him with his index finger. From these relative velocities, the resulting forces and moments applied to the elbow and the shoulder were computed for a 1 rad s-1 rotational speed of transport motion, using classical kinetic relations. The result is that the Coriolis moments are of the same order of magnitude as the corresponding inertial moments and one-tenth of the value of a typical elbow flexion moment. Thus, they should cause a significant disturbance in movement.

Immunological fine structure of the variable and constant regions of a polymorphic malarial surface antigen from Plasmodium falciparum

The 51-kDa merozoite surface antigen MSA2 of Plasmodium falciparum shows considerable strain-dependent polymorphism. Although marked sequence variation occurs in the central region of the molecule, the N and C-terminal sequences are highly conserved. A number of monoclonal antibodies directed against MSA2 have been described which inhibit parasite growth in vitro, but these are all directed against variable regions. In an attempt to raise strain independent antibodies we have prepared peptide-diphtheria toxoid (DT) constructs from 36 N-terminal octapeptides spanning the constant region and extending into the variable region of the FCQ/27 PNG variant staggered by one amino acid at either end. Similarly, we prepared 26 C-terminal octapeptides spanning the C-terminal constant region as well as 10 octapeptides from the variable region of the Indochina I variant MSA2. Most of the peptides elicited antipeptide titres in excess of 1/10(4) when administered to mice as peptide-DT adducts emulsified with Freund's complete adjuvant. Only 3 of the 43 N- and C-terminal constant region peptides elicited antibodies which reacted appropriately on immunofluorescence (IFA) or immunoblotting analysis with the intact MSA2 of both strains studied (FCQ/27 and Indochina I), whereas 3 other peptides from the variable region elicited antibodies reactive with the parent MSA2 only. Peptide constructs eliciting antibodies recognising the intact protein corresponded to elements in the cognate sequence of high antigenicity as predicted by the Jameson and Wolf algorithm.

Variable linking region immunogenicity using malarial peptide carrier protein conjugates of defined composition

Thirty-five overlapping peptides from both conserved and variable parts of the N-terminal region of a malarial merozoite surface antigen (MSA2) were synthesised using solid phase chemistry. All peptides were synthesised with an added N-terminal cysteine and purified by reverse-phase HPLC to facilitate coupling to a carrier protein diphtheria toxoid (DT) using the hetero-bifunctional reagent maleimidocaproloxysuccinimide (MCS). Mice were immunised with these peptide-DT conjugates using Freund's complete adjuvant (FCA). The immune response of these mice was tested against peptide hapten, carrier protein (DT) and the linking region itself, using enzyme-linked immunoassay (ELISA). Although there was great variation in the immune response to each part of the immunogen construct, no significant correlation could be seen between each set of responses.

Peptide vaccines derived from a malarial surface antigen: effects of dose and adjuvants on immunogenicity

Peptides P2122 (CKNNNSTNSGI) and P513 (CSQRSTNSAST) containing an epitope of a malarial surface antigen (MSA2) recognised by inhibitory monoclonal antibodies were conjugated to diphtheria toxoid (DT) protein and formulated with various gel-based and water in oil emulsion adjuvants in vaccine trials in mice and rabbits. The P2122-DT construct was effective in raising antibodies reactive with both the immunising peptide and the native antigen. Effective adjuvanticity as measured by the titre of the anti-peptide or anti-protein response in mice varied in the order: Algammulin, Montanide ISA 50 greater than or equal to Freund's adjuvant, Montanide ISA 708, 721, 70 much greater than alum, Squalene Arlacel greater than SAF-1. A similar order of adjuvant efficacy: Freund's greater than alum greater than Squalene Arlacel greater than SAF-1, was observed in rabbits.

[Use of x-ray computed tomographic data for the concept of a custom-made hip prosthesis. Exploratory approach]

A custom-made hip prosthesis has to allow to improve the arthroplasty's longevity. In a Computer Aid program Conception (CAD) of such an implant, it becomes necessary to control the accuracy of the 3-D data given by CT Scans. The method employed is based on the comparison between 3-D data given by CT Scans and by photogrammetry. The study was made with a human pelvis including femoral head, without soft tissues. The CT Scans data have been given by automatic extraction of osseous outlines on two hundreds sections (1.5 mm thickness). The photogrammetry data have required five stereocouples for the whole pelvis and four stereocouples for the hip joint (femoral head and cotyle). There nine stereocouples have provided 37,213 points of reference. The comparison between the two sorts of informations shows that the error made in CT Scans acquisition was varying between 0.65 and 1.60 mm. This error is smaller when the outlines are simple, like the femoral diaphyse. The error decreases if we reduce the field size of CT Scan acquisition. These results confirm literature data. But this study has allowed to demonstrate validity of 3-D CT reconstruction. Scanography looks like the best present way of data acquisition. The dimensional précision is sufficient to define the endo-osseous outline, but it must be preserved at the moment of the extraction of this outline. Therefore this extractive can't be manual and must be made directly with processing data given by scanography.

Cross-reactivity of antibody against an epitope of the Plasmodium falciparum second merozoite surface antigen

Monoclonal antibodies directed against the 51 kD merozoite surface antigen of Plasmodium falciparum also bind to other antigens within the infected cell. The sizes of these cross-reacting antigens have been characterized. Immunofluorescence due to the reaction of one of the monoclonal antibodies with these cross-reacting antigens was localized in the intra-erythrocytic parasite and in granules in the infected red cell cytoplasm. This immunofluorescence could be distinguished from the merozoite surface antigen in parasite lines with a variant serotype of the merozoite surface antigen which fails to react with the monoclonal antibodies. It was found that the in-vitro growth inhibition caused by the presence of one of the monoclonal antibodies, 8G10/48, was dependent on the expression of the corresponding serotype of merozoite surface antigen, a finding consistent with the inhibitory effect of this antibody being primarily directed against the merozoite surface antigen and not the cross-reacting antigens. Analysis of the frequency at which epitopes occur suggests that such cross-reacting proteins will be commonly seen in malaria, without the need to postulate a selective advantage for such cross-reacting specificities.

Habitability design of European spacecraft Hermes--ergonomic aspects

First results of a 3-D human body model conception adapted to C.A.D. studies is presented. This parametric model incorporating specific constraints due to weightlessness is well adapted to bring valuable answers to Human Factors Engineers, designing man-system interfaces of European spacecraft Hermes.

Electropalatography: thermo-formed pseudopalates and the use of three-dimensional display

Electropalatography provides a method of recording contact of the tongue against the palate; this has valuable potential in linguistics, phonetics, speech therapy, oral physiology and dentistry. The application of the technique has been limited by the time required to produce a plate (pseudopalate) carrying electrodes for each person studied. The bulk of an acrylic plate also imposes some interference with speech. A simple, relatively fast, method of producing very thin plates is described. The use of models to provide three-dimensional display is illustrated and the value of slow speed play-back of data is discussed.