Hindcasting the 2017 dispersal of Sargassum algae in the Tropical North Atlantic

Since 2011, huge amounts of Sargassum algae are detected in the equatorial Atlantic, causing large strandings events on the coasts of the West Indies, Brazil and West Africa. The distribution of this stock shows strong annual and interannual variability, whose drivers are not settled yet. Here we use satellite Sargassum observations from MODIS and currents from an ocean reanalysis to simulate the passive transport of algae in 2017. Wind effect was necessary to fit the observed distribution. Simulations reasonably reproduce the satellite monthly distribution for up to seven months, confirming the prominent role of transport in the distribution cycle. Annual cycle appears as a zonal exchange between eastern (EAR) and western accumulation regions (WAR). EAR is well explained by advection alone, with sharp meridional distribution controlled by converging currents below the inter-tropical Convergence Zone. Instead, WAR is not explained by advection alone, suggesting local growth.

From In Situ to satellite observations of pelagic Sargassum distribution and aggregation in the Tropical North Atlantic Ocean

The present study reports on observations carried out in the Tropical North Atlantic in summer and autumn 2017, documenting Sargassum aggregations using both ship-deck observations and satellite sensor observations at three resolutions (MSI-10 m, OLCI-300 m, VIIRS-750 m and MODIS-1 km). Both datasets reported that in summer, Sargassum aggregations were mainly observed off Brazil and near the Caribbean Islands, while they accumulated near the African coast in autumn. Based on in situ observations, we propose a five-class typology allowing standardisation of the description of in situ Sargassum raft shapes and sizes. The most commonly observed Sargassum raft type was windrows, but large rafts composed of a quasi-circular patch hundreds of meters wide were also observed. Satellite imagery showed that these rafts formed larger Sargassum aggregations over a wide range of scales, with smaller aggregations (of tens of m2 area) nested within larger ones (of hundreds of km2). Match-ups between different satellite sensors and in situ observations were limited for this dataset, mainly because of high cloud cover during the periods of observation. Nevertheless, comparisons between the two datasets showed that satellite sensors successfully detected Sargassum abundance and aggregation patterns consistent with in situ observations. MODIS and VIIRS sensors were better suited to describing the Sargassum aggregation distribution and dynamics at Atlantic scale, while the new sensors, OLCI and MSI, proved their ability to detect Sargassum aggregations and to describe their (sub-) mesoscale nested structure. The high variability in raft shape, size, thickness, depth and biomass density observed in situ means that caution is called for when using satellite maps of Sargassum distribution and biomass estimation. Improvements would require additional in situ and airborne observations or very high-resolution satellite imagery.

Kossel Effect in Periodic Multilayers

The Kossel effect is the diffraction by a periodically structured medium, of the characteristic X-ray radiation emitted by the atoms of the medium. We show that multilayers designed for X-ray optics applications are convenient periodic systems to use in order to produce the Kossel effect, modulating the intensity emitted by the sample in a narrow angular range defined by the Bragg angle. We also show that excitation can be done by using photons (X-rays), electrons or protons (or charged particles), under near normal or grazing incident geometries, which makes the method relatively easy to implement. The main constraint comes from the angular resolution necessary for the detection of the emitted radiation. This leads to small solid angles of detection and long acquisition times to collect data with sufficient statistical significance. Provided this difficulty is overcome, the comparison or fit of the experimental Kossel curves, i.e., the angular distributions of the intensity of an emitted radiation of one of the element of the periodic stack, with the simulated curves enables getting information on the depth distribution of the elements throughout the multilayer. Thus the same kind of information obtained from the more widespread method of X-ray standing wave induced fluorescence used to characterize stacks of nanometer period, can be obtained using the Kossel effect.

Note: Observation of the angular distribution of an x-ray characteristic emission through a periodic multilayer

We present the observation of the angular distribution of a characteristic x-ray emission through a periodic multilayer. The emission coming from the substrate on which the multilayer is deposited is used for this purpose. It is generated upon proton irradiation through the multilayer and detected with an energy sensitive CCD camera. The observed distribution in the low detection angle range presents a clear dip at a position characteristic of the emitting element. Thus, such a device can be envisaged as a spectrometer without mechanical displacement and using various ionizing sources (electrons, x-rays, and ions), their incident direction being irrelevant.

EUV stimulated emission from MgO pumped by FEL pulses

Stimulated emission is a fundamental process in nature that deserves to be investigated and understood in the extreme ultra-violet (EUV) and x-ray regimes. Today, this is definitely possible through high energy density free electron laser (FEL) beams. In this context, we give evidence for soft-x-ray stimulated emission from a magnesium oxide solid target pumped by EUV FEL pulses formed in the regime of travelling-wave amplified spontaneous emission in backward geometry. Our results combine two effects separately reported in previous works: emission in a privileged direction and existence of a material-dependent threshold for the stimulated emission. We develop a novel theoretical framework, based on coupled rate and transport equations taking into account the solid-density plasma state of the target. Our model accounts for both observed mechanisms that are the privileged direction for the stimulated emission of the Mg L_2,3 characteristic emission and the pumping threshold.

Enhancement of the reflectivity of Al/Zr multilayers by a novel structure

The reflectivity of Al/Zr multilayers is enhanced by the use of a novel structure. The Al layers are divided by insertion of Si layers. In addition, Si barrier layers are inserted at the Al/Zr interfaces (Zr-on-Al and Al-on-Zr). As a result, crystallization of the Al layer is inhibited and that of Zr is enhanced. In grazing incidence x-ray reflectometry, x-ray diffraction, and extreme ultraviolet measurements, the novel multilayers exhibit lower interfacial roughness compared with traditional multilayer structures, and their reflectivity is increased from 48.2% to 50.0% at a 5° angle of incidence. These novel multilayers also have potential applications in other multilayer systems and the semiconductor industry.

Detection of QTL controlling metabolism, meat quality, and liver quality traits of the overfed interspecific hybrid mule duck

The mule duck, an interspecific hybrid obtained by crossing common duck (Anas platyrhynchos) females with Muscovy (Cairina moschata) drakes, is widely used for fatty liver production. The purpose of the present study was to detect and map single and pleiotropic QTL that segregate in the common duck species, and influence the expression of traits in their overfed mule duck offspring. To this end, we generated a common duck backcross (BC) population by crossing Kaiya and heavy Pekin experimental lines, which differ notably in regard to the BW and overfeeding ability of their mule progeny. The BC females were mated to Muscovy drakes and, on average, 4 male mule ducks hatched per BC female (1600 in total) and were measured for growth, metabolism during growth and the overfeeding period, overfeeding ability, and the quality of their breast meat and fatty liver. The phenotypic value of BC females was estimated for each trait by assigning to each female the mean value of the phenotypes of her offspring. Estimations allowed for variance, which depended on the number of male offspring per BC and the heritability of the trait considered. The genetic map used for QTL detection consisted of 91 microsatellite markers aggregated into 16 linkage groups (LG) covering a total of 778 cM. Twenty-two QTL were found to be significant at the 1% chromosome-wide threshold level using the single-trait detection option of the QTLMap software. Most of the QTL detected were related to the quality of breast meat and fatty liver: QTL for meat pH 20 min post mortem were mapped to LG4 (at the 1% genome-wide significance level), and QTL for meat lipid content and cooking losses were mapped to LG2a. The QTL related to fatty liver weight and liver protein and lipid content were for the most part detected on LG2c and LG9. Multitrait analysis highlighted the pleiotropic effects of QTL in these chromosome regions. Apart from the strong QTL for plasma triglyceride content at the end of the overfeeding period mapped to chromosome Z using single-trait analysis, all metabolic trait QTL were detected with the multitrait approach: the QTL mapped to LG14 and LG21 affected the plasma cholesterol and triglyceride contents, whereas the QTL mapped to LG2a seemed to impact glycemia and the basal plasma corticosterone content. A greater density genetic map will be needed to further fine map the QTL.

Optical and structural performance of the Al(1%wtSi)/Zr reflection multilayers in the 17-19nm region

Two kinds of Al/Zr (Al(1%wtSi)/Zr and Al(Pure)/Zr) multilayers for extreme ultraviolet (EUV) optics were deposited on fluorine doped tin oxide coated glass by using direct-current magnetron sputtering technology. The comparison of the two systems shows that the Al(1%wtSi)/Zr multilayers have the lowest interfacial roughness and highest reflectivity. Based on the X-ray diffraction, the performance of the two systems is determined by the crystallization of Al layer. To fully understand the Al(1%wtSi)/Zr multilayer, we built up a two-layer model to fit situation of the AFM images, and simulate the grazing incident x-ray reflection-measurements of multilayers with various periods (N = 10, 40, 60, 80). Below 40 periods, the roughness components are lowered. After 40 periods, both surface and interfacial roughness increase with the period number, and decrease the reflectance. According to transmission electron microscope images, the model can represent the variable structure of the system.

Thermal stability of Mg/Co multilayer with B4C, Mo or Zr diffusion barrier layers

The efficiency of B(4)C, Mo and Zr barrier layers to improve thermal stability of Mg/Co multilayer up to 400 °C is investigated. Multilayers were deposited by direct current magnetron sputtering and characterized using X-ray and extreme ultraviolet reflection. The results suggest that B(4)C barrier layer is not effective due to drastic diffusion at Mg-B(4)C interface. Although introducing Mo barriers improves the thermal stability from 200 to 300 °C, it increases the interface roughness and thus degrades the optical performances. On the contrary, Zr barriers can significantly increase the thermal stability of Mg/Co up to 400 °C without optical performance degradation. Thus, Mg/Zr/Co/Zr is suitable for EUV applications requiring both optimal optical performances and heat resistance.

Structural properties of Al/Mo/SiC multilayers with high reflectivity for extreme ultraviolet light

We present the results of an optical and chemical, depth and surface study of Al/Mo/SiC periodic multilayers, designed as high reflectivity coatings for the extreme ultra-violet (EUV) range. In comparison to the previously studied Al/SiC system, the introduction of Mo as a third material in the multilayer structure allows us to decrease In comparison to the previously studied Al/SiC system with a reflectance of 37% at near normal incidence around 17 nm, the introduction of Mo as a third material in the multilayer structure allows us to decrease the interfacial roughness and achieve an EUV reflectivity of 53.4%, measured with synchrotron radiation. This is the first report of a reflectivity higher than 50% around 17 nm. Time-of-flight secondary ion mass spectrometry (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS) measurements are performed on the Al/Mo/SiC system in order to analyze the individual layers within the stack. ToF-SIMS and XPS results give evidence that the first SiC layer is partially oxidized, but the O atoms do not reach the first Mo and Al layers. We use these results to properly describe the multilayer stack and discuss the possible reasons for the difference between the measured and simulated EUV reflectivity values.

Comparison of Mg-based multilayers for solar He II radiation at 30.4 nm wavelength

Mg-based multilayers, including SiC/Mg, Co/Mg, B(4)C/Mg, and Si/Mg, are investigated for solar imaging and a He II calibration lamp at a 30.4 nm wavelength. These multilayers were fabricated by a magnetron sputtering method and characterized by x-ray reflection. The reflectivities of these multilayers were measured by synchrotron radiation. Near-normal-incidence reflectivities of Co/Mg and SiC/Mg multilayer mirrors are as high as 40.3% and 44.6%, respectively, while those of B(4)C/Mg and Si/Mg mirrors are too low for application. The measured results suggest that SiC/Mg, Co/Mg multilayers are promising for a 30.4 nm wavelength.

Influence of lipoprotein-lipase activity on plasma triacylglycerol concentration and lipid storage in three genotypes of ducks

The lipoprotein-lipase (LPL) hydrolyses the triacylglycerols (TG) secreted by the liver and, thus, allows the storage of lipids onto the extrahepatic tissues. The LPL activity has been studied by injection of LPL antibodies in three genotypes of ducks (Muscovy (Cairina moschat), Pekin (Anas plathyrhynchos) and Mule (hybrids of male Muscovy ducks and female Pekin ducks)) under overfeeding condition. The results show a similar weight gain between injected and control animals. A higher liver steatosis is observed in Mule ducks (616+/-18 g; 8.79% of body mass (BW)) and Muscovy ducks (514+/-13 g; 7.05% BW) compared to Pekin ducks (353+/-21 g; 5.89% BW, p<0.05). Pekin ducks showed a much marked extrahepatic fattening of abdominal and subcutaneous adipose tissues. The LPL activity was evaluated by comparing the evolution of the plasma TG concentrations after injections of saline (control animals) or injections of specific LPL-antibodies. Inhibition of LPL activity performed by intravenous injections of LPL-antibodies showed a spectacular increase in the plasma TG concentrations in the three genotypes. That increase was considerably higher in Pekin ducks (98+/-10 g/L) compared to Muscovy ducks (35+/-2 g/L, p<0.01) and Mule ducks (30+/-4 g/L, p<0.01). Those data suggest that a high export of lipids synthesized in liver and a high LPL activity occur in overfed Pekin ducks, which can favour the extrahepatic fattening to the detriment of the liver steatosis, and conversely in overfed Muscovy and Mule ducks.

Carotid atherosclerosis is not related to past tuberculosis in hypercholesterolemic patients

BACKGROUND

Tuberculosis is a chronic recurrent infection and inflammation is part of the disease which may remain undiagnosed for months. Furthermore immunization with recombinant heat shock protein-65-rich mycobacterium tuberculosis increased atherogenesis in hypercholesterolemic animal models.

OBJECTIVE

To investigate the potential interrelationships between past tuberculosis with carotid and femoral atherosclerosis in hypercholesterolemic patients.

DESIGN AND SETTING

Case control study in a university hospital.

PATIENTS

Two groups of hypercholesterolemic patient group (n=147) studied in a cardiovascular prevention unit during the same quarter, age (+/-1 year) and sex-matched. The first group presented a history of tuberculosis in the past and the second group never.

METHODS

Atherosclerosis was assessed by carotid and femoral external echography. Measurements of maximum plaque diameter were done in longitudinal planes, and the extent of atherosclerosis was graded according to the most severe visible changes on the scanned arteries.

RESULTS

The frequency and the distribution of atherosclerosis was similar in the two groups, whatever the arterial site explored, carotid or femoral. None of the clinical and biological studied variables were different between the two groups of patients.

CONCLUSION

Past tuberculosis is not associated with increased frequency of atherosclerotic lesions in hypercholesterolemic patients.

Violence to and maltreatment of people with disabilities: a short review

OBJECTIVE

Violence to disabled persons constitutes a major ethical problem. The European Academy of Rehabilitation Medicine has debated the matter; it presents this short report to alert a wider audience to the problem, with the aim of provoking debate and facilitating prevention.

DESIGN

The Academy has produced a full report on the literature. The present short report summarizes the essential features of this and significant references to violence. This is defined, types described, and risk factors and signs identified with the aim of informing rehabilitation practitioners.

CONCLUSION

Violence may take many forms, often being subtle, insidious and difficult to recognize. However, the members of the rehabilitation team may be able to provide significant help and act preventively as they work towards the better social integration of the disabled individual helping them gain more control of their lives. European legislation may help us in this task; we are reminded that our roles are set within the context of our civic duties of respect for and tolerance of all.

Increasing shoe instep improves gait dynamics in patients with a tibiotalar arthrodesis

Degenerative osteoarthritis in subtalar and midtarsal joints occurring after tibiotalar arthrodesis may be related to biomechanical factors. For patients with tibiotalar arthrodesis walking with their everyday shoes, the ground reaction force is posterior at heel-off and the maximal foot-tibia dorsiflexion is at its upper limit. We hypothesized that increasing the instep of the shoes would improve these abnormalities. Three-dimensional gait analysis was done in nine patients with ankle arthrodesis fused in the neutral position and for 10 control subjects. Four conditions of walking were tested: barefoot, wearing everyday shoes, wearing everyday shoes with the instep increased by 1 cm, and wearing everyday shoes with the instep increased by 2 cm. In the arthrodesis group, the two modified delayed heel-off shoe conditions shifted the ground reaction force closer to the metatarsal heads at heel-off to a normal range, and reduced the maximal foot and tibia dorsiflexion angle. Based on these results, patients with a tibiotalar arthrodesis in the neutral sagittal position may be advised to choose shoes with an instep of approximately 25 mm.

Effects of dietary fructose on liver steatosis in overfed mule ducks

Overfeeding of some waterfowl species results in obesity, which is mainly characterized by a dramatic hepatic steatosis induced by strong accumulation of lipids synthesized from dietary glucose in the liver. In mammals, fructose is known to be able to raise plasma triacylglycerol concentrations significantly; consequently, this may induce obesity. The aim of this study was to assess the effect of partial replacement of dietary glucose provided by corn starch with fructose on metabolism and fatty liver production in the Mule ducks. On the basis of 9.5 kg maize (132,920 kJ) given twice a day for 14 days, a supplementation of 9,800 kJ was provided in form of glucose, sucrose or high fructose corn syrup (HFCS: 50 % glucose, 42 % fructose and 8 % other saccharides). Fatty liver weight in ducks fed with glucose supplementation was 499 +/- 21 g. Sucrose or HFCS supplementation brought about a significant increase in liver weight (+ 18.7 % and + 16.3 % vs. glucose supplementation respectively, p < 0.05). These results suggest that the dietary fructose favors the liver steatosis by increasing hepatic lipogenesis. Postprandial plasma insulin concentrations were similar in ducks fed diets with or without fructose, suggesting that the effect of fructose on liver steatosis is not mediated by insulin.

Mirror asomatognosia in right lesions stroke victims

The objectives of this prospective study were: to search for mirror-induced disorders of the body image in right hemisphere stroke victims using a description task of the contralateral upper limb, to analyze their clinical features, and to discuss possible mechanisms. Sixteen consecutive patients with documented unilateral right hemisphere stroke were examined for asomatognosia at the acute phase of stroke, then at least 2 months after stroke under three test conditions: without a mirror, with a conventional mirror, with an inverted mirror. Video recordings of the tests were analyzed to assess performance. The diagnosis of asomatognosia was retained if the subject reported at least one of three sensations: limb transformation, limb strangeness, and/or limb alienation. During the acute phase, 14/16 patients presented manifestations of asomatognosia. All of these spontaneous manifestations had disappeared 2 months later, but were reactivated in 12 patients when exposed to mirror images. The mirror tests revealed four situations: no disorder (n = 4), asomatognosia with both mirrors (n = 5), asomatognosia with the conventional or inverted mirrors (n = 1 and 5), and asomatognosia with the inverted mirror (n = 1). These manifestations were designated as mirror-asomatognosia, a disorder resulting from adaptations of the procedures leading to reorganization of the internal representations of the body image. These findings suggest there are several such internal representations of the body image and that direct body image and mirror body image would be two specific ones. These clinical manifestations and their evolution over time are an expression of the progressive nature of the underlying compensatory mechanisms made possible by brain plasticity.

Pancreatic hormonal and metabolic responses in overfed ducks

When overfed at their maximum (intensive overfeeding) or at only 80% (moderate overfeeding) of food intake capacity, Mule ducks developed strong liver steatosis, whereas Pekin ducks showed very marked extrahepatic fattening. During overfeeding, evolution of plasma glucose and triacylglycerol concentrations suggested a very strong increase in the hepatic lipogenesis as well as genotype- and diet-independent lipoprotein secretion. In contrast, lipoprotein-lipase activity was dependent on alimentary status (the intensive overfeeding induces the highest activities), and Pekin ducks showed higher lipoprotein-lipase activity than Mule ducks, which could favor extrahepatic fattening to the detriment of hepatic steatosis. In Pekin ducks, plasma pancreatic hormone concentrations are related to diet levels and blood sugar. With similar food intake, Mule ducks (moderately overfed) showed global blood insulin lower than that of Pekin ducks (intensively overfed) despite similar blood sugar levels, suggesting a trend towards reduced pancreas response to glucose in Mule ducks. This may result from their lower lipoprotein-lipase activity as previously shown in these two ducks overfed at only 60% of their maximal food intake capacity (unpublished results). These results suggest that high plasma insulin concentrations may be necessary to induce an optimum lipoprotein-lipase activity in overfed ducks.

[Comparative study of effort training in deconditioned patients with and without pain. A preliminary study]

INTRODUCTION

The deconditioning or disuse syndrome is a recent nosological entity, based on medical, professional, social and psychological arguments. The aim of the study was to measure the physical condition in deconditioning situation and to evaluate the effectivity of a training program on five chronic painful patients and five painless subjects.

METHODS

After determining the physical aspects of the deconditioning syndrome using three tests and evaluating pain, this prospective study evaluated the benefits of a six weeks effort training period called "interval training" in subjects with and without chronic pain. The inclusion criteria were the patient's consent, the absence of etiological treatment of the pain and the absence cardiotropic medication. The data were compared using the t-test of Student. After the training protocol, people were satisfied. A significant increase of Maximum Oxygen Uptake, Maximum Tolerance Power duration of recovery and cardiac adaptation of effort were observed. Pain didn't seem to be a limited factor to cardiac effort training and decreased actively after the program.

CONCLUSION

A training effort protocol can help to reduce the deconditioning syndrome whether people are painful or not. The improvements of physical parameters seem to be reinforced by a better self assurance.

Functional asymmetries of the lower limbs. A comparison between clinical assessment of laterality, isokinetic evaluation and electrogoniometric monitoring of knees during walking

We used bilateral electrogoniometric gait monitoring of the knees to demonstrate the existence of an angular asymmetry between the two legs in healthy subjects. We also searched for correlations between this asymmetry and handedness, footedness and ocular laterality and isokinetic strength of the flexor-extensor muscles of the two knees. Among the 40 subjects studied, 25 (62.5%) showed an asymmetric maximal knee flexion: the difference being superior or equal to 5 degrees between the knees. There was no correlation between this asymmetry and the lateralities studied. We termed this type of asymmetry 'angular preponderance' to differentiate it from the laterality defined by clinical tests. Isokinetic strength of the knee flexors and extensors was correlated with the gender and speed, but not with side or laterality. Appropriate interpretation of lower limb examination should take into consideration angular gait asymmetry in the healthy subject.

Charge-transfer transitions in triarylamine mixed-valence systems: a joint density functional theory and vibronic coupling study

A theoretical model is developed to describe the intramolecular transfer in organic mixed-valence systems. It is applied to rationalize the intervalence charge-transfer transitions in triarylamine mixed-valence compounds. The electronic coupling parameter is evaluated at the density functional theory (DFT) and time-dependent density functional theory (TD-DFT) levels. The shapes of the charge-transfer absorption bands are analyzed in the framework of a dynamic vibronic model. The influence on the optical properties of diagonal and nondiagonal vibronic couplings is discussed. Our results are compared to recent experimental data.

Nottingham Health Profile: reliability in a sample of 542 subjects with major amputation of one or several limbs

The reliability of a generic health-related quality of life measure was assessed for subjects with major amputation of one or several limbs. The Nottingham Health Profile was sent a first time to 1011 limb amputees, and a second time to the 542 respondents to the first inquiry. The intraclass correlation coefficient (ICC) between the answers to each survey was highest for the categories of distress caused by pain (ICC = 0.83), emotional reactions (ICC = 0.83) and mobility (ICC = 0.81). It was found satisfactory for energy level (ICC = 0.75), sleep (ICC = 0.75) and social isolation (ICC = 0.64). It is concluded that the NHP is a reliable health related quality of life measure for amputees.

Mirror images and unilateral spatial neglect

Responding correctly to a mirror image requires the creation of a rather peculiar form of dual representation. Mirror agnosia and mirror ataxia, i.e. a deficit in reaching an object reflected in a mirror, have been reported to be associated with parietal lobe lesions. This prospective study was conducted to investigate the capacity of subjects with neglect to identify the mirror image nature of visual information. Four consecutive brain-damaged patients with neglect, selected on the basis of specific criteria, and four control subjects performed grasping and object displacement tests under two response conditions (normal mirror and inverted mirror). Video recordings of the tests were analyzed to assess performance using the following criteria: (i) direction of the arm movement during the initial phase of movement, (ii) number of corrections of the hand position before grasping. The control subjects successfully grasped the objects in both experimental conditions. The patients (1) neglected the contralesional space, grasping objects correctly in the ipsilesional space (normal mirror condition) and (2) neglected the ipsilesional space, grasping correctly objects in the contralesional space (inverted mirror). Controls used real object-centered correction clues to modify the position and direction of their hand movement. The patients only produced horizontal displacements of the upper limb in the "healthy" and neglected space. These results suggest that patients with neglect do not use the same clues and do not modify their procedures as they cannot recalibrate their spatial representations. These differences concerned non-mirror-image clues and directional and positional as well as attentional vectors. Theoretical and rehabilitative implications are discussed.

X-ray multilayer monochromator with enhanced performance

An x-ray multilayer monochromator with improved resolution and a low specular background is presented. The monochromator consists of a lamellar multilayer amplitude grating with appropriate parameters used at the zeroth diffraction order. The device is fabricated by means of combining deposition of thin films on a nanometer scale, UV lithography, and reactive ion etching. The performance of this new monochromator at photon energies near 1500 eV is shown.

Elevated C-reactive protein constitutes an independent predictor of advanced carotid plaques in dyslipidemic subjects

Inflammation plays a key role in the physiopathology of atherosclerosis. C-reactive protein (CRP) has been found to predict cardiac events in healthy subjects and in patients with coronary heart disease. However, the relationship between CRP and subclinical atherosclerosis is not well established. We examined the potential relationship between CRP and common carotid artery intima-media thickness and carotid plaques in dyslipidemic subjects. Dyslipidemic patients (n=1051) were recruited for the study. All patients had a complete clinical examination and systematically underwent ultrasonographic evaluation of the extracranial carotid arteries on a duplex system. The serum concentration of CRP was measured by using a sensitive immunoradiometric assay. In a univariate model, a strong positive relationship was found between CRP and the severity of carotid stenosis (P<0.0001). In multivariate analysis, the association between CRP and the degree of carotid atherosclerosis remained significant for advanced plaques (P=0.0007) in male subjects only. Significant correlations were found between CRP and body mass index (P<0.0001) and between CRP and other markers associated with the metabolic syndrome. In this large dyslipidemic population, elevated CRP is an independent predictor of advanced carotid plaques in male subjects. Body mass index and other markers of the metabolic syndrome (HDL cholesterol, triglycerides, diabetes, and high blood pressure) are significant determinants of CRP levels in this population.

[Early surgery management of pelvic region pressure ulcers versus directed cicatrization in a population of spinal cord injured patients]

OBJECTIVE

To estimate the benefit brought by an early surgery management of pelvis region pressure ulcers compared to medical processing in a population of subjects spinal cord disabled.

MATERIAL AND METHOD

The studied population consist of 53 patients (62 pressure ulcers) divided into two groups: the group 1 includes 30 patients (34 pressure ulcers) presenting pressure ulcers stage III or IV (NPUAP scale) with early surgery management, included consecutively during a period of 2 years; the group 2 includes 23 patients (28 escarres) included in a retrospective way, with medical processing by the same team of care. The criteria of judgment are the delay of healing and the delay of delivery of the station sat in the armchair.

RESULTS

In the group 1, the average delay of healing is of 42 days and the average delay of delivery for the armchair of 39 days. In the group 2 healing can be obtained only in 13 cases and in an average delay of 180 days. Differences are significant (p < 0.05).

DISCUSSION - CONCLUSION

The originality of this study results in the comparison of two processing within two groups of patients having close demographic characteristics. It clearly shows the interest of the early surgery of the pelvic pressure ulcers comparing to medical processing and illustrates the requirement for a close cooperation between teams specialized in plastic surgery and teams specialized physical medicine.

[MRI and leg stump neuroma]

OBJECTIVE

To describe RMI aspects of leg stump neuroma and to evaluate RMI scan interest for neuroma diagnosis and management.

POPULATION AND METHOD

During a 2 years period, 224 amputated patients consulting for pain or prostetics problems were studied. In 10 cases, a characteristic pain leads to neurona diagnosis. This is described as a sensation of ascending or descending electric shock induced by the stimulation of an identified point with a reproducible topography. In all these cases, RMI scans were performed. In thirty two other cases, a RMI scan was performed to confirm a pathology (bursitis, bone abnormality) or in order to establish an etiologic diagnosis. Twelve neuromas were diagnosed.

RESULTS

RMI scan showed a neuroma in the ten cases with a clinical suspicion and two asymptomatic neuromas were diagnosed out of the 32 patients without clinical suspicion. Medium delay between amputation and neuroma diagnosis is 11,6 year. In six cases, staking was modified and in six other cases, surgery was necessary. In aIl cases, clinical manifestations disappeared. Vanous RMI aspects ofneuromas are described and illustrated. Neuroma is observed on the extremity of a nerve that have a wavy aspect on its top. The neuroma is an oblong structure, with clear limits. There is an hyposignal with Ti sequence and variable signal with T2 and after gadolinium injection.

DISCUSSION

RMI scan is a good way to diagnose amputee neuroma. It makes it possible to demonstrate the pathological character of the neuroma. It has to be performed when a neuroma is suspected. It enables to confirm the diagnosis and establish the exact topography and anatomic connection. Mechanical strains role as a factor of discovering the neuroma is discussed because of the concomitant evolution of associated lesions (bursitis, bone edema). Surgical repair takes place after correcting abnormal mechanical strains.

[Rehabilitation protocols after repairs of zone 2 of the flexor tendon of the hand: presentation and indications]

We report the results of a retrospective study of 47 adult patients corresponding to 54 fingers, operated on in the emergency room at Nancy University Hospital between December 1996 and October 1998. These patients were managed using three different postoperative therapy protocols: passive mobilisation according to the Duran technique, active-passive mobilisation according to the Kleinert technique and immediate active mobilisation as described by Strickland. Patients were evaluated in three different ways; active range of movement obtained according to the Strickland scale, the "400 points" flexor function test and the delay in returning to work. Combining all three evaluations showed a 65% rate of satisfactory results, 22% fair and bad results and 13% ruptures. Analysis according to the re-education technique showed a strong superiority of the Strickland protocol. This now needs to be confirmed by a more extensive prospective study. Delay before return to work is not affected by the type or re-education technique chosen, but side-effects are less frequent with the Strickland method. A result in terms of range of active movement alone did not fully evaluate the result of a flexor tendon repair: functional testing was better at this end and the global "400" points test score gave more useful information than each of its component tests taken individually (Purdue pegboard, Minnesota test, Box and Block). Functional testing seemed more helpful in guiding the medical team in its treatment strategy.

[Illusions of body normality in amputees and paraplegic patients]

Phantom limbs in amputees, or body illusion in hemiplegics, have been the subject of wide ranging descriptions. The detected abnormalities involve morphological, postural and/or kinetic features. The aim of this prospective study carried out in 25 amputees and 10 adult paraplegics was to describe the typology of these perceptions. Data were collected from free and semi-directive investigations before and after caloric vestibular stimulation. Amputees and paraplegics perceived normal, deformed and painful body phantom segments, reffered perceptions and "normal limbs" which took on the request posture considering the general body position (illusion of body normality). This perception corresponds to an image of the body, such as it should be and not such as it is. In amputees, the limb follows the movements of the prothesis. These perceptions conform quite well reality so that the loss of the paralyzed limb is not perceived as a missing limb. This illusion of body normality should be distinguished from the normal phantom limb, characterized by a stronger perception of the lost limb compared with the other. In both amputees and paraplegics, vestibular stimulation can generate or modify phantoms limbs or body illusion and can abolish painful phantom limbs. The neuromatrix, which rebuilds body representations, could get its information from reorganized cortical areas (instantaneous body image), autobiographical engrams (painful phantoms limbs), or innate engrams (identity body schema) that, via congruence mechanisms, could be identified as a somatic reference, particularly for motor programming. This interpretation is compatible with current knowledge and suggests how amputees can easily use a prothesis.

Temporary phantom limbs evoked by vestibular caloric stimulation in amputees

OBJECTIVE

Relationships between the vestibular system and the body schema have been suggested but never demonstrated in amputees. We studied the effects of vestibular stimulation on body representation in amputees focusing on the phantom limb phenomenon.

METHOD

Prospective study in 31 amputated subjects of one or several limbs before the age of 16 years. The amputees underwent a caloric vestibular stimulation test, ipsilateral (n = 31) and contralateral (n = 8) to the side of amputation. Amputees were asked to report their perceptions spontaneously and to answer open questions. Four types of perceptions were analyzed: normal phantom, deformed phantom, painful phantom, and no phantom, before, during, and after the vestibular stimulation test. Data were compared between the two groups for pre- and post-test perceptions (chi2 test).

RESULTS

Vestibular caloric stimulation provoked temporary perception of a normal phantom limb in 16 of 17 amputees who previously did not experience phantoms. For 12 of 12 amputees who currently experienced deformed or painful phantom limbs, caloric stimulation led to temporary replacement of the abnormal phantom with a non-painful normal phantom.

CONCLUSIONS

The phenomena observed: 1) throw light on assumed mechanisms controlling construction of static and dynamic engrams used to produce the body schema; 2) complete the neuromatrix theory proposed to explain the phantom limb phenomenon; and 3) suggest that the vestibular system triggers the procedure of reconstruction of the global body schema.

[Georges Gilles of Tourette, pioneer of gait analysis in the nervous system diseases]

Georges Gilles de la Tourette's contribution to neurology goes beyond the description of the neurological disorder named after him. On December 28, 1885, he defended his doctoral thesis devoted to "gait in the diseases of the nervous system, studied by the method of imprints". In collaboration with Albert Londe, he worked for two years in Charcot's department on "a simple method applicable to both healthy and unhealthy patients", establishing the scientific and modern basis of functional exploration of human gait. The purpose was to "record the modifications of the gait and to fix them permanently, using suitable devises to guarantee not only rigorous comparison, but also to prevent observers, making use of the same method, from disputing or canceling the results completely independent of the experimenter himself". Georges Gilles de la Tourette defined the various characteristic parameters and provided the normal reference values in males and females, determining the physiological asymmetry of steps. He described spastic gait, shaking palsy, and locomotor ataxia. He distinguished between disorders of nervous control and related joint diseases. He also classified gait disorders occurring during hemiplegia. Modern development of kinetic, kinematic and biomechanical studies is a good illustration of the current relevancy of Gilles de la Tourette's contribution.

Vestibular caloric stimulation evokes phantom limb illusions in patients with paraplegia

STUDY DESIGN

Prospective study.

OBJECTIVES

To determine the mechanisms of body illusions in paraplegia patients as compared with the amputee phantom phenomena.

METHODS

A vestibular caloric stimulation was performed in 10 consecutive patients with complete section of the spinal cord. Perception of body, before and after stimulation, was classed as illusion of a normal body (lower limbs with normal morphological, postural and kinetic characteristics perceived as before spinal injury), normal phantom (overly vivid perception of all or part of the lower limbs), deformed phantom (perception of all or part of the limbs below the injury level as abnormal in shape, posture, movement or even number), or painful phantom.

RESULTS

After vestibular caloric stimulation, nine out of 10 patients stated their perception of body segments below the injury level had changed to normal phantoms or to deformed phantoms (morphological, postural or kinetic changes). Among the four patients who initially had painful limbs, two stated the stimulation greatly relieved their pain.

CONCLUSION

The normal or deformed phantom evoked by vestibular stimulation would result from use of identity data or instantaneous data as is observed in amputees. Cerebral remapping following deafferentation could be the origin of the deformed phantoms. Illusions corresponding to phenomena perceived at the time of the accident corresponding to autobiographical engrammes do not appear to be evoked by vestibular stimulation, as is also the case in amputees.

[Classification and mechanisms of body perceptions in the amputees]

OBJECTIVE

Amputees can experience several types of physical illusions and phantom limb phenomenon. The objective was to establish a synthetic classification of theses perceptions.

METHOD

Prospective study in 75 amputees (group 1: amputation (n = 60), group 2: congenital defect). The subjects were asked first to report their perceptions spontaneously and then to detail the perception, if exist, of the missing limb: form recognition, posture, movement, reminiscence of a lost limb.

RESULTS

Different types of perception were described besides the perception of the real state : normal, deformed or commemorative phantom limb and illusion of a normal body.

DISCUSSION

Whatever the model (i.e.: neuro-matrix) which support the construction of the scheme and the body image, the representations related to identified perceptions, use various innate, autobiographic and identity frames of references as well as instantaneous peripheral information, treated by reorganized cerebral structures. Each type of perception is related to a particular representation pattern.

CONCLUSION

This approach, in accordance with the literature, offers a better understanding of the differences between amelic and amputated subjects and of their perception of any prosthetic equipment.

A matricial theory of soft x-ray resonant transition radiation in periodic multilayer structures

When a charged particle crosses an interface between two different materials, electromagnetic radiation called Transition Radiation is emitted. The spectrum of this radiation extends up to x-ray domain. The Resonant Transition Radiation (R.T.R.) can be observed with a periodic arrangement of interfaces. The R.T.R. in the soft x-ray range has been recently measured by K. Yamada and coll. with a Nickel-Carbon multilayer structure [1]. In this paper, a rigorous electromagnetic theory of the R.T.R in finite and infinite multilayer structures is developed using the matricial formalism and compared with the experimental quoted data [1].

Classical theory of resonant transition radiation in multilayer structures

A rigorous classical electromagnetic theory of the transition radiation in finite and infinite multilayer structures is presented. It makes the standard results of thin-film optics, such as the matrix formalism, accountable; it allows thus an exact treatment of the propagation of the waves induced by the electron. This method is applied to the particular case of the periodic structures to treat the resonant transition radiation (RTR). It is noted that the present theory gives, in the hard x-ray domain, results previously published. The reason for this approach is to make the numerical calculations rigorous and easy. The numerical results of our theory are compared to experimental RTR data obtained recently by Yamada et al. [Phys. Rev. A 59, 3673 (1999)] with a nickel-carbon multilayer structure.

Buccal hemineglect

OBJECTIVES

To determine whether the peripersonal and intrapersonal buccal space can be affected by a hemispheric stroke and to evaluate the clinical signs resulting from buccal neglect.

METHODS

A prospective study comparing 2 groups of patients with hemiplegia, 1 with a right hemispheric lesion and the other with a left hemispheric lesion. Patients were selected consecutively on the basis of specific criteria at least 1 month after stroke.

RESULTS

Buccal hemineglect was usually concomitant with other hemineglect phenomena resulting from lesions of the right hemisphere (10 of 12 in right lesions and 1 of 12 in left lesions). Clinical signs associated with this condition consisted of impaired swallowing (retention, defective insalivation, presence of food debris in the left hemibuccal space, loss of saliva from the left side of the mouth, and choking); loss of the ability to perceive salty, sweet, or acid tastes; and impaired buccal representation. These problems were usually incorrectly diagnosed initially. Outcome was usually favorable, but functional disorders persisted in some patients for more than 18 months. The underlying attention and representation mechanisms are discussed with reference to experimental lesions of the postarcuate (area 6) cortex in rhesus monkeys. The area around the mouth may be considered to be, as in monkeys, a peripersonal space, ie, probably of little functional importance. The lesion may involve area 6 or its projections to the thalamus or posterior parietal cortex.

CONCLUSIONS

Buccal hemineglect, which is likely to cause social embarrassment, should be considered whenever the oral phase of swallowing is impaired in a context of neglect syndromes. Prophylactic measures and rehabilitation can reduce the impact and complications of the condition (food bolus).

Xuv resonant transition radiations from periodic stratified media

General formulation of the xuv intensity emitted when relativistic electrons cross through any periodic stratified medium is presented in the framework of electromagnetism in continuous media. Application is made to the resonant transition radiation emitted in the geometries of both normal and oblique incidence. In the first case, agreement is found between our calculated results and published values. Intensity emitted by a periodic multilayer stack used in the Bragg conditions is determined and the practical interest of a such a radiation source is discussed.

Eye patching in unilateral spatial neglect: efficacy of two methods

OBJECTIVES

To determine whether patches obscuring half the visual field affect eye movement in subjects with unilateral spatial neglect and whether there is consequent improvement in the subject's everyday life, and to interpret the potential changes observed with the aid of a theoretical model.

DESIGN

Prospective and randomized study.

SETTING

Rehabilitation medicine department in an urban general hospital.

PATIENTS

Twenty-two subjects with left unilateral neglect.

INTERVENTION

Two eye-patching procedures-right half-field patches (n = 7) and right mononuclar patch (n = 7)-and control group (n = 8).

MAIN OUTCOME MEASURES

Functional tests (FIM) and analytical tests (measurement of right eye movements by photo-oculography) at admission and after 3 months.

RESULTS

Results of the paired comparison tests showed (1) significant differences between the control group and the group with the half-eye patches for total FIM score (p = .01) and the displacements of the right eye in the left field (p = .02), and (2) no significant differences between the control group and the group with the right monocular patch.

CONCLUSION

Patching the right half-field helped subjects initially regain voluntary control over the deficit. The actual interpretation is based on physiologic and psychophysiologic models.

Event-related potentials in the segmental exclusion syndrome of the upper limb

Upper limb segmental exclusion syndromes are frequent after traumatic or infectious affections. They can be defined as an insufficient utilization of a limb segment--fingers or hand--reversible on verbal exhortation and arising in subjects with no other neurologic or psychiatric disorder. Our hypothesis was that the segmental exclusion syndrome could be likened to a neglect behavior. To verify the validity of this hypothesis, we measured digital nerve short-latency SEP and SEP-P300 waves in response to odd-ball task target stimuli in healthy volunteers (n = 11) and patients with digit exclusion syndromes (n = 19). For N20 latency, there was no significant difference (Wilcoxon's test: p = 0.52) between normal and excluded digits. Stimulation of the excluded vs normal digit resulted in a significant lengthening in SEP-P300 latency (p = 0.0003). The implication of these results and means of extending our knowledge of the pathophysiology of exclusion syndromes are discussed.

[Gastrointestinal hemorrhage caused by rupture of an aneurysm of visceral arteries. Presentation of 4 cases]

STUDY AIM

Gastrointestinal bleeding by rupture of splanchnic artery aneurysms is very rare. The aim of this study is to report four cases observed between 1990 and 1996.

MATERIALS AND METHODS

In the first case, the celiac trunk aneurysm was revealed by hematemesis due to erosion of the posterior wall of the stomach. Excision of the aneurysm associated with splenopancreatectomy was followed by revascularization of the common hepatic artery with a bypass implanted in the aorta. The second case concerned a splenic artery aneurysm revealed by hemosuccus pancreaticus and intestinal bleeding which was treated by excision and splenopancreatectomy. In the third case, the common hepatic artery aneurysm revealed by hemosuccus pancreaticus and intestinal bleeding was treated by obstructive endoaneurysmorrhaphy. The fourth case concerned a superior mesenteric aneurysm revealed by duodenal erosion causing gastric and intestinal bleeding, which was treated by obstructive endoaneurysmorrhaphy and revascularization of the mesenteric artery by a spleno-mesenteric bypass.

RESULTS

Surgical treatment was successful in all four patients. In the first case, an acute acalculous cholecystitis required a cholecystectomy after 3 weeks. In the fourth case, a splenic infarction disappeared spontaneously.

CONCLUSION

Such observations are rare. The site of the bleeding was located by endoscopy. The aneurysm was recognized by contrast-enhanced computerized tomography (CT) scan and/or celiac and mesenteric arteriography which was performed in all cases and was very useful for the management of such aneurysms. After excision (n = 2) or obliterative endoaneurysmorrhaphy (n = 2), revascularization had to be done in two cases for celiac and mesenteric aneurysms.

X-UV lamellar multilayer amplitude gratings

The concept of X-UV Lamellar Multilayer Amplitude Grating (LMAG) is introduced and a method of fabrication is given. Dynamical and kinematic theories of the diffraction by a LMAG are presented. Different applications of the LMAGs are considered. The first one is the achievement of a narrow bandpass multilayer monochromator for the X-UV domain. The second one is the reduction of specular background in the reflectivity curve of a multilayer structure. The third one is the polychromator system which allows one to split spatially and to perform a spectral sampling of a polychromatic beam. Finally we studied experimentally the behavior of an LMAG in conical mounting.

Asymmetry correction equations for hand volume, grip and pinch strengths in healthy working people

Assessments of oedema and decrease in hand strength are useful for patients with a hand lesion. This study examined the asymmetry of the arms and determined the estimates of the unknown prior to lesion values for hand volume, grip strengths assessed with a Jamar dynamometer (GS[J]) and a Collins dynamometer (GS[C]), and pinch strength with a Jamar pinch gauge (PS) in 100 healthy working people. Hand volume, GS(J), GS(C) and PS of the dominant hand were respectively 3.6 +/- 4.1%, 6.6 +/- 9.2%, 11.7 +/- 11.2%, and 8.0 +/- 13.2% higher than those of the non-dominant hand (p < 0.001). Very good estimates were obtained with the values of the contralateral arm for all the indices studied. The correlation coefficient equalled 0.95 for hand volume, 0.91 for GS(J), 0.83 for GS(C), and 0.72 for PS. These estimates allow us to evaluate the evolution of oedema and hand strengths in patients with hand injury, especially to determine whether they could return to work as they are mostly manual workers with demanding jobs.

Comparison between estimates of hand volume and hand strengths with sex and age with and without anthropometric data in healthy working people

Edema and hand strength measurements are useful for the recovery assessment of patients with a hand lesion. This work determined and compared estimates of hand volume, grip strengths (measured with a Jamar and a Collins dynamometer), and pinch strength (with a Jamar pinch gauge) in terms of sex and age with or without anthropometric indices in healthy working people. The sample included 100 subjects from within the staffs of two rehabilitation centres. For both grip strengths, multiple linear regression models including body height, weight, and arm muscle area were very good (multiple correlation coefficient R of about 0.84) and clearly better than those obtained with sex and age only. For pinch strength, the best estimate was obtained with sex and arm muscle area (R of 0.76); for hand volume, the model with sex, body height, and weight provided the best result (R of 0.93). These findings suggested that anthropometric indices easy to measure must be taken into account to estimate hand volume and hand strengths.

Experimental study and simulation of the damage induced to various multilayer interferential mirrors by soft x-ray plasma-laser sources

The damage induced to various multilayer interferential mirrors (MIMs) by intense soft X-ray plasma-laser sources are studied both experimentally and theoretically. The mirrors consist of periodic bilayers made up with C/W, Si/Mo, Si/W\. One set of Si/W MIMs is coated with a 100 nm Si film devised to protect the multilayer structure. In the experiment, one resolves in time the evolution of the diffraction pattern of a MIM illuminated by the radiation of a NaCl probing laser-plasma and exposed to the heating radiation emitted by a gold laser-plasma. One measures the damage threshold time and the damage threshold fluence. Simulations are performed by combining an optical code with a Lagrangian thermomechanical code giving at each time the density and the thickness of each layer in the MIM.

[Unidimensionality of a functional measure for patient with an injured upper limb]

The construction of an instrument including a number of tests requires an analysis of its structure and its unidimensionality (which allows calculation of global score), and the determination of the difficulty level of various tests. This study examined a tool including 67 tests designed to evaluate the functional ability of patients with an injured upper limb. The patients seen in a rehabilitation centre during 12 months (173 subjects) were evaluated by the occupational therapists familiar with the tool. The statistical analyses were made using the principal component analysis method (PCAM), the Cronbach's coefficient and the Rasch model. The PCAM showed 3 principal factors which explained 44%, 10% and 4% of the total variance respectively in the case of patients with injured dominant limb. The predominance of the first axis and the high ratio of first by second eigenvalues suggested the unidimensionality of the tool. The Cronbach's value of 0.97 attested the good congruence of the items. The results obtained with the Rasch model seemed to be consistent with the hypothesis of the unidimensionality of the tool. This analysis also provided the difficulty scale of various tests. Similar results were obtained in patients with injured non dominant limb or with all the sample. The methods used provide complementary results.