Feasibility and Effectiveness of Basic Lymphedema Management in Leogane, Haiti, an Area Endemic for Bancroftian Filariasis

Lymphatic filariasis is a parasitic disease that is spread by mosquitoes. In tropical countries where lymphatic filariasis occurs, approximately 14 million people suffer from chronic swelling of the leg, known as lymphedema. Repeated episodes of bacterial skin infection (acute attacks) cause lymphedema to progress to its disfiguring form, elephantiasis. To help achieve the goal of eliminating lymphatic filariasis globally, the World Health Organization recommends basic lymphedema management, which emphasizes hygiene, skin care, exercise, and leg elevation. Its effectiveness in reducing acute attack frequency, as well as the role of compressive bandaging, have not been adequately evaluated in filariasis-endemic areas. Between 1995 and 1998, we studied 175 people with lymphedema of the leg in Leogane, Haiti. During Phase I of the study, when compression bandaging was used to reduce leg volume, the average acute attack rate was 1.56 episodes per year; it was greater in people who were illiterate and those who used compression bandages. After March 1997, when hygiene and skin care were emphasized and bandaging discouraged, acute attack frequency significantly decreased to 0.48 episodes per year. This study highlights the effectiveness of hygiene and skin care, as well as limitations of compressive bandaging, in managing lymphedema in filariasis-endemic areas

Contact operations using an instrumented compliant wrist

Teleprogramming was developed as a solution to problems of teleoperation systems with significant time delays [5]. In teleprogramming, the human operator interacts in real time with a graphical model of the remote site, which provides for real time visual and force feedback. The master system automatically generates symbolic commands based on the motions of the master arm and the manipulator/model interactions, given predefined criteria of what types of motions are to be expected. These commands are then sent via a communication link, which may delay the signals, to the remote site. Based upon a remote world model, predefined and possibly refined as more information is obtained, the slave carries out commanded operations in the remote world and decides whether each step has been executed correctly. Contact operations involve the remote site manipulator interacting with the environment, including planned collisions, and motion with contact with the environment. A hybrid position/force control scheme using a instrumented compliant wrist has been demonstrated to be very effective for these types of operations. In particular, switching between position and force modes (when contacting a surface, for example) does not present problems for the system. A brief introduction of teleprogramming and contact operations is presented, including a model of sliding motions and early experimental results. Problems with these earl

Physicochemical characterisation of calcium phosphatesprepared from milk ultrafiltrates: Effect of the mineralcomposition

This study deals with the precipitation of calcium phosphate in permeates removed from milks at differentpH (6.7, 5.2 and 4.6). An overall high yield of precipitation of calcium and phosphate (70–80%, respectively)was obtained for all precipitates with Ca⁄P molar ratios close to 1.5. The suspended milk-derivedcalcium phosphate (MDCP) precipitates had 8–14 lm size and )14 to )28 mV zeta potential. The driedMDCP precipitates were identified as amorphous calcium phosphate (ACP), stable over 18 months ofstorage at room temperature

ABC Rotor Blades: Design, Manufacturing and Testing

ABC is the acronym for "Active Blade Concept" and represents a 38% Mach scaled model rotor of the Advanced Technology Rotor (ATR) of Eurocopter Germany (ECD, [4]). In contrast to the ATR the model rotor is fully articulated. Specifically, it is equipped with a flap at the trailing edge of each blade, which is driven by a piezo-electric actuator. The ABC project is a cooperation between the French ONERA and the German DLR within the research concept "The Active Rotor". This rotor will be used for investigations of the effect of different flap positions on noise, vibrations and performance. ONERA was responsible for the structural design of the blade and the manufacturing of a prototype blade. DLR’s responsibilities covered manufacturing of carbon fibre moulds and the five series blades (including one spare blade) using the experiences of the prototype blade manufacturing. Additionally, all instrumentation with Kulite pressure sensors, strain gages, hall sensors and accelerometers was part of DLR’s contribution. In 2005 a wind tunnel test in S1MA is scheduled under the lead of ONERA with validation of the flap efficiency for vibration reduction and performance enhancement. Following this, a second test under the lead of DLR is planned in the large low-speed facility of DNW with emphasis on flap effectiveness to reduce noise radiation. This paper deals with the particularities of the mould, the build up of the blades including the mechanism to drive the flaps, the test of the flap units in laboratory and in the S3MA wind tunnel, the manufacturing of the prototype blade and its testing and the series blades manufacturing and laboratory test of these

Structural organization of casein micelles concentrated layer during cross-flow ultrafiltration

Ultra- and microfiltration of skim milk are widely used in the dairy industry as tools for the concentration and the fractionation of proteins but their performances are limited by formation of a concentrated layer of casein micelles at the membrane surface. Significant technological efforts are being made in order to reduce the concentrated layer formation and increase the permeate flux but there is a lack of knowledge on the behaviour of concentrated layer (mainly layer formation, sol-gel transition and reversibility) during cross-flow filtration. However some evidences of the possibly effect of operational conditions have been highlighted. Qu and co-workers showed indeed the effect of time and hydrodynamics conditions in the structural organization of casein micelles in concentrated layer respectively in static and dead-end filtration [1, 2]. Moreover, previous experiments [3] using Small-angle X-ray scattering (SAXS) showed the impact of strong shearing (the ultrasound) on cross-flow ultrafiltration of skim milk and allowed to give unique information about the concentrated layers in-situ. The aim of this work is to understand the properties of casein micelles accumulated layer under various operational conditions during cross-flow ultrafiltration.Combining SAXS (ID02 TRUSAXS beamline, ESRF) and cross-flow filtration in dedicated ultrafiltration cells, we studied the effect of time, shear and temperature on the structural organization of casein micelles during cross-flow filtration. Concentration profiles have been deduced from the scattering intensities registered in-situ in the course of the cross-flow filtration of casein micelles dispersions. Relaxation phases of layers formed under various operating conditions have been studied.SAXS and filtration results for a reference experiment (0.06L/min, 3h of filtration, ambient temperature) show some reversibility of the upper layer of accumulated casein micelles layers and an irreversibility of fraction closed to the membrane surface. A stronger shearing (0.1L/min instead of 0.06L/min), a shorter time of contact between casein micelles (1h50 instead of 3h) and a change of temperature (45°C or 12°C instead of 25°C) led to a different organization of concentrated layer and a thinner irreversible layer.Those results are important for understanding the concentrated layer properties of casein micelles during cross-flow filtration and they could be used to adjust the filtration parameters in order to avoid the formation of an irreversible concentrated layer at the membrane surface

Addition of citrate to casein micelles: Modifications of their physico-chemistry and acid gelation.

The organization and functional properties of casein micelles (CMs) are influenced by several factors such as temperature, pH, and ionic environment. In this study, different CMs suspensions were obtained by addition of citrate to milk at final added concentrations: 8.5, 14.5 and 18.7 mM and readjustment of pH to 6.75. Modified milks were concentrated by ultrafiltration at ~10°C and some samples were then diafiltered against milk ultrafiltrate and standardized at ~45 g.kg-1 total proteins. The analyses revealed that CMs were demineralized in Ca and P and dissociated. After acidification to pH 4.6 by HCl, set-style gels from samples containing 8.5 and 18.7 mM added citrate have a firmness reduced to 75 and 56% of that of the gel from the control sample, respectively (without citrate). In the opposite, the firmness obtained after addition of 14.5 mM of citrate increased to 116% of the value of the control sample. Same trends were observed with the viscosity values determined on the different stirred acid gels. For both rheological analyses, the comparison of diafiltered samples against undiafiltered samples did not show significant differences. These changes in the rheological properties of acid gels were probably related to the modifications of the micellar calcium phosphate responsible for the structure of CMs

Addition of citrate to casein micelles: Modifications of their physico-chemistry and acid gelation.

The organization and functional properties of casein micelles (CMs) are influenced by several factors such as temperature, pH, and ionic environment. In this study, different CMs suspensions were obtained by addition of citrate to milk at final added concentrations: 8.5, 14.5 and 18.7 mM and readjustment of pH to 6.75. Modified milks were concentrated by ultrafiltration at ~10°C and some samples were then diafiltered against milk ultrafiltrate and standardized at ~45 g.kg-1 total proteins. The analyses revealed that CMs were demineralized in Ca and P and dissociated. After acidification to pH 4.6 by HCl, set-style gels from samples containing 8.5 and 18.7 mM added citrate have a firmness reduced to 75 and 56% of that of the gel from the control sample, respectively (without citrate). In the opposite, the firmness obtained after addition of 14.5 mM of citrate increased to 116% of the value of the control sample. Same trends were observed with the viscosity values determined on the different stirred acid gels. For both rheological analyses, the comparison of diafiltered samples against undiafiltered samples did not show significant differences. These changes in the rheological properties of acid gels were probably related to the modifications of the micellar calcium phosphate responsible for the structure of CMs

Catalytic light-triggered reduction promoted by a dithienylethene derivative

International audienceA pyridinium substituted dithienylethene derivative was used for the first time as an efficient photo-reducing agent of two different substrates. This reaction exhibits high catalytic yields due to the continuous regeneration of the initial state of the photochromic molecule