Monoolein–Water Liquid Crystalline Gels of Gentamicin as Bioresorbable Implants for the Local Treatment of Chronic Osteomyelitis: In Vitro Characterization

To maximize the efficacy of chronic osteomyelitis antibiotherapy while reducing antibiotic systemic toxicity, as well as time and costs of hospitalizations, it has been thought that monoolein–water gels incorporating gentamicin sulfate could be used as local, bioresorbable, and sustained-release implants. For this purpose, four formulations were examined with regard to their physicochemical and in vitro drug release characteristics. Hot stage microscopy, differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), and X-ray diffraction showed cubic liquid crystalline and eutectic structures. The more suitable formulation consisting of 80–15–5% wt/wt monoolein–water–gentamicin sulfate progressively released the antibiotic for a period of 3 weeks without burst effect. Moreover, the content and the release profile of gentamicin sulfate were not significantly changed after storage at 2–6°C for a period of 10 months.     

Patterns of Innovation Capabilities in KIBS Firms: Evidence from the 2003 Statistics Canada Innovation Survey on Services

The aim of this paper is to shed light on complementarities and substitutions between various types of innovation capabilities in knowledge-intensive-based service (KIBS) firms. The data used in this study are the responses of 2,625 innovative firms to the 2003 Statistics Canada Innovation Survey on services. The empirical results suggest the presence of three patterns of complementary innovation capabilities, one pattern of substitute activities and finally, four patterns of innovation capabilities that are independent from each other. Hence, the results suggest the presence of complementarities: first, between internal R&D, external R&D, acquisition of equipment and machinery, and marketing activities; second, between external R&D, acquisition of equipment and machinery, acquisition of external knowledge and marketing activities; third, between acquisition of equipment and machinery, acquisition of external knowledge and marketing activities. Such complementarities lead to the conclusion that, in practice, managers of KIBS firms consider the consolidation of these capabilities jointly instead of separately. The paper also discusses issues related to patterns of capabilities that are substitutes and independent from each other. The results of this study also show significant heterogeneity in the determinants of the different patterns of innovation capabilities.     

An analytic method to predict the thermal map of cryosurgery iceballs in MR images

This paper presents a newly developed method to estimate, in magnetic resonance (MR) images, the temperatures reached within the volume of an iceball produced by a cryogenic probe. Building on the direct measurements of the MR signal intensity and its correlation with independent temperature variations at the phase transition from liquid to solid, the thermal information embedded in the images was accessed. The volume and diameter of the growing iceball were estimated from a time series of MR images. Using regressions over the volume in the time and thermal domains, this method predicted the cryogenic temperatures beyond the range of sensitivity of the MR signal itself. We present a validation of this method in samples of gelatin and ex vivo pig liver. Temperature predictions are shown to agree with independent thermosensor readings over a range extending from 20 degrees C down to -65 degrees C, with an average error of less than 6 degrees C.     

Fumonisin contamination of maize in Burkina Faso, West Africa.

Maize throughout the world is frequently contaminated with a family of mycotoxins, the fumonisins, produced by species of Fusaria. The study investigated the level of fumonisin contamination of maize samples from village farms and large market traders in Burkina Faso, West Africa. Maize samples (5 kg) from each of five to six large storage barns from farms in five villages in the district of N'Dorola, Kénédougou province, western Burkina Faso, were sampled (n = 26) in Jan 1999 (> 1 year storage), and a further 26 maize samples from the same farms were collected directly from the field in October 1999. In addition, 72 maize samples were obtained in July 1999 from large markets in Bobo Dioulasso. Fumonisins were extracted from dried maize, derivatized with o-phthaldialdehyde and quantified by reversed-phase high-performance liquid chromatography with fluorescence detection. All 26 samples from the first (mean 1170 microg kg(-1), range 110-3120 microg kg(-1)) and from the second (mean 130 microg kg(-1), range 10-450 microg kg(-1)) village collection were fumonisin positive. All 72 maize samples from the large markets were also positive for fumonisins, and had the highest levels of contamination (mean 2900 microg kg(-1), range 130-16,040 microg kg(-1)). As fumonisins were a ubiquitous contaminant of maize and given that this crop is a dietary staple in this region, chronic exposure is likely.     

The cost of the surgical treatment of cataracts at the African Institute of Tropical Ophthalmology (Bamako, Mali)

In developing countries, cataracts are a serious public health problem. There are a large number of patients, an estimated 3 millions in Africa alone, awaiting operations. However, the number of surgical interventions is small for a variety of reasons, including the cost. To try to reduce the cost of surgery, we analysed the various elements involved at the African Institute of Tropical Ophthalmology (AITO) in Bamako (Mali). The route followed by the patient, from contact with the health service through to post-operative health care was analysed in terms of individual jobs, supplies and equipment required. The unit cost of each of these elements was assessed using an adapted calculation method. The results show that the cost of the removal of the lens at the AITO is 15,200 FCFA (or $56). Installing an intra-ocular lens significantly improves the outcome for a similar cost (16,500 FCFA or $60). The relative costs of various elements were as follows: food, 32%, the suture, 12%; and equipment only 13%. Thus, to reduce the overall cost of surgery for cataracts, ambulatory surgery should be organised, with efforts to reduce the costs of suture. High quality equipment should be used, because its life-span is such that it can be amortised over a long period.     

Community assessment of availability, consumption, and cultural acceptability of food sources of (pro)vitamin A: toward the development of a dietary intervention among preschool children in rural Burkina Faso

BACKGROUND: Vitamin A deficiency remains a public health problem in Burkina Faso and elsewhere in the developing world. Dietary diversification is a promising strategy that needs to be explored to strengthen the country's ongoing supplementation program. OBJECTIVE: The purpose of this study was to identify locally available and acceptable (pro)vitamin A-rich foods to be included in a dietary intervention addressing vitamin A deficiency in children aged six months to three years. METHODS: A food ethnographic study combining recall methods, observation, and focused group discussion was conducted in the dry and rainy seasons. Thirty-five mother-child pairs were randomly selected and included in the study. RESULTS: The dietary pattern of children was characterized by low diversity with extremely low energy and vitamin A intake in both seasons. The study identified the availability of numerous (pro)vitamin A-rich foods, but these foods are either not consumed or consumed by few in low amounts and/or in low frequencies. The main constraining factors identified are related to financial accessibility (for liver), seasonal availability (for egg, milk, mango, papaya, and green leafy vegetables), and beliefs related to consumption and preparation (for green leafy vegetables). However, the study also revealed that the study population associated all identified (pro)vitamin A-rich foods with positive attributes such as health, strength, and vitamin richness, which might offer an entry point for designing and implementing dietary interventions. CONCLUSIONS: Based on the findings of this formative research, intervention strategies with mango and liver are proposed to improve the vitamin A intake and status of children in the rural areas of Burkina Faso.     

Prevalence of Salmonella enterica and the hygienic indicator Escherichia coli in raw meat at markets in Ouagadougou, Burkina Faso

This study investigated the hygienic status and prevalence of Salmonella and Escherichia coli in retail meat sold at open markets in Ouagadougou, Burkina Faso. A total of 150 samples of beef meat (n = 45), beef intestine (n = 45), mutton (n = 30), and chicken (n = 30) were collected from four local markets for investigation. The prevalence of Salmonella enterica subsp. enterica was 9.3%, and six serotypes, all previously unreported in Burkina Faso, were identified: Derby, Tilene, Hato, Bredeney, Agona, and Senftenberg. Most of the Salmonella isolates were sensitive to the 12 antimicrobial drugs tested. The prevalence of E. coli was 100% in all the meat types. An assessment of hygiene practices for the production, transportation, display, and vending of the meat revealed unhygienic conditions. Meat sellers had a low education level and poor knowledge of foodborne pathogens and their transmission routes. The findings showed that foodstuff handlers were in dire need of education about safe food handling practices.     

Risk of Vibrio transmission linked to the consumption of crustaceans in coastal towns of Côte d'Ivoire

The purpose of this study was to assess the risk of Vibrio spp. transmission from crustaceans to humans in two coastal towns of C?te d'Ivoire. Bacteriologic analysis was performed on 322 crustacean samples obtained from six markets in Abidjan and one in Dabou. Suspected Vibrio colonies were identified by morphological, cultural, biochemical, and molecular tests and matrix-assisted laser desorption ionization-time-of-flight mass spectrometry. PCR assays were used to further characterize Vibrio strains. A survey on consumption of crustaceans was conducted among 120 randomly selected households in Abidjan. Overall, Vibrio spp. were isolated from 7.8% of the crustacean samples studied, at levels as high as 6.3 log CFU/g. Of the Vibrio strains identified, 40% were V. alginolyticus, 36% were V. parahaemolyticus, and 24% were nontoxigenic V. cholerae; the latter two species can cause mild to severe forms of seafood-associated gastroenteritis. Among interviewed households, 11.7% reported daily consumption of crustaceans, confirming the high probability of exposure of human population to Vibrio spp., and 7.5% reported symptoms of food poisoning after consumption of crustaceans. The absence of genes encoding major virulence factors in the studied strains, i.e., cholera toxin (ctxA and ctxB) in V. cholerae and thermostable direct hemolysin (tdh) and thermostable direct hemolysin-related hemolysin (trh) in V. parahaemolyticus, does not exclude the possibility of exposure to pathogenic strains. However, human infections are not common because most households (96.7%) boil crustaceans, usually for at least 45 min (85.9% of households) before consumption.     

Application of multiple residual stress determination methods to coarse-grained biomedical implant castings

ASTM F75 femoral knee implant components distort during manufacture due to residual stress re-distribution or inducement. X-ray diffraction, neutron diffraction, centre-hole drilling and the contour method residual stress determination techniques were applied to as-cast and/or shot-blasted components. The centre-hole drilling and contour methods can only be considered qualitative as a result of uncertainty associated with the elastic anisotropy of gauge volumes. Additionally, neutron diffraction experimentation returned unfeasible results. However, it was qualitatively identified that a shot-blasting shell-removal process has the ability to significantly alter the bulk residual stress state of the implants and induce a stress state which would cause distortion by re-distribution following material removal during manufacturing processes.     

Artificial intelligence tools and inverse methods for estimating the thermal diffusivity of building materials

The actual European energy context highlights the building sector as one of the largest sectors of energy consumption. Consequently, the “Energy Performance of Buildings Directive”, adopted in 2002 and focusing on energy use in buildings, requires all the EU members to enhance their building regulations and to introduce energy certification schemes, with the aim of both reducing energy consumption and improving energy efficiency. That is why carrying out an energy performance diagnosis is mandatory, notably when buying or selling properties. Indeed, invisible defaults, like, for example, non-emerging cracks or delaminations, could have a detrimental effect on insulating qualities. Esimaing in situ thermo-physical properties allowing locating these defaults, the present work focuses on proposing new and efficient approaches based on the use of both artificial intelligence tools (artificial neural networks and neuro-fuzzy systems) and inverse methods for characterizing building materials i.e. for estimating their thermal diffusivity using thermograms obtained thanks to a non-destructive photothermal method.