[Ability of ophthalmic technicians to identify a normal ophthalmological examination]. / Capacité discriminative de la normalité de l'examen ophtalmologique par les orthoptistes.

INTRODUCTION: Ophthalmology care has been growing for several years. Since ophthalmic technicians have the opportunity to perform delegated procedures, it is important to evaluate their training. OBJECTIVE: To evaluate the ability of 3rd year ophthalmic technician students and graduates to assess the normality of an ophthalmological examination and to determine a proposed time delay for seeing an ophthalmologist. MATERIALS AND METHODS: One hundred records including ophthalmology examinations were shown to 8 ophthalmic technician students in their third year of study and to 3 graduated technicians. Three ophthalmologists determined the content of the files, the pathological nature or not of the case, as well as the proposed time for seeing an ophthalmologist. We calculated the sensitivity and specificity to recognize the normality of the case, as well as the concordance between the proposed time for seeing an ophthalmologist. RESULTS: For recognition of a normal case, the sensitivity was 80%, and the specificity was 83% in the group of technician students, and 81% versus 80% respectively in the group of graduated technicians. For the proposed time of consultation for seeing an ophthalmologist, the kappa agreement coefficient was 0.30 in the group of students and 0.41 in the group of graduates (low and moderate agreement respectively). CONCLUSION: The study showed a good ability of technicians to recognize the normality or not of clinical cases, but their ability to judge the appropriate timing of treatment by an ophthalmologist remains insufficient.

Comparison of five organic wastes regarding their behaviour during composting: part 1, biodegradability, stabilization kinetics and temperature rise.

This paper aims to compare household waste, separated pig solids, food waste, pig slaughterhouse sludge and green algae regarding their biodegradability, their stabilization kinetics and their temperature rise during composting. Three experiments in lab-scale pilots (300 L) were performed for each waste, each one under a constant aeration rate. The aeration rates applied were comprised between 100 and 1100 L/h. The biodegradability of waste was expressed as function of dry matter, organic matter, total carbon and chemical oxygen demand removed, on one hand, and of total oxygen consumption and carbon dioxide production on the other. These different variables were found closely correlated. Time required for stabilization of each waste was determined too. A method to calculate the duration of stabilization in case of limiting oxygen supply was proposed. Carbon and chemical oxygen demand mass balances were established and gaseous emissions as carbon dioxide and methane were given. Finally, the temperature rise was shown to be proportional to the total mass of material biodegraded during composting.

Comparison of five organic wastes regarding their behaviour during composting: part 2, nitrogen dynamic.

This paper aimed to compare household waste, separated pig solids, food waste, pig slaughterhouse sludge and green algae regarding processes ruling nitrogen dynamic during composting. For each waste, three composting simulations were performed in parallel in three similar reactors (300 L), each one under a constant aeration rate. The aeration flows applied were comprised between 100 and 1100 L/h. The initial waste and the compost were characterized through the measurements of their contents in dry matter, total carbon, Kjeldahl and total ammoniacal nitrogen, nitrite and nitrate. Kjeldahl and total ammoniacal nitrogen and nitrite and nitrate were measured in leachates and in condensates too. Ammonia and nitrous oxide emissions were monitored in continue. The cumulated emissions in ammonia and in nitrous oxide were given for each waste and at each aeration rate. The paper focused on process of ammonification and on transformations and transfer of total ammoniacal nitrogen. The parameters of nitrous oxide emissions were not investigated. The removal rate of total Kjeldahl nitrogen was shown being closely tied to the ammonification rate. Ammonification was modelled thanks to the calculation of the ratio of biodegradable carbon to organic nitrogen content of the biodegradable fraction. The wastes were shown to differ significantly regarding their ammonification ability. Nitrogen balances were calculated by subtracting nitrogen losses from nitrogen removed from material. Defaults in nitrogen balances were assumed to correspond to conversion of nitrate even nitrite into molecular nitrogen and then to the previous conversion by nitrification of total ammoniacal nitrogen. The pool of total ammoniacal nitrogen, i.e. total ammoniacal nitrogen initially contained in waste plus total ammoniacal nitrogen released by ammonification, was calculated for each experiment. Then, this pool was used as the referring amount in the calculation of the rates of accumulation, stripping and nitrification of total ammoniacal nitrogen. Separated pig solids were characterised by a high ability to accumulate total ammoniacal nitrogen. Whatever the waste, the striping rate depended mostly on the aeration rate and on the pool concentration in biofilm. The nitrification rate was observed as all the higher as the concentration in total ammoniacal nitrogen in the initial waste was low. Thus, household waste and green algae exhibited the highest nitrification rates. This result could mean that in case of low concentrations in total ammoniacal nitrogen, a nitrifying biomass was already developed and that this biomass consumed it. In contrast, in case of high concentrations, this could traduce some difficulties for nitrifying microorganisms to develop.